Search results for: surface mechanical attrition treatment

Authors: Andreas Rudisch, Ralf Lampert, Andreas Kolbitsch

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It is a well-known fact among the engineering community that earthquakes with comparatively low magnitudes can cause serious damage to nonstructural components (NSCs) of buildings, even when the supporting structure performs relatively well. Past research works focused mainly on NSCs of nuclear power plants and industrial plants. Particular attention should also be given to architectural façade elements of old masonry buildings (e.g. ornamental figures, balustrades, vases), which are very vulnerable under seismic excitation. Large numbers of these historical nonstructural components (HiNSCs) can be found in highly frequented historical city centers and in the event of failure, they pose a significant danger to persons. In order to estimate the vulnerability of acceleration sensitive HiNSCs, the peak horizontal floor acceleration (PHFA) is used. The PHFA depends on the dynamic characteristics of the building, the ground excitation, and induced nonlinearities. Consequently, the PHFA can not be generalized as a simple function of height. In the present research work, an extensive case study was conducted to investigate the influence of induced nonlinearity on the PHFA for old masonry buildings. Probabilistic nonlinear FE time-history analyses considering three different hazard levels were performed. A set of eighteen synthetically generated ground motions was used as input to the structure models. An elastoplastic macro-model (multiPlas) for nonlinear homogenized continuum FE-calculation was calibrated to multiple scales and applied, taking specific failure mechanisms of masonry into account. The macro-model was calibrated according to the results of specific laboratory and cyclic in situ shear tests. The nonlinear macro-model is based on the concept of multi-surface rate-independent plasticity. Material damage or crack formation are detected by reducing the initial strength after failure due to shear or tensile stress. As a result, shear forces can only be transmitted to a limited extent by friction when the cracking begins. The tensile strength is reduced to zero. The first goal of the calibration was the consistency of the load-displacement curves between experiment and simulation. The calibrated macro-model matches well with regard to the initial stiffness and the maximum horizontal load. Another goal was the correct reproduction of the observed crack image and the plastic strain activities. Again the macro-model proved to work well in this case and shows very good correlation. The results of the case study show that there is significant scatter in the absolute distribution of the PHFA between the applied ground excitations. An absolute distribution along the normalized building height was determined in the framework of probability theory. It can be observed that the extent of nonlinear behavior varies for the three hazard levels. Due to the detailed scope of the present research work, a robust comparison with code-recommendations and simplified PHFA distributions are possible. The chosen methodology offers a chance to determine the distribution of PHFA along the building height of old masonry structures. This permits a proper hazard assessment of HiNSCs under seismic loads.

Keywords: nonlinear macro-model, nonstructural components, time-history analysis, unreinforced masonry

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Authors: Amin Masoumiganjgah, Luke Salmon, Julianne Burnton, Fahimeh Bagheri, Gavin Lenton, S. L. Ezekial Tan

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Introduction: The incidence of proximal biceps tenodesis and acute distal biceps repair is increasing, and rehabilitation protocols following both are variable. Golf is a popular sport within Australia, and the Gold Coast has become a Mecca for golfers, with more courses per capita than anywhere else in the world. Currently, there are no clear guidelines regarding return to golf play following biceps procedures. The aim of this study was to determine biceps brachii activation during the golf swing through electromyographic analysis, and subsequently, aid in rehabilitation guidelines and return to golf following tenodesis and repair. Methods: Subjects were amateur golfers with no previous upper limb surgery. Surface electromyography (EMG) and high-speed video recording were used to analyse activation of the left and right biceps brachii and the anterior deltoid during the golf swing. Each participant’s maximum voluntary contraction (MVC) was recorded, and they were then required to hit a golf ball aiming for specific distances of 2, 50, 100 and 150 metres at a driving range. Noraxon myoResearch and Matlab were used for data analysis. Mean % MVC was calculated for leading and trailing arms during the full swing and its’ 4 phases: back-swing, acceleration, early follow-through and late follow-through. Results: 12 golfers (2 female and 10 male), participated in the study. Median age was 27 (25 – 38), with all being right handed. Over all distances, the mean activation of the short and long head of biceps brachii was < 10% through the full swing. When breaking down the 50, 100 and 150m swing into phases, mean MVC activation was lowest in backswing (5.1%), followed by acceleration (9.7%), early follow-through (9.2%), and late follow-through (21.4%). There was more variation and slightly higher activation in the right biceps (trailing arm) in backswing, acceleration, and early follow-through; with higher activation in the leading arm in late follow-through (25.4% leading, 17.3% trailing). 2m putts resulted in low MVC values (3.1% ) with little variation across swing phases. There was considerable individual variation in results – one tense subject averaged 11.0% biceps MVC through the 2m putting stroke and others recorded peak mean MVC biceps activations of 68.9% at 50m, 101.3% at 100m, and 111.3% at 150m. Discussion: Previous studies have investigated the role of rotator cuff, spine, and hip muscles during the golf swing however, to our knowledge, this is the first study that investigates the activation of biceps brachii. Many rehabilitation programs following a biceps tenodesis or repair allow active range against gravity and restrict strengthening exercises until 6 weeks, and this does not appear to be associated with any adverse outcome. Previous studies demonstrate a range of < 10% MVC is similar to the unloaded biceps brachii during walking(1), active elbow flexion with the hand positioned either in pronation or supination will produce MVC < 20% throughout range(2) and elbow flexion with a 4kg dumbbell can produce mean MVC’s of around 40%(3). Our study demonstrates that increasing activation is associated with the leading arm, increasing shot distance and the late follow-through phase. Although the cohort mean MVC of the biceps brachii is <10% through the full swing, variability is high and biceps activation reach peak mean MVC’s of over 100% in different swing phases for some individuals. Given these EMG values, caution is advised when advising patients post biceps procedures to return to long distance golf shots, particularly when the leading arm is involved. Even though it would appear that putting would be as safe as having an unloaded hand out of a sling following biceps procedures, the variability of activation patterns across different golfers would lead us to caution against accelerated golf rehabilitation in those who may be particularly tense golfers. The 50m short iron shot was too long to consider as a chip shot and more work can be done in this area to determine the safety of chipping.

Keywords: electromyographic analysis, biceps brachii rupture, golf swing, tendon surgery

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Authors: Lucile Rapin, Cynthia El Hage, Rihab Gamaoun, Maria-Fernanda Arboleda, Erin Prosk

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Introduction: Sante Cannabis (SC), a Canadian group of clinics dedicated to medical cannabis, based in Montreal and in the province of Quebec, has served more than 8000 patients seeking cannabis-based treatment over the past five years. As randomized clinical trials with natural medical cannabis are scarce, real-world evidence offers the opportunity to fill research gaps between scientific evidence and clinical practice. Data on the use of medical cannabis products from SC patients were prospectively collected, leading to a large real-world database on the use of medical cannabis. The aim of this study was to report information on the profiles of both patients and prescribed medical cannabis products at SC clinics, and to assess the safety of medical cannabis among Canadian patients. Methods: This is an observational retrospective study of 1342 adult patients who were authorized with medical cannabis products between October 2017 and September 2019. Information regarding demographic characteristics, therapeutic indications for medical cannabis use, patterns in dosing and dosage form of medical cannabis and adverse effects over one-year follow-up (initial and 4 follow-up (FUP) visits) were collected. Results: 59% of SC patients were female, with a mean age of 56.7 (SD= 15.6, range= (19-97)). Cannabis products were authorized mainly for patients with a diagnosis of chronic pain (68.8% of patients), cancer (6.7%), neurological disorders (5.6%), and mood disorders (5.4 %). At initial visit, a large majority (70%) of patients were authorized exclusively medical cannabis products, 27% were authorized a combination of pharmaceutical cannabinoids and medical cannabis and 3% were prescribed only pharmaceutical cannabinoids. This pattern was recurrent over the one-year follow-up. Overall, oil was the preferred formulation (average over visits 72.5%) followed by a combination of oil and dry (average 19%), other routes of administration accounted for less than 4%. Patients were predominantly prescribed products with a balanced THC:CBD ratio (59%-75% across visits). 28% of patients reported at least one adverse effect (AE) at the 3-month follow-up visit and 12% at the six-month FUP visit. 84.8% of total AEs were mild and transient. No serious AE was reported. Overall, the most common side effects reported were dizziness (11.95% of total AEs), drowsiness (11.4%), dry mouth (5.5%), nausea (4.8%), headaches (4.6%), cough (4.4%), anxiety (4.1%) and euphoria (3.5%). Other adverse effects accounted for less than 3% of total AE. Conclusion: Our results confirm that the primary area of clinical use for medical cannabis is in pain management. Patients in this cohort are largely utilizing plant-based cannabis oil products with a balanced ratio of THC:CBD. Reported adverse effects were mild and included dizziness and drowsiness. This real-world data confirms the tolerable safety profile of medical cannabis and suggests medical indications not yet validated in controlled clinical trials. Such data offers an important opportunity for the investigation of the long-term effects of cannabinoid exposure in real-life conditions. Real-world evidence can be used to direct clinical trial research efforts on specific indications and dosing patterns for product development.

Keywords: medical cannabis, safety, real-world data, Canada

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Authors: Petra Gruber, Ariana Rupp, Peter Niewiarowski

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This paper presents a concept for a biomimetic fablab as a physical space for education, research and development of innovation inspired by nature. Biomimetics as a discipline finds increasing recognition in academia and has started to be institutionalized at universities in programs and centers. The Biomimicry Research and Innovation Center was founded in 2012 at the University of Akron as an interdisciplinary venture for the advancement of innovation inspired by nature and is part of a larger community fostering the approach of bioimimicry in the Great Lakes region of the US. With 30 faculty members the center has representatives from Colleges of Arts and Sciences (e.g., biology, chemistry, geoscience, and philosophy) Engineering (e.g., mechanical, civil, and biomedical), Polymer Science, and Myers School of Arts. A platform for training PhDs in Biomimicry (17 students currently enrolled) is co-funded by educational institutions and industry partners. Research at the center touches on many areas but is also currently biased towards materials and structures, with highlights being materials based on principles found in spider silk and gecko attachment mechanisms. As biomimetics is also a novel scientific discipline, there is little standardisation in programming and the equipment of research facilities. As a field targeting innovation, design and prototyping processes are fundamental parts of the developments. For experimental design and prototyping, MIT's maker space concept seems to fit well to the requirements, but facilities need to be more specialised in terms of accessing biological systems and knowledge, specific research, production or conservation requirements. For the education and research facility BRIC we conceptualize the concept of a biomimicry fablab, that ties into the existing maker space concept and creates the setting for interdisciplinary research and development carried out in the program. The concept takes on the process of biomimetics as a guideline to define core activities that shall be enhanced by the allocation of specific spaces and tools. The limitations of such a facility and the intersections to further specialised labs housed in the classical departments are of special interest. As a preliminary proof of concept two biomimetic design courses carried out in 2016 are investigated in terms of needed tools and infrastructure. The spring course was a problem based biomimetic design challenge in collaboration with an innovation company interested in product design for assisted living and medical devices. The fall course was a solution based biomimetic design course focusing on order and hierarchy in nature with the goal of finding meaningful translations into art and technology. The paper describes the background of the BRIC center, identifies and discusses the process of biomimetics, evaluates the classical maker space concept and explores how these elements can shape the proposed research facility of a biomimetic fablab by examining two examples of design courses held in 2016.

Keywords: biomimetics, biomimicry, design, biomimetic fablab

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Authors: Duncan Wallace, M-Tahar Kechadi

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In recent years, Machine Learning (ML) approaches have been successfully applied to an analysis of patient symptom data in the context of disease diagnosis, at least where such data is well codified. However, much of the data present in Electronic Health Records (EHR) are unlikely to prove suitable for classic ML approaches. Furthermore, as scores of data are widely spread across both hospitals and individuals, a decentralized, computationally scalable methodology is a priority. The focus of this paper is to develop a method to predict outliers in an out-of-hours healthcare provision center (OOHC). In particular, our research is based upon the early identification of patients who have underlying conditions which will cause them to repeatedly require medical attention. OOHC act as an ad-hoc delivery of triage and treatment, where interactions occur without recourse to a full medical history of the patient in question. Medical histories, relating to patients contacting an OOHC, may reside in several distinct EHR systems in multiple hospitals or surgeries, which are unavailable to the OOHC in question. As such, although a local solution is optimal for this problem, it follows that the data under investigation is incomplete, heterogeneous, and comprised mostly of noisy textual notes compiled during routine OOHC activities. Through the use of Deep Learning methodologies, the aim of this paper is to provide the means to identify patient cases, upon initial contact, which are likely to relate to such outliers. To this end, we compare the performance of Long Short-Term Memory, Gated Recurrent Units, and combinations of both with Convolutional Neural Networks. A further aim of this paper is to elucidate the discovery of such outliers by examining the exact terms which provide a strong indication of positive and negative case entries. While free-text is the principal data extracted from EHRs for classification, EHRs also contain normalized features. Although the specific demographical features treated within our corpus are relatively limited in scope, we examine whether it is beneficial to include such features among the inputs to our neural network, or whether these features are more successfully exploited in conjunction with a different form of a classifier. In this section, we compare the performance of randomly generated regression trees and support vector machines and determine the extent to which our classification program can be improved upon by using either of these machine learning approaches in conjunction with the output of our Recurrent Neural Network application. The output of our neural network is also used to help determine the most significant lexemes present within the corpus for determining high-risk patients. By combining the confidence of our classification program in relation to lexemes within true positive and true negative cases, with an inverse document frequency of the lexemes related to these cases, we can determine what features act as the primary indicators of frequent-attender and non-frequent-attender cases, providing a human interpretable appreciation of how our program classifies cases.

Keywords: artificial neural networks, data-mining, machine learning, medical informatics

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Authors: Faris Algahtani

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Background: In Saudi Arabia, it is essential to know what practices are employed and considered effective by special education teachers working with preschool children with intellectual disabilities, as a prerequisite for identifying areas for improvement. Preschool provision for these children is expanding through a network of Intellectual Disability Centres while, in primary schools, a policy of inclusion is pursued and, in mainstream preschools, pilots have been aimed at enhancing learning in readiness for primary schooling. This potentially widens the attainment gap between preschool children with and without intellectual disabilities, and influences the scope for improvement. Goal: The aim of the study was to explore special education teachers’ practices and perceived perceptions of those practices for preschool children with intellectual disabilities in Saudi Arabia Method: A qualitative interpretive approach was adopted in order to gain a detailed understanding of how special education teachers in an IDC operate in the classroom. Fifteen semi-structured interviews were conducted with experienced and qualified teachers. Data were analysed using thematic analysis, based on themes identified from the literature review together with new themes emerging from the data. Findings: American methods strongly influenced teaching practices, in particular TEACCH (Treatment and Education of Autistic and Communication related handicapped Children), which emphasises structure, schedules and specific methods of teaching tasks and skills; and ABA (Applied Behaviour Analysis), which aims to improve behaviours and skills by concentrating on detailed breakdown and teaching of task components and rewarding desired behaviours with positive reinforcement. The Islamic concept of education strongly influenced which teaching techniques were used and considered effective, and how they were applied. Tensions were identified between the Islamic approach to disability, which accepts differences between human beings as created by Allah in order for people to learn to help and love each other, and the continuing stigmatisation of disability in many Arabic cultures, which means that parents who bring their children to an IDC often hope and expect that their children will be ‘cured’. Teaching methods were geared to reducing behavioural problems and social deficits rather than to developing the potential of the individual child, with some teachers recognizing the child’s need for greater freedom. Relationships with parents could in many instances be improved. Teachers considered both initial teacher education and professional development to be inadequate for their needs and the needs of the children they teach. This can be partly attributed to the separation of training and development of special education teachers from that of general teachers. Conclusion: Based on the findings, teachers’ practices could be improved by the inclusion of general teaching strategies, parent-teacher relationships and practical teaching experience in both initial teacher education and professional development. Coaching and mentoring support from carefully chosen special education teachers could assist the process, as could the presence of a second teacher or teaching assistant in the classroom.

Keywords: special education, intellectual disabilities, early intervention , early childhood

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Authors: Md Tanvir Rahman, Mahbube Subhani, Mahmud Ashraf, Paul Kremer

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Cross-laminated timber (CLT) is made from layers of timber boards orthogonally oriented in the thickness direction, and due to this, CLT can withstand bi-axial bending in contrast with most other engineered wood products such as laminated veneer lumber (LVL) and glued laminated timber (GLT). Wood is cylindrically anisotropic in nature and is characterized by significantly lower elastic modulus and shear modulus in the planes perpendicular to the fibre direction, and is therefore classified as orthotropic material and is thus characterized by 9 elastic constants which are three elastic modulus in longitudinal direction, tangential direction and radial direction, three shear modulus in longitudinal tangential plane, longitudinal radial plane and radial tangential plane and three Poisson’s ratio. For simplification, timber materials are generally assumed to be transversely isotropic, reducing the number of elastic properties characterizing it to 5, where the longitudinal plane and radial planes are assumed to be planes of symmetry. The validity of this assumption was investigated through numerical modelling of CLT with both orthotropic mechanical properties and transversely isotropic material properties for three softwood species, which are Norway spruce, Douglas fir, Radiata pine, and three hardwood species, namely Victorian ash, Beech wood, and Aspen subjected to uniformly distributed loading under simply supported boundary condition. It was concluded that assuming the timber to be transversely isotropic results in a negligible error in the order of 1 percent. It was also observed that along with longitudinal elastic modulus, ratio of longitudinal shear modulus (GL) and rolling shear modulus (GR) has a significant effect on a deflection for CLT panels of lower span to depth ratio. For softwoods such as Norway spruce and Radiata pine, the ratio of longitudinal shear modulus, GL to rolling shear modulus GR is reported to be in the order of 12 to 15 times in literature. This results in shear flexibility in transverse layers leading to increased deflection under out-of-plane loading. The rolling shear modulus of hardwoods has been found to be significantly higher than those of softwoods, where the ratio between longitudinal shear modulus to rolling shear modulus as low as 4. This has resulted in a significant rise in research into the manufacturing of CLT from entirely from hardwood, as well as from a combination of softwood and hardwoods. The commonly used beam theory to analyze the performance of CLT panels under out-of-plane loads are the Shear analogy method, Gamma method, and k-method. The shear analogy method has been found to be the most effective method where shear deformation is significant. The effect of the ratio of longitudinal shear modulus and rolling shear modulus of cross-layer on the deflection of CLT under uniformly distributed load with respect to its length to depth ratio was investigated using shear analogy method. It was observed that shear deflection is reduced significantly as the ratio of the shear modulus of the longitudinal layer and rolling shear modulus of cross-layer decreases. This indicates that there is significant room for improvement of the bending performance of CLT through developing hybrid CLT from a mix of softwood and hardwood.

Keywords: rolling shear modulus, shear deflection, ratio of shear modulus and rolling shear modulus, timber

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Authors: Areej Al-Khabbaz, Swapna Goerge, Majedah Abdul-Rasoul

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Introduction: The most prevalent periodontal disease among children is gingivitis, and it usually becomes more severe in adolescence. A number of intervention studies suggested that resolution of periodontal inflammation can improve metabolic control in patients diagnosed with diabetes mellitus. Aim: to assess the effect of non-surgical periodontal therapy on glycemic control of children diagnosed with diabetes mellitus. Method: Twenty-eight children diagnosed with diabetes mellitus were recruited with established diagnosis diabetes for at least 1 year. Informed consent and child assent form were obtained from children and parents prior to enrolment. The dental examination for the participants was performed on the same week directly following their annual medical assessment. All patients had their glycosylated hemoglobin (HbA1c%) test one week prior to their annual medical and dental visit and 3 months following non-surgical periodontal therapy. All patients received a comprehensive periodontal examination The periodontal assessment included clinical attachment loss, bleeding on probing, plaque score, plaque index and gingival index. All patients were referred for non-surgical periodontal therapy, which included oral hygiene instruction and motivation followed by supra-gingival and subg-ingival scaling using ultrasonic and hand instruments. Statistical Analysis: Data were entered and analyzed using the Statistical Package for Social Science software (SPSS, Chicago, USA), version 18. Statistical analysis of clinical findings was performed to detect differences between the two groups in term of periodontal findings and HbA1c%. Binary logistic regression analysis was performed in order to examine which factors were significant in multivariate analysis after adjusting for confounding between effects. The regression model used the dependent variable ‘Improved glycemic control’, and the independent variables entered in the model were plaque index, gingival index, bleeding %, plaque Statistical significance was set at p < 0.05. Result: A total of 28 children. The mean age of the participants was 13.3±1.92 years. The study participants were divided into two groups; Compliant group (received dental scaling) and non-complaints group (received oral hygiene instructions only). No statistical difference was found between compliant and non-compliant group in age, gender distribution, oral hygiene practice and the level of diabetes control. There was a significant difference between compliant and non-compliant group in term of improvement of HBa1c before and after periodontal therapy. Mean gingival index was the only significant variable associated with improved glycemic control level. In conclusion, this study has demonstrated that non-surgical mechanical periodontal therapy can improve HbA1c% control. The result of this study confirmed that children with diabetes mellitus who are compliant to dental care and have routine professional scaling may have better metabolic control compared to diabetic children who are erratic with dental care.

Keywords: children, diabetes, metabolic control, periodontal therapy

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Authors: Irmak Karaduman, Tugba Corlu, Sezin Galioglu, Burcu Akata, M. Ali Yildirim, Aytunç Ateş, Selim Acar

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Breath analysis represents a promising non-invasive, fast and cost-effective alternative to well-established diagnostic and monitoring techniques such as blood analysis, endoscopy, ultrasonic and tomographic monitoring. Portable, non-invasive, and low-cost breath analysis devices are becoming increasingly desirable for monitoring different diseases, especially asthma. Beacuse of this, NO gas sensing at low concentrations has attracted progressive attention for clinical analysis in asthma. Recently, nanomaterials based sensors are considered to be a promising clinical and laboratory diagnostic tool, because its large surface–to–volume ratio, controllable structure, easily tailored chemical and physical properties, which bring high sensitivity, fast dynamic processand even the increasing specificity. Among various nanomaterials, semiconducting metal oxides are extensively studied gas-sensing materials and are potential sensing elements for breathanalyzer due to their high sensitivity, simple design, low cost and good stability.The sensitivities of metal oxide semiconductor gas sensors can be enhanced by adding noble metals. Doping contents, distribution, and size of metallic or metal oxide catalysts are key parameters for enhancing gas selectivity as well as sensitivity. By manufacturing doping MOS structures, it is possible to develop more efficient sensor sensing layers. Zeolites are perhaps the most widely employed group of silicon-based nanoporous solids. Their well-defined pores of sub nanometric size have earned them the name of molecular sieves, meaning that operation in the size exclusion regime is possible by selecting, among over 170 structures available, the zeolite whose pores allow the pass of the desired molecule, while keeping larger molecules outside.In fact it is selective adsorption, rather than molecular sieving, the mechanism that explains most of the successful gas separations achieved with zeolite membranes. In view of their molecular sieving and selective adsorption properties, it is not surprising that zeolites have found use in a number of works dealing with gas sensing devices. In this study, the Cu doped ZnO nanostructure film was produced by SILAR method and investigated the NO gas sensing properties. To obtain the selectivity of the sample, the gases including CO,NH3,H2 and CH4 were detected to compare with NO. The maximum response is obtained at 85 C for 20 ppb NO gas. The sensor shows high response to NO gas. However, acceptable responses are calculated for CO and NH3 gases. Therefore, there are no responses obtain for H2 and CH4 gases. Enhanced to selectivity, Cu doped ZnO nanostructure film was coated with zeolite A thin film. It is found that the sample possess an acceptable response towards NO hardly respond to CO, NH3, H2 and CH4 at room temperature. This difference in the response can be expressed in terms of differences in the molecular structure, the dipole moment, strength of the electrostatic interaction and the dielectric constant. The as-synthesized thin film is considered to be one of the extremely promising candidate materials in electronic nose applications. This work is supported by The Scientific and Technological Research Council of Turkey (TUBİTAK) under Project No, 115M658 and Gazi University Scientific Research Fund under project no 05/2016-21.

Keywords: Cu doped ZnO, electrical characterization, gas sensing, zeolite

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Authors: A. F. C. Nassar, D. K. Tessler, L. Okuda, C. Del Fava, D. P. Chiebao, A. H. C. N. Romaldini, A. P. Alvim, M. J. Sanchez-Vazquez, M. S. Rosa, J. C. Pompei, R. Harakava, M. C. S. Araujo, G. H. F. Marques, E. M. Pituco

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Glanders is a zoonotic disease of Equidae caused by the bacterium Burkholderia mallei presented in acute or chronic clinical forms with inflammatory nodules in the respiratory tract, lymphangitis and caseous lymph nodes. There is not a treatment with veterinary drugs to this life-threatening disease; thus, its occurrence must be notified to official animal health services and any infected animal must be eliminated. This study aims to detect B. mallei from horses euthanized in outbreaks of glanders in Brazil, providing a better understanding of the bacterial characteristics and determine a proper protocol for isolation. The work was carried out with the collaboration of the Ministry of Agriculture and the Sao Paulo State Animal Health Department, while its procedures were approved by the Committee of Ethics in Animal Experimentation from the Instituto Biologico (CETEA n°156/2017). To the present time, 16 horses from farms with outbreaks of glanders detected by complement fixation test (CFT) serology method were analyzed. During the necropsy, samples of possibly affected organs (lymph nodes, lungs, heart, liver, spleen, kidneys and trachea) were collected for bacterial isolation, molecular tests and pathology. Isolation was performed using two enriched mediums, a potato infusion agar with 5% sheep blood, 4% glycerol and antibiotics (penicilin100U/ mL), and another with the same ingredients except the antibiotic. A PCR protocol was modified for this study using primers design to identify a region of the Flip gen of B. mallei. Thru isolation, 12.5% (2/16) animals were confirmed positive using only the enriched medium with antibiotic and confirmed by PCR: from mediastinal and submandibular lymph nodes and lungs in one animal and from mediastinal lymph node in the other. The detection of the bacterium using PCR showed positivity of 100% (16/16) horses from 144 samples of organs. Pathology macroscopic lesions observed were catarrhal nasal discharge, fetlock ulcers, emaciation, lymphangitis in limbs, suppurative lymphangitis, lymph node enlargement, star shaped liver, and spleen scars, adherence of the renal capsule, pulmonary hemorrhage, and miliary nodules. Microscopic lesions were suppurative bronchopneumonia with microabscesses and Langhans giant cells in lungs; lymph nodes with abscesses and intense lymphoid reaction; hemosiderosis and abscesses in spleen. Positive samples on PCR will be sequenced later and analyzed comparing with previous records in the literature. A throughout description of the recent acute cases of glanders occurring in Brazil and characterization of the bacterium related will contribute to advances in the knowledge of the pathogenicity, clinical symptoms, and epidemiology of this zoonotic disease. Acknowledgment: This project is sponsored by FAPESP.

Keywords: equines, bacterial isolation, zoonosis, PCR, pathology

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Authors: I. N. Nwafia, U. C. Ozumba, M. E. Ohanu, S. O. Ebede

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Antibiotic resistance is increasing globally and has become a major health challenge. Extended-spectrum beta-lactamase is clinically important because the ESBL gene are mostly plasmid encoded and these plasmids frequently carry genes encoding resistance to other classes of antimicrobials thereby limiting antibiotic options in the treatment of infections caused by these organisms. The specific objectives of this study were to determine the prevalence of ESBLs production in Escherichia coli, to determine the antibiotic susceptibility pattern of ESBLs producing Escherichia coli, to detect TEM, SHV and CTX-M genes and the risk factors to acquisition of ESBL producing Escherichia coli. The protocol of the study was approved by Health Research and Ethics committee of the University of Nigeria Teaching Hospital (UNTH), Enugu. It was a descriptive cross-sectional study that involved all hospitalized patients in UNTH from whose specimens Escherichia coli was isolated during the period of the study. The samples analysed were urine, wound swabs, blood and cerebrospinal fluid. These samples were cultured in 5% sheep Blood agar and MacConkey agar (Oxoid Laboratories, Cambridge UK) and incubated at 35-370C for 24 hours. Escherichia coli was identified with standard biochemical tests and confirmed using API 20E auxanogram (bioMerieux, Marcy 1'Etoile, France). The antibiotic susceptibility testing was done by disc diffusion method and interpreted according to the Clinical and Laboratory Standard Institute guideline. ESBL production was confirmed using ESBL Epsilometer test strips (Liofilchem srl, Italy). The ESBL bla genes were detected with polymerase chain reaction, after extraction of DNA with plasmid mini-prep kit (Jena Bioscience, Jena, Germany). Data analysis was with appropriate descriptive and inferential statistics. One hundred and six isolates (53.00%) out of the 200 were from urine, followed by isolates from different swabs specimens 53(26.50%) and the least number of the isolates 4(2.00) were from blood (P value = 0.096). Seventy (35.00%) out of the 200 isolates, were confirmed positive for ESBL production. Forty-two (60.00%) of the isolates were from female patients while 28(40.00%) were from male patients (P value = 0.13). Sixty-eight (97.14%) of the isolates were susceptible to imipenem while all of the isolates were resistant to ampicillin, chloramphenicol and tetracycline. From the 70 positive isolates the ESBL genes detected with polymerase chain reaction were blaCTX-M (n=26; 37.14%), blaTEM (n=7; 10.00%), blaSHV (n=2; 2.86%), blaCTX-M/TEM (n=7; 10.0%), blaCTX-M/SHV (n=14; 20.0%) and blaCTX-M/TEM/SHV (n=10; 14.29%). There was no gene detected in 4(5.71%) of the isolates. The most associated risk factors to infections caused by ESBL producing Escherichia coli was previous antibiotics use for the past 3 months followed by admission in the intensive care unit, recent surgery, and urinary catheterization. In conclusion, ESBLs was detected in 4 of every 10 Escherichia coli with the predominant gene detected being CTX-M. This knowledge will enable appropriate measures towards improvement of patient health care, antibiotic stewardship, research and infection control in the hospital.

Keywords: antimicrobial, Escherichia coli, extended spectrum beta lactamase, resistance

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Authors: Laura Roe

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This study draws on twelve months of ethnographic fieldwork conducted in 2017 with heroin and poly-substance users in Scotland and explores experiences of time and temporality as factors in continuing drug use. The research largely took place over the year in which drug-related deaths in Scotland reached a record high, and were statistically recorded as the highest in Europe. This qualitative research is therefore significant in understanding both evolving patterns of drug use and the experiential lifeworlds of those who use heroin and other substances in high doses. Methodologies included participant observation, structured and semi-structured interviews, and unstructured conversations with twenty-two regular participants. The fieldwork was conducted in two needle exchanges, a community recovery group and in the community. The initial aim of the study was to assess evolving patterns of drug preferences in order to explore a clinical and user-reported rise in the use of novel psychoactive substances (NPS), which are typically considered to be highly potent, synthetic substances, often available at a low cost. It was found, however, that while most research participants had experimented with NPS with varying intensity, those who used every day regularly consumed heroin, methadone, and alcohol with benzodiazepines such as diazepam or anticonvulsants such as gabapentin. The research found that many participants deliberately pursued the non-fatal effects of overdose, aiming to induce states of dissociation, detachment and uneven consciousness, and did so by both mixing substances and experimenting with novel modes of consumption. Temporality was significant in the decision to consume cocktails of substances, as users described wishing to sever themselves from time; entering into states of ‘non-time’ and insensibility through specific modes of intoxication. Time and temporality similarly impacted other aspects of addicted life. Periods of attempted abstinence witnessed a slowing of time’s passage that was tied to affective states of boredom and melancholy, in addition to a disruptive return of distressing and difficult memories. Abject past memories frequently dominated and disrupted the present, which otherwise could be highly immersive due to the time and energy-consuming nature of seeking drugs while in financial difficulty. There was furthermore a discordance between individual user temporalities and the strict time-based regimes of recovery services and institutional bodies, and the study aims to highlight the impact of such a disjuncture on the efficacy of treatment programs. Many participants had difficulty in adhering to set appointments or temporal frameworks due to their specific temporal situatedness. Overall, exploring increasing tendencies of heroin users in Scotland towards poly-substance use, this study draws on experiences and perceptions of time, analysing how temporality comes to bear on the ways drugs are sought and consumed, and how recovery is imagined and enacted. The study attempts to outline the experiential, intimate and subjective worlds of heroin and poly-substance users while explicating the structural and historical factors that shape them.

Keywords: addiction, poly-substance use, temporality, timelessness

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Authors: Henok Biruk Alemayehu, Kalkidan Berhane Tsegaye, Fozia Seid Ali, Nebiyat Feleke Adimassu, Getasew Alemu Mersha

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Background: Strabismus is a visual disorder where the eyes are misaligned and point in different directions. Untreated strabismus can lead to amblyopia, loss of binocular vision, and social stigma due to its appearance. Since it is assumed that knowledge is pertinent for early screening and prevention of strabismus, the main objective of this study was to assess knowledge and attitudes toward strabismus in Woreta town, Northwest Ethiopia. Providing data in this area is important for planning health policies. Methods: A community-based cross-sectional study was done in Woreta town from April–May 2020. The sample size was determined using a single population proportion formula by taking a 50% proportion of good knowledge, 95% confidence level, 5% margin of errors, and 10% non- response rate. Accordingly, the final computed sample size was 424. All four kebeles were included in the study. There were 42,595 people in total, with 39,684 adults and 9229 house holds. A sample fraction ’’k’’ was obtained by dividing the number of the household by the calculated sample size of 424. Systematic random sampling with proportional allocation was used to select the participating households with a sampling fraction (K) of 21 i.e. each household was approached in every 21 households included in the study. One individual was selected ran- domly from each household with more than one adult, using the lottery method to obtain a final sample size. The data was collected through a face-to-face interview with a pretested and semi-structured questionnaire which was translated from English to Amharic and back to English to maintain its consistency. Data were entered using epi-data version 3.1, then processed and analyzed via SPSS version- 20. Descriptive and analytical statistics were employed to summarize the data. A p-value of less than 0.05 was used to declare statistical significance. Result: A total of 401 individuals aged over 18 years participated, with a response rate of 94.5%. Of those who responded, 56.6% were males. Of all the participants, 36.9% were illiterate. The proportion of people with poor knowledge of strabismus was 45.1%. It was shown that 53.9% of the respondents had a favorable attitude. Older age, higher educational level, having a history of eye examination, and a having a family history of strabismus were significantly associated with good knowledge of strabismus. A higher educational level, older age, and hearing about strabismus were significantly associated with a favorable attitude toward strabismus. Conclusion and recommendation: The proportion of good knowledge and favorable attitude towards strabismus were lower than previously reported in Gondar City, Northwest Ethiopia. There is a need to provide health education and promotion campaigns on strabismus to the community: what strabismus is, its’ possible treatments and the need to bring children to the eye care center for early diagnosis and treatment. it advocate for prospective research endeavors to employ qualitative study design.Additionally, it suggest the exploration of studies that investigate causal-effect relationship.

Keywords: strabismus, knowledge, attitude, Woreta

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Authors: Renu Satish Nair

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Indian higher education system is the third largest in the world next to United States and China. India is experiencing a rapid growth in higher education in terms of student enrollment as well as establishment of new universities, colleges and institutes of national importance. Presently about 22 million students are being enrolled in higher education and more than 46 thousand institutions’ are functioning as centers of higher education. Indian government plays a 'command and control' role in higher education. The main governing body is University Grants Commission, which enforces its standards, advises the government, and helps coordinate between the centre and the state. Accreditation of higher learning is over seen by 12 autonomous institutions established by the University Grants Commission. The present paper is an effort to analyze the strength, weakness, opportunities and threat (SWOT Analysis) of Indian Higher education system. The higher education in India is progressing ahead by virtue of its strength which is being recognized at global level. Several institutions of India, such as Indian Institutes of Technology (IITs), Indian Institutes of Management (IIMs) and National Institutes of Technology (NITs) have been globally acclaimed for their standard of education. Three Indian universities were listed in the Times Higher Education list of the world’s top 200 universities i.e. Indian Institutes of Technology, Indian Institute of Management and Jawahar Lal Nehru University in 2005 and 2006. Six Indian Institutes of Technology and the Birla Institute of Technology and Science - Pilani were listed among the top 20 science and technology schools in Asia by the Asia Week. The school of Business situated in Hyderabad was ranked number 12 in Globe MBA ranking by the Financial Times of London in 2010 while the All India Institute of Medical Sciences has been recognized as a global leader in medical research and treatment. But at the same time, because of vast expansion, the system bears several weaknesses. The Indian higher education system in many parts of the country is in the state of disrepair. In almost half the districts in the country higher education enrollment are very low. Almost two third of total universities and 90% of colleges are rated below average on quality parameters. This can be attributed to the under prepared faculty, unwieldy governance and other obstacles to innovation and improvement that could prohibit India from meeting its national education goals. The opportunities in Indian higher education system are widely ranged. The national institutions are training their products to compete at global level and make them capable to grab opportunities worldwide. The state universities and colleges with their limited resources are giving the products that are capable enough to secure career opportunities and hold responsible positions in various government and private sectors with in the country. This is further creating opportunities for the weaker section of the society to join the main stream. There are several factors which can be defined as threats to Indian higher education system. It is a matter of great concern and needs proper attention. Some important factors are -Conservative society, particularly for women education; -Lack of transparency, -Taking higher education as a means of business

Keywords: Indian higher education system, SWOT analysis, university grants commission, Indian institutes of technology

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Authors: BoSheng Liu

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The research goal is to re-image a locally-sourced waste product as abuilding material. The author aims to contribute to the compressed stabilized earth block (CSEB) by investigating the promising role of dredged material as an alternative building ingredient in the production of bricks and tiles. Dredged material comes from the sediment deposited near the shore or downstream, where the water current velocity decreases. This sediment needs to be dredged to provide water transportation; thus, there are mounds of the dredged material stored at bay. It is the interest of this research to reduce the filtered un-organic soil in the production of CSEB and replace it with locally dredged material from the Atchafalaya River in Morgan City, Louisiana. Technology and mechanical innovations have evolved the traditional adobe production method, which mixes the soil and natural fiber into molded bricks, into chemically stabilized CSEB made by compressing the clay mixture and stabilizer in a compression chamber with particular loads. In the case of dredged material CSEB (DM-CSEB), cement plays an essential role as the bending agent contributing to the unit strength while sustaining the filtered un-organic soil. Each DM-CSEB unit is made in a compression chamber with 580 PSI (i.e., 4 MPa) force. The research studied the cement content from 5% to 10% along with the range of dredged material mixtures, which differed from 20% to 80%. The material mixture content affected the DM-CSEB's strength and workability during and after its compression. Results indicated two optimal workabilities of the mixture: 27% fine clay content and 63% dredged material with 10% cement, or 28% fine clay content, and 67% dredged material with 5% cement. The final product of DM-CSEB emitted between 10 to 13 times fewer carbon emissions compared to the conventional fired masonry structure. DM-CSEB satisfied the strength requirement given by the ASTM C62 and ASTM C34 standards for construction material. One of the final evaluations tested and validated the material performance by designing and constructing an architectural, conical tile-vault prototype that was 28" by 40" by 24." The vault utilized a computational form-finding approach to generate the form's geometry, which optimized the correlation between the vault geometry and structural load distribution. A series of scaffolding was deployed to create the framework for the tile-vault construction. The final tile-vault structure was made from 2 layers of DM-CSEB tiles jointed by mortar, and the construction of the structure used over 110 tiles. The tile-vault prototype was capable of carrying over 400 lbs of live loads, which further demonstrated the dredged material feasibility as a construction material. The presented case study of Dredged Material Compressed Stabilized Earth Block (DM-CSEB) provides the first impression of dredged material in the clayey mixture process, structural performance, and construction practice. Overall, the approach of integrating dredged material in building material can be feasible, regionally sourced, cost-effective, and environment-friendly.

Keywords: dredged material, compressed stabilized earth block, tile-vault, regionally sourced, environment-friendly

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Authors: Enya Trenholm-Jensen

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This paper employs various semiotic methodologies to examine the mechanism of soft power. Soft power refers to a country’s global reputation and their ability to leverage that reputation to achieve certain aims. South Korea has invested heavily in their soft power strategy for a multitude of predominantly historical and geopolitical reasons. On account of this investment and the global prominence of their strategy, South Korea was considered to be the optimal candidate for the aims of this investigation. Having isolated the entertainment industry as one of the most heavily funded segments of the South Korean soft power strategy, the analysis restricted itself to this sector. Within this industry, two entertainment products were selected as case studies. The case studies were chosen based on commercial success according to metrics such as streams, purchases, and subsequent revenue. This criterion was deemed to be the most objective and verifiable indicator of the products general appeal. The entertainment products which met the chosen criterion were Netflix’ “Squid Game” and BTS’ hit single “Butter”. The methodologies employed were chosen according to the medium of the entertainment products. For “Squid Game,” an aesthetic analysis was carried out to investigate how multi- layered meanings were mobilized in a show popularized by its visual grammar. To examine “Butter”, both music semiology and linguistic analysis were employed. The music section featured an analysis underpinned by denotative and connotative music semiotic theories borrowing from scholars Theo van Leeuwen and Martin Irvine. The linguistic analysis focused on stance and semantic fields according to scholarship by George Yule and John W. DuBois. The aesthetic analysis of the first case study revealed intertextual references to famous artworks, which served to augment the emotional provocation of the Squid Game narrative. For the second case study, the findings exposed a set of musical meaning units arranged in a patchwork of familiar and futuristic elements to achieve a song that existed on the boundary between old and new. The linguistic analysis of the song’s lyrics found a deceptively innocuous surface level meaning that bore implications for authority, intimacy, and commercial success. Whether through means of visual metaphor, embedded auditory associations, or linguistic subtext, the collective findings of the three analyses exhibited a desire to conjure a form of positive arousal in the spectator. In the synthesis section, this process is likened to that of branding. Through an exploration of branding, the entertainment products can be understood as cogs in a larger operation aiming to create positive associations to Korea as a country and a concept. Limitations in the form of a timeframe biased perspective are addressed, and directions for future research are suggested. This paper employs semiotic methodologies to examine two entertainment products as mechanisms of soft power. Through means of visual metaphor, embedded auditory associations, or linguistic subtext, the findings reveal a desire to conjure positive arousal in the spectator. The synthesis finds similarities to branding, thus positioning the entertainment products as cogs in a larger operation aiming to create positive associations to Korea as a country and a concept.

Keywords: BTS, cognitive semiotics, entertainment, soft power, south korea, squid game

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Authors: Lauren Dhugga, Meena Parameswaran, David Blundell, Abbas Khushnood

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Context: A multidisciplinary weekly safety briefing was implemented at the Paediatric Cardiothoracic Unit at the Freeman Hospital in Newcastle-upon-Tyne. It is a tertiary referral centre with a quarternary cardiac paediatric intensive care unit and provides complexed care including heart and lung transplants, mechanical support and advanced heart failure assessment. Aim: The aim of this briefing is to provide a structured platform of communication, in an effort to improve efficiency, safety, and patient care. Problem: The paediatric cardiothoracic unit is made up of a vast multidisciplinary team including doctors, intensivists, anaesthetists, surgeons, specialist nurses, echocardiogram technicians, physiotherapists, psychologists, dentists, and dietitians. It provides care for children with congenital and acquired cardiac disease and is one of only two units in the UK to offer paediatric heart transplant. The complexity of cases means that there can be many teams involved in providing care to each patient, and frequent movement of children between ward, high dependency, and intensive care areas. Currently, there is no structured forum for communicating important information across the department, for example, staffing shortages, prescribing errors and significant events. Strategy: An initial survey questioning the need for better communication found 90% of respondents agreed that they could think of an incident that had occurred due to ineffective communication, and 85% felt that incident could have been avoided had there been a better form of communication. Lastly, 80% of respondents felt that a weekly 60 second safety briefing would be beneficial to improve communication within our multidisciplinary team. Based on those promising results, a weekly 60 second safety briefing was implemented to be conducted on a Monday morning. The safety briefing covered four key areas (SAFE): staffing, awareness, fix and events. This was to highlight any staffing gaps, any incident reports to be learned from, any issues that required fixing and any events including teachings for the week ahead. The teams were encouraged to email suggestions or issues to be raised for the week or to approach in person with information to add. The safety briefing was implemented using change theory. Effect: The safety briefing has been trialled over 6 weeks and has received a good buy in from staff across specialties. The aim is to embed this safety briefing into a weekly meeting using the PDSA cycle. There will be a second survey in one month to assess the efficacy of the safety briefing and to continue to improve the delivery of information. The project will be presented at the next clinical governance briefing to attract wider feedback and input from across the trust. Lessons: The briefing displays promise as a tool to improve vigilance and communication in a busy multi-disciplinary unit. We have learned about how to implement quality improvement and about the culture of our hospital - how hierarchy influences change. We demonstrate how to implement change through a grassroots process, using a junior led briefing to improve the efficiency, safety, and communication in the workplace.

Keywords: briefing, communication, safety, team

Procedia PDF Downloads 126

Authors: I. M. K. Ho, S. K. Y. Chan, K. H. P. Lam, G. M. W. Tong, N. C. Y. Yeung, J. T. C. Luk

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Low-dye taping (LDT) is commonly used for treating foot problems, such as plantar fasciitis, and supporting foot arch for runners and non-athletes patients with pes planus. The potential negative impact of pronated feet leading to tibial and femoral internal rotation via the entire kinetic chain reaction was postulated and identified. The changed lower limb biomechanics potentially leading to poor activation of hip and knee stabilizers, such as gluteus maximus and medius, may associate with higher risk of knee injuries including patellofemoral pain syndrome and ligamentous sprain in many team sports players. It is therefore speculated that foot arch correction with LDT might enhance the use of gluteal muscles. The purpose of this study was to investigate the effect of applying LDT on surface electromyographic (sEMG) activity of superior gluteus maximus (SGMax), inferior gluteus maximus (IGMax), gluteus medius (GMed) and tibialis anterior (TA) during double-leg squat. 12 male collegiate basketball players (age: 21.72.5 years; body fat: 12.43.6%; navicular drop: 13.72.7mm) with at least three years regular basketball training experience participated in this study. Participants were excluded if they had recent history of lower limb injuries, over 16.6% body fat and lesser than 10mm drop in navicular drop (ND) test. Recruited subjects visited the laboratory once for the within-subject crossover study. Maximum voluntary isometric contraction (MVIC) tests on all selected muscles were performed in randomized order followed by sEMG test on double-leg squat during LDT and non-LDT conditions in counterbalanced order. SGMax, IGMax, GMed and TA activities during the entire 2-second concentric and 2-second eccentric phases were normalized and interpreted as %MVIC. The magnitude of the difference between taped and non-taped conditions of each muscle was further assessed via standardized effect90% confidence intervals (CI) with non-clinical magnitude-based inference. Paired samples T-test showed a significant decrease (4.71.4mm) in ND (95% CI: 3.8, 5.6; p < 0.05) while no significant difference was observed between taped and non-taped conditions in sEMG tests for all muscles and contractions (p > 0.05). On top of traditional significant testing, magnitude-based inference showed possibly increase in IGMax activity (small standardized effect: 0.270.44), likely increase in GMed activity (small standardized effect: 0.340.34) and possibly increase in TA activity (small standardized effect: 0.220.29) during eccentric phase. It is speculated that the decrease of navicular drop supported by LDT application could potentially enhance the use of inferior gluteus maximus and gluteus medius especially during eccentric phase in this study. As the eccentric phase of double-leg squat is an important component of landing activities in basketball, further studies on the onset and amount of gluteal activation during jumping and landing activities with LDT are recommended. Since both hip and knee kinematics were not measured in this study, the underlying cause of the observed increase in gluteal activation during squat after LDT is inconclusive. In this regard, the investigation of relationships between LDT application, ND, hip and knee kinematics, and gluteal muscle activity during sports specific jumping and landing tasks should be focused in the future.

Keywords: flat foot, gluteus maximus, gluteus medius, injury prevention

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Authors: Olivier Mills, Bernard McDonell, Laura A. S. MacDonald

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The increasing availability and quality of internet access throughout the developing world provides an opportunity to utilize online spaces to disseminate water, sanitation and hygiene (WASH) knowledge to practitioners. Since 2001, CAWST has provided in-person education, training and consulting services to thousands of WASH practitioners all over the world, supporting them to start, troubleshoot, improve and expand their WASH projects. As CAWST continues to grow, the organization faces challenges in meeting demand from clients and in providing consistent, timely technical support. In 2012, CAWST began utilizing online spaces to expand its reach by developing a series of resources websites and webinars. CAWST has developed a WASH Education and Training resources website, a Biosand Filter (BSF) Knowledge Base, a Household Water Treatment and Safe Storage Knowledge Base, a mobile app for offline users, a live chat support tool, a WASH e-library, and a series of webinar-style online training sessions to complement its in-person capacity development services. In order to determine the preliminary outcomes of providing these online services, CAWST has monitored and analyzed registration to the online spaces, downloads of the educational materials, and webinar attendance; as well as conducted user surveys. The purpose of this analysis was to find out who was using the online spaces, where users came from, and how the resources were being used. CAWST’s WASH Resources website has served over 5,800 registered users from 3,000 organizations in 183 countries. Additionally, the BSF Knowledge Base has served over 1000 registered users from 68 countries, and over 540 people from 73 countries have attended CAWST’s online training sessions. This indicates that the online spaces are effectively reaching a large numbers of users, from a range of countries. A 2016 survey of the Biosand Filter Knowledge Base showed that approximately 61% of users are practitioners, and 39% are either researchers or students. Of the respondents, 46% reported using the BSF Knowledge Base to initiate a BSF project and 43% reported using the information to train BSF technicians. Finally, 61% indicated they would like even greater support from CAWST’s Technical Advisors going forward. The analysis has provided an encouraging indication that CAWST’s online spaces are contributing to its objective of engaging and supporting WASH practitioners to start, improve and expand their initiatives. CAWST has learned several lessons during the development of these online spaces, in particular related to the resources needed to create and maintain the spaces, and respond to the demand created. CAWST plans to continue expanding its online spaces, improving user experience of the sites, and involving new contributors and content types. Through the use of online spaces, CAWST has been able to increase its global reach and impact without significantly increasing its human resources by connecting WASH practitioners with the information they most need, in a practical and accessible manner. This paper presents on CAWST’s use of online spaces through the CAWST-developed platforms discussed above and the analysis of the use of these platforms.

Keywords: education and training, knowledge sharing, online resources, water and sanitation

Procedia PDF Downloads 249

Authors: Laura Norfolk, Georgina Zimbitas, Jan Sefcik, Sarah Staniland

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Magnetite nanoparticles (MNP) have been an area of increasing research interest due to their extensive applications in industry, such as in carbon capture, water purification, and crucially, the biomedical industry. The use of MNP in the biomedical industry is rising, with studies on their effect as Magnetic resonance imaging contrast agents, drug delivery systems, and as hyperthermic cancer treatments becoming prevalent in the nanomaterial research community. Particles used for biomedical purposes must meet stringent criteria; the particles must have consistent shape and size between particles. Variation between particle morphology can drastically alter the effective surface area of the material, making it difficult to correctly dose particles that are not homogeneous. Particles of defined shape such as octahedral and cubic have been shown to outperform irregular shaped particles in some applications, leading to the need to synthesize particles of defined shape. In nature, highly homogeneous MNP are found within magnetotactic bacteria, a unique bacteria capable of producing magnetite nanoparticles internally under ambient conditions. Biomineralisation proteins control the properties of the MNPs, enhancing their homogeneity. One of these proteins, Mms6, has been successfully isolated and used in vitro as an additive in room-temperature co-precipitation reactions (RTCP) to produce particles of defined mono-dispersed size & morphology. When considering future industrial scale-up it is crucial to consider the costs and feasibility of an additive, as an additive that is not readily available or easily synthesized at a competitive price will not be sustainable. As such, additives selected for this research are inspired by the functional groups of biomineralisation proteins, but cost-effective, environmentally friendly, and compatible with scale-up. Diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), and pentaethylenehexamine (PEHA) have been successfully used in RTCP to modulate the properties of particles synthesized, leading to the formation of octahedral nanoparticles with no use of organic solvents, heating, or toxic precursors. By extending this principle to a fluidic system, ongoing research will reveal whether the amine additives can also exert morphological control in an environment which is suited toward higher particle yield. Two fluidic systems have been employed; a peristaltic turbulent flow mixing system suitable for the rapid production of MNP, and a macrofluidic system for the synthesis of tailored nanomaterials under a laminar flow regime. The presence of the amine additives in the turbulent flow system in initial results appears to offer similar morphological control as observed under RTCP conditions, with higher proportions of octahedral particles formed. This is a proof of concept which may pave the way to green synthesis of tailored MNP on an industrial scale. Mms6 and amine additives have been used in the macrofluidic system, with Mms6 allowing magnetite to be synthesized at unfavourable ferric ratios, but no longer influencing particle size. This suggests this synthetic technique while still benefiting from the addition of additives, may not allow additives to fully influence the particles formed due to the faster timescale of reaction. The amine additives have been tested at various concentrations, the results of which will be discussed in this paper.

Keywords: bioinspired, green synthesis, fluidic, magnetite, morphological control, scale-up

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Authors: Mariyah Poonawala, Selvan Ravindran, Anuradha Vaidya

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Despite much progress in understanding the regulatory factors and cytokines that support the maturation of the various cell lineages of the hematopoietic system, factors that govern the self-renewal and proliferation of hematopoietic stem cells (HSCs) is still a grey area of research. Hematopoietic stem cell transplantation (HSCT) has evolved over the years and gained tremendous importance in the treatment of both malignant and non-malignant diseases. However, factors such as graft rejection and multiple organ failure have challenged HSCT from time to time, underscoring the urgent need for development of milder processes for successful hematopoietic transplantation. An emerging concept in the field of stem cell biology states that the interactions between the bone-marrow micro-environment and the hematopoietic stem and progenitor cells is essential for regulation, maintenance, commitment and proliferation of stem cells. Understanding the role of mesenchymal stromal cells in modulating the functionality of HSCs is, therefore, an important area of research. Trans-resveratrol has been extensively studied for its various properties to combat and prevent cancer, diabetes and cardiovascular diseases etc. The aim of the present study was to understand the effect of trans-resveratrol on HSCs using single and co-culture systems. We have used KG1a cells since it is a well accepted hematopoietic stem cell model system. Our preliminary experiments showed that low concentrations of trans-resveratrol stimulated the HSCs to undergo proliferation whereas high concentrations of trans-resveratrol did not stimulate the cells to proliferate. We used a murine fibroblast cell line, M210B4, as a stromal feeder layer. On culturing the KG1a cells with M210B4 cells, we observed that the stimulatory as well as inhibitory effects of trans-resveratrol at low and high concentrations respectively, were enhanced. Our further experiments showed that low concentration of trans-resveratrol reduced the generation of reactive oxygen species (ROS) and nitric oxide (NO) whereas high concentrations increased the oxidative stress in KG1a cells. We speculated that perhaps the oxidative stress was imposing inhibitory effects at high concentration and the same was confirmed by performing an apoptotic assay. Furthermore, cell cycle analysis and growth kinetic experiments provided evidence that low concentration of trans-resveratrol reduced the doubling time of the cells. Our hypothesis is that perhaps at low concentration of trans-resveratrol the cells get pushed into the G0/G1 phase and re-enter the cell cycle resulting in their proliferation, whereas at high concentration the cells are perhaps arrested at G2/M phase or at cytokinesis and therefore undergo apoptosis. Liquid Chromatography-Quantitative-Time of Flight–Mass Spectroscopy (LC-Q-TOF MS) analyses indicated the presence of trans-resveratrol and its metabolite(s) in the supernatant of the co-cultured cells incubated with high concentration of trans-resveratrol. We conjecture that perhaps the metabolites of trans-resveratrol are responsible for the apoptosis observed at the high concentration. Our findings may shed light on the unsolved problems in the in vitro expansion of stem cells and may have implications in the ex vivo manipulation of HSCs for therapeutic purposes.

Keywords: co-culture system, hematopoietic micro-environment, KG1a cell line, M210B4 cell line, trans-resveratrol

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Authors: Recep Kesli, Cengiz Demir, Onur Turkyilmaz, Hayriye Tokay

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Objective: Gram-negative rods are a large group of bacteria, and include many families, genera, and species. Most clinical isolates belong to the family Enterobacteriaceae. Resistance due to the production of extended-spectrum β-lactamases (ESBLs) is a difficulty in the handling of Enterobacteriaceae infections, but other mechanisms of resistance are also emerging, leading to multidrug resistance and threatening to create panresistant species. We aimed in this study to evaluate resistance rates of Gram-negative rods bacteria isolated from clinical specimens in Microbiology Laboratory, Afyon Kocatepe University, ANS Research and Practice Hospital, between October 2012 and September 2015. Methods: The Gram-negative rods strains were identified by conventional methods and VITEK 2 automated identification system (bio-Mérieux, Marcy l’etoile, France). Antibiotic resistance tests were performed by both the Kirby-Bauer disk-diffusion and automated Antimicrobial Susceptibility Testing (AST, bio-Mérieux, Marcy l’etoile, France) methods. Disk diffusion results were evaluated according to the standards of Clinical and Laboratory Standards Institute (CLSI). Results: Of the totally isolated 1.701 Enterobacteriaceae strains 1434 (84,3%) were Klebsiella pneumoniae, 171 (10%) were Enterobacter spp., 96 (5.6%) were Proteus spp., and 639 Nonfermenting gram negatives, 477 (74.6%) were identified as Pseudomonas aeruginosa, 135 (21.1%) were Acinetobacter baumannii and 27 (4.3%) were Stenotrophomonas maltophilia. The ESBL positivity rate of the totally studied Enterobacteriaceae group were 30.4%. Antibiotic resistance rates for Klebsiella pneumoniae were as follows: amikacin 30.4%, gentamicin 40.1%, ampicillin-sulbactam 64.5%, cefepime 56.7%, cefoxitin 35.3%, ceftazidime 66.8%, ciprofloxacin 65.2%, ertapenem 22.8%, imipenem 20.5%, meropenem 20.5 %, and trimethoprim-sulfamethoxazole 50.1%, and for 114 Enterobacter spp were detected as; amikacin 26.3%, gentamicin 31.5%, cefepime 26.3%, ceftazidime 61.4%, ciprofloxacin 8.7%, ertapenem 8.7%, imipenem 12.2%, meropenem 12.2%, and trimethoprim-sulfamethoxazole 19.2 %. Resistance rates for Proteus spp. were: 24,3% meropenem, 26.2% imipenem, 20.2% amikacin 10.5% cefepim, 33.3% ciprofloxacin and levofloxacine, 31.6% ceftazidime, 20% ceftriaxone, 15.2% gentamicin, 26.6% amoxicillin-clavulanate, and 26.2% trimethoprim-sulfamethoxale. Resistance rates of P. aeruginosa was found as follows: Amikacin 32%, gentamicin 42 %, imipenem 43%, merpenem 43%, ciprofloxacin 50%, levofloxacin 52%, cefepim 38%, ceftazidim 63%, piperacillin/tacobactam 85%, for Acinetobacter baumannii; Amikacin 53.3%, gentamicin 56.6 %, imipenem 83%, merpenem 86%, ciprofloxacin 100%, ceftazidim 100%, piperacillin/tacobactam 85 %, colisitn 0 %, and for S. malthophilia; levofloxacin 66.6 % and trimethoprim/sulfamethoxozole 0 %. Conclusions: This study showed that resistance in Gram-negative rods was a serious clinical problem in our hospital and suggested the need to perform typification of the isolated bacteria with susceptibility testing regularly in the routine laboratory procedures. This application guided to empirical antibiotic treatment choices truly, as a consequence of the reality that each hospital shows different resistance profiles.

Keywords: antibiotic resistance, gram negative rods, ESBL, VITEK 2

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Authors: Alena Cejkova, Martina Paldrychova, Jana Michailidu, Olga Matatkova, Jan Masak

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Increasing the resistance of pathogenic microorganisms to many antibiotics is a serious threat to the treatment of infectious diseases and cleaning medical instruments. It should be added that the resistance of microbial populations growing in biofilms is often up to 1000 times higher compared to planktonic cells. Biofilm formation in a number of microorganisms is largely influenced by the quorum sensing regulatory mechanism. Finding external factors such as natural substances or physical processes that can interfere effectively with quorum sensing signal molecules should reduce the ability of the cell population to form biofilm and increase the effectiveness of antibiotics. The present work is devoted to the effect of chitosan as a representative of natural substances with anti-biofilm activity and non- thermal plasma (NTP) alone or in combination with polymyxin B on biofilm formation of Pseudomonas aeruginosa. Particular attention was paid to the influence of these agents on the level of quorum sensing signal molecules (acyl-homoserine lactones) during planktonic and biofilm cultivations. Opportunistic pathogenic strains of Pseudomonas aeruginosa (DBM 3081, DBM 3777, ATCC 10145, ATCC 15442) were used as model microorganisms. Cultivations of planktonic and biofilm populations in 96-well microtiter plates on horizontal shaker were used for determination of antibiotic and anti-biofilm activity of chitosan and polymyxin B. Biofilm-growing cells on titanium alloy, which is used for preparation of joint replacement, were exposed to non-thermal plasma generated by cometary corona with a metallic grid for 15 and 30 minutes. Cultivation followed in fresh LB medium with or without chitosan or polymyxin B for next 24 h. Biofilms were quantified by crystal violet assay. Metabolic activity of the cells in biofilm was measured using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) colorimetric test based on the reduction of MTT into formazan by the dehydrogenase system of living cells. Activity of N-acyl homoserine lactones (AHLs) compounds involved in the regulation of biofilm formation was determined using Agrobacterium tumefaciens strain harboring a traG::lacZ/traR reporter gene responsive to AHLs. The experiments showed that both chitosan and non-thermal plasma reduce the AHLs level and thus the biofilm formation and stability. The effectiveness of both agents was somewhat strain dependent. During the eradication of P. aeruginosa DBM 3081 biofilm on titanium alloy induced by chitosan (45 mg / l) there was an 80% decrease in AHLs. Applying chitosan or NTP on the P. aeruginosa DBM 3777 biofilm did not cause a significant decrease in AHLs, however, in combination with both (chitosan 55 mg / l and NTP 30 min), resulted in a 70% decrease in AHLs. Combined application of NTP and polymyxin B allowed reduce antibiotic concentration to achieve the same level of AHLs inhibition in P. aeruginosa ATCC 15442. The results shown that non-thermal plasma and chitosan have considerable potential for the eradication of highly resistant P. aeruginosa biofilms, for example on medical instruments or joint implants.

Keywords: anti-biofilm activity, chitosan, non-thermal plasma, opportunistic pathogens

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Authors: R. R. Galiev, I. I. Lykov, A. E. Shitikov, I. A. Bilenko

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Dual-comb interferometry is based on the mixing of two optical frequency combs with slightly different lines spacing which results in the mapping of the optical spectrum into the radio-frequency domain for future digitizing and numerical processing. The dual-comb approach enables diverse applications, including metrology, fast high-precision spectroscopy, and distance range. Ordinary frequency-modulated continuous-wave (FMCW) laser-based Light Identification Detection and Ranging systems (LIDARs) suffer from two main disadvantages: slow and unreliable mechanical, spatial scan and a rather wide linewidth of conventional lasers, which limits speed measurement resolution. Dual-comb distance measurements with Allan deviations down to 12 nanometers at averaging times of 13 microseconds, along with ultrafast ranging at acquisition rates of 100 megahertz, allowing for an in-flight sampling of gun projectiles moving at 150 meters per second, was previously demonstrated. Nevertheless, pump lasers with EDFA amplifiers made the device bulky and expensive. An alternative approach is a direct coupling of the laser to a reference microring cavity. Backscattering can tune the laser to the eigenfrequency of the cavity via the so-called self-injection locked (SIL) effect. Moreover, the nonlinearity of the cavity allows a solitonic frequency comb generation in the very same cavity. In this work, we developed a fully integrated, power-efficient, electrically driven dual-micro comb source based on the semiconductor lasers SIL to high-quality integrated Si3N4 microresonators. We managed to obtain robust 1400-1700 nm combs generation with a 150 GHz or 1 THz lines spacing and measure less than a 1 kHz Lorentzian withs of stable, MHz spaced beat notes in a GHz band using two separated chips, each pumped by its own, self-injection locked laser. A deep investigation of the SIL dynamic allows us to find out the turn-key operation regime even for affordable Fabry-Perot multifrequency lasers used as a pump. It is important that such lasers are usually more powerful than DFB ones, which were also tested in our experiments. In order to test the advantages of the proposed techniques, we experimentally measured a minimum detectable speed of a reflective object. It has been shown that the narrow line of the laser locked to the microresonator provides markedly better velocity accuracy, showing velocity resolution down to 16 nm/s, while the no-SIL diode laser only allowed 160 nm/s with good accuracy. The results obtained are in agreement with the estimations and open up ways to develop LIDARs based on compact and cheap lasers. Our implementation uses affordable components, including semiconductor laser diodes and commercially available silicon nitride photonic circuits with microresonators.

Keywords: dual-comb spectroscopy, LIDAR, optical microresonator, self-injection locking

Procedia PDF Downloads 55

Authors: Scott M. Black, Craig Maclean, Pauline Hall Barrientos, Konstantinos Ritos, Asimina Kazakidi

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Aortic aneurysms and dissections are leading causes of death in cardiovascular disease. Both inevitably lead to hemodynamic instability without surgical intervention in the form of vascular stent-graft deployment. An accurate description of the aortic geometry and blood flow in patient-specific cases is vital for treatment planning and long-term success of such grafts, as they must generate physiological branch perfusion and in-stent hemodynamics. The aim of this study was to create patient-specific computational fluid dynamics (CFD) models through a multi-modality, multi-dimensional approach with boundary condition optimization to predict branch flow rates and in-stent hemodynamics in custom stent-graft configurations. Three-dimensional (3D) thoracoabdominal aortae were reconstructed from four-dimensional flow-magnetic resonance imaging (4D Flow-MRI) and computed tomography (CT) medical images. The former employed a novel approach to generate and enhance vessel lumen contrast via through-plane velocity at discrete, user defined cardiac time steps post-hoc. To produce patient-specific boundary conditions (BCs), the aortic geometry was reduced to a one-dimensional (1D) model. Thereafter, a zero-dimensional (0D) 3-Element Windkessel model (3EWM) was coupled to each terminal branch to represent the distal vasculature. In this coupled 0D-1D model, the 3EWM parameters were optimized to yield branch flow waveforms which are representative of the 4D Flow-MRI-derived in-vivo data. Thereafter, a 0D-3D CFD model was created, utilizing the optimized 3EWM BCs and a 4D Flow-MRI-obtained inlet velocity profile. A sensitivity analysis on the effects of stent-graft configuration and BC parameters was then undertaken using multiple stent-graft configurations and a range of distal vasculature conditions. 4D Flow-MRI granted unparalleled visualization of blood flow throughout the cardiac cycle in both the pre- and postsurgical states. Segmentation and reconstruction of healthy and stented regions from retrospective 4D Flow-MRI images also generated 3D models with geometries which were successfully validated against their CT-derived counterparts. 0D-1D coupling efficiently captured branch flow and pressure waveforms, while 0D-3D models also enabled 3D flow visualization and quantification of clinically relevant hemodynamic parameters for in-stent thrombosis and graft limb occlusion. It was apparent that changes in 3EWM BC parameters had a pronounced effect on perfusion distribution and near-wall hemodynamics. Results show that the 3EWM parameters could be iteratively changed to simulate a range of graft limb diameters and distal vasculature conditions for a given stent-graft to determine the optimal configuration prior to surgery. To conclude, this study outlined a methodology to aid in the prediction post-surgical branch perfusion and in-stent hemodynamics in patient specific cases for the implementation of custom stent-grafts.

Keywords: 4D flow-MRI, computational fluid dynamics, vascular stent-grafts, windkessel

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Authors: Gokulan Vethanayakam, Daniel Aston

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Introduction: The ReSPECT process supports healthcare professionals when making patient-centered decisions in the event of an emergency. It has been widely adopted by the NHS in England and allows patients to express thoughts and wishes about treatments and outcomes that they consider acceptable. It includes (but is not limited to) cardiopulmonary resuscitation decisions. ReSPECT conversations should ideally occur prior to ICU admission and should be documented in the eight sections of the nationally-standardised ReSPECT form. This audit evaluated the use of ReSPECT on a busy cardiothoracic ICU in an NHS Trust where established policies advocating its use exist. Methods: This audit was a retrospective review of ReSPECT forms for a sample of high-risk patients admitted to ICU at the Royal Papworth Hospital between January 2021 and March 2022. Patients all received one of the following interventions: Veno-Venous Extra-Corporeal Membrane Oxygenation (VV-ECMO) for severe respiratory failure (retrieved via the national ECMO service); cardiac or pulmonary transplantation-related surgical procedures (including organ transplants and Ventricular Assist Device (VAD) implantation); or elective non-transplant cardiac surgery. The quality of documentation on ReSPECT forms was evaluated using national standards and a graded ranking tool devised by the authors which was used to assess narrative aspects of the forms. Quality was ranked as A (excellent) to D (poor). Results: Of 230 patients (74 VV-ECMO, 104 transplant, 52 elective non-transplant surgery), 43 (18.7%) had a ReSPECT form and only one (0.43%) patient had a ReSPECT form completed prior to ICU admission. Of the 43 forms completed, 38 (88.4%) were completed due to the commencement of End of Life (EoL) care. No non-transplant surgical patients included in the audit had a ReSPECT form. There was documentation of balance of care (section 4a), CPR status (section 4c), capacity assessment (section 5), and patient involvement in completing the form (section 6a) on all 43 forms. Of the 34 patients assessed as lacking capacity to make decisions, only 22 (64.7%) had reasons documented. Other sections were variably completed; 29 (67.4%) forms had relevant background information included to a good standard (section 2a). Clinical guidance for the patient (section 4b) was given in 25 (58.1%), of which 11 stated the rationale that underpinned it. Seven forms (16.3%) contained information in an inappropriate section. In a comparison of ReSPECT forms completed ahead of an EoL trigger with those completed when EoL care began, there was a higher number of entries in section 3 (considering patient’s values/fears) that were assessed at grades A-B in the former group (p = 0.014), suggesting higher quality. Similarly, forms from the transplant group contained higher quality information in section 3 than those from the VV-ECMO group (p = 0.0005). Conclusions: Utilisation of the ReSPECT process in high-risk patients is yet to be well-adopted in this trust. Teams who meet patients before hospital admission for transplant or high-risk surgery should be encouraged to engage with the ReSPECT process at this point in the patient's journey. VV-ECMO retrieval teams should consider ReSPECT conversations with patients’ relatives at the time of retrieval.

Keywords: audit, critical care, end of life, ICU, ReSPECT, resuscitation

Procedia PDF Downloads 56

Authors: Jacques M. Berner, Lehlogonolo Maloma

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Context: Glyphosate, a widely used herbicide, has raised concerns about its impact on various crops. Amaranthus cruentus, an important grain crop species, is particularly susceptible to glyphosate. Understanding the specific disruptions caused by glyphosate on the photosynthetic process in Amaranthus cruentus is crucial for assessing its effects on crop productivity and ecological sustainability. Research Aim: This study aimed to investigate the dose-dependent impact of glyphosate on the photochemical efficiency of Amaranthus cruentus using the OJIP transient analysis. The goal was to assess the specific disruptions caused by glyphosate on key parameters of photosystem II. Methodology: The experiment was conducted in a controlled greenhouse environment. Amaranthus cruentus plants were exposed to different concentrations of glyphosate, including half, recommended, and double the recommended application rates. The photochemical efficiency of the plants was evaluated using non-invasive chlorophyll a fluorescence measurements and subsequent analysis of OJIP transients. Measurements were taken on 1-hour dark-adapted leaves using a Hansatech Handy PEA+ chlorophyll fluorimeter. Findings: The study's results demonstrated a significant reduction in the photochemical efficiency of Amaranthus cruentus following glyphosate treatment. The OJIP transients showed distinct alterations in the glyphosate-treated plants compared to the control group. These changes included a decrease in maximal fluorescence (FP) and a delay in the rise of the fluorescence signal, indicating impairment in the energy conversion process within the photosystem II. Glyphosate exposure also led to a substantial decrease in the maximum quantum yield efficiency of photosystem II (FV/FM) and the total performance index (PItotal), which reflects the overall photochemical efficiency of photosystem II. These reductions in photochemical efficiency were observed even at half the recommended dose of glyphosate. Theoretical Importance: The study provides valuable insights into the specific disruptions caused by glyphosate on the photochemical efficiency of Amaranthus cruentus. Data Collection and Analysis Procedures: Data collection involved non-invasive chlorophyll a fluorescence measurements using a chlorophyll fluorimeter on dark-adapted leaves. The OJIP transients were then analyzed to assess specific disruptions in key parameters of photosystem II. Statistical analysis was conducted to determine the significance of the differences observed between glyphosate-treated plants and the control group. Question Addressed: The study aimed to address the question of how glyphosate exposure affects the photochemical efficiency of Amaranthus cruentus, specifically examining disruptions in the photosynthetic electron transport chain and overall photochemical efficiency. Conclusion: The study demonstrates that glyphosate severely impairs the photochemical efficiency of Amaranthus cruentus, as indicated by the alterations in OJIP transients. Even at half the recommended dose, glyphosate caused significant reductions in photochemical efficiency. These findings highlight the detrimental effects of glyphosate on crop productivity and emphasize the need for further research to evaluate its long-term consequences and ecological implications in agriculture. The authors gratefully acknowledge the support from North-West University for making this research possible.

Keywords: glyphosate, amaranthus cruentus, ojip transient analysis, pitotal, photochemical efficiency, chlorophyll fluorescence, weeds

Procedia PDF Downloads 71

Authors: Martin Alexander Eder, Sergei Semenov

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Many glass-epoxy composite structures, such as large utility wind turbine rotor blades (WTBs), comprise of adhesive joints with typically thick bond lines used to connect the different components during assembly. Performance optimization of rotor blades to increase power output by simultaneously maintaining high stiffness-to-low-mass ratios entails intricate geometries in conjunction with complex anisotropic material behavior. Consequently, adhesive joints in WTBs are subject to multiaxial stress states with significant stress gradients depending on the local joint geometry. Moreover, the dynamic aero-elastic interaction of the WTB with the airflow generates non-proportional, variable amplitude stress histories in the material. Empiricism shows that a prominent failure type in WTBs is high cycle fatigue failure of adhesive bond line interfaces, which in fact over time developed into a design driver as WTB sizes increase rapidly. Structural optimization employed at an early design stage, therefore, sets high demands on computationally efficient interface fatigue models capable of predicting the critical locations prone for interface failure. The numerical stress-based interface fatigue model presented in this work uses the Drucker-Prager criterion to compute three different damage indices corresponding to the two interface shear tractions and the outward normal traction. The two-parameter Drucker-Prager model was chosen because of its ability to consider shear strength enhancement under compression and shear strength reduction under tension. The governing interface damage index is taken as the maximum of the triple. The damage indices are computed through the well-known linear Palmgren-Miner rule after separate rain flow-counting of the equivalent shear stress history and the equivalent pure normal stress history. The equivalent stress signals are obtained by self-similar scaling of the Drucker-Prager surface whose shape is defined by the uniaxial tensile strength and the shear strength such that it intersects with the stress point at every time step. This approach implicitly assumes that the damage caused by the prevailing multiaxial stress state is the same as the damage caused by an amplified equivalent uniaxial stress state in the three interface directions. The model was implemented as Python plug-in for the commercially available finite element code Abaqus for its use with solid elements. The model was used to predict the interface damage of an adhesively bonded, tapered glass-epoxy composite cantilever I-beam tested by LM Wind Power under constant amplitude compression-compression tip load in the high cycle fatigue regime. Results show that the model was able to predict the location of debonding in the adhesive interface between the webfoot and the cap. Moreover, with a set of two different constant life diagrams namely in shear and tension, it was possible to predict both the fatigue lifetime and the failure mode of the sub-component with reasonable accuracy. It can be concluded that the fidelity, robustness and computational efficiency of the proposed model make it especially suitable for rapid fatigue damage screening of large 3D finite element models subject to complex dynamic load histories.

Keywords: adhesive, fatigue, interface, multiaxial stress

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Authors: B. Sudhakara Reddy

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This study provides a snapshot of the sustainability of selected Indian cities by employing 70 indicators in four dimensions to develop an overall city sustainability index. In recent years, the concept of ‘urban sustainability’ has become prominent due to its complexity. Urban areas propel growth and at the same time poses a lot of ecological, social and infrastructural problems and risks. In case of developing countries, the high population density of and the continuous in-migration run the highest risk in natural and man-made disasters. These issues combined with the inability of policy makers in providing basic services makes the cities unsustainable. To assess whether any given policy is moving towards or against urban sustainability it is necessary to consider the relationships among its various dimensions. Hence, in recent years, while preparing the sustainability index, an integral approach involving indicators of different dimensions such as ‘economic’, ‘environmental’ and 'social' is being used. It is also important for urban planners, social analysts and other related institutions to identify and understand the relationships in this complex system. The objective of the paper is to develop a city performance index (CPI) to measure and evaluate the urban regions in terms of sustainable performances. The objectives include: i) Objective assessment of a city’s performance, ii) setting achievable goals iii) prioritise relevant indicators for improvement, iv) learning from leaders, iv) assessment of the effectiveness of programmes that results in achieving high indicator values, v) Strengthening of stakeholder participation. Using the benchmark approach, a conceptual framework is developed for evaluating 25 Indian cities. We develop City Sustainability index (CSI) in order to rank cities according to their level of sustainability. The CSI is composed of four dimensions: Economic, Environment, Social, and Institutional. Each dimension is further composed of multiple indicators: (1) Economic that considers growth, access to electricity, and telephone availability; (2) environmental that includes waste water treatment, carbon emissions, (3) social that includes, equity, infant mortality, and 4) institutional that includes, voting share of population, urban regeneration policies. The CSI, consisting of four dimensions disaggregate into 12 categories and ultimately into 70 indicators. The data are obtained from public and non-governmental organizations, and also from city officials and experts. By ranking a sample of diverse cities on a set of specific dimensions the study can serve as a baseline of current conditions and a marker for referencing future results. The benchmarks and indices presented in the study provide a unique resource for the government and the city authorities to learn about the positive and negative attributes of a city and prepare plans for a sustainable urban development. As a result of our conceptual framework, the set of criteria we suggest is somewhat different to any already in the literature. The scope of our analysis is intended to be broad. Although illustrated with specific examples, it should be apparent that the principles identified are relevant to any monitoring that is used to inform decisions involving decision variables. These indicators are policy-relevant and, hence they are useful tool for decision-makers and researchers.

Keywords: benchmark, city, indicator, performance, sustainability

Procedia PDF Downloads 252

Authors: Eric Bang

Abstract:

Interactions between receptors and ligands are crucial for many essential biological processes, including neurotransmission and metabolism. Ligand-receptor analyses that examine cell behavior and interactions often utilize cell type-specific RNA expressions from single-cell RNA sequencing (scRNA-seq) data. Using CellPhoneDB, a public repository consisting of ligands, receptors, and ligand-receptor interactions, the cell-cell interactions were explored in a specific scRNA-seq dataset from kidney tissue and portrayed the results with dot plots and heat maps. Depending on the type of cell, each ligand-receptor pair was aligned with the interacting cell type and calculated the positori probabilities of these associations, with corresponding P values reflecting average expression values between the triads and their significance. Using single-cell data (sample kidney cell references), genes in the dataset were cross-referenced with ones in the existing CellPhoneDB dataset. For example, a gene such as Pleiotrophin (PTN) present in the single-cell data also needed to be present in the CellPhoneDB dataset. Using the single-cell transcriptomics data via slide-seq and reference data, the CellPhoneDB program defines cell types and plots them in different formats, with the two main ones being dot plots and heat map plots. The dot plot displays derived measures of the cell to cell interaction scores and p values. For the dot plot, each row shows a ligand-receptor pair, and each column shows the two interacting cell types. CellPhoneDB defines interactions and interaction levels from the gene expression level, so since the p-value is on a -log10 scale, the larger dots represent more significant interactions. By performing an interaction analysis, a significant interaction was discovered for myeloid and T-cell ligand-receptor pairs, including those between Secreted Phosphoprotein 1 (SPP1) and Fibronectin 1 (FN1), which is consistent with previous findings. It was proposed that an effective protocol would involve a filtration step where cell types would be filtered out, depending on which ligand-receptor pair is activated in that part of the tissue, as well as the incorporation of the CellPhoneDB data in a streamlined workflow pipeline. The filtration step would be in the form of a Python script that expedites the manual process necessary for dataset filtration. Being in Python allows it to be integrated with the CellPhoneDB dataset for future workflow analysis. The manual process involves filtering cell types based on what ligand/receptor pair is activated in kidney cells. One limitation of this would be the fact that some pairings are activated in multiple cells at a time, so the manual manipulation of the data is reflected prior to analysis. Using the filtration script, accurate sorting is incorporated into the CellPhoneDB database rather than waiting until the output is produced and then subsequently applying spatial data. It was envisioned that this would reveal wherein the cell various ligands and receptors are interacting with different cell types, allowing for easier identification of which cells are being impacted and why, for the purpose of disease treatment. The hope is this new computational method utilizing spatially explicit ligand-receptor association data can be used to uncover previously unknown specific interactions within kidney tissue.

Keywords: bioinformatics, Ligands, kidney tissue, receptors, spatial transcriptome

Procedia PDF Downloads 124