Search results for: size effects on emission in CDs
Commenced in January 2007
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Paper Count: 16698

Search results for: size effects on emission in CDs

1008 Xylanase Impact beyond Performance: A Prebiotic Approach in Laying Hens

Authors: Veerle Van Hoeck, Ingrid Somers, Dany Morisset

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Anti-nutritional factors such as non-starch polysaccharides (NSP) are present in viscous cereals used to feed poultry. Therefore, exogenous carbohydrases are commonly added to monogastric feed to degrade these NSP. Our hypothesis is that xylanase not only improves laying hen performance and digestibility but also induces a significant shift in microbial composition within the intestinal tract and, thereby, can cause a prebiotic effect. In this context, a better understanding of whether and how the chicken gut flora can be modulated by xylanase is needed. To do so, in the herein laying hen study, the effects of dietary supplementation of xylanase on performance, digestibility, and cecal microbiome were evaluated. A total of 96 HiSex laying hens was used in this experiment (3 diets and 16 replicates of 2 hens). Xylanase was added to the diets at concentrations of 0, 45,000 (15 g/t XygestTM HT) and 90,000 U/kg (30 g/t Xygest HT). The diets were based on wheat (~55 %), soybean, and sunflower meal. The lowest dosage, 45,000 U/kg, significantly increased average egg weight and improved feed efficiency compared to the control treatment (p < 0.05). Egg quality parameters were significantly improved in the experiment in response to the xylanase addition. For example, during the last 28 days of the trial, the 45,000 U/kg and the 90,000 U/kg treatments exhibited an increase in Haugh units and albumin heights (p < 0.05). Compared with the control, organic matter digestibility and N retention were drastically improved in the 45,000 U/kg treatment group, which implies better nutrient digestibility at this lowest recommended dosage compared to the control (p < 0.05). Furthermore, gross energy and crude fat digestibility were improved significantly for birds fed 90,000 U/kg group compared to the control. Importantly, 16S rRNA gene analysis revealed that xylanase at 45,000 U/kg dosages can exert a prebiotic effect. This conclusion was drawn based on studying the sequence variation in the 16S rRNA gene in order to characterize diverse microbial communities of the cecal content. A significant increase in beneficial bacteria (Lactobacilli spp and Enterococcus casseliflavus) was documented when adding 45,000 U/kg xylanase to the diet of laying hens. In conclusion, dietary supplementation of xylanase, even at the lowest dose of (45,000 U/kg), significantly improved laying hen performance and digestibility. Furthermore, it is generally accepted that a proper bacterial balance between the number of beneficial bacteria and pathogenic bacteria in the intestine is vital for the host. It seems that the xylanase enzyme is able to modulate the laying hen microbiome beneficially and thus exerts a prebiotic effect. This microbiome plasticity in response to the xylanase provides an attractive target for stimulating intestinal health.

Keywords: laying hen, prebiotic, XygestTM HT, xylanase

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1007 Characterization of the Lytic Bacteriophage VbɸAB-1 against Drug Resistant Acinetobacter baumannii Isolated from Hospitalized Pressure Ulcers Patients

Authors: M. Doudi, M. H. Pazandeh, L. Rahimzadeh Torabi

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Bedsores are pressure ulcers that occur on the skin or tissue due to being immobile and lying in bed for extended periods. Bedsores have the potential to progress into open ulcers, increasing the possibility of variety of bacterial infection. Acinetobacter baumannii, a pathogen of considerable clinical importance, exhibited a significant correlation with Bedsores (pressure ulcers) infections, thereby manifesting a wide spectrum of antibiotic resistance. The emergence of drug resistance has led researchers to focus on alternative methods, particularly phage therapy, for tackling bacterial infections. Phage therapy has emerged as a novel therapeutic approach to regulate the activity of these agents. The management of bacterial infections greatly benefits from the clinical utilization of bacteriophages as a valuable antimicrobial intervention. The primary objective of this investigation consisted of isolating and discerning potent bacteriophage capable of targeting multi drug-resistant (MDR) and extensively drug-resistant (XDR) bacteria obtained from pressure ulcers. In present study, analyzed and isolated A. baumannii strains obtained from a cohort of patients suffering from pressure ulcers at Taleghani Hospital in Ahvaz, Iran. An approach that included biochemical and molecular identification techniques was used to determine the taxonomic classification of bacterial isolates at the genus and species levels. The molecular identification process was facilitated by using the 16S rRNA gene in combination with universal primers 27 F, and 1492 R. Bacteriophage was obtained through the isolation process conducted on treatment plant sewage located in Isfahan, Iran. The main goal of this study was to evaluate different characteristics of phage, such as their appearance, range of hosts they can infect, how quickly they can enter a host, their stability at varying temperatures and pH levels, their effectiveness in killing bacteria, the growth pattern of a single phage stage, mapping of enzymatic digestion, and identification of proteomics patterns. The findings demonstrated that an examination was conducted on a sample of 50 specimens, wherein 15 instances of A. baumannii were identified. These microorganisms are the predominant Gram-negative agents known to cause wound infections in individuals suffering from bedsores. The study's findings indicated a high prevalence of antibiotic resistance in the strains isolated from pressure ulcers, excluding the clinical strains that exhibited responsiveness to colistin.According to the findings obtained from assessments of host range and morphological characteristics of bacteriophage VbɸAB-1, it can be concluded that this phage possesses specificity towards A. Baumannii BAH_Glau1001 was classified as a member of the Plasmaviridae family. The bacteriophage mentioned earlier showed the strongest antibacterial effect at a temperature of 18 °C and a pH of 6.5. Through the utilization of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis on protein fragments, it was established that the bacteriophage VbɸAB-1 exhibited a size range between 50 and 75 kilodaltons (KDa). The numerous research findings on the effectiveness of phages and the safety studies conducted suggest that the phages studied in this research can be considered as a practical solution and recommended approach for controlling and treating stubborn pathogens in burn wounds among hospitalized patients.

Keywords: acinetobacter baumannii, extremely drug- resistant, phage therapy, surgery wound

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1006 Leadership in the Emergence Paradigm: A Literature Review on the Medusa Principles

Authors: Everard van Kemenade

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Many quality improvement activities are planned. Leaders are strongly involved in missions, visions and strategic planning. They use, consciously or unconsciously, the PDCA-cycle, also know as the Deming cycle. After the planning, the plans are carried out and the results or effects are measured. If the results show that the goals in the plan have not been achieved, adjustments are made in the next plan or in the execution of the processes. Then, the cycle is run through again. Traditionally, the PDCA-cycle is advocated as a means to an end. However, PDCA is especially fit for planned, ordered, certain contexts. It fits with the empirical and referential quality paradigm. For uncertain, unordered, unplanned processes, something else might be needed instead of Plan-Do-Check-Act. Due to the complexity of our society, the influence of the context, and the uncertainty in our world nowadays, not every activity can be planned anymore. At the same time organisations need to be more innovative than ever. That provides leaders with ‘wicked tendencies’. However, that raises the question how one can innovate without being able to plan? Complexity science studies the interactions of a diverse group of agents that bring about change in times of uncertainty, e.g. when radical innovation is co-created. This process is called emergence. This research study explores the role of leadership in the emergence paradigm. Aim of the article is to study the way that leadership can support the emergence of innovation in a complex context. First, clarity is given on the concepts used in the research question: complexity, emergence, innovation and leadership. Thereafter a literature search is conducted to answer the research question. The topics ‘emergent leadership’ or ‘complexity leadership’ are chosen for an exploratory search in Google and Google Scholar using the berry picking method. Exclusion criterion is emergence in other disciplines than organizational development or in the meaning of ‘arising’. The literature search conducted gave 45 hits. Twenty-seven articles were excluded after reading the title and abstract because they did not research the topic of emergent leadership and complexity. After reading the remaining articles as a whole one more was excluded because the article used emergent in the limited meaning of ‗arising‘ and eight more were excluded because the topic did not match the research question of this article. That brings the total of the search to 17 articles. The useful conclusions from the articles are merged and grouped together under overarching topics, using thematic analysis. The findings are that 5 topics prevail when looking at possibilities for leadership to facilitate innovation: enabling, sharing values, dreaming, interacting, context sensitivity and adaptivity. Together they form In Dutch the acronym Medusa.

Keywords: complexity science, emergence, leadership in the emergence paradigm, innovation, the Medusa principles

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1005 Finite Element Analysis of Layered Composite Plate with Elastic Pin Under Uniaxial Load Using ANSYS

Authors: R. M. Shabbir Ahmed, Mohamed Haneef, A. R. Anwar Khan

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Analysis of stresses plays important role in the optimization of structures. Prior stress estimation helps in better design of the products. Composites find wide usage in the industrial and home applications due to its strength to weight ratio. Especially in the air craft industry, the usage of composites is more due to its advantages over the conventional materials. Composites are mainly made of orthotropic materials having unequal strength in the different directions. Composite materials have the drawback of delamination and debonding due to the weaker bond materials compared to the parent materials. So proper analysis should be done to the composite joints before using it in the practical conditions. In the present work, a composite plate with elastic pin is considered for analysis using finite element software Ansys. Basically the geometry is built using Ansys software using top down approach with different Boolean operations. The modelled object is meshed with three dimensional layered element solid46 for composite plate and solid element (Solid45) for pin material. Various combinations are considered to find the strength of the composite joint under uniaxial loading conditions. Due to symmetry of the problem, only quarter geometry is built and results are presented for full model using Ansys expansion options. The results show effect of pin diameter on the joint strength. Here the deflection and load sharing of the pin are increasing and other parameters like overall stress, pin stress and contact pressure are reducing due to lesser load on the plate material. Further material effect shows, higher young modulus material has little deflection, but other parameters are increasing. Interference analysis shows increasing of overall stress, pin stress, contact stress along with pin bearing load. This increase should be understood properly for increasing the load carrying capacity of the joint. Generally every structure is preloaded to increase the compressive stress in the joint to increase the load carrying capacity. But the stress increase should be properly analysed for composite due to its delamination and debonding effects due to failure of the bond materials. When results for an isotropic combination is compared with composite joint, isotropic joint shows uniformity of the results with lesser values for all parameters. This is mainly due to applied layer angle combinations. All the results are represented with necessasary pictorial plots.

Keywords: bearing force, frictional force, finite element analysis, ANSYS

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1004 Effect of Low Calorie Sweeteners on Chemical, Sensory Evaluation and Antidiabetic of Pumpkin Jam Fortified with Soybean

Authors: Amnah M. A. Alsuhaibani, Amal N. Al-Kuraieef

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Introduction: In the recent decades, production of low-calorie jams is needed for diabetics that comprise low calorie fruits and low calorie sweeteners. Object: the research aimed to prepare low calorie formulated pumpkin jams (fructose, stevia and aspartame) incorporated with soy bean and evaluate the jams through chemical analysis and sensory evaluation after storage for six month. Moreover, the possible effect of consumption of low calorie jams on diabetic rats was investigated. Methods: Five formulas of pumpkin jam with different sucrose, fructose, stevia and aspartame sweeteners and soy bean were prepared and stored at 10 oC for six month compared to ordinary pumpkin jam. Chemical composition and sensory evaluation of formulated jams were evaluated at zero time, 3 month and 6 month of storage. The best three acceptable pumpkin jams were taken for biological study on diabetic rats. Rats divided into group (1) served as negative control and streptozotocin induce diabetes four rat groups that were positive diabetic control (group2), rats fed on standard diet with 10% sucrose soybean jam, fructose soybean jam and stevia soybean jam (group 3, 4&5), respectively. Results: The content of protein, fat, ash and fiber were increased but carbohydrate was decreased in low calorie formulated pumpkin jams compared to ordinary jam. Production of aspartame soybean pumpkin jam had lower score of all sensory attributes compared to other jam then followed by stevia soybean Pumpkin jam. Using non nutritive sweeteners (stevia & aspartame) with soybean in processing jam could lower the score of the sensory attributes after storage for 3 and 6 months. The highest score was recorded for sucrose and fructose soybean jams followed by stevia soybean jam while aspartame soybean jam recorded the lowest score significantly. The biological evaluation showed a significant improvement in body weight and FER of rats after six weeks of consumption of standard diet with jams (Group 3,4&5) compared to Group1. Rats consumed 10% low calorie jam with nutrient sweetener (fructose) and non nutrient sweetener (stevia) soybean jam (group 4& 5) showed significant decrease in glucose level, liver function enzymes activity, and liver cholesterol & total lipids in addition of significant increase of insulin and glycogen compared to the levels of group 2. Conclusion: low calorie pumpkin jams can be prepared by low calorie sweeteners and soybean and also storage for 3 months at 10oC without change sensory attributes. Consumption of stevia pumpkin jam fortified with soybean had positive health effects on streptozoticin induced diabetes in rats.

Keywords: pumpkin jam, HFCS, aspartame, stevia, storage

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1003 Changes in Cognition of Elderly People: A Longitudinal Study in Kanchanaburi Province, Thailand

Authors: Natchaphon Auampradit, Patama Vapattanawong, Sureeporn Punpuing, Malee Sunpuwan, Tawanchai Jirapramukpitak

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Longitudinal studies related to cognitive impairment in elderly are necessary for health promotion and development. The purposes of this study were (1) to examine changes in cognition of elderly over time and (2) to examine the impacts of changes in social determinants of health (SDH) toward changes in cognition of elderly by using the secondary data derived from the Kanchanaburi Demographic Surveillance System (KDSS) by the Institute for Population and Social Research (IPSR) which contained longitudinal data on individuals, households, and villages. Two selected projects included the Health and Social Support for Elderly in KDSS in 2007 and the Population, Economic, Social, Cultural, and Long-term Care Surveillance for Thai Elderly People’s Health Promotion in 2011. The samples were 586 elderly participated in both projects. SDH included living arrangement, social relationships with children, relatives, and friends, household asset-based wealth index, household monthly income, loans for livings, loans for investment, and working status. Cognitive impairment was measured by category fluency and delayed recall. This study employed Generalized Estimating Equation (GEE) model to investigate changes in cognition by taking SDH and other variables such as age, gender, marital status, education, and depression into the model. The unstructured correlation structure was selected to use for analysis. The results revealed that 24 percent of elderly had cognitive impairment at baseline. About 13 percent of elderly still had cognitive impairment during 2007 until 2011. About 21 percent and 11 percent of elderly had cognitive decline and cognitive improvement, respectively. The cross-sectional analysis showed that household asset-based wealth index, social relationship with friends, working status, age, marital status, education, and depression were significantly associated with cognitive impairment. The GEE model revealed longitudinal effects of household asset-based wealth index and working status against cognition during 2007 until 2011. There was no longitudinal effect of social conditions against cognition. Elderly living with richer household asset-based wealth index, still being employed, and being younger were less likely to have cognitive impairment. The results strongly suggested that poorer household asset-based wealth index and being unemployed were served as a risk factor for cognitive impairment over time. Increasing age was still the major risk for cognitive impairment as well.

Keywords: changes in cognition, cognitive impairment, elderly, KDSS, longitudinal study

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1002 Technological Affordances of a Mobile Fitness Application- A Role of Escapism and Social Outcome Expectation

Authors: Inje Cho

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The leading health risks threatening the world today are associated with a modern lifestyle characterized by sedentary behavior, stress, anxiety, and an obesogenic food environment. To counter this alarming trend, the Centers for Disease Control and Prevention have proffered Physical Activity guidelines to bolster physical engagement. Concurrently, the burgeon of smartphones and mobile applications has witnessed a proliferation of fitness applications aimed at invigorating exercise adherence and real-time activity monitoring. Grounded in the Uses and gratification theory, this study delves into the technological affordances of mobile fitness applications, discerning the mediating influences of escapism and social outcome expectations on attitudes and exercise intention. The theory explains how individuals employ distinct communication mediums to satiate their exigencies and desires. Technological affordances manifest as attributes of emerging technologies that galvanize personal engagement in physical activities. Several features of mobile fitness applications include affordances for goal setting, virtual rewards, peer support, and exercise information. Escapism, denoting the inclination to disengage from normal routines, has emerged as a salient motivator for the consumption of new media. This study postulates that individual’s perceptions technological affordances within mobile fitness applications, can affect escapism and social outcome expectations, potentially influencing attitude, and behavior formation. Thus, the integrated model has been developed to empirically examine the interrelationships between technological affordances, escapism, social outcome expectations, and exercise intention. Structural Equation Modelling serves as the methodological tool, and a cohort of 400 Fitbit users shall be enlisted from the Prolific, data collection platform. A sequence of multivariate data analyses will scrutinize both the measurement and hypothesized structural models. By delving into the effects of mobile fitness applications, this study contributes to the growing of new media studies in sport management. Moreover, the novel integration of the uses and gratification theory, technological affordances, via the prism of escapism, illustrates the dynamics that underlies mobile fitness user’s attitudes and behavioral intentions. Therefore, the findings from this study contribute to theoretical understanding and provide pragmatic insights to developers and practitioners in optimizing the impact of mobile fitness applications.

Keywords: technological affordances, uses and gratification, mobile fitness apps, escapism, physical activity

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1001 A Novel Paradigm in the Management of Pancreatic Trauma

Authors: E. Tan, O. McKay, T. Clarnette T., D. Croagh

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Background: Historically with pancreatic trauma, complete disruption of the main pancreatic duct (MPD), classified as Grade IV-V by the American Association for the Surgery of Trauma (AAST), necessitated a damage-control laparotomy. This was to avoid mortality, shorten diet upgrade timeframe, and hence shorter length of stay. However, acute pancreatic resection entailed complications of pancreatic fistulas and leaks. With the advance of imaging-guided interventions, non-operative management such as percutaneous and transpapillary drainage of traumatic peripancreatic collections have been trialled favourably. The aim of this case series is to evaluate the efficacy of endoscopic ultrasound-guided (EUS) transmural drainage in managing traumatic peripancreatic collections as a less invasive alternative to traditional approaches. This study also highlights the importance of anatomical knowledge regarding peripancreatic collection’s common location in the lesser sac, the pancreas relationship to adjacent organs, and the formation of the main pancreatic duct in regards to the feasibility of therapeutic internal drainage. Methodology: A retrospective case series was conducted at a single tertiary endoscopy unit, analysing patient data over a 5-year period. Inclusion criteria outlined patients age 5 to 80-years-old, traumatic pancreatic injury of at least Grade IV and haemodynamic stability. Exclusion criteria involved previous episodes of pancreatitis or abdominal trauma. Patient demographics and clinicopathological characteristics were retrospectively collected. Results: The study identified 7 patients with traumatic pancreatic injuries that were managed from 2018-2022; age ranging from 5 to 34 years old, with majority being female (n=5). Majority of the mechanisms of trauma were a handlebar injury (n=4). Diagnosis was confirmed with an elevated lipase and computerized tomotography (CT) confirmation of proximal pancreatic transection with MPD disruption. All patients sustained an isolated single organ grade IV pancreatic injury, except case 4 and 5 with other intra-abdominal visceral Grade 1 injuries. 6 patients underwent early ERCP-guided transpapillary drainage with 1 being unsuccessful for pancreatic duct stent insertion (case 1) and 1 complication of stent migration (case 2). Surveillance imaging post ERCP showed the stents were unable to bridge the disrupted duct and development of symptomatic collections with an average size of 9.9cm. Hence, all patients proceeded to EUS-guided transmural drainage, with 2/7 patients requiring repeat drainages (case 6 and 7). Majority (n=6) had a cystogastrostomy, whilst 1 (case 6) had a cystoenterostomy due to feasibility of the peripancreatic collection being adjacent to duodenum rather than stomach. However, case 6 subsequently required repeat EUS-guided drainage with cystogastrostomy for ongoing collections. Hence all patients avoided initial laparotomy with an average index length of stay of 11.7 days. Successful transmural drainage was demonstrated, with no long-term complications of pancreatic insufficiency; except for 1 patient requiring a distal pancreatectomy at 2 year follow-up due to chronic pain. Conclusion: The early results of this series support EUS-guided transmural drainage as a viable management option for traumatic peripancreatic collections, showcasing successful outcomes, minimal complications, and long-term efficacy in avoiding surgical interventions. More studies are required before the adoption of this procedure as a less invasive and complication-prone management approach for traumatic peripancreatic collections.

Keywords: endoscopic ultrasound, cystogastrostomy, pancreatic trauma, traumatic peripancreatic collection, transmural drainage

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1000 Self-Assembling Layered Double Hydroxide Nanosheets on β-FeOOH Nanorods for Reducing Fire Hazards of Epoxy Resin

Authors: Wei Wang, Yuan Hu

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Epoxy resins (EP), one of the most important thermosetting polymers, is widely applied in various fields due to its desirable properties, such as excellent electrical insulation, low shrinkage, outstanding mechanical stiffness, satisfactory adhesion and solvent resistance. However, like most of the polymeric materials, EP has the fatal drawbacks including inherent flammability and high yield of toxic smoke, which restricts its application in the fields requiring fire safety. So, it is still a challenge and an interesting subject to develop new flame retardants which can not only remarkably improve the flame retardancy, but also render modified resins low toxic gases generation. In recent work, polymer nanocomposites based on nanohybrids that contain two or more kinds of nanofillers have drawn intensive interest, which can realize performance enhancements. The realization of previous hybrids of carbon nanotubes (CNTs) and molybdenum disulfide provides us a novel route to decorate layered double hydroxide (LDH) nanosheets on the surface of β-FeOOH nanorods; the deposited LDH nanosheets can fill the network and promote the work efficiency of β-FeOOH nanorods. Moreover, the synergistic effects between LDH and β-FeOOH can be anticipated to have potential applications in reducing fire hazards of EP composites for the combination of condense-phase and gas-phase mechanism. As reported, β-FeOOH nanorods can act as a core to prepare hybrid nanostructures combining with other nanoparticles through electrostatic attraction through layer-by-layer assembly technique. In this work, LDH nanosheets wrapped β-FeOOH nanorods (LDH-β-FeOOH) hybrids was synthesized by a facile method, with the purpose of combining the characteristics of one dimension (1D) and two dimension (2D), to improve the fire resistance of epoxy resin. The hybrids showed a well dispersion in EP matrix and had no obvious aggregation. Thermogravimetric analysis and cone calorimeter tests confirmed that LDH-β-FeOOH hybrids into EP matrix with a loading of 3% could obviously improve the fire safety of EP composites. The plausible flame retardancy mechanism was explored by thermogravimetric infrared (TG-IR) and X-ray photoelectron spectroscopy. The reasons were concluded: condense-phase and gas-phase. Nanofillers were transferred to the surface of matrix during combustion, which could not only shield EP matrix from external radiation and heat feedback from the fire zone, but also efficiently retard transport of oxygen and flammable pyrolysis.

Keywords: fire hazards, toxic gases, self-assembly, epoxy

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999 Aorta Adhesion Molecules in Cholesterol-Fed Rats Supplemented with Extra Virgin Olive Oil or Sunflower Oil, in Either Commercial or Modified Forms

Authors: Ageliki I. Katsarou, Andriana C. Kaliora, Antonia Chiou, Apostolos Papalois, Nick Kalogeropoulos, Nikolaos K. Andrikopoulos

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Chronic inflammation plays a pivotal role in CVD development, while phytochemicals have been shown to reduce CVD risk. Several studies have correlated olive oil consumption with CVD prevention and CVD risk reduction. However, the effect of individual olive oil macro- or micro-constituents and possible synergisms among them needs to be further elucidated. Herein, extra virgin olive oil (EVOO) lipidic and polar phenolics fractions were evaluated for their effect on inflammatory markers in cholesterol-fed rats. Oils combining different characteristics as to their polar phenolic content and lipid profile were used. Male Wistar rats were fed for 9 weeks on either a high-cholesterol diet (HCD) or a HCD supplemented with oils, either commercially available, i.e. EVOO, sunflower oil (SO), or modified as to their polar phenol content, i.e. phenolics deprived-EVOO (EVOOd), SO enriched with the EVOO phenolics (SOe). Post-intervention, aorta and blood samples were collected. HCD induced dyslipidemia, manifested by serum total cholesterol and low-density lipoprotein cholesterol elevation. Additionally, HCD resulted in higher adhesion molecules’ levels in rat aorta. In the case of E-selectin, this increase was attenuated by HCD supplementation with EVOO and EVOOd, while no alterations were observed in SO and SOe groups. No differences were observed between pairs of commercial and modified oils, indicating that oleates may be the components responsible for aorta E-selectin levels lowering. The same was true for vascular adhesion molecule-1 (VCAM-1); augmentation in cholesterol-fed animals was attenuated by EVOO and EVOOd diets, highlighting oleates effect. In addition, VCAM-1 levels were higher in SO group compared to the respective SOe, indicating that in the presence of phenolic compounds linoleic acid have become less prone to oxidation. Intercellular adhesion molecule-1 (ICAM-1) levels were higher in cholesterol-fed rats, however not affected by any of the oils supplemented during the intervention. Overall, EVOO was found superior in regulating adhesion molecule levels in rat aorta compared to SO. EVOO and EVOOd exhibited analogous effects on all adhesion molecules assessed, indicating that EVOO major constituents (oleates) improve E-selectin and VCAM-1 levels in rat aorta, independently from phenolics presence. Further research is needed to elucidate the effect of phenolics and oleates in other tissues.

Keywords: extra virgin olive oil, cholesterol-fed rats, polar phenolics, adhesion molecules

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998 Progressive Damage Analysis of Mechanically Connected Composites

Authors: Şeyma Saliha Fidan, Ozgur Serin, Ata Mugan

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While performing verification analyses under static and dynamic loads that composite structures used in aviation are exposed to, it is necessary to obtain the bearing strength limit value for mechanically connected composite structures. For this purpose, various tests are carried out in accordance with aviation standards. There are many companies in the world that perform these tests in accordance with aviation standards, but the test costs are very high. In addition, due to the necessity of producing coupons, the high cost of coupon materials, and the long test times, it is necessary to simulate these tests on the computer. For this purpose, various test coupons were produced by using reinforcement and alignment angles of the composite radomes, which were integrated into the aircraft. Glass fiber reinforced and Quartz prepreg is used in the production of the coupons. The simulations of the tests performed according to the American Society for Testing and Materials (ASTM) D5961 Procedure C standard were performed on the computer. The analysis model was created in three dimensions for the purpose of modeling the bolt-hole contact surface realistically and obtaining the exact bearing strength value. The finite element model was carried out with the Analysis System (ANSYS). Since a physical break cannot be made in the analysis studies carried out in the virtual environment, a hypothetical break is realized by reducing the material properties. The material properties reduction coefficient was determined as 10%, which is stated to give the most realistic approach in the literature. There are various theories in this method, which is called progressive failure analysis. Because the hashin theory does not match our experimental results, the puck progressive damage method was used in all coupon analyses. When the experimental and numerical results are compared, the initial damage and the resulting force drop points, the maximum damage load values ​​, and the bearing strength value are very close. Furthermore, low error rates and similar damage patterns were obtained in both test and simulation models. In addition, the effects of various parameters such as pre-stress, use of bushing, the ratio of the distance between the bolt hole center and the plate edge to the hole diameter (E/D), the ratio of plate width to hole diameter (W/D), hot-wet environment conditions were investigated on the bearing strength of the composite structure.

Keywords: puck, finite element, bolted joint, composite

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997 Perceived Restorativeness Scale– 6: A Short Version of the Perceived Restorativeness Scale for Mixed (or Mobile) Devices

Authors: Sara Gallo, Margherita Pasini, Margherita Brondino, Daniela Raccanello, Roberto Burro, Elisa Menardo

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Most of the studies on the ability of environments to recover people’s cognitive resources have been conducted in laboratory using simulated environments (e.g., photographs, videos, or virtual reality), based on the implicit assumption that exposure to simulated environments has the same effects of exposure to real environments. However, the technical characteristics of simulated environments, such as the dynamic or static characteristics of the stimulus, critically affect their perception. Measuring perceived restorativeness in situ rather than in laboratory could increase the validity of the obtained measurements. Personal mobile devices could be useful because they allow accessing immediately online surveys when people are directly exposed to an environment. At the same time, it becomes important to develop short and reliable measuring instruments that allow a quick assessment of the restorative qualities of the environments. One of the frequently used self-report measures to assess perceived restorativeness is the “Perceived Restorativeness Scale” (PRS) based on Attention Restoration Theory. A lot of different versions have been proposed and used according to different research purposes and needs, without studying their validity. This longitudinal study reported some preliminary validation analyses on a short version of original scale, the PRS-6, developed to be quick and mobile-friendly. It is composed of 6 items assessing fascination and being-away. 102 Italian university students participated to the study, 84% female with age ranging from 18 to 47 (M = 20.7; SD = 2.9). Data were obtained through a survey online that asked them to report their perceived restorativeness of the environment they were in (and the kind of environment) and their positive emotion (Positive and Negative Affective Schedule, PANAS) once a day for seven days. Cronbach alpha and item-total correlations were used to assess reliability and internal consistency. Confirmatory Factor Analyses (CFA) models were run to study the factorial structure (construct validity). Correlation analyses between PRS and PANAS scores were used to check discriminant validity. In the end, multigroup CFA models were used to study measurement invariance (configural, metric, scalar, strict) between different mobile devices and between day of assessment. On the whole, the PRS-6 showed good psychometric proprieties, similar to those of the original scale, and invariance across devices and days. These results suggested that the PRS-6 could be a valid alternative to assess perceived restorativeness when researchers need a brief and immediate evaluation of the recovery quality of an environment.

Keywords: restorativeness, validation, short scale development, psychometrics proprieties

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996 Colorful Ethnoreligious Map of Iraq and the Current Situation of Minorities in the Country

Authors: Meszár Tárik

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The aim of the study is to introduce the minority groups living in Iraq and to shed light on their current situation. The Middle East is a rather heterogeneous region in ethnic terms. It includes many ethnic, national, religious, linguistic, or ethnoreligious groups. The relationship between the majority and minority is the main cause of various conflicts in the region. It seems that most of the post-Ottoman states have not yet developed a unified national identity capable of integrating their multi-ethnic societies. The issue of minorities living in the Middle East is highly politicized and controversial, as the various Arab states consider the treatment of minorities as their internal affair, do not recognize discrimination or even deny the existence of any kind of minorities on their territory. This attitude of the Middle Eastern states may also be due to the fact that the minority issue can be abused and can serve as a reference point for the intervention policies of Western countries at any time. Methodologically, the challenges of these groups are perceived through the manifestos of prominent individuals and organizations belonging to minorities. The basic aim is to present the minorities’ own history in dealing with the issue. It also introduces the different ethnic and religious minorities in Iraq and analyzes their situation during the operation of the terrorist organization „Islamic State” and in the aftermath. It is clear that the situation of these communities deteriorated significantly with the advance of ISIS, but it is also clear that even after the expulsion of the militant group, we cannot necessarily report an improvement in this area, especially in terms of the ability of minorities to assert their interests and physical security. The emergence of armed militias involved in the expulsion of ISIS sometimes has extremely negative effects on them. Until the interests of non-Muslims are adequately represented at the local level and in the legislature, most experts and advocates believe that little will change in their situation. When conflicts flare, many Iraqi citizens usually leave Iraq, but because of the poor public security situation (threats from terrorist organizations, interventions by other countries), emigration causes serious problems not only outside the country’s borders but also within the country. Another ominous implication for minorities is that their communities are very slow if ever, to return to their homes after fleeing their own settlements. An important finding of the study is that this phenomenon is changing the face of traditional Iraqi settlements and threatens to plunge groups that have lived there for thousands of years into the abyss of history. Therefore, we not only present the current situation of minorities living in Iraq but also discuss their future possibilities.

Keywords: Middle East, Iraq, Islamic State, minorities

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995 MicroRNA-1246 Expression Associated with Resistance to Oncogenic BRAF Inhibitors in Mutant BRAF Melanoma Cells

Authors: Jae-Hyeon Kim, Michael Lee

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Intrinsic and acquired resistance limits the therapeutic benefits of oncogenic BRAF inhibitors in melanoma. MicroRNAs (miRNA) regulate the expression of target mRNAs by repressing their translation. Thus, we investigated miRNA expression patterns in melanoma cell lines to identify candidate biomarkers for acquired resistance to BRAF inhibitor. Here, we used Affymetrix miRNA V3.0 microarray profiling platform to compare miRNA expression levels in three cell lines containing BRAF inhibitor-sensitive A375P BRAF V600E cells, their BRAF inhibitor-resistant counterparts (A375P/Mdr), and SK-MEL-2 BRAF-WT cells with intrinsic resistance to BRAF inhibitor. The miRNAs with at least a two-fold change in expression between BRAF inhibitor-sensitive and –resistant cell lines, were identified as differentially expressed. Averaged intensity measurements identified 138 and 217 miRNAs that were differentially expressed by 2 fold or more between: 1) A375P and A375P/Mdr; 2) A375P and SK-MEL-2, respectively. The hierarchical clustering revealed differences in miRNA expression profiles between BRAF inhibitor-sensitive and –resistant cell lines for miRNAs involved in intrinsic and acquired resistance to BRAF inhibitor. In particular, 43 miRNAs were identified whose expression was consistently altered in two BRAF inhibitor-resistant cell lines, regardless of intrinsic and acquired resistance. Twenty five miRNAs were consistently upregulated and 18 downregulated more than 2-fold. Although some discrepancies were detected when miRNA microarray data were compared with qPCR-measured expression levels, qRT-PCR for five miRNAs (miR-3617, miR-92a1, miR-1246, miR-1936-3p, and miR-17-3p) results showed excellent agreement with microarray experiments. To further investigate cellular functions of miRNAs, we examined effects on cell proliferation. Synthetic oligonucleotide miRNA mimics were transfected into three cell lines, and proliferation was quantified using a colorimetric assay. Of the 5 miRNAs tested, only miR-1246 altered cell proliferation of A375P/Mdr cells. The transfection of miR-1246 mimic strongly conferred PLX-4720 resistance to A375P/Mdr cells, implying that miR-1246 upregulation confers acquired resistance to BRAF inhibition. We also found that PLX-4720 caused much greater G2/M arrest in A375P/Mdr cells transfected with miR-1246mimic than that seen in scrambled RNA-transfected cells. Additionally, miR-1246 mimic partially caused a resistance to autophagy induction by PLX-4720. These results indicate that autophagy does play an essential death-promoting role inPLX-4720-induced cell death. Taken together, these results suggest that miRNA expression profiling in melanoma cells can provide valuable information for a network of BRAF inhibitor resistance-associated miRNAs.

Keywords: microRNA, BRAF inhibitor, drug resistance, autophagy

Procedia PDF Downloads 326
994 Tracing Sources of Sediment in an Arid River, Southern Iran

Authors: Hesam Gholami

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Elevated suspended sediment loads in riverine systems resulting from accelerated erosion due to human activities are a serious threat to the sustainable management of watersheds and ecosystem services therein worldwide. Therefore, mitigation of deleterious sediment effects as a distributed or non-point pollution source in the catchments requires reliable provenance information. Sediment tracing or sediment fingerprinting, as a combined process consisting of sampling, laboratory measurements, different statistical tests, and the application of mixing or unmixing models, is a useful technique for discriminating the sources of sediments. From 1996 to the present, different aspects of this technique, such as grouping the sources (spatial and individual sources), discriminating the potential sources by different statistical techniques, and modification of mixing and unmixing models, have been introduced and modified by many researchers worldwide, and have been applied to identify the provenance of fine materials in agricultural, rural, mountainous, and coastal catchments, and in large catchments with numerous lakes and reservoirs. In the last two decades, efforts exploring the uncertainties associated with sediment fingerprinting results have attracted increasing attention. The frameworks used to quantify the uncertainty associated with fingerprinting estimates can be divided into three groups comprising Monte Carlo simulation, Bayesian approaches and generalized likelihood uncertainty estimation (GLUE). Given the above background, the primary goal of this study was to apply geochemical fingerprinting within the GLUE framework in the estimation of sub-basin spatial sediment source contributions in the arid Mehran River catchment in southern Iran, which drains into the Persian Gulf. The accuracy of GLUE predictions generated using four different sets of statistical tests for discriminating three sub-basin spatial sources was evaluated using 10 virtual sediments (VS) samples with known source contributions using the root mean square error (RMSE) and mean absolute error (MAE). Based on the results, the contributions modeled by GLUE for the western, central and eastern sub-basins are 1-42% (overall mean 20%), 0.5-30% (overall mean 12%) and 55-84% (overall mean 68%), respectively. According to the mean absolute fit (MAF; ≥ 95% for all target sediment samples) and goodness-of-fit (GOF; ≥ 99% for all samples), our suggested modeling approach is an accurate technique to quantify the source of sediments in the catchments. Overall, the estimated source proportions can help watershed engineers plan the targeting of conservation programs for soil and water resources.

Keywords: sediment source tracing, generalized likelihood uncertainty estimation, virtual sediment mixtures, Iran

Procedia PDF Downloads 74
993 A Minimally Invasive Approach Using Bio-Miniatures Implant System for Full Arch Rehabilitation

Authors: Omid Allan

Abstract:

The advent of ultra-narrow diameter implants initially offered an alternative to wider conventional implants. However, their design limitations have restricted their applicability primarily to overdentures and cement-retained fixed prostheses, often with unpredictable long-term outcomes. The introduction of the new Miniature Implants has revolutionized the field of implant dentistry, leading to a more streamlined approach. The utilization of Miniature Implants has emerged as a promising alternative to the traditional approach that entails the traumatic sequential bone drilling procedures and the use of conventional implants for full and partial arch restorations. The innovative "BioMiniatures Implant System serves as a groundbreaking bridge connecting mini implants with standard implant systems. This system allows practitioners to harness the advantages of ultra-small implants, enabling minimally invasive insertion and facilitating the application of fixed screw-retained prostheses, which were only available to conventional wider implant systems. This approach streamlines full and partial arch rehabilitation with minimal or even no bone drilling, significantly reducing surgical risks and complications for clinicians while minimizing patient morbidity. The ultra-narrow diameter and self-advancing features of these implants eliminate the need for invasive and technically complex procedures such as bone augmentation and guided bone regeneration (GBR), particularly in cases involving thin alveolar ridges. Furthermore, the absence of a microcap between the implant and abutment eliminates the potential for micro-leakage and micro-pumping effects, effectively mitigating the risk of marginal bone loss and future peri-implantitis. The cumulative experience of restoring over 50 full and partial arch edentulous cases with this system has yielded an outstanding success rate exceeding 97%. The long-term success with a stable marginal bone level in the study firmly establishes these implants as a dependable alternative to conventional implants, especially for full arch rehabilitation cases. Full arch rehabilitation with these implants holds the promise of providing a simplified solution for edentulous patients who typically present with atrophic narrow alveolar ridges, eliminating the need for extensive GBR and bone augmentation to restore their dentition with fixed prostheses.

Keywords: mini-implant, biominiatures, miniature implants, minimally invasive dentistry, full arch rehabilitation

Procedia PDF Downloads 76
992 Psychological Distress and Associated Factors among Patients Attending Orthopedic Unit of at Dilla University Referral Hospital in Ethiopia, 2022

Authors: Chalachew Kassaw, Henok Ababu, Bethelhem Sileshy, Lulu Abebe, Birhanie Mekuriaw

Abstract:

Background: Psychological discomfort is a state of emotional distress caused by everyday stressors and obligations that are difficult to manage. Orthopedic trauma has a wide range of effects on survivors' physical health, as well as a variety of mental health concerns that impede recovery. Psychiatric and behavioral conditions are 3-5 times more common in people who have undergone physical trauma, and they are a predictor of poor outcomes. Despite the above facts, there is a shortage of research done on the subject. Therefore, this study aimed to determine the magnitude of psychological distress and associated factor among patients attending orthopedic treatment at Gedeo zone, South Ethiopia 2022. Methods: A cross-sectional study was undertaken at Dilla University Referral Hospital from October –November 2022. The data was collected via a face-to-face interview, and the Kessler psychological distress scale (K-10) was used to assess psychological distress. A total of 386 patients receiving outpatient and inpatient services at the orthopedic unit were chosen using a simple random selection technique. A Statistical Package for the Social Science version 21 (SPSS-21) was used to enter and evaluate the data. To find related factors, bivariate, and multivariate logistic regressions were used. Variables having a p-value of less than 0.05 were deemed statistically significant. Result: A total of 386 participants with a response rate of 94.8% were included in the study. Out of all respondents, 114 (31.4%) of the individuals have experienced psychological distress. Independent variables such as Females [Adjusted odds ratio (AOR)=5.8, 95%CI=(4.6-15.6)], Average monthly income of <3500 birrs [Adjusted odds ratio (AOR) =4.8, 95% CI=(2.4-9.8) ], Current history of substance use [Adjusted odds ratio (AOR) =2.6, 95% CI=(1.66-4.7)], Strong social support [Adjusted odds ratio (AOR)=0.4, 95% CI= 0.4(0.2-0.8)], and Poor sleep quality (PSQI score>5) [Adjusted odds ratio (AOR)=2.0, 95%CI= 2.0(1.2-2.8)] were significantly associated with psychological distress. Conclusion: The prevalence of psychological distress was high. Being female, having poor social support, and having a high PSQI score were significantly associated factors with psychological distress. It is good if clinicians emphasize orthopedic patients, especially females and those having poor social support and low sleep quality symptoms.

Keywords: psychological distress, orthopedic unit, Dilla University hospital, Dilla Town, Southern Ethiopia

Procedia PDF Downloads 89
991 Heat Transfer Dependent Vortex Shedding of Thermo-Viscous Shear-Thinning Fluids

Authors: Markus Rütten, Olaf Wünsch

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Non-Newtonian fluid properties can change the flow behaviour significantly, its prediction is more difficult when thermal effects come into play. Hence, the focal point of this work is the wake flow behind a heated circular cylinder in the laminar vortex shedding regime for thermo-viscous shear thinning fluids. In the case of isothermal flows of Newtonian fluids the vortex shedding regime is characterised by a distinct Reynolds number and an associated Strouhal number. In the case of thermo-viscous shear thinning fluids the flow regime can significantly change in dependence of the temperature of the viscous wall of the cylinder. The Reynolds number alters locally and, consequentially, the Strouhal number globally. In the present CFD study the temperature dependence of the Reynolds and Strouhal number is investigated for the flow of a Carreau fluid around a heated cylinder. The temperature dependence of the fluid viscosity has been modelled by applying the standard Williams-Landel-Ferry (WLF) equation. In the present simulation campaign thermal boundary conditions have been varied over a wide range in order to derive a relation between dimensionless heat transfer, Reynolds and Strouhal number. Together with the shear thinning due to the high shear rates close to the cylinder wall this leads to a significant decrease of viscosity of three orders of magnitude in the nearfield of the cylinder and a reduction of two orders of magnitude in the wake field. Yet the shear thinning effect is able to change the flow topology: a complex K´arm´an vortex street occurs, also revealing distinct characteristic frequencies associated with the dominant and sub-dominant vortices. Heating up the cylinder wall leads to a delayed flow separation and narrower wake flow, giving lesser space for the sequence of counter-rotating vortices. This spatial limitation does not only reduce the amplitude of the oscillating wake flow it also shifts the dominant frequency to higher frequencies, furthermore it damps higher harmonics. Eventually the locally heated wake flow smears out. Eventually, the CFD simulation results of the systematically varied thermal flow parameter study have been used to describe a relation for the main characteristic order parameters.

Keywords: heat transfer, thermo-viscous fluids, shear thinning, vortex shedding

Procedia PDF Downloads 298
990 The Link Between Collaboration Interactions and Team Creativity Among Nursing Student Teams in Taiwan: A Moderated Mediation Model

Authors: Hsing Yuan Liu

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Background: Considerable theoretical and empirical work has identified a relationship between collaboration interactions and creativity in an organizational context. The mechanisms underlying this link, however, are not well understood in healthcare education. Objectives: The aims of this study were to explore the impact of collaboration interactions on team creativity and its underlying mechanism and to verify a moderated mediation model. Design, setting, and participants: This study utilized a cross-sectional, quantitative, descriptive design. The survey data were collected from 177 nursing students who enrolled in 18-week capstone courses of small interdisciplinary groups collaborating to design healthcare products in Taiwan during 2018 and 2019. Methods: Questionnaires assessed the nursing students' perceptions about their teams' swift trust (of cognition- and affect-based), conflicts (of task, process, and relationship), interaction behaviors (constructive controversy, helping behaviors, and spontaneous communication), and creativity. This study used descriptive statistics to compare demographics, swift trust scores, conflict scores, interaction behavior scores, and creativity scores for interdisciplinary teams. Data were analyzed using Pearson’s correlation coefficient and simple and hierarchical multiple regression models. Results: Pearson’s correlation analysis showed the cognition-based team swift trust was positively correlated with team creativity. The mediation model indicated constructive controversy fully mediated the effect of cognition-based team swift trust on student teams’ creativity. The moderated mediation model indicated that task conflict negatively moderates the mediating effect of the constructive controversy on the link between cognition-based team swift trust and team creativity. Conclusion: Our findings suggest nursing student teams’ interaction behaviors and task conflict are crucial mediating and moderated mediation variables on the relationship between collaboration interactions and team creativity, respectively. The empirical data confirms the validity of our proposed moderated mediation models of team creativity. Therefore, this study's validated moderated mediation model could provide guidance for nursing educators to improve collaboration interaction outcomes and creativity on nursing student teams.

Keywords: team swift trust, team conflict, team interaction behavior, moderated mediating effects, interdisciplinary education, nursing students

Procedia PDF Downloads 187
989 Associations between Mindfulness, Temporal Discounting, Locus of Control, and Reward-Based Eating in a Sample of Overweight and Obese Adults

Authors: Andrea S. Badillo-Perez, Alexis D. Mitchell, Sara M. Levens

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Overeating, and obesity have been associated with addictive behavior, primarily due to behaviors like reward-based eating, the tendency to overeat due to factors such as lack of control, preoccupation over food, and lack of satiation. Temporal discounting (TD), the ability to select future rewards over short term gains, and mindfulness, the process of maintaining present moment awareness, have been suggested to have significant, differential impacts on health-related behaviors. An individual’s health locus of control, the degree to which they feel that they have control over their health is also known to have an impact on health outcomes. The goal of this study was to investigate the relationship between health locus of control and reward-based eating, as well as the relation between TD and mindfulness in a sample (N = 126) of overweight or obese participants from larger health-focused study. Through the use of questionnaires (including the Five Facet Mindfulness Questionnaire (FFMQ), Reward-Based Eating Drive (RED), and Multidimensional Health Locus of Control (MHLOC)), anthropometric measurements, and a computerized TD task, a series of regressions tested the association between subscales of these measures. Results revealed differences in how the mindfulness subscales are associated with TD measures. Specifically the ‘Observing’ (beta =-.203) and ‘Describing’ (beta =.26) subscales were associated with lower TD rates and a longer subjective devaluation time-frame respectively. In contrast, the ‘Acting with Awareness’ subscale was associated with a shorter subjective devaluation timeframe (beta =-.23). These findings suggest that the reflective perspective initiated through the observing and describing components of mindfulness may facilitate delay of gratification, whereas the acting with awareness component of mindfulness, which focuses on the present moment, may make delay of gratification more challenging. Results also indicated that a higher degree of reward-based eating was associated with a higher degree of an external health locus of control based on the power of chance (beta =.10). However, an external locus of control based on the power of others had no significant association with reward-based eating. This finding implies that the belief that health is due to chance is associated with greater reward-based eating behavior, suggesting that interventions that focus on locus of control may be helpful. Overall, findings demonstrate that weight loss interventions may benefit from health locus of control and mindfulness exercises, but caution should be taken as the components of mindfulness appear to have different effects on increasing or decreasing delay of gratification.

Keywords: health locus of control, mindfulness, obesity, reward-based eating, temporal discounting

Procedia PDF Downloads 138
988 Cosmic Radiation Hazards and Protective Strategies in Space Exploration

Authors: Mehrnaz Mostafavi, Alireza Azani, Mahtab Shabani, Fatemeh Ghafari

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While filled with promise and wonder, space exploration also presents significant challenges, one of the foremost being the threat of cosmic radiation to astronaut health. Recent advancements in assessing these risks and developing protective strategies have shed new light on this issue. Cosmic radiation encompasses a variety of high-energy particles originating from sources like solar particle events, galactic cosmic rays, and cosmic rays from beyond the solar system. These particles, composed of protons, electrons, and heavy ions, pose a substantial threat to human health in space due to the lack of Earth's protective atmosphere and magnetic field. Researchers have made significant progress in assessing the risks associated with cosmic radiation exposure. By employing advanced dosimetry techniques and conducting biological studies, they have gained insights into how cosmic radiation affects astronauts' health, including increasing the risk of cancer and radiation sickness. This research has led to personalized risk assessment methods tailored to individual astronaut profiles. Distinctive protection strategies have been proposed to combat the dangers of cosmic radiation. These include developing spacecraft shielding materials and designs to enhance radiation protection. Additionally, researchers are exploring pharmacological interventions such as radioprotective drugs and antioxidant therapies to mitigate the biological effects of radiation exposure and preserve astronaut well-being. The findings from recent research have significant implications for the future of space exploration. By advancing our understanding of cosmic radiation risks and developing effective protection strategies, we pave the way for safer and more sustainable human missions beyond Earth's orbit. This is especially crucial for long-duration missions to destinations like Mars, where astronauts will face prolonged exposure to cosmic radiation. In conclusion, recent research has marked a milestone in addressing the challenges posed by cosmic radiation in space exploration. By delving into the complexities of cosmic radiation exposure and developing innovative protection strategies, scientists are ensuring the health and resilience of astronauts as they venture into the vast expanse of the cosmos. Continued research and collaboration in this area are essential for overcoming the cosmic radiation challenge and enabling humanity to embark on new frontiers of exploration and discovery in space.

Keywords: Space exploration, cosmic radiation, astronaut health, risk assessment, protective strategies

Procedia PDF Downloads 81
987 Examining the Concept of Sustainability in the Scenery Architecture of Naqsh-e-Jahan Square

Authors: Mahmood Naghizadeh, Maryam Memarian, Hourshad Irvash

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Following the rise in the world population and the upward growth of urbanization, the design, planning, and management of the site scenery for the purpose of presentation and expansion of sustainable site scenery has turned to be the greatest concern to experts. Since the fundamental principles of the site scenery change more and less haphazardly over time, sustainable site scenery can be viewed as an ideal goal because both sustainability and dynamism come into view in urban site scenery and it wouldn’t be designed according to a set of pre-determined principles. Sustainable site scenery, as the ongoing interaction between idealism and pragmatism with sustainability factors, is a dynamic phenomenon created by bringing cultural, historical, social and natural scenery together. Such an interaction is not to subdue other factors but to reinforce the aforementioned factors. The sustainable site scenery is a persistently occurring event not only has attenuated over time but has gained strength. The sustainability of a site scenery or an event over time depends on its site identity which grows out of its continuous association with the past. The sustainability of a site scene or an event in a time frame intertwined with the identity of the place from past to present. This past history supports the present and future of the scene. The result of such a supportive role is the sustainability of site scenery. Isfahan Naqsh-e-Jahan Square is one of the most outstanding squares in the world and the best embodiment of Iranian site scenery architecture. This square is an arena that brings people together and a dynamic city center comprising various urban and religious complexes, spaces and facilities and is considered as one of the most favorable traditional urban space of Iran. Such a place can illustrate many factors related to sustainable site scenery. One the other hand, there are still no specific principles concerning sustainability in the architecture of site scenery. Meanwhile, sustainability is recognized as a rather modern view in architecture. The purpose of this research is to identify factors involved in sustainability in general and to examine their effects on site scenery architecture in particular. Finally, these factors will be studied with taking Naqsh-e-Jahan Square into account. This research adopts an analytic-descriptive approach that has benefited from the review of literature available in library studies and the documents related to sustainability and site scenery architecture. The statistical population used for the purpose of this research includes square constructed during the Safavid dynasty and Naqsh-e-Jahan Square was picked out as the case study. The purpose of this paper is to come up with a rough definition of sustainable site scenery and demonstrate this concept by analyzing it and recognizing the social, economic and ecological aspects of this project.

Keywords: Naqsh-e-Jahan Square, site scenery architecture, sustainability, sustainable site scenery

Procedia PDF Downloads 313
986 Factors Influencing the Adoption of Interpersonal Communication Media to Maximize Business Competitiveness among Small and Medium Enterprises in Hong Kong: Industry Types and Entrepreneur Characteristics

Authors: Olivine Lo

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Small- and Medium-Sized Enterprises (SMEs) consist of a broad variety of businesses, ranging from small grocery shops to manufacturing concerns. Some are dynamic and innovative, while others are more traditional. The definition of SMEs varies by country but is most determined by the number of employees, though business assets and sales revenues are alternative measures. There are eight main types of SME industries in Hong Kong: garment, electronics, plastics, metal and machinery, trading and logistics, building, manufacturing, and service industries. Information exchange is a key goal of human communication, and communicators have used a variety of media to maintain relationships through traditional face-to-face interactions and written forms like letters and faxes. With the advancement of mediated-interpersonal communication media from telephone to synchronic online tools like email, instant messaging, voice messaging, and video conferencing for sustaining relationships, particularly enabling geographically distanced relationships. Although these synchronous tools are gaining popularity, they are facilitating relationship maintenance in everyday life and complementing rather than replacing the more conventional face-to-face interactions. This study will test if there are any variances in effects by industry type among Hong Kong SMEs. The competitiveness of the business environment refers to the competition faced by a business within its particular industry. The more intense the competition in a given sector, the greater the potential for strategic uses of specific needs in a business. Both internal organization characteristics and external environments may affect firm performance and financial resources. The level of competitiveness within an industry will be a more reliable indicator to show how Hong Kong SMEs are striving to achieve their business goals using different techniques in their communication media preferences, rather than mere classification by industry type. This study thus divides the competitiveness of the business environment into internal and external: (1) the internal environment competition is the inherent competitiveness of the products or services provided by the SMEs, whereas (2) the external environment competition includes the economic and political realities and competitors joining the market. This study will test various organizational characteristics and competitiveness of the business environment to predict entrepreneurs’ communication media preferences.

Keywords: competitiveness of business environment, small- and medium-sized enterprises, organizational characteristics, communication media preference

Procedia PDF Downloads 34
985 Improving Photocatalytic Efficiency of TiO2 Films Incorporated with Natural Geopolymer for Sunlight-Driven Water Purification

Authors: Satam Alotibi, Haya A. Al-Sunaidi, Almaymunah M. AlRoibah, Zahraa H. Al-Omaran, Mohammed Alyami, Fatehia S. Alhakami, Abdellah Kaiba, Mazen Alshaaer, Talal F. Qahtan

Abstract:

This research study presents a novel approach to harnessing the potential of natural geopolymer in conjunction with TiO₂ nanoparticles (TiO₂ NPs) for the development of highly efficient photocatalytic materials for water decontamination. The study begins with the formulation of a geopolymer paste derived from natural sources, which is subsequently applied as a coating on glass substrates and allowed to air-dry at room temperature. The result is a series of geopolymer-coated glass films, serving as the foundation for further experimentation. To enhance the photocatalytic capabilities of these films, a critical step involves immersing them in a suspension of TiO₂ nanoparticles (TiO₂ NPs) in water for varying durations. This immersion process yields geopolymer-loaded TiO₂ NPs films with varying concentrations, setting the stage for comprehensive characterization and analysis. A range of advanced analytical techniques, including UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM), were meticulously employed to assess the structural, morphological, and chemical properties of the geopolymer-based TiO₂ films. These analyses provided invaluable insights into the materials' composition and surface characteristics. The culmination of this research effort sees the geopolymer-based TiO₂ films being repurposed as immobilized photocatalytic reactors for water decontamination under natural sunlight irradiation. Remarkably, the results revealed exceptional photocatalytic performance that exceeded the capabilities of conventional TiO₂-based photocatalysts. This breakthrough underscores the significant potential of natural geopolymer as a versatile and highly effective matrix for enhancing the photocatalytic efficiency of TiO₂ nanoparticles in water treatment applications. In summary, this study represents a significant advancement in the quest for sustainable and efficient photocatalytic materials for environmental remediation. By harnessing the synergistic effects of natural geopolymer and TiO₂ nanoparticles, these geopolymer-based films exhibit outstanding promise in addressing water decontamination challenges and contribute to the development of eco-friendly solutions for a cleaner and healthier environment.

Keywords: geopolymer, TiO2 nanoparticles, photocatalytic materials, water decontamination, sustainable remediation

Procedia PDF Downloads 67
984 Dynamic Simulation of Disintegration of Wood Chips Caused by Impact and Collisions during the Steam Explosion Pre-Treatment

Authors: Muhammad Muzamal, Anders Rasmuson

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Wood material is extensively considered as a raw material for the production of bio-polymers, bio-fuels and value-added chemicals. However, the shortcoming in using wood as raw material is that the enzymatic hydrolysis of wood material is difficult because the accessibility of enzymes to hemicelluloses and cellulose is hindered by complex chemical and physical structure of the wood. The steam explosion (SE) pre-treatment improves the digestion of wood material by creating both chemical and physical modifications in wood. In this process, first, wood chips are treated with steam at high pressure and temperature for a certain time in a steam treatment vessel. During this time, the chemical linkages between lignin and polysaccharides are cleaved and stiffness of material decreases. Then the steam discharge valve is rapidly opened and the steam and wood chips exit the vessel at very high speed. These fast moving wood chips collide with each other and with walls of the equipment and disintegrate to small pieces. More damaged and disintegrated wood have larger surface area and increased accessibility to hemicelluloses and cellulose. The energy required for an increase in specific surface area by same value is 70 % more in conventional mechanical technique, i.e. attrition mill as compared to steam explosion process. The mechanism of wood disintegration during the SE pre-treatment is very little studied. In this study, we have simulated collision and impact of wood chips (dimension 20 mm x 20 mm x 4 mm) with each other and with walls of the vessel. The wood chips are simulated as a 3D orthotropic material. Damage and fracture in the wood material have been modelled using 3D Hashin’s damage model. This has been accomplished by developing a user-defined subroutine and implementing it in the FE software ABAQUS. The elastic and strength properties used for simulation are of spruce wood at 12% and 30 % moisture content and at 20 and 160 OC because the impacted wood chips are pre-treated with steam at high temperature and pressure. We have simulated several cases to study the effects of elastic and strength properties of wood, velocity of moving chip and orientation of wood chip at the time of impact on the damage in the wood chips. The disintegration patterns captured by simulations are very similar to those observed in experimentally obtained steam exploded wood. Simulation results show that the wood chips moving with higher velocity disintegrate more. Moisture contents and temperature decreases elastic properties and increases damage. Impact and collision in specific directions cause easy disintegration. This model can be used to efficiently design the steam explosion equipment.

Keywords: dynamic simulation, disintegration of wood, impact, steam explosion pretreatment

Procedia PDF Downloads 401
983 Evidence on the Nature and Extent of Fall in Oil Prices on the Financial Performance of Listed Companies: A Ratio Analysis Case Study of the Insurance Sector in the UAE

Authors: Pallavi Kishore, Mariam Aslam

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The sharp decline in oil prices that started in 2014 affected most economies in the world either positively or negatively. In some economies, particularly the oil exporting countries, the effects were felt immediately. The Gulf Cooperation Council’s (GCC henceforth) countries are oil and gas-dependent with the largest oil reserves in the world. UAE (United Arab Emirates) has been striving to diversify away from oil and expects higher non-oil growth in 2018. These two factors, falling oil prices and the economy strategizing away from oil dependence, make a compelling case to study the financial performance of various sectors in the economy. Among other sectors, the insurance sector is widely recognized as an important indicator of the health of the economy. An expanding population, surge in construction and infrastructure, increased life expectancy, greater expenditure on automobiles and other luxury goods translate to a booming insurance sector. A slow-down of the insurance sector, on the other hand, may indicate a general slow-down in the economy. Therefore, a study on the insurance sector will help understand the general nature of the current economy. This study involves calculations and comparisons of ratios pre and post the fall in oil prices in the insurance sector in the UAE. A sample of 33 companies listed on the official stock exchanges of UAE-Dubai Financial Market and Abu Dhabi Stock Exchange were collected and empirical analysis employed to study the financial performance pre and post fall in oil prices. Ratios were calculated in 5 categories: Profitability, Liquidity, Leverage, Efficiency, and Investment. The means pre- and post-fall are compared to conclude that the profitability ratios including ROSF (Return on Shareholder Funds), ROCE (Return on Capital Employed) and NPM (Net Profit Margin) have all taken a hit. Parametric tests, including paired t-test, concludes that while the fall in profitability ratios is statistically significant, the other ratios have been quite stable in the period. The efficiency, liquidity, gearing and investment ratios have not been severely affected by the fall in oil prices. This may be due to the implementation of stronger regulatory policies and is a testimony to the diversification into the non-oil economy. The regulatory authorities can use the findings of this study to ensure transparency in revealing financial information to the public and employ policies that will help further the health of the economy. The study will also help understand which areas within the sector could benefit from more regulations.

Keywords: UAE, insurance sector, ratio analysis, oil price, profitability, liquidity, gearing, investment, efficiency

Procedia PDF Downloads 247
982 Reducing Pressure Drop in Microscale Channel Using Constructal Theory

Authors: K. X. Cheng, A. L. Goh, K. T. Ooi

Abstract:

The effectiveness of microchannels in enhancing heat transfer has been demonstrated in the semiconductor industry. In order to tap the microscale heat transfer effects into macro geometries, overcoming the cost and technological constraints, microscale passages were created in macro geometries machined using conventional fabrication methods. A cylindrical insert was placed within a pipe, and geometrical profiles were created on the outer surface of the insert to enhance heat transfer under steady-state single-phase liquid flow conditions. However, while heat transfer coefficient values of above 10 kW/m2·K were achieved, the heat transfer enhancement was accompanied by undesirable pressure drop increment. Therefore, this study aims to address the high pressure drop issue using Constructal theory, a universal design law for both animate and inanimate systems. Two designs based on Constructal theory were developed to study the effectiveness of Constructal features in reducing the pressure drop increment as compared to parallel channels, which are commonly found in microchannel fabrication. The hydrodynamic and heat transfer performance for the Tree insert and Constructal fin (Cfin) insert were studied using experimental methods, and the underlying mechanisms were substantiated by numerical results. In technical terms, the objective is to achieve at least comparable increment in both heat transfer coefficient and pressure drop, if not higher increment in the former parameter. Results show that the Tree insert improved the heat transfer performance by more than 16 percent at low flow rates, as compared to the Tree-parallel insert. However, the heat transfer enhancement reduced to less than 5 percent at high Reynolds numbers. On the other hand, the pressure drop increment stayed almost constant at 20 percent. This suggests that the Tree insert has better heat transfer performance in the low Reynolds number region. More importantly, the Cfin insert displayed improved heat transfer performance along with favourable hydrodynamic performance, as compared to Cfinparallel insert, at all flow rates in this study. At 2 L/min, the enhancement of heat transfer was more than 30 percent, with 20 percent pressure drop increment, as compared to Cfin-parallel insert. Furthermore, comparable increment in both heat transfer coefficient and pressure drop was observed at 8 L/min. In other words, the Cfin insert successfully achieved the objective of this study. Analysis of the results suggests that bifurcation of flows is effective in reducing the increment in pressure drop relative to heat transfer enhancement. Optimising the geometries of the Constructal fins is therefore the potential future study in achieving a bigger stride in energy efficiency at much lower costs.

Keywords: constructal theory, enhanced heat transfer, microchannel, pressure drop

Procedia PDF Downloads 338
981 Risk Assessment of Lead Element in Red Peppers Collected from Marketplaces in Antalya, Southern Turkey

Authors: Serpil Kilic, Ihsan Burak Cam, Murat Kilic, Timur Tongur

Abstract:

Interest in the lead (Pb) has considerably increased due to knowledge about the potential toxic effects of this element, recently. Exposure to heavy metals above the acceptable limit affects human health. Indeed, Pb is accumulated through food chains up to toxic concentrations; therefore, it can pose an adverse potential threat to human health. A sensitive and reliable method for determination of Pb element in red pepper were improved in the present study. Samples (33 red pepper products having different brands) were purchased from different markets in Turkey. The selected method validation criteria (linearity, Limit of Detection, Limit of Quantification, recovery, and trueness) demonstrated. Recovery values close to 100% showed adequate precision and accuracy for analysis. According to the results of red pepper analysis, all of the tested lead element in the samples was determined at various concentrations. A Perkin- Elmer ELAN DRC-e model ICP-MS system was used for detection of Pb. Organic red pepper was used to obtain a matrix for all method validation studies. The certified reference material, Fapas chili powder, was digested and analyzed, together with the different sample batches. Three replicates from each sample were digested and analyzed. The results of the exposure levels of the elements were discussed considering the scientific opinions of the European Food Safety Authority (EFSA), which is the European Union’s (EU) risk assessment source associated with food safety. The Target Hazard Quotient (THQ) was described by the United States Environmental Protection Agency (USEPA) for the calculation of potential health risks associated with long-term exposure to chemical pollutants. THQ value contains intake of elements, exposure frequency and duration, body weight and the oral reference dose (RfD). If the THQ value is lower than one, it means that the exposed population is assumed to be safe and 1 < THQ < 5 means that the exposed population is in a level of concern interval. In this study, the THQ of Pb was obtained as < 1. The results of THQ calculations showed that the values were below one for all the tested, meaning the samples did not pose a health risk to the local population. This work was supported by The Scientific Research Projects Coordination Unit of Akdeniz University. Project Number: FBA-2017-2494.

Keywords: lead analyses, red pepper, risk assessment, daily exposure

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980 Investigating the Role of Organizational Politics in Human Resource Management: Effects on Performance Appraisal and Downsizing Decisions

Authors: Ibrahim Elshaer, Samar Kamel

Abstract:

Organizational politics (OP) has received a great deal of attention in the management literature due to its popularity, mystery, and potential advantages for those how can use it. It involves the use of power and social networks within an organization to promote interests and gain potential benefits. Its implication for human resource (HR) management decisions is heretofore one of its least studied aspects, and awaits further investigation. Therefore, it is our intention to investigate certain relations between organizational politics and the validity of HR decisions in addition to the expected dysfunctional consequences. The study is undertaken on two HR management practices- Performance appraisal (measured by the distributive justice scale) and downsizing- depending on data gathered from the hotel industry in Egypt; a developing Non-Western country, in which Political practices of HR management are common in public and private organizations. Data was obtained from a survey of 600 employees in the Egyptian hotel industry. A total of 500 responses were attained. 100 uncompleted questionnaires were excluded leaving 400 usable with response rate of around 80%. Structural equation modeling (SEM) was employed to test the causal relationship between the research variables. The analysis of the current study data reveals that organizational politics is negatively linked to the perception of distributive justice of performance appraisal, additionally, the perception of distributive justice in performance appraisal is positively linked to the perception of validity in the downsizing decisions and finally the perception of OP is negatively linked to the perception of downsizing decisions validity. This study makes three important contributions. First although there have been several studies on OP, the majority of these studies have focused on examining its effect on employees’ attitudes in workplace. This empirical study helps in identifying the influence of OP on the effectiveness and success of HR decisions and accordingly the organizational system. Second, it draws attention to OP as an important phenomenon that influence HR management in hospitality industry, since empirical evidences concerning OP in the hospitality management literature are meager. Third, this study contributes to the existing downsizing literature by examining OP and low distributive justice as challenges of the effectiveness of the downsizing process. Finally, to the best of the authors’ knowledge, no empirical study in the tourism and hospitality management literature has examined the effect of OP and distributive justice on the workplace using data gathered from the hotel industry in Egypt; a developing non-Western setting.

Keywords: organizational politics, performance appraisal, downsizing, structural equation modeling, hotel industry

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979 Isolation of Nitrosoguanidine Induced NaCl Tolerant Mutant of Spirulina platensis with Improved Growth and Phycocyanin Production

Authors: Apurva Gupta, Surendra Singh

Abstract:

Spirulina spp., as a promising source of many commercially valuable products, is grown photo autotrophically in open ponds and raceways on a large scale. However, the economic exploitation in an open system seems to have been limited because of lack of multiple stress-tolerant strains. The present study aims to isolate a stable stress tolerant mutant of Spirulina platensis with improved growth rate and enhanced potential to produce its commercially valuable bioactive compounds. N-methyl-n'-nitro-n-nitrosoguanidine (NTG) at 250 μg/mL (concentration permitted 1% survival) was employed for chemical mutagenesis to generate random mutants and screened against NaCl. In a preliminary experiment, wild type S. platensis was treated with NaCl concentrations from 0.5-1.5 M to calculate its LC₅₀. Mutagenized colonies were then screened for tolerance at 0.8 M NaCl (LC₅₀), and the surviving colonies were designated as NaCl tolerant mutants of S. platensis. The mutant cells exhibited 1.5 times improved growth against NaCl stress as compared to the wild type strain in control conditions. This might be due to the ability of the mutant cells to protect its metabolic machinery against inhibitory effects of salt stress. Salt stress is known to adversely affect the rate of photosynthesis in cyanobacteria by causing degradation of the pigments. Interestingly, the mutant cells were able to protect its photosynthetic machinery and exhibited 4.23 and 1.72 times enhanced accumulation of Chl a and phycobiliproteins, respectively, which resulted in enhanced rate of photosynthesis (2.43 times) and respiration (1.38 times) against salt stress. Phycocyanin production in mutant cells was observed to enhance by 1.63 fold. Nitrogen metabolism plays a vital role in conferring halotolerance to cyanobacterial cells by influx of nitrate and efflux of Na+ ions from the cell. The NaCl tolerant mutant cells took up 2.29 times more nitrate as compared to the wild type and efficiently reduce it. Nitrate reductase and nitrite reductase activity in the mutant cells also improved by 2.45 and 2.31 times, respectively against salt stress. From these preliminary results, it could be deduced that enhanced nitrogen uptake and its efficient reduction might be a reason for adaptive and halotolerant behavior of the S. platensis mutant cells. Also, the NaCl tolerant mutant of S. platensis with significant improved growth and phycocyanin accumulation compared to the wild type can be commercially promising.

Keywords: chemical mutagenesis, NaCl tolerant mutant, nitrogen metabolism, photosynthetic machinery, phycocyanin

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