Search results for: low voltage trigger silicon controlled rectifier (LVTSCR)

Authors: S. Kudlacik-Kramarczyk, M. Kedzierska, B. Tyliszczak

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Recently, the continuous development of medicine and related sciences has been observed. Particular emphasis is directed on the development of biomaterials, i.e., non-toxic, biocompatible and biodegradable materials that may improve the effectiveness of treatment as well as the comfort of patients. This is particularly important in the case of cancer treatment. Currently, there are many methods of cancer treatment based primarily on chemotherapy and the surgical removal of the tumor, but it is worth noting that these therapies also cause many side effects. Among women, the most common cancer is breast cancer. It may be completely cured, but the consequence of treatment is partial or complete breast mastectomy and radiation therapy, which results in severe skin burns. The skin of the patient after radiation therapy is very burned, and therefore requires intensive care and high frequency of dressing changes. The traditional dressing adheres to the burn wounds and does not absorb adequate amount of exudate from injuries and the patient is forced to change the dressing every 2 hours. Therefore, the main purpose was to develop an innovative combination of dressing material with drug carriers that may be used in anti-cancer therapy. The innovation of this solution is the combination of these two products into one system, i.e., a transdermal system with the possibility of a controlled release of the drug- cytostatic. Besides, the possibility of modifying the hydrogel matrix with aloe vera juice provides this material with new features favorable from the point of view of healing processes of burn wounds resulting from the radiation therapy. In this study, hydrogel materials containing protein spheres with the active substance have been obtained as a result of photopolymerization process. The reaction mixture consisting of the protein (albumin) spheres incorporated with cytostatic, chitosan, adequate crosslinking agent and photoinitiator has been subjected to the UV radiation for 2 minutes. Prepared materials have been subjected to the numerous studies including the analysis of cytotoxicity using murine fibroblasts L929. Analysis was conducted based on the mitochondrial activity test (MTT reduction assay) which involves the determining the number of cells characterized by proper metabolism. Hydrogel materials obtained using different amount of crosslinking agents have been subjected to the cytotoxicity analysis. According to the standards, tested material is defined as cytotoxic when the viability of cells after 24 h incubation with this material is lower than 70%. In the research, hydrogel polymer materials containing protein spheres incorporated with the active substance, i.e. a cytostatic, have been developed. Such a dressing may support the treatment of cancer due to the content of the anti-cancer drug - cytostatic, and may also provide a soothing effect on the healing of the burn wounds resulted from the radiation therapy due to the content of aloe vera juice in the hydrogel matrix. Based on the conducted cytotoxicity studies, it may be concluded that the obtained materials do not adversely affect the tested cell lines, therefore they can be subjected to more advanced analyzes.

Keywords: hydrogel polymers, cytostatics, drug carriers, cytotoxicity

Procedia PDF Downloads 132

Authors: K. Mohon Singh

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Cambro-Ordovician (512.5 ± 8.7 Ma) felsic magmatism in the Kyrdem region of Meghalaya plateau, herewith referred to as Kyrdem granitoids (KG), intrudes the low-grade Shillong Group of metasediments and Precambrian Basement Gneissic complex forming an oval-shaped plutonic body with longer axis almost trending N-S. Thermal aureole is poorly developed or covered under the alluvium. KG exhibit very coarse grained porphyritic texture with abundant K-feldspar megacrysts (up to 9cm long) and subordinate amount of amphibole, biotite, plagioclase, and quartz. The size of K-feldspar megacrysts increases from margin (Dwarksuid) to the interior (Kyrdem) of the KG pluton. Late felsic pulses as fine grained granite, leucocratic (aplite), and pegmatite veins intrude the KG at several places. Grey and pink varieties of KG can be recognized, but pink colour of KG is the result of post-magmatic fluids, which have not affected the magnetic properties of KG. Modal composition of KG corresponds to quartz monzonite, monzogranite, and granodiorite. KG has been geochemically characterized as metaluminous (I-type) to peraluminous (S-type) granitoids. The KG is characterized by development of variable attitude of primary foliations mostly marked along the margin of the pluton and is located at the proximity of Tyrsad-Barapani lineament. The KG contains country rock xenoliths (amphibolite, gneiss, schist, etc.) which are mostly confined to the margin of the pluton, and microgranular enclaves (ME) are hosted in the porphyritic variety of KG. Microgranular Enclaves (ME) in Kyrdem Granitoids are fine- to medium grained, mesocratic to melanocratic, phenocryst bearing or phenocryst-free, rounded to ellipsoidal showing typical magmatic textures. Mafic-felsic phenocrysts in ME are partially corroded and dissolved because of their involvement in magma-mixing event, and thus represent xenocrysts. Sharp to diffused contacts of ME with host Kyrdem Granitoids, fine grained nature and presence of acicular apatite in ME suggest comingling and undercooling of coeval, semi-solidified ME magma within partly crystalline felsic host magma. Geochemical features recognize the nature of ME (molar A/CNK=0.76-1.42) and KG (molar A/CNK =0.41-1.75) similar to hybrid-type formed by mixing of mantle-derived mafic and crustal-derived felsic magmas. Major and trace including rare earth elements variations of ME suggest the involvement of combined processes such as magma mixing, mingling and crystallization differentiation in the evolution of ME but KG variations appear primarily controlled by fractionation of plagioclase, hornblende biotite, and accessory phases. Most ME are partially to nearly re-equilibrate chemically with felsic host KG during magma mixing and mingling processes.

Keywords: geochemistry, Kyrdem Granitoids, microgranular enclaves, Northeast India

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Authors: Reuben Newell, Edward Archer, Alistair McIlhagger, Calvin Ralph

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Modern industry has developed a need for innovative 3D composite materials due to their attractive material properties. Composite materials are composed of a fibre reinforcement encased in a polymer matrix. The fibre reinforcement consists of warp, weft and binder yarns or tows woven together into a preform. The mechanical performance of composite material is largely controlled by the properties of the preform. As a result, the bulk of recent textile research has been focused on the design of high-strength preform architectures. Studies looking at optimisation of the weaving process have largely been neglected. It has been reported that yarns experience varying levels of damage during weaving, resulting in filament breakage and ultimately compromised composite mechanical performance. The weaving parameters involved in causing this yarn damage are not fully understood. Recent studies indicate that poor yarn tension control may be an influencing factor. As tension is increased, the yarn-to-yarn and yarn-to-weaving-equipment interactions are heightened, maximising damage. The correlation between yarn tension variation and weaving damage severity has never been adequately researched or quantified. A novel study is needed which accesses the influence of tension variation on the mechanical properties of woven yarns. This study has looked to quantify the variation of yarn tension throughout weaving and sought to link the impact of tension to weaving damage. Multiple yarns were randomly selected, and their tension was measured across the creel and shedding stages of weaving, using a hand-held tension meter. Sections of the same yarn were subsequently cut from the loom machine and tensile tested. A comparison study was made between the tensile strength of pristine and tensioned yarns to determine the induced weaving damage. Yarns from bobbins at the rear of the creel were under the least amount of tension (0.5-2.0N) compared to yarns positioned at the front of the creel (1.5-3.5N). This increase in tension has been linked to the sharp turn in the yarn path between bobbins at the front of the creel and creel I-board. Creel yarns under the lower tension suffered a 3% loss of tensile strength, compared to 7% for the greater tensioned yarns. During shedding, the tension on the yarns was higher than in the creel. The upper shed yarns were exposed to a decreased tension (3.0-4.5N) compared to the lower shed yarns (4.0-5.5N). Shed yarns under the lower tension suffered a 10% loss of tensile strength, compared to 14% for the greater tensioned yarns. Interestingly, the most severely damaged yarn was exposed to both the largest creel and shedding tensions. This study confirms for the first time that yarns under a greater level of tension suffer an increased amount of weaving damage. Significant variation of yarn tension has been identified across the creel and shedding stages of weaving. This leads to a variance of mechanical properties across the woven preform and ultimately the final composite part. The outcome from this study highlights the need for optimised yarn tension control during preform manufacture to minimize yarn-induced weaving damage.

Keywords: optimisation of preform manufacture, tensile testing of damaged tows, variation of yarn weaving tension, weaving damage

Procedia PDF Downloads 236

Authors: Mohammad Javaherian, Siamak Bashardoust Tajali, Monavvar Hadizadeh

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Objective: This systematic review study was conducted to evaluate the effects of Pulsed Electromagnetic (PEMF) and Static Magnetic Fields (SMG) on pain relief and functional improvement in patients with musculoskeletal Low Back Pain (LBP). Methods: Seven electronic databases were searched by two researchers independently to identify the published Randomized Controlled Trials (RCTs) on the efficacy of pulsed electromagnetic, static magnetic, and therapeutic nuclear magnetic fields. The identified databases for systematic search were Ovid Medline®, Ovid Cochrane RCTs and Reviews, PubMed, Web of Science, Cochrane Library, CINAHL, and EMBASE from 1968 to February 2016. The relevant keywords were selected by Mesh. After initial search and finding relevant manuscripts, all references in selected studies were searched to identify second hand possible manuscripts. The published RCTs in English would be included to the study if they reported changes on pain and/or functional disability following application of magnetic fields on chronic musculoskeletal low back pain. All studies with surgical patients, patients with pelvic pain, and combination of other treatment techniques such as acupuncture or diathermy were excluded. The identified studies were critically appraised and the data were extracted independently by two raters (M.J and S.B.T). Probable disagreements were resolved through discussion between raters. Results: In total, 1505 abstracts were found following the initial electronic search. The abstracts were reviewed to identify potentially relevant manuscripts. Seventeen possibly appropriate studies were retrieved in full-text of which 48 were excluded after reviewing their full-texts. Ten selected articles were categorized into three subgroups: PEMF (6 articles), SMF (3 articles), and therapeutic nuclear magnetic fields (tNMF) (1 article). Since one study evaluated tNMF, we had to exclude it. In the PEMF group, one study of acute LBP did not show significant positive results and the majority of the other five studies on Chronic Low Back Pain (CLBP) indicated its efficacy on pain relief and functional improvement, but one study with the lowest sessions (6 sessions during 2 weeks) did not report a significant difference between treatment and control groups. In the SMF subgroup, two articles reported near significant pain reduction without any functional improvement although more studies are needed. Conclusion: The PEMFs with a strength of 5 to 150 G or 0.1 to 0.3 G and a frequency of 5 to 64 Hz or sweep 7 to 7KHz can be considered as an effective modality in pain relief and functional improvement in patients with chronic low back pain, but there is not enough evidence to confirm their effectiveness in acute low back pain. To achieve the appropriate effectiveness, it is suggested to perform this treatment modality 20 minutes per day for at least 9 sessions. SMFs have not been reported to be substantially effective in decreasing pain or improving the function in chronic low back pain. More studies are necessary to achieve more reliable results.

Keywords: pulsed electromagnetic field, static magnetic field, magnetotherapy, low back pain

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Authors: Wei Xu, Abdo S. Haidar, Jianxin Gao

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Prosthetic socket is a component that connects the residual limb of an amputee with an artificial prosthesis. It is widely recognized as the most critical component that determines the comfort of a patient when wearing the prosthesis in his/her daily activities. Through the socket, the body weight and its associated dynamic load are distributed and transmitted to the prosthesis during walking, running or climbing. In order to achieve a good-fit socket for an individual amputee, it is essential to obtain the biomechanical properties of the residual limb. In current clinical practices, this is achieved by a touch-and-feel approach which is highly subjective. Although there have been significant advancements in prosthetic technologies such as microprocessor controlled knee and ankle joints in the last decade, the progress in designing a comfortable socket has been rather limited. This means that the current process of socket design is still very time-consuming, and highly dependent on the expertise of the prosthetist. Supported by the state-of-the-art sensor technologies and numerical simulations, a new socket design system is being developed to help prosthetists achieve rapid design of comfortable sockets for above knee amputees. This paper reports the research work related to establishing biomechanical models for socket design. Through numerical simulation using finite element method, comprehensive relationships between pressure on residual limb and socket geometry were established. This allowed local topological adjustment for the socket so as to optimize the pressure distributions across the residual limb. When the full body weight of a patient is exerted on the residual limb, high pressures and shear forces between the residual limb and the socket occur. During numerical simulations, various hyperplastic models, namely Ogden, Yeoh and Mooney-Rivlin, were used, and their effectiveness in representing the biomechanical properties of soft tissues of the residual limb was evaluated. This also involved reverse engineering, which resulted in an optimal representative model under compression test. To validate the simulation results, a range of silicone models were fabricated. They were tested by an indentation device which yielded the force-displacement relationships. Comparisons of results obtained from FEA simulations and experimental tests showed that the Ogden model did not fit well the soft tissue material indentation data, while the Yeoh model gave the best representation of the soft tissue mechanical behavior under indentation. Compared with hyperplastic model, the result showed that elastic model also had significant errors. In addition, normal and shear stress distributions on the surface of the soft tissue model were obtained. The effect of friction in compression testing and the influence of soft tissue stiffness and testing boundary conditions were also analyzed. All these have contributed to the overall goal of designing a good-fit socket for individual above knee amputees.

Keywords: above knee amputee, finite element simulation, hyperplastic model, prosthetic socket

Procedia PDF Downloads 205

Authors: Mari Jaakkola, Jasmiina Haverinen, Tiina Tolonen, Vesa Virtanen

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These process monitoring of biogas plant gives valuable information of the function of the process and help to maintain a stable process. The costs of basic monitoring are often much lower than the costs associated with re-establishing a biologically destabilised plant. Reactor acidification through reactor overload is one of the most common reasons for process deterioration in anaerobic digesters. This occurs because of a build-up of volatile fatty acids (VFAs) produced by acidogenic and acetogenic bacteria. VFAs cause pH values to decrease, and result in toxic conditions in the reactor. Ammonia ensures an adequate supply of nitrogen as a nutrient substance for anaerobic biomass and increases system's buffer capacity, counteracting acidification lead by VFA production. However, elevated ammonia concentration is detrimental to the process due to its toxic effect. VFAs are considered the most reliable analytes for process monitoring. To obtain accurate results, sample storage and transportation need to be carefully controlled. This may be a challenge for off-line laboratory analyses especially when the plant is located far away from the laboratory. The aim of this study was to investigate the correlation between fatty acids, ammonium, and bacteria in the anaerobic digestion samples obtained from an industrial biogas factory. The stability of the analytes was studied comparing the results of the on-site analyses performed in the factory site to the results of the samples stored at room temperature and -18°C (up to 30 days) after sampling. Samples were collected in the biogas plant consisting of three separate mesofilic AD reactors (4000 m³ each) where the main feedstock was swine slurry together with a complex mixture of agricultural plant and animal wastes. Individual VFAs, ammonium, and nutrients (K, Ca, Mg) were studied by capillary electrophoresis (CE). Longer chain fatty acids (oleic, hexadecanoic, and stearic acids) and bacterial profiles were studied by GC-MSD (Gas Chromatography-Mass Selective Detector) and 16S rDNA, respectively. On-site monitoring of the analytes was performed by CE. The main VFA in all samples was acetic acid. However, in one reactor sample elevated levels of several individual VFAs and long chain fatty acids were detected. Also bacterial profile of this sample differed from the profiles of other samples. Acetic acid decomposed fast when the sample was stored in a room temperature. All analytes were stable when stored in a freezer. Ammonium was stable even at a room temperature for the whole testing period. One reactor sample had higher concentration of VFAs and long chain fatty acids than other samples. CE was utilized successfully in the on-site analysis of separate VFAs and NH₄ in the biogas production site. Samples should be analysed in the sampling day if stored in RT or freezed for longer storage time. Fermentation reject can be stored (and transported) at ambient temperature at least for one month without loss of NH₄. This gives flexibility to the logistic solutions when reject is used as a fertilizer.

Keywords: anaerobic digestion, capillary electrophoresis, ammonium, bacteria

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Authors: B. Ozarisoy, E. Ampatzi, G. Z. Lancaster

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This research project is undertaken in the Turkish Republic of Northern Cyprus (T.R.N.C). The study focuses on identifying refurbishment activities capable of diagnosing and detecting the underlying problems alongside the challenges offered by the buildings’ typology in addition to identifying the correct construction materials in the refurbishment process which allow for the maximisation of expected energy savings. Attention is drawn to, the level of awareness and understanding of refurbishment activity that needs to be raised in the current construction process alongside factors that include the positive environmental impact and the saving of energy. The approach here is to look at buildings that have been built by private construction companies that have already been refurbished by occupants and to suggest additional control mechanisms for retrofitting that can further enhance the process of renewal. The objective of the research is to investigate the occupants’ behaviour and role in the refurbishment activity; to explore how and why occupants decide to change building components and to understand why and how occupants consider using energy-efficient materials. The present work is based on data from this researcher’s first-hand experience and incorporates the preliminary data collection on recent housing sector statistics, including the year in which housing estates were built, an examination of the characteristics that define the construction industry in the T.R.N.C., building typology and the demographic structure of house owners. The housing estates are chosen from 16 different projects in four different regions of the T.R.N.C. that include urban and suburban areas. There is, therefore, a broad representation of the common drivers in the property market, each with different levels of refurbishment activity and this is coupled with different samplings from different climatic regions within the T.R.N.C. The study is conducted through semi-structured interviews to identify occupants’ behaviour as it is associated with refurbishment activity. The interviews provide all the occupants’ demographic information, needs and intentions as they relate to various aspects of the refurbishment process. This research paper presents the results of semi-structured interviews with 70 homeowners in a selected group of 16 housing estates in five different parts of the T.R.N.C. The people who agreed to be interviewed in this study are all residents of single or multi-family housing units. Alongside the construction process and its impact on the environment, the results point out the need for control mechanisms in the housing sector to promote and support the adoption of retrofit strategies and minimize non-controlled refurbishment activities, in line with diagnostic information of the selected buildings. The expected solutions should be effective, environmentally acceptable and feasible given the type of housing projects under review, with due regard for their location, the climatic conditions within which they were undertaken, the socio-economic standing of the house owners and their attitudes, local resources and legislative constraints. Furthermore, the study goes on to insist on the practical and long-term economic benefits of refurbishment under the proper conditions and why this should be fully understood by the householders.

Keywords: construction process, energy-efficiency, refurbishment activity, retrofitting

Procedia PDF Downloads 325

Authors: Francisco Pereira, António Augusto Vicente, Filipe Vaz, Joel Borges, Pedro Geada

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Light is a growth-limiting factor in microalgae cultivation, where factors like spectral components, intensity, and duration, often characterized by its wavelength, are well-reported to have a substantial impact on cell growth rates and, consequently, photosynthetic performance and mitigation of CO2, one of the most significant greenhouse gases (GHGs). Photobioreactors (PBRs) are commonly used to grow microalgae under controlled conditions, but they often fail to provide an even light distribution to the cultures. For this reason, there is a pressing need for innovations aiming at enhancing the efficient utilization of light. So, one potential approach to address this issue is by implementing plasmonic films, such as the localized surface plasmon resonance (LSPR). LSPR is an optical phenomenon connected to the interaction of light with metallic nanostructures. LSPR excitation is characterized by the oscillation of unbound conduction electrons of the nanoparticles coupled with the electromagnetic field from incident light. As a result of this excitation, highly energetic electrons and a strong electromagnetic field are generated. These effects lead to an amplification of light scattering, absorption, and extinction of specific wavelengths, contingent on the nature of the employed nanoparticle. Thus, microalgae might benefit from this biotechnology as it enables the selective filtration of inhibitory wavelengths and harnesses the electromagnetic fields produced, which could lead to enhancements in both biomass and metabolite productivity. This study aimed at implementing and evaluating a “plasmon-enhanced PBR”. The goal was to utilize LSPR thin films to enhance the growth and CO2 bio-fixation rate of Chlorella vulgaris. The internal/external walls of the PBRs were coated with a TiO2 matrix containing different nanoparticles (Au, Ag, and Au-Ag) in order to evaluate the impact of this approach on microalgae’s performance. Plasmonic films with distinct compositions resulted in different Chlorella vulgaris growth, ranging from 4.85 to 6.13 g.L-1. The highest cell concentrations were obtained with the metallic Ag films, demonstrating a 14% increase compared to the control condition. Moreover, it appeared to be no differences in growth between PBRs with inner and outer wall coatings. In terms of CO2 bio-fixation, distinct rates were obtained depending on the coating applied, ranging from 0.42 to 0.53 gCO2L-1d-1. Ag coating was demonstrated to be the most effective condition for carbon fixation by C. vulgaris. The impact of LSPR films on the biochemical characteristics of biomass (e.g., proteins, lipids, pigments) was analysed as well. Interestingly, Au coating yielded the most significant enhancements in protein content and total pigments, with increments of 15 % and 173 %, respectively, when compared to the PBR without any coating (control condition). Overall, the incorporation of plasmonic films in PBRs seems to have the potential to improve the performance and efficiency of microalgae cultivation, thereby representing an interesting approach to increase both biomass production and GHGs bio-mitigation.

Keywords: CO₂ bio-fixation, plasmonic effect, photobioreactor, photosynthetic microalgae

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Authors: Jo Anne Rey

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Caring for Country (Ngurrain Dharug language) is core to Aboriginal identity, Law/Lore, practice, and resilience within the continent called ‘Australia’. It is the basis of thousands of years of sustainability. However, when Ngurra is a city known as Sydney, due to 235 years of colonial impact, caring for the Country is limited, being controlled by the State and private ownership of the land title. Recent research indicates that localised Indigenous activism is most successful when community members are geographically proximate to the presences and places of connection, caring, and belonging. This article frames these findings through the cadence that proximity provides. This presentation is centred on the proximate agency that is being exercised by Dharug community through three significant sites within the Sydney basin. Those sites include, firstly, Shaw’s Creek Aboriginal Place, at the foot of the Blue Mountains in far western Sydney. Second inclusion is the site of Blacktown Native Institution, that was the part of the authoritarian colonial governance of British Governor Lachlan Macquarie (after who Macquarie University is named), which saw the beginnings of the removal of children from their families and culture to ‘civilize’ them. The third site is that of the so-called Brown’s Waterhole in the State government administered Lane Cove National Park. Each of these sites is being activated through Dharug and, more broadly, Aboriginalways of knowing, doing, and being. These ways involvethe land, water, wind, and star-based ecologies interwoven with traditional transgenerational storying of the presences (Ancestral and spiritual) creating them. Activations include, but are not limited to, the return of cultural fire for reviving plants, soils, animals, and birds. These fire practices have traditionally been at the basis of sustainable, regenerative biodiversity. These practices involve the literacy of reading Ngurra and the seasonal interactions across the ecologies. Together, they both care for the Country and support humanity, and have done so across thousands of years. However, when the cost of real-estate and rental accommodation prevents community members from being able to live on Dharug Ngurra when bureaucratic governance restricts and/or excludes traditional custodial relationships, and when private treaty land title destroys the presences and places while disconnecting people from their Ancestral practices, it becomes clear that caring for Country is only possible when the community can afford to live nearby. Recognising the cadence of proximityas the agency that underpinscaring for Country-in-the-city, sustainable change opportunities don’t have to only focus on regional and remote areas. Urban-based Aboriginal relationality offers an alternative to the unsustainable practices that underpin human-centric disconnection. Weaving Indigenous cadence offers opportunities for sustainable futures even when facing the extremes of climate changing catastrophes.

Keywords: australian aboriginal, biocultural knowledges, climate change, dharug ngurra, sustainability, resilience

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Authors: Kyoung Lee

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Numerous aerobic bacteria have the ability to form multicellular communities on the surface layer of the air-liquid (A-L) interface as a biofilm called a pellicle. Pellicles occupied at the A-L interface will benefit from the utilization of oxygen from air and nutrient from liquid. Buoyancy of cells can be obtained by high surface tension at the A-L interface. Thus, formation of pellicles is an adaptive advantage in utilization of excess nutrients in the standing culture where oxygen depletion is easily set up due to rapid cell growth. In natural environments, pellicles are commonly observed on the surface of lake or pond contaminated with pollutants. Previously, we have shown that when cultured in standing LB media an alkylphenol-degrading bacteria Pseudomonas alkylphenolia KL28 forms pellicles in a diameter of 0.3-0.5 mm with a thickness of ca 40 µm. The pellicles have unique features for possessing flatness and unusual rigidity. In this study, the biogenesis of the circular pellicles has been investigated by observing the cell organization at early stages of pellicle formation and cell arrangements in pellicle, providing a clue for highly organized cellular arrangement to be adapted to the air-liquid niche. Here, we first monitored developmental patterns of pellicle from monolayer to multicellular organization. Pellicles were shaped by controlled growth of constituent cells which accumulate extracellular polymeric substance. The initial two-dimensional growth was transited to multilayers by a constraint force of accumulated self-produced extracellular polymeric substance. Experiments showed that pellicles are formed by clonal growth and even with knock-out of genes for flagella and pilus formation. In contrast, the mutants in the epm gene cluster for alginate-like polymer biosynthesis were incompetent in cell alignment for initial two-dimensional growth of pellicles. Electron microscopic and confocal laser scanning microscopic studies showed that the fully matured structures are highly packed by matrix-encased cells which have special arrangements. The cells on the surface of the pellicle lie relatively flat and inside longitudinally cross packed. HPLC analysis of the extrapolysaccharide (EPS) hydrolysate from the colonies from LB agar showed a composition with L-fucose, L-rhamnose, D-galactosamine, D-glucosamine, D-galactose, D-glucose, D-mannose. However, that from pellicles showed similar neutral and amino sugar profile but missing galactose. Furthermore, uronic acid analysis of EPS hydrolysates by HPLC showed that mannuronic acid was detected from pellicles not from colonies, indicating the epm-derived polymer is critical for pellicle formation as proved by the epm mutants. This study verified that for the circular pellicle architecture P. alkylphenolica KL28 cells utilized EPS building blocks different from that used for colony construction. These results indicate that P. alkylphenolica KL28 is a clever architect that dictates unique cell arrangements with selected EPS matrix material to construct sophisticated building, circular biofilm pellicles.

Keywords: biofilm, matrix, pellicle, pseudomonas

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Authors: Md. Wasiul Islam, Md. Jamius Shams Sowrov

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The Sundarbans is the largest single tract of mangrove forest in the world. This is located in the southwest corner of Bangladesh. This is a unique ecosystem which is a great breeding and nursing ground for a great biodiversity. It supports the livelihood of about 3.5 million coastal dwellers and also protects the coastal belt and inland areas from various natural calamities. Historically, the management of the Sundarbans was controlled by the Bangladesh Forest Department following top-down approach without the involvement of local communities. Such fence and fining-based blue-print approach was not effective to protect the forest which caused Sundarbans to degrade severely in the recent past. Fifty percent of the total tree cover has been lost in the last 30 years. Therefore, local multi-stakeholder based bottom-up co-management approach was introduced at some of the parts of the Sundarbans in 2006 to improve the biodiversity status by enhancing the protection level of the forest. Various co-management organizations were introduced under co-management approach where the local community people could actively involve in various activities related to the management and welfare of the Sundarbans including the decision-making process to achieve the goal. From this backdrop, the objective of the study was to assess the performance of co-management organizations to facilitate sustainable management of the Sundarbans mangrove forests. The qualitative study followed face-to-face interview to collect data using two sets of semi-structured questionnaires. A total of 40 respondents participated in the research that was from eight villagers under two forest ranges. 32 representatives from the local communities as well as 8 official representatives involved in co-management approach were interviewed using snowball sampling technique. The study shows that the co-management approach improved governance system of the Sundarbans through active participation of the local community people and their interactions with the officials via the platform of co-management organizations. It facilitated accountability and transparency system to some extent through following some formal and informal rules and regulations. It also improved the power structure of the management process by fostering local empowerment process particularly the women. Moreover, people were able to learn from their interactions with and within the co-management organizations as well as interventions improved environmental awareness and promoted social learning. The respondents considered good governance as the most important factor for achieving the goal of sustainable management and biodiversity conservation of the Sundarbans. The success of co-management planning process also depends on the active and functional participation of different stakeholders including the local communities where co-management organizations were considered as the most functional platform. However, the governance system was also facing various challenges which resulted in barriers to the sustainable management of the Sundarbans mangrove forest. But still there were some members involved in illegal forest operations and created obstacles against sustainable management of the Sundarbans. Respondents recommended greater patronization from the government, financial and logistic incentives for alternative income generation opportunities with effective participatory monitoring and evaluation system to improve sustainable management of the Sundarbans.

Keywords: Bangladesh, co-management approach, co-management organizations, governance, Sundarbans, sustainable management

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Authors: Aman Johri, Sidhant Sood, Pooja Suresh

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This paper suggests a new and more efficient method of atomization of fuel in a combustor nozzle of a high bypass turbofan engine, using ultrasonic vibrations. Since atomization of fuel just before the fuel spray is injected into the combustion chamber is an important and crucial aspect related to functioning of a propulsion system, the technology suggested by this paper and the experimental analysis on the system components eventually proves to assist in complete and rapid combustion of the fuel in the combustor module of the engine. Current propulsion systems use carburetors, atomization nozzles and apertures in air intake pipes for atomization. The idea of this paper is to deploy new age hybrid technology, namely the Ultrasound Field Effect (UFE) to effectively atomize fuel before it enters the combustion chamber, as a viable and effective method to increase efficiency and improve upon existing designs. The Ultrasound Field Effect is applied axially, on diametrically opposite ends of an atomizer tube that gloves onto the combustor nozzle, where the fuel enters and exits under a pre-defined pressure. The Ultrasound energy vibrates the fuel particles to a breakup frequency. At reaching this frequency, the fuel particles start disintegrating into smaller diameter particles perpendicular to the axis of application of the field from the parent boundary layer of fuel flow over the baseplate. These broken up fuel droplets then undergo swirling effect as per the original nozzle design, with a higher breakup ratio than before. A significant reduction of the size of fuel particles eventually results in an increment in the propulsive efficiency of the engine. Moreover, the Ultrasound atomizer operates within a control frequency such that effects of overheating and induced vibrations are least felt on the overall performance of the engine. The design of an electrical manifold for the multiple-nozzle system over a typical can-annular combustor is developed along with this study, such that the product can be installed and removed easily for maintenance and repairing, can allow for easy access for inspections and transmits least amount of vibrational energy to the surface of the combustor. Since near-field ultrasound is used, the vibrations are easily controlled, thereby successfully reducing vibrations on the outer shell of the combustor. Experimental analysis is carried out on the effect of ultrasonic vibrations on flowing jet turbine fuel using an ultrasound generator probe and results of an effective decrease in droplet size across a constant diameter, away from the boundary layer of flow is noted using visual aid by observing under ultraviolet light. The choice of material for the Ultrasound inducer tube and crystal along with the operating range of temperatures, pressures, and frequencies of the Ultrasound field effect are also studied in this paper, while taking into account the losses incurred due to constant vibrations and thermal loads on the tube surface.

Keywords: atomization, ultrasound field effect, titanium mesh, breakup frequency, parent boundary layer, baseplate, propulsive efficiency, jet turbine fuel, induced vibrations

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Authors: Jiri Cecrdle

Abstract:

This paper describes the concept of the W-WING whirl flutter aeroelastic demonstrator. Whirl flutter is the specific case of flutter that accounts for the additional dynamic and aerodynamic influences of the engine rotating parts. The instability is driven by motion-induced unsteady aerodynamic propeller forces and moments acting in the propeller plane. Whirl flutter instability is a serious problem that may cause the unstable vibration of a propeller mounting, leading to the failure of an engine installation or an entire wing. The complicated physical principle of whirl flutter required the experimental validation of the analytically gained results. W-WING aeroelastic demonstrator has been designed and developed at Czech Aerospace Research Centre (VZLU) Prague, Czechia. The demonstrator represents the wing and engine of the twin turboprop commuter aircraft. Contrary to the most of past demonstrators, it includes a powered motor and thrusting propeller. It allows the changes of the main structural parameters influencing the whirl flutter stability characteristics. Propeller blades are adjustable at standstill. The demonstrator is instrumented by strain gauges, accelerometers, revolution-counting impulse sensor, sensor of airflow velocity, and the thrust measurement unit. Measurement is supported by the in house program providing the data storage and real-time depiction in the time domain as well as pre-processing into the form of the power spectral densities. The engine is linked with a servo-drive unit, which enables maintaining of the propeller revolutions (constant or controlled rate ramp) and monitoring of immediate revolutions and power. Furthermore, the program manages the aerodynamic excitation of the demonstrator by the aileron flapping (constant, sweep, impulse). Finally, it provides the safety guard to prevent any structural failure of the demonstrator hardware. In addition, LMS TestLab system is used for the measurement of the structure response and for the data assessment by means of the FFT- and OMA-based methods. The demonstrator is intended for the experimental investigations in the VZLU 3m-diameter low-speed wind tunnel. The measurement variant of the model is defined by the structural parameters: pitch and yaw attachment stiffness, pitch and yaw hinge stations, balance weight station, propeller type (duralumin or steel blades), and finally, angle of attack of the propeller blade 75% section (). The excitation is provided either by the airflow turbulence or by means of the aerodynamic excitation by the aileron flapping using a frequency harmonic sweep. The experimental results are planned to be utilized for validation of analytical methods and software tools in the frame of development of the new complex multi-blade twin-rotor propulsion system for the new generation regional aircraft. Experimental campaigns will include measurements of aerodynamic derivatives and measurements of stability boundaries for various configurations of the demonstrator.

Keywords: aeroelasticity, flutter, whirl flutter, W WING demonstrator

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Authors: Md. Samsuddin Ansari, Ashish Arora

Abstract:

Every year 10 million people fall ill with one of the oldest diseases known as tuberculosis, caused by Mycobacterium tuberculosis. The success of M. tuberculosis as a pathogen is because of its ability to persist in host tissues. Multidrug resistance (MDR) mycobacteria cases increase every day, which is associated with efflux pumps controlled at the level of transcription. The transcription regulators of MDR transporters in bacteria belong to one of the following four regulatory protein families: AraC, MarR, MerR, and TetR. Phenolic acid decarboxylase repressor (PadR), like a family of transcription regulators, is closely related to the MarR family. Phenolic acid decarboxylase repressor (PadR) was first identified as a transcription factor involved in the regulation of phenolic acid stress response in various microorganisms (including Mycobacterium tuberculosis H37Rv). Recently research has shown that the PadR family transcription factors are global, multifunction transcription regulators. Rv0047c is a PadR subfamily-1 protein. We are exploring the biophysical and structural characterization of Rv0047c. The Rv0047 gene was amplified by PCR using the primers containing EcoRI and HindIII restriction enzyme sites cloned in pET-NH6 vector and overexpressed in DH5α and BL21 (λDE3) cells of E. coli following purification with Ni2+-NTA column and size exclusion chromatography. We did DSC to know the thermal stability; the Tm (transition temperature) of protein is 55.29ºC, and ΔH (enthalpy change) of 6.92 kcal/mol. Circular dichroism to know the secondary structure and conformation and fluorescence spectroscopy for tertiary structure study of protein. To understand the effect of pH on the structure, function, and stability of Rv0047c we employed spectroscopy techniques such as circular dichroism, fluorescence, and absorbance measurements in a wide range of pH (from pH-2.0 to pH-12). At low and high pH, it shows drastic changes in the secondary and tertiary structure of the protein. EMSA studies showed the specific binding of Rv0047c with its own 30-bp promoter region. To determine the effect of complex formation on the secondary structure of Rv0047c, we examined the CD spectra of the complex of Rv0047c with promoter DNA of rv0047. The functional role of Rv0047c was characterized by over-expressing the Rv0047c gene under the control of hsp60 promoter in Mycobacterium tuberculosis H37Rv. We have predicted the three-dimensional structure of Rv0047c using the Swiss Model and Modeller, with validity checked by the Ramachandra plot. We did molecular docking of Rv0047c with dnaA, through PatchDock following refinement through FireDock. Through this, it is possible to easily identify the binding hot-stop of the receptor molecule with that of the ligand, the nature of the interface itself, and the conformational change undergone by the protein pattern. We are using X-crystallography to unravel the structure of Rv0047c. Overall the studies show that Rv0047c may have transcription regulation along with providing an insight into the activity of Rv0047c in the pH range of subcellular environment and helps to understand the protein-protein interaction, a novel target to kill dormant bacteria and potential strategy for tuberculosis control.

Keywords: mycobacterium tuberculosis, phenolic acid decarboxylase repressor, Rv0047c, Circular dichroism, fluorescence spectroscopy, docking, protein-protein interaction

Procedia PDF Downloads 121

Authors: Md. Afroz Ansari

Abstract:

The Bengal basin is a spectacular example of a peripheral foreland basin formed by the convergence of the Indian plate beneath the Eurasian and Burmese plates. The basin is embraced on three sides; north, west and east by different fault-controlled tectonic features whereas released in the south where the rivers are drained into the Bay of Bengal. The Bengal basin in the eastern part of the Indian subcontinent constitutes the largest fluvio-deltaic to shallow marine sedimentary basin in the world today. This continental basin coupled with the offshore Bengal Fan under the Bay of Bengal forms the biggest sediment dispersal system. The continental basin is continuously receiving the sediments by the two major rivers Ganga and Brahmaputra (known as Jamuna in Bengal), and Meghna (emerging from the point of conflux of the Ganga and Brahmaputra) and large number of rain-fed, small tributaries originating from the eastern Indian Shield. The drained sediments are ultimately delivered into the Bengal fan. The significance of the present study is to delineate the variations in thicknesses of the sediments, different crustal structures, and the mantle lithosphere throughout the onshore-offshore Bengal basin. In the present study, the different crustal/geological units and the shallower mantle lithosphere were delineated by analyzing the Bouguer Gravity Anomaly (BGA) data along two long traverses South-North (running from Bengal fan cutting across the transition offshore-onshore of the Bengal basin and intersecting the Main Frontal Thrust of India-Himalaya collision zone in Sikkim-Bhutan Himalaya) and West-East (running from the Peninsular Indian Shield across the Bengal basin to the Chittagong–Tripura Fold Belt). The BGA map was derived from the analysis of topex data after incorporating Bouguer correction and all terrain corrections. The anomaly map was compared with the available ground gravity data in the western Bengal basin and the sub-continents of India for consistency of the data used. Initially, the anisotropy associated with the thicknesses of the different crustal units, crustal interfaces and moho boundary was estimated through spectral analysis of the gravity data with varying window size over the study area. The 2D density sections along the traverses were finalized after a number of iterations with the acceptable root mean square (RMS) errors. The estimated thicknesses of the different crustal units and dips of the Moho boundary along both the profiles are consistent with the earlier results. Further the results were encouraged by examining the earthquake database and focal mechanism solutions for better understanding the geodynamics. The earthquake data were taken from the catalogue of US Geological Survey, and the focal mechanism solutions were compiled from the Harvard Centroid Moment Tensor Catalogue. The concentrations of seismic events at different depth levels are not uncommon. The occurrences of earthquakes may be due to stress accumulation as a result of resistance from three sides.

Keywords: anisotropy, interfaces, seismicity, spectrum analysis

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Authors: James Cairns, Marco Vezza, Richard Green, Donald MacVicar

Abstract:

Significant legislative changes are set to revolutionise the commercial shipping industry. Upcoming emissions restrictions will force operators to look at technologies that can improve the efficiency of their vessels -reducing fuel consumption and emissions. A device which may help in this challenge is the Ship Wind-Assisted Propulsion system (SWAP), an actively controlled aerofoil mounted vertically on the deck of a ship. The device functions in a similar manner to a sail on a yacht, whereby the aerodynamic forces generated by the sail reach an equilibrium with the hydrodynamic forces on the hull and a forward velocity results. Numerical and experimental testing of the SWAP device is presented in this study. Circulation control takes the form of a co-flow jet aerofoil, utilising both blowing from the leading edge and suction from the trailing edge. A jet at the leading edge uses the Coanda effect to energise the boundary layer in order to delay flow separation and create high lift with low drag. The SWAP concept has been originated by the research and development team at SMAR Azure Ltd. The device will be retrofitted to existing ships so that a component of the aerodynamic forces acts forward and partially reduces the reliance on existing propulsion systems. Wind tunnel tests have been carried out at the de Havilland wind tunnel at the University of Glasgow on a 1:20 scale model of this system. The tests aim to understand the airflow characteristics around the aerofoil and investigate the approximate lift and drag coefficients that an early iteration of the SWAP device may produce. The data exhibits clear trends of increasing lift as injection momentum increases, with critical flow attachment points being identified at specific combinations of jet momentum coefficient, Cµ, and angle of attack, AOA. Various combinations of flow conditions were tested, with the jet momentum coefficient ranging from 0 to 0.7 and the AOA ranging from 0° to 35°. The Reynolds number across the tested conditions ranged from 80,000 to 240,000. Comparisons between 2D computational fluid dynamics (CFD) simulations and the experimental data are presented for multiple Reynolds-Averaged Navier-Stokes (RANS) turbulence models in the form of normalised surface pressure comparisons. These show good agreement for most of the tested cases. However, certain simulation conditions exhibited a well-documented shortcoming of RANS-based turbulence models for circulation control flows and over-predicted surface pressures and lift coefficient for fully attached flow cases. Work must be continued in finding an all-encompassing modelling approach which predicts surface pressures well for all combinations of jet injection momentum and AOA.

Keywords: CFD, circulation control, Coanda, turbo wing sail, wind tunnel

Procedia PDF Downloads 134

Authors: Sherif Keddis, Rafik Mitry, Norbert Schwesinger

Abstract:

Intelligent networking of devices has rapidly been gaining importance over the past years and with recent advances in the fields of microcontrollers, integrated circuits and wireless communication, low power applications have emerged, enabling this trend even more. Connected devices provide a much larger database thus enabling highly intelligent and accurate systems. Ensuring safe drinking water is one of the fields that require constant monitoring and can benefit from an increased accuracy. Monitoring is mainly achieved either through complex measures, such as collecting samples from the points of use, or through metering systems typically distant to the points of use which deliver less accurate assessments of the quality of water. Constant metering near the points of use is complicated due to their inaccessibility; e.g. buried water pipes, locked spaces, which makes system maintenance extremely difficult and often unviable. The research presented here attempts to overcome this challenge by providing these systems with enough energy through a flow harvester inside the pipe thus eliminating the maintenance requirements in terms of battery replacements or containment of leakage resulting from wiring such systems. The proposed flow harvester exploits the piezoelectric properties of polyvinylidene difluoride (PVDF) films to convert turbulence induced oscillations into electrical energy. It is intended to be used in standard water pipes with diameters between 0.5 and 1 inch. The working principle of the harvester uses a ring shaped bluff body inside the pipe to induce pressure fluctuations. Additionally the bluff body houses electronic components such as storage, circuitry and RF-unit. Placing the piezoelectric films downstream of that bluff body causes their oscillation which generates electrical charge. The PVDF-film is placed as a multilayered wrap fixed to the pipe wall leaving the top part to oscillate freely inside the flow. The warp, which allows for a larger active, consists of two layers of 30µm thick and 12mm wide PVDF layered alternately with two centered 6µm thick and 8mm wide aluminum foil electrodes. The length of the layers depends on the number of windings and is part of the investigation. Sealing the harvester against liquid penetration is achieved by wrapping it in a ring-shaped LDPE-film and welding the open ends. The fabrication of the PVDF-wraps is done by hand. After validating the working principle using a wind tunnel, experiments have been conducted in water, placing the harvester inside a 1 inch pipe at water velocities of 0.74m/s. To find a suitable placement of the wrap inside the pipe, two forms of fixation were compared regarding their power output. Further investigations regarding the number of windings required for efficient transduction were made. Best results were achieved using a wrap with 3 windings of the active layers which delivers a constant power output of 0.53µW at a 2.3MΩ load and an effective voltage of 1.1V. Considering the extremely low power requirements of sensor applications, these initial results are promising. For further investigations and optimization, machine designs are currently being developed to automate the fabrication and decrease tolerance of the prototypes.

Keywords: maintenance-free sensors, measurements at point of use, piezoelectric flow harvesting, universal micro generator, wireless metering systems

Procedia PDF Downloads 193

Authors: Carmen W. H. Chan, Helen Y. L. Chan, Kai Chow Choi, Ka Ming Chow, Cecilia W. M. Kwan, Nancy H. Y. Ng, Jackie Robinson

Abstract:

Introduction: In Hong Kong, a significant number of deaths occur in acute care wards, which requires nurses in these settings to provide end-of-life care and lead ACP implementation. However, nurses in these settings, in fact, have very low-level involvement in ACP discussions because of limited training in ACP conversations. Objective: This study aims to assess the impact of a multi-media experiential ACP (MEACP) training program, which is guided by the experiential learning model and theory of planned behaviour, on nurses' knowledge and confidence in assisting patients with ACP. Methodology: The study utilizes a cluster randomized controlled trial with a 12-week follow-up. Eligible nurses working in acute care hospital wards are randomly assigned at the ward level, in a 1:1 ratio, to either the control group (no ACP education) or the intervention group (4-week MEACP training program). The training programme includes training through a webpage and mobile application, as well as a face-to-face training workshop with enhanced lectures and role play, which is based on the Theory of Planned Behavior and Kolb's Experiential Learning Model. Questionnaires were distributed to assess nurses' knowledge (a 10-item true/false questionnaire) and level of confidence (five-point Likert scale) in ACP at baseline (T0), four weeks after the baseline assessment (T1), and 12 weeks after T1 (T2). In this interim report, data analysis was mainly descriptive in nature. Result: The interim report focuses on the preliminary results of 165 nurses at T0 (Control: 74, Intervention: 91) over a 5-month period, 69 nurses from the control group who completed the 4-week follow-up and 65 nurses from the intervention group who completed the 4-week MEACP training program at T1. The preliminary attrition rate is 6.8% and 28.6% for the control and intervention groups, respectively, as some nurses did not complete the whole set of online modules. At baseline, the two groups were generally homogeneous in terms of their years of nursing practice, weekly working hours, working title, and level of education, as well as ACP knowledge and confidence levels. The proportion of nurses who answered all ten knowledge questions correctly increased from 13.8% (T0) to 66.2% (T1) for the intervention group and from 13% (T0) to 20.3% (T1) for the control group. The nurses in the intervention group answered an average of 7.57 and 9.43 questions correctly at T0 and T1, respectively. They showed a greater improvement in the knowledge assessment at T1 with respect to T0 when compared with their counterparts in the control group (mean difference of change score, Δ=1.22). They also exhibited a greater gain in level of confidence at T1 compared to their colleagues in the control group (Δ=0.91). T2 data is yet available. Conclusion: The prevalence of nurses engaging in ACP and their level of knowledge about ACP in Hong Kong is low. The MEACP training program can enrich nurses by providing them with more knowledge about ACP and increasing their confidence in conducting ACP.

Keywords: advance directive, advance care planning, confidence, knowledge, multi-media experiential, randomised control trial

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Authors: Okolie Pius Ifeanyi, Emerenini Emilymary Chima

Abstract:

Aims: The study investigated the diversity and identities of Lactic Acid Bacteria (LAB) isolated from different fresh fruits using Molecular Nested PCR analysis and the efficacy of cell free supernatants from Lactic Acid Bacteria (LAB) isolated from fresh fruits for in vitro control of some tomato pathogens. Study Design: Nested PCR approach was used in this study employing universal 16S rRNA gene primers in the first round PCR and LAB specific Primers in the second round PCR with the view of generating specific Nested PCR products for the LAB diversity present in the samples. The inhibitory potentials of supernatant obtained from LAB isolates of fruits origin that were molecularly characterized were investigated against some tomato phytopathogens using agar-well method with the view to develop biological agents for some tomato disease causing organisms. Methodology: Gram positive, catalase negative strains of LAB were isolated from fresh fruits on Man Rogosa and Sharpe agar (Lab M) using streaking method. Isolates obtained were molecularly characterized by means of genomic DNA extraction kit (Norgen Biotek, Canada) method. Standard methods were used for Nested Polymerase Chain Reaction (PCR) amplification targeting the 16S rRNA gene using universal 16S rRNA gene and LAB specific primers, agarose gel electrophoresis, purification and sequencing of generated Nested PCR products (Macrogen Inc., USA). The partial sequences obtained were identified by blasting in the non-redundant nucleotide database of National Center for Biotechnology Information (NCBI). The antimicrobial activities of characterized LAB against some tomato phytopathogenic bacteria which include (Xanthomonas campestries, Erwinia caratovora, and Pseudomonas syringae) were obtained by using the agar well diffusion method. Results: The partial sequences obtained were deposited in the database of National Centre for Biotechnology Information (NCBI). Isolates were identified based upon the sequences as Weissella cibaria (4, 18.18%), Weissella confusa (3, 13.64%), Leuconostoc paramensenteroides (1, 4.55%), Lactobacillus plantarum (8, 36.36%), Lactobacillus paraplantarum (1, 4.55%) and Lactobacillus pentosus (1, 4.55%). The cell free supernatants of LAB from fresh fruits origin (Weissella cibaria, Weissella confusa, Leuconostoc paramensenteroides, Lactobacillus plantarum, Lactobacillus paraplantarum and Lactobacillus pentosus) can inhibits these bacteria by creating clear zones of inhibition around the wells containing cell free supernatants of the above mentioned strains of lactic acid bacteria. Conclusion: This study shows that potentially LAB can be quickly characterized by molecular methods to specie level by nested PCR analysis of the bacteria isolate genomic DNA using universal 16S rRNA primers and LAB specific primer. Tomato disease causing organisms can be most likely biologically controlled by using extracts from LAB. This finding will reduce the potential hazard from the use of chemical herbicides on plant.

Keywords: nested pcr, molecular characterization, 16s rRNA gene, lactic acid bacteria

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Authors: Omair Anas

Abstract:

The Persian Gulf has been in turmoil for a long time since the colonial administration has handed over the role to the small and weak kings and emirs who were assured of protection in return of many economic and security promises to them. The regional order, Saudi Arabia evolved was a rentier regional order secured by an expansion of rentier economy and taking responsibility for much of the expenses of the regional order on behalf of relatively poor countries. The two oil booms helped the Saudi state to expand the 'rentier order' driven stability and bring the countries like Egypt, Jordan, Syria, and Palestine under its tutelage. The disruptive misadventure, however, came with Iran's proclamation of the Islamic Revolution in 1979 which it wanted to be exported to its 'un-Islamic and American puppet' Arab neighbours. For Saudi Arabia, even the challenge presented by the socialist-nationalist Arab dictators like Gamal Abdul Nasser and Hafez Al-Assad was not that much threatening to the Saudi Arabia’s then-defensive realism. In the Arab uprisings, the Gulf monarchies saw a wave of insecurity and Iran found it an opportune time to complete the revolutionary process it could not complete after 1979. An alliance of convenience and ideology between Iran and Islamist groups had the real potential to challenge both Saudi Arabia’s own security and its leadership in the region. The disruptive threat appeared at a time when the Saudi state had already sensed an impending crisis originating from the shifts in the energy markets. Low energy prices, declining global demands, and huge investments in alternative energy resources required Saudi Arabia to rationalize its economy according to changing the global political economy. The domestic Saudi reforms remained gradual until the death of King Abdullah in 2015. What is happening now in the region, the Qatar crisis, the Lebanon crisis and the Saudi-Iranian proxy war in Iraq, Syria, and Yemen has combined three immediate objectives, rationalising Saudi economy and most importantly, the resetting the Saudi royal power for Saudi Arabia’s longest-serving future King Mohammad bin Salman. The Saudi King perhaps has no time to wait and watch the power vacuum appearing because of Iran’s expansionist foreign policy. The Saudis appear to be employing an offensive realism by advancing a pro-active regional policy to counter Iran’s threatening influence amid disappearing Western security from the region. As the Syrian civil war is coming to a compromised end with ceding much ground to Iran-controlled militias, Hezbollah and Al-Hashad, the Saudi state has lost much ground in these years and the threat from Iranian proxies is more than a reality, more clearly in Bahrain, Iraq, Syria, and Yemen. This paper attempts to analyse the changing Saudi behaviour in the region, which, the author understands, is shaped by an offensive-realist approach towards finding a favourable security environment for the Saudi-led regional order, a post-rentier order perhaps.

Keywords: terrorism, Saudi Arabia, Rentier State, gulf crisis

Procedia PDF Downloads 136

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

Abstract:

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

Procedia PDF Downloads 132

Authors: Eda Ozkara San

Abstract:

Nurse educators have been charged by several nursing organizations and accrediting bodies to provide innovative and evidence-based educational experiences, both didactic and clinical, to help students to develop the knowledge, skills, and attitudes needed to provide culturally competent nursing care to patients. Clinical simulation, which offers the opportunity for students to practice nursing skills in a risk-free, controlled environment and helps develop self-efficacy (confidence) within the nursing role. As one simulation method, the standardized patients (SPs) simulation helps educators to teach nursing students variety of skills in nursing, medicine, and other health professions. It can be a helpful tool for nurse educators to enhance cultural competence of nursing students. An alarming gap exists within the literature concerning the effectiveness of SP strategy to enhance cultural competence development of diverse student groups, who must work with patients from various backgrounds. This grant-supported, longitudinal, one-group, pretest and post-test educational intervention study aimed to examine the effect of the Diverse Standardized Patient Simulation (DSPS) cultural competence education strategy on students’ (n = 53) transcultural self-efficacy (TSE). The researcher-developed multidimensional DSPS strategy involved careful integration of transcultural nursing skills guided by the Cultural Competence and Confidence (CCC) model. As a carefully orchestrated teaching and learning strategy by specifically utilizing the SP pedagogy, the DSPS also followed international guidelines and standards for the design, implementation, evaluation, and SP training; and had content validity review. The DSPS strategy involved two simulation scenarios targeting underrepresented patient populations (Muslim immigrant woman with limited English proficiency and Irish-Italian American gay man with his partner (Puerto Rican) to be utilized in a second-semester, nine-credit, 15-week medical-surgical nursing course at an urban public US university. Five doctorally prepared content experts reviewed the DSPS strategy for content validity. The item-level content validity index (I-CVI) score was calculated between .80-1.0 on the evaluation forms. Jeffreys’ Transcultural Self-Efficacy Tool (TSET) was administered as a pretest and post-test to assess students’ changes in cognitive, practical, and affective dimensions of TSE. Results gained from this study support that the DSPS cultural competence education strategy assisted students to develop cultural competence and caused statistically significant changes (increase) in students’ TSE perceptions. Results also supported that all students, regardless of their background, benefit (and require) well designed cultural competence education strategies. The multidimensional DSPS strategy is found to be an effective way to foster nursing students’ cultural competence development. Step-by-step description of the DSPS provides an easy adaptation of this strategy with different student populations and settings.

Keywords: cultural competence development, the cultural competence and confidence model, CCC model, educational intervention, transcultural self-efficacy, TSE, transcultural self-efficacy tool, TSET

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Authors: Marta Paszkiewicz, Justyna Łuczak, Martyna Marchelek, Adriana Zaleska-Medynska

Abstract:

In recent years, photocatalytical processes have been intensively investigated for destruction of pollutants, hydrogen evolution, disinfection of water, air and surfaces, for the construction of self-cleaning materials (tiles, glass, fibres, etc.). Titanium dioxide (TiO2) is the most popular material used in heterogeneous photocatalysis due to its excellent properties, such as high stability, chemical inertness, non-toxicity and low cost. It is well known that morphology and microstructure of TiO2 significantly influence the photocatalytic activity. This characteristics as well as other physical and structural properties of photocatalysts, i.e., specific surface area or density of crystalline defects, could be controlled by preparation route. In this regard, TiO2 particles can be obtained by sol-gel, hydrothermal, sonochemical methods, chemical vapour deposition and alternatively, by ionothermal synthesis using ionic liquids (ILs). In the TiO2 particles synthesis ILs may play a role of a solvent, soft template, reagent, agent promoting reduction of the precursor or particles stabilizer during synthesis of inorganic materials. In this work, the effect of the ILs anion type on morphology and photoactivity of TiO2 is presented. The preparation of TiO2 microparticles with spherical structure was successfully achieved by solvothermal method, using tetra-tert-butyl orthotitatane (TBOT) as the precursor. The reaction process was assisted by an ionic liquids 1-butyl-3-methylimidazolium bromide [BMIM][Br], 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4] and 1-butyl-3-methylimidazolium haxafluorophosphate [BMIM][PF6]. Various molar ratios of all ILs to TBOT (IL:TBOT) were chosen. For comparison, reference TiO2 was prepared using the same method without IL addition. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brenauer-Emmett-Teller surface area (BET), NCHS analysis, and FTIR spectroscopy were used to characterize the surface properties of the samples. The photocatalytic activity was investigated by means of phenol photodegradation in the aqueous phase as a model pollutant, as well as formation of hydroxyl radicals based on detection of fluorescent product of coumarine hydroxylation. The analysis results showed that the TiO2 microspheres had spherical structure with the diameters ranging from 1 to 6 µm. The TEM micrographs gave a bright observation of the samples in which the particles were comprised of inter-aggregated crystals. It could be also observed that the IL-assisted TiO2 microspheres are not hollow, which provides additional information about possible formation mechanism. Application of the ILs results in rise of the photocatalytic activity as well as BET surface area of TiO2 as compared to pure TiO2. The results of the formation of 7-hydroxycoumarin indicated that the increased amount of ·OH produced at the surface of excited TiO2 for samples TiO2_ILs well correlated with more efficient degradation of phenol. NCHS analysis showed that ionic liquids remained on the TiO2 surface confirming structure directing role of that compounds.

Keywords: heterogeneous photocatalysis, IL-assisted synthesis, ionic liquids, TiO2

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Authors: Sonia A. Stoica, Lexi Frankel, Amalia Ardeljan, Selena Rashid, Ali Yasback, Omar Rashid

Abstract:

Introduction Enterococcus is a vast genus of lactic acid bacteria, gram-positivecocci species. They are common commensal organisms in the intestines of humans: E. faecalis (90–95%) and E. faecium (5–10%). Rare groups of infections can occur with other species, including E. casseliflavus, E. gallinarum, and E. raffinosus. The most common infections caused by Enterococcus include urinary tract infections, biliary tract infections, subacute endocarditis, diverticulitis, meningitis, septicemia, and spontaneous bacterial peritonitis. The treatment for sensitive strains of these bacteria includes ampicillin, penicillin, cephalosporins, or vancomycin, while the treatment for resistant strains includes daptomycin, linezolid, tygecycline, or streptogramine. Enterococcus faecalis CECT7121 is an encouraging nominee for being considered as a probiotic strain. E. faecalis CECT7121 enhances and skews the profile of cytokines to the Th1 phenotype in situations such as vaccination, anti-tumoral immunity, and allergic reactions. It also enhances the secretion of high levels of IL-12, IL-6, TNF alpha, and IL-10. Cytokines have been previously associated with the development of cancer. The intention of this study was to therefore evaluate the correlation between Enterococcus infections and incidence of bone carcinoma. Methods A retrospective cohort study (2010-2019) was conducted through a Health Insurance Portability and Accountability Act (HIPAA) compliant national database and conducted using International Classification of Disease (ICD) 9th and 10th codes for bone carcinoma diagnosis in a previously Enterococcus infected population. Patients were matched for age range and Charlson Comorbidity Index (CCI). Access to the database was granted by Holy Cross Health for academic research. Chi-squared test was used to assess statistical significance. Results A total number of 17,056 patients was obtained in Enterococcus infected group as well as in the control population (matched by Age range and CCI score). Subsequent bone carcinoma development was seen at a rate of 1.07% (184) in the Enterococcal infectious group and 3.42% (584) in the control group, respectively. The difference was statistically significant by p= 2.2x10-¹⁶, Odds Ratio = 0.355 (95% CI 0.311 - 0.404) Treatment for enterococcus infection was analyzed and controlled for in both enterococcus infected and noninfected populations. 78 out of 6,624 (1.17%) patients with a prior enterococcus infection and treated with antibiotics were compared to 202 out of 6,624 (3.04%) patients with no history of enterococcus infection (control) and received antibiotic treatment. Both populations subsequently developed bone carcinoma. Results remained statistically significant (p<2.2x10-), Odds Ratio=0.456 (95% CI 0.396-0.525). Conclusion This study shows a statistically significant correlation between Enterococcus infection and a decreased incidence of bone carcinoma. The immunologic response of the organism to Enterococcus infection may exert a protecting mechanism from developing bone carcinoma. Further exploration is needed to identify the potential mechanism of Enterococcus in reducing bone carcinoma incidence.

Keywords: anti-tumoral immunity, bone carcinoma, enterococcus, immunologic response

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Authors: Muhammad Waqas Baqai, Noman Shahzad, Rehman Alvi

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Communication among health care givers is the essence of quality patient care and any compromise results in errors and inefficiency leading to cumbersome outcomes. The use of smartphone among health professionals has increased tremendously. Almost every health professional carries it and majority of them uses a third party communication software called whatsApp for work related communications. It gives instant access to the person responsible for any particular query and therefore helps in efficient and timely decision making. It is also an easy way of sharing medical documents, multimedia and provides platform for consensual decision making through group discussions. However clinical communication through whatsApp has some demerits too including reduction in verbal communication, worsening professional relations, unprofessional behavior, risk of confidentiality breach and threats from cyber-attacks. On the other hand the traditional pager device being used in many health care systems is a unidirectional communication that lacks the ability to convey any information other than the number to which the receiver has to respond. Our study focused on these two widely used modalities of communication among doctors of the largest tertiary care center of Pakistan i.e. The Aga Khan University Hospital. Our aim was to note which modality is considered better and has fewer threats to medical data. Approval from ethical review committee of the institute was taken prior to conduction of this study. We submitted an online survey form to all the interns and residents working at our institute and collected their response in a month’s time. 162 submissions were recorded and analyzed using descriptive statistics. Only 20% of them were comfortable with using pagers exclusively, 52% with whatsApp and 28% with both. 65% think that whatsApp is time-saving and quicker than pager. 54% of them considered whatsApp to be causing nuisance from work related notifications in their off-work hours. 60% think that they are more likely to miss information through pager system because of the unidirectional nature. Almost all (96%) of residents and interns found whatsApp to be useful in terms of saving information for future reference. For urgent issues, majority (70%) preferred pager over whatsApp and also pager was considered more valid in terms of hospital policies and legal issues. Among major advantages of whatsApp as listed by them were; easy mass communication, sharing of clinical pictures, universal access and no need of carrying additional device. However the major drawback of using whatsApp for clinical communication that everyone shared was threat to patients’ confidentiality as clinicians usually share pictures of wounds, clinical documents etc. Lastly we asked them if they think there is a need of a separate application for instant communication dedicated to clinical communication only and 90% responded positively. Therefore, we concluded that both modalities have their merits and demerits but the greatest drawback with whatsApp is the risk of breach in patients’ confidentiality and off-work disturbance. Hence, we recommend a more secure, institute-run application for all intra hospital communications where they can share documents, pictures etc. easily under a controlled environment.

Keywords: WhatsApp, pager, clinical communication, confidentiality

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Authors: Wanvipa Thongborisute, Punyaphat Sirithanabadeekul, Pichit Suvanprakorn, Anan Jiraviroon

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Background: Acne vulgaris is one of the most common dermatologic problems, and can have a significant psychological and physical effect on patients. Propionibacterium acnes' roles in acne vulgaris involve the activation of toll-like receptor 4 (TLR4), and toll-like receptor 2 (TLR2) pathways. By activating these pathways, inflammatory events of acne lesions, comedogenesis and sebaceous lipogenesis can occur. Currently, there are several topical agents commonly use in treating acne vulgaris that are known to have an effect on TLRs, such as retinoic acid and adapalene, but these drugs still have some irritating effects. At present, there is an alarming increase in rate of bacterial resistance due to irrational used of antibiotics both orally and topically. For this reason, acne treatments should contain bioactive molecules targeting at the site of action for the most effective therapeutic effect with the least side effects. Sparganium stoloniferumis a Chinese aquatic herb containing a compound called Sparstolonin B (SsnB), which has been reported to selectively blocks Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4)-mediated inflammatory signals. Therefore, this topical TLR2 and TLR4 antagonist, in a form of Sparganium stoloniferum-derived compound containing SsnB, should give a benefit in reducing inflammation of acne vulgaris lesions and providing an alternative treatments for patients with this condition. Materials and Methods: The objectives of this randomized double blinded split faced placebo controlled trial is to study the safety and efficacy of the Sparganium stoloniferum-derived compound. 32 volunteered patients with mild to moderate degree of acne vulgaris according to global acne grading system were included in the study. After being informed and consented the subjects were given 2 topical treatments for acne vulgaris, one being topical 2.40% Sparganium stoloniferum extraction (containing Sparstolonin B) and the other, placebo. The subjects were asked to apply each treatment to either half of the face daily morning and night by randomization for 8 weeks, and come in for a weekly follow up. For each visit, the patients went through a procedure of lesion counting, including comedones, papules, nodules, pustules, and cystic lesions. Results: During 8 weeks of experimentation, the result shows a reduction in total lesions number between the placebo and the treatment side show statistical significance starting at week 4, where the 95% confidence interval begin to no longer overlap, and shows a trend of continuing to be further apart. The decrease in the amount of total lesions between week 0 and week 8 of the placebo side shows no statistical significant at P value >0.05. While the decrease in the amount of total lesions of acne vulgaris of the treatment side comparing between week 0 and week 8 shows statistical significant at P value <0.001. Conclusion: The data demonstrates that 2.40% Sparganium stoloniferum extraction (containing Sparstolonin B) is more effective in treating acne vulgaris comparing to topical placebo in treating acne vulgaris, by showing significant reduction in the total numbers of acne lesions. Therefore, this topical Sparganium stoloniferum extraction could become a potential alternative treatment for acne vulgaris.

Keywords: acne vulgaris, sparganium stoloniferum, sparstolonin B, toll-like receptor 2, toll-like receptor 4

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Authors: Patrick Louie Robles, Jerry Suls, Ciaran Friel, Mark Butler, Samantha Gordon, Frank Vicari, Joan Duer-Hefele, Karina W. Davidson

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Physical activity guidelines focus on increasing moderate-intensity activity for older adults, but adherence to recommendations remains low. This is despite the fact that scientific evidence finds increasing physical activity is positively associated with health benefits. Behavior change techniques (BCTs) have demonstrated some effectiveness in reducing sedentary behavior and promoting physical activity. This pilot study uses a personalized trials (N-of-1) design, delivered virtually, to evaluate the efficacy of using five BCTs in increasing low-intensity physical activity (by 2,000 steps of walking per day) in adults aged 45-75 years old. The 5 BCTs described in habit formation theory are goal setting, action planning, rehearsal, rehearsal in a consistent context, and self-monitoring. The study recruited health system employees in the target age range who had no mobility restrictions and expressed interest in increasing their daily activity by a minimum of 2,000 steps per day at least five days per week. Participants were sent a Fitbit Charge 4 fitness tracker with an established study account and password. Participants were recommended to wear the Fitbit device 24/7 but were required to wear it for a minimum of ten hours per day. Baseline physical activity was measured by Fitbit for two weeks. Participants then engaged remotely with a clinical research coordinator to establish a “walking plan” that included a time and day interval (e.g., between 7am -8am on Monday-Friday), a location for the walk (e.g., park), and how much time the plan would need to achieve a minimum of 2,000 steps over their baseline average step count (20 minutes). All elements of the walking plan were required to remain consistent throughout the study. In the 10-week intervention phase of the study, participants received all five BCTs in a single, time-sensitive text message. The text message was delivered 30 minutes prior to the established walk time and signaled participants to begin walking when the context (i.e., day of the week, time of day) they pre-selected is encountered. Participants were asked to log both the start and conclusion of their activity session by pressing a button on the Fitbit tracker. Within 30 minutes of the planned conclusion of the activity session, participants received a text message with a link to a secure survey. Here, they noted whether they engaged in the BCTs when prompted and completed an automaticity survey to identify how “automatic” their walking behavior had become. At the end of their trial, participants received a personalized summary of their step data over time, helping them learn more about their responses to the five BCTs. Whether the use of these 5 ‘habit formation’ BCTs in combination elicits a change in physical activity behavior among older adults will be reported. This study will inform the feasibility of a virtually-delivered N-of-1 study design to effectively promote physical activity as a component of healthy aging.

Keywords: aging, exercise, habit, walking

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Authors: Ruth Shapira

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Introduction: The rapid urbanization of the last century confronts planners, regulatory bodies, developers and most of all – the public with seemingly unsolved conflicts regarding values, capital, and wellbeing of the built and un-built urban space. This is reflected in the quality of the urban form and life which has known no significant progress in the last 2-3 decades despite the on-growing urban population. It is the objective of this paper to analyze some of these fundamental issues through the case study of a relatively small town in the center of Israel (Kiryat-Ono, 100,000 inhabitants), unfold the deep structure of qualities versus disruptors, present some cure that we have developed to bridge over and humbly suggest a practice that may be generic for similar cases. Basic Methodologies: The OBJECT, the town of Kiryat Ono, shall be experimented upon in a series of four action processes: De-composition, Re-composition, the Centering process and, finally, Controlled Structural Disintegration. Each stage will be based on facts, analysis of previous multidisciplinary interventions on various layers – and the inevitable reaction of the OBJECT, leading to the conclusion based on innovative theoretical and practical methods that we have developed and that we believe are proper for the open ended network, setting the rules for the contemporary urban society to cluster by. The Study: Kiryat Ono, was founded 70 years ago as an agricultural settlement and rapidly turned into an urban entity. In spite the massive intensification, the original DNA of the old small town was still deeply embedded, mostly in the quality of the public space and in the sense of clustered communities. In the past 20 years, the recent demand for housing has been addressed to on the national level with recent master plans and urban regeneration policies mostly encouraging individual economic initiatives. Unfortunately, due to the obsolete existing planning platform the present urban renewal is characterized by pressure of developers, a dramatic change in building scale and widespread disintegration of the existing urban and social tissue. Our office was commissioned to conceptualize two master plans for the two contradictory processes of Kiryat Ono’s future: intensification and conservation. Following a comprehensive investigation into the deep structures and qualities of the existing town, we developed a new vocabulary of conservation terms thus redefying the sense of PLACE. The main challenge was to create master plans that should offer a regulatory basis to the accelerated and sporadic development providing for the public good and preserving the characteristics of the PLACE consisting of a tool box of design guidelines that will have the ability to reorganize space along the time axis in a coherent way. In Conclusion: The system of rules that we have developed can generate endless possible patterns making sure that at each implementation fragment an event is created, and a better place is revealed. It takes time and perseverance but it seems to be the way to provide a healthy framework for the accelerated urbanization of our chaotic present.

Keywords: housing, architecture, urban qualities, urban regeneration, conservation, intensification

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Authors: Ifeoma Anozie, Teka Apalata, Dominic Abaver

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Introduction: Despite use of Anti-retroviral therapy to reduce the incidence of opportunistic infections among HIV/AIDS patients, rapid episodes of re-infection after deworming are still common occurrences because pharmaceutical intervention alone does not prevent reinfection. Unsafe water and inadequate personal hygiene and parasitic infections are widely expected to accelerate the progression of HIV infection. This is because the chronic immunosuppression of HIV infection encourages susceptibility to opportunistic (including parasitic) infections which is linked to CD4+ cell count of <200 cells/μl. Intestinal parasites such as G. intestinalis and Entamoeba spp are ubiquitous protozoa that remain infectious over a long time in an environment and show resistance to standard disinfection. To control re-infection, the social factors that underpin the prevention need to be controlled. This study aims at prevention of intestinal parasites in people living with HIV/AIDS by using a treatment, hygiene education and sanitation (THEdS) bundle approach. Methods: This study was conducted in four clinics (Ngangelizwe health centre, Tsolo gateway clinic, Idutywa health centre and Nqamakwe health centre) across the seven districts in Eastern cape, South Africa. The four clinics were divided in two: experimental and control, for the purpose of intervention. Data was collected from March 2019 to February 2020. Six hundred participants were screened for intestinal parasitic infections. Stool samples were collected and analysed twice: before (Pre-test infection screening) and after (Post-test re-infection) THEdS bundle intervention. The experimental clinics received full intervention package, which include therapeutic treatment, health education on personal hygiene and sanitation training, while the control clinics received only therapeutic treatment for those found with intestinal parasitic infections. Results: Baseline prevalence of Intestinal Parasites isolated shows 12 intestinal parasites with overall frequency of 65, with Ascaris lumbricoides having most frequency (44.6%). The intervention had a cure rate of 60%, with odd ratio of 1.42, which indicates that the intervention group is 1.42 times more likely of parasite clearing as compared to the control group. The relative risk ratio of 1.17 signifies that there is 1.17 times more likelihood to clear intestinal parasite if there no intervention. Discussion and conclusion: Infection with multiple parasites can cause health defects, especially among HIV/AIDS patients. Efficiency of some HIV vaccines in HIV/AIDS patients is affected because treatment of re-infection amplifies drug resistance, affects the efficacy of the front-line drugs, and still permits transmission. In South Africa, treatment of intestinal parasites is usually offered to clinic attending HIV/AIDS patients upon suspicion but not as a mandate for patients being initiated into Antiretroviral (ART) program. The effectiveness of THEdS bundle advocates for inclusiveness of mandatory screening for intestinal parasitic infections among attendees of HIV/Aids clinics on regular basis.

Keywords: cure rate, , HIV/AIDS patients, intestinal parasites, intervention studies, reinfection rate

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Authors: J. Desbrieres, M. Popa, C. Peptu, S. Bacaita

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Because of their favorable properties (non-toxicity, biodegradability, mucoadhesivity etc.), polysaccharides were studied as biomaterials and as pharmaceutical excipients in drug formulations. These formulations may be produced in a wide variety of forms including hydrogels, hydrogel based particles (or capsules), films etc. In these formulations, the polysaccharide based materials are able to provide local delivery of loaded therapeutic agents but their delivery can be rapid and not easily time-controllable due to, particularly, the burst effect. This leads to a loss in drug efficiency and lifetime. To overcome the consequences of burst effect, systems involving liposomes incorporated into polysaccharide hydrogels may appear as a promising material in tissue engineering, regenerative medicine and drug loading systems. Liposomes are spherical self-closed structures, composed of curved lipid bilayers, which enclose part of the surrounding solvent into their structure. The simplicity of production, their biocompatibility, the size and similar composition of cells, the possibility of size adjustment for specific applications, the ability of hydrophilic or/and hydrophobic drug loading make them a revolutionary tool in nanomedicine and biomedical domain. Drug delivery systems were developed as hydrogels containing chitosan or carboxymethylcellulose (CMC) as polysaccharides and gelatin (GEL) as polypeptide, and phosphatidylcholine or phosphatidylcholine/cholesterol liposomes able to accurately control this delivery, without any burst effect. Hydrogels based on CMC were covalently crosslinked using glutaraldehyde, whereas chitosan based hydrogels were double crosslinked (ionically using sodium tripolyphosphate or sodium sulphate and covalently using glutaraldehyde). It has been proven that the liposome integrity is highly protected during the crosslinking procedure for the formation of the film network. Calcein was used as model active matter for delivery experiments. Multi-Lamellar vesicles (MLV) and Small Uni-Lamellar Vesicles (SUV) were prepared and compared. The liposomes are well distributed throughout the whole area of the film, and the vesicle distribution is equivalent (for both types of liposomes evaluated) on the film surface as well as deeper (100 microns) in the film matrix. An obvious decrease of the burst effect was observed in presence of liposomes as well as a uniform increase of calcein release that continues even at large time scales. Liposomes act as an extra barrier for calcein release. Systems containing MLVs release higher amounts of calcein compared to systems containing SUVs, although these liposomes are more stable in the matrix and diffuse with difficulty. This difference comes from the higher quantity of calcein present within the MLV in relation with their size. Modeling of release kinetics curves was performed and the release of hydrophilic drugs may be described by a multi-scale mechanism characterized by four distinct phases, each of them being characterized by a different kinetics model (Higuchi equation, Korsmeyer-Peppas model etc.). Knowledge of such models will be a very interesting tool for designing new formulations for tissue engineering, regenerative medicine and drug delivery systems.

Keywords: controlled and delayed release, hydrogels, liposomes, polysaccharides

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