Search results for: workplace stress
2596 Genome Editing in Sorghum: Advancements and Future Possibilities: A Review
Authors: Micheale Yifter Weldemichael, Hailay Mehari Gebremedhn, Teklehaimanot Hailesslasie
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The advancement of target-specific genome editing tools, including clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein9 (Cas9), mega-nucleases, base editing (BE), prime editing (PE), transcription activator-like endonucleases (TALENs), and zinc-finger nucleases (ZFNs), have paved the way for a modern era of gene editing. CRISPR/Cas9, as a versatile, simple, cost-effective and robust system for genome editing, has dominated the genome manipulation field over the last few years. The application of CRISPR/Cas9 in sorghum improvement is particularly vital in the context of ecological, environmental and agricultural challenges, as well as global climate change. In this context, gene editing using CRISPR/Cas9 can improve nutritional value, yield, resistance to pests and disease and tolerance to different abiotic stress. Moreover, CRISPR/Cas9 can potentially perform complex editing to reshape already available elite varieties and new genetic variations. However, existing research is targeted at improving even further the effectiveness of the CRISPR/Cas9 genome editing techniques to fruitfully edit endogenous sorghum genes. These findings suggest that genome editing is a feasible and successful venture in sorghum. Newer improvements and developments of CRISPR/Cas9 techniques have further qualified researchers to modify extra genes in sorghum with improved efficiency. The fruitful application and development of CRISPR techniques for genome editing in sorghum will not only help in gene discovery, creating new, improved traits in sorghum regulating gene expression sorghum functional genomics, but also in making site-specific integration events.Keywords: CRISPR/Cas9, genome editing, quality, sorghum, stress, yield
Procedia PDF Downloads 592595 The Effects of Traditional Thai Massage Technique Delivered by Parents on Stereotypical Behaviors in Children with Autism: A Pilot Study
Authors: Chanada Aonsri, Wichai Eungpinichpong
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Stereotypical behavior is one of the learning and social skills development problems that affect children with autism. Previous studies found that traditional Thai massage (TTM) could reduce stereotypical behaviors in autistic children. However, the effects of TTM delivered by the parents of autistic children have not been explored. This pilot study investigated the effects of TTM by parents on stereotypical behaviors in children with autism. A one-group pretest-posttest design was applied for 15 children, aged 4-16 years, with their parents' permissions. They participated in the study at the Special Education program of the Special Education Center of Khon Kaen University, Thailand. After being trained in a specialized TTM for children, the parents delivered 50-minute TTM to children once a day, twice a week for eight weeks. The severity of autism and autistic behaviors were measured using the Childhood Autism Rating Scale (CARS), and the Autism Treatment Evaluation Checklist (ATEC), respectively. The functions of autonomic nervous systems were measured using Heart Rate Variability (HRV) to indicated physical and mental disorders such as stress. The data at baseline and the 8th week were analyzed using either an independent t-test or Wilcoxon signed-rank test. The study found that 16 sessions of TTM significantly improved measured data for autism in all children including the CARS (p<0.001), ATEC, speech/language/communication (p<0.001), sociability (p<0.001), sensory/cognitive awareness (p<0.001), health/physical/behavior (p < 0.001), and HRV (p<0.001). The results indicated that TTM performed by parents could be useful as an adjunct therapy for autistic children as it can reduce stereotypical behaviors and stress.Keywords: traditional Thai massage, stereotypical behaviors, Autistic children, parent
Procedia PDF Downloads 652594 CAP-Glycine Protein Governs Growth, Differentiation, and the Pathogenicity of Global Meningoencephalitis Fungi
Authors: Kyung-Tae Lee, Li Li Wang, Kwang-Woo Jung, Yong-Sun Bahn
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Microtubules are involved in mechanical support, cytoplasmic organization as well as in a number of cellular processes by interacting with diverse microtubule-associated proteins (MAPs), such as plus-end tracking proteins, motor proteins, and tubulin-folding cofactors. A common feature of these proteins is the presence of a cytoskeleton-associated protein-glycine-rich (CAP-Gly) domain, which is evolutionarily conserved and generally considered to bind to α-tubulin to regulate functions of microtubules. However, there has been a dearth of research on CAP-Gly proteins in fungal pathogens, including Cryptococcus neoformans, which causes fatal meningoencephalitis globally. In this study, we identified five CAP-Gly proteins encoding genes in C. neoformans. Among these, Cgp1, encoded by CNAG_06352, has a unique domain structure that has not been reported before in other eukaryotes. Supporting the role of Cpg1 in microtubule-related functions, we demonstrate that deletion or overexpression of CGP1 alters cellular susceptibility to thiabendazole, a microtubule destabilizer, and Cgp1 is co-localized with cytoplasmic microtubules. Related to the cellular functions of microtubules, Cgp1 also governs maintenance of membrane stability and genotoxic stress responses. Furthermore, we demonstrate that Cgp1 uniquely regulates sexual differentiation of C. neoformans with distinct roles in the early and late stage of mating. Our domain analysis reveals that the CAP-Gly domain plays major roles in all the functions of Cgp1. Finally, the cgp1Δ mutant is attenuated in virulence. In conclusion, this novel CAP-Gly protein, Cgp1, has pleotropic roles in regulating growth, stress responses, differentiation and pathogenicity of C. neoformans.Keywords: human fungal pathogen, CAP-Glycine protein, microtubule, meningoencephalitis
Procedia PDF Downloads 3152593 Professional Working Conditions, Mental Health And Mobility In The Hungarian Social Sector Preliminary Findings From A Multi-method Study
Authors: Ágnes Győri, Éva Perpék, Zsófia Bauer, Zsuzsanna Elek
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The aim of the research (funded by Hungarian national grant, NFKI- FK 138315) is to examine the professional mobility, mental health and work environment of social workers with a complex approach. Previous international and Hungarian research has pointed out that those working in the helping professions are strongly exposed to the risk of emotional-mental-physical exhaustion due to stress. Mental and physical strain, as well as lack of coping (can) cause health problems, but its role in career change and high labor turnover has also been proven. Even though satisfaction with working conditions of those employed in the human service sector in the context of the stress burden has been researched extensively, there is a lack of large-sample international and Hungarian domestic studies exploring the effects of profession-specific conditions. Nor has it been examined how the specific features of the social profession and mental health affect the career mobility of the professionals concerned. In our research, these factors and their correlations are analyzed by means of mixed methodology, utilizing the benefits of netnographic big data analysis and a sector-specific quantitative survey. The netnographic analysis of open web content generated inside and outside the social profession offers a holistic overview of the influencing factors related to mental health and the work environment of social workers. On the one hand, the topics and topoi emerging in the external discourse concerning the sector are examined, and on the other hand, focus on mentions and streams of comments regarding the profession, burnout, stress, coping, as well as labor turnover and career changes among social professionals. The analysis focuses on new trends and changes in discourse that have emerged during and after the pandemic. In addition to the online conversation analysis, a survey of social professionals with a specific focus has been conducted. The questionnaire is based on input from the first two research phases. The applied approach underlines that the mobility paths of social professionals can only be understood if, apart from the general working conditions, the specific features of social work and the effects of certain aspects of mental health (emotional-mental-physical strain, resilience) are taken into account as well. In this paper, the preliminary results from this innovative methodological mix are presented, with the aim of highlighting new opportunities and dimensions in the research on social work. A gap in existing research is aimed to be filled both on a methodological and empirical level, and the Hungarian domestic findings can create a feasible and relevant framework for a further international investigation and cross-cultural comparative analysis. Said results can contribute to the foundation of organizational and policy-level interventions, targeted programs whereby the risk of burnout and the rate of career abandonment can be reduced. Exploring different aspects of resilience and mapping personality strengths can be a starting point for stress-management, motivation-building, and personality-development training for social professionals.Keywords: burnout, mixed methods, netnography, professional mobility, social work
Procedia PDF Downloads 1432592 The Long – Term Effects of a Prevention Program on the Number of Critical Incidents and Sick Leave Days: A Decade Perspective
Authors: Valerie Isaak
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Background: This study explores the effectiveness of refresher training sessions of an intervention program at reducing the employees’ risk of injury due to patient violence in a forensic psychiatric hospital. Methods: The original safety intervention program that consisted of a 3 days’ workshop was conducted in the maximum-security ward of a psychiatric hospital in Israel. Ever since the original intervention, annual refreshers were conducted, highlighting one of the safety elements covered in the original intervention. The study examines the effect of the intervention program along with the refreshers over a period of 10 years in four wards. Results: Analysis of the data demonstrates that beyond the initial reduction following the original intervention, refreshers seem to have an additional positive long-term effect, reducing both the number of violent incidents and the number of actual employee injuries in a forensic psychiatric hospital. Conclusions: We conclude that such an intervention program followed by refresher training would promote employees’ wellbeing. A healthy work environment is part of management’s commitment to improving employee wellbeing at the workplace.Keywords: wellbeing, violence at work, intervention program refreshers, public sector mental healthcare
Procedia PDF Downloads 1372591 The Stereotypes of Female Roles in TV Drama of Taiwan and Japan
Authors: Ya Ting Tang
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Social learning theory has told us that the cognitions of gender roles come from learning. Thus, the images of gender roles which media describes will shape our cognitions. Taiwan and Japan are both in the East Asian cultural Sphere, and more or less influenced by the traditional Chinese culture. But our social structure and changes must be different. Others, the study also concerns that, with the rise of female consciousness in society, whether the female stereotype in drama of Taiwan and Japan are improved. This research first uses content analysis to analyze drama of Taiwan and Japan in 2003 and 2013 on how to shape female roles. Then use text analysis to conduct a qualitative analysis. Result of this study showed that drama on how to depict women indeed have changed, women are no longer just talk about love, but can serve as president or doctor, and show its mettle in the workplace. In Japanese drama, the female roles have diverse occupation than Taiwanese drama, and not just a background character set. But in most Taiwanese drama, female roles are given a career, but it always put emphasis on women emotionally. To include, although the stereotype in the drama of Taiwan and Japan are improved, female will still be derided due to their ages, love or marriage situations. Taiwanese drama must depict the occupation of female more diverse and let the female roles have more space to play, rather than focusing on romance which women of any occupation can have.Keywords: female images, stereotype, TV drama, gender roles
Procedia PDF Downloads 2782590 Fatigue in Association with Road Crashes Among Healthcare Workers in Malaysia
Authors: Sharifah Liew, Azlihanis Abdul Hadi, Nurul Shahida Mohd Saffe, Azhar Hamzah, Maslina Musa
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Fatigue is a common health problem among healthcare workers, ranging from ambulance drivers to specialist doctors. In Malaysia, majority of healthcare workers prefer to commute to work by their own vehicle compared to public transport. Thus, exposed to risk on the road while commuting to work. The aim of the study is to find out the effects of fatigue on road crashes among healthcare workers while they commute to work. The research conducted using the semi-quantitative approach based on self- reported questionnaires. In total, five hundred and fifty-one healthcare workers from selected five hospitals were involved in this study. Results showed significant differences between crash involvement, travelling distance and time to and from work among healthcare workers. Most of the participants (37%) reported that causes of road crashes were due to fatigue, sleepiness and microsleep while driving to and back from work. In addition, there were significant differences between fatigue and road crashes and near misses. This research suggests that the hospitals’ management may need to review their staffs’ job scopes and workloads to overcome the fatigue problems and, consider their feedback when designing work schedules and investigate staff commuting distance from home to workplace and vice-versa.Keywords: fatigue, healthcare, road crashes, near misses, Malaysia
Procedia PDF Downloads 722589 Information Technology and Occupational Safety and Health
Authors: Muhammad Afiq Anaqi Bin Baharudin, Muhammad Izamuddin Bin Mohd Nasir, Syarifuddin Bin Sujuanda, Muhammad Syahmi Rusyaidi Bin Sham Suddin, Danish Hakimi Bin Kamaruzaman, Muhammad Haqimi Nazim Bin Hasmanizam, Mohammad Akmal Zakwan Bin Amran, Muhammad Alparizi Bin Latif
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By improving efficiency and production, information technology (IT) has transformed working environments, but it has also created new threats to occupational safety and health (OSH). This study evaluates the literature that has already been written on the subject of IT and OSH, identifies major findings and discussion points, and highlights gaps in the material that call for additional research. The study's findings, which look at how IT affects OSH in a sizable multinational organization, are also presented in the report. According to the report, IT poses a number of OSH problems, such as ergonomic dangers, eye strain, dangers related to cybersecurity, and psychological hazards. The report suggests using tactics like providing comfortable workstations, encouraging a healthy balance between work and life, and putting strong cybersecurity safeguards in place to reduce these dangers. The implications of these findings for OSH and IT are discussed in the paper's conclusion, and it emphasizes the need for more study and action to address these dangers and promote healthy and secure working environments in the age of digitization.Keywords: information technology, occupational safety and health (OSH), ergonomic, hazards, workplace.
Procedia PDF Downloads 1282588 An Empirical Study on Employees’ Theft Behavior in Insurance Industry
Authors: B. Khorsandi Talab, M. Kordi
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It is highly deplorable that every year, theft behavior among employees of the insurance industry is growing throughout the world. A very significant source of contraction (despite many costly technological and widespread security measures) needs to be addressed and prevented. Employee and agent theft cannot be ignored as it causes significant losses to employers. This study investigates the workplace factors that affect the insurance employee and agent theft behavior. Although identifying theft is difficult, this study will help employers to further understand employees’ theft behavior. This study was conducted in two service small and medium organizations (two branches of insurance companies) in ALBORZ’s capital city, KARAJ. Data has been collected via questionnaire from 30 employees and agents consisting employees and supervisors of branches and agencies. According to the results, it must be acknowledged that compensation, organizational justice, internal control systems, penalties and personal characteristics were associated with employees' theft behavior, it is despite the fact that, no effect could be assumed for organizational ethics and requirement in this case. Nevertheless, poor financial status cannot be considered as the driving factor in pushing employees to steal property as well as increasing their theft behavior. As mentioned earlier, the purpose of this study was to determine the factors contributing to employees’ theft (insurance employees and agencies) behavior in insurance organizations in Karaj.Keywords: service theft, employee theft behavior, work theft, insurance agency, SMEs
Procedia PDF Downloads 4372587 Estimation of Source Parameters and Moment Tensor Solution through Waveform Modeling of 2013 Kishtwar Earthquake
Authors: Shveta Puri, Shiv Jyoti Pandey, G. M. Bhat, Neha Raina
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TheJammu and Kashmir region of the Northwest Himalaya had witnessed many devastating earthquakes in the recent past and has remained unexplored for any kind of seismic investigations except scanty records of the earthquakes that occurred in this region in the past. In this study, we have used local seismic data of year 2013 that was recorded by the network of Broadband Seismographs in J&K. During this period, our seismic stations recorded about 207 earthquakes including two moderate events of Mw 5.7 on 1st May, 2013 and Mw 5.1 of 2nd August, 2013.We analyzed the events of Mw 3-4.6 and the main events only (for minimizing the error) for source parameters, b value and sense of movement through waveform modeling for understanding seismotectonic and seismic hazard of the region. It has been observed that most of the events are bounded between 32.9° N – 33.3° N latitude and 75.4° E – 76.1° E longitudes, Moment Magnitude (Mw) ranges from Mw 3 to 5.7, Source radius (r), from 0.21 to 3.5 km, stress drop, from 1.90 bars to 71.1 bars and Corner frequency, from 0.39 – 6.06 Hz. The b-value for this region was found to be 0.83±0 from these events which are lower than the normal value (b=1), indicating the area is under high stress. The travel time inversion and waveform inversion method suggest focal depth up to 10 km probably above the detachment depth of the Himalayan region. Moment tensor solution of the (Mw 5.1, 02:32:47 UTC) main event of 2ndAugust suggested that the source fault is striking at 295° with dip of 33° and rake value of 85°. It was found that these events form intense clustering of small to moderate events within a narrow zone between Panjal Thrust and Kishtwar Window. Moment tensor solution of the main events and their aftershocks indicating thrust type of movement is occurring in this region.Keywords: b-value, moment tensor, seismotectonics, source parameters
Procedia PDF Downloads 3132586 Development and Characterization of Ceramic-Filled Composite Filaments and Functional Structures for Fused Deposition Modeling
Authors: B. Khatri, K. Lappe, M. Habedank, T. Müller, C. Megnin, T. Hanemann
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We present a process flow for the development of ceramic-filled polymer composite filaments compatible with the fused deposition modeling (FDM) 3D printing process. Thermoplastic-ceramic composites were developed using acrylonitrile butadiene styrene (ABS) and 10- and 20 vol.% barium titanate (BaTiO3) powder (corresponding to 39.47- and 58.23 wt.% respectively) and characterized for their flow properties. To make them compatible with the existing FDM process, the composites were extruded into filaments. These composite filaments were subsequently structured into tensile stress specimens using a commercially available FDM 3D printer and characterized for their mechanical properties. Rheometric characterization of the material composites revealed non-Newtonian behavior with the viscosity logarithmically decreasing over increasing shear rates, as well as higher viscosities for samples with higher BaTiO3 filler content for a given shear rate (with the ABS+20vol.% BaTiO3 composite being over 50% more viscous compared to pure ABS at a shear rate of 1x〖10〗^3 s^(-1)). Mechanical characterization of the tensile stress specimens exhibited increasingly brittle behavior as well as a linearly decreasing ultimate tensile strength of the material composites with increasing volumetric ratio of BaTiO3 (from σ_max=32.4MPa for pure ABS to σ_max=21.3MPa for ABS+20vol.% BaTiO3). Further studies being undertaken include the development of composites with higher filler concentrations, sintering of the printed composites to yield pure dielectric structures and the determination of the dielectric characteristics of the composites.Keywords: ceramic composites, fused deposition modeling, material characterization, rapid prototyping
Procedia PDF Downloads 3312585 Loss of Green Space in Urban Metropolitan and Its Alarming Impacts on Teenagers' Life: A Case Study on Dhaka
Authors: Nuzhat Sharmin
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Human being is the most integral part of the nature and responsible for maintaining ecological balance both in rural and urban areas. But unfortunately, we are not doing our job with a holistic approach. The rapid growth of urbanization is making human life more isolated from greenery. Nowadays modern urban living involves sensory deprivation and overloaded stress. In many cities and towns of the world are expanding unabated in the name of urbanization and industrialization and in fact becoming jungles of concrete. Dhaka is one of the examples of such cities where open and green spaces are decreasing because of accommodating the overflow of population. This review paper has been prepared based on interviewing 30 teenagers, both male and female in Dhaka city. There were 12 open-ended questions in the questionnaire. For the literature review information had been gathered from scholarly papers published in various peer-reviewed journals. Some information was collected from the newspapers and some from fellow colleagues working around the world. Ideally about 25% of an urban area should be kept open or with parks, fields and/or plants and vegetation. But currently Dhaka has only about 10-12% open space and these also are being filled up rapidly. Old Dhaka has only about 5% open space while the new Dhaka has about 12%. Dhaka is now one of the most populated cities in the world. Accommodating this huge influx of people Dhaka is continuously losing its open space. As a result, children and teenagers are losing their interest in playing games and making friends, rather they are mostly occupied by television, gadgets and social media. It has been known from the interview that only 28% of teenagers regularly play. But the majority of them have to play on the street and rooftop for the lack of open space. On an average they are occupied with electronic devices for 8.3 hours/day. 64% of them has chronic diseases and often visit doctors. Most shockingly 35% of them claimed for not having any friends. Green space offers relief from stress. Areas of natural environment in towns and cities are theoretically seen providing setting for recovery and recuperation from anxiety and strains of the urban environment. Good quality green spaces encourage people to walk, run, cycle and play. Green spaces improve air quality and reduce noise, while trees and shrubbery help to filter out dust and pollutants. Relaxation, contemplation and passive recreation are essential to stress management. All city governments that are losing its open spaces should immediately pay attention to this aesthetic issue for the benefit of urban people. All kinds of development must be sustainable both for human being and nature.Keywords: greenery, health, human, urban
Procedia PDF Downloads 1752584 A Non-Invasive Method for Assessing the Adrenocortical Function in the Roan Antelope (Hippotragus equinus)
Authors: V. W. Kamgang, A. Van Der Goot, N. C. Bennett, A. Ganswindt
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The roan antelope (Hippotragus equinus) is the second largest antelope species in Africa. These past decades, populations of roan antelope are declining drastically throughout Africa. This situation resulted in the development of intensive breeding programmes for this species in Southern African, where they are popular game ranching herbivores in with increasing numbers in captivity. Nowadays, avoidance of stress is important when managing wildlife to ensure animal welfare. In this regard, a non-invasive approach to monitor the adrenocortical function as a measure of stress would be preferable, since animals are not disturbed during sample collection. However, to date, a non-invasive method has not been established for the roan antelope. In this study, we validated a non-invasive technique to monitor the adrenocortical function in this species. Herein, we performed an adrenocorticotropic hormone (ACTH) stimulation test at Lapalala reserve Wilderness, South Africa, using adult captive roan antelopes to determine the stress-related physiological responses. Two individually housed roan antelope (a male and a female) received an intramuscular injection with Synacthen depot (Norvatis) loaded into a 3ml syringe (Pneu-Dart) at an estimated dose of 1 IU/kg. A total number of 86 faecal samples (male: 46, female: 40) were collected 5 days before and 3 days post-injection. All samples were then lyophilised, pulverized and extracted with 80% ethanol (0,1g/3ml) and the resulting faecal extracts were analysed for immunoreactive faecal glucocorticoid metabolite (fGCM) concentrations using five enzyme immunoassays (EIAs); (i) 11-oxoaetiocholanolone I (detecting 11,17 dioxoandrostanes), (ii) 11-oxoaetiocholanolone II (detecting fGCM with a 5α-pregnane-3α-ol-11one structure), (iii) a 5α-pregnane-3β-11β,21-triol-20-one (measuring 3β,11β-diol CM), (iv) a cortisol and (v) a corticosterone. In both animals, all EIAs detected an increase in fGCM concentration 100% post-ACTH administration. However, the 11-oxoaetiocholanolone I EIA performed best, with a 20-fold increase in the male (baseline: 0.384 µg/g, DW; peak: 8,585 µg/g DW) and a 17-fold in the female (baseline: 0.323 µg/g DW, peak: 7,276 µg/g DW), measured 17 hours and 12 hours post-administration respectively. These results are important as the ability to assess adrenocortical function non-invasively in roan can now be used as an essential prerequisite to evaluate the effects of stressful circumstances; such as variation of environmental conditions or reproduction in other to improve management strategies for the conservation of this iconic antelope species.Keywords: adrenocorticotropic hormone challenge, adrenocortical function, captive breeding, non-invasive method, roan antelope
Procedia PDF Downloads 1452583 The Three-dimensional Response of Mussel Plaque Anchoring to Wet Substrates under Directional Tensions
Authors: Yingwei Hou, Tao Liu, Yong Pang
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The paper explored the three-dimensional deformation of mussel plaques anchor to wet polydimethylsiloxane (PDMS) substrates under tension stress with different angles. Mussel plaques exhibiting natural adhesive structures, have attracted significant attention for their remarkable adhesion properties. Understanding their behavior under mechanical stress, particularly in a three-dimensional context, holds immense relevance for biomimetic material design and bio-inspired adhesive development. This study employed a novel approach to investigate the 3D deformation of the PDMS substrates anchored by mussel plaques subjected to controlled tension. Utilizing our customized stereo digital image correlation technique and mechanical mechanics analyses, we found the distributions of the displacement and resultant force on the substrate became concentrated under the plaque. Adhesion and sucking mechanisms were analyzed for the mussel plaque-substrate system under tension until detachment. The experimental findings were compared with a developed model using finite element analysis and the results provide new insights into mussels’ attachment mechanism. This research not only contributes to the fundamental understanding of biological adhesion but also holds promising implications for the design of innovative adhesive materials with applications in fields such as medical adhesives, underwater technologies, and industrial bonding. The comprehensive exploration of mussel plaque behavior in three dimensions is important for advancements in biomimicry and materials science, fostering the development of adhesives that emulate nature's efficiency.Keywords: adhesion mechanism, mytilus edulis, mussel plaque, stereo digital image correlation
Procedia PDF Downloads 572582 Finite Element Modeling of Global Ti-6Al-4V Mechanical Behavior in Relationship with Microstructural Parameters
Authors: Fatna Benmessaoud, Mohammed Cheikh, Vencent Velay, Vanessa Vedal, Farhad Rezai-Aria, Christine Boher
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The global mechanical behavior of materials is strongly linked to their microstructure, especially their crystallographic texture and their grains morphology. These material aspects determine the mechanical fields character (heterogeneous or homogeneous), thus, they give to the global behavior a degree of anisotropy according the initial microstructure. For these reasons, the prediction of global behavior of materials in relationship with the microstructure must be performed with a multi-scale approach. Therefore, multi-scale modeling in the context of crystal plasticity is widely used. In this present contribution, a phenomenological elasto-viscoplastic model developed in the crystal plasticity context and finite element method are used to investigate the effects of crystallographic texture and grains sizes on global behavior of a polycrystalline equiaxed Ti-6Al-4V alloy. The constitutive equations of this model are written on local scale for each slip system within each grain while the strain and stress mechanical fields are investigated at the global scale via finite element scale transition. The beta phase of Ti-6Al-4V alloy modeled is negligible; its percent is less than 10%. Three families of slip systems of alpha phase are considered: basal and prismatic families with a burgers vector and pyramidal family with aKeywords: microstructural parameters, multi-scale modeling, crystal plasticity, Ti-6Al-4V alloy
Procedia PDF Downloads 1262581 Alleviation of Thermal Stress in Pinus ponderosa by Plant-Growth Promoting Rhizobacteria Isolated from Mixed-Conifer Forests
Authors: Kelli G. Thorup, Kristopher A. Blee
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Climate change enhances the occurrence of extreme weather: wildfires, drought, rising summer temperatures, all of which dramatically decline forest growth and increase tree mortality in the mixed-conifer forests of Sierra Nevada, California. However, microbiota living in mutualistic relations with plant rhizospheres have been found to mitigate the effects of suboptimal environmental conditions. The goal of this research is to isolate native beneficial bacteria, plant-growth promoting rhizobacteria (PGPR), that can alleviate heat stress in Pinus ponderosa seedlings. Bacteria were isolated from the rhizosphere of Pinus ponderosa juveniles located in mixed-conifer stand and further characterized for PGP potential based on their ability to produce key growth regulatory phytohormones including auxin, cytokinin, and gibberellic acid. Out of ten soil samples taken, sixteen colonies were isolated and qualitatively confirmed to produce indole-3-acetic acid (auxin) using Salkowski’s reagent. Future testing will be conducted to quantitatively assess phytohormone production in bacterial isolates. Furthermore, bioassays will be performed to determine isolates abilities to increase tolerance in heat-stressed Pinus ponderosa seedlings. Upon completion of this research, a PGPR could be utilized to support the growth and transplantation of conifer seedlings as summer temperatures continue to rise due to the effects of climate change.Keywords: conifer, heat-stressed, phytohormones, Pinus ponderosa, plant-growth promoting rhizobacteria
Procedia PDF Downloads 1182580 Clinical Efficacy and Tolerability of Dropsordry™ in Spanish Perimenopausal Women with Urgency Urinary Incontinence (UUI)
Authors: J. A. Marañón, L. Lozano C. De Los Santos, L. Martínez-Campesino, E. Caballero-Garrido, F. Galán-Estella
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Urinary incontinence (UI) is a significant health problem with considerable social and economic impact. An estimated 30% of women aged 30 to 60 years old have urinary incontinence (UI), while more than 50% of community-dwelling older women have the condition. Stress urinary incontinence and overactive bladder are the common types of incontinence The prevalence of stress and mixed (stress and urge) incontinence is higher than urge incontinence, but the latter is more likely to require treatment. In women, moderate and severe have a prevalence ranging from about 12% to 17% The objectives of this study was to examine the effect of the supplementation of tablets containing Dropsordry in women with urge urinary incontinence (UUI). Dropsordry is a novel active containing phytoestrogens from SOLGEN, the high genistin soy bean extract and pyrogallol plus polyphenols from standarized pumpkin seed extract,. The study was a single-center, not randomiized open prospective, study. 28 women with urinary incontinence ≥45 years were enrolled in this study (45-62 y. old age . Mean 52 y old). Items related to UI symptoms, were previously collected (T0) and these ítems were reviewed at the final of the study – 8 weeks. (T2). The presence of UI was previously diagnosed using the International Continence Society standards (ICS). Relationships between presence of UI and potential related factors as diabetes were also explored. Daily urinary test control was performed during the 8 weeks of treatment. Daily dosage was 1 g/ day (500 mg twice per day) from 0 to 4 week (T1), following a 500 mg/day daily intake from 4 to 8 week (T2). After eight weeks of treatment, the urgency grade score was reduced a 24,7%. The total urge episodes was reduced a 46%. Surprisingly there was no a significant change in daytime urinations (< 5%), however nocturia was reduced a 69,35%. Strenght Urinary Incontinence (SUI) was also tested showing a remarkably 52,17% reduction. Moreover the use of daily pantyliners was reduced a 66,25%. In addition, it was performed a panel test survey with quests when subjects of the study were enrolled (T0) and the same quests was performed after 8 weeks of supplementation (T2). 100% of the enrolled women fullfilled the ICIQ-SF quest (Spanish versión) and they were also questioned about the effects they noticed in response to taking the supplement and the change in quality of life. Interestingly no side effects were reported. There was a 96,2% of subjective satisfaction and a 85,8% objective score in the improvement of quality of life. CONCLUSION: the combination of High genistin isoflavones and pumpkin seed pyrogallol in Dropsordry tablets seems to be a safe and highly effective supplementation for the relieve of the urinary incontinence symptoms and a better quality of life in perimenopause women .Keywords: isoflavones, pumpkin, menopause, incontinence, genistin
Procedia PDF Downloads 4052579 The Effect of Low and High Dose Curcumin Supplementation on Prevention and Treatment of Sarcopenia: The Concept of Hormesis
Authors: Sevana Daneghian, Leila Chodari, Sahar Mehranfar, Shadi Mohammadpour-Asl, Diman Mahdi
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Sarcopenia is an age-related muscle disease. Lack of antioxidant protection, and cumulative oxidative damage to skeletal muscle are recognized mechanisms. Curcumin is a hormetin as it has a stimulating effect in low doses and an inhibitory effect in high doses. The purpose of this study was to examine the effects of four weeks of curcumin supplementation in presarcopenic and sarcopenic rats, and likelihood of potential negative effects while co-exist with sarcopenia. The rats were divided into 7 groups: young sham rats, 18 months old; presarcopenic control, supplemented with 400 and 1500 mg/kg/day, 24 months old; Sarcopenia control, sarcopenia supplemented with 400 and 1500 mg/kg/day. MDA levels were significantly reduced in the low-dose pre-sarcopenic group compared to the control group. Compared to the corresponding control groups, SOD levels decreased in the groups treated with low-dose presarcopenic supplementation and increased in the high-dose sarcopenic supplemented. GPx levels increased at both doses only in the sarcopenic group compared to the control group. SIRT-1 only increased at low doses in the sarcopenic groups and PGC-1α in both pre-sarcopenia groups compared to the corresponding control. IGF-1 increased compared to the control group at both doses in the pre-sarcopenic group and at high doses in sarcopenic group. Considering the hormetic effects of curcumin, it can be argued that, curcumin supplementation has some positive effects not only at low but also at high doses in both groups. This means that the high doses of curcumin have no negative synergistic effects in addition to oxidative stress during sarcopenia and high-dose supplementation in patients already suffering from high oxidative stress due to sarcopenia is safe and could be considered hormetic.Keywords: curcumin, hormesis, sarcopenia, muscular atrophy, PGC protein, Sirtuins
Procedia PDF Downloads 392578 Psychological Distress during the COVID-19 Pandemic in Nursing Students: A Mixed-Methods Study
Authors: Mayantoinette F. Watson
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During such an unprecedented time of the largest public health crisis, the COVID-19 pandemic, nursing students are of the utmost concern regarding their psychological and physical well-being. Questions are emerging and circulating about what will happen to the nursing students and the long-term effects of the pandemic, especially now that hospitals are being overwhelmed with a significant need for nursing staff. Expectations, demands, change, and the fear of the unknown during this unprecedented time can only contribute to the many stressors that accompany nursing students through laborious clinical and didactic courses in nursing programs. The risk of psychological distress is at a maximum, and its effects can negatively impact not only nursing students but also nursing education and academia. The high exposures to interpersonal, economic, and academic demands contribute to the major health concerns, which include a potential risk for psychological distress. Achievement of educational success among nursing students is directly affected by the high exposure to anxiety and depression from experiences within the program. Working relationships and achieving academic success is imperative to positive student outcomes within the nursing program. The purpose of this study is to identify and establish influences and associations within multilevel factors, including the effects of the COVID-19 pandemic on psychological distress in nursing students. Neuman’s Systems Model Theory was used to determine nursing students’ responses to internal and external stressors. The research in this study utilized a mixed-methods, convergent study design. The study population included undergraduate nursing students from Southeastern U.S. The research surveyed a convenience sample of undergraduate nursing students. The quantitative survey was completed by 202 participants, and 11 participants participated in the qualitative follow-up interview surveys. Participants completed the Kessler Psychological Distress Scale (K6), the Perceived Stress Scale (PSS4), and the Dundee Readiness Educational Environment Scale (DREEM12) to measure psychological distress, perceived stress, and perceived educational environment. Participants also answered open-ended questions regarding their experience during the COVID-19 pandemic. Statistical tests, including bivariate analyses, multiple linear regression analyses, and binary logistics regression analyses were performed in effort to identify and highlight the effects of independent variables on the dependent variable, psychological distress. Coding and qualitative content analysis were performed to identify overarching themes within participants’ interviews. Quantitative data were sufficient in identifying correlations between psychological distress and multilevel factors of coping, marital status, COVID-19 stress, perceived stress, educational environment, and social support in nursing students. Qualitative data were sufficient in identifying common themes of students’ perceptions during COVID-19 and included online learning, workload, finances, experience, breaks, time, unknown, support, encouragement, unchanged, communication, and transmission. The findings are significant, specifically regarding contributing factors to nursing students’ psychological distress, which will help to improve learning in the academic environment.Keywords: nursing education, nursing students, pandemic, psychological distress
Procedia PDF Downloads 862577 The COVID-19 Pandemic and Supply Chain Resilience of Food Banks: A Multiple-Case Study
Authors: Karima Afif, Jacinthe Clouthier, Marie-Ève Gaboury-Bonhomme, Véronique Provencher, Morgane Leclercq
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This paper investigates how food banks have secured and improved their supply chain resilience to pursue their mission during COVID-19. More specifically, the implications of the COVID-19 outbreak on the food aid needs, donations, operations, and mission of food banks are explored. To develop an in-depth understanding of the reactions and actions that they have been taken, a qualitative approach has been adopted using a multiple case study design. Data from two focus groups, 12 semi-structured interviews with key informants covering all supply chain levels, and field notes from 7 workplace observations in donation points, food bank facilities, and community-based organizations in Québec (Canada) are triangulated. The results highlight that the pandemic has significantly and unpredictably increased the number of food aid demands, causing significant operational challenges for the food banks supply chain, as well as an unprecedented shortage of donations to food banks. Besides, the sanitary measures have required several adaptative strategies. These implications have caused food banks to enhance their operational flexibility, optimize their logistics operations, enhance their human resources management, and expand collaboration within their supply chain.Keywords: supply chain resilience, food banks, food donations, food aid, COVID-19
Procedia PDF Downloads 712576 Shielding Engineered Islets with Mesenchymal Stem Cells Enhance Survival under Hypoxia by Inhibiting p38 MAPK
Authors: Bhawna Chandravanshi, Ramesh Bhonde
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In the present study, we focused on the improvisation of islet survival in hypoxia. The Islet-like cell aggregates (ICAs) derived from Wharton's jelly mesenchymal stem cells (WJ-MSC) were cultured with and without WJ-MSC for 48h in hypoxia and normoxia and tested for their direct trophic effect on β cell survival. The WJ MSCs themselves secreted insulin upon glucose challenge and expressed the pancreatic markers at both transcription and translational level (C-peptide, Insulin, Glucagon and Glut 2). Direct contact of MSCs with ICAs facilitate the highest viability under hypoxia as evidenced by fluorescein diacetate/propidium iodide and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cytokine analysis of the co-cultured ICAs revealed amplification of anti-inflammatory cytokine-like TGFβ and TNFα accompanied by depletion of pro-inflammatory cytokines. The increment in VEGF and PDGFa was also seen showing their ability to vascularize upon transplantation. This was further accompanied by reduction in total reactive oxygen species, nitric oxide, and super oxide ions and down-regulation of Caspase3, Caspase8, p53 and up regulation of Bcl2 confirming prevention of apoptosis in ICAs. There was a significant reduction in the expression of p38 protein in the presence of MSCs making the ICAs responsive to glucose. Taken together our data demonstrate for the first time that the WJ-MSC expressed pancreatic markers and their supplementation protected engineered islets against hypoxia, oxidative stress, and inflammatory cytokines by inhibiting p38 MAPK protein.Keywords: hypoxia, islet-like cell aggregates, inflammatory cytokines, oxidative stress
Procedia PDF Downloads 2612575 Adaptive Strategies of European Sea Bass (Dicentrarchus labrax) to Ocean Acidification and Salinity Stress
Authors: Nitin Pipralia, Amit Kmar Sinha, Gudrun de Boeck
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Atmospheric carbon dioxide (CO2) concentrations have been increasing since the beginning of the industrial revolution due to combustion of fossils fuel and many anthropogenic means. As the number of scenarios assembled by the International Panel on Climate Change (IPCC) predict a rise of pCO2 from today’s 380 μatm to approximately 900 μatm until the year 2100 and a further rise of up to 1900 μatm by the year 2300. A rise in pCO2 results in more dissolution in ocean surface water which lead to cange in water pH, This phenomena of decrease in ocean pH due to increase on pCO2 is ocean acidification is considered a potential threat to the marine ecosystems and expected to affect fish as well as calcerious organisms. The situation may get worste when the stress of salinity adds on, due to migratory movement of fishes, where fish moves to different salinity region for various specific activities likes spawning and other. Therefore, to understand the interactive impact of these whole range of two important environmental abiotic stresses (viz. pCO2 ranging from 380 μatm, 900 μatm and 1900 μatm, along with salinity gradients of 32ppt, 10 ppt and 2.5ppt) on the ecophysiologal performance of fish, we investigated various biological adaptive response in European sea bass (Dicentrarchus labrax), a model estuarine teleost. Overall, we hypothesize that effect of ocean acidification would be exacerbate with shift in ambient salinity. Oxygen consumption, ammonia metabolism, iono-osmoregulation, energy budget, ion-regulatory enzymes, hormones and pH amendments in plasma were assayed as the potential indices of compensatory responses.Keywords: ocean acidification, sea bass, pH climate change, salinity
Procedia PDF Downloads 2272574 Impact of Cd and Pb Impregnation on the Health of an Adult Population Neighbouring a Landfill
Authors: M. Cabral, A. Verdin, G. Garçon, A. Touré, C. Diop, M. Fall, S. Bouhsina, D. Dewaele, F.Cazier, A. Tall Dia, P. Shirali, A. Diouf
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This case-control study dealt with the health adverse effects within the population neighboring the Mbeubeuss waste dump, which is located near the district of Malika (Diamalaye II) in Dakar (Senegal). All the household and industrial waste arising from Dakar are stored in this open landfill without being covered and are therefore possible sources of Pb and Cd contaminated air emissions and lixiviates. The objective of this study is part of improving the health of the population neighboring Mbeubeuss by determining Pb and Cd concentrations both in environment and humans, and studying possible renal function alterations within the adults. Soil and air samples were collected in the control site (Darou Salam) and the waste dump neighboring site (Diamalaye II). Control and exposed adults were recruited as living in Darou Salam (n = 52) and in Diamalaye II (n = 77). Pb and Cd concentrations in soil, air and biological samples were determined. Moreover, we were interested in analyzing some impregnation (zinc protoporphyrin, d-aminolevulinic acid dehydratase) and oxidative stress biomarkers (malonedialdehyde, gluthatione status), in addition to several nephrotoxicity parameters (creatinuria, proteinuria, lactate dehydrogenase, CC16 protein, glutathione S-transferase-alpha and retinol binding protein) in blood and/or urine. The results showed the significant Pb and Cd contamination of the soil and air samples derived from the landfill, and therefore of the neighboring population of adults. This critical exposure to environmental Pb and Cd had some harmful consequences for their health, as shown by the reported oxidative stress and nephrotoxicity signs.Keywords: Pb and Cd environmental exposure, impregnation markers, landfill, nephrotoxicity markers
Procedia PDF Downloads 4412573 The Role Support Groups Play in Decreasing Depression and PTSD in Cancer Survivors: A Literature Review
Authors: Julianne Macmullen
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Due to advances in technology and early detection and treatment of cancer, many cancer patients are surviving longer than five years post-diagnosis. Most cancer patients suffer from depression, anxiety, and post-traumatic stress disorder (PTSD) at some point during diagnosis, treatment, and survivorship. A subgroup of patients will continue to suffer from depression and PTSD and require early intervention. Support groups provide patients with the emotional and informational support they require while also giving survivors a sense of community, friendship, and purpose. This type of support is recognized by researchers to improve the quality of life while also decreasing depression and PTSD symptoms. The gaps in the literature include cultural diversity, minorities, and support groups involving cancer types other than breast cancer. Another gap in the literature includes the perceptions of cancer patients as well as longitudinal studies to determine the relationships between support groups and decreased depression and PTSD rates over time. Future research is required to fill the gaps in the literature mentioned previously. Future research is also needed to analyze the difference in age groups and different types of support groups such as professionally-led, peer-led, and online. Implications for practice involve providers assessing for the symptoms of depression and PTSD in order to offer prompt treatment and support services to those patients. In conclusion, social support by way of support groups improves the quality of life, gives survivors a sense of purpose to help others while also gaining the support they need, and reduces the rate of depressive episodes related to PTSD.Keywords: cancer survivor, survivorship, post-traumatic stress disorder (PTSD), depression, support groups
Procedia PDF Downloads 1762572 Evaluation of the Self-Efficacy and Learning Experiences of Final year Students of Computer Science of Southwest Nigerian Universities
Authors: Olabamiji J. Onifade, Peter O. Ajayi, Paul O. Jegede
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This study aimed at investigating the preparedness of the undergraduate final year students of Computer Science as the next entrants into the workplace. It assessed their self-efficacy in computational tasks and examined the relationship between their self-efficacy and their learning experiences in Southwest Nigerian universities. The study employed a descriptive survey research design. The population of the study comprises all the final year students of Computer Science. A purposive sampling technique was adopted in selecting a representative sample of interest from the final year students of Computer Science. The Students’ Computational Task Self-Efficacy Questionnaire (SCTSEQ) was used to collect data. Mean, standard deviation, frequency, percentages, and linear regression were used for data analysis. The result obtained revealed that the final year students of Computer Science were averagely confident in performing computational tasks, and there is a significant relationship between the learning experiences of the students and their self-efficacy. The study recommends that the curriculum be improved upon to accommodate industry experts as lecturers in some of the courses, make provision for more practical sessions, and the learning experiences of the student be considered an important component in the undergraduate Computer Science curriculum development process.Keywords: computer science, learning experiences, self-efficacy, students
Procedia PDF Downloads 1432571 The Effect of Manggong Bamboo Leaves Extract (Gigantochloa manggong) on Rat (Rattus novergicus) Blood Profile
Authors: Sri Rahayu, Supriyatin, Yuli Rahma Dini
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One of the consequences of excess physical activity is the oxidative stress which resulted in damage to blood cells. Oxidative stress condition can be reduced by an exogenous antioxidant. The natural exogenous antioxidant can be extracted from Manggong bamboo (Gigantochloa manggong). This research was aim to evaluate the effect of physical exercise and Manggong bamboo (Gigantochloa manggong) leaf extract on blood profile of rats. This research was conducted in July 2013 to May 2014 using experimental method with completely randomized design (CRD) with two factors, physical exercise and Manggong bamboo leaf extract. The rats blood profile to be measured were the level of erythrocyte cells, leucocyte cells and hemoglobin. Data were analyzed with parametric statistical 2-way ANOVA test (α = 0.05). Manggong bamboo leaf extract was non toxic and contained flavonoid, triterpenoid, saponin and alkaloid. There was an effect of physical exercise and manggong bamboo leaf extract on blood profile of rats. Data obtained on physical activity, giving erythrocyte cells (2.5 million/µl) and hemoglobin (12,42g/dL) declined compared to the number of leucocyte cells increases (6,500cells/L). Extract treatment was increased the erythrocytes (5,13 million/µl) and hemoglobin level (14,72 g/dL.) while the leukocytes level were decreased (1.591,67 cells/L). The extract and physical activity treatment showed an increase in erythrocytes (2,96 million/µl) and hemoglobin (14,3 g/dL) but decrease the number of leukocytes (1.291,67 cells/L). The conclusion was that physical activity and Manggong bamboo leafs extract gaves effect on the blood profile of white rat.Keywords: antioxidant, blood profile of rats, Manggong bamboo leaf extract, leukocytes
Procedia PDF Downloads 2902570 Stability and Rheology of Sodium Diclofenac-Loaded and Unloaded Palm Kernel Oil Esters Nanoemulsion Systems
Authors: Malahat Rezaee, Mahiran Basri, Raja Noor Zaliha Raja Abdul Rahman, Abu Bakar Salleh
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Sodium diclofenac is one of the most commonly used drugs of nonsteroidal anti-inflammatory drugs (NSAIDs). It is especially effective in the controlling the severe conditions of inflammation and pain, musculoskeletal disorders, arthritis, and dysmenorrhea. Formulation as nanoemulsions is one of the nanoscience approaches that have been progressively considered in pharmaceutical science for transdermal delivery of drug. Nanoemulsions are a type of emulsion with particle sizes ranging from 20 nm to 200 nm. An emulsion is formed by the dispersion of one liquid, usually the oil phase in another immiscible liquid, water phase that is stabilized using surfactant. Palm kernel oil esters (PKOEs), in comparison to other oils; contain higher amounts of shorter chain esters, which suitable to be applied in micro and nanoemulsion systems as a carrier for actives, with excellent wetting behavior without the oily feeling. This research was aimed to study the effect of O/S ratio on stability and rheological behavior of sodium diclofenac loaded and unloaded palm kernel oil esters nanoemulsion systems. The effect of different O/S ratio of 0.25, 0.50, 0.75, 1.00 and 1.25 on stability of the drug-loaded and unloaded nanoemulsion formulations was evaluated by centrifugation, freeze-thaw cycle and storage stability tests. Lecithin and cremophor EL were used as surfactant. The stability of the prepared nanoemulsion formulations was assessed based on the change in zeta potential and droplet size as a function of time. Instability mechanisms including coalescence and Ostwald ripening for the nanoemulsion system were discussed. In comparison between drug-loaded and unloaded nanoemulsion formulations, drug-loaded formulations represented smaller particle size and higher stability. In addition, the O/S ratio of 0.5 was found to be the best ratio of oil and surfactant for production of a nanoemulsion with the highest stability. The effect of O/S ratio on rheological properties of drug-loaded and unloaded nanoemulsion systems was studied by plotting the flow curves of shear stress (τ) and viscosity (η) as a function of shear rate (γ). The data were fitted to the Power Law model. The results showed that all nanoemulsion formulations exhibited non-Newtonian flow behaviour by displaying shear thinning behaviour. Viscosity and yield stress were also evaluated. The nanoemulsion formulation with the O/S ratio of 0.5 represented higher viscosity and K values. In addition, the sodium diclofenac loaded formulations had more viscosity and higher yield stress than drug-unloaded formulations.Keywords: nanoemulsions, palm kernel oil esters, sodium diclofenac, rheoligy, stability
Procedia PDF Downloads 4232569 The Relation between Authenticity at Work and Job Satisfaction
Authors: Godiva Kwan, Winton Au, Fanny Cheung
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Authenticity, being true to oneself and acting in congruence with one’s values and beliefs, is a basic human strength, and is instrumental to understanding well-being. While dispositional authenticity was found to be associated with positive affect and subjective well-being, others have demonstrated that individuals assumed different levels of authenticity when they took up different social roles, suggesting that state authenticity can be an alternative mechanism. This study examined the relation between workplace authenticity and job satisfaction. We hypothesize that state authenticity at work will be predicted by psychological safety climate (organizational climate where employees feel safe to speak up without being embarrassed or rejected). Employees are expected to experience higher subjective well-being and job satisfaction as a result of being authentic at work. Survey results provided support to the hypotheses. Psychological safety climate enhanced employees’ authenticity state at work, which in turn improved well-being and job satisfaction. In conclusion, we found that employees become more authentic at work in an organizational climate where they feel safe to express themselves, leading to a higher job satisfaction and well-being. The current study contributes to the understanding of underlying mechanisms behind experiencing authenticity at work among employees in Hong Kong. Our findings are expected to provide insights and to raise organizations’ awareness of creating an open and trustful culture in order to enhance job satisfaction of employees through encouraging them to “be themselves”.Keywords: authenticity, job satisfaction, psychological safety climate, organizational climate
Procedia PDF Downloads 4282568 Effect of Anisotropy on Steady Creep in a Whisker Reinforced Functionally Graded Composite Disc
Authors: V. K. Gupta, Tejeet Singh
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In many whisker reinforced composites, anisotropy may result due to material flow during processing operations such as forging, extrusion etc. The consequence of anisotropy, introduced during processing of disc material, has been investigated on the steady state creep deformations of the rotating disc. The disc material is assumed to undergo plastic deformations according to Hill’s anisotropic criterion. Steady state creep has been analyzed in a constant thickness rotating disc made of functionally graded 6061Al-SiCw (where the subscript ‘w’ stands for whisker) using Hill’s The content of reinforcement (SiCw) in the disc is assumed to decrease linearly from the inner to outer radius. The stresses and strain rates in the disc are estimated by solving the force equilibrium equation along with the constitutive equations describing multi-axial creep. The results obtained for anisotropic FGM disc have been compared with those estimated for isotropic FGM disc having the same average whisker content. The anisotropic constants, appearing in Hill’s yield criterion, have been obtained from the available experimental results. The results show that the presence of anisotropy reduces the tangential stress in the middle of the disc but near the inner and outer radii the tangential stress is higher when compared to isotropic disc. On the other hand, the steady state creep rates in the anisotropic disc are reduced significantly over the entire disc radius, with the maximum reduction observed at the inner radius. Further, in the presence of anisotropy the distribution of strain rate becomes relatively uniform over the entire disc, which may be responsible for reducing the extent of distortion in the disc.Keywords: anisotropy, creep, functionally graded composite, rotating disc
Procedia PDF Downloads 3912567 Experimental Uniaxial Tensile Characterization of One-Dimensional Nickel Nanowires
Authors: Ram Mohan, Mahendran Samykano, Shyam Aravamudhan
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Metallic nanowires with sub-micron and hundreds of nanometer diameter have a diversity of applications in nano/micro-electromechanical systems (NEMS/MEMS). Characterizing the mechanical properties of such sub-micron and nano-scale metallic nanowires are tedious; require sophisticated and careful experimentation to be performed within high-powered microscopy systems (scanning electron microscope (SEM), atomic force microscope (AFM)). Also, needed are nanoscale devices for placing the nanowires; loading them with the intended conditions; obtaining the data for load–deflection during the deformation within the high-powered microscopy environment poses significant challenges. Even picking the grown nanowires and placing them correctly within a nanoscale loading device is not an easy task. Mechanical characterizations through experimental methods for such nanowires are still very limited. Various techniques at different levels of fidelity, resolution, and induced errors have been attempted by material science and nanomaterial researchers. The methods for determining the load, deflection within the nanoscale devices also pose a significant problem. The state of the art is thus still at its infancy. All these factors result and is seen in the wide differences in the characterization curves and the reported properties in the current literature. In this paper, we discuss and present our experimental method, results, and discussions of uniaxial tensile loading and the development of subsequent stress–strain characteristics curves for Nickel nanowires. Nickel nanowires in the diameter range of 220–270 nm were obtained in our laboratory via an electrodeposition method, which is a solution based, template method followed in our present work for growing 1-D Nickel nanowires. Process variables such as the presence of magnetic field, its intensity; and varying electrical current density during the electrodeposition process were found to influence the morphological and physical characteristics including crystal orientation, size of the grown nanowires1. To further understand the correlation and influence of electrodeposition process variables, associated formed structural features of our grown Nickel nanowires to their mechanical properties, careful experiments within scanning electron microscope (SEM) were conducted. Details of the uniaxial tensile characterization, testing methodology, nanoscale testing device, load–deflection characteristics, microscopy images of failure progression, and the subsequent stress–strain curves are discussed and presented.Keywords: uniaxial tensile characterization, nanowires, electrodeposition, stress-strain, nickel
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