Search results for: drilling response

Authors: Markus Meyer, Bastian Maucher, Rolf Witzmann

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The ever increasing amount of distributed generation in low voltage distribution grids (mainly PV and micro-CHP) can lead to reverse load flows from low to medium/high voltage levels at times of high feed-in. Reverse load flow leads to rising voltages that may even exceed the limits specified in the grid codes. Furthermore, the share of electrical loads connected to low voltage distribution grids via switched power supplies continuously increases. In combination with inverter-based feed-in, this results in high harmonic levels reducing overall power quality. Especially high levels of third-order harmonic currents can lead to neutral conductor overload, which is even more critical if lines with reduced neutral conductor section areas are used. This paper illustrates a possible concept for smart grids in order to increase the feed-in capacity, improve power quality and to ensure safe operation of low voltage distribution grids at all times. The key feature of the concept is a hierarchically structured control strategy that is run on a superordinated controller, which is connected to several distributed grid analyzers and inverters via broad band powerline (BPL). The strategy is devised to ensure both quick response time as well as the technically and economically reasonable use of the available inverters in the grid (PV-inverters, batteries, stepless line voltage regulators). These inverters are provided with standard features for voltage control, e.g. voltage dependent reactive power control. In addition they can receive reactive power set points transmitted by the superordinated controller. To further improve power quality, the inverters are capable of active harmonic filtering, as well as voltage balancing, whereas the latter is primarily done by the stepless line voltage regulators. By additionally connecting the superordinated controller to the control center of the grid operator, supervisory control and data acquisition capabilities for the low voltage distribution grid are enabled, which allows easy monitoring and manual input. Such a low voltage distribution grid can also be used as a virtual power plant.

Keywords: distributed generation, distribution grid, power quality, smart grid, virtual power plant, voltage control

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Authors: Lucas Berrini

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Academic libraries have always struggled with engaging with students and faculty. Striking the balance between what the community needs and what the library can afford has also been a point of contention for libraries. As academia begins to return to a new normal after COVID, library staff are rethinking how remind patrons that the library is open and ready for business. NC Wesleyan, a small liberal arts school in eastern North Carolina, decided to be proactive and reach out to the academic community. After shutting down in 2020 for COVID, the campus library saw a marked decrease in in-person attendance. For a small school whose operational budget was tied directly to tuition payments, it was imperative for the library to remind faculty and staff that they were open for business. At the beginning of the Summer 2022 term and continuing into the fall, the reference team created a marketing plan using email, physical meetings, and virtual events targeted at students and faculty as well as community members who utilized the facilities prior to COVID. The email blasts were gentle reminders that the building was open and available for use The target audiences were the community at large. Several of the emails contained reminders of previous events in the library that were student centered. The next phase of the email campaign centers on reminding the community about the libraries physical and electronic resources, including the makerspace lab. Language will indicate that student voices are needed, and a QR code is included for students to leave feedback as to what they want to see in the library. The final phase of the email blasts were faculty focused and invited them to connect with library reference staff for an in-person consultation on their research needs. While this phase is ongoing, the response has been positive, and staff are compiling data in hopes of working with administration to implement some of the requested services and materials. These email blasts will be followed up by in-person meetings with faculty and students who responded to the QR codes. This research is ongoing. This type of targeted outreach is new for Wesleyan. It is the hope of the library that by the end of Fall 2022, there will be a plan in place to address the needs and concerns of the students and faculty. Furthermore, the staff hopes to create a new sense of community for the students and staff of the university.

Keywords: academic, education, libraries, outreach

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Authors: Chow Jeng Hei, Pavel Tkalich, Low Kai Sheng Bryan

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Due to the growing demand for sustainability in the maritime industry, there has been a significant increase in focus on alternative fuels such as biofuels, liquefied natural gas (LNG), hydrogen, methanol and ammonia to reduce the carbon footprint of vessels. Alternative fuels offer efficient transportability and significantly reduce carbon dioxide emissions, a critical factor in combating global warming. In an era where the world is determined to tackle climate change, the utilization of methanol is projected to witness a consistent rise in demand, even during downturns in the oil and gas industry. Since 2022, there has been an increase in methanol loading and discharging operations for industrial use in Singapore. These operations were conducted across various storage tank terminals at Jurong Island of varying capacities, which are also used to store alternative fuels for bunkering requirements. The key objective of this research is to support the green shipping industries in the transformation to new fuels such as methanol and ammonia, especially in evolving the capability to inform risk assessment and management of spills. In the unlikely event of accidental spills, a highly reliable forecasting system must be in place to provide mitigation measures and ahead planning. The outcomes of this research would lead to an enhanced metocean prediction capability and, together with advanced sensing, will continuously build up a robust digital twin of the bunkering operating environment. Outputs from the developments will contribute to management strategies for alternative marine fuel spills, including best practices, safety challenges and crisis management. The outputs can also benefit key port operators and the various bunkering, petrochemicals, shipping, protection and indemnity, and emergency response sectors. The forecasted datasets provide a forecast of the expected atmosphere and hydrodynamic conditions prior to bunkering exercises, enabling a better understanding of the metocean conditions ahead and allowing for more refined spill incident management planning

Keywords: clean fuels, hydrodynamics, coastal engineering, impact assessments

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Authors: Janneth Gonzalez, Andrés Pinzon Velasco, Maria Angarita

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Astrocytes play an important role in various processes in the brain, including pathological conditions such as neurodegenerative diseases. Recent studies have shown that the increase in saturated fatty acids such as palmitic acid (PA) triggers pro-inflammatorypathways in the brain. The use of synthetic neurosteroids such as tibolone has demonstrated neuro-protective mechanisms. However, broad studies with a systemic point of view on the neurodegenerative role of PA and the neuro-protective mechanisms of tibolone are lacking. In this study, we performed the integration of multi-omic data (transcriptome and proteome) into a human astrocyte genomic scale metabolic model to study the astrocytic response during palmitate treatment. We evaluated metabolic fluxes in three scenarios (healthy, induced inflammation by PA, and tibolone treatment under PA inflammation). We also applied a control theory approach to identify those reactions that exert more control in the astrocytic system. Our results suggest that PA generates a modulation of central and secondary metabolism, showing a switch in energy source use through inhibition of folate cycle and fatty acid β‐oxidation and upregulation of ketone bodies formation. We found 25 metabolic switches under PA‐mediated cellular regulation, 9 of which were critical only in the inflammatory scenario but not in the protective tibolone one. Within these reactions, inhibitory, total, and directional coupling profiles were key findings, playing a fundamental role in the (de)regulation of metabolic pathways that may increase neurotoxicity and represent potential treatment targets. Finally, the overall framework of our approach facilitates the understanding of complex metabolic regulation, and it can be used for in silico exploration of the mechanisms of astrocytic cell regulation, directing a more complex future experimental work in neurodegenerative diseases.

Keywords: astrocytes, data integration, palmitic acid, computational model, multi-omics

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Authors: Eliott Guérin, Remi Daudin, Georges Kalepsi, Alexis Lenain, Sebastien Gravier, Benoit Ter-Ovanessian, Damien Fabregue, Jean-Jacques Blandin

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Due to interesting compromise between mechanical and corrosion properties, Zr-based BMGs are attractive for biomedical applications. However, the enhancement of their glass forming ability (GFA) is often achieved by addition of toxic elements like Ni or Be, which is of course a problem for such applications. Consequently, the development of Ni-free Be-free Zr-based BMGs is of great interest. We have developed a Zr-based (Ni and Be-free) amorphous metallic alloy with an elastic limit twice the one of Ti-6Al-4V. The Zr56Co28Al16 composition exhibits a yield strength close to 2 GPa and low Young’s modulus (close to 90 GPa) [1-2]. In this work, we investigated Niobium (Nb) addition through substitution of Zr up to 8 at%. Cobalt substitution has already been reported [3], but we chose Zr substitution to preserve the glass forming ability. In this case, we show that the glass forming ability for 5 mm diameters rods is maintained up to 3 at% of Nb substitution using suction casting in cooper moulds. Concerning the thermal stability, we measure a strong compositional dependence on the glass transition (Tg). Using DSC analysis (heating rate 20 K/min), we show that the Tg rises from 752 K for 0 at% of Nb to 759 K for 3 at% of Nb. Yet, the thermal range between Tg and the crystallisation temperature (Tx) remains almost unchanged from 33 K to 35 K. Uniaxial compression tests on 2 mm diameter pillars and 3 points bending (3PB) tests on 1 mm thick plates are performed to study the Nb addition on the mechanical properties and the plastic behaviour. With these tests, an optimal Nb concentration is found, improving both plasticity and fatigue resistance. Through interpretations of DSC measurements, an attempt is made to correlate the modifications of the mechanical properties with the structural changes. The optimized chemical, structural and mechanical properties through Nb addition are encouraging to develop the potential of this BMG alloy for biomedical applications. For this purpose, we performed polarisation, immersion and cytotoxicity tests. The figure illustrates the polarisation response of Zr56Co28Al16, Zr54Co28Al16Nb2 and TA6V as a reference after 2h of open circuit potential. The results show that the substitution of Zr by a small amount of Nb significantly improves the corrosion resistance of the alloy.

Keywords: metallic glasses, amorphous metal, medical, mechanical resistance, biocompatibility

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Authors: Binaya Tamang, Buddhhi Raj Pokhrel, Narayan Gautam

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Background: There may be a connection between thyroid function and vitamin D status since both bind to similar nuclear hormone receptors and have similar response regions on gene promoters. The purpose of the current study was to investigate the relationship between thyroid hormones and vitamin D levels in females who were attending a tertiary care center in western Nepal and were either hypothyroid or euthyroid. Methods: This hospital-based cross-sectional study was carried out between March 2020 and March 2021 by the Biochemistry department of the Universal College of Medical Sciences (UCMS), Bhairahawa, Province No. 5, Nepal, in cooperation with Internal medicine. Prior to the study, institutional review committee approval (UCMS/IRC/008/20) was acquired from UCMS. Women who visited the Internal Medicine OPD of UCMS and were advised to get a thyroid function test (TFT) were included in the study population. Only those who were willing to participate in the study were enrolled after the goals and advantages of the study had been explained to them. Participants who had recently used vitamin D supplements and medications that affected thyroid hormones were excluded. The participants gave their consent verbally and in writing. After getting the consent, a convenient sample technique was applied. Serum was isolated after drawing 3 ml of blood in a plain vial. Chemiluminescence assay was used to analyze vitamin D and thyroid hormones (MAGLUMI 2000). SPSS version 16.0 for Windows was used to conduct the statistical analysis. Statistical significance was defined as a P-value < 0.05. Results: Majority of the study population (n=214, 71%) had insufficient serum vitamin D levels. Among the thyroid groups, the median Vitamin D levels were significantly lower in hypothyroid (16.88 ng/ml) as compared to the euthyroid groups (25.01 ng/ml) (P<0.001). Similarly, serum Vitamin D levels were considerably lower in the obese population (16.86 ng/ml) as compared to the normal BMI group (24.90 ng/ml) (P<0.001) as well as in the vegetarian (15.43 ng.ml) than mixed diet consumer (24.89 ng/ml) (P<0.01). Even after the adjustment for these variables, the Vitamin D levels were significantly lower in the hypothyroid population than in the euthyroid group (P<0.001). Conclusion: Comparing the hypothyroid population to the euthyroid, the median serum vitamin D levels were considerably lower. We were alarmed to see that the majority of euthyroid participants also had low levels of vitamin D. Therefore if left untreated, low vitamin D levels in hypothyroid patients could worsen their health further.

Keywords: vitamin D, thyroid hormones, euthyroid, hypothyroid, Nepal

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Authors: Agatha Bebbington, Terry Tetley, Kathryn Hadler

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Background: Astronauts will set foot on the Moon later this decade, and are at high risk of lunar dust inhalation. Freshly-fractured lunar dust produces reactive oxygen species in solution, which are known to cause cellular damage and inflammation. Cytotoxicity and inflammatory mediator release was measured in pulmonary alveolar epithelial cells (cells that line the gas-exchange zone of the lung) exposed to a lunar dust simulant, LMS-1. It was hypothesised that freshly-fractured LMS-1 would result in increased cytotoxicity and inflammatory mediator release, owing to the angular morphology and high reactivity of fractured particles. Methods: A human alveolar epithelial type 1-like cell line (TT1) and a human macrophage-like cell line (THP-1) were exposed to 0-200μg/ml of unground, aged-ground, and freshly-ground LMS-1 (screened at <22μm). Cell viability, cytotoxicity, and inflammatory mediator release (IL-6, IL-8) were assessed using MMT, LDH, and ELISA assays, respectively. LMS-1 particles were characterised for their size, surface area, and morphology before and after grinding. Results: Exposure to LMS-1 particles did not result in overt cytotoxicity in either TT1 epithelial cells or THP-1 macrophage-like cells. A dose-dependent increase in IL-8 release was observed in TT1 cells, whereas THP-1 cell exposure, even at low particle concentrations, resulted in increased IL-8 release. Both cytotoxic and pro-inflammatory responses were most marked and significantly greater in TT1 and THP-1 cells exposed to freshly-fractured LMS-1. Discussion: LMS-1 is a novel lunar dust simulant; this is the first study to determine its toxicological effects on respiratory cells in vitro. An increased inflammatory response in TT1 and THP-1 cells exposed to ground LMS-1 suggests that low particle size, increased surface area, and angularity likely contribute to toxicity. Conclusions: Evenlow levels of exposure to LMS-1 could result in alveolar inflammation. This may have pathological consequences for astronauts exposed to lunar dust on future long-duration missions. Future research should test the effect of low-dose, intermittent lunar dust exposure on the respiratory system.

Keywords: lunar dust, LMS-1, lunar dust simulant, long-duration space travel, lunar dust toxicity

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Authors: Catherine Wheatley, Emma L. Davies, Helen Dawes

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The health benefits of exercise are widely recognised, but numerous interventions have failed to halt a sharp decline in physical activity during early adolescence. Many such projects are underpinned by the Theory of Planned Behaviour, yet this model of rational decision-making leaves variance in behavior unexplained. This study investigated whether the Prototype Willingness Model, which proposes a second, reactive decision-making path to account for spontaneous responses to the social environment, has potential to improve understanding of adolescent exercise behaviour in school by exploring constructs in the model with young people. PE teachers in 4 Oxfordshire schools each nominated 6 pupils who were active in school, and 6 who were inactive, to participate in the study. Of these, 45 (22 male) aged 12-13 took part in 8 focus group discussions. These were transcribed and subjected to deductive thematic analysis to search for themes relating to the prototype willingness model. Participants appeared to make rational decisions about commuting to school or attending sports clubs, but spontaneous choices to be inactive during both break and PE. These reactive decisions seemed influenced by a social context described as more ‘judgmental’ than primary school, characterised by anxiety about physical competence, negative peer evaluation and inactive playground norms. Participants described their images of typical active and inactive adolescents: active images included negative social characteristics including ‘show-off’. There was little concern about the long-term risks of inactivity, although participants seemed to recognise that physical activity is healthy. The Prototype Willingness Model might more fully explain young adolescents’ physical activity in school than rational behavioural models, indicating potential for physical activity interventions that target social anxieties in response to the changing playground environment. Images of active types could be more complex than earlier research has suggested, and their negative characteristics might influence willingness to be active.

Keywords: adolescence, physical activity, prototype willingness model, school

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Authors: Hernández Marieta, Aguayo Mauricio, Pedreros María, Llompart Ovidio

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The hydrological cycle is influenced by multiple factors, including climate change, land use changes, and anthropogenic activities, all of which threaten water availability and quality worldwide. In recent decades, numerous investigations have used landscape metrics and hydrological modeling to demonstrate the influence of landscape patterns on the hydrological cycle components' natural dynamics. Many of these investigations have determined the repercussions on the quality and availability of water, sedimentation, and erosion regime, mainly in Asian basins. In fact, there is progress in this branch of science, but there are still unanswered questions for our region. This study examines the hydrological response in Chilean basins under various land use change scenarios (LUCC) and the influence of climate change. The components of the water cycle were modeled using a physically distributed type hydrological and hydraulic simulation model based on and oriented to mountain basins TETIS model. Future climate data were derived from Chilean regional simulations using the WRF-MIROC5 model, forced with the RCP 8.5 scenario, at a 25 km resolution for the periods 2030-2060 and 2061-2091. LUCC scenarios were designed based on nature-based solutions, landscape pattern influences, current national and international water conservation legislation, and extreme scenarios of non-preservation and conservation of native forests. The scenarios that demonstrate greater water availability, even under climate change, are those promoting the restoration of native forests in over 30% of the basins, even alongside agricultural activities. Current legislation promoting the restoration of native forests only in riparian zones (30-60 m or 200 m in steeper areas) will not be resilient enough to address future water shortages. Evapotranspiration, direct runoff, and water availability at basin outlets showed the greatest variations due to LUCC. The relationship between hydrological modeling and landscape configuration is an effective tool for establishing future territorial planning that prioritizes water resource protection.

Keywords: TETIS, landscape pattern, hydrological process, water availability, Chilean basins

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Authors: C. Silvestros, K. Mellou, T. Georgakopoulou, A. Koustenis, E. Kokkinou, C. Botsi, A. Terzidis

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'PHILOS – Emergency health response to refugee crisis' is a programme of the Greek Ministry of Health, implemented by the Hellenic Center for Disease Control and Prevention (HCDCP) funded by the Asylum, Migration and Integration Fund (AMIF) of EU’s DG Migration and Home Affairs. One of the main objectives of the program is the immunization coverage of the target – population to assure the prevention of vaccine-preventable diseases. The program foresees vaccination needs assessment of children hosted at camps at the mainland and implementation of interventions to cover the vaccination gaps in co-operation with the Ministry of Health. The National Immunization Advisory Committee in Greece recommended that MMR (Measles, Mumps, and Rubella), PCV (Pneumococcal conjugate vaccine) and HEXA (diphtheria, tetanus, pertussis, polio, hepatitis B and Haemophilus influenzae type b) vaccines should be performed in priority. Recording was completed at 24 camps (May - June 2017); 3381 children (0-18 years) were recorded. The median number of children hosted at each camp was 95 (range: 5-553). For 68% of the children, the WHO vaccination booklet was available. 44%, 48.5% and 61% of the children were vaccinated with at least one dose of PCV, HEXA, and MMR, respectively. The proportion of vaccinated children for the three vaccines mentioned above is significantly lower for the remaining doses; PCV (second dose 8%, third dose 1.3%), HEXA (second dose 13%, third dose 2.7%, forth dose 0.1%) and MMR (second dose 23%). None of the 37 (10 from Afghanistan, 3 from Bangladesh, 23 from Pakistan, 1 from Syria) recorded unaccompanied children did not have a WHO vaccination booklet and were considered unvaccinated. There is no differentiation in vaccination coverage among different ethnicities. Massive catch up vaccination was performed at 4 camps, and 671 vaccinations were performed (245 PCV, 307 HEXA, and 119 MMR). Similar interventions are planned for all camps of the country. Recording reveled gaps in vaccination coverage of the population, mainly because of the mobility of the population, the influx of refugees- which is still ongoing- and new births. Mass vaccination campaigns are considered vital in order to increase vaccination coverage, and continuous efforts are needed in order all children living at the camps to have full access to the National Childhood Immunization Program.

Keywords: vaccine preventable, refugee–migrants camps, vaccination coverage, PCV, MMR, HEXA

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Authors: Ramon Alberto Paredes Camacho, Li Lu

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Sustainable batteries are possible through the development of cheaper and greener alternatives whose most feasible option is epitomized by Sodium-Ion Batteries (SIB). Na₃V₂(PO₄)₂F₃ (NVPF) an important member of the Na-superionic-conductor (NASICON) materials, has recently been in the spotlight due to its interesting electrochemical properties when used as cathode namely, high specific capacity of 128 mA h g-¹, high energy density of 507 W h Kg-¹, increased working potential at which vanadium redox couples can be activated (with an average value around 3.9 V), and small volume variation of less than 2%. These traits grant NVPF an excellent perspective as a cathode material for the next generation of sodium batteries. Unfortunately, because of its low inherent electrical conductivity and a high energy barrier that impedes the mobilization of all the available Na ions per formula, the overall electrochemical performance suffers substantial degradation, finally obstructing its industrial use. Many approaches have been developed to remediate these issues where nanostructural design, carbon coating, and ion doping are the most effective ones. This investigation is focused on enhancing the electrochemical response of NVPF by doping metal ions in the crystal lattice, substituting vanadium atoms. A facile sol-gel process is employed, with citric acid as the chelator and the carbon source. The optimized conditions circumvent fluorine sublimation, ratifying the material’s purity. One of the reasons behind the large ionic improvement is the attraction of extra Na ions into the crystalline structure due to a charge imbalance produced by the valence of the doped ions (+2), which is lower than the one of vanadium (+3). Superior stability (higher than 90% at a current density of 20C) and capacity retention at an extremely high current density of 50C are demonstrated by our doped NVPF. This material continues to retain high capacity values at low and high temperatures. In addition, full cell NVPF//Hard Carbon shows capacity values and high stability at -20 and 60ºC. Our doping strategy proves to significantly increase the ionic and electronic conductivity of NVPF even at extreme conditions, delivering outstanding electrochemical performance and paving the way for advanced high-potential cathode materials.

Keywords: sodium-ion batteries, cathode materials, NASICON, Na3V2(PO4)2F3, Ion doping

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Authors: Engin Berber, Nurettin Canakoglu, Ibrahim Sozdutmaz, Merve Caliskan, Shaikh Terkis Islam Pavel, Hazel Yetiskin, Aykut Ozdarendeli

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Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus in the family Bunyaviridae, genus Nairovirus. The CCHFV genome consists of three molecules of negative-sense single-stranded RNA, each encapsulated separately. The virion particle contains viral RNA polymerase (L segment), surface glycoproteins Gn and Gc (Msegment), and a nucleocapsid protein NP (S segment). CCHF is characterized by high case mortality, occurring in Asia, Africa, the Middle East and Eastern Europe. Clinical CCHF was first recognized in Turkey in 2002. The numbers of CCHF cases have gradually increased in Turkey making the virus a public health concern. Between 2002 and 2014, more than 8000 the CCHF cases have been reported in Turkey and mortality rate is around 5%. So, Turkey is one of the countries where the epidemy has become spread to the wider geography and the biggest outbreaks of CCHF have occurred in the world. We have recently developed an inactivated cell-culture based vaccine against CCHF. We have showed that the Balb/c mice immunized with the CCHF vaccine induced the high level of neutralizing antibodies. In this study, we aimed to determine the immunodominant regions of nucleoprotein (NP) CCHFV Kelkit06 strain which stimulate T cells. For this purpose, pools of overlapping NP were used for an IFN- γ ELISPOT assay. Balb/c mice were divided into two groups for the experiment. Two groups (n = 10 each) were immunized via the intraperitoneal route with 5, or 10μg of the cell culture-based vaccine. The control group (n = 6) was mock immunized with PBS. Booster injections with the same formulation were given on days 21 and 42 after the first immunization. The higher reactivity against the CCHFV NP pools 31-40 and 80-90 was determined in the two dose groups. In order to analyze the vaccine-induced T cell responses in Balb/c mice immunized with varying doses of the vaccine, we have been also currently working on CD4+, CD8+ and CD3 + T cells by flow cytometry.

Keywords: Crimean-Congo hemorrhagic fever virus, immunodominant regions of NP, T cell response, vaccine

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Authors: Moumen Abdelhafidh, Stribu Bogdan, Laboureur Delphine, Gallant Johan, Hendrick Patrick

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This study is part of an ongoing effort to improve the understanding of phenomena occurring during the intermediate ballistic phase, such as muzzle flows. A thorough comprehension of muzzle flow fields is essential for optimizing muzzle device and projectile design. This flow characterization has heretofore been almost entirely limited to local and intrusive measurement techniques such as pressure measurements using pencil probes. Consequently, the body of quantitative experimental data is limited, so is the number of numerical codes validated in this field. The objective of the work presented here is to demonstrate the applicability of the Particle Image Velocimetry (PIV) technique in the challenging environment of the propellant flow of a .300 blackout weapon to provide accurate velocity measurements. The key points of a successful PIV measurement are the selection of the particle tracer, their seeding technique, and their tracking characteristics. We have experimentally investigated the aforementioned points by evaluating the resistance, gas dispersion, laser light reflection as well as the response to a step change across the Mach disk for five different solid tracers using two seeding methods. To this end, an experimental setup has been performed and consisted of a PIV system, the combustion chamber pressure measurement, classical high-speed schlieren visualization, and an aerosol spectrometer. The latter is used to determine the particle size distribution in the muzzle flow. The experimental results demonstrated the ability of PIV to accurately resolve the salient features of the propellant flow, such as the under the expanded jet and vortex rings, as well as the instantaneous velocity field with maximum centreline velocities of more than 1000 m/s. Besides, naturally present unburned particles in the gas and solid ZrO₂ particles with a nominal size of 100 nm, when coated on the propellant powder, are suitable as tracers. However, the TiO₂ particles intended to act as a tracer, surprisingly not only melted but also functioned as a combustion accelerator and decreased the number of particles in the propellant gas.

Keywords: intermediate ballistic, muzzle flow fields, particle image velocimetry, propellant gas, particle size distribution, under expanded jet, solid particle tracers

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Authors: Bhargav Baruah, Ali Shemsedin Reshad, Pankaj Tiwari

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This work presents a detailed study on the thermal degradation kinetics of co-pyrolysis of oil shale of Upper Assam, India with rubber seed shell, and lab-scale pyrolysis to investigate the influence of pyrolysis parameters on product yield and composition of products. The physicochemical characteristics of oil shale and rubber seed shell were studied by proximate analysis, elemental analysis, Fourier transform infrared spectroscopy and X-ray diffraction. The physicochemical study showed the mixture to be of low moisture, high ash, siliceous, sour with the presence of aliphatic, aromatic, and phenolic compounds. The thermal decomposition of the oil shale with rubber seed shell was studied using thermogravimetric analysis at heating rates of 5, 10, 20, 30, and 50 °C/min. The kinetic study of the oil shale pyrolysis process was performed on the thermogravimetric (TGA) data using three model-free isoconversional methods viz. Friedman, Flynn Wall Ozawa (FWO), and Kissinger Akahira Sunnose (KAS). The reaction mechanisms were determined using the Criado master plot. The understanding of the composition of Indian oil shale and rubber seed shell and pyrolysis process kinetics can help to establish the experimental parameters for the extraction of valuable products from the mixture. Response surface methodology (RSM) was employed usinf central composite design (CCD) model to setup the lab-scale experiment using TGA data, and optimization of process parameters viz. heating rate, temperature, and particle size. The samples were pre-dried at 115°C for 24 hours prior to pyrolysis. The pyrolysis temperatures were set from 450 to 650 °C, at heating rates of 2 to 20°C/min. The retention time was set between 2 to 8 hours. The optimum oil yield was observed at 5°C/min and 550°C with a retention time of 5 hours. The pyrolytic oil and gas obtained at optimum conditions were subjected to characterization using Fourier transform infrared spectroscopy (FT-IR) gas chromatography and mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR).

Keywords: Indian oil shale, rubber seed shell, co-pyrolysis, isoconversional methods, gas chromatography, nuclear magnetic resonance, Fourier transform infrared spectroscopy

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Authors: Chia Yu Chen, Shu Fen Wu, Chen-Fuh Lam, I-Ling Tsai, Shu Jiuan Chen, Yen Ling Liu

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Aim: It remains undetermined that whether increased work stress may affect the job satisfaction and career loyalty among nursing staffs in the operating room. The long-term goal of this study is to lengthen the professional life of operating room nurses by attenuating the work stress and enhancing their contentment in work. Method: This was a cross-sectional, descriptive study performed in a metropolitan teaching hospital in the southern Taiwan between May 2017 to July 2017. A structured self-administered questionnaire, modified from the Occupational Stress Indicator-2 (OSI-2) and Maslach Burnout Inventory (MBI) manual was collected from the operating room nurses. Chi-square test was used to analyze the categorical data and Pearson correlation was used to analyze the association between two numerical datasets (SPSS version 20.0). Results: The response rate was 80% (80/100) and a total of 73 (73%) completed forms were eventually proceeded for analysis. The average scores for work stress and job satisfaction of the operating room nurses were 145.96±32.91 and 47.38±6.07, respectively. The correlation coefficients of work stress versus job satisfaction and organizational identity were (r=-0.338, p=0.003 and r=-0.354, p=0.002), respectively. There were more nurses who took rotating shift quitted works from the operating room than those who took only dayshift (2＝5.176, p<0.05). Nurses who reported of having lower job satisfaction were associated with significantly higher turnover intention (t=3.714, p< 0.01). Following multivariate regression analysis, rotating shift and low job satisfaction were identified as the two independent predictors of intention to quit from working in the operating room. Conclusion: Our study clearly demonstrates that increased work stress significantly attenuates job satisfaction and organizational identity. Rotating shift is associated with higher work stress, lower job satisfaction, and higher turnover intention, which is consistent with the previous surveys carried out in the department of medical technology. Therefore, improvement of working quality in the operating rooms is essential to increase the retain intention of the well-trained nursing staffs. Further investigation into types of work shifts and other strategies of attenuating stress in workplace is currently undertaken in order to improve the job satisfaction and to decrease turnover intention in the operating room.

Keywords: rotating shift, work stress, job satisfaction, turnover intention

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Authors: Natalia Moreno-Castellanos, Amaia Rodriguez, Gema Frühbeck

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Introduction: In adipocytes, the cytoskeleton undergoes important expression and distribution in adipocytes rearrangements during adipogenesis and in obesity. Indeed, a role for these proteins in the regulation of adipocyte differentiation and response to insulin has been demonstrated. Recently, septins have been considered as new components of the cytoskeletal network that interact with other cytoskeletal elements (actin and tubulin) profoundly modifying their dynamics. However, these proteins have not been characterized as yet in adipose tissue. In this work, were examined the cellular, molecular and functional features of a member of this family, septin 11 (SEPT11), in adipocytes and evaluated the impact of obesity on the expression of this protein in human adipose tissue. Methods: Adipose gene and protein expression levels of SEPT11 were analysed in human samples. SEPT11 distribution was evaluated by immunocytochemistry, electronic microscopy, and subcellular fractionation techniques. GST-pull down, immunoprecipitation and a Yeast-Two Hybrid (Y2H) screening were used to identify the SEPT11 interactome. Gene silencing was employed to assess the role of SEPT11 in the regulation of insulin signaling and lipid metabolism in adipocytes. Results: SEPT11 is expressed in human adipocytes, and its levels increased in both omental and subcutaneous adipose tissue in obesity, with SEPT11 mRNA content positively correlating with parameters of insulin resistance in subcutaneous fat. In non-stimulated adipocytes, SEPT11 immunoreactivity showed a ring-like distribution at the cell surface and associated to caveolae. Biochemical analyses showed that SEPT11 interacted with the main component of caveolae, caveolin-1 (CAV1) as well as with the fatty acid-binding protein, FABP5. Notably, the three proteins redistributed and co-localized at the surface of lipid droplets upon exposure of adipocytes to oleate. In this line, SEPT11 silencing in 3T3-L1 adipocytes impaired insulin signaling and decreased insulin-induced lipogenesis. Conclusions: Those findings demonstrate that SEPT11 is a novel component of the adipocyte cytoskeleton that plays an important role in the regulation of lipid traffic, metabolism and can thus represent a potential biomarker of insulin resistance in obesity in adipocytes through its interaction with both CAV1 and FABP5.

Keywords: caveolae, lipid metabolism, obesity, septins

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Authors: Samira Mehrabi

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Geriatric depression is a common late-life mental health disorder that increases morbidity and mortality. It has been shown that exercise is effective in alleviating symptoms of geriatric depression. However, inconsistencies across studies and lack of optimal dose-response of exercise for improving geriatric depression have made it challenging to draw solid conclusions on the effectiveness of exercise in late-life depression. Purpose: To further investigate the moderators of the effectiveness of exercise on geriatric depression across the current body of evidence. Methods: Based on the Arksey and O’Malley framework, an extensive search strategy was performed by exploring PubMed, Scopus, Sport Discus, PsycInfo, ERIC, and IBSS without limitations in the time frame. Eight systematic reviews with empirical results that evaluated the effect of exercise on depression among people aged ≥ 60 years were identified and their individual studies were screened for inclusion. One additional study was found through the hand searching of reference lists. After full-text screening and applying inclusion and exclusion criteria, 21 studies were retained for inclusion. Results: The review revealed high variability in characteristics of the exercise interventions and outcome measures. Sample characteristics, nature of comparators, main outcome assessment, and baseline severity of depression also varied notably. Mind-body and aerobic exercises were found to significantly reduce geriatric depression. However, results on the relationship between resistance training and improvements in geriatric depression were inconsistent, and results of the intensity-related antidepressant effects of exercise interventions were mixed. Extensive use of self-reported questionnaires for the main outcome assessment and lack of evidence on the relationship between depression severity and observed effects were of the other important highlights of the review. Conclusion: Several literature gaps were found regarding the potential effect modifiers of exercise and geriatric depression. While acknowledging the complexity of establishing recommendations on the exercise variables and geriatric depression, future studies are required to understand the interplay and threshold effect of exercise for treating geriatric depression.

Keywords: exercise, geriatric depression, healthy aging, older adults, physical activity intervention, scoping review

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Authors: Selam M. Tefera

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Soil constitutes a crucial component of rural and urban environments. This fact is making role of heavy and trace elements in the soil system an issue of global concern. Heavy metals constitute an ill-defined group of inorganic chemical hazards, whose main source is anthropogenic activities mainly related to fabrications. This accumulation of heavy metals soils can prove toxic to the environment. The application of biochar to soil is one way of immobilizing these contaminants through sorption by exploiting the high surface area of this material among its other essential properties. This research examined the ability of sugar cane straw, an organic waste material from sugar farm, derived biochar and ash to remediate soil contaminated with heavy metals mainly Chromium and Zinc from the effluent of electroplating industry. Biochar was produced by varying the temperature from 300 °C to 500 °C and ash at 700 °C. The highest yield (50%) was obtained at the lowest temperature (300 °C). The proximate analysis showed ash content of 42.8%, ultimate analysis with carbon content of 67.18%, the Hydrogen to Carbon ratio of 0.54 and the results from FTIR analysis disclosed the organic nature of biochar. Methylene blue absorption indicated its fine surface area and pore structure, which increases with severity of temperature. Biochar was mixed with soil with at a ration varying from 4% w/w to 10% w/w of soil, and the response variables were determined at a time interval of 150 days, 180 days, and 210 days. As for ash (10% w/w), the characterization was performed at incubation time of 210 days. The results of pH indicated that biochar (9.24) had a notable liming capacity of acidic soil (4.8) by increasing it to 6.89 whereas ash increased it to 7.5. The immobilization capacity of biochar was found to effected mostly by the highest production temperature (500 °C), which was 75.5% for chromium and 80.5% for nickel. In addition, ash was shown to possess an outstanding immobilization capacity of 95.5% and 90.5% for Chromium and Nickel, respectively. All in all, the results from these methods showed that biochar produced from this specific biomass possesses the typical functional groups that enable it to store carbon, the appropriate pH that could remediate acidic soil, a fine amount of macro and micro nutrients that would aid plant growth.

Keywords: biochar, biomass, heavy metal immobalization, soil remediation

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Authors: Shreya Sirohi, Vineeta Sirohi

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In the 21st century, the nature of work has become quite complex and dynamic, and in response to this, the organizational culture continues to change and develop new perspectives. Organizational culture and leadership are important elements of any organization. Organization’s performance and success to a large extent, depend upon these two factors. The ability of a leader lies in confronting with the challenge of evolving and adapting the culture of the organization as per the situational demands. Leadership and organizational culture are conceptually intertwined. Leadership is a key ingredient for the successful transformation of any organization, and a favorable organizational culture helps to motivate the employees towards their work. Organizational culture and leadership style plays a crucial role in achieving the specified objectives of an organization. The harmony between culture and leader within organization undoubtedly affects relationships, processes, and employee performance. The present investigation aimed to study the Leadership style and Organisational Culture of private organizations and the relationship between the two. The study was carried out on a sample of 100 employees from five private organizations located in the cities of Gurgaon and Delhi in India. The data was collected by employing organisational culture profile and multifactor leadership questionnaire. The findings of the study indicate that the selected organizations had dominant transformation leadership style, whereas the organizational culture varied from one organization to another. However, technocratic culture was found to be prominent, followed by entrepreneurial organizational culture. A low positive correlation was found between leadership style and organizational culture. The transformational leaders have a positive and significant relationship with employee’s satisfaction, productivity, and organization’s culture. The leaders practicing transformational leadership style inspire their followers, are innovative and are aware of their needs as well as of their followers. Such leadership style has a positive impact both on employees and working culture. Employees of such organization are able to come up with innovative ideas and are efficient in handling situations and making effective decisions. However, low correlation is self indicative of the fact that a single leadership style or a single culture type alone cannot contribute solely towards the growth of an organization. There is a need to blend the culture types and leadership styles suiting the needs of the organization. Organisational culture represents the deeper values and beliefs of the employees and influences organizational performance; hence, the leader has a crucial role to play in creating and managing organizational culture in aligning to the requirements of the present era of competitiveness, globalization and technological advancement.

Keywords: leadership style, organizational culture, technocratic, transformational

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Authors: Anna Cameron, Chunxia Zhao, Haofei Wang, Yun Liu, Guang Ze Yang

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Since the first publication in 1775, cancer research has built a comprehensive understanding of how cellular components of the tumor niche promote disease development. However, only within the last decade has research begun to establish the impact of non-cellular components of the niche, particularly the extracellular matrix (ECM). The ECM, a three-dimensional scaffold that sustains the tumor microenvironment, plays a crucial role in disease progression. Cancer cells actively deregulate and remodel the ECM to establish a tumor-promoting environment. Recent work has highlighted the need to further our understanding of the complexity of this cancer-ECM relationship. In vitro models use hydrogels to mimic the ECM, as hydrogel matrices offer biological compatibility and stability needed for long term cell culture. However, natural hydrogels are being used in these models verbatim, without tuning their biophysical characteristics to achieve pathophysiological relevance, thus limiting their broad use within cancer research. The biophysical attributes of these gels dictate cancer cell proliferation, invasion, metastasis, and therapeutic response. Evaluating the three most widely used natural hydrogels, Matrigel, collagen, and agarose gel, the permeability, stiffness, and pore-size of each gel were measured and compared to the in vivo environment. The pore size of all three gels fell between 0.5-6 µm, which coincides with the 0.1-5 µm in vivo pore size found in the literature. However, the stiffness for hydrogels able to support cell culture ranged between 0.05 and 0.3 kPa, which falls outside the range of 0.3-20,000 kPa reported in the literature for an in vivo ECM. Permeability was ~100x greater than in vivo measurements, due in large part to the lack of cellular components which impede permeation. Though, these measurements prove important when assessing therapeutic particle delivery, as the ECM permeability decreased with increasing particle size, with 100 nm particles exhibiting a fifth of the permeability of 10 nm particles. This work explores ways of adjusting the biophysical characteristics of hydrogels by changing protein concentration and the trade-off, which occurs due to the interdependence of these factors. The global aim of this work is to produce a more pathophysiologically relevant model for each tumor type.

Keywords: cancer, extracellular matrix, hydrogel, microfluidic

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Authors: Colin David La Grange, Lisa Frost Ramsay

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Hydrogen sulphide (H2S) is a minor component of landfill gas, but significant in its distinct odorous quality and its association with landfill-related community complaints. The World Health Organisation (WHO) provides two guidelines for H2S: a health guideline at 150 µg/m3 on a 24-hour average, and a nuisance guideline at 7 µg/m3 on a 30-minute average. Albeit a practical distinction for impact assessment, this paper highlights the danger of the apparent dualism between nuisance and health impact, particularly when it is used to dismiss community concerns of perceived health impacts at low concentrations of H2S, as in the case of a community battle against the impacts of a landfill in Shongweni, KwaZulu-Natal, South Africa. Here community members reported, using a community developed mobile phone application, a range of health symptoms that coincided with, or occurred subsequent to, odour events and localised H2S peaks. Local doctors also documented increased visits for symptoms of respiratory distress, eye and skin irritation, and stress after such odour events. Objectively measured H2S and other pollutant concentrations during these events, however, remained below WHO health guidelines. This case study highlights the importance of the physiological link between the experience of environmental nuisance and overall health and wellbeing, showing these to be less distinct than the WHO guidelines would suggest. The potential mechanisms of impact of an odorous plume, with key constituents at concentrations below traditional health thresholds, on psychologically and/or physiologically sensitised individuals are described. In the case of psychological sensitisation, previously documented mechanisms such as aversive conditioning and odour-triggered panic are relevant. Physiological sensitisation to environmental pollutants, evident as a seemingly disproportionate physical (allergy-type) response to either low concentrations or a short duration exposure of a toxin or toxins, remains extensively examined but still not well understood. The links between a heightened sensitivity to toxic compounds, accumulation of some compounds in the body, and a pre-existing or associated immunological stress disorder are presented as a possible explanation.

Keywords: immunological stress disorder, landfill odour, odour nuisance, odour sensitisation, toxin accumulation

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Authors: Basma Yassa

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Evidence on cash transfers’ effectiveness in mitigating macro and idiosyncratic shocks’ impacts has been mixed and is mostly concentrated in Latin America, Sub-Saharan Africa, and South Asia with very limited evidence from the MENA region. Yet conditional cash transfers schemes have been continually used, especially in Egypt, as the main social protection tool in response to the recent socioeconomic crises and macro shocks. We use 2 panel datasets and 1 cross-sectional dataset to estimate the effectiveness of cash transfers as a shock-mitigative mechanism in the Egyptian context. In this paper, the results from the different models (Panel Fixed Effects model and the Regression Discontinuity Design (RDD) model) confirm that micro and macro shocks lead to significant decline in several household-level welfare outcomes and that Takaful cash transfers have a significant positive impact in mitigating the negative shock impacts, especially on households’ debt incidence, debt levels, and asset ownership, but not necessarily on food, and non-food expenditure levels. The results indicate large positive significant effects on decreasing household incidence of debt by up to 12.4 percent and lowered the debt size by approximately 18 percent among Takaful beneficiaries compared to non-beneficiaries’. Similar evidence is found on asset ownership levels, as the RDD model shows significant positive effects on total asset ownership and productive asset ownership, but the model failed to detect positive impacts on per capita food and non-food expenditures. Further extensions are still in progress to compare the models’ results with the DID model results when using a nationally representative ELMPS panel data (2018/2024) rounds. Finally, our initial analysis suggests that conditional cash transfers are effective in buffering the negative shock impacts on certain welfare indicators even after successive macro-economic shocks in 2022 and 2023 in the Egyptian Context.

Keywords: cash transfers, fixed effects, household welfare, household debt, micro shocks, regression discontinuity design

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Authors: Priyal Chikhaliwala, Sudeshna Chandra

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Liver cancer is one of the most common malignant tumors with poor prognosis. This is because liver cancer does not exhibit any symptoms in early stage of disease. Increased serum level of AFP is clinically considered as a diagnostic marker for liver malignancy. The present diagnostic modalities include various types of immunoassays, radiological studies, and biopsy. However, these tests undergo slow response times, require significant sample volumes, achieve limited sensitivity and ultimately become expensive and burdensome to patients. Considering all these aspects, electrochemical biosensors based on dendrimer-magnetic nanoparticles (MNPs) was designed. Dendrimers are novel nano-sized, three-dimensional molecules with monodispersed structures. Poly-amidoamine (PAMAM) dendrimers with eight –NH₂ groups using ethylenediamine as a core molecule were synthesized using Michael addition reaction. Dendrimers provide added the advantage of not only stabilizing Fe₃O₄ NPs but also displays capability of performing multiple electron redox events and binding multiple biological ligands to its dendritic end-surface. Fe₃O₄ NPs due to its superparamagnetic behavior can be exploited for magneto-separation process. Fe₃O₄ NPs were stabilized with PAMAM dendrimer by in situ co-precipitation method. The surface coating was examined by FT-IR, XRD, VSM, and TGA analysis. Electrochemical behavior and kinetic studies were evaluated using CV which revealed that the dendrimer-Fe₃O₄ NPs can be looked upon as electrochemically active materials. Electrochemical immunosensor was designed by immobilizing anti-AFP onto dendrimer-MNPs by gluteraldehyde conjugation reaction. The bioconjugates were then incubated with AFP antigen. The immunosensor was characterized electrochemically indicating successful immuno-binding events. The binding events were also further studied using magnetic particle imaging (MPI) which is a novel imaging modality in which Fe₃O₄ NPs are used as tracer molecules with positive contrast. Multicolor MPI was able to clearly localize AFP antigen and antibody and its binding successfully. Results demonstrate immense potential in terms of biosensing and enabling MPI of AFP in clinical diagnosis.

Keywords: alpha-fetoprotein, dendrimers, electrochemical biosensors, magnetic nanoparticles

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Authors: Sharmistha Chowdhury, Shuva Chowdhury

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Buying-selling new as well as second-hand goods like tools, furniture, household, electronics, clothing, baby stuff, vehicles, and hobbies through the Facebook marketplace has become a new paradigm for c2c sellers. This phenomenon encourages and empowers decentralised home-oriented sellers. This study adopts Elaboration Likelihood Model (ELM) to explain consumer behaviour on Facebook Marketplace (FM). ELM suggests that consumers process information through the central and peripheral routes, which eventually shape their attitudes towards posts. The central route focuses on information quality, and the peripheral route focuses on cues. Sellers’ FM posts usually include product features, prices, conditions, pictures, and pick-up location. This study uses information relevance and accuracy as central route factors. The post’s attractiveness represents cues and creates positive or negative associations with the product. A post with remarkable pictures increases the attractiveness of the post. So, post aesthetics is used as a peripheral route factor. People influenced via the central or peripheral route forms an attitude that includes multiple processes – response and purchase intention. People respond to FM posts through save, share and chat. Purchase intention reflects a positive image of the product and higher purchase intention. This study proposes trust on sellers as a moderator to test the strength of its influence on consumer attitudes and behaviour. Trust on sellers is assessed whether sellers have badges or not. A sample questionnaire will be developed and distributed among a group of random FM sellers who are selling vehicles on this platform to conduct the study. The chosen product of this study is the vehicle, a high-value purchase item. High-value purchase requires consumers to consider forming their attitude without any sign of impulsiveness seriously. Hence, vehicles are the perfect choice to test the strength of consumers attitudes and behaviour. The findings of the study add to the elaboration likelihood model and online second-hand marketplace literature.

Keywords: consumer behaviour, elaboration likelihood model, facebook marketplace, c2c marketing

Procedia PDF Downloads 138

Authors: Y. Landkocz, C. Lepers, P.J. Martin, B. Fougère, F. Roy Saint-Georges. A. Verdin, F. Cazier, F. Ledoux, D. Courcot, F. Sichel, P. Gosset, P. Shirali, S. Billet

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In 2013, the International Agency for Research on Cancer (IARC) classified air pollution and fine particles as carcinogenic to humans. Causal relationships exist between elevated ambient levels of airborne particles and increase of mortality and morbidity including pulmonary diseases, like lung cancer. However, due to a double complexity of both physicochemical Particulate Matter (PM) properties and tumor mechanistic processes, mechanisms of action remain not fully elucidated. Furthermore, because of several common properties between air pollution PM and tobacco smoke, like the same route of exposure and chemical composition, potential mechanisms of synergy could exist. Therefore, smoking could be an aggravating factor of the particles toxicity. In order to identify some mechanisms of action of particles according to their size, two samples of PM were collected: PM0.03 2.5 and PM0.33 2.5 in the urban-industrial area of Dunkerque. The overall cytotoxicity of the fine particles was determined on human bronchial cells (BEAS-2B). Toxicological study focused then on the metabolic activation of the organic compounds coated onto PM and some genetic and epigenetic changes induced on a co-culture model of BEAS-2B and alveolar macrophages isolated from bronchoalveolar lavages performed in smokers and non-smokers. The results showed (i) the contribution of the ultrafine fraction of atmospheric particles to genotoxic (eg. DNA double-strand breaks) and epigenetic mechanisms (eg. promoter methylation) involved in tumor processes, and (ii) the influence of smoking on the cellular response. Three main conclusions can be discussed. First, our results showed the ability of the particles to induce deleterious effects potentially involved in the stages of initiation and promotion of carcinogenesis. The second conclusion is that smoking affects the nature of the induced genotoxic effects. Finally, the in vitro developed cell model, using bronchial epithelial cells and alveolar macrophages can take into account quite realistically, some of the existing cell interactions existing in the lung.

Keywords: air pollution, fine and ultrafine particles, genotoxic and epigenetic alterations, smoking

Procedia PDF Downloads 347

Authors: Sergio D’Ambrosioa, Azza Dobousa, Chiara Schiraldia, Donatella Ciminib

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Probiotics are living microorganisms that give beneficial effects while consumed. Lactic acid bacteria and bifidobacteria are among the most representative strains assessed as probiotics and exploited as food supplements. Numerous studies demonstrated their potential as a therapeutic candidate for a variety of diseases (restoring gut flora, lowering cholesterol, immune response-enhancing, anti-inflammation and anti-oxidation activities). These beneficial actions are also due to biomolecules produced by probiotics, such as exopolysaccharides (EPSs), that demonstrate plenty of beneficial properties such as antimicrobial, antitumor, anti-biofilm, antiviral and immunomodulatory activities. Limosilactobacillus fermentum is a widely studied member of probiotics; however, few data are available on the development of fermentation and downstream processes for the production of viable biomasses for potential industrial applications. However, few data are available on the development of fermentation processes for the large-scale production of probiotics biomass for industrial applications and for purification processes of EPSs at an industrial scale. For this purpose, L. fermentum strain was isolated from buffalo milk and used as a test example for biotechnological process development. The strain was able to produce up to 109 CFU/mL on a (glucose-based) semi-defined medium deprived of animal-derived raw materials up to the pilot scale (150 L), demonstrating improved results compared to commonly used, although industrially not suitable, media-rich of casein and beef extract. Biomass concentration via microfiltration on hollow fibers, and subsequent spray-drying allowed to recover of about 5.7 × 1010CFU/gpowder of viable cells, indicating strain resistance to harsh processing conditions. Overall, these data demonstrate the possibility of obtaining and maintaining adequate levels of viable L. fermentum cells by using a simple approach that is potentially suitable for industrial development. A downstream EPS purification protocol based on ultrafiltration, precipitation and activated charcoal treatments showed a purity of the recovered polysaccharides of about 70-80%.

Keywords: probiotics, fermentation, exopolysaccharides (EPSs), purification

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Authors: Pedro Esteban

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Most installations nowadays are exposed to many power quality problems, and they also face numerous challenges to comply with grid code and energy efficiency requirements. The reason behind this is that they are not designed to support nonlinear, non-balanced, and variable loads and generators that make up a large percentage of modern electric power systems. These problems and challenges become especially critical when designing green buildings and smart cities. These problems and challenges are caused by equipment that can be typically found in these installations like variable speed drives (VSD), transformers, lighting, battery chargers, double-conversion UPS (uninterruptible power supply) systems, highly dynamic loads, single-phase loads, fossil fuel generators and renewable generation sources, to name a few. Moreover, events like capacitor switching (from existing capacitor banks or passive harmonic filters), auto-reclose operations of transmission and distribution lines, or the starting of large motors also contribute to these problems and challenges. Active power filters (APF) are one of the fastest-growing power electronics technologies for solving power quality problems and meeting grid code and energy efficiency requirements for a wide range of segments and applications. They are a high performance, flexible, compact, modular, and cost-effective type of power electronics solutions that provide an instantaneous and effective response in low or high voltage electric power systems. They enable longer equipment lifetime, higher process reliability, improved power system capacity and stability, and reduced energy losses, complying with most demanding power quality and energy efficiency standards and grid codes. There can be found several types of active power filters, including active harmonic filters (AHF), static var generators (SVG), active load balancers (ALB), hybrid var compensators (HVC), and low harmonic drives (LHD) nowadays. All these devices can be used in applications in Smart Cities bringing several technical and economic benefits.

Keywords: power quality improvement, energy efficiency, grid code compliance, green buildings, smart cities

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Authors: Obuzor Eze Obuzor, Ekpoke Okurube Sliver

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The study was carried out at Debee farms at Ahoada West Local Government area, Rivers State, Nigeria. To evaluate the impact of two different cost-effective available feed composition on growth performance of weaned piglets. Thirty weaned uncontrolled cross bred (Large white x pietrain) piglets of average initial weight of 3.04 Kg weaned at 30days were assigned to three dietary treatments, comprising three replicates of 10 weaned piglets each, piglets were kept at 7 °C in different pens with dimensions of 4.50 × 4.50 m. The design of the experiment was completely randomized design, data from the study were subjected to one-way analysis of variance (ANOVA) and significant means were separated using Duncan's Multiple Range Test using Statistical Analysis System (SAS) software for windows (2 0 0 3), statistical significance was assessed at P < 0.05 (95% confidence interval) while survival rate was calculated using simple percentage. A standard diet was prepared to meet the nutrient requirements of weaned piglets at (20.8% crude protein). The three diets were fed to the animals in concrete feeding trough, control diet (C) had soybean meal while first treatment had spent grain (T1) and the second treatment had wheat offal (T2) respectively. The experiment was partitioned into four weeks periods (days 1-7, 8-14, 15-21 and 22-28). Feed and water were given unrestrictedly throughout the period of the experiment. The feed intake and weights of the pigs were recorded on weekly basis. Feed conversion ratio and daily weight gain were calculated and the study lasted for four weeks. There was no significant (P>0.05) effect of diet on survival rate, final body weight, average daily weight gain, daily feed intake and feed conversion ratio. The overall performance showed that treatment one (T1) had survival rate (93%), improved daily weight gain (36.21 g), average daily feed intake (120.14 g) and had the best feed conversion ratio (0.29) similar high mean value with the control while treatment two (T2) had lowest and negative response to all parameters. It could be concluded that feed formulated with spent grain is cheaper than control (soybean meal) and also improved the growth performance of weaned piglets.

Keywords: piglets, weaning, feed conversions ratio, daily weight gain

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Authors: Jui-Teng Liao

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The selected-response (SR) format has been commonly adopted to assess academic reading in both formal and informal testing (i.e., standardized assessment and classroom assessment) because of its strengths in content validity, construct validity, as well as scoring objectivity and efficiency. When developing a second language (L2) reading test, researchers indicate that the longer the test (e.g., more test items) is, the higher reliability and validity the test is likely to produce. However, previous studies have not provided specific guidelines regarding the optimal length of a test or the most suitable number of test items or reading passages. Additionally, reading tests often include different question types (e.g., factual, vocabulary, inferential) that require varying degrees of reading comprehension and cognitive processes. Therefore, it is important to investigate the impact of question types on the number of items in relation to the score reliability of L2 reading tests. Given the popularity of the SR question format and its impact on assessment results on teaching and learning, it is necessary to investigate the degree to which such a question format can reliably measure learners’ L2 reading comprehension. The present study, therefore, adopted the generalizability (G) theory to investigate the score reliability of the SR format in L2 reading tests focusing on how many test items a reading test should include. Specifically, this study aimed to investigate the interaction between question types and the number of items, providing insights into the appropriate item count for different types of questions. G theory is a comprehensive statistical framework used for estimating the score reliability of tests and validating their results. Data were collected from 108 English as a second language student who completed an English reading test comprising factual, vocabulary, and inferential questions in the SR format. The computer program mGENOVA was utilized to analyze the data using multivariate designs (i.e., scenarios). Based on the results of G theory analyses, the findings indicated that the number of test items had a critical impact on the score reliability of an L2 reading test. Furthermore, the findings revealed that different types of reading questions required varying numbers of test items for reliable assessment of learners’ L2 reading proficiency. Further implications for teaching practice and classroom-based assessments are discussed.

Keywords: second language reading assessment, validity and reliability, Generalizability theory, Academic reading, Question format

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Authors: Md. Abdul Kader

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Several reports released by Global Financial Integrity (GFI) in recent times have identified Bangladesh as being among the worst affected countries to the scourge of money laundering (ML) and terrorist financing (TF). The money laundering (ML) and terrorist financing (TF) risks associated with conventional finance are generally well identified and understood by the relevant national authorities. There is, however, no common understanding of ML/TF risks associated with Islamic Banking. This paper attempts to examine the issues of money laundering (ML) and terrorist financing (TF) in Islamic Banks of Bangladesh. This study also investigates the risk factors associated with Islamic Banking system of Bangladesh that are favorable for ML and TF and which prevent the government to control such issues in the Islamic Banks of Bangladesh. Qualitative research methods were employed by studying various reports from journals, newspapers, bank reports and periodicals. In addition, five ex-bankers who were in the policy making bodies of three Islamic Banks were also interviewed. Findings suggest that government policies regarding Islamic Banking system in Bangladesh are not well defined and clear. Shariah law, that is the guiding principle of Islamic Banking, is not well recognized by the government policy makers, and thus they left the responsibility to the governing bodies of the banks. Other challenges that were found in the study are: the complexity of some Islamic banking products, the different forms of relationship between the banks and their clients, the inadequate ability and skill in the supervision of Islamic finance, particularly in jurisdictions, to evaluate their activities. All these risk factors paved the ground for ML and TF in the Islamic Banks of Bangladesh. However, due to unconventional nature of Banking and lack of investigative reporting on Islamic Banking, this study could not cover the whole picture of the ML/TF of Islamic Banks of Bangladesh. However, both qualitative documents and interviewees confirmed that Islamic Banking in Bangladesh could be branded as risky when it comes to money laundering and terror financing. This study recommends that the central bank authorities who supervise Islamic finance and the government policy makers should obtain a greater understanding of the specific ML/TF risks that may arise in Islamic Banks and develop a proper response. The study findings are expected to considerably impact Islamic banking management and policymakers to develop strong and appropriate policy to enhance transparency, accountability, and efficiency in banking sector. The regulatory bodies can consider the findings to disseminate anti money laundering and terror financing related rules and regulations.

Keywords: money laundering, terror financing, islamic banking, bangladesh

Procedia PDF Downloads 94