320 research outputs found

    The perception of COVID-19 and avoidance behavior in Turkey: the role of income level, gender and education

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    Purpose This study aims to reveal both the effect of the perception of COVID-19 on avoidance behaviors and the mediating role of the perception of personal control in this relationship. COVID-19 emerged in December 2019 and since then, it has spread globally in a short period and has affected people socially, economically and culturally. Design/methodology/approach The data for the research was collected from 418 participants during COVID-19, through online questionnaires. The obtained data were analyzed through AMOS and SPSS software using structural equation modeling. Findings The research results show that some perceptions of COVID-19 affect avoidance behavior and that personal control has a mediating role. It has also been found that gender plays a moderating role in the relationship between COVID-19 and avoidance behavior. It has been found that women are especially more sensitive compared to men in perceiving COVID-19. This study also found that perception of COVID-19 changes depending on income. Practical implications After the pandemic is over, people will get in contact with each other less than before, and trade will change accordingly. People will avoid shopping in crowded places, and consumer behaviors will undergo different changes. All of these results considered, it is expected that avoidance behavior will cause some permanent behavioral changes in consumers. Originality/value The study answers the critical question about the effect of the perception of COVID-19 on avoidance behavior. Furthermore, the role of income level, gender and education in this relationship will be highlighted

    Nonlinear computations of heave motions for a generic Wave Energy Converter

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    A bench-marking activity of numerical methods for analysis of Wave Energy Converters (WEC) was proposed under the Ocean Energy Systems (OES) International Energy Agency (IEA) Task 10 in 2015. The purpose of the benchmark is to do a code-2-code comparison of the predicted motions and power take out for a WEC. A heaving sphere was used as a first simple test case. The participants sim- ulated heave decay and regular and irregular wave cases. The numerical methods ranged from linear methods to viscous methods solving the Navier-Stokes equa- tions (CFD). An overview of the results from the first phase of the benchmark was reported in [1]. The present paper focus on the simulations of the sphere using one fully nonlinear time-domain BEM one transient RANS method and one transient Direct FE method with no turbulence model. The theory of the three methods as well as the modeling of the sphere are described. Heave decay and heave motions for steep regular waves were selected as test cases in order to study and compare the capability to handle nonlinear effects. Computational efficiency and applicability of the three methods are also discussed

    Operando potassium K-edge X-ray absorption spectroscopy: investigating potassium catalysts during soot oxidation.

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    The chemical and structural nature of potassium compounds involved in catalytic soot oxidation have been studied by a combination of temperature programmed oxidation and operando potassium K-edge X-ray absorption spectroscopy experiments. These experiments are the first known operando studies using tender X-rays (āˆ¼3.6 keV) under high temperature oxidation reaction conditions. X-ray absorption near edge structure analysis of K2CO3/Al2O3 catalysts during heating shows that, at temperatures between 100 and 200 Ā°C, potassium species undergo a structural change from an initial hydrated K2CO3Ā·xH2O and KHCO3 mixture to well-defined K2CO3. As the catalyst is heated from 200 Ā°C to 600 Ā°C, a feature associated with multiple scattering shifts to lower energy, indicating increased K2CO3 dispersion, due to its mobility at high reaction temperature. This shift was noted to be greater in samples containing soot than in control experiments without soot and can be attributed to enhanced mobility of the K2CO3, due to the interaction between soot and potassium species. No potassium species except K2CO3 could be defined during reactions, which excludes a potential reaction mechanism in which carbonate ions are the active soot-oxidising species. Simulations of K-edge absorption near edge structures were performed to rationalise the observed changes seen. Findings showed that cluster size, unit cell distortions and variation in the distribution of potassium crystallographic sites influenced the simulated spectra of K2CO3. While further simulation studies are required for a more complete understanding, the current results support the hypothesis that changes in the local structure on dispersion can influence the observed spectra. Ex situ characterisation was carried out on the fresh and used catalyst, by X-ray diffraction and X-ray photoelectron spectroscopy, which indicated changes to the carbonate species, in line with the X-ray absorption spectroscopy experiments

    Processing of agricultural apple fruit waste into sugar rich feedstocks for the catalytic production of 5-HMF over a Sn Amberlyst-15 resin catalyst

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    In this study we considered processes of treatment of agricultural apple waste which is normally discarded. We show the effect of various pre-treatment procedures on the final catalytic performance to produce 5-HMF from this real world biomass waste. Our study of the various potential pre-treatment steps, and their effect on the catalytic performance, provides valuable new insights which can be used for the development of new processes for the localised small scale valorization of agricultural fruit waste. The apple waste is aimed to be converted into a sugar rich feedstock stream for the catalytic conversion to 5-hydroxymethyl furfural (5-HMF) at low temperatures (āˆ¼120 Ā°C). Filters with varying pore sizes were studied for the filtration of apple pomace after milling the rotten apples in order to reduce the solids content. The tested filters varied in pore sizes of 0.2 Ī¼m, 2 Ī¼m and 54 Ī¼m. The effect of heating, acid or base treatment of the apple slurry was evaluated for increasing the speed of filtration. The highest flow rate was obtained for the filter with 54 Ī¼m pores. The sugar rich filtrates were investigated in the catalytic conversion to 5-HMF over an easy-to-manufacture Sn exchanged resin (Amberlyst-15) catalyst. Results showed that filtrates obtained over a 2 Ī¼m filter lead to the highest 5-HMF yields (18 %) without extra additives. Adjustment of the reaction mixtures to pH 7 resulted in a lower catalytic activity. 5-HMF is proposed to be extracted from the aqueous layer by using an organic liquid layer (methyl isobutyl ketone, MIBK). In order to increase the diffusion of 5-HMF to the MIBK layer the addition of salts to the reaction mixture was investigated. This leads to lower catalytic activity, possibly due to catalyst deactivation. Our results showed that a relatively wide pore filter (54 Ī¼m) provides the fastest apple processing method and a filtrate reacting to the highest 5-HMF yield in catalytic conversion of the sugar rich product stream obtained from agricultural waste apples

    Complex regional pain syndrome type I: efficacy of stellate ganglion blockade

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    PubMed ID: 19888550Background: This study was performed to evaluate the treatment of complex regional pain syndrome (CRPS) type I with stellate ganglion blockade. Materials and methods: We performed three blockades at weekly intervals in 22 patients with CRPS type I in one hand. The patients were divided into two groups depending on the time between symptom onset and treatment initiation. Group 1and 2 patients had short and long symptom-onset-to-treatment intervals, respectively. Pain intensity, using a visual analog score (VAS), and range of motion (ROM) for the wrist joint were assessed before and 2 weeks after treatment and were compared using nonparametric statistical analysis. Results: Treatment produced a statistically significant difference in wrist ROM for all patients (P < 0.001). VAS values showed an overall decrease from 8 Ā± 1 to 1 Ā± 1 following treatment, and there was a significant difference in VAS value between groups 1 and 2 (P < 0.05). Conclusions: We concluded that stellate ganglion blockade successfully decreased VAS and increased ROM of wrist joints in patients with CRPS type I. Further, the duration between symptom onset and therapy initiation was a major factor affecting blockade success. Ā© 2009 Springer-Verlag

    Concern for information privacy:a cross-nation study of the United Kingdom and South Africa

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    Individuals have differing levels of information privacy concern, formed by their expectations and the confidence they have that organisations meet this in practice. Variance in privacy laws and national factors may also play a role. This study analyses individualsā€™ information privacy expectation and confidence across two nations, the United Kingdom and South Africa, through a survey of 1463 respondents. The findings indicate that the expectation for privacy in both countries are very high. However, numerous significant differences exist between expectations and confidence when examining privacy principles. The overall results for both countries show that there is a gap in terms of the privacy expectations of respondents compared to the confidence they have in whether organisations are meeting their expectations. Governments, regulators, and organisations with an online presence need to consider individualsā€™ expectations and ensure that controls that meet regulatory requirements, as well as expectations, are in place

    Ex vivo modelling of drug efficacy in a rare metastatic urachal carcinoma

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    Background Ex vivo drug screening refers to the out-of-body assessment of drug efficacy in patient derived vital tumor cells. The purpose of these methods is to enable functional testing of patient specific efficacy of anti-cancer therapeutics and personalized treatment strategies. Such approaches could prove powerful especially in context of rare cancers for which demonstration of novel therapies is difficult due to the low numbers of patients. Here, we report comparison of different ex vivo drug screening methods in a metastatic urachal adenocarcinoma, a rare and aggressive non-urothelial bladder malignancy that arises from the remnant embryologic urachus in adults. Methods To compare the feasibility and results obtained with alternative ex vivo drug screening techniques, we used three different approaches; enzymatic cell viability assay of 2D cell cultures and image-based cytometry of 2D and 3D cell cultures in parallel. Vital tumor cells isolated from a biopsy obtained in context of a surgical debulking procedure were used for screening of 1160 drugs with the aim to evaluate patterns of efficacy in the urachal cancer cells. Results Dose response data from the enzymatic cell viability assay and the image-based assay of 2D cell cultures showed the best consistency. With 3D cell culture conditions, the proliferation rate of the tumor cells was slower and potency of several drugs was reduced even following growth rate normalization of the responses. MEK, mTOR, and MET inhibitors were identified as the most cytotoxic targeted drugs. Secondary validation analyses confirmed the efficacy of these drugs also with the new human urachal adenocarcinoma cell line (MISB18) established from the patientā€™s tumor. Conclusions All the tested ex vivo drug screening methods captured the patientā€™s tumor cellsā€™ sensitivity to drugs that could be associated with the oncogenic KRASG12V mutation found in the patientā€™s tumor cells. Specific drug classes however resulted in differential dose response profiles dependent on the used cell culture method indicating that the choice of assay could bias results from ex vivo drug screening assays for selected drug classes
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