Preparation and Properties of Chitosan–PVA Fibers Produced by Wet Spinning

Chitosan fibers were prepared by wet spinning in three stages. Initially, a polymer solution of chitosan and polyvinyl alcohol (PVA) was solidified in a mixture of potassium hydroxide and ethanol. The polymers were then crosslinked with sodium tripolyphosphate (TPP) or glutaraldehyde, and finally dried in methanol or acetone. The effect of these conditions was evaluated based on scanning electron microscopy images, water-holding capacity, and swelling and mechanical properties. The miscibility of the mixture was evaluated using Fourier Transform Infrared spectroscopy and differential scanning calorimetry. The results obtained showed that chitosan fibers containing 45% (v/v) PVA and crosslinked using TPP have properties similar to those of commercial sutures prepared using other biomaterials.     

Do national levels of individualism and internal locus of control relate to well‐being: an ecological level international study

Data were collected from managers in 24 nations/territories on work locus of control (LOC), individualism–collectivism (I–C), and well‐being (job satisfaction, absence of psychological strain, and absence of physical strain). There were significant mean differences across samples on all five of these measures, and consistent with our hypothesis, at the ecological or sample mean level well‐being was associated with an internal locus of control. However, contrary to our hypothesis, well‐being was not associated with I–C, despite a strong correlation between I–C and LOC. Findings at the ecological level were consistent with the literature concerning the salutary effects of control on well‐being. Copyright © 2001 John Wiley & Sons, Ltd.     

Job stress,incivility, and counterproductive work behavior (CWB): the moderating role of negative affectivity

The current study was designed to replicate findings from previous research regarding the relationships between job stressors, negative affectivity, and counterproductive work behavior (CWB) using peer‐reported data and to assess the effects of workplace incivility on employee satisfaction and CWB. Results indicate that incivility, organizational constraints, and interpersonal conflict were negatively related to job satisfaction and positively related to CWB. Support was also found for the role of negative affectivity as a moderator of the relationship between job stressors and CWB, although only one significant moderator was found using peer‐reported CWB. In general, the relationships between job stressors and CWB were stronger for individuals high in negative affectivity than for individuals low in negative affectivity. Copyright © 2005 John Wiley & Sons, Ltd.     

Cross‐national job stress: a quantitative and qualitative study

Using both quantitative and qualitative methods, this study contrasted employees' job stress perceptions and their relationships to strains in China and the United States. Significant job stressor–strain correlations were found in both countries. However, hierarchical regression analyses revealed significant interactions of country by job stressors in predicting job strains, indicating the unique patterns of stressor–strain relationships in China and the United States. In the qualitative analyses, American employees reported significantly more incidents of lack of job control, direct interpersonal conflict, lack of team coordination, anger, frustration, feeling overwhelmed, and stomach problems than the Chinese. Chinese employees reported significantly more incidents of job evaluations, work mistakes, indirect conflict, employment conditions, lack of training, anxiety, helplessness, sleep problems, and feeling hot than the Americans. The qualitative approach contributed above and beyond the quantitative results in that it revealed culture‐specific job stressors of job evaluations, work mistakes, and indirect conflict that had been overlooked in western‐based stress research. Copyright © 2007 John Wiley & Sons, Ltd.     

Long-term influence of tillage and fertilization on net carbon dioxide exchange rate on two soils with different textures

The importance of agricultural practices to greenhouse gas mitigation is examined worldwide. However, there is no consensus on soil organic carbon (SOC) content and CO emissions as affected by soil management practices and their relationships with soil texture. No-till (NT) agriculture often results in soil C gain, though, not always. Soil net CO exchange rate (NCER) and environmental factors (SOC, soil temperature [T], and water content [W]), as affected by soil type (loam and sandy loam), tillage (conventional, reduced, and NT), and fertilization, were quantified in long-term field experiments in Lithuania. Soil tillage and fertilization affected total CO flux (heterotrophic and autotrophic) through effect on soil SOC sequestration, water, and temperature regime. After 11 yr of different tillage and fertilization management, SOC content was 23% more in loam than in sandy loam. Long-term NT contributed to 7 to 27% more SOC sequestration on loam and to 29 to 33% more on sandy loam compared with reduced tillage (RT) or conventional tillage (CT). Soil water content in loam was 7% more than in sandy loam. Soil gravimetric water content, averaged across measurement dates and fertilization treatments, was significantly less in NT than CT and RT in both soils. Soil organic carbon content and water storage capacity of the loam and sandy loam soils exerted different influences on NCER. The NCER from the sandy loam soil was 13% greater than that from the loam. In addition, NCER was 4 to 9% less with NT than with CT and RT systems on both loam and sandy loam soils. Application of mineral NPK fertilizers promoted significantly greater NCER from loam but suppressed NCER by 15% from sandy loam.     

Statistical control in correlational studies: 10 essential recommendations for organizational researchers

Statistical control is widely used in correlational studies with the intent of providing more accurate estimates of relationships among variables, more conservative tests of hypotheses, or ruling out alternative explanations for empirical findings. However, the use of control variables can produce uninterpretable parameter estimates, erroneous inferences, irreplicable results, and other barriers to scientific progress. As a result, methodologists have provided a great deal of advice regarding the use of statistical control, to the point that researchers might have difficulties sifting through and prioritizing the available suggestions. We integrate and condense this literature into a set of 10 essential recommendations that are generally applicable and which, if followed, would substantially enhance the quality of published organizational research. We provide explanations, qualifications, and examples following each recommendation. Copyright © 2015 John Wiley & Sons, Ltd.     

Topiramate potential neurotoxicity and mitigating role of ginger oil in mice brain

Environmental Science and Pollution Research - Topiramate has multiple pharmacological mechanisms that are efficient in treating epilepsy and migraine. Ginger has been established to have gingerols...