Microwave-assisted rapid synthesis of alumina nanoparticles using tea,coffee and triphala extracts

Alumina nanoparticles （A1NP） were synthe- sized from aluminium nitrate using extracts of tea, coffee and triphala--a well known herbal plant as well as a non- toxic and eco--friendly green material. The synthesis was carried out taking 1：4 ratio of metal salt and these extracts under microwave irradiations at 540 W, which gave better yield of nanoparticles. Water was taken as solvent medium. The formations of A1NP were initially monitored by the colour changes occurring in the reaction mixture during the incubation period. As synthesized nanoparticles were characterized by scanning electron microscope （SEM）, UV-Visible （UV-Vis） spectroscopy and Fourier transform infrared spectroscopy （FTIR）. The A1NP were found to be spherical in shape in case of tea and coffee extracts with a size of 50-200 nm and to be oval shaped in case of triphala extract with an average size of 200-400 nm. The formation of A1NP with the microwave-assistance using these plant extracts has proved to be very faster than any other methods. In addition, excellent reproducibility of these nanoparticles, without the use of any additional capping agent or stabilizer will have great advantages in compari- son with microbial synthesis, avoiding all the tedious and hygienic complications.     

Dual flow immunochromatographic assay for rapid and simultaneous quantitative detection of ochratoxin A and zearalenone in corn,wheat, and feed samples

A one-step dual flow immunochromatographic assay (DICGA), based on a competitive format, was developed for simultaneous quantification of ochratoxin A (OTA) and zearalenone (ZEN) in corn, wheat, and feed samples. The limit of detection for OTA was 0.32 ng/ml with a detection range of 0.53?12.16 ng/ml, while for ZEN it was 0.58 ng/ml with a detection range of 1.06?39.72 ng/ml. The recovery rates in corn, wheat, and feed samples ranged from 77.3% to 106.3% with the coefficient of variation lower than 15%. Naturally contaminated corn, wheat, and feed samples were analyzed using both DICGA and liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the correlation between the two methods was evaluated using a regression analysis. The DICGA method shows great potential for simple, rapid, sensitive, and cost-effective quantitative detection of OTA and ZEN in food safety control.     

Enumeration of lymphocyte subsets using flow cytometry: Effect of storage before and after staining in a developing country setting

Lymphocyte subset estimations by flow cytometry in population-based studies require transportation of samples from the field site to the laboratory. As samples arrive late in the day they have to wait overnight before being processed. The effect of two possible approaches, sample storage for 24 h before staining and immediate staining with analysis after 24 h and 48 h were evaluated. Two sets of experiments were performed with EDTA (ethylenediamine tetra-acetate) anticoagulated peripheral blood. In the first experiment, after collection, each sample was divided into two portions. One portion was stained at the time of blood collection and the other 24 h later after keeping it at room temperature (38–45°C). In the second experiment, blood samples were stained within 1–2 h. Each sample was analyzed immediately upon completion of staining process and subsequently after 24 h and 48 h of storage at 4°C. Results suggest that blood collected in EDTA can be processed using whole blood lysis method, after storage at room temperature (38–45°C) for 24 h with some but not significant alteration in T-cell subsets. Storage at 4°C after staining for 24 h results in a lesser and insignificant loss of cells or alteration of T-cell subsets and may be the method of choice.     

Science teachers accelerated programme model: a joint partnership in the Pacific region

The paper heralds a new pedagogical model known as the Science Teachers Accelerated Programme as a platform to upgrade the qualifications of secondary school science teachers throughout the Pacific region. Based on a tripartite partnership between a higher education provider, a regional government and a cohort of science teachers, the model offers an accelerated Bachelor’s degree programme to the cohort. Using this tripartite partnership model, a pilot of the Science Teachers Accelerated Programme is underway between the University of the South Pacific, the Government of Samoa and a cohort of science teachers in Samoa. The underpinning activities garnering social and academic integration are highlighted with analytics. The strengths, challenges and opportunities of the new, cohort-taught science model are presented with relevant diagnoses, interventions and adaptive works carried out in the first half of the delivery plan. While the Government of Samoa is considering the implementation of a second cycle, the University of the South Pacific is considering extending the model to other regional countries.     

Biochemical Profile of Nonalcoholic Fatty Liver Disease Patients in Eastern India with Histopathological Correlation

Aminotransferase assay is often used as a screening test as well as an endpoint for resolution of disease in nonalcoholic fatty liver disease (NAFLD). Aim of the study was to evaluate the relationship of transaminase level with metabolic variables and histology in NAFLD. Single center observational study was conducted in a gastroenterology clinic at Cuttack in coastal Odisha. Subjects were consecutive patients presenting with functional bowel disease and undergoing abdominal sonography. All participants were evaluated for the presence of metabolic syndrome (MS), insulin resistance, liver function test and lipid profile. Various parameters were compared between NAFLD subjects and controls. 53.5 % of NAFLD had normal serum transaminases, whereas 20.8 % of healthy controls had transaminitis. NAFLD patients had significantly higher BMI, fasting plasma glucose, serum transaminases, serum triglycerides, serum insulin and homeostatic model assessment (HOMA) IR than controls. NAFLD patients who had transaminitis had significantly higher incidence of MS and higher mean HOMA IR than those without. There was no significant difference in histopathological features between NAFLD with and without transaminitis. To conclude, over half of NAFLD subjects do not have transaminitis while transaminitis is present in a fifth of healthy people without fatty liver. Hence serum transaminase should not be used as screening test for NAFLD. NAFLD patients with transaminitis had a higher incidence of MS and insulin resistance than those without. However, there was no significant difference in histopathological features between these two groups.     

Exploring Elementary Pre-service Teachers’ Beliefs About Science Teaching and Learning as Revealed in Their Metaphor Writing

This study examined elementary preservice teachers’ beliefs about the role/image of a science teacher and science teaching and how these beliefs change during an elementary science methods course; this examination was conducted through an analysis of their metaphor writing. Data included personal metaphors and rationale papers for supporting them collected from 106 participants at the start and end of the semester. Data were analyzed using the constant comparative method and also quantified for statistical analysis. Results indicate that most participants came to the course with traditional views and developed more constructivist views during the course. However, they tended to keep their traditional views and added new constructivist perspectives into their original belief systems. This study suggests that metaphor writing can be used as both a reflection tool for preservice teachers to clarify and refine their beliefs about science teaching and learning and a diagnostic assessment tool for teacher educators to understand their students for tailoring a methods course accordingly.     

Infant Attachment Insecurity and Baseline Physiological Activity and Physiological Reactivity to Interpersonal Stress: A Meta-Analytic Review

This meta-analytic review (k = 5–10; N = 258–895) examined links between attachment insecurity and physiological activity at baseline and in response to interpersonal stress elicited by separation–reunion procedures in the early life course (1–5 years). Insecurity was trivially, nonsignificantly associated with baseline physiological activity (heart rate [HR]: g = −.06; respiratory sinus arrhythmia [RSA]: g = −.06; cortisol: g = .01) and nonsignificantly associated with physiological reactivity to separation from parents (HR: g = −.001; RSA: g = .24). However, insecurity was moderately associated with heightened RSA (g = .26) and cortisol (g = .27) reactivity upon reunion with parents. Findings provide insight into the biobehavioral organization of attachment, suggesting that early insecurity is associated with heightened physiological reactivity to interpersonal stress.     

Notable and Emerging Variants of SARS-CoV-2 Virus: A Quick Glance

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the etiological agent of coronavirus disease-2019 (COVID-19), is a highly contagious pathogenic coronavirus to emerge and spread in human populations. Although substantial exertions have been laid to avert spread of COVID-19 by therapeutic and preventive countermeasures, but emergence of SARS-CoV-2 variants as a result of mutations make the infection more ominous. New viral confers a higher nasopharyngeal viral load, increased viral transmissibility, higher infectiousness, immune escape, increased resistance to monoclonal/polyclonal antibodies from convalescence sera/vaccine, and an enhanced virulence. Thus, it is pertinent to monitor evolving mutations and genetic diversity of SARS-CoV-2 as it is decisive for understanding the viral variants. In this review we provide an overview of colloquial nomenclature and the genetic characteristics of different SARS-CoV-2 variants in the context of mutational changes of the circulating strains, transmissibility potential, virulence and infectivity.     

Knowledge complementarity and knowledge exchange in supply channel relationships

Existing literature on knowledge exchange in inter-organizational relationships (e.g., a supply channel) reveals two opposing forces at work: (1) collaborative behavior and (2) opportunistic behavior. A concurrent assessment of the opposing perspectives and the contingencies under which each is relevant for supply channel performance can add valuable insights about the dynamics of knowledge exchange. We juxtapose the two behavior patterns using social capital theory and transaction cost economics (TCE) respectively as the explicators and employ knowledge complementarity as the contingency to reconcile the opposing behavior patterns. The choice of knowledge complementarity in this role stems from ample theoretical and empirical support in prior literature about the criticality of this factor in inter-firm knowledge exchange.