Predictors of Adolescents’ Interest in Stem Majors and Careers

Advanced Research Winner 2019: The United States currently faces a shortage of qualified workers in fields related to science, technology, engineering, and math (STEM). The first critical step in preventing the labor shortage in STEM is understanding the factors that guide adolescents toward STEM pursuits. Drawing on Eccles’ expectancy-value theory (EVT), the current study aims to identify factors that are relevant to adolescents’ interest in STEM majors and careers. Data were collected from 629 adolescents (Mage = 16.09). Participants attended a high school in northern California and predominantly identified as Asian American (82% of the sample). Preliminary analyses revealed that adolescent boys had higher STEM self-expectancies than did adolescent girls, whereas there was no gender difference in STEM values. Consistent with expectations, multiple regression demonstrated that STEM self-expectancies and values accounted for a significant amount of variance in participants’ interest in STEM majors and careers. STEM value was an especially strong predictor; adolescents tended to be most interested in STEM pursuits when they were also high in STEM value. Moderation analyses showed that the association between STEM value and interest in STEM majors and careers was stronger for girls than for boys. As a whole, this study’s findings suggest that valuing and enjoying STEM pursuits during high school could be an important antecedent of pursuing a STEM major and a STEM career later in life

The half-lives of biological activity of some pesticides in water

In the absence of analytical methods, the half-lives of biological activity of pesticides can be estimated by bioassays. To determine the half-lives of biological acivity of pesticides to fish, static bioassays were conducted in the laboratory with ten different formulations of pesticides using Labeo rohita as a bio-indicator. The half-lives of biological activity for ten different pesticides in soft water at pH 7.5 and 27°C, ranged from 4.6 days to 11.8 days. The half-life of biological activity of Sumithion 50% EC was only 4.6 days. In contrast, Dimecron 50% EC degraded very slowly and its half-life of biological activity on L. rohita was about 11.8 days. Sumithion 50% EC, Padan 50% SP, EPN 45% EC, Diazinon 40% EC and Diazinon 10 G degraded in less than five to seven days indicating that these pesticides are desirable for rice-fish culture. Contamination by pesticides with long-term residual toxicity in waters may eventually cause high levels of fish mortality

An Alternative Electrode System for Monitoring Belousov-Zhabotinsky Chemical Oscillations

The capability of copper-platinum (Cu/Pt) electrode system as a BelousovZhabotinsky (BZ) chemical oscillation monitor was compared with that of the normally used SCE/Pt electrode system, by testing it on three BZ systems, which were obtained by varying the oscillator in the combination bromate, oscillator and malonic acid. The oscillators, used separately, were cerium(IV), manganese(II) and ferroin [iron (II)-1,10- phenanthroline complex].Cu/Pt electrode gave essentially identical values of oscillation characteristics (oscillation period, peak potential, induction period, peak width) except peak potentials. This indicated that the Cu/Pt electrode system would be more useful than the SCE/Pt electrode system (which had chloride leakage problem), in electrical applications of chemical oscillations, such as electrical switches, which would depend only on the on/off frequency

A Potential Model for Chemical Oscillations

Oscillation characteristics: induction period, oscillation period, peak potential, and total oscillation time of Belousov-Zhabotinsky systems, which consisted of bromate - oscillator [Ce4+ or Mn2+ or ferroin] - malonic acid were deter- mined using SCE/Pt and Cu/Pt electrodes. The solution potential requirements for appearance of chemical oscillations were determined by finding the concentra- tion limits of the reactants, bromate and malonic acid, and measuring the corres-ponding solution reduction potentials. A chemical oscillation model was proposed

Study on Wing Venations of Some Papilionid Butterfly Species from Meiktila University Campus

The study on wing venations of some papilionid butterfly species from Meiktila University campus was conducted during November 2013 to February 2014 and resulted in the identification of 2 genera, 3 species, namely Papilio demoleus malayanus, Papilio polytes romulus (male and female) and Graphium agamemnon agamemnon. Differences observed among the respective wing venations were described and discussed

Effect of non-esterified fatty acids on insulin resistance and cardiovascular risk in polycystic ovary syndrome

Introduction: Insulin resistance (IR) and obesity coexist in polycystic ovary syndrome (PCOS) and contribute to increased risk of diabetes and cardiovascular disease. An intrinsic insulin signalling defect is present in skeletal muscle of PCOS and it affects insulin mediated glucose transport in the presence of lipid in vitro studies.Methods: The effect of non-esterified fatty acids (NEFA) on IR, postprandial lipids and cardiovascular risk in obese women with PCOS compared to controls was examined by lowering NEFA levels with acute overnight acipimox and chronic 12 week tredaptive therapy. Additional studies included elevating NEFA by lipid infusions and improving NEFA metabolism by moderate intensity exercise.Results: Effective lowering of NEFA with overnight acipimox therapy improved fasting and postprandial IR in PCOS. It enhanced chylomicron clearance with reduced overnight VLDL production. A rebound rise in NEFA following chronic tredaptive therapy worsened fasting and postprandial IR. However, despite this, tredaptive had the counterintuitive effect of lowering fasting and postprandial triglycerides without effecting endothelial function and hsCRP.PCOS women were found to be less tolerant to acutely induced lipaemia than controls with an exaggerated fall in their rate of glucose disposal during a hyperinsulinaemic euglycaemic clamp. Exercise improved cardiovascular fitness and cardiovascular risk in PCOS. Exercise enhanced fasting insulin sensitivity and the rate of glucose disposal during the saline and hyperlipidaemia. Unlike controls, the platelets from PCOS subjects were more susceptible to platelet agonists and less responsive to platelet antagonists in induced hyperlipidaemia, triggering platelet hyper-activation that was not corrected by a supraphysiological dose of insulin.Conclusions: These studies demonstrate the definite role of NEFA in the pathophysiology of IR in PCOS and support the in vitro findings of high NEFA reducing insulin mediated glucose transport. This work also supports the concept that platelet insulin resistance in PCOS during lipaemia might increase cardiovascular risk in these patients