San Diego State University

About: San Diego State University is a education organization based out in San Diego, California, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 12418 authors who have published 27950 publications receiving 1192375 citations. The organization is also known as: SDSU & San Diego State College.

Lead-Halide Perovskites for Photocatalytic α-Alkylation of Aldehydes.

Abstract: Cost-effective and efficient photocatalysis are highly desirable in chemical synthesis. Here we demonstrate that readily prepared suspensions of APbBr3 (A = Cs or methylammonium (MA)) type perovskite colloids (ca. 2–100 nm) can selectively photocatalyze carbon–carbon bond formation reactions, i.e., α-alkylations. Specifically, we demonstrate α-alkylation of aldehydes with a turnover number (TON) of over 52,000 under visible light illumination. Hybrid organic/inorganic perovskites are revolutionizing photovoltaic research and are now impacting other research fields, but their exploration in organic synthesis is rare. Our low-cost, easy-to-process, highly efficient and bandedge-tunable perovskite photocatalyst is expected to bring new insights in chemical synthesis.

The characteristics of the outdoor school environment associated with physical activity

Abstract: The school is an important setting for physical activity. The purpose of the present study was to examine the association between physical environmental characteristics and participation in daily physical activity during school breaks. Data from 130 schools and 16 471 students (Grades 4–10) in Norway were obtained in 2004 through self-administered questionnaires to principals and students. Multilevel logistic regression models revealed that boys at secondary level with a larger number of outdoor facilities at school had 2.69 times [95% confidence interval (CI) = 1.21–5.98] and girls 2.90 times (95% CI = 1.32–6.37) higher odds of being physically active compared with students in schools with fewer facilities. Boys at secondary level with areas for hopscotch/skipping rope had 2.53 times (95% CI = 1.55–4.13), with a soccer field 1.68 times (95% CI = 1.15–2.45), with playground equipment 1.66 times (95% CI = 1.16– 2.37) and with a sledding hill 1.70 times (95% CI = 1.23–2.35) higher odds to be physically active compared with students in schools without these facilities. A sledding hill was also associated with girls’ physical activity participation in secondary school (odds ratio = 1.58, 95% CI = 1.11–2.24). Outdoor facilities in secondary schools are associated with students’ daily physical activity participation during school breaks. Therefore, improving the outdoor environment should be considered in physical activity promotion school programs in secondary schools.

Impacts of mosquitofish (Gambusia affinis) predation on plankton communities

Abstract: An investigation of the effects of mosquitofish (Gambusia affinis) predation was conducted in 12 experimental ponds in southern California over a period of 10 months.Gambusia essentially eliminatedDaphnia pulex andCeriodaphnia sp. populations, reducedDiaptomus pallidus andKeratella quadrata populations, had little impact onCyclops vernalis, and caused large increases inK. cochlearis, Polyarthra sp.,Synchaeta sp., andTrichocerca spp. populations and in total phytoplankton.Gambusia caused a decrease in the PIE (probability of interspecific encounter) of the planktonic crustaceans and an increase in the PIE of the planktonic rotifers. Hemiptera, such as neustonicMicrovelia sp. and nektonicBuenoa sp. andNotonecta sp., andHyla regilla tadpoles were absent from fish ponds but sometimes abundant in control ponds.Gambusia caused higher pH and oxygen levels, presumably via its effect on the phytoplankton. The impact ofGambusia on the pond ecosystems was less in winter, when fish numbers and feeding rates were low, than in summer. Results of other fish-plankton studies are summarized in tabular form. A model is proposed to account for variation in the calanoid/cyclopoid ratio; evidence is summarized suggesting that in general calanoids are more susceptible to predation by predaceous zooplankters while cyclopoids are more susceptible to fish predation. Some parallels are drawn between the effects ofGambusia predation and those of insecticide treatments.