San Francisco State University

About: San Francisco State University is a education organization based out in San Francisco, California, United States. It is known for research contribution in the topics: Population & Planet. The organization has 5669 authors who have published 11433 publications receiving 408075 citations. The organization is also known as: San Francisco State & San Francisco State Normal School.

Bayesian change point analysis of abundance trends for pelagic fishes in the upper San Francisco Estuary

Abstract: We examined trends in abundance of four pelagic fish species (delta smelt, longfin smelt, striped bass, and threadfin shad) in the upper San Francisco Estuary, California, USA, over 40 years using Bayesian change point models. Change point models identify times of abrupt or unusual changes in absolute abundance (step changes) or in rates of change in abundance (trend changes). We coupled Bayesian model selection with linear regression splines to identify biotic or abiotic covariates with the strongest associations with abundances of each species. We then refitted change point models conditional on the selected covariates to explore whether those covariates could explain statistical trends or change points in species abundances. We also fitted a multispecies change point model that identified change points common to all species. All models included hierarchical structures to model data uncertainties, including observation errors and missing covariate values. There were step declines in abundances of all four species in the early 2000s, with a likely common decline in 2002. Abiotic variables, including water clarity, position of the 2 per thousand isohaline (X2), and the volume of freshwater exported from the estuary, explained some variation in species' abundances over the time series, but no selected covariates could explain statistically the post-2000 change points for any species.

Approaches to Biology Teaching and Learning: Understanding the Wrong Answers—Teaching toward Conceptual Change

Abstract: Underpinning science education reform movements in the last 20 years—at all levels and within all disciplines—is an explicit shift in the goals of science teaching from students simply creating a knowledge base of scientific facts to students developing deeper understandings of major concepts within a scientific discipline. For example, what use is a detailed working knowledge of the chemical reactions of the Krebs cycle without a deeper understanding of the relationship between these chemical reactions of cellular respiration and an organism’s need to harvest energy from food? This emphasis on conceptual understanding in science education reform has guided the development of standards and permeates all major science education reform policy docu

Timing of Entry in International Market: An Empirical Study of U.S. Fortune 500 Firms in China

Abstract: This study attempts to explain the timing of entry of firms in international markets. Based on the existing literature, we propose a framework that consists of firm-specific factors, industry/market factors, and host country factors. Empirical results, based on the entry information of U.S. Fortune 500 firms in China between 1979 and 1996, show that larger firms with greater level of internalization and scope economies are likely to enter this foreign market earlier. In addition, non-equity modes, competitors' behavior in the product market, and lower levels of country risk are significantly associated with early entry.

Genetic evidence for the effect of a postglacial population expansion on the phylogeography of a North American songbird

Abstract: Phylogeographical studies of Nearctic songbirds conducted to date have yielded unexpectedly low levels of genetic differentiation and weak phylogeographical structure in mitochondrial DNA lineages as compared with species studied in Neotropical areas. Factors leading to this pattern may include (i) gene flow, (ii) population expansions from bottlenecked populations, and (iii) selective sweeps. Here we provide evidence for the role played by Pleistocene postglacial population expansions on the phylogeography of MacGillivray's warbler (Oporornis tolmiei), a long-distance migratory bird. Samples from 12 breeding localities in the temperate USA were compared with those from two localities in north-eastern Mexico. The former showed evidence of a Late Pleistocene population expansion as indicated by low haplotype and nucleotide diversity, a star-like phylogeny of alleles, and a mismatch distribution indicating a sudden increase in effective population size. By contrast, the Mexican population showed high levels of genetic diversity and a mismatch distribution as expected for a population unaffected by sudden demographic change. Haplotypes from the two regions formed two distinct phylogroups which separated roughly one million years ago according to a conventional molecular clock for songbirds. This study provides support for the Pleistocene expansion hypothesis in MacGillivray's warbler and suggests that postglacial expansion of bottlenecked populations is responsible for the lack of variation and structure reported for most North American songbird species.

Evidence for training the ability to read microexpressions of emotion

Abstract: Microexpressions are extremely quick facial expressions of emotion that appear on the face for less than ½ a s. To date, no study has demonstrated that the ability to read them can be trained. We present two studies that do so, as well as evidence for the retention of the training effects. In Study 1 department store employees were randomly assigned to a training or comparison group. The training group had significantly higher scores than the comparison group in microexpression reading accuracy at the end of the training; 2 weeks later the training group had better third-party ratings of social and communicative skills on the job. Study 2 demonstrated that individuals trained in reading microexpressions retained their ability to read them better than a comparison group tested 2–3 weeks after initial training. These results indicated that the ability to read microexpressions can be trained and are retained.