Asian Survey最新文献

AbstractDistinguishing between genetic, environmental, and genotype × environment effects is central to understanding geographic variation in phenotypic clines. Two of the best-documented phenotypic clines are Bergmann's rule and Allen's rule, which describe larger body sizes and shortened extremities in colder climates, respectively. Although numerous studies have found inter- and intraspecific evidence for both ecogeographic patterns, we still have a poor understanding of the extent to which these patterns are driven by genetics, environment, or both. Here, we measured the genetic and environmental contributions to Bergmann's rule and Allen's rule across introduced populations of house mice (Mus musculus domesticus) in the Americas. First, we documented clines for body mass, tail length, and ear length in natural populations and found that these conform to both Bergmann's rule and Allen's rule. We then raised descendants of wild-caught mice in the lab and showed that these differences persisted in a common environment and are heritable, indicating that they have a genetic basis. Finally, using a full-sib design, we reared mice under warm and cold conditions. We found very little plasticity associated with body size, suggesting that Bergmann's rule has been shaped by strong directional selection in house mice. However, extremities showed considerable plasticity, as both tails and ears grew shorter in cold environments. These results indicate that adaptive phenotypic plasticity as well as genetic changes underlie major patterns of clinal variation in house mice and likely facilitated their rapid expansion into new environments across the Americas.

Aims: Neurotransmitter release from the synaptic vesicles can occur through two modes of exocytosis: "full-collapse" or "kiss-and-run". Here we investigated how increasing the nerve activity and pharmacological stimulation of adrenoceptors can influence the mode of exocytosis in the motor nerve terminal.

Methods: Recording of endplate potentials with intracellular microelectrodes was used to estimate acetylcholine release. A fluorescent dye FM1-43 and its quenching with sulforhodamine 101 were utilized to visualize synaptic vesicle recycling.

Key findings: An increase in the frequency of stimulation led to a decrease in the rate of FM1-43 unloading despite the higher number of quanta released. High frequency activity promoted neurotransmitter release via the kiss-and-run mechanism. This was confirmed by experiments utilizing (I) FM1-43 dye quencher, that is able to pass into the synaptic vesicle via fusion pore, and (II) loading of FM1-43 by compensatory endocytosis. Noradrenaline and specific α2-adrenoreceptors agonist, dexmedetomidine, controlled the mode of synaptic vesicle recycling at high frequency activity. Their applications favored neurotransmitter release via full-collapse exocytosis rather than the kiss-and-run pathway.

Significance: At the diaphragm neuromuscular junctions, neuronal commands are translated into contractions necessary for respiration. During stress, an increase in discharge rate of the phrenic nerve shifts the exocytosis from the full-collapse to the kiss-and-run mode. The stress-related molecule, noradrenaline, restricts neurotransmitter release in response to a high frequency activity, and prevents the shift in the mode of exocytosis through α2-adrenoceptor activation. This may be a component of the mechanism that limits overstimulation of the respiratory system during stress.

In 2019, members of the Executive Committee of the International Association for Statistical Computing (IASC) were contacted by members of the IASC from Africa asking whether it would be feasible to establish a new regional IASC section in Africa. The establishment of a new regional section requires several steps that are outlined in the IASC Statutes at https://iasc-isi.org/statutes/. The approval likely depends on whether the proposed new regional section has the potential to conduct typical section activities, such as organizing regional conferences, workshops, and short courses. To establish whether it is feasible to add a regional section in Africa, the IASC must know whether there is currently enough high-level activity within African countries with respect to computational statistics. To answer this question, we looked at author affiliations of articles published in the Springer journal Computational Statistics (COST) and the Elsevier journal Computational Statistics & Data Analysis (CSDA) from 2015 to 2020 and used these data as a proxy to compare author productivity for authors with an affiliation in Africa in 2019 and 2020, compared to authors with an affiliation in Latin America in 2015 and 2016. This article looks at quantitative results to the questions above, provides insight on how students from Utah State University's STAT 5080/6080 "Data Technologies" course from the Fall 2019 semester used web scraping techniques in a homework assignment to gather author affiliations from COST and CSDA to answer these questions, and includes the evaluation of student feedback obtained after the end of the course.