The Impact of Choice on Exercise Motivation and Physical Activity in College Students

Background:   While research suggests that college courses contribute to significant health benefits, there is limited research on the effectiveness of these courses in increasing motivation and lifetime PA habits of college students.Aim:  The purpose of this study was to investigate the impact of choice in a conceptually-based college health and wellness course on exercise motivation and physical activity of undergraduate students.Method:  Participants included undergraduate students (N = 81) enrolled in a health and wellness course at a four-year liberal arts university located in the mid-Atlantic region of the U.S. Quantitative data from the Behavioral Regulation in Exercise Questionnaire and the Leisure Time in Exercise Questionnaire were collected over three time points from two groups (choice and non-choice). Qualitative data from semistructured interviews with course instructors (N = 4) and open-ended questions were also collected.Results: There was a significant increase in intrinsic regulation F(2, 158) = 10.13, p = .00, ηp2 =.114; identified regulation F(2, 158) = 7.35, p = .001, ηp2= .085; introjected regulation F(2, 158) = 6.61, p = .002, ηp2= .077; and PA F(2, 158) = 5.63, p = .004, ηp2 = .067 over time. No significant differences were found between groups.Conclusion:  While there was no significant difference between instruction type, instructors and participants suggested that choice was the preferred method for adult learners

Isolation and ultrastructural characterization of squid synaptic vesicles

Author Posting. © Marine Biological Laboratory, 2011. This article is posted here by permission of Marine Biological Laboratory for personal use, not for redistribution. The definitive version was published in Biological Bulletin 220 (2011): 89-96.Synaptic vesicles contain a variety of proteins and lipids that mediate fusion with the pre-synaptic membrane. Although the structures of many synaptic vesicle proteins are known, an overall picture of how they are organized at the vesicle surface is lacking. In this paper, we describe a better method for the isolation of squid synaptic vesicles and characterize the results. For highly pure and intact synaptic vesicles from squid optic lobe, glycerol density gradient centrifugation was the key step. Different electron microscopic methods show that vesicle membrane surfaces are largely covered with structures corresponding to surface proteins. Each vesicle contains several stalked globular structures that extend from the vesicle surface and are consistent with the V-ATPase. BLAST search of a library of squid expressed sequence tags identifies 10 V-ATPase subunits, which are expressed in the squid stellate ganglia. Negative-stain tomography demonstrates directly that vesicles flatten during the drying step of negative staining, and furthermore shows details of individual vesicles and other proteins at the vesicle surface.JAD is supported by the RI-INBRE program award # P20RR016457-10 from the National Center for Research Resources (NCRR), NIH

Layer-by-layer crystallization and the role of fluctuations in free standing smectic films

Specular x-ray reflectivity has been used to study the changes in the thermal fluctuation behavior of eight layer freely suspended N−(4−n−butoxybenzilidene)−4−n−octylaniline (4O.8) films during the process of successive layer-by-layer crystallizations. Each of these steps is preceded by the formation of an intermediate layer structure with in-plane hexatic ordering. We find an unusually large reduction of the fluctuations after the emergence of only the first hexatic toplayer. The fluctuation profiles over the film are in all cases quenched at the surfaces though less so after each crystallization step. This behavior supports theoretical arguments that hexatic order is reduced by out-of-plane smectic layer fluctuations

Effects of Benzo[a]pyrene in human testicular organotypic culture.

Benzo[a]pyrene (BaP) is a well-known polycyclic aromatic hydrocarbon, generated by the incomplete combustion of organic compounds. BaP, which exerts its genotoxic effects after metabolic activation by cytochrome P450s, can induce DNA damage through the formation of adducts or by inducing oxidative stress. Although BaP is currently one of the most studied pollutants, to date the toxicogenomic effect of BaP in the adult human testis has never been studied. The aim of this study is to evaluate the direct effect of this pollutant on human testis using an organotypic culture in vitro model

Identification of Spermatogonial Stem Cell Subsets by Morphological Analysis and Prospective Isolation

Spermatogenesis is maintained by a pool of spermatogonial stem cells (SSCs). Analyses of the molecular profile of SSCs have revealed the existence of subsets, indicating that the stem cell population is more heterogeneous than previously believed. However, SSC subsets are poorly characterized. In rodents, the first steps in spermatogenesis have been extensively investigated, both under physiological conditions and during the regenerative phase that follows germ cell damage. In the widely accepted model, the SSCs are type Asingle (As) spermatogonia. Here, we tested the hypothesis that As spermatogonia are phenotypically heterogeneous by analyzing glial cell line-derived neurotrophic factor (GDNF) family receptor alpha1 (GFRA1) expression in whole-mounted seminiferous tubules, via cytofluorimetric analysis and in vivo colonogenic assays. GFRA1 is a coreceptor for GDNF, a Sertoli cell-derived factor essential for SSC self-renewal and proliferation. Morphometric analysis demonstrated that 10% of As spermatogonia did not express GFRA1 but were colonogenic, as shown by germ cell transplantation assay. In contrast, cells selected for GFRA1 expression were not colonogenic in vivo. In human testes, GFRA1 was also heterogeneously expressed in Adark and in Apale spermatogonia, the earliest spermatogonia. In vivo 5-bromo-2'-deoxyuridine administration showed that both GFRA1(+) and GFRA1(-) As spermatogonia were engaged in the cell cycle, a finding supported by the lack of long-term label-retaining As spermatogonia. GFRA1 expression was asymmetric in 5% of paired cells, suggesting that As subsets may be generated by asymmetric cell division. Our data support the hypothesis of the existence of SSC subsets and reveal a previously unrecognized heterogeneity in the expression profile of As spermatogonia in vivo

The GenTree Leaf Collection: Inter‐ and intraspecific leaf variation in seven forest tree species in Europe

Trait variation within species can reveal plastic and/or genetic responses to environmental gradients, and may indicate where local adaptation has occurred. Here, we present a dataset of rangewide variation in leaf traits from seven of the most ecologically and economically important tree species in Europe. Sample collection and trait assessment are embedded in the GenTree project (EU-Horizon 2020), which aims at characterizing the genetic and phenotypic variability of forest tree species to optimize the management and sustainable use of forest genetic resources. Our dataset captures substantial intra- and interspecific leaf phenotypic variability, and provides valuable information for studying the relationship between ecosystem functioning and trait variability of individuals, and the response and resilience of species to environmental changes.Optimising the management and sustainable use of forest genetic resources in Europ