The Role of Social Context in Shaping Student-Athlete Opinions

How do student-athletes form opinions? This is a particularly important question given ongoing debates about whether student-athletes should be paid and/or allowed to unionize. These debates concern the rights and benefits accrued directly to student-athletes, and thus, understanding their attitudes is of obvious import. Yet, virtually no recent work has delved into how student-athletes form opinions on these issues. We fill this gap with a theoretical framework that predicts changes in social context alter opinions. This leads to the hypothesis that opinions will change once a student-athlete completes his/her career and finds him/herself in a distinct social network. We test the prediction with a survey, implemented in 2012, of one of the most notable athletic conferences in the National Collegiate Athletic Association (NCAA): the Big Ten. We find that post-career student-athletes demonstrate higher levels of support for pay for play and unionization. Our results suggest that student-athletes'' opinions seem to depend on their extant social contexts. While our data, from 2012, neither speak to current opinions – given the quickly evolving landscape of college athletics – nor demonstrate what reforms may be “best,” they do accentuate the power of social context in shaping student-athletes'' attitudes.     

X-Ray Fluorescence Imaging: A New Tool for Studying Manganese Neurotoxicity

The neurotoxic effect of manganese (Mn) establishes itself in a condition known as manganism or Mn induced parkinsonism. While this condition was first diagnosed about 170 years ago, the mechanism of the neurotoxic action of Mn remains unknown. Moreover, the possibility that Mn exposure combined with other genetic and environmental factors can contribute to the development of Parkinson''s disease has been discussed in the literature and several epidemiological studies have demonstrated a correlation between Mn exposure and an elevated risk of Parkinson''s disease. Here, we introduce X-ray fluorescence imaging as a new quantitative tool for analysis of the Mn distribution in the brain with high spatial resolution. The animal model employed mimics deficits observed in affected human subjects. The obtained maps of Mn distribution in the brain demonstrate the highest Mn content in the globus pallidus, the thalamus, and the substantia nigra pars compacta. To test the hypothesis that Mn transport into/distribution within brain cells mimics that of other biologically relevant metal ions, such as iron, copper, or zinc, their distributions were compared. It was demonstrated that the Mn distribution does not follow the distributions of any of these metals in the brain. The majority of Mn in the brain was shown to occur in the mobile state, confirming the relevance of the chelation therapy currently used to treat Mn intoxication. In cells with accumulated Mn, it can cause neurotoxic action by affecting the mitochondrial respiratory chain. This can result in increased susceptibility of the neurons of the globus pallidus, thalamus, and substantia nigra pars compacta to various environmental or genetic insults. The obtained data is the first demonstration of Mn accumulation in the substantia nigra pars compacta, and thus, can represent a link between Mn exposure and its potential effects for development of Parkinson''s disease.     

A shot in the dark: same-sex sexual behaviour in a deep-sea squid

Little is known about the reproductive habits of deep-living squids. Using remotely operated vehicles in the deep waters of the Monterey Submarine Canyon, we have found evidence of mating, i.e. implanted sperm packages, on similar body locations in males and females of the rarely seen mesopelagic squid Octopoteuthis deletron. Equivalent numbers of both sexes were found to have mated, indicating that male squid routinely and indiscriminately mate with both males and females. Most squid species are short-lived, semelparous (i.e. with a single, brief reproductive period) and promiscuous. In the deep, dark habitat where O. deletron lives, potential mates are few and far between. We suggest that same-sex mating behaviour by O. deletron is part of a reproductive strategy that maximizes success by inducing males to indiscriminately and swiftly inseminate every conspecific that they encounter.     

Species identity influences secondary removal of seeds of Neotropical pioneer tree species

Primary dispersal agents move seeds from the maternal plant to the soil surface where they are often moved again by secondary dispersal agents. However, the extent to which different species in the same location experience secondary dispersal is often unknown despite the importance of this mechanism for determining recruitment opportunities and consequently community structure. Here we examine the secondary removal rates of 12 Neotropical pioneer species placed either on or 2 cm below the soil surface at five locations in lowland tropical forest on Barro Colorado Island, Panama. We investigated whether species identity, primary dispersal mode (animal or wind), dormancy type, seed mass, and capacity to persist in the seed bank were correlated with removal rate. We also investigated whether season (dry or wet) influences removal from the soil surface. In general, both superficial and buried seeds were highly mobile. We found an effect of primary dispersal mode and dormancy type on removal rates both on (12 species) and beneath the soil surface (six species). However, this pattern was largely driven by species identity. Season had no influence on seed removal rates from the soil surface. The dispersal of small-seeded pioneer species is highly species dependent, indicating that generalizations made using broader categories, such as primary dispersal mode or dormancy type, do not accurately describe the observed patterns hindering our understanding of community assembly within even a single functional group of plants.     

Decreased DNA repair in familial Alzheimer's disease

Alterations in the capacity of a cell to repair DNA lesions play an important role in a number of human diseases. We and others have demonstrated defective DNA repair of alkylation damage in cells from patients with Alzheimer's disease. It has been hypothesized that this defect is related to the cause of Alzheimer's disease and results in the accumulation of lesions in the central nervous system neurons. One prediction of this hypothesis is that in dominantly inherited Alzheimer's disease, the repair defect will be present in half of the offspring of affected patients long before they develop symptoms of the disease. In order to test the hypothesis that decreased DNA repair is responsible for familial Alzheimer's disease and their at-risk offspring we have studied DNA repair in these individuals after exposure of lymphoblasts to alkylating agents. Our results indicate that cell lines from affected patients repair significantly less damage in 3 h than cell lines from healthy controls. A small number of at-risk individuals were also studied and some of these had lower levels of repair, although more cell lines from individuals in this group must be studied. These findings provide further support for defective DNA repair playing a role in the pathogenesis of Alzheimer's disease.     

Deep-Sea Octopus (Graneledone boreopacifica) Conducts the Longest-Known Egg-Brooding Period of Any Animal

Octopuses typically have a single reproductive period and then they die (semelparity). Once a clutch of fertilized eggs has been produced, the female protects and tends them until they hatch. In most shallow-water species this period of parental care can last from 1 to 3 months, but very little is known about the brooding of deep-living species. In the cold, dark waters of the deep ocean, metabolic processes are often slower than their counterparts at shallower depths. Extrapolations from data on shallow-water octopus species suggest that lower temperatures would prolong embryonic development periods. Likewise, laboratory studies have linked lower temperatures to longer brooding periods in cephalopods, but direct evidence has not been available. We found an opportunity to directly measure the brooding period of the deep-sea octopus Graneledone boreopacifica, in its natural habitat. At 53 months, it is by far the longest egg-brooding period ever reported for any animal species. These surprising results emphasize the selective value of prolonged embryonic development in order to produce competitive hatchlings. They also extend the known boundaries of physiological adaptations for life in the deep sea.     

Inference for set-based effects in genetic association studies with interval-censored outcomes

The rapid acceleration of genetic data collection in biomedical settings has recently resulted in the rise of genetic compendiums filled with rich longitudinal disease data. One common feature of these data sets is their plethora of interval-censored outcomes. However, very few tools are available for the analysis of genetic data sets with interval-censored outcomes, and in particular, there is a lack of methodology available for set-based inference. Set-based inference is used to associate a gene, biological pathway, or other genetic construct with outcomes and is one of the most popular strategies in genetics research. This work develops three such tests for interval-censored settings beginning with a variance components test for interval-censored outcomes, the interval-censored sequence kernel association test (ICSKAT). We also provide the interval-censored version of the Burden test, and then we integrate ICSKAT and Burden to construct the interval censored sequence kernel association test—optimal (ICSKATO) combination. These tests unlock set-based analysis of interval-censored data sets with analogs of three highly popular set-based tools commonly applied to continuous and binary outcomes. Simulation studies illustrate the advantages of the developed methods over ad hoc alternatives, including protection of the type I error rate at very low levels and increased power. The proposed approaches are applied to the investigation that motivated this study, an examination of the genes associated with bone mineral density deficiency and fracture risk.     

Culture variability associated with the U.S. Environmental Protection Agency Tuberculocidal Activity Test Method.

Tuberculosis continues to be a major world health threat. The etiologic agent is among the vegetative organisms most resistant to chemical disinfection. Tuberculocidal efficacy testing for regulatory approval of chemical germicides has evolved considerably over the past decade. A method currently in use is the Environmental Protection Agency Tuberculocidal Activity Test Method, a suspension test using a Mycobacterium bovis culture grown under specific conditions and stored frozen until used. Differing tuberculocidal label claims on products with similar formulations have raised questions concerning the equivalence of test suspensions prepared by different laboratories. Five M. bovis suspensions from laboratories currently performing this test were compared against a battery of three disinfectants at a single test site. A significant difference between test cultures was found, with two of the five exhibiting a significant difference from the other three and also from each other. There was a significant culture-by-disinfectant interaction, indicating that the five cultures did not respond in a consistent manner across the different disinfectants used. However, these differences were due to cultures that were not prepared in accordance with the standard procedure or otherwise did not meet the test suspension criteria. In addition, a 0.55% sodium hypochlorite solution was found to be a sensitive indicator of culture variability. These data reinforce the need to adhere to published procedures and guidelines when growing and preparing a tuberculocidal test suspension and shed light on the variables associated with this type of testing.     

LH and FSH stimulation of cyclic AMP in specific cell types isolated from the testes.

The direct effect of LH and FSH on cyclic AMP levels in specific cell types, isolated from the rat testes, was investigated in vitro. LH significantly stimulated cyclic AMP production in isolated interstitial cells and had only a slight effect on the isolated germ cells. FSH significantly stimulated cyclic AMP production in isolated seminiferous tubules, organ cultures of testes explants, and isolated Sertoli cells, with only a small response elicited in the germ cells. FSH had no effect on the cyclic AMP levels in interstitial cells and either freshly isolated or cultured peritubular cells. These data indicate that the Sertoli cells and interstitial cells are the main cell types in the testes which respond to FSH and LH respectively with increased cyclic AMP production. A possible slight effect of either hormone on the cyclic AMP level in the germ cells has not be ruled out.