Impact of Service Learning: High School Students as Health Coaches for Children

The current study examined high school students’ perceptions of healthy eating and exercise lessons in an obesity prevention curriculum being delivered to children in an urban area. Evaluators assessed high school student perceptions of their service learning. Forty-seven high school students participated and coached 65 children. The high school students recorded their perceptions of their experience by answering a series of questions in their journals after each teaching session. The high school students also recorded the children’s daily eating and exercise goals, roadblocks to reaching goals, and ideas for overcoming roadblocks. Results indicated that the majority of high school students (n = 45) wanted to participate in service learning in the future and that they were learning about teaching, setting goals with children, and learning about themselves as leaders. Future research should examine the long-term impact of the service experience for the high school students

Testosterone fluctuations in response to a democratic election predict partisan attitudes toward the elected leader

Intergroup competitions such as democratic elections can intensify intergroup polarization and conflict. Partisan attitudes toward the elected leader can also shift from before to after an election, but the biology underlying these attitudinal shifts remains largely unknown. An important factor could be the hormone testosterone, which is theorized to fluctuate during competition and to influence status seeking. In a naturalistic study of 113 registered voters, we measured changes in testosterone levels and attitudes toward the winner of the 2012 US Presidential Election. We found that supporters of the losing candidate (Mitt Romney) showed acute increases in testosterone levels compared to supporters of the winner (Barack Obama) on the evening of Election Day. Supporters of the losing candidate also demonstrated flatter diurnal testosterone slopes on Election Day that persisted up to two days after the election. Furthermore, greater increases in acute testosterone levels and flatter diurnal slopes among supporters of the losing candidate were associated with less positive evaluations of the winning candidate. These testosterone-moderated attitudinal shifts observed in the days after the election showed a directionally similar pattern with a weaker effect size six months later. Finally, we confirmed that the main results were robust to alternative data analytic choices using multiverse specification curve analysis. The findings from this paper suggest that hormonal responses to large-scale intergroup competitions may shape how we perceive our elected leaders, shedding light on the biology of intergroup relations

A comparison of salivary testosterone measurement using immunoassays and tandem mass spectrometry

Enzyme immunoassays (EIAs) are widely used to measure salivary testosterone. However, little is known about how accurately different EIAs assess testosterone, partially because estimates across various EIAs differ considerably. We compared testosterone concentrations across EIAs of three commonly used manufacturers (DRG International, Salimetrics, and IBL International) to liquid chromatography tandem mass spectrometry (LC–MS/MS). Relative to EIAs from Salimetrics and IBL International, EIAs supplied by DRG International provided the closest approximation to LC–MS/MS testosterone concentrations, followed closely by EIAs from Salimetrics, and then IBL. Additionally, EIAs tended to inflate estimates of lower testosterone concentrations in women. Examining our results and comparing them to existing data revealed that testosterone EIAs had decreased linear correspondence with LC–MS/MS in comparison to cortisol EIAs. Overall, this paper provides researchers with information to better measure testosterone in their research and more accurately compare testosterone measurements across different methods

Correction to: No Compelling Evidence that Self-Reported Personality Traits Explain Basal Testosterone and Cortisol’s Associations with Status-Relevant Behavior

The originally published version of this article contained mistakes. The article note that can be found in the first page of the published article that says “These authors contributed equally” should be changed to “The first two authors contributed equally to this work”

No Compelling Evidence that Self-Reported Personality Traits Explain Basal Testosterone and Cortisol’s Associations with Status-Relevant Behavior

OBJECTIVE: A goal of behavioral neuroendocrinology is to understand how basal hormone levels relate to behavior. Studies of human participants sometimes measure self-reported personality traits, in addition to or instead of direct behavioral observation. Although personality traits often predict their respective behaviors, whether personality explains hormone-behavior relationships remains unclear. METHODS: We obtained data from eight previous studies (total N = 985) that examined baseline testosterone and cortisol as predictors of status-relevant behavior (competitiveness, dominance, risk-taking, aggression, affiliation, and social status). We tested whether the previously reported hormone-behavior relationships are mediated by self-reported personality traits (e.g., trait dominance, prestige, extraversion). As a secondary research question, we also tested whether trait dominance moderated the testosterone-behavior relationships. RESULTS: As expected, self-reported personality traits often predicted status-relevant behaviors, but there was little evidence that traits also correlated with basal testosterone or the testosterone × cortisol interaction. Across all eight studies, personality traits did not significantly mediate hormone-behavior relationships. Indeed, the effect sizes of the hormone-behavior relationships were robust to the inclusion of personality traits as covariates. Further, we did not find strong or consistent evidence that trait dominance moderates the testosterone-behavior association. CONCLUSION: Results suggest that basal testosterone and cortisol predict status-related behavior independent of self-reported personality. We discuss how these results may have broader implications for the physiological mechanisms by which testosterone and cortisol influence behavior, a process that could be unconscious and automatic. We also discuss alternative explanations, limitations, and future directions

Galaxy merger histories and the role of merging in driving star formation at z>1

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.We use Horizon-AGN, a hydrodynamical cosmological simulation, to explore the role of mergers in the evolution of massive (M > 10^10 MSun) galaxies around the epoch of peak cosmic star formation (1zR(4:1 3 are 'blue' (i.e. have significant associated star formation), the proportion of 'red' mergers increases rapidly at ztodays stellar mass was formed.Peer reviewe

Precision Mass Measurements of 129-131Cd and Their Impact on Stellar Nucleosynthesis via the Rapid Neutron Capture Process

Masses adjacent to the classical waiting-point nuclide 130Cd have been measured by using the Penning- trap spectrometer ISOLTRAP at ISOLDE/CERN. We find a significant deviation of over 400 keV from earlier values evaluated by using nuclear beta-decay data. The new measurements show the reduction of the N = 82 shell gap below the doubly magic 132Sn. The nucleosynthesis associated with the ejected wind from type-II supernovae as well as from compact object binary mergers is studied, by using state-of-the-art hydrodynamic simulations. We find a consistent and direct impact of the newly measured masses on the calculated abundances in the A = 128 - 132 region and a reduction of the uncertainties from the precision mass input data

Basal cortisol's relation to testosterone changes may not be driven by social challenges

Multiple studies show a negative correlation between basal cortisol and testosterone changes in the presence of competition and social-evaluative stressors. These negative associations are proposed to be derived from psychological responses to competition and social-evaluative stress. However, we argue that the association between basal cortisol and testosterone change may instead be a statistical consequence of positively associated variables. In this paper, we present a mathematical rationale for this alternative explanation and examples from two studies that are consistent with this alternative explanation. Both studies show that the associations between basal cortisol and testosterone change have covariance patterns consistent with this alternative possibility. We conclude that the often-found positive association between basal cortisol and basal testosterone opens the door for alternative explanations of the basal cortisol-testosterone change association rooted in the patterns of associations between hormones measured over time. We also suggest future research directions and methods for testing alternative explanations

Occurrence of a Synchronous Hermaphroditic Striped Mullet, Mugil cephalus, from the Northern Gulf of Mexico

A synchronous hermaphroditic striped mullet, Mugil cephalus, was captured offshore of Southwest Pass, Louisiana on 6 December 1996 during the commercial roe mullet fishery harvest. The fish measured 412 mm FL, weighed 824 g and was determined to be 4 years old by otolith analysis. Gross examination of the gonads revealed four lobes: right and left ovaries and right and left testis which represents a unique occurrence among hermaphroditic fish. All lobes ended in a common sperm duct/oviduct with the exception of the left ovary which had no oviduct. Both ovaries contained vitellogenic oocytes and both testis had freely running spermatozoa. Histological examination showed many oocytes undergoing final oocyte maturation, the presence of some post ovulatory follicles and lobules full of tailed spermatozoa. There was no evidence of the intermingling of sperm and oocytes within the gonad. The capture of this fish on the spawning grounds and the advanced stage of both ovarian and testicular development suggests spawning probably would involve the release of both oocytes and spermatozoa