Search

Sex differences in spatial abilities are well documented, even though their underlying causes are poorly understood. Some studies assume a biological basis of these differences and study the relationship of sex hormone levels to spatial abilities. Other studies assume social influences and study the relationship of gender role (masculinity/femininity) to spatial abilities. Contemporary theories postulate a psychobiosocial model of sex differences in spatial abilities, in which both biological (e.g., hormonal) and psychosocial (e.g., gender role) variables interactively modulate spatial abilities. However, few studies have addressed both aspects simultaneously. Accordingly, the present study explores potential interactive effects between gender role and sex hormones on spatial performance. 41 men and 41 women completed a mental rotation and a virtual navigation task. Sex hormone levels and gender role were assessed in all participants. Sex differences favoring men were observed in both tasks. We found that neither sex hormones nor gender role alone emerged as mediators of these sex differences. However, several interactive effects between gender role and sex hormones were identified. Combined effects of masculinity and testosterone were observed for those variables that displayed sex differences. Participants with both, high masculinity and high testosterone showed the best performance. However, this association was further modulated by biological sex and progesterone levels. Furthermore, we observed an interactive effect of femininity, estradiol and testosterone on response times in both tasks. Consistent across both tasks and irrespective of biological sex, testosterone related to response times in participants with low estradiol levels, depending on their femininity. In participants with low femininity, testosterone was related to slower reaction times, while in participants with higher femininity, testosterone was related to faster reaction times.

The present study investigates the relationship of circulating sex hormone levels and gender role to gray matter volumes in sexually dimorphic brain areas and explores, whether these relationships are modulated by biological sex (as assigned at birth based on sexual anatomy) or oral contraceptive (OC) use. It was hypothesized that testosterone and masculinity relate positively to gray matter volumes in areas that are typically larger in men, like the hippocampus or cerebellum, while estradiol/progesterone and femininity relate positively to gray matter volumes in the frontal cortex. To that end, high resolution structural MRI scans, sex hormone levels and gender role self-assessments were obtained in a large sample 89 men, 89 naturally cycling (NC) women, and 60 OC users. Men showed larger regional gray matter volumes than women in the cerebellum and bilateral clusters spanning the putamen and parts of the hippocampi/parahippocampi and fusiform gyri. In accordance with our hypotheses, a significant positive association of testosterone to hippocampal volumes was observed in women irrespective of OC use. Participant’s self-reported femininity was significantly positively associated with gray matter volumes in the left middle frontal gyrus (MFG) in men. In addition several differences between OC-users and NC women were identified.

Researchers and practitioners have long been interested in the relations of basic personality domains with health. Whereas previous meta-analyses have focused on the Big Five traits, we provide the first meta-analysis of the relations between the HEXACO domains, as assessed by HEXACO Personality Inventories, and various health outcomes (k = 276, N = 92,319). In general, relations of the HEXACO domains were strongest with mental health, followed by health behavior, whereas relations with physical health outcomes were weak and largely non-significant. All HEXACO domains were significantly linked to mental health and health behavior outcomes. Extraversion exhibited the strongest correlation with mental health ( ρ ¯ =.48), whereas Honesty-Humility ( ρ ¯ =.31), Agreeableness versus Anger ( ρ ¯ =.25), and Conscientiousness ( ρ ¯ =.31) were most predictive of health behavior. Physical health was only significantly associated with Emotionality ( ρ ¯ = −.14) and Conscientiousness ( ρ ¯ =.10). Honesty-Humility explained incremental variance over the Big Five in several health behavior outcomes, whereas it had little incremental validity for mental and physical health outcomes. Finally, comparing the variance that the HEXACO and the Big Five domains explained in specific health outcomes demonstrated that each personality model occasionally exhibited superior criterion-related validity. Hence, the choice of the more useful personality model could be outcome-dependent. [ABSTRACT FROM AUTHOR]

Hydrogen-powered hypersonic aircraft are designed to travel in the middle stratosphere at approximately 30–40 km. These aircraft can have a considerable impact on climate-relevant species like stratospheric water vapor, ozone, and methane and thus would contribute to climate warming. The impact of hypersonic aircraft emissions on atmospheric composition and, in turn, on radiation fluxes differs strongly depending on cruise altitude. However, in contrast to variations in the altitude of emission, differences from variations in the latitude of emission are currently unknown. Using an atmospheric chemistry general circulation model, we show that a variation in the latitude of emission can have a larger effect on perturbations and stratospheric-adjusted radiative forcing than a variation in the altitude of emission. Our results include the individual impacts of water vapor and nitrogen oxide emissions, as well as unburned hydrogen, on middle-atmospheric water vapor, ozone, and methane and the resulting radiative forcing. Water vapor perturbation lifetime continues the known tropospheric increase with altitude and reaches almost 6 years in the middle stratosphere. Our results demonstrate how atmospheric composition changes caused by emissions of hypersonic aircraft are controlled by large-scale processes like the Brewer–Dobson circulation and, depending on the latitude of emission, local phenomena like polar stratospheric clouds. The analysis includes a model evaluation of ozone and water vapor with satellite data and a novel approach to reduce simulated years by one-third. A prospect for future hypersonic research is the analysis of seasonal sensitivities and simulations with emissions from combustion of liquefied natural gas instead of liquid hydrogen. [ABSTRACT FROM AUTHOR]

The McMurdo Dry Valleys (MDV) are home to a unique microbial ecosystem that is dependent on the availability of freshwater. This is a polar desert and freshwater originates almost entirely from surface and near-surface melt of the cold-based glaciers. Understanding the future evolution of these environments requires the simulation of the full chain of physical processes from net radiative forcing, surface energy balance, melt, runoff and transport of meltwater in stream channels from the glaciers to the terminal lakes where the microbial community resides. To establish a new framework to do this, we present the first application of WRF-Hydro/Glacier in the MDV, which as a fully distributed hydrological model has the capability to resolve the streams from the glaciers to the bare land that surround them. Given that meltwater generation in the MDV is almost entirely dependent on small changes in the energy balance of the glaciers, the aim of this study is to optimize the multi-layer snowpack scheme that is embedded in WRF-Hydro/Glacier to ensure that the feedbacks between albedo, snowfall and melt are fully resolved. To achieve this, WRF-Hydro/Glacier is implemented at a point scale using automatic weather station data on Commonwealth Glacier to physically model the onset, duration and end of melt over a 7-month period (1 August 2021 to 28 February 2022). To resolve the limited energetics controlling melt, it was necessary to (1) limit the percolation of meltwater through the ice layers in the multi-layer snowpack scheme and (2) optimize the parameters controlling the albedo of both snow and ice over the melt season based on observed spectral signatures of albedo. These modifications enabled the variability of broadband albedo over the melt season to be accurately simulated and ensured that modelled surface and near-surface temperatures, surface height change and runoff were fully resolved. By establishing a new framework that couples a detailed snowpack model to a fully distributed hydrological model, this work provides a stepping stone to model the spatial and temporal variability of melt and streamflow in the future, which will enable some of the unknown questions about the hydrological connectivity of the MDV to be answered. [ABSTRACT FROM AUTHOR]

The hybrid model of number magnitude processing suggests that multi-digit numbers are simultaneously processed holistically (whole number magnitudes) and in a decomposed manner (digit magnitudes). Thus, individual tendencies and situational factors may affect which type of processing becomes dominant in a certain individual in a given situation. The unit-decade compatibility effect has been described as indicative of stronger decomposed number processing. This effect occurs during the comparison of two-digit numbers. Compatible items in which the larger number contains the larger unit digit are easier to solve than incompatible items in which the larger number contains the smaller unit digit. We have previously described women show a larger compatibility effect than men. Furthermore, the compatibility effect is modulated by situational factors like the vertical spacing of the presented numbers. However, it has not been addressed whether situational factors and sex affect the unit-decade compatibility effect interactively. We have also demonstrated that the unit-decade compatibility effects relates to global-local processing, which in turn also affects spatial processing strategies. However, a link between spatial processing strategies and the unit-decade compatibility effect has not yet been established. In the present study we investigate, whether sex differences in the unit-decade compatibility effect (i) depend on the vertical spacing between numbers, (ii) are mediated via sex hormone levels of participants, and (iii) relate to sex differences in spatial processing strategies. 42 men and 41 women completed a two-digit number comparison task as well as a spatial navigation task. The number comparison task modulates compatibility and vertical spacing in a 2 × 2 design. The results confirm a larger compatibility effect in women compared to men and with dense compared to sparse spacing. However, no interactive effect was observed, suggesting that these factors modulate number magnitude processing independently. The progesterone/testosterone ratio was related to the compatibility effect, but did not mediate the sex difference in the compatibility effect. Furthermore, spatial processing strategies were related to the compatibility effect and did mediate the sex difference in the compatibility effect. Participants with a stronger focus on landmarks in the spatial navigation task showed a larger compatibility effect.

With the antibiotic development pipeline running dry, many fear that we might soon run out of treatment options. High-density infections are particularly difficult to treat due to their adaptive multidrug-resistance and currently there are no therapies that adequately address this important issue. Here, a large-scale in vivo study was performed to enhance the activity of antibiotics to treat high-density infections caused by multidrug-resistant Gram-positive and Gram-negative bacteria. It was shown that synthetic peptides can be used in conjunction with the antibiotics ciprofloxacin, meropenem, erythromycin, gentamicin, and vancomycin to improve the treatment outcome of murine cutaneous abscesses caused by clinical hard-to-treat pathogens including all ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter cloacae) pathogens and Escherichia coli. Promisingly, combination treatment often showed synergistic effects that significantly reduced abscess sizes and/or improved clearance of bacterial isolates from the infection site, regardless of the antibiotic mode of action. In vitro data suggest that the mechanisms of peptide action in vivo include enhancement of antibiotic penetration and potential disruption of the stringent stress response.