387 research outputs found
Wild chimpanzee behavior suggests that a savanna-mosaic habitat did not support the emergence of hominin terrestrial bipedalism
Bipedalism, a defining feature of the human lineage, is thought to have evolved as forests retreated in the late Miocene-Pliocene. Chimpanzees living in analogous habitats to early hominins offer a unique opportunity to investigate the ecological drivers of bipedalism that cannot be addressed via the fossil record alone. We investigated positional behavior and terrestriality in a savanna-mosaic community of chimpanzees (Pan troglodytes schweinfurthii) in the Issa Valley, Tanzania as the first test in a living ape of the hypothesis that wooded, savanna habitats were a catalyst for terrestrial bipedalism. Contrary to widely accepted hypotheses of increased terrestriality selecting for habitual bipedalism, results indicate that trees remained an essential component of the hominin adaptive niche, with bipedalism evolving in an arboreal context, likely driven by foraging strategy
âWe are getting there slowlyâ: lesbian teacher experiences in the post-Section 28 environment
Prior to the subtraction of Section 28 from the 1988 Local Government Act in 2003, a substantial amount of research was published that specifically examined the experiences of lesbian physical education (PE) teachers. This article contributes to the existing academic literature by exploring the lives of lesbian, gay, bisexual and transsexual teachers working in a post-Section 28 school environment. Drawing on life history interviews of two lesbian PE teachers, we offer insights into how the abolition of Section 28 has affected their lives. Comparable to previous studies, both women reported feeling fearful of the consequences of identifying as lesbian and employed various strategies in order to maintain a divide between their public and private lives so as to conceal their sexual identities from colleagues, pupils and parents. However, in contrast to much of the previous literature, we found that the teachers in this study also identified with narratives of resistance. Despite being fearful of coming out at work, they nevertheless remained committed to coming out when the context is appropriate, to challenging the heteronormative symbolic order configured around the heterosexual/homosexual binary and to more proactively promoting sexual diversity and tolerance in schools
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Over-activation of primate subgenual cingulate cortex enhances the cardiovascular, behavioral and neural responses to threat
Abstract: Stress-related disorders such as depression and anxiety are characterized by enhanced negative emotion and physiological dysfunction. Whilst elevated activity within area 25 of the subgenual anterior cingulate cortex (sgACC/25) has been implicated in these illnesses, it is unknown whether this over-activity is causal. By combining targeted intracerebral microinfusions with cardiovascular and behavioral monitoring in marmosets, we show that over-activation of sgACC/25 reduces vagal tone and heart rate variability, alters cortisol dynamics during stress and heightens reactivity to proximal and distal threat. 18F-FDG PET imaging shows these changes are accompanied by altered activity within a network of brain regions including the amygdala, hypothalamus and dorsolateral prefrontal cortex. Ketamine, shown to have rapid antidepressant effects, fails to reverse elevated arousal to distal threat contrary to the beneficial effects we have previously demonstrated on over-activation induced reward blunting, illustrating the symptom-specificity of its actions
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Plasma metabolites altered by sulforaphane in humans
Consuming cruciferous vegetables such as broccoli sprouts, kale, Brussels sprouts, and bok choy is associated with several health benefits, such as a decreased risk of certain cancers. Cruciferous vegetables contain the glucosinolate, glucoraphanin (GFN). Cutting, chopping or chewing these vegetables releases the enzyme myrosinase, which transforms GFN into sulforaphane (SFN). SFN has many demonstrated health benefits including anticarcinogenic, antioxidant, and antibacterial properties. SFN has been shown to target apoptosis and excretion of carcinogens, cell cycle arrest, and eradication of H. pylori infections. The purpose of this project was to identify new biological pathways altered by SFN consumption in humans and potential biomarkers of SFN action. To achieve this goal, we utilized novel metabolomics technologies that profile global metabolite levels in biological fluids. We evaluated metabolomic profiles following sprout consumption using high-performance liquid chromatography - tandem mass spectrometry in plasma from healthy human subjects consuming 200 ”mol SFN equivalents from fresh broccoli sprouts. We observed changes in these metabolite profiles following SFN consumption. One feature significantly increased 48 hours following sprout consumption was matched to creatinine in the Human Metabolome Database. This information will improve understanding of SFNâs mechanisms of action and direct further study of SFNâs role in human health
Assessment of brain age in posttraumatic stress disorder: Findings from the ENIGMA PTSD and brain age working groups
Background: Posttraumatic stress disorder (PTSD) is associated with markers of accelerated aging. Estimates of brain age, compared to chronological age, may clarify the effects of PTSD on the brain and may inform treatment approaches targeting the neurobiology of aging in the context of PTSD. Method: Adult subjects (N = 2229; 56.2% male) aged 18â69 years (mean = 35.6, SD = 11.0) from 21 ENIGMA-PGC PTSD sites underwent T1-weighted brain structural magnetic resonance imaging, and PTSD assessment (PTSD+, n = 884). Previously trained voxel-wise (brainageR) and region-of-interest (BARACUS and PHOTON) machine learning pipelines were compared in a subset of control subjects (n = 386). Linear mixed effects models were conducted in the full sample (those with and without PTSD) to examine the effect of PTSD on brain predicted age difference (brain PAD; brain age â chronological age) controlling for chronological age, sex, and scan site. Results: BrainageR most accurately predicted brain age in a subset (n = 386) of controls (brainageR: ICC = 0.71, R = 0.72, MAE = 5.68; PHOTON: ICC = 0.61, R = 0.62, MAE = 6.37; BARACUS: ICC = 0.47, R = 0.64, MAE = 8.80). Using brainageR, a three-way interaction revealed that young males with PTSD exhibited higher brain PAD relative to male controls in young and old age groups; old males with PTSD exhibited lower brain PAD compared to male controls of all ages. Discussion: Differential impact of PTSD on brain PAD in younger versus older males may indicate a critical window when PTSD impacts brain aging, followed by age-related brain changes that are consonant with individuals without PTSD. Future longitudinal research is warranted to understand how PTSD impacts brain aging across the lifespan
Comparing benefits from many possible computed tomography lung cancer screening programs: Extrapolating from the National Lung Screening Trial using comparative modeling
Background: The National Lung Screening Trial (NLST) demonstrated that in current and former smokers aged 55 to 74 years, with at least 30 pack-years of cigarette smoking history and who had quit smoking no more than 15 years ago, 3 annual computed tomography (CT) screens reduced lung cancer-specific mortality by 20% relative to 3 annual chest X-ray screens. We compared the benefits achievable with 576 lung cancer screening programs that varied CT screen number and frequency, ages of screening, and eligibility based on smoking. Methods and Findings: We used five independent microsimulation models with lung cancer natural history parameters previously calibrated to the NLST to simulate life histories of the US cohort born in 1950 under all 576 programs. 'Efficient' (within model) programs prevented the greatest number of lung cancer deaths, compared to no screening, for a given number of CT screens. Among 120 'consensus efficient' (identified as efficient across models) programs, the average starting age was 55 years, the stopping age was 80 or 85 years, the average minimum pack-years was 27, and the maximum years since quitting was 20. Among consensus efficient programs, 11% to 40% of the cohort was screened, and 153 to 846 lung cancer deaths were averted per 100,000 people. In all models, annual screening based on age and smoking eligibility in NLST was not efficient; continuing screening to age 80 or 85 years was more efficient. Conclusions: Consensus results from five models identified a set of efficient screening programs that include annual CT lung cancer screening using criteria like NLST eligibility but extended to older ages. Guidelines for screening should also consider harms of screening and individual patient characteristics
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Clash of pans: pan-Africanism and pan-Anglo-Saxonism and the global colour line, 1919â1945
The article demonstrates both conceptually and empirically that pan-Anglo-Saxonist knowledge networks reconstructed and reimagined an apparently de-racialised, scientific, sober and liberal world order that outwardly abandoned, but did not eradicate the twin phenomena of racism and imperialism. Rather the new liberal (imperial) internationalists, organised in newly formed âthink tanksâ such as Chatham House and the Council on Foreign Relations, and through their increasingly global elite networks, mounted a top-down battle for minds at home and in the wider world. Operating in state-private elite networks, they drove the movement to manage change and develop a new liberal world order particularly to contain pan-Africanists who combatted the domination and exploitation of Africans worldwide. More broadly, we indicate that the pragmatic response to the extremes of Nazi ideology and a countering movement from the cadres of Asian, African and African American intellectuals, anti-colonial and anti-racist struggles within the national and global context, forced the Anglo-centric elites to promote change, albeit limited
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