75 research outputs found

    Allopreening in birds is associated with parental cooperation over offspring care and stable pair bonds across years

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    Individuals of many species form bonds with their breeding partners, yet the mechanisms maintaining these bonds are poorly understood. In birds, allopreening is a conspicuous feature of interactions between breeding partners and has been hypothesized to play a role in strengthening and maintaining pair bonds within and across breeding attempts. Many avian species, however, do not allopreen and the relationship between allopreening and pair bonding across species remains unexplored. In a comparative analysis of allopreening and pair bond behavior, we found that allopreening between breeding partners was more common among species where parents cooperate to rear offspring. The occurrence of allopreening was also associated with an increased likelihood that partners would remain together over successive breeding seasons. However, there was no strong evidence for an association between allopreening and sexual fidelity within seasons or time spent together outside the breeding season. Allopreening between partners was also no more common in colonial or cooperatively breeding species than in solitary species. Analyses of evolutionary transitions indicated that allopreening evolved from an ancestral state of either high parental cooperation or high partner retention, and we discuss possible explanations for this. Overall, our results are consistent with an important role for allopreening in the maintenance of avian pair bonds

    Effect of subunit on allosteric modulation of ion channel function in stably expressed human recombinant -aminobutyric acidA receptors determined using 36Cl ion flux.

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    ABSTRACT Inhibitory ␥-aminobutyric acid (GABA) A receptors are subject to modulation at a variety of allosteric sites, with pharmacology dependent on receptor subunit combination. The influence of different ␣ subunits in combination with ␤3␥2s was examined in stably expressed human recombinant GABA A receptors by measuring 36 Cl influx through the ion channel pore. Muscimol and GABA exhibited similar maximal efficacy at each receptor subtype, although muscimol was more potent, with responses blocked by picrotoxin and bicuculline. Receptors containing the ␣3 subunit exhibited slightly lower potency. The comparative pharmacology of a range of benzodiazepine site ligands was examined, revealing a range of intrinsic efficacies at different receptor subtypes. Of the diazepam-sensitive GABA A receptors (␣1, ␣2, ␣3, ␣5), ␣5 showed the most divergence, being discriminated by zolpidem in terms of very low affinity, and CL218,872 and CGS9895 with different efficacies. Benzodiazepine potentiation at ␣3␤3␥2s with nonselective agonist chlordiazepoxide was greater than at ␣1, ␣2, or ␣5 (P Ͻ 0.001). The presence of an ␣4 subunit conferred a unique pharmacological profile. The partial agonist bretazenil was the most efficacious benzodiazepine, despite lower ␣4 affinity, and FG8205 displayed similar efficacy. Most striking were the lack of affinity/ efficacy for classical benzodiazepines and the relatively high efficacy of Ro15-1788 (53 Ϯ 12%), CGS8216 (56 Ϯ 6%), CGS9895 (65 Ϯ 6%), and the weak partial inverse agonist Ro15-4513 (87 Ϯ 5%). Each receptor subtype was modulated by pentobarbital, loreclezole, and 5␣-pregnan-3␣-ol-20-one, but the type of ␣ subunit influenced the level of potentiation. The maximal pentobarbital response was significantly greater at ␣4␤3␥2s (226 Ϯ 10% increase in the EC 20 response to GABA) than any other modulator. The rank order of potentiation for pregnanolone was ␣5 Ͼ ␣2 Ͼ ␣3 ϭ ␣4 Ͼ ␣1, for loreclezole ␣1 ϭ ␣2 ϭ ␣3 Ͼ ␣5 Ͼ ␣4, and for pentobarbital ␣4 ϭ ␣5 ϭ ␣2 Ͼ ␣1 ϭ ␣3

    From 'event-led' to 'event-themed' regeneration: the 2002 Commonwealth Games Legacy Programme

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    Hosting large events has long been associated with the physical regeneration of cities. To supplement these ‘hard’ impacts, cities are now attempting to use events to stimulate ‘softer’ social and economic regeneration. This paper evaluates the impacts of a regeneration Programme adopted in conjunction with the 2002 Commonwealth Games held in Manchester, UK. Alongside its emphasis on social and economic regeneration, this Programme was unusual in that the projects were Games-themed, rather than being directly linked to the event. Despite some concerns about the organisational structures employed and the sustainability of impacts, target beneficiaries have received valuable assistance from the Programme. As such there appears to be valuable lessons that other cities can learn from this example of event regeneration

    Suppression of star formation in early-type galaxies by feedback from supermassive black holes

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    Detailed high-resolution observations of the innermost regions of nearby galaxies have revealed the presence of supermassive black holes1. These black holes may interact with their host galaxies by means of 'feedback' in the form of energy and material jets; this feedback affects the evolution of the host and gives rise to observed relations between the black hole and the host. Here we report observations of the ultraviolet emissions of massive early-type galaxies. We derive an empirical relation for a critical black-hole mass (as a function of velocity dispersion) above which the outflows from these black holes suppress star formation in their hosts by heating and expelling all available cold gas. Supermassive black holes are negligible in mass compared to their hosts but nevertheless seem to play a critical role in the star formation history of galaxies.Comment: Nature, in press. 27 pages, 4 Figures. Article & supplements with high-resolution figures can be downloaded at: http://www-astro.physics.ox.ac.uk/~kevins/PAPERS/AGN_feedback.pd

    Stellar Kinematics and Populations of Early-Type Galaxies with the SAURON and OASIS Integral-Field Spectrographs

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    We summarise the results and achievements of integral-field spectroscopy of early-type galaxies, observed as part of a survey using both the SAURON and OASIS spectrographs. From the perspective of integral-field spectroscopy, these otherwise smooth and featureless objects show a wealth of structure, both in their stellar kinematics and populations. We focus on the stellar content, and examine properties on both kiloparsec scales with SAURON, and scales of 100's of parsecs with OASIS. These complementary studies reveal two types of kinematically distinct components (KDCs), differing primarily in their intrinsic sizes. In previous studies, KDCs and their host galaxies have generally been found to be unremarkable in other aspects. We show that large KDCs, typical of the well-studied cases, indeed show little or no age differences with their host galaxy. The KDCs detected with the higher spatial-resolution of OASIS are intrinsically smaller and include, in contrast, a significant fraction of young stars. We speculate on the relationship between KDCs and their host galaxies, and the implications for young populations in early-type galaxies.Comment: 20 pages, 6 figures. Invited talk, submitted to "Adaptive Optics-Assisted Integral-Field Spectroscopy", Rutten R.G.M., Benn C.R., Mendez J., eds., May 2005, La Palma (Spain), New Astr. Rev. For full resolution PS, see http://www.strw.leidenuniv.nl/~mcdermid/mcdermid_ao_workshop_20050830.ps.g

    HST/NICMOS Imaging of Bright High-Redshift 24{\mu}m-selected Galaxies: Merging Properties

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    We present new results on the physical nature of infrared-luminous sources at 0.5<z<2.8 as revealed by HST/NICMOS imaging and IRS mid-infrared spectroscopy. Our sample consists of 134 galaxies selected at 24\mum with a flux of S(24\mum) > 0.9 mJy. We find many (~60%) of our sources to possess an important bulge and/or central point source component, most of which reveal additional underlying structures after subtraction of a best-fit sersic (or sersic+PSF) profile. Based on visual inspection of the NIC2 images and their residuals, we estimate that ~80% of all our sources are mergers. We calculate lower and upper limits on the merger fraction to be 62% and 91% respectively. At z < 1.5, we observe objects in early (pre-coalescence) merging stages to be mostly disk and star formation dominated, while we find mergers to be mainly bulge-dominated and AGN-starburst composites during coalescence and then AGN-dominated in late stages. This is analogous to what is observed in local ULIRGs. At z \geq 1.5, we find a dramatic rise in the number of objects in pre-coalescence phases of merging, despite an increase in the preponderance of AGN signatures in their mid-IR spectra and luminosities above 10^12.5 L_sun. We further find the majority of mergers at those redshifts to retain a disk-dominated profile during coalescence. We conclude that, albeit still driven by mergers, these high-z ULIRGs are substantially different in nature from their local counterparts and speculate that this is likely due to their higher gas content. Finally, we observe obscured ({\tau}_{9.7\mum} > 3.36) quasars to live in faint and compact hosts and show that these are likely high-redshift analogs of local dense-core mergers. We find late-stage mergers to show predominantly unobscured AGN spectra, but do not observe other morphological classes to occupy any one specific region in the Spoon diagram. [abridged]Comment: 31 pages, 19 figures. Accepted for publication in Ap

    Physical Health, Media Use, and Mental Health in Children and Adolescents With ADHD During the COVID-19 Pandemic in Australia

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    Objective: To examine the impact of COVID-19 restrictions among children with attention-deficit/hyperactivity disorder (ADHD). Methods: Parents of 213 Australian children (5–17 years) with ADHD completed a survey in May 2020 when COVID-19 restrictions were in place (i.e., requiring citizens to stay at home except for essential reasons). Results: Compared to pre-pandemic, children had less exercise (Odds Ratio (OR) = 0.4; 95% CI 0.3–0.6), less outdoor time (OR = 0.4; 95% 0.3–0.6), and less enjoyment in activities (OR = 6.5; 95% CI 4.0–10.4), while television (OR = 4.0; 95% CI 2.5–6.5), social media (OR = 2.4; 95% CI 1.3–4.5), gaming (OR = 2.0; 95% CI 1.3–3.0), sad/depressed mood (OR = 1.8; 95% CI 1.2–2.8), and loneliness (OR = 3.6; 95% CI 2.3–5.5) were increased. Child stress about COVID-19 restrictions was associated with poorer functioning across most domains. Most parents (64%) reported positive changes for their child including more family time. Conclusions: COVID-19 restrictions were associated with both negative and positive impacts among children with ADHD

    Consortium neuroscience of attention deficit/hyperactivity disorder and autism spectrum disorder:The ENIGMA adventure

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    International audienc

    Brain imaging of the cortex in ADHD: a coordinated analysis of large-scale clinical and population-based samples

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    Objective: Neuroimaging studies show structural alterations of various brain regions in children and adults with attention deficit hyperactivity disorder (ADHD), although nonreplications are frequent. The authors sought to identify cortical characteristics related to ADHD using large-scale studies. Methods: Cortical thickness and surface area (based on the Desikan–Killiany atlas) were compared between case subjects with ADHD (N=2,246) and control subjects (N=1,934) for children, adolescents, and adults separately in ENIGMA-ADHD, a consortium of 36 centers. To assess familial effects on cortical measures, case subjects, unaffected siblings, and control subjects in the NeuroIMAGE study (N=506) were compared. Associations of the attention scale from the Child Behavior Checklist with cortical measures were determined in a pediatric population sample (Generation-R, N=2,707). Results: In the ENIGMA-ADHD sample, lower surface area values were found in children with ADHD, mainly in frontal, cingulate, and temporal regions; the largest significant effect was for total surface area (Cohen’s d=−0.21). Fusiform gyrus and temporal pole cortical thickness was also lower in children with ADHD. Neither surface area nor thickness differences were found in the adolescent or adult groups. Familial effects were seen for surface area in several regions. In an overlapping set of regions, surface area, but not thickness, was associated with attention problems in the Generation-R sample. Conclusions: Subtle differences in cortical surface area are widespread in children but not adolescents and adults with ADHD, confirming involvement of the frontal cortex and highlighting regions deserving further attention. Notably, the alterations behave like endophenotypes in families and are linked to ADHD symptoms in the population, extending evidence that ADHD behaves as a continuous trait in the population. Future longitudinal studies should clarify individual lifespan trajectories that lead to nonsignificant findings in adolescent and adult groups despite the presence of an ADHD diagnosis
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