116 research outputs found
MOLECULAR SEX DETERMINATION IN NEOTROPICAL MONOCHROMATIC HUMMINGBIRDS
Abstract â Many species of hummingbirds are sexually monochromatic. This is surprising because in all hummingbird species parental care is carried out by females, while males are promiscuous, and this mating system is usually associated with some form of sexual dimorphism. To study sexual selection in monochromatic species, the identification of sex is a prerequisite. Using blood and feathers from live individuals we apply a simple method to identify sex. We amplified fragments of the CHD-1 gene through PCR, using P2 and P8 primers with fluorescence, followed by genotyping in an automatic sequencer. We sexed 110 individuals of five species: Versicolored Emerald (Amazilia versicolor), White-throated Hummingbird (Leucochloris albicollis), White-vented Violetear (Colibri serrirostris), Black Jacobin (Florisuga fusca), and Swallow-tailed Hummingbird (Eupetomena macroura). We found gene fragments of two sizes: 374 bp in both sexes (Z chromosome) and either 379 or 383 bp in females (W chromosome). Using this method for monochromatic species permits sexing in species with similar fragment sizes between sexes (i.e., hummingbirds). Sexing monochromatic birds will be very useful for field studies that require continuous monitoring of individuals in the wild. Resumo â Determinação sexual molecular em beija-flores monocromĂĄticos neotropicais Muitas espĂ©cies de beija-flores sĂŁo sexualmente monocromĂĄticas, o que pode ser surpreendente, jĂĄ que todas as espĂ©cies desta famĂlia apresentam cuidado parental realizado pelas fĂȘmeas. Os machos sĂŁo promĂscuos e esse sistema de acasalamento geralmente estĂĄ associado ao dimorfismo sexual. Para estudar a seleção sexual em espĂ©cies monocromĂĄticas, devemos primeiramente identificar os sexos. Aqui, utilizando sangue e penas de indivĂduos vivos, aplicamos um mĂ©todo simples para sexagem. Amplificamos os fragmentos do gene CHD-1 atravĂ©s de PCR, utilizando iniciadores P2 e P8 com fluorescĂȘncia, seguido de genotipagem em sequenciador automĂĄtico. Foram sexados 110 indivĂduos de cinco espĂ©cies: Amazilia versicolor, Leucochloris albicollis, Colibri serrirostris, Florisuga fusca e Eupetomena macroura. Os fragmentos foram identificados em: 374 pb para ambos os sexos (cromossomo Z) e 379 ou 383 pb para fĂȘmeas (cromossomo W). Esta aplicação do mĂ©todo em espĂ©cies monocromĂĄticas beneficiarĂĄ a sexagem em espĂ©cies onde hĂĄ similaridade entre os tamanhos dos fragmentos, como nos beija-flores. AlĂ©m disso, se tornarĂĄ uma Ăștil ferramenta para estudos de campo que exijam o monitoramento contĂnuo de indivĂduos na natureza
Aves que nidificam em cavidades na Reserva Natural Salto Morato - Guaraqueçaba (PR) /
Orientador : James Joseph RoperDissertaçÄo (mestrado) - Universidade Federal do ParanĂĄ, Setor de CiÄncias BiolĂłgicas, Programa de PĂłs-GraduaçÄo em Ecologia e Conservaçao. Defesa: Curitiba, 2007Inclui bibliografi
The JWST Hubble Sequence: The Rest-frame Optical Evolution of Galaxy Structure at 1.5 < z < 6.5
© 2023. The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, see: https://creativecommons.org/licenses/by/4.0/We present results on the morphological and structural evolution of a total of 3956 galaxies observed with JWST at 1.5 109 M â at z > 3 are not dominated by irregular and peculiar structures, either visually or quantitatively, as previously thought. We find a strong dominance of morphologically selected disk galaxies up to z = 6 in this mass range. We also find that the stellar mass and star formation rate densities are dominated by disk galaxies up to z ⌠6, demonstrating that most stars in the Universe were likely formed in a disk galaxy. We compare our results to theory to show that the fraction of types we find is predicted by cosmological simulations, and that the Hubble Sequence was already in place as early as one billion years after the Big Bang. Additionally, we make our visual classifications public for the community.Peer reviewe
Seeing sharper and deeper: JWST's first glimpse of the photometric and spectroscopic properties of galaxies in the epoch of reionisation
We analyse the photometric and spectroscopic properties of four galaxies in
the epoch of reionisation (EoR) within the SMACS 0723 JWST Early Release
Observations field. Given the known spectroscopic redshifts of these sources,
we investigated the accuracy with which photometric redshifts can be derived
using NIRCam photometry alone, finding that F115W imaging is essential to
distinguish between z~8 galaxies with high equivalent width (EW) [O III]
{\lambda}5007 emission and z~10 Balmer break galaxies. We find that all four
sources exhibit strong (> 0.6 mag) F356W-F444W colours, which sit at the
extreme end of theoretical predictions from numerical simulations. We find that
these galaxies deviate (by roughly 0.5 dex) from the local correlation between
[O III] {\lambda}5007/H\beta and [Ne III] {\lambda}3869/[O II], which is
consistent with the predictions from simulations of high-redshift galaxies. We
measure the [O III] {\lambda}5007 rest-frame equivalent widths both directly
from the spectroscopy, and indirectly as inferred from the strong F356W-F444W
colours, finding large [O III] {\lambda}5007 EWs of 400-1000 {\AA}. The [O III]
{\lambda}5007 and H\beta EWs are consistent with those seen in extreme,
intensely star-forming dwarf galaxies in the local Universe. Our structural
analysis indicates that these galaxies are resolved, exhibiting irregular
shapes with bright clumps and colour gradients. In line with the predictions
from the FLARES hydrodynamic simulations, such intense star formation and
extreme nebular conditions are likely the norm, rather than the exception, in
the EoR. Finally, although star-forming galaxies and AGN often occupy similar
regions within the [O III] {\lambda}5007/H\beta-[O II]/H{\delta} plane, we find
that AGN exhibit distinct, red colours in the F150W-F200W, F200W-F277W plane.Comment: 14 pages, 8 figure
First Light And Reionisation Epoch Simulations (FLARES) XI: [OIII] emitting galaxies at
JWST has now made it possible to probe the rest-frame optical line emission
of high-redshift galaxies extending to z~9, and potentially beyond. To aid in
the interpretation of these emerging constraints, in this work we explore
predictions for [OIII] emission in high-redshift galaxies using the First Light
and Reionisation Epoch Simulations (FLARES). We produce predictions for the
[OIII] luminosity function, its correlation with the UV luminosity, and the
distribution of equivalent widths (EWs). We also explore how the [OIII] EW
correlates with physical properties including specific star formation rate,
metallicity, and dust attenuation. Our predictions are largely consistent with
recent observational constraints on the luminosity function, average equivalent
widths, and line ratios. However, they fail to reproduce the observed tail of
high-EW sources and the number density of extreme line emitters. Possibilities
to explain these discrepancies include an additional source of ionising photons
and/or greater stochasticity in star formation in the model or photometric
scatter and/or bias in the observations. With JWST now rapidly building larger
samples and a wider range of emission lines the answer to this remaining
discrepancy should be available imminently.Comment: 15 pages, accepted for publication in MNRAS, minor changes from
original versio
Translational pharmacology of an inhaled small molecule αvÎČ6 integrin inhibitor for idiopathic pulmonary fibrosis
The αvÎČ6 integrin plays a key role in the activation of transforming growth factor-ÎČ (TGFÎČ), a pro-fibrotic mediator that is pivotal to the development of idiopathic pulmonary fibrosis (IPF). We identified a selective small molecule αvÎČ6 RGD-mimetic, GSK3008348, and profiled it in a range of disease relevant pre-clinical systems. To understand the relationship between target engagement and inhibition of fibrosis, we measured pharmacodynamic and diseaserelated end points. Here we report, GSK3008348 binds to αvÎČ6 with high affinity in human IPF lung and reduces downstream pro-fibrotic TGFÎČ signaling to normal levels. In human lung epithelial cells, GSK3008348 induces rapid internalization and lysosomal degradation of the αvÎČ6 integrin. In the murine bleomycin-induced lung fibrosis model, GSK3008348 engages αvÎČ6, induces prolonged inhibition of TGFÎČ signaling and reduces lung collagen deposition and serum C3M, a marker of IPF disease progression. These studies highlight the potential of inhaled GSK3008348 as an anti-fibrotic therapy
Self-love and sociability: the ârudiments of commerceâ in the state of nature
Istvan Hontâs classic work on the theoretical links between the seventeenth-century natural jurists Hugo Grotius and Samuel Pufendorf and the eighteenth-century Scottish political economists remains a popular trope among intellectual and economic historians of various stamps. Despite this, a common criticism levelled at Hont remains his relative lack of engagement with the relationship between religion and economics in the early modern period. This paper challenges this aspect of Hontâs narrative by drawing attention to an alternative, albeit complementary, assessment of the natural jurisprudential heritage of eighteenth-century British political economy. Specifically, the article attempts to map on to Hontâs thesis the Christian Stoic interpretation of Grotius and Pufendorf which has gained greater currency in recent years. In doing so, the paper argues that Grotius and Pufendorfâs contributions to the âunsocial sociabilityâ debate do not necessarily lead directly to the Scottish school of political economists, as is commonly assumed. Instead, it contends that a reconsideration of Grotius and Pufendorf as neo-Stoic theorists, particularly via scrutiny of their respective adaptations of the traditional Stoic theory of oikeiosis, steers us towards the heart of the early English âclericalâ Enlightenment
Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.
Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability
Language endangerment and language documentation in Africa
Non peer reviewe
Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic
This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic
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