Abstract
We present new evidence for AGN feedback in a subset of 69 quenched low-mass galaxies (M⋆ ≲ 5 × 109 M⊙, Mr > −19) selected from the first 2 yr of the Sloan Digital Sky Survey-IV Mapping ...Nearby Galaxies at APO (SDSS-IV MaNGA) survey. The majority (85 per cent) of these quenched galaxies appear to reside in a group environment. We find six galaxies in our sample that appear to have an active AGN that is preventing on-going star formation; this is the first time such a feedback mechanism has been observed in this mass range. Interestingly, five of these six galaxies have an ionized gas component that is kinematically offset from their stellar component, suggesting the gas is either recently accreted or outflowing. We hypothesize these six galaxies are low-mass equivalents to the ‘red geysers’ observed in more massive galaxies. Of the other 63 galaxies in the sample, we find 8 do appear for have some low level, residual star formation, or emission from hot, evolved stars. The remaining galaxies in our sample have no detectable ionized gas emission throughout their structures, consistent with them being quenched. This work shows the potential for understanding the detailed physical properties of dwarf galaxies through spatially resolved spectroscopy.
Abstract
Post-starburst galaxies are crucial to disentangling the effect of star formation and quenching on galaxy demographics. They comprise, however, a heterogeneous population of objects, ...described in numerous ways. To obtain a well-defined and uncontaminated sample, we take advantage of spatially resolved spectroscopy to construct an unambiguous sample of E + A galaxies—post-starburst systems with no observed ongoing star formation. Using data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) Survey, in the fourth generation of the Sloan Digital Sky Survey (SDSS-IV), we have identified 30 E + A galaxies that lie within the green valley of color–stellar mass space. We first identified E + A candidates by their central, single-fiber spectra and (
u
–
r
) color from SDSS DR15, and then further required each galaxy to exhibit E + A properties throughout the entirety of the system to three effective radii. We describe our selection criteria in detail, note common pitfalls in E + A identification, and introduce the basic characteristics of the sample. We will use this E + A sample, which has been assembled with stringent criteria and thus re-establishes a well-defined subpopulation within the broader category of post-starburst galaxies, to study the evolution of galaxies and their stellar populations in the time just after star formation within them is fully quenched.
The Embryonic State Greene, Olivia
Radical history review,
2014, Letnik:
2014, Številka:
119
Journal Article
Recenzirano
This article argues that the African National Congress's (ANC) Geneva Conventions declaration and Code of Conduct were important precursors to the ANC's constitutional proposals and that they ...demonstrated an emerging, yet tentative, shift within the ANC toward thinking about rights in terms of human rights. The article situates the ANC's Geneva Conventions declaration and Code of Conduct against the background of internal debates about what constituted a just war and what foundation its days in exile should set for a postapartheid South Africa and the nature of the law that would shape the country. It considers these two moments in light of the organization's efforts to earn support internationally, protect its soldiers from the death penalty, and restrain its armed struggle. The article also addresses the discordances in these actions, namely, the human rights abuses of suspected informants perpetrated by some ANC members.
The Embryonic State Greene, Olivia
Radical history review,
05/2014, Letnik:
2014, Številka:
119
Journal Article
Recenzirano
This article argues that the African National Congress's (ANC) Geneva Conventions declaration and Code of Conduct were important precursors to the ANC's constitutional proposals and that they ...demonstrated an emerging, yet tentative, shift within the ANC toward thinking about rights in terms of human rights. The article situates the ANC's Geneva Conventions declaration and Code of Conduct against the background of internal debates about what constituted a just war and what foundation its days in exile should set for a postapartheid South Africa and the nature of the law that would shape the country. It considers these two moments in light of the organization's efforts to earn support internationally, protect its soldiers from the death penalty, and restrain its armed struggle. The article also addresses the discordances in these actions, namely, the human rights abuses of suspected informants perpetrated by some ANC members.
This article argues that the African National Congress's (ANC) Geneva Conventions declaration and Code of Conduct were important precursors to the ANC's constitutional proposals and that they ...demonstrated an emerging, yet tentative, shift within the ANC toward thinking about rights in terms of human rights. The article situates the ANC's Geneva Conventions declaration and Code of Conduct against the background of internal debates about what constituted a just war and what foundation its days in exile should set for a postapartheid South Africa and the nature of the law that would shape the country. It considers these two moments in light of the organization's efforts to earn support internationally, protect its soldiers from the death penalty, and restrain its armed struggle. The article also addresses the discordances in these actions, namely, the human rights abuses of suspected informants perpetrated by some ANC members. Reprinted by permission of Cambridge University Press. An electronic version of this article can be accessed via the internet at http://journals.cambridge.org
INTRODUCTION: Worldwide, approximately 800 women die daily from preventable maternal causes of death (COD). These CODs (e.g. prolonged labor, hemorrhage) are frequently connected to biomechanical ...limitations during childbirth. There is increased risk for complications/death during labor/delivery if pelvis/hip anatomy does not biomechanically change enough. Monitoring pelvic/hip biomechanical changes throughout pregnancy may help detect complications that arise during or prior to labor/delivery.METHODS: Sixteen females (10 nulligravid female control participants, 6 gravid female participants) were enrolled. All participants performed walking, stair ascent, and stair descent while lower extremity optical motion capture and electromyography data (bilateral hip/knee flexors/extensors) were captured. Controls were assessed once, while gravid participants completed 5 timepoints (1 x T1, 1 x T2, 2 x T3, 1 x postpartum). Outcome variables included 3D peak pelvis/hip joint angles, neuromuscular features (peak EMG magnitude and dominant frequency), and post-partum patient reported outcome measures (PROMs). A Pearson’s Correlation evaluated associations between peak joint angles/EMG magnitude and post-partum PROMs.RESULTS: There was a significant impact of pregnancy status and gestation cycle timepoint on peak pelvis and hip joint angles in the sagittal plane during walking and stair descent. Kinematics changed significantly throughout pregnancy and returned towards pre-pregnancy values after parturition (p<0.05). While gestation cycle timepoint was not significantly connected with EMG variables, the dominant frequency of the gluteus maximums was significantly different between the control cohort and pregnant cohort (p=-0.026). Additionally, kinematic values were significantly correlated with postpartum outcomes during walking. Specifically, it was found that hip transverse plane motion (i.e. internal/external rotation) was significantly correlated to Birth Satisfaction Scale scores (r>0.98, p<0.02). Additionally, hip extension was significantly correlated with active pushing time during labor (r=0.97, p=0.03).DISCUSSION: Biomechanics are significantly impacted by pregnancy, mostly in the sagittal plane. More critically, these changes are correlated to clinical delivery outcomes, implying there may be a direct link between how the pelvis/hips biomechanically prepare for labor and intra-/post-partum outcomes. This result indicates there is the possibility for developing better screening and treatment modalities to reduce complications during labor and delivery.
Post-starburst galaxies are crucial to disentangling the effect of star formation and quenching on galaxy demographics. They comprise, however, a heterogeneous population of objects, described in ...numerous ways. To obtain a well-defined and uncontaminated sample, we take advantage of spatially resolved spectroscopy to construct an unambiguous sample of E + A galaxies - post-starburst systems with no observed ongoing star formation. Using data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) Survey, in the fourth generation of the Sloan Digital Sky Survey (SDSS-IV), we have identified 30 E + A galaxies that lie within the green valley of color-stellar mass space. We first identified E + A candidates by their central, single-fiber spectra and (u-r) color from SDSS DR15, and then further required each galaxy to exhibit E + A properties throughout the entirety of the system to three effective radii. We describe our selection criteria in detail, note common pitfalls in E + A identification, and introduce the basic characteristics of the sample. We will use this E + A sample, which has been assembled with stringent criteria and thus re-establishes a well-defined subpopulation within the broader category of post-starburst galaxies, to study the evolution of galaxies and their stellar populations in the time just after star formation within them is fully quenched.
We present new evidence for AGN feedback in a subset of 69 quenched low-mass galaxies (\(M_{\star} \lesssim 5\times10^{9}\) M\(_{\odot}\), \(M_{\rm{r}} > -19\)) selected from the first two years of ...the SDSS-IV MaNGA survey. The majority (85 per cent) of these quenched galaxies appear to reside in a group environment. We find 6 galaxies in our sample that appear to have an active AGN that is preventing on-going star-formation; this is the first time such a feedback mechanism has been observed in this mass range. Interestingly, five of these six galaxies have an ionised gas component that is kinematically offset from their stellar component, suggesting the gas is either recently accreted or outflowing. We hypothesise these six galaxies are low-mass equivalents to the "red geysers" observed in more massive galaxies. Of the other 63 galaxies in the sample, we find 8 do appear for have some low-level, residual star formation, or emission from hot, evolved stars. The remaining galaxies in our sample have no detectable ionised gas emission throughout their structures, consistent with them being quenched. This work shows the potential for understanding the detailed physical properties of dwarf galaxies through spatially resolved spectroscopy.
Magnetic resonance imaging (MRI) has transformed our understanding of the human brain through well-replicated mapping of abilities to specific structures (for example, lesion studies) and functions
...(for example, task functional MRI (fMRI)). Mental health research and care have yet to realize similar advances from MRI. A primary challenge has been replicating associations between inter-individual differences in brain structure or function and complex cognitive or mental health phenotypes (brain-wide association studies (BWAS)). Such BWAS have typically relied on sample sizes appropriate for classical brain mapping
(the median neuroimaging study sample size is about 25), but potentially too small for capturing reproducible brain-behavioural phenotype associations
. Here we used three of the largest neuroimaging datasets currently available-with a total sample size of around 50,000 individuals-to quantify BWAS effect sizes and reproducibility as a function of sample size. BWAS associations were smaller than previously thought, resulting in statistically underpowered studies, inflated effect sizes and replication failures at typical sample sizes. As sample sizes grew into the thousands, replication rates began to improve and effect size inflation decreased. More robust BWAS effects were detected for functional MRI (versus structural), cognitive tests (versus mental health questionnaires) and multivariate methods (versus univariate). Smaller than expected brain-phenotype associations and variability across population subsamples can explain widespread BWAS replication failures. In contrast to non-BWAS approaches with larger effects (for example, lesions, interventions and within-person), BWAS reproducibility requires samples with thousands of individuals.
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