Abstract
Current observational evidence suggests that all large galaxies contain globular clusters (GCs), while the smallest galaxies do not. Over what galaxy mass range does the transition from GCs ...to no GCs occur? We investigate this question using galaxies in the Local Group (LG), nearby dwarf galaxies, and galaxies in the Virgo Cluster Survey. We consider four types of statistical model: (1) logistic regression to model the probability that a galaxy of stellar mass
M
*
has any number of GCs; (2) Poisson regression to model the number of GCs versus
M
*
; (3) linear regression to model the relation between GC system mass (
log
M
gcs
) and host galaxy mass (
log
M
⋆
); and (4) a Bayesian lognormal hurdle model of the GC system mass as a function of galaxy stellar mass for the entire data sample. From the logistic regression, we find that the 50% probability point for a galaxy to contain GCs is
M
*
= 10
6.8
M
⊙
. From postfit diagnostics, we find that Poisson regression is an inappropriate description of the data. Ultimately, we find that the Bayesian lognormal hurdle model, which is able to describe how the mass of the GC system varies with
M
*
even in the presence of many galaxies with no GCs, is the most appropriate model over the range of our data. In an Appendix, we also present photometry for the little-known GC in the LG dwarf Ursa Major II.
Canada-France-Hawaii Telescope Megacam data in (g', r', i') are used to obtain deep, wide-field photometry of the globular cluster system (GCS) around M87. A total of 6200 GCs brighter than i' = 23.0 ...(roughly equivalent to MI = -8.5) are included in the study, essentially containing almost the entire bright half of the total GC population in the galaxy. The classic bimodal metal-poor and metal-rich sequences of GCs show up clearly. While the spatial distribution of the GCs can be traced detectably outward to R gc 100 kpc and perhaps further, the blue, metal-poor subpopulation is very much more spatially extended than the red subpopulation. Both the red and blue GC subsystems have radial metallicity gradients, where mean heavy-element abundance scales with a projected galactocentric distance as Z ~ R -0.12 (blue) and R -0.17 (red). The blue sequence exhibits a strongly significant mass/metallicity relation (MMR) in which the mean metallicity gradually increases with cluster luminosity as Z ~ L 0.25 +/- 0.05 for the luminosity range MI -10 and the assumption of a constant M/L. However, this relation is also clearly nonlinear: fainter than this level, the sequence is more nearly vertical. This mass/metallicity trend can be understood as the result of self-enrichment within the most massive metal-poor GCs during their formation. The red sequence formally exhibits a negatively sloped MMR, but the numerical solutions and tests show that this red-GC slope is not very significant. In giant elliptical galaxies, the red GCs are likely to represent a broad composite population formed during several major starbursts. If so, the red sequence might display a population-based MMR that could in principle be either positive or negative.
The Etiology of Osteoarthritis of the Hip Ganz, Reinhold; Leunig, Michael; Leunig-Ganz, Katharina ...
Clinical orthopaedics and related research,
02/2008, Letnik:
466, Številka:
2
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The etiology of osteoarthritis of the hip has long been considered secondary (eg, to congenital or developmental deformities) or primary (presuming some underlying abnormality of articular ...cartilage). Recent information supports a hypothesis that so-called primary osteoarthritis is also secondary to subtle developmental abnormalities and the mechanism in these cases is femoroacetabular impingement rather than excessive contact stress. The most frequent location for femoroacetabular impingement is the anterosuperior rim area and the most critical motion is internal rotation of the hip in 90° flexion. Two types of femoroacetabular impingement have been identified. Cam-type femoroacetabular impingement, more prevalent in young male patients, is caused by an offset pathomorphology between head and neck and produces an outside-in delamination of the acetabulum. Pincer-type femoroacetabular impingement, more prevalent in middle-aged women, is produced by a more linear impact between a local (retroversion of the acetabulum) or general overcoverage (coxa profunda/protrusio) of the acetabulum. The damage pattern is more restricted to the rim and the process of joint degeneration is slower. Most hips, however, show a mixed femoroacetabular impingement pattern with cam predominance. Surgical attempts to restore normal anatomy to avoid femoroacetabular impingement should be performed in the early stage before major cartilage damage is present.
Level of Evidence:
Level V, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
ABSTRACT We present mass and mass profile estimates for the Milky Way (MW) Galaxy using the Bayesian analysis developed by Eadie et al. and using globular clusters (GCs) as tracers of the Galactic ...potential. The dark matter and GCs are assumed to follow different spatial distributions; we assume power-law model profiles and use the model distribution functions described in Evans et al. and Deason et al. We explore the relationships between assumptions about model parameters and how these assumptions affect mass profile estimates. We also explore how using subsamples of the GC population beyond certain radii affect mass estimates. After exploring the posterior distributions of different parameter assumption scenarios, we conclude that a conservative estimate of the Galaxy's mass within 125 kpc is , with a 50% probability region of . Extrapolating out to the virial radius, we obtain a virial mass for the MW of with 50% credible region of ( . If we consider only the GCs beyond 10 kpc, then the virial mass is ( kpc). We also arrive at an estimate of the velocity anisotropy parameter β of the GC population, which is with a 50% credible region (0.21, 0.35). Interestingly, the mass estimates are sensitive to both the dark matter halo potential and visible matter tracer parameters, but are not very sensitive to the anisotropy parameter.
This pilot study examined the psychometric properties of the Benevolent Childhood Experiences (BCEs) scale, a new instrument designed to assess positive early life experiences in adults with ...histories of childhood maltreatment and other adversities. A counterpart to the Adverse Childhood Experiences (ACEs) questionnaire, the BCEs was developed to be multiculturally-sensitive and applicable regardless of socioeconomic position, urban-rural background, or immigration status. Higher levels of BCEs were hypothesized to predict lower levels of psychopathology and stress beyond the effects of ACES in a sample of ethnically diverse, low-income pregnant women. BCEs were also expected to show adequate internal validity across racial/ethnic groups and test-retest stability from the prenatal to the postnatal period. Participants were 101 pregnant women (M=29.10years, SD=6.56, range=18–44; 37% Latina, 22% African-American, 20% White, 21% biracial/multiracial/other; 37% foreign-born, 26% Spanish-speaking) who completed the BCEs and ACEs scales; assessments of prenatal depression and post-traumatic stress disorder (PTSD) symptoms, perceived stress, and exposure to stressful life events (SLEs) during pregnancy; and demographic information. Higher levels of BCEs predicted less PTSD symptoms and SLEs, above and beyond ACEs. The BCEs showed excellent test-retest reliability, and mean levels were comparable across racial/ethnic and Spanish-English groups of women. Person-oriented analyses also showed that higher levels of BCEs offset the effects of ACEs on prenatal stress and psychopathology. The BCEs scale indexes promising promotive factors associated with lower trauma-related symptomatology and stress exposure during pregnancy and illuminates how favorable childhood experiences may counteract long-term effects of childhood adversity.
Information on the Omega-3 Index (O3I) in the United Kingdom (UK) is scarce. The UK-Biobank (UKBB) contains data on total plasma n3-PUFA% and DHA% measured by NMR. The aim of our study was to create ...an equation to estimate the O3I (eO3I) from these data. We first performed an inter-laboratory experiment with 250 random blood samples in which the O3I was measured in erythrocytes by GC, and total n3 % and DHA% were measured in plasma by NMR. The best predictor of eO3I included both DHA% and a derived metric, the total n3 %–DHA%. Together these explained 65 % of the variability (r = 0·832, P < 0·0001). We then estimated the O3I in 117 108 UKBB subjects and correlated it with demographic and lifestyle variables in multivariable-adjusted models. The mean eO3I was 5·58 % (sd 2·35 %) in this UKBB cohort. Several predictors were significantly correlated with eO3I (all P < 0·0001). In general order of impact and with directionality (–, inverse and +, direct): oily-fish consumption (+), fish oil supplement use (+), female sex (+), older age (+), alcohol use (+), smoking (–), higher waist circumference and BMI (–), lower socioeconomic status and less education (–). Only 20·5 % of eO3I variability could be explained by predictors investigated, and oily fish consumption accounted for 7·0 % of that. With the availability of the eO3I in the UKBB cohort, we will be in a position to link risk for a variety of diseases with this commonly used and well-documented marker of n3-PUFA biostatus.
We investigate pre-processing using the observed quenched fraction of group and cluster galaxies in the Yang et al. Sloan Digital Sky Survey (SDSS)-seventh data release (DR7) group catalogue in the ...redshift range of 0.01 < z < 0.045. We categorize group galaxies as virialized, infall or backsplash and we apply a combination of the Dressler–Shectman statistic and group member velocities to identify subhaloes. On average, the fraction of galaxies that reside in subhaloes is a function of host halo mass, where more massive systems have a higher fraction of subhalo galaxies both in the overall galaxy and infall populations. Additionally, we find that within the range 2 ≲ r
200 < 3 the quiescent fraction is higher in the subhalo population with respect to both the field and non-subhalo populations. At these large radii (2 ≲ r
200 < 3), the majority of galaxies (∼80 per cent) belong to the infall population and therefore, we attribute the enhanced quenching to infalling subhalo galaxies, indicating that pre-processing has occurred in the subhalo population. We conclude that pre-processing plays a significant role in the observed quiescent fraction, but only for the most massive (M
halo > 1014.5 M⊙) systems in our sample.
Abstract In almost any study involving optical/near-infrared photometry, understanding the completeness of detection and recovery is an essential part of the work. The recovery fraction is, in ...general, a function of several variables including magnitude, color, background sky noise, and crowding. We explore how completeness can be modeled, with the use of artificial-star tests, in a way that includes all of these parameters simultaneously within a neural network (NN) framework. The method is able to manage common issues including asymmetric completeness functions and the bilinear dependence of the detection limit on color index. We test the method with two sample Hubble Space Telescope data sets: the first involves photometry of the star cluster population around the giant Perseus galaxy NGC 1275, and the second involves the halo-star population in the nearby elliptical galaxy NGC 3377. The NN-based method achieves a classification accuracy of > 94% and produces results entirely consistent with more traditional techniques for determining completeness. Additional advantages of the method are that none of the issues arising from the binning of the data are present and that a recovery probability can be assigned to every individual star in real photometry. Our data, models, and code (called COINTOSS) can be found online on Zenodo at the following link: https://doi.org/10.5281/zenodo.8306488 .
Numerous studies find a cumulative effect of different types of childhood adversities on increasing risk for serious adult mental and medical outcomes. This study uses the National Comorbidity ...Survey‐Replication sample to investigate the cumulative impact of 8 childhood adversities on complex adult psychopathology as indexed by (a) number of lifetime diagnoses according to the Diagnostic and Statistical Manual of Mental Disorders (4th ed., DSM‐IV; American Psychiatric Association, 1994); (b) number of 4 DSM‐IV disorder categories (mood, anxiety, impulse control, and substance abuse disorders); and (c) coexistence of internalizing and externalizing disorders. Seven of the 8 childhood adversities were significantly associated with complex adult psychopathology. Individuals with 4 or more childhood adversities had an odds ratio of 7.3, 95% confidence interval 4.7, 11.7 for 4 disorder categories. Additive and multiplicative synergistic effects increasing adult psychopathology were found for specific pairwise combinations of childhood adversities. Synergistic patterns differed by gender suggesting that women are more impacted by sexual abuse and men by economic hardship. The absence of childhood adversities was protective, in that it significantly decreased an individual's risk for subsequent adult mental illness. The results support the clinical impression that increased childhood adversity is associated with more complex adult psychopathology.
Traditional and Simplified Chinese s by AsianSTSS
標題:童年協同逆境與複雜成人精神病理學
撮要:眾多研究指出不同種類的童年逆境的累進效應增加成人嚴重精神和身体疾病的風險。我們採用全國共病普查－複製樣本來研究8種童年逆境的累進影響,在下列複雜成人精神病理等方面：(1)終身DSM‐IV診斷數目；(2)4個DSM病類別的數目(情緒、焦慮、控制衝動、和物質濫用)；及(3)內化和外化疾病的共存。8種童年逆境中有7種與複雜成人精神病理學有統計學上顯著關連，有4個或以上童年逆境人士對4種疾病類別的優勢比為7.3, 95%CI4.7,11.7 。只有童年逆境專屬配對組合才能有添加和相乘的協同效應去增加成人精神病理學方面。協同模式有性別差異,如女性受性侵犯影響大些，而男性則被經濟困難影響多些。沒有任何童年逆境是有保護作用，對日後成人精神病的個人發病風險有統計上顯著的減少。本研究証實臨床經驗，即更多童年逆境與更複雜成人精神病學有相連。
标题:童年协同逆境与复杂成人精神病理学
撮要:众多研究指出不同种类的童年逆境的累进效应增加成人严重精神和身体疾病的风险。我们采用全国共病普查－复制样本来研究8种童年逆境的累进影响,在下列复杂成人精神病理等方面：(1)终身DSM‐IV诊断数目；(2)4个DSM病类别的数目(情绪、焦虑、控制冲动、和物质滥用)；及(3)内化和外化疾病的共存。8种童年逆境中有7种与复杂成人精神病理学有统计学上显著关连，有4个或以上童年逆境人士对4种疾病类别的优势比为7.3, 95%CI4.7,11.7 。只有童年逆境专属配对组合才能有添加和相乘的协同效应去增加成人精神病理学方面。协同模式有性别差异,如女性受性侵犯影响大些，而男性则被经济困难影响多些。没有任何童年逆境是有保护作用，对日后成人精神病的个人发病风险有统计上显著的减少。本研究证实临床经验，即更多童年逆境与更复杂成人精神病学有相连。
The cystic fibrosis transmembrane conductance regulator (CFTR) and Calcium-activated Chloride Conductance (CaCC) each play critical roles in maintaining normal hydration of epithelial surfaces ...including the airways and colon. TGF-beta is a genetic modifier of cystic fibrosis (CF), but how it influences the CF phenotype is not understood.
We tested the hypothesis that TGF-beta potently downregulates chloride-channel function and expression in two CF-affected epithelia (T84 colonocytes and primary human airway epithelia) compared with proteins known to be regulated by TGF-beta.
TGF-beta reduced CaCC and CFTR-dependent chloride currents in both epithelia accompanied by reduced levels of TMEM16A and CFTR protein and transcripts. TGF-beta treatment disrupted normal regulation of airway-surface liquid volume in polarized primary human airway epithelia, and reversed F508del CFTR correction produced by VX-809. TGF-beta effects on the expression and activity of TMEM16A, wtCFTR and corrected F508del CFTR were seen at 10-fold lower concentrations relative to TGF-beta effects on e-cadherin (epithelial marker) and vimentin (mesenchymal marker) expression. TGF-beta downregulation of TMEM16A and CFTR expression were partially reversed by Smad3 and p38 MAPK inhibition, respectively.
TGF-beta is sufficient to downregulate two critical chloride transporters in two CF-affected tissues that precedes expression changes of two distinct TGF-beta regulated proteins. Our results provide a plausible mechanism for CF-disease modification by TGF-beta through effects on CaCC.
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