The intergalactic medium near high-redshift galaxies

Over the past 15 years, the field of extragalactic astronomy has pushed to high redshift and our knowledge of natal galaxies has grown dramatically. Galaxies are now routinely detected at redshifts z ! 6__7 (e.g. Bouwens et al. 2010; Labb_e et al. 2010; Oesch et al. 2010; Bouwens et al. 2011; McLure et al. 2011). However, there are fundamental concepts that are still poorly understood. How do galaxies get their gas? How does galactic feedback affect galaxy evolution?UBL - phd migration 201

On the galactic rotation curves problem within an axisymmetric approach

In U. Nucamendi et al. Phys. Rev. D63 (2001) 125016 and K. Lake, Phys. Rev. Lett. 92 (2004) 051101 it has been shown that galactic potentials can be kinematically linked to the observed red/blue shifts of the corresponding galactic rotation curves under a minimal set of assumptions: the emitted photons come from stable timelike circular geodesic orbits of stars in a static spherically symmetric gravitational field, and propagate to us along null geodesics. It is remarkable that this relation can be established without appealing at all to a concrete theory of gravitational interaction. Here we generalize this kinematical spherically symmetric approach to the galactic rotation curves problem to the stationary axisymmetric realm since this is precisely the symmetry that spiral galaxies possess. Thus, by making use of the most general stationary axisymmetric metric, we also consider stable circular orbits of stars that emit signals which travel to a distant observer along null geodesics and express the galactic red/blue shifts in terms of three arbitrary metric functions, clarifying the contribution of the rotation as well as the dragging of the gravitational field. This stationary axisymmetric approach distinguishes between red and blue shifts emitted by circularly orbiting receding and approaching stars, respectively, even when they are considered with respect to the center of a spiral galaxy, indicating the need of precise measurements in order to confront predictions with observations. We also point out the difficulties one encounters in the attempt of determining the metric functions from observations and list some possible strategies to overcome them.Comment: 7 pages in latex (MNRAS format), no figures, discussion and references adde

Inpatient morbidity and cost of cytoreductive radical prostatectomy in the United States

INTRODUCTION AND OBJECTIVES: Clinical trials are currently examining the role of local therapy in metastatic prostate cancer (mPCa). While the safety of RP in localized disease is proven, few studies have looked at perioperative complications and cost of cytoreductive RP (cRP). We used the National Inpatient Sample (NIS) to study the inpatient morbidity, and cost of cRP in the United States (US). METHODS: Analyzing the NIS dataset from 2008-2014, we identified 90,662 patients (weighted estimate 449,025 in the US) who underwent RP for non-metastatic disease, and 1,173 patients (weighted estimate 5,835) who underwent cRP for mPCa (see Fig. 1). Outcomes of interest were inpatient complications, individual complications, hospital stay, and total cost. Covariates included age, race, Charlson Comorbidity score, insurance status, rural/semi-urban/urban location, income, hospital location (rural/urban), teaching status, geographical location of hospital, and hospital volume. Multivariable logistic regression was used to evaluate the effect of metastatic disease on morbidity after adjusting for covariates. RESULTS: Inpatient complication rates were 14.9% (13,688/91,835) overall, 14.9% (13,464/90,662) in the non-metastatic group, and 19.1% (224/1,173) in the cRP group (p = 0.01). On multivariable analysis, metastasis was an independent predictor of inpatient complications (OR 1.329; 95% CI: 1.077-1.640; p = 0.01). The cRP group also had higher rates of blood transfusion (6.9% [82/1,173] vs 4.3% [3,869/90,662]; p \u3c 0.001), longer hospital stay (median 1.25 vs 0.97 days; p \u3c 0.001), and higher cost (median $14,123 vs$11,591; p \u3c 0.001) compared to the non-metastatic group (see table 1). Majority of cRP was performed in urban teaching hospitals. CONCLUSIONS: cRP is associated with higher inpatient morbidity, longer hospital stay, and higher cost compared to RP for non-metastatic disease. This information may be valuable for informed decision-making in practice and before recruiting patients in clinical trials on this subject. Source of Funding: Nonehttps://scholarlycommons.henryford.com/merf2019hvc/1006/thumbnail.jp

Impact of treatment modality on overall survival in localized ductal prostate adenocarcinoma: A National Cancer Database analysis

INTRODUCTION AND OBJECTIVE: Ductal adenocarcinoma is considered a rare histological variant of prostate adenocarcinoma (PCa). Given the rarity of this subtype, optimal treatment strategies for men with nonmetastatic ductal PCa is largely unknown. We aimed to describe the impact of surgery, radiotherapy, and systemic therapy on overall survival (OS) in men with nonmetastatic ductal PCa. METHODS: We retrospectively selected 2209 cases of ductal PCa, diagnosed between 2004 and 2015, within the National Cancer Database (NCDB). Exclusion of metastatic patients yielded a total sample of 1993 individuals. Cox regression analysis tested the impact of treatment (surgery, radiotherapy, systemic therapy and no treatment) on OS. Covariates included age, race, Charlson comorbidity score (CCI), clinical T stage, biopsy Gleason score, serum prostate specific antigen (PSA), and income. Adjusted Kaplan-Meier estimates were used to visualize the impact of treatment modality on OS. RESULTS: In men with nonmetastatic ductal PCa, median (IQR) age and PSA were 67 (61-74) years and 6.3 (4.3-10.8) ng/mL, respectively. Further, 9.8% (n=195) of patients presented with cT3 disease or higher, 3.4% (n=68) presented a CCI score ≥ 4, and 40.6% (808) presented with a Gleason biopsy score ≥ 4. Further, 1212 (60.8%) patients were treated surgically, 406 (20.4%) with radiotherapy, 102 (5.1%) with systemic therapies, and 273 (13.7%) received no treatment. Multivariable analysis showed that in comparison to men treated surgically, OS was significantly lower for patients receiving radiotherapy (HR 2.6; 95% CI 1.7-4.0) and systemic therapies (HR 9.1; 95% CI 5.0-16.5). Adjusted Kaplan-Meier curves are shown in the associated figure. CONCLUSIONS: Our findings show that in the rare ductal PCa variant, starting treatment with surgery offers more favorable long-term OS outcomes than radiotherapy and systemic therapies. While residual selection bias might persist after adjustment, the rarity of this disease precludes the possibility of a future trial, and the presented data represents the best available level of evidence on this topic

1Identification of genes differentially expressed in the embryonic pig cerebral cortex before and after appearance of gyration

<p>Abstract</p> <p>Background</p> <p>Mammalian evolution is characterized by a progressive expansion of the surface area of the cerebral cortex, an increase that is accompanied by gyration of the cortical surface. The mechanisms controlling this gyration process are not well characterized but mutational analyses indicate that genes involved in neuronal migration play an important function. Due to the lack of gyration of the rodent brain it is important to establish alternative models to examine brain development during the gyration process. The pig brain is gyrated and accordingly is a candidate alternative model.</p> <p>Findings</p> <p>In this study we have identified genes differentially expressed in the pig cerebral cortex before and after appearance of gyration. Pig cortical tissue from two time points in development representing a non-folded, lissencephalic, brain (embryonic day 60) and primary-folded, gyrencephalic, brain (embryonic day 80) were examined by whole genome expression microarray studies. 91 differentially expressed transcripts (fold change >3) were identified. 84 transcripts were annotated and encoding proteins involved in for example neuronal migration, calcium binding, and cytoskeletal structuring. Quantitative real-time PCR was used to confirm the regulation of a subset of the identified genes.</p> <p>Conclusion</p> <p>This study provides identification of genes which are differentially expressed in the pig cerebral cortex before and after appearance of brain gyration. The identified genes include novel candidate genes which could have functional importance for brain development.</p

Contrasting prefrontal cortex contributions to episodic memory dysfunction in behavioural variant frontotemporal dementia and alzheimer's disease

Recent evidence has questioned the integrity of episodic memory in behavioural variant frontotemporal dementia (bvFTD), where recall performance is impaired to the same extent as in Alzheimer's disease (AD). While these deficits appear to be mediated by divergent patterns of brain atrophy, there is evidence to suggest that certain prefrontal regions are implicated across both patient groups. In this study we sought to further elucidate the dorsolateral (DLPFC) and ventromedial (VMPFC) prefrontal contributions to episodic memory impairment in bvFTD and AD. Performance on episodic memory tasks and neuropsychological measures typically tapping into either DLPFC or VMPFC functions was assessed in 22 bvFTD, 32 AD patients and 35 age- and education-matched controls. Behaviourally, patient groups did not differ on measures of episodic memory recall or DLPFC-mediated executive functions. BvFTD patients were significantly more impaired on measures of VMPFC-mediated executive functions. Composite measures of the recall, DLPFC and VMPFC task scores were covaried against the T1 MRI scans of all participants to identify regions of atrophy correlating with performance on these tasks. Imaging analysis showed that impaired recall performance is associated with divergent patterns of PFC atrophy in bvFTD and AD. Whereas in bvFTD, PFC atrophy covariates for recall encompassed both DLPFC and VMPFC regions, only the DLPFC was implicated in AD. Our results suggest that episodic memory deficits in bvFTD and AD are underpinned by divergent prefrontal mechanisms. Moreover, we argue that these differences are not adequately captured by existing neuropsychological measures

Patterns of Neurogenesis and Amplitude of Reelin Expression Are Essential for Making a Mammalian-Type Cortex

The mammalian neocortex is characterized as a six-layered laminar structure, in which distinct types of pyramidal neurons are distributed coordinately during embryogenesis. In contrast, no other vertebrate class possesses a brain region that is strictly analogous to the neocortical structure. Although it is widely accepted that the pallium, a dorsal forebrain region, is specified in all vertebrate species, little is known of the differential mechanisms underlying laminated or non-laminated structures in the pallium. Here we show that differences in patterns of neuronal specification and migration provide the pallial architectonic diversity. We compared the neurogenesis in mammalian and avian pallium, focusing on subtype-specific gene expression, and found that the avian pallium generates distinct types of neurons in a spatially restricted manner. Furthermore, expression of Reelin gene is hardly detected in the developing avian pallium, and an experimental increase in Reelin-positive cells in the avian pallium modified radial fiber organization, which resulted in dramatic changes in the morphology of migrating neurons. Our results demonstrate that distinct mechanisms govern the patterns of neuronal specification in mammalian and avian pallial development, and that Reelin-dependent neuronal migration plays a critical role in mammalian type corticogenesis. These lines of evidence shed light on the developmental programs underlying the evolution of the mammalian specific laminated cortex

A flare in the optical spotted in the changing-look Seyfert NGC 3516

We present observations from the short-term intensive optical campaign (from Sep2019 to Jan2020) of the changing-look Seyfert NGC 3516. This active galactic nucleus is known to have strong optical variability and has changed its type in the past. It has been in the low-activity state in the optical since 2013, with some rebrightening from the end of 2015 to the beginning of 2016, after which it remained dormant. We aim to study the photometric and spectral variability of NGC 3516 from the new observations in U- and B-bands and examine the profiles of the optical broad emission lines in order to demonstrate that this object may be entering a new state of activity. NGC 3516 has been monitored intensively for the past 4 months with an automated telescope in U and B filters, enabling accurate photometry of 0.01 precision. Spectral observations were triggered when an increase in brightness was spotted. We support our analysis of past-episodes of violent variability with the UV and X-ray long-term light curves constructed from the archival Swift data. An increase of the photometric magnitude is seen in both U and B filters to a maximum amplitude of 0.25mag and 0.1 mag, respectively. During the flare, we observe stronger forbidden high-ionization iron lines than reported before, as well as the complex broad Ha and Hb lines. This is especially seen in Ha which appears to be double-peaked. It seems that a very broad component of ~10,000 km/s in width in the Balmer lines is appearing. The trends in the optical, UV, and X-ray light curves are similar, with the amplitudes of variability being significantly larger in the case of UV and X-ray bands. The increase of the continuum emission, the variability of the coronal lines, and the very broad component in the Balmer lines may indicate that the AGN of NGC 3516 is finally leaving the low-activity state in which it has been for the last ~3 years.Comment: 7 pages, 6 figures, accepted in A&A (corrected after receiving comments from the language editor

Causal hierarchy within the thalamo-cortical network in spike and wave discharges

Background: Generalised spike wave (GSW) discharges are the electroencephalographic (EEG) hallmark of absence seizures, clinically characterised by a transitory interruption of ongoing activities and impaired consciousness, occurring during states of reduced awareness. Several theories have been proposed to explain the pathophysiology of GSW discharges and the role of thalamus and cortex as generators. In this work we extend the existing theories by hypothesizing a role for the precuneus, a brain region neglected in previous works on GSW generation but already known to be linked to consciousness and awareness. We analysed fMRI data using dynamic causal modelling (DCM) to investigate the effective connectivity between precuneus, thalamus and prefrontal cortex in patients with GSW discharges. Methodology and Principal Findings: We analysed fMRI data from seven patients affected by Idiopathic Generalized Epilepsy (IGE) with frequent GSW discharges and significant GSW-correlated haemodynamic signal changes in the thalamus, the prefrontal cortex and the precuneus. Using DCM we assessed their effective connectivity, i.e. which region drives another region. Three dynamic causal models were constructed: GSW was modelled as autonomous input to the thalamus (model A), ventromedial prefrontal cortex (model B), and precuneus (model C). Bayesian model comparison revealed Model C (GSW as autonomous input to precuneus), to be the best in 5 patients while model A prevailed in two cases. At the group level model C dominated and at the population-level the p value of model C was ∼1. Conclusion: Our results provide strong evidence that activity in the precuneus gates GSW discharges in the thalamo-(fronto) cortical network. This study is the first demonstration of a causal link between haemodynamic changes in the precuneus - an index of awareness - and the occurrence of pathological discharges in epilepsy. © 2009 Vaudano et al

Three-Dimensional Regulation of Radial Glial Functions by Lis1-Nde1 and Dystrophin Glycoprotein Complexes

Lis1-Nde1 integrates cerebral cortical neurogenesis with neuronal migration by stabilizing the basal-lateral surface of radial glial cells