Resolving the signatures of the environmental quenching of star formation with SAMI

In this thesis we use spatially resolved spectroscopy from the SAMI Galaxy Survey to investigate the mechanisms that suppress, or quench, the star formation (SF) in galaxies in dense environments. We calculate integrated star formation rate (SFR) and quantify the distribution of SF in different ways, including the radial distribution of SF and the non-parametric r50,Hα/r50,cont. These measurements are compared to various environment density metrics from the GAMA survey. The spatial signatures of environment quenching vary with the stellar mass of the galaxies. Massive galaxies in dense environments are quenched outside-in, while low mass galaxies do not appear to exhibit such behaviour. We find that the signatures of environment quenching are most likely to be seen in galaxy groups more massive than 1012.5 M⊙. Above this halo mass the fraction of galaxies that appear to be environmentally affected rises significantly. Within groups there is no correlation between the indicators of environment quenching and other measures of environment. From the projected phase-space distribution of the quenching galaxies in the groups, we speculate that the changes in the SF properties of these galaxies must occur over timescales longer than the group dynamical time. Using a case study of 4 galaxies with centrally-concentrated SF and a mass-matched control sample, we study how the gradients in the stellar populations of galaxies change during quenching. We derive stellar population age profiles and find that the quenching galaxies are 0.7 ± 0.6 Gyr older at Re than the controls. Based on their residence in massive groups and their star-formation morphology, we suggest that the outer parts of these galaxies have been quenched by an event that rapidly stripped the gas in their discs, leaving the inner parts of the galaxy to quench by starvation

Asking new questions with old data: The Centralized Open-Access Rehabilitation database for Stroke

Background: This paper introduces a tool for streamlining data integration in rehabilitation science, the Centralized Open-Access Rehabilitation database for Stroke (SCOAR), which allows researchers to quickly visualize relationships among variables, efficiently share data, generate hypotheses, and enhance clinical trial design. Methods: Bibliographic databases were searched according to inclusion criteria leaving 2,892 titles that were further screened to 514 manuscripts to be screened by full text, leaving 215 randomized controlled trials in the database (489 independent groups representing 12,847 patients). Demographic, methodological, and statistical data were extracted by independent coders and entered into SCOAR. Results: Trial data came from 114 locations in 27 different countries and represented patients with a wide range of ages, 62 yr 41; 85, (shown as median range) and at various stages of recovery following their stroke, 141 d 1; 3372. There was considerable variation in the dose of therapy that patients received, 20 h 0; 221, over interventions of different durations, 28 d 10; 365. There was also a lack of common data elements (CDEs) across trials, but this lack of CDEs was most pronounced for baseline assessments of patient impairment and severity of stroke. Conclusions: Data integration across hundreds of RCTs allows clinicians and researchers to quickly visualize data from the history of the field and lays the foundation for making SCOAR a living database to which researchers can upload new data as trial results are published. SCOAR is a useful tool for clinicians and researchers that will facilitate data visualization, data sharing, the finding of relevant past studies, and the design of clinical trials by enabling more accurate and comprehensive power analyses. Furthermore, these data speak to the need for CDEs specific to stroke rehabilitation in randomized controlled trials.PROSPERO# CRD420140901

A significant problem with using the Amati relation for cosmological purposes

We consider the distribution of many samples of gamma-ray bursts when plotted in a diagram with their bolometric fluence (Sbolo) versus the observed photon energy of peak spectral flux (E peak, obs). In this diagram, all bursts that obey the Amati relation (a luminosity relation where the total burst energy has a power-law relation to E peak, obs) must lie above some limiting line, although observational scatter is expected to be substantial. We confirm that early bursts with spectroscopic redshifts are consistent with this Amati limit. But we find that the bursts from BATSE, Swift, Suzaku, and Konus are all greatly in violation of the Amati limit, and this is true whether or not the bursts have measured spectroscopic redshifts. That is, the Amati relation has definitely failed. In the S bolo-E peak, obs diagram, wefind that every satellite has a greatly different distribution. This requires that selection effects are dominating these distributions, which we quantitatively identify. For detector selections, the trigger threshold and the threshold for the burst to obtain a measured E peak, obs combine to make a diagonal cutoff with the position of this cutoff varying greatly detector to detector. For selection effects due to the intrinsic properties of the burst population, the distribution of E peak, obs makes bursts with low and high values rare, while the fluence distribution makes bright bursts relatively uncommon. For a detector with a high threshold, the combination of these selection effects serves to allow only bursts within a region along the Amati limit line to be measured, and these bursts will then appear to follow an Amati relation. Therefore, the Amati relation is an artifact of selection effects within the burst population and the detector. As such, the Amati relation should not be used for cosmological tasks. This failure of the Amati relation is in no way prejudicial against the other luminosity relations. © 2012. The American Astronomical Society. All rights reserved

In vitro induction of Entamoeba gingivalis cyst-like structures from trophozoites in response to antibiotic treatment

Background: Entamoeba gingivalis (E. gingivalis) is an anaerobic protozoan that is strongly associated with inflamed periodontal pockets. It is able to invade the mucosal epithelium of the human host, where it can feed on epithelial cells and elicit a severe innate immune response. Unlike other Entamoeba species, it is considered that E. gingivalis cannot form cysts, because it is a non-infectious protozoan. The lack of encystation capability would make it susceptible to periodontal treatment. However, it is not clear how the human host becomes infected with E. gingivalis trophozoites. We investigated the ability of E. gingivalis to encapsulate in response to an unfavorable environment in vitro. Methods: Different strains of E. gingivalis, isolated from inflamed periodontal pocket samples, were cultured for 8 days in the presence or absence of the antimicrobials amoxycillin and metronidazole. To reveal cyst formation, we investigated the morphology and ultrastructure of the amoeba by light, fluorescence, transmission and scanning electron microscopy. We also used the fluorescent dye calcofluor white M2R to demonstrate chitin present in the cyst wall. Results: We observed exocysts and an intra-cystic space separating the encapsulated trophozoite from the environment. Remarkably, cysts showed a smooth surface, polygonal edges and smaller size compared to free-living trophozoites. In addition, encapsulated trophozoites that detached from the cyst wall had a dense cytoplasma without phagocytic vesicles. The cyst walls consisted of chitin as in other Entamoba species. The encapsulated trophozoids were mononuclear after antibioticinduced encapsulation. Discussion: We conclude that E. gingivalis cyst formation has significant implications for dissemination and infection and may explain why established treatment approaches often fail to halt periodontal tissue destruction during periodontitis and peri-implantitis.Peer Reviewe

Risk Factors for Colonization of E. coli in Atlantic Bottlenose Dolphins (Tursiops truncatus) in the Indian River Lagoon, Florida

Opportunistic pathogens related to degradation in water quality are of concern to both wildlife and public health. The objective of this study was to identify spatial, temporal, and environmental risk factors for E. coli colonization among Atlantic bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon (IRL), FL between 2003 and 2007. Age, gender, capture location, coastal human population density, proximity of sewage treatment plants, number of septic tanks, cumulative precipitation 48 hrs and 30 days prior to capture, salinity, and water temperature were analyzed as potential risk factors. Highest E. coli colonization rates occurred in the northern segments of the IRL. The risk of E. coli colonization was the highest among the youngest individuals, in counties with the highest cumulative rainfall 48 hrs and in counties with the highest number of septic systems during the year of capture. The prevalence of colonization was the highest during 2004, a year during which multiple hurricanes hit the coast of Florida. Septic tanks, in combination with weather-related events suggest a possible pathway for introduction of fecal coliforms into estuarine ecosystems. The ability of E. coli and related bacteria to act as primary pathogens or cause opportunistic infections adds importance of these findings

Predictors of New-Onset Atrial Fibrillation in Geriatric Trauma Patients

Geriatric patients (age \u3e65) comprise a growing segment of the trauma population. New-onset atrial fibrillation may occur after injury, complicating clinical management and resulting in significant morbidity and mortality. This study was undertaken to identify clinical and demographic factors associated with new-onset atrial fibrillation among geriatric trauma patients . Methods: In this case control study, eligible participants included admitted trauma patients age 65 and older who developed new-onset atrial fibrillation during the hospitalization. Controls were admitted trauma patients who were matched for age and injury severity score, who did not develop atrial fibrillation. We evaluated the associations between new-onset atrial fibrillation and clinical characteristics, including patient demographics, health behaviors, chronic medical conditions, and course of care. Results: Data were available for 63 cases and 25 controls. Patients who developed atrial fibrillation were more likely to be male, compared to controls (49% versus 24%; odds ratio 3.0[1.0, 8.9]). Other demographic and clinical factors were not associated with new-onset atrial fibrillation, including mechanism of injury, co-morbid medical conditions, drug or alcohol use, surgical procedures, and intravenous fluid administration. Conclusions: Male geriatric trauma patients were at higher risk for developing new-onset atrial fibrillation. Other demographic and clinical factors were not associated with new-onset atrial fibrillation. Competing Interests: The authors report no conflicts of interest