University of Alabama

About: University of Alabama is a education organization based out in Tuscaloosa, Alabama, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 27323 authors who have published 48609 publications receiving 1565337 citations. The organization is also known as: Alabama & Bama.

The spitzer survey of stellar structure in galaxies (s^4g)

Abstract: The Spitzer Survey of Stellar Structure in Galaxies (S^4G) is an Exploration Science Legacy Program approved for the Spitzer post–cryogenic mission. It is a volume-, magnitude-, and size-limited (d < 40 Mpc, |b|> 30°,m_(Bcorr) 1') survey of 2331 galaxies using the Infrared Array Camera (IRAC) at 3.6 and 4.5 μm. Each galaxy is observed for 240 s and mapped to ≥ 1:5 × D_(25). The final mosaicked images have a typical 1 σ rms noise level of 0.0072 and 0:0093 MJy sr^-1 at 3.6 and 4.5 μm, respectively. Our azimuthally averaged surface brightness profile typically traces isophotes at μ_(3.6μm (AB)(1σ) ~ 27 mag arcsec^(-2), equivalent to a stellar mass surface density of ~1 M_⊙pc^(-2). S^4G thus provides an unprecedented data set for the study of the distribution of mass and stellar structures in the local universe. This large, unbiased, and extremely deep sample of all Hubble types from dwarfs to spirals to ellipticals will allow for detailed structural studies, not only as a function of stellar mass, but also as a function of the local environment. The data from this survey will serve as a vital testbed for cosmological simulations predicting the stellar mass properties of present-day galaxies. This article introduces the survey and describes the sample selection, the significance of the 3.6 and 4.5 μm bands for this study, and the data collection and survey strategies. We describe the S^4G data analysis pipeline and present measurements for a first set of galaxies, observed in both the cryogenic and warm mission phases of Spitzer. For every galaxy we tabulate the galaxy diameter, position angle, axial ratio, inclination at μ_(3.6μm)(AB) = 25:5, and 26:5 mag arcsec^(-2) (equivalent to ≈μ_B(AB) = 27:2 and 28:2 mag arcsec^(-2), respectively). These measurements will form the initial S^4G catalog of galaxy properties. We also measure the total magnitude and the azimuthally averaged radial profiles of ellipticity, position angle, surface brightness, and color. Finally, using the galaxy-fitting code GALFIT, we deconstruct each galaxy into its main constituent stellar components: the bulge/spheroid, disk, bar, and nuclear point source, where necessary. Together, these data products will provide a comprehensive and definitive catalog of stellar structures, mass, and properties of galaxies in the nearby universe and will enable a variety of scientific investigations, some of which are highlighted in this introductory S^4G survey paper.

Detection of Faults and Attacks Including False Data Injection Attack in Smart Grid Using Kalman Filter

Abstract: By exploiting the communication infrastructure among the sensors, actuators, and control systems, attackers may compromise the security of smart-grid systems, with techniques such as denial-of-service (DoS) attack, random attack, and data-injection attack. In this paper, we present a mathematical model of the system to study these pitfalls and propose a robust security framework for the smart grid. Our framework adopts the Kalman filter to estimate the variables of a wide range of state processes in the model. The estimates from the Kalman filter and the system readings are then fed into the $\chi^{2}$ -detector or the proposed Euclidean detector. The $\chi^{2}$ -detector is a proven effective exploratory method used with the Kalman filter for the measurement of the relationship between dependent variables and a series of predictor variables. The $\chi^{2}$ -detector can detect system faults/attacks, such as DoS attack, short-term, and long-term random attacks. However, the studies show that the $\chi^{2}$ -detector is unable to detect the statistically derived false data-injection attack. To overcome this limitation, we prove that the Euclidean detector can effectively detect such a sophisticated injection attack.

Guidelines for the management of acute cervical spine and spinal cord injuries: 2013 update.

Abstract: In 2002, an author group selected and sponsored by the Joint Section on Spine and Peripheral Nerves of the American Association of Neurological Surgeons and Congress of Neurological Surgeons published the first evidence-based guidelines for the management of patients with acute cervical spinal cord injuries (SCIs). In the spirit of keeping up with changes in information available in the medical literature that might provide more contemporary and more robust medical evidence, another author group was recruited to revise and update the guidelines. The review process has been completed and is published and can be once again found as a supplement to Neurosurgery. The purpose of this article is to provide an overview of the changes in the recommendations as a result of new evidence or broadened scope.

Screening by Chest Radiograph and Lung Cancer Mortality: The Prostate, Lung, Colorectal, and Ovarian (PLCO) Randomized Trial

Abstract: Context The effect on mortality of screening for lung cancer with modern chest radiographs is unknown Objective To evaluate the effect on mortality of screening for lung cancer using radiographs in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial Design, Setting, and Participants Randomized controlled trial that involved 154 901 participants aged 55 through 74 years, 77 445 of whom were assigned to annual screenings and 77 456 to usual care at 1 of 10 screening centers across the United States between November 1993 and July 2001 The data from a subset of eligible participants for the National Lung Screening Trial (NLST), which compared chest radiograph with spiral computed tomographic (CT) screening, were analyzed Intervention Participants in the intervention group were offered annual posteroanterior view chest radiograph for 4 years Diagnostic follow-up of positive screening results was determined by participants and their health care practitioners Participants in the usual care group were offered no interventions and received their usual medical care All diagnosed cancers, deaths, and causes of death were ascertained through the earlier of 13 years of follow-up or until December 31, 2009 Main Outcome Measures Mortality from lung cancer Secondary outcomes included lung cancer incidence, complications associated with diagnostic procedures, and all-cause mortality Results Screening adherence was 866% at baseline and 79% to 84% at years 1 through 3; the rate of screening use in the usual care group was 11% Cumulative lung cancer incidence rates through 13 years of follow-up were 201 per 10 000 person-years in the intervention group and 192 per 10 000 person-years in the usual care group (rate ratio [RR]; 105, 95% CI, 098-112) A total of 1213 lung cancer deaths were observed in the intervention group compared with 1230 in usual care group through 13 years (mortality RR, 099; 95% CI, 087-122) Stage and histology were similar between the 2 groups The RR of mortality for the subset of participants eligible for the NLST, over the same 6-year follow-up period, was 094 (95% CI, 081-110) Conclusion Annual screening with chest radiograph did not reduce lung cancer mortality compared with usual care Trial Registration clinicaltrialsgov Identifier: NCT00002540

Impact of a physiologic definition on bronchopulmonary dysplasia rates.

Abstract: Objective. Bronchopulmonary dysplasia (BPD) is the endpoint of many intervention trials in neonatology, yet the outcome measure when based solely on oxygen administration may be confounded by differing criteria for oxygen administration between physicians. We previously reported a technique to standardize the definition of BPD between sites by using a timed room-air challenge in selected infants. We hypothesized that a physiologic definition of BPD would reduce the variation in observed rates of BPD among different neonatal centers. Methodology. A total of 1598 consecutive inborn premature infants (501–1249 g birth weight) who remained hospitalized at 36 weeks9 postmenstrual age were prospectively assessed and assigned an outcome with both a clinical definition and physiologic definition of BPD. The clinical definition of BPD was oxygen supplementation at exactly 36 weeks9 postmenstrual age. The physiologic definition of BPD was assigned at 36 ± 1 weeks9 postmenstrual age and included 2 distinct subpopulations. First, neonates on positive pressure support or receiving >30% supplemental oxygen with saturations between 90% and 96% were assigned the outcome BPD and not tested further. Second, those receiving ≤30% oxygen or effective oxygen >30% with saturations >96% underwent a room-air challenge with continuous observation and oxygen-saturation monitoring. Outcomes of the room-air challenge were “no BPD” (saturations ≥90% during weaning and in room air for 30 minutes) or “BPD” (saturation Results. A total of 560 (35.0%) neonates were diagnosed with BPD by the clinical definition of oxygen use at 36 weeks9 postmenstrual age. The physiologic definition diagnosed BPD in 398 (25.0%) neonates in the cohort. All infants were safely studied. There were marked differences in the impact of the definition on BPD rates between centers (mean reduction: 10%; range: 0–44%). Sixteen centers had a decrease in their BPD rate, and 1 center had no change in their rate. Conclusions. The physiologic definition of BPD reduced the overall rate of BPD and reduced the variation among centers. Significant center differences in the impact of the physiologic definition were seen, and differences remained even with the use of this standardized definition. The magnitude of the change in BPD rate is comparable to the magnitude of treatment effects seen in some clinical trials in BPD. The physiologic definition of BPD facilitates the measurement of BPD as an outcome in clinical trials and the comparison between and within centers over time.