398 research outputs found
The KELT-South Telescope
The Kilodegree Extremely Little Telescope (KELT) project is a survey for new
transiting planets around bright stars. KELT-South is a small-aperture,
wide-field automated telescope located at Sutherland, South Africa. The
telescope surveys a set of 26 degree by 26 degree fields around the southern
sky, and targets stars in the range of 8 < V < 10 mag, searching for transits
by Hot Jupiters. This paper describes the KELT-South system hardware and
software and discusses the quality of the observations. We show that KELT-South
is able to achieve the necessary photometric precision to detect transits of
Hot Jupiters around solar-type main-sequence stars.Comment: 26 pages, 13 figure
Living in God's time: African-American faith and politics in post-emancipation North Carolina
This dissertation argues that black southerners' theology guided their collective action from emancipation to the beginning of the Jim Crow era. Black theology in this time produced both conservative and radical political agendas and set the terms for political debates within African-American communities. This project makes their rich, diverse, and at times confusing religious thought intelligible to the twenty-first-century reader and demonstrates the weight of those theological ideas on the ground in particular places and particular times. The branch of their theology that located them within a divine plan for the race--their eschatology--gave black political leaders more hope and confidence than a mere secular reading of their circumstances could justify. The dissertation focuses on one southern state, North Carolina, to reveal the importance of black theology to local and statewide political issues: emancipation and Reconstruction, migration and black land ownership, temperance and prohibition, and disfranchisement and segregation
Identifying Parkinson’s Disease Through the Classification of Audio Recording Data
Developments in artificial intelligence can be leveraged to support the diagnosis of degenerative disorders, such as epilepsy and Parkinson’s disease. This study aims to provide a software solution, focused initially towards Parkinson’s disease, which can positively impact medical practice surrounding degenerative diagnoses. Through the use of a dataset containing numerical data representing acoustic features extracted from an audio recording of an individual, it is determined if a neural approach can provide an improvement over previous results in the area. This is achieved through the implementation of a feedforward neural network and a layer recurrent neural network. By comparison with the state-of-the-art, a Bayesian approach providing a classification accuracy benchmark of 87.1%, it is found that the implemented neural networks are capable of average accuracy of 96%, highlighting improved accuracy for the classification process. The solution is capable of supporting the diagnosis of Parkinson’s disease in an advisory capacity and is envisioned to inform the process of referral through general practice
Prevalence, risk factors and awareness of albuminuria on a Canadian First Nation: A community-based screening study
BACKGROUND: Both diabetic and non-diabetic end stage renal disease (ESRD) are more common among Canadian First Nations people than among the general Canadian population. The purpose of this research was to determine the prevalence of and risk factors for albuminuria in a Canadian First Nation population at high risk for ESRD and dialysis. METHODS: Data from a community-based screening study of 483 residents of a Plains Ojibway First Nation in Manitoba was used. Participants provided random urine samples. Proteinuria was defined as any dipstick positive for protein (≥1 g/L) or those with ACR in the macroalbuminuric range (≥30 mg/mmol) on at least one sample. Microalbuminuria was defined as ACR ≥2 mg/mmol for males and ≥2.8 mg/mmol for females. Other measures included fasting glucose, haemoglobin A(1c), triglycerides, cholesterol, blood pressure, height, weight and waist and hip circumferences. RESULTS: Twenty percent of study participants had albuminuria, (5% proteinuria and 15% microalbuminuria). Of participants with diabetes, 42% (56/132) had albuminuria compared to 26% (7/27) among those with impaired fasting glucose and 10% (30/303) among those with normal glucose tolerance. Only 5.3% of those with albuminuria were aware of any degree of renal disease. In a multivariate logistic regression, independent associations with albuminuria were male gender [p = 0.002], increasing fasting glucose [p <0.0001], years diagnosed with diabetes [p = 0.03], increasing systolic blood pressure [p = 0.009], and increasing body mass index (BMI) [p = 0.04]. CONCLUSIONS: The independent association between BMI and albuminuria has not been previously reported among indigenous populations. There is a high prevalence of albuminuria in this Canadian First Nation population; the high proportion of patients with diabetes and undiagnosed kidney disease demonstrates the need for screening, education and intervention to halt the progression and development of albuminuria and ultimately ESRD and CVD
A New X-Ray Analysis of the Open Cluster Blanco 1 Using Wide-Field BVIc Photometric and Proper Motion Surveys
We perform a new analysis of the extant ROSAT and XMM-Newton X-ray surveys of
the southern open cluster Blanco 1, utilizing new BVIc photometric and proper
motion data sets. In our study, we match optical counterparts to 47 X-ray
sources associated with Blanco 1 cluster members, 6 of which were listed in
previous X-ray studies as cluster nonmembers. Our new catalog of optical
counterparts to X-ray sources clearly traces out the Blanco 1 main sequence in
a CMD, extending from early G to mid-M spectral types. Additionally, we derive
new Lx as well as Lx/Lbol ratios for confirmed cluster members. We compare
these X-ray properties to other young open clusters, including the coeval
Pleiades cluster, to investigate the relationship between age and X-ray
activity. We find that stars in Blanco 1 generally exhibit X-ray properties
similar to those of other open clusters, namely increasing Lx/Lbol with
reducing mass for earlier-type stars, and a saturation limit of Lx/Lbol at a
magnitude of 10^-3 for stars with V-Ic > 1.25. More generally, the X-ray
detected stars in Blanco 1 have X-ray emission magnitudes that agree with the
overall trends seen in the other young clusters. In a direct comparison of
Blanco 1 to the Pleiades open cluster, members of both clusters have similar
X-ray characteristics; however, there does appear to be some discrepancies in
the distribution of Lx/Lbol as a function of color that may be related to
scatter seen in the Pleiades CMD. Moreover, previous comparisons of this nature
for Blanco 1 were not possible due to the reliance on photographic photometry.
This is where the power of precise, homogeneous, and standardized CCD
photometry allows for a high fidelity, detailed study of the X-ray properties
of stars in Blanco 1. [abridged]Comment: 16 Pages, 11 Figures, 4 Tables, accepted for publication in The
Astronomical Journa
Hepatitis B Vaccination for Patients with Chronic Renal Failure
Background Chronic renal failure patients are at particular risk of hepatitis B virus infection. Early studies have demonstrated that renal failure patients benefit from vaccination; however, not all studies have consistently shown benefit.
Objectives To determine the beneficial and harmful effects of hepatitis B vaccine and of a reinforced vaccination series in chronic renal failure patients.
Search methods We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Renal Group Controlled Trials Register, The Cochrane Controlled Trials Register on The Cochrane Library (Issue 1, 2002), PubMed/MEDLINE (1966 to July 2003), EMBASE (1985 toNovember 2003), Current Clinical Practice Guidelines (Canadian Immunization Guide and Vaccine Preventable Diseases Surveillance Manual), and Science Citation Index as well as journals, published abstracts, and reference lists of articles.
Selection criteria Randomised clinical trials comparing plasma vaccine with placebo, recombinant vaccine with placebo, recombinant vaccine with plasma vaccine, and a reinforced vaccination series (ie, more than three inoculations) with three inoculations of vaccine in chronic renal failure patients.
Data collection and analysis Primary outcome measures included incidence of patients developing hepatitis B virus antibodies and infections while secondary outcomes included adverse events, liver-related morbidity, and mortality. Random effects models were used and reported relative risks and 95% confidence intervals (RR and 95% CI).
Main results We included seven randomised clinical trials. None of them had high quality. Plasma vaccine was significantly more effective than placebo in achieving hepatitis B antibodies (RR 23.0, 95% CI 14.39 to 36.76, 3 trials). We found no statistically significant difference between plasma vaccine or placebo regarding hepatitis B virus infections (RR 0.50, 95% CI 0.20 to 1.24). We found no statistically significant differences between recombinant vaccine and plasma vaccine in achieving hepatitis B antibodies (RR 0.65, 95% CI 0.28 to 1.53, 2 trials). Heterogeneity was significant and appeared to be attributable to the dose of vaccine. Two trials examined a reinforced recombinant vaccine strategy, which was not statistically more effective than three inoculations of recombinant vaccine regarding development of hepatitis B antibodies (RR 1.36, 95% CI 0.85 to 2.16).
Authors’ conclusions Plasma derived vaccines are more effective than placebo in achieving hepatitis B antibodies, while no statistically significant difference was found between recombinant and plasma vaccines. No statistically significant difference of effectiveness was observed between a reinforced vaccination series versus routine vaccinations of three inoculations of recombinant vaccine
Deep, Wide-field CCD Photometry for the Open Cluster NGC3532
We present the results of a deep, wide-field CCD survey for the open cluster
NGC~3532. Our new photometry effectively covers a one square
degree area and reaches an unprecedented depth of to reveal that
NGC~3532 is a rich open cluster that harbors a large number of faint, low-mass
stars. We employ a number of methods to reduce the impact of field star
contamination in the cluster color-magnitude diagrams, including supplementing
our photometry with data from the 2MASS catalog. These efforts allow
us to define a robust sample of candidate main sequence stars suitable for a
purely empirical determination of the cluster's parameters by comparing them to
the well-established Hyades main sequence. Our results confirm previous
findings that NGC~3532 lies fairly near to the Sun [;
~pc] and has an extremely low reddening for its location near
the Galactic plane []. Moreover, an age of \,Myr
has been derived for the cluster by fitting a set of overshooting isochrones to
the well-populated upper main-sequence. This new photometry also extends faint
enough to reach the cluster white dwarf sequence, as confirmed by our
photometric recovery of eight spectroscopically identified members of the
cluster. Using the location of these eight members, along with the latest
theoretical cooling tracks, we have identified additional white dwarf
stars in the color-magnitude diagram that have a high probability
of belonging to NGC~3532. The age we derive from fitting white dwarf isochrones
to the locus of these stars, \,Myr, is consistent with the age
derived from the turnoff. Our analysis of the photometry also includes an
estimation of the binary star fraction, as well as a determination of the
cluster's luminosity and mass functions.Comment: Accepted for publication in AJ. 55 pages, 21 figures. High-quality
version with complete data tables can be downloaded from
http://www.phys.lsu.edu/~jclem/NGC3532
A Hot DQ White Dwarf in the Open Star Cluster M35
We report the discovery of a hot DQ white dwarf, NGC 2168:LAWDS 28, that is a
likely member of the 150-Myr old cluster NGC 2168 (Messier 35). The spectrum of
the white dwarf is dominated by CII features. The effective temperature is
difficult to estimate but likely > 20,000 K based on the temperatures of hot
DQs with similar spectra. NGC2168:LAWDS 28 provides further evidence that hot
DQs may be the ``missing'' high-mass helium-atmosphere white dwarfs. Based on
published studies, we find that the DBA WD LP 475-242 is likely a member of the
Hyades open cluster, as often assumed. These two white dwarfs are the entire
sample of known He-atmosphere white dwarfs in open clusters with turnoff masses
>2 solar masses. Based on the number of known cluster DA white dwarfs and a
redetermination of the H-atmosphere:He-atmosphere ratio, commonly known as the
DA:DB ratio, we re-examine the hypothesis that the H- to He-atmosphere ratio in
open clusters is the same as the ratio in the field. Under this hypothesis, we
calculate that five He-atmosphere WDs are expected to have been discovered,
with a probability of finding fewer than three He-atmosphere white dwarfs of
0.08, or at the ~ 2-sigma level.Comment: 9 pages with 2 figures, uses LaTeX/AASTeX 5.2. Accepted for
publications in ApJ Letter
- …