5,584 research outputs found
Approximating a Wavefunction as an Unconstrained Sum of Slater Determinants
The wavefunction for the multiparticle Schr\"odinger equation is a function
of many variables and satisfies an antisymmetry condition, so it is natural to
approximate it as a sum of Slater determinants. Many current methods do so, but
they impose additional structural constraints on the determinants, such as
orthogonality between orbitals or an excitation pattern. We present a method
without any such constraints, by which we hope to obtain much more efficient
expansions, and insight into the inherent structure of the wavefunction. We use
an integral formulation of the problem, a Green's function iteration, and a
fitting procedure based on the computational paradigm of separated
representations. The core procedure is the construction and solution of a
matrix-integral system derived from antisymmetric inner products involving the
potential operators. We show how to construct and solve this system with
computational complexity competitive with current methods.Comment: 30 page
Delusions in frontotemporal lobar degeneration
We assessed the significance and nature of delusions in frontotemporal lobar degeneration (FTLD), an important cause of young-onset dementia with prominent neuropsychiatric features that remain incompletely characterised. The case notes of all patients meeting diagnostic criteria for FTLD attending a tertiary level cognitive disorders clinic over a three year period were retrospectively reviewed and eight patients with a history of delusions were identified. All patients underwent detailed clinical and neuropsychological evaluation and brain MRI. The diagnosis was confirmed pathologically in two cases. The estimated prevalence of delusions was 14 %. Delusions were an early, prominent and persistent feature. They were phenomenologically diverse; however paranoid and somatic delusions were prominent. Behavioural variant FTLD was the most frequently associated clinical subtype and cerebral atrophy was bilateral or predominantly right-sided in most cases. We conclude that delusions may be a clinical issue in FTLD, and this should be explored further in future work
Monitoring Fatigue During the In-Season Competitive Phase in Elite Soccer Players.
Purpose:To quantify the relationship between daily training load and a range of potential measures of fatigue in elite soccer players during an in-season competitive phase (17 d).Methods:Total high-intensity-running (THIR) distance, perceived ratings of wellness (fatigue, muscle soreness, sleep quality), countermovement-jump height (CMJ), postexercise heart-rate recovery (HRR), and heart-rate variability (Ln rMSSD) were analyzed during an in-season competitive period (17 d). General linear models were used to evaluate the influence of daily fluctuation in THIR distance on potential fatigue variables.Results:Fluctuations in fatigue (r = −.51, large, P < .001), Ln rMSSD (r = −.24, small, P = .04), and CMJ (r = .23, small, P = .04) were significantly correlated with fluctuations in THIR distance. Correlations between variability in muscle soreness, sleep quality, and HRR and THIR distance were negligible and not statistically significant.Conclusions:Perceived ratings of fatigue and Ln rMSSD were sensitive to daily fluctuations in THIR distance in a sample of elite soccer players. Therefore, these particular markers show promise as simple, noninvasive assessments of fatigue status in elite soccer players during a short in-season competitive phase.</jats:sec
VLBA Continuum and H I Absorption Observations of the Ultra-Luminous Infrared Galaxy IRAS 17208-0014
We present phase-referenced VLBI observations of the radio continuum emission
from, and the neutral hydrogen 21 cm absorption toward, the Ultra-Luminous
Infrared Galaxy IRAS 17208-0014. The observations were carried out at 1362 MHz
using the Very Long Baseline Array, including the phased Very Large Array as an
element. The high-resolution radio continuum images reveal a nuclear starburst
region in this galaxy, which is composed of diffuse emission approximately 670
x 340 pc on the plane of the sky, and a number of compact sources. These
sources are most likely to be clustered supernova remnants and/or luminous
radio supernovae. Their brightness temperatures range over (2.2-6.6) x 10^{5}
K, with radio spectral luminosities between (1-10) x 10^{21} W Hz^{-1}. The
total VLBI flux density of the starburst region is ~52 mJy, which is about 50%
of the total flux density detected with the VLA at arcsecond resolution. For
this galaxy, we derive a massive star formation rate of ~84pm13 M{_\odot}
yr^{-1}, and a supernova rate of ~4pm1 yr^{-1}. H I absorption is detected in
multiple components with optical depths ranging between 0.3 and 2.5, and
velocity widths between 58 and 232 km s^{-1}. The derived column densities,
assuming T_{s}=100 K, range over (10-26) x 10^{21} cm^{-2}. The H I absorption
shows a strong velocity gradient of 453 km s^{-1} across 0.36 arcsec (274 pc).
Assuming Keplerian motion, the enclosed dynamical mass is about 2.3 x 10^9
sin^{-2}i M{_\odot}, comparable to the enclosed dynamical mass estimated from
CO observations.Comment: 26 pages total, 6 figures. ApJ accepted. To appear in the April 1,
2003 issue of ApJ. For a version with better images, see
http://www.aoc.nrao.edu/~emomjian/IRAS.p
Effectiveness of iGlarLixi (Insulin Glargine-Lixisenatide) in People with Type 2 Diabetes According to the Time of Administration through the Day
Attoyac Bayou Bacterial Source Tracking Report
The Attoyac Bayou, a sub-watershed within the Upper Neches River Watershed, extends approximately 82 miles through Rusk, Nacogdoches, San Augustine and Shelby counties before emptying into Sam Rayburn Reservoir. With several rural communities in the area, the majority of the land in the watershed is used for cattle and poultry operations, forestry or recreational and wildlife uses. The bayou is listed as an impaired water body on the Texas Integrated Report for Clean Water Act Sections 305(b) and 303(d) due to high levels of E. coli. Three monitoring stations managed by the Angelina & Neches River Authority, U.S. Geological Survey, and Texas Commission on Environmental Quality have provided water quality data on the bayou for a number of years. Beginning in 2000, data collected for E. coli have consistently shown elevated E. coli levels that exceed the applicable Texas Water Quality Standards. Through the Development of a Watershed Protection Plan for Attoyac Bayou project, additional water quality and stream flow data was collected to better understand E. coli loadings to the water body
Type 0A 2D Black Hole Thermodynamics and the Deformed Matrix Model
Recently, it has been proposed that the deformed matrix model describes a
two-dimensional type 0A extremal black hole. In this paper, the thermodynamics
of 0A charged non-extremal black holes is investigated. We observe that the
free energy of the deformed matrix model to leading order in 1/q can be seen to
agree to that of the extremal black hole. We also speculate on how the deformed
matrix model is able to describe the thermodynamics of non-extremal black
holes.Comment: 12 page
Incidence and risk factors for disease and non-battle injury aboard the hospital ship USNS COMFORT during a Humanitarian Assistance and Disaster Response Mission, Continuing Promise 2011
Behavioral strategies during incubation influence nest and female survival of Wild Turkeys
Females must balance physiological and behavioral demands of producing offspring with associated expenditures, such as resource acquisition and predator avoidance. Nest success is an important parameter underlying avian population dynamics. Galliforms are particularly susceptible to low nest success due to exposure of ground nests to multiple predator guilds, lengthy incubation periods, and substantive reliance on crypsis for survival. Hence, it is plausible that nesting individuals prioritize productivity and survival differently, resulting in a gradient of reproductive strategies. Fine-scale movement patterns during incubation are not well documented in ground-nesting birds, and the influence of reproductive movements on survival is largely unknown. Using GPS data collected from female wild turkeys (n = 278) across the southeastern United States, we evaluated the influence of incubation recess behaviors on trade-offs between nest and female survival. We quantified daily recess behaviors including recess duration, recess frequency, total distance traveled, and incubation range size for each nest attempt as well as covariates for nest concealment, nest attempt, and nest age. Of 374 nests, 91 (24%) hatched and 39 (14%) females were depredated during incubation. Average nest survival during the incubation period was 0.19, whereas average female survival was 0.78. On average, females took 1.6 daily unique recesses (SD = 1.2), spent 2.1 hr off the nest each day (SD = 1.8), and traveled 357.6 m during recesses (SD = 396.6). Average nest concealment was 92.5 cm (SD = 47). We found that females who took longer recess bouts had higher individual survival, but had increased nest loss. Females who recessed more frequently had lower individual survival. Our findings suggest behavioral decisions made during incubation represent life-history trade-offs between predation risk and reproductive success on an unpredictable landscape
Characteristics of patients with atrial high rate episodes detected by implanted defibrillator and resynchronization devices
AIMS: Atrial high rate episodes (AHREs) are associated with increased risks of thromboembolism and cardiovascular mortality. However, the clinical characteristics of patients developing AHRE of various durations are not well studied. METHODS AND RESULTS: This was an ancillary analysis of the multicentre, randomized IMPACT trial. In the present analysis, we classified patients according to the duration of AHRE ≤6 min, >6 min to ≤6 h, >6 to ≤24 h and >24 h, and investigated the association between clinical factors and the development of each duration of AHRE. Of 2718 patients included in the trial, 945 (34.8%) developed AHRE. The incidence rates of each AHRE duration category were 5.4/100, 12.0/100, 6.8/100, and 3.3/100 patient-years, respectively. The incidence rates of AHRE >6 h were significantly higher in patients at high risk of thromboembolism (CHADS(2) score ≥3) compared to those at low risk (CHADS(2) score 1 or 2). Using Cox regression analysis, age ≥65 years and history of atrial fibrillation (AF) and/or atrial flutter (AFL) were risk factors for AHRE >6 min. In addition, hypertension was associated with AHRE >24 h (hazard ratio 2.13, 95% confidence interval 1.24–3.65, P = 0.006). CONCLUSION: Atrial high rate episode >6 min to ≤6 h were most prevalent among all AHRE duration categories. Longer AHREs were more common in patients at risk of thromboembolism. Age and history of AF/AFL were risk factors for AHRE >6 min. Furthermore, hypertension showed a strong impact on the development of AHRE >24 h rather than age
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