1,084 research outputs found
Recommended from our members
Endoscopy is of low yield in the identification of gastrointestinal neoplasia in patients with dermatomyositis: A cross-sectional study.
AimTo determine the prevalence of gastrointestinal neoplasia among dermatomyositis patients who underwent an esophagogastroduodenoscopy and/or colonoscopy.MethodsA cross-sectional study examining the results of upper endoscopy and colonoscopy in adults with dermatomyositis at an urban, university hospital over a ten year period was performed. Chart review was performed to confirm the diagnosis of dermatomyositis. Findings on endoscopy were collected and statistical analyses stratified by age and presence of symptoms were performed.ResultsAmong 373 adult patients identified through a code based search strategy, only 163 patients had dermatomyositis confirmed by chart review. Of the 47 patients who underwent upper endoscopy, two cases of Barrett's esophagus without dysplasia were identified and there were no cases of malignancy. Of the 67 patients who underwent colonoscopy, no cases of malignancy were identified and an adenoma was identified in 15% of cases. No significant differences were identified in the yield of endoscopy when stratified by age or presence of symptoms.ConclusionThe yield of endoscopy is low in patients with dermatomyositis and is likely similar to the general population; we identified no cases of malignancy. A code based search strategy is inaccurate for the diagnosis of dermatomyositis, calling into question the results of prior population-based studies. Larger studies with rigorously validated search strategies are necessary to understand the risk of gastrointestinal malignancy in patients with dermatomyositis
Black Hole Attractors and the Topological String
A simple relationship of the form Z_BH = |Z_top|^2 is conjectured, where Z_BH
is a supersymmetric partition function for a four-dimensional BPS black hole in
a Calabi-Yau compactification of Type II superstring theory and Z_top is a
second-quantized topological string partition function evaluated at the
attractor point in moduli space associated to the black hole charges. Evidence
for the conjecture in a perturbation expansion about large graviphoton charge
is given. The microcanonical ensemble of BPS black holes can be viewed as the
Wigner function associated to the wavefunction defined by the topological
string partition function.Comment: 32 pages, harvma
Space Use, Daily Movements, and Roosting Behavior of Male Wild Turkeys During Spring in Louisiana and Texas
Because wild turkeys (Meleagris gallopavo) are an important game species and turkey hunter numbers are increasing, the need for better information on how turkeys use their environment is critical. With the recent advent of GPS technology suitable for use on wild turkeys, we are now able to collect data on a scale not previously possible. We used backpack style GPS units to detail home range and core area sizes, daily movement distances, and roosting characteristics of male Eastern (M. g. silvestris) and Rio Grande (M. g. intermedia) wild turkeys in Louisiana and Texas. Mean home range size was larger in Louisiana (383 ha) than in Texas (270 ha), and mean distance between consecutive roost sites was farther in Louisiana (803 m) than in Texas (211 m). However, average daily distance traveled was shorter in Louisiana (3725 m) than in Texas (4608 m). The mean distance between consecutive roost sites was 803m in Louisiana and 211m in Texas. Our findings suggest that space use and daily movements of male wild turkeys vary little from Eastern to Rio Grande, but that roosting habits and movements associated with roosting differ strongly. Managers should recognize that availability of roost sites may greatly influence daily movements and behavior of Rio Grande wild turkeys but may have limited impacts on Eastern wild turkeys
The Youth Mental Health Risk and Resilience Study (YouR-Study)
Abstract
Background
The transition from adolescence to adulthood is associated with the emergence of psychosis and other mental health problems, highlighting the importance of this developmental period for the understanding of developing psychopathology and individual differences in risk and resilience. The Youth Mental Health Risk and Resilience Study (YouR-Study) aims to identify neurobiological mechanisms and predictors of psychosis-risk with a state-of-the-art neuroimaging approach (Magnetoencephalography, Magnetic Resonance Spectroscopy, Magnetic Resonance Imaging) in combination with core psychological processes, such as affect regulation and attachment, that have been implicated in the development and maintenance of severe mental health problems.
Methods/Design
One hundred participants meeting clinical high-risk criteria (CHR) for psychosis through the Comprehensive Assessment of At-Risk Mental State and Schizophrenia Proneness Instrument, Adult Version, in the age range from 16 to 35 years of age will be recruited. Mental-state monitoring up to a total of 2\ua0years will be implemented to detect transition to psychosis. In addition, a sample of n \u2009=\u200940 help-seeking participants will be recruited who do not meet CHR-criteria, a group of n \u2009=\u200950 healthy control participants and a sample of n \u2009=\u200925 patients with first-episode psychosis. MEG-activity will be obtained during auditory and visual tasks to examine neural oscillations and event-related fields. In addition, we will obtain estimates of GABA and Glutamate levels through Magnetic Resonance Spectroscopy (MRS) to examine relationships between neural synchrony and excitatory-inhibition (E/I) balance parameters. Neuroimaging will be complemented by detailed neuropsychological assessments as well as psychological measures investigating the impact of childhood abuse, attachment experiences and affect regulation.
Discussion
The YouR-study could potentially provide important insights into the neurobiological mechanisms that confer risk for psychosis as well as biomarkers for early diagnosis of severe mental health problems. Moreover, we expect novel data related to the contribution of affect regulation and attachment-processes in the development of mental health problems, leading to an integrative model of early stage psychosis and the factors underlying risk and resilience of emerging psychopathology
Ex vivo determination of bone tissue strains for an in vivo mouse tibial loading model
AbstractPrevious studies introduced the digital image correlation (DIC) as a viable technique for measuring bone strain during loading. In this study, we investigated the sensitivity of a DIC system in determining surface strains in a mouse tibia while loaded in compression through the knee joint. Specifically, we examined the effect of speckle distribution, facet size and overlap, initial vertical alignment of the bone into the loading cups, rotation with respect to cameras, and ex vivo loading configurations on the strain contour maps measured with a DIC system.We loaded tibiae of C57BL/6 mice (12 and 18 weeks old male) up to 12N at 8N/min. Images of speckles on the bone surface were recorded at 1N intervals and DIC was used to compute strains. Results showed that speckles must have the correct size and density with respect to the facet size of choice for the strain distribution to be computed and reproducible. Initial alignment of the bone within the loading cups does not influence the strain distribution measured during peak loading, but bones must be placed in front of the camera with the same orientation in order for strains to be comparable. Finally, the ex vivo loading configurations with the tibia attached to the entire mouse, or to the femur and foot, or only to the foot, showed different strain contour maps.This work provides a better understanding of parameters affecting full field strain measurements from DIC in ex vivo murine tibial loading tests
Measurement-based quantum computation in a 2D phase of matter
Recently it has been shown that the non-local correlations needed for
measurement based quantum computation (MBQC) can be revealed in the ground
state of the Affleck-Kennedy-Lieb-Tasaki (AKLT) model involving nearest
neighbor spin-3/2 interactions on a honeycomb lattice. This state is not
singular but resides in the disordered phase of ground states of a large family
of Hamiltonians characterized by short-range-correlated valence bond solid
states. By applying local filtering and adaptive single particle measurements
we show that most states in the disordered phase can be reduced to a graph of
correlated qubits that is a scalable resource for MBQC. At the transition
between the disordered and Neel ordered phases we find a transition from
universal to non-universal states as witnessed by the scaling of percolation in
the reduced graph state.Comment: 8 pages, 6 figures, comments welcome. v2: published versio
- …