7,394 research outputs found
Quantum estimation of a damping constant
We discuss an interferometric approach to the estimation of quantum
mechanical damping. We study specific classes of entangled and separable probe
states consisting of superpositions of coherent states. Based on the assumption
of limited quantum resources we show that entanglement improves the estimation
of an unknown damping constant.Comment: 7 pages, 5 figure
First Structure Formation: A Simulation of Small Scale Structure at High Redshift
We describe the results of a simulation of collisionless cold dark matter in
a LambdaCDM universe to examine the properties of objects collapsing at high
redshift (z=10). We analyze the halos that form at these early times in this
simulation and find that the results are similar to those of simulations of
large scale structure formation at low redshift. In particular, we consider
halo properties such as the mass function, density profile, halo shape, spin
parameter, and angular momentum alignment with the minor axis. By understanding
the properties of small scale structure formation at high redshift, we can
better understand the nature of the first structures in the universe, such as
Population III stars.Comment: 31 pages, 14 figures; accepted for publication in ApJ. Figure 1 can
also be viewed at http://cfa-www.harvard.edu/~hjang/research
Early changes in pro-inflammatory cytokine levels in neonates with encephalopathy are associated with remote epilepsy.
BackgroundNeonatal seizures are associated with adverse neurologic sequelae including epilepsy in childhood. Here we aim to determine whether levels of cytokines in neonates with brain injury are associated with acute symptomatic seizures or remote epilepsy.MethodsThis is a cohort study of term newborns with encephalopathy at UCSF between 10/1993 and 1/2000 who had dried blood spots. Maternal, perinatal/postnatal, neuroimaging, and epilepsy variables were abstracted by chart review. Logistic regression was used to compare levels of cytokines with acute seizures and the development of epilepsy.ResultsIn a cohort of 26 newborns with neonatal encephalopathy at risk for hypoxic ischemic encephalopathy with blood spots for analysis, diffuse alterations in both pro- and anti-inflammatory cytokine levels were observed between those with (11/28, 39%) and without acute symptomatic seizures. Seventeen of the 26 (63%) patients had >2 years of follow-up and 4/17 (24%) developed epilepsy. Higher levels of pro-inflammatory cytokines IL-6 and TNF-α within the IL-1ÎČ pathway were significantly associated with epilepsy.ConclusionsElevations in pro-inflammatory cytokines in the IL-1ÎČ pathway were associated with later onset of epilepsy. Larger cohort studies are needed to confirm the predictive value of these circulating biomarkers
Ecosystem Food Web Lift-the-Flap Pages
In the lesson on which this practical article is based, third grade students constructed a âlift-the-flapâ page to explore food webs on the prairie. The moveable papercraft focused student attention on prairie animalsâ external structures and how the inferred functions of those structures could support further inferences about the animalsâ diets. In general, most students made simple causal connections between an animalâs observable characteristics and the food it would probably eat. Some students were also able to make multi-agent connections to develop a more complex mental model of a food web. Ultimately, the lift-the flap project was engaging to students and motivated them to focus their attention on the characteristics of animals of different ecosystems to infer their probable diets
Predicting suitable environments and potential occurrences for coelacanths (Latimeria spp.)
This is the author's accepted manuscript. The original publication is available at www.springerlink.com.Extant coelacanths (Latimeria chalumnae) were first discovered in the western Indian Ocean in 1938; in 1998, a second species of coelacanth, Latimeria menadoensis, was discovered off the north coast of Sulawesi, Indonesia, expanding the known distribution of the genus across the Indian Ocean Basin. This study uses ecological niche modeling techniques to estimate dimensions of realized niches of coelacanths and generate hypotheses for additional sites where they might be found. Coelacanth occurrence information was integrated with environmental and oceanographic data using the Genetic Algorithm for Rule-set Production (GARP) and a maximum entropy algorithm (Maxent). Resulting models were visualized as maps of relative suitability of sites for coelacanths throughout the Indian Ocean, as well as scatterplots of ecological variables. Our findings suggest that the range of coelacanths could extend beyond their presently known distribution and suggests alternative mechanisms for currently observed distributions. Further investigation into these hypotheses could aid in forming a more complete picture of the distributions and populations of members of genus Latimeria, which in turn could aid in developing conservation strategies, particularly in the case of L. menadoensis
Droplet digital PCR for oncogenic KMT2A fusion detection
Acute myeloid leukemia (AML) is an aggressive blood cancer diagnosed in approximately 120,000 individuals worldwide each year. During treatment for AML, detecting residual disease is essential for prognostication and treatment decision-making. Currently, methods for detecting residual AML are limited to identifying approximately 1:100 to 1:1000 leukemic cells (morphology and DNA sequencing) or are difficult to implement (flow cytometry). AML arising after chemotherapy or radiation exposure is termed therapy-related AML (t-AML) and is exceptionally aggressive and treatment resistant. t-AML is often driven by oncogenic fusions that result from prior treatments that introduce double-strand DNA breaks. The most common t-AML-associated translocations affect KMT2A. There are at least 80 known KMT2A fusion partners, but approximately 80% of fusions involve only five partners-AF9, AF6, AF4, ELL, and ENL. We present a novel droplet digital PCR assay targeting the most common KMT2A-rearrangements to enable detection of rare AML cells harboring these fusions. This assay was benchmarked in cell lines and patient samples harboring oncogenic KMT2A fusions and demonstrated a limit of detection of approximately 1:1,000,000 cells. Future application of this assay could improve disease detection and treatment decision-making for patients with t-AML with KMT2A fusions and premalignant oncogenic fusion detection in at-risk individuals after chemotherapy exposure
Evaluation of the Audicor Acoustic Cardiography Device as a Diagnostic Tool in Horses with Mitral or Aortic Valve Insufficiency
Mitral and aortic valve insufficiencies have been commonly reported in horses. The objective of this study was to establish the use of acoustic cardiography (AudicorÂź) in horses with aortic (AI) or mitral valve insufficiency (MI). A total of 17 healthy horses, 18 horses with AI, and 28 horses with MI were prospectively included. None of the horses was in heart failure. Echocardiography and AudicorÂź analyses were conducted. Electromechanical activating time (EMAT), rate-corrected EMATc, left ventricular systolic time (LVST), rate-corrected LVSTc, and intensity and persistence of the third and fourth heart sound (S3, S4) were reported by AudicorÂź. Graphical analysis of the three-dimensional (3D) phonocardiogram served to visually detect murmurs. AudicorÂź snapshot variables were compared between groups using one-way ANOVA followed by Tukeyâs multiple-comparisons test. The association between AudicorÂź snapshot variables and the corresponding echocardiographic variables was investigated by linear regression and BlandâAltman analyses. Heart murmurs were not displayed on AudicorÂź phonocardiograms. No significant differences were found between AudicorÂź variables obtained in clinically healthy horses and horses with valvular insufficiency. The AudicorÂź device is unable to detect heart murmurs in horses. AudicorÂź variables representing cardiac function are not markedly altered, and their association with corresponding echocardiographic variables is poor in horses with valvular insufficiency that are not in heart failure
Exploring Felix Staltenâs Bambi Narrative: Biblical Tenets and Lois Tyson in Dialogue
Our presentation offers three critical feminist interpretations of Felix Salten\u27s 1923 novel Bambi: The Story of a Life in the Forest. As Christian theorists, we explore oppressive influences in societal structures as represented in the novel, as well as in Walt Disney\u27s 1942 film adaptation of Salten\u27s work. The Bambi narrative proposes a unique perspective on 20th century interwar Europe and its implications for today\u27s culture. We invite the audience to consider a Christian understanding of the story as we also rely on scholar Lois Tysonâs instructional presentations in Critical Theory Today on the uses of feminism to help us arrive at a Biblical view on human equality, dignity, and diversity. These Biblical tenets applied to the Bambi narrative help us see how women have often been disregarded or mistreated historically, views which should inform Christians seeking to minister to marginalized women, children, and men. We hope to encourage the audience to honor the dignity of women and value them in social structures with our interpretation of the Bambi narrative
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Robust algorithm for detecting floodwater in urban areas using Synthetic Aperture Radar images
Flooding is a major hazard in both rural and urban areas worldwide, but it is in urban areas that the impacts are most severe. High resolution Synthetic Aperture Radar (SAR) sensors are able to detect flood extents in urban areas during both day- and night-time. If obtained in near real-time, these flood extents can be used for emergency flood relief management or as observations for assimilation into flood forecasting models. In this paper a method for detecting flooding in urban areas using near real-time SAR data is developed and extensively tested under a variety of scenarios involving different flood events and different images. The method uses a SAR simulator in conjunction with LiDAR data of the urban area to predict areas of radar shadow and layover in the image caused by buildings and taller vegetation. Of the urban water pixels visible to the SAR, the flood detection accuracy averaged over the test examples was 83%, with a false alarm rate of 9%. The results indicate that flooding can be detected in the urban area to reasonable accuracy, but that this accuracy is limited partly by the SARâs poor visibility of the urban ground surface due to shadow and layover
Alarmins in frozen shoulder: a molecular association between inflammation and pain
Background:
The pathophysiological mechanisms behind proliferation of fibroblasts and deposition of dense collagen matrix in idiopathic frozen shoulder remain unclear. Alarmins (also known as danger signals) are endogenous molecules that are released into the extracellular milieu after infection or tissue injury and that signal cell and tissue damage.
Purpose:
To investigate whether the presence of alarmins is higher in patients with idiopathic frozen shoulder than in control subjects.
Study Design:
Controlled laboratory study.
Methods:
Shoulder capsule samples were collected from 10 patients with idiopathic frozen shoulder and 10 patients with unstable shoulders (control). The samples were stained with hematoxylin and eosin (H&E) and analyzed by immunohistochemistry using antibodies against alarmin molecules including high-mobility group protein B1 (HMGB1), interleukin 33, S100A8, S100A9, and the peripheral nerve marker PGP9.5. Immunoreactivities were rated in a blinded fashion from ânoneâ to âstrong.â Immunohistochemical distribution within the capsule was noted. Before surgery, patient-ranked pain frequency, severity, stiffness, and the range of passive shoulder motion were recorded and statistically analyzed.
Results:
Compared with control patients, patients with frozen shoulder had greater frequency and severity of self-reported pain (P = .02) and more restricted range of motion in all planes (P < .05). H&E-stained capsular tissue from frozen shoulder showed fibroblastic hypercellularity and increased subsynovial vascularity. Immunoreactivity of alarmins was significantly stronger in frozen shoulder capsules compared with control capsules (P < .05). Furthermore, the expression of the alarmin molecule HMGB1 significantly correlated (r > 0.9, P < .05) with the severity of patient-reported pain.
Conclusion:
This study demonstrates a potential role for key molecular danger signals in frozen shoulder and suggests an association between the expression of danger molecules and the pain experienced by patients
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