4,358 research outputs found
A large effective population size for established within-host influenza virus infection
Strains of the influenza virus form coherent global populations, yet exist at the level of single infections in individual hosts. The relationship between these scales is a critical topic for understanding viral evolution. Here we investigate the within-host relationship between selection and the stochastic effects of genetic drift, estimating an effective population size of infection Ne for influenza infection. Examining whole-genome sequence data describing a chronic case of influenza B in a severely immunocompromised child we infer an Ne of 2.5 × 107 (95% confidence range 1.0 × 107 to 9.0 × 107) suggesting that genetic drift is of minimal importance during an established influenza infection. Our result, supported by data from influenza A infection, suggests that positive selection during within-host infection is primarily limited by the typically short period of infection. Atypically long infections may have a disproportionate influence upon global patterns of viral evolution
A Composite Method for Human Foot Structural Modeling
© 2015 The Authors A novel method including range-sensing scanning with texture and foot anatomical structure morphing basing on OpenSim is proposed. Palpation of important anatomical landmarks on foot surface was conducted by a physical therapist, and a range-sensing device, Microsoft Kinect sensor, was adopted for the 3D textured model acquisition. 3D coordinate data of the landmarks were measured and harnessed in OpenSim for subject-specific skeletal scaling based on a generic foot musculoskeletal model. The muscle attachment point coordinates derived from an anatomy database basing on sampling from East Asia people were used for muscle modelling. Then the 3D textured foot surface was registered with the morphed anatomical structures so that an integrated foot model was generated. The surface landmark locations were then compared with the corresponding internal bony sites and the errors were calculated to evaluate the accuracy and validity of this method. The potential error sources such as soft tissue thickness and scaling error were also mentioned and discussed. This technique is useful to create individual anatomically accurate human digital models for product design and development
CAR-Net: Clairvoyant Attentive Recurrent Network
We present an interpretable framework for path prediction that leverages
dependencies between agents' behaviors and their spatial navigation
environment. We exploit two sources of information: the past motion trajectory
of the agent of interest and a wide top-view image of the navigation scene. We
propose a Clairvoyant Attentive Recurrent Network (CAR-Net) that learns where
to look in a large image of the scene when solving the path prediction task.
Our method can attend to any area, or combination of areas, within the raw
image (e.g., road intersections) when predicting the trajectory of the agent.
This allows us to visualize fine-grained semantic elements of navigation scenes
that influence the prediction of trajectories. To study the impact of space on
agents' trajectories, we build a new dataset made of top-view images of
hundreds of scenes (Formula One racing tracks) where agents' behaviors are
heavily influenced by known areas in the images (e.g., upcoming turns). CAR-Net
successfully attends to these salient regions. Additionally, CAR-Net reaches
state-of-the-art accuracy on the standard trajectory forecasting benchmark,
Stanford Drone Dataset (SDD). Finally, we show CAR-Net's ability to generalize
to unseen scenes.Comment: The 2nd and 3rd authors contributed equall
Infectious Keratitis in Patients Over 65: A Review on Treatment and Preserving Eyesight
Christine K Kim,1 Melisa Z Karslioglu,1 Sharon H Zhao,2 Olivia L Lee1 1Gavin Herbert Eye Institute, University of California, Irvine School of Medicine, Irvine, CA, USA; 2Feinberg School of Medicine, Northwestern University, Chicago, IL, USACorrespondence: Olivia L Lee, Gavin Herbert Eye Institute, University of California Irvine School of Medicine, 850 Health Sciences Road, Irvine, CA, 92617, USA, Tel +1 949 824 0573, Email [email protected]: Infectious keratitis (IK) represents a significant global health concern, ranking as the fifth leading cause of blindness worldwide despite being largely preventable and treatable. Elderly populations are particularly susceptible due to age-related changes in immune response and corneal structure. However, research on IK in this demographic remains scarce. Age-related alterations such as increased permeability and reduced endothelial cell density further compound susceptibility to infection and hinder healing mechanisms. Additionally, inflammaging, characterized by chronic inflammation that develops with advanced age, disrupts the ocular immune balance, potentially exacerbating IK and other age-related eye diseases. Understanding these mechanisms is paramount for enhancing IK management, especially in elderly patients. This review comprehensively assesses risk factors, clinical characteristics, and management strategies for bacterial, viral, fungal, and acanthamoeba keratitis in the elderly population, offering crucial insights for effective intervention.Keywords: aging, inflammaging, bacterial keratitis, viral keratitis, fungal keratitis, acanthamoeba keratiti
Influence of indium-tin-oxide thin-film quality on reverse leakage current of indium-tin-oxide/n-GaN Schottky contacts
Author name used in this publication: X. M. Tao2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Electronic Origin of High Temperature Superconductivity in Single-Layer FeSe Superconductor
The latest discovery of high temperature superconductivity signature in
single-layer FeSe is significant because it is possible to break the
superconducting critical temperature ceiling (maximum Tc~55 K) that has been
stagnant since the discovery of Fe-based superconductivity in 2008. It also
blows the superconductivity community by surprise because such a high Tc is
unexpected in FeSe system with the bulk FeSe exhibiting a Tc at only 8 K at
ambient pressure which can be enhanced to 38 K under high pressure. The Tc is
still unusually high even considering the newly-discovered intercalated FeSe
system A_xFe_{2-y}Se_2 (A=K, Cs, Rb and Tl) with a Tc at 32 K at ambient
pressure and possible Tc near 48 K under high pressure. Particularly
interesting is that such a high temperature superconductivity occurs in a
single-layer FeSe system that is considered as a key building block of the
Fe-based superconductors. Understanding the origin of high temperature
superconductivity in such a strictly two-dimensional FeSe system is crucial to
understanding the superconductivity mechanism in Fe-based superconductors in
particular, and providing key insights on how to achieve high temperature
superconductivity in general. Here we report distinct electronic structure
associated with the single-layer FeSe superconductor. Its Fermi surface
topology is different from other Fe-based superconductors; it consists only of
electron pockets near the zone corner without indication of any Fermi surface
around the zone center. Our observation of large and nearly isotropic
superconducting gap in this strictly two-dimensional system rules out existence
of node in the superconducting gap. These results have provided an unambiguous
case that such a unique electronic structure is favorable for realizing high
temperature superconductivity
Propensity score analysis in the Genetic Analysis Workshop 17 simulated data set on independent individuals
Genetic Analysis Workshop 17 provided simulated phenotypes and exome sequence data for 697 independent individuals (209 case subjects and 488 control subjects). The disease liability in these data was influenced by multiple quantitative traits. We addressed the lack of statistical power in this small data set by limiting the genomic variants included in the study to those with potential disease-causing effect, thereby reducing the problem of multiple testing. After this adjustment, we could readily detect two common variants that were strongly associated with the quantitative trait Q1 (C13S523 and C13S522). However, we found no significant associations with the affected status or with any of the other quantitative traits, and the relationship between disease status and genomic variants remained obscure. To address the challenge of the multivariate phenotype, we used propensity scores to combine covariates with genetic risk factors into a single risk factor and created a new phenotype variable, the probability of being affected given the covariates. Using the propensity score as a quantitative trait in the case-control analysis, we again could identify the two common single-nucleotide polymorphisms (C13S523 and C13S522). In addition, this analysis captured the correlation between Q1 and the affected status and reduced the problem of multiple testing. Although the propensity score was useful for capturing and clarifying the genetic contributions of common variants to the disease phenotype and the mediating role of the quantitative trait Q1, the analysis did not increase power to detect rare variants
Local antiferromagnetic exchange and collaborative Fermi surface as key ingredients of high temperature superconductors
Cuprates, ferropnictides and ferrochalcogenides are three classes of
unconventional high-temperature superconductors, who share similar phase
diagrams in which superconductivity develops after a magnetic order is
suppressed, suggesting a strong interplay between superconductivity and
magnetism, although the exact picture of this interplay remains elusive. Here
we show that there is a direct bridge connecting antiferromagnetic exchange
interactions determined in the parent compounds of these materials to the
superconducting gap functions observed in the corresponding superconducting
materials. High superconducting transition temperature is achieved when the
Fermi surface topology matches the form factor of the pairing symmetry favored
by local magnetic exchange interactions. Our result offers a principle guide to
search for new high temperature superconductors.Comment: 12 pages, 5 figures, 1 table, 1 supplementary materia
Structural and magnetic phase diagram of CeFeAsO1-xFx and its relationship to high-temperature superconductivity
We use neutron scattering to study the structural and magnetic phase
transitions in the iron pnictides CeFeAsO1-xFx as the system is tuned from a
semimetal to a high-transition-temperature (high-Tc) superconductor through
Fluorine (F) doping x. In the undoped state, CeFeAsO develops a structural
lattice distortion followed by a stripe like commensurate antiferromagnetic
order with decreasing temperature. With increasing Fluorine doping, the
structural phase transition decreases gradually while the antiferromagnetic
order is suppressed before the appearance of superconductivity, resulting an
electronic phase diagram remarkably similar to that of the high-Tc copper
oxides. Comparison of the structural evolution of CeFeAsO1-xFx with other
Fe-based superconductors reveals that the effective electronic band width
decreases systematically for materials with higher Tc. The results suggest that
electron correlation effects are important for the mechanism of high-Tc
superconductivity in these Fe pnictides.Comment: 19 pages, 5 figure
Nuclear receptors in vascular biology
Nuclear receptors sense a wide range of steroids and hormones (estrogens, progesterone, androgens, glucocorticoid, and mineralocorticoid), vitamins (A and D), lipid metabolites, carbohydrates, and xenobiotics. In response to these diverse but critically important mediators, nuclear receptors regulate the homeostatic control of lipids, carbohydrate, cholesterol, and xenobiotic drug metabolism, inflammation, cell differentiation and development, including vascular development. The nuclear receptor family is one of the most important groups of signaling molecules in the body and as such represent some of the most important established and emerging clinical and therapeutic targets. This review will highlight some of the recent trends in nuclear receptor biology related to vascular biology
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