The Prominin-1-Derived Peptide Improves Cardiac Function Following Ischemia

Myocardial infarction (MI) remains the leading cause of death in the western world. Despite advancements in interventional revascularization technologies, many patients are not candidates for them due to comorbidities or lack of local resources. Non-invasive approaches to accelerate revascularization within ischemic tissues through angiogenesis by providing Vascular Endothelial Growth Factor (VEGF) in protein or gene form has been effective in animal models but not in humans likely due to its short half-life and systemic toxicity. Here, we tested the hypothesis that PR1P, a small VEGF binding peptide that we developed, which stabilizes and upregulates endogenous VEGF, could be used to improve outcome from MI in rodents. To test this hypothesis, we induced MI in mice and rats via left coronary artery ligation and then treated animals with every other day intraperitoneal PR1P or scrambled peptide for 14 days. Hemodynamic monitoring and echocardiography in mice and echocardiography in rats at 14 days showed PR1P significantly improved multiple functional markers of heart function, including stroke volume and cardiac output. Furthermore, molecular biology and histological analyses of tissue samples showed that systemic PR1P targeted, stabilized and upregulated endogenous VEGF within ischemic myocardium. We conclude that PR1P is a potential non-invasive candidate therapeutic for MI.     

The effect of microstructure on hydrogen permeability of high strength steels

Hydrogen diffusivity and trapping have been studied in two advanced high strength steel grades and model samples using electrochemical permeation test. Microstructures of CP1000 and DP1000 steels consist of ferrite, martensite and a small fraction of retained austenite. In addition, bainite is present in CP1000. Model phases with predominance of a particular phase have been prepared by specific heat treatment. DP1000 has shown the lowest diffusivity among all materials, while ferritic model sample has shown the highest. Differences in hydrogen diffusion coefficient values are linked to trapping microstructural characteristics and grain size.     

Naming and identification of tastes in aqueous solutions.

Several taste substances were tested in aqueous solutions; tannic and tartaric acids were found unsuitable as a standard substance for the taste identification. Monosodium glutamate, sodium hydrogen carbonate and potassium chloride were often identified as salty substances even when the subjects were able to distinguish between the tastes. They probably identified the taste as salty owing to the lack of proper terms, and unsufficient experience with tasting monosodium glutamate and sodium hydrogen carbonate as substances possessing defined tastes different from the salty taste.     

Novel algorithms for the network lifetime problem in wireless settings

One of the major concerns in wireless ad-hoc networks design is energy efficiency. Wireless devices are typically equipped with a limited energy supply sufficient only for a limited amount of time which is reversely proportional to the transmission power of the device. The network lifetime is defined as the time the first device runs out of its initial energy charge. In this paper we study the maximum network lifetime problem for broadcast and data gathering in wireless settings. We provide polynomial time approximation algorithms, with guaranteed performance bounds while considering omnidirectional and unidirectional transmissions. We also consider an extended variant of the maximum lifetime problem, which simultaneously satisfies additional constraints, such as bounded hop-diameter and degree of the routing tree, and minimizing the total energy used in a single transmission. Finally, we evaluate the performance of some of our algorithms through simulations.     

Is there more to complicated grief than depression and posttraumatic stress disorder? A test of incremental validity.

There is growing interest in complicated grief reactions as a possible new diagnostic category for inclusion in the Diagnostic and Statistical Manual of Mental Disorders. However, no research has yet shown that complicated grief has incremental validity (i.e., predicts unique variance in functioning). The authors addressed this issue in 2 studies by comparing grief, depression, and posttraumatic stress disorder (PTSD) symptoms with different measures of functioning (interviewer ratings, friend ratings, self-report, and autonomic arousal). The 1st study (N = 73) used longitudinal data collected at 4 and 18 months postloss, and the 2nd study (N = 447) used cross-sectional data collected 2.5-3.5 years postloss. With depression and PTSD controlled, grief emerged as a unique predictor of functioning, both cross-sectionally and prospectively. The findings provide convergent support for the incremental validity of complicated grief as an independent marker of bereavement-related psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling the Heat Wave Generated during Microwave Heating of Powdered Zinc Oxide in a Nitrogen Atmosphere

A theoretical investigation of previous experiments on the microwave heating of cylindrical samples of powdered ZnO in nitrogen and air environments has been presented. Unlike heating in air, which showed an exponentially saturating temperature behavior, a large discontinuity in the measured temperature was observed in nitrogen. Energy considerations suggested that the microwave power was mostly absorbed in a narrow, localized region that moved radially outward as a propagating heat wave. It was assumed that this behavior was caused by an anomaly in the temperature dependence of the permittivity, and the present simulations verify this assumption. The phenomenon has been investigated using a newly developed two-dimensional code, and the results are in good agreement with the experimental observations. The calculated width of the microwave absorbing region was ∼1 mm, and the radial velocity of the electromagnetically driven heat wave was inversely proportional to the square of the distance from the center of the sample, with a maximum speed of ∼20 mm/min.     

Anisotropic Magnetoresistance of GaMnAs Ferromagnetic Semiconductors

The angular dependence of the magnetoresistance has been studied for two sets of samples: annealed and hydrogenated, respectively. Different behavior of magnetoresistance anisotropy has been discussed in terms of change of scattering rate and/or introduction of strain during treatment.     

Reduced Aggregate Scattering Operators for Path Tracing

Aggregate scattering operators (ASOs) describe the overall scattering behavior of an asset (i.e., an object or volume, or collection thereof) accounting for all orders of its internal scattering. We propose a practical way to precompute and compactly store ASOs and demonstrate their ability to accelerate path tracing. Our approach is modular avoiding costly and inflexible scene‐dependent precomputation. This is achieved by decoupling light transport within and outside of each asset, and precomputing on a per‐asset level. We store the internal transport in a reduced‐dimensional subspace tailored to the structure of the asset geometry, its scattering behavior, and typical illumination conditions, allowing the ASOs to maintain good accuracy with modest memory requirements. The precomputed ASO can be reused across all instances of the asset and across multiple scenes. We augment ASOs with functionality enabling multi‐bounce importance sampling, fast short‐circuiting of complex light paths, and compact caching, while retaining rapid progressive preview rendering. We demonstrate the benefits of our ASOs by efficiently path tracing scenes containing many instances of objects with complex inter‐reflections or multiple scattering.     

CoRAL: A transparent fault-tolerant web service

The Web is increasingly used for critical applications and services. We present a client-transparent mechanism, called CoRAL, that provides high reliability and availability for Web service. CoRAL provides fault tolerance even for requests being processed at the time of server failure. The scheme does not require deterministic servers and can thus handle dynamic content. CoRAL actively replicates the TCP connection state while maintaining logs of HTTP requests and replies. In the event of a primary server failure, active client connections fail over to a spare, where their processing continues seamlessly. We describe key aspects of the design and implementation as well as several performance optimizations. Measurements of system overhead, failover performance, and preliminary validation using fault injection are presented.     

Using artificial neural networks to detect unknown computer worms

Detecting computer worms is a highly challenging task. We present a new approach that uses artificial neural networks (ANN) to detect the presence of computer worms based on measurements of computer behavior. We compare ANN to three other classification methods and show the advantages of ANN for detection of known worms. We then proceed to evaluate ANN’s ability to detect the presence of an unknown worm. As the measurement of a large number of system features may require significant computational resources, we evaluate three feature selection techniques. We show that, using only five features, one can detect an unknown worm with an average accuracy of 90%. We use a causal index analysis of our trained ANN to identify rules that explain the relationships between the selected features and the identity of each worm. Finally, we discuss the possible application of our approach to host-based intrusion detection systems.