509 research outputs found
Instability of scale-free networks under node-breaking avalanches
The instability introduced in a large scale-free network by the triggering of
node-breaking avalanches is analyzed using the fiber-bundle model as conceptual
framework. We found, by measuring the size of the giant component, the
avalanche size distribution and other quantities, the existence of an abrupt
transition. This test of strength for complex networks like Internet is more
stringent than others recently considered like the random removal of nodes,
analyzed within the framework of percolation theory. Finally, we discuss the
possible implications of our results and their relevance in forecasting
cascading failures in scale-free networks.Comment: 4 pages, 4 figures, final version to be published in Europhys. Let
Characterization of Polymeric Proteins from Vitreous and Floury Sorghum Endosperm
Differences in protein content and composition between vitreous and floury endosperm were investigated using a number of different techniques. Differences in protein cross-linking between vitreous and floury endosperm were investigated using differential solubility, size exclusion chromatography (SEC), and analysis of sulfhydryl content and composition. Vitreous endosperm was found to have higher levels of total protein and kafirins, but floury endosperm had a higher proportion of γ-kafirins than the vitreous. Floury endosperm was found to have higher levels of SDS-soluble proteins than SDS-insoluble proteins extracted using sonication than vitreous endosperm. Conversely, vitreous endosperm had a greater proportion of the insoluble proteins. SEC analysis of the polymeric proteins revealed that the insoluble proteins had more polymeric proteins than did the soluble proteins, indicating greater cross-linking and a larger Mw distribution. Vitreous endosperm was also found to have a greater percentage (i.e., a higher ratio of disulfide to total sulfhydryls) of disulfide bonds than floury endosperm. These results show that the proteins in vitreous endosperm have a higher degree of cross-linking and a greater Mw distribution than those found in floury endosperm
Community views on ‘Can perinatal services safely identify Aboriginal and Torres Strait Islander parents experiencing complex trauma?’
Family and extended kinship systems which nurture healthy, happy children are central to Aboriginal and Torres Strait Islander cultures. Since colonisation, Aboriginal and Torres Strait Islander communities have been impacted by intergenerational cycles of trauma, stemming from colonial violence, genocidal policies and discrimination, including the forced removal of children from their families. Becoming a parent offers a unique life-course opportunity for trauma recovery and preventing intergenerational trauma. However, identifying or ‘recognising’ complex trauma carries significant risk of harm for Aboriginal and Torres Strait Islander parents due to reactive prenatal child protection involvement potentially compounding experiences of trauma, and limited benefits due to lack of culturally appropriate support. The Aboriginal-led participatory Healing the Past by Nurturing the Future project aims to co-design safe, accessible and feasible perinatal awareness, recognition, assessment and support strategies for Aboriginal and Torres Strait Islander parents experiencing complex trauma. This paper presents views of 38 workshop participants to determine prerequisites for ensuring benefits outweigh risks of assessment to safely recognise parents experiencing complex trauma, consistent with screening criteria. Six essential elements were identified from thematic analysis: high-quality holistic care; cultural, social and emotional safety; empowerment, choice and control; flexible person-centred approaches; trusting relationships; and sensitive, skilled communication
Determining weight-bearing tissue condition using peak reactive hyperemia response trend and ultrasonographic features: implications for pressure ulcer prevention
Frequent repositioning is important to prevent pressure ulcer (PU) development, by relieving pressure and recovering damages on skin areas induced by repetitive loading. Although repositioning is the gold standard to prevent PU, there is currently no strategy for determining tissue condition under preventive approaches. In this study, the peak reactive hyperemia (RH) trends and ultrasonographic (US) features are compared with the tissue condition under histopathological examination to determine the potential use of these features in determining the tissue condition noninvasively. Twenty-one male Sprague–Dawley rats (seven per group), with body weight of 385–485 g, were categorized into three groups and subjected to different recovery times, each with three repetitive loading cycles at skin tissues above of right trochanter area. The first, second, and third groups were subjected to short (3 minutes), moderate (10 minutes), and prolonged (40 minutes) recovery, respectively, while applying fixed loading time and pressure (10 minutes and 50 mmHg, respectively), to provide different degree of recovery and tissue conditions (tissue damage and tissue recovery). Peak RH was measured in the three cycles to determine RH trend (increasing, decreasing, and inconsistent). All rat tissues were evaluated using ultrasound at pre- and post-experiment and rated by two raters to categorize the severity of tissue changes (no, mild, moderate, and severe). The tissue condition was also evaluated using histopathological examination to distinguish between normal and abnormal tissues. Most of the samples with increasing RH trend is related to abnormal tissue (71%); while inconsistent RH trends is more related to normal tissue (82%). There is no relationship between the tissue conditions evaluated under ultrasonographic and histopathological examination. Peak RH trend over repetitive loading may serve as a new feature for determining the tissue condition that leading to pressure ulcer
Co-Evolution of quasispecies: B-cell mutation rates maximize viral error catastrophes
Co-evolution of two coupled quasispecies is studied, motivated by the
competition between viral evolution and adapting immune response. In this
co-adaptive model, besides the classical error catastrophe for high virus
mutation rates, a second ``adaptation-'' catastrophe occurs, when virus
mutation rates are too small to escape immune attack. Maximizing both regimes
of viral error catastrophes is a possible strategy for an optimal immune
response, reducing the range of allowed viral mutation rates to a minimum. From
this requirement one obtains constraints on B-cell mutation rates and receptor
lengths, yielding an estimate of somatic hypermutation rates in the germinal
center in accordance with observation.Comment: 4 pages RevTeX including 2 figure
Voltage Regulator Module Noise Analysis for High-Volume Server Applications
This paper presents a methodology to analyze voltage regulator module (VRM) noise coupling problems in high-volume server applications. The technique is applied on a real engineering design. The comprehensive model includes irregular power shapes, decoupling capacitors, and dielectric and conductive loss. Irregular shaped power plane modeling is cross-checked with four separate methods to demonstrate accuracy
Kaon production in heavy-ion collisions and maximum mass of neutron stars
We determine an `empirical' kaon dispersion relation by analysing and fitting
recent experimental data on kaon production in heavy-ion collisions. We then
investigate its effects on hadronic equation of state at high densities and on
neutron star properties. We find that the maximum mass of neutron stars can be
lowered by about 0.4, once kaon condensation as constrained by our
empirical dispersion relation is introduced. We emphasize the growing interplay
between hadron physics, relativistic heavy-ion physics and the physics of
compact objects in astrophysics.Comment: 6 pages with 3 postscript figures, to appear in Physical Review
Letter
A participatory intervention to improve the mental health of widows of injecting drug users in north-east India as a strategy for HIV prevention
BACKGROUND: Manipur and Nagaland, in the north-east of India, are classified as high prevalence states for HIV, and intravenous drug use is an important route of transmission. Most injecting drug users (IDUs) are men, an estimated 40% are married, and death rates have been high in the last five years, consequently the number of widows of IDUs has increased. Many of these widows and their children are HIV-infected and experience poor health, discrimination, and impoverishment; all factors likely to be compromising their mental health. People with poor mental health are more likely to engage in HIV risk behaviours. Mental health can be promoted by public health actions with vulnerable population groups. METHODS: We designed an intervention study to assess the feasibility and impact of a participatory action process to promote the mental health and well-being of widows of IDUs in Manipur and Nagaland, as a strategy for reducing the risk of engagement in HIV risk behaviours. This paper describes the background and rationale for the study, the intervention, and the study methods in detail. RESULTS: Pending analysis. CONCLUSION: This intervention study will make a significant contribution to the emerging evidence that supports associations between mental health and HIV. The concept of promoting mental health among women who are vulnerable to HIV infection or already infected as a strategy for HIV prevention in a development setting is breaking new ground
First‐in‐Human Study of the Safety and Efficacy of TOL101 Induction to Prevent Kidney Transplant Rejection
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/107383/1/ajt12698.pd
- …