Prevention and treatment of pressure ulcers

The prevention and treatment of pressure ulcers continues topresent a challenge across acute and long-term care settings, and costs the NHS up to £2.64 billion annually. As well as causing a reduced quality of life for sufferers, they can prove to be fatal. The complexity of the exact causes of skin breakdown and accurate risk assessment has proved problematic to fully understanding this common nursing problem, yet despite limited evidence clear guidelines on best practice exist, suggesting that prevention strategies should encompass interventions in three areas: risk assessment; relief of pressure, and education. Evidence exists that where these strategies are adopted at an organizational level, and strong leadership provided, the outcomes can be remarkable. This article outlines effective prevention and risk-reduction strategies, together with interventions that can promote healing.<br/

Percolation on dense graph sequences

In this paper we determine the percolation threshold for an arbitrary sequence of dense graphs $(G_n)$. Let $\lambda_n$ be the largest eigenvalue of the adjacency matrix of $G_n$, and let $G_n(p_n)$ be the random subgraph of $G_n$ obtained by keeping each edge independently with probability $p_n$. We show that the appearance of a giant component in $G_n(p_n)$ has a sharp threshold at $p_n=1/\lambda_n$. In fact, we prove much more: if $(G_n)$ converges to an irreducible limit, then the density of the largest component of $G_n(c/n)$ tends to the survival probability of a multi-type branching process defined in terms of this limit. Here the notions of convergence and limit are those of Borgs, Chayes, Lov\'asz, S\'os and Vesztergombi. In addition to using basic properties of convergence, we make heavy use of the methods of Bollob\'as, Janson and Riordan, who used multi-type branching processes to study the emergence of a giant component in a very broad family of sparse inhomogeneous random graphs.Comment: Published in at http://dx.doi.org/10.1214/09-AOP478 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

Using Twitter Post Data to Ascertain the Sentiment of Alcohol-related Blackouts in the United States

Research shows variability in how alcohol-related blackouts (periods of memory loss during/after drinking) are subjectively evaluated. We accessed 3.5 million original Tweets written in the U.S. between July 2009 and February 2020 that referenced blackouts, and coded the sentiment (positive or negative) of those Tweets, using the machine learning function of a Twitter-sponsored commercial platform. The sentiment of Tweets was examined by day of week and compared to the sentiment of blackout Tweets on certain holidays to non-celebration matched days. Tweets were more likely to have a positive (73%) than negative sentiment, and positive Tweets were more common during weekends. Relative to typical non-celebratory weekends, a greater proportion of blackout Tweets were positive around Thanksgiving and New Year’s Eve, though differences were not observed relative to several other celebratory periods (e.g., Superbowl). Results have implications for online interventions, which can use social networking sites to target alcohol during high-risk periods

Directed scale-free graphs.

Abstract We introduce a model for directed scale-free graphs that grow with preferential attachment depending in a natural way on the in-and out-degrees. We show that the resulting in-and out-degree distributions are power laws with different exponents, reproducing observed properties of the worldwide web. We also derive exponents for the distribution of in-(out-) degrees among vertices with fixed out-(in-) degree. We conclude by suggesting a corresponding model with hidden variables

Situational determinants of cognitive, affective, and compassionate empathy in naturalistic digital interactions

Empathy is apparent in computer-mediated communication (CMC), yet little is known about the situational predictors of empathic responses when interacting digitally. We used a diary methodology to explore: (1) the degree three types of empathy (cognitive, affective, and compassionate) are experienced in students' everyday (text- and image-based) dyadic digital interactions; (2) which situational factors are important for (different types of) empathy in CMC; and (3) how empathy reported in everyday CMC affects participants' perceptions of their empathy in CMC and face-to-face (FtF) contexts. One hundred student volunteers (50 women, Mage = 22.57 years) completed a “digital interaction diary” for three consecutive days, yielding 1939 observations. Participants reported significantly more cognitive than affective empathy, and significantly greater affective than compassionate empathy. Several situational variables (e.g., number of communications, recipient) were related to empathy overall, while others (e.g., subject, mood) contributed to discrete contextual profiles for the empathy subtypes. Empathy reported in the diaries predicted a more favourable ratio of perceived CMC to FtF empathy, particularly for those lower in baseline trait empathy. These findings help elucidate the multidimensional experience of empathy in CMC interactions

Histo-Blood Group Gene Polymorphisms as Potential Genetic Modifiers of Infection and Cystic Fibrosis Lung Disease Severity

The pulmonary phenotype in cystic fibrosis (CF) is variable; thus, environmental and genetic factors likely contribute to clinical heterogeneity. We hypothesized that genetically determined ABO histo-blood group antigen (ABH) differences in glycosylation may lead to differences in microbial binding by airway mucus, and thus predispose to early lung infection and more severe lung disease in a subset of patients with CF. infection in the severe or mild groups. Multivariate analyses of other clinical phenotypes, including gender, asthma, and meconium ileus demonstrated no differences between groups based on ABH type. infection, nor was there any association with other clinical phenotypes in a group of 808 patients homozygous for the ΔF508 mutation

The Arctic freshwater system : changes and impacts

Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 112 (2007): G04S54, doi:10.1029/2006JG000353.Dramatic changes have been observed in the Arctic over the last century. Many of these involve the storage and cycling of fresh water. On land, precipitation and river discharge, lake abundance and size, glacier area and volume, soil moisture, and a variety of permafrost characteristics have changed. In the ocean, sea ice thickness and areal coverage have decreased and water mass circulation patterns have shifted, changing freshwater pathways and sea ice cover dynamics. Precipitation onto the ocean surface has also changed. Such changes are expected to continue, and perhaps accelerate, in the coming century, enhanced by complex feedbacks between the oceanic, atmospheric, and terrestrial freshwater systems. Change to the arctic freshwater system heralds changes for our global physical and ecological environment as well as human activities in the Arctic. In this paper we review observed changes in the arctic freshwater system over the last century in terrestrial, atmospheric, and oceanic systems.The authors gratefully acknowledge the National Science Foundation (NSF) for funding this synthesis work. This paper is principally the work of authors funded under the NSF-funded Freshwater Integration (FWI) study

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder