Compression and amplification algorithms in hearing aids impair the selectivity of neural responses to speech

In quiet environments, hearing aids improve the perception of low-intensity sounds. However, for high-intensity sounds in background noise, the aids often fail to provide a benefit to the wearer. Here, using large-scale single-neuron recordings from hearing-impaired gerbils—an established animal model of human hearing—we show that hearing aids restore the sensitivity of neural responses to speech, but not their selectivity. Rather than reflecting a deficit in supra-threshold auditory processing, the low selectivity is a consequence of hearing-aid compression (which decreases the spectral and temporal contrasts of incoming sound) and amplification (which distorts neural responses, regardless of whether hearing is impaired). Processing strategies that avoid the trade-off between neural sensitivity and selectivity should improve the performance of hearing aids

Accelerating epistasis analysis in human genetics with consumer graphics hardware

BACKGROUND: Human geneticists are now capable of measuring more than one million DNA sequence variations from across the human genome. The new challenge is to develop computationally feasible methods capable of analyzing these data for associations with common human disease, particularly in the context of epistasis. Epistasis describes the situation where multiple genes interact in a complex non-linear manner to determine an individual's disease risk and is thought to be ubiquitous for common diseases. Multifactor Dimensionality Reduction (MDR) is an algorithm capable of detecting epistasis. An exhaustive analysis with MDR is often computationally expensive, particularly for high order interactions. This challenge has previously been met with parallel computation and expensive hardware. The option we examine here exploits commodity hardware designed for computer graphics. In modern computers Graphics Processing Units (GPUs) have more memory bandwidth and computational capability than Central Processing Units (CPUs) and are well suited to this problem. Advances in the video game industry have led to an economy of scale creating a situation where these powerful components are readily available at very low cost. Here we implement and evaluate the performance of the MDR algorithm on GPUs. Of primary interest are the time required for an epistasis analysis and the price to performance ratio of available solutions. FINDINGS: We found that using MDR on GPUs consistently increased performance per machine over both a feature rich Java software package and a C++ cluster implementation. The performance of a GPU workstation running a GPU implementation reduces computation time by a factor of 160 compared to an 8-core workstation running the Java implementation on CPUs. This GPU workstation performs similarly to 150 cores running an optimized C++ implementation on a Beowulf cluster. Furthermore this GPU system provides extremely cost effective performance while leaving the CPU available for other tasks. The GPU workstation containing three GPUs costs $2000 while obtaining similar performance on a Beowulf cluster requires 150 CPU cores which, including the added infrastructure and support cost of the cluster system, cost approximately$82,500. CONCLUSION: Graphics hardware based computing provides a cost effective means to perform genetic analysis of epistasis using MDR on large datasets without the infrastructure of a computing cluster

Proposed New Antiproton Experiments at Fermilab

Fermilab operates the world's most intense source of antiprotons. Recently various experiments have been proposed that can use those antiprotons either parasitically during Tevatron Collider running or after the Tevatron Collider finishes in about 2010. We discuss the physics goals and prospects of the proposed experiments.Comment: 6 pages, 2 figures, to appear in Proceedings of IXth International Conference on Low Energy Antiproton Physics (LEAP'08), Vienna, Austria, September 16 to 19, 200

Pathotypic diversity of Hyaloperonospora brassicae collected from Brassica oleracea

Downy mildew caused by Hyaloperonospora brassicae is an economically destructive disease of brassica crops in many growing regions throughout the world. Specialised pathogenicity of downy mildews from different Brassica species and closely related ornamental or wild relatives has been described from host range studies. Pathotypic variation amongst Hyaloperonospora brassicae isolates from Brassica oleracea has also been described; however, a standard set of B. oleracea lines that could enable reproducible classification of H. brassicae pathotypes was poorly developed. For this purpose, we examined the use of eight genetically refined host lines derived from our previous collaborative work on downy mildew resistance as a differential set to characterise pathotypes in the European population of H. brassicae. Interaction phenotypes for each combination of isolate and host line were assessed following drop inoculation of cotyledons and a spectrum of seven phenotypes was observed based on the level of sporulation on cotyledons and visible host responses. Two host lines were resistant or moderately resistant to the entire collection of isolates, and another was universally susceptible. Five lines showed differential responses to the H. brassicae isolates. A minimum of six pathotypes and five major effect resistance genes are proposed to explain all of the observed interaction phenotypes. The B. oleracea lines from this study can be useful for monitoring pathotype frequencies in H. brassicae populations in the same or other vegetable growing regions, and to assess the potential durability of disease control from different combinations of the predicted downy mildew resistance genes

Hypertrophic pulmonary osteoarthropathy secondary to bronchial adenocarcinoma and coexisting pulmonary tuberculosis: a case report

A 44-year-old man presented with painful swelling of wrists and ankles, severe pain at both tibiae, clubbing of fingers and toes and arthritis in wrist and ankle joints. The chest roentgenogram showed consolidation of the right lower lobe, whereas plain roentgenograms revealed solid periosteal reaction at both tibiae. CT and bronchoscopy confirmed the presence of adenocarcinoma of the right lower lobe. Moreover, mycobacterium of tuberculosis was isolated by culture of the patient's sputum

The influence of rs53576 polymorphism in the oxytocin receptor (OXTR) gene on empathy in healthy adults by subtype and ethnicity: a systematic review and meta-analysis

Empathy is essential for navigating complex social environments. Prior work has shown associations between rs53576, a single nucleotide polymorphism (SNP) located in the oxytocin receptor gene (OXTR), and generalized empathy. We undertook a systematic review and meta-analysis to assess the effects of rs53576 on subdomains of empathy, specifically cognitive empathy (CE) and affective empathy (AE), in healthy adults. Twenty cohorts of 8933 participants aged 18-98 were identified, including data from the Sydney Memory and Ageing Study, a cohort of older community adults. Meta-analyses found G homozygotes had greater generalized empathic abilities only in young to middle-aged adults. While meta-analyses of empathy subdomains yielded no significant overall effects, there were differential effects based on ethnicity. G homozygotes were associated with greater CE abilities in Asian cohorts (standardized mean difference; SMD: 0.09 [2.8·10-3-0.18]), and greater AE performance in European cohorts [SMD: 0.12 (0.04-0.21)]. The current literature highlights a need for further work that distinguishes between genetic and ethnocultural effects and explores effects of advanced age on this relationship

Thrombosis Is Reduced by Inhibition of COX-1, but Unaffected by Inhibition of COX-2, in an Acute Model of Platelet Activation in the Mouse

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

A study of prognostic factors in Chinese patients with diabetic foot ulcers

Objective: Few studies have identified factors as predictors of clinical prognosis of patients with diabetic foot ulcers (DFUs), especially of Chinese patients. In this study, we assessed the prognostic factors of Chinese patients with DFUs. Methods and materials: This was a retrospective study (January 2009–January 2011) of 194 DFUs conducted in an inpatient population at PLA 454 Hospital in Nanjing, China, to determine the prognostic influential factors of DFUs in Chinese patients. All of the studied patients were grouped into an amputation group, a non-healing group, and a cured group, according to the clinical prognosis. Patient parameters, including gender, age, smoking habits, education level, family history of diabetes mellitus, medical history, duration of foot lesions and complications, ankle-brachial index (ABI), transcutaneous oxygen pressure (TcPO2), urinary albumin/creatinine ratio (Alb/Cr), fundus oculi, electrocardiogram, DFU characteristics, bacterial nature, and neuropathy, were cross-studied among the three groups. Results: Compared with the other two groups, the amputation group showed a higher number of males, older in age, lower ABI and TcPO2 levels, higher Wagner wound grading and size, and significantly higher urinary Alb/Cr ratio, blood urea nitrogen, serum creatinine, white blood cell count, and erythrocyte sedimentation rate. Compared to the cured group (162 patients), more patients with an older age, smoking, family history of diabetes mellitus, medical history of foot ulcerations, lower ABI and TcPO2 levels, higher urine Alb/Cr ratio, and serum creatinine were found in the non-healing group. Regression analysis was used to study the correlation between various factors and clinical prognosis, and the results were as follows: age, Wagner wound classification, and heel ulcerations were negatively correlated to the DFU prognosis, whereas the female population, ABI, and TcPO2 were positively correlated with DFU prognosis. Conclusion: In this retrospective study, we conclude that the DFU prognosis may be related to age, gender, wound location (heel), Wagner wound classification, ABI, and TcPO2 levels in the Chinese population

Group interventions to improve health outcomes : a framework for their design and delivery

Peer reviewedPublisher PD