Bending Stiffness in Cadaveric and Composite Long Bones Following Total Joint Replacement

Several biomechanics studies have utilized commercially available replicate bone models as an alternative to cadaveric tissue specimens, in part due to their ease of handling and reduced expense. In an effort to validate the use of replicate bone specimens in biomechanics research, a number of studies have compared material properties of whole tibia and femur specimens to those of similar cadaveric specimens. Many of these validation studies have ascertained that the material properties of whole bone composite models fall within the range of those properties of cadaveric specimens, while offering reduced interspecimen variability. Current literature lacks, however, the direct comparison between cadaveric and composite specimens after the implantation of joint replacement components. Because of this, the interactions between orthopaedic implant and replicate bone model, and how those interactions compare with those between implants and cadaveric tissue, are relatively unknown. The purpose of this study was to evaluate the use of composite femur specimens in test scenarios aside from the whole-bone instances currently evaluated in the literature. Six cadaveric and six composite tibias and femurs were tested at different stages of surgical intervention. Flexural rigidity was measured using a 4-point bending test as a whole bone, after unicompartimental cut and implantation (UKA), and after total knee cut and implantation (TKA) or total hip arthroplasty (THA). The data did not show a definite trend between tests and specimens but is conclusive enough to use composite models for cadaveric specimens

Evaluation of nutritional status among school-aged children in rural Kwahu-eastern region, Ghana; anthropometric measures and environmental influences

School-age children in developing countries are particularly vulnerable to undernutrition as the priority of nutritional interventions focus on fetal development and the first years of life. This study examines anthropometric indices of school-age children in five communities located in rural Kwahu-Eastern Region, Ghana, West Africa and discusses environmental influences that contribute to their nutritional and growth status. Anthropometric indices of heights and weights were obtained from 411 school- aged children, (5-12 years old) in 5 villages (Asakraka, Awiseasu, Miaso, Oframase and Oworobong) during June 2012. Anthropometric parameters and influences that contributed to nutritional status (environmental, health facilities, availability of markets and gender) were assessed. Factorial ANOVAs were conducted with age, gender and village as factors for the z-score for ‘BMI-for-age’ and the z-score for ‘height-for-age’. The z-score of ‘BMI-for-age’ showed a significant two-way interaction effect between ‘Age’ and ‘Village’, F (4, 391) = 6.06, p-value < 0.001, η2 = 0.06. The mean z-score for ‘BMI- for-age’ was significantly lower for older children in Oframase. The z-score of ‘Height-for-age’ showed a small but significant three-way interaction effect among ‘Age’, ‘Gender’, and ‘Village’, F (4, 391) = 3.79, p-value = 0.005, η2 = 0.04. The mean z-score for ‘Height-for-age’ was significantly lower in older children (ages 10-12 years) in all villages except Asakraka. Lower mean z-score for ‘Height-for-age’ in older children (ages 10-12 years) remains to be significant in boys in villages of Awiseasu and Oworobong and in girls in villages of Awiseasu, Miaso and Oframase. Children in isolated communities are at increased risk for lower z-scores in ‘Height-for-age’ and ‘BMI-for-age’. Communities with a clinic, paved road and established infrastructure did not demonstrate evidence of chronic malnutrition. Acute malnutrition in the form of lower z-scores was demonstrated in older children in Oframase. Gender disparities are present and increased awareness of the nutritional status of girls needs to be addressed.Keywords: Nutrition, School children, Ghana, Environmen

Taken by strum: ukuleles and participatory music-making in Hamilton, Aotearoa/New Zealand

Ethnographic study of ukulele playing in Hamilton, N

Comparative study of nonlinear properties of EEG signals of a normal person and an epileptic patient

Background: Investigation of the functioning of the brain in living systems has been a major effort amongst scientists and medical practitioners. Amongst the various disorder of the brain, epilepsy has drawn the most attention because this disorder can affect the quality of life of a person. In this paper we have reinvestigated the EEGs for normal and epileptic patients using surrogate analysis, probability distribution function and Hurst exponent. Results: Using random shuffled surrogate analysis, we have obtained some of the nonlinear features that was obtained by Andrzejak \textit{et al.} [Phys Rev E 2001, 64:061907], for the epileptic patients during seizure. Probability distribution function shows that the activity of an epileptic brain is nongaussian in nature. Hurst exponent has been shown to be useful to characterize a normal and an epileptic brain and it shows that the epileptic brain is long term anticorrelated whereas, the normal brain is more or less stochastic. Among all the techniques, used here, Hurst exponent is found very useful for characterization different cases. Conclusions: In this article, differences in characteristics for normal subjects with eyes open and closed, epileptic subjects during seizure and seizure free intervals have been shown mainly using Hurst exponent. The H shows that the brain activity of a normal man is uncorrelated in nature whereas, epileptic brain activity shows long range anticorrelation.Comment: Keywords:EEG, epilepsy, Correlation dimension, Surrogate analysis, Hurst exponent. 9 page

Small for gestational age: Case definition & guidelines for data collection, analysis, and presentation of maternal immunisation safety data.

Need for developing case definitions and guidelines for data collection, analysis, and presentation for small for gestational age (SGA) as an adverse event following maternal immunisation Small for gestational age (SGA) fetuses or newborns are those smaller in size than normal for their gestational age, most commonly defined as a weight below the 10th percentile for the gestational age. This classification was originally developed by a 1995 World Health Organization (WHO) expert committee, and the definition is based on a birthweight-for-gestational-age measure compared to a gender-specific reference population [1,2]

No Detectable Fertility Benefit from a Single Additional Mating in Wild Stalk-Eyed Flies

Background: Multiple mating by female insects is widespread, and the explanation(s) for repeated mating by females has been the subject of much discussion. Females may profit from mating multiply through direct material benefits that increase their own reproductive output, or indirect genetic benefits that increase offspring fitness. One particular direct benefit that has attracted significant attention is that of fertility assurance, as females often need to mate multiply to achieve high fertility. This hypothesis has never been tested in a wild insect population.Methodology/Principal Findings: Female Malaysian stalk-eyed flies (Teleopsis dalmanni) mate repeatedly during their lifetime, and have been shown to be sperm limited under both laboratory and field conditions. Here we ask whether receiving an additional mating alleviates sperm limitation in wild females. In our experiment one group of females received a single additional mating, while a control group received an interrupted, and therefore unsuccessful, mating. Females that received an additional mating did not lay more fertilised eggs in total, nor did they lay proportionately more fertilised eggs. Female fertility declined significantly through time, demonstrating that females were sperm limited. However, receipt of an additional mating did not significantly alter the rate of this decline.Conclusions/Significance: Our data suggest that the fertility consequences of a single additional mating were small. We discuss this effect (or lack thereof), and suggest that it is likely to be attributed to small ejaculate size, a high proportion of failed copulations, and the presence of X-linked meiotic drive in this species

ADAM17-Mediated Processing of TNF-α Expressed by Antiviral Effector CD8+ T Cells Is Required for Severe T-Cell-Mediated Lung Injury

Influenza infection in humans evokes a potent CD8+ T-cell response, which is important for clearance of the virus but may also exacerbate pulmonary pathology. We have previously shown in mice that CD8+ T-cell expression of TNF-a is required for severe and lethal lung injury following recognition of an influenza antigen expressed by alveolar epithelial cells. Since TNF-a is first expressed as a transmembrane protein that is then proteolytically processed to release a soluble form, we sought to characterize the role of TNF-a processing in CD8+ T-cell-mediated injury. In this study we observed that inhibition of ADAM17-mediated processing of TNF-a by CD8+ T cells significantly attenuated the diffuse alveolar damage that occurs after T-cell transfer, resulting in enhanced survival. This was due in part to diminished chemokine expression, as TNF-aprocessing was required for lung epithelial cell expression of CXCL2 and the subsequent inflammatory infiltration. We confirmed the importance of CXCL2 expression in acute lung injury by transferring influenza-specific CD8+ T cells into transgenic mice lacking CXCR2. These mice exhibited reduced airway infiltration, attenuated lung injury, and enhanced survival. Theses studies describe a critical role for TNF-a processing by CD8+ T cells in the initiation and severity of acute lung injury, which may have important implications for limiting immunopathology during influenza infection and other human infectious or inflammatory diseases

A broad distribution of the alternative oxidase in microsporidian parasites

Microsporidia are a group of obligate intracellular parasitic eukaryotes that were considered to be amitochondriate until the recent discovery of highly reduced mitochondrial organelles called mitosomes. Analysis of the complete genome of Encephalitozoon cuniculi revealed a highly reduced set of proteins in the organelle, mostly related to the assembly of ironsulphur clusters. Oxidative phosphorylation and the Krebs cycle proteins were absent, in keeping with the notion that the microsporidia and their mitosomes are anaerobic, as is the case for other mitosome bearing eukaryotes, such as Giardia. Here we provide evidence opening the possibility that mitosomes in a number of microsporidian lineages are not completely anaerobic. Specifically, we have identified and characterized a gene encoding the alternative oxidase (AOX), a typically mitochondrial terminal oxidase in eukaryotes, in the genomes of several distantly related microsporidian species, even though this gene is absent from the complete genome of E. cuniculi. In order to confirm that these genes encode functional proteins, AOX genes from both A. locustae and T. hominis were over-expressed in E. coli and AOX activity measured spectrophotometrically using ubiquinol-1 (UQ-1) as substrate. Both A. locustae and T. hominis AOX proteins reduced UQ-1 in a cyanide and antimycin-resistant manner that was sensitive to ascofuranone, a potent inhibitor of the trypanosomal AOX. The physiological role of AOX microsporidia may be to reoxidise reducing equivalents produced by glycolysis, in a manner comparable to that observed in trypanosome

Multiple interactions between the alpha2C- and beta1-adrenergic receptors influence heart failure survival

<p>Abstract</p> <p>Background</p> <p>Persistent stimulation of cardiac β₁-adrenergic receptors by endogenous norepinephrine promotes heart failure progression. Polymorphisms of this gene are known to alter receptor function or expression, as are polymorphisms of the α_2C-adrenergic receptor, which regulates norepinephrine release from cardiac presynaptic nerves. The purpose of this study was to investigate possible synergistic effects of polymorphisms of these two intronless genes (<it>ADRB1 </it>and <it>ADRA2C</it>, respectively) on the risk of death/transplant in heart failure patients.</p> <p>Methods</p> <p>Sixteen sequence variations in <it>ADRA2C </it>and 17 sequence variations in <it>ADRB1 </it>were genotyped in a longitudinal study of 655 white heart failure patients. Eleven sequence variations in each gene were polymorphic in the heart failure cohort. Cox proportional hazards modeling was used to identify polymorphisms and potential intra- or intergenic interactions that influenced risk of death or cardiac transplant. A leave-one-out cross-validation method was utilized for internal validation.</p> <p>Results</p> <p>Three polymorphisms in <it>ADRA2C </it>and five polymorphisms in <it>ADRB1 </it>were involved in eight cross-validated epistatic interactions identifying several two-locus genotype classes with significant relative risks ranging from 3.02 to 9.23. There was no evidence of intragenic epistasis. Combining high risk genotype classes across epistatic pairs to take into account linkage disequilibrium, the relative risk of death or transplant was 3.35 (1.82, 6.18) relative to all other genotype classes.</p> <p>Conclusion</p> <p>Multiple polymorphisms act synergistically between the <it>ADRA2C </it>and <it>ADRB1 </it>genes to increase risk of death or cardiac transplant in heart failure patients.</p