On the fretting fatigue behavior of quenched and tempered steel in smooth point contact

Fretting fatigue can lead to a rapid decrease in the life of machine components when their contact surfaces have to transfer high tractions. Fretting fatigue was studied in partial, mixed and gross slip conditions made on quenched and tempered steel 34CrNiMo6. Measurements were made with sphere-on-plane contact geometry for smooth surfaces to detect macroscopic cracks. The fretting map type test series outlined a certain zone in partial and mixed slip conditions, where cracking occurred. The parameters affecting cracking threshold values and crack initiation are discussed

Clinical and Microbiologic Efficacy of a Water Filter Program in a Rural Honduran Community

Water purification in the rural Honduras is a focus of the nonprofit organization Honduras Outreach Medical Brigade Relief Effort (HOMBRE). We assessed water filter use and tested filter microbiologic and clinical efficacy. A 22-item questionnaire assessed water sources, obtainment/storage, purification, and incidence of gastrointestinal disease. Samples from home clay-based filters in La Hicaca were obtained and paired with surveys from the same home. We counted bacterial colonies of four bacterial classifications from each sample. Sixty-five surveys were completed. Forty-five (69%) individuals used a filter. Fifteen respondents reported diarrhea in their home in the last 30 days; this incidence was higher in homes not using a filter. Thirty-three paired water samples and surveys were available. Twenty-eight samples (85%) demonstrated bacterial growth. A control sample was obtained from the local river, the principal water source; number and bacterial colony types were innumerable within 24 hours. Access to clean water, the use of filters, and other treatment methods differed within a geographically proximal region. Although the majority of the water samples failed to achieve bacterial eradication, water filters may sufficiently reduce bacterial coliform counts to levels below infectious inoculation. Clay water filters may be sustainable water treatment measures in resource poor settings

Development of a decision aid to inform patients' and families' renal replacement therapy selection decisions.

BACKGROUND: Few educational resources have been developed to inform patients' renal replacement therapy (RRT) selection decisions. Patients progressing toward end stage renal disease (ESRD) must decide among multiple treatment options with varying characteristics. Complex information about treatments must be adequately conveyed to patients with different educational backgrounds and informational needs. Decisions about treatment options also require family input, as families often participate in patients' treatment and support patients' decisions. We describe the development, design, and preliminary evaluation of an informational, evidence-based, and patient-and family-centered decision aid for patients with ESRD and varying levels of health literacy, health numeracy, and cognitive function. METHODS: We designed a decision aid comprising a complementary video and informational handbook. We based our development process on data previously obtained from qualitative focus groups and systematic literature reviews. We simultaneously developed the video and handbook in "stages." For the video, stages included (1) directed interviews with culturally appropriate patients and families and preliminary script development, (2) video production, and (3) screening the video with patients and their families. For the handbook, stages comprised (1) preliminary content design, (2) a mixed-methods pilot study among diverse patients to assess comprehension of handbook material, and (3) screening the handbook with patients and their families. RESULTS: The video and handbook both addressed potential benefits and trade-offs of treatment selections. The 50-minute video consisted of demographically diverse patients and their families describing their positive and negative experiences with selecting a treatment option. The video also incorporated health professionals' testimonials regarding various considerations that might influence patients' and families' treatment selections. The handbook was comprised of written words, pictures of patients and health care providers, and diagrams describing the findings and quality of scientific studies comparing treatments. The handbook text was written at a 4th to 6th grade reading level. Pilot study results demonstrated that a majority of patients could understand information presented in the handbook. Patient and families screening the nearly completed video and handbook reviewed the materials favorably. CONCLUSIONS: This rigorously designed decision aid may help patients and families make informed decisions about their treatment options for RRT that are well aligned with their values

The Amphibian Extinction Crisis - what will it take to put the action into the Amphibian Conservation Action Plan?

The current mass extinction episode is most apparent in the amphibians. With approximately 7,000 species, amphibians are dependent on clean fresh water and damp habitats and are considered vulnerable to habitat loss (deforestation), changes in water or soil quality and the potential impacts of climate change, and in addition many species are suffering from an epidemic caused by a chytrid fungus. Because of their sensitivity and general dependence on both terrestrial and aquatic habitats they are often regarded as indicators of the health of the environment. The latest figures from the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species™ show that there are nearly as many species of amphibians categorised as Threatened as those of Threatened birds and mammals put together, with an estimated 40% of amphibian species in danger of extinction. Furthermore, although amphibians have survived multiple previous global mass extinctions, in the last 20-40 years precipitous population declines have taken place on a scale not previously seen. Although amphibian declines were first reported in the 1950s, the magnitude and global scope of the problem were only fully realised during discussions at the 1st World Congress of Herpetology in England in 1989. Shortly thereafter, the Declining Amphibian Populations Task Force (DAPTF) was established by the IUCN Species Survival Commission (SSC) to investigate the causes and severity of the declines. Many projects and publications were stimulated by the DAPTF and the results of these prompted the IUCN to conduct a global amphibian assessment in 2004. IUCN SSC’s Amphibian Conservation Action Plan (ACAP) was published in 2007, following an Amphibian Conservation Summit held in 2005. The ACAP identified the key issues that require attention in order to curb this crisis, and provided the framework for interventions. While there have been significant efforts in the last five years, the response to the crisis has not progressed across all areas of the action plan at a scale sufficient to halt the crisis. As a direct result, species continue to decline and go extinct. Finding solutions to counter amphibian declines and extinctions is one of the greatest conservation challenges of the century, which comes with alarming and serious implications for the health of ecosystems globally. The Amphibian Survival Alliance (ASA), launched in June 2011, acts as a global partnership for amphibian conservation. It is in a pivotal position to implement the ACAP, acting to mobilise a motivated and effective consortium of organisations working together to stem the rapid losses of amphibian populations and species worldwide. The Alliance brings focus, coordination, and leadership in addressing one of the world’s most serious extinction crises. Its goal is the restoration of all threatened native amphibian species to their natural roles and population levels in ecosystems worldwide. The recently formed Amphibian Survival Alliance will address the multiple ACAP issues with several new initiatives, including creating a web-based ‘living’ version of ACAP and driving the implementation of the ACAP themes in a more progressive and collaborative manner than ever before, thereby stemming the loss of an important part of the biological diversity of our planet.   

The providing resources to enhance African American patients' readiness to make decisions about kidney disease (PREPARED) study: protocol of a randomized controlled trial.

BACKGROUND: Living related kidney transplantation (LRT) is underutilized, particularly among African Americans. The effectiveness of informational and financial interventions to enhance informed decision-making among African Americans with end stage renal disease (ESRD) and improve rates of LRT is unknown. METHODS/DESIGN: We report the protocol of the Providing Resources to Enhance African American Patients' Readiness to Make Decisions about Kidney Disease (PREPARED) Study, a two-phase study utilizing qualitative and quantitative research methods to design and test the effectiveness of informational (focused on shared decision-making) and financial interventions to overcome barriers to pursuit of LRT among African American patients and their families. Study Phase I involved the evidence-based development of informational materials as well as a financial intervention to enhance African American patients' and families' proficiency in shared decision-making regarding LRT. In Study Phase 2, we are currently conducting a randomized controlled trial in which patients with new-onset ESRD receive 1) usual dialysis care by their nephrologists, 2) the informational intervention (educational video and handbook), or 3) the informational intervention in addition to the option of participating in a live kidney donor financial assistance program. The primary outcome of the randomized controlled trial will include patients' self-reported rates of consideration of LRT (including family discussions of LRT, patient-physician discussions of LRT, and identification of a LRT donor). DISCUSSION: Results from the PREPARED study will provide needed evidence on ways to enhance the decision to pursue LRT among African American patients with ESRD

Meta-analysis of molecular response of kidney to ischemia reperfusion injury for the identification of new candidate genes

Abstract Background Accumulated to-date microarray data on ischemia reperfusion injury (IRI) of kidney represent a powerful source for identifying new targets and mechanisms of kidney IRI. In this study, we conducted a meta-analysis of gene expression profiles of kidney IRI in human, pig, rat, and mouse models, using a new scoring method to correct for the bias of overrepresented species. The gene expression profiles were obtained from the public repositories for 24 different models. After filtering against inclusion criteria 21 experimental settings were selected for meta-analysis and were represented by 11 rat models, 6 mouse models, and 2 models each for pig and human, with a total of 150 samples. Meta-analysis was conducted using expression-based genome-wide association study (eGWAS). The eGWAS results were corrected for a rodent species bias using a new weighted scoring algorithm, which favors genes with unidirectional change in expression in all tested species. Results Our meta-analysis corrected for a species bias, identified 46 upregulated and 1 downregulated genes, of which 26 (55%) were known to be associated with kidney IRI or kidney transplantation, including LCN2, CCL2, CXCL1, HMOX1, ICAM1, ANXA1, and TIMP1, which justified our approach. Pathway analysis of our candidates identified “Acute renal failure panel” as the most implicated pathway, which further validates our new method. Among new IRI candidates were 10 novel (<5 published reports related to kidney IRI) and 11 new candidates (0 reports related to kidney IRI) including the most prominent candidates ANXA2, CLDN4, and TYROBP. The cross-species expression pattern of these genes allowed us to generate three workable hypotheses of kidney IRI, one of which was confirmed by an additional study. Conclusions Our first in the field kidney IRI meta-analysis of 150 microarray samples, corrected for a species bias, identified 10 novel and 11 new candidate genes. Moreover, our new meta-analysis correction method improved gene candidate selection by identifying genes that are model and species independent, as a result, function of these genes can be directly extrapolated to the disease state in human and facilitate translation of potential diagnostic or therapeutic properties of these candidates to the bedside.Peer Reviewe

Lymphocyte Modulation with FTY720 Improves Hemorrhagic Shock Survival in Swine

The inflammatory response to severe traumatic injury results in significant morbidity and mortality. Lymphocytes have recently been identified as critical mediators of the early innate immune response to ischemia-reperfusion injury. Experimental manipulation of lymphocytes following hemorrhagic shock may prevent secondary immunologic injury in surgical and trauma patients. The objective of this study is to evaluate the lymphocyte sequestration agent FTY720 as an immunomodulator following experimental hemorrhagic shock in a swine liver injury model. Yorkshire swine were anesthetized and underwent a grade III liver injury with uncontrolled hemorrhage to induce hemorrhagic shock. Experimental groups were treated with a lymphocyte sequestration agent, FTY720, (n = 9) and compared to a vehicle control group (n = 9). Animals were observed over a 3 day survival period after hemorrhage. Circulating total leukocyte and neutrophil counts were measured. Central lymphocytes were evaluated with mesenteric lymph node and spleen immunohistochemistry (IHC) staining for CD3. Lung tissue infiltrating neutrophils were analyzed with myeloperoxidase (MPO) IHC staining. Relevant immune-related gene expression from liver tissue was quantified using RT-PCR. The overall survival was 22.2% in the vehicle control and 66.7% in the FTY720 groups (p = 0.081), and reperfusion survival (period after hemorrhage) was 25% in the vehicle control and 75% in the FTY720 groups (p = 0.047). CD3+ lymphocytes were significantly increased in mesenteric lymph nodes and spleen in the FTY720 group compared to vehicle control, indicating central lymphocyte sequestration. Lymphocyte disruption significantly decreased circulating and lung tissue infiltrating neutrophils, and decreased expression of liver immune-related gene expression in the FTY720 treated group. There were no observed infectious or wound healing complications. Lymphocyte sequestration with FTY720 improves survival in experimental hemorrhagic shock using a porcine liver injury model. These results support a novel and clinically relevant lymphocyte immunomodulation strategy to ameliorate secondary immune injury in hemorrhagic shock

Reversal to air-driven sound production revealed by a molecular phylogeny of tongueless frogs, family Pipidae

<p>Abstract</p> <p>Background</p> <p>Evolutionary novelties often appear by conferring completely new functions to pre-existing structures or by innovating the mechanism through which a particular function is performed. Sound production plays a central role in the behavior of frogs, which use their calls to delimit territories and attract mates. Therefore, frogs have evolved complex vocal structures capable of producing a wide variety of advertising sounds. It is generally acknowledged that most frogs call by moving an air column from the lungs through the glottis with the remarkable exception of the family Pipidae, whose members share a highly specialized sound production mechanism independent of air movement.</p> <p>Results</p> <p>Here, we performed behavioral observations in the poorly known African pipid genus <it>Pseudhymenochirus </it>and document that the sound production in this aquatic frog is almost certainly air-driven. However, morphological comparisons revealed an indisputable pipid nature of <it>Pseudhymenochirus </it>larynx. To place this paradoxical pattern into an evolutionary framework, we reconstructed robust molecular phylogenies of pipids based on complete mitochondrial genomes and nine nuclear protein-coding genes that coincided in placing <it>Pseudhymenochirus </it>nested among other pipids.</p> <p>Conclusions</p> <p>We conclude that although <it>Pseudhymenochirus </it>probably has evolved a reversal to the ancestral non-pipid condition of air-driven sound production, the mechanism through which it occurs is an evolutionary innovation based on the derived larynx of pipids. This strengthens the idea that evolutionary solutions to functional problems often emerge based on previous structures, and for this reason, innovations largely depend on possibilities and constraints predefined by the particular history of each lineage.</p