A sulfated glycoprotein synthesized by Sertoli cells and by epididymal cells is a component of the sperm membrane

We report here the purification, partial characterization and immunofluorescent localization of a dimeric acidic glycoprotein (DAG-protein) secreted by cultures of Sertoli cells of rat testes. Partially purified protein was obtained after chromatography over Sepharose 4B under conditions which favored a soluble, nonaggregated form of the protein. Rechromatography over the same column under reducing conditions yielded very pure monomers of 41,000 daltons and 29,000 daltons. Antibodies were prepared against the mixed monomers and used to immunoprecipitate proteins in spent medium from cultures incubated with [35S] methionine, 35SO4 = or tunicamycin. DAG-protein and another protein (Band 4, 70,000 daltons) were coprecipitated by the antiserum and all contained 35SO4 = in their structures. It was shown by Western blotting that the antiserum cross-reacted very weakly with Band 4 protein. The DAG-protein polypeptides secreted in the presence of tunicamycin were assumed to lack N-glycosylation and exhibited apparent molecular weights of 27,000 and 21,000 daltons. Immunoprecipitations of media from organ cultures of testis and epididymis yielded DAG-protein of slightly lower molecular weight than the protein secreted in Sertoli cell cultures. Indirect immunofluorescence of DAG-protein in paraffin sections of testis and epididymis revealed that the protein was concentrated in the cytoplasm of Sertoli cells, on the stereocilia of epididymal principal cells, in the cytoplasm of epididymal halo cells, and was associated with late spermatids and mature sperm. Sperm were specifically labeled on the acrosome, at the neck, and on the endpiece of the tail. No enzymatic or structural function has been ascribed to DAG-protein as yet, but the protein must play a pivotal role in spermatogenesis because it is secreted by both the testis and epididymis and becomes an integral component of sperm

Fatigue analysis-based numerical design of stamping tools made of cast iron

This work concerns stress and fatigue analysis of stamping tools made of cast iron with an essentially pearlitic matrix and containing foundry defects. Our approach consists at first, in coupling the stamping numerical processing simulations and structure analysis in order to improve the tool stiffness geometry for minimizing the stress state and optimizing their fatigue lifetime. The method consists in simulating the stamping process by considering the tool as a perfect rigid body. The estimated contact pressure is then used as boundary condition for FEM structure loading analysis of the tool. The result of this analysis is compared with the critical stress limit depending on the automotive model. The acceptance of this test allows calculating the fatigue lifetime of the critical zone by using the S–N curve of corresponding load ratio. If the prescribed tool life requirements are not satisfied, then the critical region of the tool is redesigned and the whole simulation procedures are reactivated. This method is applied for a cast iron EN-GJS-600-3. The stress-failure (S–N) curves for this material is determined at room temperature under push pull loading with different load ratios R0σmin/σmax0−2, R0−1 and R00.1. The effects of the foundry defects are determined by SEM observations of crack initiation sites. Their presence in tested specimens is associated with a reduction of fatigue lifetime by a factor of 2. However, the effect of the load ratio is more important

Capacity and Maximal Inspiratory Pressure in Healthy Adults

Introduction Diaphragmatic fatigue during maximal exercise causes decreased blood flow to exercising limbs. Inspiratory muscle strength training (IMST) may decrease diaphragm fatigue. Current studies use 50% of maximal inspiratory pressure (MIP) for IMST, but optimal dosing at higher intensities has not been well explored. Objective Investigate the impact of high intensity IMST on aerobic capacity and maximal inspiratory pressure in healthy adults. Methods This study was IRB approved by the university. All participants provided informed consent, and demographic information was collected. Results VO2 max did not change significantly in either intervention group after intervention period (p=0.143). Groups demonstrated significant improvement in MIP (p=0.011), but there was no significant difference between groups (p\u3c0.638). Conclusion VO2 max did not significantly change in the control or intervention groups. Post-intervention MIP measurements were significantly improved in both groups, but there was no significant difference between either group. High intensity IMST may not improve aerobic capacity in young, healthy adults after an 8-week intervention period. Clinical Relevance Maintaining diaphragmatic strength with IMST may help minimize respiratory fatigue and be useful for healthy adults with injuries limiting their mobility. Further research is needed to evaluate optimal IMST intensity for maximal benefit as 80% may be too intense

Effects of a refugee elective on medical student perceptions

<p>Abstract</p> <p>Background</p> <p>There are growing numbers of refugees throughout the world. Refugee health is a relatively unstudied and rarely taught component of medical education. In response to this need, a Refugee Health Elective was begun. Medical student perceptions toward cultural aspects of medicine and refugee health before and after participation in the elective were measured.</p> <p>Methods</p> <p>Preliminary questionnaires were given to all preclinical students at the academic year commencement with follow-up questionnaires at the refugee elective's conclusion. Both questionnaires examined students' comfort in interacting with patients and familiarity with refugee medical issues, alternative medical practices, and social hindrances to medical care. The preliminary answers served as a control and follow-up questionnaire data were separated into participant/non-participant categories. All preclinical medical students at two Midwestern medical schools were provided the opportunity to participate in the Refugee Health Elective and surveys. The 3 data groups were compared using unadjusted and adjusted analysis techniques with the Kruskall-Wallis, Bonferroni and ANCOVA adjustment. P-values < 0.05 were considered significant.</p> <p>Results</p> <p>408 and 403 students filled out the preliminary and follow-up questionnaires, respectfully, 42 of whom participated in the elective. Students considering themselves minorities or multilingual were more likely to participate. Elective participants were more likely to be able to recognize the medical/mental health issues common to refugees, to feel comfortable interacting with foreign-born patients, and to identify cultural differences in understanding medical/mental health conditions, after adjusting for minority or multilingual status.</p> <p>Conclusion</p> <p>As medical schools integrate a more multicultural curriculum, a Refugee Health Elective for preclinical students can enhance awareness and promote change in attitude toward medical/mental health issues common to refugees. This elective format offers tangible and effective avenues for these topics to be addressed.</p

Prediabetes and Diabetes Are Associated With Arterial Stiffness in Older Adults: The ARIC Study

To determine whether prediabetes and diabetes in older adults are associated with arterial stiffness measured in central and peripheral arteries and to examine characteristics that modify these associations

Gender-Sensitive Violence Risk Assessment:Predictive Validity of Six Tools in Female Forensic Psychiatric Patients

Most violence risk assessment tools have been validated predominantly in males. In this multicenter study, the Historical, Clinical, Risk Management-20 (HCR-20), Historical, Clinical, Risk Management-20 Version 3 (HCR-20(V3)), Female Additional Manual (FAM), Short-Term Assessment of Risk and Treatability (START), Structured Assessment of Protective Factors for violence risk (SAPROF), and Psychopathy Checklist-Revised (PCL-R) were coded on file information of 78 female forensic psychiatric patients discharged between 1993 and 2012 with a mean follow-up period of 11.8 years from one of four Dutch forensic psychiatric hospitals. Notable was the high rate of mortality (17.9%) and readmission to psychiatric settings (11.5%) after discharge. Official reconviction data could be retrieved from the Ministry of Justice and Security for 71 women. Twenty-four women (33.8%) were reconvicted after discharge, including 13 for violent offenses (18.3%). Overall, predictive validity was moderate for all types of recidivism, but low for violence. The START Vulnerability scores, HCR-20(V3), and FAM showed the highest predictive accuracy for all recidivism. With respect to violent recidivism, only the START Vulnerability scores and the Clinical scale of the HCR-20(V3) demonstrated significant predictive accuracy

Spintronics: Fundamentals and applications

Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes from the published versio

Midlife Cardiovascular Health and Robust Versus Frail Late-Life Status: The Atherosclerosis Risk in Communities Study

Background: We examined the relationship of midlife cardiovascular health (CVH) with late-life robustness among men and women and the impact of survivorship bias on sex differences in robustness. Methods: Prospective analysis of 15 744 participants aged 45-64 (visit 1 median age: 54 years, 55% female, 27% Black) in 1987-1989 from the population-based Atherosclerosis Risk in Communities Study. CVH was operationalized according to the Life's Simple 7 (LS7) metric of health behaviors (smoking, weight, physical activity, diet, cholesterol, blood pressure, and glucose); each behavior was scored as ideal (2 points), intermediate (1 point), or poor (0 points) and summed. Late-life robust/prefrail/frailty was defined at visit 5 (2011-2013). Multinomial regression estimated relative prevalence ratios (RPRs) of late-life robustness/prefrailty/frailty/death across overall midlife LS7 score and components, for the full visit 1 sample. Separate analyses considered visit 5 survivors-only. Results: For each 1-unit greater midlife LS7 score, participants had a 37% higher relative prevalence of being robust versus frail (overall RPR = 1.37 [95% confidence interval {CI}: 1.30-1.44]; women = 1.45 [1.36-1.54]; men = 1.24 [1.13-1.36]). Among the full visit 1 sample, women had a similar 1-level higher robustness category prevalence (RPR = 1.35 [95% CI: 1.32-1.39]) than men (RPR = 1.31 [95% CI: 1.27-1.35]) for every 1-unit higher midlife LS7 score. Among survivors, men were more likely to be robust than women at lower LS7 levels; differences were attenuated and not statistically different at higher midlife LS7 levels. Conclusions: Midlife CVH is positively associated with robustness in late life among men and women. Accounting for mortality in part explains documented sex differences in robustness across all levels of LS7