Cold Reactions of Alkali and Water Clusters inside Helium Nanodroplets

The reaction of alkali (Na, Cs) clusters with water clusters embedded in helium nanodroplets is studied using femtosecond photo-ionization as well as electron impact ionization. Unlike Na clusters, Cs clusters are found to completely react with water in spite of the ultracold helium droplet environment. Mass spectra of the Cs$_n$+(H$_2$O)$_m$ reaction products are interpreted in terms of stability with respect to fragmentation using high-level molecular structure calculations

Further Expansion of Nested E-Modules to Address Anatomical Knowledge Retention in Medical Students entering the Obstetrics and Gynecology Clinical Rotation

Previous work has shown that a curriculum that included computer-based teaching modules (“e-modules”) improved retention of preclinical concepts of gross anatomy, as medical students transitioned to the third-year OBGYN clerkship. However, data showed that deficiencies still remained in areas not addressed by the curriculum. Two of these areas were microscopic anatomy and embryology, where retention scores were 4% and 38%, respectively (Jurjus et al., unpublished). Based on this research, an expanded series of e-modules will be created to target these anatomical topics that still require improvement, specifically in microscopic anatomy and embryology: 1) Ultrasound in Pregnancy using Embryological Knowledge 2) Pregnancy Timeline and the Embryo and 3) The Cervix in Health and Disease. The learning objectives correlate clinical medicine and anatomical categories. Once finalized, these e-modules will be live on the Himmelfarb Library website. By further expanding the number of e-modules available to students, we hope to improve retention of clinically relevant anatomical knowledge in adult learners. Funding: GW Office of the Vice Provost for Teaching and Learning, Spring 2013 Grants for High Impact Teaching and Learning Practices

Improving Anatomical Knowledge Through Interactive Modules on the OB/GYN Clinical Clerkship

The goal of this study is to evaluate the impact of a newly designed interactive method of teaching clinically relevant anatomy to medical students on the OB/GYN clerkship. A 20-question multiple-choice exam was administered to 143 consenting third-year medical students at the beginning and end of each OB/GYN rotation. Students participated in a skills lab with preparatory e-modules that linked anatomy to clinical applications during each rotation. Topics included perineal muscle anatomy (laceration), anterior abdominal wall anatomy (cesarean section), vulvovaginal and uterine anatomy (IUD), and pelvic organ, vasculature, and neural anatomy (hysterectomy). Mean scores improved significantly after the nesting of interactive modules, increasing from 55.1% to 67.4% (p\u3c0.001). In comparing mean scores from questions that were covered in the e-modules (intervention) and questions that were not covered in the e-modules (non-intervention), students improved significantly after receiving an intervention (9.4% difference; p\u3c0.001). Therefore, completing the clerkship without an intervention did not yield significant improvement in relevant anatomical knowledge, compared to intervention. Thus, nesting anatomical science into the clinical curriculum through preparatory e-modules and hands-on anatomy lab sessions may improve clinically-significant anatomy knowledge. This data may be used to increase longitudinal integration of the various disciplines across the undergraduate medical curriculum

Functional human sperm capacitation requires both bicarbonate dependent-PKA activation and down-regulation of Ser/Thr phosphatases by Src family kinases

In all mammalian species studied so far, sperm capacitation correlates with an increase in protein tyrosine (Tyr) phosphorylation mediated by a bicarbonate-dependent cAMP/PKA pathway. Recent studies in mice revealed however that a Src Family Kinase (SFK) induced inactivation of serine/threonine (Ser/Thr) phosphatases is also involved in the signaling pathways leading to Tyr phosphorylation. In view of these observations and with the aim of getting a better understanding of the signaling pathways involved in human sperm capacitation, in the present work we investigated the involvement of both the cAMP/PKA and SFK/phosphatase pathways in relation to the capacitation state of the cells. For this purpose, different signaling events and sperm functional parameters were analyzed as a function of capacitation time. Results revealed a very early bicarbonate-dependent activation of PKA indicated by the rapid (1 min) increase in both phospho-PKA substrates and cAMP levels (p<0.05). However, a complete pattern of Tyr phosphorylation was detected only after 6 h-incubation at which time sperm exhibited the ability to undergo the acrosome reaction (AR) and to penetrate zona-free hamster eggs. Sperm capacitated in the presence of the SFK inhibitor SKI606 showed a decrease in both PKA substrate and Tyr phosphorylation levels which was overcome by exposure of sperm to the Ser/Thr phosphatase inhibitor okadaic acid (OA). However, OA was unable to induce phosphorylation when sperm were incubated under PKA-inhibitory conditions (i.e. in the absence of bicarbonate or presence of PKA inhibitor). Moreover, the increase in PKA activity by exposure to a cAMP analogue and a phosphodiesterase inhibitor did not overcome the inhibition produced by SKI606. Whereas the presence of SKI606 during capacitation produced a negative effect (p<0.05) on sperm motility, progesterone-induced AR and fertilizing ability, none of these inhibitions were observed when sperm were exposed to SKI606 and OA. Interestingly, different concentrations of inhibitors were required to modulate human and mouse capacitation revealing the species-specificity of the molecular mechanisms underlying this process. In conclusion, our results describe for the first time the involvement of both PKA activation and Ser/Thr phosphatase down-regulation in functional human sperm capacitation and provide convincing evidence that early PKA-dependent phosphorylation is the convergent regulatory point between these two signaling pathways.Fil: Battistone, Maria Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas -conicet. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Da Ros, Vanina Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas -conicet. Instituto de Biología y Medicina Experimental (i); ArgentinaFil: Salicioni, A.. University Of Massachussets; Estados UnidosFil: Navarrete, F.. University Of Massachussets; Estados UnidosFil: Krapf, Dario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Rosario. Instituto de Biología Molecular y Celular de Rosario; Argentina. Universidad Nacional de Rosario; ArgentinaFil: Visconti, P. E.. University Of Massachussets;Fil: Cuasnicu, Patricia Sara. Consejo Nacional de Investigaciones Científicas y Técnicas -conicet. Instituto de Biología y Medicina Experimental (i); Argentin

Family health climate scale (FHC-scale): Development and validation

Background: The family environment is important for explaining individual health behaviour. While previous research mostly focused on influences among family members and dyadic interactions (parent-child), the purpose of this study was to develop a new measure, the Family Health Climate Scale (FHC-Scale), using a family-based approach. The FHC is an attribute of the whole family and describes an aspect of the family environment that is related to health and health behaviour. Specifically, a questionnaire measuring the FHC (a) for nutrition (FHC-NU) and (b) for activity behaviour (FHC-PA) was developed and validated. Methods: In Study 1 (N = 787) the FHC scales were refined and validated. The sample was randomly divided into two subsamples. With random sample I exploratory factor analyses were conducted and items were selected according to their psychometric quality. In a second step, confirmatory factor analyses were conducted using the random sample II. In Study 2 (N = 210 parental couples) the construct validity was tested by correlating the FHC to self-determined motivation of healthy eating and physical activity as well as the families’ food environment and joint physical activities. Results: Exploratory factor analyses with random sample I (Study 1) revealed a four (FHC-NU) and a three (FHC-PA) factor model. These models were cross-validated with random sample II and demonstrated an acceptable fit [FHC-PA: χ2 = 222.69, df = 74, p < .01; χ2/df = 3.01; CFI = .96; SRMR = .04; RMSEA = .07, CI .06/.08; FHC-NU: χ2 = 278.30, df = 113, p < .01, χ2/df = 2.46, CFI = .96; SRMR = .04; RMSEA = .06, CI .05/.07]. The perception of FHC correlated (p < .01) with the intrinsic motivation of healthy eating (r = .42) and physical activity (r = .56). Moreover, parental perceptions of FHC-NU correlated with household soft drink availability (r = −.31) and perceptions of FHC-PA with the frequency of joint physical activities with the child (r = .51). These patterns were found on the intraindividual and interindividual level. Conclusions: Two valid instruments measuring the FHC within families were developed. The use of different informants’ ratings demonstrated that the FHC is a family level variable. The results confirm the high relevance of the FHC for individuals’ health behaviour. The FHC and the measurement instruments are useful for examining health-related aspects of the family environment

SPAG17 Mediates Nuclear Translocation of Protamines During Spermiogenesis

Protamines (PRM1 and PRM2) are small, arginine-rich, nuclear proteins that replace histones in the final stages of spermiogenesis, ensuring chromatin compaction and nuclear remodeling. Defects in protamination lead to increased DNA fragmentation and reduced male fertility. Since efficient sperm production requires the translocation of protamines from the cytoplasm to the nucleus, we investigated whether SPAG17, a protein crucial for intracellular protein trafficking during spermiogenesis, participates in protamine transport. Initially, we assessed the protein-protein interaction between SPAG17 and protamines using proximity ligation assays, revealing a significant interaction originating in the cytoplasm and persisting within the nucleus. Subsequently, immunoprecipitation and mass spectrometry (IP/MS) assays validated this initial observation. Sperm and spermatids fro

The Swiss Kidney Stone Cohort (SKSC), a longitudinal, multi-centric, observational cohort to study course and causes of kidney stone disease in Switzerland.

Kidney stone disease has a high prevalence worldwide of approximately 10 % of the population and is characterized by a high recurrence rate Kidney stone disease results from a combination of genetic, environmental, and life-style risk factors, and the dissection of these factors is complex. The Swiss Kidney Stone Cohort (SKSC) is an investigator-initiated prospective, multi-centric longitudinal, observational study in patients with kidney stones followed with regular visits over a period of 3 years after inclusion. Ongoing follow-ups by biannual telephone interviews will provide long-term outcome data up to 10 years. SKSC comprises 782 adult patients (age &gt; 18 yrs) with either recurrent stones or a single stone event with at least one risk factor for recurrence. In addition, a control cohort of 207 individuals without kidney stone history and absence of kidney stones on a low-dose CT-scan at enrolment has also been recruited. SKSC includes extensive collections of clinical data, biochemical data in blood and 24 hr urine samples, and genetic data. Biosamples are stored at a dedicated biobank. Information on diet and dietary habits were collected through food frequency questionnaires and standardized recall interviews by trained dieticians with the Globodiet software. SKSC provides an unique opportunity and resource to further study cause and course of kidney disease in a large population with data and samples collected of a homogenous collective of patients throughout the whole Swiss population

Morphology of supported polymer electrolyte ultra-thin films: a numerical study

Morphology of polymer electrolytes membranes (PEM), e.g., Nafion, inside PEM fuel cell catalyst layers has significant impact on the electrochemical activity and transport phenomena that determine cell performance. In those regions, Nafion can be found as an ultra-thin film, coating the catalyst and the catalyst support surfaces. The impact of the hydrophilic/hydrophobic character of these surfaces on the structural formation of the films has not been sufficiently explored yet. Here, we report about Molecular Dynamics simulation investigation of the substrate effects on the ionomer ultra-thin film morphology at different hydration levels. We use a mean-field-like model we introduced in previous publications for the interaction of the hydrated Nafion ionomer with a substrate, characterized by a tunable degree of hydrophilicity. We show that the affinity of the substrate with water plays a crucial role in the molecular rearrangement of the ionomer film, resulting in completely different morphologies. Detailed structural description in different regions of the film shows evidences of strongly heterogeneous behavior. A qualitative discussion of the implications of our observations on the PEMFC catalyst layer performance is finally proposed

The role of low-volatility organic compounds in initial particle growth in the atmosphere

About half of present-day cloud condensation nuclei originate from atmospheric nucleation, frequently appearing as a burst of new particles near midday1. Atmospheric observations show that the growth rate of new particles often accelerates when the diameter of the particles is between one and ten nanometres2, 3. In this critical size range, new particles are most likely to be lost by coagulation with pre-existing particles4, thereby failing to form new cloud condensation nuclei that are typically 50 to 100 nanometres across. Sulfuric acid vapour is often involved in nucleation but is too scarce to explain most subsequent growth5, 6, leaving organic vapours as the most plausible alternative, at least in the planetary boundary layer7, 8, 9, 10. Although recent studies11, 12, 13 predict that low-volatility organic vapours contribute during initial growth, direct evidence has been lacking. The accelerating growth may result from increased photolytic production of condensable organic species in the afternoon2, and the presence of a possible Kelvin (curvature) effect, which inhibits organic vapour condensation on the smallest particles (the nano-Köhler theory)2, 14, has so far remained ambiguous. Here we present experiments performed in a large chamber under atmospheric conditions that investigate the role of organic vapours in the initial growth of nucleated organic particles in the absence of inorganic acids and bases such as sulfuric acid or ammonia and amines, respectively. Using data from the same set of experiments, it has been shown15 that organic vapours alone can drive nucleation. We focus on the growth of nucleated particles and find that the organic vapours that drive initial growth have extremely low volatilities (saturation concentration less than 10−4.5 micrograms per cubic metre). As the particles increase in size and the Kelvin barrier falls, subsequent growth is primarily due to more abundant organic vapours of slightly higher volatility (saturation concentrations of 10−4.5 to 10−0.5 micrograms per cubic metre). We present a particle growth model that quantitatively reproduces our measurements. Furthermore, we implement a parameterization of the first steps of growth in a global aerosol model and find that concentrations of atmospheric cloud concentration nuclei can change substantially in response, that is, by up to 50 per cent in comparison with previously assumed growth rate parameterizations