Effect of Jump Direction and External Load on Single-Legged Jump-Landing Biomechanics

International Journal of Exercise Science 13(1): 234-248, 2020. External load may increase an individual’s risk of non-contact anterior cruciate ligament (ACL) injury during single-legged jump-landing (SLJL).This study evaluated the effects of jump direction and external load on hip and knee joint motion and time to stabilization (TTS) during SLJL. Seventeen active males (n = 8) and females (22.2 ± 3.0 y, 1.75 ± 0.08 m, 73.4 ± 12.0 kg) participated in this randomized, crossover designed study. Single-legged jump-landings performed in two conditions, including without external load (BW) and with a torso-worn weight vest equal to 10% of the participant’s body weight (BW+10%), from backward, forward, medial, and lateral SLJL directions. Two-way repeated measures ANOVA did not identify any significant interactions (P \u3e .01, η2: \u3c .001 - .037), but some main effects for condition with small effect sizes were identified (P \u3c .01,η2: .009 - .039). Several main effects for SLJL direction were identified with larger effect sizes (P \u3c .01, η2: .010 - .574). This suggests SLJL direction may challenge different components of SLJL biomechanics, and that recreationally active, college-aged individuals may possess effective compensatory mechanisms that can mitigate the effect of BW+10%

On the ion coupling mechanism of the MATE transporter ClbM

Bacteria use a number of mechanisms to defend themselves from antimicrobial drugs. One important defense strategy is the ability to export drugs by multidrug transporters. One class of multidrug transporter, the so-called multidrug and toxic compound extrusion (MATE) transporters, extrude a variety of antibiotic compounds from the bacterial cytoplasm. These MATE transporters are driven by a Na+, H+, or combined Na+/H+ gradient, and act as antiporters to drive a conformational change in the transporter from the outward to the inward-facing conformation. In the inward-facing conformation, a chemical compound (drug) binds to the protein, resulting in a switch to the opposite conformation, thereby extruding the drug. Using molecular dynamics simulations, we now report the structural basis for Na+ and H+ binding in the dual ion coupled MATE transporter ClbM from Escherichia coli, which is connected to colibactin-induced genotoxicity, yielding novel insights into the ion/drug translocation mechanism of this bacterial transporter.</p

Single mutations in the ε subunit from thermophilic Bacillus PS3 generate a high binding affinity site for ATP

The ε subunit from ATP synthases acts as an ATP sensor in the bacterial cell to prevent ATP hydrolysis and thus the waste of ATP under conditions of low ATP concentration. However, the ATP binding affinities from various bacterial organisms differ markedly, over several orders of magnitude. For example, the ATP synthases from thermophilic Bacillus PS3 and Escherichia coli exhibit affinities of 4 µM and 22 mM, respectively. The recently reported R103A/R115A double mutant of Bacillus PS3 ATP synthase demonstrated an increased binding affinity by two orders of magnitude with respect to the wild type. Here, we used atomic-resolution molecular dynamics simulations to determine the role of the R103A and R115A single mutations. These lead us to predict that both single mutations also cause an increased ATP binding affinity. Evolutionary analysis reveals R103 and R115 substitutions in the ε subunit from other bacillic organisms, leading us to predict they likely have a higher ATP binding affinity than previously expected

Developing Virtual Reality Simulations for Office-Based Medical Emergencies

Virtual reality simulation may significantly benefit a geographically dispersed learner demographic in the medical outpatient setting. Our research used an immersive virtual reality platform as a novel way to recreate high-risk medical scenarios targeted for office-based emergencies. Using a design-based research approach we designed virtual-reality-based simulation scenarios to prepare interprofessional office personnel for emergencies. Learners were connected using laptop computers, via a browser interface, with learner controlled team member avatars and educator controlled patient avatars. The virtual environment was modeled after a multi-provider healthcare office setting in a large suburban health network. Evaluation occurred via post-event surveys and feedback transcribed from video recordings and debriefings. Three office-based emergency scenarios were created (chest pain, respiratory distress/allergic reaction, and suicidal risk), with progressively smaller changes to the virtual environment with each iterative improvement. In total, 18 individuals representative of a typical outpatient office interprofessional care team participated in the study. Qualitative design-related feedback from participants and faculty improved the educational environment, artifacts, and scenarios. Participant feedback was overwhelmingly positive and enthusiastic about the use of virtual reality-based simulations to explore teamwork, build scope of practice, and rehearse infrequently used clinical skills. We successfully created novel outpatient virtual reality simulations in a first-person-perspective virtual environment. Pilot testing revealed successful rapid development, implementation, and participant orientation, with the ability to present learning opportunities. Future efforts will include assessments and attempt to overcome development barriers by switching to a more versatile platform

Redshift-Space Enhancement of Line-of-Sight Baryon Acoustic Oscillations in the SDSS Main-Galaxy Sample

We show that redshift-space distortions of galaxy correlations have a strong effect on correlation functions with distinct, localized features, like the signature of the baryon acoustic oscillations (BAO). Near the line of sight, the features become sharper as a result of redshift-space distortions. We demonstrate this effect by measuring the correlation function in Gaussian simulations and the Millennium Simulation. We also analyze the SDSS DR7 main-galaxy sample (MGS), splitting the sample into slices 2.5 degrees on the sky in various rotations. Measuring 2D correlation functions in each slice, we do see a sharp bump along the line of sight. Using Mexican-hat wavelets, we localize it to (110 +/- 10) Mpc/h. Averaging only along the line of sight, we estimate its significance at a particular wavelet scale and location at 2.2 sigma. In a flat angular weighting in the (pi,r_p) coordinate system, the noise level is suppressed, pushing the bump's significance to 4 sigma. We estimate that there is about a 0.2% chance of getting such a signal anywhere in the vicinity of the BAO scale from a power spectrum lacking a BAO feature. However, these estimates of the significances make some use of idealized Gaussian simulations, and thus are likely a bit optimistic.Comment: 17 pages, 27 figures. Minor changes to match final version accepted to Ap

Binocular vision and foraging in ducks, geese and swans (Anatidae)

Wide variation in visual field configuration across avian species is hypothesized to be driven primarily by foraging ecology and predator detection. While some studies of selected taxa have identified relationships between foraging ecology and binocular field characteristics in particular species, few have accounted for the relevance of shared ancestry. We conducted a large-scale, comparative analysis across 39 Anatidae species to investigate the relationship between the foraging ecology traits of diet or behaviour and binocular field parameters, while controlling for phylogeny. We used phylogenetic models to examine correlations between traits and binocular field characteristics, using unidimensional and morphometric approaches. We found that foraging behaviour influenced three parameters of binocular field size: maximum binocular field width, vertical binocular field extent, and angular separation between the eye-bill projection and the direction of maximum binocular field width. Foraging behaviour and body mass each influenced two descriptors of binocular field shape. Phylogenetic relatedness had minimal influence on binocular field size and shape, apart from vertical binocular field extent. Binocular field differences are associated with specific foraging behaviours, as related to the perceptual challenges of obtaining different food items from aquatic and terrestrial environments

Unpaid work and access to science professions

Unpaid work in the sciences is advocated as an entry route into scientific careers. We compared the success of UK science graduates who took paid or unpaid work six-months after graduation in obtaining a high salary or working in a STEM (Science, Technology Engineering and Mathematics) field 3.5 years later. Initially taking unpaid work was associated with lower earnings and lower persistence in STEM compared with paid work, but those using personal connections to obtain unpaid positions were as likely to persist in STEM as paid workers. Obtaining a position in STEM six months after graduation was associated with higher rates of persistence in STEM compared with a position outside STEM for both paid and unpaid workers, but the difference is considerably smaller for unpaid workers. Socio-economic inequality in the likelihood of obtaining entry in STEM by taking an unpaid position is a well-founded concern for scientific workforce diversity

Cancer cell adaptation to hypoxia involves a HIF-GPRC5A-YAP axis

© 2018 The Authors. Published under the terms of the CC BY 4.0 license Hypoxia is a hallmark of solid tumours and a key physiological feature distinguishing cancer from normal tissue. However, a major challenge remains in identifying tractable molecular targets that hypoxic cancer cells depend on for survival. Here, we used SILAC-based proteomics to identify the orphan G protein-coupled receptor GPRC5A as a novel hypoxia-induced protein that functions to protect cancer cells from apoptosis during oxygen deprivation. Using genetic approaches invitro and invivo, we reveal HIFs as direct activators of GPRC5A transcription. Furthermore, we find that GPRC5A is upregulated in the colonic epithelium of patients with mesenteric ischaemia, and in colorectal cancers high GPRC5A correlates with hypoxia gene signatures and poor clinical outcomes. Mechanistically, we show that GPRC5A enables hypoxic cell survival by activating the Hippo pathway effector YAP and its anti-apoptotic target gene BCL2L1. Importantly, we show that the apoptosis induced by GPRC5A depletion in hypoxia can be rescued by constitutively active YAP. Our study identifies a novel HIF-GPRC5A-YAP axis as a critical mediator of the hypoxia-induced adaptive response and a potential target for cancer therapy