Impact of leptin deficiency on male tibia and vertebral body 3D bone architecture independent of changes in body weight

Leptin an adipokine with potent effects on energy balance and body weight plays an important role in defining bone architecture in growing mammals. However, major changes in body weight can also influence morphology of trabecular and cortical bone. Therefore, we examined the impact of leptin deficiency on tibia and vertebral body 3D bone architecture independent of changes in body weight. Furthermore, advances in computational 3D image analysis suggest that average morphological values may mask regional specific differences in trabecular bone thickness. The study utilized leptin-deficient Ob/Ob mice (n = 8) weight-paired to C57BL/6 (C57) control mice (n = 8) which were split into either lean or obese groups for 24 ± 2 weeks. Whole tibias and L3 vertebrae were fixed before high resolution microcomputed tomography (μCT) scanning was performed. Leptin deficiency independent of body weight reduced tibia cortical bone volume, trabecular bone volume/tissue volume, number, and mineral density. Mean tibia trabecular thickness showed no significant differences between all groups; however, significant changes in trabecular thickness were found when analyzed by region. This study demonstrates that leptin deficiency significantly impacts tibia and vertebral body trabecular and cortical bone 3D architecture independent of changes in body weight

Inmunolocalización de receptores de estrógenos acoplados a proteína g en placentas porcinas.

En la gestación porcina, las hormonas esteroideas Estrógenos y Progesterona interaccionan con receptores nucleares y de membrana. El propósito de esta investigación fue determinar la distribución y localización del receptor de estrógenos acoplado a proteína G (GPER) en placentas porcinas de diversos periodos de gestación. Se utilizaron cerdas mestizas gestantes (G) de 15-17 días de gestación (dg) (n= 4), de 30-35 dg (n= 4) y de 60-70 dg (n= 4), provenientes de frigoríficos de la zona de General Pico, La Pampa. Y cerdas no gestantes (NG) (n=4). De cada muestra se realizó una tinción de Hematoxilina/Eosina para determinar la integridad de los tejidos, y posteriormente se realizó la determinación de los receptores de estrógenos por la técnica de inmunoperoxidasa indirecta LSAB (Labelled Streptavidin Biotin). Los resultados de la técnica de inmunomarcación para la determinación de receptores de hormonas esteroideas, se expresaron en forma cualitativa. Se evaluó la expresión según la coloración detectada (diferentes intensidades de marrón). En todos los períodos estudiados se observó inmunomarcación de GPER en células trofoblásticas. En el componente materno se expresó en epitelio luminal y glandular además de músculo liso. Los resultados de este estudio confirman la localización de GPER en endometrio de placentas porcinas de 5, 17, 30 y 70 dg y en células trofoblásticas de 17, 30 y 70 dg. La expresión de los receptores de estrógenos de membrana acuerda con estudios previos en los cuales se cuantificó los niveles de estrógenos en sueros y en el componente materno y fetal de similares etapas de la gestación. Sugerimos que en la interfase materno fetal, los estrógenos podrían ligarse a GPER y establecer vías de señalización específicamente reguladas. Esa comunicación entre la hembra y sus conceptus permitiría inducir y sostener la expresión de moléculas que modulan la implantación, el desarrollo y el mantenimiento de la gestació

The G0 Experiment: Apparatus for Parity-Violating Electron Scattering Measurements at Forward and Backward Angles

In the G0 experiment, performed at Jefferson Lab, the parity-violating elastic scattering of electrons from protons and quasi-elastic scattering from deuterons is measured in order to determine the neutral weak currents of the nucleon. Asymmetries as small as 1 part per million in the scattering of a polarized electron beam are determined using a dedicated apparatus. It consists of specialized beam-monitoring and control systems, a cryogenic hydrogen (or deuterium) target, and a superconducting, toroidal magnetic spectrometer equipped with plastic scintillation and aerogel Cerenkov detectors, as well as fast readout electronics for the measurement of individual events. The overall design and performance of this experimental system is discussed.Comment: Submitted to Nuclear Instruments and Method

Psychological benefits of weight loss following behavioural and/or dietary weight loss interventions. A systematic research review

It is generally accepted that weight loss has significant physiological benefits, such as reduced risk of diabetes, lowered blood pressure and blood lipid levels. However, few behavioural and dietary interventions have investigated psychological benefit as the primary outcome. Hence, systematic review methodology was adopted to evaluate the psychological outcomes of weight loss following participation in a behavioural and/or dietary weight loss intervention in overweight/obese populations. 36 Studies were selected for inclusion and were reviewed. Changes in self-esteem, depressive symptoms, body image and health related quality of life (HRQoL) were evaluated and discussed. Where possible, effect sizes to indicate the magnitude of change pre- to post- intervention were calculated using Hedges’ g standardised mean difference. The results demonstrated consistent improvements in psychological outcomes concurrent with and sometimes without weight loss. Improvements in body image and HRQoL (especially vitality) were closely related to changes in weight. Calculated effect sizes varied considerably and reflected the heterogeneous nature of the studies included in the review. Although the quality of the studies reviewed was generally acceptable, only 9 out of 36 studies included a suitable control/comparison group and the content, duration of intervention and measures used to assess psychological outcomes varied considerably. Further research is required to improve the quality of studies assessing the benefits of weight loss to fully elucidate the relationship between weight loss and psychological outcomes.The Kellogg Company, The Kellogg Building, Talbot Road, Manchester M16 0PU, U

The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

Strange Quark Contributions to Parity-Violating Asymmetries in the Backward Angle G0 Electron Scattering Experiment

We have measured parity-violating asymmetries in elastic electron-proton and quasi-elastic electron-deuteron scattering at Q2 = 0.22 and 0.63 GeV2. They are sensitive to strange quark contributions to currents in the nucleon, and to the nucleon axial current. The results indicate strange quark contributions of <∼ 10% of the charge and magnetic nucleon form factors at these four-momentum transfers. We also present the first measurement of anapole moment effects in the axial current at these four-momentum transfer

Physical demands of tennis across the different court surfaces, performance levels and sexes: a systematic review with meta-analysis

BACKGROUND : Tennis is a multidirectional high-intensity intermittent sport for male and female individuals played across multiple surfaces. Although several studies have attempted to characterise the physical demands of tennis, a meta-analysis is still lacking. OBJECTIVE : We aimed to describe and synthesise the physical demands of tennis across the different court surfaces, performance levels and sexes. METHODS : PubMed, Embase, CINAHL and SPORTDiscus were searched from inception to 19 April, 2022. A backward citation search was conducted for included articles using Scopus. The PECOS framework was used to formulate eligibility criteria. Population: tennis players of regional, national or international playing levels (juniors and adults). Exposure: singles match play. Comparison: sex (male/female), court surface (hard, clay, grass). Outcome: duration of play, on-court movement and stroke performance. Study design: cross-sectional, longitudinal. Pooled means or mean differences with 95% confidence intervals were calculated. A random-effects meta-analysis with robust variance estimation was performed. The measures of heterogeneity were Cochrane Q and 95% prediction intervals. Subgroup analysis was used for different court surfaces. RESULTS : The literature search generated 7736 references; 64 articles were included for qualitative and 42 for quantitative review. Mean [95% confidence interval] rally duration, strokes per rally and effective playing time on all surfaces were 5.5 s [4.9, 6.3], 4.1 [3.4, 5.0] and 18.6% [15.8, 21.7] for international male players and 6.4 s [5.4, 7.6], 3.9 [2.4, 6.2] and 20% [17.3, 23.3] for international female players. Mean running distances per point, set and match were 9.6 m [7.6, 12.2], 607 m [443, 832] and 2292 m [1767, 2973] (best-of-5) for international male players and 8.2 m [4.4, 15.2], 574 m [373, 883] and 1249 m [767, 2035] for international female players. Mean first- and second-serve speeds were 182 km·h−1 [178, 187] and 149 km·h−1 [135, 164] for international male players and 156 km·h−1 95% confidence interval [151, 161] and 134 km·h−1 [107, 168] for international female players. CONCLUSIONS : The findings from this study provide a comprehensive summary of the physical demands of tennis. These results may guide tennis-specific training programmes. We recommend more consistent measuring and reporting of data to enable future meta-analysts to pool meaningful data. CLINICAL TRIAL REGISTRATION : The protocol for this systematic review was registered a priori at the Open Science Framework (Registration DOI https://doi.org/10.17605/OSF.IO/MDWFY).https://link.springer.com/journal/402792023-02-08hj2023Sports Medicin

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements