478 research outputs found

    Aerobic Fitness Level Affects Cardiovascular and Salivary Alpha Amylase Responses to Acute Psychosocial Stress

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    BACKGROUND: Good physical fitness seems to help the individual to buffer the potential harmful impact of psychosocial stress on somatic and mental health. The aim of the present study is to investigate the role of physical fitness levels on the autonomic nervous system (ANS; i.e. heart rate and salivary alpha amylase) responses to acute psychosocial stress, while controlling for established factors influencing individual stress reactions. METHODS: The Trier Social Stress Test for Groups (TSST-G) was executed with 302 male recruits during their first week of Swiss Army basic training. Heart rate was measured continuously, and salivary alpha amylase was measured twice, before and after the stress intervention. In the same week, all volunteers participated in a physical fitness test and they responded to questionnaires on lifestyle factors and personal traits. A multiple linear regression analysis was conducted to determine ANS responses to acute psychosocial stress from physical fitness test performances, controlling for personal traits, behavioural factors, and socioeconomic data. RESULTS: Multiple linear regression revealed three variables predicting 15 % of the variance in heart rate response (area under the individual heart rate response curve during TSST-G) and four variables predicting 12 % of the variance in salivary alpha amylase response (salivary alpha amylase level immediately after the TSST-G) to acute psychosocial stress. A strong performance at the progressive endurance run (high maximal oxygen consumption) was a significant predictor of ANS response in both models: low area under the heart rate response curve during TSST-G as well as low salivary alpha amylase level after TSST-G. Further, high muscle power, non-smoking, high extraversion, and low agreeableness were predictors of a favourable ANS response in either one of the two dependent variables. CONCLUSIONS: Good physical fitness, especially good aerobic endurance capacity, is an important protective factor against health-threatening reactions to acute psychosocial stress

    Transformational Leadership, Achievement Motivation, and Perceived Stress in Basic Military Training: A Longitudinal Study of Swiss Armed Forces

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    In Switzerland, military service is a civic obligation for all adult male citizens, and thus, leadership style can be particularly challenging. The present study investigated the impact of superiors’ leadership styles on recruits’ achievement motivation, organizational citizenship behavior (OCB), and perceived stress during their Basic Military Training (BMT). To this end, a total of 525 male recruits (mean age: 20.3 years) recruits were assessed both cross-sectionally and longitudinally. At the start of BMT (baseline), at week 7, and at week 11, participants completed a series of selfrating questionnaires covering demographic information, achievement motivation, organizational citizenship behavior (OCB), perceived stress, and their superiors’ leadership styles (transformational, transactional und laissez-faire). Longitudinally, scores for achievement motivation and OCB showed no significant difference between baseline and the 11th week. In a group comparison, the group experiencing higher transformational leadership (from week 7 to week 11) had the highest scores for achievement motivation and OCB, and the lowest scores for perceived stress, all at week 11. Exploratively, achievement motivation and OCB at baseline were associated with transformational leadership and transactional leadership at week 7 and week 11. Perceived stress at baseline correlated only with transformational leadership but not with transactional leadership, both at week 7 and week 11. Transformational leadership style fostered achievement motivation and OCB in Swiss military recruits and protected them from stress, both cross-sectionally and longitudinally.ISSN:2071-105

    Apolipoprotein E and Alzheimer’s disease: The influence of apolipoprotein E on amyloid- and other amyloidogenic proteins

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    New Insight on the Increasing Seismicity during Tenerife's 2004 Volcanic Reactivation

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    Starting in April 2004, unusual seismic activity was observed in the interior of the island of Tenerife (Canary Islands, Spain) with much evidence pointing to a reawakening of volcanic activity. This seismicity is now analyzed with techniques unprecedented in previous studies of this crisis. The 200 earthquakes located onshore during 2004 and 2005 have been classified by cross-correlation, resulting in a small number of significant families. The application of a relative location algorithm (hypoDD) revealed important features about the spatial distribution of the earthquakes. The seismic catalogue has been enhanced with more than 800 additional events, detected only by the closest seismic station. These events were assigned to families by correlation and as a consequence their hypocentral location and magnitude were estimated by comparing them to the earthquakes of each family. The new catalogue obtained by these methods identifies two major seismogenic zones, one to the northwest and the other to the southwest of the Teide-Pico Viejo complex and having a separation of at least 10 km between them. These regions alternate their activity starting in January 2004, i.e., three months earlier than previously thought. We propose a simple model based on the results of this work which will also concur with all previous geophysical and geochemical studies of the 2004 crisis. The model proposes a single magma intrusion affecting the central part of the island with lateral dikes driven by the rifts to the northwest and southwest.Comment: 20 pages, 15 figure

    Comparative analysis of the impact of geological activity on astronomical sites of the Canary Islands, Hawaii and Chile

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    An analysis of the impact of seismic and volcanic activity was carried out at selected astronomical sites, namely the observatories of El Teide (Tenerife, Canary Islands), Roque de los Muchachos (La Palma, Canary Islands), Mauna Kea (Hawaii) and Paranal (Chile) and the candidate site of Cerro Ventarrones (Chile). Hazard associated to volcanic activity is low or negligible at all sites, whereas seismic hazard is very high in Chile and Hawaii. The lowest geological hazard in both seismic and volcanic activity was found at Roque de los Muchachos observatory, in the island of La Palma.Comment: 12 pages and 11 figure

    Dietary creatine supplementation in gilthead seabream (Sparus aurata) increases dorsal muscle area and the expression of myod1 and capn1 genes

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    Creatine (Cr) is an amino acid derivative with an important role in the cell as energy buffer that has been largely used as dietary supplement to increase muscle strength and lean body mass in healthy individuals and athletes. However, studies in fish are scarce. The aim of this work is to determine whether dietary Cr supplementation affects muscle growth in gilthead seabream (Sparus aurata) juveniles. Fish were fed ad libitum for 69 days with diets containing three increasing levels of creatine monohydrate (2, 5, and 8%) that were compared with a non-supplemented control (CTRL) diet. At the end of the trial, the fast-twist skeletal muscle growth dynamics (muscle cellularity) and the expression of muscle-related genes were evaluated. There was a general trend for Cr-fed fish to be larger and longer than those fed the CTRL, but no significant differences in daily growth index (DGI) were registered among dietary treatments. The dorsal cross-sectional muscle area (DMA) of fish fed Cr 5 and Cr 8% was significantly larger than that of fish fed CTRL. The groups supplemented with Cr systematically had a higher relative number of both small-sized (= 20)mu m). Dorsal total fibers number was highest in fish fed 5% Cr. In fish supplemented with 5% Cr, the relative expression of myogenic differentiation 1 (myod1) increased almost four times compared to those fed the CTRL diet. The relative expression of calpain 3 (capn3) was highest in fish fed diets with 2% Cr supplementation, but did not differ significantly from those fed the CTRL or Cr 5%. The myod1 gene expression had a positive and significant correlation with that of capn1, capnsla, and capn3 expression. These results suggest that the observed modulation of gene expression was not enough to produce a significant alteration in muscle phenotype under the tested conditions, as a non-significant increase in muscle fiber diameter and higher total number of fiber was observed, but still resulted in increased DMA. Additional studies may be required in order to better clarify the effect of dietary Cr supplementation in fish, possibly in conjunction with induced resistance training.project AQUAVALOR Development of a farmed fish as a functional food: Natural nutrient fortification and allergenic potential reduction, PROMAR - Projeto Piloto 31-03-05-FEP-0060 ValorMar Valorizacao integral dos recursos marinhos: potencial, inovacao tecnologica e novas aplicacoes, (Mobilizing R&TD Programs, Portugal 2020) - European Regional Development Fund (ERDF) 24517 10/SI/2016 European Social Fund (ESF) Fundacao para a Ciencia e Tecnologia (Portugal) PD/BDE/114436/2016 FCT - Foundation for Science and Technology UID/Multi/04326/2019info:eu-repo/semantics/publishedVersio

    γ-Aminobutyric Acid Transporter 2 Mediates the Hepatic Uptake of Guanidinoacetate, the Creatine Biosynthetic Precursor, in Rats

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    Guanidinoacetic acid (GAA) is the biosynthetic precursor of creatine which is involved in storage and transmission of phosphate-bound energy. Hepatocytes readily convert GAA to creatine, raising the possibility that the active uptake of GAA by hepatocytes is a regulatory factor. The purpose of this study is to investigate and identify the transporter responsible for GAA uptake by hepatocytes. The characteristics of [14C]GAA uptake by hepatocytes were elucidated using the in vivo liver uptake method, freshly isolated rat hepatocytes, an expression system of Xenopus laevis oocytes, gene knockdown, and an immunohistochemical technique. In vivo injection of [14C]GAA into the rat femoral vein and portal vein results in the rapid uptake of [14C]GAA by the liver. The uptake was markedly inhibited by γ-aminobutyric acid (GABA) and nipecotinic acid, an inhibitor of GABA transporters (GATs). The characteristics of Na+- and Cl−-dependent [14C]GAA uptake by freshly isolated rat hepatocytes were consistent with those of GAT2. The Km value of the GAA uptake (134 µM) was close to that of GAT2-mediated GAA transport (78.9 µM). GABA caused a marked inhibition with an IC50 value of 8.81 µM. The [14C]GAA uptake exhibited a significant reduction corresponding to the reduction in GAT2 protein expression. GAT2 was localized on the sinusoidal membrane of the hepatocytes predominantly in the periportal region. This distribution pattern was consistent with that of the creatine biosynthetic enzyme, S-adenosylmethionine∶guanidinoacetate N-methyltransferase. GAT2 makes a major contribution to the sinusoidal GAA uptake by periportal hepatocytes, thus regulating creatine biosynthesis in the liver

    Weak Spatial and Temporal Population Genetic Structure in the Rosy Apple Aphid, Dysaphis plantaginea, in French Apple Orchards

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    We used eight microsatellite loci and a set of 20 aphid samples to investigate the spatial and temporal genetic structure of rosy apple aphid populations from 13 apple orchards situated in four different regions in France. Genetic variability was very similar between orchard populations and between winged populations collected before sexual reproduction in the fall and populations collected from colonies in the spring. A very small proportion of individuals (∼2%) had identical multilocus genotypes. Genetic differentiation between orchards was low (FST<0.026), with significant differentiation observed only between orchards from different regions, but no isolation by distance was detected. These results are consistent with high levels of genetic mixing in holocyclic Dysaphis plantaginae populations (host alternation through migration and sexual reproduction). These findings concerning the adaptation of the rosy apple aphid have potential consequences for pest management

    VIP Enhances Phagocytosis of Fibrillar Beta-Amyloid by Microglia and Attenuates Amyloid Deposition in the Brain of APP/PS1 Mice

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    Vasoactive intestinal peptide (VIP) is a multifunctional neuropeptide with demonstrated immunosuppressive and neuroprotective activities. It has been shown to inhibit Amyloid beta (Aβ)-induced neurodegeneration by indirectly suppressing the production and release of a variety of inflammatory and neurotoxic factors by activated microglia. We demonstrated that VIP markedly increased microglial phagocytosis of fibrillar Aβ42 and that this enhanced phagocytotic activity depended on activation of the Protein kinase C (PKC) signaling pathway. In addition, VIP suppressed the release of tumor necrosis factor alpha (TNF-α) and nitric oxide(NO) from microglia activated by combined treatment with fibrillar Aβ42 and low dose interferon-γ (IFN-γ). We utilized an adenovirus-mediated gene delivery method to overexpress VIP constitutively in the hippocampus of APPswPS1 transgenic mice. The Aβ load was significantly reduced in the hippocampus of this animal model of Alzheimer's disease, possibly due to the accumulation and activation of cd11b-immunoactive microglial cells. The modulation of microglial activation, phagocytosis, and secretion by VIP is a promising therapeutic option for the treatment of Alzheimer's disease(AD)

    Disease-Causing 7.4 kb Cis-Regulatory Deletion Disrupting Conserved Non-Coding Sequences and Their Interaction with the FOXL2 Promotor: Implications for Mutation Screening

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    To date, the contribution of disrupted potentially cis-regulatory conserved non-coding sequences (CNCs) to human disease is most likely underestimated, as no systematic screens for putative deleterious variations in CNCs have been conducted. As a model for monogenic disease we studied the involvement of genetic changes of CNCs in the cis-regulatory domain of FOXL2 in blepharophimosis syndrome (BPES). Fifty-seven molecularly unsolved BPES patients underwent high-resolution copy number screening and targeted sequencing of CNCs. Apart from three larger distant deletions, a de novo deletion as small as 7.4 kb was found at 283 kb 5′ to FOXL2. The deletion appeared to be triggered by an H-DNA-induced double-stranded break (DSB). In addition, it disrupts a novel long non-coding RNA (ncRNA) PISRT1 and 8 CNCs. The regulatory potential of the deleted CNCs was substantiated by in vitro luciferase assays. Interestingly, Chromosome Conformation Capture (3C) of a 625 kb region surrounding FOXL2 in expressing cellular systems revealed physical interactions of three upstream fragments and the FOXL2 core promoter. Importantly, one of these contains the 7.4 kb deleted fragment. Overall, this study revealed the smallest distant deletion causing monogenic disease and impacts upon the concept of mutation screening in human disease and developmental disorders in particular
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