87 research outputs found

    Heat Acclimation with or without Normobaric Hypoxia Exposure Leads to Similar Improvements in Endurance Performance in the Heat

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    Background: Combining the key adaptation of plasma volume (PV) expansion with synergistic physiological effects of other acclimation interventions to maximise endurance performance in the heat has potential. The current study investigated the effects of heat acclimation alone (H), combined with normobaric hypoxia exposure (H+NH), on endurance athletic performance. Methods: Well-trained participants completed a heat-stress trial (30 °C, 80% relative humidity (RH), 20.8% fraction of inspired oxygen (FiO2)) of a 75 min steady-state cycling (fixed workload) and a subsequent 15 min cycling time trial for distance before and after intervention. Participants completed 12 consecutive indoor training days with either heat acclimation (H; 60 min·day−1, 30 °C, 80% RH; 20.8% FiO2) or heat acclimation and overnight hypoxic environment (H+NH; ~12 h, 60% RH; 16% FiO2 simulating altitude of ~2500 m). Control (CON) group trained outdoors with average maximum daily temperature of 16.5 °C and 60% RH. Results: Both H and H+NH significantly improved time trial cycling distance by ~5.5% compared to CON, with no difference between environmental exposures. PV increased (+3.8%) and decreased (−4.1%) following H and H+NH, respectively, whereas haemoglobin concentration decreased (−2%) and increased (+3%) in H and H+NH, respectively. Conclusion: Our results show that despite contrasting physiological adaptations to different environmental acclimation protocols, heat acclimation with or without hypoxic exposure demonstrated similar improvements in short-duration exercise performance in a hot environment

    Bioengineered small extracellular vesicles deliver multiple SARS‐CoV‐2 antigenic fragments and drive a broad immunological response

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    The COVID‐19 pandemic highlighted the clear risk that zoonotic viruses pose to global health and economies. The scientific community responded by developing several efficacious vaccines which were expedited by the global need for vaccines. The emergence of SARS‐CoV‐2 breakthrough infections highlights the need for additional vaccine modalities to provide stronger, long‐lived protective immunity. Here we report the design and preclinical testing of small extracellular vesicles (sEVs) as a multi‐subunit vaccine. Cell lines were engineered to produce sEVs containing either the SARS‐CoV‐2 Spike receptor‐binding domain, or an antigenic region from SARS‐CoV‐2 Nucleocapsid, or both in combination, and we tested their ability to evoke immune responses in vitro and in vivo. B cells incubated with bioengineered sEVs were potent activators of antigen‐specific T cell clones. Mice immunised with sEVs containing both sRBD and Nucleocapsid antigens generated sRBD‐specific IgGs, nucleocapsid‐specific IgGs, which neutralised SARS‐CoV‐2 infection. sEV‐based vaccines allow multiple antigens to be delivered simultaneously resulting in potent, broad immunity, and provide a quick, cheap, and reliable method to test vaccine candidates

    The Ol1mpiad: concordance of behavioural faculties of stage 1 and stage 3 Drosophila larvae

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    This publication hasn't any creative commons license associated. This article has a Company of Biologists User Licence 1.1. The deposited article version contains attached the supplementary materials within the pdf.Mapping brain function to brain structure is a fundamental task for neuroscience. For such an endeavour, the Drosophila larva is simple enough to be tractable, yet complex enough to be interesting. It features about 10,000 neurons and is capable of various taxes, kineses and Pavlovian conditioning. All its neurons are currently being mapped into a light-microscopical atlas, and Gal4 strains are being generated to experimentally access neurons one at a time. In addition, an electron microscopic reconstruction of its nervous system seems within reach. Notably, this electron microscope-based connectome is being drafted for a stage 1 larva - because stage 1 larvae are much smaller than stage 3 larvae. However, most behaviour analyses have been performed for stage 3 larvae because their larger size makes them easier to handle and observe. It is therefore warranted to either redo the electron microscopic reconstruction for a stage 3 larva or to survey the behavioural faculties of stage 1 larvae. We provide the latter. In a community-based approach we called the Ol1mpiad, we probed stage 1 Drosophila larvae for free locomotion, feeding, responsiveness to substrate vibration, gentle and nociceptive touch, burrowing, olfactory preference and thermotaxis, light avoidance, gustatory choice of various tastants plus odour-taste associative learning, as well as light/dark-electric shock associative learning. Quantitatively, stage 1 larvae show lower scores in most tasks, arguably because of their smaller size and lower speed. Qualitatively, however, stage 1 larvae perform strikingly similar to stage 3 larvae in almost all cases. These results bolster confidence in mapping brain structure and behaviour across developmental stages.Fundação para a CiĂȘncia e a Tecnologia grants: (SFRH/BPD/75993/2011EXPL/BEX-BID/0497/2013); Cluster of Excellence Cells in Motion; CiM International Max Planck research school; Spanish Ministry of Economy and Competitiveness; ‘Centro de Excelencia Severo Ochoa 2013-2017’ grant: (SEV-2012-0208); CERCA Programme/Generalitat de Catalunya; the ‘la Caixa’ International PhD Programme; Spanish Ministry of Science and Innovation grant: (BFU2011-26208); Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz; State of Sachsen-Anhalt; Center for Behavioral Brain Sciences Magdeburg; Otto von Guericke UniversitĂ€t Magdeburg; Deutsche Forschungsgemeinschaft grants: (CRC 779 Motivated behaviour: B11; GE1091/4-1, SPP 1926, Next generation optogenetics, SO1337/2-1, CRC 779 Motivated behaviour: B15; YA272/2-1, PA 787/7-1, (TH1584/1-1, TH1584/3-1); European Commission grant: (FP7-ICT project Miniature Insect Model for Active Learning MINIMAL); Howard Hughes Medical Institute; European Research Council grant: (ERC-2012-StG 309832-PhotoNaviNet); Swiss National Science Foundation grant: (31003A_169993); Landesforschungsförderung Hamburg grant: (LFF-FV27); Wissenschaftsgemeinschaft Gottfried Wilhelm Leibniz; State of Sachsen-Anhalt; Center for Behavioral Brain Sciences Magdeburg; Cluster of Excellence ImmunoSensation; Baden-WĂŒrttemberg Stiftung; Zukunftskolleg of the University of Konstanz.info:eu-repo/semantics/publishedVersio

    Effects of a school-based health intervention program in marginalized communities of Port Elizabeth, South Africa (the KaziBantu Study): protocol for a randomized controlled trial

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    The burden of poverty-related infectious diseases remains high in low- and middle-income countries, while noncommunicable diseases (NCDs) are rapidly gaining importance. To address this dual disease burden, the KaziBantu project aims at improving and promoting health literacy as a means for a healthy and active lifestyle. The project implements a school-based health intervention package consisting of physical education, moving-to-music, and specific health and nutrition education lessons from the KaziKidz toolkit. It is complemented by the KaziHealth workplace health intervention program for teachers.; The aim of the KaziBantu project is to assess the effect of a school-based health intervention package on risk factors for NCDs, health behaviors, and psychosocial health in primary school children in disadvantaged communities in Port Elizabeth, South Africa. In addition, we aim to test a workplace health intervention for teachers.; A randomized controlled trial (RCT) will be conducted in 8 schools. Approximately 1000 grade 4 to grade 6 school children, aged 9 to 13 years, and approximately 60 teachers will be recruited during a baseline survey in early 2019. For school children, the study is designed as a 36-week, cluster RCT (KaziKidz intervention), whereas for teachers, a 24-week intervention phase (KaziHealth intervention) is planned. The intervention program consists of 3 main components; namely, (1) KaziKidz and KaziHealth teaching material, (2) workshops, and (3) teacher coaches. After randomization, 4 of the 8 schools will receive the education program, whereas the other schools will serve as the control group. Intervention schools will be further randomized to the different combinations of 2 additional intervention components: teacher workshops and teacher coaching.; This study builds on previous experience and will generate new evidence on health intervention responses to NCD risk factors in school settings as a decision tool for future controlled studies that will enable comparisons among marginalized communities between South African and other African settings.; The KaziKidz teaching material is a holistic educational and instructional tool designed for primary school teachers in low-resource settings, which is in line with South Africa's Curriculum and Assessment Policy Statement. The ready-to-use lessons and assessments within KaziKidz should facilitate the use and implementation of the teaching material. Furthermore, the KaziHealth interventions should empower teachers to take care of their health through knowledge gains regarding disease risk factors, physical activity, fitness, psychosocial health, and nutrition indicators. Teachers as role models will be able to promote better health behaviors and encourage a healthy and active lifestyle for children at school. We conjecture that improved health and well-being increase teachers' productivity with trickle-down effects on the children they teach and train.; International Standard Randomized Controlled Trial Number (ISRCTN): 18485542; http://www.isrctn.com/ISRCTN18485542.; DERR1-10.2196/14097

    Analysis of shared heritability in common disorders of the brain

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    ience, this issue p. eaap8757 Structured Abstract INTRODUCTION Brain disorders may exhibit shared symptoms and substantial epidemiological comorbidity, inciting debate about their etiologic overlap. However, detailed study of phenotypes with different ages of onset, severity, and presentation poses a considerable challenge. Recently developed heritability methods allow us to accurately measure correlation of genome-wide common variant risk between two phenotypes from pools of different individuals and assess how connected they, or at least their genetic risks, are on the genomic level. We used genome-wide association data for 265,218 patients and 784,643 control participants, as well as 17 phenotypes from a total of 1,191,588 individuals, to quantify the degree of overlap for genetic risk factors of 25 common brain disorders. RATIONALE Over the past century, the classification of brain disorders has evolved to reflect the medical and scientific communities' assessments of the presumed root causes of clinical phenomena such as behavioral change, loss of motor function, or alterations of consciousness. Directly observable phenomena (such as the presence of emboli, protein tangles, or unusual electrical activity patterns) generally define and separate neurological disorders from psychiatric disorders. Understanding the genetic underpinnings and categorical distinctions for brain disorders and related phenotypes may inform the search for their biological mechanisms. RESULTS Common variant risk for psychiatric disorders was shown to correlate significantly, especially among attention deficit hyperactivity disorder (ADHD), bipolar disorder, major depressive disorder (MDD), and schizophrenia. By contrast, neurological disorders appear more distinct from one another and from the psychiatric disorders, except for migraine, which was significantly correlated to ADHD, MDD, and Tourette syndrome. We demonstrate that, in the general population, the personality trait neuroticism is significantly correlated with almost every psychiatric disorder and migraine. We also identify significant genetic sharing between disorders and early life cognitive measures (e.g., years of education and college attainment) in the general population, demonstrating positive correlation with several psychiatric disorders (e.g., anorexia nervosa and bipolar disorder) and negative correlation with several neurological phenotypes (e.g., Alzheimer's disease and ischemic stroke), even though the latter are considered to result from specific processes that occur later in life. Extensive simulations were also performed to inform how statistical power, diagnostic misclassification, and phenotypic heterogeneity influence genetic correlations. CONCLUSION The high degree of genetic correlation among many of the psychiatric disorders adds further evidence that their current clinical boundaries do not reflect distinct underlying pathogenic processes, at least on the genetic level. This suggests a deeply interconnected nature for psychiatric disorders, in contrast to neurological disorders, and underscores the need to refine psychiatric diagnostics. Genetically informed analyses may provide important "scaffolding" to support such restructuring of psychiatric nosology, which likely requires incorporating many levels of information. By contrast, we find limited evidence for widespread common genetic risk sharing among neurological disorders or across neurological and psychiatric disorders. We show that both psychiatric and neurological disorders have robust correlations with cognitive and personality measures. Further study is needed to evaluate whether overlapping genetic contributions to psychiatric pathology may influence treatment choices. Ultimately, such developments may pave the way toward reduced heterogeneity and improved diagnosis and treatment of psychiatric disorders

    Brand recognition in television advertising : the influence of brand presence and brand introduction

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    CITATION: Gerber, C., Terblanche-Smit, M. & Crommelin, T. 2014. Brand recognition in television advertising : the influence of brand presence and brand introduction. Acta Commercii, 14(1): 1-8, doi: 10.4102/ac.v14i1.182.The original publication is available at http://www.actacommercii.co.zaPurpose: To assess the relationship between brand recognition and brand presence and brand introduction. Problem investigated: Brand recognition and recall are established advertising effectiveness measurements to assess brand awareness. Of particular interest is whether encoding of brand information as measured by brand recognition is influenced by brand presence and brand introduction. Design/methodology/approach: A meta-analysis was performed on responses to 25 television advertisements, gathered from 50 000 respondents. Findings: The findings indicated a positive linear relationship between brand presence and brand recognition but a negative linear relationship between brand introduction and brand recognition, whilst brand introduction and brand presence predicted variance in brand recognition. Value of research: The researchers concluded that a brand should be present in an advertisement for about two-thirds of the time for optimum brand recognition.http://www.actacommercii.co.za/index.php/acta/article/view/182Publisher's versio

    High-intensity intermittent cycling increases purine loss compared with workload-matched continuous moderate intensity cycling

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    PURPOSE: Exercise at 50–60 % of peak oxygen consumption (VO(2 peak)) stimulates maximal fat oxidation rates. Despite a lower estimated work performed; high-intensity intermittent exercise (HIIE) training produces greater fat mass reductions when compared with workload-matched continuous (CON) steady state exercise. No metabolic basis has been documented nor mechanisms offered to explain this anomaly. This study investigated the physiological and metabolic responses of two different workload-matched exercise protocols. METHODS: On separate occasions and at least 1 week apart, eight apparently healthy males cycled for 30 min at either 50 % VO(2 peak) (CON) or performed repeated 20 s bouts of supramaximal exercise at 150 %VO(2 peak) separated by 40 s rest (HIIE). RESULTS: The average heart rate, oxygen consumption, plasma glycerol and free fatty acid concentrations were not different during exercise and recovery between the trials. Plasma lactate and hypoxanthine (Hx) concentrations were elevated and urinary excretion rates of Hx and uric acid were greater following HIIE as compared to CON (P < 0.05). CONCLUSION: Exercise-induced plasma Hx accumulation and urinary purine excretion are greater following HIIE and indirectly represents a net loss of adenosine triphosphate (ATP) from the muscle. The subsequent restorative processes required for intramuscular de novo replacement of ATP may contribute to a negative energy balance and in part, account for the potential accelerated fat loss observed with HIIE when compared with CON training programs
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