Hasil untuk "Physiology"

D. Anderson, A. Cembella, G. Hallegraeff

B. Stewart, H. Atwood, J. Renger et al.

R. Levenson, A. Ruef

D. Kamimura, K. Ishihara, T. Hirano

M. Wehling

T. Gunter, K. Gunter, S. Sheu et al.

I. Seregin, V. Ivanov

Hans Lambers, F. Stuart Chapin, T. Pons

J. Reis, O. Swayne, Y. Vandermeeren et al.

M. Sawka, Lisa R Leon, S. Montain et al.

This article emphasizes significant recent advances regarding heat stress and its impact on exercise performance, adaptations, fluid electrolyte imbalances, and pathophysiology. During exercise‐heat stress, the physiological burden of supporting high skin blood flow and high sweating rates can impose considerable cardiovascular strain and initiate a cascade of pathophysiological events leading to heat stroke. We examine the association between heat stress, particularly high skin temperature, on diminishing cardiovascular/aerobic reserves as well as increasing relative intensity and perceptual cues that degrade aerobic exercise performance. We discuss novel systemic (heat acclimation) and cellular (acquired thermal tolerance) adaptations that improve performance in hot and temperate environments and protect organs from heat stroke as well as other dissimilar stresses. We delineate how heat stroke evolves from gut underperfusion/ischemia causing endotoxin release or the release of mitochondrial DNA fragments in response to cell necrosis, to mediate a systemic inflammatory syndrome inducing coagulopathies, immune dysfunction, cytokine modulation, and multiorgan damage and failure. We discuss how an inflammatory response that induces simultaneous fever and/or prior exposure to a pathogen (e.g., viral infection) that deactivates molecular protective mechanisms interacts synergistically with the hyperthermia of exercise to perhaps explain heat stroke cases reported in low‐risk populations performing routine activities. Importantly, we question the “traditional” notion that high core temperature is the critical mediator of exercise performance degradation and heat stroke. Published 2011 This article is a U.S. Government work and is in the public domain in the USA. Compr Physiol 1:1883‐1928, 2011.

I. Seregin, A. Kozhevnikova

D. Moran, A. Shitzer, K. Pandolf

Sarkity Dios, Liana Metta, Fitriani Rita et al.

The need to develop 21st-century skills requires lecturers to apply appropriate learning to develop skills. This study aims to describe how the implementation of case-method learning for physics lectures on the topic of hydrostatic pressure by integrating the maritime context. This research is a descriptive study. The approach used in this study is a qualitative approach. Data collection was carried out through observation and documentation. Data were analyzed descriptively and presented based on the stages of case- method learning. The implementation of the case method in physics learning on the topic of hydrostatic pressure by linking the maritime context can be done by providing problems that are in accordance with the conditions or events that students often encounter. For instance, we present a problem related to the sinking of the KRI Nanggala 402 ship, a real-life maritime incident involving a steel ship that split into 3 parts. Students discuss in groups to find solutions to problems using appropriate physics concepts and strategies. After going through a series of problem-solving processes, students can understand the essence of the concept of hydrostatic pressure, what events are related to this concept, and how to apply it in solving problems.

Ieshita Pan, Suganiya Umapathy

Applications for plastic polymers can be found all around the world, often discarded without any prior care, exacerbating the environmental issue. When large waste materials are released into the environment, they undergo physical, biological, and photo-degradation processes that break them down into smaller polymer fragments known as microplastics (MPs). The time it takes for residual plastic to degrade depends on the type of polymer and environmental factors, with some taking as long as 600 years or more. Due to their small size, microplastics can contaminate food and enter the human body through food chains and webs, causing gastrointestinal (GI) tract pain that can range from local to systemic. Microplastics can also acquire hydrophobic organic pollutants and heavy metals on their surface, due to their large surface area and surface hydrophobicity. The levels of contamination on the microplastic surface are significantly higher than in the natural environment. The gut-brain axis (GB axis), through which organisms interact with their environment, regulate nutritional digestion and absorption, intestinal motility and secretion, complex polysaccharide breakdown, and maintain intestinal integrity, can be altered by microplastics acting alone or in combination with pollutants. Probiotics have shown significant therapeutic potential in managing various illnesses mediated by the gut-brain axis. They connect hormonal and biochemical pathways to promote gut and brain health, making them a promising therapy option for a variety of GB axis-mediated illnesses. Additionally, taking probiotics with or without food can reduce the production of pro-inflammatory cytokines, reactive oxygen species (ROS), neuro-inflammation, neurodegeneration, protein folding, and both motor and non-motor symptoms in individuals with Parkinson's disease. This study provides new insight into microplastic-induced gut dysbiosis, its associated health risks, and the benefits of using both traditional and next-generation probiotics to maintain gut homeostasis

R. Feyereisen, W. Dermauw, T. Van Leeuwen

Hirofumi Tanaka, D. Seals

D. Hollinger, A. Richardson

Denise Soares, Joana Lourenço, Ana Filipa Silva et al.

PURPOSE Shot-put is a complex ballistic movement that involves segments’ translational and rotational motions. Its goal is to release the shot at maximum forward velocity (strength) at an angle of approximately 40º (rotation). Considering the adapted shot-put, those two components could be more limited in action. Therefore, the present study aimed to examine the correlations among the one-repe-tition maximum (1RM) test in the bench press (BP1RM) and trunk rotation (TR1RM) and the throwing distance of the adapted shot-put and body composition (Fat mass and Fat-free mass [FFM]), and the throwing distance of the adapted shot-put (TD) and 1RM results. METHODS Eighteen non-professional athletes were evaluated, and their anthropometric data were obtained (bio-impedance measurements). Afterward, the participants performed the BP1RM and TR1RM exercises. Finally, they performed the adapted shot-put in similar conditions as the official competitions, where three trials of ASP were performed, and the best of these trials were assessed. RESULTS The results showed a significant relationship between the throwing distance and 1RM results for both exercises (BP1RM (p=.040) and TR1RM (p=.002)) and with the amount of FFM (p=.045). Concerning FFM relationships, the results showed a positive relationship with both 1RM exercises (BP1RM (p=.034) and TR1RM (p=.003)). The Fat Mass results demonstrated an inverse correlation only with BP1RM (p=.035). CONCLUSIONS The results suggest that physical preparation, including BP1RM and TR1RM exercises, are fundamental to improving adapted shot-put performance. This showed preliminary indicators of which variables may influence the adapted shot-put that might help coaches and athletes to improve their performance. Nevertheless, those results should be carefully considered since the movement evaluated was very complex, especially when performed by participants unfamiliar with them, and because the same analysis included both sexes.

Mary B. Sheppard, Mary B. Sheppard, Mary B. Sheppard et al.

In human, pathogenic variants in smad3 are one cause of familial aortopathy. We describe a novel SMAD3 variant of unknown significance (VUS), V244F, in a patient who presented with aortic root dilation, right coronary artery ectasia, abdominal aortic aneurysm, right vertebral artery atresia, and cavernoma. Determination of variant pathogenicity impacted multiple aspects of the patient’s care, including the most appropriate surgical threshold for which to recommend a valve-sparing aortic root replacement. To determine whether the newly identified SMAD3 variant, and whether SMAD3 induced aortopathy in general, can be assayed in a zebrafish embryo model, we injected smad3a mRNA into Tg[kdrl:mCherry] zebrafish embryos. By measuring the size of the dorsal aorta at 48hpf we found a correlation between pathogenic SMAD3 variants and increased dorsal aortic diameter. The newly identified V244F variant increased dorsal aortic diameter (p < 0.0001) similar to that of the pathogenic control variant T261I (p < 0.0084). In addition, we examined several previously identified variants of uncertain significance and found P124T (p < 0.0467), L296P (p < 0.0025) and A349P (p < 0.0056) to behave like T261I. These results demonstrate that the zebrafish embryo assay was successful in validating known pathogenic variants, classifying our newly identified variant V244F as likely pathogenic, and classifying previously identified variants P124T, L296P, and A349P as likely pathogenic. Overall, our findings identify a novel SMAD3 variant that is likely pathogenic as well as offer a new mechanism to model SMAD3 VUSs in vivo.

Takuma Kurachi, Kazutaka Shinozuka, Chihiro Yoshihara et al.

Abstract Calcitonin receptor (Calcr) and its brain ligand amylin in the medial preoptic area (MPOA) are found to be critically involved in infant care and social contact behaviors in mice. In primates, however, the evidence is limited to an excitotoxic lesion study of the Calcr-expressing MPOA subregion (cMPOA) in a family-living primate species, the common marmoset. The present study utilized pharmacological manipulations of the cMPOA and shows that reversible inactivation of the cMPOA abolishes infant-care behaviors in sibling marmosets without affecting other social or non-social behaviors. Amylin-expressing neurons in the marmoset MPOA are distributed in the vicinity of oxytocin neurons in the anterior paraventricular nucleus of the hypothalamus. While amylin infusion facilitates infant carrying selectively, an oxytocin’s inverse agonist, atosiban, reduces physical contact with non-infant family members without grossly affecting infant care. These data suggest that the amylin and oxytocin signaling mediate intrafamilial social interactions in a complementary manner in marmosets.