60 research outputs found

    A model linking digital media dependence, exercise empowerment, and social physique anxiety among emerging adulthood college students

    Get PDF
    Background/objectiveSocial physique anxiety (SPA) is a prevalent psychological issue among emerging adults, regardless of gender. Many studies have shown that high levels of SPA are associated with various negative consequences on both physical and mental well-being. Considering the potential severity of SPA’s consequences and its high prevalence among emerging adults, it is imperative to investigate the factors and mechanisms that contribute to SPA in this population. Although prior studies have identified associations between emerging adulthood, digital media use, and SPA in young individuals, the underlying mechanisms remain unclear. The objective of this study is to examine the associations between SPA, emerging adulthood characteristics, digital media dependency, and exercise empowerment.MethodsIn this cross-sectional study, Chinese college students were recruited using snowball sampling. The study utilized an online survey to assess SPA, emerging adulthood characteristics, digital media dependency, and exercise empowerment. The collected data was analyzed using path analysis.ResultsA total of 1,661 Chinese college students (mean age = 19.63 ± 0.32 years, 44.97% male) were included in this study. The results showed that SPA exhibited positive correlations with responsibility and instability in emerging adulthood characteristics, digital media dependency, and exercise empowerment. Additionally, digital media dependency showed positive correlations with responsibility and instability, as well as with exercise empowerment. Furthermore, exercise empowerment demonstrated positive correlations with self-exploration, responsibility, instability, and possibilities in emerging adulthood characteristics. SPA can be directly influenced by digital media dependency, self-exploration, and instability. Furthermore, digital media dependency has a positive indirect impact on SPA through exercise empowerment. Similarly, self-exploration also has a positive indirect impact on SPA through exercise empowerment. On the other hand, instability has a negative indirect impact on SPA through exercise empowerment.ConclusionThis study provides new insights into the complex correlations with emerging adulthood characteristics, digital media dependency, exercise empowerment, and SPA. Instability, self-exploration in emerging adulthood characteristics, as well as digital media dependency, have the potential to influence SPA among college students through exercise empowerment Interventions and strategies aimed at addressing these psychological factors may prove beneficial in reducing SPA among emerging adults, especially college students

    Inside-out Ca2+ signalling prompted by STIM1 conformational switch

    Get PDF
    Store-operated Ca(2+) entry mediated by STIM1 and ORAI1 constitutes one of the major Ca(2+) entry routes in mammalian cells. The molecular choreography of STIM1–ORAI1 coupling is initiated by endoplasmic reticulum (ER) Ca(2+) store depletion with subsequent oligomerization of the STIM1 ER-luminal domain, followed by its redistribution towards the plasma membrane to gate ORAI1 channels. The mechanistic underpinnings of this inside-out Ca(2+) signalling were largely undefined. By taking advantage of a unique gain-of-function mutation within the STIM1 transmembrane domain (STIM1-TM), here we show that local rearrangement, rather than alteration in the oligomeric state of STIM1-TM, prompts conformational changes in the cytosolic juxtamembrane coiled-coil region. Importantly, we further identify critical residues within the cytoplasmic domain of STIM1 (STIM1-CT) that entail autoinhibition. On the basis of these findings, we propose a model in which STIM1-TM reorganization switches STIM1-CT into an extended conformation, thereby projecting the ORAI-activating domain to gate ORAI1 channels

    Tissue-Autonomous Function of Drosophila Seipin in Preventing Ectopic Lipid Droplet Formation

    Get PDF
    Obesity is characterized by accumulation of excess body fat, while lipodystrophy is characterized by loss or absence of body fat. Despite their opposite phenotypes, these two conditions both cause ectopic lipid storage in non-adipose tissues, leading to lipotoxicity, which has health-threatening consequences. The exact mechanisms underlying ectopic lipid storage remain elusive. Here we report the analysis of a Drosophila model of the most severe form of human lipodystrophy, Berardinelli-Seip Congenital Lipodystrophy 2, which is caused by mutations in the BSCL2/Seipin gene. In addition to reduced lipid storage in the fat body, dSeipin mutant flies accumulate ectopic lipid droplets in the salivary gland, a non-adipose tissue. This phenotype was suppressed by expressing dSeipin specifically within the salivary gland. dSeipin mutants display synergistic genetic interactions with lipogenic genes in the formation of ectopic lipid droplets. Our data suggest that dSeipin may participate in phosphatidic acid metabolism and subsequently down-regulate lipogenesis to prevent ectopic lipid droplet formation. In summary, we have demonstrated a tissue-autonomous role of dSeipin in ectopic lipid storage in lipodystrophy

    mTORC2 Regulates Amino Acid Metabolism in Cancer by Phosphorylation of the Cystine-Glutamate Antiporter xCT

    Full text link
    Mutations in cancer reprogram amino acid metabolism to drive tumor growth, but the molecular mechanisms are not well understood. Using an unbiased proteomic screen, we identified mTORC2 as a critical regulator of amino acid metabolism in cancer via phosphorylation of the cystine-glutamate antiporter xCT. mTORC2 phosphorylates serine 26 at the cytosolic N terminus of xCT, inhibiting its activity. Genetic inhibition of mTORC2, or pharmacologic inhibition of the mammalian target of rapamycin (mTOR) kinase, promotes glutamate secretion, cystine uptake, and incorporation into glutathione, linking growth factor receptor signaling with amino acid uptake and utilization. These results identify an unanticipated mechanism regulating amino acid metabolism in cancer, enabling tumor cells to adapt to changing environmental conditions

    Biomimetic Design of a New Semi-Rigid Spatial Mesh Antenna Reflector

    No full text
    The reflective surface accuracy (RSA) of traditional space mesh antennas typically ranges from 0.2 to 6 mmRMS. To improve the RSA, an active control scheme can be employed, although it presents challenges in determining the installation position of the actuator. In this study, we propose a novel design for a semi-rigid cable mesh that combines rigid members and a flexible woven mesh, drawing inspiration from both rigid ribbed antennas and biomimicry. Initially, we investigate the planar mesh topology of spider webs and determine the bionic cable surface’s mesh topology based on the existing hexagonal meshing method, with RSA serving as the evaluation criterion. Subsequently, through motion simulations and careful observation, we establish the offset angle as the key design parameter for the bionic mesh and complete the design of the bionic cable mesh accordingly. Finally, by analyzing the impact of the node quantity on RSA, we determine a layout scheme for the flexible woven mesh with a variable number of nodes, ultimately settling for 26 nodes. Our results demonstrate that the inclusion of numerous rigid components on the bionic cable mesh surface offers viable installation positions for the actuator of the space mesh antenna. The reflector accuracy achieved is 0.196 mmRMS, slightly surpassing the lower limit of reflector accuracy observed in most traditional space-space mesh antennas. This design presents a fresh research perspective on combining active control schemes with reflective surfaces, offering the potential to enhance the RSA of traditional rigid rib antennas to a certain extent

    Effect of Nano-Particle Addition on Grain Structure Evolution of Friction Stir-Processed Al 6061 During Postweld Annealing

    No full text
    The fabrication of nano-composites is challenging because uniform dispersion of nano-sized reinforcements in metallic substrate is difficult to achieve using powder metallurgy or liquid processing methods. In the present study, Al-based nano-composites reinforced with Al2O3 particles have been successfully fabricated using friction stir processing. The effects of nano-Al2O3 particle addition on grain structure evolution of friction stir-processed Al matrix during post-weld annealing were investigated. It was revealed that the pinning effect of Al2O3 particles retarded grain growth and completely prevented abnormal grain growth during postweld annealing at 470°C. However, abnormal grain growth can still occur when the composite material was annealed at 530°C. The mechanism involved in the grain structure evolution and the effect of nano-sized particle addition on the mechanical properties were discussed therein.Accepted versio

    Paleoclimate quantitative reconstruction and characteristics of continental red beds: a case study of the lower fourth sub-member of Shahejie Formation in the Bonan Sag

    No full text
    Abstract Varied origins have the ability to construct the continental red beds, such as paleoclimate, provenance, drainage status, etc. Reconstructing paleoclimate is the key to investigate the origin. Thus, this paper outlines the normal distribution constrained method (NDCM) to reconstruct paleoclimate quantitatively and accurately during the lower fourth sub-member of Shahejie (Es4x) in the Bonan Sag, which is in low requirement of data and environmental conditions. Based on the NDCM, the paleoclimate is still in a long-term arid background as the potential evapotranspiration rates (PERs) are larger than 6 in the transgressive system tract (TST) and regressive system tract (RST) during the period of Es4x. The decreasing PERs that range from 6.28 to 6.04, decreasing atmospheric temperature range from 14.37 to 13.95 °C and increasing mean precipitation of the wettest month and mean precipitation of the driest month indicate the paleoclimate is breaking away from the hot and arid background from TST to RST. Meanwhile, the paleoclimate fluctuation develops decreasing frequency and increasing amplitude which can be inferred from the increasing standard deviation (std), Th/K and Th/U curves. The hot and arid background is still the main origin of red color during the Es4x. Moreover, the other origin may also develop since there is no clear law between red coloration and the developing location of sediments
    corecore