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Cortisol and High-Risk People for Schizophrenia: A Mini Review
(2024)
Schizophrenia is a psychiatric disorder characterized by neurocognitive symptoms and a generalized sensitivity to stress due to a neurodevelopment predisposition to this condition. We review some difficulties studying the relationship between subjacent vulnerability and stress response. These are mainly delimited to the selection of the samples and the scientific community's different conceptions of the clinical symptoms. With some of our work, we hold that the neurocognitive performance interacts positively with the allostatic load, mainly in the genetic high-risk group.
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Numerical Analysis of Machining Part Distortion in Aircraft Aluminum Structures
(ASME, 2020)
Ledesma-Orozco, Elías
;
The inherent residual stresses in the raw materials of large monolithic structural components whereby machining procedures are needed to produce aircraft components, cause deviations, and distortions that are undesired and rise challenges for engineering design and engineering production teams of the aerospace companies. A numerical approach to address part distortion is proposed in this paper. An algorithm was developed and implemented as a finite element subroutine in the software ANSYS APDL, which uses the raw inherent residual stress parameters of the aluminum alloy and the machining locations of a structural specimen to simulate the machining distortion phenomenon in aircraft aluminum structures. This algorithm uses as inputs the finite element mesh of a component, the coefficients of residual stresses functions, and the machining location parameters from where a part is made of a raw material blank. The numerical results predicted the part distortion phenomenon with an Absolute Error of 2.79% with respect to initial experimental measurements of part distortion. Additionally, the proposed approach was used to develop part distortion curves by considering the machining location of the specimen. From these, numerical optimization techniques led to determine the machining location of the representative specimen that attained lower distortions. Such location corresponded to a vertical value around of 3.15 mm for the two simulated residual stresses conditions in the material. An additional measurement was carried out to validate the optimal numerical results and errors below 3% were obtained. Consequently, the proposed approach can be of use to determine, to reduce and to optimize part distortion without further experimental testing in structural aluminum 7050-T7451 alloy aircraft components.
14 1
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Modeling Nonlinear Compressive Stress Responses in Closed-Cell Polymer Foams Using Artificial Neural Networks: A Comprehensive Case Study
(ACS Publications, 2022-06-14)
Closed-cell polymer foams are versatile materials that have multiple applications in several industries due to their mechanical energy absorption capabilities, and they are used to design protective devices as engineering solutions or to produce packaging solutions to protect goods. Because most of these products and devices operate in compression, it is necessary to know the material behavior to compressive loadings for modeling and design purposes. In this work, the compressive response of a closed-cell expanded polypropylene polymer foam is modeled using feed-forward artificial neural network models as a case study. Practical considerations and a methodology that includes the basic steps to conduct the modeling of the compressive stress of foams of this class are presented. The modeling uses foam densities, loading rates, and strain as inputs in an artificial neural network system to model compressive stress in the foam. Results help conclude that feed-forward neural networks can model the response at compression for expanded polypropylene foams considering different variables since prediction errors close to the unity of the coefficient of determination R2 and error results below 2% regarding testing data were obtained.
Scopus© Citations 3 9
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Salesperson turnover intention: a tale of two countries
(Emerald Publishing Limited, 2021)
Onyemah, Vincent
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Mulki, Jay P.
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Rivera-Pesquera, Martha
Purpose: A significant amount of research has shown that drivers of employee attitudes, and behaviors leading to outcome variables such as turnover intentions, are strongly influenced by national culture. This study focuses on the difference in relationships among some critical variables between two emerging economies with similar cultural indices. Design/methodology/approach: Survey questionnaire was used to collect responses from salespeople in two countries. Correlation analysis and structural equation modeling were used to provide support for the stated hypotheses. Publisher: Emerald Publishing Limited Copyright © 2021, Emerald Publishing Limited
Scopus© Citations 3 17 1
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The stress granule RNA-binding protein TIAR-1 protects female germ cells from heat shock in Caenorhabditis elegans
(2016)
Huelgas-Morales, Gabriela
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Salinas, Laura S.
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Greenstein, David
;
Navarro, Rosa E.
In response to stressful conditions, eukaryotic cells launch an arsenal of regulatory programs to protect the proteome. One major protective response involves the arrest of protein translation and the formation of stress granules, cytoplasmic ribonucleoprotein complexes containing the conserved RNA-binding proteins TIA-1 and TIAR. The stress granule response is thought to preserve mRNA for translation when conditions improve. For cells of the germline-the immortal cell lineage required for sexual reproduction-protection from stress is critically important for perpetuation of the species, yet how stress granule regulatory mechanisms are deployed in animal reproduction is incompletely understood. Here, we show that the stress granule protein TIAR-1 protects the Caenorhabditis elegans germline from the adverse effects of heat shock. Animals containing strong loss-of-function mutations in tiar-1 exhibit significantly reduced fertility compared to the wild type following heat shock. Analysis of a heat-shock protein promoter indicates that tiar-1 mutants display an impaired heat-shock response. We observed that TIAR-1 was associated with granules in the gonad core and oocytes during several stressful conditions. Both gonad core and oocyte granules are dynamic structures that depend on translation; protein synthesis inhibitors altered their formation. Nonetheless, tiar-1 was required for the formation of gonad core granules only. Interestingly, the gonad core granules did not seem to be needed for the germ cells to develop viable embryos after heat shock. This suggests that TIAR-1 is able to protect the germline from heat stress independently of these structures. © 2016 Huelgas-Morales et al.
Scopus© Citations 28 9 1
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Mindfulness affects stress, ghrelin, and BMI of obese children: a clinical trial
(2020)
López-Alarcón, Mardia
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Zurita-Cruz, Jessie N.
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Torres-Rodríguez, Alonso
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Bedia-Mejía, Karla
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Pérez-Güemez , Manuel
Childhood obesity is associated with stress. However, most treatment strategies include only dietary and physical activity approaches. Mindfulness may assist in weight reduction, but its effectiveness is unclear. We assessed the effect of mindfulness on stress, appetite regulators, and weight of children with obesity and anxiety. A clinical study was conducted in a pediatric hospital. Eligible children were 10–14 years old, BMI ≥95th percentile, Spence anxiety score ≥55, and who were not taking any medication or supplementation. Participants were assigned to receive an 8-week conventional nutritional intervention (CNI) or an 8-week mindfulness-based intervention plus CNI (MND-CNI). Anthropometry, body composition, leptin, insulin, ghrelin, cortisol, and Spence scores were measured at baseline and at the end of the intervention. Anthropometry was analyzed again 8 weeks after concluding interventions. Log-transformed and delta values were calculated for analysis. Thirty-three MND-CNI and 12 CNI children finished interventions; 17 MND-CNI children accomplished 16 weeks. At the end of the intervention, significant reductions in anxiety score (−6.21 ± 1.10), BMI (−0.45 ± 1.2 kg/m2), body fat (−1.28 ± 0.25%), ghrelin (−0.71 ± 0.37 pg/mL), and serum cortisol (−1.42 ± 0.94 µg/dL) were observed in MND-CNI children. Changes in anxiety score, ghrelin, and cortisol were different between groups (P < 0.05). Children who completed 16 weeks decreased BMI after intervention (−0.944 ± 0.20 kg/m2, P < 0.001) and remained lower 8 weeks later (−0.706 ± 0.19 kg/m2, P = 0.001). We concluded that mindfulness is a promising tool as an adjunctive therapy for childhood obesity. However, our findings need confirmation in a larger sample population. © 2020 The authors.Endocrine Connections, BioScientifica Ltd.
Scopus© Citations 14 12 1

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