59 research outputs found
Improvement Transient Stability of Fixed Speed Wind Energy Conversion System by Using Transformer-Type Superconducting Fault Current Limiter
International audienceThe wind turbine generation system (WTGS) is one of the representative renewable energy systems. With the rapid development of WTGS and its increased capacity, the level of short circuit current will increase in distribution systems. The application of the Superconducting Fault Current Limiter (SFCL), would not only reduce the level of the short circuit current but also offer a reliable interconnection to the network. The transformer-type superconducting fault current limiter (SFCL) is one of the fault current limiters, and has many advantages such as design flexibility. In this paper, the effect of transformer-type SFCL on transient behavior of grid connected to WTGS is studied. The WTGS is considered as a fixed-speed system, equipped with a squirrel-cage induction generator. The drive-train is represented by two-mass model. The simulation results show that the transformer-type SFCL not only limits the fault current but also can improve the dynamic performance of the WTGS
Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age.
The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.
Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age
Abstract
The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset – with data collected between 2020 and 2022 – to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research
Exposure and connectedness to natural environments: An examination of the measurement invariance of the Nature Exposure Scale (NES) and Connectedness to Nature Scale (CNS) across 65 nations, 40 languages, gender identities, and age groups
Detachment from nature is contributing to the environmental crisis and reversing this trend requires detailed monitoring and targeted interventions to reconnect people to nature. Most tools measuring nature exposure and attachment were developed in high-income countries and little is known about their robustness across national and linguistic groups. Therefore, we used data from the Body Image in Nature Survey to assess measurement invariance of the Nature Exposure Scale (NES) and the Connectedness to Nature Scale (CNS) across 65 nations, 40 languages, gender identities, and age groups (N = 56,968). While multi-group confirmatory factor analysis (MG-CFA) of the NES supported full scalar invariance across gender identities and age groups, only partial scalar invariance was supported across national and linguistic groups. MG-CFA of the CNS also supported full scalar invariance across gender identities and age groups, but only partial scalar invariance of a 7-item version of the CNS across national and linguistic groups. Nation-level associations between NES and CNS scores were negligible, likely reflecting a lack of conceptual clarity over what the NES is measuring. Individual-level associations between both measures and sociodemographic variables were weak. Findings suggest that the CNS-7 may be a useful tool to measure nature connectedness globally, but measures other than the NES may be needed to capture nature exposure cross-culturally
Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age
The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research
The effect of gold, silver and zinc oxide nanoparticles on oxidative stress parameters level in the liver, heart and lung of male mice
Background & Objective: Nowadays, the beneficial effects of nanomaterials are accepted in medicine and industry. Considering the increasing use of nanoparticles and their possible toxicity, the effect of nanoparticles on oxidative stress markers was investigated in this study.
Material & Methods: In this experimental- interventional study, 32 Balb mice were divided into 4 groups of 8. The control group received saline, and other three groups received gold, silver, and zinc oxide nanoparticles at a concentration of 100 PPM with IP injection during 28 days. After anesthesia, the tissues of liver, heart and lung were removed, and the activity level of oxidative stress markers was evaluated.
Results: MDA level was significantly increased in zinc oxide treatment group in all three tissues and in gold treatment group in liver tissue. This factor showed a significant decrease in silver nanoparticle treatment in these tissues. The activity of catalase and glutathione peroxidase enzymes in the treatment of silver nanoparticle showed a significant increase. While in the treatment group with zinc oxide and gold nanoparticles, the activity of these enzymes decreased, this decrease was significant only in zinc oxide nanoparticle.
Conclusion: It is concluded that the silver nanoparticle acts as a useful nanoparticle by decreasing MDA and oxidative stress and inducing antioxidant enzymes, while the effect of zinc oxide nanoparticle shows its toxicity
Trade-off between feed efficiency and immunity in specialized high-performing chickens
ABSTRACT: Based on resource allocation theory, ignoring importance of immunity, and focus on growth and feed efficiency (FE) traits in breeding plans may lead to serious weakness in immune system performance. However, in poultry the adverse effects of selection for FE on the immune system are unclear. Therefore, an experiment was conducted to study the trade-off between FE and immunity using a total of 180 high-performing specialized male chickens from a commercial broiler line which were selected over 30 generations for growth (body weight gain, BWG) and FE (residual feed intake, RFI). Birds were reared for 42 d and 5 FE-related traits of the birds in the last week were considered including daily feed intake (DFI), feed conversion ratio (FCR), residual feed intake (RFI), residual BW gain (RG), and residual intake and gain (RIG). For all 180 chickens, immune system performance including humoral immune response, cell-mediated immunity (CMI), and the activity of lysozyme enzyme (L. activity) as innate immunity was measured. After ascending sort of each FE records, 10% of higher records (H-FE: N = 18) and 10% of lower records (L-FE: N = 18) were determined, and immunity between L-FE and H-FE groups were compared. Moreover, L-BWG and H-BWG were analyzed because BWG is one of components in the FE formula. Performance of the immune system was not statistically different for CMI in none of the studied FE groups. Moreover, high and low groups for DFI and BWG were not different regarding the immunity of the birds. Antibody titers against Newcastle disease virus (NDV) were different between low and high groups of FCR, RG, and RIG. Likewise, SRBC-derived antibodies were significantly different between RFI groups. Rather than humoral immunity, RIG had adversely effect on the innate immunity. Results of the present study showed that although RIG is a more appropriate indicator for FE, choosing for high RIG can weaken the performance of the both humoral and innate immune systems, while RFI had fewer adverse effects
Monocyte and Neutrophil Chemotactic Activity at the Site of Interstitial Inflammation in Patients on High-Flux Hemodialysis or Hemodiafiltration
Background/Aims: We have observed a difference between patients on low-flux hemodialysis (HD) or peritoneal dialysis and patients on hemodiafiltration (HDF) or high-flux HD in the capacity of transmigrated leukocytes to mobilize CD11b in response to inflammatory stimuli compared with healthy subjects. This could be due to different interstitial chemokine concentrations. Methods: We measured concentrations of circulating and interstitial macrophage inflammatory protein-1 alpha (MIP-1 alpha), matrix metalloproteinase-9 (MMP-9)/neutrophil gelatinase-associated lipocalin (NGAL), monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) in 10 patients on HDF or high-flux HD and 11 healthy subjects by using immunoassay. Results: The interstitial concentrations of MIP-1 alpha, MMP-9/NGAL and IL-8 were similar in patients and healthy subjects, while the corresponding concentration of MCP-1 was significantly higher in patients on HDF or high-flux HD as compared with healthy subjects (p < 0.01). Conclusion: We suggest that an equal or higher concentration of chemokines in the interstitium in patients with HDF or high-flux HD might be one mechanism responsible for the preserved function of transmigrated leukocytes. Copyright (C) 2009 S. Karger AG, Base
An analytical study on behavioral-cerebral system activities and alexithymia among drug abused and none drug abused people
Introduction: One of the common problems in contemporary world is addiction and its side effects. Dependency and addiction due to drug consumption is a chronic disorder which is followed by cultural, psychological, social, and spiritual effects. The aim of the present research was comparing behavioral-cerebral systems with alexithymia among addictive and normal people.
Materials and methods: The statistical population was all referred people to therapy centers of addiction in Ilam among which 40 cases were selected by accessible methods and also 40 cases of normal people without addiction background were selected based on their age, gender, education level, and married conditions by homogeneity procedure. Research method was comparative. Questionnaire of characterization by Wilson and questionnaire of Alexithymia by Toronto were used as research instrument to collect the data. Also, SPSS software and multi variable analysis were used to analysis the collected data.
Results: The findings showed that activated systems of behavior and fight-flight in people with addiction background was more than normal people, while behavioral deterrent system activities in normal people was more than people with addiction background (P0.001).
Conclusion: So, by identifying people that their behavioral activating system is more active than that of normal ones the risky group can be determined and then they can be benefited from behavioral and educational programs to be prevented from the likelihood of addiction in these groups. Also, cultivating capabilities of control and emotion regulation helps to prevent addiction and also helps people to adopt with changes and stress factors
Epigenetic Changes in the CRH Gene are Related to Severity of Suicide Attempt and a General Psychiatric Risk Score in Adolescents
The aim of this study, comprising 88 suicide attempters, was to identify hypothalamic-pituitary-adrenal (HPA) -axis coupled CpG-sites showing methylation shifts linked to severity of the suicide attempt. Candidate methylation loci were further investigated as risk loci for a general psychiatric risk score in two cohorts of adolescents (cohort 1 and 2). The genome-wide methylation pattern was measured in whole blood using the Illumina Infinium Methylation EPIC BeadChip. Subjects were stratified into high-risk and low-risk groups based on the severity of the suicidal behavior. We included CpG sites located within 2000 basepairs away from transcriptional start site of the following HPA-axis coupled genes: corticotropin releasing hormone (CRH), corticotropin releasing hormone binding protein (CRHBP), corticotropin releasing hormone receptor 1 (CRHR1), corticotropin releasing hormone receptor 2 (CRHR2), FK506-binding protein 51 (FKBP5) and the glucocorticoid receptor (NR3C1). The methylation state of two corticotropin releasing hormone (CRH)-associated CpG sites were significantly hypomethylated in the high-risk group of suicide attempters (n = 31) (cg19035496 and cg23409074) (p ~50% risk) or controls. In adolescent cohort 2, cg19035496 was hypermethylated in subjects with a high general psychiatric risk score. Our results show epigenetic changes in the CRH gene related to severity of suicide attempt in adults and a general psychiatric risk score in adolescents
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