1,124 research outputs found

    Model Atmospheres for Irradiated Giant Stars: Implications for the Galactic Center

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    Irradiation of a stellar atmosphere by an external source (e.g. an AGN) changes its structure and therefore its spectrum. Using a state-of-the-art stellar atmosphere code, we calculate the infrared spectra of such irradiated and transformed stars. We show that the original spectrum of the star, which is dominated by molecular bands, changes dramatically when irradiated even by a low-luminosity AGN (LX=1033L_{\rm X} = 10^{33} erg s1^{-1}), becoming dominated by atomic lines in absorption. We study the changes in the spectrum of low-mass carbon- and oxygen-rich giant stars as they are irradiated by a modest AGN, similar to the one at the Galactic center (GC). The resulting spectra are similar to those of the faintest S-cluster stars observed in the GC. The spectrum of a star irradiated by a much brighter AGN, like that powered by a tidally disrupted star, is very different from that of any star currently observed near the GC. For the first time we have discovered that the structure of the atmosphere of an irradiated giant changes dramatically and induces a double inversion layer. We show that irradiation at the current level can explain the observed trend of CO band intensities decreasing as a function of increasing proximity to Sg AA^{*}. This may indicate that (contrary to previous claims) there is no paucity of old giants in the GC, which coexist simultaneously with young massive stars.Comment: Submitted to ApJ; typo in name correcte

    Sex Differences in Desiccation Tolerance Varies by Colony in the Mesic Liverwort \u3ci\u3ePlagiochila porelloides\u3c/i\u3e

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    Water scarcity, a common stress factor, negatively impacts plant performance. Strategies to cope with it, such as desiccation tolerance, are becoming increasingly important to investigate. However, phenomena, such as intraspecific variation in stress responses have not received much attention. Knowledge of this variability and the environmental drivers can be leveraged to further investigate the mechanisms of desiccation tolerance. Here we tested for variation in desiccation tolerance in Plagiochila porelloides among colonies and sexes within the same riparian zone. Field-collected dehardened plants were subjected to a desiccation event, under controlled conditions and then rehydrated. Plant water status, photosynthetic rates, net carbon gain, and efficiency of photosystem II (PSII) were assayed to evaluate tissue desiccation, basic metabolic processes and plant recovery. To establish a linkage between plant response and environmental factors, field light conditions were measured. We detected intraspecific variation, where a more exposed colony (high percentage of open sky, large temporal range of light quantity, and high red/far-red ratio) showed sex differences in desiccation tolerance and recovery. Overall, PSII recovery occurred by 72 h after rehydration, with a positive carbon gain occurring by day 30. This within species variation suggests plastic or genetic effects, and likely association with light conditions

    What are the motives underlying Brazilians' food choices? An analysis of the Food Choice Questionnaire and its relationship with different sample characteristics

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    ABSTRACT: The first aim of this study was to evaluate the psychometric properties of the Food Choice Questionnaire (FCQ)—using the original model—in a sample of 1480 Brazilian adults (69.5% female). The second aim was to rank the reasons underlying the participants' food choices using average FCQ scores and 95% confidence interval. The third aim was to evaluate the relationship between food choice motives and sample characteristics using multiple logistic regression and odds ratios. The validity, the invariance across different groups, and the reliability of the FCQ were confirmed for the sample. Sensory appeal and price emerged as the most important reasons, while ethical concern was the least valued. The factors associated with greater odds of choosing food for specific reasons were being older, female, and a student; practicing physical activity; dieting frequently; self-rating eating quality as good; having a higher body mass index; and having low income. Practical Applications Assessing food choice is a complex task, as it encompasses several factors, such as sensory characteristics, health status, income, culture, lifestyle, and cognitive-affective issues; therefore, the use of appropriate tools should be encouraged. The set analyses followed confirmed that the FCQ was an adequate instrument to evaluate the reasons for food choice of the participants who valued strongly the sensory aspects of the foods and presented specific characteristics (e.g., diet practice) that may influence their decisions. These findings may guide future research and clinical interventions aimed at producing food choices that are more oriented to health and well-being.FAPESPinfo:eu-repo/semantics/publishedVersio

    A qualitative study of the spiritual aspects of parenting a child with Down syndrome

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    Parenting a child with Down syndrome can sometimes present certain difficulties and, thus, spirituality may function as a dimension related to finding meaning in life and as a coping resource. Spirituality is a critical dimension of nursing care, but scarce knowledge is available to specifically inform family nursing practice. The aim of this study was to explore the spiritual aspects of parenting a child with Down syndrome, as a qualitative secondary analysis. This is an observational qualitative study, based on in-depth interviews from 42 participants. Data analysis found seven categories that concern meaning and purpose in life: hope, family strength, spiritual practices, personal beliefs, and love, and trust in healthcare providers. Spirituality is a resource in parents' lives who are living in this situation. Nurses should consider this dimension in supporting families and in improving management of this life and health condition.info:eu-repo/semantics/publishedVersio

    A Portuguese Adaptation of the Teruel Orthorexia Scale and a Test of Its Utility with Brazilian Young Adults

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    The aims for this study were to perform a Portuguese language cross-cultural adaptation of the Teruel Orthorexia Scale (TOS) and to evaluate the scale's psychometric properties, including verifying the frequency of behaviors characteristic of orthorexia nervosa and healthy orthorexia, among a group of Brazilian gym users. First, we adapted the Spanish version of the TOS to the Brazilian Portuguese language following international protocols to guarantee idiomatic, semantic, conceptual, and cultural equivalence. Then participants completed both the new Portuguese version of the TOS and a socioeconomic questionnaire. Among our sample of 226 young Brazilian adults (63.7% men; M age = 28.8, SD = 5.1 years), we assessed the bi-factorial model of the TOS through factorial, convergent, and discriminant validity, reliability, and factorial invariance. We calculated the mean scores of the TOS factors and the frequency of behaviors of both orthorexia nervosa and healthy orthorexia. The new Portuguese version was well understood by participants, and the TOS bi-factorial model presented adequate psychometric properties and showed invariance in independent subsamples and in men and women. The mean scores were different between sexes only for orthorexia nervosa, with women obtaining higher values. The frequency of orthorexia nervosa behaviors was 5.3% and of healthy orthorexia was 41.2%. Based on these findings, the Brazilian Portuguese version of the TOS can be a useful tool for investigating orthorexia-like behaviors in future research.info:eu-repo/semantics/publishedVersio

    Impact of body and orofacial appearance on life satisfaction among Brazilian adults

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    Aims 1. to elaborate a general model of physical appearance taking into account body image (BI) and orofacial appearance (OA) components; and 2. to evaluate the impact of BI and OA on life satisfaction among Brazilian adults. Methods This is a cross-sectional observational study. The cognitive, behavioral, affective, and satisfaction/ dissatisfaction aspects of BI, the satisfaction and psychosocial impact of OA, and life satisfaction were evaluated by self-reported psychometric scales. Principal Component Analysis and Parallel Analysis were performed. Structural equation models were elaborated to estimate the impact of BI and OA on life satisfaction. The fit of the models was verified and the significance of the path estimates (β) was evaluated using z-tests (α = 5%). Results A total of 1,940 individuals participated in the study (age: mean = 24.8, standard deviation = 5.7 years; females = 70.1%). In the male sample, three physical appearance factors were retained (OA, cognitive and behavioral components of BI, and affective and satisfaction/dissatisfaction components of BI). In the female sample, two factors were retained (OA and all components of BI). All factors had significant impact on life satisfaction (β = |0.26|-|0.48|, p<0.001) in both samples. Individuals dissatisfied with BI and OA had lower levels of life satisfaction. For men, the affective and satisfaction components of BI had a greater impact on life satisfaction (β = 0.48, p<0.001) than the other factors (β =] -0.30;-0.25[, p<0.001). For women, both BI and OA had a similar impact (BI: β = -0.30, p<0.001; OA: β = -0.32, p<0.001). Conclusion BI and OA formed distinct clusters in the physical appearance evaluation. Physical appearance was perceived differently by men and women, fostering discussion about the sociocultural construction of the body. BI and OA had a significant impact on life satisfaction and should be considered in assessment and treatment protocols.info:eu-repo/semantics/publishedVersio

    European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30: factorial models to Brazilian cancer patients

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    Objective To evaluate the psychometric properties of the seven theoretical models proposed in the literature for European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30), when applied to a sample of Brazilian cancer patients. Methods Content and construct validity (factorial, convergent, discriminant) were estimated. Confirmatory factor analysis was performed. Convergent validity was analyzed using the average variance extracted. Discriminant validity was analyzed using correlational analysis. Internal consistency and composite reliability were used to assess the reliability of instrument. Results A total of 1,020 cancer patients participated. The mean age was 53.3±13.0 years, and 62% were female. All models showed adequate factorial validity for the study sample. Convergent and discriminant validities and the reliability were compromised in all of the models for all of the single items referring to symptoms, as well as for the "physical function" and "cognitive function" factors. Conclusion All theoretical models assessed in this study presented adequate factorial validity when applied to Brazilian cancer patients. The choice of the best model for use in research and/or clinical protocols should be centered on the purpose and underlying theory of each model.FAPESPinfo:eu-repo/semantics/publishedVersio

    Estolides Synthesis Catalyzed by Immobilized Lipases

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    Estolides are vegetable-oil-based lubricants obtained from oleic acid or any source of hydroxy fatty acids. In this work, the estolides synthesis from oleic acid and methyl ricinoleate (biodiesel from castor oil), using immobilized commercial lipases (Novozym 435, Lipozyme RM-IM, and Lipozyme TL-IM) in a solvent-free medium was investigated. Acid value was used to monitor the reaction progress by determining the consumption of acid present in the medium. Novozym 435 showed the best performance. Water removal improved the conversion. Novozym 435 was more active at atmospheric pressure. Novozym 435 was reused four times with conversion reaching 15% after the fourth reaction at 80°C. Estolides produced under the reaction conditions used in this work presented good properties, such as, low temperature properties as pour point (−24°C), viscosity (23.9 cSt at 40°C and 5.2 cSt at 100°C), and viscosity index (153)

    Social Appearance Anxiety Scale: A psychometric investigation and evaluation of the influence of individual characteristics on social appearance anxiety in Brazilian adults who practice physical exercise

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    fntroduction: Evaluating signs of anxiety related to body appearance is becoming increasingly important in contemporary society and, in this sense, the Social Appearance Anxiety Scale (SAAS) seems an interesting alternative of measurement. Objectives: To evaluate the psychometric properties of the Portuguese version of the SAAS when applied to Brazilian adults who practice physical exercise and verify the influence of individual characteristics on participants’ social appearance anxiety. Methods: This was a cross-sectional study conducted online. The participants completed the SAAS and a demographic questionnaire. The psychometric properties of the SAAS one-factor model were evaluated using confirmatory factor analysis. A structural model was built for men and women to verify the influence of individual characteristics of the participants on social appearance anxiety. Results: 1,495 individuals participated in the study (70.8% women; mean age  =  29.5, SD  =  8.9  years). The data obtained with the SAAS presented good indicators of validity and reliability for both genders (CFI  >  0.97, TLI  >  0.97, SRMR  =  0.04, α  >  0.97, ω  >  0.85). For both men and women, greater levels of social appearance anxiety were observed among younger participants, who had a higher body mass index, self-reported an eating disorder, and perceived a change in their body after the onset of the COVID-19 pandemic. For women specifically, higher income and having started physical exercise more recently were associated with greater levels of social appearance anxiety. Conclusion: The findings supported the validity and reliability of the data obtained with the SAAS and revealed that when investigating social appearance anxiety in uture research and clinical protocols, specific individual characteristics should be considered.info:eu-repo/semantics/publishedVersio
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