601 research outputs found
Multiplicity of 2-nodal solutions the Yamabe equation
Given any closed Riemannian manifold , we use the gradient flow
method and Sign-Changing Critical Point Theory to prove multiplicity results
for 2-nodal solutions of a subcritical Yamabe type equation on . If
is a closed Riemannian manifold of constant positive scalar curvature
our result gives multiplicity results for the type Yamabe equation on the
Riemannian product , for small
Rapid weight gain, infant feeding practices, and subsequent body mass index trajectories: The calina study
We aimed to study growth patterns according to rapid weight gain (RWG) and infant feeding practices during the first 120 days and whether infant feeding practices mediated the association between RWG in the first semester of life and subsequent body mass index (BMI) z-score in children from age 1 to 6. (1) Methods: 862 children from the Growth and Feeding during Lactation and Early Childhood in Children of Aragon study (CALINA in Spanish) were examined. Repeated-measures ANOVA analyses were conducted to assess growth trajectories according to RWG and type of feeding practice. The product of coefficients mediation method was used to assess the potential contribution of infant feeding practices to the association between RWG and BMI z-score. Mediation models were conducted using IBM SPSS-PROCESS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp. (2) Results: BMI and weight z-score trajectories were significantly higher in the RWG group and the formula-fed group. No significant differences were found regarding height. Infant feeding practices did not mediate the association between RWG and BMI z-score but were associated with BMI at 6 years. (3) Conclusions: Infant feeding practices and RWG determine different growth trajectories of BMI and weight during childhood. Although infant feeding practices did not mediate the association between early RWG and BMI later in life, formula feeding is independently related to higher BMI growth patterns later in childhood
Self- but not other-mentalizing moderates the association between BPD symptoms and somatic complaints in community-dwelling adolescents
Acord transformatiu CRUE-CSICObjectives: The aim of this study was to evaluate the potential moderator role of poor mentalization in the association between borderline personality disorder (BPD) traits and somatization, specifically focusing on the polarities of self- and other-mentalizing. Design: This is a cross-sectional, general population study evaluating adolescents (n = 162, 61.3% female; ages 12-18, M = 14.63, SD = 1.02). The relationship between BPD traits and somatization was evaluated with self-mentalization (attention to emotions and clarity of emotions) and other-mentalizing as moderator variables. Methods: One hundred sixty-two adolescents without serious mental health disorders were evaluated using self-report measures for borderline personality disorder traits (screening questionnaire for the Structured Clinical Interview for DSM-IV Personality Disorders (SCID-II), somatic symptoms using the Somatic Symptoms Questionnaire (SSQ), self-mentalizing using the Trait Meta-Mood Scale-24 (TMMS) and other-mentalizing using the Adolescent Mentalizing Interview (AMI)). Linear regressions were conducted to test the moderation effects of self- and other-mentalizing in the relationship between BPD symptoms and somatic complaints, controlling for age and sex. Moderation analysis was conducted using PROCESS version 3.5. Results: The association between BPD symptoms and somatic complaints was moderated by a self-mentalizing dimension (emotional clarity) (b = −0.019, 95% CI = −0.0379 to −0.0002, p =.0476), but not other-mentalizing (b = 0.027, 95% CI = 0.000 to 0.053, p =.051). The effect of BPD symptoms on somatization disappears when emotional clarity is high, regardless the level of attention to emotions. Conclusions: Self-mentalizing appears to be an adaptive skill as it attenuates the relationship between BPD traits and somatization. Specifically, emotional clarity rather than simple attention to emotions is the aspect of self-mentalizing attenuating this association. These results support that self-mentalization is an important function in the management of body-associated emotions even in non-clinical levels of BPD traits. Findings suggest that strengthening self-mentalizing skills across development might contribute to resilience and salutogenesis
Imaging the Electrocyte of Torpedo Marmorata by Scanning Force Microscopy
Scanning force microscopy (SFM) and scanning electron microscopy (SEM) were used to examine the tissue structure of the electric organ of Torpedo marmorata in air and in liquid after applying fracturing and cryosectioning techniques and chemical fixation. The electric organ is organized in columns of stacked electrocytes, arranged in a honeycomb pattern. The columns were cut along a plane normal to the cell stack and thin sections were transferred to polylysine coated glass coverslips. The polarity of the electrocytes was made apparent by immunofluorescence microscopy directed to different domains of the acetylcholine receptor (AChR), thus revealing the innervated face of the cell. SFM and SEM both showed cell surfaces to be overlaid by a network of collagen fibers by their characteristic banding pattern with about 64 nm periodicity and about 2.5 nm corrugation amplitude. In liquid, significantly lower structural resolution was achieved by SFM, probably due to sample elasticity
Desempenho ambiental e eficiência energética do óleo de pinhão-manso, pela abordagem da avaliação do ciclo de vida.
Resumo: A sociedade vem buscando cada vez mais fontes renováveis de energia para substituição dos combustíveis fósseis, devido ao seu inevitável esgotamento futuro e à sua contribuição ao fenômeno do aquecimento global. Em função disso, o incentivo para a produção de combustíveis de base vegetal cresceu no Brasil, merecendo atenção, dentre as culturas oleaginosas, o pinhão-manso (Jatropha curcas L.), conhecido por sua elevada produção de óleo, alta rusticidade e adaptabilidade a condições de solo e clima nos quais a produção de alimentos é impraticável. Visando o desenvolvimento de tal cultura para a produção de biodiesel, os seus impactos ambientais potenciais devem ser analisados. No presente trabalho, diferentes eficiências de produção de grãos e óleo de pinhão-manso e diferentes opções de aproveitamento de resíduos foram estudados, por meio da metodologia de Avaliação do Ciclo que Vida (ACV), buscando-se identificar as alternativas mais sustentáveis para esta cadeia produtiva. No que se refere à Demanda Cumulativa de Energia e às Mudanças Climáticas, a produtividade agrícola e a eficiência da extração de óleo foram determinantes para o bom desempenho do sistema. O cenário de aproveitamento de resíduos mais favorável foi o que empregou resíduos agrícolas e industriais em substituição aos fertilizantes. Abstract: The seek for renewable energy sources to replace fossil fuels, due to its inevitable future depletion and its contribution to the global warming phenomenon, is a worldwide pursuit. As a result, the incentive for the production of plant-based fuels expanded in Brazil, deserving attention, among oilseed crops, the jatropha (Jatropha curcas L.), known for its high oil yield, high rusticity and adaptability to conditions of soil and climate in which food production is impracticable. Aiming at the development of the jatropha crop for the production of biodiesel, its potential environmental impacts should be evaluated. In this study, efficiency of jatropha grain production and of oil production, and options for reuse of the residues were evaluated, using the methodology of Life Cycle Assessment (LCA), seeking to identify more sustainable alternatives to this production chain. Concerning the impact categories of Cumulative Energy Demand and Climate Change, the crop yield and the efficiency of oil extraction were crucial to the performance of the whole system. Considering the reuse of residues, the scenario where the agricultural and industrial residues were used to replace fertilizers shown to be more favorable
Resolution of complex fluorescence spectra of lipids and nicotinic acetylcholine receptor by multivariate analysis reveals protein-mediated effects on the receptor's immediate lipid microenvironment
Analysis of fluorescent spectra from complex biological systems containing various fluorescent probes with overlapping emission bands is a challenging task. Valuable information can be extracted from the full spectra, however, by using multivariate analysis (MA) of measurements at different wavelengths. We applied MA to spectral data of purified Torpedo nicotinic acetylcholine receptor (AChR) protein reconstituted into liposomes made up of dioleoylphosphatidic acid (DOPA) and dioleoylphosphatidylcholine (DOPC) doped with two extrinsic fluorescent probes (NBD-cholesterol/pyrene-PC). Förster resonance energy transfer (FRET) was observed between the protein and pyrene-PC and between pyrene-PC and NBD-cholesterol, leading to overlapping emission bands. Partial least squares analysis was applied to fluorescence spectra of pyrene-PC in liposomes with different DOPC/DOPA ratios, generating a model that was tested by an internal validation (leave-one-out cross-validation) and was further used to predict the apparent lipid molar ratio in AChR-containing samples. The values predicted for DOPA, the lipid with the highest Tm, indicate that the protein exerts a rigidifying effect on its lipid microenvironment. A similar conclusion was reached from excimer formation of pyrene-PC, a collisional-dependent phenomenon. The excimer/monomer ratio (E/M) at different DOPC/DOPA molar ratios revealed the restricted diffusion of the probe in AChR-containing samples in comparison to pure lipid samples devoid of protein. FRET from the AChR (donor) to pyrene-PC (acceptor) as a function of temperature was found to increase with increasing temperature, suggesting a shorter distance between AChR and pyrene PC. Taken together, the results obtained by MA on complex spectra indicate that the AChR rigidifies its surrounding lipid and prefers DOPA rather than DOPC in its immediate microenvironment
Copper deposition on fabrics by rf plasma sputtering for medical applications
https://www.scopus.com/inward/record.url?eid=2-s2.0-84938151607&partnerID=40&md5=bf2da795caced442546f442aa330773aThe present work is about preparation and characterization of RF sputtered Cu films on cotton by the usage of a Magnetron Sputter Source and 99.995% purity Cu target at room temperature. Cotton fabric samples of 1, 2 and 4 min of sputtering time at discharge pressure of 1×10-2 Torr and distance between target and sample of 8 cm were used. The main goal was to qualitatively test the antimicrobial action of copper on fabrics. For that purpose, a reference strain of Escherichia Coli ATCC 35218 that were grown in TSA plates was implemented. Results indicated a decrease in the growth of bacteria by contact with Cu; for fabric samples with longer sputtering presented lower development of E. coli colonies. The scope of this research focused on using these new textiles in health field, for example socks can be made with this textile for the treatment of athlete's foot and the use in pajamas, sheets, pillow covers and robes in hospital setting for reducing the spread of microorganisms. © Published under licence by IOP Publishing Ltd.Ad Astra Rocket Company,Instituto Tecnologico de Costa Rica,International Atomic Energy Agency (IAEA),Universidad Nacional de Costa Ric
Cues guiding uloborid construction behavior support orb web monophyly
Behavior can provide useful traits for testing phylogenetic hypotheses, and some details of orb web construction behavior have been especially useful in characterizing higher-level groups in spiders. The cues used to guide construction behavior and behavioral responses to these cues hold similar promise, but have never been used in phylogenetic studies. Here we use several techniques to test the hypothesis that orb webs in the two major branches of orb-weaving araneomorph spiders (Araneoidea and Deinopoidea) are monophyletic, using both the cues that guide orb construction and the spiders’ responses to these cues. If orb webs evolved only once, the expectation is that these traits should be similar in members of both evolutionary lines. This prediction was supported: species in the two groups use several of the same cues, and respond to them in similar ways. These cues include two identical reference stimuli for positioning sticky spiral lines; supplies of silk available in their glands that affect the positioning of sticky spiral loops; and at least one stimulus related to the size of the available space for the orb, which is used to trigger similar modifications of seven independent orb design traits. Neither group used tension-related cues to guide sticky spiral placement. These comparisons reinforce previous conclusions supporting orb web monophyly that were derived from morphological, molecular, and behavioral traits.Smithsonian Tropical Research Institute, Panama, USAUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí
Avaliação do ciclo de vida da produção de algodão em dois sistemas de rotação de culturas.
Resumo: Os nanomateriais, por suas propriedades físico-químicas únicas, podem estabelecer interações imprevistas com substâncias naturalmente presentes nos componentes ambientais, fazendo-se indispensável a avaliação dos seus potenciais impactos ambientais. O objetivo deste trabalho foi avaliar a contribuição da fase agrícola da produção de algodão - matéria-prima para obtenção de nanomateriais ? no desempenho ambiental desta tecnologia. Consideraram-se dois sistemas de produção de algodão por plantio direto: em rotação com o milheto e em rotação com soja e capim Mombaça. O método adotado foi a Avaliação do Ciclo de Vida (ACV). Para ambos os sistemas, a fase mais impactante foi a produção agrícola de algodão, de modo que para o sistema em rotação com o milheto, maiores efeitos foram encontrados nas categorias de impacto de mudanças climáticas; ecotoxicidade aquática e terrestre; e toxicidade humana. Para o sistema em rotação com soja e capim, os impactos ambientais mais relevantes foram eutrofização de água doce e mudanças climáticas. Notou-se ainda que a soja, pelo fato de ser uma cultura beneficiada pelas bactérias fixadoras de nitrogênio, diminui o aporte de fertilizantes nitrogenados, reduzindo os impactos ambientais decorrentes da sua produção
Disclosure of cholesterol recognition motifs in transmembrane domains of the human nicotinic acetylcholine receptor
Cholesterol influences ion-channel function, distribution and clustering in the membrane, endocytosis, and exocytic sorting of the nicotinic acetylcholine receptor (AChR). We report the occurrence of a cholesterol recognition motif, here coined “CARC”, in the transmembrane regions of AChR subunits that bear extensive contact with the surrounding lipid, and are thus optimally suited to convey cholesterol-mediated signaling from the latter. Three cholesterol molecules could be docked on the transmembrane segments of each AChR subunit, rendering a total of 15 cholesterol molecules per AChR molecule. The CARC motifs contribute each with an energy of interaction between 35 and 52 kJ.mol−1, adding up to a total of about 200 kJ.mol−1 per receptor molecule, i.e. ∼40% of the lipid solvation free energy/ AChR molecule. The CARC motif is remarkably conserved along the phylogenetic scale, from prokaryotes to human, suggesting that it could be responsible for some of the above structural/functional properties of the AChR
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