84 research outputs found
Viscous dark fluid Universe: a unified model of the dark sector?
The Universe is modeled as consisting of pressureless baryonic matter and a
bulk viscous fluid which is supposed to represent a unified description of the
dark sector. In the homogeneous and isotropic background the \textit{total}
energy density of this mixture behaves as a generalized Chaplygin gas. The
perturbations of this energy density are intrinsically nonadiabatic and source
relative entropy perturbations. The resulting baryonic matter power spectrum is
shown to be compatible with the 2dFGRS and SDSS (DR7) data. A joint statistical
analysis, using also Hubble-function and supernovae Ia data, shows that,
different from other studies, there exists a maximum in the probability
distribution for a negative present value of the deceleration parameter.
Moreover, the unified model presented here favors a matter content that is of
the order of the baryonic matter abundance suggested by big-bang
nucleosynthesis. A problem of simple bulk viscous models, however, is the
behavior of the gravitational potential and the reproduction of the CMB power
spectrum.Comment: 12 pages, 3 figures, contributed paper to 8th Friedmann Seminar, 30
May to 3 June 2011, Rio de Janeiro, Brazi
Roland Morris disability questionnaire adaptation and validation for the Portuguese speaking patients with back pain
O objectivo do presente estudo foi adaptar e validar para a língua portuguesa o Roland
Morris Disability Questionnaire (RMDQ) por não existirem escalas em Português Euro-
peu para avaliar o grau de incapacidade dos doentes com lombalgias. Após os procedi-
mentos de tradução e retroversão, a versão portuguesa do RMDQ foi testada em 112
doentes com lombalgias (30 homens e 82 mulheres), a fim de analisar as suas característi-
cas psicométricas. A análise da fidelidade das medidas indica que o RMDQ apresenta
níveis elevados de consistência interna (
α
de Cronbach: 0,81) e de estabilidade temporal
(correlação teste-reteste: 0,86). A validade externa foi avaliada através da convergência
com resultados obtidos através da Escala Numérica de Dor (END), do Teste de Schober
(TS) e do grau de flexão anterior da coluna (GFA). Os resultados revelaram uma correlação
elevada entre o RMDQ e o END (r = 0,73) e uma correlação moderada com o TS e o GFA
(respectivamente, r = -0,52 e r = 0,42). A análise psicométrica mostrou, assim, que o RMDQ
fornece medidas fiáveis e válidas de incapacidade para o doente com lombalgia, encontrando-se assim adaptado e validado para os doentes portugueses
Attachment orientations and family functioning: The mediating role of emotion regulation.
Attachment insecurity has been found to be associated with poor family functioning. The mechanisms underlying this link, however, are less explored. This study examines the potential mediating role of emotion regulation in the association between attachment orientations and family functioning. Self-report scales measuring attachment, family functioning, and emotion regulation were administered to 132 adults (58% women; 57.63 years). Results showed that both attachment anxiety and attachment avoidance were associated with poor family functioning. Furthermore, emotion suppression, but not positive reappraisal, was found to partially mediate the association between attachment insecurity (both anxiety and avoidance) and perceived family functioning. Findings suggest that emotion regulation seems to play a role in the impact that attachment orientations may have on family functioning.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio
Emotion goals, emotion regulation, and mental health: A mediational hypothesis
Objective
Until recently, studies have focused their attention on the different ways individuals regulate their emotions. What remains to be known are the reasons underlying individuals’ emotion regulation choices and their consequences. In this cross-sectional study, we aimed to provide preliminary evidence on individual differences in how emotion goals, emotion regulation strategy choice, and individuals’ mental health are associated.
Method
A sample of 400 Portuguese adults from the community was used.
Results
Pro-hedonic goals were associated with the use of less suppression, more emotion communication, and more positive reappraisal, which in turn were associated with better mental health. Contra-hedonic goals were associated with the use of more suppression and less positive reappraisal, which in turn were associated with worse mental health. Finally, impression management goals were associated with the use of more suppression and more rumination, and less emotion communication, which in turn were associated with worse mental health.
Conclusions
Overall, our findings seem to suggest that emotion goals are linked to individuals’ mental health via emotion regulation strategies.
KEY POINTS
What is already known about this topic:
(1) Emotion regulation has important implications for the individuals’ psychological well-being.
(2) Emotion goals are likely to influence emotion regulation strategy choice.
(3) Emotion goals seem to influence individual’s psychological well-being.
What this topic adds:
(1) Pro-hedonic goals were associated with the use of less suppression, more emotion communication, and more positive reappraisal which in turn were associated with better mental health.
(2) Contra-hedonic goals were linked to depression and anxiety via the use of more suppression and less positive reappraisal.
(3) Impression management goals were linked to depression, anxiety, and stress via the use of more suppression, more rumination, and less emotion communication.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio
Sophorolipids: A review on production and perspectives of application in agriculture
Sophorolipids are bioactive molecules that have gained a lot of attention in the recent decades due to their unique functional properties of reducing surface and interfacial tension, emulsification and solubilization. They are mainly produced by the yeast Candida bombicola and are composed of a sugar moiety linked to a fatty acid chain. Sophorolipids are non-toxic, highly efficient and stable at extreme conditions and possess environmentally friendly characteristics over the chemical surfactants. This review is focused on the main characteristics of sophorolipids, fermentation processes, and their utilization in the agricultural field. In this context, sophorolipids are very suitable for use in agriculture, as enhancers of solubility and mobility of plant nutrients, which could result in increased plant biomass, root size and fruit yield. In addition, they could be used for biodegradation of oils, bioremediation of heavy metals in contaminated soils, and as potential biopesticides, to control phytopathogenic microorganisms in agriculture. The extensive use of chemical pesticides has led to widespread insecticide resistance and to hazards to human health and the environment due to their high toxicity. Thus, the introduction of a new biomolecule to control plant diseases and increase crop yield has become an interesting alternative. As a result of the demonstrated antimicrobial activity towards phytopathogenic bacteria and fungi, sophorolipids could be extensively explored in the agriculture field, as a sustainable and natural multifunctional agent for plant crops and soils
Cirugía menor y mayor ambulatoria
El objetivo del trabajo es generar un equipo homógeneo y coordinado para el tratamiento de la Hernia Inguinal en forma ambulatoria en un hospital público de la provincia de Buenos Aires.Facultad de Ciencias Médica
Effect of Hibiscus sabdariffa L. Dried Calyx Ethanol Extract on Fat Absorption-Excretion, and Body Weight Implication in Rats
The effect of Hibiscus sabdariffa L. (Hs) calyx extract on fat absorption-excretion and body weight in rats, was investigated. Rats were fed with either a basal diet (SDC = Control diet) or the same diet supplemented with Hs extracts at 5%, 10% and 15% (SD5, SD10
and SD15). Only SD5
did not show significant increases in weight, food consumption and efficiency compared to SDC. The opposite occurred in SD15
group which showed a significant decrease for these three parameters. The SD10
responses were similar to SD15, with the exception of food consumption. In both SDC
and SD5
groups, no body weight loss was observed; however, only in the latter group was there a significantly greater amount of fatty acids found in feces. A collateral effect emerging from the study is that components of Hs extract at the intermediate and greater concentrations used in this experiment could be considered possible antiobesity agents
Novel Perspectives in Management of Angiogenesis and Cancer Therapy
Funding: The project was funded by IPOLFG EPE and by iNOVA4Health (UID/Multi/04462/2019) a program financially supported by Fundação para a Ciência e Tecnologia (FCT)/Ministério da Educação e Ciência, through national funds. We also acknowledge funding from FCT-MCTES through the project DREAM—PTDC/MEC-ONC/29327/2017. FL-C PhD fellowship was funded by FCT (PD/BD/128337/2017).The activation of endothelial cells (ECs) is a crucial step on the road map of tumor angiogenesis and expanding evidence indicates that a pro-oxidant tumor microenvironment, conditioned by cancer metabolic rewiring, is a relevant controller of this process. Herein, we investigated the contribution of oxidative stress-induced ferroptosis to ECs activation. Moreover, we also addressed the anti-angiogenic effect of Propranolol. We observed that a ferroptosis-like mechanism, induced by xCT inhibition with Erastin, at a non-lethal level, promoted features of ECs activation, such as proliferation, migration and vessel-like structures formation, concomitantly with the depletion of reduced glutathione (GSH) and increased levels of oxidative stress and lipid peroxides. Additionally, this ferroptosis-like mechanism promoted vascular endothelial cadherin (VE-cadherin) junctional gaps and potentiated cancer cell adhesion to ECs and transendothelial migration. Propranolol was able to revert Erastin-dependent activation of ECs and increased levels of hydrogen sulfide (H2S) underlie the mechanism of action of Propranolol. Furthermore, we tested a dual-effect therapy by promoting ECs stability with Propranolol and boosting oxidative stress to induce cancer cell death with a nanoformulation comprising selenium-containing chrysin (SeChry) encapsulated in a fourth generation polyurea dendrimer (SeChry@PUREG4). Our data showed that novel developments in cancer treatment may rely on multi-targeting strategies focusing on nanoformulations for a safer induction of cancer cell death, taking advantage of tumor vasculature stabilization.publishersversionpublishe
Polaron effects in electron channels on a helium film
Using the Feynman path-integral formalism we study the polaron effects in
quantum wires above a liquid helium film. The electron interacts with
two-dimensional (2D) surface phonons, i.e. ripplons, and is confined in one
dimension (1D) by an harmonic potential. The obtained results are valid for
arbitrary temperature (), electron-phonon coupling strength (), and
lateral confinement (). Analytical and numerical results are
obtained for limiting cases of , , and . We found the
surprising result that reducing the electron motion from 2D to quasi-1D makes
the self-trapping transition more continuous.Comment: 6 pages, 7 figures, submitted to Phys. Rev.
Quantum field theory approach to the optical conductivity of strained and deformed graphene
The computation of the optical conductivity of strained and deformed graphene is discussed within the framework of quantum field theory in curved spaces. The analytical solutions of the Dirac equation in an arbitrary static background geometry for one dimensional periodic deformations are computed, together with the corresponding Dirac propagator. Analytical expressions are given for the optical conductivity of strained and deformed graphene associated with both intra and interbrand transitions. The special case of small deformations is discussed and the result compared to the prediction of the tight-binding model.The authors acknowledge financial supportfrom the Brazilian agencies FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) and CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico)
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