833 research outputs found

    Palatini approach to 1/R gravity and its implications to the late Universe

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    By applying the Palatini approach to the 1/R-gravity model it is possible to explain the present accelerated expansion of the Universe. Investigation of the late Universe limiting case shows that: (i) due to the curvature effects the energy-momentum tensor of the matter field is not covariantly conserved; (ii) however, it is possible to reinterpret the curvature corrections as sources of the gravitational field, by defining a modified energy-momentum tensor; (iii) with the adoption of this modified energy-momentum tensor the Einstein's field equations are recovered with two main modifications: the first one is the weakening of the gravitational effects of matter whereas the second is the emergence of an effective varying "cosmological constant"; (iv) there is a transition in the evolution of the cosmic scale factor from a power-law scaling at11/18a\propto t^{11/18} to an asymptotically exponential scaling aexp(t)a\propto \exp(t); (v) the energy density of the matter field scales as ρm(1/a)36/11\rho_m\propto (1/a)^{36/11}; (vi) the present age of the Universe and the decelerated-accelerated transition redshift are smaller than the corresponding ones in the Λ\LambdaCDM model.Comment: 5 pages and 2 figures. Accepted in PR

    Template coexistence in prebiotic vesicle models

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    The coexistence of distinct templates is a common feature of the diverse proposals advanced to resolve the information crisis of prebiotic evolution. However, achieving robust template coexistence turned out to be such a difficult demand that only a class of models, the so-called package models, seems to have met it so far. Here we apply Wright's Island formulation of group selection to study the conditions for the coexistence of two distinct template types confined in packages (vesicles) of finite capacity. In particular, we show how selection acting at the level of the vesicles can neutralize the pressures towards the fixation of any one of the template types (random drift) and of the type with higher replication rate (deterministic competition). We give emphasis to the role of the distinct generation times of templates and vesicles as yet another obstacle to coexistence.Comment: 7 pages, 8 figure

    Effects of dietary lipids on renal function of aged rats

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    Normal aging is accompanied by renal functional and morphological deterioration and dietetic manipulation has been used to delay this age-related decline. We examined the effects of chronic administration of diets containing 5% lipid-enriched diet (LD, w/w) on renal function of rats at different ages. Three types of LD were tested: canola oil, fish oil and butter. Mean systemic tail-cuff blood pressure and glycemia remained within the normal range whatever the age and the diet of the animals. Proteinuria began to rise from the 8th month in the groups ingesting LD, while in the control group it increased significantly (above 10 mg/24 h) only after the 10th month. With age, a significant and progressive decline in glomerular filtration rate (GFR) and renal plasma flow was observed in the LD groups but after 6 months of lipid supplementation, the decline in these parameters was more marked in the butter and fish oil groups. By the 18th month, the lowest GFR level was observed in the group ingesting the butter diet (2.93 ± 0.22 vs 5.01 ± 0.21 ml min-1 kg-1 in control, P<0.05). Net acid excretion, evaluated in 9- and 18-month-old rats, was stimulated in the fish oil group when compared both to control and to the other two LD groups. These results suggest that even low levels of LD in a chronic nutritional regimen can modify the age-related changes in renal function and that the impact of different types of lipid-supplemented diets on renal function depends on the kind of lipid present in the diet.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Disciplina de Fisiologia Renal e TermometabologiaUNIFESP, EPM, Disciplina de Fisiologia Renal e TermometabologiaSciEL

    A Note on Energy-Momentum Conservation in Palatini Formulation of L(R) Gravity

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    By establishing that Palatini formulation of L(R)L(R) gravity is equivalent to ω=3/2\omega=-3/2 Brans-Dicke theory, we show that energy-momentum tensor is covariantly conserved in this type of modified gravity theory.Comment: 7 page

    Molecular typing and differences in biofilm formation and antibiotic susceptibilities among Prototheca strains isolated in Italy and Brazil.

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    Bovine mastitis caused by Prototheca is a serious and complex problem that accounts for high economic losses in the dairy industry. The main objective of this study was to identify and characterize at genetic level different Prototheca strains and provide the most complete data about protothecal antibiotic resistance. The study involves 46 isolates from Italian (13 strains) and Brazilian (33 strains) mastitic milk. These strains were identified by multiplex PCR and single strand conformation polymorphism analysis and characterized by randomly amplified polymorphic DNA (RAPD)-PCR. Moreover, biofilm production and antibiotic susceptibility were evaluated. Forty-two strains resulted as Prototheca zopfii genotype 2, whereas 4 isolates could belong to a potential new Prototheca species. The RAPD-PCR, performed with 3 primers (M13, OPA-4, and OPA-18), showed a notable heterogeneity among isolates and grouped the strains according to the species and geographical origin. Biofilm production was species-dependent and P. zopfii genotype 2 strains were classified as strong biofilm producers. In vitro antibiotic susceptibility tests indicated that Prototheca strains were susceptible to antibacterial drugs belonging to aminoglycosides group; the highest activity against Prototheca strains was observed in the case of colistin sulfate, gentamicin, and netilmicin (100% of susceptible strains). It is interesting to note that all the Italian P. zopfii genotype 2 strains showed lower minimum inhibitory concentration values than the Brazilian ones. Nisin showed more efficacy than lysozyme and potassium sorbate, inhibiting 31% of the strains. Results obtained in this study confirmed that RAPD-PCR is a rapid, inexpensive, and highly discriminating tool for Prototheca strains characterization and could give a good scientific contribution for better understanding the protothecal mastitis in dairy herd

    Towards the integration of urban sound planning in urban development processes: the study of four test sites within the SONORUS project

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    Noise pollution in urban environments is today a major problem affecting inhabitants of many European cities. Reducing noise is therefore a necessity. As a result, many cities now have noise action plans comprising concrete actions to tackle noise issues in affected areas. Nevertheless, these often isolated documents only address existing problems. In order to change this practice an integrated strategy is necessary. A new approach to urban sound planning, a holistic approach, is being developed and tested within the SONORUS project and it is described in this paper. SONORUS, the Urban Sound Planner project, is an initial training network (ITN) that is educating researchers in a whole range of acoustic disciplines, as well as in advanced urban planning processes. An essential part of this training is the application of the holistic approach to real test sites. Although this is an ongoing work, a few innovative techniques were already developed and its application to the test sites resulted in improved urban sound planning tools. This paper promotes the discussion about the implications that the holistic approach might have in urban sound planning policies and how it can be a driving force for changing the noise pollution situation in urban environment

    Healthcare Professionals' Views on the Management of Medication Complexities in the Elderly With Mental Health Disorders: A Cross-Sectional Study

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    Background: Many challenges in elderly pharmacotherapy are identified, including the use of Potentially Inappropriate Medications (PIMs) which may increase the odds of adverse events, especially in elderly patients with mental health disorders (e. g., behavioral, and psychological symptoms of dementia–BPSD, schizophrenia, bipolar disorder). However, information on the knowledge and practice of healthcare professionals (HCPs) about this topic is still scarce. Methods: A cross-sectional study was undertaken from July-October 2019. An online questionnaire was specifically designed and validated for this study. We sought HCPs (physicians, pharmacists, and nurses) worldwide, using (a) social media, via Facebook, Twitter, and LinkedIn; and (b) email contacts of the research team (convenience sample). Either way participants were asked to share on their social media or via e-mail the questionnaires with other HCPs (snowballing sample). The survey assessed two main domains: knowledge and practice. Knowledge was evaluated by self-report (perceived knowledge by a 5-item Likert confidence scale) and using three clinical cases, scored between 0 and 30 points (each one rated from 0 to 10 points; real knowledge). Barriers in clinical practice were evaluated using a 5-item Likert scale judging practitioners' opinion. Results: A total of 165 questionnaires were collected. HCPs were mainly female (n = 114; 69.1%), with a mean age of 35.3 ± 11.3 years old. Seventy-two percent (n = 118) were pharmacists, 21.1% (n = 35) were physicians, and 7.3% (n = 12) nurses. There was a weak correlation, albeit significant, between perceived and real knowledge (r = 0.199; p = 0.001). The mean score of the clinical vignettes regarding elderly patients with dementia and bipolar disorder were 4.59 ± 4.08 and 4.86 ± 2.97 points, respectively. Most HCPs were classified as having an intermediate knowledge (n = 100; 60.6%) about medication complexities in the elderly with mental disorders. Most HCPs agreed that lack of time (81.6%; n = 138), lack of education and training on elderly pharmacotherapy (72.2%; n = 122), and lack of tools adapted to daily practice (61.8%; n = 105) were the main barriers. Conclusions: Most of the HCPs felt confident to manage medication complexities in elder patients with mental disorders, but only a minority obtained a good score in the knowledge assessment test. The main barriers identified included structural barriers (tools unfit for practice) and process barriers (time)

    Access to infertility consultations: what women tell us about it?

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    The main objective of the present paper is to evaluate the perception of women concerning the barriers and access to infertility consultations. Socio cultural and economic access to infertility consultations is detached and three municipalities of the northwest of Portugal were chosen as an example of a peripheral country. A quantitative/qualitative study was done with 60 women. Three dimensions were evaluated: geographic and structural and functional access; economic access; and sociocultural access. The main barriers were mainly identified in the last two dimensions. The economic access was the less well evaluated by women being the cost of treatment (medication, and concentration of costs in a short period) difficult to bear. This can justify a greater involvement of the Portuguese Government, by developing policies for the reimbursement of part of the costs. Also, some changes in structural and functional access must be done with special regard to the separation of the infertility consultations from the reproductive medicine section. The setting of the teams, with a follow-up by the same team of health professionals is also needed

    Epidemiological situation of bovine brucellosis in the State of Bahia, Brazil

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    O trabalho consistiu em estratificar o Estado da Bahia em quatro regiões com características homogêneas (circuitos produtores) para que fossem amostradas aleatoriamente, em cada uma delas, 300 propriedades. Em cada propriedade foram escolhidas, de forma aleatória, 10 a 15 fêmeas bovinas adultas, das quais foi obtida uma amostra de sangue. No total, foram amostrados 10.816 animais, provenientes de 1.413 propriedades. O protocolo de testes utilizado foi o da triagem com o teste do antígeno acidificado tamponado (Rosa Bengala) e a confirmação dos positivos com o teste do 2-mercaptoetanol. O rebanho foi considerado positivo se pelo menos um animal reagiu às duas provas sorológicas. As prevalências de focos e a de fêmeas adultas soropositivas do Estado foram de 4,2% [3,1-5,3%] e 0,66% [0,41-0,93%], respectivamente. Para os circuitos produtores foram: circuito 1, 5,8% [3,6-8,7%] e 0,86% [0,41-1,3%]; circuito 2, 3,1% [1,5-5,6%] e 1,2% [0,25-2,1%]; circuito 3, 6,3% [4,0-9,3%] e 1,7% [0,66-2,7%]; e circuito 4, 0,60% [0,07-2,2%] e 0,07 [0,00-0,21%]. Para a análise de fatores de riscos associados à doença foi aplicado um questionário epidemiológico em cada propriedade visitada. Os fatores de risco (odds ratio, OR) associados à condição de foco foram: compra de reprodutores (OR= 2,27) e presença de áreas alagadiças (OR= 1,76). A vacinação de fêmeas de três até oito meses de idade foi um fator de proteção (OR= 0,53). ____________________________________________________________________________________________________________________ ABSTRACTA study to characterize the epidemiological situation of bovine brucellosis in the State of Bahia was carried out in 2004. The State was divided into four similar production regions, 300 herds were randomly sampled in each region, and 10 to 15 adult bovine females were sampled in each of these herds. A total of 10,816 serum samples from 1,413 herds were collected. The serum samples were screened for antibodies to Brucella spp. by the Rose-Bengal Test (RBT), and all RBT-positive sera were re-tested by the 2-mercaptoethanol test (2-ME) for confirmation. A herd was considered positive if at least one animal was positive on both RBT and 2-ME tests. The prevalence of infected herds and seropositive adult bovine females in Bahia State were: 4.2% [3.1-5.3%] and 0.66% [0.41-0.93%], respectively. In the production regions, prevalence of infected herds and animals were, respectively: region 1, 5.8% [3.6-8.7%] and 0.86% [0.41-1.3%]; region 2, 3.1% [1.5-5.6%] and 1.2% [0.25-2.1%]; region 3, 6.3% [4.0-9.3%] and 1.7% [0.66-2.7%]; and region 4, 0.60% [0.07-2.2%] and 0.07%[0.00-0.2%]. In each herd, an epidemiological questionnaire was applied. The risk factors (odds ratio, OR) associated with the presence of the infection were: purchase of breeding animals (OR = 2.27) and presence of flood areas (OR= 1.76). Vaccination of heifers from three to eight months of age was a protective factor (OR=0.53)
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