184 research outputs found
Lepton Flavor Violation and Collider Searches in a Type I + II Seesaw Model
Neutrino are massless in the Standard Model. The most popular mechanism to
generate neutrino masses are the type I and type II seesaw, where right-handed
neutrinos and a scalar triplet are augmented to the Standard Model,
respectively. In this work, we discuss a model where a type I + II seesaw
mechanism naturally arises via spontaneous symmetry breaking of an enlarged
gauge group. Lepton flavor violation is a common feature in such setup and for
this reason, we compute the model contribution to the
and decays. Moreover, we explore the connection between
the neutrino mass ordering and lepton flavor violation in perspective with the
LHC, HL-LHC and HE-LHC sensitivities to the doubly charged scalar stemming from
the Higgs triplet. Our results explicitly show the importance of searching for
signs of lepton flavor violation in collider and muon decays. The conclusion
about which probe yields stronger bounds depends strongly on the mass ordering
adopted, the absolute neutrino masses and which much decay one considers. In
the 1-5 TeV mass region of the doubly charged scalar, lepton flavor violation
experiments and colliders offer orthogonal and complementary probes. Thus if a
signal is observed in one of the two new physics searches, the other will be
able to assess whether it stems from a seesaw framework.Comment: 41 pages, 1 figure, 2 table
Stationary solutions for the parity-even sector of the CPT-even and Lorentz-covariance-violating term of the standard model extension
In this work, we focus on some properties of the parity-even sector of the
CPT-even electrodynamics of the standard model extension. We analyze how the
six non-birefringent terms belonging to this sector modify the static and
stationary classical solutions of the usual Maxwell theory. We observe that the
parity-even terms do not couple the electric and magnetic sectors (at least in
the stationary regime). The Green's method is used to obtain solutions for the
field strengths E and B at first order in the Lorentz- covariance-violating
parameters. Explicit solutions are attained for point-like and spatially
extended sources, for which a dipolar expansion is achieved. Finally, it is
presented an Earth-based experiment that can lead (in principle) to an upper
bound on the anisotropic coefficients as stringent as
Comment: 8 pages, revtex style, revised published version, to appear in EPJC
(2009
The RNA-binding protein hnRNP K mediates the effect of BDNF on dendritic mRNA metabolism and regulates synaptic NMDA receptors in hippocampal neurons
Brain-derived neurotrophic factor (BDNF) is an important mediator of long-term synaptic potentiation (LTP) in the hippocampus. The local effects of BDNF depend on the activation of translation activity, which requires the delivery of transcripts to the synapse. In this work, we found that neuronal activity regulates the dendritic localization of the RNA-binding protein heterogeneous nuclear ribonucleoprotein K (hnRNP K) in cultured rat hippocampal neurons by stimulating BDNF-Trk signaling. Microarray experiments identified a large number of transcripts that are coimmunoprecipitated with hnRNP K, and about 60% of these transcripts are dissociated from the protein upon stimulation of rat hippocampal neurons with BDNF. In vivo studies also showed a role for TrkB signaling in the dissociation of transcripts from hnRNP K upon high-frequency stimulation (HFS) of medial perforant path-granule cell synapses of male rat dentate gyrus (DG). Furthermore, treatment of rat hippocampal synaptoneurosomes with BDNF decreased the coimmunoprecipitation of hnRNP K with mRNAs coding for glutamate receptor subunits, Ca2+- and calmodulin-dependent protein kinase IIβ (CaMKIIβ) and BDNF. Downregulation of hnRNP K impaired the BDNF-induced enhancement of NMDA receptor (NMDAR)-mediated mEPSC, and similar results were obtained upon inhibition of protein synthesis with cycloheximide. The results demonstrate that BDNF regulates specific populations of hnRNP-associated mRNAs in neuronal dendrites and suggests an important role of hnRNP K in BDNF-dependent forms of synaptic plasticity.publishe
Bone mineral density and body composition in postmenopausal women with psoriasis and psoriatic arthritis
Introduction: the aim of the present study was to compare bone mineral density (BMD) and body composition (BC) measurements as well as identify risk factors for low BMD and osteoporotic fractures in postmenopausal women with psoriasis (Ps) and psoriatic arthritis (PsA).Methods: A cross-sectional study was carried out in 45 PsA women, 52 Ps women and 98 healthy female controls (HC). Clinical risk factors for low bone density and osteoporotic fracture were evaluated by a specific questionnaire. An X-ray absorptiometry (DXA) at the lumbar spine, total femur and total body was performed on all patients. Skin and joint outcomes were measured by specific tools (PASI, HAQ and DAS28). Morphometric vertebral fractures were evaluated by lumbar and thoracic spine X-ray, according to Genant's method.Results: There were no significant differences in age, body mass index (BMI), total lean mass and bone mineral density among the groups. However, the PsA group had a significantly higher body fat percentage (BF%) than the Ps and HC groups. Osteoporotic fractures were more frequently observed in PsA and Ps groups than in the HC group (P = 0.01). Recurrent falls and a longer duration of disease increased the risk of fracture (odds ratio (OR) = 18.3 and 1.08, respectively) in the PsA group (P = 0.02). Disability was the main factor related to osteoporotic fracture in the Ps group (odds ratio (OR) = 11.1) (P = 0.02).Conclusions: Ps and PsA patients did not present lower BMD. However, they had a higher prevalence of osteoporotic fractures and higher risk of metabolic syndrome. Patients with a longer duration of disease, disability and recurrent falls need preventive measures.Rheumatology Division at UNIFESP/EPMUniversidade Federal de São Paulo, UNIFESP Paulista Sch Med, Div Rheumatol, EPM, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, UNIFESP Paulista Sch Med, Div Rheumatol, EPM, BR-04023900 São Paulo, BrazilWeb of Scienc
Foreign direct investment and institutional reform : evidence and an application to Portugal
We examine the role of geographic, economic, and institutional factors in attracting Foreign Direct Investment (FDI) in Europe, using a cross-section of inward bilateral investments. We estimate and assess the expected benefits, the required reform efforts, and the efficiency of reform options corresponding to a con- vergence of Portuguese institutions to EU standards. We conclude that improving home institutions is likely to have a quantitatively very significant role in attracting FDI. Geographical and market size factors also play a role. Reforms promoting the independence of financial institutions and a leaner bureaucracy, lowering political risk and corruption, and improving the investment code may significantly affect the amount of bilateral inward FDI that is targeted to Portugal.info:eu-repo/semantics/publishedVersio
Socioeconomic inequalities in the use of outpatient services in Brazil according to health care need: evidence from the World Health Survey
<p>Abstract</p> <p>Background</p> <p>The Brazilian health system is founded on the principle of equity, meaning provision of equal care for equal needs. However, little is known about the impact of health policies in narrowing socioeconomic health inequalities. Using data from the Brazilian World Health Survey, this paper addresses socioeconomic inequalities in the use of outpatient services according to intensity of need.</p> <p>Methods</p> <p>A three-stage cluster sampling was used to select 5000 adults (18 years and over). The non-response rate was 24.7% and calibration of the natural expansion factors was necessary to obtain the demographic structure of the Brazilian population. Utilization was established by use of outpatient services in the 12 months prior to the interview. Socioeconomic inequalities were analyzed by logistic regression models using years of schooling and private health insurance as independent variables, and controlling by age and sex. Effects of the socioeconomic variables on health services utilization were further analyzed according to self-rated health (good, fair and poor), considered as an indicator of intensity of health care need.</p> <p>Results</p> <p>Among the 5000 respondents, 63.4% used an outpatient service in the year preceding the survey. The association of health services utilization and self-rated health was significant (p < 0.001). Regarding socioeconomic inequalities, the less educated used health services less frequently, despite presenting worse health conditions. Highly significant effects were found for both socioeconomic variables, years of schooling (p < 0.001) and private health insurance (p < 0.00), after controlling for age and sex. Stratifying by self-rated health, the effects of both socioeconomic variables were significant among those with good health status, but not statistically significant among those with poor self-rated health.</p> <p>Conclusions</p> <p>The analysis showed that the social gradient in outpatient services utilization decreases as the need is more intense. Among individuals with good self-rated health, possible explanations for the inequality are the lower use of preventive services and unequal supply of health services among the socially disadvantaged groups, or excessive use of health services by the wealthy. On the other hand, our results indicate an adequate performance of the Brazilian health system in narrowing socioeconomic inequalities in health in the most serious situations of need.</p
Hospitalizações por condições cardiovasculares sensÃveis à atenção primária em municÃpios goianos
Influence of Ecto-Nucleoside Triphosphate Diphosphohydrolase Activity on Trypanosoma cruzi Infectivity and Virulence
The protozoan Trypanosoma cruzi is the causative agent of Chagas disease, an endemic zoonosis present in some countries of South and Central Americas. The World Health Organization estimates that 100 million people are at risk of acquiring this disease. The infection affects mainly muscle tissues in the heart and digestive tract. There are no vaccines or effective treatment, especially in the chronic phase when most patients are diagnosed, which makes a strong case for the development of new drugs to treat the disease. In this work we evaluate a family of proteins called Ecto-Nucleoside-Triphosphate-Diphosphohydrolase (Ecto-NTPDase) as new chemotherapy target to block T. cruzi infection in mammalian cells and in mice. We have used inhibitors and antibodies against this protein and demonstrated that T. cruzi Ecto-NTPDases act as facilitators of infection in mammalian cells and virulence factors in mice model. Two of the drugs used in this study (Suramin and Gadolinium) are currently used for other diseases in humans, supporting the possibility of their use in the treatment of Chagas disease
Comparação do acesso aos serviços de saúde bucal em áreas cobertas e não cobertas pela Estratégia Saúde da FamÃlia em Campina Grande, ParaÃba, Brasil
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