Effect of Finite Mass on Primordial Nucleosynthesis

We have calculated the small effect of finite nucleon mass on the weak-interaction rates that interconvert protons and neutrons in the early Universe. We have modified the standard code for primordial nucleosynthesis to include these corrections and find a small, systematic increase in the 4He yield, $\delta Y / Y \simeq (0.47 - 0.50)$, depending slightly on the baryon-to-photon ratio. The fractional changes in the abundances of the other light elements are a few percent or less for interesting values of the baryon-to-photon ratio.Comment: 15 pages, 8 figures, uses psfig.st

Precision Prediction for the Big-Bang Abundance of Primordial Helium

Within the standard models of particle physics and cosmology we have calculated the big-bang prediction for the primordial abundance of \he to a theoretical uncertainty of less than 0.1 \pct $(\delta Y_P < \pm 0.0002)$, improving the current theoretical precision by a factor of 10. At this accuracy the uncertainty in the abundance is dominated by the experimental uncertainty in the neutron mean lifetime, $\tau_n = 885.4 \pm 2.0 sec$. The following physical effects were included in the calculation: the zero and finite-temperature radiative, Coulomb and finite-nucleon-mass corrections to the weak rates; order-$\alpha$ quantum-electrodynamic correction to the plasma density, electron mass, and neutrino temperature; and incomplete neutrino decoupling. New results for the finite-temperature radiative correction and the QED plasma correction were used. In addition, we wrote a new and independent nucleosynthesis code designed to control numerical errors to be less than 0.1\pct. Our predictions for the \EL[4]{He} abundance are presented in the form of an accurate fitting formula. Summarizing our work in one number, $Y_P(\eta = 5\times 10^{-10}) = 0.2462 \pm 0.0004 (expt) \pm < 0.0002 (theory)$. Further, the baryon density inferred from the Burles-Tytler determination of the primordial D abundance, $\Omega_B h^2 = 0.019\pm 0.001$, leads to the prediction: $Y_P = 0.2464 \pm 0.0005 (D/H) \pm < 0.0002 (theory) \pm 0.0005 (expt)$. This ``prediction'' and an accurate measurement of the primeval \he abundance will allow an important consistency test of primordial nucleosynthesis.Comment: Replaced fitting formulas - new versions differ by small but significant amount. Other minor changes. 30 pages, 17 figures, 5 table

Bird-spiders (Arachnida, Mygalomorphae) as perceived by the inhabitants of the village of Pedra Branca, Bahia State, Brazil

This paper deals with the conceptions, knowledge and attitudes of the inhabitants of the county of Pedra Branca, Bahia State, on mygalomorph spiders locally known as 'caranguejeiras' (bird-spiders). It is launched here a new filed within ethnozoology: ethnoarachnology, which is defined as the transdisciplinary study of the relationships between human beings and bird-spiders. Data were collected from February to June 2005 by means of open-ended interviews carried out with 30 individuals, which ages ranged from 13 to 86 years old. It was recorded some traditional knowledge regarding the following items: taxonomy, biology, habitat, ecology, seasonality, and behavior. Results show that bird-spiders are classified as "insects". The most commented aspect of the interaction between bird-spiders and inhabitants of Pedra Branca is related to their dangerousness, since they said these spiders are very venomous and can cause health problems. In general, the traditional zoological knowledge of Pedra Branca's inhabitants concerning these spiders is coherent with the academic knowledge

Parental smoking patterns and their association with wheezing in children

OBJECTIVE: To investigate parental smoking patterns and their association with wheezing in children. METHODS: We performed a case-control study that included 105 children between 6 and 23 months of age who were divided into two groups: cases (children with 3 previous episodes of wheezing) and controls (healthy children without wheezing). The children's exposure to cigarette smoking was estimated using a questionnaire completed by the mothers and by the children's urinary cotinine levels. RESULTS: Based on both the questionnaire results and cotinine levels, exposure to cigarette smoking was higher in the households of cases in which the incidence of maternal smoking was significantly higher than that of paternal smoking. Children in this group were more affected by maternal smoking and by the total number of cigarettes smoked inside the house. Additionally, the questionnaire results indicated that the risk of wheezing was dose dependent. The presence of allergic components, such as atopic dermatitis and siblings with allergic rhinitis and asthma, greatly increased the odds ratio when wheezing was associated with cotinine levels. CONCLUSION: Children exposed to tobacco smoke have an increased risk of developing wheezing syndrome. This risk increases in association with the number of cigarettes smoked inside the house and the presence of other allergic components in the family

Mortality in a pediatric secondary-care hospital in post-conflict Liberia in 2009

To describe and analyze the causes of death in a pediatric secondary-care hospital (run by Médecins sans Frontières), in Monrovia, Liberia, 6 years post-civil war, to determine the quality of care and mortality in a setting with limited resources

High-fidelity simulation versus case-based discussion for teaching medical students in Brazil about pediatric emergencies

OBJECTIVE: To compare high-fidelity simulation with case-based discussion for teaching medical students about pediatric emergencies, as assessed by a knowledge post-test, a knowledge retention test and a survey of satisfaction with the method. METHODS: This was a non-randomized controlled study using a crossover design for the methods, as well as multiple-choice questionnaire tests and a satisfaction survey. Final-year medical students were allocated into two groups: group 1 participated in an anaphylaxis simulation and a discussion of a supraventricular tachycardia case, and conversely, group 2 participated in a discussion of an anaphylaxis case and a supraventricular tachycardia simulation. Students were tested on each theme at the end of their rotation (post-test) and 4-6 months later (retention test). RESULTS: Most students (108, or 66.3%) completed all of the tests. The mean scores for simulation versus case-based discussion were respectively 43.6% versus 46.6% for the anaphylaxis pre-test (p =0.42), 63.5% versus 67.8% for the post-test (p =0.13) and 61.5% versus 65.5% for the retention test (p =0.19). Additionally, the mean scores were respectively 33.9% versus 31.6% for the supraventricular tachycardia pre-test (p =0.44), 42.5% versus 47.7% for the post-test (p =0.09) and 41.5% versus 39.5% for the retention test (p =0.47). For both themes, there was improvement between the pre-test and the post-test (p 0.05). Moreover, the satisfaction survey revealed a preference for simulation (p <0.001). CONCLUSION: As a single intervention, simulation is not significantly different from case-based discussion in terms of acquisition and retention of knowledge but is superior in terms of student satisfaction

Absceso hepático de origen hematogénico en paciente con fiebre de origen indeterminado

OBJETIVO: Descrever uma apresentação atípica de abscesso hepático em paciente pediátrico e realizar uma revisão da literatura no que diz respeito às diferenças observadas na etiopatogenia do quadro, quando considerados os países desenvolvidos e aqueles em desenvolvimento. DESCRIÇÃO DO CASO: Paciente de 13 anos, do sexo masculino, foi trazido ao pronto-socorro pediátrico devido à febre diária e à perda de peso, sem alterações ao exame físico. Na investigação realizada, o ultrassom abdominal evidenciou área heterogênea nodulariforme relativamente definida, compatível com abscesso hepático. Foi realizada drenagem cirúrgica e antibioticoterapia. No material da drenagem houve crescimento de Staphylococcus aureus sensível à oxacilina. COMENTÁRIOS: O caso demonstra a importância de o pediatra conhecer as principais causas da febre de origem indeterminada, saber desenvolver a abordagem investigativa e, frente ao diagnóstico de abscesso hepático, aferir a possibilidade de o agente etiológico ser o Staphylococcus aureus, principalmente quando houver relato de rotura da pele

Management of metastatic cutaneous melanoma: updates in clinical practice

In recent years, several drugs have been approved for the treatment of patients with metastatic cutaneous melanoma, completely reshaping the landscape of this aggressive disease. Immune therapy with cytotoxic T-lymphocyte antigen 4 and programmed cell death-1 inhibitors yielded significant and durable responses, achieving long-term disease control in up to 40% of the patients. BRAF inhibitors (BRAFi), in combination with MEK inhibitors, also resulted in improved overall survival compared with single-agent BRAFi in patients with BRAFV600 -mutated metastatic melanoma. The optimized sequencing and duration of treatment, however, is yet to be found. In this article, we thoroughly review current data and discuss how to best sequence the various treatment modalities available at present, based on four distinct clinical presentations commonly seen in clinic. In addition, we review treatment options beyond checkpoint inhibitors and targeted therapy, which may be required by patients failing such effective treatments