Winds, B-Fields, and Magnetotails of Pulsars

We investigate the emission of rotating magnetized neutron stars due to the acceleration and radiation of particles in the relativistic wind and in the magnetotail of the star. We consider that the charged particles are accelerated by driven collisionless reconnection. Outside of the light cylinder, the star's rotation acts to wind up the magnetic field to form a predominantly azimuthal, slowly decreasing with distance, magnetic field of opposite polarity on either side of the equatorial plane normal to the star's rotation axis. The magnetic field annihilates across the equatorial plane with the magnetic energy going to accelerate the charged particles to relativistic energies. For a typical supersonically moving pulsar, the star's wind extends outward to the standoff distance with the interstellar medium. At larger distances, the power output of pulsar's wind $\dot{E}_w$ of electromagnetic field and relativistic particles is {\it redirected and collimated into the magnetotail} of the star. In the magnetotail it is proposed that equipartition is reached between the magnetic energy and the relativistic particle energy. For such conditions, synchrotron radiation from the magnetotails may be a significant fraction of $\dot{E}_w$ for high velocity pulsars. An equation is derived for the radius of the magnetotail $r_m(z^\prime)$ as a function of distance $z^\prime$ from the star. For large distances $z^\prime$, of the order of the distance travelled by the star, we argue that the magnetotail has a `trumpet' shape owing to the slowing down of the magnetotail flow.Comment: 11 pages, 4 figures, accepted for publication in Ap

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

Avaliação da sequência rápida de intubação em pronto-socorro pediátrico

OBJETIVOS: Descrever a experiência do pronto-socorro de um hospital pediátrico com a sequência rápida de intubação e detectar os fatores associados ao sucesso. MÉTODOS: Estudo prospectivo transversal observacional de julho de 2005 a dezembro de 2007, de coleta de dados das intubações traqueais realizadas no pronto-socorro do Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Foi considerada intubação traqueal com sucesso aquela realizada na primeira tentativa. RESULTADOS: Foram realizadas 117 intubações traqueais, 80% sob sequência rápida de intubação; 79% eram portadores de doenças de base; a insuficiência respiratória aguda foi a causa da intubação traqueal em 40%; a taxa de sucesso foi de 39%; o residente de pediatria do segundo ano foi o responsável por 74% das intubações traqueais; foi realizada ventilação com pressão positiva em 74% dos procedimentos, sendo menor a sua utilização entre os pacientes que foram intubados com sucesso (p = 0,002). Midazolam foi o sedativo utilizado em 80% dos procedimentos, e rocurônio foi o bloqueador neuromuscular em 100%; complicações decorrentes da sequência rápida de intubação foram descritas em 80%, sendo a queda da saturação de oxigênio relatada em 47% e menor nos pacientes intubados com sucesso (p < 0,001); dificuldades relativas à intubação traqueal foram menos relatadas nos procedimentos com sucesso (p < 0,001). CONCLUSÃO: A sequência rápida de intubação foi o método de escolha nas intubações traqueais realizadas no pronto-socorro (80%) e demonstrou ser um método seguro e com baixa incidência de complicações graves, apesar de ter apresentado baixa taxa de sucesso (39%) neste estudo. O sucesso da intubação traqueal com sequência rápida de intubação parece estar diretamente relacionado ao preparo adequado do procedimento e experiência do profissional, podendo-se concluir que é necessário maior treinamento dos residentes e dos assistentes envolvidos no atendimento de emergência

International safety assessment of pesticides: Dithiocarbamate pesticides, ETU, and PTU - A review and update

For the last 30 years the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) has carried out toxicological evaluations and safety assessments of dithiocarbamate pesticides, continuously adjusting previous appraisals in the light of new data and advances in the understanding of the principles and mechanisms of toxic action of these compounds. The historical narrative of the evaluative process is followed by an account of the present international safety assessment status of the dithiocarbamate pesticides so far examined by the JMPR. They are ferbam, mancozeb, maneb, metiram, nabam, propineb, thiram, zineb, ziram, and the associated substances, ethylenethiourea (ETU) and propylenethiourea (PTU). (C) 1996 Wiley-Liss, Inc.15631333