Studies of respiration rate of dairy bull spermatozoa

Publication authorized October 12, 1942Digitized 2007 AES.Includes bibliographical references (pages 22-24)

VIVÊNCIAS DO ESTÁGIO EM DOCÊNCIA NO ENSINO DE CIÊNCIAS: RELATO DE EXPERIÊNCIA SOB O OLHAR DE UMA MESTRANDA

The objective of this article is to describe and analyze the pedagogical activities developed during the Teaching Internship discipline of the Postgraduate Program in Education and Science Teaching in the Amazon, which is experienced in the discipline of Natural Sciences in Early Childhood Education and in the Early Years of the Elementary School. The internship methodology was based on autonomy, criticality and protagonism. The contents were developed through an expository dialogue, guided study of texts, construction of syntheses and records, analysis of documents, production of texts and systematization of class discussions. Through this activity, it was noticed the organization and creativity of academics, as well as the maturation to relate the contents with social, political, economic and cultural issues. The teaching internship provides enriching experiences, both practical and intellectual, becoming indispensable experiences in the formation of the future master in Science Education in the Amazon.El propósito de este artículo es describir y analizar las actividades pedagógicas desarrolladas durante la disciplina de Pasantía de Docente en el Programa de Posgrado en Educación y Enseñanza de las Ciencias en la Amazonía, que tiene experiencia en la disciplina de Ciencias Naturales en la Educación Infantil y en los Primeros Años de la Escuela Primaria. La metodología de la pasantía se basó en la autonomía, la criticidad y el protagonismo. Os conteúdos foram desenvolvidos através de aula expositiva dialogada, estudo dirigido de textos, construção de sínteses e fichamentos, análise de documentos, produção de textos e sistematização de discussões de aulas. A través de esta actividad, se notó la organización y creatividad de los académicos, así como la maduración para relacionar los contenidos con temas sociales, políticos, económicos y culturales. La pasantía docente brinda experiencias enriquecedoras, tanto prácticas como intelectuales, convirtiéndose en experiencias indispensables en la formación del futuro maestro en Educación Científica en la Amazonía.O objetivo deste artigo é descrever e analisar as atividades pedagógicas desenvolvidas durante a disciplina de Estágio de Docência do Programa de Pós-Graduação em Educação e Ensino de Ciências na Amazônia, sendo esta vivenciada na disciplina Ciências da Natureza na Educação Infantil e nos Anos Iniciais do Ensino Fundamental. A metodologia do estágio fundamentou-se na autonomia, criticidade e protagonismo. Os conteúdos foram desenvolvidos através de aula expositiva dialogada, estudo dirigido de textos, construção de sínteses e fichamentos, análise de documentos, produção de textos e sistematização de discussões de aulas. Através dessa atividade, percebeu-se a organização e a criatividade dos acadêmicos, bem como a maturação para relacionar os conteúdos com questões sociais, políticas, econômicas e culturais. O estágio de docência proporciona experiências enriquecedoras, tanto práticas quanto intelectuais, transformando-se em vivências indispensáveis na formação do futuro mestre em Educação em Ciências na Amazônia

The route of priming influences the ability of respiratory virus–specific memory CD8+ T cells to be activated by residual antigen

After respiratory virus infections, memory CD8+ T cells are maintained in the lung airways by a process of continual recruitment. Previous studies have suggested that this process is controlled, at least in the initial weeks after virus clearance, by residual antigen in the lung-draining mediastinal lymph nodes (MLNs). We used mouse models of influenza and parainfluenza virus infection to show that intranasally (i.n.) primed memory CD8+ T cells possess a unique ability to be reactivated by residual antigen in the MLN compared with intraperitoneally (i.p.) primed CD8+ T cells, resulting in the preferential recruitment of i.n.-primed memory CD8+ T cells to the lung airways. Furthermore, we demonstrate that the inability of i.p.-primed memory CD8+ T cells to access residual antigen can be corrected by a subsequent i.n. virus infection. Thus, two independent factors, initial CD8+ T cell priming in the MLN and prolonged presentation of residual antigen in the MLN, are required to maintain large numbers of antigen-specific memory CD8+ T cells in the lung airways

Timescales of transformational climate change adaptation in sub-Saharan African agriculture

Climate change is projected to constitute a significant threat to food security if no adaptation actions are taken. Transformation of agricultural systems, for example switching crop types or moving out of agriculture, is projected to be necessary in some cases. However, little attention has been paid to the timing of these transformations. Here, we develop a temporal uncertainty framework using the CMIP5 ensemble to assess when and where cultivation of key crops in sub-Saharan Africa becomes unviable. We report potential transformational changes for all major crops during the twenty-first century, as climates shift and areas become unsuitable. For most crops, however, transformation is limited to small pockets (<15% of area), and only for beans, maize and banana is transformation more widespread (â 1/430% area for maize and banana, 60% for beans). We envisage three overlapping adaptation phases to enable projected transformational changes: an incremental adaptation phase focused on improvements to crops and management, a preparatory phase that establishes appropriate policies and enabling environments, and a transformational adaptation phase in which farmers substitute crops, explore alternative livelihoods strategies, or relocate. To best align policies with production triggers for no-regret actions, monitoring capacities to track farming systems as well as climate are needed

Measurement of WγW\gamma and ZγZ\gamma Production in ppˉp\bar{p} Collisions at s\sqrt{s} = 1.96 TeV

The Standard Model predictions for $W\gamma$ and $Z\gamma$ production are tested using an integrated luminosity of 200 pb$^{-1}$ of \ppbar collision data collected at the Collider Detector at Fermilab. The cross sections are measured selecting leptonic decays of the $W$ and $Z$ bosons, and photons with transverse energy $E_T>7$ GeV that are well separated from leptons. The production cross sections and kinematic distributions for the $W\gamma$ and $Z\gamma$ are compared to SM predictions.Comment: 7 pages, 4 figures, submitted to PR

Measurement of the Lifetime Difference Between B_s Mass Eigenstates

We present measurements of the lifetimes and polarization amplitudes for B_s --> J/psi phi and B_d --> J/psi K*0 decays. Lifetimes of the heavy (H) and light (L) mass eigenstates in the B_s system are separately measured for the first time by determining the relative contributions of amplitudes with definite CP as a function of the decay time. Using 203 +/- 15 B_s decays, we obtain tau_L = (1.05 +{0.16}/-{0.13} +/- 0.02) ps and tau_H = (2.07 +{0.58}/-{0.46} +/- 0.03) ps. Expressed in terms of the difference DeltaGamma_s and average Gamma_s, of the decay rates of the two eigenstates, the results are DeltaGamma_s/Gamma_s = (65 +{25}/-{33} +/- 1)%, and DeltaGamma_s = (0.47 +{0.19}/-{0.24} +/- 0.01) inverse ps.Comment: 8 pages, 3 figures, 2 tables; as published in Physical Review Letters on 16 March 2005; revisions are for length and typesetting only, no changes in results or conclusion

Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s}=1.96 TeV using Lepton + Jets Events with Secondary Vertex b-tagging

We present a measurement of the ttbar production cross section using events with one charged lepton and jets from ppbar collisions at a center-of-mass energy of 1.96 TeV. In these events, heavy flavor quarks from top quark decay are identified with a secondary vertex tagging algorithm. From 162 pb-1 of data collected by the Collider Detector at Fermilab, a total of 48 candidate events are selected, where 13.5 +- 1.8 events are expected from background contributions. We measure a ttbar production cross section of 5.6^{+1.2}_{-1.1} (stat.) ^{+0.9}_{0.6} (syst.) pb.Comment: 28 pages, 20 figures. Published in Physical Review

Search for ZZ and ZW Production in ppbar Collisions at sqrt(s) = 1.96 TeV

We present a search for ZZ and ZW vector boson pair production in ppbar collisions at sqrt(s) = 1.96 TeV using the leptonic decay channels ZZ --> ll nu nu, ZZ --> l l l' l' and ZW --> l l l' nu. In a data sample corresponding to an integrated luminosity of 194 pb-1 collected with the Collider Detector at Fermilab, 3 candidate events are found with an expected background of 1.0 +/- 0.2 events. We set a 95% confidence level upper limit of 15.2 pb on the cross section for ZZ plus ZW production, compared to the standard model prediction of 5.0 +/- 0.4 pb.Comment: 7 pages, 2 figures. This version is accepted for publication by Phys. Rev. D Rapid Communication

Measurement of the Cross Section for Prompt Diphoton Production in p-pbar Collisions at sqrt(s) = 1.96 TeV

We report a measurement of the rate of prompt diphoton production in $p\bar{p}$ collisions at $\sqrt{s}=1.96 ~\hbox{TeV}$ using a data sample of 207 pb$^{-1}$ collected with the upgraded Collider Detector at Fermilab (CDF II). The background from non-prompt sources is determined using a statistical method based on differences in the electromagnetic showers. The cross section is measured as a function of the diphoton mass, the transverse momentum of the diphoton system, and the azimuthal angle between the two photons and is found to be consistent with perturbative QCD predictions.Comment: 7 pages, 3 figures,revtex4. Version accepted by PRL, but with cross section tables i

Measurement of the W+W- production cross section in p(p)over-bar collisions at root s=1.96 TeV using dilepton events

We present a measurement of the W+W- production cross section using 184 pb(-1) of p (p) over bar collisions at a center-of-mass energy of 1.96 TeV collected with the Collider Detector at Fermilab. Using the dilepton decay channel W+W-&RARR; l(+)ν l(-)(ν) over bar, where the charged leptons can be either electrons or muons, we find 17 candidate events compared to an expected background of 5.0(-0.8)(+2.2) events. The resulting W+W- production cross-section measurement of σ(p (p) over bar &RARR; W+W-)=14.6(-5.1)(+5.8)(stat)(-3.0)(+1.8)(syst)&PLUSMN; 0.9(lum) pb agrees well with the standard model expectation