1,184 research outputs found

    A gestão democrática via conselhos escolares: análise de experiências em Baturité

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    In the context of democracy, in neoliberal times, in Ceará, we focused this study on the democratization process of the Public School, starting from the School Council, working on the relationships between the different actors involved in the school context in terms of power sharing. We took the municipality of Baturité as the locus of investigation, working with two public schools in the state school system. For the appropriation of the educational reality of the Massif de Baturité, exploratory research was carried out to map the reality, starting from the regional view to the local view. In the Baturité scenario, a moment marked by euphoria and invitations to participate is affirmed. In this sense, driven by democratic winds, several public policy councils are created / revitalized.No âmbito da democracia, em tempos neoliberais, no Ceará, centramos esse estudo no processo de democratização da Escola Pública, a partir do Conselho Escolar, trabalhando as relações entre os diferentes atores envolvidos no contexto da escola em termos de partilha de poder. Tomamos como lócus de investigação o município de Baturité, trabalhando com duas escolas públicas da rede estadual de ensino. Para apropriação da realidade educacional do Maciço de Baturité, foi efetivado pesquisa exploratória de mapeamento da realidade, partindo da visão regional para o olhar local. Afirma-se, no cenário de Baturité, um momento marcado por uma euforia e convites à participação. Nesse sentido, levado pelos ventos democráticos, se dá a criação/revitalização de vários conselhos de políticas públicas

    Collapse of Turbulent Cores and Reconnection Diffusion

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    For a molecular cloud clump to form stars some transport of magnetic flux is required from the denser, inner regions to the outer regions of the cloud, otherwise this can prevent the collapse. Fast magnetic reconnection which takes place in the presence of turbulence can induce a process of reconnection diffusion (RD). Extending earlier numerical studies of reconnection diffusion in cylindrical clouds, we consider more realistic clouds with spherical gravitational potentials and also account for the effects of the gas self-gravity. We demonstrate that within our setup RD is efficient. We have also identified the conditions under which RD becomes strong enough to make an initially subcritical cloud clump supercritical and induce its collapse. Our results indicate that the formation of a supercritical core is regulated by a complex interplay between gravity, self-gravity, the magnetic field strength and nearly transonic and trans-Alfv\'enic turbulence, confirming that RD is able to remove magnetic flux from collapsing clumps, but only a few of them become nearly critical or supercritical, sub-Alfv\'enic cores, which is consistent with the observations. Besides, we have found that the supercritical cores built up in our simulations develop a predominantly helical magnetic field geometry which is also consistent with observations. Finally, we have evaluated the effective values of the turbulent reconnection diffusion coefficient and found that they are much larger than the numerical diffusion, especially for initially trans-Alfv\'enic clouds, ensuring that the detected magnetic flux removal is due to to the action of the RD rather than to numerical diffusivity.Comment: 24 pages, 18 figures, accepted for publication in the Ap

    JAK2 V617F Mutation Prevalence in Myeloproliferative Neoplasms in Pernambuco, Brazil

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Background: The JAK2 V617F mutation is associated with three myeloproliferative neoplasms (MPNs): polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). It generates an unregulated clonal hematopoietic progenitor and leads to abnormal increased proliferation of one or more myeloid lineages. Subjects bearing this mutation may present more frequently with complications such as thrombosis and bleeding, and no specific treatment has yet been developed for BCR-ABL-negative JAK2 V617F-negative MPNs. Aims: To determine the prevalence of JAK2 V617F in MPNs in Pernambuco, Brazil, and to compare it with previous studies. Material and Methods: 144 blood samples were collected at the Hospital of Hematology of the HEMOPE Foundation and were genotyped by polymerase chain reaction-restriction fragment length polymorphism with BsaXI enzymatic digestion. Results and Discussion: 88% (46/52) of the patients with PV, 47% (39/81) with ET, and 77% (8/11) with PMF were positive for JAK2 V617F, while more than 35% of the individuals were JAK2 V617F-negative, confirming a high prevalence of this abnormality in MPNs, more frequently with a low mutated allele burden, similar to what has been reported in other Western countries, despite differences among methods used to detect this mutation. Screening for JAK2 V617F may allow specific management of these diseases with JAK2 inhibitors in the future and highlights the need for further studies on the pathogenesis of BCR-ABL-negative JAK2 V617F-negative MPNs.167802805Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Ratio of the Isolated Photon Cross Sections at \sqrt{s} = 630 and 1800 GeV

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    The inclusive cross section for production of isolated photons has been measured in \pbarp collisions at s=630\sqrt{s} = 630 GeV with the \D0 detector at the Fermilab Tevatron Collider. The photons span a transverse energy (ETE_T) range from 7-49 GeV and have pseudorapidity η<2.5|\eta| < 2.5. This measurement is combined with to previous \D0 result at s=1800\sqrt{s} = 1800 GeV to form a ratio of the cross sections. Comparison of next-to-leading order QCD with the measured cross section at 630 GeV and ratio of cross sections show satisfactory agreement in most of the ETE_T range.Comment: 7 pages. Published in Phys. Rev. Lett. 87, 251805, (2001

    Limits on WWZ and WW\gamma couplings from p\bar{p}\to e\nu jj X events at \sqrt{s} = 1.8 TeV

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    We present limits on anomalous WWZ and WW-gamma couplings from a search for WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p -> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron Collider during the 1992-1995 run. The data sample corresponds to an integrated luminosity of 96.0+-5.1 pb^(-1). Assuming identical WWZ and WW-gamma coupling parameters, the 95% CL limits on the CP-conserving couplings are -0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also presented.Comment: 11 pages, 2 figures, 2 table

    Search for New Physics in e mu X Data at D0 Using Sleuth: A Quasi-Model-Independent Search Strategy for New Physics

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    We present a quasi-model-independent search for the physics responsible for electroweak symmetry breaking. We define final states to be studied, and construct a rule that identifies a set of relevant variables for any particular final state. A new algorithm ("Sleuth") searches for regions of excess in those variables and quantifies the significance of any detected excess. After demonstrating the sensitivity of the method, we apply it to the semi-inclusive channel e mu X collected in 108 pb^-1 of ppbar collisions at sqrt(s) = 1.8 TeV at the D0 experiment during 1992-1996 at the Fermilab Tevatron. We find no evidence of new high p_T physics in this sample.Comment: 23 pages, 12 figures. Submitted to Physical Review

    Search For Heavy Pointlike Dirac Monopoles

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    We have searched for central production of a pair of photons with high transverse energies in ppˉp\bar p collisions at s=1.8\sqrt{s} = 1.8 TeV using 70pb170 pb^{-1} of data collected with the D\O detector at the Fermilab Tevatron in 1994--1996. If they exist, virtual heavy pointlike Dirac monopoles could rescatter pairs of nearly real photons into this final state via a box diagram. We observe no excess of events above background, and set lower 95% C.L. limits of 610,870,or1580GeV/c2610, 870, or 1580 GeV/c^2 on the mass of a spin 0, 1/2, or 1 Dirac monopole.Comment: 12 pages, 4 figure

    The Dijet Mass Spectrum and a Search for Quark Compositeness in bar{p}p Collisions at sqrt{s} = 1.8 TeV

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    Using the DZero detector at the 1.8 TeV pbarp Fermilab Tevatron collider, we have measured the inclusive dijet mass spectrum in the central pseudorapidity region |eta_jet| < 1.0 for dijet masses greater than 200 Gev/c^2. We have also measured the ratio of spectra sigma(|eta_jet| < 0.5)/sigma(0.5 < |eta_jet| < 1.0). The order alpha_s^3 QCD predictions are in good agreement with the data and we rule out models of quark compositeness with a contact interaction scale < 2.4 TeV at the 95% confidence level.Comment: 11 pages, 4 figures, 2 tables, submitted to Phys. Rev. Let
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