883 research outputs found
Poor youths and ‘pacification’:dilemmas between discourse and practice from the perspective of young people about policing in Rio de Janeiro’s favelas
An Examination of Morphometric Variations in a Neotropical Toad Population (Proceratophrys cristiceps, Amphibia, Anura, Cycloramphidae)
The species Proceratophrys cristiceps belongs to the genus Proceratophrys within the family Cycloramphidae. These amphibians are found exclusively in South America in the morphoclimatic domain of the semi-arid depression zones in northeastern Brazil known as the Caatinga. We examined intrapopulational variation using univariate and multivariate statistics with traditional and geometric morphometrics, which supported the existence of two morphotypes of this species. Our results indicated significant degrees of variation in skeletal characteristics between some natural populations of this species. Careful analyses of variability levels are fundamental to avoid taxonomic errors, principally in populations that demonstrate characteristics intimately associated with their area of occurrence, as is the case of Proceratophrys cristiceps
A Partitioned Finite Element Method for the Structure-Preserving Discretization of Damped Infinite-Dimensional Port-Hamiltonian Systems with Boundary Control
Many boundary controlled and observed Partial Differential Equations can be represented as port-Hamiltonian systems with dissipation, involving a Stokes-Dirac geometrical structure together with constitutive relations. The Partitioned Finite Element Method, introduced in Cardoso-Ribeiro et al. (2018), is a structure preserving numerical method which defines an underlying Dirac structure, and constitutive relations in weak form, leading to finite-dimensional port-Hamiltonian Differential Algebraic systems (pHDAE). Different types of dissipation are examined: internal damping, boundary damping and also diffusion models
B Cells Regulate Neutrophilia during Mycobacterium tuberculosis Infection and BCG Vaccination by Modulating the Interleukin-17 Response
We have previously demonstrated that B cells can shape the immune response to Mycobacterium tuberculosis, including the level of neutrophil infiltration and granulomatous inflammation at the site of infection. The present study examined the mechanisms by which B cells regulate the host neutrophilic response upon exposure to mycobacteria and how neutrophilia may influence vaccine efficacy. To address these questions, a murine aerosol infection tuberculosis (TB) model and an intradermal (ID) ear BCG immunization mouse model, involving both the μMT strain and B cell-depleted C57BL/6 mice, were used. IL (interleukin)-17 neutralization and neutrophil depletion experiments using these systems provide evidence that B cells can regulate neutrophilia by modulating the IL-17 response during M. tuberculosis infection and BCG immunization. Exuberant neutrophilia at the site of immunization in B cell-deficient mice adversely affects dendritic cell (DC) migration to the draining lymph nodes and attenuates the development of the vaccine-induced Th1 response. The results suggest that B cells are required for the development of optimal protective anti-TB immunity upon BCG vaccination by regulating the IL-17/neutrophilic response. Administration of sera derived from M. tuberculosis-infected C57BL/6 wild-type mice reverses the lung neutrophilia phenotype in tuberculous μMT mice. Together, these observations provide insight into the mechanisms by which B cells and humoral immunity modulate vaccine-induced Th1 response and regulate neutrophila during M. tuberculosis infection and BCG immunization. © 2013 Kozakiewicz et al
Consórcios de caupi e milho em cultivo orgânico para produção de grãos e espigas verdes.
No período de outono-inverno-primavera de 2007, foi conduzido um estudo em Seropédica, Região Metropolitana do estado do Rio de Janeiro (Baixada Fluminense), com o objetivo de avaliar diferentes tipos de consórcio entre caupi (cv. Mauá) e milho (cv. AG-1051), em sistema orgânico de produção. O experimento foi instalado em área de Argissolo Vermelho-Amarelo no delineamento de blocos ao acaso, com quatro repetições. Os tratamentos constaram de diferentes épocas ou intervalos de tempo de semeadura do caupi em relação à do milho, a saber: (E1) 21 dias antes do milho; (E2) 14 dias antes do milho; (E3) 7 dias antes do milho; e (E4) no mesmo dia do milho. Tratamentos correspondentes aos cultivos solteiros do caupi e do milho foram incluídos, ambos semeados na data do tratamento E4. O cultivo consorciado com o caupi não interferiu na produtividade do milho em espigas verdes e também em termos de comprimento e diâmetro basal dessas espigas, independentemente do intervalo entre semeaduras. Com referência ao caupi, a produtividade em grãos verdes no cultivo solteiro foi superior à dos consórcios com o milho. Os valores obtidos para os Índices de Equivalência de Área (IEA), foram todos acima de 1,0, indicando que os consórcios foram eficientes quanto ao desempenho agronômico/biológico. Considerando, ainda a produtividade de cada cultura participante do consórcio, a semeadura do caupi antecipada de 21 dias em relação à do milho afigura-se mais adequada ao manejo orgânico adotado e às condições edafoclimáticas da região
Neutrophils Reduce the Parasite Burden in Leishmania (Leishmania) amazonensis-Infected Macrophages
Background: Studies on the role of neutrophils in Leishmania infection were mainly performed with L. (L) major, whereas less information is available for L. (L) amazonensis. Previous results from our laboratory showed a large infiltrate of neutrophils in the site of infection in a mouse strain resistant to L. (L.) amazonensis (C3H/HePas). in contrast, the susceptible strain (BALB/c) displayed a predominance of macrophages harboring a high number of amastigotes and very few neutrophils. These findings led us to investigate the interaction of inflammatory neutrophils with L. (L.) amazonensis-infected macrophages in vitro.Methodology/Principal Findings: Mouse peritoneal macrophages infected with L. (L.) amazonensis were co-cultured with inflammatory neutrophils, and after four days, the infection was quantified microscopically. Data are representative of three experiments with similar results. the main findings were 1) intracellular parasites were efficiently destroyed in the co-cultures; 2) the leishmanicidal effect was similar when cells were obtained from mouse strains resistant (C3H/HePas) or susceptible (BALB/c) to L. (L.) amazonensis; 3) parasite destruction did not require contact between infected macrophages and neutrophils; 4) tumor necrosis factor alpha (TNF-alpha), neutrophil elastase and platelet activating factor (PAF) were involved with the leishmanicidal activity, and 5) destruction of the parasites did not depend on generation of oxygen or nitrogen radicals, indicating that parasite clearance did not involve the classical pathway of macrophage activation by TNF-alpha, as reported for other Leishmania species.Conclusions/Significance: the present results provide evidence that neutrophils in concert with macrophages play a previously unrecognized leishmanicidal effect on L. (L.) amazonensis. We believe these findings may help to understand the mechanisms involved in innate immunity in cutaneous infection by this Leishmania species.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilWeb of Scienc
Meson-Meson Scattering in the Quark Model: Spin Dependence and Exotic Channels
We apply a quark interchange model to spin-dependent and exotic meson-meson
scattering. The model includes the complete set of standard quark model forces,
including OGE spin-orbit and tensor and scalar confinement spin-orbit.
Scattering amplitudes derived assuming SHO and Coulomb plus linear plus
hyperfine meson wavefunctions are compared. In I=2 pi pi we find approximate
agreement with the S-wave phase shift from threshold to 1.5 GeV, where we
predict an extremum that is supported by the data. Near threshold we find rapid
energy dependence that may reconcile theoretical estimates of small scattering
lengths with experimental indications of larger ones based on extrapolation of
measurements at moderate kpi^2. In PsV scattering we find that the quark-quark
L*S and T forces map into L*S and T meson-meson interactions, and the P-wave
L*S force is large. Finally we consider scattering in J^PC-exotic channels, and
note that some of the Deck effect mechanisms suggested as possible nonresonant
origins of the pi_1(1400) signal are not viable in this model.Comment: 51 pages, 10 figures, uses epsf.sty epsfig.st
Ichthyofauna, fish supply and fishermen activities on the mid-Tocantins River, Maranhão State, Brazil
STUDY OF FIRE BEHAVIOR ON A PART OF SEMIDECIDUOUS SEASONAL FOREST IN VI\uc7OSA, MINAS GERAIS
O objetivo do presente estudo foi avaliar o comportamento do fogo em um
trecho de Floresta Estacional Semidec\ueddua, usando as
vari\ue1veis: intensidade do fogo, tempo de queima, material
combust\uedvel, poder calor\uedfico e calor liberado por \ue1rea.
Foram instaladas 10 parcelas de 5 x 5 m interdistantes em 1 m,
perfazendo um total de 250 m2, em um fragmento denominado
\u201cReserva da Biologia\u201d, pertencente \ue0 Universidade
Federal de Vi\ue7osa, Minas Gerais,
(20\uba35\u2019-28\uba50\u2019S e
42\uba45\u2019-43\uba00\u2019W) onde foi realizada a queima
controlada utilizando a t\ue9cnica do fogo a favor do vento,
obedecendo ao sentido do aclive. Determinouse a quantidade de
mat\ue9ria seca, velocidade de propaga\ue7\ue3o do fogo,
intensidade, calor liberado e poder calor\uedfico. O tempo de
dura\ue7\ue3o da queima variou entre as parcelas de
3\u201930\u201d a 9\u201918\u201d. A velocidade do vento,
temperatura e umidade relativa do ar no dia da queima permaneceram
constantes em todas as parcelas, apresentando valores de 3,5 m s-1
Norte, 20\ubaC e 79%, respectivamente. Os par\ue2metros do
comportamento do fogo variaram entre as parcelas em: 0,32 a 1,10 kg m-2
para material combust\uedvel, 11,94 a 75,79 Kcal s-1 m-1 para a
intensidade de queima e 1111 a 3789 Kcal m-2 para o calor liberado por
\ue1rea. Os valores m\ue9dios para velocidade de
propaga\ue7\ue3o e poder calor\uedfico foram 0,017 m s-1 e 4411
Kcal Kg-1, respectivamente. As condi\ue7\uf5es clim\ue1ticas de
Vi\ue7osa em 2005 foram at\uedpicas em rela\ue7\ue3o aos outros
anos, n\ue3o apresentando nenhum m\ueas seco. Esta
condi\ue7\ue3o interferiu nos par\ue2metros do comportamento do
fogo, fazendo com que a queima fosse classificada como de baixa
intensidade.The purpose of this study was to evaluate the fire behavior on a part
of Semideciduous Seasonal Forest, using the variables: fire intensity,
burning time, fuel, heat content and heat released. Ten plots of 5 by 5
meters were used , totalizing 250 m2, and the distance between each
plot was 1 meter in a place named \u201cReserva da Biologia\u201d
property of Universidade Federal de Vi\ue7osa, Minas Gerais,
(20\uba35\u2019-28\uba50\u2019S e
42\uba45\u2019-43\uba00\u2019W) . In this place a control burning
was performed using strip headfire technique, obeying the slope
direction. The amount of local dry matter, fire propagation velocity,
intensity, heat released and heat content were measured. The time
duration of the burning ranged between plots of 3\u201930 \u201cto
9\u201918\u201d. Wind velocity, temperature, relative humidity were
constant in all plots, with values 3, 5 m s-1 North, 20\uba C and 79%
respectively. The values found for fire behavior variables ranged
between plots: from 0, 32 to 1, and 10 Kg m-2 for fuel, from 11, 94 to
75,79 Kcals-1m-1 for burning intensity and from 1111 to 3789 Kcal m-2
for heat released. The average values for rate of spread and heat
released were 0,017 m s-1 and 4411 Kcal Kg-1, respectively. In the year
2005, the weather conditions were atypical comparing to another years
in Vi\ue7osa, witch in every month occurs a certain amount of rain.
This fact had interference in the fire behavior parameters, for that
reason the burning were classified as low intensity
INFLU\ucaNCIA DO FOGO NO BANCO DE SEMENTES DO SOLO EM FLORESTA ESTACIONAL SEMIDECIDUAL
This study was carried out in a fragment called "Reserva da Biologia",
which belongs to the Universidade Federal de Vi\ue7osa, in Minas
Gerais State, Brazil (20\ub035'-28\ub050'S e
42\ub045'-43\ub000'W), where 10 plots of 5 x 5 m plots, 1m away
from each other, were set up. A controlled burning was performed on the
plots, following the wind-driven fire technique, according to the slope
orientation. The objective was to characterize the soil seed of the
tree community before and after fire, in order to verify the effects of
such discontinuance on both population density and floristic
composition. In the centre of each plot, one 40 x 25 cm soil sampling
was collected, from the leaf litter downward 5cm deep. One day after
the soil sampling the plots underwent controlled burning. New soil
samplings were done immediately after burning, following the previous
methodology. It was counted 528 and 429 seedlings emerging from the
soil seed bank before and after the fire, respectively. Such plants
were of 23 species and 14 botanical families, from which
Melastomataceae, Asteraceae and Urticaceae stood out. There was no
meaningful reduction in the species richness or in the density of
individuals of the populations between both samplings. The floristic
similarity was 34 %. Miconia cinnamomifolia and Leandra purpurascens
were the most frequent/abundant species. Pioneer species stood out
making up 44 and 40 % of the species found in the area before and after
fire, respectively.Este estudo foi realizado no fragmento "Reserva da Biologia", situado
na Universidade Federal de Vi\ue7osa, Minas Gerais,
(20\ub035'-28\ub050'S e 42\ub045'-43\ub000'W) onde foram
instaladas 10 parcelas de 5 x 5 m interdistantes em 1 m. Foi realizada
uma queima controlada nas parcelas instaladas, utilizando a
t\ue9cnica do fogo a favor do vento, obedecendo ao sentido do aclive.
O objetivo foi caracterizar o banco de sementes do solo antes e depois
do fogo, para verificar os efeitos desse dist\ufarbio na densidade
das popula\ue7\uf5es e na composi\ue7\ue3o flor\uedstica da
comunidade vegetal. No centro de cada parcela foi coletada uma amostra
de solo de 40 x 25 cm, a partir da superf\uedcie da serapilheira
at\ue9 5 cm de profundidade. Um dia ap\uf3s a coleta das amostras
de solos as parcelas foram submetidas \ue0 queima controlada.
Imediatamente ap\uf3s a queima foram realizadas novas coletas de solo
seguindo a mesma metodologia adotada anteriormente. Foram obtidas 528 e
429 sementes germinadas das amostras do banco de sementes do solo antes
e ap\uf3s o fogo, respectivamente, pertencentes a 23 esp\ue9cies de
14 fam\uedlias bot\ue2nicas, sendo as mais representativas
Melastomataceae, Asteraceae e Urticaceae. Entre as duas amostragens
(antes e ap\uf3s o fogo) n\ue3o houve redu\ue7\ue3o
significativa da riqueza de esp\ue9cies e a similaridade
flor\uedstica foi de 34 %. Miconia cinnamomifolia e Leandra
purpurascens foram as esp\ue9cies mais abundantes nas duas
amostragens. As esp\ue9cies pioneiras se destacaram com 44 e 40 % das
esp\ue9cies presentes no banco de sementes antes e ap\uf3s o fogo,
respectivamente
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