5,639 research outputs found
Hyperconnectivity and Slow Synapses during Early Development of Medial Prefrontal Cortex in a Mouse Model for Mental Retardation and Autism
Neuronal theories of neurodevelopmental disorders (NDDs) of autism and mental retardation propose that abnormal connectivity underlies deficits in attentional processing. We tested this theory by studying unitary synaptic connections between layer 5 pyramidal neurons within medial prefrontal cortex (mPFC) networks in the Fmr1-KO mouse model for mental retardation and autism. In line with predictions from neurocognitive theory, we found that neighboring pyramidal neurons were hyperconnected during a critical period in early mPFC development. Surprisingly, excitatory synaptic connections between Fmr1-KO pyramidal neurons were significantly slower and failed to recover from short-term depression as quickly as wild type (WT) synapses. By 4-5 weeks of mPFC development, connectivity rates were identical for both KO and WT pyramidal neurons and synapse dynamics changed from depressing to facilitating responses with similar properties in both groups. We propose that the early alteration in connectivity and synaptic recovery are tightly linked: using a network model, we show that slower synapses are essential to counterbalance hyperconnectivity in order to maintain a dynamic range of excitatory activity. However, the slow synaptic time constants induce decreased responsiveness to low-frequency stimulation, which may explain deficits in integration and early information processing in attentional neuronal networks in NDD
Tissue response evaluation of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant
PURPOSE:To evaluate the tissue response of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant.METHODS:A total of 20 male guinea pigs were divided into 2 groups. After paracentesis in both ears, a biodegradable polymer of poly lactic-co-glycolic acid was implanted in only one middle ear. Histological analysis using neutrophil exudate and vascular neoformation (acute inflammation) and fibroblast proliferation and mononuclear inflammatory cells (chronic inflammation) as parameters was performed after 10 and 30 days of survival (groups 1 and 2, respectively).RESULTS:Four ears in group 1 and 7 in group 2 had an increase of neutrophil exudate. Vascular neoformation occurred in ears with or without the implant, in both groups. Fibroblast proliferation and mononuclear inflammatory cells (lymphocytes and macrophages) increased in ears with implant in group 2.CONCLUSION:The tissue response by histological analysis of the mucosa of the tympanic cavity of guinea pigs, when receiving biodegradable implant, showed no statistically significant difference between ears with or without the implant.Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Department of OtorhinolaryngologyFederal University of Minas Gerais Faculty of PharmacyFederal University of Minas GeraisUSP Faculty of Medicine of Ribeirao PretoUniversidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM) Department of Otorhinolaryngology and Head and Neck SurgeryFederal University of São PauloFederal University of São Paulo Medical SchoolUNIFESP, EPM, Department of OtorhinolaryngologyUNIFESP, EPM, Department of Otorhinolaryngology and Head and Neck SurgeryUNIFESP, Medical SchoolSciEL
Trabajo rural y las condiciones de salud de las familias del Movimiento Sin Tierra - MST y de trabajadores rurales temporales : el caso de Unaí, MG
Colaboração editorial da Faculdade de Ciência da Informação (FCI) da UnBEsse texto é baseado em um estudo comparativo sobre as condições de saúde das famílias do MST e dos bóias-frias de Unaí-MG com enfoque nas relações de trabalho, produção, segurança alimentar, organização política, acesso aos serviços e políticas públicas. Foram coletados dados por meio de questionários aplicados a 202 famílias, e realizadas observação estruturada e discussões em grupo. Serão destacados também os resultados do processo de apresentação e discussão dos dados analisados para as comunidades pesquisadas. Os trabalhadores bóias-frias apresentaram um alto índice de insegurança alimentar (39,5%) e estavam mais expostos aos agrotóxicos se comparados aos assentados e acampados. A grande maioria das famílias de boias-frias gostaria de mudar de ocupação e entre o que havia de pior no trabalho estava a hora de acordar e o deslocamento. Mais da metade das famílias do assentamento conseguia viver apenas da produção do lote e entre as famílias acampadas 22,1% conseguiam retirar seu sustento do lote. As famílias do MST têm maior dificuldade de acesso ao SUS, porem o fato de ser Sem Terra, estar organizado, melhora as perspectivas de sua saúde em comparação com os bóias-frias. A modernização conservadora no campo brasileiro têm agravado as condições de vida e trabalho dos bóias-frias, enquanto que a Reforma Agrária tem possibilitado uma melhor condição de vida e de saúde para as famílias, quando comparadas nas áreas estudadas. _______________________________________________________________________________________ ABSTRACTThis text is based on a comparative study of the health conditions of families from the MST (Landless Movement in Brazil) and temporary rural workers of Unaí-MG focusing on labor relations, production, food security, political organization, access to services and public policy. Data were collected through questionnaires given to 202 families, structured observation and group discussions. The paper also focuses on the presentation and discussion of data analyzed for the surveyed communities. There was a high rate of food insecurity (39.5%) among temporary rural workers and those were more exposed to pesticides compared to families who were in camps and in settlements. The vast majority of the temporary rural workers’ families said they would like to change their occupation, the worst job aspects being early time to wake up and displacement to work. Over half of the families in the settlement were able to live off the production of their plots of land and among camped families, 22.1% managed to sustain their food needs from the plots. The MST families have a more difficult access to SUS public health services, however the fact of being landless and organized improves the health prospects compared to rural workers. The conservative modernization of rural Brazil has worsened the living conditions and employment of migrant farmworkers, while the Agrarian Reform has allowed a better quality of life and health for families in comparative terms within the study area. _______________________________________________________________________________________ RESUMENEste texto describe un estudio comparativo sobre las condiciones de salud de las familias del MST y los trabajadores rurales temporales de Unaí-MG. El trabajo se centra en las relaciones laborales, producción, seguridad alimenticia, organización política, acceso a los servicios y políticas públicas. Los datos fueron recolectados por medio de una encuesta aplicada a 202 familias, la observación estructurada y discusiones de grupo. Se destacan también los resultados del proceso de la presentación y discusión de los datos analizados sobre las comunidades encuestadas. Los trabajadores rurales temporales tenían un alto índice de inseguridad alimenticia (39,5%) y estaban más expuestos a los pesticidas en comparación con las familias que vivían en los campamentos y los asentamientos rurales. La gran mayoría de las familias de los trabajadores rurales temporales desea cambiar de ocupación y entre lo que consideraron negativo en cuanto al trabajo fue la hora de levantarse y la hora de tomar el transporte. Más de la mitad de las familias de los asentamientos lograba vivir solamente de la producción de su pedazo de tierra y entre las familias del campamento 22,1% lograban tomar su sustento de su tierra. Las familias del MST aun tienen mayor dificultad de acceso al SUS. El hecho de pertenecer al Movimiento Sin Tierra y estar organizados, mejora las perspectivas de su salud en comparación a los trabajadores rurales temporales. La modernización conservadora del campo brasileño ha empeorado las condiciones de vida y trabajo de los trabajadores rurales temporales, mientras que la Reforma Agraria ha permitido mejor calidad de vida y salud para las familias, al compararlas en las diferentes áreas del estudio
Wide and deep near-UV (360nm) galaxy counts and the extragalactic background light with the Large Binocular Camera
Deep multicolour surveys are the main tool to explore the formation and
evolution of the faint galaxies which are beyond the spectroscopic limit with
the present technology. The photometric properties of these faint galaxies are
usually compared with current renditions of semianalytical models to provide
constraints on the fundamental physical processes involved in galaxy formation
and evolution, namely the mass assembly and the star formation. Galaxy counts
over large sky areas in the near-UV band are important because they are
difficult to obtain given the low efficiency of near-UV instrumentation, even
at 8m class telescopes. A large instrumental field of view helps in minimizing
the biases due to the cosmic variance. We have obtained deep images in the
360nm U band provided by the blue channel of the Large Binocular Camera at the
prime focus of the Large Binocular Telescope. We have derived over an area of
~0.4 sq. deg. the galaxy number counts down to U=27 in the Vega system
(corresponding to U=27.86 in the AB system) at a completeness level of 30%
reaching the faintest current limit for this wavelength and sky area. The shape
of the galaxy counts in the U band can be described by a double power-law, the
bright side being consistent with the shape of shallower surveys of comparable
or greater areas. The slope bends over significantly at U>23.5 ensuring the
convergence of the contribution by star forming galaxies to the EBL in the
near-UV band to a value which is more than 70% of the most recent upper limits
derived for this band. We have jointly compared our near-UV and K band counts
collected from the literature with few selected hierarchical CDM models
emphasizing critical issues in the physical description of the galaxy formation
and evolution.Comment: Accepted for publication in A&A. Uses aa.cls, 9 pages, 4 figures.
Citations update
Fitomassa de adubos verdes e controle de plantas daninhas em diferentes densidades populacionias de leguminosas.
O objetivo deste trabalho foi avaliar a fitomassa de calopogônio, mucuna-preta, mucunarajada,feijão-de-porco, guandu de porte alto, Crotalaria spectabilis e C. breviflora sob diferentes densidades de semeadura (10, 20, 40, 80 e 160 sementes viáveis m-2), e o crescimento de plantas daninhas nessas densidades, em área de tabuleiros costeiros. O experimento foi desenvolvido de maio a agosto de 1996, no Campo Experimental “Antônio Martins”(EMDAGRO/Embrapa-CPATC), em Lagarto, SE. O número de plantas vivas na floração (NPVF) e a matéria seca da parte aérea das leguminosas (MSPA) foram determinados quando, em cada espécie, cerca de 50% das plantas floresceram. Maiores incrementos de MSPA, em resposta ao adensamento populacional, foram observados em C. spectabilis e C. breviflora, seguidas pelo calopogônio, mucuna-preta e mucuna-rajada. Em relação ao feijão-de-porco, a resposta foi negativa, enquanto com o guandu não houve influência. Quanto ao NPVF, as respostas ao adensamento foram lineares e positivas em C. spectabilis, C. breviflora e calopogônio, e quadráticas com ponto de máxima em feijão-de-porco,guandu e mucuna-rajada. Embora nenhum modelo tenha sido ajustado para expressar a relação entre NPVF e adensamento na semeadura de mucuna-preta, a sobrevivência dessa espécie foi reduzida em todas as densidades. Maiores inibições
de plantas daninhas ocorreram nas parcelas de mucuna-preta e feijão-de-porco
UVES/VLT high resolution spectroscopy of GRB 050730 afterglow: probing the features of the GRB environment
We analyze high resolution spectroscopic observations of the optical
afterglow of GRB050730, obtained with UVES@VLT about hours after the GRB
trigger. The spectrum shows that the ISM of the GRB host galaxy at z = 3.967 is
complex, with at least five components contributing to the main absorption
system. We detect strong CII*, SiII*, OI* and FeII* fine structure absorption
lines associated to the second and third component. For the first three
components we derive information on the relative distance from the site of the
GRB explosion. Component 1, which has the highest redshift, does not present
any fine structure nor low ionization lines; it only shows very high ionization
features, such as CIV and OVI, suggesting that this component is very close to
the GRB site. From the analysis of low and high ionization lines and fine
structure lines, we find evidences that the distance of component 2 from the
site of the GRB explosion is 10-100 times smaller than that of component 3. We
evaluated the mean metallicity of the z=3.967 system obtaining values about
0.01 of the solar metallicity or less. However, this should not be taken as
representative of the circumburst medium, since the main contribution to the
hydrogen column density comes from the outer regions of the galaxy while that
of the other elements presumably comes from the ISM closer to the GRB site.
Furthermore, difficulties in evaluating dust depletion correction can modify
significantly these values. The mean [C/Fe] ratio agrees well with that
expected by single star-formation event models. Interestingly the [C/Fe] of
component 2 is smaller than that of component 3, in agreement with GRB dust
destruction scenarios, if component 2 is closer than component 3 to the GRB
site.Comment: 11 pages, 15 postscript figures, accepted for pubblication in A&
Cost-effectiveness of non-invasive methods for assessment and monitoring of liver fibrosis and cirrhosis in patients with chronic liver disease: systematic review and economic evaluation
BACKGROUND: Liver biopsy is the reference standard for diagnosing the extent of fibrosis in chronic liver disease; however, it is invasive, with the potential for serious complications. Alternatives to biopsy include non-invasive liver tests (NILTs); however, the cost-effectiveness of these needs to be established. OBJECTIVE: To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease. DATA SOURCES: We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists. METHODS: We included studies that assessed the diagnostic accuracy of NILTs using liver biopsy as the reference standard. Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-analysis was conducted using the bivariate random-effects model with correlation between sensitivity and specificity (whenever possible). Decision models were used to evaluate the cost-effectiveness of the NILTs. Expected costs were estimated using a NHS perspective and health outcomes were measured as quality-adjusted life-years (QALYs). Markov models were developed to estimate long-term costs and QALYs following testing, and antiviral treatment where indicated, for chronic hepatitis B (HBV) and chronic hepatitis C (HCV). NILTs were compared with each other, sequential testing strategies, biopsy and strategies including no testing. For alcoholic liver disease (ALD), we assessed the cost-effectiveness of NILTs in the context of potentially increasing abstinence from alcohol. Owing to a lack of data and treatments specifically for fibrosis in patients with non-alcoholic fatty liver disease (NAFLD), the analysis was limited to an incremental cost per correct diagnosis. An analysis of NILTs to identify patients with cirrhosis for increased monitoring was also conducted. RESULTS: Given a cost-effectiveness threshold of £20,000 per QALY, treating everyone with HCV without prior testing was cost-effective with an incremental cost-effectiveness ratio (ICER) of £9204. This was robust in most sensitivity analyses but sensitive to the extent of treatment benefit for patients with mild fibrosis. For HBV [hepatitis B e antigen (HBeAg)-negative)] this strategy had an ICER of £28,137, which was cost-effective only if the upper bound of the standard UK cost-effectiveness threshold range (£30,000) is acceptable. For HBeAg-positive disease, two NILTs applied sequentially (hyaluronic acid and magnetic resonance elastography) were cost-effective at a £20,000 threshold (ICER: £19,612); however, the results were highly uncertain, with several test strategies having similar expected outcomes and costs. For patients with ALD, liver biopsy was the cost-effective strategy, with an ICER of £822. LIMITATIONS: A substantial number of tests had only one study from which diagnostic accuracy was derived; therefore, there is a high risk of bias. Most NILTs did not have validated cut-offs for diagnosis of specific fibrosis stages. The findings of the ALD model were dependent on assuptions about abstinence rates assumptions and the modelling approach for NAFLD was hindered by the lack of evidence on clinically effective treatments. CONCLUSIONS: Treating everyone without NILTs is cost-effective for patients with HCV, but only for HBeAg-negative if the higher cost-effectiveness threshold is appropriate. For HBeAg-positive, two NILTs applied sequentially were cost-effective but highly uncertain. Further evidence for treatment effectiveness is required for ALD and NAFLD. STUDY REGISTRATION: This study is registered as PROSPERO CRD42011001561. FUNDING: The National Institute for Health Research Health Technology Assessment programme
Longitudinal study of factors associated with the development of depressive symptoms in institutionalized elderly
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using √s=8 TeV proton-proton collision data
A search for squarks and gluinos in final states containing high-p T jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in s√=8 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 20.3 fb−1. Results are interpreted in a variety of simplified and specific supersymmetry-breaking models assuming that R-parity is conserved and that the lightest neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1330 GeV for a simplified model incorporating only a gluino and the lightest neutralino. For a simplified model involving the strong production of first- and second-generation squarks, squark masses below 850 GeV (440 GeV) are excluded for a massless lightest neutralino, assuming mass degenerate (single light-flavour) squarks. In mSUGRA/CMSSM models with tan β = 30, A 0 = −2m 0 and μ > 0, squarks and gluinos of equal mass are excluded for masses below 1700 GeV. Additional limits are set for non-universal Higgs mass models with gaugino mediation and for simplified models involving the pair production of gluinos, each decaying to a top squark and a top quark, with the top squark decaying to a charm quark and a neutralino. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector
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