4,138 research outputs found
Temporally Precise Cell-Specific Coherence Develops in Corticostriatal Networks during Learning
SummaryIt has been postulated that selective temporal coordination between neurons and development of functional neuronal assemblies are fundamental for brain function and behavior. Still, there is little evidence that functionally relevant coordination emerges preferentially in neuronal assemblies directly controlling behavioral output. We investigated coherence between primary motor cortex and the dorsal striatum as rats learn an abstract operant task. Striking coherence developed between these regions during learning. Interestingly, coherence was selectively increased in cells controlling behavioral output relative to adjacent cells. Furthermore, the temporal offset of these interactions aligned closely with corticostriatal conduction delays, demonstrating highly precise timing. Spikes from either region were followed by a consistent phase in the other, suggesting that network feedback reinforces coherence. Together, these results demonstrate that temporally precise coherence develops during learning specifically in output-relevant neuronal populations and further suggest that correlations in oscillatory activity serve to synchronize widespread brain networks to produce behavior
Nemabiome metabarcoding reveals differences between gastrointestinal nematode species infecting co-grazed sheep and goats
Our current understanding of differences in the epidemiology of gastrointestinal nematode (GIN) species in co-grazed sheep and goats is inadequate with reference to the development of sustainable control strategies. The next-generation metabarcoding sequencing method referred to as the ‘nemabiome’ allows some of these differences to be explored to describe the intensity of co-infecting GIN species. We applied this platform to study sheep and goats that were co-grazed on Guinea grass pasture in northeastern Brazil. Co-grazed goats and sheep were treated with a monepantel anthelmintic, then exposed to the same gastrointestinal nematode species. Overall, there were differences in the prevalence of GIN species identified in the sheep and goats; Trichostrongylus colubriformis and Teladorsagia circumcincta predominated in goat kids, while Haemonchus contortus predominated in adult does, ewes and lambs once burdens became re-established after anthelmintic treatment. Description of the pattern of re-infection following anthelmintic treatment was prevented by the unpredicted poor efficacy of 2.5 mg/kg and 5 mg/kg, respectively, of monepantel against O. columbianum and T. circumcincta in lambs, and T. circumcincta adult does. Differences in drug efficacy between host age and species groups may be important when considering sustainable GIN control strategies for co-grazed animals. The aggregated FECs of the adult does and goat kids representing re-established GIN burdens, were higher than those of the co-grazed adult ewes and lambs. This implies that there are inherent differences in GIN species adaptation to the two naïve small ruminant host species, and shows the need for better understanding of the factors giving rise to this situation associated with exposure to infective larvae and host responses. At the start of the study, the adult does were co-infected with several GIN species, with the highest intensity of T. circumcincta, contrasting with the situation in the adult ewes, in which H. contortus predominated. However, once burdens became re-established after treatment, H. contortus predominated in both adult does and ewes. This demonstrates the potential for host burdens of H. contortus to establish and predominate after anthelmintic treatment when burdens of co-infecting GIN species are low
New old star clusters in the Small Magellanic Cloud
Using Ca triplet spectroscopy and P SF photometry performed on data taken with the “Very Large Telescope” (Chile), we derived reliable ages and metallicities of 15 Small Magellanic Cloud (SMC) star clusters. Three of them were found to be very old clusters so that the determination of their fundamental properties allows us to improve our current knowledge on the SMC chemical evolution during the earliest
epochs. Based on our new data, we further discuss the age-metallicity relation. The procedures and results included in this article will be presented in a more extensive and detailed way in Parisi et al. (2011 - in preparation).Usando espectroscopıa del Triplete del Calcio Ionizado y fotometrıa P SF realizada sobre datos tomados con el “Very Large Telescope” (Chile), derivamos edades y metalicidades confiables de 15 cumulos estelares de la Nube Menor de Magallanes (NmM). Encontramos que 3 de ellos son cumulos muy viejos, por lo que la determinacion de sus propiedades fundamentales permite mejorar nuestro actual conocimiento sobre la evolucion quımica de la NmM durante su etapa mas temprana. Basados en nuestros nuevos datos, rediscutimos la relacion edad-metalicidad en esta galaxia. Los procedimientos y resultados incluidos en este artıculo, seran presentados de manera mas extensa y detallada en Parisi et al.
(2011 - en preparacion).Fil: Parisi, M. C.. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Geisler, D.. Universidad de Concepción; ChileFil: Grocholski, A. J.. University of Florida; Estados UnidosFil: Claria Olmedo, Juan Jose. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Carraro, G.. European Southern Observatory; ChileFil: Costa, E.. Universidad de Chile; ChileFil: Piatti, Andres Eduardo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Sarajedini, A.. University of Florida; Estados UnidosFil: Leiton, R.. Universidad de Concepción; Chil
Central nervous system vasculitis in a patient with HIV infection: a diagnostic challenge
Univ Fed Sao Paulo, Dept Neurol, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Div Doencas Infecciosas, Rua Napoleao Barros,715, BR-04023900 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Radiol, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Neurol, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Div Doencas Infecciosas, Rua Napoleao Barros,715, BR-04023900 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Radiol, Sao Paulo, SP, BrazilWeb of Scienc
Comparative structural response of two steel bridges constructed 100 years apart
This paper presents a comparative numerical analysis of the structural behaviour and seismic performance of two existing steel bridges, the Infiernillo II Bridge and the Pinhao Bridge, one located in Mexico and the other in Portugal. The two bridges have similar general geometrical characteristics, but were constructed 100 years apart. Three-dimensional structural models of both bridges are developed and analysed for various load cases and several seismic conditions. The results of the comparative analysis between the two bridges are presented in terms of natural frequencies and corresponding vibration modes, maximum stresses in the structural elements and maximum displacements. The study is aimed at determining the influence of a 1 century period in material properties, transverse sections and expected behaviour of two quite similar bridges. In addition, the influence of the bearing conditions in the global response of the Pinhao Bridge was evaluated
The Burden Of Eclampsia: Results From A Multicenter Study On Surveillance Of Severe Maternal Morbidity In Brazil.
Maternal mortality (MM) is a core indicator of disparities in women's rights. The study of Near Miss cases is strategic to identifying the breakdowns in obstetrical care. In absolute numbers, both MM and occurrence of eclampsia are rare events. We aim to assess the obstetric care indicators and main predictors for severe maternal outcome from eclampsia (SMO: maternal death plus maternal near miss). Secondary analysis of a multicenter, cross-sectional study, including 27 centers from all geographic regions of Brazil, from 2009 to 2010. 426 cases of eclampsia were identified and classified according to the outcomes: SMO and non-SMO. We classified facilities as coming from low- and high-income regions and calculated the WHO's obstetric health indicators. SPSS and Stata softwares were used to calculate the prevalence ratios (PR) and respective 95% confidence interval (CI) to assess maternal characteristics, clinical and obstetrical history, and access to health services as predictors for SMO, subsequently correlating them with the corresponding perinatal outcomes, also applying multiple regression analysis (adjusted for cluster effect). Prevalence of and mortality indexes for eclampsia in higher and lower income regions were 0.2%/0.8% and 8.1%/22%, respectively. Difficulties in access to health care showed that ICU admission (adjPR 3.61; 95% CI 1.77-7.35) and inadequate monitoring (adjPR 2.31; 95% CI 1.48-3.59) were associated with SMO. Morbidity and mortality associated with eclampsia were high in Brazil, especially in lower income regions. Promoting quality maternal health care and improving the availability of obstetric emergency care are essential actions to relieve the burden of eclampsia.9e9740
Retención de glifosato y nutrientes en vías de flujo preferencial
Las franjas de vegetación ribereña (RVS) reducen el volumen del flujo de escorrentía superficial y retienen los sedimentos, los pesticidas y los nutrientes que esas aguas transportan desde los campos de cultivo (CF) adyacentes. La capacidad de estas franjas para retener el glifosato se demostró por medio de parcelas experimentales, aunque se desconoce la variabilidad espacial de ese proceso. En este trabajo se analizó la influencia de la microtopografía dentro de las RVS en la retención de glifosato (y su metabolito principal, AMPA), fósforo y nitrógeno dentro de las RVS de paisajes agropecuarios. Se compararon los niveles de retención dentro y fuera de las vías de flujo preferencial (PFP), en presencia y ausencia de un estrato arbóreo. La concentración de glifosato + AMPA en los suelos dentro de las PFP fue 88 veces mayor que fuera de la PFP. Las concentraciones de fósforo y nitrógeno, el contenido de arcilla y la densidad aparente también fueron más altos dentro que fuera de las PFP. La presencia del estrato arbóreo no modificó las concentraciones de glifosato + AMPA, ni de fósforo, ni de nitrógeno, ni el contenido de arcilla, como tampoco la morfometría de las PFP. La densidad aparente y el contenido de arcilla, registrados en los CF y en las PFP, junto con las concentraciones más altas de glifosato, fósforo y nitrógeno en los suelos de las PFP, son consistentes con una conexión hidráulica entre los CF y las PFP. Estos resultados contrastan con algunas conclusiones obtenidas a partir de estudios experimentales en parcelas uniformes y ponen en evidencia la importancia de tomar en cuenta génesis y estructura de las PFP en el diseño, evaluación y manejo de la función de filtrado de las RVS.Riparian vegetation strips (RVS) reduce surface runoff volume and retain sediments, pesticides and nutrients that are transported across them from adjacent crop-fields (CF). The ability of these strips to retain glyphosate has been demonstrated using experimental plots, but the spatial variability of that process is unknown. In this work, the influence of microtopography inside the RVS on the retention of glyphosate (and its major metabolite, AMPA), phosphorus and nitrogen were analyzed within a RVS of agricultural landscapes. Retention levels inside and outside preferential flow pathways (PFP) were compared under presence and absence of a tree stratum. Soil glyphosate + AMPA concentration within PFP was 88-fold higher than outside. Phosphorus and nitrogen soil concentrations, clay and bulk density were also higher inside than outside the PFP. The tree stratum did not modify soil concentration of glyphosate + AMPA, phosphorus, nitrogen, clay content, nor the morphometry of the PFP. Bulk density and clay content recorded in adjacent CF and in PFP, in addition to the high glyphosate, phosphorus and nitrogen concentrations in PFP soil, are consistent with a hydraulic connection between the CF and the PFP. These results contrast with some conclusions obtained from experimental studies under uniform plots and emphasize the importance of taking into account the genesis and structure of PFP in the design, evaluation and management of the filtering function of RVS.Fil: Giaccio, Gustavo C. M.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Barrow; ArgentinaFil: Laterra, Pedro. Fundacion Bariloche. Departamento de Energia.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Aparicio, Virginia Carolina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Agencia de Extensión Rural Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Costa, Jose Luis. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Agencia de Extensión Rural Balcarce; ArgentinaFil: Puricelli, Marino Marcelo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Agencia de Extensión Rural Balcarce; Argentin
Discriminating among Earth composition models using geo-antineutrinos
It has been estimated that the entire Earth generates heat corresponding to
about 40 TW (equivalent to 10,000 nuclear power plants) which is considered to
originate mainly from the radioactive decay of elements like U, Th and K,
deposited in the crust and mantle of the Earth. Radioactivity of these elements
produce not only heat but also antineutrinos (called geo-antineutrinos) which
can be observed by terrestrial detectors. We investigate the possibility of
discriminating among Earth composition models predicting different total
radiogenic heat generation, by observing such geo-antineutrinos at Kamioka and
Gran Sasso, assuming KamLAND and Borexino (type) detectors, respectively, at
these places. By simulating the future geo-antineutrino data as well as reactor
antineutrino background contributions, we try to establish to which extent we
can discriminate among Earth composition models for given exposures (in units
of kt yr) at these two sites on our planet. We use also information on
neutrino mixing parameters coming from solar neutrino data as well as KamLAND
reactor antineutrino data, in order to estimate the number of geo-antineutrino
induced events.Comment: 24 pages, 10 figures, final version to appear in JHE
Omega-3 intake is associated with attenuated inflammatory response and cardiac remodeling after myocardial infarction
Myocardial infarction (MI) elicits an intense acute inflammatory response that is essential for cardiac repair. However, an excessive inflammatory response also favors myocardial apoptosis, cardiac remodeling, and cardiovascular mortality. Omega-3 polyunsaturated fatty acids (-3) bear anti-inflammatory effects, which may mitigate the inflammatory response during MI. This study investigated whether -3 intake is associated with attenuation of the MI-related inflammatory response and cardiac remodeling. ST-elevation MI (STEMI) patients (n=421) underwent clinical, biochemical, nutritional, 3D echocardiogram, Cardiac Magnetic Resonance imaging (CMRi) at 30 days and 3D echocardiogram imaging at six months after the MI. Blood tests were performed at day one (D1) and day five (D5) of hospitalization. Changes in inflammatory markers (D5-D1) were calculated. A validated food frequency questionnaire estimated the nutritional consumption and -3 intake in the last 3months before admission. The intake of -3 below the median (<1.7g/day) was associated with a short-term increase in hs-C-reactive protein [OR:1.96(1.24-3.10); p=0.004], Interleukin-2 [OR:2.46(1.20-5.04); p=0.014], brain-type natriuretic peptide [OR:2.66(1.30-5.44); p=0.007], left-ventricle end-diastolic volume [OR:5.12(1.11-23.52)]; p=0.036] and decreases in left-ventricle ejection fraction [OR:2.86(1.47-6.88); p=0.017] after adjustment for covariates. No differences were observed in the extension of infarcted mass obtained by CMRi. These findings suggest that a reduced daily intake of -3 may intensify outcome-determining mechanisms after STEMI, such as acute inflammatory response and late left ventricular remodeling.18CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ308550/2010-
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