368 research outputs found

    Assentar sem Terra ou Fortalecer Agricultores Familiares?

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    This article seeks to demystify, through deconstruction, the concept that currently in Brazil there are no agrarian policies in force. With this purpose, it is outlined a series of policies that were created in the last fifteen years, which have offered support to complement the policy framework, that was lacking in the 80's. It was introduced PRONAF, the Land Credits, the PAA, and the ATER law, recently passed. The article also presents a polemical view of models of social and productive organization within the agrarian reform settlements, which were previously seen as the most appropriate solution to the problems of public management reform.Keywords: Settlement; Farming Family; Agrarian Policy.O artigo procura desmistificar que hoje não existe no Brasil uma políticaagrária. Para isso, alinhava-se uma série de políticas criadas nos últimos quinzeanos que contribuíram para completar o arcabouço de políticas que faltavam nadécada de 80. Surgem o PRONAF, o Crédito Fundiário, o PAA e a lei de ATER,aprovada recentemente. O artigo polemiza também com os modelos de organização coletiva dos assentamentos de reforma agrária que eram vistos anteriormente como a solução máxima para os problemas de gestão da reforma agrária

    Monte-Carlo simulation of events with Drell-Yan lepton pairs from antiproton-proton collisions

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    The complete knowledge of the nucleon spin structure at leading twist requires also addressing the transverse spin distribution of quarks, or transversity, which is yet unexplored because of its chiral-odd nature. Transversity can be best extracted from single-spin asymmetries in fully polarized Drell-Yan processes with antiprotons, where valence contributions are involved anyway. Alternatively, in single-polarized Drell-Yan the transversity happens convoluted with another chiral-odd function, which is likely to be responsible for the well known (and yet unexplained) violation of the Lam-Tung sum rule in the corresponding unpolarized cross section. We present Monte-Carlo simulations for the unpolarized and single-polarized Drell-Yan pˉp(↑)→μ+μ−X\bar{p} p^{(\uparrow)} \to \mu^+ \mu^- X at different center-of-mass energies in both configurations where the antiproton beam hits a fixed proton target or it collides on another proton beam. The goal is to estimate the minimum number of events needed to extract the above chiral-odd distributions from future measurements at the HESR ring at GSI. It is important to study the feasibility of such experiments at HESR in order to demonstrate that interesting spin physics can be explored already using unpolarized antiprotons.Comment: Deeply revised text with improved discussion of kinematics and results; added one table; 12 figures. Accepted for publication in Phys. Rev.

    Brain plasticity mechanisms underlying motor control reorganization: Pilot longitudinal study on post-stroke subjects

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    Functional Electrical Stimulation (FES) has demonstrated to improve walking ability and to induce the carryover effect, long-lasting persisting improvement. Functional magnetic resonance imaging has been used to investigate effective connectivity differences and longitudinal changes in a group of chronic stroke patients that attended a FES-based rehabilitation program for foot-drop correction, distinguishing between carryover effect responders and non-responders, and in comparison with a healthy control group. Bayesian hierarchical procedures were employed, involving nonlinear models at within-subject level—dynamic causal models—and linear models at between-subjects level. Selected regions of interest were primary sensorimotor cortices (M1, S1), supplementary motor area (SMA), and angular gyrus. Our results suggest the following: (i) The ability to correctly plan the movement and integrate proprioception information might be the features to update the motor control loop, towards the carryover effect, as indicated by the reduced sensitivity to pro-prioception input to S1 of FES non-responders; (ii) FES-related neural plasticity supports the active inference account for motor control, as indicated by the modulation of SMA and M1 connections to S1 area; (iii) SMA has a dual role of higher order motor processing unit responsible for complex movements, and a superintendence role in suppressing standard motor plans as external conditions changes

    Grandes projetos, mercado de trabalho e condições de renda e pobreza de regiões impactadas: uma análise do complexo petroquímico do Rio de Janeiro (COMPERJ)

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    Among the various large industrial projects currently underway in the country, the Rio de Janeiro Petrochemical Complex (COMPERJ) stands out as the biggest investment in the history of Petrobras in progress in the country, with potential impacts on the local labor market that seem to be extremely relevant. The article is structured to achieve two goals. The first one, of more general nature, comprises the characterization of the socioeconomic context of the region impacted by the COMPERJ, in order to identify aspects that constitute stimuli and barriers to local development process, from the impacts of investments to the region. The second objective, which is more specific, includes an analysis of the determinants of em- ployment and poverty levels in the region impacted by COMPERJ, on the basis of a field research with households of the region. Data raised during the field research was analyzed using an econometric model.Dentre os diversos projetos industriais de grande porte em curso no país, o Complexo Petroquímico do Rio de Janeiro (COMPERJ) destaca-se como o maior investimento industrial da Petrobras em andamento no país, com impactos potenciais sobre o mercado de trabalho local extremamente relevantes. O artigo estrutura-se de modo a atingir dois objetivos. O primeiro deles, de natureza mais geral, compreende a caracterização do contexto socioeconômico da região impactada pelo COMPERJ, de forma identificar aspectos que constituem estímulos e entraves ao processo de desenvolvimento local, a partir dos impactos dos investimentos previstos para a região. O segundo objetivo, de natureza mais específica, contempla uma análise dos determinantes dos níveis de emprego e pobreza na região impactada pelo COMPERJ, com base numa pesquisa primária de caráter domiciliar e no tratamento econométrico das informações levantada

    Neuromuscular electrical stimulation restores upper limb sensory-motor functions and body representations in chronic stroke survivors

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    Background: A conventional treatment outcome is suboptimal for sensory impairments in stroke patients. Novel approaches based on electrical stimulation or robotics are proposed as an adjuvant for rehabilitation, though their efficacy for motor, sensory, and body representation recovery have not been tested. Methods: Sixty chronic stroke patients with unilateral motor deficits were included in a pseudo-randomized open-label multi-arm control trial (ClinicalTrials.gov: NCT03349138). We tested the effects of a robotic glove (GloReha [GR]) and a new neuromuscular electrical stimulation system (Helping Hand [HH]) and compared them with conventional treatment (CT) in restoring motor and sensory functions and the affected limb perception. HH was designed to concurrently deliver peripheral motor activation and enhanced cutaneous sensation. Patients were split in four dose-matched groups: CT, GR, HH, and GRHH (receiving 50% GR and 50% HH). Assessments were performed at inclusion, halfway, end of treatment (week 9), and follow-up (week 13). Findings: HH provided an earlier benefit, quantified by the Motricity Index (MI), than GR. At the end of the treatment, the amelioration was higher in groups GRHH and HH and extended to somatosensory functions. These benefits persisted at the follow-up. GRHH and HH also improved the perceived dimensions and altered feeling toward the affected limb. Interestingly, the reduction of altered feelings correlated with MI improvements and depended on the amount of HH. Conclusions: We suggest that HH concurrently stimulates sensory and motor systems by generating an enhanced cutaneous sensation, coherent in location with the elicited motor recruitment, leading to ameliorated sensorimotor functions and bodily perceptions in stroke patients. Funding: This work was supported by a Foundation advised by CARIGEST, by Fondazione CARIPLO, by the SNSF NCCR Robotics, and by the Bertarelli Foundation

    EEG Fractal Analysis Reflects Brain Impairment after Stroke

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    Stroke is the commonest cause of disability. Novel treatments require an improved understanding of the underlying mechanisms of recovery. Fractal approaches have demonstrated that a single metric can describe the complexity of seemingly random fluctuations of physiological signals. We hypothesize that fractal algorithms applied to electroencephalographic (EEG) signals may track brain impairment after stroke. Sixteen stroke survivors were studied in the hyperacute (<48 h) and in the acute phase (∼1 week after stroke), and 35 stroke survivors during the early subacute phase (from 8 days to 32 days and after ∼2 months after stroke): We compared resting-state EEG fractal changes using fractal measures (i.e., Higuchi Index, Tortuosity) with 11 healthy controls. Both Higuchi index and Tortuosity values were significantly lower after a stroke throughout the acute and early subacute stage compared to healthy subjects, reflecting a brain activity which is significantly less complex. These indices may be promising metrics to track behavioral changes in the very early stage after stroke. Our findings might contribute to the neurorehabilitation quest in identifying reliable biomarkers for a better tailoring of rehabilitation pathways

    Pancreatic panniculitis : the &quot;bright&quot; side of the moon in solid cancer patients

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    BACKGROUND: Pancreatic panniculitis is a rare complication of pancreas disorders occurring in 0.3-3% of patients, most often accompanied by the pancreatic acinar carcinoma. It presents multiple, painful, deep, ill-defined, red-brown, migratory nodules and plaques of hard elastic consistency; often ulcerated and typically located on the lower proximal and distal extremities. The pathogenesis is not fully understood, but it is thought to result from lipolysis and fat necrosis with secondary tissue inflammation induced by pancreatic enzymes. Histopathology shows subcutaneous lobular fat necrosis with anuclear adipocytes (called ghost cells) surrounded by a mixed inflammatory infiltrate. Focal calcification may also be seen. The treatment is directed to the underlying disorder, which may result in regression of skin lesions. CASE PRESENTATION: We present two cases of pancreatic panniculitis with similar clinical, laboratory, and histopathological features associated with different internal malignancy. The first case, after extensive investigations showed the presence of a pancreatic carcinoma with multiple liver metastases and a poor prognosis. The second one instead is the first case in literature where painful subcutaneous nodules of the legs were the early manifestation of a neuroendocrine carcinoma of the adrenal gland. CONCLUSIONS: Although subcutaneous fat necrosis usually occurs late in the course of a malignancy, recognition of the association with pancreatic panniculitis may prevent a long delay in the diagnosis and management of the occult neoplasm. It should be primarily considered when panniculitis is widespread and persistent, and frequent relapses or tendency to ulcerate of the nodules are regarded as red flags
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