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Search Results: 1 - 10 of 2497 matches for " Assis "
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The Dog as a Risk Factor in Transmission of Visceral Leishmaniasis: A Review  [PDF]
Francisco Assis Lima Costa
Advances in Infectious Diseases (AID) , 2012, DOI: 10.4236/aid.2012.22006
Abstract: Visceral leishmaniasis (VL) is a serious public health problem in Brazil and worldwide. Despite the euthanasia of dogs serologically positive, such action has not solved the endemic in Brazil. A risk area for VL involves the presence of the vector, the occurrence of canines and the record of human cases. The factors that have favored the persistence and spread of VL in Brazil are related to the predatory action of man on the environment, to the migratory movements and rural exodus, and a close coexistence of man and animals. Thus considering the epidemiological chain of VL, one fact seems clear: we do not know yet the true extent of the participation of the dog in the infectious cycle of VL. The clinical disease is an important indicator of the extent of the problem in an endemic area. The immunological events are complex and involve resistance and susceptibility to canine visceral leishmaniasis (CVL). One aspect in CVL is that many symptomatic dogs underwent xenodiagnosis not infect the vector. In such cases the pattern recognition receptors CD11b+, TLR2+, and NO present higher values for dogs with results in immunohistochemistry of skin and xenodiagnosis negative (IMH-/XENO-) than dogs with immunohistochemistry in skin and xenodiagnosis positive (IMH+/XENO+), suggesting that innate immunity modulates the competence of the dog to infect the vector. The organic response in CVL varies from individual to individual and within the same individual, with a strong evidence of being organ-specific. Only 20% of asymptomatic dogs have parasites in the skin and 15% are able to recover from clinical signs and eliminate the parasites spontaneously. In this review, we analyze the epidemiology of visceral leishmaniasis and clinical, immunological and pathological conditions that can contribute to understanding the role of dogs in transmission of visceral leishmaniasis.
A teoria da história como hermenêutica da historiografia: uma interpreta??o de Do Império à República, de Sérgio Buarque de Holanda
Assis, Arthur;
Revista Brasileira de História , 2010, DOI: 10.1590/S0102-01882010000100006
Abstract: this text features an interpretation of from the empire to the republic, the book by sérgio buarque de holanda that re-enacts brazil's late 19th century political history. based on concepts developed by the historical theorist j?rn rüsen, the article delves particularly into three aspects of the aforementioned book: the theoretical artefacts structuring the interpretation of the crisis of the brazilian monarchy; the narrative patterns deployed so as to make sense of that past experience; and the orientation context that functions as source of criteria of sense/meaning for both interpretation and representation. this analysis intends to illustrate that historical theory is not only a means to abstractly explore the complex questions connected to the production of historical knowledge, but also a tool for obtaining concrete images about the intellectual practice of professional historians.
Strong Epistatic Selection on the RNA Secondary Structure of HIV
Raquel Assis
PLOS Pathogens , 2014, DOI: doi/10.1371/journal.ppat.1004363
Abstract: A key question in evolutionary genomics is how populations navigate the adaptive landscape in the presence of epistasis, or interactions among loci. This problem can be directly addressed by studying the evolution of RNA secondary structures, for which there is constraint to maintain pairing between Watson-Crick (WC) sites. Replacement of a nucleotide at one site of a WC pair reduces fitness by disrupting binding, which can be restored via a compensatory replacement at the interacting site. Here, I present the first genome-scale analysis of epistasis on the RNA secondary structure of human immunodeficiency virus type 1 (HIV-1). Comparison of polymorphism frequencies at ancestrally conserved sites reveals that selection against replacements is ~2.7 times stronger at WC than at non-WC sites, such that nearly 50% of constraint can be attributed to epistasis. However, almost all epistatic constraint is due to selection against conversions of WC pairs to unpaired (UP) nucleotides, whereas conversions to GU wobbles are only slightly deleterious. This disparity is also evident in pairs with second-site compensatory replacements; conversions from UP nucleotides to WC pairs increase median fitness by ~4.2%, whereas conversions from GU wobbles to WC pairs only increase median fitness by ~0.3%. Moreover, second-site replacements that convert UP nucleotides to GU wobbles also increase median fitness by ~4%, indicating that such replacements are nearly as compensatory as those that restore WC pairing. Thus, WC peaks of the HIV-1 epistatic adaptive landscape are connected by high GU ridges, enabling the viral population to rapidly explore distant peaks without traversing deep UP valleys.
Visualizing Random Forest’s Prediction Results  [PDF]
Hudson F. Golino, Cristiano Mauro Assis Gomes
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.519211
Abstract: The current paper proposes a new visualization tool to help check the quality of the random forest predictions by plotting the proximity matrix as weighted networks. This new visualization technique will be compared with the traditional multidimensional scale plot. The present paper also introduces a new accuracy index (proportion of misplaced cases), and compares it to total accuracy, sensitivity and specificity. It also applies cluster coefficients to weighted graphs, in order to understand how well the random forest algorithm is separating two classes. Two datasets were analyzed, one from a medical research (breast cancer) and the other from a psychology research (medical student’s academic achievement), varying the sample sizes and the predictive accuracy. With different number of observations and different possible prediction accuracies, it was possible to compare how each visualization technique behaves in each situation. The results pointed that the visualization of random forest’s predictive performance was easier and more intuitive to interpret using the weighted network of the proximity matrix than using the multidimensional scale plot. The proportion of misplaced cases was highly related to total accuracy, sensitivity and specificity. This strategy, together with the computation of Zhang and Horvath’s (2005) clustering coefficient for weighted graphs, can be very helpful in understanding how well a random forest prediction is doing in terms of classification.
Jornalismo de variedades: cartografia de uma especialidade da imprensa
Assis, Francisco de;
Intercom: Revista Brasileira de Ciências da Comunica??o , 2011, DOI: 10.1590/S1809-58442011000100006
Abstract: the article provides a historical and evolutionary overview on the references regarding variety journalism, confronting ideas and articulating stances that most resemble the market features. its main goal is to better conceptualize this journalistic practice, which has been conquering significant space in newspapers and magazines, but that still lacks theoretical marking. the methodology is based on bibliographical research. with a special attention to the brazilian scenery, the text unveils the changes shaped by the press, since the nineteenth century, that ended up on the current design of what may be considered variety journalism: a specialty that deals with arts and entertainment focusing on leisure options available to the readership.
Mercado de terras e trajetórias tecnológicas na Amaz?nia
Costa, Francisco de Assis;
Economia e Sociedade , 2012, DOI: 10.1590/S0104-06182012000200002
Abstract: the dynamics of the rural economy in the amazon has been observed through the phenomenon of deforestation and evaluated primarily by environmental risks and inequalities in distribution. the article indicates possibilities of change and, at the same time, demonstrates the obstacles to overcome. starting from the observation of the agrarian economy of the region as a totality in motion, it establishes the foundation of the development on six technological trajectories, explaining the asymmetries of capacity between them in the context of their relations with institutions. among these, special focus is led to the mediations that ensure production and land market. regarding the latter, the article indicates policy measures to constrain it.
Desenvolvimento rural sustentável no Brasil: perspectivas a partir da integra??o de a??es públicas e privadas com base na agroecologia
Assis, Renato Linhares de;
Economia Aplicada , 2006, DOI: 10.1590/S1413-80502006000100005
Abstract: this article aims to present an option for establishment of agroecological based sustainable rural development. initially, an analysis is made of the process of diffusion of agroecological production systems in brazil. afterwards, the concept of sustainable development and possibilities of its accomplishment in relation to the difficulties brought by global economy is discussed. following this, some questions are presented about public policy demands for the accomplishment of sustainable rural development, based at local action and related to agroecological production systems. some premises and general recommendations are also presented for the accomplishment of this process. it is concluded that the execution of the proposal ideas only will be possible with enduring and integrated action of the different levels of action by public authorities, associated with real involvement of the society in the building of solutions.
Duas novas espécies de Alstroemeria L. (Alstroemeriaceae) para o Brasil
Assis, Marta Camargo de;
Acta Botanica Brasilica , 2003, DOI: 10.1590/S0102-33062003000200002
Abstract: two new species of alstroemeria l. from brazil are described: a. amabilis from paraná and santa catarina, and a. capixaba from espírito santo. descriptions, comments and illustrations are presented.
A economia colonial do Gr?o-Pará: uma avalia??o crítica (1720-1822)
Costa, Francisco de Assis;
Economia e Sociedade , 2012, DOI: 10.1590/S0104-06182012000100008
Abstract: based on work of restoration of time series of some important economic variables that extend from 1720 to 1822, the paper aims to contribute to a vision of the amazonian colonial economy that emphasizes the global context - it means a demonstrated ability to assert itself as sub-system of the portuguese colonial empire in the context of world market. in discussing this capacity, the article evaluates the evolution of fundamental conditions of efficiency of the colony, considering them as determined by the peculiar features that assumed the local operation of the colonial project in gr?o-pará. these conditions, strongly characterized by the uniqueness of the natural foundations of the amazonian biome, are evaluated in reference to the institutional changes that mark in time the trajectory of the regional economy and society.
Lugar e significado da gest?o pombalina na economia colonial do Gr?o-Pará
Costa, Francisco de Assis;
Nova Economia , 2010, DOI: 10.1590/S0103-63512010000100005
Abstract: the historiography on the colonial period in the amazon involves an opposition between reality shaped by a colonial agricultural project and the occurrence of concrete situations of extractive economies, depending on the availability of capital to be applied in the main means of production: the black slave. so, a long period of scarcity of resources would have conformed a cycle of the extractive economy in the region dominated by the "drogas do sert?o", replaced with an agricultural cycle as the very result of pombal's management. this period would be the turning point for a dynamics determined by agriculture, which improved on by world market situations, particularly those linked to the independence war in the usa, would find significant limitation only with the emergence of the new cycle centered on extractive rubber, which began around the second half of the xix century. the results discussed here do not show that pombal's period is the moment when finally the foundations of the amazon economy were established. in fact, it was a vital and creative time for a trajectory, which even though started almost ? of a century before, imposed itself marking the reforms of the period, which in turn conditioned indelibly the history of the region.
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