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We show that the power-law decay exponents in von Neumann's Ergodic Theorem (for discrete systems) are the pointwise scaling exponents of a spectral measure at the spectral value~$1$. We also prove that, under an assumption of weak convergence, in the absence of a spectral gap, the convergence rates of the time-average in von Neumann's Ergodic Theorem depend on sequences of time going to infinity.

We prove sharp estimates on the time-average behavior of the squared absolute value of the Fourier transform of some absolutely continuous measures that may have power-law singularities, in the sense that their Radon-Nikodym derivatives diverge with a power-law order. We also discuss an application to spectral measures of finite-rank perturbations of the discrete Laplacian.

The objective was to evaluate the effect of rainfall variability on the chemical composition, in vitro degradability and gas production of cacti in Semiarid region. Made available in DSpace on 2022-09-27T13:06:45Z (GMT). No. of bitstreams: 1 Rainfall-variability-affects-the-chemical-composition-2022.pdf: 458833 bytes, checksum: 36dac7c7dbc666aaefda5c78cc7db948 (MD5) Previous issue date: 2022

O espaçamento de plantio tem influenciado no crescimento e na produtividade da cultura, podendo variar em função das variedades e do manejo adotado. O objetivo do trabalho foi identificar os espaçamentos mais eficientes para o cultivo irrigado de duas variedades de sorgo forrageiro no Semiárido brasileiro. O delineamento experimental foi em blocos ao acaso, em parcelas subsubdivididas, com três repetições. As parcelas foram constituídas por duas variedades de sorgo forrageiro: Sudão e Volumax; as subparcelas por oito espaçamentos, sendo três espaçamentos com fileira simples: 40x40, 50x50, 60x60 cm e cinco com fileiras duplas: 30x40, 30x50, 30x60, 40x50 e 40x60 cm e as subsubparcelas constituídas por dois ciclos de cultivo. Foram avaliadas: altura de planta, diâmetro de colmo, área foliar e produtividade de biomassa fresca (PMF) e seca (PMS). A variedade Sudão apresentou maior altura de plantas, diâmetro de colmo, área foliar e PMS. Os arranjos de plantio nos espaçamentos de 30x40, 30x60 e 40x50 cm são mais eficientes para a variedade Sudão. Para a variedade Volumax, os arranjos de plantio do tipo fileiras simples com espaçamento de 40 cm entre fileiras e em sistema do tipo fileiras duplas nos espaçamentos de 30x60, 40x50 e 40x60 cm são os mais recomendados. Made available in DSpace on 2022-05-05T19:18:10Z (GMT). No. of bitstreams: 1 Sorgo-forrageiro-2022.pdf: 758484 bytes, checksum: ea1f986480d4ad2a7be57ad9e5eb9673 (MD5) Previous issue date: 2022

The objectives of this study were to estimate genetic parameters and identify traits that contribute to early yield in Manihot esculenta Crantz. Ten traits were evaluated in two experiments, one with 138 genotypes and the other with 133, using a completely randomized block design with four replications. All genotype effects were significant. The accuracy was high for the traits, except leaf retention (0.57), and reliability ranged from 0.33 to 0.75. Root weight (RW) and number of roots (NR) showed the highest selection effectiveness (CV r ), although the estimate was less than 1. Moreover, RW and NR obtained high genetic correlation (0.70). Path analysis showed that only number of roots had a significant direct effect on root weight (0.49), and no indirect effect was found. Therefore, accessions exhibited sufficient genetic variability, and indirect selection based on early evaluation of number of roots can be applied in cassava breeding for fresh root yield, increasing gain over time. Made available in DSpace on 2021-12-03T13:00:33Z (GMT). No. of bitstreams: 1 Oliveira-et-al-CBAB-2021-1.pdf: 356341 bytes, checksum: 0778cfcd3526e026b6613f422eceef84 (MD5) Previous issue date: 2021

A indisciplina em sala de aula constitui uma preocupação sistemática de professores, directores de escolas, funcionários, pais e dos próprios alunos. A literatura especializada tem avançado com múltiplas explicações e modelos interpretativos do fenómeno, bem como com projetos e modelos de intervenção. Dados de diversos estudos nacionais e internacionais sugerem, porém, que tais projectos e modelos poderão não estar a surtir os efeitos desejados. Neste artigo são revistos alguns dos aspectos da indisciplina em sala de aula que, apesar de muito relevantes, têm recebido uma menor atenção quer da literatura quer dos profissionais (professores, directores). São apresentados alguns resultados de um estudo sobre indisciplina que contou com a participação de 3000 professores do Ensino Básico. São ainda avançadas algumas implicações deste estudo para a prática e são apresentadas algumas sugestões específicas sobre a forma de lidar com a indisciplina em contexto de sala de aula.

Made available in DSpace on 2018-01-09T23:19:36Z (GMT). No. of bitstreams: 1 PUVenhancedozonegas....pdf: 1933813 bytes, checksum: 33f8f6a4b235fa0abd87cb88b4c614e2 (MD5) Previous issue date: 2018-01-09

Made available in DSpace on 2017-11-08T23:27:24Z (GMT). No. of bitstreams: 1 PROCIMateextract....pdf: 617675 bytes, checksum: 6724708101e23bb4bd72d61c0bf2b0be (MD5) Previous issue date: 2017-11-08

Made available in DSpace on 2018-01-09T23:18:25Z (GMT). No. of bitstreams: 1 PgC3N4Nb2O5heterostructures....pdf: 2537457 bytes, checksum: dbf7886c0576244eaf02ffbfd61ba717 (MD5) Previous issue date: 2018-01-09

Tropical soils require liming and a balanced nutrient supply to ensure high crop yield and quality. An adequate agronomic nutrient management involves balanced nutrition and fertilizers are the key factor.

Cracks that form at the interfaces between masonry structures are common uncontrolled occurrences in buildings. Numerous methods have been proposed by the construction industry to address this problem. Cracks continuously form in the joints between concrete columns and masonry infill walls. In this study, the most common methods for preventing these types of cracks were evaluated in laboratory experiments. Column masonry models were constructed using different types of joints between concrete columns and masonry infill walls, such as steel bars and steel mesh. The efficiency of each type of joint method was evaluated by performing direct tensile tests (pullout tests) on the models and monitoring the evolution of the crack opening in the joint between the column and wall, as a function of load applied to the model. The results from this study indicate that the model composed of "electrowelded wire mesh without steel angles" is the best model for controlling cracking in the joints between concrete columns and masonry infill walls. As fissuras na interface alvenaria/estrutura são ocorrências patológicas comuns nas edificações e muitos são os métodos propostos pela indústria da construção que prometem evitar este problema. De caráter recorrente encontram-se as fissuras na ligação pilar de concreto e parede de alvenaria. Neste trabalho, são avaliados, em laboratório, os métodos mais usuais de prevenção deste tipo de fissura. Modelos pilar/alvenaria foram construídos utilizando-se diferentes tipologias de ligação entre o pilar de concreto e a parede de alvenaria, desde o usual "ferro cabelo" até telas de aço. A eficiência de cada um destes métodos de ligação foi avaliada por intermédio de ensaio dos modelos à tração direta, com o monitoramento da evolução da abertura da fissura na ligação pilar/parede em função do incremento de carga aplicada ao modelo. Os resultados desta pesquisa indicaram o modelo composto por "tela metálica eletrossoldada, e sem cantoneira de aço", como a melhor técnica de controle da fissuração na ligação pilar de concreto e parede de alvenaria, dentre todos os modelos avaliados.

The resolvent convergence of self-adjoint operators via the technique of $\Gamma$-convergence of quadratic forms is adapted to incorporate complex Hilbert spaces. As an application, we find effective operators to the Dirichlet Laplacian with magnetic potentials in very thin bounded tubular regions in space built along smooth closed curves; relatively weak regularity is asked for the potentials, and the convergence is in the norm resolvent sense as the cross sections of the tubes go uniformly to zero., Comment: 22 pages; to appear in Journal of Spectral Theory

Made available in DSpace on 2016-08-29T11:11:48Z (GMT). No. of bitstreams: 1 tese_6485_CONCEICAO REGINA PINTO DE OLIVEIRA.pdf: 16352455 bytes, checksum: 5b4e30a2618ad7ff35f17fa8a8cda589 (MD5) Previous issue date: 2013-05-16 No cenário das pesquisas educacionais no Brasil, especificamente as que focalizam a Educação Infantil (EI) e a configuração do trabalho docente nesta etapa da Educação Básica (EB), nossa pesquisa intenta caracterizar as instituições designadas Escola Municipal de Educação Infantil e Ensino Fundamental EMEIEF, suas especificidades e dinâmicas de trabalho. Vinculados a essa intenção, buscamos conhecer a dinâmica de desenvolvimento da docência na EI e dos processos formativos empreendidos na instituição. Na revisão de literatura exploramos, nos estudos e pesquisas no campo da EI e no campo do trabalho docente, como vêm se configurando esses campos, as temáticas mais abordadas e o nicho no qual abrigamos nossa temática de estudo. Vinculamos nossas problematizações às considerações de Mikhail Bakhtin sobre os conceitos de dialogia, polifonia e heteroglossia, articulados aos conceitos de fazer com, lugar e espaço, táticas e estratégias, expressos nas obras de Michel de Certeau. Nossas trajetórias metodológicas têm ancoragem na pesquisa qualitativa de abordagem exploratória com inspiração etnográfica. A coleta/produção de dados se efetivou por meio da análise documental, observação participante, entrevistas e grupo focal, sem perder de vista a conduta ética implicada em nossas interações com os sujeitos no campo de pesquisa, com consentimento devidamente registrado no Termo de Consentimento Livre e Esclarecido. Das análises, podemos caracterizar a instituição EMEIEF como um lugar peculiar e complexo no qual, ao mesmo tempo em que há relações dialógicas responsivas nas interações entre crianças e profissionais docentes, implicando na diminuição da cisão histórica na passagem da EI para o EF, a infraestrutura da instituição não atende às especificidades do trabalho com crianças da EI. Manifesta-se nas falas de vários profissionais o desejo de que as crianças da EI sejam atendidas em instituições destinadas exclusivamente a elas (CEMEI). Visibilizamos, também, que os processos formativos dos profissionais docentes se dão no contexto do trabalho com as crianças, nas iniciativas pessoais das professoras de EI e do EF e nos cursos de formação continuada ofertados pela Secretaria de Educação Municipal, reverberando na configuração da docência, na EMEIEF.

The resolvent convergence of self-adjoint operators via the technique of $��$-convergence of quadratic forms is adapted to incorporate complex Hilbert spaces. As an application, we find effective operators to the Dirichlet Laplacian with magnetic potentials in very thin bounded tubular regions in space built along smooth closed curves; relatively weak regularity is asked for the potentials, and the convergence is in the norm resolvent sense as the cross sections of the tubes go uniformly to zero., 22 pages; to appear in Journal of Spectral Theory

Dentre os vírus que infectam o feijão-caupi (Vigna unguiculata L. Walp.) destacam-se, respectivamente, pela severidade e ampla ocorrência o Cowpea severe mosaic virus (CPSMV) e o Cowpea aphidborne mosaic virus (CABMV). Portanto, objetivaram-se, no presente trabalho, obter e avaliar plantas de feijão-caupi com resistência ao CPSMV e ao CABMV, visando ao desenvolvimento de cultivares essencialmente derivadas e novas cultivares.

Alzheimer's disease (AD) is the most common cause of dementia in the elderly, affecting several million of people worldwide. Pathological changes in the AD brain include the presence of amyloid plaques, neurofibrillary tangles, loss of neurons and synapses, and oxidative damage. These changes strongly associate with mitochondrial dysfunction and stress of the endoplasmic reticulum (ER). Mitochondrial dysfunction is intimately linked to the production of reactive oxygen species (ROS) and mitochondrial-driven apoptosis, which appear to be aggravated in the brain of AD patients. Concomitantly, mitochondria are closely associated with ER, and the deleterious crosstalk between both organelles has been shown to be involved in neuronal degeneration in AD. Stimuli that enhance expression of normal and/or folding-defective proteins activate an adaptive unfolded protein response (UPR) that, if unresolved, can cause apoptotic cell death. ER stress also induces the generation of ROS that, together with mitochondrial ROS and decreased activity of several antioxidant defenses, promotes chronic oxidative stress. In this paper we discuss the critical role of mitochondrial and ER dysfunction in oxidative injury in AD cellular and animal models, as well as in biological fluids from AD patients. Progress in developing peripheral and cerebrospinal fluid biomarkers related to oxidative stress will also be summarized.

O rendimento do feijão-caupi pode ser afetado por diversos fatores, em especial as viroses. As principais espécies de vírus que infectam o feijão-caupi, no Brasil, são: Cucumber mosaic virus (CMV), Cowpea aphid-borne mosaic virus (CABMV), Cowpea severe mosaic virus (CPSMV) e o Bean golden mosaic virus (BGMV). Este trabalho foi realizado em duas etapas e teve como objetivo avaliar a reação de genótipos de feijão-caupi quanto à resistência à infecção simples pelo CMV e mista nas combinações CMV+CABMV, CMV+CPSMV-I e MV+CABMV+CPSMV-I. Inicialmente, foram incluídos 57 genótipos, sendo três avaliações em gaiolas com tela antiafídeos sob infecção controlada, e uma em condição de campo sob infecção natural. Em seguida, foram selecionados 18 genótipos para serem desenvolvidos em nove ensaios, oito em gaiolas com tela antiafídeos sob infecção controlada, e um em campo sob infecção natural. Nesses ensaios, avaliaram-se os efeitos qualitativos e quantitativos resultantes das infecções. No ensaio de campo, foram avaliados o número de plantas assintomáticas, comprimento de vagem, número de grãos por vagem, massa de cem grãos e produtividade. As coinfecções reduziram a altura da planta e a massa seca. Além disso, nas infecções envolvendo os três vírus ocorreu a morte prematura de alguns genótipos. Os genótipos BR17-Gurguéia, Epace V-96, TE97-309G-9, TE97-309G-22, TE97-309G-24 e Patativa, além de bom comportamento diante das coinfecções virais, têm sementes com padrão comercial, podendo ser empregadas diretamente em programas de melhoramento.

While the etiology of Parkinson's disease remains largely elusive, there is accumulating evidence suggesting that mitochondrial dysfunction occurs prior to the onset of symptoms in Parkinson's disease. Mitochondria are remarkably primed to play a vital role in neuronal cell survival since they are key regulators of energy metabolism (as ATP producers), of intracellular calcium homeostasis, of NAD+/NADH ratio, and of endogenous reactive oxygen species production and programmed cell death. In this paper, we focus on mitochondrial dysfunction-mediated alpha-synuclein aggregation. We highlight some of the findings that provide proof of evidence for a mitochondrial metabolism control in Parkinson's disease, namely, mitochondrial regulation of microtubule-dependent cellular traffic and autophagic lysosomal pathway. The knowledge that microtubule alterations may lead to autophagic deficiency and may compromise the cellular degradation mechanisms that culminate in the progressive accumulation of aberrant protein aggregates shields new insights to the way we address Parkinson's disease. In line with this knowledge, an innovative window for new therapeutic strategies aimed to restore microtubule network may be unlocked.

[Background and purpose] Inhibitory CB1 cannabinoid receptors and excitatory TRPV1 vanilloid receptors are abundant in the hippocampus. We tested if two known hybrid endocannabinoid/endovanilloid substances, N-arachidonoyl-dopamine (NADA) and anandamide (AEA), presynapticaly increased or decreased intracellular calcium level ([Ca2+]i) and GABA and glutamate release in the hippocampus., [Experimental approach] Resting and K+-evoked levels of [Ca2+]i and the release of [3H]GABA and [3H]glutamate were measured in rat hippocampal nerve terminals., [Key results] NADA and AEA per se triggered a rise of [Ca2+]i and the release of both transmitters in a concentration- and external Ca2+-dependent fashion, but independently of TRPV1, CB1, CB2, or dopamine receptors, arachidonate-regulated Ca2+-currents, intracellular Ca2+ stores, and fatty acid metabolism. AEA was recently reported to block TASK-3 potassium channels thereby depolarizing membranes. Common inhibitors of TASK-3, Zn2+, Ruthenium Red, and low pH mimicked the excitatory effects of AEA and NADA, suggesting that their effects on [Ca2+]i and transmitter levels may be attributable to membrane depolarization upon TASK-3 blockade. The K+-evoked Ca2+ entry and Ca2+-dependent transmitter release were inhibited by nanomolar concentrations of the CB1 receptor agonist WIN55212-2; this action was sensitive to the selective CB1 receptor antagonist AM251. However, in the low micromolar range, WIN55212-2, NADA and AEA inhibited the K+-evoked Ca2+ entry and transmitter release independently of CB1 receptors, possibly through direct Ca2+ channel blockade., [Conclusions and implications] We report here for hybrid endocannabinoid/endovanilloid ligands novel dual functions which were qualitatively similar to activation of CB1 or TRPV1 receptors, but were mediated through interactions with different targets., This study was supported by the III/BIO/56/2005, and by the Fundação para a Ciência e Tecnologia (POCI2010/SFRH/BPD/18506/2004).

Snake venoms frequently vary in composition. In this work, we compared the neurotoxic and myotoxic activities of 16 lots of Bothrops neuwiedii venoms from different regions of Brazil, using chick biventer cervicis preparations. The neuromuscular blockade varied from 2% to 100% after 120 min incubation with venoms (50 mug/ml). In all cases, this blockade was irreversible and concentration-dependent; at low concentrations (10-20 mug/ml), 15 of the 16 venom lots failed to abolish responses to acetylcholine (110 muM), but blocked responses to KCl (13.4 muM), and induced contracture. At 5-20 mug/ml, the most active venom totally blocked twitch-tension without affecting responses to acetylcholine and KCl. Polyacrylamide gel electrophoresis for basic proteins showed that the most active samples contained a band that was absent in the less active venoms. These results indicate that there may be considerable intraspecific variation in the neurotoxic activity of B. neuwiedii venoms, whereas myotoxic activity is less variable.

1. The effect of central injection of selective kinin B1 and B2 receptor antagonists on the febrile response induced by endotoxin (E. coli lipopolysaccharide, LPS) in rats was investigated. 2. Intracerebroventricular (i.c.v.) injection of a selective B2 receptor antagonist (Hoe-140, 8 nmol) reduced the early (0-2 h), but increased the late phase (4-6 h) of the febrile response induced by intravenous (i.v.) injection of LPS (0.5 microgram kg-1). 3. Co-administration of Hoe-140 (8 nmol, i.c.v.) with LPS (0.5 microgram kg-1, i.v.), followed 2.5 h later by the i.c.v. injection of a selective B1 receptor antagonist [des-Arg9-Leu8]-bradykinin (BK, 8 nmol), significantly reduced the febrile response induced by LPS throughout the whole experimental period. 4. Intravenous injection of Hoe-140 (1 mg kg-1) significantly reduced the febrile response induced by LPS (0.5 microgram kg-1, i.p.). 5. Pretreatment (24 h) with LPS (0.5 microgram kg-1, i.v.) reduced the febrile response induced by BK or [Tyr8]-BK (both, 5 nmol, i.c.v.), but markedly increased the febrile response induced by [des-Arg9]-BK (5 nmol, i.c.v.). The response induced by [des-Arg9]-BK in LPS-pretreated rats was significantly inhibited by co-injection of [des-Arg9-Leu8]-BK (15 nmol, i.c.v.). 6. The results suggest that kinins are involved in the induction of LPS-induced fever and that central B2 and B1 receptors are activated during the initial and late phase of this response, respectively. The results also suggest that downregulation and/or desensitization of B2 receptors and induction and/or upregulation of B1 receptors in LPS-pretreated animals may have a significant pathophysiological role in the induction and maintenance of fever. These observations may be specifically important in the case of chronic inflammatory conditions, because the BK metabolite [des-Arg9]-BK, so far considered an inactive metabolite, acquires an active and relevant role with the progressive expression of B1 receptors that occurs in such states.