965 resultados para DIAMETRO APICAL
A new genus of grasshopper (orthoptera : acridoidea : Catantopidae : Cyrtacanthacridinae) from China
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This paper reports a new genus i.e. Parapachyacris gen. nov and a new species Parapachyacris taiwanensis sp. nov in Cyrtacathacridinae. The new genus is similar to Pachyacris Uvarov, 1923 and differs from the latter in: 1) foveolae lacking; 2) hind tibiae with 10 spines on inner side and 8 spines on outer side; 3) basal part of prostemal process thickened; 4) cross veins right angled with longitudinal veins in apical part of tegmina and 5) the back of body with yellow longitudinal stripe in middle. The new genus is also similar to Patanga Uvarov, 1923 and differs from the latter in: 1) foveolae lacking; 2) basal part of prostemal process thickened; 3) upper side of hind femora with three dark bands and 4) black spots of tegmina lacking. Type specimen is deposited in the National Museum of Natural Science (NMNH), Taichung, Taiwan, China.
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This paper reports a new genus and species of Catantopinae: Guizhouacris xiai gen et sp. nov. The new genus is similar to Genimen I. Bolivar, 1917, but differs from the latter in: 1) lateral lobes of metasternum separated in apical part and 2) prozona about 2.5 (male) and 2.7 (female) times longer than metazona. The new genus is also similar to Rhinopodisma Mishchenko, 1954 (= Aserratus Huang, 1981), but differs from the latter in: 1) diameter of tympanal aperture longer than half tergum and 2) face not projected between two eyes. Type specimens are deposited in the Museum of Hebei University ( MHU).
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Algumas espécies de ácaros encontram-se associadas com a cultura da mandioca (Manihot esculenta Crantz), com destaque para fitófagos pertencentes à família Tetranychidae. No Brasil, as seguintes espécies de Tetranychidae foram relatadas na cultura: Aponychus Shultzi, Mononychellus bondari, M. mcgregori, M. planki, M. tanajoa, Tetranychus desertorum, T. mexicanus e T. urticae. Dentre estas, merecem destaque o ácaro verde da mandioca, M. tanajoa, e o ácaro-rajado, T. urticae. Tetranychus urticae é da ampla distribuição geográfica e de ocorrência em várias culturas além de mandioca. Em geral as fêmeas apresentam cor esverdeada é encontrado na face inferior das folhas, preferencialmente nas partes medianas e basal da planta. As folhas atacadas apresentam na face superior pontos amarelados ao longo da nervura central se estendendo por toda folha, adquirindo coloração bronzeada; posteriormente secam e caem. Em ataques severos pode ocorrer perda das folhas basais e medianas da planta, avançando até a parte apical.
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O CPAA esta testando um metodo de conservacao fundamentado em aspectos genetico-ecologicos. Em uma area de 0,25ha, procurou-se representar as estrategias utilizadas pelas especies autoctones para manterem-se em equilibrio no ecossistema tropical: diversidade, densidade e variabilidade genetica. A pesquisa, iniciada em janeiro de 1994, estuda a conservacao de recursos geneticos de sete especies frutiferas (Theobroma grandiflorum, T. cacao, Bactris gasipaes, Euterpe spp, Myrciaria dubia, Rollinia mucosa e Couma utilis) e cinco florestais (Hevea spp, Ceiba pentandra, Jacaranda copaia, Buchenavia huber, Trattinickia burserifolia), utilizando-se tres espacamentos. As caracteristicas biometricas das plantas sao anualmente medidas e, apos cinco anos, a viabilidade tecnica sera avaliada quanto a sobrevivencia e capacidade das especies em deixar descendentes. Preliminarmente, as especies que apresentaram valores superiores na avaliacao de estabelecimento foram C. pentandra entre as florestais (medias de 4,76m de altura e 11,46cm de diametro, a 50cm do solo) e R. mucosa entre as fruteiras (media de 3,71m de altura e 6,28cm de diametro, a 50cm do solo).
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Com o objetivo de obter informacoes preliminares sobre o comportamento produtivo do rambuta e avaliar as caracteristicas fisicas do fruto cultivado em solo de Manaus, classe Latossolo amarelo, e clima do tipo Ami, foram avaliadas 20 plantas originadas de sementes de variedades de casca vermelha. As arvores entraram em floracao no terceiro ano apos o plantio, constatando-se a ocorrencia de sete plantas hermafroditas e 13 masculinas. As hermafroditas, no quarto ano de producao, registraram o numero maximo de 3590 e o minimo de 835 frutos por planta. Na caracterizacao fisica e quimica dos frutos, amostrada na segunda safra, verificou-se os maiores valores para: peso medio de fruto (36,52g), comprimento (5,01cm) e diametro (4,01cm) pertenceram a uma das plantas dentre as que menos se destacaram em numero de frutos. A polpa, representada por 43,97% do peso do fruto, apresentou pH de 4,2, acidez titulavel de 0,29%,solidos soluveis de 16,5oBrix e 82,19% de umidade, denotando caracteristicas apropriadas para consumo ao natural.
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Dois diferentes numeros de perfilhos de pupunheira foram estudados para producao de palmito nas condicoes edafoclimaticas do municio de Rio Preto da Eva (AM). O Espacamento utilizado foi de 2,5m x 1m, deixando-se dois perfilhos por cova. O que apresentou melhores resultados foi de dois perfilhos/cova, que produziu 713kg/ha/ano de palmito comestivel de primeira (tambem denominado creme), dos quais foram aproveitados 87%, um envasamento de 2067 frascos de vidro de 300g de peso drenado. O diametro medio do palmito creme (2,44cm), obtido por criterios fixados para abate das plantas, atendem a exigencia industrial. Foram taambem produzidas 40t/ha/ano de restos vegetais, proprios para arracoamento de ruminantes. A composicao centesimal do palmito creme, revelou que o mesmo pode usado como componente de dieta alimentar para emagrecimento.
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Foram avaliados, na colecao de fruteiras da Embrapa Amazonia Ocidental, cinco tipos de graviola (Morada, FAO II, Blanca, Lisa e B), com o objetivo de se verificar o desenvolvimento vegetativo, producao e caracteristicas do fruto. O plantio foi realizado em linha com dez plantas de cada tipo de graviola, em espacamento de 4m entre plantas e 8m entre linhas. As caracteristicas avaliadas foram: diametro do caule, diametro da copa, numero de frutos/planta, peso do fruto, peso da polpa, numero de sementes/fruto, peso das sementes, teor de solidos soluveis totais (°Brix) e periodo de frutificacao. No terceiro ano de plantio, Morada produziu, em media, 18 frutos/planta, com peso media de 2,82kg, e FAO II, 16 frutos/planta, com peso medio de 2,90kg, com producao estimada de 7,8t/ha e 7,2t/ha de frutos, respectivamente. Lisa apresentou a menor media de frutos/planta (duas unidades). Esses resultados indicam a viabilidade do cultivo de FAO II e Morada para as condicoes de Manaus.
Identificação do vírus do mosqueado do feijoeiro ("bean pod mottle virus") em soja no Brasil (2000).
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O virus do mosqueado do feijoeiro ("bean pod mottle virus" BPMV) foi identificado em plantas da soja, cultivar Itiquira, com sintomas de mosqueado, em Planaltina, Distrito Federal. Uma preparacao purificada do virus examinada em microcospio eletronico revelou a presenca de particulas isometricas em torno de 30 nm de diametro. Em testes de SDS-PAGE, foram detectadas tres proteinas com massas moleculares estimadas de 39,7, 22,9 e 21,2 kDa. A eficiencia media de transmissao do isolado do BPMV em estudo pelo crisomelideo Cerotoma arcuata Oliv. Em tres experimentos foi de 66,7%. Em experimentos de campo, o BPMV reduziu a producao de graos nas cultivares de soja Garca Branca, Garimpo, Doko, Itiquira e Pioneira em 17,1% , 17,1%, 20,4%, 20,9% e 21,4%, respectivamente.
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
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Modern neuroscience relies heavily on sophisticated tools that allow us to visualize and manipulate cells with precise spatial and temporal control. Transgenic mouse models, for example, can be used to manipulate cellular activity in order to draw conclusions about the molecular events responsible for the development, maintenance and refinement of healthy and/or diseased neuronal circuits. Although it is fairly well established that circuits respond to activity-dependent competition between neurons, we have yet to understand either the mechanisms underlying these events or the higher-order plasticity that synchronizes entire circuits. In this thesis we aimed to develop and characterize transgenic mouse models that can be used to directly address these outstanding biological questions in different ways. We present SLICK-H, a Cre-expressing mouse line that can achieve drug-inducible, widespread, neuron-specific manipulations in vivo. This model is a clear improvement over existing models because of its particularly strong, widespread, and even distribution pattern that can be tightly controlled in the absence of drug induction. We also present SLICK-V::Ptox, a mouse line that, through expression of the tetanus toxin light chain, allows long-term inhibition of neurotransmission in a small subset (<1%) of fluorescently labeled pyramidal cells. This model, which can be used to study how a silenced cell performs in a wildtype environment, greatly facilitates the in vivo study of activity-dependent competition in the mammalian brain. As an initial application we used this model to show that tetanus toxin-expressing CA1 neurons experience a 15% - 19% decrease in apical dendritic spine density. Finally, we also describe the attempt to create additional Cre-driven mouse lines that would allow conditional alteration of neuronal activity either by hyperpolarization or inhibition of neurotransmission. Overall, the models characterized in this thesis expand upon the wealth of tools available that aim to dissect neuronal circuitry by genetically manipulating neurons in vivo.
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The Gastro-Intestinal (GI) tract is a unique region in the body. Our innate immune system retains a fine homeostatic balance between avoiding inappropriate inflammatory responses against the myriad commensal microbes residing in the gut while also remaining active enough to prevent invasive pathogenic attack. The intestinal epithelium represents the frontline of this interface. It has long been known to act as a physical barrier preventing the lumenal bacteria of the gastro-intestinal tract from activating an inflammatory immune response in the immune cells of the underlying mucosa. However, in recent years, an appreciation has grown surrounding the role played by the intestinal epithelium in regulating innate immune responses, both in the prevention of infection and in maintaining a homeostatic environment through modulation of innate immune signalling systems. The aim of this thesis was to identify novel innate immune mechanisms regulating inflammation in the GI tract. To achieve this aim, we chose several aspects of regulatory mechanisms utilised in this region by the innate immune system. We identified several commensal strains of bacteria expressing proteins containing signalling domains used by Pattern Recognition Receptors (PRRs) of the innate immune system. Three such bacterial proteins were studied for their potentially subversive roles in host innate immune signalling as a means of regulating homeostasis in the GI tract. We also examined differential responses to PRR activation depending on their sub-cellular localisation. This was investigated based on reports that apical Toll-Like Receptor (TLR) 9 activation resulted in abrogation of inflammatory responses mediated by other TLRs in Intestinal Epithelial Cells (IECs) such as basolateral TLR4 activation. Using the well-studied invasive intra-cellular pathogen Listeria monocytogenes as a model for infection, we also used a PRR siRNA library screening technique to identify novel PRRs used by IECs in both inhibition and activation of inflammatory responses. Many of the PRRs identified in this screen were previously believed not to be expressed in IECs. Furthermore, the same study has led to the identification of the previously uncharacterised TLR10 as a functional inflammatory receptor of IECs. Further analysis revealed a similar role in macrophages where it was shown to respond to intracellular and motile pathogens such as Gram-positive L.monocytogenes and Gram negative Salmonella typhimurium. TLR10 expression in IECs was predominantly intracellular. This is likely in order to avoid inappropriate inflammatory activation through the recognition of commensal microbial antigens on the apical cell surface of IECs. Moreover, these results have revealed a more complex network of innate immune signalling mechanisms involved in both activating and inhibiting inflammatory responses in IECs than was previously believed. This contribution to our understanding of innate immune regulation in this region has several direct and indirect benefits. The identification of several novel PRRs involved in activating and inhibiting inflammation in the GI tract may be used as novel therapeutic targets in the treatment of disease; both for inducing tolerance and reducing inflammation, or indeed, as targets for adjuvant activation in the development of oral vaccines against pathogenic attack.
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BACKGROUND: Myosin VIIA (MyoVIIA) is an unconventional myosin necessary for vertebrate audition [1]-[5]. Human auditory transduction occurs in sensory hair cells with a staircase-like arrangement of apical protrusions called stereocilia. In these hair cells, MyoVIIA maintains stereocilia organization [6]. Severe mutations in the Drosophila MyoVIIA orthologue, crinkled (ck), are semi-lethal [7] and lead to deafness by disrupting antennal auditory organ (Johnston's Organ, JO) organization [8]. ck/MyoVIIA mutations result in apical detachment of auditory transduction units (scolopidia) from the cuticle that transmits antennal vibrations as mechanical stimuli to JO. PRINCIPAL FINDINGS: Using flies expressing GFP-tagged NompA, a protein required for auditory organ organization in Drosophila, we examined the role of ck/MyoVIIA in JO development and maintenance through confocal microscopy and extracellular electrophysiology. Here we show that ck/MyoVIIA is necessary early in the developing antenna for initial apical attachment of the scolopidia to the articulating joint. ck/MyoVIIA is also necessary to maintain scolopidial attachment throughout adulthood. Moreover, in the adult JO, ck/MyoVIIA genetically interacts with the non-muscle myosin II (through its regulatory light chain protein and the myosin binding subunit of myosin II phosphatase). Such genetic interactions have not previously been observed in scolopidia. These factors are therefore candidates for modulating MyoVIIA activity in vertebrates. CONCLUSIONS: Our findings indicate that MyoVIIA plays evolutionarily conserved roles in auditory organ development and maintenance in invertebrates and vertebrates, enhancing our understanding of auditory organ development and function, as well as providing significant clues for future research.
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The enteroendocrine cell is the cornerstone of gastrointestinal chemosensation. In the intestine and colon, this cell is stimulated by nutrients, tastants that elicit the perception of flavor, and bacterial by-products; and in response, the cell secretes hormones like cholecystokinin and peptide YY--both potent regulators of appetite. The development of transgenic mice with enteroendocrine cells expressing green fluorescent protein has allowed for the elucidation of the apical nutrient sensing mechanisms of the cell. However, the basal secretory aspects of the enteroendocrine cell remain largely unexplored, particularly because a complete account of the enteroendocrine cell ultrastructure does not exist. Today, the fine ultrastructure of a specific cell can be revealed in the third dimension thanks to the invention of serial block face scanning electron microscopy (SBEM). Here, we bridged confocal microscopy with SBEM to identify the enteroendocrine cell of the mouse and study its ultrastructure in the third dimension. The results demonstrated that 73.5% of the peptide-secreting vesicles in the enteroendocrine cell are contained within an axon-like basal process. We called this process a neuropod. This neuropod contains neurofilaments, which are typical structural proteins of axons. Surprisingly, the SBEM data also demonstrated that the enteroendocrine cell neuropod is escorted by enteric glia--the cells that nurture enteric neurons. We extended these structural findings into an in vitro intestinal organoid system, in which the addition of glial derived neurotrophic factors enhanced the development of neuropods in enteroendocrine cells. These findings open a new avenue of exploration in gastrointestinal chemosensation by unveiling an unforeseen physical relationship between enteric glia and enteroendocrine cells.
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The peptide tyrosine tyrosine (PYY) is produced and secreted from L cells of the gastrointestinal mucosa. To study the anatomy and function of PYY-secreting L cells, we developed a transgenic PYY-green fluorescent protein mouse model. PYY-containing cells exhibited green fluorescence under UV light and were immunoreactive to antibodies against PYY and GLP-1 (glucagon-like peptide-1, an incretin hormone also secreted by L cells). PYY-GFP cells from 15 μm thick sections were imaged using confocal laser scanning microscopy and three-dimensionally (3D) reconstructed. Results revealed unique details of the anatomical differences between ileal and colonic PYY-GFP cells. In ileal villi, the apical portion of PYY cells makes minimal contact with the lumen of the gut. Long pseudopod-like basal processes extend from these cells and form an interface between the mucosal epithelium and the lamina propria. Some basal processes are up to 50 μm in length. Multiple processes can be seen protruding from one cell and these often have a terminus resembling a synapse that appears to interact with neighboring cells. In colonic crypts, PYY-GFP cells adopt a spindle-like shape and weave in between epithelial cells, while maintaining contact with the lumen and lamina propria. In both tissues, cytoplasmic granules containing the hormones PYY and GLP-1 are confined to the base of the cell, often filling the basal process. The anatomical arrangement of these structures suggests a dual function as a dock for receptors to survey absorbed nutrients and as a launching platform for hormone secretion in a paracrine fashion.