Qualidade sanitária e produção de fumonisina B1 em grãos de milho em fase de pré-colheita.

Trinta e seis (36) cultivares de milho foram avaliadas em relação à incidência de grãos ardidos, mofados e produção de fumonisina B1. Amostras de 1,2 kg de grãos foram analisadas visualmente para a quantificação de grãos ardidos (Fusarium subglutinans), mofados (Penicillium oxalicum) e para a análise de fumonisina B1. Os grãos ardidos foram submetidos à análise de sanidade (papel de filtro com congelamento) visando identificar os fungos a eles associados. A cultivar Hatã 3052 apresentou 7,6% de grãos ardidos, ultrapassando o limite de tolerância que é de 6,0%. As cultivares AG 5011, HT 7105-3, Dina 1000 e C 701 apresentaram 16,8% , 3,4%, 3,2% e 3,1 % de grãos mofados, respectivamente, acima do limite de tolerância que é de 3,0%. O fungo Fusarium subglutinans (Gibberella fujikuroi var. subglutinans) foi o causador de grãos ardidos, cuja detecção variou de 50,0 a 99,0%. A análise de variância mostrou diferenças significativa entre as cultivares com relação às incidências de grãos ardidos e de grãos mofados. Com relação à produção de fumonisina B1, as cultivares Hatã 3052, NB 6077 e 983 P produziram 7,0; 6,1 e 5,9 ug.g1 de grãos, respectivamente, diferindo significativamente da cultivar P3071(2,2 ug.g-1 de grãos). Conclui-se que há diferenças significativas entre as cultivares de milho em relação à produção de grãos ardidos e mofados, bem como acentuada interação entre as cultivares e o fungo toxigênico Fusarium subglutinans (Gibberella fujikuroi var. subglutinans) quanto à biossíntese de fumonisina B1 em grãos de milho

Dilaton Quantum Cosmology with a Schrodinger-like equation

A quantum cosmological model with radiation and a dilaton scalar field is analysed. The Wheeler-deWitt equation in the mini-superspace induces a Schr\"odinger equation, which can be solved. An explicit wavepacket is constructed for a particular choice of the ordering factor. A consistent solution is possible only when the scalar field is a phantom field. Moreover, although the wavepacket is time dependent, a Bohmian analysis allows to extract a bouncing behaviour for the scale factor.Comment: 14 pages, 3 figures in eps format. Minors corrections, new figure

Manejo da fertilidade do solo na implantacao da cultura da mangueira.

bitstream/CPAC-2010/23066/1/rectec-48.pd

Manejo da fertilidade do solo e adubacao no pre-plantio e plantio da gravioleira.

bitstream/CPAC-2010/23067/1/rectec-47.pd

Planting time for maximization of yield of vinegar plant calyx (Hibiscus sabdariffa L.)

Objetivou-se avaliar a produtividade de cálices de Hibiscus sabdariffa L., planta medicinal, em quatro épocas de plantio em Lavras M.G. Os tratamentos foram quatro épocas de plantio (18 de outubro; 15 de novembro; 18 de dezembro de 2001 e 15 de janeiro de 2002) e realizada uma colheita quando praticamente não existiam cálices em desenvolvimento, quase no final do ciclo da planta. Foram considerados os números de cálices por planta, as fitomassas frescas e secas dos cálices e a qualidade. Concluiu-se que a época de plantio influenciou o rendimento por planta e as fitomassas frescas e secas dos cálices, diferindo entre si pelo teste de Tukey a 5%. No plantio de outubro, houve maior rendimento (2.522 kg/ha), com produção de 5,24 vezes a mais em relação ao plantio do mês de janeiro (481 kg/ha). Os plantios nos meses de novembro e dezembro tiveram produções de 1.695 e 1.093 kg.ha-1 de cálices secos, respectivamente, e em relação ao mês de janeiro, a produção foi 3,52 e 2,27 vezes a mais.Deve-se realizar a colheita assim que os cálices estiverem maduros, a fim de preservar a qualidade

The genomic basis of army ant chemosensory adaptations

The evolution of mass raiding has allowed army ants to become dominant arthropod predators in the tropics. Although a century of research has led to many discoveries about behavioural, morphological and physiological adaptations in army ants, almost nothing is known about the molecular basis of army ant biology. Here we report the genome of the iconic New World army ant Eciton burchellii, and show that it is unusu-ally compact, with a reduced gene complement relative to other ants. In contrast to this overall reduction, a particular gene subfamily (9-exon ORs) expressed predomi-nantly in female antennae is expanded. This subfamily has previously been linked to the recognition of hydrocarbons, key olfactory cues used in insect communication and prey discrimination. Confocal microscopy of the brain showed a correspond-ing expansion in a putative hydrocarbon response centre within the antennal lobe, while scanning electron microscopy of the antenna revealed a particularly high den-sity of hydrocarbon-sensitive sensory hairs. E. burchellii shares these features with its predatory and more cryptic relative, the clonal raider ant. By integrating genomic, transcriptomic and anatomical analyses in a comparative context, our work thus pro-vides evidence that army ants and their relatives possess a suite of modifications in the chemosensory system that may be involved in behavioural coordination and prey selection during social predation. It also lays the groundwork for future studies of army ant biology at the molecular level.National Science Foundation/[NSF IOS 1916995]/NSF/Estados UnidosNational Science Foundation/[NSF DEB 1900357]/NSF/Estados UnidosUniversity of Wisconsin-Madison/[BE 5177/4-1]//Estados UnidosUniversidad de Costa Rica/[810-B3-273]/UCR/Costa RicaNational Institutes of Health/[GM066699]/NIH/Estados UnidosMarie Skłodowska-Curie Individual Fellowship/[ID 797969]/MSCA IF/BélgicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM)UCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicin

Descontaminacao de gemas laterais de mangueira (Mangifera indica L.) visando a micropropagacao.

bitstream/CPAC-2009/24390/1/p2003_41.pd

A Transmission Power Self-Optimization Technique for Wireless Sensor Networks

Wireless sensor networks (WSNs) are generally used to monitor hazardous events in inaccessible areas. Thus, on one hand, it is preferable to assure the adoption of the minimum transmission power in order to extend as much as possible the WSNs lifetime. On the other hand, it is crucial to guarantee that the transmitted data is correctly received by the other nodes. Thus, trading off power optimization and reliability insurance has become one of the most important concerns when dealing with modern systems based on WSN. In this context, we present a transmission power self-optimization (TPSO) technique for WSNs. The TPSO technique consists of an algorithm able to guarantee the connectivity as well as an equally high quality of service (QoS), concentrating on the WSNs efficiency (Ef), while optimizing the transmission power necessary for data communication. Thus, the main idea behind the proposed approach is to trade off WSNs Ef against energy consumption in an environment with inherent noise. Experimental results with different types of noise and electromagnetic interference (EMI) have been explored in order to demonstrate the effectiveness of the TPSO technique

Ensaios preliminares para o estabelecimento de um protocolo de assepsia, visando a micropropagação de cultivares de mangueira.

RESUMO: Visando ao estabelecimento de um protocolo de assepsia para a micropropagação de diferentes cultivares de mangueira, foram coletadas no campo, por um período de dois anos (2000-2001), microestacas e folhas jovens e tratadas no laboratório com hipoclorito de sódio (v/v) 2% com Tween 80 a 0,025% por 15 minutos no caso de microestacas e, 0,5; 1,0; 1,5 e 2% com Tween 80 a 0,06 por 5 minutos no caso de folhas jovens. As microestacas, depois da assepsia com hipoclorito de sódio foram tratadas também com Benomyl 200mg/L por 30 minutos, ficando, em seguida, em magentas com vermiculita umedecidas em água estéril. As folhas jovens depois da assepsia foram colocadas em placas de Petri, contendo meio nutritivo básico SP com polivinilpirrolidona, Benomyl e carbenicilina. As condições de temperatura e de luz no laboratório foram 28± 2 °C e 12 horas de fotoperíodo. As microestacas foram retiradas das variedades Alfa (Embrapa 142), Tommy Atkins e a seleção híbrida Embrapa CPAC 136-86, que mantiveram assepsia média durante os dois anos de 49, 43, e 60% respectivamente. Também foram avaliados os brotos emitidos periodicamente por elas, constatando-se que a maior freqüência de brotação foi a da cultivar Alfa (53%) seguida por Tommy Atkins (24%). Houve efeito sazonal na indução desses brotos e que janeiro de abril de 2000, os meses em que se obteve a maior quantidade de brotos de tamanho grande. No estudo em que foram utilizadas folhas jovens, as seleções híbridas estudadas foram Embrapa CPAC 136-86 e Embrapa CPAC 2-97. Os valores médio de assepsia obtidos no período de fevereiro de 2001 foram 100% e 70% respectivamente. Ocorreu oxidação fenólica em todos os genótipos estudados, sendo esta influenciada pela concentração de hipoclorito que foi maior na seleção híbrida Embrapa CPAC 136-86. A concentração de 0,5% foi aquela em que se observou o menor número de oxidação fenólica nos explantes de seleção híbrida Embrapa CPAC 2-97 apesar de ter ocorrido maior contaminação. ABSTRACT: In order to establish an assepsy protocol to micropropagate different cultivars of mango it was collected in the field during two years (2000-2001) microshootings and young leaves, in the laboratory, they were treated with 2% sodium hypoclorite with 0.025% Tween 80 for 15 minutes in the case of microshootings and 0,5; 1; 1,5 and 2% with 0.06% Tween 80 for 5 minutes in the case of young leaves. The microshootings after assepsy with sodium hypoclorite were treated in a 200 mg/l Benomyl solution for 30 minutes and after that were put into magenta vessels containing wet vermiculite. The young leaves after assepsy were transferred in Petri dishes containing SP medium with polyvinilpirrolidone, Benomyl and carbenicilin. The temperature and photoperiod conditions in the laboratory were 28 ± 2 °C and 12 h. In the microshooting study, the evaluated varieties were Alfa (Embrapa 142), Tommy Atkins and hybrid Embrapa Embrapa CPAC 136-86. They revealed a media assepsy in these two years of 49, 43 and 60% respectively. The periodical emergency of buds were also evaluated in the microshootings and it was observed that a higher frequency of appearance was in the Alfa cultivar (53%) followed by Tommy Atkins (24%). In microshootings, the sazonal effect influenced the budding induction and, January and April of 2000 was the season in wich we observed more budding with large size. In the case of young leaves, the studied genotypes were Embrapa CPAC 136-86 and Embrapa CPAC 2-97. The media values of assepsy in February of 2001 period were 100 and 70% respectively. It was observed the production of phenolic oxidative process caused by hypoclorite concentration occurring differently among studied genotypes. The most influenced one was Embrapa CPAC 136-86. Sodium hypoclorite in 0,5% concentration demonstrated less tissue damage provided by oxidation although a higher contamination.bitstream/CPAC-2009/24661/1/bolpd_43.pd

Altered mechanobiology of Schlemm’s canal endothelial cells in glaucoma

Increased flow resistance is responsible for the elevated intraocular pressure characteristic of glaucoma, but the cause of this resistance increase is not known. We tested the hypothesis that altered biomechanical behavior of Schlemm’s canal (SC) cells contributes to this dysfunction. We used atomic force microscopy, optical magnetic twisting cytometry, and a unique cell perfusion apparatus to examine cultured endothelial cells isolated from the inner wall of SC of healthy and glaucomatous human eyes. Here we establish the existence of a reduced tendency for pore formation in the glaucomatous SC cell—likely accounting for increased outflow resistance—that positively correlates with elevated subcortical cell stiffness, along with an enhanced sensitivity to the mechanical microenvironment including altered expression of several key genes, particularly connective tissue growth factor. Rather than being seen as a simple mechanical barrier to filtration, the endothelium of SC is seen instead as a dynamic material whose response to mechanical strain leads to pore formation and thereby modulates the resistance to aqueous humor outflow. In the glaucomatous eye, this process becomes impaired. Together, these observations support the idea of SC cell stiffness—and its biomechanical effects on pore formation—as a therapeutic target in glaucoma