54,034 research outputs found
Investigation of the agricultural resources in Sri Lanka
The author has identified the following significant results. Several in-house capabilities were developed. The facilities to prepare color composites of excellent quality were developed, using bulk B/W 70 mm transparencies or 1:1,000,000 positive transparencies. These color composites were studied through optical devices on light tables. A zoom transfer scope was also added, enabling direct transfer of LANDSAT composite data on to base maps
Neuronal glucose transporter isoform 3 deficient mice demonstrate features of autism spectrum disorders.
Neuronal glucose transporter (GLUT) isoform 3 deficiency in null heterozygous mice led to abnormal spatial learning and working memory but normal acquisition and retrieval during contextual conditioning, abnormal cognitive flexibility with intact gross motor ability, electroencephalographic seizures, perturbed social behavior with reduced vocalization and stereotypies at low frequency. This phenotypic expression is unique as it combines the neurobehavioral with the epileptiform characteristics of autism spectrum disorders. This clinical presentation occurred despite metabolic adaptations consisting of an increase in microvascular/glial GLUT1, neuronal GLUT8 and monocarboxylate transporter isoform 2 concentrations, with minimal to no change in brain glucose uptake but an increase in lactate uptake. Neuron-specific glucose deficiency has a negative impact on neurodevelopment interfering with functional competence. This is the first description of GLUT3 deficiency that forms a possible novel genetic mechanism for pervasive developmental disorders, such as the neuropsychiatric autism spectrum disorders, requiring further investigation in humans
Correlation length scalings in fusion edge plasma turbulence computations
The effect of changes in plasma parameters, that are characteristic near or
at an L-H transition in fusion edge plasmas, on fluctuation correlation lengths
are analysed by means of drift-Alfven turbulence computations. Scalings by
density gradient length, collisionality, plasma beta, and by an imposed shear
flow are considered. It is found that strongly sheared flows lead to the
appearence of long-range correlations in electrostatic potential fluctuations
parallel and perpendicular to the magnetic field.Comment: Submitted to "Plasma Physics and Controlled Fusion
Bulgac-Kusnezov-Nos\'e-Hoover thermostats
In this paper we formulate Bulgac-Kusnezov constant temperature dynamics in
phase space by means of non-Hamiltonian brackets. Two generalized versions of
the dynamics are similarly defined: one where the Bulgac-Kusnezov demons are
globally controlled by means of a single additional Nos\'e variable, and
another where each demon is coupled to an independent Nos\'e-Hoover thermostat.
Numerically stable and efficient measure-preserving time-reversible algorithms
are derived in a systematic way for each case. The chaotic properties of the
different phase space flows are numerically illustrated through the
paradigmatic example of the one-dimensional harmonic oscillator. It is found
that, while the simple Bulgac-Kusnezov thermostat is apparently not ergodic,
both of the Nos\'e-Hoover controlled dynamics sample the canonical distribution
correctly
Water-Deprived Parasitic Wasps (Pachycrepoideus vindemmiae) Kill More Pupae of a Pest (Drosophila suzukii) as a Water-Intake Strategy.
Most organisms must ingest water to compensate for dehydration. In parasitic wasps, the importance of water and the behaviors driving its consumption are poorly understood. Here, we describe a waterintake strategy of Pachycrepoideus vindemmiae, a parasitoid of spotted-wing drosophila (SWD, Drosophila suzukii). Longevity measurements indicated that P. vindemmiae benefits from drinking water and from host-feeding on the water-rich hemolymph of SWD pupae. After exposing wasps to different water regimens, we observed increased host-feeding in water-deprived wasps despite honey availability. This resulted in greater SWD mortality because the host-feeding process killed the pupae, and because wasps that engaged in greater host-feeding parasitized more hosts. Behavioral observations showed that the host-feeding time of water-deprived wasps doubled compared to water-fed individuals. Host-feeding did not affect parasitoid offspring mortality. We conclude that P. vindemmiae benefits from ingesting water and that it host-feeds on SWD pupae as a water-intake strategy. These are interesting findings not only because water has rarely been reported as a critical nutrient for adult parasitoids, but especially because preying for the purpose of hydration is not a common strategy in nature. This strategy enhances parasitoid survival and reproduction, with positive consequences for its host-killing capacity and potential as a biocontrol agent
Identificação e caracterização de microssatélites de Coffea arabica a partir de dados de sequenciamento de RNA e de BACS.
O café é uma das principais commodities agrícolas mundiais, sendo consumido regularmente por 40% de toda população. As espécies, Coffea arabica L. e Coffea canephora P. são as de maior importância respondendo por 65% e 35% da produção mundial, respectivamente. Em C. arabica , o desenvolvimento de novas cultivares é demorado, podendo levar mais de 20 anos para finalização dos trabalhos. Além disso, estreita base genética de C. arabica dificulta a obtenção de cultivares resistentes a várias pragas e doenças, assim como uma maior tolerância a estresses abióticos. A utilização de marcadores moleculares para análise da diversidade e seleção de genótipos representa uma importante ferramenta para auxiliar o melhoramento e tentar diminuir esses problemas. Neste trabalho foi realizada identificação e análise in silico de SSR?s a partir de dados de RNA-seq de Iapar 59 e de sequências de BACs de Hibrido de Timor 832/2 (CaHT). Para Iapar 59 foram analisados 77 contigs, encontrados 39 SSR?s e desenhados 21 pares de oligonucleotídeos. Para CaHT foram analisados também 77 contigs, encontrados 35 SSR?s e desenhados 29 pares de oligonucleotídeos. Os motivos com maior frequência foram di, tri e tetranucleotídeos, sendo (AT) no motivo mais frequente entre os dois genótipos. Esta busca de sequências repetitivas é de grande importância para futura validação e aumento desses marcadores para estudos de diversidade genética, mapeamento, e a ssociação com características agronômicas de interesse
Stochastic Modelling Approach to the Incubation Time of Prionic Diseases
Transmissible spongiform encephalopathies like the bovine spongiform
encephalopathy (BSE) and the Creutzfeldt-Jakob disease (CJD) in humans are
neurodegenerative diseases for which prions are the attributed pathogenic
agents. A widely accepted theory assumes that prion replication is due to a
direct interaction between the pathologic (PrPsc) form and the host encoded
(PrPc) conformation, in a kind of an autocatalytic process. Here we show that
the overall features of the incubation time of prion diseases are readily
obtained if the prion reaction is described by a simple mean-field model. An
analytical expression for the incubation time distribution then follows by
associating the rate constant to a stochastic variable log normally
distributed. The incubation time distribution is then also shown to be log
normal and fits the observed BSE data very well. The basic ideas of the
theoretical model are then incorporated in a cellular automata model. The
computer simulation results yield the correct BSE incubation time distribution
at low densities of the host encoded protein
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