Gain Dependence of the Noise in the Single Electron Transistor

An extensive investigation of low frequency noise in single electron transistors as a function of gain is presented. Comparing the output noise with gain for a large number of bias points, it is found that the noise is dominated by external charge noise. For low gains we find an additional noise contribution which is compared to a model including resistance fluctuations. We conclude that this excess noise is not only due to resistance fluctuations. For one sample, we find a record low minimum charge noise of qn = 9*10^-6 e/sqrt(Hz) in the superconducting state and qn = 9*10^-6 e/sqrt(Hz) in the normal state at a frequency of 4.4 kHz.Comment: 10 pages, LaTex 2.09, 4 figures (epsfig

Statistical Modeling of Epistasis and Linkage Decay using Logic Regression

Logic regression has been recognized as a tool that can identify and model non-additive genetic interactions using Boolean logic groups. Logic regression, TASSEL-GLM and SAS-GLM were compared for analytical precision using a previously characterized model system to identify the best genetic model explaining epistatic interaction of vernalization-sensitivity in barley. A genetic model containing two molecular markers identified in vernalization response in barley was selected using logic regression while both TASSEL-GLM and SAS-GLM included spurious associations in their models. The results also suggest the logic regression can be used to identify dominant/recessive relationships between epistatic alleles through its use of conjugate
operators

Deep near-infrared imaging of W3 Main: constraints on stellar cluster formation

Embedded clusters like W3 Main are complex and dynamically evolving systems that represent an important phase of the star formation process. We aim at the characterization of the entire stellar content of W3 Main in a statistical sense to identify possible differences in evolutionary phase of the stellar populations and find clues about the formation mechanism of this massive embedded cluster. Methods. Deep JHKs imaging is used to derive the disk fraction, Ks-band luminosity functions and mass functions for several subregions in W3 Main. A two dimensional completeness analysis using artificial star experiments is applied as a crucial ingredient to assess realistic completeness limits for our photometry. We find an overall disk fraction of 7.7 $\pm$ 2.3%, radially varying from 9.4 $\pm$ 3.0 % in the central 1 pc to 5.6 $\pm$ 2.2 % in the outer parts of W3 Main. The mass functions derived for three subregions are consistent with a Kroupa and Chabrier mass function. The mass function of IRSN3 is complete down to 0.14 Msun and shows a break at M $\sim$ 0.5 Msun. We interpret the higher disk fraction in the center as evidence for a younger age of the cluster center. We find that the evolutionary sequence observed in the low-mass stellar population is consistent with the observed age spread among the massive stars. An analysis of the mass function variations does not show evidence for mass segregation. W3 Main is currently still actively forming stars, showing that the ionizing feedback of OB stars is confined to small areas ($\sim$ 0.5 pc). The FUV feedback might be influencing large regions of the cluster as suggested by the low overall disk fraction.Comment: 15 pages, 13 figures, accepted by A&

Determinação de raça fisiológica e fontes de resistência ao míldio do girassol (Plasmopara halstedii (Farl.) Berl. & de Toni.

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Harmonics added to a flickering light can upset the balance between ON and OFF pathways to produce illusory colors

The neural signals generated by the light-sensitive photoreceptors in the human eye are substantially processed and recoded in the retina before being transmitted to the brain via the optic nerve. A key aspect of this recoding is the splitting of the signals within the two major cone-driven visual pathways into distinct ON and OFF branches that transmit information about increases and decreases in the neural signal around its mean level. While this separation is clearly important physiologically, its effect on perception is unclear. We have developed a model of the ON and OFF pathways in early color processing. Using this model as a guide, we can produce imbalances in the ON and OFF pathways by changing the shapes of time-varying stimulus waveforms and thus make reliable and predictable alterations to the perceived average color of the stimulus—although the physical mean of the waveforms does not change. The key components in the model are the early half-wave rectifying synapses that split retinal photoreceptor outputs into the ON and OFF pathways and later sigmoidal nonlinearities in each pathway. The ability to systematically vary the waveforms to change a perceptual quality by changing the balance of signals between the ON and OFF visual pathways provides a powerful psychophysical tool for disentangling and investigating the neural workings of human vision

Qualidade fisiologica e sanitaria de sementes de soja.

Qualidade fisiologica da semente; Deterioracao no campo; Colheita no momento adequado; Aplicacao de dessecantes; Aplicacao de fungicidas foliares; Semeadura em epoca adequada; Determinacao de regioes mais propicias a producao de sementes; Utilizacao de cultivares para sementes de boa qualidade; Danos mecanicos; Danos causados por percevejos; Qulidade sanitaria da semente; Fungos fitopatogenicos; Phomopsis sp. - queima da haste e da vagem; Colletotrichum dematium (Pers. ex. Fr.) Grove var. truncata (Schw.) von Arx. - antracnose; Cercospora kikuchii (Matsu. & Tomoy) Gardner - mancha purpura; Cercospora sojina Hara - mancha "olho-de-ra"; Macrophomina phaseolina (Tassi) Goid - podridao preta das raizes; Rhizoctonia solani Kuhn - tombamento e morte em reboleira; Sclerotnia sclerotiorum Lib (De Bary) - podridao branca da haste e da vagem; Peronospora manshurica (Naum:) Syd. ex. Gaum. - mildio da soja; Sclerotium rolfsii Sacc. - murcha de esclerocio; Fusarium semitectum Berk & Rav; Myrothecium roridum - (Tode ex Sacc. ) mancha de mirotecio; Corynespora cassiicola (Berk & Curt) Wei - mancha-alvo; Fungos de armazenagem ou nao fitopatogenicos; Aspergillus spp.; Penicillium spp.; Outros.bitstream/item/50774/1/9.pd