31,479 research outputs found
Jumping bristletail (Insecta: Apterygota: Microcoryphia) records in the southeastern United States
Few records of Microcoryphia exist for the southeastern United States, with named species being reported only from Arkansas, Tennessee, and the mid-Atlantic states, and with an unnamed species being reported from Georgia. Records are here provided from 291 specimens housed in the Mississippi Entomological Museum, including ten new species-level state records. This is also the first published report of the order Microcoryphia from Alabama and Mississippi. Species include the machilids Pedetontoides atlanticus Mendes in Alabama, Arkansas, Georgia, Mississippi, and North Carolina; Pedetontus cf. atlanticus in Kentucky; Pedetontus (Verhoeffilis) gershneri Allen in Arkansas; and Pedetontus (Pedetontus) saltator Wygodzinsky and Schmidt in Mississippi and North Carolina; and the meinertellid Machiloides banksi (Silvestri) in Alabama, Arkansas, Mississippi, and North Carolina
Within- and between-pen transmission of Classical Swine Fever Virus: a new method to estimate the basic reproduction ratio from transmission experiments
We present a method to estimate basic reproduction ratio R0 from transmission experiments. By using previously published data of experiments with Classical Swine Fever Virus more extensively, we obtained smaller confidence intervals than the martingale method used in the original papers. Moreover, our method allows simultaneous estimation of a reproduction ratio within pens R0w and a modified reproduction ratio between pens R'0b. Resulting estimates of R0w and R'0b for weaner pigs were 100 (95% CI 54.4-186) and 7.77 (4.68-12.9), respectively. For slaughter pigs they were 15.5 (6.20-38.7) and 3.39 (1.54-7.45), respectively. We believe, because of the smaller confidence intervals we were able to obtain, that the method presented here is better suited for use in future experiments
Probabilities of spurious connections in gene networks: Application to expression time series
Motivation: The reconstruction of gene networks from gene expression
microarrays is gaining popularity as methods improve and as more data become
available. The reliability of such networks could be judged by the probability
that a connection between genes is spurious, resulting from chance fluctuations
rather than from a true biological relationship. Results: Unlike the false
discovery rate and positive false discovery rate, the decisive false discovery
rate (dFDR) is exactly equal to a conditional probability without assuming
independence or the randomness of hypothesis truth values. This property is
useful not only in the common application to the detection of differential gene
expression, but also in determining the probability of a spurious connection in
a reconstructed gene network. Estimators of the dFDR can estimate each of three
probabilities: 1. The probability that two genes that appear to be associated
with each other lack such association. 2. The probability that a time ordering
observed for two associated genes is misleading. 3. The probability that a time
ordering observed for two genes is misleading, either because they are not
associated or because they are associated without a lag in time. The first
probability applies to both static and dynamic gene networks, and the other two
only apply to dynamic gene networks. Availability: Cross-platform software for
network reconstruction, probability estimation, and plotting is free from
http://www.davidbickel.com as R functions and a Java application.Comment: Like q-bio.GN/0404032, this was rejected in March 2004 because it was
submitted to the math archive. The only modification is a corrected reference
to q-bio.GN/0404032, which was not modified at al
The Trouble with Hubble Types in the Virgo Cluster
Quantitative measures of central light concentration and star formation
activity are derived from R and Halpha surface photometry of 84 bright S0-Scd
Virgo Cluster and isolated spiral galaxies. For isolated spirals, there is a
good correlation between these two parameters and assigned Hubble types. In the
Virgo Cluster, the correlation between central light concentration and star
formation activity is significantly weaker. Virgo Cluster spirals have
systematically reduced global star formation with respect to isolated spirals,
with severe reduction in the outer disk, but normal or enhanced activity in the
inner disk. Assigned Hubble types are thus inadequate to describe the range in
morphologies of bright Virgo Cluster spirals. In particular, spirals with
reduced global star formation activity are often assigned misleading early-type
classifications, irrespective of their central light concentrations. 45+-25% of
the galaxies classified as Sa in the Virgo Cluster sample have central light
concentrations more characteristic of isolated Sb-Sc galaxies. The misleading
classification of low concentration galaxies with low star formation rates as
early-type spirals may account for part of the excess of `early-type' spiral
galaxies in clusters. Thus the morphology-density relationship is not all due
to a systematic increase in the bulge-to-disk ratio with environmental density.Comment: Accepted for publication in ApJ Letters. Latex aaspp4.sty, 9 pages, 2
Postscript (embedded) figures. Also available at
http://www.astro.yale.edu/koopmann/preprint.htm
A Look At Three Different Scenarios for Bulge Formation
In this paper, we present three qualitatively different scenarios for bulge
formation: a secular evolution model in which bulges form after disks and
undergo several central starbursts, a primordial collapse model in which bulges
and disks form simultaneously, and an early bulge formation model in which
bulges form prior to disks. We normalize our models to the local z=0
observations of de Jong & van der Kruit (1994) and Peletier & Balcells (1996)
and make comparisons with high redshift observations. We consider model
predictions relating directly to bulge-to-disk properties. As expected, smaller
bulge-to-disk ratios and bluer bulge colors are predicted by the secular
evolution model at all redshifts, although uncertainties in the data are
currently too large to differentiate strongly between the models.Comment: 19 pages, 6 figures, accepted for publication in the Astrophysical
Journa
Transport of interacting electrons in arrays of quantum dots and diffusive wires
We develop a detailed theoretical investigation of the effect of Coulomb
interaction on electron transport in arrays of chaotic quantum dots and
diffusive metallic wires. Employing the real time path integral technique we
formulate a new Langevin-type of approach which exploits a direct relation
between shot noise and interaction effects in mesoscopic conductors. With the
aid of this approach we establish a general expression for the Fano factor of
1D quantum dot arrays and derive a complete formula for the interaction
correction to the current which embraces all perturbative results previously
obtained for various quasi-0D and quasi-1D disordered conductors and extends
these results to yet unexplored regimes.Comment: 12 pages, 2 figure
Language-based multimedia information retrieval
This paper describes various methods and approaches for language-based multimedia information retrieval, which have been developed in the projects POP-EYE and OLIVE and which will be developed further in the MUMIS project. All of these project aim at supporting automated indexing of video material by use of human language technologies. Thus, in contrast to image or sound-based retrieval methods, where both the query language and the indexing methods build on non-linguistic data, these methods attempt to exploit advanced text retrieval technologies for the retrieval of non-textual material. While POP-EYE was building on subtitles or captions as the prime language key for disclosing video fragments, OLIVE is making use of speech recognition to automatically derive transcriptions of the sound tracks, generating time-coded linguistic elements which then serve as the basis for text-based retrieval functionality
Waardewerken heeft multifunctionele landbouw een gezicht gegeven
Welke invloed heeft Waardewerken, het innovatienetwerk van pionierende ondernemers in de multifunctionele landbouw, gehad op beleid en praktijk? Dit was de hoofdvraag bij de evaluatie van het innovatienetwerk Waardewerken. Via de Most Significant Change-methode hebben betrokkenen bij het netwerk gezamenlijk geleerd en gereflecteerd op veranderingen, en is door het verzamelen van verhalen de ‘oogst’’ van Waardewerken in kaart gebracht
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