1,422 research outputs found
More bathymetric evidence for block faulting on the Gorda Rise
A detailed bathymetric survey of the crest and axial valley of the Gorda Rise, between 41°10\u27 to 41° 29\u27N and 127°15\u27 to 127°36\u27W, has revealed several pronounced continuous benches. The most prominent benches are at depths of 2400 and 2800 m. The regional bathymetry is consistent with a block-faulting origin for the topography of the Gorda Rise
Integration of Host Plant Resistance and Insecticides in the Control of \u3ci\u3eNephotettix virescens\u3c/i\u3e (Homoptera: Cicadelli-dae), a Vector of Rice Tungro Virus
Combined effects of levels of vector resistance and insecticide application in control of rice tungro virus (RTV) were determined in three field tests. Cultivar “IR28,” with high levels of resistance to the vector, Nephotettix virescens (Distant), had low RTV infection in all treatments including the untreated check. In moderately resistant “IR36,” RTV decreased with an increase in level of insecticide but did not decrease to a level equaling the untreated “IR28.” The N. virescens-susceptible cultivar “IR22” had extremely high levels of RTV infection at all insecticide levels. Economic analysis indicated that gross profit and net gain were highest in the N. virescens-resistant “IR28,” intermediate in moderately resistant “IR36,” and lowest in susceptible “IR22.
Conductance and localization in disordered wires: role of evanescent states
This paper extends an earlier analytical scattering matrix treatment of
conductance and localization in coupled two- and three Anderson chain systems
for weak disorder when evanescent states are present at the Fermi level. Such
states exist typically when the interchain coupling exceeds the width of
propagating energy bands associated with the various transverse eigenvalues of
the coupled tight-binding systems. We calculate reflection- and transmission
coefficients in cases where, besides propagating states, one or two evanescent
states are available at the Fermi level for elastic scattering of electrons by
the disordered systems. We observe important qualitative changes in these
coefficients and in the related localization lengths due to ineffectiveness of
the evanescent modes for transmission and reflection in the various scattering
channels. In particular, the localization lengths are generally significantly
larger than the values obtained when evanescent modes are absent. Effects
associated with disorder mediated coupling between propagating and evanescent
modes are shown to be suppressed by quantum interference effects, in lowest
order for weak disorder
Menstrual cycle phase affects discrimination of infant cuteness
This study was supported by the Swiss National Science Foundation (SNF) awarded to JL (grant numbers PZ00P1_121622 and PP00P1_139072).Recent studies have shown that women are more sensitive than men to subtle cuteness differences in infant faces. It has been suggested that raised levels in estradiol and progesterone may be responsible for this advantage. We compared young women's sensitivity to computer-manipulated baby faces varying in cuteness. Thirty-six women were tested once during ovulation and once during the luteal phase of their menstrual cycle. In a two alternative forced-choice experiment, participants chose the baby which they thought was cuter (Task 1), younger (Task 2), or the baby that they would prefer to babysit (Task 3). Saliva samples to assess levels of estradiol, progesterone and testosterone were collected at each test session. During ovulation, women were more likely to choose the cuter baby than during the luteal phase, in all three tasks. These results suggest that cuteness discrimination may be driven by cyclic hormonal shifts. However none of the measured hormones were related to increased cuteness sensitivity. We speculate that other hormones than the ones measured here might be responsible for the increased sensitivity to subtle cuteness differences during ovulation.PostprintPeer reviewe
Theory of Second and Higher Order Stochastic Processes
This paper presents a general approach to linear stochastic processes driven
by various random noises. Mathematically, such processes are described by
linear stochastic differential equations of arbitrary order (the simplest
non-trivial example is , where is not a Gaussian white
noise). The stochastic process is discretized into time-steps, all possible
realizations are summed up and the continuum limit is taken. This procedure
often yields closed form formulas for the joint probability distributions.
Completely worked out examples include all Gaussian random forces and a large
class of Markovian (non-Gaussian) forces. This approach is also useful for
deriving Fokker-Planck equations for the probability distribution functions.
This is worked out for Gaussian noises and for the Markovian dichotomous noise.Comment: 35 pages, PlainTex, accepted for publication in Phys Rev. E
Effect of Host Plant on the Level of Virulence of \u3ci\u3eNilaparvata lugens\u3c/i\u3e (Homoptera: Delphacidae) on Rice Cultivars
The virulence of a planthopper, Nilaparvata lugens (Stål) biotype 3, reared on rice cultivar ASD7and of N. lugens colonies collected on Mindanao Island in the southern Philippines and reared on the widely grown commercial cultivars IR36 and IR42 was compared. Based on plant damage, insect weight, population growth, and feeding activity, the Mindanao N. lugens colonies reared on IR36 and IR42 were more virulent than biotype 3, although ASD7, IR36, and IR42 have the bph2 gene for N. lugens resistance. These results clearly indicate that in the screening of breeding lines for resistance to N. lugens, it is important to use insect populations reared on cultivars similar to those grown in farmers’ fields. Failure to do so may result in the release of a cultivar that is susceptible to the N. lugens field population
Response of Soybean Insects to Foliar Applications of a Chitin Synthesis Inhibitor TH 6040
The activity of TH 6040, a chitin synthesis inhibitor, was determined against velvetbean caterpillar, Anticarsia gemmatalis HĂĽbner, and other soybean defoliators in field tests in Georgia, South Carolina, and Brazil. Single applications at rates as low as 75 g AI/ha afforded adequate initial and excellent residual control of A. gemmatalis and some suppression of low populations of Plusia spp. Two applications at higher rates gave significant control of soybean looper, Pseudoplusia includens (Walker), and showed promise against green cloverworm, Plathypena scabra (F.), and Mexican bean beetle, Epilachna varivestis Mulsant. Populations of geocorids and nabids were lower in 1 test, possibly because of insecticidal activity, scarcity of prey, or both
Response of Soybean Insects to Foliar Applications of a Chitin Synthesis Inhibitor TH 6040
The activity of TH 6040, a chitin synthesis inhibitor, was determined against velvetbean caterpillar, Anticarsia gemmatalis HĂĽbner, and other soybean defoliators in field tests in Georgia, South Carolina, and Brazil. Single applications at rates as low as 75 g AI/ha afforded adequate initial and excellent residual control of A. gemmatalis and some suppression of low populations of Plusia spp. Two applications at higher rates gave significant control of soybean looper, Pseudoplusia includens (Walker), and showed promise against green cloverworm, Plathypena scabra (F.), and Mexican bean beetle, Epilachna varivestis Mulsant. Populations of geocorids and nabids were lower in 1 test, possibly because of insecticidal activity, scarcity of prey, or both
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