Suboptimal Larval Habitats Modulate Oviposition of the Malaria Vector Mosquito Anopheles coluzzii.

Selection of oviposition sites by gravid females is a critical behavioral step in the reproductive cycle of Anopheles coluzzii, which is one of the principal Afrotropical malaria vector mosquitoes. Several studies suggest this decision is mediated by semiochemicals associated with potential oviposition sites. To better understand the chemosensory basis of this behavior and identify compounds that can modulate oviposition, we examined the generally held hypothesis that suboptimal larval habitats give rise to semiochemicals that negatively influence the oviposition preference of gravid females. Dual-choice bioassays indicated that oviposition sites conditioned in this manner do indeed foster significant and concentration dependent aversive effects on the oviposition site selection of gravid females. Headspace analyses derived from aversive habitats consistently noted the presence of dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and 6-methyl-5-hepten-2-one (sulcatone) each of which unitarily affected An. coluzzii oviposition preference. Electrophysiological assays across the antennae, maxillary palp, and labellum of gravid An. coluzzii revealed differential responses to these semiochemicals. Taken together, these findings validate the hypothesis in question and suggest that suboptimal environments for An. coluzzii larval development results in the release of DMDS, DMTS and sulcatone that impact the response valence of gravid females

Full-coverage film cooling heat transfer study: Summary of data for normal-hole injection and 30 deg slant-hole injection

Heat transfer to a full coverage film cooled turbulent boundary layer over a flat surface was studied. The surface consisted of a discrete hole test section containing 11 rows of holes spaced 5 diameters apart in a staggered array and an instrumented recovery region. Ten diameter spacing was also studied by plugging appropriate holes. Two test sections were used, one having holes normal to the surface and the other having holes angled 30 deg to the surface in the downstream direction. Stanton number data were obtained both in the full coverage region and in the downstream recovery region for a range of blowing ratios, or mass flux ratios, from 0 to 1.3. Initial conditions at the upstream edge of the blowing region were varied from 500 to 5000 for momentum thickness Reynolds number and from 100 to 1800 for enthalpy thickness Reynolds number. The range of Reynolds numbers based on hole diameter and mainstream velocity was 6000 to 22000. Initial boundary layer thicknesses range from 0.5 to 2.0 hole diameters. Air was used as the working fluid. The data were taken for the secondary injection temperature equal to the wall temperature and also equal to the mainstream temperature. Superposition was then used to obtain Stanton number as a continuous function of the injectant temperature. The heat transfer coefficient was defined on the basis of a mainstream-to-wall temperature difference. This definition permits direct comparison of performance between film cooling and transpiration cooling

Inflationary Hubble Parameter from the Gravitational Wave Spectrum in the General Slow-roll Approximation

Improved general slow-roll formulae giving the primordial gravitational wave spectrum are derived in the present work. Also the first and second order general slow-roll inverse formulae giving the Hubble parameter $H$ in terms of the gravitational wave spectrum are derived. Moreover, the general slow-roll consistency condition relating the scalar and tensor spectra is obtained

Inhibitory control as a mediator of bidirectional effects between early oppositional behavior and maternal depression.

Maternal depression is an established risk factor for child conduct problems, but relatively few studies have tested whether children's behavioral problems exacerbate mothers' depression or whether other child behavioral characteristics (e.g., self-regulation) may mediate bidirectional effects between maternal depression and child disruptive behavior. This longitudinal study examined the parallel growth of maternal depressive symptoms and child oppositional behavior from ages 2 to 5; the magnitude and timing of their bidirectional effects; and whether child inhibitory control, a temperament-based self-regulatory mechanism, mediated effects between maternal depression and child oppositionality. A randomized control trial of 731 at-risk families assessed children annually from ages 2 to 5. Transactional models demonstrated positive and bidirectional associations between mothers' depressive symptoms and children's oppositional behavior from ages 2 to 3, with a less consistent pattern of reciprocal relations up to age 5. Mediation of indirect mother-child effects and child evocative effects depended on the rater of children's inhibitory control. Findings are discussed in regard to how child evocative effects and self-regulatory mechanisms may clarify the transmission of psychopathology within families

Breaking scale invariance from a singular inflaton potential

In this paper we break the scale invariance of the primordial power spectrum of curvature perturbations of inflation. Introducing a singular behaviour due to spontaneous symmetry breaking in the inflaton potential, we obtain fully analytic expressions of scale dependent oscillation and a modulation in power on small scale in the primordial spectrum. And we give the associated cosmic microwave background and matter power spectra which we can observe now and discuss the signature of the scale dependence. We also address the possibility of whether some inflationary model with featured potential might mimic the predictions of the scale invariant power spectrum. We present some examples which illustrate such degeneracies.Comment: 20 pages, 9 figures; Discussion expanded and references added; Miscellaneous typos correcte

General Slow-Roll Spectrum for Gravitational Waves

We derive the power spectrum P_\psi(k) of the gravitational waves produced during general classes of inflation with second order corrections. Using this result, we also derive the spectrum and the spectral index in the standard slow-roll approximation with new higher order corrections.Comment: 8 pages, no figure ; Discussion slightly expanded and minor typos correcte

Formation, Manipulation, and Elasticity Measurement of a Nanometric Column of Water Molecules

Nanometer-sized columns of condensed water molecules are created by an atomic-resolution force microscope operated in ambient conditions. Unusual stepwise decrease of the force gradient associated with the thin water bridge in the tip-substrate gap is observed during its stretch, exhibiting regularity in step heights (~0.5 N/m) and plateau lengths (~1 nm). Such "quantized" elasticity is indicative of the atomic-scale stick-slip at the tip-water interface. A thermodynamic-instability-induced rupture of the water meniscus (5-nm long and 2.6-nm wide) is also found. This work opens a high-resolution study of the structure and the interface dynamics of a nanometric aqueous column.Comment: 4 pages, 3 figure

Essential nonlinearities in hearing

Our hearing organ, the cochlea, evidently poises itself at a Hopf bifurcation to maximize tuning and amplification. We show that in this condition several effects are expected to be generic: compression of the dynamic range, infinitely shrap tuning at zero input, and generation of combination tones. These effects are "essentially" nonlinear in that they become more marked the smaller the forcing: there is no audible sound soft enough not to evoke them. All the well-documented nonlinear aspects of hearing therefore appear to be consequences of the same underlying mechanism.Comment: 4 pages, 3 figure

Turbulent boundary layer on a full-coverage film-cooled surface: An experimental heat transfer study with normal injection

Heat transfer behavior was studied in a turbulent boundary layer with full-coverage film cooling through an array of discrete holes and with injection normal to the wall surface. Stanton numbers were measured for a staggered hole pattern with pitch-to-diameter ratios of 5 and 10, an injection mass flux ratio range of 0.1 to 1.0, and a range of Reynolds number 170 thousand to 5 million. Air was used as the working fluid with the mainstream velocity varied from .14 to 33.5 m/sec (30 to 110 ft/sec). The data were taken for secondary injection temperatures equal to the wall temperature and also equal to the mainstream temperature. By use of linear superposition theory, the data may be used to obtain Stanton number as a continuous function of the injectant temperature. The heat transfer coefficient is defined on the basis of a mainstream-to-wall temperature difference. This difinition permits direct comparison of performance between film cooling and transpiration cooling