1,404 research outputs found

    Effect of Host Plant on Parasitism of Helicoverpa armigera (HĂŒbner) (Lepidoptera: Noctuidae) by Hyposoter didymator Thunberg (Hymenoptera: Ichneumonidae) and Cotesia kazak (Telenga) (Hymenoptera: Braconidae)

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    The effect of host plant on parasitism of second-instar Helicoverpa armigera by two introduced larval parasitoids, Hyposoter didymator and Cotesia kazak, was investigated in glasshouse experiments. Parasitism was lowest on chickpea (5.4% for H. didymator and 11.8% for C. kazak). Higher levels of parasitism (50.1-85.0% for H. didymator and 25.7-55.3% for C. kazak) were recorded on sorghum, sunflower, cotton, soybean and pigeonpea. This suggests that the parasitoids should be released against Helicoverpa spp. infestations on the major summer crops—sorghum, sunflower, cotton and soybean—rather than against the first spring generation infesting chickpea. Sorghum and sunflower are preferred release crops because parasitism levels are high and disruption by insecticide sprays is less likely

    Rapid brain discrimination of sounds of objects.

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    Electrical neuroimaging in humans identified the speed and spatiotemporal brain mechanism whereby sounds of living and man-made objects are discriminated. Subjects performed an "oddball" target detection task, selectively responding to sounds of either living or man-made objects on alternating blocks, which were controlled for in their spectrogram and harmonics-to-noise ratios between categories. Analyses were conducted on 64-channel auditory evoked potentials (AEPs) from nontarget trials. Comparing responses to sounds of living versus man-made objects, these analyses tested for modulations in local AEP waveforms, global response strength, and the topography of the electric field at the scalp. In addition, the local autoregressive average distributed linear inverse solution was applied to periods of observed modulations. Just 70 ms after stimulus onset, a common network of brain regions within the auditory "what" processing stream responded more strongly to sounds of man-made versus living objects, with differential activity within the right temporal and left inferior frontal cortices. Over the 155-257 ms period, the duration of activity of a brain network, including bilateral temporal and premotor cortices, differed between categories of sounds. Responses to sounds of living objects peaked approximately 12 ms later and the activity of the brain network active over this period was prolonged relative to that in response to sounds of man-made objects. The earliest task-related effects were observed at approximately 100 ms poststimulus onset, placing an upper limit on the speed of cortical auditory object discrimination. These results provide critical temporal constraints on human auditory object recognition and semantic discrimination processes

    Effect of nipple shield use on milk removal: A mechanistic study

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    Background Concerns about reduced milk transfer with nipple shield (NS) use are based on evidence from studies with methodological flaws. Milk removal during breastfeeding can be impacted by infant and maternal factors other than NS use. The aim of this study was to control electric breast pump vacuum strength, pattern and duration across multiple study sessions to determine if NS use reduces milk removal from the breast. Methods A within-subject study with two groups of breastfeeding mothers (infants < 6 months) were recruited; Control Group (CG): no breastfeeding difficulties; Pain Group (PG) used NS for persistent nipple pain. Mothers completed three randomised 15 min pumping sessions using the Symphony vacuum curve (Medela AG); no NS, fitted NS, and a small NS. Sessions were considered valid where the applied vacuum was within 20 mmHg of the set vacuum. Milk removal was considered as pumped milk volume, and also percentage of available milk removed (PAMR), which is calculated as the pumped volume divided by the estimated milk volume stored in the breast immediately prior to pumping. Results Of 62 sessions (all: n = 31 paired sessions) a total of 11 paired sessions from both PG (n = 03) and CG (n = 08) were valid (subset) with and without a fitted NS. Only 2 small shield sessions were valid and so all small shield measurements were excluded. Both pumped volumes and PAMR were significantly lower with NS use for all data but not for subset data. (All: Volume and PAMR median: no NS: 76.5 mL, 69%, Fitted NS: 32.1 mL, 41% respectively (volume p = 0.002, PAMR p = 0.002); Subset: Volume and PAMR median: no NS: 83.8 mL, 72%; Fitted NS: 35.2 mL, 40% (volume p = 0.111 and PAMR p = 0.045). The difference in PAMR, but not volume, was statistically significant when analysed by linear mixed modelling. A decrease of 10 mmHg was associated with a 4.4% increase in PAMR (p = 0.017). Conclusions This experimental data suggests that nipple shield use may reduce milk removal. Close clinical monitoring of breastfeeding mothers using nipple shields is warranted

    Signals that stop the rot : regulation of secondary metabolite defences in cereals

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    Plants accumulate a vast arsenal of chemically diverse secondary metabolites for defence against pathogens. This review will focus on the signal transduction and regulation of defence secondary metabolite production in five food security cereal crops: maize, rice, wheat, sorghum and oats. Recent research advances in this field have revealed novel processes and chemistry in these monocots that make this a rich field for future research.The National Research Foundation (NRF) and the Genomics Research Institute at the University of Pretoria (UP), South Africa.http://www.elsevier.com/locate/pmpp2017-04-30hb2016Forestry and Agricultural Biotechnology Institute (FABI)Plant Scienc

    Human milk macronutrients and bioactive molecules and development of regional fat depots in Western Australian infants during the first 12 months of lactation

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    We investigated associations between intakes of human milk (HM) components (macronutrients and biologically active molecules) and regional fat depots development in healthy term infants (n = 20) across the first year of lactation. Infant limb (mid-arm and mid-thigh) lean and fat areas were assessed by ultrasound imaging at 2, 5, 9 and 12 months of age. Concentrations of HM total protein, whey protein, casein, adiponectin, leptin, lysozyme, lactoferrin, secretory IGA, total carbohydrates, lactose, HM oligosaccharides (total HMO, calculated) and infant 24-h milk intake were measured, and infant calculated daily intakes (CDI) of HM components were determined. This pilot study shows higher 24-h milk intake was associated with a larger mid-arm fat area (p = 0.024), higher breastfeeding frequency was associated with larger mid-arm (p = 0.008) and mid-thigh (p < 0.001) fat areas. Lysozyme (p = 0.001) and HMO CDI (p = 0.004) were time-dependently associated with the mid-arm fat area. Intakes of HM components and breastfeeding parameters may modulate infant limb fat depots development during the first year of age and potentially promote favorable developmental programming of infant body composition; however, further studies are needed to confirm these findings

    Understanding the Observed Evolution of the Galaxy Luminosity Function from z=6-10 in the Context of Hierarchical Structure Formation

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    Recent observations of the Lyman-break galaxy (LBG) luminosity function (LF) from z~6-10 show a steep decline in abundance with increasing redshift. However, the LF is a convolution of the mass function of dark matter halos (HMF)--which also declines sharply over this redshift range--and the galaxy-formation physics that maps halo mass to galaxy luminosity. We consider the strong observed evolution in the LF from z~6-10 in this context and determine whether it can be explained solely by the behavior of the HMF. From z~6-8, we find a residual change in the physics of galaxy formation corresponding to a ~0.5 dex increase in the average luminosity of a halo of fixed mass. On the other hand, our analysis of recent LF measurements at z~10 shows that the paucity of detected galaxies is consistent with almost no change in the average luminosity at fixed halo mass from z~8. The LF slope also constrains the variation about this mean such that the luminosity of galaxies hosted by halos of the same mass are all within about an order-of-magnitude of each other. We show that these results are well-described by a simple model of galaxy formation in which cold-flow accretion is balanced by star formation and momentum-driven outflows. If galaxy formation proceeds in halos with masses down to 10^8 Msun, then such a model predicts that LBGs at z~10 should be able to maintain an ionized intergalactic medium as long as the ratio of the clumping factor to the ionizing escape fraction is C/f_esc < 10.Comment: 15 pages, 2 figures; results unchanged; accepted by JCA

    The anapole moment and nucleon weak interactions

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    From the recent measurement of parity nonconservation (PNC) in the Cs atom we have extracted the constant of the nuclear spin dependent electron-nucleon PNC interaction, Îș=0.442(63)\kappa = 0.442 (63); the anapole moment constant, Îșa=0.364(62)\kappa_a = 0.364 (62); the strength of the PNC proton-nucleus potential, gp=7.3±1.2(exp.)±1.5(theor.)g_p = 7.3 \pm 1.2 (exp.) \pm 1.5 (theor.); the π\pi-meson-nucleon interaction constant, fÏ€â‰Ąhπ1=[9.5±2.1(exp.)±3.5(theor.)]×10−7f_\pi \equiv h_\pi^{1} = [9.5 \pm 2.1 (exp.) \pm 3.5 (theor.)] \times 10^{-7}; and the strength of the neutron-nucleus potential, gn=−1.7±0.8(exp.)±1.3(theor.)g_n = -1.7 \pm 0.8 (exp.) \pm 1.3 (theor.).Comment: Uses RevTex, 12 pages. We have added an explanation of the effect of finite nuclear siz
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