A comparison of the performance and biological efficiency of new knapsack sprayers and a controlled droplet application (CDA) sprayer for the control of the diamondback moth, Plutella xylostella L. (Lepidoptera : Plutellidae)

Field trials and laboratory bioassays were undertaken to compare the performance and efficacy (mortality of diamondback moth larvae) of insecticides applied to cabbages with three high volume hydraulic knapsack sprayers (NS-16, PB-20 and Selecta 12V) and a controlled droplet application (CDA) sprayer. In field experiments, the high volume knapsack sprayers (application rate 500-600 L ha(-1)) provided better spray coverage on the upper and lower surfaces of inner leaves, the upper surfaces of middle and outer leaves, and greater biological efficacy than the CDA sprayer (application rate 20similar to40 L ha(-1)). The PB-20 provided better spray coverage on the upper surface of middle leaves and both surfaces of outer leaves when compared with the Selecta 12V. However, its biological efficacy in the field was not significantly different from that of the other high volume sprayers. Increasing the application rate from 20 to 40 L ha(-1) for the CDA sprayer significantly increased droplet density but had no impact on test insect mortality. Laboratory evaluations of biological efficacy yielded higher estimates than field evaluations and there was no significant difference between the performance of the PB-20 and the CDA sprayer. Significant positive relationships were detected between insect mortality and droplet density deposited for both the PB-20 and the CDA sprayers.

Anogenital gland secretions of Lemur catta and Propithecus verreauxi coquereli: A preliminary chemical examination

Although prosimians are greatly olfaction-oriented, little is known about the specifics of how they use scent to communicate. In this preliminary study we attempted to delineate intra- and interspecific differences among the anogenital gland secretions of two lemur species (Lemur catta and Propithecus verreauxi coquereli) using gas chromatography-mass spectrometry (GC-MS). The results indicate that the two species are discernible through scent. Furthermore, we were able to identify reproductive status using this technique. The anogenital secretions of the different sexes in L. catta, though perhaps not P. v. coquereli, are chemically distinguishable. Given this information, it appears that at least some lemur species can use scent marks to determine species, sex, and reproductive status. (C) 2004 Wiley-Liss, Inc.

The role of impulsivity in the development of substance use and eating disorders

Impulsivity is now widely viewed as a multidimensional construct consisting of a number of related dimensions. Although many measures of impulsivity are correlated, most recent factor analyses support at least a two-factor model. In the current paper, these two factors have been labelled reward sensitivity, reflecting one of the primary dimensions of Gray's personality theory, and rash-spontaneous impulsiveness. The evidence supporting the existence of two dimensions of impulsivity is reviewed in relation to substance misuse and binge eating. (C) 2004 Elsevier Ltd. All rights reserved.

The effect of tidal volume and peep on CO2 and oxygenation during resuscitation of very premature lambs

Background: Over-ventilation causing low arterial carbon dioxide levels (PaCO2) has been associated with the development of neonatal chronic lung disease and adverse outcomes. This may occur very soon after birth. Aim: To investigate the effect on PaCO2 and oxygenation of very premature lambs resuscitated with different tidal volumes and PEEP. Methods: Anaesthetised lambs delivered at 126 days gestation were randomised to 15 min resuscitation with 3 regimes: (1) Laerdal resuscitation bag (B) with 100% oxygen and no PEEP, (2) fixed tidal volume (VT) of 5 mL/kg, or (3) VT of 10 mL/kg, both delivered with a Babylog 8000 ventilator in volume guarantee mode with 8 cm H2O PEEP and variable FiO2. Frequent blood gases were measured and VT, mean airway pressure (Paw), minute volume (MV), ventilation rate (VR), respiratory system compliance (Crs) and alveolar/arterial oxygen difference (AaDO2) were recorded. Results: Twenty lambs were studied. B (1) was associated with more variable VT and peak inspiratory pressures (PIP) compared to fixed tidal volumes (2 and 3). The lambs ventilated with 10 mL/kg were over-ventilated, those ventilated with 5 mL/kg were slightly under-ventilated. Those ventilated with the Laerdal bag had a mean VT of 7.5 mL/kg and were normocarbic. The different tidal volumes had little effect on oxygenation. PEEP improved oxygenation. The table shows the values at 15 minutes expressed as mean and SEM. TABLE. No caption av... TABLE. No caption av... Image Tools Conclusion: Very premature lambs can be effectively resuscitated from birth using volume guarantee ventilation. Within minutes of birth different tidal volumes had a large effect on PaCO2 and no effect on oxygenation. Studies are needed to determine the appropriate tidal volume for resuscitating very premature infants to maintain acceptable levels of PaCO2. © International Pediatrics Research Foundation, Inc. 2004. All Rights Reserved.

Evaluation of elastic modulus and hardness of thin films by nanoindentation

Simple equations are proposed for determining elastic modulus and hardness properties of thin films on substrates from nanoindentation experiments. An empirical formulation relates the modulus E and hardness H of the film/substrate bilayer to corresponding material properties of the constituent materials via a power-law relation. Geometrical dependence of E and H is wholly contained in the power-law exponents, expressed here as sigmoidal functions of indenter penetration relative to film thickness. The formulation may be inverted to enable deconvolution of film properties from data on the film/substrate bilayers. Berkovich nanoindentation data for dense oxide and nitride films on silicon substrates are used to validate the equations and to demonstrate the film property deconvolution. Additional data for less dense nitride films are used to illustrate the extent to which film properties may depend on the method of fabrication.

A prospective comparison of two models of cannabis use and psychotic relapse in early psychosis

No abstract

Mitochondrial genome data alone are not enough to unambiguously resolve the relationships of Entognatha, Insecta and Crustacea sensu lato (Arthropoda)

An analysis of the relationships of the major arthropod groups Was undertaken using mitochondrial genome data to examine the hypotheses that Hexapoda is polyphyletic and that Collembola is more closely related to branchiopod crustaceans than insects. We sought to examine the sensitivity of this relationship to outgroup choice, data treatment. gene choice and optimality criteria used in the phylogenetic analysis of mitochondrial genome data. Additionally we sequenced the mitochondrial genome of ail archaeognathan, Nesomachilis australica. to improve taxon selection in the apterygote insects, a group poorly represented in previous mitochondrial phylogenies. The sister group of the Collembola was rarely resolved in our analyses with a significant level of support. The use of different outgroups (myriapods, nematodes, or annelids + mollusks) resulted in many different placements of Collembola. The way in which the dataset was coded for analysis (DNA, DNA with the exclusion of third codon position and as amino acids) also had marked affects on tree topology. We found that nodal Support was spread evenly throughout the 13 mitochondrial genes and the exclusion of genes resulted in significantly less resolution in the inferred trees. Optimality criteria had a much lesser effect on topology than the preceding factors; parsimony and Bayesian trees for a given data set and treatment were quite similar. We therefore conclude that the relationships of the extant arthropod groups as inferred by mitochondrial genomes are highly vulnerable to outgroup choice, data treatment and gene choice, and no consistent alternative hypothesis of Collembola's relationships is supported. Pending the resolution of these identified problems with the application of mitogenomic data to basal arthropod relationships, it is difficult to justify the rejection of hexapod monophyly, which is well supported on morphological grounds. (c) The Willi Hennig Society 2004.

Suppressing the negative effect of devaluation on group identification: The role of intergroup differentiation and intragroup respect

We examined (N = 76) how social creativity strategies such as intergroup differentiation and intragroup respect suppress the negative impact of threat to an ingroup's value on group identification. Threat was manipulated through false feedback concerning how other groups perceived an ingroup. Both intergroup differentiation and intragroup respect were higher when participants learned that the ingroup was devalued compared to when it was valued. Mediational analyses demonstrated that these factors suppressed the direct negative relationship between value threat and group identification. Discussion focused on the consequences of these social creativity strategies for group identification and collective action. (C) 2004 Elsevier Inc. All rights reserved.

The fMRI response of the LGN and V1 to cardinal red-green, blue-yellow, and achromatic visual stimuli

We compared the responsiveness of the LGN and the early retinotopic cortical areas to stimulation of the two cone-opponent systems (red - green and blue - yellow) and the achromatic system. This was done at two contrast levels to control for any effect of contrast. MR images were acquired on seven subjects with a 4T Bruker MedSpec scanner. The early visual cortical areas were localised by phase encoded retinotopic mapping with a volumetric analysis (Dumoulin et al, 2003 NeuroImage 18 576 - 587). We initially located the LGN in four subjects by using flickering stimuli in a separate scanning session, but subsequently identified it using the experimental stimuli. Experimental stimuli were sine-wave counterphasing rings (2 Hz, 0.5 cycle deg-1), cardinal for the selective activation of the L/M cone-opponent (RG), S cone-opponent (BY), and achromatic (Ach) systems. A region of interest analysis was performed. When presented at equivalent absolute contrasts (cone contrast = 5% - 6%), the BOLD response of the LGN is strongest to isoluminant red - green stimuli and weakest to blue - yellow stimuli, with the achromatic response falling in between. Area V1, on the other hand, responds best to both chromatic stimuli, with the achromatic response falling below. The key change from the LGN to V1 is a dramatic boost in the relative blue - yellow response, which occurred at both contrast levels used. This greatly enhanced cortical response to blue - yellow relative to the red - green and achromatic responses may be due to an increase in cell number and/or cell response between the LGN and V1. We speculate that the effect might reflect the operation of contrast constancy across colour mechanisms at the cortical level.