Forecasting of peak population density of the rose grain aphid Metopolophium dirhodum on wheat

Suction trap catches for the period 1969 to 1984 were used to develop a forecasting system for M. dirhodum. This was achieved by using the strong relationships that exist between: a) suction trap catches of Metopolophium dirhodum at Broom's Barn and populations of the aphid in fields near Norwich, and b) winter and spring temperatures and the time when the crop became unsuitable for this aphid. This forecasting system was tested in 1985, 1986, 1987 and 1988 and successfully forecast early in the season that it would not be necessary to apply aphicides in 1987 and 1988. The use of this forecasting system would have correctly indicated that aphicide application against this aphid was unnecessary in 9 out of the 16 seasons from 1969 to 1984.     

RESEARCH NOTE NUMERICAL SCALE-POINT LOCATIONS FOR CONSTRUCTING THE LAM (LABELED AFFECTIVE MAGNITUDE) SCALE

In a recent paper, we described the development and application of a labeled affective magnitude (LAM) scale for assessing liking/disliking (Schutz and Cardello 2001). Here we present the exact numerical scale-point locations corresponding to the verbal labels of the scale, so that investigators can easily construct the LAM scale for use with either paper or computer-based ballots.     

Randomized controlled trial of supported employment in England: 2 year follow-up of the Supported Work and Needs (SWAN) study

Studies from North America have concluded that supported employment using the Individual Placement and Support (IPS) model is effective in helping individuals with severe and persistent mental illness gain competitive employment. The aim of this study was to investigate the effectiveness and cost-effectiveness of IPS in England in patients followed up for 2 years. Patients with severe mental illness were randomised to IPS or local vocational services (treatment as usual). Service use and costs were measured. Two hundred-nineteen participants were randomised, and 86% re-assessed 2 years later. In the multivariate analysis, relatively low rates of competitive employment were found in both the intervention group and the treatment as usual group, although significantly more patients obtained competitive employment in the treatment arm (22% vs. 11%, p=0.041). There were no significant differences in costs. The employment rate among participants receiving IPS was lower than in previously published reports, and the number needed to treat to obtain the benefit of IPS was relatively high. This may reflect difficulties in the implementation of IPS where it is not structurally integrated within mental health teams, as well as economic disincentives which lead to lower levels of motivation for patients and mental health professionals.     

An Apparent Carbohydrate-Amino Acid Interaction in Tetrahymena pyriformis

SYNOPSIS. Experiments were designed to examine the nature of the response of Tetrahymena pyriformis to inhibitory levels of L-serine when growing in defined media with carbohydrate as mono-, or polysaccharide. Growth curves indicated that, when a polysaccharide is being utilized, inhibition by serine affects at least 2 different loci. At one locus, inhibition causes a marked increase in the growth lag, at the other a significant decrease in the maximum rate of growth. Since the inhibition was completely reversible by glucose supplementation, it is evident that the initial inhibition, expressed as increased lag time, is specifically related to uptake or metabolism of the polysaccharide, i.e., it precedes glucose in the metabolic sequence. The inhibition expressed as decreased rate of maximum growth appears to be due to interference at some stage in the glycolytic pathway. The results suggest that in metabolizing a polysaccharide, T. pyriformis utilizes 2 mechanisms simultaneously. One involves phagocytic ingestion of molecular dextrin followed by phosphorylytic cleavage whereby the energy of the glycosidic bond is utilized to form glucose-1-phosphate. The 2nd mechanism depends upon elaboration of extracellular hydrolytic enzymes to cleave the polysaccharide to glucose, which enters the glycolytic pathway via glucose-6-phosphate in the usual manner.     

Comparing Ground Telemetry and Global Positioning System Methods to Determine Cougar Kill Rates

ABSTRACT We assessed whether use of 2 methods, intensive very high frequency (VHF) radiotelemetry and Global Positioning System (GPS) cluster sampling, yielded similar estimates of cougar (Puma concolor) kill rates in Yellowstone National Park, 1998–2005. We additionally determined biases (underestimation or overestimation of rates) resulting from each method. We used modeling to evaluate what characteristics of clusters best predicted a kill versus no kill and further evaluated which predictor(s) minimized effort and the number of missed kills. We conducted 16 VHF ground predation sequences resulting in 37 kill intervals (KIs) and 21 GPS sequences resulting in 84 KIs on 6 solitary adult females, 4 maternal females, and 5 adult males. Kill rates (days/kill and biomass [kg] killed/day) did not differ between VHF and GPS predation sampling methods for maternal females, solitary adult females, and adult males. Sixteen of 142 (11.3%) kills detected via GPS clusters were missed through VHF ground-based sampling, and the kill rate was underestimated by an average of 5.2 (95% CI = 3.8–6.6) days/kill over all cougar social classes. Five of 142 (3.5%) kills identified by GPS cluster sampling were incorrectly identified as the focal individual's kill from scavenging, and the kill rate was overestimated within the adult male social class by an average of 5.8 (95% CI = 3.0–8.5) days/ungulate kill. The number of nights (locations between 2000 hours and 0500 hours) a cougar spent at a cluster was the most efficient variable at predicting predation, minimizing the missed kills, and minimizing number of extra clusters that needed to be searched. In Yellowstone National Park, where competing carnivores displaced cougars from their kills, it was necessary to search extra sites where a kill may not have been present to ensure we did not miss small, ungulate prey kills or kills with displacement. Using predictions from models to assign unvisited clusters as no kill, small prey kill, or large prey kill can bias downward the number of kills a cougar made and bias upward kills made by competitors that displace cougars or scavenge cougar kills. Our findings emphasize that field visitation is crucial in determining displacement and scavenging events that can result in biases when using GPS cluster methods in multicarnivore systems.