Population density and phenology of Tetranychus urticae (Acari: Tetranychidae) in hop is linked to the timing of sulfur applications.

The twospotted spider mite, Tetranychus urticae Koch, is a worldwide pest of numerous agronomic and horticultural plants. Sulfur fungicides are known to induce outbreaks of this pest on several crops, although mechanisms associated with sulfur-induced mite outbreaks are largely unknown. Studies were conducted during 2007-2009 in Oregon and Washington hop yards to evaluate the effect of timing of sulfur applications on T. urticae and key predators. In both regions, applications of sulfur made relatively late in the growing season (mid-June to mid-July) were associated with the greatest exacerbation of spider mite outbreaks, particularly in the upper canopy of the crop. The severity of mite outbreaks was closely associated with sulfur applications made during a relatively narrow time period coincident with the early exponential phase of spider mite increase and rapid host growth. A nonlinear model relating mean cumulative mite days during the time of sulfur sprays to the percent increase in total cumulative mite days (standardized to a nontreated plot) explained 58% of the variability observed in increased spider mite severity related to sulfur spray timing. Spatial patterns of spider mites in the Oregon plots indicated similar dispersal of motile stages of spider mites among leaves treated with sulfur versus nontreated leaves; however, in two of three years, eggs were less aggregated on leaves of sulfur-treated plants, pointing to enhanced dispersal. Apart from one experiment in Washington, relatively few predatory mites were observed during the course of these studies, and sulfur-induced mite outbreaks generally occurred irrespective of predatory mite abundance. Collectively, these studies indicate sulfur induces mite outbreaks through direct or indirect effects on T. urticae, mostly independent of predatory mite abundance or toxicity to these predators. Avoidance of exacerbation of spider mite outbreaks by sulfur sprays was achieved by carefully timing applications to periods of low spider mite abundance and slower host development, which is generally early to mid-spring for hop.

Effects of powdery mildew fungicide programs on twospotted spider mite (Acari: Tetranychidae), hop aphid (Hemiptera: Aphididae), and their natural enemies in hop yards.

Twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), and hop aphid, Phorodon humuli (Schrank) (Hemiptera: Aphididae), are the most important arthropod pests of hop (Humulus lupulus L.) in the Northern Hemisphere. A potential barrier for greater adoption of conservation biological control strategies for spider mites and hop aphid is the extensive use of fungicides for management of hop powdery mildew, Podosphaera macularis (Wallr.:Fr.) U. Braun & S. Takamatsu. Field studies conducted in experimental plots in Oregon and Washington in 2005 and 2006 quantified the effects of powdery mildew fungicide programs (i.e., sulfur, paraffinic oil, and synthetic fungicides) on arthropod pests and natural enemies on hop. Fungicide treatment significantly affected spider mite populations in all four studies. Multiple applications of sulfur fungicides applied before burr development resulted in 1.4-3.3-fold greater spider mite populations during summer. Near the cessation of the sulfur applications, or after a lag of 20-30 d, spider mite populations increased significantly faster on sulfur treated plants compared with water-treated plants in three of four experiments. The effect of paraffinic oil on spider mites was varied, leading to exacerbation of spider mites in Oregon and Washington in 2005, suppression of mites in Oregon in 2006, and no significant effect compared with water in Washington in 2006. Significant relative treatment effects for cone damage due to spider mite feeding were detected in Oregon in 2005 in plots treated with sulfur and paraffinic oil compared with water and synthetic fungicides. Mean populations of hop aphids were similar among treatments in Oregon, although sulfur treatment suppressed hop aphid populations in Washington in 2005 and 2006. Populations of individual predacious insect species and cumulative abundance of macropredators were not consistently suppressed or stimulated by treatments in all trials. However, predatory mite abundance in Washington was affected by fungicide treatments, with plots treated with sulfur consistently having 10-fold fewer phytoseiids per leaf compared with the other treatments. Based on the results of these studies, powdery mildew fungicide programs that minimize or eliminate applications of sulfur and paraffinic oil would tend to conserve predatory mites and minimize the severity of spider mite outbreaks. However, mechanisms other than direct or indirect toxicity to phytoseiid mites likely are associated with exacerbation of spider mite outbreaks on hop.

Predictive accuracy of the wide range assessment of memory and learning in children with attention deficit hyperactivity disorder and reading difficulties.

The predictive accuracy of the Wide Range Assessment of Memory and Learning (WRAML; Sheslow & Adams, 1990) over and above more standardized diagnostic tools in children with attention deficit hyperactivity disorder (ADHD) and reading disabilities (RD) was examined. Fifty-three children with ADHD, 63 with RD, 63 with ADHD-RD, and 112 normal comparison children were administered the WRAML, the Wechsler Intelligence Scale for Children-Third Edition (WISC-III; Wechsler, 1991), the Achenbach (1991) Child Behavior Checklist (CBCL), and the Woodcock-Johnson Psycho-Educational Battery-Revised (WJ-R; Woodcock & Johnson, 1989). Results of a series of discriminant function analyses revealed that the academic, intellectual, and behavioral measures could correctly classify 73.1% of children, but the WRAML subtests alone were able to correctly classify only 58.5% of participants. Combining all of the memory, academic, intellectual, and behavioral measures resulted in 77.5% of cases being correctly classified. These results suggest that the use of a measure of memory functioning such as the WRAML did not significantly improve the predictive accuracy of a diagnosis of ADHD, RD, or both over and above more standard diagnostic academic, intellectual, and behavioral measures.

The IQs of children with ADHD are normally distributed.

The purpose of this investigation was to determine whether or not attention-deficit/hyperactivity disorder (ADHD)-when there was an absence of reading problems-was associated with having a high IQ. The vocabulary and block design short forms of the Wechsler Intelligence Scale for Children-Third Edition were administered to 63 children with ADHD, 69 children with reading difficulties (RD), and 68 children with comorbid ADHD + RD. Results indicated that the distributions of estimated Full Scale IQs (FSIQ) for each of the three groups of children did not differ significantly from a normal distribution, with the majority of children (more than 50%) in each group scoring in the average range. The percentage of children with ADHD who scored in the above-average range for FSIQ was not significantly higher than the percentages of children in the other two groups. No significant group differences emerged for estimated FSIQ, vocabulary, or block design. It was concluded that children with ADHD are no more likely to have an above-average IQ than are other children.

Deficits in long-term memory are not characteristic of ADHD. Attention Deficit Hyperactivity Disorder.

To separate the influence of inattentiveness from memory, we examined savings scores on material previously learned in 53 children with Attention Deficit Hyperactivity Disorder (ADHD), 63 with a reading disability (RD), 63 with both ADHD and RD combined, and 112 controls. Children with reading disabilities were impaired in their ability to remember previously-learned material unless it was repeated over four trials, whereas children with only ADHD performed as well as the controls for material presented only once. Children with ADHD did perform poorly on three subtests that are sensitive to attention/ concentration. We conclude that ADHD is associated with impaired initial learning due to attention deficits, but that long-term retention of learned material is normal.

Flumazenil in intensive care. The duration of arousal after an assessment dose.

The effect of an assessment dose of the benzodiazepine antagonist flumazenil was studied in 20 patients in an intensive care unit. The patients had been sedated with alfentanil and midazolam, and were ready to be weaned from mechanical ventilation. In 10 patients flumazenil was titrated just to produce full arousal whilst the midazolam infusion was continued; flumazenil administration was repeated one hour later after the infusion of midazolam had been stopped. In another 10 patients, flumazenil was administered only once, coinciding with the cessation of sedation. The duration of full arousal in both groups was less than 15 minutes in 75% of patients given a single dose of flumazenil (median dose 0.4 mg) although some effect persisted for up to 60 minutes. The cardiovascular effects of arousal were transient and probably not clinically significant. A brief duration of action is advantageous if the patient is found still to require sedation.

Cardiovascular responses to flumazenil-induced arousal after arterial surgery.

Patients who underwent peripheral arterial surgery had anaesthesia maintained with an infusion of midazolam. They were allowed either to recover spontaneously or to have the effects of midazolam reversed by flumazenil at the end of surgery. This study demonstrated that the cardiovascular responses to arousal using flumazenil are no different from those seen when the patient is allowed to recover in the normal way. This result has obvious advantages for clinical practice but the dangers of resedation must not be forgotten.

The Downs' adjustable flow generator.

A venturi powered device for the generation of continuous positive airways pressure has been assessed. Some of its functional characteristics appear to be ideal, but the oxygen concentration and adequacy of flows require checking after each adjustment. A positive pressure relief valve and an inlet valve are necessary for the safe use of the system and an airway pressure monitor is recommended.

Field evaluation of a teat dip containing dodecyl benzene sulfonic Acid in preventing new mammary gland infections in a dairy herd.

The efficacy of a teat dip containing dodecyl benzene sulfonic acid (1.94%) in reducing the incidence of new Staphylococcus aureus infections was demonstrated in a commercial dairy herd to which a number of uninfected cows and heifers were introduced. In the first three months the occurrence of new quarter infections in the teatdipped cows was reduced by 56.49% as compared to the undipped controls.