Imidacloprid Insecticide Treatments for Hemlock Woolly Adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), Affect a Non-target Soil Arthropod Community Surrounding Eastern Hemlock, Tsuga canadensis (L.) Carriere

The hemlock woolly adelgid (HWA), Adelges tsugae Annand, is an invasive pest that is causing declines in populations of eastern hemlock, Tsuga canadensis Carriere, in eastern North American forests. The threat of losing the hemlock as a foundation species in eastern forests prompted reserve managers to devise and implement HWA management strategies integrating cultural, biological, and chemical control tactics. Chemical control methods, systemic imidacloprid applications and horticultural oil foliar sprays, provide the most immediate and effective control of HWA in accessible hemlocks. Non-target impacts of HWA chemical control methods on soil arthropod communities are undocumented. Empirical studies in the field and in the laboratory were performed to determine the extent of effects of the common HWA chemical control treatments to non-target soil arthropods. Treatments were the horticultural oil foliar spray (no imidacloprid), imidacloprid trunk injection, imidacloprid soil injection, imidacloprid soil drench, and untreated controls. Microarthropods in soil drench plots displayed marginally non-significant decreases in abundance and richness. Microarthropod species composition was distinct in all of the imidacloprid treatments when compared to controls. Acari, the mites, consisted of approximately 50% of the observed abundance, and showed no responses to imidacloprid or horticultural oil treatments. Abundance and richness of Collembola, in contrast, were markedly decreased by the soil drench treatments. High performance liquid chromatography (HPLC) was used to quantify concentrations of imidacloprid from soils following imidacloprid treatments. Concentrations of imidacloprid observed in soils from imidacloprid treatment plots exceeded the LD50 and ED50 concentrations for Folsomia candida Willem (Collembola: Isotomidae) observed in the laboratory, especially in the soil drench plots, less frequently so in the soil injection plots and in a few of the trunk injection plots. The springtail Folsomia candida were reared in the laboratory on standard soil substrates containing a series of known imidacloprid concentrations to observe impacts to reproduction and survival. The imidacloprid concentration at which Folsomia candida adults displayed 50% mortality in the laboratory, as inferred from regression analysis of observed dose responses (LD50), was 1.38 mg imidacloprid / kg dry soil. The concentration at which F. candida produced half the number of juveniles observed in control microcosms (ED50) was 0.598 mg imidacloprid / kg dry soil

Development of Cold Cloud Seeding Technology for Use in Precipitation Management

This is a report of the world accomplished and results obtained under a 2-year contract. The primary objective of the Wasatch Weather Modification Project is to assess the effectiveness of selected procedures for increasing the water supply in the Wasatch Mountains by cloud seeding. As part of this overall objective, an airborne seeding experiment has been conducted for two winter seasons. Preliminary results of this experiment indicate a positive seeding effect within and on the periphery of the designated target area. A summary of project designs, procedures, and problems encountered is also included. Data processing, editing, analysis and display procedures, and computer programs are described. Hydrologic and climatological support studies are described and results presented

Underdiagnosis of mild cognitive impairment: A consequence of ignoring practice effects

INTRODUCTION: Longitudinal testing is necessary to accurately measure cognitive change. However, repeated testing is susceptible to practice effects, which may obscure true cognitive decline and delay detection of mild cognitive impairment (MCI). METHODS: We retested 995 late-middle-aged men in a ∼6-year follow-up of the Vietnam Era Twin Study of Aging. In addition, 170 age-matched replacements were tested for the first time at study wave 2. Group differences were used to calculate practice effects after controlling for attrition effects. MCI diagnoses were generated from practice-adjusted scores. RESULTS: There were significant practice effects on most cognitive domains. Conversion to MCI doubled after correcting for practice effects, from 4.5% to 9%. Importantly, practice effects were present although there were declines in uncorrected scores. DISCUSSION: Accounting for practice effects is critical to early detection of MCI. Declines, when lower than expected, can still indicate practice effects. Replacement participants are needed for accurately assessing disease progression.Published versio

An XMM-Newton Study of Six Narrow-Line Seyfert 1 Galaxies at z = 0.35--0.92

We report a detailed analysis of the XMM-Newton spectra of six Narrow-Line Seyfert 1 (NLS1) galaxies at redshift z = 0.35--0.92. Compared with the NLS1s at lower redshift in the previously most-studied sample, these NLS1s have larger black hole (BH) masses ($\log\,M_\text{BH}>7.5$) with similar or even lower Eddington ratios. Our extended XMM-Newton sample of NLS1s shows strong soft X-ray excess emission below 2 keV. The quantified soft excess strength does not show an obvious discrepancy from previous studies of the lower-redshift NLS1s. The systematic effect in the measurement of the Eddington ratio mainly lies in the bolometric correction factor. We also tentatively fit the spectra assuming two more physical models for the soft excess: warm Comptonization and relativistic reflection from the inner accretion disk. In the first scenario, we confirm the ubiquity of a warm and optically thick corona. The behavior of a single source can be better explained by relativistic reflection, although we cannot distinguish which model is a more favorable explanation for the soft excess based on the best-fit statistics.Comment: 13 pages, 10 figure

Aggregation Patterns in Stressed Bacteria

We study the formation of spot patterns seen in a variety of bacterial species when the bacteria are subjected to oxidative stress due to hazardous byproducts of respiration. Our approach consists of coupling the cell density field to a chemoattractant concentration as well as to nutrient and waste fields. The latter serves as a triggering field for emission of chemoattractant. Important elements in the proposed model include the propagation of a front of motile bacteria radially outward form an initial site, a Turing instability of the uniformly dense state and a reduction of motility for cells sufficiently far behind the front. The wide variety of patterns seen in the experiments is explained as being due the variation of the details of the initiation of the chemoattractant emission as well as the transition to a non-motile phase.Comment: 4 pages, REVTeX with 4 postscript figures (uuencoded) Figures 1a and 1b are available from the authors; paper submitted to PRL

The Mid-Infrared Emission of M87

We discuss Subaru and Spitzer Space Telescope imaging and spectroscopy of M87 in the mid-infrared from 5-35 um. These observations allow us to investigate mid-IR emission mechanisms in the core of M87 and to establish that the flaring, variable jet component HST-1 is not a major contributor to the mid-IR flux. The Spitzer data include a high signal-to-noise 15-35 $\mu$m spectrum of the knot A/B complex in the jet, which is consistent with synchrotron emission. However, a synchrotron model cannot account for the observed {\it nuclear} spectrum, even when contributions from the jet, necessary due to the degrading of resolution with wavelength, are included. The Spitzer data show a clear excess in the spectrum of the nucleus at wavelengths longer than 25 um, which we model as thermal emission from cool dust at a characteristic temperature of 55 \pm 10 K, with an IR luminosity \sim 10^{39} {\rm ~erg ~s^{-1}}. Given Spitzer's few-arcsecond angular resolution, the dust seen in the nuclear spectrum could be located anywhere within ~5'' (390 pc) of the nucleus. In any case, the ratio of AGN thermal to bolometric luminosity indicates that M87 does not contain the IR-bright torus that classical unified AGN schemes invoke. However, this result is consistent with theoretical predictions for low-luminosity AGNsComment: 9 pages, 7 figures, ApJ, in pres

Overproduction of Phospholipids by the Kennedy Pathway Leads to Hypervirulence in Candida albicans

Candida albicans is an opportunistic human fungal pathogen that causes life-threatening systemic infections, as well as oral mucosal infections. Phospholipids are crucial for pathogenesis in C. albicans, as disruption of phosphatidylserine (PS) and phosphatidylethanolamine (PE) biosynthesis within the cytidine diphosphate diacylglycerol (CDP-DAG) pathway causes avirulence in a mouse model of systemic infection. The synthesis of PE by this pathway plays a crucial role in virulence, but it was unknown if downstream conversion of PE to phosphatidylcholine (PC) is required for pathogenicity. Therefore, the enzymes responsible for methylating PE to PC, Pem1 and Pem2, were disrupted. The resulting pem1Δ/Δ pem2Δ/Δ mutant was not less virulent in mice, but rather hypervirulent. Since the pem1Δ/Δ pem2Δ/Δ mutant accumulated PE, this led to the hypothesis that increased PE synthesis increases virulence. To test this, the alternative Kennedy pathway for PE/PC synthesis was exploited. This pathway makes PE and PC from exogenous ethanolamine and choline, respectively, using three enzymatic steps. In contrast to Saccharomyces cerevisiae, C. albicans was found to use one enzyme, Ept1, for the final enzymatic step (ethanolamine/cholinephosphotransferase) that generates both PE and PC. EPT1 was overexpressed, which resulted in increases in both PE and PC synthesis. Moreover, the EPT1 overexpression strain is hypervirulent in mice and causes them to succumb to system infection more rapidly than wild-type. In contrast, disruption of EPT1 causes loss of PE and PC synthesis by the Kennedy pathway, and decreased kidney fungal burden during the mouse systemic infection model, indicating a mild loss of virulence. In addition, the ept1Δ/Δ mutant exhibits decreased cytotoxicity against oral epithelial cells in vitro, whereas the EPT1 overexpression strain exhibits increased cytotoxicity. Taken altogether, our data indicate that mutations that result in increased PE synthesis cause greater virulence and mutations that decrease PE synthesis attenuate virulence

INSIGHTS ON THE EFFICACY OF VISION EXAMINATIONS & VISION SCREENINGS FOR CHILDREN FIRST ENTERING SCHOOL

Abstract In the year 2000, a law was passed in Kentuck