Evaluation of Barrier Sprays in Eastern North Carolina

Presented for World Environmental Health Day, September 26, 2016 in Greenville, North Carolina.Suspend® Polyzone® (deltamethrin) and Bifen Insecticide/Termiticide (bifenthrin) were evaluated in two eastern North Carolina neighborhoods from May 18 – Oct 19, 2015 (23 weeks). Lots were sprayed every 21 days. At 17 fixed locations (13 treatment, four control), Centers for Disease Control and Prevention (CDC) CO2-baited traps were deployed overnight, once/week. Oviposition traps were also deployed weekly and remained for seven days to measure Aedes albopictus abundance. Mosquitoes were identified to species and tabulated by location and week. Adult and egg abundance was generally significantly higher in control versus treatment traps. The abundance of Psorophora columbiae and Ae. vexans was significantly higher in control versus treatment traps. Bifenthrin and deltamethrin showed differences in efficacy (e.g. Ae. vexans, An. punctipennis, and Ps. ferox abundance was higher in bifenthrin traps compared to deltamethrin and control traps), but this varied across neighborhoods and species.This study was funded by Bayer Crop Science and The Mosquito Authorit

VC-Dimension of Exterior Visibility

In this paper, we study the Vapnik-Chervonenkis (VC)-dimension of set systems arising in 2D polygonal and 3D polyhedral configurations where a subset consists of all points visible from one camera. In the past, it has been shown that the VC-dimension of planar visibility systems is bounded by 23 if the cameras are allowed to be anywhere inside a polygon without holes [1]. Here, we consider the case of exterior visibility, where the cameras lie on a constrained area outside the polygon and have to observe the entire boundary. We present results for the cases of cameras lying on a circle containing a polygon (VC-dimension= 2) or lying outside the convex hull of a polygon (VC-dimension= 5). The main result of this paper concerns the 3D case: We prove that the VC-dimension is unbounded if the cameras lie on a sphere containing the polyhedron, hence the term exterior visibility

Evaluation of Bifenthrin and Deltamethrin Barrier Sprays for Mosquito Control in Eastern North Carolina

Mosquitoes can be a nuisance and also transmit pathogens causing numerous diseases worldwide. Homeowners and others may hire private companies to alleviate mosquito-related issues. Here, two pyrethroids (Suspend[registered] Polyzone[registered] [deltamethrin] and Bifen Insecticide/Termiticide [bifenthrin]) used in mosquito control were evaluated on blocks of properties in two neighborhoods (Magnolia Ridge: 1-6 lot blocks, 2,100 -- 7,500 m2/block and Cedar Ridge: 1-3 lot blocks, 1,300 -- 4,200 m2/block) in eastern North Carolina for 23 weeks from May 18 -- October 19, 2015. Properties were treated by Mosquito Authority operators using backpack mist blowers every 21 days. At 17 fixed sampling locations (13 treatment and four control lots), Centers for Disease Control and Prevention CO2-baited traps were deployed overnight once/week for the duration of the experiment (377 trap nights). Oviposition traps (ovitraps) were deployed weekly at the same 17 locations and ovistrips remained in the field for seven days as a measure of Aedes albopictus abundance. Mosquitoes were identified to species, quantified, and tabulated by location and week. Differences were observed in mosquito abundance between neighborhoods, treatments, and weeks and differences varied between species. Adult and egg abundance were generally significantly (P [less than] 0.05) higher in traps placed on control properties (no insecticide) compared to traps placed on treatment properties. In both neighborhoods, the abundance of Psorophora columbiae and Ae. vexans was significantly higher in control versus treatment traps. Bifenthrin and deltamethrin showed differences in efficacy (e.g. Ae. vexans, An. punctipennis, and Ps. ferox abundance was greater in traps placed on bifenthrin compared to deltamethrin and control properties), but this varied between neighborhoods and species

Quantifying population-specific growth in benthic bacterial communities under low oxygen using H218O

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in ISME Journal (2019), doi:10.1038/s41396-019-0373-4.The benthos in estuarine environments often experiences periods of regularly occurring hypoxic and anoxic conditions, dramatically impacting biogeochemical cycles. How oxygen depletion affects the growth of specific uncultivated microbial populations within these diverse benthic communities, however, remains poorly understood. Here, we applied H218O quantitative stable isotope probing (qSIP) in order to quantify the growth of diverse, uncultured bacterial populations in response to low oxygen concentrations in estuarine sediments. Over the course of 7- and 28-day incubations with redox conditions spanning from hypoxia to euxinia (sulfidic), 18O labeling of bacterial populations exhibited different patterns consistent with micro-aerophilic, anaerobic, facultative anaerobic, and aerotolerant anaerobic growth. 18O-labeled populations displaying anaerobic growth had a significantly non-random phylogenetic distribution, exhibited by numerous clades currently lacking cultured representatives within the Planctomycetes, Actinobacteria, Latescibacteria, Verrucomicrobia, and Acidobacteria. Genes encoding the beta-subunit of the dissimilatory sulfate reductase (dsrB) became 18O labeled only during euxinic conditions. Sequencing of these 18O-labeled dsrB genes showed that Acidobacteria were the dominant group of growing sulfate-reducing bacteria, highlighting their importance for sulfur cycling in estuarine sediments. Our findings provide the first experimental constraints on the redox conditions underlying increased growth in several groups of “microbial dark matter”, validating hypotheses put forth by earlier metagenomic studies.This work was supported by a grant OR 417/1-1 from the Deutsche Forschungsgemeinschaft, and a Junior Researcher Fund grant from LMU Munich to WDO. This work was performed in part, through the Master’s Program in Geobiology and Paleontology (MGAP) at LMU Munich

An HPLC Method for the Determination of Saxagliptin in Human Plasma with Fluorescence Detection

A sensitive and selective HPLC method with fluorometric detection was developed for the determination of saxagliptin (SGX) in human plasma and applied to a pharmacokinetic study. SGX was precolumn derivatized with fluorescamine, and the fluorescent derivative was separated on an RP C18 column using a mobile phase composed of acetonitrile-10 mM orthophosphoric acid by isocratic elution with flow rate of 1.3 ml/min. The method was based on the measurement of the derivative using fluorescence detection at 378 nm, with excitation at 463 nm. The calibration curve was linear over the range of 3.0“100.0 ng/ml. LOD and LOQ were found to be 0.15 and 0.5 ng/ml, respectively. Intraday and interday RSD values were less than 2.84%. The plasma concentration“time profile and pharmacokinetic parameters such as AUC0–t, AUC0–∞, Cmax, tmax, t1/2, were calculated according to the assays

ZIF-8 metal organic framework for the conversion of glucose to fructose and 5-hydroxymethyl furfural

Herein, Zeolitic imidazolate framework-8 (ZIF-8) is considered as an easy and cheap to prepare alternative catalyst for the isomerization of glucose and production of 5-hydroxymethyl furfural (HMF). For the synthesis of the ZIF-8 catalysts two preparation methods were evaluated, being room temperature and hydrothermal synthesis at 140 °C. Of these, the hydrothermal synthesis method yields a material with exceptionally high surface area (1967 m2·g−1). As a catalyst, the ZIF-8 materials generated excellent fructose yields. Specifically, ZIF-8 prepared by hydrothermal synthesis yielded a fructose selectivity of 65% with a glucose conversion of 24% at 100 °C in aqueous reaction medium. However, this selectivity dropped dramatically when the reactions were repeated at higher temperatures (~140 °C). Interestingly, greater quantities of mannose were produced at higher temperatures too. The lack of strong Brønsted acidity in both ZIF-8 materials resulted in poor HMF yields. In order to improve HMF yields, reactions were performed at a lower pH of 1.0. At 140 °C the lower pH was found to drive the reaction towards HMF and double its yield. Despite the excellent performance of ZIF-8 catalysts in batch reactions, their activity did not translate well to the flow reactor over a continuous run of 8 h, which was operating with a residence time of 6 min. The activity of ZIF-8 halved in the flow reactor at 100 °C in ~3 h, which implies that the catalyst’s stability was not maintained in the long run