A survey of spiders (Arachnida: Araneae) of Prince of Wales Island, Alaska : combining morphological and DNA barcode identification techniques

Surveys during the summer of 2004 and August 2009 on Prince of Wales Island, Alaska, USA resulted in collection of 1064 adult spiders representing 84 species. Barcoding of spiders collected in 2009 resulted in DNA barcode data for 212 specimens representing 63 species. DNA barcode data were then used to facilitate the identification of otherwise unidentifiable juvenile and female specimens as well as to investigate phylogenetically four lineages with large branch lengths between specimens. Using morphological and DNA barcode identifications provided a more complete list of identified specimens than was possible using morphological data alone

Evaluation of Lorsban®-4E Aerially Sprayed on Sunflower Plots for Bird Repellency

Ripening sunflower fields in the northern Great Plains provide blackbirds with easily accessible sources of high-energy food. As many growers can attest, blackbirds can be nearly impossible to discourage from foraging in favored fields. To date, no single management method has been especially effective at consistently discouraging blackbirds

Color constancy for landmark detection in outdoor environments

European Workshop on Advanced Mobile Robots (EUROBOT), 2001, Lund (Suecia)This work presents an evaluation of three color constancy techniques applied to a landmark detection system designed for a walking robot, which has to operate in unknown and unstructured outdoor environments. The first technique is the well-known image conversion to a chromaticity space, and the second technique is based on successive lighting intensity and illuminant color normalizations. Based on a differential model of color constancy, we propose the third technique, based on color ratios, which unifies the processes of color constancy and landmark detection. The approach used to detect potential landmarks, which is common to all evaluated systems, is based on visual saliency concepts using multiscale color opponent features to identify salient regions in the images. These regions are selected as landmark candidates, and they are further characterized by their features for identification and recognition.This work was supported by the project 'Navegación autónoma de robots guiados por objetivos visuales' (070-720).Peer Reviewe

Using Geographic Information System (GIs) Software to Predict Blackbird Roosting Locations in North Dakota

Cattail stands provide roosting and staging areas for large congregations of blackbirds in North Dakota in late summer and early fall. Since 1991, the U.S. Depamnent of Agriculture, Ammal and Plant Health Inspection Service, Wildlife Services (WS) program has conducted a cattail management program in North Dakota to alleviate blackbird damage to ripening sunflower. To extend the capabilities of the program, a geographical mformation system (GIS) will be incorporated to help WS personnel find blackbird roosts more effectively. We will use the GIs to construct field maps showing the association between areas of moderate to hgh sunilower damage (\u3e5%) and cattail-dominated wetland basins \u3e2 ha. Buffer distances comparable to the distances blackbirds typically travel to forage will be placed around sunflower planting areas susceptible to high damage. This will lrclp WS ynsu~ult.l Cutiw heir eKurh un locating cattail-dominated wetlands that should be enrolled in the management program and improving current and fuhlre blackbird damage management programs

Heterogeneous oxidation of saturated organic aerosols by hydroxyl radicals: Uptake kinetics and condensed-phase products

International audienceThe kinetics and reaction mechanism for the heterogeneous oxidation of saturated organic aerosols by gas-phase OH radicals were investigated under NOx-free conditions. The reaction of 150 nm diameter Bis(2-ethylhexyl) sebacate (BES) particles with OH was studied as a proxy for chemical aging of atmospheric aerosols containing saturated organic matter. An aerosol reactor flow tube combined with an Aerodyne time-of-flight aerosol mass spectrometer (ToF-AMS) and scanning mobility particle sizer (SMPS) was used to study this system. Hydroxyl radicals were produced by 254 nm photolysis of O3 in the presence of water vapour. The kinetics of the heterogeneous oxidation of the BES particles was studied by monitoring the loss of a mass fragment of BES with the ToF-AMS as a function of OH exposure. We measured an initial OH uptake coefficient of ?0 = 1.26 (±0.04), confirming that this reaction is highly efficient. The density of BES particles increased by up to 20% of the original BES particle density at the highest OH exposure studied, consistent with the particle becoming more oxidized. Electrospray ionization mass spectrometry analysis showed that the major particle-phase reaction products are multifunctional carbonyls and alcohols with higher molecular weights than the starting material. Volatilization of oxidation products accounted for a maximum of 17% decrease of the particle volume at the highest OH exposure studied. Tropospheric organic aerosols will become more oxidized from heterogeneous photochemical oxidation, which may affect not only their physical and chemical properties, but also their hygroscopicity and cloud nucleation activity

Heterogeneous oxidation of saturated organic aerosols by hydroxyl radicals: uptake kinetics, condensed-phase products, and particle size change

International audienceThe kinetics and reaction mechanism for the heterogeneous oxidation of saturated organic aerosols by gas-phase OH radicals were investigated under NOx-free conditions. The reaction of 150 nm diameter Bis(2-ethylhexyl) sebacate (BES) particles with OH was studied as a proxy for chemical aging of atmospheric aerosols containing saturated organic matter. An aerosol reactor flow tube combined with an Aerodyne time-of-flight aerosol mass spectrometer (ToF-AMS) and scanning mobility particle sizer (SMPS) was used to study this system. Hydroxyl radicals were produced by 254 nm photolysis of O3 in the presence of water vapour. The kinetics of the heterogeneous oxidation of the BES particles was studied by monitoring the loss of a mass fragment of BES with the ToF-AMS as a function of OH exposure. We measured an initial OH uptake coefficient of ?0=1.3 (±0.4), confirming that this reaction is highly efficient. The density of BES particles increased by up to 20% of the original BES particle density at the highest OH exposure studied, consistent with the particle becoming more oxidized. Electrospray ionization mass spectrometry analysis showed that the major particle-phase reaction products are multifunctional carbonyls and alcohols with higher molecular weights than the starting material. Volatilization of oxidation products accounted for a maximum of 17% decrease of the particle volume at the highest OH exposure studied. Tropospheric organic aerosols will become more oxidized from heterogeneous photochemical oxidation, which may affect not only their physical and chemical properties, but also their hygroscopicity and cloud nucleation activity

Cross-Phase Modulation and Population Redistribution in a Periodic Tripod Medium

The cross-Kerr effect is studied for two pulses propagating in an atomic medium in a tripod configuration, dressed by a strong standing wave coupling beam. Nonlinear phase shifts for both transmitted and reflected beams are calculated taking into account the redistribution of the population among the atomic levels which allows one to study the phase shifts in a wide range of pulse detunings. The influence of other parameters, e.g., the intensity of the control field and the relaxation rates, on the cross-Kerr effect is also examined in detail.Comment: 6 figure