Note on the effect of low temperatures on the survival of adults and larvae of the American black flour beetle, Tribolium audax

De la farine contenant des larves et des adultes du Tribolium audax a été exposée pendant 1, 2, 4, 8, 12, 17, 24 et 45 semaines à des températures de -5, 3 et 10°C. De la farine contenant des insectes a aussi été exposé à une température de -15°C pendant 1, 3, 5, 7, 8, 13 et 15 jours. On a observé une réduction de la survie des larves et des adultes avec une augmentation de la durée d'exposition à toutes les températures. Des adultes et des larves ont survécu pendant 45 semaines à -5 et 10°C, mais seulement les larves ont survécu pendant 45 semaines à 3°C. Les valeurs de TL50 et de TL95 ont été calculées pour chaque température. Aucun insecte n'a survécu pendant 15 jours à -15°C. L'utilisation du froid pour réprimer le T. audax a peu de chances de réussir.Flour infested with adults and late-instar larvae of the American black flour beetle, Tribolium audax, was held for 1, 2, 4, 8, 12, 17, 24, and 45 weeks at each of the following temperatures: -5, 3, and 10 °C, and for 1, 3, 5, 7, 8, 13, and 15 days at -15°C. Survival of the adults and larvae declined with increasing time of exposure at each temperature. Some adults and larvae survived 45 weeks at -5 and 10°C, but only larvae survived 45 weeks of exposure at 3°C. The LT50 and LT95 were determined for each temperature. No insects survived an exposure of 15 days at -15°C. Low temperatures are unlikely to be useful as a practical means for control of T. audax

Note on the effect of low temperatures on the survival of immature stages of the rusty grain beetle, Cryptolestes ferrugineus

Du blé infesté de cucujide roux (Cryptolestes ferrugineus) a été exposé pendant quelques semaines à -5°, 0°, 5°, 10° ou 15°C. On a observé une réduction de la survie des stades immatures (oeufs, larves et pupes) à toutes les températures. Les valeurs de TL50 et de TL99 ont été calculées pour chaque température, à l'exception du traitement à -5°C pour lequel la mortalité était de 100% en moins de 2 semaines.Wheat infested with the rusty grain beetle (Cryptolestes ferrugineus) was held for varying numbers of weeks at temperatures of -5°, 0°, 5°, 10°, and 15°C in separate tests. Survival of the immature stages (eggs, larvae and pupae) of the beetle declined each week at each temperature. The LT50 and LT99 were determined for each of the temperatures except for -5°C where 100 % mortality was observed in a 1- to 2-week period of exposure

Accumulation of pharmaceuticals, perfluorinated compounds, plasticisers and illicit drug metabolite in aquatic sediment and plants in three rivers of Greater London and SE England

Accumulation of persistent organic pollutants (POPs) in sediment (n=23) and aquatic plants (n=15) was assessed by ultrasonicationassisted extraction (UAE) followed by an in-house validated method for solid phase extraction (SPE) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Eleven POPs were selected: inter alia pharmaceuticals acetaminophen, diclofenac and ethinylestradiol, illicit drug metabolite benzoylecgonine, perfluorinated compounds perfluorooctanoic acid (PFOA), perfluorononanoic acid, perfluorooctanesulfonic acid (PFOS) and perfluorobutane sulfonic acid (PFBS), and plasticisers bisphenol-A (BPA), 4’-hydroxyacetophenone (HAP) and bisphenol-S (BPS). Sediment samples were air dried, homogenised, sieved to 500 um then subjected to UAE for 20 m at 45°C in an extraction solution of 50:50 acetonitrile (ACN):Methanol (MeOH) with 1% acetic acid (v/v) followed by SPE and LC-MS/MS analysis. Bioaccumulation in aquatic plants was assessed using two species: Water Starwart (Callitriche sp., n=8) and Pondweed (Potamogeton sp., n=7). All plant samples were air dried, powdered, homogenised then subjected to UAE for 20 m at 40°C in an extraction solution of 25:75 ACN:MeOH with 1% acetic acid (v/v) followed by SPE and LCMS/MS analysis. Mean recoveries were 76% for sediment and 82% for plants. Ten of eleven POPs were detected in sediments with frequencies ranging from 22-83% (benzoylecgonine and BPA respectively) and mean quantifiable concentrations ranging from 0.84-11.1 ng/g (BPS and BPA respectively). Organic matter content in sediment samples was estimated using standard methods for loss on ignition and ranged from 1.2-6.4%. Seven of eleven POPs were detected in Callitriche sp. with frequencies ranging from 13% (acetaminophen) to 100% (HAP, BPS, PFBS and PFOA) and mean quantifiable concentrations ranging from 0.42-113 ng/g (diclofenac and PFOS respectively). Lastly, eight of eleven POPs were detected in Potamogeton sp. with frequencies ranging from 14-100% (acetaminophen and HAP respectively) and mean quantifiable concentrations from 0.38-71.0 ng/g (acetaminophen and HAP respectively). Overall, levels of target POPs were lowest in sediment and highest in Callitriche sp. with mean levels as much as 18.3 and 11.5 times higher (PFOS) than in sediment and Potamogeton sp. respectively. The extent to which POP bioaccumulation may affect higher trophic levels is unclear and warrants further investigation

A spectroscopic and thermal investigation into the relationship between composition, secondary structure and physical characteristics of electrospun zein nanofibers

Electrospun zein nanofibers have attracted interest as drug delivery systems due to their propensity for controlled drug release, flexible structure and low toxicity. However, comparatively little is known regarding the relationship between production method and fiber characteristics, both in terms of fiber architecture and protein structure. Here we use a range of imaging and spectroscopic techniques to elucidate the effects of solvent composition on zein secondary structure, fiber diameter and fiber integrity, plus we utilize the new technique of transition temperature microscopy to examine the thermal properties of the fibers. Zein nanofibers were prepared using ethanol, acetic acid and water mixes as solvents, alone and with plasticizers (polyethylene glycol, glycerol) and casein. Electrospinning was performed under controlled conditions and the products characterized using scanning electron microscopy (SEM), attenuated total reflection Fourier Transform infrared spectrometry (ATR - FTIR) and transition temperature microscopy (TTM). The choice of solvent, concentration and voltage, alongside the presence of additives (plasticizers and casein) were noted to influence both the diameter of the fibers and the tendency for bead formation. A relationship was noted between protein secondary structure and fiber architecture, with an enhanced β-sheet content, enhanced by the inclusion of casein, being associated with higher beading. In addition, thermal imaging of electrospun zein fiber mats was successfully achieved using TTM via two dimensional mapping of the softening temperatures across the spun samples, in particular demonstrating the plasticizing effects of the polyethylene glycol and glycerol

The reversible polydisperse Parking Lot Model

We use a new version of the reversible Parking Lot Model to study the compaction of vibrated polydisperse media. The particle sizes are distributed according to a truncated power law. We introduce a self-consistent desorption mechanism with a hierarchical initialization of the system. In this way, we approach densities close to unity. The final density depends on the polydispersity of the system as well as on the initialization and will reach a maximum value for a certain exponent in the power law.Comment: 7 pages, Latex, 12 figure

Performance of Hamamatsu 64-anode photomultipliers for use with wavelength--shifting optical fibres

Hamamatsu R5900-00-M64 and R7600-00-M64 photomultiplier tubes will be used with wavelength--shifting optical fibres to read out scintillator strips in the MINOS near detector. We report on measurements of the gain, efficiency, linearity, crosstalk, and dark noise of 232 of these PMTs, of which 219 met MINOS requirements.Comment: 15 pages, 12 figures. Accepted by Nucl. Inst. Meth.

Melting of a colloidal crystal

A melting transition for a system of hard spheres interacting by a repulsive Yukawa potential of DLVO form is studied. To find the location of the phase boundary, we propose a simple theory to calculate the free energies for the coexisting liquid and solid. The free energy for the liquid phase is approximated by a virial expansion. The free energy of the crystalline phase is calculated in the spirit of the Lenard-Jonnes and Devonshire (LJD) theory. The phase boundary is found by equating the pressures and chemical potentials of the coexisting phases. When the approximation leading to the equation of state for the liquid breakes down, the first order transition line is also obtained by applying the Lindemann criterion to the solid phase. Our results are then compared with the Monte Carlo simulations.Comment: 7 pages, Revtex (using twocolumn style), four figures and postscript file. Submitted to Physica

Enhancing the effectiveness of interdisciplinary mental health treatment teams

Mental health administrators often lack guidelines for promoting and evaluating the effectiveness of interdisciplinary clinical treatment teams. This article describes the use of a model of group effectiveness that elucidates several aspects of team effectiveness. Also discussed are how administrators can support such teams by reviewing their initial set-up, how the organization influences the team's productivity and longevity, and how team members can better understand one another's personal and professional frames of reference to improve mutual collaboration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44090/1/10488_2005_Article_BF02106536.pd