175 research outputs found

    Insecticide resistance in Italian populations of Tribolium flour beetles

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    As a consequence of the widespread use of chemical insecticides in the control of insect pests in grain warehouses and in the food industry, insecticide resistance in grain insect pests has greatly increased all over the world. The goal of this work was to investigate insecticide resistance levels in Italian populations of Tribolium castaneum (Herbst) and Tribolium confusum du Val collected in grain and food storage facilities of 18 different localities. Six contact insecticides were tested on seven populations of the red flour beetle and on eleven populations of the confused flour beetle. Topical application bioassays were carried out on adults. Dose-mortality lines were estimated to determine the resistance ratios for each insecticide and population. A Principal Components Analysis (PCA) was performed on a data matrix describing the pattern of occurrence of the RR values of each insecticide across the set of data provided by 18 different sites. In both species, the slopes of LD-lines range within a rather narrow interval with respect to susceptible strains, while the highest RR value can be observed in a population of the confused flour beetle from Molise assayed with deltamethrin. The distribution of the experimental points in the PCA graph suggests that T. castaneum populations were generally more susceptible to malathion, diazinon and pirethrins than the T. confusum populations. RR values obtained in bioassays suggest that insecticide resistance is not a widespread problem in Italian strains of T. castaneum and T. confusum, but there are populations in which the phenomenon exists. An extended monitoring activity could, therefore, be crucially important in adopting proper control measures for pest management

    Experimental study on the creep behavior of GFRP pultruded beams

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    The objective of the paper is to explore the validity of the Time-Temperature-Stress Superposition Principle (TTSSP) to describe the creep behaviour of glass fibre reinforced polymer (GFRP) pultruded beams. For this purpose, an experimental programme, including both short- and long-term creep tests, has been carried out. A total of twenty pultruded GFRP beams have been tested in a 4-point bending scheme. Tests have been conducted at controlled room temperature (26°C, 32°C, 41°C) and prescribed percentage of the ultimate load (26%, 35%, 45%). Findley’s law has been used to interpret the results of the short-term experiments. Then, the TTSSP has been applied to build a master curve, usable to predict the results of long-term experiments. The results demonstrate the extent of validity of the TTSSP for predicting the creep behaviour of GFRP composites, at least for the material used and the duration of the tests

    Relational Cultural Theory: A Guiding Framework for Study Abroad Experiences

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    Faculty led-study abroad programs promote cultural competence and professional and personal development for students. However, students from historically marginalized and underrepresented groups do not participate in these experiences at the same rate as students from majority cultures. Counselor educators must seek ways to recruit diverse populations to promote equity in and access to international education experiences. Relational Cultural Theory (RCT) provides a guiding framework for counselor educators to diversify study abroad programs while also attending to cultural and power dynamics. Implications for counselor educators and recommendations for future research are also included

    Insights on Funeral Practices and Insects Associated with the Tombs of King Ferrante II d'Aragona and Other Renaissance Nobles

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    The impressive Sacristy of the Basilica of San Domenico Maggiore contains 38 wooden sarcophagi with the bodies of 10 Aragonese princes and other Neapolitan nobles, who died in the 15th and 16th centuries. To improve the knowledge about the entomofauna associated with bodies in archaeological contexts, herein we provide insights on the funerary practices and the insect community associated to Ferrante II King of Naples and other Italian Renaissance mummies of the Aragonese dynasty buried in the Basilica of St. Domenico Maggiore. We identified 842 insect specimens: 88% were Diptera (Muscidae, Fanniidae, and Phoridae), followed by 9% Lepidoptera (Tineidae) and 3% Coleoptera (Dermestidae and Ptinidae). Ninety-seven percent of the specimens were collected from the coffin of Francesco Ferdinando d'Avalos, which was the best preserved. A lack of fly species characterizing the first colonization waves of exposed bodies was noted. The most common fly was the later colonizing muscid Hydrotaea capensis (Wiedemann); only a few Fanniidae (Fannia spp.) were retrieved. The lack of blowflies, coupled with recording H. capensis as the dominant fly, supports our hypothesis that corpses have been kept indoors for a long time under confined environmental conditions. Other explanations include odorous oils/balms having been used in the embalming process, causing the delay or stopping the arrival of first colonizer flies. Hermetically sealing of the coffin with bitumen may also have played a role in preventing access to the corpses. This scenario describes a historical context characterized by a well-advanced knowledge of body preparation, with specific burial techniques adopted for nobles

    Elimination of Porcine Epidemic Diarrhea Virus in an Animal Feed Manufacturing Facility

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    Citation: Huss AR, Schumacher LL, Cochrane RA, Poulsen E, Bai J, Woodworth JC, et al. (2017) Elimination of Porcine Epidemic Diarrhea Virus in an Animal Feed Manufacturing Facility. PLoS ONE 12(1): e0169612. doi:10.1371/journal.pone.0169612Porcine Epidemic Diarrhea Virus (PEDV) was the first virus of wide scale concern to be linked to possible transmission by livestock feed or ingredients. Measures to exclude pathogens, prevent cross-contamination, and actively reduce the pathogenic load of feed and ingredients are being developed. However, research thus far has focused on the role of chemicals or thermal treatment to reduce the RNA in the actual feedstuffs, and has not addressed potential residual contamination within the manufacturing facility that may lead to continuous contamination of finished feeds. The purpose of this experiment was to evaluate the use of a standardized protocol to sanitize an animal feed manufacturing facility contaminated with PEDV. Environmental swabs were collected throughout the facility during the manufacturing of a swine diet inoculated with PEDV. To monitor facility contamination of the virus, swabs were collected at: 1) baseline prior to inoculation, 2) after production of the inoculated feed, 3) after application of a quaternary ammonium-glutaraldehyde blend cleaner, 4) after application of a sodium hypochlorite sanitizing solution, and 5) after facility heat-up to 60°C for 48 hours. Decontamination step, surface, type, zone and their interactions were all found to impact the quantity of detectable PEDV RNA (P < 0.05). As expected, all samples collected from equipment surfaces contained PEDV RNA after production of the contaminated feed. Additionally, the majority of samples collected from non-direct feed contact surfaces were also positive for PEDV RNA after the production of the contaminated feed, emphasizing the potential role dust plays in cross-contamination of pathogen throughout a manufacturing facility. Application of the cleaner, sanitizer, and heat were effective at reducing PEDV genomic material (P < 0.05), but did not completely eliminate it

    The star formation histories of galaxies in different stages of pre-processing in the Fornax A group

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    We study the recent star formation histories of ten galaxies in the Fornax A galaxy group, on the outskirts of the Fornax cluster. The group galaxies are gas-rich, and their neutral atomic hydrogen (HI) was studied in detail with observations from the MeerKAT telescope. This allowed them to be classified into different stages of pre-processing (early, ongoing, advanced). We use long-slit spectra obtained with the South African Large Telescope (SALT) to analyse stellar population indicators to constrain quenching timescales and to compare these to the HI gas content of the galaxies. The Hα\alpha equivalent width, EW(Hα\alpha), suggest that the pre-processing stage is closely related to the recent (< 10 Myr) specific Star Formation Rate (sSFR). The early-stage galaxy (NGC 1326B) is not yet quenched in its outer parts, while the ongoing-stage galaxies mostly have a distributed population of very young stars, though less so in their outer parts. The galaxies in the advanced stage of pre-processing show very low recent sSFR in the outer parts. Our results suggest that NGC 1326B, FCC 35 and FCC 46 underwent significantly different histories from secular evolution during the last Gyr. The fact that most galaxies are on the secular evolution sequence implies that pre-processing has a negligible effect on these galaxies compared to secular evolution. We find EW(Hα\alpha) to be a useful tool for classifying the stage of pre-processing in group galaxies. The recent sSFR and HI morphology show that galaxies in the Fornax A vicinity are pre-processing from the outside in.Comment: 17 pages, accepted for publication in MNRA

    Distribution épidémiologique de l’infection à VIH chez les femmes enceintes dans les dix régions du Cameroun et implications stratégiques pour les programmes de prévention

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    Introduction: le Cameroun se situe dans un contexte d'épidémie  généralisée du VIH. La sous-population des femmes enceintes, facilementaccessible au sein de la population générale, représente une cible  robante pour mener la surveillance du VIH et estimer l'évolution épidémiologique. L'objectif de notre étude était d'évaluer la distribution épidémiologique du VIH chez les femmes enceintes.Méthodes: étude transversale menée en 2012 chez 6521 femmes  enceintes (49,3% âgées de 15-24 ans) en première consultation prénatale (CPN1) dans 60 sites des 10 régions Camerounaises. L'algorithme en série a été utilisé pour le sérodiagnostic du VIH.Résultats: la prévalence du VIH était de 7,8% (508/6521), avec une  différence non significative (p=0,297) entre milieu rural (7,4%) et milieu urbain (8,1%). En zone rurale, cette prévalence variait de 0,7% à  l'Extrême-Nord à 11,8% au Sud. Cependant, en zone urbaine elle variait de 4% à l'Ouest à 11,1% au Sud-Ouest. Suivant l'âge, la prévalence était plus élevée (11,3%) chez les femmes de 35-39 ans. Suivant le niveau de scolarisation, la prévalence du VIH était plus faible (4,4%) chez celles non-scolarisées, et plus élevée (9,3%) chez celles ayant un niveau  primaire. Selon la profession, l'infection était plus élevée chez les  coiffeuses (15,5%), secrétaires (14,8%), commerçantes (12,9%) et  institutrices/enseignantes (10,8%). Conclusion: la prévalence du VIH reste élevée chez les femmes enceintes au Cameroun, sans distinction entre milieux rural et urbain. Les stratégies de prévention devraient s'orienter préférentiellement chez les femmes enceintes âgées, celles du niveau d'instruction primaire, et celles du  secteur des petites et moyennes entreprises

    The CMS Micro-strip Gas Chamber Project: Development of a high resolution tracking detector for harsh radiation environments

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    Thirty-two large area Micro-Strip Gas Chambers were tested in a high intensity, 350~MeV pion beam at PSI to prove that we had reached a Milestone for the Compact Muon Solenoid (CMS) experiment. The particle rate was approximately 6 kHz/mm2, distributed over the whole active area of the detectors, and this rate was maintained for a total integrated time of 493 hours. All of the chambers were operated with signal-to-noise values at or above that corresponding to 98 % hit detection efficiency at CMS; the average S/N was 31. No indications of any gain instabilities or ageing effects were observed. In the official 3-week Milestone period, three strips from a total of 16384 were damaged, a result which is twenty times lower than the minimal requirement for CMS. The spark rate of the detectors was very low and decreased with time to an average of one spark per chamber per day. The cathode voltages of 24 of the chambers were increased over a one week period to investigate the behaviour of the detectors at higher gains; the maximum S/N value was 2.4 times that at the normal working point. No significant increase in spark rate or strip loss rate was detected and the chambers operated stably. The detector efficiencies and imaging capabilities were also investigated. The MSGC design features and the assembly and test methodologies that enabled us to achieve these results are reported

    The MeerKAT Fornax Survey -- II. The rapid removal of HI from dwarf galaxies in the Fornax cluster

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    We present MeerKAT Fornax Survey atomic hydrogen (HI) observations of the dwarf galaxies located in the central ~2.5 x 4 deg2^2 of the Fornax galaxy cluster. The HI images presented in this work have a 3σ3\sigma column density sensitivity between 2.7 and 50 x 1018^{18} cm2^{-2} over 25 km s1^{-1} for spatial resolution between 4 and 1 kpc. We are able to detect an impressive MHI = 5 x 105^{5} Msun 3σ\sigma point source with a line width of 50 km s1^{-1} at a distance of 20 Mpc. We detect HI in 17 out of the 304 dwarfs in our field -- 14 out of the 36 late type dwarfs (LTDs), and 3 of the 268 early type dwarfs (ETDs). The HI-detected LTDs have likely just joined the cluster and are on their first infall as they are located at large clustocentric radii, with comparable MHI and mean stellar surface brightness at fixed luminosity as blue, star-forming LTDs in the field. The HI-detected ETDs have likely been in the cluster longer than the LTDs and acquired their HI through a recent merger or accretion from nearby HI. Eight of the HI-detected LTDs host irregular or asymmetric HI emission and disturbed or lopsided stellar emission. There are two clear cases of ram-pressure shaping the HI, with the LTDs displaying compressed HI on the side closest to the cluster centre and a one-sided, starless tail pointing away from the cluster centre. The HI-detected dwarfs avoid the most massive potentials, consistent with massive galaxies playing an active role in the removal of HI. We create a simple toy model to quantify the timescale of HI stripping in the cluster. We find that a MHI = 108^{8} Msun dwarf will be stripped in ~ 240 Myr. The model is consistent with our observations, where low mass LTDs are directly stripped of their HI from a single encounter and more massive LTDs can harbour a disturbed HI morphology due to longer times or multiple encounters being required to fully strip their HI.Comment: Accepted in Astronomy & Astrophysics. 21 pages, 10 figures. Data available at the MeerKAT Fornax Survey website https://sites.google.com/inaf.it/meerkatfornaxsurve
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