959 research outputs found

    Molecular and phylogenetic characterization of honey bee viruses, Nosema microsporidia, protozoan parasites, and parasitic mites in China

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    China has the largest number of managed honey bee colonies, which produce the highest quantity of honey and royal jelly in the world; however, the presence of honey bee pathogens and parasites has never been rigorously identified in Chinese apiaries. We thus conducted a molecular survey of honey bee RNA viruses, Nosema microsporidia, protozoan parasites, and tracheal mites associated with nonnative Apis mellifera ligustica and native Apis cerana cerana colonies in China. We found the presence of black queen cell virus (BQCV), chronic bee paralysis virus (CBPV), deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), and sacbrood virus (SBV), but not that of acute bee paralysis virus (ABPV) or Kashmir bee virus (KBV). DWV was the most prevalent in the tested samples. Phylogenies of Chinese viral isolates demonstrated that genetically heterogeneous populations of BQCV, CBPV, DWV, and A. cerana-infecting SBV, and relatively homogenous populations of IAPV and A. meliifera-infecting new strain of SBV with single origins, are spread in Chinese apiaries. Similar to previous observations in many countries, Nosema ceranae, but not Nosema apis, was prevalent in the tested samples. Crithidia mellificae, but not Apicystis bombi was found in five samples, including one A. c. cerana colony, demonstrating that C. mellificae is capable of infecting multiple honey bee species. Based on kinetoplast-encoded cytochrome b sequences, the C. mellificae isolate from A. c. cerana represents a novel haplotype with 19 nucleotide differences from the Chinese and Japanese isolates from A. m. ligustica. This suggests that A. c. cerana is the native host for this specific haplotype. The tracheal mite, Acarapis woodi, was detected in one A. m. ligustica colony. Our results demonstrate that honey bee RNA viruses, N. ceranae, C. mellificae, and tracheal mites are present in Chinese apiaries, and some might be originated from native Asian honey bees

    Identification of genes preferentially expressed in wheat egg cells and zygotes

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    Wheat genes differentially expressed in the egg cell before and after fertilization were identified. The data support zygotic gene activation before the first cell division in wheat. To have an insight into fertilization-induced gene expression, cDNA libraries have been prepared from isolated wheat egg cells and one-celled zygotes. Two-hundred and twenty-six egg cell and 253 zygote-expressed EST sequences were determined. Most of the represented transcripts were detected in the wheat egg cell or zygote transcriptome at the first time. Expression analysis of fourteen of the identified genes and three controls was carried out by real-time quantitative PCR. The preferential expression of all investigated genes in the female gametophyte-derived samples (egg cells, zygotes, two-celled proembryos, and basal ovule parts with synergids) in comparison to the anthers, and the leaves were verified. Three genes with putative signaling/regulatory functions were expressed at a low level in the egg cell but exhibited increased (2-to-33-fold) relative expression in the zygote and the proembryo. Genes with high EST abundance in cDNA libraries exhibited strong expression in the egg cell and the zygote, while the ones coding for unknown or hypothetical proteins exhibited differential expression patterns with preferential transcript accumulation in egg cells and/or zygotes. The obtained data support the activation of the zygotic genome before the first cell division in wheat

    Образ освітніх інновацій у свідомості студентської молоді: можливості реконструювання та «позитивізації»

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    The article was edicated the ideas of students’ youth about the educational innovations in Ukraine. Significative parameters on which the image of these innovations is based in students’ consciousness and the possibilities of its «positivisation» are representedАвтором досліджено уявлення студентської молоді про запроваджувані в Україні освітні інновації. Реконструйовано смислові параметри, на яких базується образ цих інновацій у свідомості студентів, та показано можливості його «позитивізації»Автором исследованы представления студенчества о внедряемых в Украине образовательных инновациях. Реконструированы смысловые параметры, на которых основывается образ этих инноваций в сознании студентов, и показаны возможности его «позитивизации

    A randomized trial of glutamine and antioxidants in critically ill patients.

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    BACKGROUND: Critically ill patients have considerable oxidative stress. Glutamine and antioxidant supplementation may offer therapeutic benefit, although current data are conflicting. METHODS: In this blinded 2-by-2 factorial trial, we randomly assigned 1223 critically ill adults in 40 intensive care units (ICUs) in Canada, the United States, and Europe who had multiorgan failure and were receiving mechanical ventilation to receive supplements of glutamine, antioxidants, both, or placebo. Supplements were started within 24 hours after admission to the ICU and were provided both intravenously and enterally. The primary outcome was 28-day mortality. Because of the interim-analysis plan, a P value of less than 0.044 at the final analysis was considered to indicate statistical significance. RESULTS: There was a trend toward increased mortality at 28 days among patients who received glutamine as compared with those who did not receive glutamine (32.4% vs. 27.2%; adjusted odds ratio, 1.28; 95% confidence interval [CI], 1.00 to 1.64; P=0.05). In-hospital mortality and mortality at 6 months were significantly higher among those who received glutamine than among those who did not. Glutamine had no effect on rates of organ failure or infectious complications. Antioxidants had no effect on 28-day mortality (30.8%, vs. 28.8% with no antioxidants; adjusted odds ratio, 1.09; 95% CI, 0.86 to 1.40; P=0.48) or any other secondary end point. There were no differences among the groups with respect to serious adverse events (P=0.83). CONCLUSIONS: Early provision of glutamine or antioxidants did not improve clinical outcomes, and glutamine was associated with an increase in mortality among critically ill patients with multiorgan failure. (Funded by the Canadian Institutes of Health Research; ClinicalTrials.gov number, NCT00133978.)

    Robust Trajectory Planning for Autonomous Parafoils under Wind Uncertainty

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    A key challenge facing modern airborne delivery systems, such as parafoils, is the ability to accurately and consistently deliver supplies into di cult, complex terrain. Robustness is a primary concern, given that environmental wind disturbances are often highly uncertain and time-varying, coupled with under-actuated dynamics and potentially narrow drop zones. This paper presents a new on-line trajectory planning algorithm that enables a large, autonomous parafoil to robustly execute collision avoidance and precision landing on mapped terrain, even with signi cant wind uncertainties. This algorithm is designed to handle arbitrary initial altitudes, approach geometries, and terrain surfaces, and is robust to wind disturbances which may be highly dynamic throughout the terminal approach. Explicit, real-time wind modeling and classi cation is used to anticipate future disturbances, while a novel uncertainty-sampling technique ensures that robustness to possible future variation is e ciently maintained. The designed cost-to-go function enables selection of partial paths which intelligently trade o between current and reachable future states. Simulation results demonstrate that the proposed algorithm reduces the worst-case impact of wind disturbances relative to state-of-the-art approaches.Charles Stark Draper Laborator

    Curb-intersection feature based Monte Carlo Localization on urban roads

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    One of the most prominent features on an urban road is the curb, which defines the boundary of a road surface. An intersection is a junction of two or more roads, appearing where no curb exists. The combination of curb and intersection features and their idiosyncrasies carry significant information about the urban road network that can be exploited to improve a vehicle's localization. This paper introduces a Monte Carlo Localization (MCL) method using the curb-intersection features on urban roads. We propose a novel idea of “Virtual LIDAR” to get the measurement models for these features. Under the MCL framework, above road observation is fused with odometry information, which is able to yield precise localization. We implement the system using a single tilted 2D LIDAR on our autonomous test bed and show robust performance in the presence of occlusion from other vehicles and pedestrians

    Numériser et promouvoir les collections d’histoire naturelle

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    Pietų Afrikos rašytojo, Nobelio premijos laureato J. M. Coetzee (Kūcė) romano Peterburgo šeiminin­kas(The Master of Petersburg) (1994) pagrindinis herojus Fiodoras Dostojevskis 1869 m. atvyksta į Peterburgą, siekdamas išsiaiškinti savo posūnio žu­vimo aplinkybes. Romane akivaizdžiai žaidžiama su autentiškomis istorinėmis asmenybėmis ir faktais ir taip sukuriamas jau tapęs įprastu XX a. pabaigos literatūrai postmodernistinis tekstas, suponuojantis pačias įvairiausias literatūros kritikų bei skaitytojų interpretacijas. Straipsnio autorė, siekdama susiste­minti skirtingų mokyklų ir kultūrų atstovų nuomones ir pozicijas, atkreipia dėmesį į dar vieną literatūros kritikų nenagrinėtą ir galbūt matomą tik iš susipaži­nusių su rusų literatūros klasika pozicijų šio romano aspektą, kuriame svarbiausia būtų tėvų ir vaikų konf­liktas, kurį pirmą kartą rusų literatūroje išnagrinėjo I. Turgenevas. Būtent naujas šio konflikto traktavi­mas Coetzee romane, autorės nuomone, padeda pa­stebėti tiek jo latentinį autobiografinį planą, tiek su­vokti, jog klasikinės rusų literatūros realijų iškėlimas už jos erdvės ir laiko ribų – tai dar vienas būdas ver­tinti rusų literatūrą kaip vientisą nedalomą sistemą

    Combining Internet Monitoring Processes, Packaging and Isotopic Analyses to Determine The Market Structure: Example of Gamma Butyrolactone

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    The Internet is becoming more and more popular among drug users. The use of websites and forums to obtain illicit drugs and relevant information about the means of consumption is a growing phenomenon mainly for new synthetic drugs. Gamma Butyrolactone (GBL), a chemical precursor of Gamma Hydroxy Butyric acid (GHB), is used as a "club drug" and also in drug facilitated sexual assaults. Its market takes place mainly on the Internet through online websites but the structure of the market remains unknown. This research aims to combine digital, physical and chemical information to help understand the distribution routes and the structure of the GBL market. Based on an Internet monitoring process, thirty-nine websites selling GBL, mainly in the Netherlands, were detected between January 2010 and December 2011. Seventeen websites were categorized into six groups based on digital traces (e.g. IP addresses and contact information). In parallel, twenty-five bulk GBL specimens were purchased from sixteen websites for packaging comparisons and carbon isotopic measurements. Packaging information showed a high correlation with digital data confirming the links previously established whereas chemical information revealed undetected links and provided complementary information. Indeed, while digital and packaging data give relevant information about the retailers, the supply routes and the distribution close to the consumer, the carbon isotopic data provides upstream information about the production level and in particular the synthesis pathways and the chemical precursors. A three-level structured market has been thereby identified with a production level mainly located in China and in Germany, an online distribution level mainly hosted in the Netherlands and the customers who order on the Internet
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