706 research outputs found

    Matterwave Transport Without Transit

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    Classically it is impossible to have transport without transit, i.e., if the points one, two and three lie sequentially along a path then an object moving from one to three must, at some point in time, be located at two. However, for a quantum particle in a three-well system it is possible to transport the particle between wells one and three such that the probability of finding it at any time in the classically accessible state in well two is negligible. We consider theoretically the analogous scenario for a Bose-Einstein condensate confined within a three well system. In particular, we predict the adiabatic transportation of an interacting Bose-Einstein condensate of 2000 Li atoms from well one to well three without transiting the allowed intermediate region. To an observer of this macroscopic quantum effect it would appear that, over a timescale of the order of one second, the condensate had transported, but not transited, a macroscopic distance of 20 microns between wells one and three.Comment: 6 pages, 4 figure

    Infrared and sub-mm observations of outbursting young stars with Herschel and Spitzer

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    Episodic accretion plays an important role in the evolution of young stars. Although it has been under investigation for a long time, the origin of such episodic accretion events is not yet understood. We investigate the dust and gas emission of a sample of young outbursting sources in the infrared to get a better understanding of their properties and circumstellar material, and we use the results in a further work to model the objects. We used Herschel data, from our PI program of 12 objects and complemented with archival observations to obtain the spectral energy distributions (SEDs) and spectra of our targets. We report here the main characteristics of our sample, focussing on the SED properties and on the gas emission lines detected in the PACS and SPIRE spectra. The SEDs of our sample show the diversity of the outbursting sources, with several targets showing strong emission in the far-infrared from the embedded objects. Most of our targets reside in a complex environment, which we discuss in detail. We detected several atomic and molecular lines, in particular rotational CO emission from several transitions from J=38-37 to J=4-3. We constructed rotational diagrams for the CO lines, and derived in three domains of assumed local thermodynamic equilibrium (LTE) temperatures and column densities, ranging mainly between 0-100 K and 400-500K. We confirm correlation in our sample between intense CO J=16−15J=16-15 emission and the column density of the warm domain of CO, N(warm). We notice a strong increase in luminosity of HH 381 IRS and a weaker increase for PP 13 S, which shows the beginning of an outburst.Comment: 23 pages, 17 figures, A&A accepte

    Consistent dust and gas models for protoplanetary disks : II. Chemical networks and rates

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    PW acknowledge funding from the EU FP7- 2011 under Grant Agreement nr. 284405. CR also acknowledges funding by the Austrian Science Fund (FWF), project number P24790.Aims.  We aim to define a small and large chemical network which can be used for the quantitative simultaneous analysis of molecular emission from the near-IR to the submm. We also aim to revise reactions of excited molecular hydrogen, which are not included in UMIST, to provide a homogeneous database for future applications. Methods.  We have used the thermo-chemical disk modeling code ProDiMo and a standard T Tauri disk model to evaluate the impact of various chemical networks, reaction rate databases and sets of adsorption energies on a large sample of chemical species and emerging line fluxes from the near-IR to the submm wavelength range. Results. We find large differences in the masses and radial distribution of ice reservoirs when considering freeze-out on bare or polar ice coated grains. Most strongly the ammonia ice mass and the location of the snow line (water) change. As a consequence molecules associated to the ice lines such as N2H+ change their emitting region; none of the line fluxes in the sample considered here changes by more than 25% except CO isotopologues, CN and N2H+ lines. The three-body reaction N+H2+M plays a key role in the formation of water in the outer disk. Besides that, differences between the UMIST 2006 and 2012 database change line fluxes in the sample considered here by less than a factor of two (a subset of low excitation CO and fine structure lines stays even within 25%); exceptions are OH, CN, HCN, HCO+ and N2H+ lines. However, different networks such as OSU and KIDA 2011 lead to pronounced differences in the chemistry inside 100 au and thus affect emission lines from high excitation CO, OH and CN lines. H2 is easily excited at the disk surface and state-to-state reactions enhance the abundance of CH+ and to a lesser extent HCO+. For sub-mm lines of HCN, N2H+ and HCO+, a more complex larger network is recommended. Conclusions. More work is required to consolidate data on key reactions leading to the formation of water, molecular ions such as HCO+ and N2H+ as well as the nitrogen chemistry. This affects many of the key lines used in the interpretation of disk observations. Differential analysis of various disk models using the same chemical input data will be more robust than the interpretation of absolute fluxes.PostprintPeer reviewe

    Comparison of chloroquine, sulfadoxine/pyrimethamine, mefloquine and mefloquine-artesunate for the treatment of falciparum malaria in Kachin State, North Myanmar.

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    Multi-drug resistant falciparum malaria is widespread in Asia. In Thailand, Cambodia and Vietnam the national protocols have changed largely to artesunate combined treatment regimens but elsewhere in East and South Asia chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) are still widely recommended by national malaria control programmes. In Kachin State, northern Myanmar, an area of low seasonal malaria transmission, the efficacy of CQ (25 mg base/kg) and SP (1.25/25 mg/kg), the nationally recommended treatments at the time, were compared with mefloquine alone (M; 15 mg base/kg) and mefloquine combined with artesunate (MA; 15:4 mg/kg). An open randomized controlled trial enrolled 316 patients with uncomplicated Plasmodium falciparum malaria, stratified prospectively into three age-groups. Early treatment failures (ETF) occurred in 41% (32/78) of CQ treated patients and in 24% of patients treated with SP (18/75). In young children the ETF rates were 87% after CQ and 35% after SP. Four children (two CQ, two SP) developed symptoms of cerebral malaria within 3 days after treatment. By day 42, failure rates (uncorrected for reinfections) had increased to 79% for CQ and 81% for SP. ETF rates were 2.5% after treatment with M and 3.9% after treatment with MA (P > 0.2). Overall uncorrected treatment failure rates at day 42 following M and MA were 23% and 21%, respectively. Chloroquine and SP are completely ineffective for the treatment of falciparum malaria in northern Myanmar. Mefloquine treatment is much more effective, but three day combination regimens with artesunate will be needed for optimum efficacy and protection against resistance

    Advancements in the development of non-BET bromodomain chemical probes

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    The bromodomain and extra terminal (BET) family of bromodomain‐containing proteins (BCPs) have been the subject of extensive research over the past decade, resulting in a plethora of high‐quality chemical probes for their tandem bromodomains. In turn, these chemical probes have helped reveal the profound biological role of the BET bromodomains and their role in disease, ultimately leading to a number of molecules in active clinical development. However, the BET subfamily represents just 8/61 of the known human bromodomains, and attention has now expanded to the biological role of the remaining 53 non‐BET bromodomains. Rapid growth of this research area has been accompanied by a greater understanding of the requirements for an effective bromodomain chemical probe and has led to a number of new non‐BET bromodomain chemical probes being developed. Advances since December 2015 are discussed, highlighting the strengths/caveats of each molecule, and the value they add toward validating the non‐BET bromodomains as tractable therapeutic targets

    Molecular evidence for gender differences in the migratory behaviour of a small seabird

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    Molecular sexing revealed an unexpectedly strong female bias in the sex ratio of pre-breeding European Storm Petrels (Hydrobates pelagicus), attracted to playback of conspecific calls during their northwards migration past SW Europe. This bias was consistent across seven years, ranging from 80.8% to 89.7% female (mean annual sex ratio ± SD = 85.5% female ±4.1%). The sex ratio did not differ significantly from unity (i.e., 50% female) among (i) Storm Petrel chicks at a breeding colony in NW France, (ii) adults found dead on beaches in Southern Portugal, (iii) breeding birds attending nest burrows in the UK, captured by hand, and (iv) adults captured near a breeding colony in the UK using copies of the same sound recordings as used in Southern Europe, indicating that females are not inherently more strongly attracted to playback calls than males. A morphological discriminant function analysis failed to provide a good separation of the sexes, showing the importance of molecular sexing for this species. We found no sex difference in the seasonal or nocturnal timing of migration past Southern Europe, but there was a significant tendency for birds to be caught in sex-specific aggregations. The preponderance of females captured in Southern Europe suggests that the sexes may differ in migration route or in their colony-prospecting behaviour during migration, at sites far away from their natal colonies. Such differences in migration behaviour between males and females are poorly understood but have implications for the vulnerability of seabirds to pollution and environmental change at sea during the non-breeding season

    Pregnant Women\u27s perceptions of exposure to brominated flame retardants

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    Background: Recent media reports on human studies associating brominated flame retardants (BFRs) in household products in pregnancy with urogenital anomalies in boys and endocrine disruption in both sexes. We sought to explore the perceptions of pregnant women of brominated flame retardant (BFR) exposure, in light of recent media reports on the adverse health effects of BFR exposure prenatally. Methods: Pregnant women were recruited for interviews through posters and pamphlets in prenatal clinics, prenatal fairs and community centres. Interviews were audiotaped and transcribed verbatim for Charmaz-based qualitative analysis supported by NVIVO 10ℱ. Results: Theoretical sufficiency was reached after analyzing the interviews of 23 pregnant women. Themes co-constructed were: I-Lack of Awareness of BFRs; II-Factors Influencing BFR Exposure; III-Responsibility; IV-Informed Choice. Almost all participants felt it was difficult to make informed choices to avoid BFRs, and wanted communication from clinicians and regulation from governments regarding decreasing BFR exposure. Conclusion: Pregnant women in Canada may be unaware of the potential risks of exposure to BFRs. Professional organizations and governments should further study risk associated with BFR exposure in pregnancy and provide educational materials for pregnant women and clinicians regarding BFR exposure

    Trace samples of human blood in mosquitoes as a forensic investigation tool

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    Investigations of any type of crime invariably starts at the crime scene by collecting evidence. Thus, the purpose of this research was to collect and analyze an entomological trace from an environment that is similar to those of indoor crime scenes. Hematophagous mosquitoes were collected from two residential units; saliva of volunteers that were residents in the units was also collected for genetic analysis as reference samples. We examined the allele frequencies of 15 short tandem repeat loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, and FGA) and amelogenin. A total of 26 female hematophagous mosquitoes were identified as Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus; we were able to obtain 11 forensically valid genetic profiles, with a minimum of 0.028203 ng/\u3bcL of human DNA. Thus, the results of this study showed that it was possible to correlate human genetic information from mosquitoes with the volunteer reference samples, which validates the use of this information as forensic evidence. Furthermore, we observed mixed genetic profiles from one mosquito. Therefore, it is clearly important to collect these insects indoors where crimes were committed, because it may be possible to find intact genetic profiles of suspects in the blood found in the digestive tract of hematophagous mosquitoes for later comparison to identify an offender and/or exclude suspects
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