694 research outputs found

    Neutrinoless Double Beta Decay with SNO+

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    SNO+ will search for neutrinoless double beta decay by loading 780 tonnes of linear alkylbenzene liquid scintillator with O(tonne) of neodymium. Using natural Nd at 0.1% loading will provide 43.7 kg of 150Nd given its 5.6% abundance and allow the experiment to reach a sensitivity to the effective neutrino mass of 100-200 meV at 90% C.L in a 3 year run. The SNO+ detector has ultra low backgrounds with 7000 tonnes of water shielding and self-shielding of the scintillator. Distillation and several other purification techniques will be used with the aim of achieving Borexino levels of backgrounds. The experiment is fully funded and data taking with light-water will commence in 2012 with scintillator data following in 2013.Comment: 4 pages, 2 figures, prepared for TAUP 201

    Search for the disappearance of muon antineutrinos in the NuMI neutrino beam

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    We report constraints on muon antineutrino oscillation parameters that were obtained by using the two MINOS detectors to measure the 7% antineutrino component of the NuMI neutrino beam. In the Far Detector, we select 130 events in the charged-current muon antineutrino sample, compared to a prediction of 136.4 +/- 11.7(stat) ^{+10.2}_{-8.9}(syst) events under the assumption |dm2bar|=2.32x10^-3 eV^2, snthetabar=1.0. A fit to the two-flavor oscillation approximation constrains |dm2bar|<3.37x10^-3 eV^2 at the 90% confidence level with snthetabar=1.0

    Long-baseline neutrino oscillation experiments

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    A review of accelerator long-baseline neutrino oscillation experiments is provided, including all experiments performed to date and the projected sensitivity of those currently in progress. Accelerator experiments have played a crucial role in the confirmation of the neutrino oscillation phenomenon and in precision measurements of the parameters. With a fixed baseline and detectors providing good energy resolution, precise measurements of the ratio of distance/energy (L/E) on the scale of individual events have been made and the expected oscillatory pattern resolved. Evidence for electron neutrino appearance has recently been obtained, opening a door for determining the CP violating phase as well as resolving the mass hierarchy and the octant of θ23; some of the last unknown parameters of the standard model extended to include neutrino mass

    Cyanobacterial Abundance and Microcystin Profiles in Two Southern British Lakes: The Importance of Abiotic and Biotic Interactions.

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    Freshwater cyanobacteria blooms represent a risk to ecological and human health through induction of anoxia and release of potent toxins; both conditions require water management to mitigate risks. Many cyanobacteria taxa may produce microcystins, a group of toxic cyclic heptapeptides. Understanding the relationships between the abiotic drivers of microcystins and their occurrence would assist in the implementation of targeted, cost-effective solutions to maintain safe drinking and recreational waters. Cyanobacteria and microcystins were measured by flow cytometry and liquid chromatography coupled to tandem mass spectrometry in two interconnected reservoirs varying in age and management regimes, in southern Britain over a 12-month period. Microcystins were detected in both reservoirs, with significantly higher concentrations in the southern lake (maximum concentration >7 µg L-1). Elevated microcystin concentrations were not positively correlated with numbers of cyanobacterial cells, but multiple linear regression analysis suggested temperature and dissolved oxygen explained a significant amount of the variability in microcystin across both reservoirs. The presence of a managed fishery in one lake was associated with decreased microcystin levels, suggestive of top down control on cyanobacterial populations. This study supports the need to develop inclusive, multifactor holistic water management strategies to control cyanobacterial risks in freshwater bodies

    Synchrotron Macro ATR-FTIR Microspectroscopy for High Resolution Chemical Mapping of Single Cells

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    Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy has been used widely for probing the molecular properties of materials. Coupling a synchrotron infrared (IR) beam to an ATR element using a high numerical aperture (NA) microscope objective enhances the spatial resolution, relative to transmission or transflectance microspectroscopy, by a factor proportional to the refractive index (n) of the ATR element. This work presents the development of the synchrotron macro ATR-FTIR microspectroscopy at Australian Synchrotron Infrared Microspectroscopy (IRM) Beamline, and demonstrates that high quality FTIR chemical maps of single cells and tissues can be achieved at an enhanced spatial resolution. The so-called “hybrid” macro ATR-FTIR device was developed by modifying the cantilever arm of a standard Bruker macro ATR-FTIR unit to accept germanium (Ge) ATR elements with different facet sizes (i.e. 1 mm, 250 μm and 100 μm in diameter) suitable for different types of sample surfaces. We demonstrated the capability of the technique for high-resolution single cell analysis of malaria-infected red blood cells, individual neurons in a brain tissue and cellular structures of a Eucalyptus leaf. The ability to measure a range of samples from soft membranes to hard cell wall structures demonstrates the potential of the technique for high-resolution chemical mapping across a broad range of applications in biology, medicine and environmental science

    Exploiting eco-physiological niche to facilitate the separation of the freshwater cyanobacteria Microcystis sp. and Synechococcus sp.

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    In a novel approach to separate the co-occurring freshwater cyanobacteria Microcystis and Synechoccous, published ecological characteristics are used to manipulate temperature and nutrient concentrations to successfully establish a unialgal Microcystis strain. The simple protocol has implications for future cyanobacterial culturing approaches and the establishment of new cyanobacteria strains

    Effect of Feeding Glyphosate-Tolerant (Roundup-Ready Events GA21 or nk603) Corn Compared with Reference Hybrids on Feedlot Steer Performance and Carcass Characteristics

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    Three experiments were conducted to compare the feeding value of genetically enhanced corn (Roundup Ready corn events GA21 and nk603) with nontransgenic hybrids. The four treatments included two separate reference hybrids (REF), the near-isogenic control hybrid (CON), and the genetically enhanced corn (RR), resulting in two preplanned comparisons of CON vs. RR and RR vs. the average of REF. In Exp. 1 (RR event GA21), 175 steers (BW = 427 kg) were fed in 25 pens with seven pens per corn hybrid, except CON, which contained four pens due to limited quantities of that hybrid. In Exp. 2 (RR event nk603), 196 steers (BW = &#;420 kg) were fed in 28 pens with seven pens per corn. In Exp. 3 (RR event nk603), 200 steers were fed in 20 pens, with a similar treatment design to Exp. 2 and five pens per corn. All experiments were conducted as completely randomized designs and utilized corn produced at University of Illinois (Exp. 1 and 2) and University of Nebraska (Exp. 3) research farms under identity-preserved protocols. In all experiments, DMI, ADG, and feed efficiency were similar (P \u3e 0.30) between RR and REF. In Exp. 1 and Exp. 2, RR was not different (P \u3e 0.25) than CON for growth performance. In Exp. 3, RR was not different from CON for ADG and DMI (P \u3e 0.15) or for feed efficiency (P = 0.08). No differences were observed between RR and CON or RR and REF for carcass weight, longissimus dorsi area, and marbling scores in any of the experiments. Subtle differences were observed between RR and either CON or REF for fat depth in each experiment; however, cattle fed RR were not consistently greater and varied from either the CON or the REF (but not both contrasts) within an experiment. Based on these results, insertion of glyphosate- tolerant genes had no significant effect on nutritive quality of corn. Performance and carcass characteristics were not influenced, which suggests that Roundup Ready corn is similar to conventional, nontransgenic corn when fed to finishing feedlot cattle

    Searches for neutrinoless double beta decay

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    Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of 136^{136}Xe. The sensitivities of the different proposals are reviewed.Comment: 8 pages, prepared for TAUP 201
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