823 research outputs found
Neutrinoless Double Beta Decay with SNO+
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
Uptake and metabolism of 35S-sulphate by wine yeast
The 35S-labelled metabolites obtained by growing three strains of wine yeast in a medium with 35S-sulphate as the sole source of sulphur were methionine, cystine, cystathionine, glutathione and S-adenosylmethionine. Two further compounds were separated and thought to be adducts of sulphite associated non-metabolically with cell wall components.The yeast strains were chosen to represent high sulphide formation, high sulphite formation and a combination of low sulphite and sulphide formation. Comparison of the relative 35S activities of the compounds formed by each strain suggested that sulphide production could be explained in terms of a lowered rate of synthesis of methionine and its activated metabolites leading to lowered control over the production of sulphite reductase. Lowered SAM and methionine production allowing derepression of ATP sulphurylase, together with the reported low activity of sulphite reductase in sulphite producing yeast, could be an explanation for sulphite production.Aufnahme und Umsetzung von 35S-Sulfat durch WeinhefenNach Vergärung eines Substrates mit 35S-Sulfat als einziger Schwefelquelle durch drei Weinhefenstämme - viel H2S, viel SO2 und sowohl wenig H2S als auch SO2 bildend - waren folgende Stoffwechselprodukte radioaktiv markiert: Methionin, Cystin, Cystathionin, Glutathion und S-Adenosylmethionin {SAM). Zwei weitere nicht identifizierte Komponenten könnten Anlagerungsprodukte von Sulfit mit Zellwandkomponenten darstellen.Aus der relativen 35S-Aktivität der Stoffwechselprodukte bei den verschiedenen Hefestämmen kann auf eine verminderte Synthese von Methionin und seinen Metaboliten geschlossen werden. Die möglichen Auswirkungen auf die H2S- und SO2- Bildung werden diskutiert
Measurement of the calorimetric energy scale in MINOS
MINOS is a long-baseline neutrino oscillation experiment. A neutrino beam is created at the Fermi National Accelerator Laboratory in Illinois and fired down through the Earth. Measurements of the energy spectra and composition of the neutrino beam are made both at the source using the Near detector and 735 km away at the Soudan Underground Laboratory in Minnesota using the Far detector. By comparing the spectrum and flavour composition of the neutrino beam between the two detectors neutrino oscillations can be observed. Such a comparison depends on the accuracy of the relative calorimetric energy scale. This thesis details a precise measurement of the calorimetric energy scale of the MINOS Far detector and Calibration detector using stopping muons with a new ''track window'' technique. These measurements are used to perform the relative calibration between the two detectors. This calibration has been accomplished to 1.7% in data and to significantly better than 2% in the Monte Carlo simulation, thus achieving the MINOS relative calibration target of 2%. A number of cross-checks have been performed to ensure the robustness of the calorimetric energy scale measurements. At the Calibration detector the test-beam energy between run periods is found to be consistent with the detector response to better than 2% after the relative calibration is applied. The muon energy loss in the MINOS detectors determined from Bethe-Bloch predictions, data and Monte Carlo are compared and understood. To estimate the systematic error on the measurement of the neutrino oscillation parameters caused by a relative miscalibration a study is performed. A 2% relative miscalibration is shown to cause a 0.6% bias in the values of {Delta}m{sup 2} and sin{sup 2}(2{theta})
Search for the disappearance of muon antineutrinos in the NuMI neutrino beam
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
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.
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
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Adaptability of Closed-Loop during Labour, Delivery and Postpartum: A secondary analysis of data from two randomized crossover trials in type 1 diabetes pregnancy
Background: Tight glucose control during labour and delivery is recommended for pregnant women with type 1 diabetes. This can be challenging to achieve using the current treatment modalities. The automated nature of closed-loop and its ability to adapt to real-time glucose levels make it well suited for use during labour, delivery and the immediate postpartum period.
Methods: We report observational data of participants from two randomized crossover trials who chose to continue using closed-loop during labour, delivery and postpartum. Labour was defined as the 24 hours prior to delivery and postpartum as the 48 hours after delivery. The glucose target range during pregnancy was 3.5-7.8mmol/L (63-140mg/dL) and 3.9-10mmol/L (70-180mg/dL) after delivery.
Results: Twenty-seven (84.4%) of the potential 32 trial participants used closed-loop through labor, delivery, and postpartum. Use of closed-loop was associated with 82.0% (IQR 49.3,93.0) time-in-target range during labor and delivery and a mean glucose of 6.9±1.4mmol/L (124±25mg/dL). Closed-loop performed well throughout vaginal, elective and emergency caesarean section deliveries. Postpartum, women spent 83.3% (IQR 75.2,94.6) time-in-target range (3.9-10.0mmol/L [70-180mg/dL]), with a mean glucose of 7.2±1.4mmol/L (130±25mg/dL). There was no difference in maternal glucose concentration between mothers of infants with and without neonatal hypoglycemia (6.9±1.6 and 6.8±1.1 mmol/L [124±29 and 122±20mg/dL] respectively; p=0.84).
Conclusions: Automated closed-loop insulin delivery is feasible during hospital admissions for labour, delivery and postpartum. Larger scale studies are needed to evaluate its efficacyThe trials were funded by the National Institute for Health Research (HRM Career Development Fellowship, CDF-2013-06-035), Diabetes UK (BDA 07/0003551), Gates Cambridge Trust PhD fellowship (ZAS), Jean Hailes for Women’s Health (ZAS); Allen-Carey Scholarship in Women’s Health (JMY) and a grant from the NIHR Cambridge Biomedical Research Centre (RH). Abbott Diabetes Care supplied discounted CGM devices, sensors, and details of communication protocol to facilitate real-time connectivity. HRM conducts independent research supported by the National Institute for Health Research
Synchrotron Macro ATR-FTIR Microspectroscopy for High Resolution Chemical Mapping of Single Cells
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.
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
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
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