1,164 research outputs found
Caliope: A search for CPT-violation in o-ps
CALIOPE, or CP(T) Aberrant Leptons in ortho-Positronium Experiment, is a tabletop search for fundamental symmetry violations, including CP-and CPT-violation, in ortho-positronium (o-Ps). We use a tagged 22Na source adjacent to a cylinder of aerogel to generate o-Ps at the center of a cylindrical array of 24 NaI(Tl) bars. We search for CPT-violating angular correlations in the gamma rays emitted in the decay of o-Ps. With an angular acceptance of 75% of 4Ď€, and the ability to acquire statistics over a longer period of time, CALIOPE will improve upon the limit set by previous experiments. The experimental setup can also be used in a search for CP-violation in o-Ps with the addition of an electromagnet. We describe the design of the experiment, results from a characterization of the systematics for the CPT-and CP-violating measurements, and a demonstration of the DAQ
Demonstration of o-Ps detection with a cylindrical array of NaI detectors
Ortho-positronium (o-Ps), the triplet bound state of an electron and positron, is a promising system in which to search for new physics. O-Ps production and detection can be achieved with a tabletop setup, involving a 22Na source, aerogel and a detector. We present our approach to o-Ps detection using the APEX array, which consists of 24 NaI(Tl) bars, arranged cylindrically. Our approach involves tagging on the 1.27 MeV gamma ray, a technique which is used in positron annihilation spectroscopy (PALS) Gidley et al. (2006). We demonstrate the ability to tag with any one of the bars in the array. Using a NaI(Tl) array of high angular coverage (75%) with this technique provides many benefits. This method provides some advantages over tagging on the positron directly insofar as it minimizes the amount of material inside the source holder and simplifies the design of the DAQ. This has potential applications to CP- and CPT-violation searches in o-Ps
Health Risk Perceptions Are Associated with Domestic Use of Basic Water and Sanitation Services—Evidence from Rural Ethiopia
We examine factors associated with the use of basic water supply and sanitation services as part of an integrated community-based nutrition programme which included a drinking water, sanitation and hygiene (WaSH) intervention and emphasise findings related to health risk perceptions. Data were collected from 2658 households in four regions in Ethiopia with a cross-sectional survey in WaSH intervention areas, as well as in control areas, where the intervention was not implemented. The data were analysed using bivariate and multivariable regression analysis. Awareness of health risk factors related to inadequate WaSH was high in the programme area. The use of basic water and sanitation services was associated with several health risk perceptions: Perceiving water quality as good increased the odds of using basic water services as opposed to believing the water quality was poor (OR 3.94; CI 3.06–5.08; p ≤ 0.001). Believing that drinking unsafe water was the main cause for diarrhoea increased the odds of using basic water services (OR 1.48; CI 1.20–1.81; p ≤ 0.001). In the WaSH intervention group, the use of basic sanitation was more likely than in the control group. The use of basic sanitation was associated with households who had previously received sanitation training, as opposed to such who had not (OR 1.55; CI 1.22–1.97; p ≤ 0.001). Perceiving dirty space as the main cause of diarrhoea (OR 1.81; CI 1.50–2.19; p ≤ 0.001), and privacy when using a latrine (OR 2.00; CI 1.67–2.40; p ≤ 0.001), were associated with higher odds of using basic sanitation. Households that indicated a disadvantage of owning a latrine was maintenance costs were less likely to use basic sanitation (OR 0.49; CI 0.38–0.63; p ≤ 0.001). Risk perceptions were important determinants of use of basic services. The findings point to risk perceptions motivating the application of positive WaSH-related and health-protective behaviours. This suggests that well-designed health risk communication strategies may be effective for engaging households in healthy WaSH behaviour
Coprophagous features in carnivorous Nepenthes plants: a task for ureases
Most terrestrial carnivorous plants are specialized on insect prey digestion to obtain additional nutrients. Few species of the genus Nepenthes developed mutualistic relationships with mammals for nitrogen supplementation. Whether dietary changes require certain enzymatic composition to utilize new sources of nutrients has rarely been tested. Here, we investigated the role of urease for Nepenthes hemsleyana that gains nitrogen from the bat Kerivoula hardwickii while it roosts inside the pitchers. We hypothesized that N. hemsleyana is able to use urea from the bats’ excrements. In fact, we demonstrate that 15N-enriched urea provided to Nepenthes pitchers is metabolized and its nitrogen is distributed within the plant. As ureases are necessary to degrade urea, these hydrolytic enzymes should be involved. We proved the presence and enzymatic activity of a urease for Nepenthes plant tissues. The corresponding urease cDNA from N. hemsleyana was isolated and functionally expressed. A comprehensive phylogenetic analysis for eukaryotic ureases, including Nepenthes and five other carnivorous plants’ taxa, identified them as canonical ureases and reflects the plant phylogeny. Hence, this study reveals ureases as an emblematic example for an efficient, low-cost but high adaptive plasticity in plants while developing a further specialized lifestyle from carnivory to coprophagy
Boundary Condition Study for the Juncture Flow Experiment in the NASA Langley 14x22-Foot Subsonic Wind Tunnel
Because future wind tunnel tests associated with the NASA Juncture Flow project are being designed for the purpose of CFD validation, considerable effort is going into the characterization of the wind tunnel boundary conditions, particularly at inflow. This is important not only because wind tunnel flowfield nonuniformities can play a role in integrated testing uncertainties, but also because the better the boundary conditions are known, the better CFD can accurately represent the experiment. This paper describes recent investigative wind tunnel tests involving two methods to measure and characterize the oncoming flow in the NASA Langley 14- by 22-Foot Subsonic Tunnel. The features of each method, as well as some of their pros and cons, are highlighted. Boundary conditions and modeling tactics currently used by CFD for empty-tunnel simulations are also described, and some results using three different CFD codes are shown. Preliminary CFD parametric studies associated with the Juncture Flow model are summarized, to determine sensitivities of the flow near the wing-body juncture region of the model to a variety of modeling decisions
Does global progress on sanitation really lag behind water? An analysis of global progress on community- and household-level access to safe water and sanitation.
Safe drinking water and sanitation are important determinants of human health and wellbeing and have recently been declared human rights by the international community. Increased access to both were included in the Millennium Development Goals under a single dedicated target for 2015. This target was reached in 2010 for water but sanitation will fall short; however, there is an important difference in the benchmarks used for assessing global access. For drinking water the benchmark is community-level access whilst for sanitation it is household-level access, so a pit latrine shared between households does not count toward the Millennium Development Goal (MDG) target. We estimated global progress for water and sanitation under two scenarios: with equivalent household- and community-level benchmarks. Our results demonstrate that the "sanitation deficit" is apparent only when household-level sanitation access is contrasted with community-level water access. When equivalent benchmarks are used for water and sanitation, the global deficit is as great for water as it is for sanitation, and sanitation progress in the MDG-period (1990-2015) outstrips that in water. As both drinking water and sanitation access yield greater benefits at the household-level than at the community-level, we conclude that any post-2015 goals should consider a household-level benchmark for both
Assessing the impact of drinking water and sanitation on diarrhoeal disease in low- and middle-income settings: Systematic review and meta-regression
Objective: To assess the impact of inadequate water and sanitation on diarrhoeal disease in low- and middle-income settings. Methods: The search strategy used Cochrane Library, MEDLINE & PubMed, Global Health, Embase and BIOSIS supplemented by screening of reference lists from previously published systematic reviews, to identify studies reporting on interventions examining the effect of drinking water and sanitation improvements in low- and middle-income settings published between 1970 and May 2013. Studies including randomised controlled trials, quasi-randomised trials with control group, observational studies using matching techniques and observational studies with a control group where the intervention was well defined were eligible. Risk of bias was assessed using a modified Ottawa-Newcastle scale. Study results were combined using meta-analysis and meta-regression to derive overall and intervention-specific risk estimates. Results: Of 6819 records identified for drinking water, 61 studies met the inclusion criteria, and of 12 515 records identified for sanitation, 11 studies were included. Overall, improvements in drinking water and sanitation were associated with decreased risks of diarrhoea. Specific improvements, such as the use of water filters, provision of high-quality piped water and sewer connections, were associated with greater reductions in diarrhoea compared with other interventions. Conclusions: The results show that inadequate water and sanitation are associated with considerable risks of diarrhoeal disease and that there are notable differences in illness reduction according to the type of improved water and sanitation implemented
So rare we need to hunt for them: reframing the ethical debate on incidental findings
Incidental findings are the subject of intense ethical debate in medical genomic research. Every human genome contains a number of potentially disease-causing alterations that may be detected during comprehensive genetic analyses to investigate a specific condition. Yet available evidence shows that the frequency of incidental findings in research is much lower than expected. In this Opinion, we argue that the reason for the low level of incidental findings is that the filtering techniques and methods that are applied during the routine handling of genomic data remove these alterations. As incidental findings are systematically filtered out, it is now time to evaluate whether the ethical debate is focused on the right issues. We conclude that the key question is whether to deliberately target and search for disease-causing variations outside the indication that has originally led to the genetic analysis, for instance by using positive lists and algorithms
Using eye-tracking and click-stream data to design adaptive training of children's inhibitory control in a maths and science game
Computerised educational neuroscience interventions that
train within-domain inhibitory control (IC) can improve children's coun-
terintuitive reasoning. However, the HCI or adaptive design of such en-
vironments often receive less attention. Eye-tracking and click data were
used to compare four versions of an IC-training game in terms of their
HCI design and potential for supporting adaptive feedback. Our results
provide insights for developing an adaptive system to scaffold pupils'
transition towards using IC in un-cued, self-regulated scenarios
Use of PDV to measure the overdriven products equation of state in PBX 9502 and PBX 9501 and the EOS in shocked foams
Author Institution: Los Alamos National LaboratorySlides presented at the 2014 Photonic Doppler Velocimetry (PDV) Workshop Hosted by National Security Technologies, LLC, and the University of Nevada Las Vegas, June 24-26, 2014, Las Vegas, Nevada
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