129 research outputs found

    Adi Ophir and Ishay Rosen-Zvi. Goy: Israel’s Multiple Others and the Birth of the Gentile

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    Enhanced ferric sulphate leaching of copper from CuFeS2 and C particulate aggregates

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    Journal ArticleSignificantly faster leaching kinetics for ferric sulphate are achieved for particulate aggregates of CuFeS2 and C than for CuFeS2 itself. The effect of carbon particles upon the rate of dissolution of chalcopyrite has been increased by a factor of 4 (after 10 hours' leaching), depending upon the carbon type, which varies in electronic conductivity and particle size. Interestingly, when the carbon content is reduced, even to 2 per cent, the enhanced leaching by ferric sulphate is sustained. The leaching characteristics of aggregates of CuFeS2 and C are described from reaction-rate experiments, conductivity measurements, and scanning-electron-microscope photographs of the elemental-sulphur reaction product. The results provide further evidence for the kinetic significance of the elemental-sulphur reaction-product layer in the leaching of chalcopyrite by ferric sulphate. Rate control by surface reaction is extended in the presence of carbon particles, but eventually the rate appears to become limited by the transport of electrons through the elemental-sulphur reaction-product layer, as was suggested in previous studies

    Balancing Vanguard Satellites

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    The Vanguard satellites and component parts were balanced within the specified limits by using a Gisholt Type-S balancer in combination with a portable International Research and Development vibration analyzer and filter, with low-frequency pickups. Equipment and procedures used for balancing are described; and the determination of residual imbalance is accomplished by two methods: calculation, and graphical interpretation. Between-the-bearings balancing is recommended for future balancing of payloads

    Molecular identification and characterization of viral pathogens infecting sweet cherry

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    Stone fruits are a valuable crop grown worldwide, however pathogens such as viruses threaten fruit production by reducing tree health and fruit yield. In an orchard within the Niagara region of Ontario, symptoms typical of viral infection such as chlorosis and leaf deformation were seen on sweet cherry (Prunus avium L.) trees. Next generation sequencing was performed on symptomatic and asymptomatic leaves and four viruses were identified. On the tree displaying the most severe symptoms, Prune dwarf virus (PDV), was the only virus detected. A survey conducted during this work showed 42% of cherry trees on a single orchard plot are infected by PDV. The first infectious clone of PDV was developed for molecular characterization of this virus. Introduction of the infectious clone into cherry revealed PDV caused dwarfing symptoms but did not induce the foliar symptoms found on orchard grown trees. A mass spectrometry (MS)-based label-free quantitative proteomic analysis was performed to identify host proteins affected by PDV infection. The results show in PDV infected cherry many defense related proteins are upregulated, and many photosynthesis-related proteins are downregulated. In the model plant cucumber (Cucumis sativus L.) infected by PDV, significant accumulation changes of proteins related to translation and photosynthesis were identified using proteomics, suggesting a possible role of these proteins in the viral infection cycle of PDV. Two proteins identified through proteomic analysis of cucumber were further studied. These proteins are predicted to be important in the infection cycle of PDV as both co-localized with the viral coat protein (CP) of PDV when visualized using confocal microscopy. Finally, to further understand the intra-host spread of PDV, the movement protein (MP) of PDV was characterized. In plant cells, MP expressed alone formed tubules, a typical structure for virus movement. Additionally, domains of MP crucial for tubule formation and subcellular localization were identified. Taken together, this work advances knowledge in the molecular biology of PDV and host impact caused by PDV infection. In the long run, these findings will assist the development of novel strategies against PDV for the sustainable production of cherry and related Prunus fruits

    A risk assessment tool for resumption of research activities during the COVID-19 pandemic for field trials in low resource settings

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    RATIONALE: The spread of severe acute respiratory syndrome coronavirus-2 has suspended many non-COVID-19 related research activities. Where restarting research activities is permitted, investigators need to evaluate the risks and benefits of resuming data collection and adapt procedures to minimize risk. OBJECTIVES: In the context of the multicountry Household Air Pollution Intervention (HAPIN) trial conducted in rural, low-resource settings, we developed a framework to assess the risk of each trial activity and to guide protective measures. Our goal is to maximize the integrity of reseach aims while minimizing infection risk based on the latest scientific understanding of the virus. METHODS: We drew on a combination of expert consultations, risk assessment frameworks, institutional guidance and literature to develop our framework. We then systematically graded clinical, behavioral, laboratory and field environmental health research activities in four countries for both adult and child subjects using this framework. National and local government recommendations provided the minimum safety guidelines for our work. RESULTS: Our framework assesses risk based on staff proximity to the participant, exposure time between staff and participants, and potential viral aerosolization while performing the activity. For each activity, one of four risk levels, from minimal to unacceptable, is assigned and guidance on protective measures is provided. Those activities that can potentially aerosolize the virus are deemed the highest risk. CONCLUSIONS: By applying a systematic, procedure-specific approach to risk assessment for each trial activity, we were able to protect our participants and research team and to uphold our ability to deliver on the research commitments we have made to our staff, participants, local communities, and funders. This framework can be tailored to other research studies conducted in similar settings during the current pandemic, as well as potential future outbreaks with similar transmission dynamics. The trial is registered with clinicaltrials.gov NCT02944682 on October 26. 2016

    Double beta decay to the first 2+2^+ state within a boson expansion formalism with a projected spherical single particle basis

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    The Gamow-Teller transition operator is written as a polynomial in the dipole proton-neutron and quadrupole charge conserving QRPA boson operators, using the prescription of the boson expansion technique of Belyaev-Zelevinski type. Then, the 2νββ2\nu\beta\beta process ending on the first 2+2^+ state in the daughter nucleus is allowed via one, two and three boson states describing the odd-odd intermediate nucleus. The approach uses a single particle basis which is obtained by projecting out the good angular momentum from an orthogonal set of deformed functions. The basis for mother and daughter nuclei have different deformations. The GT transition amplitude as well as the half lives were calculated for ten transitions. Results are compared with the available data as well as with some predictions obtained with other methods.Comment: 12 page

    A Systematic Review to Evaluate the Association between Clean Cooking Technologies and Time Use in Low- and Middle-Income Countries

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    Interventions implementing clean fuels to mitigate household air pollution in low- and middle-income countries have focused on environmental and health outcomes, but few have evaluated time savings. We performed a systematic review, searching for studies of clean fuel interventions that measured time use. A total of 868 manuscripts were identified that met the search criteria, but only 2 met the inclusion criteria. Both were cross-sectional and were conducted in rural India. The first surveyed the female head of household (141 using biogas and 58 using biomass) and reported 1.2 h saved per day collecting fuel and 0.7 h saved cooking, resulting in a combined 28.9 days saved over an entire year. The second surveyed the head of household (37 using biogas and 68 using biomass, 13% female) and reported 1.5 h saved per day collecting fuel, or 22.8 days saved over a year. Based on these time savings, we estimated that clean fuel use could result in a 3.8% or 4.7% increase in daily income, respectively, not including time or costs for fuel procurement. Clean fuel interventions could save users time and money. Few studies have evaluated this potential benefit, suggesting that prospective studies or randomized controlled trials are needed to adequately measure gains

    Effects of a household air pollution intervention using liquefied petroleum gas stoves, continuous fuel distribution and behavioural messaging on dietary and sodium intake of adult women in Puno, Peru: a randomised controlled trial

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    Abstract Objective: Household air pollution (HAP) is a widespread environmental exposure worldwide. While several cleaner fuel interventions have been implemented to reduce personal exposures to HAP, it is unclear if cooking with cleaner fuels also affects the choice of meals and dietary intake. Design: Individually randomised, open-label controlled trial of a HAP intervention. We aimed to determine the effect of a HAP intervention on dietary and Na intake. Intervention participants received a liquefied petroleum gas (LPG) stove, continuous fuel delivery and behavioural messaging during 1 year whereas control participants continued with usual cooking practices that involved the use of biomass-burning stoves. Dietary outcomes included energy, energy-adjusted macronutrients and Na intake at baseline, 6 months and 12 months post-randomisation using 24-h dietary recalls and 24-h urine. We used t-tests to estimate differences between arms in the post-randomisation period. Setting: Rural settings in Puno, Peru. Participants: One hundred women aged 25–64 years. Results: At baseline, control and intervention participants were similar in age (47·4 v. 49·5 years) and had similar daily energy (8894·3 kJ v. 8295·5 kJ), carbohydrate (370·8 g v. 373·3 g) and Na intake (4·9 g v. 4·8 g). One year after randomisation, we did not find differences in average energy intake (9292·4 kJ v. 8788·3 kJ; P = 0·22) or Na intake (4·5 g v. 4·6 g; P = 0·79) between control and intervention participants. Conclusions: Our HAP intervention consisting of an LPG stove, continuous fuel distribution and behavioural messaging did not affect dietary and Na intake in rural Peru

    Compensating control participants when the intervention is of significant value: experience in Guatemala, India, Peru and Rwanda

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    The Household Air Pollution Intervention Network (HAPIN) trial is a randomised controlled trial in Guatemala, India, Peru and Rwanda to assess the health impact of a clean cooking intervention in households using solid biomass for cooking. The HAPIN intervention—a liquefied petroleum gas (LPG) stove and 18-month supply of LPG—has significant value in these communities, irrespective of potential health benefits. For control households, it was necessary to develop a compensation strategy that would be comparable across four settings and would address concerns about differential loss to follow-up, fairness and potential effects on household economics. Each site developed slightly different, contextually appropriate compensation packages by combining a set of uniform principles with local community input. In Guatemala, control compensation consists of coupons equivalent to the LPG stove’s value that can be redeemed for the participant’s choice of household items, which could include an LPG stove. In Peru, control households receive several small items during the trial, plus the intervention stove and 1 month of fuel at the trial’s conclusion. Rwandan participants are given small items during the trial and a choice of a solar kit, LPG stove and four fuel refills, or cash equivalent at the end. India is the only setting in which control participants receive the intervention (LPG stove and 18 months of fuel) at the trial’s end while also being compensated for their time during the trial, in accordance with local ethics committee requirements. The approaches presented here could inform compensation strategy development in future multi-country trials
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