1,027 research outputs found

    The X-ray nebula around the Seyfert 2 galaxy NGC4388

    Full text link
    We report on X-ray emission from the Seyfert 2 galaxy NGC4388 observed with the Chandra X-ray Observatory. A hard X-ray peak is found at the position of the active nucleus suggested by optical and radio observations. Extended soft X-ray emission correlates well with the ionization cone found in optical line emission. A large soft X-ray extension is found up to 16 kpc to the north of the galaxy. Photoionized gas with low ionization parameters (xi<3) appears to be the likely explanation of this emission. The same ionized gas clouds could be responsible for the optical [OIII] emission. Fe K line emission from cold material is found to be extended by a few kpc.Comment: 12 pages, one colour figure included, MNRAS in pres

    Creating diamond color centers for quantum optical applications

    Full text link
    Nitrogen vacancy (NV) centers in diamond have distinct promise as solid-state qubits. This is because of their large dipole moment, convenient level structure and very long room-temperature coherence times. In general, a combination of ion irradiation and subsequent annealing is used to create the centers, however for the rigorous demands of quantum computing all processes need to be optimized, and decoherence due to the residual damage caused by the implantation process itself must be mitigated. To that end we have studied photoluminescence (PL) from NV^-, NV0^0 and GR1 centers formed by ion implantation of 2MeV He ions over a wide range of fluences. The sample was annealed at 600600^{\circ}C to minimize residual vacancy diffusion, allowing for the concurrent analysis of PL from NV centers and irradiation induced vacancies (GR1). We find non-monotic PL intensities with increasing ion fluence, monotonic increasing PL in NV0^0/NV^- and GR1/(NV0^0 + NV1^1) ratios, and increasing inhomogeneous broadening of the zero-phonon lines with increasing ion fluence. All these results shed important light on the optimal formation conditions for NV qubits. We apply our findings to an off-resonant photonic quantum memory scheme using vibronic sidebands

    A self-optimised approach to synthesising DEHiBA for advanced nuclear reprocessing, exploiting the power of machine-learning

    Get PDF
    In an effort to advance the development of hydrometallurgical reprocessing of used nuclear fuel across the globe, this work sets out to explore and identify an optimised, cost effective pathway to synthesise the ligand DEHiBA (N,N-di-(2-ethylhexyl)isobutyramide). Currently, very few chemical suppliers stock and distribute this specialist ligand, designed for selective uranium chelation and extraction from nuclear fuel. The current high cost of DEHiBA therefore restricts access to essential large-scale testing of this promising ligand designed to advance nuclear reprocessing. This work utilises an automated flow reactor platform for the efficient optimisation of four synthetic routes to DEHiBA. These optimisations focus on optimising cost, reagent efficiency, yield, and productivity target functions by exploiting the power of machine-learning algorithms for rapid process development. Ultimately, we have identified an efficient and cost-effective solvent-free route to DEHiBA from isobutyric anhydride and di-2-ethylhexylamine for 99%, at a purity of 76%, and a process mass intensity of 1.29 g g−1, whilst alternative conditions demonstrated productivities >75 kg L−1 h−1, all whilst maintaining a high level of process control with outlet temperatures not exceeding 35 °C

    Making community-supported agriculture accessible to low-income families: Findings from the Farm Fresh Foods for Healthy Kids process evaluation

    Get PDF
    A randomized trial of Farm Fresh Foods for Healthy Kids (F3HK) was initiated across 4 states and 12 farms to test whether cost-offset community-supported agriculture (CO-CSA) could improve diet quality among children in low-income families. Intervention households purchased a 50% subsidized share of local produce and were invited to nine complimentary nutrition classes. The purpose of this study was to assess F3HK reach, dose, and fidelity via a mixed methods process evaluation. Screening and enrollment records indicated reach; study records and postlesson educator surveys tracked dose delivered; CSA pickup logs, lesson sign-in sheets, postseason participant surveys, and postlesson caregiver surveys assessed dose received; and coordinator audits and educator surveys tracked fidelity. Educator interviews contextualized findings. The results of this study were as follows. Reach: enrolled caregivers (n = 305) were older (p =. 005) than eligible nonenrollees (n = 243) and more likely to be female (p <. 001). Dose: mean CSA season was 21 weeks (interquartile range [IQR]: 19-23). Median CSA pickup was 88% of the weeks (IQR: 40-100). All sites offered each class at least once. Most adults (77%) and children (54%) attended at least one class; few attended all. Eighty-two percent of caregivers indicated that their household consumed most or all produce. Median lesson activity ratings were 5/5 ("very useful"). Fidelity: CSA locations functioned with integrity to project standards. Educators taught 92% of activities but frequently modified lesson order. This study demonstrates the feasibility of pairing a CO-CSA intervention with nutrition education across geographically dispersed sites. Greater integration of intervention elements and clearer allowance for site-level modifications, particularly for educational elements, may improve intervention dose and, ultimately, impact

    A modified choice experiment to examine willingness to participate in a Community Supported Agriculture (CSA) program among low-income parents

    Get PDF
    There is a need to improve geographical and financial access to healthy foods for limited resource populations in rural areas. Community Supported Agriculture (CSA) programs can improve access to healthy foods in rural and limited-resource populations. However, research is needed to discern the most appealing conditions for a CSA (e.g. price, frequency, food quantity) among rural, low-income customers. The goal of this study was to understand low-income consumers' preferences related to participation in a CSA program, considering price, frequency, food quantity and accessibility (e.g. distance) conditions. A modified exploratory choice experiment exercise was embedded within in-depth interviews to examine willingness to participate in CSA under a variety of conditions among 42 low-income adults with at least one child in the household in North Carolina, New York, Vermont and Washington. Willingness to participate in a CSA under each condition was summed and compared across conditions. Results were stratified by race, number of children and household members and McNemar's test and Student's t-test were used to examine differences in willingness between conditions. Salient quotes were extracted to support themes related to each condition. Our analysis suggests that the ideal CSA would be a full-sized share of eight to nine items of mixed variety, distributed every other week, priced at less than US$15, no more than 10 min further than the supermarket (SM) from their home and preferably less expensive but no more than 20% more expensive than SM prices. CSAs interested in reaching rural low-income populations may benefit from considering these consumer-level preferences

    Fruit and vegetable intake assessed by repeat 24 h recalls, but not by a dietary screener, is associated with skin carotenoid measurements in children

    Get PDF
    Accurate measurement of fruit and vegetable (FV) intake is important for nutrition surveillance and evaluation of dietary interventions. We compared two tools for reporting FV intake to objective measurement of skin carotenoids among children. FV cups/day was assessed by repeated 24 h dietary recalls (24H FV) and the National Cancer Institute’s All-Day Fruit and Vegetable Screener (NCI FV). Skin carotenoids were measured by repeated resonance Raman spectroscopy (RRS) of the palm. FV cups were regressed on RRS scores in unadjusted, field-based, and research-setting models with covariates feasible in each scenario. Data were baseline values from children aged 2–12 years in low-income households enrolled in a healthy eating randomized trial in four U.S. states (n = 177). Twenty-four-hour FV cups were associated with skin carotenoids in all models (p < 0.001) but NCI FV cups were not. Predicted RRS scores for discrete 24H FV cups provide a guide to interpretation of RRS in children (2 cups FV intake ~36,000 RRS units), with the research-setting scenario generally providing the narrowest prediction range (+/−1924). When self-reported data are required, 24 h recalls are more accurate than NCI FV screener data; and, when limited time, resources, or literacy must be considered, RRS scores can be quickly obtained and easily interpreted

    Tune in to your emotions: a robust personalized affective music player

    Get PDF
    The emotional power of music is exploited in a personalized affective music player (AMP) that selects music for mood enhancement. A biosignal approach is used to measure listeners’ personal emotional reactions to their own music as input for affective user models. Regression and kernel density estimation are applied to model the physiological changes the music elicits. Using these models, personalized music selections based on an affective goal state can be made. The AMP was validated in real-world trials over the course of several weeks. Results show that our models can cope with noisy situations and handle large inter-individual differences in the music domain. The AMP augments music listening where its techniques enable automated affect guidance. Our approach provides valuable insights for affective computing and user modeling, for which the AMP is a suitable carrier application

    The perceived influence of cost-offset community-supported agriculture on food access among low-income families

    Get PDF
    Objective To examine perspectives on food access among low-income families participating in a cost-offset community-supported agriculture (CO-CSA) programme.Design Farm Fresh Foods for Healthy Kids (F3HK) is a multicentre randomized intervention trial assessing the effect of CO-CSA on dietary intake and quality among children from low-income families. Focus groups were conducted at the end of the first CO-CSA season. Participants were interviewed about programme experiences, framed by five dimensions of food access: Availability, accessibility, affordability, acceptability and accommodation. Transcribed data were coded on these dimensions plus emergent themes.Setting Nine communities in the US states of New York, North Carolina, Washington and Vermont.Subjects Fifty-Three F3HK adults with children.Results CSA models were structured by partner farms. Produce quantity was abundant; however, availability was enhanced for participants who were able to select their own produce items. Flexible CSA pick-up times and locations made produce pick-up more accessible. Despite being affordable to most, payment timing was a barrier for some. Unfamiliar foods and quick spoilage hindered acceptability through challenging meal planning, despite accommodations that included preparation advice.Conclusions Although CO-CSA may facilitate increased access to fruits and vegetables for low-income families, perceptions of positive diet change may be limited by the ability to incorporate share pick-up into regular travel patterns and meal planning. Food waste concerns may be particularly acute for families with constrained resources. Future research should examine whether CO-CSA with flexible logistics and produce self-selection are sustainable for low-income families and CSA farms

    Knowledge, attitudes, beliefs and behaviors regarding fruits and vegetables among cost-offset community-supported agriculture (csa) applicants, purchasers, and a comparison sample

    Get PDF
    Community-supported agriculture (CSA) participation has been associated with high fruit and vegetable (FV) consumption, which may be due to better access to FV for CSA purchasers, or to positive knowledge, attitudes, and beliefs (KAB) regarding healthy eating among CSA applicants. The objective of this study was to examine KAB and consumption, in association with application to a cost-offset CSA (CO-CSA) program, and with CO-CSA purchase among applicants. We conducted a cross-sectional survey of CO-CSA applicants and a comparison sample in August 2017. All respondents were English-reading adults with a child 2–12 years old and household income of < 185% of the federal poverty level. Among CO-CSA applicants, some were CO-CSA purchasers (n = 46) and some were not (n = 18). An online comparison sample met equivalent eligibility criteria, but had not participated in CSA for three years (n = 105). We compared CO-CSA applicants to the comparison sample, and compared purchasers and non-purchaser sub-groups, using Mann- Whitney U tests and chi-square analysis. CO-CSA applicants reported better knowledge, selfefficacy, home habits, and diet than the comparison sample. Among applicants, CO-CSA purchasers and non-purchasers had equivalent KAB, but children in purchaser households had higher FV consumption than in non-purchaser households (4.14 vs. 1.83 cups, P = 0.001). Future research should explore associations between CO-CSA participation and diet using experimental methods

    Gaining and maintaining a competitive edge: Evidence from CSA members and farmers on local food marketing strategies

    Get PDF
    Community-supported agriculture (CSA) is a widely-used approach for farmers to sell directly to consumers. We used the product, place, price, and promotion (4P) marketing mix framework to examine characteristics that help farms offering CSA maintain member satisfaction and thus competitiveness. We conducted semi-structured interviews with 20 CSA members and 24 CSA farmers in four states. CSA members additionally completed a modified choice experiment. Qualitative data were coded iteratively, and choice experiment data were summarized and compared across scenarios. CSA members and farmers were motivated by a range of personal, social, environmental, and economic objectives. Members favored high-quality staple vegetables (e.g., lettuce, green beans), ideally produced organically. Trust and a sense of personal connection with the farmer comprised part of the "value added" of CSA participation. Time and location of share pick-up were very important; thus, farmers tried to offer convenient sites or an enriched pick-up experience. Small changes in price appeared unlikely to impact participation among current members. Social networks and word-of-mouth were powerful for marketing, but may limit the ability to reach diverse populations. Future research should examine the ability of CSAs to meet the needs of those who do not currently participate
    corecore