234 research outputs found

    A systematic review of the health and well-being impacts of school gardening: synthesis of quantitative and qualitative evidence

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    Background: School gardening programmes are increasingly popular, with suggested benefits including healthier eating and increased physical activity. Our objectives were to understand the health and well-being impacts of school gardens and the factors that help or hinder their success. Methods: We conducted a systematic review of quantitative and qualitative evidence (PROSPERO CRD42014007181). We searched multiple databases and used a range of supplementary approaches. Studies about school gardens were included if they reported on physical or mental health or well-being. Quantitative studies had to include a comparison group. Studies were quality appraised using appropriate tools. Findings were narratively synthesised and the qualitative evidence used to produce a conceptual framework to illustrate how benefits might be accrued. Results: Evidence from 40 articles (21 quantitative studies; 16 qualitative studies; 3 mixed methods studies) was included. Generally the quantitative research was poor. Evidence for changes in fruit and vegetable intake was limited and based on self-report. The qualitative research was better quality and ascribed a range of health and well-being impacts to school gardens, with some idealistic expectations for their impact in the long term. Groups of pupils who do not excel in classroom activities were thought to particularly benefit. Lack of funding and over reliance on volunteers were thought to threaten success, while involvement with local communities and integration of gardening activities into the school curriculum were thought to support success. Conclusion: More robust quantitative research is needed to convincingly support the qualitative evidence suggesting wide ranging benefits from school gardens

    Space-charge mechanism of aging in ferroelectrics: an exactly solvable two-dimensional model

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    A mechanism of point defect migration triggered by local depolarization fields is shown to explain some still inexplicable features of aging in acceptor doped ferroelectrics. A drift-diffusion model of the coupled charged defect transport and electrostatic field relaxation within a two-dimensional domain configuration is treated numerically and analytically. Numerical results are given for the emerging internal bias field of about 1 kV/mm which levels off at dopant concentrations well below 1 mol%; the fact, long ago known experimentally but still not explained. For higher defect concentrations a closed solution of the model equations in the drift approximation as well as an explicit formula for the internal bias field is derived revealing the plausible time, temperature and concentration dependencies of aging. The results are compared to those due to the mechanism of orientational reordering of defect dipoles.Comment: 8 pages, 4 figures. accepted to Physical Review

    Fastpass: A Centralized “Zero-Queue” Datacenter Network

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    An ideal datacenter network should provide several properties, including low median and tail latency, high utilization (throughput), fair allocation of network resources between users or applications, deadline-aware scheduling, and congestion (loss) avoidance. Current datacenter networks inherit the principles that went into the design of the Internet, where packet transmission and path selection decisions are distributed among the endpoints and routers. Instead, we propose that each sender should delegate control—to a centralized arbiter—of when each packet should be transmitted and what path it should follow. This paper describes Fastpass, a datacenter network architecture built using this principle. Fastpass incorporates two fast algorithms: the first determines the time at which each packet should be transmitted, while the second determines the path to use for that packet. In addition, Fastpass uses an efficient protocol between the endpoints and the arbiter and an arbiter replication strategy for fault-tolerant failover. We deployed and evaluated Fastpass in a portion of Facebook’s datacenter network. Our results show that Fastpass achieves high throughput comparable to current networks at a 240 reduction is queue lengths (4.35 Mbytes reducing to 18 Kbytes), achieves much fairer and consistent flow throughputs than the baseline TCP (5200 reduction in the standard deviation of per-flow throughput with five concurrent connections), scalability from 1 to 8 cores in the arbiter implementation with the ability to schedule 2.21 Terabits/s of traffic in software on eight cores, and a 2.5 reduction in the number of TCP retransmissions in a latency-sensitive service at Facebook.National Science Foundation (U.S.) (grant IIS-1065219)Irwin Mark Jacobs and Joan Klein Jacobs Presidential FellowshipHertz Foundation (Fellowship

    Exploring community perceptions in preparation for a randomised controlled trial of biofortified flour in Pakistan

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    Background: Biofortification of staple food crops may be a cost-effective and sustainable approach to reducing micronutrient deficiencies in resource-poor settings with low dietary diversity. However, its success depends on uptake by the local population. This paper presents formative research conducted in a remote, rural community in North West Pakistan, prior to commencing a randomised controlled trial to test the effectiveness of consuming zinc-biofortified wheat flour for alleviating zinc deficiency. It explored local community members’ knowledge, understanding and attitudes towards biofortification and views on members of their community taking part in the trial. Methods: Four focus group discussions were conducted with male and female community members (separately for cultural reasons) and four in-depth interviews were conducted with Jirga members—respected male elders. Participation was limited to households that were ineligible for the trial so that we could explore the perspectives of community members who were not influenced by the incentives of the trial. Focus group participants were selected at community events for transparency. Data collection took place at the local school and homes of Jirga members. Thematic analysis was undertaken, using a combination of deductive and inductive approaches to identify key themes. Results: A total of 47 men and women participated in this study. Participants reported clear motivation to access and consume more nutritious flour, believing this would bring health benefits, particularly to women and children. Trusted members of the local community, including Jirga members and female health workers, should be involved in providing information on biofortified flour (and the trial) to increase levels of awareness and acceptance. Without their involvement, there is a risk that biofortified flour would be mistrusted. The cost of flour is the main factor affecting purchasing decisions, and biofortified flour will need to be cost-competitive to achieve widespread uptake in marginalised, rural communities. Conclusion: This formative study generated rich, qualitative data from a range of community stakeholders to improve the understanding of important barriers and facilitators to the widespread acceptability and adoption of biofortified wheat. Implementation research such as this will inform future decision-making in relation to scaling up biofortified wheat in Pakistan

    Making things happen : a model of proactive motivation

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    Being proactive is about making things happen, anticipating and preventing problems, and seizing opportunities. It involves self-initiated efforts to bring about change in the work environment and/or oneself to achieve a different future. The authors develop existing perspectives on this topic by identifying proactivity as a goal-driven process involving both the setting of a proactive goal (proactive goal generation) and striving to achieve that proactive goal (proactive goal striving). The authors identify a range of proactive goals that individuals can pursue in organizations. These vary on two dimensions: the future they aim to bring about (achieving a better personal fit within one’s work environment, improving the organization’s internal functioning, or enhancing the organization’s strategic fit with its environment) and whether the self or situation is being changed. The authors then identify “can do,” “reason to,” and “energized to” motivational states that prompt proactive goal generation and sustain goal striving. Can do motivation arises from perceptions of self-efficacy, control, and (low) cost. Reason to motivation relates to why someone is proactive, including reasons flowing from intrinsic, integrated, and identified motivation. Energized to motivation refers to activated positive affective states that prompt proactive goal processes. The authors suggest more distal antecedents, including individual differences (e.g., personality, values, knowledge and ability) as well as contextual variations in leadership, work design, and interpersonal climate, that influence the proactive motivational states and thereby boost or inhibit proactive goal processes. Finally, the authors summarize priorities for future researc

    Attention Restoration Theory: A Systematic Review of the Attention Restoration Potential of Exposure to Natural Environments

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    All authors contributed to the design of this review, critically revised the article, and approved the final versions. HO contributed to all stages of the systematic review (searching, screening, data extraction, quality appraisal and synthesis) and drafted the article. MW and BW contributed to double data extraction and preparation of the article. AB devised the search strategy, ran the literature searches, carried out citation searching, and contributed to double screening. OU and VN provided statistical advice and designed and conducted the meta-analyses. RG conceived the idea for the review, contributed to double screening, double data extraction, quality appraisal, and preparation of the article, and is the guarantor

    Biofortification of wheat with zinc for eliminating deficiency in Pakistan: Study protocol for a cluster-randomised, double-blind, controlled effectiveness study (BIZIFED2)

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    Introduction: Micronutrient deficiencies, commonly referred to as “hidden hunger”, affect more than two billion people worldwide, with zinc and iron deficiency frequently reported. The aim of this study is to examine the impact of consuming zinc biofortified flour (Zincol-2016) on biochemical and functional measures of status in adolescent girls and children living in a low resource setting in Pakistan. Methods and analysis: We are conducting a pragmatic, cluster-randomised, double-blind, controlled trial. A total of 483 households have been recruited from two catchment areas approximately 30-40 km distance from Peshawar. Household inclusion criteria are the presence of both an adolescent girl, aged 10-16 years, and a child aged 2-5 years. The study duration is 12 months, divided into two 6-month phases. During phase 1, all households will be provided with locally procured flour from standard varieties of wheat. During phase 2, clusters will be paired, and randomised to either the control or intervention arm of the study. The intervention arm will be provided with zinc biofortified wheat flour, with a target zinc concentration of 40 mg/kg. The control arm will be provided with locally procured wheat flour from standard varieties with an expected zinc concentration of 20 mg/kg. The primary outcome measure is plasma zinc concentration. Secondary outcomes include anthropometric measurements, biomarkers of iron and zinc status, and the presence and duration of respiratory tract infections and diarrhoea. Ethics and dissemination: Ethical approval was granted from the University of Central Lancashire STEMH Ethics Committee (reference number: STEMH 1014) and Khyber Medical University Ethics Committee (DIR/KMU-EB/BZ/000683). The final study methods will be published in peer reviewed journals, alongside the study outcomes. In addition, findings will be disseminated to the scientific community via conference presentations and abstracts and communicated to the study participants through the village elders at an appropriate community forum. Registration details: The trial has been registered with the ISRCTN registry, study ID ISRCTN17107812

    Autologous graft-versus-host disease induction in advanced breast cancer: role of peripheral blood progenitor cells

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    The purpose of the present study was to investigate the impact of the use of peripheral blood progenitor cells (PBPCs) on the induction of autologous graft-versus-host disease (GVHD) in patients with advanced breast cancer. 14 women with stage IIIB and 36 women with stage IV breast cancer received cyclosporine (CsA) 2.5 mg kg–1 i.v. daily, d 0–28, and interferon-gamma (IFNg) 0.025 mg/m2 s.c. qod, d7–28, following PBPC-T ± bone marrow transplantation (BMT). Preceding high-dose chemotherapy consisted of cyclophosphamide 6 g/m2 and thiotepa 800 mg/m2. Histologically proven ≥grade II cutaneous GVHD was induced in18/50 (36%) of patients and was independent of the source of haematopoietic support. In vitro studies showed that post-transplant, 76% of patients had developed auto-cytotoxicity against their own pre-transplant PHA-lymphoblasts. A significant correlation between the occurrence of GVHD ≥grade II and cytolysis was observed in the NK cell-line K562 and the T47D breast cancer cell-line. With a median follow-up of 2½ years, the overall survival (OS) is 58%, the disease-free survival (DFS) 26%, both independent of the development of GVHD and similar to what has been observed in other studies on high-dose chemotherapy in advanced breast cancer. It therefore remains unclear whether the induction of autologous GVHD with the occurrence of auto-cytotoxic lymphocytes can result in an anti-tumour effect in this group of patients. © 2000 Cancer Research Campaign http://www.bjcancer.co
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