2,578 research outputs found

    Zeeman Slowers for Strontium based on Permanent Magnets

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    We present the design, construction, and characterisation of longitudinal- and transverse-field Zeeman slowers, based on arrays of permanent magnets, for slowing thermal beams of atomic Sr. The slowers are optimised for operation with deceleration related to the local laser intensity (by the parameter ϵ\epsilon), which uses more effectively the available laser power, in contrast to the usual constant deceleration mode. Slowing efficiencies of up to \approx 1818 % are realised and compared to those predicted by modelling. We highlight the transverse-field slower, which is compact, highly tunable, light-weight, and requires no electrical power, as a simple solution to slowing Sr, well-suited to spaceborne application. For 88^{88}Sr we achieve a slow-atom flux of around 6×1096\times 10^9 atoms\,s1^{-1} at 3030 ms1^{-1}, loading approximately 5×1085\times 10^8 atoms in to a magneto-optical-trap (MOT), and capture all isotopes in approximate relative natural abundances

    Cancer symptom awareness and barriers to medical help seeking in Scottish adolescents:a cross-sectional study

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    Background: Initiatives to promote early diagnosis include raising public awareness of signs and symptoms ofcancer and addressing barriers to seeking medical help about cancer. Awareness of signs and symptoms of cancerand emotional barriers, such as, fear, worry, and embarrassment strongly influence help seeking behaviour. Whetheranxiety influences seeking medical help about cancer is not known. The purpose of this study about adolescentswas to examine: 1) the relationship between contextual factors and awareness of signs and symptoms of cancerand barriers (including emotional barriers) to seeking medical help, and 2) associations between anxiety andendorsed barriers to seeking medical help. Interpretation of data is informed by the common sense model of theself-regulation of health and illness.Methods: A cross-sectional study of 2,173 Scottish adolescents (age 12/13 years) using the Cancer AwarenessMeasure. Socio-demographic questions were also included. Descriptive statistics were calculated and two Poissonregression models were built to determine independent predictors of: 1) the number of cancer warning signsrecognized, and; 2) number of barriers to help seeking endorsed.Results: Analysis identified that knowing someone with cancer was a significant independent predictor ofrecognising more cancer warning signs whereas Black and Minority Ethnic status was a significant independentpredictor of recognising fewer cancer warning signs. Emotional barriers were the most commonly endorsed,followed by family, service and practical barriers. Over two thirds of adolescents were ‘worried about what thedoctor would find’ and over half were ‘scared’. Higher anxiety scores, knowing more cancer warning signs andfemale gender were significant independent predictors of barriers to help seeking.Conclusion: Improving cancer awareness and help seeking behaviour during adolescence may contribute to earlypresentation. Contextual factors (for example, ethnicity, gender, knowing someone with cancer), and emotionaldimensions (for example, anxiety, fear, worry) are critical components in help seeking behaviours. The role ofemotional factors indicates that public health campaigns focused on awareness and help seeking may benefit fromhaving a more emotional focus, for example, including references to feelings, such as, fears and worries

    Relationship of social factors including trust, control over life decisions, problems with transport and safety, to psychological distress in the community

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    PURPOSE: Psychological distress encompasses anxiety and depression with the previous studies showing that psychological distress is unequally distributed across population groups. This paper explores the mechanisms and processes which may affect the distribution of psychological distress, including a range of individual and community level socioeconomic determinants. METHODS: Representative cross-sectional data was collected for respondents aged 16+ from July 2008 to June 2009, as a part of the South Australian Monitoring and Surveillance System (SAMSS) using Computer Assisted Telephone Interviews (CATI). Univariate and multivariate analyses (n = 5,763) were conducted to investigate the variables that were associated with psychological distress. RESULTS: The overall prevalence of psychological distress was 8.9%. In the multivariate model, females, those aged 16–49, respondents single with children, unable to work or unemployed, with a poorer family financial situation, earning $20,000 or less, feeling safe in their home some or none of the time, feeling as though they have less then total control over life decisions and sometimes experiencing problems with transport, were significantly more likely to experience psychological distress. CONCLUSIONS: This paper has demonstrated the relationship between low-income, financial pressure, less than optimal safety and control, and high-psychological distress. It is important that the groups highlighted as vulnerable be targeted in policy, planning, and health promotion and prevention campaigns

    Neonatal resuscitation and immediate newborn assessment and stimulation for the prevention of neonatal deaths: a systematic review, meta-analysis and Delphi estimation of mortality effect

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    BACKGROUND: Of 136 million babies born annually, around 10 million require assistance to breathe. Each year 814,000 neonatal deaths result from intrapartum-related events in term babies (previously "birth asphyxia") and 1.03 million from complications of prematurity. No systematic assessment of mortality reduction from tactile stimulation or resuscitation has been published. OBJECTIVE: To estimate the mortality effect of immediate newborn assessment and stimulation, and basic resuscitation on neonatal deaths due to term intrapartum-related events or preterm birth, for facility and home births. METHODS: We conducted systematic reviews for studies reporting relevant mortality or morbidity outcomes. Evidence was assessed using GRADE criteria adapted to provide a systematic approach to mortality effect estimates for the Lives Saved Tool (LiST). Meta-analysis was performed if appropriate. For interventions with low quality evidence but strong recommendation for implementation, a Delphi panel was convened to estimate effect size. RESULTS: We identified 24 studies of neonatal resuscitation reporting mortality outcomes (20 observational, 2 quasi-experimental, 2 cluster randomized controlled trials), but none of immediate newborn assessment and stimulation alone. A meta-analysis of three facility-based studies examined the effect of resuscitation training on intrapartum-related neonatal deaths (RR= 0.70, 95%CI 0.59-0.84); this estimate was used for the effect of facility-based basic neonatal resuscitation (additional to stimulation). The evidence for preterm mortality effect was low quality and thus expert opinion was sought. In community-based studies, resuscitation training was part of packages with multiple concurrent interventions, and/or studies did not distinguish term intrapartum-related from preterm deaths, hence no meta-analysis was conducted. Our Delphi panel of 18 experts estimated that immediate newborn assessment and stimulation would reduce both intrapartum-related and preterm deaths by 10%, facility-based resuscitation would prevent a further 10% of preterm deaths, and community-based resuscitation would prevent further 20% of intrapartum-related and 5% of preterm deaths. CONCLUSION: Neonatal resuscitation training in facilities reduces term intrapartum-related deaths by 30%. Yet, coverage of this intervention remains low in countries where most neonatal deaths occur and is a missed opportunity to save lives. Expert opinion supports smaller effects of neonatal resuscitation on preterm mortality in facilities and of basic resuscitation and newborn assessment and stimulation at community level. Further evaluation is required for impact, cost and implementation strategies in various contexts. FUNDING: This work was supported by the Bill & Melinda Gates Foundation through a grant to the US Fund for UNICEF, and to the Saving Newborn Lives program of Save the Children, through Save the Children US

    CO2 enrichment and soil type additively regulate grassland productivity

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    The development of a predictive understanding of how atmospheric CO2 enrichment is affecting the primary productivity of the terrestrial biosphere is among the most pressing of ecological challenges. The terrestrial biosphere absorbs c. 25% of anthropogenic carbon (C) emissions (Le Quere et al., 2018). Uncertainty in CO2 effects on ecosystem C uptake is a major constraint in the prediction of C cycling and the provisioning of productivity- related ecosystem services. Grasslands cover c. 25% of the terrestrial area and are an important contributor to the global C balance (Sala et al., 1996). CO2 enrichment stimulates the aboveground net primary productivity (ANPP) of most water-limited grasslands by increasing plant water use efficiency (WUE; productivity per unit of transpiration; Morgan et al., 2004; Nowak et al., 2004; Fatichi et al., 2016), but grassland ANPP, as other ecosystem functions, is determined by drivers in addition to water availability which act simultaneously and often interactively with CO2 (Polley et al., 2011). CO2 enrichment usually shows greater stimulation of plant productivity when nitrogen (N) availability is relatively high (Owensby et al., 1994; Reich & Hobbie, 2013; Mueller et al., 2016), for example. Other drivers include precipitation timing (Hovenden et al., 2014), disturbance regimes (Newton et al., 2014), plant species composition (Langley & Megonigal, 2010; Fay et al., 2012; Polley et al., 2012) and soil properties (Epstein et al., 1997, 1998), including soil texture, which influences water availability to plants (Tor-Ngern et al., 2017)

    CO2 enrichment and soil type additively regulate grassland productivity

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    The development of a predictive understanding of how atmospheric CO2 enrichment is affecting the primary productivity of the terrestrial biosphere is among the most pressing of ecological challenges. The terrestrial biosphere absorbs c. 25% of anthropogenic carbon (C) emissions (Le Quere et al., 2018). Uncertainty in CO2 effects on ecosystem C uptake is a major constraint in the prediction of C cycling and the provisioning of productivity- related ecosystem services. Grasslands cover c. 25% of the terrestrial area and are an important contributor to the global C balance (Sala et al., 1996). CO2 enrichment stimulates the aboveground net primary productivity (ANPP) of most water-limited grasslands by increasing plant water use efficiency (WUE; productivity per unit of transpiration; Morgan et al., 2004; Nowak et al., 2004; Fatichi et al., 2016), but grassland ANPP, as other ecosystem functions, is determined by drivers in addition to water availability which act simultaneously and often interactively with CO2 (Polley et al., 2011). CO2 enrichment usually shows greater stimulation of plant productivity when nitrogen (N) availability is relatively high (Owensby et al., 1994; Reich & Hobbie, 2013; Mueller et al., 2016), for example. Other drivers include precipitation timing (Hovenden et al., 2014), disturbance regimes (Newton et al., 2014), plant species composition (Langley & Megonigal, 2010; Fay et al., 2012; Polley et al., 2012) and soil properties (Epstein et al., 1997, 1998), including soil texture, which influences water availability to plants (Tor-Ngern et al., 2017)
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