Field dependent spin - lattice relaxation

The spin-lattice relaxation times,T(_1), of Cr(^3+)ions in a range of samples of artificial ruby have been measured at 4.2ºK, in the direct ( one phonon ) relaxation process regime, at frequencies of 9.3, 16, 22, 35.5, and 71 GHz, corresponding to magnetic fields, H, up to 25 kG. These results have been compared with the predictions of the Van Vleck theory of paramagnetic relaxation, that T(_1) should be proportional to H(^-2) for a non-Kramer's ion and H(^-4) for an isolated Kramer's doublet. The observed dependencies, between -0.3 and -1, at low magnetic fields are not in agreement with theory, but at high fields (between fields corresponding to 55.5 and 71 GHz) the average dependency for ΔM=1 transitions at polar angle 90 is T(_1) -H(^-2.55) indicating that the energy levels are tending to behave as isolated Kramer's doublets, due to their increasing separation in energy and the decreasing degree of mixing of pure spin states. At low fields the high degree of mixing of states and the masking effect of the zero field splitting on the field dependent energy separation of the energy levels appear to cause the low degree of dependence of T(_1) on H. In contrast to other published collations of T(_1) measurements performed en different samples at various frequencies, all of these results have been obtained under the same experimental conditions from the same samples, frequency of observation (magnetic field) being the only variable. In addition to the variation of T(_1) with H, a linear variation of T(_1) with mean lattice strain, ε , derived from observations of the line width broadening in the samples used, has been observed. The design and construction of the spectrometers used for these measurements is described in detai

The effects of changes in the order of verbal labels and numerical values on children's scores on attitude and rating scales

Research with adults has shown that variations in verbal labels and numerical scale values on rating scales can affect the responses given. However, few studies have been conducted with children. The study aimed to examine potential differences in children’s responses to Likert-type rating scales according to their anchor points and scale direction, and to see whether or not such differences were stable over time. 130 British children, aged 9 to 11, completed six sets of Likert-type rating scales, presented in four different ways varying the position of positive labels and numerical values. The results showed, both initially and 8-12 weeks later, that presenting a positive label or a high score on the left of a scale led to significantly higher mean scores than did the other variations. These findings indicate that different arrangements of rating scales can produce different results which has clear implications for the administration of scales with children

Variation of electric shielding on virtual Frisch-grid detectors

Because of the low mobility of holes, CdZnTe (CZT) detectors operate as electron-transport-only type devices whose particular geometrical parameters and contacts configurations are specially chosen to minimize the contribution of uncollected holes into the output signal amplitudes (induction effect). Several detector configurations have been proposed to address this problem. One of them employs a large geometrical aspect ratio, parallelepiped-shaped crystal with two planar contacts on the top and bottom surfaces (anode and cathode) and an additional shielding electrode placed on a crystal\u27s side to create the virtual Frisch-grid effect. We studied the effect of the shielding electrode length, as well as its location, on the responses of 6 x 6 x 15 mm(3) virtual Frisch-grid detectors. We found that the length of the shielding electrode placed next to the anode can be reduced to 5 mm with no adverse effects on the device performance. Meanwhile, this allows for charge loss correction by reading the cathode signal

The effect of neoadjuvant chemotherapy and chemoradiotherapy on exercise capacity and outcome following upper gastrointestinal cancer surgery: an observational cohort study

Background: In 2014 approximately 21,200 patients were diagnosed with oesophageal and gastric cancer in England and Wales, of whom 37 % underwent planned curative treatments. Potentially curative surgical resection is associated with significant morbidity and mortality. For operable locally advanced disease, neoadjuvant chemotherapy (NAC) improves survival over surgery alone. However, NAC carries the risk of toxicity and is associated with a decrease in physical fitness, which may in turn influence subsequent clinical outcome. Lower levels of physical fitness are associated with worse outcome following major surgery in general and Upper Gastrointestinal Surgery (UGI) surgery in particular. Cardiopulmonary exercise testing (CPET) provides an objective assessment of physical fitness. The aim of this study is to test the hypothesis that NAC prior to upper gastrointestinal cancer surgery is associated with a decrease in physical fitness and that the magnitude of the change in physical fitness will predict mortality 1 year following surgery.Methods: This study is a multi-centre, prospective, blinded, observational cohort study of participants with oesophageal and gastric cancer scheduled for neoadjuvant cancer treatment (chemo- and chemoradiotherapy) and surgery. The primary endpoints are physical fitness (oxygen uptake at lactate threshold measured using CPET) and 1-year mortality following surgery; secondary endpoints include post-operative morbidity (Post-Operative Morbidity Survey (POMS)) 5 days after surgery and patient related quality of life (EQ-5D-5 L).Discussion: The principal benefits of this study, if the underlying hypothesis is correct, will be to facilitate better selection of treatments (e.g. NAC, Surgery) in patients with oesophageal or gastric cancer. It may also be possible to develop new treatments to reduce the effects of neoadjuvant cancer treatment on physical fitness. These results will contribute to the design of a large, multi-centre trial to determine whether an in-hospital exercise-training programme that increases physical fitness leads to improved overall survival.<br/

Biofortified Maize Improves Selenium Status of Women and Children in a Rural Community in Malawi: Results of the Addressing Hidden Hunger With Agronomy Randomized Controlled Trial

Background: Selenium deficiency is widespread in the Malawi population. The selenium concentration in maize, the staple food crop of Malawi, can be increased by applying selenium-enriched fertilizers. It is unknown whether this strategy, called agronomic biofortification, is effective at alleviating selenium deficiency. Objectives: The aim of the Addressing Hidden Hunger with Agronomy (AHHA) trial was to determine whether consumption of maize flour, agronomically-biofortified with selenium, affected the serum selenium concentrations of women, and children in a rural community setting. Design: An individually-randomized, double-blind placebo-controlled trial wasconducted in rural Malawi. Participants were randomly allocated in a 1:1 ratio to receive either intervention maize flour biofortified with selenium through application of selenium fertilizer, or control maize flour not biofortified with selenium. Participant households received enough flour to meet the typical consumption of all household members (330 g capita−1 day−1) for a period of 8 weeks. Baseline and endline serum selenium concentration (the primary outcome) was measured by inductively coupled plasma mass spectrometry (ICP-MS). Results: One woman of reproductive age (WRA) and one school-aged child (SAC) from each of 180 households were recruited and households were randomized to each group. The baseline demographic and socioeconomic status of participants were well-balanced between arms. No serious adverse events were reported. In the intervention arm, mean (standard deviation) serum selenium concentration increased over the intervention period from 57.6 (17.0) μg L−1 (n = 88) to 107.9 (16.4) μg L−1 (n = 88) among WRA and from 46.4 (14.8) μg L−1 (n = 86) to 97.1 (16.0) μg L−1 (n = 88) among SAC. There was no evidence of change in serum selenium concentration in the control groups Conclusion: Consumption of maize flour biofortified through application of selenium-enriched fertilizer increased selenium status in this community providing strong proof of principle that agronomic biofortification could be an effective approach to address selenium deficiency in Malawi and similar settings. Clinical Trial Registration http://www.isrctn.com/ISRCTN85899451, identifier: ISRCTN85899451

Understanding Compliance Dynamics in Community Justice Settings

This article seeks to expand the existing literature on compliance in community justice settings by highlighting the importance of service user participation in efforts to achieve compliance. The article’s central argument is that although co-productive strategies can enhance service user participation, the degree to which co-production is achievable in penal supervision is perhaps uncertain, and has received insufficient theoretical or empirical attention. To address the gap in knowledge, the article draws on the data generated from a study of compliance in Wales, United Kingdom, and employs the Bourdieusian concepts of habitus, field, and capital to argue that the convergence of two key factors undermines the viability of co-productive strategies in penal settings. One factor is the service users’ habitus of powerlessness which may breed passivity rather than active participation. The second also relates to the power dynamics that characterize penal supervision contexts. Within these contexts, practitioners are statutorily empowered to implement and enforce the requirements of community orders. In the current target-focused policy climate in England and Wales, practitioners may prioritize measurable compliance over forms of compliance that stem from service user participation and engagement perhaps because these are not readily quantifiable

Pretend play and parents\u27 view of social competence: the construct validity of the Child-Initiated Pretend Play Assessment.

Background and Aims: Play is the primary means through which children develop skills and socially interact with other children. The aim of this study was to investigate the relationship between pretend play and social competence in 4&ndash;5-year-old typically developing children, thereby adding further knowledge to the construct validity of the Child-Initiated Pretend Play Assessment (ChIPPA). Procedure: The pretend play ability of 35 preschool children aged 4&ndash;5 years was assessed using the ChIPPA. Parent/guardians of the children were interviewed regarding their child\u27s social competence using the Vineland Social&ndash;Emotional Early Childhood Scales (Vineland SEEC Scales). Main Findings: No significant correlations were found between the children\u27s play scores and their Vineland SEEC Scales scores. A significant and negative relationship was found between cooperation and sharing and elaborate play scores, suggesting that children who scored poorly on the play assessment were rated as cooperative by parents. Principal Conclusions: Parent report of social competence cannot be inferred from play scores. Reasons for the negative and significant finding are put forward and clinical implications of the findings are discussed. Additional investigations are necessary to further explore the construct validity of inferring social competence using the ChIPPA. <br /