Tweeting For a Better World

Recognizing the need to build the social media capacity of nonprofits, the Rita Allen Foundation began a pilot project last spring, engaging the expertise and assistance of The Bridgespan Group, to help six grantees plan effective social media strategies. We and these six smaller-sized nonprofits (on average $1.8 million in annual revenue) worked together to determine if and how social media could advance each organization's mission, to develop implementation plans and measurement systems, and to collectively identify and address social media challenges

Ising Chain with Competing Interactions in a Staggered Field

Work on the Ising chain with competing interactions is extended to the case where a staggered field is included as well as the usual direct field. A simple transformation enables one to interpret the behavior of this model as a metamagnet. Tricritical points are found and analyzed, and the observability of the tricritical exponents, as distinguished from the usual critical exponents, is discussed

Phase Behavior of Models with Competing Interactions

Models with competing nearest-neighbor and very long-range interactions are solved exactly for several one-dimensional cases, including the usual Ising chain (lCCI) , the X Y model (XYCI) , the transverse Ising model (TICCI), and the spherical model (SCCI). For certain ratios of the competing interaction strengths, ICCI and XYCI display triple points and two critical points in a field. In addition TICCI has an apparently enclosed phase in an H-T phase diagram; however, this phase is really paramagnetic as can be seen when an extended phase diagram is used. The extended phase diagrams for ICCI, XYCI, and TICCI display tricritical points and the tricritical exponents have different values from the usual classical values. In contrast to the rich phase behavior of the preceding models, SCCI shows very simple phase behavior, which is directly related to the ground state. Finally, the introduction of a staggered field to ICCI and a simple transformation allows reinterpretation as a metamagnetic model. Using ICCI as a guide the observability of the tricritical exponents is discussed

The Association between Change in Physical Activity and Weight during Adolescence

Abstract Objective: To investigate the association between annual change in physical activity and subsequent annual change in weight status in adolescents over a 4 year period. Design: Longitudinalstudy design with annualdata collection over 4 years. Setting: Suburban school district in Pittsburgh, PA. Participants: 1245 adolescents aged 11-16 years. Main outcome measures: Physical activity and body mass index (BMI) percentile. Analysis: Generalized estimating equation (GEE). Results: 994 participants (53% male) were included in the analyses. The longitudinal associations between changes in physical activity and BMI% were mostly small and non-significant. However, compared with those who did not change their physical activity, a large annual increase in physical activity (>10 hr/wk) was associated with a significant increase in BMI%. Results were broadly similar for total and vigorous physical activity, boys and girls and for healthy and unhealthy (>85th percentile) BMI%. Conclusions and Implications: The role of physical activity in the development of obesity during adolescence therefore remains unclear. Further work is needed to elucidate the role of physical activity in the preventionof obesity

The Right to Water for Food and Agriculture

The right to water emerged in the Nineties primarily as the right to domestic water for drinking, washing and cooking, and was closely related to the right to sanitation, both of which are seen as a component of the right to an adequate standard of living. This study examines the question of the right to water for food and agriculture and asks whether such a right can be found in the right to water, or whether it is more appropriate to examine the right to adequate food for that purpose. Seeking inspiration from the right to adequate food and from other fields of international law, the study explores the content of the right to water for food and agriculture and then considers its implications for water law. Recognizing a human right to water – for drinking and household needs as well as for growing food – has implications for water allocation and sets limits to the extent that water can be allocated for other uses. In addition, it entails the respect for procedural rights and attention to important principles, such as the principle of non-discrimination and the rights of indigenous peoples

One-Dimensional Model Systems: Theoretical Survey

In the early 1960’s one-dimensional model systems were regarded as amusing toys with the advantage of being far more easily solvable than their ’’real’’ three-dimensional counterparts. Now essentially 1-D (quasi-1-D) magnets can be ’’tailor-made’’ in the laboratory. Even more popular is the field of organic conductors like TTF⋅TCNQ, which are naturally quasi-1-D. Currently solitons and related solutions of non-linear, dispersive 1-D differential equations are ubiquitous in physics, including the area of 1-D magnetism. These developments are discussed in the Introduction. The rest of this paper is concerned with model Hamiltonians, model comparisons, critical singularities in 1-D (quasi-1-D) systems, accuracy of numerical techniques in comparison with exact solutions, brief accounts of dilute and disordered 1-D systems, and 1-D spin dynamics. Finally, a comment is made on a variety of interesting isomorphisms between 1-D magnets and phenomena in several other areas of physics, for example 2-D ferroelectrics, field-theoretic models, and realistic fluids. Comparison of theory and experiment has been the subject of several excellent reviews and is therefore not discussed here

Evaluation of a Theory-Informed Implementation Intervention for the Management of Acute Low Back Pain in General Medical Practice: The IMPLEMENT Cluster Randomised Trial

Introduction: This cluster randomised trial evaluated an intervention to decrease x-ray referrals and increase giving advice to stay active for people with acute low back pain (LBP) in general practice. Methods: General practices were randomised to either access to a guideline for acute LBP (control) or facilitated interactive workshops (intervention). We measured behavioural predictors (e.g. knowledge, attitudes and intentions) and fear avoidance beliefs. We were unable to recruit sufficient patients to measure our original primary outcomes so we introduced other outcomes measured at the general practitioner (GP) level: behavioural simulation (clinical decision about vignettes) and rates of x-ray and CT-scan (medical administrative data). All those not involved in the delivery of the intervention were blinded to allocation. Results: 47 practices (53 GPs) were randomised to the control and 45 practices (59 GPs) to the intervention. The number of GPs available for analysis at 12 months varied by outcome due to missing confounder information; a minimum of 38 GPs were available from the intervention group, and a minimum of 40 GPs from the control group. For the behavioural constructs, although effect estimates were small, the intervention group GPs had greater intention of practising consistent with the guideline for the clinical behaviour of x-ray referral. For behavioural simulation, intervention group GPs were more likely to adhere to guideline recommendations about x-ray (OR 1.76, 95%CI 1.01, 3.05) and more likely to give advice to stay active (OR 4.49, 95%CI 1.90 to 10.60). Imaging referral was not statistically significantly different between groups and the potential importance of effects was unclear; rate ratio 0.87 (95%CI 0.68, 1.10) for x-ray or CT-scan. Conclusions: The intervention led to small changes in GP intention to practice in a manner that is consistent with an evidence-based guideline, but it did not result in statistically significant changes in actual behaviour. Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN01260600009853

Comment on Magnetic Cooling of Solid He\u3csup\u3e3\u3c/sup\u3e

The possibility of cooling solid He3 by adiabatic magnetization is discussed using the antiferromagnetic nearest-neighbor spin-½ Heisenberg linear chain as a reference system. The lack of a phase transition is not important in this discussion since the locus of maximum cooling generally lies outside (i.e., is unrelated to) the T−H phase boundary, contrary to previous predictions using mean-field and spin-wave theories. Exact calculations on linear chains demonstrate a potentially useful degree of equilibrium cooling. The results are in qualitative agreement with earlier spin-wave arguments, although the details of the energy spectrum are more complicated than is assumed in spin-wave theory

Factors associated with referral to outpatient cardiac rehabilitation services

Background: Although practice guidelines and policy statements for cardiac rehabilitation recommend that it be offered to all patients with cardiovascular disease, the participation rates in most Western countries are low. Purpose: This study aimed to determine the factors associated with referral to outpatient cardiac rehabilitation in the Hunter region of New South Wales, Australia. Methods: The study sample comprised 1933 patients discharged from public hospitals in the Hunter region between March 1, 1998 and February 28, 1999 who were eligible for cardiac rehabilitation, and for inclusion on the Hunter Area Heart and Stroke Register (the Register). Data were obtained from the Register database (gender, age, clinical information) and via a self-completed questionnaire eliciting referral, sociodemographic, and cardiovascular disease risk factor information. Multiple logistic regression analysis was conducted to determine the factors independently associated with referral. Results: Of the respondents (1202/1933), 41% (493/1202; 95% confidence interval, 38–44%) reported that they had been referred to outpatient cardiac rehabilitation. The factors independently associated with referral were age younger than 65 years, previous participation in an outpatient cardiac rehabilitation program, admission to a hospital that provides outpatient cardiac rehabilitation, a discharge diagnosis of acute myocardial infarction, and coronary artery bypass surgery. Conclusions: Younger age, previous participation in outpatient cardiac rehabilitation, admission to a hospital that provides outpatient cardiac rehabilitation, a discharge diagnosis of acute myocardial infarction, and coronary artery bypass surgery were associated with referral to cardiac rehabilitation. Research testing strategies designed to increase cardiac rehabilitation referral rates are needed and could include testing the potential role of modern quality management methods