General existence and uniqueness of viscosity solutions for impulse control of jump-diffusions

General theorems for existence and uniqueness of viscosity solutions for Hamilton-Jacobi-Bellman quasi-variational inequalities (HJBQVI) with integral term are established. Such nonlinear partial integro-differential equations (PIDE) arise in the study of combined impulse and stochastic control for jump-diffusion processes. The HJBQVI consists of an HJB part (for stochastic control) combined with a nonlocal impulse intervention term. Existence results are proved via stochastic means, whereas our uniqueness (comparison) results adapt techniques from viscosity solution theory. This paper is to our knowledge the first treating rigorously impulse control for jump-diffusion processes in a general viscosity solution framework; the jump part may have infinite activity. In the proofs, no prior continuity of the value function is assumed, quadratic costs are allowed, and elliptic and parabolic results are presented for solutions possibly unbounded at infinity

Health status, adherence with health recommendations, self-efficacy and social support in patients with rheumatoid arthritis

A study was performed in 86 patients with rheumatoid arthritis (RA) to assess their health problems, the problems they experience in adhering to health recommendations and the relationships of these problems with self-efficacy and social support. Feeling dependent, disability and pain were the most important health related problems. The results showed self-efficacy to be related to the subjective experience of health status as measured by DUTCH-AIMS. Social emotional support was not related to health status and contrary to what we expected social instrumental support was positively related to health status. The majority of the patients (55%) experienced adherence problems with health recommendations. These problems were not related to functional incapacity, pain or other aspects of health status but to the patient's self-efficacy expectations about coping with arthritis. Our conclusion is that to improve the self-management of disability and pain and adherence to health recommendations, patient education should be aimed at strengthening self-efficacy expectations in which social emotional support might be a motivating factor

Espacios de rememoración transgeneracionales y transnacionales: los hijos de detenidos-desaparecidos en el cine documental mexicano y argentino

El debate que tras el fin de la dictadura se ha venido desarrollando en Argentina acerca de las políticas de la memoria, la justicia, el perdón y el olvido, ha sido significativo para que, en el nuevo milenio, los grupos de derechos humanos en México impulsaran el debate acerca de los crímenes de lesa humanidad que se cometieron durante la llamada "guerra sucia" (1969-1982) y lograran, así, obtener mayor visibilidad en el espacio público mexicano. En ambos países, desde fines del siglo XX, los hijos de los desaparecidos se han unido a la lucha de sus abuelas por la justicia y verdad y tratan de construir una imagen de sus padres. En el presente artículo se abordará la creación de un espacio de rememoración transnacional y la constitución de una memoria transgeneracional. Concretamente, se analizará la historia de búsqueda identitaria y la representación del proceso de reconstrucción de los lazos familiares rotos por la represión estatal en los largometrajes documentales (h) historias cotidianas, de Andrés Habegger (2000), y Trazando Aleida, de Christiane Burkhard (2007).* (Agradezco al PASPA-DGAPA-UNAM por el apoyo financiero que se me otorgó durante mi estancia sabática para poder elaborar el presente artículo.

Does mammographic screening and a negative result affect attitudes towards future breast screening?

OBJECTIVES:To investigate the impact of an experience of a benign mammographic result on intention to seek medical help immediately in the case of breast abnormalities, and on intentions and thoughts about future participation in screening. SETTING:The Dutch Breast Cancer Screening Programme for women aged 50¿69. METHODS:Subjects were women who were invited for an initial breast examination: 223 women filled out a questionnaire about 10 days before and about 6 weeks after their initial breast examination. To be able to control for possible test effects, another group of 293 women filled out a questionnaire only after mammography. Changes in thoughts and intentions were examined. RESULTS:Most women were very satisfied with the course of their initial breast examination, although pain or discomfort was often mentioned. No clues to suggest false reassurance were found: more than 99% of the women would consider the possibility of breast cancer if they felt a lump in one of their breasts. In such a situation, most women intended to seek medical help within a week. These variables were not influenced by the experience of mammography with a benign result. In general, women were very positive about (repeat) participation, both before and after screening. After screening, the average woman perceived fewer costs in participating, and perceived her own ability to engage in future screening as higher. However, the experience of pain and anxiety during the initial screening did lead to reverse effects. Women who were less satisfied about their treatment by the staff were more likely to change their intentions to reparticipate in a negative way. CONCLUSIONS:As, in general, women became more positive about regular participation after they had attended breast cancer screening, efforts to improve first round attendance must be continued. At the same time, the screening organisations must continue to prioritise the high level of client friendliness throughout the screening. No evidence for detrimental effects of screening through false reassurance among participants was found

Nanosecond molecular relaxations in lipid bilayers studied by high energy resolution neutron scattering and in-situ diffraction

We report a high energy-resolution neutron backscattering study to investigate slow motions on nanosecond time scales in highly oriented solid supported phospholipid bilayers of the model system DMPC -d54 (deuterated 1,2-dimyristoyl-sn-glycero-3-phoshatidylcholine), hydrated with heavy water. Wave vector resolved quasi-elastic neutron scattering (QENS) is used to determine relaxation times $\tau$, which can be associated with different molecular components, i.e., the lipid acyl chains and the interstitial water molecules in the different phases of the model membrane system. The inelastic data are complemented both by energy resolved and energy integrated in-situ diffraction. From a combined analysis of the inelastic data in the energy and time domain, the respective character of the relaxation, i.e., the exponent of the exponential decay is also determined. From this analysis we quantify two relaxation processes. We associate the fast relaxation with translational diffusion of lipid and water molecules while the slow process likely stems from collective dynamics

Effectiveness of a web-based intervention aimed at healthy dietary and physical activity behavior: a randomized controlled trial about users and usage

Background:\ud Recent studies have shown the potential of Web-based interventions for changing dietary and physical activity (PA) behavior. However, the pathways of these changes are not clear. In addition, nonusage poses a threat to these interventions. Little is known of characteristics of participants that predict usage.\ud \ud Objective:\ud In this study we investigated the users and effect of the Healthy Weight Assistant (HWA), a Web-based intervention aimed at healthy dietary and PA behavior. We investigated the value of a proposed framework (including social and economic factors, condition-related factors, patient-related factors, reasons for use, and satisfaction) to predict which participants are users and which participants are nonusers. Additionally, we investigated the effectiveness of the HWA on the primary outcomes, self-reported dietary and physical activity behavior.\ud \ud Methods:\ud Our design was a two-armed randomized controlled trial that compared the HWA with a waiting list control condition. A total of 150 participants were allocated to the waiting list group, and 147 participants were allocated to the intervention group. Online questionnaires were filled out before the intervention period started and after the intervention period of 12 weeks. After the intervention period, respondents in the waiting list group could use the intervention. Objective usage data was obtained from the application itself.\ud \ud Results:\ud In the intervention group, 64% (81/147) of respondents used the HWA at least once and were categorized as “users.” Of these, 49% (40/81) used the application only once. Increased age and not having a chronic condition increased the odds of having used the HWA (age: beta = 0.04, P = .02; chronic condition: beta = 2.24, P = .003). Within the intervention group, users scored better on dietary behavior and on knowledge about healthy behavior than nonusers (self-reported diet: χ22 = 8.4, P = .02; knowledge: F1,125 = 4.194, P = .04). Furthermore, users underestimated their behavior more often than nonusers, and nonusers overestimated their behavior more often than users (insight into dietary behavior: χ22 = 8.2, P = .02). Intention-to-treat analyses showed no meaningful significant effects of the intervention. Exploratory analyses of differences between pretest and posttest scores of users, nonusers, and the control group showed that on dietary behavior only the nonusers significantly improved (effect size r = −.23, P = .03), while on physical activity behavior only the users significantly improved (effect size r = −.17, P = .03).\ud \ud Conclusions:\ud Respondents did not use the application as intended. From the proposed framework, a social and economic factor (age) and a condition-related factor (chronic condition) predicted usage. Moreover, users were healthier and more knowledgeable about healthy behavior than nonusers. We found no apparent effects of the intervention, although exploratory analyses showed that choosing to use or not to use the intervention led to different outcomes. Combined with the differences between groups at baseline, this seems to imply that these groups are truly different and should be treated as separate entities

Moving beyond a limited follow-up in cost-effectiveness analyses of behavioral interventions

Background Cost-effectiveness analyses of behavioral interventions typically use a dichotomous outcome criterion. However, achieving behavioral change is a complex process involving several steps towards a change in behavior. Delayed effects may occur after an intervention period ends, which can lead to underestimation of these interventions. To account for such delayed effects, intermediate outcomes of behavioral change may be used in cost-effectiveness analyses. The aim of this study is to model cognitive parameters of behavioral change into a cost-effectiveness model of a behavioral intervention. Methods The cost-effectiveness analysis (CEA) of an existing dataset from an RCT in which an high-intensity smoking cessation intervention was compared with a medium-intensity intervention, was re-analyzed by modeling the stages of change of the Transtheoretical Model of behavioral change. Probabilities were obtained from the dataset and literature and a sensitivity analysis was performed. Results In the original CEA over the first 12 months, the high-intensity intervention dominated in approximately 58% of the cases. After modeling the cognitive parameters to a future 2nd year of follow-up, this was the case in approximately 79%. Conclusion This study showed that modeling of future behavioral change in CEA of a behavioral intervention further strengthened the results of the standard CEA. Ultimately, modeling future behavioral change could have important consequences for health policy development in general and the adoption of behavioral interventions in particular