A variational approach to strongly damped wave equations

We discuss a Hilbert space method that allows to prove analytical well-posedness of a class of linear strongly damped wave equations. The main technical tool is a perturbation lemma for sesquilinear forms, which seems to be new. In most common linear cases we can furthermore apply a recent result due to Crouzeix--Haase, thus extending several known results and obtaining optimal analyticity angle.Comment: This is an extended version of an article appeared in \emph{Functional Analysis and Evolution Equations -- The G\"unter Lumer Volume}, edited by H. Amann et al., Birkh\"auser, Basel, 2008. In the latest submission to arXiv only some typos have been fixe

Sequence History Analysis (SHA) : Estimating the Effect of Past Trajectories on an Upcoming Event

In this article, we propose an innovative method which is a combination of Sequences Analysis and Event History Analysis. We called this method Sequence History Analysis (SHA). We start by identifying typical past trajectories of individuals over time by using Sequence Analysis. We then estimate the effect of these typical past trajectories on the event under study using discrete-time models. The aim of this approach is to estimate the effect of past trajectories on the chances of experiencing an event. We apply the proposed methodological approach to an original study of the effect of past childhood co-residence structures on the chances of leaving the parental home in Switzerland. The empirical research was based on the LIVES Cohort study, a panel survey that started in autumn 2013 in Switzerland. Analyses show that it is not only the occurrence of an event that increases the risk of experiencing another event, but also the order in which various states occurred. What is more, it seems that two features have a significant influence on departure from the parental home: the co-residence structures and the arrival or departure of siblings from the parental home

Demographic characteristics and food choices of participants in the Special Diabetes Program for American Indians Diabetes Prevention Demonstration Project

OBJECTIVE: American Indians and Alaska Natives (AI/ANs) suffer a disproportionate burden of diabetes. Identifying food choices of AI/ANs at risk of type 2 diabetes, living in both rural and urban settings, is critical to the development of culturally relevant, evidence-based education strategies designed to reduce morbidity and mortality in this population. DESIGN: At baseline, 3135 AI/AN adults participating in the Special Diabetes Program for American Indians Diabetes Prevention Demonstration Project (SDPI-DP) completed a socio-demographic survey and a 27-item food frequency questionnaire (FFQ). The primary dietary behavior goal of SDPI-DP education sessions and lifestyle coaching is changes in food choices, i.e., increased fruits, vegetables and whole grains, decreased high sugar beverages, red meat, and processed foods. Subsequently, program assessment focuses on changes in food types. Foods were delineated using a ‘healthy’ and ‘unhealthy’ classification as defined by the educators advising participants. Urban and rural differences were examined using χ(2) tests and two sample t-tests. Multiple linear regressions and linear mixed models were used to assess the association between socio-demographic factors and food choice. RESULTS: Retired participants, those living in urban areas and with high income and education selected healthy foods most frequently. Young males, those with low income and education consumed unhealthy foods most frequently. Selection of unhealthy foods did not differ by urban and rural setting. CONCLUSIONS: The ubiquitous nature of unhealthy food choices makes them hard to avoid. Food choice differences by gender, age, income, and setting suggest that nutrition education should more effectively target and meets the needs of young AI/AN males

Self-reported recognition of undiagnosed life threatening conditions in chiropractic practice: a random survey

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to identify the type and frequency of previously undiagnosed life threatening conditions (LTC), based on self-reports of chiropractic physicians, which were first recognized by the chiropractic physician. Additionally this information may have a preliminary role in determining whether chiropractic education provides the knowledge necessary to recognize these events.</p> <p>Methods</p> <p>The study design was a postal, cross-sectional, epidemiological self-administered survey. Two thousand Doctors of Chiropractic in the US were randomly selected from a list of 57878. The survey asked respondents to state the number of cases from the list where they were the first physician to recognize the condition over the course of their practice careers. Space was provided for unlisted conditions.</p> <p>Results</p> <p>The response rate was 29.9%. Respondents represented 11442 years in practice and included 3861 patients with a reported undiagnosed LTC. The most commonly presenting conditions were in rank order: carcinoma, abdominal aneurysm, deep vein thrombosis, stroke, myocardial infarction, subdural hematoma and a large group of other diagnoses. The occurrence of a previously undiagnosed LTC can be expected to present to the chiropractic physician every 2.5 years based on the responding doctors reports.</p> <p>Conclusion</p> <p>Based on this survey chiropractic physicians report encountering undiagnosed LTC’s in the normal course of practice. The findings of this study are of importance to the chiropractic profession and chiropractic education. Increased awareness and emphasis on recognition of LTC is a critical part of the education process and practice life.</p