Stress mirror polishing for future large lightweight mirrors: design using shape optimization.

This study proposes a new way to manufacture large lightweight aspherics for space telescopes using stress mirror polishing (SMP). This technique is well known to allow reaching high quality optical surfaces in a minimum time period, thanks to a spherical full-size polishing tool. To obtain the correct surface's aspheric shape, it is necessary to define precisely the thickness distribution of the mirror to be deformed, according to the manufacturing parameters. We first introduce active optics and stress mirror polishing techniques, and then we describe the process to obtain the appropriate thickness mirror distribution, allowing to generate the required aspheric shape during polishing phase. Shape optimization procedure using PYTHON programing and NASTRAN optimization solver using finite element model (FEM) is developed and discussed in order to assist this process. The main result of this paper is the ability of the shape optimization process to support SMP technique to generate a peculiar aspherical shape from a spherical optical surface thanks to a thickness distribution reshaping. This paper is primarily focused on a theoretical framework with numerical simulations as the first step before the manufacturing of a demonstrator. This two-step approach was successfully used for previous projects.

[Depression Symptoms of Mothers and Fathers of Persons with Schizophrenia]. / Die Depressivität von Müttern und Vätern von Schizophreniekranken.

OBJECTIVE: The purpose of the present study was to investigate if depression symptomatology of patients' parents is predicted by the symptoms of schizophrenia. METHODS: 101 mothers and 101 fathers of the same patients suffering from schizophrenia were included into this study. Parents filled in the "Beck Depression Inventory". Patients were assessed by means of the "Positive and Negative Syndrome Scale". For statistical analyses a Multidimensional Random Coefficients Multinomial Logit Model was applied. RESULTS: We found a significant positive association between negative symptoms and depression severity of fathers and mothers. Further, a significant positive association between positive symptoms and depression severity of fathers, but not of mothers was found. CONCLUSION: Our results show that depression of mothers and of fathers is associated with symptoms of schizophrenia even when controlling for potential predictors.

[Projections about the future number of dementia sufferers: increasing life expectancy not sufficiently considered?].

BACKGROUND: Several authors pointed out that in the next decades dementia will affect a considerably increasing number of the elderly. The question was raised if life-expectancy was projected to conservative, resulting in revisions with higher life-expectancy and larger numbers of the oldest population. The present paper analyses the influence of such revisions on the future numbers of dementia sufferers in Austria. SUBJECTS AND METHODS: For this purpose we used meta-analyses of epidemiological studies and the population projections for the period until 2050 of the Austrian Bureau of Statistics as well as of the United Nations Population Division of the year 2001 as well of the year 2005. RESULTS: Using the extrapolations of the Austrian Bureau of Statistics of the year 1999 as well as of the United Nations Population Division of the year 2001, the number of dementia cases in Austria in the year 2050 will rise to about 233 thousands. According to the four years later performed extrapolations of the United Nations Population Division of the year 2005, dementia cases in Austria will raise to about 262 thousands in the year 2050. CONCLUSIONS: In the next decades, the number of persons suffering from dementia will rise considerably. Increasing life-expectancy will result in markedly higher numbers of persons with dementia than estimated from earlier population projections. Nevertheless, this is the first analysis of future dementia cases based on projections from two different dates, but using the same source. We must conclude that the dramatically increasing number of dementia cases requires comprehensive planning of the health and social care system.

Using Rasch-models to compare the 30-, 20-, and 12-items version of the general health questionnaire taking four recoding schemes into account.

BACKGROUND: The present study compares the 30-, 20-, and 12-items versions of the General Health Questionnaire (GHQ) in the original coding and four different recoding schemes (Bimodal, Chronic, Modified Likert and a newly proposed Modified Chronic) with respect to their psychometric qualities. METHODS: The dichotomized versions (i.e. Bimodal, Chronic and Modified Chronic) were evaluated with the Rasch-Model and the polytomous original version and the Modified Likert version were evaluated with the Partial Credit Model. RESULTS: In general, the versions under consideration showed agreement with the model assumption. However, the recoded versions exhibited some deficits with respect to the Outfit index. CONCLUSIONS: Because of the item deficits and for theoretical reasons we argue in favor of using the any of the three length versions with the original four-categorical coding scheme. Nevertheless, any of the versions appears apt for clinical use from a psychometric perspective.

[Prevalence and recognition of depression among inpatients of non-psychiatric hospital departments]. / Prävalenz und Erkennen der Depression an nicht-psychiatrischen Krankenhausabteilungen.

PURPOSE: The purpose of this study is to compare the prevalence of depression among different types of hospital departments. Furthermore, it compares different methods for assessment of its recognition by non-psychiatric physicians. METHODS: 993 inpatients of internal, surgical, gynecological and physical rehabilitation wards of community hospitals were interviewed by research psychiatrists using the Clinical Interview Schedule. Ward physicians were asked to fill in a short questionnaire in order to assess whether they could correctly identify patients with mental illnesses. In addition, routine discharge diagnoses were assessed. RESULTS: Of the total sample, 13.3 % suffered from depression. Depression was most frequent on physical rehabilitation units (24.2 %), followed by surgical (9.8 %) and internal (9.5 %) wards. On gynecological wards, prevalence of depression was lowest (8.7 %). Of those suffering from depression, 45.7 % were identified as mentally ill by non-psychiatric ward physicians when using questionnaire data. Only 21.0 % of the depressed received a psychiatric discharge diagnosis, which equals less than half of those identified by questionnaire. RESULTS: Of the total sample, 13.3 % of patients suffered from depression. Depression was most frequent in physical rehabilitation units (24.2 %), followed by surgical (9.8 %) and internal (9.5 %) wards. In gynecological wards, the prevalence of depression was the lowest (8.7 %). Of those suffering from depression, 45.7 % were identified as mentally ill by non-psychiatric ward physicians when using questionnaire data. Only 21.0 % of the depressed received a psychiatric discharge diagnosis, less than half of those identified by the questionnaire. CONCLUSIONS: Depression is very common among inpatients of physical hospital departments. Unfortunately, depression is frequently overlooked in everyday clinical work. Routine discharge diagnoses give only very limited information about how often ward physicians recognize mental disorders. Furthermore, hospital discharge diagnoses should not be used for planning mental health services.