Showing papers by "University of Mannheim published in 1992"

Role of octreotide in the prevention of postoperative complications following pancreatic resection.

Abstract: Though morbidity and mortality rates following pancreatic resection have improved in recent years, they are still around 35% and 5%, respectively. Typical complications, such as pancreatic fistula, abscess, and subsequent sepsis, are chiefly associated with exocrine pancreatic secretion. In order to clarify whether the perioperative inhibition of exocrine pancreatic secretion prevents complications, we assessed the efficacy of octreotide, a long-acting somatostatin analogue. We conducted a randomized, double-blind, placebo-controlled, multicenter trial in 246 patients undergoing major elective pancreatic surgery. Patients were stratified into a high-risk stratum (limited to patients with pancreatic and periampullary tumors) or low-risk stratum (patients with chronic pancreatitis). Patients received octreotide (3 x 100 micrograms) or placebo subcutaneously for 7 days perioperatively. Eleven complications were defined: death, leakage of anastomosis, pancreatic fistula, abscess, fluid collection, shock, sepsis, bleeding, pulmonary insufficiency, renal insufficiency, and postoperative pancreatitis. Two hundred patients underwent pancreatic head resection, 31 patients underwent left resection, and 15 patients had other procedures. The overall mortality rate within 90 days was 4.5%, with 3.2% in the octreotide group and 5.8% in the placebo group. The complication rate was 32% in the patients receiving octreotide (40 of 125 patients) and 55% in patients receiving placebo (67 of 121 patients) (p less than 0.005). In the patients in the high-risk stratum, complications were observed in 26 of the 68 (38%) patients treated with octreotide and in 46 of 71 (65%) patients given placebo (p less than 0.01). Whereas in patients in the low-risk stratum, the complication rate was 25% (14 of 57 patients) in those treated with octreotide and 42% (21 of 50 patients) in patients given placebo (p = NS). The perioperative application of octreotide reduces the occurrence of typical postoperative complications after pancreatic resection, particularly in patients with tumors.

Mood effects on attitude judgments: independent effects of mood before and after message elaboration.

Abstract: This study investigated the independent effects of induced mood on the encoding of persuasive messages and on the assessment of attitude judgments. In Experiment 1, positive or negative mood was induced either before the encoding of a counterattitudinal message or before the assessment of attitude judgments. When mood was induced before message presentation, Ss in a bad mood were more persuaded by strong than by weak arguments, whereas Ss in a good mood were equally persuaded by strong and by weak arguments. When Ss encoded the message in a neutral mood, however, the advantage of strong over weak arguments was more pronounced when Ss were in a good rather than in a bad mood at the time of attitude assessment. In Experiment 2, Ss exposed to a counterattitudinal message composed of either strong or weak arguments formed either a global evaluation or a detailed representation of the message. Positive, negative, or neutral mood was then induced. Ss in a good mood were most likely and Ss in a negative mood least likely to base their reported attitudes on global evaluations.

Scandals and the Public's Trust in Politicians: Assimilation and Contrast Effects

Abstract: Subjects either were or were not asked to recall the names of politicians who had been involved in a scandal and subsequently evaluated the trustworthiness of politicians in general and of three specific exemplars. Answering the scandal question decreased judgments of trustworthiness of politicians in general but increased perceived trustworthiness of specific exemplars. Thus, an assimilation effect was obtained when the target category 'politicians in general" invited inclusion of the scandal politicians in the temporary representation formed of the target. In contrast, the primed politicians could not be included in the representations formed of specific individuals. In this case, they were used as a standard of comparison, resulting in contrast effects. These findings are consistent with the inclusion/exclusion model of assimilation and contrast effects, which emphasizes the role of categorization processes in the construction of targets and standards.

Saving and consumption patterns of the elderly: the German case.

Abstract: The paper provides an empirical analysis of saving and consumption choices of the elderly in Germany, based on the German income and expenditure surveys 1978 and 1983. Main feature of these data is the large sample size making it possible to analyze saving and consumption patterns of the very old (aged 75 and above).

Mood effects on the organization of person information

Abstract: Subjects in a positive, neutral, or negative mood were presented with behaviour descriptions exemplifying different categories to investigate mood effects on the organization of person information Subjects were instructed either to form an impression about the person performing the behaviours (impression set) or to memorize the behaviours (memory set) Neutral mood subjects showed higher recall and more clustering under impression instructions than under memory instructions, replicating previous findings Regardless of instructions, subjects in both positive and negative mood showed recall as high as that shown by those in a neutral mood under impression set Subjects in a positive mood showed considerable clustering regardless of instruction set, whereas subjects in a negative mood showed little clustering regardless of instructional set Thus, recall appeared to be mediated by different processes in the positive and negative mood conditions Results are consistent with the interpretation that different affective states influence processing styles which in turn mediate recall

Life cycle savings and consumption constraints

Abstract: Recent tests of both the pure and the extended life cycle hypothesis have generated inconclusive results on the life cycle behavior of the elderly We extend the life cycle model by introducing a constraint on the physical consumption opportunities of the elderly which, if binding, imposes a consumption trajectory declining in age This explains much of the received evidence on the elderly's consumption and savings behavior, in particular declining consumption, and increasing savings and wealth with increasing age Our analysis of German data gives additional support to our theory We finally draw the implications of the theory on the incidence of consumption and income (wealth) taxes, and on the recent (inconclusive) tests of intergenerational altruism

Contemporary right‐wing extremism in West Germany

Abstract: . The sudden rise of the extreme right-wing party ‘The Republicans’in the late 1980s in the Federal Republic of Germany has attracted high attention within and outside Germany. After a few remarks on the definition and history of right-wing extremism in the Federal Republic of Germany, the paper gives an overview of the Republicans’genesis, organization, membership, platforms and style of electoral campaigns. The final part concentrates on the empirical test of hypotheses deduced from various theoretical approaches to explain support for extreme right-wing parties. The results of this analysis indicate that a considerable part of the Republicans’electorate does not have an extreme right-wing ideology but consists of protest voters. The party has benefited from socioeconomically and politically motivated dissatisfaction and feelings of threat. At the same time, the established parties have failed to respond adequately to these problems.

The Dirichlet series of Koecher and Maaß and modular forms of weight 3/2

Abstract: The basis problem for modular forms is the question which modular forms can be expressed as linear combinations of theta series, in order that this question makes sense one has of course to specify which type of theta series should be taken into account. We want here to follow (in a special case) the approach taken e.g. in [B61, W a l l which (in its general form) asks" Which (cuspidal) modular forms F of degree n and weight k for the group FoC")(N) can be expressed as linear combinations of the theta series of degree n of integral quadratic forms of rank m = 2 k and the same level N? Moreover, one wants to derive an explicit expression for such a linear combination in terms of the Petersson inner products of F with the theta series involved. The representation theoretic version of this question is to ask: Which (cuspidat) automorphic representations of the adelic symplectic (or metaplectic) group

Mobilization of cognitive resources and the generation effect.

Abstract: The generation effect refers to the memory advantage of words that have been generated rather than read. Such a read-generate comparison confounds qualitative task differences and raises methodological problems. A revised methodology is proposed circumventing these problems in that the encoding task is held constant and all stimuli have to be generated, but the degree of generativeness (i.e. the amount of cueing) is varied. In Experiment 1, 1, the (refined version of the) generation effect is demonstrated in a within-subjects design; with increasing generation activity left to the subject, free recall performance increases. No effect is obtained for degree of target masking. The same finding is replicated and shown to be independent of self-paced study time when generative activity is manipulated between subjects (Experiment 2) or within subjects (Experiment 3). As all learning trials involve generation, encoding time is controlled statistically, and free recall is used as a measure of memory, this refine...

Adolescents' Development of Romantic Friendship and Change in Favorite Leisure Contexts

Abstract: Hopes for successful dating for the year ahead, the actual state of romantic friendships, and preferred leisure contexts were assessed for a German sample of male and female students in early and middle adolescence. Data were collected twice, with a 1-year time interval. Using confirmatory prediction analyses, hypotheses concerning the association between transition to dating and change in preferred leisure contexts were tested. Novices in dating were expected to prefer home and neutral settings throughout the year or to change to public, development-enhancing places by the second time of measurement. More experienced adolescents were expected to prefer public, development-enhancing places throughout the year or to fall back on home and neutral settings. Results showed that frustrated hopes for romantic friendship led to a retreat from public contexts. A desire for romantic friendship increased the use ofpublic contexts where one could meet members of the other sex. The use of public settings reflects ado...

Subclinical hyperthyroidism: physical and mental state of patients.

Abstract: We investigated whether subclinical hyperthyroidism [subnormal basal thyroid-stimulating hormone (TSH) level, attenuated TSH response to thyrotropin-releasing hormone (TRH) stimulation, peripheral thyroid hormones within normal range] is accompanied by physical and mental changes. Thirty-five subclinically hyperthyroid patients (27 female, 8 male) were compared with 60 overtly hyperthyroid patients (51 female, 9 male) and with 28 euthyroid control patients (18 female, 10 male) with respect to physical symptoms, affective state, short-term memory, ability to concentrate and psychomotor performance. Patients with subclinical hyperthyroidism ranged between the other two groups. The major difference between controls and subclinically hyperthyroid patients was an increase in frequency of nervous symptoms and symptoms due to an increase of metabolic rate and thermal regulation changes. The major differences between subclinically hyperthyroid and overtly hyperthyroid patients were psychomotor impairment and symptoms of increased metabolic rate. Self-ratings of affective state tended to be similar in patients with subclinical and overt hyperthyroidism. The ability to concentrate and short-term memory were not impaired in any group. Symptoms in patients with subclinical hyperthyroidism probably result from central changes which lead to attenuated TSH responses to TRH, or from elevated but still normal thyroxine levels, which possibly enhance the effect of catecholamines.

Higher education and confidence in institutions: A secondary analysis of the ‘European values survey’, 1981–83

Abstract: A secondary analysis of the ‘European Values Survey’ tests some of the theoretical conclusions regarding the rationality of trust and distrust in established institutions. A reanalysis of the data set's question relating to confidence in ten particular institutions shows that the expected impact of higher education on confidence in institutions to punish governments for breach of trust applies only to those countries with a long, uninterrupted tradition of upholding civil liberties. In these countries multivariate analyses reveal a latent pattern of ‘civil society’ which is the most important dimension of how institutions are perceived by respondents.

Disclosure risk for microdata stemming from official statistics

Abstract: In the research project on data anonymity, the possibilities and difficulties of restoring the identity of respondents, whose data have been anonymized, were tested in realistic simulations. In this paper the results of an application of a) a matching procedure and of b) a method based on discriminate analysis are reported. In the experiments carried out, empirical data of a handbook about German scientists and scholars and the German microcensus were used. A check of the results by an independent data-trustee demonstrated that a real intruder has more difficulties achieving an identification than is frequently assumed.

String branchings on complex tori and algebraic representations of generalized Krichever-Novikov algebras

Abstract: The propagation differential for bosonic strings on a complex torus with three symmetric punctures is investigated. We study deformation aspects between two-and three-point differentials as well as the behaviour of the corresponding Krichever-Novikov algebras. The structure constants are calculated and from this we derive a central extension of the Krichever-Novikov algebras by means of b−c systems. The defining cocycle for this central extension deforms to the well-known Virasoro cocycle for certain kinds of degenerations of the torus.

Asking difficult questions: task complexity increases the impact of response alternatives

Abstract: In providing behavioural frequency reports, respondents use the range of the response alternatives as a frame of reference, resulting in higher estimates on scales that offer high rather than low values The present study demonstrates that the size of this effect increases with increasing question difficulty

Income, Uncertainty and the Probability of Self-Employment

Abstract: Politicians and economists are beoming more and more interested in the determinants of self-employment. Two empirical obervations from West Germany can be help to explain this explain. Firstly, the self-employment ratio, which nearly monotonically declined in the last hundred years from about 25.6% in 1882 to 8.4% in 1981, slowly began to rise in the eigthies and accounted for 8.9% of the total labour force in 1989. Secondly, the number of jobs has risen in the small business sector and has declined in the large business sector. From 1970 to 1987 employment incereased by 1.5 million employees in the small business, which is defined here as all business entities with less than 50 workers. During the same period the large business sector lost 0.85 million jobs. The two observations are linked by the fact that the sel-employed belong to the small business sector. In the West Germany a self-employed worker employed an average of two additional emplyoyess in 1987.

The “Public Capital Hypothesis”: The Case of Germany

Abstract: According to the "public capital hypothesis" public investment crowds in private investment by increasing the rate of return to private capital. The present paper uses an extended cost function with public capital included as an unpaid fixed factor of production to ex- amine the impact public capital has on the private economy. Using a panel of four highly aggregated sectors of the West German Economy, it is shown, that the provision of public capital raises the demand for private capital, as suggested by the public capital hypothesis. In addition, it is shown that public infrastructure capital contributes to the productivity of the private economy.

Unconventional Participation in Party Politics: the Experience of the German Greens

Abstract: The German Green Party, which is one of the most successful Green parties in Western Europe, has not only been efficient in changing the political agenda of the Federal Republic. It has also challenged the conventional way of organizing party politics by institutionalizing a series of organizational principles that are inspired by the ideals of grass-roots democracy. However, despite the ideological appeal of grass-roots democracy to Green sympathizers, the party has failed to attract sufficiently large numbers of active party members. The Greens are caught in a dilemma, because they appeal to those segments of West German society where ‘non-partisans' are most numerous. This undermines the functioning, and hence the credibility, of Green grass-roots democracy.

Therapeutic use of surfactant in neonatal respiratory distress syndrome. Correlation between pulmonary X-ray changes and clinical data.

Abstract: As part of a multicenter surfactant rescue study, the chest X-rays of 239 preterm and term infants were analyzed. To study the influence of surfactant administration on radiographic appearance, 130 patients with a clinical and radiological diagnosis of typical respiratory distress syndrome were selected, in whom adequate chest x-rays before and within 48 h after treatment were available. Median gestational age was 30 weeks (range 25–38 weeks), median birth weight was 1335 g (range 625–3450). The time of surfactant application ranged between 90 min and 24 h after birth (median 6 h). The most common finding after surfactant administration was uniform (n=47) or disproportionate (n=46) improvement of pulmonary aeration, which showed a significant correlation to posttreatment reduction of oxygen requirement (p<0.001). Asymmetric clearance was more often localized on the right side and usually disappeared within two to five days. Only in 13 patients no change of ventilation was found. Development of interstitial emphysema (n=24, including three patients with pneumothorax) after surfactant treatment was an unfavourable prognostic sign. 54% of these patients (13 of 24) died within the first month of life, compared to 8% (7 of 93) in the group of patients with initial improvement of ventilation.

Premium Calculation Without Arbitrage? A note on a contribution by G. Venter

Abstract: Stimulated by a recent contribution by G. Venter in this journal the adequateness of (re-)insurance premium calculation based on the hypothesis of arbitrage free (re-)insurance markets is questioned. It is argued that--in contrast to the theory of financial markets--it is not reasonable to demand that insurance markets are arbitrage free. In addition the adjusted distribution principles put forward by Venter are claimed to be invalid.

Income, Uncertainty and the Probability of Self-Employment

Abstract: This paper aims at investigating the determinants of self- employment within a structural model of discrete choice under uncertainty. The basic idea of our approach centres around Knight's (1921) famous view of entrepreneurs receiving risk-adjusted income that has to exceed the income of employees because of the greater variance of the income stream. Unlike previous econometric approaches, which use reduced form specifications that are more or less based on ad-hoc reasoning, we derive a choice equation of which the parameters have a clear interpretation in terms of the parameters of the underlying von Neumann- Morgenstern utility function. The specification allows to identify how the difference in income risk between wage-employment and self- employment enters the choice equation without approximating the risk difference via a reduced form specification. The model is estimated using a random effects panel probit estimator with unrestricted autocorrelation structure. Estimates are based on a balanced panel of 1,926 working men selected from the West German Socio-Economic Panel 1984 to 1989.

Biochemical analysis of cervical mucus by nuclear magnetic resonance spectroscopy.

Abstract: Biochemical evaluation of cervical mucus is difficult due to the characteristic rheological properties of this hydrogel. The application of high resolution nuclear magnetic resonance spectroscopy proved to be a valuable new method for differentiated biochemical analyses of human cervical mucus. A particular advantage is that it is non-destructive, that it can be applied to specimens of small volume and that no sample preparation, such as solubilization, is necessary.

On the Parallel Implementation of OSI Protocols

Abstract: In this paper we describe design considerations for the implementation of OSI protocols on parallel processors. We consider parallelism to be an appropriate technology for implementing protocols for high-speed networks. Parallelism can help to overcome the gap between fast fiber optics and slow protocol execution.

Semi-nonparametric estimation of binary choice models using panel data : An application to the innovative activity of german firms

Abstract: In the last few years panel data have become an increasingly popular data source among microeconometricians. Panel data sets allow the estimation and testing of more realistic behavioral models. Which could not be identified using a single cross section or a time series data set alone. More applied econometricians would agree that for linear models the grains from using panel data by far linear outweigh the additional complexity involved by coping with heteroscedasticity and autocorrelation problems simultaneously. For models with qualitative or limmited dependent variables the use of panel data introduces a nimber of additional theoretical and computational problems. In the most usual situation of a short time series of cross sections with a large number of individuals observatuion, convensional maximum likelihood estimation of models with individual effects leads to inconssitent parameter estimates if the individual effects are assumed to be fixed, becauseof the corrresponding incidental parameter problem: The Number of parameters to be estimated increases with the number of individual observations(1). On the other hand, for random effects additional distributional assumptions are required, as well as the evaluation of multivariate distribution, since the observations for a single individual over time are no longer independent.