Optimal designs for non-competitive enzyme inhibition kinetic models

In this paper, we present a new method for determining optimal designs for enzyme inhibition kinetic models, which are used to model the influence of the concentration of a substrate and an inhibition on the velocity of a reaction. The approach uses a nonlinear transformation of the vector of predictors such that the model in the new coordinates is given by an incomplete response surface model. Although there exist no explicit solutions of the optimal design problem for incomplete response surface models so far, the corresponding design problem in the new coordinates is substantially more transparent, such that explicit or numerical solutions can be determined more easily. The designs for the original problem can finally be found by an inverse transformation of the optimal designs determined for the response surface model. We illustrate the method determining explicit solutions for the D-optimal design and for the optimal design problem for estimating the individual coefficients in a non-competitive enzyme inhibition kinetic model.     

Gender Bias in Parental Leave: Evidence from Sweden

This paper estimates the effect of child gender on mothers’ and fathers’ parental leave using population-wide register data from Statistics Sweden and the Swedish Social Insurance Agency. The results showed that a first-born son increased fathers’ parental leave with 0.6 days (1.5 %) and decreased mothers’ leave by a similar amount. Both the sign and size of this effect is in line with previous research, showing that these types of biases exist also in a society with top ratings on gender equality. However, non-traditional families, with high maternal relative earnings and/or educational levels, showed even larger gender biases which suggest that it may be mothers, rather than fathers, that are the driving force behind this child gender bias.     

Determinants of voluntary CSR disclosure: empirical evidence from Germany

Currently, companies spend a great deal of effort on Corporate Social Responsibility (CSR) disclosures. CSR disclosure relates to the provision of information on companies’ environmental and social performance. From an economic perspective, companies might disclose this information to avoid or decrease potential political costs. We construct a CSR disclosure index based on the Global Reporting Initiative (GRI) guidelines. Using content analysis, we analyze 130 listed German companies’ CSR disclosures (470 firm-year observations) to investigate the determinants of these voluntary disclosure activities. Our results show that, consistent with the political cost theory, German companies’ disclosures of all CSR issues are affected by their visibility, shareholder structure, and relationship with their US stakeholders. In addition, higher profitability is associated with more environmental disclosures. Finally, size and industry membership affect the amount of CSR disclosure.     

On an assumption of bandemer and ketzel in optimal experimental design theory

In bandemee et al. [1] and ketzel [4] assumptions in the construction of optimal experimental designs are given according to which the convergence of certain iteration procedures is stated. in this paper modifications of these well-known procedures are made allowing that the given theorems stand, although in slightly different versions.     

D s -optimal designs for Kozak's tree taper model

In this work, we study D _s -optimal design for Kozak's tree taper model. The approximate D _s -optimal designs are found invariant to tree size and hence create a ground to construct a general replication-free D _s -optimal design. Even though the designs are found not to be dependent on the parameter value p of the Kozak's model, they are sensitive to the s×1 subset parameter vector values of the model. The 12 points replication-free design (with 91% efficiency) suggested in this study is believed to reduce cost and time for data collection and more importantly to precisely estimate the subset parameters of interest.     

Effects of corporate equity ownership on firm value

We investigate the valuation effects related to corporate minority block purchases for a European sample of 113 purchases over 1993–2006. We argue that corporate block ownership, as opposed to institutional or individual block ownership, has several unique characteristics and can create significant short- and long-term wealth for target and acquiring firm shareholders. Because target firms that exhibit signs of inefficient monitoring or agency problems benefit the most, we conclude that corporate block ownerships can align incentives and mitigate information problems in corporate business relationships.     

Book review

G.Bamberg:Statistische Entseheldungstheorle, Physica-Verlag, Würzburg-Wien 1972, 149 S., DM 20,–.

J.M.Mendel:Discrete Techniques of Parameter Estimation. Marcel Dekker, Inc., New York 1973, XIV, 385 S., $ 19.50.

P.Eykhoff:System Identification. Parameter and State Estimation. John Wiley & Sons, London 1974, XX, 555 pp., £ 12.50.

G.Härtler:Versuchsplanung und Statistische Datenanalyse, Akademie-Verlag, Berlin 1976, 103 S., 6 Abb., 12,– M.

P.Mertens(Hrsg.):Prognoserechnung. Physica-Verlag, Würzburg-Wien 1973; 295 S., DM 48,–

E.Schaich, D. Kohle, W.Schweitzer, F.Wegner:Statistik I (für Volkswirte, Betriebswirte und Soziologen.) Verlag Franz Vahlen GrnbH, München 1974, 160 S., DM 22,80.

A.Rosengard: Probabilltés et Statistique en Recherche Scientifique. Dunod, Paris 1972, XIV, 310 S.

D. Zschocke:Betriebsökonometrie.Physica-Verlag, Würzburg-Wien 1974, 287 S., DM 90.–.

J.C.G. Boot, E.B. Cox:Statistical Analysis for Managerial Decisions. McGraw-Hill, Inc., New York 1970, XI, 651 S.

H.Richter, V. Mammitzsch: Methode der kleinsten Quallrate (mit Übungen und Aufgaben).Verlag Berliner Union GmbH, Stuttgart, und Verlag W. Kohlharnmer GmbH, Stuttgart-Berlin-Köln-Mainz 1973, 144 S., DM 24,–.

O.Anderson, W. Popp, M. Schaffranek, D. Steinmetz, H. Stenger: Schätzen und Testen. Eine Einfhrung in die Wahrscheinlichkeitsrechnung und schließeude Statistik.Springer-Verlag, Berlin-Heidelberg-New York 1976, XI, 385 S., 68 Abb., 56 Tab., DM 19,80.

H.Bauer:Wahrscheinlichkeitstheorie und Grundzilge der Maßtheorie. Walter de Gruyter, Berlin-New York 1974, 407 S., DM 48,–.

A.M.Mathai, P.N. Rathie:Basic Concepts in Information and Statistics(Axioluatic Foundations and Applications). Wiley Eastern Limited, New Delhi 1975, X, 137 S., £ 2.75; $ 5.50.

D.F.Merriam (Hrsg.): Random Processes in Geology.Springer-Verlag, Berlin-Heidelberg-New York 1976, VIII, 168 S., 63 Abb., 18 Tab., DM 34,50.

G.Matheron: Random Sets and Integral Geometry. Wiley Series in Probability and Mathematical Statistics, J. Wiley and Sons, New York 1975, XXIII, 261 S., £ 10.60; $ 21.20.

L.Kleinrock: Queueing Systems. Volume I: Theory. J. Wiley and Sons, New York-London-Sydney-Toronto 1975, XVIII, 417 S.; £ 13.55; $ 24.30.

Bartsch, H.-J.:Mathematische Formeln, VEB Fachbuchverlag, Leipzig 1976,15. Auflage, 510 S., 362 Abb., 9,80 M.     

SUFFERING AND LEGITIMACY

This study aims to discover what sort of consumption culture developed among Yugoslavians due to the fact that in the 1960s and 1970s several thousands of them went to Western Europe as guest workers. By analyzing life interviews and literary works the author comes to the conclusion that while consumption culture had evolved in Yugoslavia much earlier than in any other socialist countries thanks to the returning guest workers, these people also created the ‘culture of suffering’ which emerged in the context of feeling homeless, strange and homesick. All of that also meant that in Yugoslavia the system was partly legitimized by the consumption culture imported by the guest workers.     

The prevalence of sexual aggression and victimization among homosexual men

This study examined the prevalence of unwanted sexual contacts among a sample of 310 homosexual men with an average age of 21.8 years recruited in Berlin, Germany. A modified version of the Sexual Experiences Survey was developed to record unwanted contacts involving different means of coercion, sexual acts, and victim‐perpetrator relationships. Reports were elicited about (a) sexual victimization and (b) perpetration of sexually aggressive acts. Three methods of victimization were studied: physical force, exploitation of the victim's incapacitated state, and verbal coercion. Of the 310 respondents, about 15% reported sexual victimization through the use or threat of forcé. Twenty percent were victimized through exploitation of their inability to offer resistance when in an incapacitated state. Ten percent reported victimization through verbal coercion. In terms of being the perpetrator of sexual aggression, over 5% of respondents reported using or threatening to use physical force. Over 16% reported exploiting a person's incapacitated state, and over 6% admitted to the use of verbal coercion. Acceptance of money for sex was identified as a risk factor for both victimization and perpetration. The data show that sexual aggression is a serious problem among homosexual men which requires further exploration.     

The desire for control: Negotiating the arrangement of help for older people in Sweden

The interface between formal (public) and informal help for older people is unclear and subject to change in many welfare states. Our aim in this study was to contribute to increased understanding of the experiences of older people, their next of kin, and the care managers from the municipalities in the process of negotiating help in the everyday lives of older people who can no longer manage on their own. We took a qualitative approach, using qualitative interviews as the main data collection method. The results revealed that the different actors had contrary interests that made it difficult for all parties to be content with the outcome of the negotiations. The everyday lives of dependent older people and their next of kin are strongly affected by the conditions of formal eldercare.