bluuebunny/crossref_metadata_2025_split huggingface dataset:
SOME METHODOLOGICAL ASPECTS OF ESTIMATING THE FIRST FEW MOMENTS OF THE DISTRIBUTION OF THE GAMMA RAY MULTIPLI
Authors: BRON K. , KOSSE B. , POORTEMA K. , SCHAAFSMA W. , de VOIGT M.J.A. , WERF S.Y. VAN DER 
Published: April 2008

AbstractThe non–identifiability of relevant parameters is often used as a decisive argument to reject the mathematical model and (or) experimental design. This study shows by means of an example that the argument is not compelling. The experiment to be considered has been designed to determine the first few moments of the distribution of the number of gamma rays, emitted after a nuclear fusion reaction of a particular type. This task of determining moments is so complicated that certain systematic errors cannot be completely avoided. In consequence, the moments are not identifiable with respect to the usual mathematical model and the current experiment (section 2). There is no sense in rejecting the model or the experiment on the basis of this non–identifiability. It is easy to construct a simple estimator for the first moment, with properties that are not too bad (section 2). The current estimation procedures seem to be more accurate. They can even be used to estimate some higher moments. The systematic errors cannot be avoided but are negligible in many reasonable situations (section 3 and 4).The actual analysis of the data is more complicated than suggested in the first four sections. Nevertheless these sections are relevant because the underlying model gives an adequate description of the observations after a preliminary reduction of the data. This fact is intuitively clear but can also be proved (section 5).A test–case suggests that even the standard errors provided by the current technology are reliable (section 6).
A LIMIT THEOREM FOR BERNOULLI RV'S AND FELLER'S SHOE PROBLEM
Authors: Dwass M. 
Published: April 2008

AbstractConsider n sets of objects, each set consisting of m distinct types (for instance n place settings each made up of m distinct dishes and silverware pieces.) s items are drawn at random from the mn items. The distribution of the number of complete sets (each consisting of all m items) in the sample of s is asymptotically Poisson distributed with parameter (a /m)m if s = an1–1 and n→∞. This fact can be interpreted in terms of a certain limit theorem for a sequence of i.i.d Bernoulli rv's.
MODEL REFERENCE ADAPTIVE SYSTEM ESTIMATES FOR COUNTING PROCESSES
Authors: Thavaneswaran A. 
Published: April 2008

AbstractThe adaptive estimation procedure of the model reference adaptive system is modified and applied to counting process models. Maximum likelihood estimates constitute a subclass of the adaptive estimators considered. The adaptive estimator is shown to be strongly consistent and to converge in law to a normal variate. Applications are considered; for example properties of the adaptive estimate are obtained for a periodic intensity model.
Waiting Time Distribution for a Semaphone System
Authors: Wallin J.F.E. 
Published: April 2008

A queueing system is considered, that is representative for the serving of semaphone calls in the Netherlands.First the model is generalized and formulae for the waiting time distribution and the mean waiting time are derived. Two special cases are considered: the first one being a simplification of the actual system of the Dutch PTT, the second one being the real situation.Cumulative waiting time distributions and mean waiting times are calculated, the distributions are plotted.
Logistic Regression, a review
Authors: van Houwelingen J.C. , le Cessie S. 
Published: April 2008

A review is given of the development of logistic regression as a multi‐purpose statistical tool.A historical introduction shows several lines culminating in the unifying paper of Cox (1966), in which theory as developed in the field of bio‐assay is shown to be applicable to designs as discriminant‐analysis and case‐control study. A review is given of several designs all leading to the same analysis. The link is made with epidemiological literature.Several optimization criteria are discussed that can be used in the case of more observations per cell, namely maximum likelihood, minimum chi‐square and weighted regression on the observed logits. Recent literature on the goodness of fit problem is reviewed and finally, comments are made about the non‐parametric approach to logistic regression which is still in rapid development.
Statistics of extremes in climatology
Authors: Buishand T.A. 
Published: April 2008

Climatology is an area with many applications of extreme–value theory. In applications to climatic data it is necessary to consider the distribution ol extremes for dependent random variables and to make allowance for non–stationarity (seasonal variation). It is shown that also for such data the classical limiting distributions for normalized maxima of independent and identically distributed random variables remain useful candidates to describe the distribution of the largest value in a year.Parameter estimation of extreme–value distributions is briefly reviewed. Attention is paid to variance–reduction of quantile estimates by making use of more observations than just the annual maxima. Three examples of applications deal with topics like the estimation of large quantiles by combining information from several records in a region, shifts in the distribution of maxima due to changes in measurement practices, and the use of covariates.
Simulated annealing: An introduction
Authors: Aarts E.H.L. , van Laarhoven P.J.M. 
Published: April 2008

Simulated annealing is a general approach for approximately solving large combinatorial optimization problems. The algorithm is based on an intriguing combination of ideas from at first sight completely unrelated fields of science, viz. combinatorial optimization and statistical physics. On the one hand the algorithm can be viewed as an analogue of an algorithm used in statistical physics for computer simulation of the annealing of a solid to its minimum–energy state, on the other hand it can be considered as a generalization of the well–known iterative improvement approach to combinatorial optimization problems.In this introductory paper we give a mathematical description of the simulated annealing algorithm and discuss its behaviour from both a theoretical and a practical point of view. The latter is illustrated by applying the algorithm to the travelling salesman problem.This paper was written to familiarize the readers of Statistica Neerlandica with simulated annealing. It is a summary of papers written earlier by the authors and does not contain any new material.
An analytical theory of multi‐echelon production/distribution systems
Authors: Langenhoff L.J.G. , Zijm W.H.M. 
Published: April 2008

In this paper, we study inventory control problems arising in multi‐echelon production/distribution chains. In these chains, material is delivered by outside suppliers, proceeds through a number of manufacturing stages, and is distributed finally among a number of local warehouses in order to meet market demand. Each stage requires a fixed leadtime; furthermore, we assume a stochastic, stationary end‐item demand process.The problem to balance inventory levels and service degrees can be modelled and analyzed by defining appropriate cost functions. Under an average cost criterion, we study the three most important structures arising in multi‐echelon systems: assembly systems, serial systems and distribution systems. For all three systems, it is possible to prove exact decomposition results which reduce complex multi‐dimensional control problems to simple one‐dimensional problems. In addition, we establish the optimality of base‐stock control policies.
Characterizing systems of distributions by quantile measures
Authors: Moors J. J. A. , Wagemakers R. Th. A. , Coenen V. M. J. , Heuts R. M. J. , Janssens M. J. B. T. 
Published: April 2008

Modelling an empirical distribution by means of a simple theoretical distribution is an interesting issue in applied statistics. A reasonable first step in this modelling process is to demand that measures for location, dispersion, skewness and kurtosis for the two distributions coincide. Up to now, the four measures used hereby were based on moments.In this paper measures are considered which are based on quantiles. Of course, the four values of these quantile measures do not uniquely determine the modelling distribution. They do, however, within specific systems of distributions, like Pearson's or Johnson's; they share this property with the four moment‐based measures.This opens the possibility of modelling an empirical distribution—within a specific system—by means of quantile measures. Since moment‐based measures are sensitive to outliers, this approach may lead to a better fit. Further, tests of fit—e.g. a test for normality—may be constructed based on quantile measures. In view of the robustness property, these tests may achieve higher power than the classical moment‐based tests.For both applications the limiting joint distribution of quantile measures will be needed; they are derived here as well.
The classic lacunar syndromes: clinical and neuroimaging correlates
Authors: De Reuck J. , De Groote L. , Van Maele G. 
Published: April 2008

Background:  Although lacunar syndromes (LSs) are aimed to be linked to lacunar infarcts, the relation between both is still not very well defined.Purpose:  The present retrospective study tries to define more specifically the clinical and the neuroimaging characteristics of the five most classic LSs.Patients and methods:  Out of a series of 1617 consecutive stroke patients, admitted to the Ghent University Hospital, 293 presented a classic LS. Magnetic resonance imaging (MRI) with diffusion‐weighted imaging (DWI) was performed within 5 days after stroke onset in 227 patients. An acute territorial infarct was demonstrated in 54 patients. The study population finally consisted of 173 patients with a classic LS in whom the responsible lacune was demonstrated or in the absence of another type of infarct.Results:  The responsible lacune was demonstrated with DWI in 104 patients. Pure motor stroke (MS) correlated significantly with the presence of the responsible lacune in the internal capsule (P = 0.000147) and with the stroke severity (P = 0.00724). No significant correlation was observed between the location of the lacunes and the other LS’s.Conclusion:  Pure MS has to be considered as the most specific lacunar syndrome.
A PRAGMATIST DEFENSE OF NON‐RELATIVISTIC EXPLANATORY PLURALISM IN HISTORY AND SOCIAL SCIENCE
Authors: VAN BOUWEL JEROEN , WEBER ERIK 
Published: April 2008

ABSTRACTExplanatory pluralism has been defended by several philosophers of history and social science, recently, for example, by Tor Egil Førland in this journal. In this article, we provide a better argument for explanatory pluralism, based on the pragmatist idea of epistemic interests. Second, we show that there are three quite different senses in which one can be an explanatory pluralist: one can be a pluralist about questions, a pluralist about answers to questions, and a pluralist about both. We defend the last position. Finally, our third aim is to argue that pluralism should not be equated with “anything goes”: we will argue for non‐relativistic explanatory pluralism. This pluralism will be illustrated by examples from history and social science in which different forms of explanation (for example, structural, functional, and intentional explanations) are discussed, and the fruitfulness of our framework for understanding explanatory pluralism is shown.
EXCEPTIONAL HISTORY? THE ORIGINS OF HISTORIOGRAPHY IN THE UNITED STATES1
Authors: CHENG EILEEN KA‐MAY 
Published: April 2008

ABSTRACTThis essay examines how and why historiography—defined to mean the study of the history of historical writing—first emerged as a legitimate subject of historical inquiry in the United States during the period from 1890 to the 1930s by focusing on the practice of historiography by three of the most influential American historiographers whose work spans this period: J. Franklin Jameson, John Spencer Bassett, and Harry Elmer Barnes. Whereas the development of historiography as a field of study signified a recognition that historians and historical writing are themselves products of the historical process, American historiographers in this period at the same time used historiography to further a scientific ideal of objectivity that was premised on the belief in the ability of historians to separate themselves from that process. Modern scholars (notably, Peter Novick) have attributed to scientific historians like Jameson and Bassett a simplistic and naive positivism; but the ability of these historiographers to recognize the subjective character of historical writing and yet affirm a belief in objectivity reveals that their understanding of historical truth was more complex than modern scholars have acknowledged. In turn, by questioning the belief that the historical profession was originally founded on a naïve faith in the ideal of objective truth, I demonstrate that New Historians like Barnes were more similar to their predecessors, the scientific historians, than they (or later scholars) acknowledged. Thus, rather than portraying the shift from scientific history to the New History as a linear trajectory of development from objectivity to a more relativist viewpoint, I argue that New Historians like Barnes at once expressed a greater recognition than his scientific predecessors of how historical writing was the product of its context, while still insisting on his commitment to an ideal of objectivity that divorced the historian from that context.
INFORMED CONSENT PRACTICES IN NIGERIA
Authors: EZEOME EMMANUEL R. , MARSHALL PATRICIA A. 
Published: April 2008

ABSTRACTMost writing on informed consent in Africa highlights different cultural and social attributes that influence informed consent practices, especially in research settings. This review presents a composite picture of informed consent in Nigeria using empirical studies and legal and regulatory prescriptions, as well as clinical experience. It shows that Nigeria, like most other nations in Africa, is a mixture of sociocultural entities, and, notwithstanding the multitude of factors affecting it, informed consent is evolving along a purely Western model.Empirical studies show that 70–95% of Nigerian patients report giving consent for their surgical treatments. Regulatory prescriptions and adjudicated cases in Nigeria follow the Western model of informed consent. However, adversarial legal proceedings, for a multiplicity of reasons, do not play significant roles in enforcing good medical practice in Nigeria. Gender prejudices are evident, but not a norm. Individual autonomy is recognized even when decisions are made within the family. Consent practices are influenced by the level of education, extended family system, urbanization, religious practices, and health care financing options available. All limitations notwithstanding, consent discussions improved with increasing level of education of the patients, suggesting that improved physician's knowledge and increasing awareness and education of patients can override other influences.Nigerian medical schools should restructure their teaching of medical ethics to improve the knowledge and practices of physicians. More research is needed on the preferences of the Nigerian people regarding informed consent so as to adequately train physicians and positively influence physicians’ behaviors.
Colonial Legacy in African Museology: The Case of the Ghana National Museum
Authors: Fogelman Arianna 
Published: April 2008

AbstractAfrican museums were largely founded during the colonial era to house artifacts amassed by imperial agents whose contemporaneous understandings of race, evolution and culture led them to believe local populations were “backward” or otherwise “primitive.” Today in the hands of independent governments, scholars frequently cite “colonial legacy” to explain these institutions' continued irrelevance to the local communities they purport to serve. Recent efforts to “localize” African museums have proceeded without a critical analysis of the “colonial legacy” concept, which both denies local agency and cultural malleability in the museum concept, as demonstrated with the case of the Ghana National Museum.
Cerebrovascular risk factors and incident depression in community‐dwelling elderly
Authors: Luijendijk H. J. , Stricker B. H. , Hofman A. , Witteman J. C. M. , Tiemeier H. 
Published: April 2008

Objective:  The ‘vascular depression’ hypothesis suggests that late‐life depression results from vascular brain damage. We studied the longitudinal association between cerebrovascular risk factors and incident depression in a large population‐based study.Method:  Two thousand nine hundred and thirty‐one persons with the age of ≥61 years were followed up. Data on a comprehensive set of cerebrovascular risk factors were collected at baseline. Participants received a psychiatric assessment 5 years later to establish DSM‐IV diagnoses.Results:  Only current smoking and antihypertensive drug use were independently associated with incident depressive symptoms. Diabetes mellitus and the Framingham stroke risk score were related to incident depressive disorder. No relation with depression was observed for cholesterol, diastolic and systolic blood pressure, history of cardiovascular disease, atrial fibrillation, left ventricular hypertrophy or the use of statins and anticoagulants.Conclusion:  These results moderately support the ‘vascular depression’ hypothesis.
Quantified superiority of cognitive behaviour therapy to antidepressant drugs: a challenge to an earlier meta‐analysis
Authors: Parker G. B. , Crawford J. , Hadzi‐Pavlovic D. 
Published: April 2008

Objective:  The study aimed to review the conclusion of a previously published meta‐analysis which quantified distinct superiority of cognitive therapy to antidepressant drug‐therapy (P < 0.0001).Method:  We sought to include all studies used in the original meta‐analysis. Adopting both that study’s inclusion criteria and additional criteria resulted in a reduced set of studies. We analysed both ‘completer’ and ‘intention to treat’ data, using effect size and odds ratio quantification.Results:  There was an overall trend for cognitive therapy to be superior to antidepressant drug‐therapy, but this was significant for only one of the four meta‐analyses (an intention to treat analysis). We demonstrated considerable heterogeneity between studies, and a significantly higher drop‐out rate in the antidepressant groups.Conclusion:  The previous interpretation – cognitive therapy being distinctly superior to antidepressant medication – cannot be sustained from the currently analysed data set.
Early exposure to cannabis and risk for psychosis in young adolescents in Trinidad
Authors: Konings M. , Henquet C. , Maharajh H. D. , Hutchinson G. , Van Os J. 
Published: April 2008

Objective:  Cannabis use increases the risk for psychosis, but psychotogenic effects of cannabis may be restricted to exposure during early adolescence.Method:  Four hundred and seventy‐two participants (aged 12–23 years), randomly selected from the general population in Trinidad, completed questionnaires on past and current cannabis use and psychotic symptoms (using the Community Assessment of Psychic Experiences).Results:  Cannabis use increased the risk of experiencing psychotic symptoms and this effect was conditional on early exposure, defined around the mean age of onset of cannabis use. Thus, exposure before but not after the age of 14 years predicted psychotic symptoms (respectively β: 0.71, 95% CI 0.22; 1.19, P = 0.004 and β: −0.11, 95% CI −0.57; 0.36, P = 0.66). The developmental effect of cannabis use was independent of use of other drugs or current use of cannabis.Conclusion:  Early adolescence may be a critical period with regard to the psychotogenic effect of cannabis across geographical settings and ethnic groups.
Antipruritic effect of cyclosporine microemulsion in prurigo nodularis: Results of a case series
Authors: Siepmann Dorothee , Luger Thomas A. , Ständer Sonja 
Published: April 2008

Summary Background: Prurigo nodularis shows intense itching nodules, which are often persistent and therapy refractory. Histological alterations include fibrosis of collagen fibers and presence of inflammatory infiltrate, which partly explains the clinical persistence of lesions. Inflammatory cells may directly contribute to induction and maintenance of pruritus at nerve fibers. Cyclosporine microemulsion (ME) suppresses the migration and proliferation of inflammatory cells and may thereby interfere with pathogenesis of prurigo nodularis. The aim of this investigation was to assess the antipruritic efficiency of cyclosporine ME in therapy of prurigo nodularis. Patients and methods: 14 patients with prurigo nodularis of diverse origin and failure to previous therapy were treated with oral cyclosporine ME (3 to 5 mg per kg daily). Blood pressure, liver enzymes, renal function and differential blood count were monitored. Results: In 13 of 14 prurigo patients (92.9 %) there was a significant response to monotherapy with cyclosporine ME. The maximal antipruritic effect occurred after 2 weeks to 12 months. Prurigo nodules also healed during therapy. Seven patients (50.0 %) described side effects. In one case the therapy was stopped. Conclusions: Oral cyclosporine ME is an effective therapy for prurigo nodularis of diverse origin. It appears to function by inhibiting dermal inflammatory cells.
Correlation between spirometry and impulse oscillometry in children with asthma
Authors: Song Tae Won , Kim Kyung Won , Kim Eun Soo , Kim Kyu‐Earn , Sohn Myung Hyun 
Published: April 2008

AbstractAim: In certain patients, such as young children or individuals with cerebral palsy or severe mental retardation, it is difficult to perform forced expiratory manoeuvres to measure expiratory flow volume. In such cases, we could evaluate obstructive lung disease through the measurement of airway resistance instead of expiratory flow volume.Methods: In this study, we evaluated the correlation of Impulse Oscillometry (IOS) parameters with spirometry values and peak expiratory flow rate (PEFR) measurements to give coherence to IOS recordings in lung function exploration. Total serum IgE levels, total eosinophil counts and specific IgE levels were measured in 48 children with asthma and 66 control subjects, aged 7–15 years of age. IOS, spirometry and PEFR measurements were performed, as well as methacholine challenge. We further analyzed the correlations in atopic asthma, atopic control, nonatopic asthma and nonatopic control groups.Results: FEV1 and PEFR showed a significant correlation with impedance and resistance (R) at 5, 10, 20 and 35 Hz, both in atopic asthmatic and in atopic control children. FVC also showed a correlation with impedance and R at 10, 20 and 35 Hz, both in atopic asthmatic and atopic control children. FEF25–75% did not show a correlation with resistances.Conclusion: FEV1, FVC and PEFR were significantly correlated with IOS parameters, in both asthmatic and control subjects, especially for atopic children. IOS could be used as a suitable measure of lung function when spirometry and PEF cannot be performed.