bluuebunny/crossref_metadata_2025 huggingface dataset:
Bone morphogenetic protein 15 and growth differentiation factor 9 co-operate to regulate granulosa cell function
Authors: McNatty Kenneth P , Juengel Jennifer L , Reader Karen L , Lun Stan , Myllymaa Samu , Lawrence Steve B , Western Andrea , Meerasahib Mohamed F , Mottershead David G , Groome Nigel P , Ritvos Olli , Laitinen Mika P E
Published: March 2005

The oocyte-secreted polypeptide growth factors, growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15, also known as GDF9B) have both been shown to be essential for ovarian follicular growth and function. The effects of murine (m) and ovine (o) GDF9 as well as oBMP15, alone or together, on 3H-thymidine uptake and progesterone and inhibin production by granulosa cells from rats were determined. Murine GDF9 stimulated thymidine incorporation by granulosa cells whereas oGDF9 and oBMP15 alone had no effect. However, oBMP15 given together with mGDF9 or oGDF9 was very potent in stimulating 3H-thymidine incorporation by granulosa cells with a greater than 3-fold stimulation compared with any growth factor alone. The synergistic effect of oBMP15 and oGDF9 was almost completely blocked by antibodies generated against these growth factors when administered either alone or in combination. While neither GDF9 (murine or ovine) nor oBMP15 were able to modulate FSH-stimulated progesterone production on their own, FSH-stimulated progesterone production by granulosa cells was potently inhibited when BMP15 and GDF9 were administered together. Immunoreactive α-inhibin levels increased more than 15-fold from granulosa cells when BMP15 and GDF9 were given together whereas consistent stimulatory effects of either growth factor alone were not observed. The effects of GDF9 and BMP15, when added together, were different than those observed for the growth factors alone. Therefore, we hypothesize that within the ovary, these oocyte-secreted growth factors co-operate to regulate proliferation and gonadotropin-induced differentiation of granulosa cells in mammals.
Inducible nitric oxide synthase-derived nitric oxide regulates germinal vesicle breakdown and first polar body emission in the mouse oocyte
Authors: Huo Li-Jun , Liang Cheng-Guang , Yu Ling-Zhu , Zhong Zhi-Sheng , Yang Zeng-Ming , Fan Heng-Yu , Chen Da-Yuan , Sun Qing-Yuan
Published: March 2005

The present study investigated the subcellular localization of inducible nitric oxide synthase (iNOS) during mouse oocyte meiotic maturation and fertilization using confocal microscopy, and further studied the roles of iNOS-derived NO in oocyte maturation by using an iNOS-specific inhibitor aminoguanidine (AG) and iNOS antibody microinjection. In germinal vesicle-stage oocytes, iNOS immunoreactivity was mainly localized in the germinal vesicle. Shortly after germinal vesicle breakdown, the iNOS immunoreactivity accumulated around the condensed chromosomes. At metaphase I and metaphase II, with the organization of chromosomes to the equatorial plate, iNOS immunoreactivity was concentrated around the aligned chromosomes, putatively the position of the metaphase spindle. The accumulation of iNOS immunoreactivity could not be detected at anaphase I and anaphase II. However, at telophase I and telophase II, the staining of iNOS was concentrated in the region between the separating chromosomes/chromatids. Furthermore, the staining of iNOS also accumulated in the male and female pronuclei in fertilized eggs. Germinal vesicle breakdown and the first polar body emission of the oocytes were significantly blocked by the iNOS-specific inhibitor AG in a dose-dependent manner. The germinal vesicle breakdown in oocytes injected with iNOS antibody was also inhibited. We found that the phosphorylation of mitogen-activated protein kinase in oocytes after germinal vesicle breakdown was inhibited by AG treatment. The control oocytes extruded a normal first polar body, while the AG-treated oocytes exhibited an elongated protrusion or no elongated protrusion. The results of confocal microscopy showed that the AG-treated oocytes were arrested at anaphase I–telophase I. Our results suggest that the iNOS-derived NO pathway plays important roles in mouse oocyte meiotic maturation, especially in germinal vesicle breakdown and the anaphase–telophase transition.
Results of a Decellularized Porcine Heart Valve Implanted into the Juvenile Sheep Model
Authors: Dohmen P. M. , Costa F. da , Lopes S. V. , Yoshi S. , Souza F. P. da , Vilani R. , Da Costa M. B. , Konertz W.
Published: March 2005

Objective: This study was performed to evaluate the possibility of creating a glutaraldehyde-free porcine xenograft to improve long-term durability. Methods: A decellularized porcine pulmonary valve was implanted into the right ventricular outflow tract of 7 juvenile sheep. Valves were explanted after 3 months (n = 4) and 6 months (n = 3). Evaluation was performed by gross examination, radiography, histology (hematoxylin-eosin and Sirius red staining), and immunohistochemistry. Quantitative determination of calcium content was investigated by atomic absorption spectrometry. Results: All animals showed fast recovery without complications. At explantation, all decellularized valves showed smooth and pliable leaflets without evidence of thrombosis. The valve wall was also smooth and pliable without hardness. Light microscopy showed a monolayer of host endothelial cells covering the inner surface of the heart valves and repopulation of host fibroblasts into the deeper layers. Sirius red staining enabled visualization of the production of new collagen. Radiographic results showed an absence of calcification, confirmed by the low calcium levels (1.08 0.28 m g/g and 0.73 0.31 m g/g at 3 and 6 months, respectively) revealed by atomic absorption spectrometry. Conclusions: The results with the juvenile sheep model showed that decellularized heart valves are recellularized in vivo. Host endothelial cells form a monolayer on the inner surface of the valve matrix. Furthermore, host fibroblasts repopulate the valve matrix and produce collagen; thus, a remodeling potential can be expected.
Surgical Resection of a Lupus-Related Left Ventricular Aneurysm in a Patient with Normal Coronary Arteries: Case Report
Authors: Samuels Louis E. , Spangler William D. , Goel Inder
Published: March 2005

A 52-year-old woman with systemic lupus erythematosus (SLE) presented with shortness of breath. Echocardiography and cardiac catheterization demonstrated a discrete left ventricular aneurysm (LVA) with normal coronary arteries. Although her heart failure symptomatically improved with medical therapy, she suffered an embolic stroke from a thrombus within the LVA. She was treated with anticoagulation and rehabilitation for 6 weeks. Reevaluation with echocardiography demonstrated persistent depressed LV function and mural thrombus within the LVA. Surgical resection of the LVA was performed with evacuation of the thrombus and local repair of the LV.
Malignant Pericardial Effusion--An Uncommon Complication of Multiple Myeloma: Case Report
Authors: Samuels Louis E. , Van Philbert Y. , Gladstone Douglas E , Haber Marian M.
Published: March 2005

Multiple myeloma is a condition usually associated with lesions of the skeleton. However, under rare circumstances, the malignant plasma cells may infiltrate the pericardium, resulting in an effusion. If left untreated, the abnormal accumulation of pericardial fluid will result in cardiac tamponade, requiring drainage. The following report describes a multiple myeloma patient who developed secondary pericardial and pleural effusions, which were surgically drained via a pleuropericardial window.
Dehiscence of a Valved Conduit in the Ascending Aorta following Low-Velocity Blunt Chest Trauma: Case Report
Authors: Meuris B. , Daenen W. , Flameng W.
Published: March 2005

We report a case of a 56-year old man presenting with dehiscence of a valved conduit in the ascending aorta following low-velocity blunt thoracic trauma. The patient had a history of a Bentall procedure in 1994. Two weeks before referral to our hospital, the patient fell during a bicycle ride and hit the handlebars of the bicycle with his chest. During the days following the accident, the patient developed progressively worsening fatigue, shortness of breath, and intolerance for even minor physical effort. The presence of an enlarged ascending aorta surrounding the implanted valved graft was confirmed, and the patient was referred to our department for surgical repair, after which the patient had an uneventful recovery and was discharged home on postoperative day 12.
Videoscopic Resection of a Giant Symptomatic Pericardial Cyst: Case Report
Authors: Samuels Louis E , Cassano Anthony
Published: March 2005

A 47-year-old woman presented with shortness of breath, chest discomfort, and hoarseness. She was found to have an enlarged cardiac silhouette on plain chest radiography. Computed tomographic scan and magnetic resonance imaging were diagnostic of a giant pericardial cyst. The patient underwent successful videoscopic removal of the cyst with complete resolution of her symptoms.
Adult Socioeconomic Position and the Association Between Height and Coronary Heart Disease Mortality: Findings From 33 Years of Follow-Up in the Whitehall Study
Authors: Langenberg Claudia , Shipley Martin J. , Batty G. David , Marmot Michael G.
Published: March 2005

In the Whitehall Study, which followed 17139 male civil servants over 33 years, the association between tall stature and coronary heart disease (CHD) mortality differed between employment grades. In men without CHD at study entry, the hazard ratio per 15-cm increase in height was 0.77 (95% confidence interval [CI]=0.69, 0.85; P<0.001) for the highest grades, but 0.84 (95% CI=0.69, 1.03; P=.10) for middle and 0.95 (95% CI = 0.75, 1.20; P = .65) for low grades, suggesting that childhood and adult social conditions may interact in their influence on coronary risk.
Asthma, Suicidal Ideation, and Suicide Attempts: Findings From the Baltimore Epidemiologic Catchment Area Follow-Up
Authors: Goodwin Renee D. , Eaton William W.
Published: March 2005

Objectives. We examined cross-sectional and longitudinal associations between asthma, suicidal ideation, and suicide attempt among adults in the community.

Methods. Data were drawn from 3 waves (1981,1982,1993–1996) of the Baltimore follow-up of the Epidemiologic Catchment Area study. Multiple logistic regression analyses were used to examine associations between asthma, asthma treatment, suicidal ideation, suicide attempt, and suicide completion.

Results. Asthma at wave 1 was associated with a significantly increased odds of suicidal ideation (odds ratio [OR] = 2.33; confidence interval [CI] = 1.03, 5.25) and suicide attempt (OR=3.54; CI=1.4, 8.99), which persisted independent of lifetime National Institute of Mental Health Diagnostic Interview Schedule/Diagnostic and Statistical Manual of Mental Disorders, Third Edition major depression and treatment for asthma at wave 2.

Conclusions. These findings provide preliminary evidence suggestive of an association between asthma and an increased likelihood of suicidal ideation and suicide attempt among adults in the community. Neither lifetime major depression nor treatment for asthma explained this relation. These results provide important directions for future research, and if replicated these data may have clinical and public health implications.
Becoming the Framingham Study 1947–1950
Authors: Oppenheimer Gerald M.
Published: March 2005

In the epidemiological imagination, the Framingham Heart Study has attained iconic status, both as the prototype of the cohort study and as a result of its scientific success.

When the Public Health Service launched the study in 1947, epidemiological knowledge of coronary heart disease was poor, and epidemiology primarily involved the study of infectious disease. In constructing their investigation, Framingham’s initiators had to invent new approaches to epidemiological research. These scientific goals were heavily influenced by the contending institutional and personal interests buffeting the study.

The study passed through vicissitudes and stages during its earliest years as its organizers grappled to define its relationship to medicine, epidemiology, and the local community.
Primary Care, Social Inequalities, and All-Cause, Heart Disease, and Cancer Mortality in US Counties, 1990
Authors: Shi Leiyu , Macinko James , Starfield Barbara , Politzer Robert , Wulu John , Xu Jiahong
Published: March 2005

Objectives. We tested the association between the availability of primary care and income inequality on several categories of mortality in US counties.

Methods. We used cross-sectional analysis of data from counties (n=3081) in 1990, including analysis of variance and multivariate ordinary least squares regression. Independent variables included primary care resources, income inequality, and sociodemographics.

Results. Counties with higher availability of primary care resources experienced between 2% and 3% lower mortality than counties with less primary care. Counties with high income inequality experienced between 11% and 13% higher mortality than counties with less inequality.

Conclusions. Primary care resources may partially moderate the effects of income inequality on health outcomes at the county level.
Immigration and Geographic Access to Prenatal Clinics in Brooklyn, NY: A Geographic Information Systems Analysis
Authors: McLafferty Sara , Grady Sue
Published: March 2005

We compared levels of geographic access to prenatal clinics in Brooklyn, NY, between immigrant and US-born mothers and among immigrant groups by country of birth. We used birth data to characterize the spatial distribution of mothers and kernel estimation to measure clinic density within a 2-mile radius of each mother. Results showed that geographic access to clinics differs substantially by country of birth. Certain groups (e.g., Pakistani, Bangladeshi) have relatively poor geographic access despite a high need for prenatal care.
“Come and Take a Walk”: Listening to Early Head Start Parents on School-Readiness as a Matter of Child, Family, and Community Health
Authors: McAllister Carol L. , Wilson Patrick C. , Green Beth L. , Baldwin Jennifer L.
Published: March 2005

We explored the perspectives and experiences of low-income, predominantly African American families regarding children’s school-readiness. Our research, which involved qualitative interviews, ethnographic case studies, and “photovoice” methods, focused on families participating in the national evaluation of Early Head Start. While valuing academic skills, study parents emphasized the importance of social and emotional health in regard to both children’s and parents’ readiness to begin school. These developments are especially critical given the challenges parents perceive in local school environments. On the basis of a social ecology framework, we argue that psychological and environmental dimensions of school-readiness are public health matters and that understanding the perspectives of low-income and minority parents on such issues is a critical aspect of health communication dedicated to eliminating health disparities.
Tackling the Wider Determinants of Health Disparities in England: A Model for Evaluating the New Deal for Communities Regeneration Initiative
Authors: Parry Jayne , Judge Ken
Published: March 2005

The National Strategy for Neighbourhood Renewal (NSNR) is a central component of British policy to reduce health disparities. This program seeks to improve local socioeconomic and physical environments through the intensive regeneration of disadvantaged communities. We describe the challenges facing evaluators tasked with assessing the impacts of 1 component of the NSNR—the New Deal for Communities initiative—and explore techniques that may be adopted in the evaluation process.
The Community Action Model: A Community-Driven Model Designed to Address Disparities in Health
Authors: Hennessey Lavery Susana , Smith Mele Lau , Esparza Alma Avila , Hrushow Alyonik , Moore Melinda , Reed Diane F.
Published: March 2005

The community action model is a 5-step, community-driven model designed to build communities’ capacity to address health disparities through mobilization. Fundamental to the model is a critical analysis identifying the underlying social, economic, and environmental forces that create health and social inequities in a community. The goal is to provide communities with the framework necessary to acquire the skills and resources to plan, implement, and evaluate health-related actions and policies.

The model was developed in the context of tobacco-related health disparities. Concrete policy outcomes demonstrate the model’s potential application to a wide variety of grassroots policy development efforts.
Building on Leadership and Social Capital to Create Change in 2 Urban Communities
Authors: Farquhar Stephanie A. , Michael Yvonne L. , Wiggins Noelle
Published: March 2005

There has been an appeal to reduce health inequities by increasing community involvement and social capital. Poder es Salud/Power for Health is a community-based participatory prevention research project that seeks to address health disparities in the African American and Latino communities by enhancing community-level social capital.

We provide specific examples of how this intervention uses community health workers and popular education to reduce language and cultural barriers and enhance community social capital. Although the communities share fundamental challenges related to health disparities, the ways in which the Latino and African American communities identify health concerns, create solutions, and think about social capital vary. Members of the project are working together to identify opportunities for cross-cultural collaboration.
Jacobson v Massachusetts at 100 Years: Police Power and Civil Liberties in Tension
Authors: Gostin Lawrence O.
Published: March 2005

A century ago, the US Supreme Court in Jacobson v Massachusetts upheld the exercise of the police power to protect the public’s health. Despite intervening scientific and legal advances, public health practitioners still struggle with Jacobson’s basic tension between individual liberty and the common good.

In affirming Massachusetts’ compulsory vaccination law, the Court established a floor of constitutional protections that consists of 4 standards: necessity, reasonable means, proportionality, and harm avoidance. Under Jacobson, the courts are to support public health matters insofar as these standards are respected.

If the Court today were to decide Jacobson once again, the analysis would likely differ—to account for developments in constitutional law—but the outcome would certainly reaffirm the basic power of government to safeguard the public’s health.
Jacobson v Massachusetts: It’s Not Your Great-Great-Grandfather’s Public Health Law
Authors: Mariner Wendy K. , Annas George J. , Glantz Leonard H.
Published: March 2005

Jacobson v Massachusetts, a 1905 US Supreme Court decision, raised questions about the power of state government to protect the public’s health and the Constitution’s protection of personal liberty. We examined conceptions about state power and personal liberty in Jacobson and later cases that expanded, superseded, or even ignored those ideas.

Public health and constitutional law have evolved to better protect both health and human rights. States’ sovereign power to make laws of all kinds has not changed in the past century. What has changed is the Court’s recognition of the importance of individual liberty and how it limits that power. Preserving the public’s health in the 21st century requires preserving respect for personal liberty.
Efficient Portfolios in the Asset Liability Context
Authors: Keel Alex , Müller Heinz H.
Published: March 2005

The set of efficient portfolios in an asset liability model is discussed in detail. The occurence of liabilities leads to a parallel shift of the efficient set. Under an appropriate assumption, the shift vector can be decomposed in different components. For the special case, where the investor is a pension fund, it is shown how shortfall constraints can be reconciled with efficiency. Finally, optimality conditions for the market portfolio are derived.
Does Markov-Modulation Increase the Risk?
Authors: Asmussen Søren , Frey Andreas , Rolski Tomasz , Schmidt Volker
Published: March 2005

In this paper we compare ruin functions for two risk processes with respect to stochastic ordering, stop-loss ordering and ordering of adjustment coefficients. The risk processes are as follows: in the Markov-modulated environment and the associated averaged compound Poisson model. In the latter case the arrival rate is obtained by averaging over time the arrival rate in the Markov modulated model and the distribution of the claim size is obtained by averaging the ones over consecutive claim sizes.
Community Rating and Equalisation
Authors: Neuhaus Walther
Published: March 2005

Several countries have made community rating mandatory for certain lines of insurance, particularly health insurance. This paper offers a theoretical solution to the problem of designing equalisation schemes to support community rating in a market where different insurers are selling different benefit plans. The criterion chosen is that an equalisation scheme should minimise the opportunities for arbitrage between insurers, which community rating otherwise would generate. Several possible measures of arbitrage are presented, and the optimal schemes are compared against data from Australian health insurers. Finally, the approach is extended to partial community rating, for example unisex rating.
Modelling of Discretized Claim Numbers in Loss Reserving
Authors: Hesselager Ole
Published: March 2005

We investigate the usual method of discretizing loss reserving data by calendar year and show how this procedure may introduce fluctuations in the delay probabilities. These fluctuations, when treated as random fluctuations, possess a special correlation structure and we present a simple credibility method accounting for these fluctuations. The results are illustrated by a numerical example.
Some Stable Algorithms in Ruin Theory and Their Applications
Authors: Dickson David C.M. , dos Reis Alfredo D. Egídio , Waters Howard R.
Published: March 2005

In this paper we present a stable recursive algorithm for the calculation of the probability of ultimate ruin in the classical risk model. We also present stable recursive algorithms for the calculation of the joint and marginal distributions of the surplus prior to ruin and the severity of ruin. In addition we present bounds for these distributions.
Pension Funding With Time Delays and the Optimal Spread Period
Authors: Haberman Steven
Published: March 2005

The paper extends earlier results by demonstrating that there is an optimal range of values for the period for amortizing valuation surpluses or deficiencies, in the case when there is a one year time delay between fixing a contribution rate and the accounting information about current fund levels. The optimal range is compared for the cases where there is no time delay and there is a one year time delay.
A Teacher's Remark on Exact Credibility
Authors: Gerber Hans U.
Published: March 2005

In the classical Bayesian approach to credibility the claims are conditionally independent and identically distributed random variables, with common density f(x, ϑ). The unknown parameter ϑ is a realization of a random variable Θ having initial (prior) density u(ϑ). Let

The initial pure premium is

The premium for X t + 1, given X1 +, …, Xt, is the conditional expectation

A central question is for which pairs f(x, ϑ) and u (ϑ) this expression is linear, i.e. of the form

where is the observed average. This is indeed the case for about half a dozen famous examples. Jewell (1974) has found an elegant and general approach to unify these examples, see also Goovaerts and Hoogstad (1987, chapter 2). The classical examples can be retrieved as special cases; however a preliminary reparameterization has to be performed on a case by case basis. The purpose of this note is to propose an alternative (but of course strongly related) formulation of the general model, from which the classical examples can be retrieved in a straightforward way.
A semimartingale approach to some problems in Risk Theory
Authors: Sørensen Michael
Published: March 2005

The purpose of this note is to draw attention to a semimartingale method which can be applied to very general types of risk models to obtain local martingales or martingales, which can then be used in the now classical way to evaluate ruin probabilities. Relations to the theory of exponential families of stochastic processes are also pointed out and utilized.
Premium Calculation by Transforming the Layer Premium Density
Authors: Wang Shaun
Published: March 2005

This paper examines a class of premium functionals which are (i) comonotonic additive and (ii) stochastic dominance preservative. The representation for this class is a transformation of the decumulative distribution function. It has close connections with the recent developments in economic decision theory and non-additive measure theory. Among a few elementary members of this class, the proportional hazard transform seems to stand out as being most plausible for actuaries.
Claims Reserving in Continuous Time; A Nonparametric Bayesian Approach
Authors: Haastrup Svend , Arjas Elja
Published: March 2005

Occurrences and developments of claims are modelled as a marked point process. The individual claim consists of an occurrence time, two covariates, a reporting delay, and a process describing partial payments and settlement of the claim. Under certain likelihood assumptions the distribution of the process is described by 14 one-dimensional components. The modelling is nonparametric Bayesian. The posterior distribution of the components and the posterior distribution of the outstanding IBNR and RBNS liabilities are found simultaneously. The method is applied to a portfolio of accident insurances.
Improved Analytical Bounds for Some Risk Quantities
Authors: Hürlimann Werner
Published: March 2005

Simple analytical lower and upper bounds are obtained for stop-loss premiums and ruin probabilities of compound Poisson risks in case the mean, variance and range of the claim size distribution are known. They are based on stop-loss extremal distributions and improve the bounds derived earlier from dangerous extremal distributions. The special bounds obtained in case the relative variance of the claim size is unknown, but its maximal value is known, are related to other actuarial results.
On Bounds for the Difference Between the Stop-Loss Transforms of Two Compound Distributions
Authors: Sundt Bjørn , Jan Dhaene
Published: March 2005

In the present note we deduce a class of bounds for the difference between the stop-loss transforms of two compound distributions with the same severity distribution. The class contains bounds of any degree of accuracy in the sense that the bounds can be chosen as close to the exact value as desired; the time required to compute the bounds increases with the accuracy.
Optimal Estimation Under Linear Constraints
Authors: Neuhaus Walther
Published: March 2005

This paper shows how a multivariate Bayes estimator can be adjusted to satisfy a set of linear constraints. In the direct approach, the constraint is enforced by a restriction on the class of admissible estimators. In an alternative approach, the constraint is merely encouraged by a mixed risk function which penalises misbalance between the estimator and the constraint. The adjustment to the optimal unconstrained estimator is shown to depend on the risk function and the linear constraints only, not on the probability model underlying the Bayes estimator. Two practical examples are given, one of which involves reconciliation of independently assessed share values with current market values.
An Extension of Mack's Model for the Chain Ladder Method
Authors: Schmidt Klaus D. , Schnaus Anja
Published: March 2005

The chain ladder method is a simple and suggestive tool in claims reserving, and various attempts have been made aiming at its justification in a stochastic model. Remarkable progress has been achieved by Schnieper and Mack who considered models involving assumptions on conditional distributions. The present paper extends the model of Mack and proposes a basic model in a decision theoretic setting. The model allows to characterize optimality of the chain ladder factors as predictors of non-observable development factors and hence optimality of the chain ladder predictors of aggregate claims at the end of the first non-observable calendar year. We also present a model in which the chain ladder predictor of ultimate aggregate claims turns out to be unbiased.
Credibility Theory and Generalized Linear Models
Authors: Nelder J.A. , Verrall R.J.
Published: March 2005

This paper shows how credibility theory can be encompassed within the theory of Hierarchical Generalized Linear Models. It is shown that credibility estimates are obtained by including random effects in the model. The framework of Hierarchical Generalized Linear Models allows a more extensive range of models to be used than straightforward credibility theory. The model fitting and testing procedures can be carried out using a standard statistical package. Thus, the paper contributes a further range of models which may be useful in a wide range of actuarial applications, including premium rating and claims reserving.
Estimating the Tails of Loss Severity Distributions Using Extreme Value Theory
Authors: McNeil Alexander J.
Published: March 2005

Good estimates for the tails of loss severity distributions are essential for pricing or positioning high-excess loss layers in reinsurance. We describe parametric curve-fitting methods for modelling extreme historical losses. These methods revolve around the generalized Pareto distribution and are supported by extreme value theory. We summarize relevant theoretical results and provide an extensive example of their application to Danish data on large fire insurance losses.
On the Distribution of the Surplus Prior to Ruin in a Discrete Semi-Markov Risk Model
Authors: J.M. Reinhard  , Snoussi M.
Published: March 2005

In this paper we extend the work of Reinhard and Snoussi (2000) by developing a recursive system for finding the distribution of the surplus prior to ruin in a discrete semi-Markov risk model.
The Practical Replacement of a Bonus-Malus System
Authors: Walhin J.F. , Paris J.
Published: March 2005

In this paper we will show how to set up a practical bonus-malus system with a finite number of classes. We will use the actual claim amount and claims frequency distributions in order to predict the future observed claims frequency when the new bonus-malus system will be in use. The future observed claims frequency is used to set up an optimal bonus-malus system as well as the transient and stationary distributions of the drivers in the new bonus-malus system. When the number of classes as well as the transition rules of the new bonus-malus system have been adopted, the premium levels are obtained by minimizing a certain distance between the levels of the practical bonus-malus system and the corresponding optimal bonus-malus system. Some iterations are necessary in order to reach stabilization of the future observed claims frequency and the levels of the practical bonus-malus system.
Reduced folate carrier gene is a risk factor for neural tube defects in a Chinese population
Authors: Pei Lijun , Zhu Huiping , Ren Aiguo , Li Zhiwen , Hao Ling , Finnell Richard H. , Li Zhu
Published: March 2005

BACKGROUND

There is a considerable body of data demonstrating that periconceptional supplementation of folic acid can prevent a significant proportion of neural tube defects (NTDs). At present, the mechanism by which folic acid exerts its beneficial effect remains unknown. Folate transporter genes, including the reduced folate carrier gene (RFC1), have been proposed as NTD risk factors.

METHODS

The study population included 104 nuclear families with NTDs and 100 nonmalformed control families. We investigated the possible association between a common RFC1 polymorphism (A80G) and NTD risk among offspring, as well as potential gene‐environment interactions between the infant RFC1 genotype and maternal periconceptional use of folic acid through a population‐based case‐control study.

RESULTS

We observed that the infants of the GG genotype were associated with a 2.56‐fold increased risk of NTDs when compared to the AA genotype (odds ratio [OR], 2.56; 95% confidence interval [CI], 1.04–6.36) in our study population. Among mothers who did not utilize folic acid supplements, the risk for having a child with an NTD was 3.30 (95% CI, 1.15–9.65) for offspring with the GG genotype, compared to the reference (AA) genotype. Children who had the GG genotype and whose mothers did not take folic acid had an elevated risk for NTDs (OR, 8.80; 95% CI, 2.83–28.69), compared to offspring with the AA and GA genotypes whose mothers utilized folic acid supplements.

CONCLUSIONS

Our findings suggest that the RFC1 G allele is likely to be an important genetic factor in determining folate transport and subsequently may be a risk factor for NTDs in this Chinese population. Birth Defects Research (Part A), 2005. © 2005 Wiley‐Liss, Inc.
Who are the multichannel shoppers and how do they perform?: Correlates of multichannel shopping behavior
Authors: Kumar V. , Venkatesan Rajkumar
Published: March 2005

We develop a conceptual framework, which identifies the customer-level characteristics and supplier factors that are associated with purchase behavior across multiple channels. We also propose that multichannel shoppers provide benefits as measured by several customer-based metrics. We conduct an empirical analysis of our propositions using the customer database of a high technology hardware and software manufacturer. We find that customers who buy across multiple product categories, initiate more contacts with the firm, have past experience with the supplier through the online channel, have longer tenure, purchase more frequently, are larger and receive communication from the supplier through multiple communication channels, especially through highly interpersonal channels. We also find evidence for a nonlinear relationship between returns and multichannel shopping, and that there is a positive synergy towards multichannel shopping when customers are contacted through various communication channels. Customers who shop across multiple transaction channels provide higher revenues, higher share of wallet, have higher past customer value, and have a higher likelihood of being active than other customers.We derive several implications for managers who wish to target customers for a multichannel strategy.
Multichannel retailing: A case study of early experiences
Authors: Dholakia Ruby Roy , Zhao Miao , Dholakia Nikhilesh
Published: March 2005

As retailers offer multiple channels in response to competitive pressures, switching costs incurred by both retailers and consumers will shape the evolution of retailing channels. In this paper we examine propositions regarding channel loyalty, channel switching, order size, and merchandise returns based on purchase data from a specific catalog retailer that has expanded its channels to include Internet shopping. The data for this retailer shows that all four groups of customers—those who entered the database as catalog buyers, as store buyers, as Internet buyers, and as non-buyers—used multiple channels. Switching solely to this established catalog retailer's new Internet channel appears to be more difficult for consumers than relying on two or more channels. The use of multiple channels is greatest among those who entered as Internet customers, reflecting their lower risk-aversion and lower learning costs. Since the database contained only transactional information, we can make limited inferences about customers’ underlying characteristics and motivations that influence their purchase behaviors. We draw case-specific inferences and eschew generalization. Other retailers’ experiences will be affected by their own past strategies and costs and not just by the general characteristics of the channels.
Free riding and customer retention across retailers’ channels
Authors: van Baal Sebastian , Dach Christian
Published: March 2005

When consumers employ more than one channel within a single transaction, they can obtain services from one retailer and place their business with another, hence they can engage in free riding. Conversely, customers may be inclined to stay with the same retailer, even when they switch channels. We used empirical data to determine the magnitude of both effects in two directions: from online shops to traditional retail stores and vice versa. We found that over 20% of consumers are free riders, and that retailers retain substantially fewer customers in both directions. To explain the variance within the free-riding rate and the customer-retention rate, we investigated the influence of selected product characteristics (search characteristics, speed of technological change, and purchase frequency) on cross-channel consumer behavior. Managerial recommendations based on the magnitude of the effects concern channel management and the relationship between retailers and manufacturers.
The effects of psychosocial methods on depressed, aggressive and apathetic behaviors of people with dementia: a systematic review
Authors: Verkaik Renate , van Weert Julia C. M. , Francke Anneke L.
Published: March 2005

Objectives

This systematic review seeks to establish the extent of scientific evidence for the effectiveness of 13 psychosocial methods for reducing depressed, aggressive or apathetic behaviors in people with dementia.

Methods

The guidelines of the Cochrane Collaboration were followed. Using a predefined protocol, ten electronic databases were searched, studies selected, relevant data extracted and the methodological quality of the studies assessed. With a Best Evidence Synthesis the results of the included studies were synthesized and conclusions about the level of evidence for the effectiveness of each psychosocial method were drawn.

Results

There is some evidence that Multi Sensory Stimulation/Snoezelen in a Multi Sensory Room reduces apathy in people in the latter phases of dementia. Furthermore, there is scientific evidence, although limited, that Behavior Therapy‐Pleasant Events and Behavior Therapy‐Problem Solving reduce depression in people with probable Alzheimer's disease who are living at home with their primary caregiver. There is also limited evidence that Psychomotor Therapy Groups reduce aggression in a specific group of nursing home residents diagnosed with probable Alzheimer's disease. For the other ten psychosocial methods there are no or insufficient indications that they reduce depressive, aggressive or apathetic behaviors in people with dementia.

Conclusions

Although the evidence for the effectiveness of some psychosocial methods is stronger than for others, overall the evidence remains quite modest and further research needs to be carried out. Copyright © 2005 John Wiley & Sons, Ltd.
The effect of integrated emotion‐oriented care versus usual care on elderly persons with dementia in the nursing home and on nursing assistants: a randomized clinical trial
Authors: Finnema Evelyn , Dröes Rose‐Marie , Ettema Teake , Ooms Marcel , Adèr Herman , Ribbe Miel , Tilburg Willem van
Published: March 2005

Objectives

To examine the effect of integrated emotion‐oriented care on nursing home residents with dementia and nursing assistants.

Design

A multi‐site randomized clinical trial with matched groups, and measurements at baseline and after seven months.

Setting

Sixteen psychogeriatric wards in fourteen nursing homes in the Netherlands.

Participants

One hundred and forty‐six elderly residents with the diagnosis dementia of the Alzheimer (DAT) type, mixed DAT and vascular dementia, and dementia syndrome (NAO) and 99 nursing assistants.

Interventions

Integrated emotion‐oriented care and usual care.

Mesurements

Demented elderly: Behaviour and mood related to adaptation to the illness and the institutionalization. Nursing assistants: General health as measured by feelings of stress, stress reactions, feeling of competence and illness.

Results

Positive effects in favour of the integrated emotion‐oriented care were found in mild to moderately demented residents on two adaptive tasks: maintaining an emotional balance (less anxiety) and preserving a positive self‐image (less dissatisfaction). In the trained group of nursing assistants fewer stress reactions were found only in those who perceived improvement in their emotion‐oriented care skills after training.

Conclusion

Emotion‐oriented care is more effective with regard to the emotional adaptation in nursing homes of persons with a mild to moderate dementia. For the severely demented elderly we did not find this surplus value. This outcome is of clinical importance for elderly persons with dementia who are cared for in nursing homes. With respect to the nursing assistants it is concluded that emotion‐oriented care has a positive influence on stress reactions in some of them. Copyright © 2005 John Wiley & Sons, Ltd.
The factor structure of the hospital anxiety and depression scale in older individuals with acquired amputations: a comparison of four models using confirmatory factor analysis
Authors: Desmond Deirdre M. , MacLachlan Malcolm
Published: March 2005

Background

There has been little attention to the underlying dimensional structure of the Hospital Anxiety and Depression Scale (HADS) in analyses involving individuals older than 65 years of age despite its routine application in this age group.

Methods

The factor structure of the HADS was investigated using a sample of 680 veterans with limb amputations who were aged at least 66 years (mean 79.0, SD 5.02; range 66–92) Four models were specified and estimated using Lisrel 8.54. Model 1 specified a uni‐dimensional structure. Model 2 specified a correlated two‐factor model. Model 3 specified a correlated two‐factor model but with cross factor loadings for item 7. Model 4 specified a three‐factor model after Clark and Watson's (1991) tripartite theory of anxiety and depression.

Results

Models 2, 3 and 4 were found to adequately fit the data. However, on balance, model 4 was found to be a better explanation of the data than the alternative specifications.

Conclusions

The results indicate that factor models for the HADS developed in younger samples are replicable with older adults, thus supporting the suggestion that the HADS structure is invariant for age. However, considering the composition of the current sample, i.e. veterans with limb amputations, further research is necessary to determine whether these findings are generalisable to the wider population of older adults. Copyright © 2005 John Wiley & Sons, Ltd.
The sensitivity of somatic symptoms in post‐stroke depression: a discriminant analytic approach
Authors: Coster Liesbeth de , Leentjens Albert F. G. , Lodder Jan , Verhey Frans R. J.
Published: March 2005

Background

Somatic and neurocognitive symptoms of depression may overlap with the physical symptoms of stroke, and thus make the diagnosis of post‐stroke depression difficult.

Aim

To assess the sensitivity of individual depressive symptoms and their contribution to the diagnosis of post‐stroke depression.

Patients and methods

Two hundred and six patients with first‐ever stroke, participating in a longitudinal study, were administered the Structured Clinical Interview for DSM‐IV and the Hamilton Depression Rating Scale (HAM‐D). In a discriminant analysis the relative contribution of the individual HAM‐D items to the diagnosis of major depressive disorder was evaluated.

Results

The cumulative incidence of post‐stroke major depressive disorder was 32%. The discriminant model based on HAM‐D item scores was highly significant (p<0.001) and classified 88.3% of patients correctly as depressed or nondepressed. As expected, ‘depressed mood’ discriminated best between depressed and non‐depressed stroke patients. ‘Reduced interests’ had a relatively low sensitivity and may in part reflect ‘apathy’, which often is considered a separate construct. With the exception of ‘suicidal thoughts’, most psychological symptoms, such as ‘hypochondriasis’, ‘lack of insight’ and ‘feelings of guilt’, were not very sensitive. Some somatic symptoms, such as ‘reduced appetite’, ‘psychomotor retardation’, and ‘fatigue’ had high discriminative properties.

Conclusion

Psychological, neurocognitive and somatic symptoms of depression differ among themselves in terms of diagnostic sensitivity, and should be considered individually. Some somatic symptoms are highly sensitive for depression and should not be neglected by following an ‘exclusive’ or ‘attributional’ approach to the diagnosis of PSD. Copyright © 2005 John Wiley & Sons, Ltd.
Screening for dementia in an Irish community sample using MMSE: a comparison of norm‐adjusted versus fixed cut‐points
Authors: Cullen Breda , Fahy Sabina , Cunningham Conal J. , Coen Robert F. , Bruce Irene , Greene Elaine , Coakley Davis , Walsh J. Bernard , Lawlor Brian A.
Published: March 2005

Background

The MMSE is a widely‐used instrument in screening for dementia in the community. The traditional cut‐point of <24/30 may be unsuitable for use in some settings, due to biases in age and education.

Objectives

This study aimed to investigate whether cut‐points derived from age‐ and education‐specific norms would improve the performance of the MMSE as a screening tool for dementia and cognitive impairment in an Irish community setting, potentially reducing the number of onward referrals. A secondary aim was to obtain score norms in an Irish sample.

Methods

One thousand one hundred and fifteen people aged over 65 (mean age 74.8±6.8 years; 68% female) were assessed in their own homes, using MMSE (world) and the AGECAT computerised diagnostic system for mental illness in the elderly. The performance of the MMSE in identifying case‐ and sub‐case‐level dementia was investigated using cut‐points of <24 and <23, as well as adjusted cut‐points based on published norms and norms derived from the Irish sample.

Results

Published norms did not prove useful in improving screening accuracy. Cut‐points based on 10th percentile Irish norms and the <23 cut‐point performed comparably well, both yielding 93% specificity, with overall accuracy of 90% and 91% respectively (as sensitivity was higher for the <23 cut‐point).

Conclusions

Locally‐derived norms yielded better screening accuracy than did published norms or the traditional <24 cut‐point. The importance of selecting an appropriate percentile cut‐off when using norms is discussed. The best results were obtained with a simple <23 cut‐point, and this may be optimal when screening for dementia in an Irish community setting. Copyright © 2005 John Wiley & Sons, Ltd.