bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring of tunnel behaviour through cataclastic rocks
Authors: Georgiannou V. N. , Lefas I. D. , Boronkay K. A.
Published: March 2006

Field instrumentation was used in the construction of two twin tunnels for the new Egnatia Motorway in Greece. This paper describes the displacement monitoring results taken during tunnelling through heavily fragmented limestone varying from a block size >10 cm down to sandy gravel and sandy silt or gouge. The primary lining displacements monitored by surveying methods appear to be directly related to the detailed geological subdivisions of the limestone observed at the tunnel face. Maximum values of settlement were recorded during tunnelling through the gouge and reached 80 mm, while horizontal movements up to 40 mm were recorded associated with outward deflection of the support frames. The development of settlement with time shows that settlement of the tunnel crown and sides increased sharply while the face of the tunnel was within a tunnel diameter of the station point under consideration and reached equilibrium when the excavation face was at least 3 to 4 tunnel diameters beyond it. Surface settlements above the axis of the tunnel were first observed when the face of the tunnel was directly beneath the station. At the entrance portals of the tunnels the limestone overlies a thin sedimentary clay formation and gypsum. Horizontal movements along the interface between the limestone and the underlying clay sequence as well as within a clay/gypsum layer at the portals were observed using a standard inclinometer.
Numerical analysis of matric suction effects of tree roots
Authors: Indraratna B. , Fatahi B. , Khabbaz H.
Published: March 2006

The use of native vegetation in the coastal regions of Australia has become increasingly popular for stabilising railway corridors built over expansive clays and compressive soft soils. The tree roots provide three stabilising functions: (a) they reinforce the soil; (b) they dissipate excess pore pressures; and (c) they establish sufficient matric suction to increase the shear strength. The matric suction generated within the tree root zone propagates radially into the soil matrix, as a function of the moisture content change. Considering soil conditions, the type of vegetation and atmospheric conditions, a mathematical model for the rate of root water uptake is developed. A conical shape is considered to represent the geometry of the tree root zone. Based on this model for the rate of root water uptake, the pore water pressure distribution and the movement of the ground adjacent to the tree are numerically analysed. Field measurements taken from the previously published literature are compared with the authors’ numerical predictions. It is found that, given the approximation of the assumed model parameters, the agreement between the predicted results and field data is still promising. The study indicates that native vegetation improves the shear strength of the soil by increasing the matric suction, and also curtails soil movements.
Pareto Optimal Risk Exchanges and a System of Differential Equations: a Duality Theorem
Authors: Wyler Erich
Published: March 2006

This article, based on a result of Borch and an extension of Bühlmann, gives a complete characterization of Pareto optimal risk exchanges by a system of differential equations linking the derivate of agents contributions to their risk aversion coefficients.
Pseudo Compound Poisson Distributions in Risk Theory
Authors: Hürlimann W.
Published: March 2006

Using Laplace transforms and the notion of a pseudo compound Poisson distribution, some risk theoretical results are revisited. A well-known theorem by Feller (1968) and Van Harn (1978) on infinitely divisible distributions is generalized. The result may be used for the efficient evaluation of convolutions for some distributions. In the particular arithmetic case, alternate formulae to those recently proposed by De Pril (1985) are derived and shown more adequate in some cases. The individual model of risk theory is shown to be pseudo compound Poisson. It is thus computable using numerical tools from the theory of integral equations in the continuous case, a formula of Panjer type or the Fast Fourier transform in the arithmetic case. In particular our results contain some of De Pril's (1986/89) recursive formulae for the individual life model with one and multiple causes of decrement. As practical illustration of the continuous case we construct a new two-parametric family of claim size density functions whose corresponding compound Poisson distributions are analytical finite sum expressions. Analytical expressions for the finite and infinite time ruin probabilities are also derived.
Distributions in Life Insurance
Authors: Dhaene Jan
Published: March 2006

In most textbooks and papers that deal with the stochastic theory of life contingencies, the stochastic approach is restricted to the computation of expectations and higher order moments. For a wide class of insurances on a single life, we derive the distribution and the probability density function of the benefit and the loss functions. Both the continuous and the discrete case are considered.
Predicting IBNYR Events and Delays II. Discrete Time
Authors: Jewell William S.
Published: March 2006

An IBNYR event is one that occurs randomly during some fixed exposure interval and incurs a random delay before it is reported. A previous paper developed a continuous-time model of the IBNYR process in which both the Poisson rate at which events occur and the parameters of the delay distribution are unknown random quantities; a full-distributional Bayesian method was then developed to predict the number of unreported events. Using a numerical example, the success of this approach was shown to depend upon whether or not the occurrence dates were available in addition to the reporting dates. This paper considers the more usual practical situation in which only discretized epoch information is available; this leads to a loss of predictive accuracy, which is investigated by considering various levels of quantization for the same numerical example.
Estimation in the Pareto Distribution
Authors: Rytgaard Mette
Published: March 2006

In the present paper, different estimators of the Pareto parameter α will be proposed and compared to each others.

First traditional estimators of α as the maximum likelihood estimator and the moment estimator will be deduced and their statistical properties will be analyzed. It is shown that the maximum likelihood estimator is biased but it can easily be modified to an minimum-variance unbiased estimator of a. But still the coefficient of variance of this estimator is very large.

For similar portfolios containing same types of risks we will expect the estimated α-values to be at the same level. Therefore, credibility theory is used to obtain an alternative estimator of α which will be more stable and less sensitive to random fluctuations in the observed losses.

Finally, an estimator of the risk premium for an unlimited excess of loss cover will be proposed. It is shown that this estimator is a minimum-variance unbiased estimator of the risk premium. This estimator of the risk premium will be compared to the more traditional methods of calculating the risk premium.
Combining Quota-Share and Excess of Loss Treaties on the Reinsurance of n Independent Risks
Authors: Centeno Lourdes , Simões Onofre
Published: March 2006

In this paper, we seek to find the optimal retentions for an insurance company which intends to reinsure each of n risks belonging to its portfolio, by means of a pure quota-share treaty, a pure excess of loss treaty or any combination of the two. The criterion chosen to the selection of the optimal programme is the maximization of the adjustment coefficient, attending to the relationship existing between this coefficient and Lundberg's upper bound of the ruin probability.
Credibility Models with Time-Varying Trend Components
Authors: Ledolter Johannes , Klugman Stuart , Lee Chang-Soo
Published: March 2006

Traditional credibility models have treated the process generating the losses as stable over time, perhaps with a deterministic trend imposed. However, there is ample evidence that these processes are not stable over time. What is required is a method that allows for time-varying parameters in the process, yet still provides the shrinkage needed for sound ratemaking. In this paper we use an automobile insurance example to illustrate how this can be accomplished.
A Simple Parametric Model for Rating Automobile Insurance or Estimating IBNR Claims Reserves
Authors: Mack Thomas
Published: March 2006

It is shown that there is a connection between rating in automobile insurance and the estimation of IBNR claims amounts because automobile insurance tariffs are mostly cross-classified by at least two variables (e.g. territory and driver class) and IBNR claims run-off triangles are always cross-classified by the two variables accident year and development year. Therefore, by translating the most well-known automobile rating methods into the claims reserving situation, some known and some unknown claims reserving methods are obtained. For instance, the automobile rating method of Bailey and Simon produces a new claims reserving method, whereas the model leading to the rating method called “marginal totals” produces the well-known IBNR claims estimation method called “chain ladder”. A drawback of this model is the fact that it is designed for the number of claims and not for the total claims amount for which it is usually applied.

As an alternative for both, rating and claims reserving, we describe a simple but realistic parametric model for the total claims amount which is based on the Gamma distribution and has the advantage of providing the possibility of assessing the goodness-of-fit and calculating the estimation error. This method is not very well known in automobile insurance—although a satisfactory application is reported—and seems to be completely unknown in the field of claims reserving, although its execution is nearly as simple as that of the chain ladder method.
A Mixed Model for Loss Ratio Analysis
Authors: El-Bassiouni M. Y.
Published: March 2006

The model introduced may be treated as a mixed two-way analysis of variance with fixed company effects and random time effects. Further, the risk volumes are integrated into the model in such a way that the unexplained variance is inversely proportional to the risk volume of each company. The proposed model is used to analyze loss ratio data from the general insurance market in Kuwait. The maximum likelihood estimates of the structural parameters are obtained. These estimates are then used to compute the loss ratios and solvency margins for the four domestic insurance companies.
Distillation configurations and their energy requirements
Authors: Fidkowski Zbigniew T.
Published: March 2006

A method for systematic generation of all possible configurations of distillation columns for multicomponent separation is described. Classic configurations with sharp splits and all the possible (partially and fully) thermally coupled systems are generated by listing all the splits between components and applying various interconnecting streams and column stacking. Separation systems with multiple streams producing the same product (with the same or different purity) are also being generated. Additionally, a method for systematic evaluation of minimum vapor flows in all the configurations has been developed. The method can be used in evaluating various possibilities to select the optimum configuration for a new design or to improve an existing plant. Energy requirements of various column configurations for separation of four components have been evaluated and compared. © 2006 American Institute of Chemical Engineers AIChE J, 2006
History and results of the two inter‐laboratory round robin endotoxin assay studies on cotton dust
Authors: Chun David T.W. , Bartlett Karen , Gordon Terry , Jacobs Robert R. , Larsson Britt‐Marie , Larsson Lennart , Lewis Daniel M. , Liesivuori Jyrki , Michel Olivier , Milton Donald K. , Rylander Ragnar , Thorne Peter S. , White Eugene M. , Brown Mary E. , Gunn Varina S. , Würtz Helle
Published: March 2006

Background

In the US cotton industry, airborne cotton dust levels are regulated, and other countries are moving to specify safety limits for airborne endotoxins. There is concern about potential respiratory health hazards associated with agricultural and other organic dusts. In laboratories, ranking which samples have high and low levels of endotoxin is usually in good agreement between laboratories. When different laboratories assay identical samples, the levels differ. The objective of this research was to evaluate the intra‐ and inter‐laboratory variability for 13 laboratories measuring endotoxin in cotton dust.

Method

Two inter‐laboratory round robin endotoxin assay studies were conducted using cotton dust. In the first round robin, each laboratory used their normal in‐house assay method and then used a common extraction protocol. In the second round robin, a common extraction protocol and endotoxin assay kit was used.

Results

The intra‐laboratory results had small variations but inter‐laboratory results had very high variations. The inter‐laboratory results using a common extraction protocol showed reduced differences. Using the same extraction protocol and endotoxin assay kit, the intra‐laboratory variation was small and inter‐laboratory variation was reduced but not enough for inter‐laboratory agreement. Most of the laboratories were able to discern between the high and low endotoxin concentration dusts.

Conclusions

Standardization has reduced the differences in results between laboratories and possibly further standardization may bring closer inter‐laboratory agreement. Am. J. Ind. Med. 49:301–306, 2006. Published 2006 Wiley‐Liss, Inc.
Delineation of a 2q deletion in a girl with dysmorphic features and epilepsy
Authors: Langer Sabine , Geigl Jochen B. , Wagenstaller Janine , Lederer Gaby , Hempel Maja , Daumer‐Haas Cornelia , Leifheit Hans‐Jürgen , Speicher Michael R.
Published: March 2006

In recent years, the spectrum of available methods for the characterization of chromosomal aberrations has significantly increased. Micro‐array technologies now allow the rapid fine mapping of small genomic imbalances. Here we used various technologies to characterize a de novo translocation t(2;15) in a girl with dysmorphic features, severe developmental delay and frequent seizures. Multiplex‐FISH (M‐FISH) excluded the involvement of other chromosomes than chromosomes 2 and 15. We used an oligonucleotide array containing more than 10.000 SNPs, that is, the GeneChip Mapping 10K 2.0 SNP Affymetrix array, and readily fine‐mapped a deletion in chromosomal region 2q24.1 → 2q31.1. The extent of this deletion was verified with multicolor BAC‐clone hybridizations. The deletion has a size of about 13 Mb and is within a gene rich region containing about 76 genes. Interestingly, several of these genes are ion channel genes or genes involved in neuron differentiation, so that the frequently occurring seizures are probably due to loss or haploinsufficiency of one or more of these genes. © 2006 Wiley‐Liss, Inc.
Oculocerebrocutaneous and encephalocraniocutaneous lipomatosis syndromes: Blind men and an elephant or separate syndromes?
Authors: Hunter Alasdair G.W.
Published: March 2006

The discovery of relevant causative genes has subdued the lumping versus splitting debate with respect to a growing number of syndromes. However, it remains paramount to define unknown genesis syndromes as precisely and appropriately as possible in order to provide accurate prognosis and to facilitate future research. The presentation of a 14‐month‐old girl, of normal intelligence, who had a colobomatous right eye with cyst, minor intracranial MRI variants, and an area of sparse scalp hair containing a 1 by 1.5 cm, soft, domed, and indented skin lesion suggested a diagnosis of mild oculocerebrocutaneous syndrome (OCCS). An initial exploration of the literature exposed the extreme variability in cases that have been reported as OCCS, and emphasized its possible relationship to encephalocraniocutaneous lipomatosis (ECCL), thus challenging the initial diagnosis. Cases reported, or discussed by others, as possible OCCS (40) and ECCL (44) were reviewed as completely as possible in an effort to determine whether diagnostic criteria could be developed for these syndromes, and to see whether or not evidence favored their continued separation as two syndromes. The approach used was to summarize the data for all cases, to select major and minor diagnostic criteria on the basis of the relative specificity and/or frequency of a sign, to then apply the criteria in a standard fashion and to review the outcome to see if the classification of cases made clinical sense, and to make appropriate adjustments. The criteria were not chosen so as to separate the syndromes and in some instances the same criteria could apply to either syndrome. An approach is outlined for handling reports of patients that purport to be variants or to expand the spectrum of a syndrome, and in the case of OCCS and ECCL this resulted in most such examples being excluded. Application of diagnostic criteria suggests that OCCS and ECCL are distinct, and that some case reports, including some purporting to expand the spectrum of OCCS, should be excluded, at least until such time as the etiology of these conditions is known and those cases can be tested. These diagnostic criteria were developed on the basis of literature reports that varied in their quantity and quality of detail. Furthermore, in many cases reliance had to be placed on copies of original studies with resultant degradation of photographic information. Modern ocular imaging, and histopathology of eye and skin malformations, will often clarify the specific nature of a malformation and, therefore, define exact diagnostic criteria and leave fewer uncertain cases. In the absence of anomalies in those systems, or if histopathology or appropriate imaging is unavailable, the diagnosis in some cases will continue to remain uncertain; this is not an argument for lumping the syndromes. © 2006 Wiley‐Liss, Inc.
Fetus with two identical reciprocal translocations: Description of a rare complication of consanguinity
Authors: Martinet Danielle , Vial Yvan , Thonney Francine , Beckmann Jacques S. , Meagher‐Villemure Kathleen , Unger Sheila
Published: March 2006

We report on a 24‐week fetus with multiple organ anomalies secondary to biparental inheritance of an apparently balanced t(17;20) reciprocal translocation. The pregnancy was terminated following the discovery by ultrasound of an abnormal heart and micrognathia. At autopsy, the following anomalies were found: Pierre–Robin sequence, hypoplasia of the right ventricle with muscular hypertrophy, and endocardial fibroelastosis, hypoplastic lungs, dysplastic left kidney, bilateral pelvicalyceal dilatation, central nervous system periventricular heterotopias and right sided club foot. Given the endocardial fibroelastosis and cleft palate, Eastman–Bixler syndrome (Facio‐cardio‐renal) is a possible diagnosis. The parents were first cousins and each had an identical t(17;20)(q21.1;p11.21) translocation. The fetal karyotype was 46,XX,t(17;20)(q21.1;p11.21)mat,t(17;20)(q21.1;p11.21)pat. While there are a few reports of consanguineous families where both the mother and father had the same reciprocal translocation and offspring with unbalanced karyotypes, we were unable to find any reports of a fetus/child with double identical reciprocal translocations. We propose that although the fetus had an apparently balanced karyotype, inheriting only the translocated chromosomes led to the unmasking of a recessive syndrome. It seems most likely that a gene (or genes) was disrupted by the breaks but the parents might also be heterozygous carriers of a recessive gene mutation since the fetus must be homozygous by descent for many loci on both chromosomes 17 and 20 (as well as on other chromosomal segments). It was not possible to totally exclude segmental uniparental disomy as a cause of the anomalies as no recombinations were detected for chromosome 17. However, there is no evidence to suggest that chromosome 17 is imprinted and UPD 20 was excluded thus making an imprinting error unlikely. © 2006 Wiley‐Liss, Inc.
Thirty‐two year follow‐up of the first patient reported with the Floating‐Harbor syndrome
Authors: Feingold Murray
Published: March 2006

A 32‐year follow‐up of the first patient reported with the Floating‐Harbor syndrome is discussed. He has been in good overall health. His facial appearance, a hallmark of this syndrome, had remained fairly characteristic except for some changes secondary to age. While he does have mild to moderate mental retardation, he has been employed for the past 15 years. Because no laboratory tests are presently available to diagnose the Floating‐Harbor syndrome, the author recommends that the typical facial features present in the first two patients reported with this syndrome be present before the diagnosis can be made. © 2006 Wiley‐Liss, Inc.
Linkage and association of schizophrenia with genetic variations in the locus of neuregulin 1 in Korean population
Authors: Kim Jong Won , Lee Yu‐Sang , Cho Eun‐Young , Jang Yong Lee , Park Dong Yeon , Choi Kyeong‐Sook , Jeun Hyun Ok , Cho Seung‐Hee , Jang Sue‐Yon , Hong Kyung Sue
Published: March 2006

Chromosome 8p21‐12 has been reported to be a susceptibility locus for schizophrenia based on genome‐wide linkage scans. After neuregulin 1 (NRG1) was identified as a positional candidate gene for schizophrenia in this locus, several independent association studies have reported controversial results. To determine whether genetic variations in this locus are associated with schizophrenia in the Korean population, we investigated multiplex families and unrelated patients using linkage and association analyses. Seven microsatellite markers in 8p21‐12 were genotyped for 40 families with schizophrenia, and a non‐parametric linkage analysis was applied. The association study was performed with 242 unrelated schizophrenia patients and the same number of normal controls for three single nucleotide polymorphisms (SNPs), two microsatellite markers and their haplotypes. A significant linkage signal was observed on D8S1769, which is located 352 kb upstream of the 5′ end of the first exon of NRG1 for two (“narrow” and “narrow with auditory hallucination (AH)”) of the three adopted phenotype classes. In the association study, the G allele of SNP8NRG241930 was significantly in excess in the subgroup of patients with AHs. We also found haplotypes which were associated with schizophrenia with a protective effect. This study provides additional suggestive evidence for both the linkage and association of genetic variations on 8p12, a locus of NRG1, with schizophrenia. NRG1 might either play a role in the predisposition to schizophrenia or be in linkage disequilibrium (LD) with a causal locus of this illness. © 2006 Wiley‐Liss, Inc.
Intergeneration CAG expansion and contraction in a Chinese HD family
Authors: Tang Yanping , Wang Ying , Yang Ping , Liu Yuan , Wang Bo , Podolsky Robert , McIndoe Richard , Wang Cong‐Yi
Published: March 2006

The prevalence of juvenile‐onset Huntington's disease (HD) is about ten times lower than adult HD. Here we report a Chinese HD family showing both intergeneration CAG expansion and contraction. The expansion resulted from a paternal transmission which leads to juvenile‐onset HD for a 17‐year‐old Chinese boy (III‐5). More interestingly, a contraction was noticed in a maternal transmission (III‐3), which changed the CAG repeat from an expanded, disease‐causing allele (48 repeats) to a normal or intermediate allele (34 repeats). Of note, the contraction resulted in a deletion of 14 CAG repeats, which is much larger than previously reported contractions. Our results are consistent with previous observations in Western Caucasians that juvenile‐onset HD is more likely inherited through the male germline. © 2006 Wiley‐Liss, Inc.
Evaluating the comparability of gene expression in blood and brain
Authors: Sullivan Patrick F. , Fan Cheng , Perou Charles M.
Published: March 2006

The availability of an accessible tissue whose gene expression profile is similar to more inaccessible CNS tissues has the potential to advance research in neuropsychiatric disorders. We conducted secondary data analysis of transcriptional profiling of 79 human tissues for 33,698 genes using the Affymetrix U133A microarray augmented with a custom microarray (Affymetrix GNF1H), which were produced by the Genomics Institute of the Novartis Research Foundation (http://symatlas.gnf.org). Our analyses suggested that: (a) on a transcriptome level, whole blood shares significant gene expression similarities with multiple CNS tissues; (b) the median non‐parametric correlation between transcripts present in both whole blood and CNS was around 0.5; (c) this correlation of 0.5 was intermediate relative to all tissues in the Novartis data set—less than for the maximum achievable value of 0.85, less than a set of immune tissues (0.64), comparable to a heterogeneous set of somatic tissues (0.57) but greater than muscle (0.48) and peripheral nervous system tissues (0.36); (d) about half of a set of candidate genes relevant to schizophrenia were expressed in both whole blood and prefrontal cortex; and (e) the expression levels of many classes of biologically relevant processes were not significantly different between whole blood and prefrontal cortex. These analyses suggest that gene expression in whole blood is neither perfectly correlated and useful nor perfectly uncorrelated and useless with gene expression in multiple brain tissues. This suggests that the cautious and thoughtful use of peripheral gene expression may be a useful surrogate for gene expression in the CNS when it has been determined that the relevant gene is expressed in both. © 2006 Wiley‐Liss, Inc.
Association of the DAT1 polymorphism with attention deficit hyperactivity disorder (ADHD): A family‐based approach
Authors: Lim Myung‐Ho , Kim Hyun Woo , Paik Ki‐Chung , Cho Soo Churl , Yoon Do Young , Lee Heon‐Jeong
Published: March 2006

The dopamine transporter gene (DAT1) is of particular interest in the genetic study of attention deficit hyperactivity disorder (ADHD), because psychostimulants interact directly with the dopamine transporter protein. Association between ADHD and the 10‐repeat allele of a 40 base pair (bp) variable number of tandem repeats (VNTR) polymorphism of DAT1 was first reported in 1995 [Cook et al. (1995); Am J Hum Genet 56:993–998]. Subsequently, several investigators have also confirmed this association, although others reported conflicting results. We analyzed the DAT1 polymorphism in a sample of 33 Korean probands with a Diagnostic and Statistical Manual of Mental Disorders version IV (DSM‐IV) diagnosis of ADHD and found evidence of increased transmission of the 10‐repeat allele using transmission disequilibrium test (TDT) (P = 0.001; OR = 7.88, CI = 2.20–28.29). These data support the role of DAT1 in ADHD susceptibility among Asian populations. © 2006 Wiley‐Liss, Inc.
Smoking cessation, weight gain, and DRD4 −521 genotype
Authors: Munafò Marcus R. , Murphy Michael F.G. , Johnstone Elaine C.
Published: March 2006

We investigated change in body mass index following long‐term smoking cessation in a representative cohort of treatment‐seeking heavy smokers in the United Kingdom, to determine the extent of long‐term weight gain in successful quitters versus continuing smokers. We further investigated whether DRD4 genotype moderated any weight gain in either group. Smoking cessation was associated with an increase in BMI, and persisted up to 8 years after smoking cessation. Ex‐smokers at 8‐year follow‐up weighed over 2.5 kg/m3 more on average than they did at baseline, while participants who were smokers at both baseline and 8‐year follow‐up did not demonstrate any change in BMI. We did not observe an interaction between smoking status and DRD4 genotype. However, independently of the weight gain among those who stopped smoking during the course of the study, DRD4 genotype was significantly associated with BMI, with possession of the −521 C‐allele associated with increased BMI. The magnitude of increase in BMI following smoking cessation, and the persistence of this change at 8‐year follow‐up, suggests that health benefits associated with smoking cessation may to some extent be negated by the detrimental effects on health of associated weight gain. Smoking cessation programmes should therefore consider incorporating follow‐up support to promote weight loss among those who successfully stop smoking. © 2006 Wiley‐Liss, Inc.
MAOA‐uVNTR polymorphism in a Brazilian sample: Further support for the association with impulsive behaviors and alcohol dependence
Authors: Contini Verônica , Marques Francine Z.C. , Garcia Carlos E.D. , Hutz Mara H. , Bau Claiton H.D.
Published: March 2006

The enzyme monoamine oxidase A (MAO A) plays an important role in the metabolism of neurotransmitters. The MAOA gene presents several polymorphisms, including a 30‐bp VNTR in the promoter region (MAOA‐uVNTR). Alleles with 3.5 and 4 repeats are 2–10 times more efficient than the 3‐repeat allele. Several studies have shown an association between the 3‐repeat allele and a cluster of externalizing behaviors including alcoholism, antisocial personality, and impulsivity. The objective of the present study is to replicate in a different culture the associations between the MAOA‐uVNTR with alcoholism and other phenotypes. The sample comprises 125 Brazilian alcoholics of European descent and 235 controls. The results suggest that the 3‐repeat allele is associated to: (1) alcohol dependence (P < 0.05); (2) an earlier onset of alcoholism (P < 0.01); (3) comorbid drug abuse among alcoholics (P < 0.05); and (4) a higher number of antisocial symptoms (P < 0.02). Our results confirmed previous reports showing an association of the low activity 3‐repeat allele of MAOA‐uVNTR polymorphism with substance dependence and impulsive/antisocial behaviors. These findings in a different culture further support the influence of the MAOA‐uVNTR in psychiatric disorders. © 2006 Wiley‐Liss, Inc.
Association study of the adrenergic receptors and childhood‐onset mood disorders in Hungarian families
Authors: Burcescu I. , Wigg K. , Gomez L. , King N. , Vetró Á. , Kiss E. , Kapornai K. , Gádoros J. , Kennedy J.L. , Kovacs M. , Barr C.L. ,   The International Consortium for Childhood‐Onset Mood Disorders
Published: March 2006

The adrenergic system has been implicated in the etiology of depression based on a number of lines of evidence, particularly, the mechanism of some classes of antidepressants which increase the synaptic levels of norepinephrine. Further, several genome scans for mood disorders, both unipolar and bipolar, have indicated linkage to the chromosomal regions of 5q23–q33.3, 8p12–p11.2, 4p16, and 10q24–q26, the location of the adrenergic receptors α1B (ADRA1B), β3 (ADRB3), α2C (ADRA2C), α2A (ADRA2A), and β1 (ADRB1). In this manuscript, we report on the relationship of the adrenergic receptors and depression using a family based association approach and 189 families (223 affected children) with childhood‐onset mood disorder (COMD) collected in Hungary. We found no significant evidence for an association with any of the 24 markers, in total, tested across these genes using single marker analysis or haplotypes of markers across these genes. The results in the present sample indicate that these nine genes are unlikely to be major susceptibility genes contributing to COMD. © 2006 Wiley‐Liss, Inc.
Array‐based genomic delineation of a familial duplication 11q14.1–q22.1 associated with recurrent depression
Authors: Kolomietz Elena , Ben‐Omran Tawfeg , Chitayat David , Mah Mimi , Murphy Jillian , Nie Gloria , Teshima Ikuko
Published: March 2006

Detection of abnormal karyotypes with associated clinical manifestations is an important tool for the identification of genes that confer susceptibility to genetic disorders. We present a family with a duplication 11q14.1–q22.1 resulting from an unbalanced familial insertion, associated with a mild dysmorphic phenotype and mood disorders, mainly major depression. This relatively large duplication of a segment from chromosome 11 is associated with a surprisingly little physical phenotypic effect in this family. The finding of mood disorders in adult members of the family who carry the insertion supports the view that the duplication may be important for the identification of contributing gene(s) to mood disorders. Major depression is considered to be a complex trait with multiple genetic alterations interacting with environmental factors. Array‐based comparative genome hybridization (array CGH) analysis with a 1 Mb genomic array, defined the duplication region that extended over 16 Mb from 11q14.1 to 11q22.1. Brain‐expressed genes that map within this 16 Mb region, are considered worthy of further investigation as gene(s) contributing to the etiology of major depression. © 2006 Wiley‐Liss, Inc.
Validation of population‐based ADHD subtypes and identification of three clinically impaired subtypes
Authors: Volk Heather E. , Henderson Cynthia , Neuman Rosalind J. , Todd Richard D.
Published: March 2006

Statistically based classification methods have successfully refined ADHD into homogenous and heritable subtypes. External validity and impairment of these subtypes was examined using the Child Behavior Checklist (CBCL). We compared mean CBCL syndrome and competency t‐scores across ADHD subtypes defined by latent class analysis in a sample of 1,346 individual twins from Missouri. The potential for comorbidity with conduct disorder (CD), oppositional defiant disorder (ODD), or major depression (MD) to increase impairment in specific ADHD subtypes was also examined. CBCL profiles confirm differences in severity, with more severe classes having increased syndrome scale and decreased competency scale CBCL scores. Clinically significant impairment was found for severe inattentive and combined subtypes and the mild combined subtype. Overall, the presence of comorbid CD, ODD, or MD did not result in increased ADHD subtype impairment. CBCL scores distinguish impairment in ADHD subtypes created through LCA. Comorbidity with CD, ODD, or MD does not significantly increase impairment among ADHD subtypes. The mild combined ADHD subtype represents a clinically significant but under‐studied form of ADHD. © 2006 Wiley‐Liss, Inc.
Intrinsic viscosity–molecular weight relationship and hydrodynamic volume for pullulan
Authors: Kasaai Mohammad R.
Published: March 2006

A numerical method for determination of Mark–Houwink–Sakurada (MHS) equation constants, a and K, was tested with success for two series of pullulan standard samples having narrow and broad molecular weight distributions (MWD) and taken into account their polydispersity. Different solvents, which were used to determine the intrinsic viscosities and the viscometric constants, a and K (published in the literature for pullulan), were compared. The various parameters affecting the constants are discussed. The procedure to determine the correct value of the hydrodynamic volume for pullulan was also described. This study resulted in the following MHS equations for narrow and broad MWD series of pullulan samples with Mw in the range of 5–1000 kDa:

equation image

equation image

where qMHS is the polydispersity correction factor and [η] is the intrinsic viscosity in dL g−1. The plot of log K versus exponent a was linear and inversely related. This curve was used to estimate the constant K for pullulan with a known exponent a. Among various reported solvents, the diluted aqueous salt solutions have more advantages than other solvents. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4325–4332, 2006
Diffusion coefficient of DMSO in polyacrylonitrile fiber formation
Authors: Ying Liang , Hou Chen , Fei Wang
Published: March 2006

A H2O/dimethyl sulfoxide(DMSO) mixture was used as the coagulation bath for the wet‐spun process of acrylonitrile/ammonium itaconate copolymers fibers. Diffusion coefficient of DMSO in the protofibers prepared by acrylonitrile/ammonium itaconate copolymers was determined. It has been found that diffusion coefficient of DMSO outflow of the protofibers prepared by acrylonitrile/ammonium itaconate copolymers synthesized by the solution polymerization is highest compared with those of acrylonitrile/ammonium itaconate copolymers synthesized by H2O/DMSO mixture suspension polymerization and the aqueous suspension polymerization. With an increase of copolymer concentration in the dope, diffusion coefficient of DMSO decreases continuously. Diffusion coefficient of DMSO increases along with the bath temperature, but the changes of diffusion coefficient values are less prominent as temperature goes beyond 60°C. When DMSO concentration in the coagulation bath was 55 wt %, the value of the diffusion coefficient of DMSO was minimal. Diffusion coefficient of H2O increases with the jet stretch minus ratio increasing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4447–4451, 2006
Automatic measurement of the absolute CTE of thin polymer samples. II. Effect of chain orientation on thermal expansion of drawn polymer films
Authors: El‐Tonsy M. M. , Meikhail M. S. , Felfel R. M.
Published: March 2006

More details about the coefficient of thermal expansion (CTE) and thermal expansion anisotropy, Δα, of drawn films from polypropylene (PP) and high density polyethylene (HDPE) are discussed. CTE of the selected polymers are measured along different directions relative to the drawing direction (MD). The coefficient of thermal expansion parallel to drawing direction (α∥) was less than that in the transverse direction for both of the used polycrystalline polymers. Also α∥ for PP and HDPE for different draw ratios are measured. The morphology of measured samples is investigated by using an optical polarizing microscope and from the 2D‐plot of the angular distribution of the absorption coefficient of light through a polymer sample between two crossed polarizers. An agreement between obtained figures was found. Birefringence of samples was measured photometrically. The orientation of drawn polymer chains is estimated from the birefringence measurement. The set up of the used optical system is explained. The CTE variations of drawn polycrystalline polymer are explained on bases of the associated morphological variations. A recommendation was given to produce an all‐PP‐composite with satisfactory dimension stability at elevated temperature. Construction and operation of a simple drawing machine is given too. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4452–4460, 2006
Effect of particle size on flame retardancy of Mg(OH)2‐filled ethylene vinyl acetate copolymer composites
Authors: Huang Honghai , Tian Ming , Liu Li , Liang Wenli , Zhang Liqun
Published: March 2006

Four kinds of magnesium hydroxide (Mg(OH)2) with different particle sizes are chosen and mixed with ethylene vinyl acetate copolymer (EVA) to investigate the effect of particle size on the flame retardancy of composites, which is evaluated by limiting oxygen index (LOI) testing, horizontal fire testing, and cone calorimeter. When Mg(OH)2 filling level changes from 35 to 70 wt %, the composites filled with nano‐Mg(OH)2 do not always possess the best flame retardancy, and among the composites filled with micro‐Mg(OH)2, the composites filled with 800 mesh Mg(OH)2 show the best flame retardancy; however, the composites filled with 1250 mesh presents the worst one. So the effect of particle size on the flame retardancy of micro‐Mg(OH)2‐filled EVA is not linear as expected. All the differences are thought to result from both particle size effect and distributive dispersion level of Mg(OH)2. To prepare the composites with better mechanical properties and flame retardancy, authors suggested that Mg(OH)2 of smaller size should be chosen as flame retardant, and good dispersion of Mg(OH)2 particles also should be assured. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4461–4469, 2006
Radiation‐induced crosslinking of acetylene‐impregnated polyesters. II. Effects of preirradiation crystallinity, molecular structure, and postirradiation crosslinking on mechanical properties
Authors: Punyodom W. , Jones R. A. , Ward I. M. , Johnson A. F.
Published: March 2006

Electron beam‐irradiated crosslinking has been studied in a series of acetylene‐impregnated polyesters and amorphous copolyesters, including poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(cyclohexane dimethylene terephthalate) (PCDT), and poly(cyclohexane dimethylene terephthalate‐co‐ethylene terephthalate) (P(CDT‐co‐ET)) having 29 and 60 wt % ethylene terephthalate (ET). The extent of crosslinking was observed by gel fraction measurements and was found to be significantly influenced by the aliphatic chain content of the polyesters (PET < PBT < PCDT). In addition, as the preirradiation crystallinity of the polyesters was reduced, the extent of acetylene‐enhanced crosslinking was greatly raised. Decreases in the postirradiation crystalline melting temperature and degree of crystallinity were observed in all the polyesters, using differential scanning calorimetry measurements. Particularly significant findings have been the shift in the glass‐transition temperatures (Tg) to higher temperatures and the decrease in loss tangents at higher temperatures, both of which confirm that crosslinking has taken place. The storage moduli (E′) in the rubbery plateau region of PCDT and P(CDT‐co‐ET) were significantly affected by irradiation dose. Increased network tightness in postirradiated PBT and PCDT films was also inferred from melt‐rheology measurements, in which stress relaxed more slowly following a stepped strain. Improvements in the mechanical properties of the irradiated polyesters and copolyesters were clearly evidenced by the increased modulus at higher temperatures, observed using dynamic mechanical thermal analysis and melt‐rheology methods. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4476–4490, 2006
Synthesis and characterization of phenolic novolacs modified by chestnut and mimosa tannin extracts
Authors: Peña C. , Larrañaga M. , Gabilondo N. , Tejado A. , Echeverria J. M. , Mondragon I.
Published: March 2006

The possibility of reacting chestnut and mimosa tannins with the intermediates of the synthesis reaction for phenolic novolacs under acid conditions has been proved using differential scanning calorimetry (DSC). The amount of intermediate compounds and the percentage of free phenol and formaldehyde in the reaction mixture is decisive for the determination of the stage in which the addition of tannin is suitable. Synthesis of novolac resins modified with 14 wt % mimosa tannin extract or with several percentages (until 40 wt %) of chestnut tannin have been performed. The reaction pathways have been investigated by DSC, fourier transformed infrared spectroscopy and gel permeation chromatography. Ester groups of chestnut tannin result in a reaction pathway different from the one for mimosa‐modified resins and nonmodified resins. Preliminary studies of curing reactions of synthesized resins with hexamethylenetetramine indicate that the cure of modified‐resins is even more favorable than the one for nonmodified resins. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4412–4419, 2006
Interaction of toughening mechanisms in a hybrid epoxy system
Authors: Kim Nam Ho , Kim Ho Sung
Published: March 2006

Interaction between different toughening mechanisms is studied using a heat treated hybrid system, consisting of carboxyl‐terminated butadiene acrylonitrile (CTBN) rubber and EXPANCEL (expandable hollow microspheres) as modifiers for an epoxy resin. It was found that the fracture toughness of the hybrid system is higher than that of either individually EXPANCEL‐ or CTBN‐modified system for a given content of modifier, although the maximum toughness was not substantially high compared with maxima of single modifier systems. Microscopic examination revealed that damage zone due to CTBN particles ahead of the crack reduces due to the presence of EXPANCEL particles and nevertheless its fracture toughness increased. A possibility was deduced that the cavitation due to CTBN assists with promoting compressive stresses around EXPANCEL particles ahead of the crack tip, resulting in increase in fracture toughness. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4470–4475, 2006
Rheology and dispersion behavior of high‐impact polystyrene/ethylene–vinyl acetate copolymer/TiO2 nanocomposites
Authors: Wang Zhaobo , Xie Guangwen , Wang Xin , Zhang Zhikun
Published: March 2006

TiO2 nanoparticles were introduced into high‐impact polystyrene (HIPS) in the form of a master batch in which TiO2 was predispersed in composites of HIPS and ethylene–vinyl acetate copolymer (EVA) by melt compounding. The resulting materials were analyzed with a Rosand Precision rheometer, transmission electron microscopy, atomic force microscopy, and ultraviolet–visible light spectrophotometry. The results showed that the introduction of TiO2 nanoparticles into HIPS influenced the apparent viscosity of the composites to a rather small extent. The addition of EVA could regulate the rheological behavior of the HIPS/TiO2 master batch greatly. EVA helped the dispersions of the agglomerates of TiO2 nanoparticles in the flow; this was featured by the distinct yielding in the flow after the introduction of EVA, as well as the large change in the non‐Newtonian indices. The dispersions of the HIPS/TiO2 master batch in the HIPS matrix were improved greatly by the addition of EVA. TiO2 nanoparticles were dispersed randomly in HIPS/EVA/TiO2 nanocomposites. The dispersion improvement of the HIPS/EVA/TiO2 master batch was also proved by atomic force microscopy and ultraviolet–visible spectroscopy investigations. The mechanical properties of HIPS/EVA/TiO2 nanocomposites with low TiO2 contents were slightly higher than those of pure HIPS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4434–4438, 2006
Effects of short chain alcohols on the styrene emulsion polymerization
Authors: Chern Chorng‐Shyan , Yu Ting‐Chuan , Hu Ling‐Ling
Published: March 2006

The effects of a series of short chain alcohols, 1‐butanol (C4OH), 1‐pentanol (C5OH), and 1‐hexanol (C6OH), on the styrene (ST) emulsion polymerization mechanisms and kinetics were investigated. The CMC of the ST emulsions stabilized by sodium dodecyl sulfate (SDS) first decreases rapidly and then levels off when the CiOH (i = 4, 5, or 6) concentration ([CiOH]) increases from 0 to 72 mM. Furthermore, at constant [CiOH], the CMC data in decreasing order is CMC (C4OH) > CMC (C5OH) > CMC (C6OH). The effects of CiOH (i = 4, 5, and 6) on the ST emulsion polymerization stabilized by 6 mM SDS are significant. This is attributed to the reduction in CMC by CiOH, the different oil–water interfacial properties, the different concentrations of monomer within latex particles, and the different effectiveness of SDS/CiOH in stabilizing latex particles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4406–4411, 2006
Kinetic and molecular weight control for methyl methacrylate semibatch polymerization. II. Open control
Authors: Wu Jian‐Yi , Shan Guo‐Rong
Published: March 2006

The gel effect will bring a violent increase of conversion for methyl methacrylate (MMA) polymerization in a short time. It will be very dangerous for the reactor, as it causes an increase of molecular weight and broadens the molecular weight distribution. To unify the kinetics, molecular weight, and its distribution, on the basis of the mathematical models for semibatch polymerization of MMA, three controlled objectives that are the heat load distribution index, the change in molecular weight, and molecular weight distribution index are presented. Three materials (monomer, solvent, and chain transfer agent) and their flow rate and feeding mode are analyzed for the open control of kinetics, molecular weight, and its distribution. The optimum flow rate and mode are obtained. The heat load distribution index and molecular weight distribution index are even less than 2.0 and 2.2, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4399–4405, 2006