bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk Measurement Performance of Alternative Distribution Functions
Authors: Bali Turan G. , Theodossiou Panayiotis 
Published: May 2008

AbstractThis paper evaluates the performance of three extreme value distributions, i.e., generalized Pareto distribution (GPD), generalized extreme value distribution (GEV), and Box‐Cox‐GEV, and four skewed fat‐tailed distributions, i.e., skewed generalized error distribution (SGED), skewed generalizedt(SGT), exponential generalized beta of the second kind (EGB2), and inverse hyperbolic sign (IHS) in estimating conditional and unconditional value at risk (VaR) thresholds. The results provide strong evidence that the SGT, EGB2, and IHS distributions perform as well as the more specialized extreme value distributions in modeling the tail behavior of portfolio returns. All three distributions produce similar VaR thresholds and perform better than the SGED and the normal distribution in approximating the extreme tails of the return distribution. The conditional coverage and the out‐of‐sample performance tests show that the actual VaR thresholds are time varying to a degree not captured by unconditional VaR measures. In light of the fact that VaR type measures are employed in many different types of financial and insurance applications including the determination of capital requirements, capital reserves, the setting of insurance deductibles, the setting of reinsurance cedance levels, as well as the estimation of expected claims and expected losses, these results are important to financial managers, actuaries, and insurance practitioners.
Foreign Affiliates of the Largest Insurance Groups: Location‐Specific Advantages
Authors: Outreville J. François 
Published: May 2008

AbstractThis article has two objectives. The first is the documentation of the relative importance of the largest insurance or reinsurance companies in the world and changes that may have occurred in the past 15 years. The second objective is to identify some of the factors that may explain the increased internationalization and most‐favored locations of the world's largest insurance groups in transition and developing economies. The results of this study have important implications. First, they indicate that as expected, location‐specific factors such as the size of a market, human capital, and good governance do provide an explication of the internationalization of insurance groups. Second, they also show that other factors, such as cultural distance, regulatory barriers, and competitiveness have a significant impact on the choice of countries.
Sense of coherence and psychosocial factors among adolescents
Authors: Myrin B , Lagerström M 
Published: May 2008

AbstractAim: The overall aim of the present study was to investigate whether there was a relationship between sense of coherence and psychosocial factors among adolescents.Methods: A cross‐sectional study was conducted in a sample of pupils in year eight from comprehensive schools in Stockholm city, selected with regard to socioeconomic area. In the final sample of the study there were 383 pupils: 196 girls and 187 boys. Two questionnaires, the Sense of Coherence Scale and the Health Profile Scale measuring health behaviour, were used to collect data.Results: Girls showed a significantly more negative outcome compared with boys, in eight psychosocial factors. The most pronounced difference between boys and girls was seen in feeling depressed: 17% and 54% respectively. Five factors proved to be associated with low SOC in the multivariate analysis: life dissatisfaction, feeling depressed, worries about family members, poor psychosomatic health and being a girl.Conclusion: The findings reveal domains where adolescents, especially girls, seem to be more vulnerable. Psychosomatic health and mental health are related to low sense of coherence.
Age at menarche in contemporary Greek girls: evidence for levelling‐off of the secular trend
Authors: Papadimitriou Anastasios , Fytanidis Grigorios , Douros Konstandinos , Bakoula Chryssa , Nicolaidou Polyxeni , Fretzayas Andreas 
Published: May 2008

AbstractAim: To examine the secular trend of menarcheal age in Greek girls during the last decade.Methods: Seven hundred and fifty senior high schoolgirls were asked through a questionnaire to report their date of menarche, participation in physical activities and their weight status at menarche. The data were compared with those of a study of 1996.Results: Mean age at menarche (±SD) in 2006 was 12.29 (1.19) and in 1996 it was 12.27 (1.13) years, p = 0.73. Maternal menarcheal age was 13.02 (1.32). There was a significant correlation between age at menarche of the schoolgirls and their mothers, p < 0.0001. There was a significant difference in the age at menarche according to the schoolgirls' perceived weight status. Menarcheal age of obese girls (n = 56) was 11.73 (1.21) years, of normal weight girls (n = 474) was 12.29 (1.21) years and of lean girls (n = 220) was 12.42 (1.14) years, p < 0.001. There was no significant difference in the age at menarche between the girls that participated, 12.23 (1.19), and those that did not participate in sporting activities, 12.32 (1.19), p = 0.31.Conclusion: Levelling‐off of the age at menarche over the last 10 years occurred in Greek girls living in Athens. Menarcheal age is influenced by the weight status and maternal menarcheal age.
Turned Brånemark System® Implants in Wide and Narrow Edentulous Maxillae: A Retrospective Clinical Study
Authors: Friberg Bertil , Jemt Torsten 
Published: May 2008

ABSTRACTBackground: The available jawbone volume is regarded as one of the most important factors when assessing the prognosis of oral implants in the rehabilitation of the edentulous maxilla.Purpose: The aim of the current investigation was to retrospectively evaluate and compare the outcome of implants placed in edentulous maxillae with either wide or narrow jaw shapes. The marginal bone loss and implant cumulative survival rates (CSRs) were calculated and analyzed with special reference to smoking habits.Materials and Methods: The study included 75 individuals with edentulous maxillae, of which 33 patients exhibited wide (group A) and 42 patients exhibited narrow jaw shapes (group B). A total of 506 turned Brånemark System® (Nobel Biocare AB, Göteborg, Sweden) implants were inserted (226 in group A and 279 in group B) and followed clinically up to 7 years. Smoking habits were recorded. Radiographs were obtained at connection of prostheses, and at the 1‐ and 5‐year follow‐up visit. The marginal bone loss was calculated for the groups and analyzed using t‐test.Results: Twenty‐eight implants were lost during the study period, revealing implant CSRs at 7 years of 94.6% (11/226) and 93.6% (17/279) for wide and narrow crests, respectively. No difference in marginal bone loss was seen between the two groups, although a trend toward more bone loss was recorded for patients with wide crests. Smoking habits were more common in group A (45%) than in group B (31%). During the first year of function, smokers lost significantly more marginal bone than nonsmokers (p = .0447), albeit this difference did not prevail (p > .05) at the end of the study period.Conclusions: The implant CSRs at 7 years were equally good for the two groups of patients with various jaw shapes. Initially, smokers showed significantly more marginal bone loss than nonsmokers.
Patient Satisfaction with Implant‐Retained Mandibular Overdentures: A Retrospective Study
Authors: Siadat Hakimeh , Alikhasi Marzieh , Mirfazaelian Ali , Geramipanah Farideh , Zaery Farid 
Published: May 2008

ABSTRACTPurpose: The aim of this study was evaluation of the effect of age, gender, and past prosthetic history (duration of edentulism, number of complete dentures before implant treatment, and number of adjustment appointments) on patients' ratings of satisfaction (comfort, hygiene, retention, appearance, speech, mastication, and overall satisfaction).Materials and Methods: In this retrospective study, 55 patients who were treated with mandibular overdentures retained by splinted implants from 1998 to 2004 and met the inclusion criteria of the study were selected. Each patient was asked to fill out a questionnaire to evaluate his/her general satisfaction with the implant prostheses and other aspects of satisfaction such as comfort, aesthetic, function, and hygiene. Data were analyzed using a marginal model and the generalized estimating equations methodology to assess the relationship between the scores and the patients’ demographic and past prosthetic histories. Significance was accepted at 5% and expressed as p values and odds ratio (OR).Results: Gender had significant correlation with comfort (p < .0001). Years of being edentulous prior to implant/prosthetic treatment had direct effects on the general satisfaction and satisfaction of comfort (p < .01). One extra denture used before implant treatment resulted in less comfort (p < .01) and poorer function (p < .001). Elders were more satisfied with aesthetic (OR = 0.96) and comfort (OR = 2.96). Number of adjustment appointments had a positive correlation with comfort (p < .001) and a negative correlation with satisfaction of aesthetic (p < .001).Conclusion: The results of this study demonstrated that satisfaction was correlated with age, gender, and past prosthetic history in the patients rehabilitated with the implant‐supported overdentures.
Effect of Solely Applied Platelet‐Rich Plasma on Osseous Regeneration Compared to Bio‐Oss®: A Morphometric and Densitometric Study on Rabbit Calvaria
Authors: Torres Jesús , Tamimi Faleh M. , Tresguerres Isabel F. , Alkhraisat Mohammad H. , Khraisat Ameen , Lopez‐Cabarcos Enrique , Blanco Luis 
Published: May 2008

ABSTRACTBackground: The use of platelet‐rich plasma (PRP) in bone augmentation procedures is well documented; however, the exact benefit of this material is not yet established.Purpose: This study aimed to evaluate the benefits of using PRP, when only used, and compare it to Bio‐Oss® (Geistlich Biomaterials, Wolhusen, Switzerland) in vertical bone augmentation capacity.Materials and Methods: The study was performed in calvaria of eight adult female New Zealand rabbits using titanium bone conduction cylinder. Two titanium cylinders were fixed into perforated slits made on the parietal bone of each rabbit. On each rabbit, one chamber was grafted with Bio‐Oss, and the contralateral was filled with PRP. Animals were sacrificed 4 weeks after intervention and biopsies were taken. Densitometric, histological, and histomorphometric analyses were performed to evaluate bone mineral density, vertical bone augmentation, and remaining graft volume, respectively. Statistical analyses were performed with Mann–Whitney test, using a significance level of p < .05.Results: Densitometric and histomorphometric data analysis revealed that mean bone mineral densities and bone augmentation were significantly lower in the cylinders treated with PRP (p < .0001) 4 weeks after implantation.Conclusion: This study showed no beneficial effect of using PRP on osseous regeneration. In addition, it was emphasized that Bio‐Oss presents good osteoconductive properties by achieving suitable bone volume values.
Thymic Hypoplasia due to a Bis‐diamine
Authors: MATSUO Takeshi , IKEDA Takayoshi 
Published: May 2008

AbstractBis(dichloroacetyl)diamine is capable of producing characteristic congenital malformations in high incidence. Wistar rats were given 200 mg/day of bis‐diamine via a gastric tube on gestation days 9, 10 and 11. The fetuses of 14, 16, 18, 20 days and new born rats were examined using light and electron microscopes as well as rat T‐cell surface markers. The thymus rudiment in rats treated with bis‐diamine has been compared to the normal at each stages.A high incidence of aplasia or hypoplasia of the thymus was observed in treated groups. Histological studies of those revealed a short delay in appearance of lymphocytic cells in the thymus, which initially were blast like and later small lymphocytes, and also a delay in cortical and medullary differentiation of the thymus. Immunohistological studies using anti rat T‐cell monoclonal antibodies confirmed the histological findings which show a delay of the development of the thymus.Bis‐diamine induced anomalies were similar to those of the human primary immunodeficiency syndrome, particularly the DiGeorge syndrome.
Pathogenesis of Ochratoxin A‐ and Concanavalin A‐Induced Exencephalies in Mice
Authors: HAYASAKA Ikuo , HOSHINO Kiyoshi , KAMEYAMA Yoshiro 
Published: May 2008

Abstract Early morphogenetic changes of exencephaly induced by ochratoxin A (OA) were compared with those induced by concanavalin A (Con A) in mice in order to examine possible differences in the pathogenesis of neural tube defect. OA and Con A were administered to pregnant mice on day 7 of gestation, and the process of neural tube closure of embryos was observed at different times from 6 to 72 hours after treatment by SEM and light microscopy. In OA‐treated embryos, the cranial neural folds in the fore‐ and midbrains did not elevate and remained in the biconvex shape. The cellular changes were found in the neuroepithelium and surface ectoderm. Neural crest cells, which appeared at the lateral edges of the neural folds, were also involved in degeneration. In Con A‐treated embryos, the neural folds in the mid‐ and hindbrains elevated to assume the V shape, but remained wide open. The main cellular change was a degeneration of the primary mesenchyme underlying the neuroepithelium, resulting in a paucity of the supporting mesenchymal tissue.These findings suggest that the exencephalies produced by either OA or Con A are primarily due to non‐closure of the neural tube, but that the pathogenesis differs with each agent. Failure of neural tube closure in OA‐treated embryos appears to result from damage of the neuroepithelium and neural crest cells, whereas that in Con A‐treated embryos from damage of the primary mesenchyme.
The Role of Fibronectin in the Interstitial Migration of Primordial Germ Cells in Amniotes*
Authors: FUJIMOTO Toyoaki , YOSHINAGA Kazuya 
Published: May 2008

Abstract Primordial germ cells (PGCs) in amniotes separate from the endoderm of the early embryo and finally migrate through the dorsal mesentery (DM), which is the last portion of the migratory pathway, into the gonadal anlage, while in birds and some reptiles, the cells temporarily circulate via the blood vascular system before undergoing this migration. To understand the role of extracellular matrix in the migration of PGCs, the distribution and localization of fibronectin (FN) were examined using direct immunoperoxidase staining in embryos of mice, chicks and man. In mouse embryos of 10.0 to 11.0 days of gestation, the DM was rich in FN, at which time the PGCs were at the peak of their migration. FN was localized at the sites of interaction between cytoplasmic processes of PGCs and the neighboring somatic cells. In man, a positive reaction to FN was found in the DM of 5‐week old embryos, in which most of PGCs were migrating. In chick embryos at 2.5 days of incubation, the splanchnic mesoderm (SPM), into which the PGCs were passing from the blood vessels, was rich in FN. In 3.0‐day‐embryos, the DM, which was derived from the SPM, was rich in FN. FN was localized at the sites of interaction between pseudopodia of PGCs and the adjacent somatic cells. After the completion of PGC migration into the gonad, FN reaction was weakened or disappeared in every species examined.These results indicate that fibronectin plays a significant role in the interstitial migration of PGCs.
Developmental Disturbance of the Cerebral Cortex of Mouse Offspring from Dams Treated with Ochratoxin A during Pregnancy
Authors: HOSHINO Kiyoshi , FUKUI Yoshihiro , HAYASAKA Ikuo , KAMEYAMA Yoshiro 
Published: May 2008

Abstract This study was designed to elucidate long‐term pathological effects of ochratoxin A, one of the food contaminating mycotoxins, on the developing brain in mice. A single intraperitoneal injection of ochratoxin A at a dose of 2 or 3 mg/kg was given to pregnant mice on day 10 of gestation. They were allowed to give birth and the offspring were examined 6 weeks after birth. Their body weight, brain weight, brain size, thickness and cell packing density of dorsal neocortex in histological sections were examined. Growth of basal dendrites of pyramidal neurons in the layer V of dorsal neocortex was also examined with Golgi‐Cox specimens in terms of number of dendrites directly arising from the perikaryon, number of endings of dendrites, branching index (No. of endings/No. of arisings), mean distance from the perikaryon to the tips of dendrites, and number of intersections of dendrites with the zonal boundaries.Significant changes were found in brain weight, anteroposterior length of cerebrum, mean distance from the perikaryon to the tips of dendrites and number of intersections of dendrites with the zonal boundaries. These parameters can be recommended as sensitive ones in order to estimate rather weak effects of cytotoxic chemical agents exposed in utero on the development of cerebral cortex.
The Use of Animal Models in Understanding Human Teratogens
Authors: WEBSTER William S. 
Published: May 2008

ABSTRACT  The testing of drags and other chemicals in pregnant animals is required by legislation in a number of countries as a screening procedure for tera‐togenic potential in the human. The testing procedure involves methodology designed in the 1960s which was based on regimens established in the 1940s for toxicity testing. The requirement that animals are dosed to maternally toxic levels, frequently means that the embryos are exposed to inappropriately high concentrations of the test substance. Positive results in this type of experiment may have no relevence to the human situation where the exposure profile is often quite different, with the human embryo being exposed for prolonged periods to much lower drug concentrations. One way of duplicating the anticipated human exposure is to grow rat embryos in serum containing the drag and/or its metabolites at concentrations determined in the human during early clinical testing. It is proposed that mammalian embryos will respond in a similar manner to a particular concentration of a test substance.In vitro experiments using isotretinoin and its main metabolite 4–oxo‐isotretinoin showed that the metabolite was teratogenic at concentrations which occurred in the human during normal repetitive dosing and hence the metabolite was the likely human teratogen. Similarly, rat embryo culture studies showed that the anticonvulsant drug, valproic acid, was teratogenic at blood concentrations which occurred during normal dosing in the human. Other in vitro studies showed that cadmium is unlikely to be a human teratogen, despite the fact that it is well established as a teratogen in experimental animals in vivo.It is proposed that embryo culture should be used as an adjunct procedure during teratology testing making use of metabolic and pharmacokinetic data obtained from the human during clinical testing.
Anatomical Investigation of 39 Cases of Congenital Duplication in Calves
Authors: HIRAGA Takeo , ABE Mitsuo , IWASA Kenji , TAKE‐HANA Kazushige 
Published: May 2008

Abstract The anatomical features of congenital duplication in the bovine calf encountered in 39 cases over eleven years in Hokkaido were investigated macroscopically. Among the animals studied, 14 were male, 20 female and 5 of unknown gender, and the anomaly was noted in 35 Holstein‐Friesians, 3 Japanese Blacks and 1 Hereford.The duplications observed in this study were classified by four types: free asymmetrical, 4 (all 4 acardius); attached symmetrical, 25 (14 cranial duplication, 2 dipygus, 2 dicephalus dipygus, 5 thoracopagus, and 2 pygopagus); attached asymmetrical, 6 (1 parasitic dipygus, 4 notomelia, and 1 pygomelia); and miscellaneous, 4. The four acardii were holoacardii amorphi covered with skin and hair. Cranial duplication was subdivided into five types based on the number of eyes and ears. In symmetrical twins the anterior part of the body was affected in 16 out of 25 cases (64%), the posterior part in 2 out of 25 (8%) and both the anterior and posterior in 7 out of 25 (28%). All were mirror‐image duplicates on the various planes, and in some the internal organs had a center of symmetry. All four notomeli calves were female. Among the miscellaneous duplications, three were of the genital organs (male 1, and female 2) and one was a spinal cord duplication.
Development of Cerebellar Hypoplasia in Jaundiced Gunn Rats: A Morphological Study
Authors: TAKAGISHI Yoshiko 
Published: May 2008

Abstract The developmental process of cerebellar hypoplasia was investigated in homozygous (j/j) Gunn rats (born from heterozygous (+/j) mothers) with hereditary hyperbilirubinemia by light microscopy of Epon‐embedded sections and Golgi preparations, electron microscopy and immunofluorescence with anti‐SlOO protein immune serum. No abnormalities were found in the cerebellar cortex at postnatal day 1. But at day 3, some Purkinje cells contained whorled membranous inclusions, enlarged Golgi cisternae and vesicles, and/or dilated endoplasmic reticulum. Membranous inclusions filled the cytoplasm of a large number of Purkinje cells at day 10. These severely damaged Purkinje cells died and disappeared by day 30. The remaining Purkinje cells contained only a few membranous inclusions at day 30. At the adult stage, membranous inclusions were no longer detected in the remaining Purkinje cells. In these Purkinje cells, the dendrites were poorly developed and primitive synaptic junctions with parallel fibers were occasionally found on the dendritic shafts even at the adult stage. The perisomatic processes were often present on the remaining Purkinje cell soma from day 18 to the adult stage and were in synaptic contact with climbing fibers.The external granular layer was thinner in j/j than in +/j rats without hyperbilirubinemia at days 12 and 15 and disappeared at day 18 in j/j rats, i.e., earlier in j/j than in +/j rats. The molecular layer was thinner at day 10 and became slightly thicker thereafter. Cells in the molecular layer were scarce after day 12. The internal granular layer was thinner after day 12. An insufficient number of cells in the internal granular layer was apparent after day 12. Bergmann glia cells were hypertrophied after day 10 and filledthe spaces where Purkinje cells had disappeared. Subsequently, Bergmann fibers and astrocytes in the internal granular layer were hypertrophied after day 15.Thus, in the developmental process of cerebellar hypoplasia in j/j Gunn rats, Purkinje cell damage preceded the histogenetic abnormalities of the cortex including astrocytic changes.