bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrahigh‐pressure metamorphism and exhumation of garnet peridotite in Pohorje, Eastern Alps
Authors: JANÁK M. , FROITZHEIM N. , VRABEC M. , KROGH RAVNA E. J. , De HOOG J. C. M.
Published: November 2005

New evidence for ultrahigh‐pressure metamorphism (UHPM) in the Eastern Alps is reported from garnet‐bearing ultramafic rocks from the Pohorje Mountains in Slovenia. The garnet peridotites are closely associated with UHP kyanite eclogites. These rocks belong to the Lower Central Austroalpine basement unit of the Eastern Alps, exposed in the proximity of the Periadriatic fault. Ultramafic rocks have experienced a complex metamorphic history. On the basis of petrochemical data, garnet peridotites could have been derived from depleted mantle rocks that were subsequently metasomatized by melts and/or fluids either in the plagioclase‐peridotite or the spinel‐peridotite field. At least four stages of recrystallization have been identified in the garnet peridotites based on an analysis of reaction textures and mineral compositions. Stage I was most probably a spinel peridotite stage, as inferred from the presence of chromian spinel and aluminous pyroxenes. Stage II is a UHPM stage defined by the assemblage garnet + olivine + low‐Al orthopyroxene + clinopyroxene + Cr‐spinel. Garnet formed as exsolutions from clinopyroxene, coronas around Cr‐spinel, and porphyroblasts. Stage III is a decompression stage, manifested by the formation of kelyphitic rims of high‐Al orthopyroxene, aluminous spinel, diopside and pargasitic hornblende replacing garnet. Stage IV is represented by the formation of tremolitic amphibole, chlorite, serpentine and talc. Geothermobarometric calculations using (i) garnet‐olivine and garnet‐orthopyroxene Fe‐Mg exchange thermometers and (ii) the Al‐in‐orthopyroxene barometer indicate that the peak of metamorphism (stage II) occurred at conditions of around 900 °C and 4 GPa. These results suggest that garnet peridotites in the Pohorje Mountains experienced UHPM during the Cretaceous orogeny. We propose that UHPM resulted from deep subduction of continental crust, which incorporated mantle peridotites from the upper plate, in an intracontinental subduction zone. Sinking of the overlying mantle and lower crustal wedge into the asthenosphere (slab extraction) caused the main stage of unroofing of the UHP rocks during the Upper Cretaceous. Final exhumation was achieved by Miocene extensional core complex formation.
Febrile Convulsions Induced by the Combination of Lipopolysaccharide and Low‐dose Kainic Acid Enhance Seizure Susceptibility, Not Epileptogenesis, in Rats
Authors: Heida James G. , Teskey G. Campbell , Pittman Quentin J.
Published: November 2005

Summary: Purpose:Febrile convulsions (FCs) are seizures that occur as a result of fever. Retrospective clinical studies show a large percentage of adults with temporal lobe epilepsy have a positive history of FCs, but it is unknown whether FCs during infancy alter susceptibility to developing late epilepsy. We have tested the hypothesis that FCs affect seizure susceptibility and epileptogenesis in adults.

Methods:A novel model of FCs was used, in which lipopolysaccharide (LPS,Escherichia coli), in combination with a subconvulsant dose of kainic acid, caused FCs in 50% of 14‐day‐old male rats. Eight to 10 weeks later, electrodes were implanted into the basolateral amygdalae of all rats. After completion of the kindling procedure, animals were killed and brains examined for neurodegeneration by using Fluoro‐Jade histochemistry.

Results:Amygdala stimulation revealed that rats that had a FC as pups had lower afterdischarge thresholds and longer afterdischarge durations when compared with rats that received the same treatment but did not convulse. Despite this, when kindled daily, rats that had FCs as pups kindled at the same rate as did controls. However, an increase in the number of degenerating neurons was noted within the hippocampus of rats with a previous FC.

Conclusions:These results suggest that, although FCs during infancy can reduce seizure thresholds, it does not facilitate epileptogenesis in adulthood. Our results indicate that FCs affected local circuits in the amygdala and possibly in the hippocampus but not circuits responsible for seizure generalization.
Causal Links between Brain Cytokines and Experimental Febrile Convulsions in the Rat
Authors: Heida James G. , Pittman Quentin J.
Published: November 2005

Summary: Purpose:Despite the prevalence of febrile convulsions (FCs), their pathophysiology has remained elusive. We tested the hypothesis that components of the immune response, particularly the proinflammatory cytokine interleukin‐1β (IL‐1β) and its naturally occurring antagonist interleukin‐1 receptor antagonist (IL‐1ra) may play a role in the genesis of FC.

Methods:Postnatal day 14 rats were treated with lipopolysaccharide (LPS; 200 μg/kg, i.p.) followed by a subconvulsant dose of kainic acid (1.75 mg/kg, i.p.). Brains were harvested at and 2 h after onset of FCs to measure brain levels of IL‐1β and IL‐1ra. Separate groups of animals were given intracerebroventricular (ICV) injections of IL‐1β, or IL‐1ra in an attempt to establish a causal relation between the IL‐1β/IL‐1ra system and FCs.

Results:Animals with FCs showed increased IL‐1β in the hypothalamus and hippocampus but not in the cortex compared with noFC animals that also received LPS and kainic acid. This increase was first detected in the hippocampus at onset of FCs. No detectable difference in IL‐1ra was found in brain regions examined in either group. When animals were treated with IL‐1β ICV, a dose‐dependant increase was noted in the proportion of animals that experienced FCs, whereas increasing doses of IL‐1ra, given to separate groups of animals, were anticonvulsant.

Conclusions:Our results suggest that excessive amounts of IL‐1β may influence the genesis of FCs. This may occur by overproduction of IL‐1β, or by alteration in the IL‐1β/IL‐1ra ratio in the brain after an immune challenge.
Prevalence of Active Epilepsy in a Rural Area in South Tanzania: A Door‐to‐Door Survey
Authors: Dent Wolfgang , Helbok Raimund , Matuja William Bahati Pungu , Scheunemann Sönke , Schmutzhard Erich
Published: November 2005

Summary:  Objective: A door‐to‐door survey was carried out to assess the prevalence of active epilepsy in the rural population within the catchment area of the Mnero Diocesan Hospital in Southern Tanzania.

Methods: A total of 4,905 individuals living in 1,047 households were enrolled in a study, consisting of a screening dialogue with a representative family member followed by a face‐to‐face interview with the affected subject. The diagnosis of epilepsy followed clinical guidelines proposed by the International League Against Epilepsy (ILAE).

Results: We detected 42 cases (21 males and 21 females) of active epilepsy (8.6/1,000; 95% CI: 6.0/1,000–11.1/1,000; age‐adjusted prevalence ratio: 7.4/1,000). Thirty of them met the case definitions of generalized seizures, whereas 12 patients reported partial seizures. The peak prevalence was found in both sexes in the second decade of life (f: 16.9/1,000; m: 15.8/1,000; t: 16.4/1,000), with a second peak in the group aged 30–39 years (f: 10.4/1,000; m: 8.8/1,000; t: 9.7/1,000). Eleven patients (26.2%) were classified as “strongly suspected of symptomatic” epilepsy, the remaining 31 patients (73.8%) as possibly being idiopathic, symptomatic, or cryptogenic epilepsy cases.

Discussion: This study provides baseline data about the active epilepsy prevalence in a rural African population. Compared to western countries, our study confirmed a pattern toward higher prevalence of epilepsy in tropical countries. As shown in previous studies, we observed a higher prevalence of epilepsy in children and adolescents, followed by a steady decline with increasing age. Reasons for this type of frequency could be ascribed to malnutrition, trauma, genetic conditions, antenatal and prenatal care, diseases resulting in febrile convulsions, cerebral infections and may even result in death in specifically diseased individuals.
Pregabalin Add‐on Treatment in Patients with Partial Seizures: A Novel Evaluation of Flexible‐dose and Fixed‐dose Treatment in a Double‐blind, Placebo‐controlled Study
Authors: Elger Christian E. , Brodie Martin J. , Anhut Henning , Lee Caroline M. , Barrett Jeannette A.
Published: November 2005

Summary:  Purpose: To evaluate pregabalin as add‐on therapy for patients with partial seizures administered as fixed dose or as flexible dose adjusted to optimal seizure reduction and tolerability.

Methods: Patients receiving antiepileptic drugs (98.8% between 1 and 3 AEDs; 1.2% on more than 3 AEDs) and experiencing ≥4 partial seizures during the 6‐week baseline period and no 4‐week seizure‐free interval were randomized (1:2:2) to placebo (n = 73), pregabalin fixed dose (600 mg/day BID; n = 137), or pregabalin flexible dose (n = 131; 150 and 300 mg/day for 2 weeks each; 450 and 600 mg/day for 4 weeks each, BID) for 12 weeks. Dosage could be adjusted based on tolerability and maintained when a 4‐week seizure‐free period was achieved. Primary efficacy parameter was reduction in seizure frequency from baseline.

Results: Both pregabalin regimens significantly reduced seizure frequency compared with placebo, by 35.4%, for flexible dose (p = 0.0091) and 49.3% for fixed dose (p = 0.0001) versus 10.6% for placebo, and the fixed‐dose group was superior to the flexible‐dose group (p = 0.0337). Most adverse events were mild or moderate. Discontinuation rates due to adverse events were 6.8% (placebo), 12.2% (pregabalin flexible dose), and 32.8% (pregabalin fixed dose). Patients receiving pregabalin fixed dose discontinued due to adverse event earlier than other groups.

Conclusions: Pregabalin administered twice daily, either as fixed (600 mg/day), or as flexible (150–600 mg/day) dose, was highly effective and generally well‐tolerated as add‐on therapy for partial seizures with or without secondary generalization. Lower incidence of adverse events and discontinuations were achieved in patients receiving pregabalin when dosing was individualized to optimize efficacy and tolerability.
Somatic Comorbidity of Epilepsy in the General Population in Canada
Authors: Téllez‐Zenteno José F. , Matijevic Suzan , Wiebe Samuel
Published: November 2005

Summary: Purpose:There is a notion that people with epilepsy have substantial and often unrecognized comorbidity of chronic conditions. However, most studies focus on selected patient groups; population‐based studies are scarce. We compared the prevalence of chronic somatic conditions in people with epilepsy with that in the general population using Canadian, nationwide, population‐based health data.

Method:We examined epilepsy‐specific and general population health data obtained through two previously validated, independently performed, door‐to‐door Canadian health surveys, the National Population Health Survey (NPHS, N = 49,000) and the Community Health Survey (CHS, N = 130882), which represent 98% of the Canadian population. The prevalence of epilepsy and 19 other chronic conditions was ascertained through direct inquiry from respondents about physician‐diagnosed illnesses. Weighted prevalence, prevalence ratios (PR), and 95% confidence intervals were obtained for the entire population and for males and females separately. Multivariate analyses assessed the strength of association of comorbid conditions with epilepsy as compared with the general population.

Results:People with epilepsy had a statistically significant higher prevalence of most chronic conditions than the general population. Conditions with particularly high prevalence in epilepsy (prevalence ratio ≥ 2.0) include stomach/intestinal ulcers (PR, CHS 2.5, NPHS 2.7), stroke (PR, CHS 3.9, NPHS 4.7), urinary incontinence (PR, CHS 3.2, NPHS 4.4), bowel disorders (PR, CHS 2.0, NPHS 3.3), migraine (PR, CHS 2.0, NPHS 2.6), Alzheimer's disease (PR, NPHS 4.3), and chronic fatigue (PR, CHS 4.1). There were no gender‐specific differences in prevalence of chronic conditions among people with epilepsy.

Conclusions:People with epilepsy in the general population, not only those actively seeking medical care, have a high prevalence of chronic somatic comorbid conditions. The findings are consistent across two independent surveys, which show that people with epilepsy in the general population have a two‐ to five‐fold risk of somatic comorbid conditions, as compared with people without epilepsy. This patient‐centered comorbidity profile reflects health aspects that are important to people with epilepsy, and indicate the need for a more integrated approach to people with epilepsy. The impact of epilepsy relative to other comorbid conditions requires further analysis, as does the contribution of comorbidity to epilepsy intractability and to differential health care needs. Similarly, it remains to be determined whether the observed comorbidity patterns are specific to epilepsy or simply reflect a pattern that is common to chronic illnesses in general.
Electroclinical and Genetic Findings in a Family with Cortical Tremor, Myoclonus, and Epilepsy
Authors: Striano Pasquale , Madia Francesca , Minetti Carlo , Striano Salvatore , Zara Federico
Published: November 2005

Summary:  We report a five‐generation family showing cortical tremor, myoclonus, and epilepsy, originating from Naples, Italy. Eleven members, aged 24–56 years (mean: 39.2 years), suffered from hand tremor and myoclonus, whereas generalized seizures occurred in six. Electrophysiological study confirmed the presence of cortical reflex myoclonus in all affected members. In addition, giant somatosensory‐evoked potential components and enhanced long loop reflex I were found also in three presymptomatic members who manifested hand tremor and myoclonus at upper limbs after 1.5 years of follow‐up. Genetic study of the pedigree revealed a significant linkage on chromosome 2p (maximum lod score = 5.9). Further observations are needed to clarify the pathophysiology of this condition.
G. Stanley Hall: Neither Psychology Alone Nor Basic Research is Sufficient
Authors: Youniss James
Published: November 2005

In his monumental work, Adolescence, G. Stanley Hall showed the value of interdisciplinary scholarship and respect for research, which had a policy orientation. Over the course of the 20th century these two characteristics faded in adolescent studies as psychology took dominance and basic research was given priority over policy considerations. An argument is made that there is value in revisiting Hall's approach as studies of adolescence can be enriched through interdisciplinary efforts and research which brings policy to the forefront.
One Hundred Years of Knowing: The Changing Science of Adolescence, 1904 and 2004
Authors: Shanahan Michael J. , Erickson Lance D. , Bauer Daniel J.
Published: November 2005

The practice of science as a mode of discovery is subject to change. This paper examines the “sciences” practiced by G. Stanley Hall in his Adolescence of 1904 and by contemporary researchers who study youth in 2004. After briefly reviewing the nature of Hall's empiricism, we draw on a representative sample of articles (n=182) published between 1999 and 2004 in specialty journals to analyze the interdisciplinary science of adolescence today. Results reveal that Hall was largely concerned with the conceptual and empirical description of phenomena, and he seldom offered causal explanations. In contrast, contemporary research frequently neglects description and emphasizes causal modeling. While a shift in focus from description to causation may seem a natural progression, we conclude by arguing that description is necessary even for a “mature” science. The study of adolescence needs a new regime of scientific practice that fully appreciates the value of both description and causal modeling.
Understanding Social Change in Conducting Research on Adolescence
Authors: Pinquart Martin , Silbereisen Rainer K.
Published: November 2005

In the present essay, we focus on G. Stanley Hall's contributions to the study of the role of social change for adolescent development. After introducing Hall's main ideas, we discuss recent demands adolescents face because of social change and how Hall's work could inform research on adolescent development in times of social change.
Financial Strain, Neighborhood Stress, Parenting Behaviors, and Adolescent Adjustment in Urban African American Families
Authors: Morrison Gutman Leslie , McLoyd Vonnie C. , Tokoyawa Teru
Published: November 2005

Using latent variable structural equation modeling, we tested a theoretical model linking financial strain, neighborhood stress, parenting behavior, and adolescent adjustment. The sample consisted of 305 African American families living in inner city neighborhoods. Of the families, 40% were living at or below the U.S. poverty threshold. The primary caregiver and a focal adolescent (mean age 13.5 years) were interviewed separately in each family. The results indicated that the income‐to‐need ratio was significantly related to financial strain and neighborhood stress, both of which were positively associated with psychological distress in parents. Parent psychological distress was positively related to more negative and less positive parent–adolescent relations, which predicted a lower positive and higher negative adjustment in adolescents. The results extend previous findings by demonstrating that neighborhood characteristics are an important mediator between economic hardship and parent and adolescent behaviors.
Applicability of the Social Development Model to Urban Ethnic Minority Youth: Examining the Relationship between External Constraints, Family Socialization, and Problem Behaviors
Authors: Choi Yoonsun , Harachi Tracy W. , Gillmore Mary Rogers , Catalano Richard F.
Published: November 2005

The development of preventive interventions targeting adolescent problem behaviors requires a thorough understanding of risk and protective factors for such behaviors. However, few studies examine whether different cultural and ethnic groups share these factors. This study is an attempt to fill a gap in research by examining similarities and differences in risk factors across racial and ethnic groups. The social development model has shown promise in organizing predictors of problem behaviors. This article investigates whether a version of that model can be generalized to youth in different racial and ethnic groups (N=2,055, age range from 11 to 15), including African American (n=478), Asian Pacific Islander (API) American (n=491), multiracial (n=442), and European American (n=644) youth. The results demonstrate that common risk factors can be applied to adolescents, regardless of their race and ethnicity. The findings also demonstrate that there are racial and ethnic differences in the magnitudes of relationships among factors that affect problem behaviors. Further study is warranted to develop a better understanding of these differential magnitudes.
Moving Forward with Research on Adolescence: Some Reflections on the State of JRA and the State of the Field
Authors: Brown B. Bradford
Published: November 2005

Over the past 5 years the scientific study of adolescence has continued to grow in volume and sophistication. Drawing on recent articles published in the Journal of Research on Adolescence, I take this opportunity to comment on some common understandings about the nature of adolescent development and behavior, recurrent tensions in the research, and promising directions or special challenges for future investigations. The journal also has changed in significant ways over this period, thanks to the outstanding contributions of scholars and journal/publisher support staff. This editorial pays homage to their efforts.
Fraud Detection Using a Multinomial Logit Model With Missing Information
Authors: Caudill Steven B. , Ayuso Mercedes , Guillén Montserrat
Published: November 2005

Abstract

Recently,Artís, Ayuso, and Guillén(2002,Journal of Risk and Insurance69: 325–340; henceforth AAG) estimate a logit model using claims data. Some of the claims are categorized as “honest” and other claims are known to be fraudulent. Using the approach ofHausman, Abrevaya, and Scott‐Morton(1998Journal of Econometrics87: 239‐269), AAG estimate a modified logit model allowing for the possibility that some claims classified as honest might actually be fraudulent. Applying this model to data on Spanish automobile insurance claims, AGG find that 5 percent of the fraudulent claims go undetected. The purpose of this article is to estimate the model of AAG using a logit model with missing information. A constrained version of this model is used to reexamine the Spanish insurance claim data. The results indicate how to identify misclassified claims. We also show how misclassified claims can be identified using the AAG approach. We show that both approaches can be used to probabilistically identify misclassified claims.
The (1992) Bonus‐Malus System in Tunisia: An Empirical Evaluation
Authors: Dionne Georges , Ghali Olfa
Published: November 2005

Abstract

The objective of this study is to assess empirically what impact introduction of the bonus‐malus system (BMS) has had on road safety in Tunisia. The results of the Tunisian experiment are of particular importance since, during the last decade, many European countries decided to eliminate their mandatory bonus‐malus scheme. These results indicate that the BMS reduced the probability of reported accidents for good risks but had no effect on bad risks. Moreover, the reform's overall effect on reported accident rates is not statistically significant, but the exit variable is positive in explaining the number of reported accidents. To avoid any potential selectivity bias, we also made a joint estimate of the reported accident and selection equations. The reform has a positive effect on the exit variable but still does not affect the accidents reported. This indicates that policyholders who switch companies are those attempting to skirt the imposed incentive effects of the new rating policy. Some of the control variables are statistically significant in explaining the number of reported accidents: the vehicle's horsepower, the policyholder's place of residence, and the coverages for which policyholders are underwritten.
An Empirical Investigation of Market Structure, Efficiency, and Performance in Property‐Liability Insurance
Authors: Choi Byeongyong Paul , Weiss Mary A.
Published: November 2005

Abstract

This study examines the relationships among market structure and performance in property‐liability insurers over the period 1992–1998 using data at the company and group levels. Three specific hypotheses are tested: traditional structure‐conduct‐performance, relative market power, and efficient structure (ES). The results provide support for the ES hypothesis. The ES hypothesis posits that more efficient firms can charge lower prices than competitors, enabling them to capture larger market shares and economic rents, leading to increased concentration. Both revenue and cost efficiency are used in the analysis, and this is the first study to use revenue efficiency in this type of analysis. The results for the sample period as a whole and by year are consistent. The overall results suggest that cost‐efficient firms charge lower prices and earn higher profits, in conformance with the ES hypothesis. On the other hand, prices and profits are found to be higher for revenue‐efficient firms. Revenue X‐efficiency is derived from activities such as cross‐selling and may rely heavily on the use of detailed information from customer databases to identify potential customers. The implications of this research are that regulators should be more concerned with efficiency (both cost and revenue) rather than the market power that arises from the consolidation activity taking place in insurance.
Habitat and food resource use of perch and roach in a deep mesotrophic reservoir: enough space to avoid competition?
Authors: Kahl U. , Radke R. J.
Published: November 2005

Abstract –  The aim of this study was to test assumptions about the interaction of perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) concerning their food and habitat use in a deep and mesotrophic reservoir. From 1998 to 2001 the fish were caught with gillnets to perform diet analyses. Additionally, vertical gillnets were set to study vertical spatial distribution of both species. The results indicate that in a large and deep reservoir perch and roach are able to avoid competition by separating their niches first in the spatial dimension and then in the dimension of food utilisation. These separations result in low inter‐ and intraspecific competition of both species. We conclude that these niche separations can widen the juvenile competitive bottleneck to such an extent that the perch are not forced to compete with their older conspecifics during their first year of life, enabling perch to become large and consequently piscivorous.
Satiation effects in piscivore prey size selection
Authors: Turesson H. , Brönmark C. , Wolf A.
Published: November 2005

Abstract –  We present a functional response model that primarily evaluates effects of satiation in piscivore prey‐size selection. The model also includes other passive processes, such as prey‐size‐dependent encounter rate and prey‐size‐dependent capture success, where capture success decreases and encounter rate increases with prey size. The model generates a wide variety of outcomes, where small, intermediate or large prey is positively selected for. These very different selectivity patterns are generated without any active prey choice included in the model. The results stress the importance of controlling for satiation and other passive processes in empirical studies on prey‐size selection, especially if the aim is to test active prey choice in piscivores.
Fmr1 knockout mice are impaired in a leverpress escape/avoidance task
Authors: Brennan F. X. , Albeck D. S. , Paylor R.
Published: November 2005

Fragile X syndrome (FXS) is the most common form of inherited mental retardation (MR). FXS is typically caused by a mutation of the Fmr1 gene (Verkerk et al. 1991, Cell 65, 905–914). To better understand the role of Fmr1 and its gene product fragile X mental‐retardation protein (FMRP) in central nervous system function, researchers have turned to the use of animal model systems to generate an Fmr1 knockout (KO) mouse that is deficient in FMRP (Bakker et al. 1994, Cell 78, 23–33). Unfortunately, a number of studies have found no consistent, robust learning and memory impairment in the Fmr1 KO mice. We conducted a study to assess the performance of Fmr1 KO and wildtype (WT) animals in a leverpress escape/avoidance paradigm. Fmr1 KO and WT littermates were studied in four daily 1‐h sessions. The Fmr1 KO mice performed fewer avoidance and total responses than WT mice. The KO animals were not simply deficient in avoidance, but a within‐factor anova revealed that they did not acquire the leverpress response to any appreciable degree. Observation during the sessions indicated that the Fmr1 KO animals clearly responded to the shock, eliminating an obvious sensory explanation for the deficit. The fact that other studies have found that the KO mice displayed increased exploratory and locomotor activity compared with WT controls argues against a motoric deficit. Future studies will attempt to delineate the nature of the behavioral deficit as well as attempt to rescue the response with glutamatergic or dopaminergic agents.
Dissociation of food and opiate preference by a genetic mutation in zebrafish
Authors: Lau B. , Bretaud S. , Huang Y. , Lin E. , Guo S.
Published: November 2005

Both natural rewards and addictive substances have the ability to reinforce behaviors. It has been unclear whether identical neural pathways mediate the actions of both. In addition, little is known about these behaviors and the underlying neural mechanisms in a genetically tractable vertebrate, the zebrafish Danio rerio. Using a conditioned place preference paradigm, we demonstrate that wildtype zebrafish exhibit a robust preference for food as well as the opiate drug morphine that can be blocked by the opioid receptor antagonist naloxone. Moreover, we show that the too few mutant, which disrupts a conserved zinc finger‐containing gene and exhibits a reduction of selective groups of dopaminergic and serotonergic neurons in the basal diencephalon, displays normal food preference but shows no preference for morphine. Pretreatment with dopamine receptor antagonists abolishes morphine preference in the wildtype. These studies demonstrate that zebrafish display measurable preference behavior for reward and show that the preference for natural reward and addictive drug is dissociable by a single‐gene mutation that alters subregions of brain monoamine neurotransmitter systems. Future genetic analysis in zebrafish shall uncover further molecular and cellular mechanisms underlying the formation and function of neural circuitry that regulate opiate and food preference behavior.
The Mystery of the Lost Star: A Statistical Detective Story
Authors: Spiegelhalter David
Published: November 2005

In July 2005 the Healthcare Commission released its annual “star ratings” for English National Health Service (NHS) trusts1, in which acute or specialist hospitals, mental health services, ambulance services and primary care trusts were each given 0, 1, 2 or 3 stars. There was some surprise that the Cambridge University Hospitals NHS Foundation Trust (better known as Addenbrooke's Hospital) dropped from the 3 stars obtained in 2004 to 2 stars. David Spiegelhalter investigated.
The Downside of Publication
Authors: Copas John
Published: November 2005

No one questions the vital role that publication and peer review play in scientific progress, says John Copas. Results and ideas are made available for discussion and debate, having been vetted first by independent referees. Although the system is not perfect, on the whole it works pretty well. But in the empirical sciences, the selection of papers for publication poses a very challenging problem.
Experimental Design and Systematic Monitoring
Authors: Finney David
Published: November 2005

David Finney has enjoyed a long and distinguished career, both as an academic statistician and in various areas of agricultural research and medical statistics. He tells Helen Joyce about his career, and shares his views on the state of statistics today.
Sexes and Statistics
Authors: Edwards A. W. F.
Published: November 2005

Arthur Geissler's data for the distribution of the sexes in families with eight children, published in 1889, became famous through its use by R. A. Fisher in Statistical Methods for Research Workers in 1925 as an example of the binomial distribution. Geissler compiled data from Saxony for the period 1876-1885 for all family sizes. How did Fisher obtain the figures for his example? And why did he change the sixth significant figure of his value for the variance in his fourth edition of 1932?
Prisoner Escort in Scotland: Costs, Projection and Performance under Scrutiny
Authors: Eyre David , Bird Sheila
Published: November 2005

David Eyre is a journalist. He says that he is a little ignorant when it comes to statistics, as he thinks many people in the media are. Which is pretty surprising when you consider the number of stories that are based on statistics—everything from crime surveys to NHS waiting lists. Here he and Sheila Bird describe how they sought to address this problem in the context of prisoner escort in Scotland.
Understanding heart development and congenital heart defects through developmental biology: A segmental approach
Authors: Sakabe Masahide , Matsui Hiroko , Sakata Hirokazu , Ando Katsumi , Yamagishi Toshiyuki , Nakajima Yuji
Published: November 2005

ABSTRACT  The heart is the first organ to form and function during development. In the pregastrula chick embryo, cells contributing to the heart are found in the postero‐lateral epiblast. During the pregastrula stages, interaction between the posterior epiblast and hypoblast is required for the anterior lateral plate mesoderm (ALM) to form, from which the heart will later develop. This tissue interaction is replaced by an Activin‐like signal in culture. During gastrulation, the ALM is committed to the heart lineage by endoderm‐secreted BMP and subsequently differentiates into cardiomyocyte. The right and left precardiac mesoderms migrate toward the ventral midline to form the beating primitive heart tube. Then, the heart tube generates a right‐side bend, and the d‐loop and presumptive heart segments begin to appear segmentally: outflow tract (OT), right ventricle, left ventricle, atrioventricular (AV) canal, atrium and sinus venosus. T‐box transcription factors are involved in the formation of the heart segments: Tbx5 identifies the left ventricle and Tbx20 the right ventricle. After the formation of the heart segments, endothelial cells in the OT and AV regions transform into mesenchyme and generate valvuloseptal endocardial cushion tissue. This phenomenon is called endocardial EMT (epithelial‐mesenchymal transformation) and is regulated mainly by BMP and TGFβ. Finally, heart septa that have developed in the OT, ventricle, AV canal and atrium come into alignment and fuse, resulting in the completion of the four‐chambered heart. Altered development seen in the cardiogenetic process is involved in the pathogenesis of congenital heart defects. Therefore, understanding the molecular nature regulating the ‘nodal point’ during heart development is important in order to understand the etiology of congenital heart defects, as well as normal heart development.
Descriptive epidemiology of anotia and microtia, Hawaii, 1986–2002
Authors: Forrester Mathias B. , Merz Ruth D.
Published: November 2005

ABSTRACT  The objective of this investigation was to describe the epidemiology of anotia and microtia with respect to various factors. The cases studied were all infants and fetuses with anotia or microtia identified by a population‐based birth defects registry in Hawaii. The anotia and microtia rates were determined for selected factors and comparisons made among the subgroups by calculating the rate ratio (RR) and 95% confidence interval (CI). A total of 120 cases were identified, for a rate of 3.79 per 10 000 live births. The anotia and microtia rate increased during 1986–2002, although the trend was not significant (P = 0.715). Of 49 specific structural birth defects examined, four were found to be significantly more common in the presence of anotia and microtia. When compared with Caucasians, the anotia and microtia rates were higher among Far East Asians (RR 1.79, 95% CI 0.89–3.68), Pacific Islanders (RR 2.26, 95% CI 1.24–4.32), and Filipinos (RR 2.34, 95% CI 1.23–4.64). The defects were less common among females (RR 0.64, 95% CI 0.43–0.93) and more common with multiple birth (RR 3.72, 95% CI 1.66–7.33), birth weight < 2500 g (RR 3.35, 95% CI 2.04–5.30), and gestational age <38 weeks (RR 2.27, 95% CI 1.49–3.40). In conclusion, the rate for anotia and microtia increased in Hawaii during the study period. The rates for only a few structural birth defects were substantially greater than expected in association with anotia and microtia. Anotia and microtia rates varied significantly according to maternal race/ethnicity, infant sex, plurality, birth weight, and gestational age.
Massive cystic lymphangiomas of a fetus
Authors: Hayashi Akiko , Kikuchi Akihiko , Matsumoto Yasuhiro , Tatematsu Mikiko , Horikoshi Tsuguhiro , Ogiso Yoshifumi , Unno Nobuya
Published: November 2005

ABSTRACT  We present a fetus with progressive massive subcutaneous lymphangiomas leading to intrauterine death. A 28‐year‐old woman was referred to our hospital because of a precordial cystic mass of the fetus. An ultrasound revealed lymphangiomas extending from bilateral axillae to the anterior chest wall. At 18 weeks’ gestation, amniocentesis was performed and the karyotype of the fetus was found to be normal 46, XY. Thereafter the lesions increased in size gradually and spread over the body. Amniotic fluid decreased, pericardial, and pleural effusion appeared, and cardiomegaly became evident. The fetus died in utero at 25 weeks’ gestation. Postmortem examination revealed a male fetus surrounded with multicystic soft masses spreading over the body, and syndactyly (left third and fourth fingers) was present. Histologically, a number of irregularly dilated lymphatics extended through subcutaneous tissues to the skeletal muscles. No communications between the cysts and the thoracic or abdominal cavity existed, and no lymphatic dilations in the viscera were confirmed. As far as we know, such conditions have rarely been reported. Considering that in previous literature, a favorable prognosis of a fetus with an atypically located (lateral cervical or non‐cervical) lymphangioma with a normal karyotype has been reported, our case may be included in a distinct pathological entity. When we find a lymphangioma in a fetus, careful follow‐up by ultrasound is mandatory.
Plant–Plant and Plant–Topography Interactions on a Rock Outcrop at High Altitude in Southeastern Brazil1
Authors: Medina Branca Maria Opazo , Ribeiro Kátia Torres , Scarano Fabio Rubio
Published: November 2005

Plant establishment and growth on rocky outcrops in the Itatiaia massif (2400 m a.s.l.), southeastern Brazil, are limited by lack of soil and by freezing temperatures in winter nights. Mat‐forming species of different sizes and shapes on bare rock provide substrate for other plants to establish. The habitat preference of two geophytes, Stevia camporum (Asteraceae) and Alstroemeria foliosa (Alstroemeriaceae), was compared with regard to their association with the type of mat species and distinct rock topographies. The habitat preference of the mat species in regard to topography was also assessed. We found 1706 ramets of S. camporum and 1317 of A. foliosa in 253 vegetation islands ranging in size from 0.005 to 18.097 m2. Mat species in these islands were Fernseea itatiaiae, Vriesea itatiaiae (both Bromeliaceae), Pleurostima gounelleana (Velloziaceae) and/or Campylopus pilifer (Dicranaceae) and other mosses. Mat species were segregated by topography. Geophytes were similarly distributed across types of topography but showed negative interspecific association. S. camporum occurred mostly on the moss‐dominated islands, whereas A. foliosa was more common in P. gounelleana islands. We found geophyte co‐occurrence in larger vegetation islands containing both P. gounelleana and mosses as mat species. Thus, the effect of topography on geophyte segregation was indirect, since topography affects mat species distribution, and the geophyte preference for distinct mat species as substrate resulted in their segregation.
Roosting Ecology of the Tent‐Roosting Bat Artibeus watsoni (Chiroptera: Phyllostomidae) in Southwestern Costa Rica1
Authors: Chaverri Gloriana , Kunz Thomas H.
Published: November 2005

We described the plants used as roost resources by Artibeus watsoni in southwestern Costa Rica, assessed roost fidelity, and compared roosting ecology between two sites, Golfito and Corcovado, which vary in the degree of human influence. A total of 349 tents from 25 different plant species were used by A. watsoni as roosts; some plant species (e.g., Carludovica palmata, Asplundia alata, Heliconia imbricata and Calathea lutea) were modified into tents with significantly higher frequency than others. The highest tents above the ground were observed in Philodendron popenoei and Rhodospatha wendlandii, whereas tents in Philodendron grandipes and A. alata were significantly lower than any other species. Asplundia alata and R. wendlandii also had the highest frequency of leaves modified per plant. Fidelity of bats to tents was low, although bats used several tents intermittently within a restricted area. Males generally were more faithful to tents than females, although not significantly so. This observation, along with indirect evidence of leaf modification, suggests that males are primarily responsible for tent construction. The two study sites differed in the plants used for roosting and in tent fidelity. Bats in Corcovado used a greater variety of plant species for tent roosting, whereas bats in Golfito were more faithful, suggesting that roosting resources were scarcer at the latter site.
Transient NMDA receptor‐mediated hypoperfusion following umbilical cord occlusion in preterm fetal sheep
Authors: Dean Justin M. , Gunn Alistair Jan , Wassink Guido , Bennet Laura
Published: November 2005

Exposure to severe hypoxia leads to delayed cerebral and peripheral hypoperfusion. There is evidence in the very immature brain that transient abnormal glutaminergic receptor activity can occur during this phase of recovery. We therefore examined the role ofN‐methyl‐d‐aspartate (NMDA) receptor activity in mediating secondary hypoperfusion in preterm fetal sheep at 70% of gestation. Fetuses received either sham asphyxia or asphyxia and were studied for 12 h recovery. The specific, non‐competitive NMDA receptor antagonist dizocilpine maleate (2 mg kg−1bolus plus 0.07 mg kg h−1i.v.) or saline (vehicle) was infused from 15 min after asphyxia until 4 h. In the asphyxia–vehicle group abnormal epileptiform EEG transients were observed during the first 4 h of reperfusion, the peak of which corresponded approximately to the nadir in peripheral and cerebral hypoperfusion. Dizocilpine significantly suppressed this activity (2.7 ± 1.3versus11.2 ± 2.7 counts min−1at peak frequency,P< 0.05) and markedly delayed and attenuated the rise in vascular resistance in both peripheral and cerebral vascular beds observed after asphyxia, effectively preventing the initial deep period of hypoperfusion in carotid blood flow and femoral blood flow (P< 0.01). However, while continued infusion did attenuate subsequent transient tachycardia, it did not prevent the development of a secondary phase of persistent but less profound hypoperfusion. In conclusion, the present studies suggest that in the immature brain the initial phase of delayed cerebral and peripheral hypoperfusion following exposure to severe hypoxia is mediated by NMDA receptor activity. The timing of this effect in the cerebral circulation corresponds closely to abnormal EEG activity, suggesting a pathological glutaminergic activation that we speculate is related to evolving brain injury.
Exploring Dynamics and Stereochemistry in Mechanically-Interlocked Compounds
Authors: Vignon Scott A. , Stoddart J. Fraser
Published: November 2005

The advent of self-assembly and template-directed synthetic protocols has led to a tremendous surge in the number of mechanically-interlocked compounds being prepared and studied. As these investigations are being carried out, it is becoming increasingly apparent that many of these compounds, known as catenanes and rotaxanes, possess unique dynamic and stereochemical properties. In addition, the drive to create molecular switches and machines for nanotechnological applications has generated a need to understand how to control those properties in condensed phases. Here, we present an overview of the field with regard to the solution dynamics and stereochemistry of mechanically-interlocked compounds - as well as to some related structural types - and review the recent results from our own research in some detail. 1H NMR spectroscopy has proven to be a powerful tool for probing both degenerate and nondegenerate dynamic processes in these compounds, as well as for identifying stereoisomers if they are present in solution. The results of several variable temperature NMR investigations on the effects of structural changes upon the dynamic processes and stimulated relative motions of components in catenanes and rotaxanes, as well as in some self-complexes and pretzelanes, are discussed. A review with 90 references.
Preparation and Crystal Structure of Bis(tert-butyltetramethylcyclopentadienyl)dichlorotitanium
Authors: Lukešová Lenka , Gyepes Róbert , Pinkas Jiří , Horáček Michal , Kubišta Jiří , Čejka Jiří , Mach Karel
Published: November 2005

[TiCl2(η5-C5Me4t-Bu)2] (1) was prepared by the reaction of [TiCl3(thf)3] with 2 equivalents of Li(η5-C5Me4t-Bu) (made by adding BuLi to a 1.33 molar excess of a mixture of tert-butyltetramethylcyclopentadiene isomers in THF) and subsequent oxidation of the Ti(III) intermediate to 1 by adding aqueous HCl. Neglecting the presence of cyclopentadiene isomers not forming the cyclopentadienide anion in the isomer mixture used for the synthesis of 1 resulted in the formation of hydrolytic product [{TiCl2(η5-C5Me4t-Bu)}2(μ-O)] (2) and a considerable decrease of yield of 1. The half sandwich complex [TiCl3(η5-C5Me4t-Bu)] (3) was obtained by synproportionation of 1 and TiCl4. Crystal structures of 1, 2, and 3 were determined. The electronic absorption spectra of 1 and 3 indicate a stronger electron-donor effect of tert-butyl group compared with methyl group.
In situ Chiral Modification of Nickel Catalysts for Enantioselective Hydrogenation of Methyl Acetoacetate
Authors: Bartek Lukáš , Klusoň Petr , Červený Libor
Published: November 2005

Chiral modifications of SiO2-supported and Raney nickel catalysts were studied. The catalysts were employed in asymmetric hydrogenation of methyl acetoacetate (MAA) to (R)- and (S)-enantiomers of methyl 3-hydroxybutanoate. The effects of modification parameters such as type and concentration of modifier; presence of a co-modifier and other additives, pH of modification solution on the enantioselectivity of MAA hydrogenation were discussed. Characteristic features of the in situ modification of Ni/SiO2 were also evaluated and the results obtained were compared with the conventional (premodification) approach. Parameters for the conventional and in situ methods were optimised in a series of experiments for both types of catalysts. The in situ modified Ni/SiO2 was found specifically suitable for repeated use due to virtually no decrease in selectivity and activity.
Children’s understanding of the risks and benefits associated with research
Authors: Burke T M , Abramovitch R , Zlotkin S
Published: November 2005

Objective:The objective of the current study was to maximise the amount of information children and adolescents understand about the risks and benefits associated with participation in a biomedical research study.

Design:Participants were presented with one of six hypothetical research protocols describing how to fix a fractured thigh using either a “standard” cast or “new” pins procedure. Risks and benefits associated with each of the treatment options were manipulated so that for each one of the six protocols there was either a correct or ambiguous choice.

Participants and setting:Two hundred and fifty one children, ages 6–15 (53% boys), and 237 adults (30% men) were interviewed while waiting for a clinic appointment at the Hospital for Sick Children.

Results:Using standardised procedures and questionnaires, it was determined that most participants, regardless of age group, were able to understand the basic purpose and procedures involved in the research, and most were able to choose the “correct” operation. The younger children, however, showed an overall preference for a cast operation, whereas the older participants were more likely to choose the pins.

Conclusions:By creating age appropriate modules of information, children as young as six years can understand potentially difficult and complex concepts such as the risks and benefits associated with participation in biomedical research. It appears, however, that different criteria were used for treatment preference, regardless of associated risks; older participants tended to opt for mobility (the pins procedure) whereas younger participants stayed with the more familiar cast operation.