bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic variability in natural populations of Arabidopsis thaliana in northern Europe
Authors: STENØIEN HANS K. , FENSTER CHARLES B. , TONTERI ANNI , SAVOLAINEN OUTI
Published: January 2005

Ten populations of the model plant Arabidopsis thaliana were collected along a north–south gradient in Norway and screened for microsatellite polymorphisms in 25 loci and variability in quantitative traits. Overall, the average levels of genetic diversity were found to be relatively high in these populations, compared to previously published surveys of within population variability. Six of the populations were polymorphic at microsatellite loci, resulting in an overall proportion of polymorphic loci of 18%, and a relatively high gene diversity for a selfing species (HE = 0.06). Of the overall variability, 12% was found within populations. Two of six polymorphic populations contained heterozygous individuals. Both FST and phylogenetic analyses showed no correlation between geographical and genetic distances. Haplotypic diversity patterns suggested postglacial colonization of Scandinavia from a number of different sources. Heritable variation was observed for many of the studied quantitative traits, with all populations showing variability in at least some traits, even populations with no microsatellite variability. There was a positive association between variability in quantitative traits and microsatellites within populations. Several quantitative traits exhibited QST values significantly less than FST, suggesting that selection may be acting to retard differentiation for these traits.
Colonization history of the high‐arctic pink‐footed gooseAnser brachyrhynchus
Authors: RUOKONEN M. , AARVAK T. , MADSEN J.
Published: January 2005

Population structure and phylogeography of the pink‐footed goose,Anser brachyrhynchusBaillon 1833, was studied using mtDNA control region sequences (221 bp) from 142 individuals. Present breeding areas of the species in Greenland, Iceland, and Svalbard were largely covered by ice during the late Pleistocene. In pairwise comparisons φSTestimates showed significant differentiation among eastern and western populations, whereas sampling localities within both areas were not differentiated. The mtDNA data indicate that the populations have separated recently (less than 10 000 years ago) and present breeding areas were colonized from one refugial population. The levels of haplotype and nucleotide diversity were approximately five times higher for the eastern population compared to the western population and suggest that the latter was colonized by a subset of eastern birds. Time to the most recent common ancestor of the species is 32 000–46 000 years, i.e. the present mtDNA variation of the pink‐footed goose has accumulated during the last 0.1 My. Estimates of the long‐term female effective population size (5400–7700 for the eastern population) imply that the refugial population of the pink‐footed goose has been large. Tundra habitats were more extensive in cold periods of the late Pleistocene than today and may have sustained population sizes that allowed the accumulation of extant genetic polymorphism. It is not probable that the postulated small refugial areas in the high latitudes had a significant role in maintaining this diversity.
Tracking the invasive history of the green alga Codium fragile ssp. tomentosoides
Authors: PROVAN JIM , MURPHY SUSAN , MAGGS CHRISTINE A.
Published: January 2005

The spread of nonindigenous species into new habitats is having a drastic effect on natural ecosystems and represents an increasing threat to global biodiversity. In the marine environment, where data on the movement of invasive species is scarce, the spread of alien seaweeds represents a particular problem. We have employed a combination of plastid microsatellite markers and DNA sequence data from three regions of the plastid genome to trace the invasive history of the green alga Codium fragile ssp. tomentosoides. Extremely low levels of genetic variation were detected, with only four haplotypes present in the species’ native range in Japan and only two of these found in introduced populations. These invasive populations displayed a high level of geographical structuring of haplotypes, with one haplotype localized in the Mediterranean and the other found in Northwest Atlantic, northern European and South Pacific populations. Consequently, we postulate that there have been at least two separate introductions of C. fragile ssp. tomentosoides from its native range in the North Pacific.
Isolation by distance and post‐glacial range expansion in the rough‐skinned newt, Taricha granulosa
Authors: KUCHTA SHAWN R. , TAN AN‐MING
Published: January 2005

Allozymes and mitochondrial DNA sequences were used to examine the phylogeographical history of the rough‐skinned newt, Taricha granulosa, in western North America. Nineteen populations were analysed for allozyme variation at 45 loci, and 23 populations were analysed for cytochrome b sequence variation. Both data sets agree that populations in the southern part of the range are characterized by isolation by distance, whereas northern populations fit the expectations of a recent range expansion. However, the northern limit of isolation by distance (and the southern limit of range expansion) is located in Oregon State by the mtDNA data, and in Washington State by the allozyme data. Nevertheless, both data sets are consistent with the known Pleistocene history of western North America, with phylogenetically basal populations in central and northern California, and a recent range expansion in the north following the retreat of the Cordilleran ice sheet 10 000 years ago. Additionally, a population in Idaho, previously considered introduced from central California based on morphometric analyses, possesses a distinct mtDNA haplotype, suggesting it could be native. The relevance of these results for Pacific Northwest biogeography is discussed.
Genetic quality and sexual selection: an integrated framework for good genes and compatible genes
Authors: NEFF BRYAN D. , PITCHER TREVOR E.
Published: January 2005

Why are females so choosy when it comes to mating? This question has puzzled and marveled evolutionary and behavioral ecologists for decades. In mating systems in which males provide direct benefits to the female or her offspring, such as food or shelter, the answer seems straightforward — females should prefer to mate with males that are able to provide more resources. The answer is less clear in other mating systems in which males provide no resources (other than sperm) to females. Theoretical models that account for the evolution of mate choice in such nonresource‐based mating systems require that females obtain a genetic benefit through increased offspring fitness from their choice. Empirical studies of nonresource‐based mating systems that are characterized by strong female choice for males with elaborate sexual traits (like the large tail of peacocks) suggest that additive genetic benefits can explain only a small percentage of the variation in fitness. Other research on genetic benefits has examined nonadditive effects as another source of genetic variation in fitness and a potential benefit to female mate choice. In this paper, we review the sexual selection literature on genetic quality to address five objectives. First, we attempt to provide an integrated framework for discussing genetic quality. We propose that the term ‘good gene’ be used exclusively to refer to additive genetic variation in fitness, ‘compatible gene’ be used to refer to nonadditive genetic variation in fitness, and ‘genetic quality’ be defined as the sum of the two effects. Second, we review empirical approaches used to calculate the effect size of genetic quality and discuss these approaches in the context of measuring benefits from good genes, compatible genes and both types of genes. Third, we discuss biological mechanisms for acquiring and promoting offspring genetic quality and categorize these into three stages during breeding: (i) precopulatory (mate choice); (ii) postcopulatory, prefertilization (sperm utilization); and (iii) postcopulatory, postfertilization (differential investment). Fourth, we present a verbal model of the effect of good genes sexual selection and compatible genes sexual selection on population genetic variation in fitness, and discuss the potential trade‐offs that might exist between mate choice for good genes and mate choice for compatible genes. Fifth, we discuss some future directions for research on genetic quality and sexual selection.
Explosive radiation of Cape VerdeConus, a marine species flock
Authors: DUDA THOMAS F. , ROLÁN EMILIO
Published: January 2005

Nearly 50 species of the marine gastropod genusConusare restricted to the Cape Verde archipelago. This unusual concentration of endemics within a single set of oceanic islands is extremely uncharacteristic of marine taxa. Here we used phylogenetic analyses of 90Conusspecies, including 30 endemics from Cape Verde, to reveal the relationships and origins of the endemic Cape VerdeConus. Results show that these species group in two distinct clades and represent a marine species flock that is restricted to a very narrowly confined geographical area. Species’ originations occurred in exceptionally limited parts of the archipelago and in some cases radiations took place solely within single islands. Finally, comparison of levels of divergence between Cape Verde endemics and otherConusspecies suggests that the radiation ofConusin Cape Verde occurred during the last few million years.
Spatial genetic structure among and within populations of Primula sieboldii growing beside separate streams
Authors: KITAMOTO N. , HONJO M. , UENO S. , TAKENAKA A. , TSUMURA Y. , WASHITANI I. , OHSAWA R.
Published: January 2005

We investigated the hierarchical genetic structure of SSR (simple sequence repeats) and cpDNA (chloroplast DNA) polymorphisms among and within populations of Primula sieboldii, a heterostylous clonal herb. Seven out of eight populations at the study site, located in a mountainous region of Nagano Prefecture, had each developed alongside a different stream, and the other occurred on a flat area 70 m from the nearest stream. The magnitude of genetic differentiation among streamside populations in maternally inherited cpDNA (Φ = 0.341) was much higher than that in biparentally inherited SSRs (Φ = 0.011). This result suggests that seed dispersal among streams was restricted, and pollen was the primary agent of gene flow among streamside populations. In contrast, genetic differentiation among subpopulations within streams were low at both markers (Φ = 0.053 for cpDNA, Φ = 0.025 for SSR). This low differentiation among subpopulations in cpDNA compared with that among streamside populations suggest that seed dispersal occur along the stream probably during flooding. This hypothesis was supported by the fact that in cpDNA haplotypes, no clear genetic structure was detected within the streamside population, while a significant genetic structure was found within 20 m in the nonstreamside population. Furthermore, within the streamside populations, two pairs of ramets with identical multilocus genotypes for eight SSR loci were distantly (> 50 m) distributed along the same streamside, suggesting dispersal of clonal propagule. Our study showed that the heterogeneity of the landscape can influence gene flow and hence spatial genetic structure.
Varying degrees of Apis mellifera ligustica introgression in protected populations of the black honeybee, Apis mellifera mellifera, in northwest Europe
Authors: JENSEN ANNETTE B. , PALMER KELLIE A. , BOOMSMA JACOBUS J. , PEDERSEN BO V.
Published: January 2005

The natural distribution of honeybee subspecies in Europe has been significantly affected by human activities during the last century. Non‐native subspecies of honeybees have been introduced and propagated, so that native black honeybee (Apis mellifera mellifera) populations lost their identity by gene‐flow or went extinct. After previous studies investigated the remaining gene‐pools of native honeybees in France and Spain, we here assess the genetic composition of eight northwest European populations of the black honeybee, using both mitochondrial (restriction fragment length polymorphisms of the intergenic transfer RNAleu‐COII region) and nuclear (11 microsatellite loci) markers. Both data sets show that A. m. mellifera populations still exist in Norway, Sweden, Denmark, England, Scotland and Ireland, but that they are threatened by gene flow from commercial honeybees. Both Bayesian admixture analysis of the microsatellite data and DraI‐RFLP (restriction fragment length polymorphism) analysis of the intergenic region indicated that gene‐flow had hardly occurred in some populations, whereas almost 10% introgression was observed in other populations. The most introgressed population was found on the Danish Island of Læsø, which is the last remaining native Danish population of A. m. mellifera and the only one of the eight investigated populations that is protected by law. We discuss how individual admixture analysis can be used to monitor the restoration of honeybee populations that suffer from unwanted hybridization with non‐native subspecies.
Nucleotide variation at the myrosinase‐encoding locus, TGG1, and quantitative myrosinase enzyme activity variation in Arabidopsis thaliana
Authors: STRANGER BARBARA E. , MITCHELL‐OLDS THOMAS
Published: January 2005

The Arabidopsis thaliana TGG1 gene encodes thioglucoside glucohydrolase (myrosinase), an enzyme catalysing the hydrolysis of glucosinolate compounds. The enzyme is involved in plant defence against some insect herbivores, and is present in species of the order Capparales (Brassicales). Nucleotide variation was surveyed by sequencing c. 2.4 kb of the TGG1 locus in a sample of 28 worldwide A. thaliana accessions, and one Arabidopsis lyrata ssp. lyrata individual. Myrosinase activity was quantified for 27 of these same A. thaliana accessions, plus five additional others. Overall, estimated nucleotide diversity in A. thaliana was low compared to other published A. thaliana surveys, and the frequency distribution was skewed toward an excess of low‐frequency variants. Furthermore, comparison to the outgroup species A. lyrata demonstrated that A. thaliana exhibited an excess of high‐frequency derived variants relative to a neutral equilibrium model, suggesting a selective sweep. A. thaliana accessions differed significantly in total myrosinase activity, but analysis of variance detected no statistical evidence for an association between quantitative enzyme activity and alleles at the TGG1 myrosinase‐encoding locus. We thus conclude that other, unsurveyed factors primarily affect the observed myrosinase activity levels in this species. The pattern of nucleotide variation was consistent with a model of positive selection but might also be compatible with a completely neutral model that takes into account the metapopulation behaviour of this highly inbreeding species which experienced a relatively recent worldwide expansion.
Accounting for coalescent stochasticity in testing phylogeographical hypotheses: modelling Pleistocene population structure in the Idaho giant salamanderDicamptodon aterrimus
Authors: CARSTENS B. C. , DEGENHARDT J. D. , STEVENSON A. L. , SULLIVAN J.
Published: January 2005

Several theoretical studies have demonstrated the importance of accounting for coalescent stochasticity in phylogeographical studies, however, there are few empirical examples that do so in the context of explicit hypothesis testing. Here, we provide an example from the Idaho giant salamander (Dicamptodon aterrimus) using 118 mtDNA sequences, nearly 2 kb in length. This species is endemic to mesic forests in northern and central Idaho, and several a priori hypotheses have been erected based both on palaeoclimatic grounds and from phylogeographical studies of codistributed amphibians. Phylogenetic analysis of theD. aterrimusdata suggests an expansion from a single refugium south of the Salmon River, whereas the inference from nested clade analysis is one of expansion from a single refugium in the Clearwater drainage. Explicit testing of these hypotheses, using geographically structured coalescent simulations to erect null distributions, indicates we can reject expansion from the Clearwater drainage (pCLW = 0.089), but not expansion from the South Fork of the Salmon drainage (pSAL = 0.329). Furthermore, data from codistributed amphibians suggest that there may have been two refugia, and anamovashows that most of the molecular variance partitioned between the Clearwater and the Salmon drainages (54.40%;P < 0.001) and within drainages (43.61%;P < 0.001). As a result, we also tested three a priori hypotheses which predicted that both the Clearwater and Salmon drainages functioned as refugia during the late Pleistocene; we could reject (PCORD = 0.019) divergence dates during the Cordilleran glacial maxima [c.20 000 years before present (ybp)], during the Sangamon interglacial (c.35 000 ybp;pSANG = 0.032), as well as pre‐Pleistocene divergence (c.1.7 Ma;ppP < 0.001). Mismatch distributions and Tajima'sDwithin the individual drainages provide further support to recent population expansion. This work demonstrates coalescent stochasticity is an important phenomenon to consider in testing phylogeographical hypotheses, and suggests that analytical methods which fail to sufficiently quantify this uncertainty can lead to false confidence in the conclusions drawn from these methods.
Gastrointestinal infectious disease complications following transplantation and their differentiation from immunosuppressant‐induced gastrointestinal toxicities
Authors: Rubin Robert H
Published: January 2005

Abstract It is often very difficult to distinguish between infection‐related and immunosuppression‐related gastrointestinal (GI) complications after transplantation. The risk of infection itself is determined by the patient's net state of immunosuppression as well as the presence of anatomic or technical abnormalities and the patient's epidemiological exposures. Of the anatomic abnormalities, diverticulitis is a particular problem in transplant patients, with a high rate of perforation and abscess formation. The causes of infectious disease syndromes are very different immediately after, early after, and late after transplantation. Infection during the first month may result from a pre‐existing infection in the donor or recipient, or from the surgical wound, endotracheal tube, vascular access or drainage. During 1–6 months after transplantation, viruses attack and, with sustained immunosuppression, make opportunistic infections possible. Beyond 6 months after transplantation, the 80% of patients with good result from the transplant are at risk primarily for community‐acquired microbes, including such enteric pathogens as Salmonella. Of the remaining patients, 10% have chronic viral infections and the 10% who have poor allograft function are at greatest risk for opportunistic infection. This time line is helpful in determining whether a GI complication is likely to be related to infection rather than a specific effect of an immunosuppressant drug. Fever, inflammatory cells in the stool, abnormalities on endoscopy or computed tomography and leukocytosis can be useful in the diagnosis but are inconsistent markers for an infectious cause.
Immunosuppressive therapy and post‐transplantation diarrhea
Authors: Pescovitz Mark D , Navarro Mercidita T
Published: January 2005

Abstract Gastrointestinal complications, including diarrhea, are among the anticipated adverse events secondary to immunosuppression. The reported overall rate of diarrhea may be affected by drug‐specific effects, dose—response effects, interactions with other medications, drug formulation, the length of study follow‐up, reporting bias and population characteristics such as ethnicity and baseline disease, including transplant organ type. The true incidence of diarrhea is often difficult to assess from the numerous published clinical trials. A number of deficiencies, including self‐reporting, interstudy comparisons, lack of blinding, concomitant medications and a general lack of standardization and quantification of diarrhea may greatly obscure comparisons among the different immunosuppressive medications. This review considers each of these factors in assessing the overall incidence of post‐transplantation diarrhea for the various immunosuppressive medications currently in use.
Ultrasonic C‐Scan Imaging of Post‐Tensioned Concrete Bridge Structures for Detection of Corrosion and Voids
Authors: Iyer Shivprakash R. , Sinha Sunil K. , Schokker Andrea J.
Published: January 2005

Abstract:  Corrosion of the nation's transportation infrastructure is a widespread and costly problem. Efficiency, durability, safety, and environmental concerns have made the inspection and structural assessment of these structures a vital issue. The current state of the art in concrete bridge condition evaluation relies on visual inspection. However, deterioration in pre‐stressing/post‐tensioned strand or tendon condition is not always reflected by distress visible on the concrete surface. Further, the effect of deterioration of pre‐stressing/post‐tensioned steel is more disruptive than that of mild reinforcement. Strand, due to its high mechanical strength and metallurgical characteristics, is smaller in cross section than conventional reinforcing steel and is proportionally more impaired by loss of section. Methodology for pre‐stressed concrete bridge condition evaluation, therefore, could be revolutionized through the development of accurate, quantitative nondestructive test methods for strand in pre‐tensioned and post‐tensioned structures. This article presents a new sensing method using ultrasound C‐scan imaging for structural health monitoring of post‐tensioned bridges. Preliminary results from tests are presented that show promising potential for the detection of corrosion and voids in concrete post‐tensioned bridges.
Influence of Stabilizing Cables on Seismic Response of a Multispan Cable‐Stayed Bridge
Authors: Ni Y. Q. , Wang J. Y. , Lo L. C.
Published: January 2005

Abstract:  A recent trend in the design of long‐span bridges is multispan cable‐stayed bridges with three or more towers. A critical problem of multispan cable‐stayed bridges is the stabilization of the central tower(s), which has resulted in increasing application of stabilizing cables. The Ting Kau Bridge in Hong Kong is one of a few multispan cable‐stayed bridges adopting stabilizing cables ever built. In this article, the dynamic properties of multispan cable‐stayed bridges with stabilizing cables and the effect of stabilizing cables on bridge seismic response are studied by referring to the Ting Kau Bridge. Based on a validated 3D finite‐element model, modal analysis is conducted which shows that the longitudinal stabilizing cables bring about a number of global modes with strong modal interaction among the deck, towers, and cables. The seismic response and internal force in the central tower are found to be much larger than those in the side towers. The longitudinal stabilizing cables are very effective in reducing the internal force in the central tower generated by longitudinal earthquake excitation, but insignificantly affect the seismic response in the bridge deck and side towers. As a whole, the stabilizing cables act favorably in the reduction of seismic response of the bridge.
The Third Sex: Women Leaders in Australian Agriculture
Authors: Pini Barbara
Published: January 2005

This article uses data from interviews with 20 women involved in decision‐making positions in Australian farm organizations to explore the ways in which women actively create a subject position which locates them as both ‘agricultural leader’ and ‘woman’. This is a subject position one participant describes as ‘a third sex’. In negotiating their outsider status, the participants describe being engaged in a constant process of self‐monitoring and movement between and across different discourses of managerial masculinity and normative femininity. They describe no such difficult identity work being undertaken by the male leaders with whom they work. Based on a range of gender comparisons, the article concludes that women's entry to positions of agricultural leadership does not necessarily suggest that a more inclusive or equitable Australian farming sector is emerging.
Body and Management Pedagogy
Authors: Sinclair Amanda
Published: January 2005

In this article I explore the impact of bodies in management education — why they have been ignored and what possibilities may be created when we understand them better. Bodies — including gestures, stature, posture and voice — shape and constrain how teachers and students act, what they think and what is taken away. The bodies of male and female teachers and students occupy different spaces and carry contrasting significations, resulting in different repertoires of embodied and disembodied pedagogical styles. Drawing on feminist scholarship, organizational research and my own bodily experiences and observations in management teaching, and despite the myth of disembodiment in rational classrooms, I suggest management pedagogy increasingly assumes and celebrates particular bodily performances. Rather than lament the constriction of stereotypical body regimes, I argue that making bodies more visible in management pedagogy has liberating possibilities for teachers and students and their learning.
Using self‐report to identify the broad phenotype in parents of children with autistic spectrum disorders: a study using the Autism‐Spectrum Quotient
Authors: Bishop Dorothy V.M. , Maybery Murray , Maley Alana , Wong Dana , Hill Wayne , Hallmayer Joachim
Published: January 2005

Background:  The concept of the ‘broad phenotype’ of autism refers to the finding that relatives of people with autism often have mild forms of autistic‐like characteristics, such as social and communicative difficulties. This study used the Autism Spectrum Quotient (AQ), a questionnaire devised to assess features of the broad phenotype in adults, with parents of people with autism, to see whether they would be more likely to obtain extreme scores than a control group.

Methods:  The AQ was administered to parents of 69 people with an autism spectrum disorder and parents of 52 controls.

Results:  On two of the five subscales of the AQ, social skills and communication, parents of people with autism obtained higher scores than control parents. The other three scales, attention to detail, attention switching, and imagination, did not differentiate groups. The correlation between social skills and communication scales was .663. The scales can be combined to give an index of broad phenotype.

Conclusions:  The AQ appears to be sensitive to the broad phenotype, provided attention is restricted to the social skills and communication scales.
Can the Children's Communication Checklist differentiate between children with autism, children with ADHD, and normal controls?
Authors: Geurts Hilde M. , Verté Sylvie , Oosterlaan Jaap , Roeyers Herbert , Hartman Catharina A. , Mulder Erik J. , van Berckelaer‐Onnes Ina A. , Sergeant Joseph A.
Published: January 2005

Background:  The Children's Communication Checklist (CCC; Bishop, 1998) is a questionnaire that was developed to measure pragmatic language use and may be completed by parents and teachers. Two studies are reported, which were designed to investigate: (1) whether children with Attention Deficit Hyperactivity Disorder (ADHD) encounter pragmatic language problems in comparison with normal controls (NC), (2) whether children with ADHD and children with High Functioning Autism (HFA) can be differentiated using the CCC, (3) the usefulness of the CCC for parents and teachers in a clinical and in a research setting, and (4) the role of age in pragmatic language use in ADHD and HFA.

Method:  In the first study (clinical sample) 50 children with ADHD, 50 children with HFA, and 50 NC were compared to each other using the CCC. In the second study (research sample) CCC data was gathered on 23 children with ADHD (without co‐morbid disorders), 42 children with HFA, and 35 NC.

Results:  Compared to NC, children with HFA showed pragmatic deficits on all CCC scales. Children with ADHD demonstrated deficits compared to NC as well. Moreover, the ADHD and HFA groups differed from each other on most of the scales. Discriminant analyses showed that CCC scales were relevant for case identification in these samples. Furthermore, profiles of impairment seen in children with HFA and ADHD did not vary with age.

Conclusion:  Pragmatic difficulties do occur in both HFA and ADHD. The present studies indicate that the CCC is a useful instrument to obtain information concerning pragmatic language use in both a clinical and a research setting. Although the information of parents is more tightly linked to the diagnosis, combining the information of both parent and teacher slightly improves case identification.
Behavioral and emotional adjustment, family functioning, academic performance, and social relationships in children with selective mutism
Authors: Cunningham Charles E. , McHolm Angela , Boyle Michael H. , Patel Sejal
Published: January 2005

This study addressed four questions which parents of children with selective mutism (SM) frequently ask: (1) Is SM associated with anxiety or oppositional behavior? (2) Is SM associated with parenting and family dysfunction? (3) Will my child fail at school? and (4) Will my child make friends or be teased and bullied? In comparison to a sample of 52 community controls, 52 children with SM were more anxious, obsessive, and prone to somatic complaints. In contrast, children with SM were less oppositional and evidenced fewer attentional difficulties at school. We found no group differences in family structure, economic resources, family functioning, maternal mood difficulties, recreational activities, or social networks. While parents reported no differences in parenting strategies, children with SM were described as less cooperative in disciplinary situations. The academic (e.g., reading and math) and classroom cooperative skills of children with SM did not differ from controls. Parents and teachers reported that children with SM had significant deficits in social skills. Though teachers and parents rated children with SM as less socially assertive, neither teachers nor parents reported that children with SM were victimized more frequently by peers.
Time trends in adolescent mental health
Authors: Collishaw Stephan , Maughan Barbara , Goodman Robert , Pickles Andrew
Published: January 2005

Background: Existing evidence points to a substantial rise in psychosocial disorders affecting young people over the past 50 years (Rutter & Smith, 1995). However, there are major methodological challenges in providing conclusive answers about secular changes in disorder. Comparisons of rates of disorder at different time points are often affected by changes in diagnostic criteria, differences in assessment methods, and changes in official reporting practices. Few studies have examined this issue using the same instruments at each time point.

Methods: The current study assessed the extent to which conduct, hyperactive and emotional problems have become more common over a 25‐year period in three general population samples of UK adolescents. The samples used in this study were the adolescent sweeps of the National Child Development Study and the 1970 Birth Cohort Study, and the 1999 British Child and Adolescent Mental Health Survey. Comparable questionnaires were completed by parents of 15–16‐year‐olds at each time point (1974, 1986, and 1999).

Results and conclusions: Results showed a substantial increase in adolescent conduct problems over the 25‐year study period that has affected males and females, all social classes and all family types. There was also evidence for a recent rise in emotional problems, but mixed evidence in relation to rates of hyperactive behaviour. Further analyses using longitudinal data from the first two cohorts showed that long‐term outcomes for adolescents with conduct problems were closely similar. This provided evidence that observed trends were unaffected by possible changes in reporting thresholds.
The European Union after 9/11: The Demise of a Liberal Democratic Asylum Regime?
Authors: Levy Carl
Published: January 2005

This article examines the domestic and international pressures since 11 September 2001 on the liberal democratic asylum regime practised within the European Union. It looks at three areas of confrontation. The pressures exerted upon national governments by anti-immigrant and anti-asylum seeker/refugee far right populist parties. It examines the attempts by the European Union and its member states to arrive at a Common European Asylum System in light of policy developments over the past 20 years, and places these long-standing processes within the events of 11 September 2001. It discusses whether or not the liberal democratic tradition of asylum embodied in the Geneva Convention of 1951 been sacrificed to the dual pressures of the electoral victories of the far right in Europe and a new form of terrorism that threatens European societies.
Can Presidentialism Work Like Parliamentarism?
Authors: Colomer Josep M. , Negretto Gabriel L.
Published: January 2005

Inter-institutional cooperation between the congress and the presidency may be the best way to promote good governance in a regime of separation of powers. In order to evaluate the performance of different political institutions, especially the different frameworks associated with ‘presidentialism’ and ‘parliamentarism’, we adopt the criterion that policy outcomes coinciding with the median voter's preference can produce the highest satisfaction or social utility. From this perspective, proportional representation in congress can be very appropriate since it tends to establish a close correspondence between the median party's and the median voter's preferences. Likewise, cooperation – rather than conflict or mutual checks – between the median party in congress and the presidency for both legislative decisions and cabinet formation can favour socially efficient outcomes. A survey of some recent institutional reforms in democratic presidential regimes in Latin America shows that ‘parliamentarization’ of presidentialism is gaining acceptance, although intermediate formulae may be more conflictual than a global, more coherent institutional reform.
Modulation of gastro‐oesophageal vagal afferents by galanin in mouse and ferret
Authors: Page Amanda J. , Slattery James A. , O'Donnell Tracey A. , Cooper Nicole J. , Young Richard L. , Blackshaw L. Ashley
Published: January 2005

The neuropeptide galanin is found in the central and peripheral nervous systems. It may have excitatory or inhibitory actions via three subtypes of G‐protein‐coupled receptor, and it modulates the mechanosensitivity of somatic sensory fibres. We aimed to determine if galanin also modulates vagal afferent mechanosensitivity, and to localize endogenous sources. The responses of ferret and mouse gastro‐oesophageal vagal afferents to graded mechanical stimuli were investigated in vitro. The effects of galanin and/or the galanin receptor antagonist galantide on these responses were quantified. Immunohistochemistry for galanin was performed in ferret and mouse proximal stomach and nodose ganglion. In ferrets, retrograde labelling of gastric afferents to the nodose ganglion was combined with immunohistochemistry. When exposed to galanin (1–10 nm), 18/31 ferret and 12/15 mouse gastro‐oesophageal afferents (tension, mucosal and tension/mucosal receptors) showed inhibition of mechanosensitivity. Four of 31 ferret afferents showed potentiation of mechanosensitivity, and 9/31 were unaffected (2/15 and 1/15 in mouse, respectively). Galanin effects were reversed after washout or by galantide (10–30 nm). Galantide given alone increased mechanosensitivity. Galanin immunoreactivity was found in nodose neurones, including those innervating the stomach in ferret. Enteric neurones were also galanin immunoreactive, as were endings associated with myenteric ganglia and smooth muscle. We conclude that galanin potently modulates mechanosensitivity of gastro‐oesophageal vagal afferents with either facilitatory or inhibitory actions on individual afferent fibres. Both intrinsic and extrinsic (vagal) neurones contain galanin and are therefore potential sources of endogenous galanin.
Elementary purinergic Ca2+ transients evoked by nerve stimulation in rat urinary bladder smooth muscle
Authors: Heppner Thomas J. , Bonev Adrian D. , Nelson Mark T.
Published: January 2005

The translation of nerve transmission to Ca2+ signals in urinary bladder smooth muscle (UBSM) is incompletely understood. Thus, we sought to characterize Ca2+ signals in strips of UBSM loaded with the Ca2+‐sensitive fluorescent dye, fluo‐4, using laser scanning confocal microscopy. Two types of Ca2+ signals occurred spontaneously and could be evoked with field stimulation: large, rapid, global Ca2+ transients termed ‘global Ca2+ flashes’, and much smaller, localized Ca2+ transients. Global Ca2+ flashes were inhibited by the L‐type voltage‐dependent Ca2+ channel (VDCC) inhibitor, diltiazem and with P2X receptor blockade. Simultaneous intracellular recordings and Ca2+ measurements indicated that these events are caused by Ca2+ influx through VDCCs during action potentials. Small, local Ca2+ transients occurred spontaneously, and their frequency could be elevated with field stimulation. Atropine, an inhibitor of muscarinic receptors, did not affect these local Ca2+ transients. However, the desensitizing P2X receptor agonist α,β‐methylene ATP, and the purinergic antagonist, suramin, effectively inhibited the local Ca2+ transients. The frequency of these ‘purinergic Ca2+ transients’ was increased about 7‐fold by a 10 s stimulus train (1 Hz). The amplitude, duration at one‐half amplitude and the spatial spread of the evoked purinergic Ca2+ transients were F/Fo= 2.4 ± 0.13, 111.7 ± 9.3 ms and 14.0 ± 1.0 μm2, respectively. Tetrodotoxin inhibited evoked purinergic Ca2+ transients, indicating that they were dependent on nerve fibre activation. Purinergic Ca2+ transients were not dependent on VDCC activity. Neither 2‐APB, an inhibitor of inositol 1,4,5‐triphosphate (Ins(1,4,5)P3) (IP3)‐induced Ca2+ release, nor ryanodine inhibited the purinergic Ca2+ transients. We have identified two novel Ca2+ signals in rat UBSM. Large, rapid, global Ca2+ flashes that represent Ca2+ influx through VDCCs during action potentials, and local, purinergic Ca2+ transients that represent Ca2+ entry through P2X receptors. Our results indicate that purinergic Ca2+ transients evoked by release of ATP from nerve varicosities are elementary signals in the process of nerve‐smooth muscle communication.
GABAergic activation of an inwardly rectifying K+ current in mouse cerebellar Purkinje cells
Authors: Tabata Toshihide , Haruki Shigeki , Nakayama Hisako , Kano Masanobu
Published: January 2005

Cerebellar Purkinje cells integrate motor information conveyed by excitatory synaptic inputs from parallel and climbing fibres. Purkinje cells abundantly express B‐type G‐protein‐coupled γ‐aminobutyric acid receptors (GABABR) that are assumed to mediate major responses, including postsynaptic modulation of the synaptic inputs. However, the identity and function of effectors operated by GABABR are not fully elucidated. Here we characterized an inwardly rectifying current activated by baclofen (Ibacl), a GABABR agonist, in cultured mouse Purkinje cells using a ruptured‐patch whole‐cell technique. Ibacl is operated by GABABR via Gi/o‐proteins, as it is not inducible in pertussis‐toxin‐pretreated cells. Ibacl is carried by K+ because its reversal potential shifts with the equilibrium potential of K+. Ibacl is blocked by 10−3m Ba2+ or Cs+, and 10−8m tertiapin‐Q. Upon the onset and offset of a hyperpolarizing step, Ibacl is activated and deactivated, respectively, with double‐exponential time courses (time constants, <1 ms and 30–80 ms). Based on similarities in the above properties, G‐protein‐coupled inwardly rectifying K+ (GIRK) channels are thought to be responsible for Ibacl. Perforated‐patch recordings from cultured Purkinje cells demonstrate that Ibacl hyperpolarizes the resting potential and the peak level achieved by glutamate‐evoked potentials initiated in the dendrites. Moreover, cell‐attached recordings from Purkinje cells in cerebellar slices demonstrate that Ibacl impedes spontaneous firing. Therefore, Ibacl may reduce the postsynaptic and intrinsic excitability of Purkinje cells under physiological conditions. These findings give a new insight into the role of GABABR signalling in cerebellar information processing.
Requirement of Voltage-Gated Calcium Channel β
4
Subunit for T Lymphocyte Functions
Authors: Badou Abdallah , Basavappa Srisaila , Desai Rooma , Peng You-Qing , Matza Didi , Mehal Wajahat Z. , Kaczmarek Leonard K. , Boulpaep Emile L. , Flavell Richard A.
Published: January 2005

Calcium is known to play vital roles in diverse physiological processes, and it is known that voltage-gated calcium channels (Ca
v
) mediate calcium influx in excitable cells. However, no consensus exists on the molecular identity of the calcium channels present in nonexcitable cells such as T lymphocytes. Here, we demonstrate that T lymphocytes express both regulatory β
4
and poreforming Ca
v
1 α
1
subunits of Ca
v
channels. Ca
v
β
4
-mutant T lymphocytes fail to acquire normal functions and display impairment in the calcium response, activation of the transcription factor NFAT, and cytokine production. Although Ca
v
1 channels of lymphocytes retain their voltage dependency, T cell receptor stimulation dramatically increases channel opening, providing a new mechanism for calcium entry in lymphocytes.
The Centromeric Protein Sgo1 Is Required to Sense Lack of Tension on Mitotic Chromosomes
Authors: Indjeian Vahan B. , Stern Bodo M. , Murray Andrew W.
Published: January 2005

Chromosome alignment on the mitotic spindle is monitored by the spindle checkpoint. We identify Sgo1, a protein involved in meiotic chromosome cohesion, as a spindle checkpoint component. Budding yeast cells with mutations in
SGO1
respond normally to microtubule depolymerization but not to lack of tension at the kinetochore, and they have difficulty attaching sister chromatids to opposite poles of the spindle. Sgo1 is thus required for sensing tension between sister chromatids during mitosis, and its degradation when they separate may prevent cell cycle arrest and chromosome loss in anaphase, a time when sister chromatids are no longer under tension.
A Comprehensive Survey of the
Plasmodium
Life Cycle by Genomic, Transcriptomic, and Proteomic Analyses
Authors: Hall Neil , Karras Marianna , Raine J. Dale , Carlton Jane M. , Kooij Taco W. A. , Berriman Matthew , Florens Laurence , Janssen Christoph S. , Pain Arnab , Christophides Georges K. , James Keith , Rutherford Kim , Harris Barbara , Harris David , Churcher Carol , Quail Michael A. , Ormond Doug , Doggett Jon , Trueman Holly E. , Mendoza Jacqui , Bidwell Shelby L. , Rajandream Marie-Adele , Carucci Daniel J. , Yates John R. , Kafatos Fotis C. , Janse Chris J. , Barrell Bart , Turner C. Michael R. , Waters Andrew P. , Sinden Robert E.
Published: January 2005

Plasmodium berghei
and
Plasmodium chabaudi
are widely used model malaria species. Comparison of their genomes, integrated with proteomic and microarray data, with the genomes of
Plasmodium falciparum
and
Plasmodium yoelii
revealed a conserved core of 4500
Plasmodium
genes in the central regions of the 14 chromosomes and highlighted genes evolving rapidly because of stage-specific selective pressures. Four strategies for gene expression are apparent during the parasites' life cycle: (i) housekeeping; (ii) host-related; (iii) strategy-specific related to invasion, asexual replication, and sexual development; and (iv) stage-specific. We observed posttranscriptional gene silencing through translational repression of messenger RNA during sexual development, and a 47-base 3′ untranslated region motif is implicated in this process.
Gigantic Photoresponse in ¼-Filled-Band Organic Salt (EDO-TTF)
2
PF
6
Authors: Chollet Matthieu , Guerin Laurent , Uchida Naoki , Fukaya Souichi , Shimoda Hiroaki , Ishikawa Tadahiko , Matsuda Kazunari , Hasegawa Takumi , Ota Akira , Yamochi Hideki , Saito Gunzi , Tazaki Ryoko , Adachi Shin-ichi , Koshihara Shin-ya
Published: January 2005

We report that the organic salt (EDO-TTF)
2
PF
6
with ¾-filled-band (¼-filled in terms of holes), which forms an organic metal with strong electron and lattice correlation, shows a highly sensitive response to photoexcitation. An ultrafast, photoinduced phase transition from the insulator phase to the metal phase can be induced with very weak excitation intensity at near room temperature. This response makes the material attractive for applications in switching devices with room-temperature operation. The observed photo-induced spectroscopic change shows that this photoinduced phase transition process is caused by the cooperative melting of charge ordering assisted by coherent phonon generation.
Coral
230
Th Dating of the Imposition of a Ritual Control Hierarchy in Precontact Hawaii
Authors: Kirch Patrick V. , Sharp Warren D.
Published: January 2005

In proto-historic Hawaii (1500–1795 A.D.), as in many other evolving polities, temples functioned as centers for control over production and the extraction of surplus food and goods. Thorium-230 dates (uncertainty ± ∼10 years) on branch coral dedicatory offerings from temples in the Kahikinui district (Maui) indicate that its temple system was constructed within 60 years, far more rapidly than indicated by radiocarbon dating. Introduction of the temple system in 1580–1640 A.D. coincided with predatory expansion and consolidation of the Maui polity to form an incipient archaic state.
Nutrient-Specific Foraging in Invertebrate Predators
Authors: Mayntz David , Raubenheimer David , Salomon Mor , Toft Søren , Simpson Stephen J.
Published: January 2005

Many herbivores and omnivores adjust their food selection behavior to regulate the intake of multiple nutrients. Carnivores, however, are generally assumed to optimize the rate of prey capture rather than select prey according to nutrient composition. We showed experimentally that invertebrate predators can forage selectively for protein and lipids to redress specific nutritional imbalances. This selection can take place at different stages of prey handling: The predator may select among foods of different nutritional composition, eat more of a prey if it is rich in nutrients that the predator is deficient in, or extract specific nutrients from a single prey item.
Liquid Crystalline Networks Composed of Pentagonal, Square, and Triangular Cylinders
Authors: Chen Bin , Zeng Xiangbing , Baumeister Ute , Ungar Goran , Tschierske Carsten
Published: January 2005

T-shaped molecules are designed in such a way that they self-organize into nanoscale liquid crystalline honeycombs based on polygons with any chosen number of sides. One of the phases reported here is a periodic organization of identical pentagonal cylinders; the other one is a structure composed of square-shaped and triangular cylinders in the ratio 2:1. These two different packing motifs represent duals of the same topological class. The generalization of the concept applied here allows the prediction of a whole range of unusual complex liquid crystalline phases.