bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geographic structure, genetic diversity and source tracking of Spartina alterniflora
Authors: Blum Michael J. , Jun Bando K. , Katz M. , Strong Donald R. 
Published: August 2007

AbstractAim  To examine the distribution and structure of genetic variation among native Spartina alterniflora and to characterize the evolutionary mechanisms underlying the success of non‐native S. alterniflora.Location  Intertidal marshes along the Atlantic, Gulf and Pacific coasts of North America.Methods  amova, parsimony analysis, haplotype networks of chloroplast DNA (cpDNA) sequences, neighbour‐joining analysis, Bayesian analysis of population structure, and individual assignment testing were used.Results  Low levels of gene flow and geographic patterns of genetic variation were found among native S. alterniflora from the Atlantic and Gulf coasts of North America. The distribution of cpDNA haplotypes indicates that Atlantic coast S. alterniflora are subdivided into ‘northern’ and ‘southern’ groups. Variation observed at microsatellite loci further suggests that mid‐Atlantic S. alterniflora are differentiated from S. alterniflora found in southern Atlantic and New England coastal marshes. Comparisons between native populations on the Atlantic and Gulf coasts and non‐native Pacific coast populations substantiate prior studies demonstrating reciprocal interspecific hybridization in San Francisco Bay. Our results corroborate historical evidence that S. alterniflora was introduced into Willapa Bay from multiple source populations. However, we found that some Willapa Bay S. alterniflora are genetically divergent from putative sources, probably as a result of admixture following secondary contact among previously allopatric native populations. We further recovered evidence in support of models suggesting that S. alterniflora has secondarily spread within Washington State, from Willapa Bay to Grays Harbor.Main conclusions  Underlying genetic structure has often been cited as a factor contributing to ecological variation of native S. alterniflora. Patterns of genetic structure within native S. alterniflora may be the result of environmental differences among biogeographical provinces, of migration barriers, or of responses to historical conditions. Interactions among these factors, rather than one single factor, may best explain the distribution of genetic variation among native S. alterniflora. Comprehensive genetic comparisons of native and introduced populations can illustrate how biological invasions may result from dramatically different underlying factors – some of which might otherwise go unrecognized. Demonstrating that invasions can result from several independent or interacting mechanisms is important for improving risk assessment and future forecasting. Further research on S. alterniflora not only may clarify what forces structure native populations, but also may improve the management of non‐native populations by enabling post‐introduction genetic changes and the rapid evolution of life‐history traits to be more successfully exploited.
Guild composition and mustelid morphology – character displacement but no character release
Authors: Meiri Shai , Dayan Tamar , Simberloff Daniel 
Published: August 2007

AbstractAim Competition is hypothesized to lead to the evolution of reduced morphological overlap between competitors. Within guilds, this is believed to lead to overdispersed size ratios of the trophic apparatus of adjacent‐sized species. In allopatry, conditions are believed to favour character release. We examined whether character displacement is prevalent in mainland musteline guilds and sought evidence for character release in adjacent island guilds.Location Holarctic, from Japan through western Europe to Pacific North America.Methods We measured skulls and canines of members of the mustelid subfamily Mustelinae and examined whether size ratios tend towards equality. We then examined whether insular guilds are characterized by larger size ratios and a higher degree of sexual size dimorphism than mainland guilds, and whether this reflects evolution towards the size of missing guild members.Results We found equal ratios between skull lengths but not canine diameters in all mainland guilds. Few insular guilds showed equal ratios for either trait. There was scant evidence for character release: insular mustelines do not evolve towards the size of a missing guild member, nor is sexual size dimorphism greater on islands. There was no evidence for a lower limit on the size similarity of co‐existing mustelids.Main conclusions We propose that different guild compositions in different localities produce different evolutionary trajectories. Similar sizes on islands and mainlands can be explained by similar prey sizes in both settings. Morphological evidence suggests that competition is probably not a ubiquitous force in the assembly and evolution of musteline guilds.
Ecogeographical rules: elements of a synthesis
Authors: Gaston Kevin J. , Chown Steven L. , Evans Karl L. 
Published: August 2007

AbstractThe development of a more synthetic approach to understanding spatial patterns in biogeography, particularly of the way in which these patterns interact, constitutes a major challenge for the field. Here we propose some key elements of such a synthesis for what can broadly be termed ‘ecogeographical rules’, that is spatial patterns in biological traits. These include understanding: (1) the different kinds of patterns (intraspecific, interspecific and assemblage), and the distinctions between them; (2) the unifying role that geographical ranges play in linking the patterns together; (3) that this unification can be obscured by the methodological assumptions made in documenting some patterns (e.g. assuming that intraspecific variation does not significantly influence interspecific and assemblage patterns in traits); (4) the implications of other methodological issues for the nature of observed patterns (e.g. how ranges are located on positional or environmental axes for interspecific patterns); (5) the need for further development of models linking different types of traits; (6) the nature of the generality of documented patterns at all levels, and particularly the difference between the frequency with which patterns are documented in the literature and the variety of extant species; and (7) the constraints that the form of intraspecific patterns place on interspecific and assemblage patterns, and that interspecific patterns place on assemblage patterns.
Siblings of individuals with autism or Down syndrome: effects on adult lives
Authors: Orsmond G. I. , Seltzer M. M. 
Published: August 2007

AbstractBackground  In this study, we examine instrumental and affective involvement in the sibling relationship for adults who have a brother or sister with an autism spectrum disorder (ASD) or Down syndrome (DS). We ask three research questions: (1) How do adult siblings of individuals with ASD differ from siblings of individuals with DS in their assessment of the quality of the sibling relationship and their experience of growing up with a brother or sister with a disability? (2) Are there gender effects on the sibling relationship and sibling experience in these two groups? (3) Which factors are predictive of variation in the sibling relationship for siblings of adults with ASD or DS?Methods  Data from 154 siblings who participated in two linked longitudinal studies were used. Seventy‐seven siblings with a brother or sister with ASD were matched by age and gender to 77 siblings with a brother or sister with DS. The siblings in each group were between 21 and 56 years of age and over half were sisters. Siblings completed questionnaires on instrumental and affective involvement with their brother or sister with ASD or DS, the impact of growing up with a brother or sister with a disability on their lives, and their coping skills and feelings of pessimism.Results  Compared with the siblings of adults with DS, siblings of adults with ASD had less contact with their brother or sister, reported lower levels of positive affect in the relationship, felt more pessimistic about their brother or sister's future, and were more likely to report that their relationships with their parents had been affected. For siblings of adults with ASD, a closer sibling relationship was observed when the sibling had lower educational levels, lived closer to the brother or sister with ASD, used more problem‐focused coping strategies, and when his or her brother or sister with ASD had higher levels of functional independence. In contrast, for siblings of adults with DS, a closer sibling relationship was observed when the sibling did not have children, had lower levels of education, lived closer to the brother or sister with DS, when he or she used more problem‐focused coping, was less pessimistic about the brother or sister's future, and when his or her life had been impacted to a greater extent by growing up with a brother or sister with DS.Conclusions  We discuss the implications of these findings for future caregiving roles for siblings. Siblings of individuals with ASD may face difficulty when their parents are no longer able to be the primary caregivers for their brother or sister with ASD, as they tend to have less emotional closeness and are more pessimistic about their brother or sister's future than siblings of individuals with DS. Moreover, in both groups, a closer sibling relationship was observed when the sibling used more problem‐focused coping strategies, which may have implications for intervention.
Infant attentional behaviours as prognostic indicators in Cornelia‐de‐Lange syndrome
Authors: Sarimski K. 
Published: August 2007

AbstractBackground  Cornelia‐de‐Lange syndrome is a rare congenital syndrome with poor social relatedness as one of several characteristics of its behavioural phenotype.Methods  Video observations were collected from seven children in their first year of life and again with age 2–4 years. Data were analysed for distribution of object‐related and social attention and for relationships between early and later observations.Results  The findings suggest some inter‐individual stability for social relatedness.Conclusions  Low frequency of eye‐contact in early interaction may serve as a risk factor. Intensive early interaction is recommended in early stimulation programmes.
Interviewing alleged victims with intellectual disabilities
Authors: Cederborg A.‐C. , Lamb M. 
Published: August 2007

AbstractBackground  When interviewing alleged victims of crime, it is important to obtain reports that are as accurate and complete as possible. This can be especially difficult when the alleged victims have intellectual disabilities (ID). This study explored how alleged victims with ID are interviewed by police officers in Sweden and how this may affect their ability to report information as accurately as possible.Methods  Twelve interviews with 11 alleged victims were selected from a larger sample. The complainants were interviewed when their chronological ages ranged from 6.1 to 22 years. A quantitative analysis examined the type of questions asked and the numbers of words and details they elicited in response.Results  Instead of open‐ended questions, the interviewers relied heavily on focused questions, which are more likely to elicit inaccurate information. When given the opportunity, the witnesses were able to answer directive questions informatively.Conclusions  Interviewers need special skills in order to interview alleged victims who have ID. In addition to using more open‐ended questions, interviewers should speak in shorter sentences.
The behavioural phenotype of Cornelia de Lange Syndrome: a study of 56 individuals
Authors: Basile E. , Villa L. , Selicorni A. , Molteni M. 
Published: August 2007

AbstractBackground  Few studies have investigated functional and behavioural variables of Cornelia de Lange Syndrome (CdLS) in a large sample of individuals. The aim of this study is to provide greater insight into the clinical, behavioural and cognitive characteristics that are associated with CdLS.Methods  In total, 56 individuals with CdLS participated in the study. During hospitalization, their mothers received a number of questionnaires to complete. The behavioural phenotype was investigated using the following scales: Developmental Behaviour Scale Primary Carer Version; Autism Behaviour Checklist; Childhood Autism Rating Scale.Results  Our participants demonstrated some behavioural characteristics that are frequently associated with CdLS (hyperactivity, attention disorder, anxiety, compulsive disorders, self‐injurious behaviour and autistic‐like features). Our findings demonstrate the variability of behavioural characteristics in CdLS in addition to highlighting the contribution of some variables to both the CdLS behavioural profile and the developmental trajectory of the behavioural pattern.Conclusions  The behavioural characteristics identified in our sample were correlated with some clinical and functional aspects (chronological age, cognitive level and clinical phenotype). The variability of the behavioural profile in CdLS reflected the wide variability in cognitive and adaptive functioning across individuals and led us to conclude that there may be multiple behavioural phenotypes associated with the syndrome. Further comparative studies between CdLS and individuals with intellectual disability or other genetic syndromes may help to provide further understanding of the behavioural phenotype of CdLS.
Feasibility and outcomes of multiplex ligation‐dependent probe amplification on buccal smears as a screening method for microdeletions and duplications among 300 adults with an intellectual disability of unknown aetiology
Authors: Peppink D. , Douma‐Kloppenburg D. D. , De Rooij‐Askes E. S. P. , Van Zoest I. M. , Evenhuis H. M. , Gille J. J. P. , Van Hagen J. M. 
Published: August 2007

AbstractBackground  Determining the aetiology of intellectual disability (ID) enables anticipation of specific comorbidity and can thus be beneficial. Blood sampling, however, is considered stressful for people with ID. Our aim was to evaluate the feasibility of a non‐invasive screening technique of nine microdeletions/duplications among adults with ID of unknown aetiology.Methods  In a random sample of 300 adult clients of Dutch ID services without an aetiological diagnosis, DNA was collected on site using oral swabs. Multiplex Ligation‐dependent Probe Amplification was applied to screen for nine microdeletions/duplications related to ID syndromes (Williams 22q11‐deletion, 1p‐deletion, Miller–Dieker, Smith–Magenis, Prader–Willi, Alagille, Saethre–Chotzen and Sotos syndrome).Results  Feasibility: prior to the consent procedure, for 2.1% (10/471 eligible participants), the method was considered undesirable. In 0.7% (2/300 participants) oral swabs failed because of resistant behaviour, while in 16.1% (48/298 swabs) analysis was unsuccessful because of insufficient amounts of DNA. A repeated attempt yielded an equal success rate.Outcome  Microdeletions were diagnosed in four participants: 22q11 deletion (n = 2), 5q35 deletion (Sotos syndrome) (n = 1) and 1p deletion (n = 1). One participant had a duplication of the Prader–Willi Region (15q11‐13) owing to mosaicism of a supernumerary marker chromosome (15).Conclusions  Oral swabs are a feasible method for DNA sampling in adults with IDs. A diagnosis could be made in five out of 275 people with ID of unknown aetiology. After screening, in the total population sample (n = 620), the prevalence of syndromes associated with the microdeletions/duplications studied was at least 2.3% (95% confidence interval 1.1–3.4%).
Foundations of phonological awareness in pre‐school children with cerebral palsy: the impact of intellectual disability
Authors: Peeters M. , Verhoeven L. , Van Balkom H. , De Moor J. 
Published: August 2007

AbstractBackground  Children with cerebral palsy (CP) and accompanying disabilities are prone to reading difficulties. The aim of the present study was to examine the foundations of phonological awareness in pre‐school children with CP in comparison with a normally developing control group. Rhyme perception was regarded as an early indicator of phonological awareness, whereas non‐verbal reasoning, speech ability, auditory perception, auditory short‐term memory and vocabulary were regarded as foundation measures.Methods  A number of tasks were administrated to examine group differences in rhyme perception and its foundation measures. Correlations between the tasks were analysed for both groups followed by multiple regression analyses wherein rhyme perception was predicted by its foundation measures.Results  Children with CP scored below their normally developing peers on emergent phonological awareness and its foundation measures. Regarding the prediction of phonological awareness, non‐verbal reasoning followed by pseudoword articulation, were found to predict phonological awareness, i.e. rhyme perception, in the group of children with CP. In the control group, auditory perception was a significant predictor of emergent phonological awareness. The CP group was further split up into two groups according to the children's non‐verbal reasoning skills, i.e. general IQ. The below‐average IQ group scored below the average IQ group on phonological awareness and on most foundation measures. In addition, the average IQ group of the children with CP scored lower than the control group.Conclusion  The results of this study indicate that general intelligence and speech ability (i.e. pseudoword articulation) can be seen as important facilitators of emergent phonological awareness in children with CP. These findings support the role of intelligence in the emergence of phonological awareness in children with CP. Children with CP with intellectual disabilities seem to have a disadvantage in acquiring phonological awareness, especially when their speech abilities are also impaired. However, general intelligence is not enough to predict phonological awareness as other foundation measures are also important for phonological awareness independent of general intelligence.
Population structure of a large blue butterfly and its specialist parasitoid in a fragmented landscape
Authors: ANTON CHRISTIAN , ZEISSET INGA , MUSCHE MARTIN , DURKA WALTER , BOOMSMA JACOBUS J. , SETTELE JOSEF 
Published: August 2007

AbstractHabitat fragmentation may interrupt trophic interactions if herbivores and their specific parasitoids respond differently to decreasing connectivity of populations. Theoretical models predict that species at higher trophic levels are more negatively affected by isolation than lower trophic level species. By combining ecological data with genetic information from microsatellite markers we tested this hypothesis on the butterflyMaculinea nausithousand its specialist hymenopteran parasitoidNeotypus melanocephalus. We assessed the susceptibility of both species to habitat fragmentation by measuring population density, rate of parasitism, overall genetic differentiation (θST) and allelic richness in a large metapopulation. We also simulated the dynamics of genetic differentiation among local populations to asses the relative effects of migration rate, population size, and haplodiploid (parasitoid) and diploid (host) inheritance on metapopulation persistence. We show that parasitism byN. melanocephalusis less frequent at larger distances to the nearest neighbouring population ofM. nausithoushosts, but that host density itself is not affected by isolation. Allelic richness was independent of isolation, but the mean genetic differentiation among local parasitoid populations increased with the distance between these populations. Overall, genetic differentiation in the parasitoid wasp was much greater than in the butterfly host and our simulations indicate that this difference is due to a combination of haplodiploidy and small local population sizes. Our results thus support the hypothesis thatNeotypusparasitoid wasps are more sensitive to habitat fragmentation than theirMaculineabutterfly hosts.
Multilocus heterozygosity and inbreeding depression in an insular house sparrow metapopulation
Authors: JENSEN HENRIK , BREMSET ERLEND MYRE , RINGSBY THOR HARALD , SÆTHER BERNT‐ERIK 
Published: August 2007

AbstractInbreeding causes reduction of genetic variability that may have severe fitness consequences. In spite of its potentially huge impact on viability and evolutionary processes especially in small populations, quantitative demonstrations of genetic and demographic effects of inbreeding in natural populations are few. Here, we examine the relationship between individual inbreeding coefficients (F) and individual standardized multilocus heterozygosity (H) in an insular metapopulation of house sparrows (Passer domesticus) in northern Norway in order to evaluate whetherHis a good predictor forF. We then relate variation in fitness (i.e. the probability of surviving from fledging to recruitment) toFandH, which enables us to examine whether inbreeding depression is associated with a reduction in genetic variability. The average level of inbreeding in the house sparrow metapopulation was high, and there was large inter‐individual variation inF. As expected, standardized multilocus heterozygosity decreased with the level of inbreeding. The probability of recruitment was significantly negatively related toF, and, accordingly, increased withH. However,Hexplained no significant additional variation in recruitment rate than was explained byF. This suggests thatHis a good predictor forFin this metapopulation, and that an increase inFis likely to be associated with a general increase in the level of homozygosity on loci across the genome, which has severe fitness consequences.
Cryptic speciation and patterns of phenotypic variation of a highly variable acanthocephalan parasite
Authors: STEINAUER M. L. , NICKOL B. B. , ORTÍ G. 
Published: August 2007

AbstractAn investigation of a parasite species that is broadly host‐ and habitat‐specific and exhibits alternative transmission strategies was undertaken to examine intraspecific variability and if it can be attributed to cryptic speciation or environmentally induced plasticity. Specimens of an acanthocephalan parasite, Leptorhynchoides thecatus, collected throughout North America were analysed phylogenetically using sequences of the cytochrome oxidase I gene and the internal transcribed spacer region. Variation in host use, habitat use, and transmission were examined in a phylogenetic context to determine if they were more likely phylogenetically based or due to environmental influences. Results indicated that most of the variation detected can be explained by the presence of cryptic species. The majority of these species have narrow host and microhabitat specificities although one species, which also may comprise a complex of species, exhibits broad host and habitat specificity. Alternate transmission pathways only occurred in two of the cryptic species and correlate with host use patterns. Taxa that mature in piscivorous piscine hosts use a paratenic fish host to bridge the trophic gap between their amphipod intermediate host and piscivorous definitive host. One potential example of environmentally induced variation was identified in three populations of these parasites, which differ on their abilities to infect different host species.