bluuebunny/crossref_metadata_2025_split huggingface dataset:
A systematic review of informal caregivers’ needs in providing home‐based end‐of‐life care to people with cancer
Authors: Bee Penny E , Barnes Pamela , Luker Karen A 
Published: July 2008

Aims.  This paper presents the results of a systematic review examining the practical information needs of informal caregivers providing home‐based palliative and end‐of‐life care to people with advanced cancer.Background.  Modern hospice care has led to increases in home‐based palliative care services, with informal caregivers assuming responsibility for the majority of care. In response, health policy emphasises the provision of palliative care services in which both the patient and carer receive adequate support throughout illness and death. While the emotional needs of carers have been extensively researched, their practical needs with respect to the provision of physical care are yet to receive systematic attention.Design.  Systematic review.Methods.  Eligible articles were identified via electronic searches of research and evidence‐based databases, hand‐searching of academic journals and searches of non‐academic grey literature websites. Quality of research was assessed via accepted guidelines for reviewing non‐randomised, observational and qualitative literature. Data were synthesised by comparing and contrasting the findings to identify prominent themes.Results.  Research consistently highlights this lack of practical support, often related to inadequate information exchange. These deficits typically manifest in relatives adopting a ‘trial and error’ approach to palliative care. Informal carers request a greater quantity of practically‐focussed information, improvements in quality and increased methods of dissemination.Conclusion.  Synthesis of the literature suggests that home‐based palliative care services have been insufficiently focussed on assisting informal caregivers acquire practical nursing skills.Relevance to clinical practice.  Enhanced access to professional advice represents a potentially effective method of increasing carers’ confidence in their ability to undertake practical aspects of home‐based care. Evidence suggests that nurses and other health providers may better assist home‐based carers by providing the information and skills‐training necessary to facilitate this. This may necessitate the involvement of carers in the design and testing of new educational interventions.
Evidence for multiple sources of invasion and intraspecific hybridization inBrachypodium sylvaticum(Hudson) Beauv. in North America
Authors: ROSENTHAL DAVID M. , RAMAKRISHNAN ALISA P. , CRUZAN MITCHELL B. 
Published: July 2008

AbstractWe compared the levels and distribution of genetic diversity in Eurasian and North American populations ofBrachypodium sylvaticum(Huds.) Beauv. (false brome), a newly invasive perennial bunchgrass in western North America. Our goals were to identify source regions for invasive populations, determine the number of independent invasion events, and assess the possibility that postinvasion bottlenecks and hybridization have affected patterns of genetic diversity in the invaded range. We tested the hypothesis that this Eurasian grass was accidentally introduced into two areas in Oregon and one site in California by examining nuclear microsatellites and chloroplast haplotype variation in 23 introduced and 25 native populations. In the invaded range, there was significantly lower allelic richness (RS), observed heterozygosity (HO) and within‐population gene diversity (HS), although a formal test failed to detect a significant genetic bottleneck. Most of the genetic variation existed among populations in the native range but within populations in the invaded range. All of the allelic variation in the invaded range could be explained based on alleles found in western European populations. The distribution of identified genetic clusters in the North American populations and the unique alleles associated with them is consistent with two historical introductions in Oregon and a separate introduction to California. Further analyses of population structure indicate that intraspecific hybridization among genotypes from geographically distinct regions of western Europe occurred following colonization in Oregon. The California populations, however, are more likely to be derived from one or perhaps several genetically similar regions in the native range. The emergence and spread of novel recombinant genotypes may be facilitating the rapid spread of this invasive species in Oregon.
Fungal specificity bottlenecks during orchid germination and development
Authors: BIDARTONDO MARTIN I. , READ DAVID J. 
Published: July 2008

AbstractFungus‐subsidized growth through the seedling stage is the most critical feature of the life history for the thousands of mycorrhizal plant species that propagate by means of ‘dust seeds.’ We investigated the extent of specificity towards fungi shown by orchids in the genera Cephalanthera and Epipactis at three stages of their life cycle: (i) initiation of germination, (ii) during seedling development, and (iii) in the mature photosynthetic plant. It is known that in the mature phase, plants of these genera can be mycorrhizal with a number of fungi that are simultaneously ectomycorrhizal with the roots of neighbouring forest trees. The extent to which earlier developmental stages use the same or a distinctive suite of fungi was unclear. To address this question, a total of 1500 packets containing orchid seeds were buried for up to 3 years in diverse European forest sites which either supported or lacked populations of helleborine orchids. After harvest, the fungi associated with the three developmental stages, and with tree roots, were identified via cultivation‐independent molecular methods. While our results show that most fungal symbionts are ectomycorrhizal, differences were observed between orchids in the representation of fungi at the three life stages. In Cephalanthera damasonium and C. longifolia, the fungi detected in seedlings were only a subset of the wider range seen in germinating seeds and mature plants. In Epipactis atrorubens, the fungi detected were similar at all three life stages, but different fungal lineages produced a difference in seedling germination performance. Our results demonstrate that there can be a narrow checkpoint for mycorrhizal range during seedling growth relative to the more promiscuous germination and mature stages of these plants’ life cycle.
Mitochondrial DNA‐inferred population structure and demographic history of the mitten crab (Eriocheir sensu stricto) found along the coast of mainland China
Authors: WANG CHENGHUI , LI CHENHONG , LI SIFA 
Published: July 2008

AbstractThe mitten crab, Eriocheir sensu stricto, is economically important in East Asia, although it is an invasive species in Europe and North America. Little is known about its population structure and historical demography in its native range, especially along the Pacific coast of China. We collected mitochondrial cytochrome oxidase subunit II and cytochrome b sequences from 154 individuals distributed in the rivers along the Chinese coast and 15 individuals from Japan. Phylogenetic analysis resulted in three major monophyletic groups: northern China, southern China and Japan. Negligible migration was detected among those groups by coalescent analysis. Hence, we support the recognition of three species: Eriocheir hepuensis in southern China, Eriocheir sinensis in northern China and Eriocheir japonica in Japan. The populations in the middle (the Oujiang and Minjiang Rivers) possess a mixture of haplotypes similar to either the northern or the southern haplotypes. We believe that secondary intergradation as the most likely cause of the clinal variation based on examining the genetic variation in the latitudinal space. The estimated divergence time between E. sinensis and E. hepuensis is 2.24 million years ago (Ma), while the divergence time between E. japonica and E. sinensis is 1.83 Ma. Both are in the late Pliocene, suggesting that land bridges associated with low sea level during that time might have severed as vicariant barriers for speciation. The divergence of the northern population and the ‘northern haplotypes’ in the middle population was estimated at 0.12 Ma, while the time separating the southern population and the ‘southern haplotypes’ in the middle populations was estimated as 0.16 Ma, implicating possible secondary contact in the late Pleistocene.
Differentiating salmon populations at broad and fine geographical scales with microsatellites and single nucleotide polymorphisms
Authors: NARUM S. R. , BANKS M. , BEACHAM T. D. , BELLINGER M. R. , CAMPBELL M. R. , DEKONING J. , ELZ A. , GUTHRIE III C. M. , KOZFKAY C. , MILLER K. M. , MORAN P. , PHILLIPS R. , SEEB L. W. , SMITH C. T. , WARHEIT K. , YOUNG S. F. , GARZA J. C. 
Published: July 2008

AbstractSingle nucleotide polymorphisms (SNPs) are appealing genetic markers due to several beneficial attributes, but uncertainty remains about how many of these bi‐allelic markers are necessary to have sufficient power to differentiate populations, a task now generally accomplished with highly polymorphic microsatellite markers. In this study, we tested the utility of 37 SNPs and 13 microsatellites for differentiating 29 broadly distributed populations of Chinook salmon (n = 2783). Information content of all loci was determined by In and , and the top 12 markers ranked by In were microsatellites, but the 6 highest, and 7 of the top 10 ranked markers, were SNPs. The mean ratio of random SNPs to random microsatellites ranged from 3.9 to 4.1, but this ratio was consistently reduced when only the most informative loci were included. Individual assignment test accuracy was higher for microsatellites (73.1%) than SNPs (66.6%), and pooling all 50 markers provided the highest accuracy (83.2%). When marker types were combined, as few as 15 of the top ranked loci provided higher assignment accuracy than either microsatellites or SNPs alone. Neighbour‐joining dendrograms revealed similar clustering patterns and pairwise tests of population differentiation had nearly identical results with each suite of markers. Statistical tests and simulations indicated that closely related populations were better differentiated by microsatellites than SNPs. Our results indicate that both types of markers are likely to be useful in population genetics studies and that, in some cases, a combination of SNPs and microsatellites may be the most effective suite of loci.
A population genomic approach to map recent positive selection in model species
Authors: PAVLIDIS P. , HUTTER S. , STEPHAN W. 
Published: July 2008

AbstractBased on nearly complete genome sequences from a variety of organisms data on naturally occurring genetic variation on the scale of hundreds of loci to entire genomes have been collected in recent years. In parallel, new statistical tests have been developed to infer evidence of recent positive selection from these data and to localize the target regions of selection in the genome. These methods have now been successfully applied to Drosophila melanogaster, humans, mice and a few plant species. In genomic regions of normal recombination rates, the targets of positive selection have been mapped down to the level of individual genes.
Landscape genetics, historical isolation and cross‐Andean gene flow in the wax palm,Ceroxylon echinulatum(Arecaceae)
Authors: TRÉNEL PHILIPP , HANSEN MICHAEL M. , NORMAND SIGNE , BORCHSENIUS FINN 
Published: July 2008

AbstractKnowledge of the role of landscapes in shaping genetic connectivity and divergence is essential for understanding patterns of biogeography and diversity. This is particularly relevant for the Andes region, a major biodiversity hotspot of relatively recent origin. We examined the phylogeography and landscape genetics of the Andean wax palmCeroxylon echinulatum(Arecaceae) that occurs in two narrow bands of montane forests on each side of the Andes in Ecuador and northeastern Peru. First, we tested the hypothesis ofC. echinulatumbeing a geographic cline species crossing the Andes in the Amotape–Huancabamba zone (AHZ) of southern Ecuador/northern Peru, as indicated by observations on fruit morphology. Second, we assessed the timeframe of cross‐Andean divergence, and third, we investigated the impact of contemporary and historical landscape features on observed spatio‐genetic patterns. Individual‐based Bayesian clustering (BC) identified a northeastern, southeastern, southwestern, and northwestern cluster, with areas of genetic discontinuity coinciding with the Andes and the Giron–Paute deflection.F‐statistics derived from BC suggested an east‐to‐west dispersal history. Population‐based analyses revealed strong genetic structuring at both small and large geographic scales. Interpopulation relationships and Mantel tests strongly supported the cline model with cross‐Andean dispersal in the AHZ. Along the cline, gene flow measured asFSTwas mainly limited by distance, with less but significant impact of climatic friction. Coalescent analysis revealed that cross‐Andean divergence took place during the Quaternary. Significant historical isolation (RST > FST) was found in the southwestern population. The current study illustrates a joint effect of founder dynamics, divergence by distance and historical isolation on patterns of Andean diversity and distribution.
In‐stream and overland dispersal across a river network influences gene flow in a freshwater insect, Calopteryx splendens
Authors: CHAPUT‐BARDY A. , LEMAIRE C. , PICARD D. , SECONDI J. 
Published: July 2008

AbstractGene flow in riverine species is constrained by the dendritic (branching) structure of the river network. Spatial genetic structure (SGS) of freshwater insects is particularly influenced by catchment characteristics and land use in the surroundings of the river. Gene flow also depends on the life cycle of organisms. Aquatic larvae mainly drift downstream whereas flying adults can disperse actively overland and along watercourses. In‐stream movements can generate isolation by distance (IBD) at a local scale and differentiation between subcatchments. However, these patterns can be disrupted by overland dispersal. We studied SGS across the Loire River in the damselfly Calopteryx splendens which is able to disperse along and between watercourses. Our sampling design allowed us to test for overland dispersal effects on genetic differentiation between watercourses. Amplified fragment length polymorphism markers revealed high genetic differentiation at the catchment scale but the genetic structure did not reflect the geographical structure of sampling sites. We observed IBD patterns when considering the distance following the watercourse but also the Euclidean distance, i.e. the shortest distance, between pairs of sites. Altogether, our results support the hypothesis of overland dispersal between watercourses. From a conservation perspective, attention should be paid to the actual pathways of gene flow across complex landscapes such as river networks.
Twenty years of phylogeography: the state of the field and the challenges for the Southern Hemisphere
Authors: BEHEREGARAY LUCIANO B. 
Published: July 2008

AbstractPhylogeography is a young, vigorous and integrative field of study that uses genetic data to understand the history of populations. This field has recently expanded into many areas of biology and also into several historical disciplines of Earth sciences. In this review, I present a numerical synthesis of the phylogeography literature based on an examination of over 3000 articles published during the first 20 years of the field (i.e. from 1987 to 2006). Information from several topics needed to evaluate the progress, tendencies and deficiencies of the field is summarized for 10 major groups of organisms and at a global scale. The topics include the geography of phylogeographic surveys, comparative nature of studies, temporal scales and major environments investigated, and genetic markers used. I also identify disparities in research productivity between the developing and the developed world, and propose ways to reduce some of the challenges faced by phylogeographers from less affluent countries. Phylogeography has experienced explosive growth in recent years fuelled by developments in DNA technology, theory and statistical analysis. I argue that the intellectual maturation of the field will eventually depend not only on these recent developments, but also on syntheses of comparative information across different regions of the globe. For this to become a reality, many empirical phylogeographic surveys in regions of the Southern Hemisphere (and in developing countries of the Northern Hemisphere) are needed. I expect the information and views presented here will assist in promoting international collaborative work in phylogeography and in guiding research efforts at both regional and global levels.
A comparison of techniques for assessing dispersal behaviour in gundis: revealing dispersal patterns in the absence of observed dispersal behaviour
Authors: NUTT KAREN J 
Published: July 2008

AbstractKnowledge of the dispersal status of group members is important to understanding how sociality may have evolved within a species. I assessed the effectiveness of four techniques for elucidating dispersal behaviour in a rock‐dwelling rodent (Ctenodactylus gundi) with small group sizes (2–10 animals): genetic parentage assignment, haplotype data and kinship analyses, assignment testing, andF‐statistics. The first two methods provided the greatest insight into gundi dispersal behaviour. Assignment testing andF‐statistics proved of limited use for elucidating fine‐scale dispersal, but could detect large‐scale patterns despite low sex‐biased dispersal intensity (1.9 : 1) because of moderate genetic differentiation among groups (FST = 0.10). Findings are discussed in light of current dispersal theory. In general, gundi dispersal is plastic, and seems to be dependent on body weight (for males), group composition, and scale of analysis (total dispersal events recorded within the population were almost twice the immigration rate into the population). Most groups were comprised of a single matriline and one immigrant male. Immigrant rather than philopatric males bred with group females. Dispersal among groups was male‐biased, but dispersal or philopatry could occur by either sex. During a drought, both sexes delayed dispersal and cooperative social units formed. Whether such behaviour resulted directly from the drought or not remains unclear, however, since comparative information was not available from nondrought years. Combining fine‐scale analyses with information on large‐scale patterns provided substantial insight into gundi dispersal behaviour despite the limited movement of animals during a drought, and may prove useful for elucidating dispersal behaviour in other social animals.
Male‐biased dispersal in a tropical Australian snake (Stegonotus cucullatus, Colubridae)
Authors: DUBEY S. , BROWN G. P. , MADSEN T. , SHINE R. 
Published: July 2008

AbstractSex‐based differences in dispersal distances can affect critical population parameters such as inbreeding rates and the spatial scale of local adaptation. Males tend to disperse further than females in mammals, whereas the reverse is true for birds; too few reptiles have been studied to reveal generalities for that group. Although reptiles are most diverse and abundant in the tropics, few tropical reptiles have been studied in this respect. We combine data from a long‐term (10‐year) mark–recapture study with genetic information (based on nine microsatellite markers) on slatey‐grey snakes (Stegonotus cucullatus, Colubridae) in the Australian wet‐dry tropics. Males attain larger body sizes than females, and both genetic and mark–recapture data show that males also disperse further than females. Recapture records show that hatchling males dispersed away from their release points whereas hatchling females did not, and adult males moved further than adult females. In the genetic analysis, males contributed less to overall FST and relatedness than did females (FSTm = 0.0025, FSTf = 0.0275, P < 0.001; rm = 0.0053; rf = 0.0550; P < 0.001). Spatial autocorrelation analyses within the largest population revealed a similar pattern, with spatial structuring stronger for females than males. Overall, our genetic analyses not only supported the mark–recapture data, but also extended our insights by revealing occasional long‐distance dispersal not detected by the mark–recapture study.
Selection and sticklebacks
Authors: BEAUMONT MARK A. 
Published: July 2008

AbstractOver the last decade, there has been increasing circumstantial evidence for the action of natural selection in the genome, arising largely from molecular genetic surveys of large numbers of markers. In nonmodel organisms without densely mapped markers, a frequently used method is to identify loci that have unusually high or low levels of genetic differentiation, or low genetic diversity relative to other populations. The paper by Mäkinen et al. (2008a) in this issue of Molecular Ecology reports the results of a survey of microsatellite allele frequencies at more than 100 loci in seven populations of the three‐spined stickleback (Gasterosteus aculeatus). They show that a microsatellite locus and two indel markers located within the intron of the Eda gene, known to control the number of lateral plates in the stickleback (Fig. 1), tend to be much more highly genetically differentiated than other loci, a finding that is consistent with the action of local selection. They identify a further two independent candidates for local selection, and, most intriguingly, they further suggest that up to 15% of their loci may provide evidence of balancing selection.Three‐spined stickleback (Gasterosteus aculeatus).image
RecA‐mediated SOS induction requires an extended filament conformation but no ATP hydrolysis
Authors: Gruenig Marielle C. , Renzette Nicholas , Long Edward , Chitteni‐Pattu Sindhu , Inman Ross B. , Cox Michael M. , Sandler Steven J. 
Published: July 2008

SummaryThe Escherichia coli SOS response to DNA damage is modulated by the RecA protein, a recombinase that forms an extended filament on single‐stranded DNA and hydrolyzes ATP. The RecA K72R (recA2201) mutation eliminates the ATPase activity of RecA protein. The mutation also limits the capacity of RecA to form long filaments in the presence of ATP. Strains with this mutation do not undergo SOS induction in vivo. We have combined the K72R variant of RecA with another mutation, RecA E38K (recA730). In vitro, the double mutant RecA E38K/K72R (recA730,2201) mimics the K72R mutant protein in that it has no ATPase activity. The double mutant protein will form long extended filaments on ssDNA and facilitate LexA cleavage almost as well as wild‐type, and do so in the presence of ATP. Unlike recA K72R, the recA E38K/K72R double mutant promotes SOS induction in vivo after UV treatment. Thus, SOS induction does not require ATP hydrolysis by the RecA protein, but does require formation of extended RecA filaments. The RecA E38K/K72R protein represents an improved reagent for studies of the function of ATP hydrolysis by RecA in vivo and in vitro.