bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cladistic analysis of distributions and endemism (CADE): using raw distributions of birds to unravel the biogeography of the South American aridlands
Authors: Porzecanski Ana Luz , Cracraft Joel 
Published: January 2005

AbstractAim To use published distributional and taxonomic information on Neotropical birds in a cladistic analysis of distributions and endemism (CADE) to generate a testable hypothesis of area‐relationships for the arid areas of endemism, particularly those of Central South America (the ‘arid diagonal’), and to clarify the different methodologies commonly associated with parsimony analysis of endemicity (PAE).Location South America.Methods Cladistic analysis of distributions and endemism.Results We obtain a tree where the relationships of most areas are resolved, and we find support for an exclusive clade of Central South American areas, with the Caatinga as sister to both the Chaco and Cerrado.Main conclusions There is a substantial amount of historical signal in avian distributions, when large numbers of taxa and multiple taxonomic levels are considered. Ecological noise and historical information are more easily distinguished in CADE analyses than they would be in PAE analyses. Based on our results we predict that among aridland birds, the Cerrado and Chaco species will be more closely related to each other than to Caatinga species.
Insular black files (Diptera: Simuliidae) of North America: tests of colonization hypotheses
Authors: Adler Peter H. , Giberson Donna J. , Purcell Lisa A. 
Published: January 2005

AbstractAim  To understand factors that facilitate insular colonization by black flies, we tested six hypotheses related to life‐history traits, phylogeny, symbiotes, island area, and distance from source areas.Location  Four northern islands, all within 150 km of the North American mainland, were included in the study: Isle Royale, Magdalen Islands, Prince Edward Island, and Queen Charlotte Islands.Methods  Immature black flies and their symbiotes were surveyed in streams on the Magdalen Islands, and the results combined with data from similar surveys on Isle Royale, Prince Edward Island, and the Queen Charlotte Islands. Black flies were analysed chromosomally to ensure that all sibling species were revealed. Tests of independence were used to examine the frequency of life‐history traits and generic representation of black flies on islands vs. source areas.Results  A total of 13–20 species was found on each of the islands, but no species was unique to any of the islands. The simuliid faunas of the islands reflected the composition of their source areas in aspects of voltinism (univoltine vs. multivoltine), blood feeding (ornithophily vs. mammalophily), and phylogeny (genus Simulium vs. other genera). Five symbiotic species were found on the most distant island group, the Magdalen Islands, supporting the hypothesis that obligate symbiotes are effectively transported to near‐mainland islands. An inverse relationship existed between the number of species per island and distance from the source. The Queen Charlotte Islands did not conform to the species–area relationship.Main conclusions  The lack of precinctive insular species and an absence of life‐history and phylogenetic characteristics related to the presence of black flies on these islands argue for gene flow and dispersal capabilities of black flies over open waters, possibly aided by winds. However, the high frequency of precinctive species on islands 500 km or more from the nearest mainland indicates that at some distance beyond 100 km, open water provides a significant barrier to colonization and gene exchange. An inverse relationship between number of species and distance from the source suggests that as long as suitable habitat is present, distance plays an important role in colonization. Failure of the Queen Charlotte Islands to conform to an area–richness trend suggests that not all resident species have been found.
Grass water stress estimated from phytoliths in West Africa
Authors: Bremond Laurent , Alexandre Anne , Peyron Odile , Guiot Joël 
Published: January 2005

AbstractAim  This study calibrates the relationship between phytolith indices, modern vegetation structure, and a climate parameter (AET/PET, i.e. the ratio of annual actual evapotranspiration to annual potential evapotranspiration), in order to present new proxies for long‐term Quaternary climate and vegetation changes, and model/data comparisons.Location  Sixty‐two modern soil surface samples from West Africa (Mauritania and Senegal), collected along a latitudinal transect across four bioclimatic zones, were analysed.Methods  Two phytolith indices are defined as normalized data: (1) humidity‐aridity index [Iph (%) = saddle vs. cross + dumbbell + saddle], and (2) water stress index [fan‐shaped index (Fs) (%) = fan‐shaped vs. sum of characteristic phytoliths]. Vegetation structures are delimited according to Iph and Fs boundaries. Bootstrapped regression methods are used for evaluating the strength of the relationship between the two phytolith indices and AET/PET. Additional modern phytolith assemblages, from Mexico, Cameroon and Tanzania are extracted in order to test the calibration established from the West African samples. Accuracy of the AET/PET phytolith proxy is compared with equivalent pollen proxy from the same area.Results  Characterization of the grass cover is accurately made through Iph. A boundary of 20 ± 1.4% discriminates tall grass savannas from short grass savannas. Water stress and transpiration experienced by the grass cover can be estimated through Fs. AET/PET is accurately estimated from phytoliths by a transfer function: AET/PET = −0.605 Fs − 0.387 Iph + 0.272 (Iph – 20)2 (r = 0.80 ± 0.04) in the application domain (AET/PET ranging from 0.1 ± 0.04 to 0.45 ± 0.04). Phytolith and pollen estimate with similar precision (rpollen = 0.84 ± 0.04) the AET/PET in the studied area.Conclusions  This study demonstrates that we can rely on the phytolith indices Iph and Fs to distinguish the different grasslands in tropical areas. Moreover, a new phytolith proxy of AET/PET, linked to water availability, is presented. We suggest from these results that combining phytolith and pollen proxies of AET/PET would help to constrain this climate parameter better, especially when phytolith assemblages are dominated by Panicoideae and Chloridoideae C4‐grass phytoliths, are devoid of Pooideae C3‐grass phytoliths, and occur with a few tropical ligneous woody dicotyledon phytoliths. As AET/PET is a bioclimatic indicator commonly used in vegetation models, such a combination would help to make model/data comparisons more efficient.
Species richness and structure of ant communities in a dynamic archipelago: effects of island area and age
Authors: Badano Ernesto I. , Regidor Héctor A. , Núñez Hector A. , Acosta Rebeca , Gianoli Ernesto 
Published: January 2005

AbstractAim  To assess how ant species richness and structure of ant communities are influenced by island age (disturbance history) in a dynamic archipelago.Location  Cabra Corral dam, Salta Province, north‐west Argentina (25°08′ S, 65°20′ W).Methods  Ant species richness on remaining fragments (islands) of a flooded forest was determined, as well as island area, isolation and age. Simple linear regressions were performed to assess relationships between ant species richness and those insular variables. Furthermore, a stepwise multiple linear regression analysis was conducted in order to determine the relative influence of each insular variable on ant species richness. Islands were categorized in two age classes (old and young) and co‐occurrence analyses were applied within each class to evaluate changes in community structure because of interspecific competition.Results  Simple regression analyses indicated a moderate, positive effect of island area on ant species richness. Weak, marginally non‐significant relationships were found between ant species richness and both island isolation and island age, showing the tendency for there to be a decrease in ant species richness with island isolation and that ant species richness might be higher in old islands. The multiple regression analysis indicated that island isolation and age had no significant effects on the number of ant species, island area being the only independent variable retained in the analysis. On the contrary, whereas a random pattern of species co‐occurrence was found on young islands, ant communities in old islands showed a significantly negative pattern of species co‐occurrence, suggesting that the effect of competition on community structure was stronger on older islands than on younger islands.Main conclusions  Island area was the most important variable explaining ant species richness on the islands of Cabra Corral dam. However, both island isolation and island age (or disturbance history) might also contribute to shape the observed community patterns. The present study also shows that island age significantly affects the strength with which interspecific interactions structure ant communities on islands.
Effects of life‐history traits and species distribution on genetic structure at maternally inherited markers in European trees and shrubs
Authors: Aguinagalde Itziar , Hampe Arndt , Mohanty Aparajita , Martín Juan Pedro , Duminil Jérôme , Petit Rémy J. 
Published: January 2005

AbstractAim To examine relationships between life‐history traits, ecological and chorological characteristics of woody plant species and patterns of genetic differentiation among populations as assessed by chloroplast DNA (cpDNA) markers, and to compare them with patterns previously described from nuclear markers.Location Europe.Methods Data on cpDNA variation were compiled for 29 temperate European broad‐leaved tree and shrub species. Six qualitative and three quantitative characters of the species were tested for their relationship with two parameters of genetic population differentiation (GSTandNST). Both direct species comparisons and phylogenetically independent contrast analyses were performed.Results When the phylogeny was not taken into account, five characters were significantly related to levels of population differentiation. The relationship disappeared in all but two cases (distribution type and seed mass) when analyses controlled for phylogenetic relationships among species.Main conclusions The correlation between distribution type (boreal‐temperate or temperate) and cpDNA differentiation of temperate European woody plant species suggests that their Quaternary history, in particular the location and isolation of their glacial refugia, is an important determinant of their present‐day level of genetic structure. By contrast, the relationship between life‐history traits and genetic differentiation at maternally inherited markers is weaker, especially when phylogenetic effects are controlled for.
Biogeography of the nearshore rocky‐reef fishes at the southern and Baja California islands
Authors: Pondella Daniel J. , Gintert Brooke E. , Cobb Jana R. , Allen Larry G. 
Published: January 2005

AbstractAim  To examine the uniqueness and relationship of islands in the San Diegan Province using reef fishes.Location  Pacific coast of Baja and Southern California.Methods  Quantitative scuba surveys and statistics were used. Between June 2000 and August 2002, the nearshore rocky‐reef fishes of eight southern California and Baja California islands were quantitatively surveyed. The islands surveyed were: Santa Cruz, San Nicolas, Santa Barbara, Santa Catalina, San Clemente, North Coronado, San Martin and San Benito. These islands span the latitudinal range of offshore islands within the San Diegan marine province. This regional scale approach provided not only the first quantitative description of rocky‐reef fishes at five of these islands, but also allowed comparisons with known biogeographical patterns.Results  Here we discuss the distribution and abundance of 84 conspicuous rocky‐reef fishes from 35 families. In general, the richness, diversity and composition of fish assemblages at these islands were found to reflect previously described biogeographical processes. The rocky reef fish assemblages of all islands in the survey were found to be significantly distinctive form each other. Phenetic analyses revealed two clusters. San Clemente, Santa Catalina and North Coronado clustered as a warm‐water assemblage in the middle of the San Diegan Province. The remaining islands grouped together as a cold‐water assemblage, despite the geographically disjunct position of the islands within this cluster. The relatedness of islands was independent of distance. Examination of the most common fish species at all islands revealed that while some conformed to the north–south trending density distributions predicted by previous investigators, the distribution of others could not be explained by latitude or temperature regimes. No single pattern explained the density of fishes at all islands. Both the rock croaker, Pareques sp., and flag cabrilla, Epinephelus labriformis, were observed at San Benito during these surveys, representing northern range extensions and may be indicators of the warming trend observed in this marine province.Main conclusion  For nearshore rocky‐reef fishes, the islands of the San Diegan marine province are distinct and their interrelatedness is independent of the distance between them.
Geographic range size, seedling ecophysiology and phenotypic plasticity in AustralianAcaciaspecies
Authors: Pohlman Catherine L. , Nicotra Adrienne B. , Murray Brad R. 
Published: January 2005

AbstractAim The degree to which eco‐physiological traits critical to seedling establishment are related to differences in geographic range size among species is not well understood. Here, we first tested the idea that seedling eco‐physiological attributes associated with establishment differ between narrowly distributed and geographically widespread plant species. Secondly, we tested the notion that species occupying wide geographic ranges have greater phenotypic plasticity in response to the environment than contrasted species with more restricted distributions.Location Eastern Australia.Methods We compared five pairs of geographically restricted and widespreadAcaciaspecies grown under glasshouse conditions for differences in seedling relative growth rate and associated allocational, morphological and physiological traits. We then examined whether widespread species displayed greater phenotypic plasticity in these traits than narrowly distributed species in response to changes in soil water availability.Results Neither relative growth rate nor any measure of biomass accumulation or allocation differed significantly between seedlings of narrowly distributed and widespread species. In addition, the plasticity of biomass allocation was not greater in widespread species. However, the leaflets of widespread species had higher photosynthetic capacity and greater plasticity of water use efficiency than the leaflets of narrowly distributed species.Main conclusions We demonstrated fundamental differences in the physiology and plasticity of leaflets of widespread and narrowly distributed species. The greater plasticity of these seedling leaflet traits may allow widespreadAcaciaspecies to utilize a wider range of environmental conditions in relation to soil moisture than restrictedAcaciaspecies. However, we did not find corresponding differences in mean or plasticity of seedling growth and allocational traits. In general, we suggest that relationships between rarity and species traits are both context and taxon specific.
A Model of Toxoplasmosis Incidence in the UK: Evidence Synthesis and Consistency of Evidence
Authors: Welton N. J. , Ades A. E. 
Published: January 2005

SummaryWe present a Bayesian evidence synthesis model combining data on seroprevalence, seroconversion and tests of recent infection, to produce estimates of current incidence of toxoplasmosis in the UK. The motivation for the study was the need for an estimate of current average incidence in the UK, with a realistic assessment of its uncertainty, to inform a decision model for a national screening programme to prevent congenital toxoplasmosis. The model has a hierarchical structure over geographic region, a random-walk model for temporal effects and a fixed age effect, with one or more types of data informing the regional estimates of incidence. Inference is obtained by using Markov chain Monte Carlo simulations. A key issue in the synthesis of evidence from multiple sources is model selection and the consistency of different types of evidence. Alternative models of incidence are compared by using the deviance information criterion, and we find that temporal effects are region specific. We assess the consistency of the various forms of evidence by using cross-validation where practical, and posterior and mixed prediction otherwise, and we discuss how these measures can be used to assess different aspects of consistency in a complex evidence structure. We discuss the contribution of the various forms of evidence to estimated current average incidence.
Hierarchical Modelling of Orthopaedic Hip Replacement Damage Accumulation and Reliability
Authors: Wilson Simon P. 
Published: January 2005

Summary
We describe the modelling of crack initiation and growth in a group of orthopaedic hip replacements. A hierarchical model is proposed and fitted with Bayesian methods, implemented by the Gibbs sampler. Our interest is in predicting the failure of the replacements, which is predominately caused by crack activity in the cement that fixates the metal prosthesis to the bone. Simulation from the model based on posterior distribution samples allows us to approx-imate the reliability function and to assess the effect on reliability of the properties of the replacement. We discuss the ideas behind this approach, which can be generalized to any group of physical systems and any function of their state that interests us.
Pharmacoepidemiology of anabolic androgenic steroids: a review
Authors: Thiblin Ingemar , Petersson Anna 
Published: January 2005

AbstractNon‐prescribed use of anabolic androgenic steroids (AAS) has been associated with a number of physical and psychiatric/behavioural complications, some of which are potentially lethal. Here, we review both observational and experimental studies on human subjects concerned with such side‐effects. The only physical complication of AAS use that receives definitive support from such investigations is unfavourable changes in blood lipid profiles. Support for various psychiatric complications has also been provided by a number of cross‐sectional studies, most involving comparisons between weight‐training individuals who use or do not use AAS. Certain of these complications, in particular hypomania and increased aggressiveness, have been confirmed in some, but not all, randomized controlled studies. Epidemiological attempts to determine whether AAS use triggers violent behaviour have failed, primarily because of high rates of non‐participation. Studies regarding the prevalence of AAS use in different populations typically report life‐time prevalences of 1–5% among adolescents. However, the life‐time prevalence (i.e. use on at least one occasion) is of doubtful relevance in attempting to estimate the number of individuals at risk for side‐effects, as most of these complications appear to develop during prolonged use of AAS. Furthermore, it is reasonable to assume that the symptoms and signs of AAS use are often overlooked by healthcare professionals, so that the number of cases of possible AAS‐related complications is virtually unknown. These limitations, together with an apparently low prevalence of prolonged AAS use among the general population, indicate that future epidemiological research in this area should focus on retrospective case–control studies and, perhaps, also on prospective cohort studies of populations selected for a high prevalence of AAS use, rather than attempting to perform large‐scale population‐based studies.
Protective effect of taurine against alendronate‐induced gastric damage in rats
Authors: Şener Göksel , Şehirli Özer , Cetinel Sule , Midillioğlu Şükrü , Gedik Nursal , Ayanoğlu‐Dülger Gül 
Published: January 2005

AbstractAlendronate (ALD) causes serious gastrointestinal adverse effects. The aim of this study was to investigate whether taurine (TAU), a semi‐essential amino acid and an antioxidant, improves the alendronate‐induced gastric injury. Rats were administered 20 mg/kg ALD by gavage for 4 days, either alone or following treatment with TAU (50 mg/kg, i.p.). On the last day of treatment, following drug administration, pylorus ligation was performed and 2 h later, rats were killed and stomachs were removed. Gastric acidity and tissue ulcer index values, lipid peroxidation and glutathione (GSH) levels, myeloperoxidase (MPO) activity as well as the histologic appearance of the stomach tissues were determined. Chronic oral administration of ALD induced significant gastric damage, increasing lipid peroxidation, MPO activity and collagen content, as well as decreasing tissue GSH levels. Treatment with TAU prevented the damage and also the changes in biochemical parameters. Findings of the present study suggest that ALD induces oxidative gastric damage by a local irritant effect, and that TAU ameliorates this damage by its antioxidant and/or membrane‐stabilizing effects.
G protein‐coupled receptors: a count of 1001 conformations
Authors: Vauquelin G. , Van Liefde I. 
Published: January 2005

AbstractG protein‐coupled receptors (GPCRs) were initially regarded to adopt an inactive and an active conformation and to activate a single type of G protein. Studies with recombinant cell systems have led to a more complex picture. First, GPCRs can activate distinct G protein species. Second, GPCR multistate models have been invoked to explain their complex behaviour in the presence of agonists, antagonists and other binding partners. The occurrence of intermediate receptor conformational states during GPCR activation and antagonist binding is suggested by fluorescence measurements and studies with constitutively active receptor mutants and insurmountable antagonists. Different agonists may trigger distinct effector pathways through a single receptor by dictating its preference for certain G proteins (i.e. ‘agonist trafficking’). Structural modification and exogenous and endogenous (e.g. other cellular proteins, lipids) allosteric modulators also affect ligand–GPCR interaction and receptor activation. These new developments in GPCR research could lead to the development of more selective therapeutic drugs.