bluuebunny/crossref_metadata_2025 huggingface dataset:
Narrating and Performing Identity: Literacy Specialists' Writing Identities
Authors: McKinney Marilyn , Giorgis Cyndi
Published: March 2009

In this study, we explored ways that four literacy specialists who worked in three schools that were part of one state's Reading Excellence Act (REA) grant constructed their identities as writers and as teachers of writing. We also explored how they negotiated the performance of those identities in different contexts over a two-year period. Literacy specialists' writer's autobiographies composed during the first year and interviews conducted near the end of the second year comprised the major data sources that were analyzed through narrative analysis. Using Wortham's (2001) process of recording events and characters associated with those events allowed us to examine not only identity construction but also the performative nature of the telling of narratives through interactional positioning. The analysis explored complicated ways in which identities and contexts associated with schooled literacies aligned and conflicted, uncovering layers and intricacies of identity construction and enactment over time, and within and across narratives. Implications of these explorations for work in teacher education in terms of preparation of literacy educators and professional development suggest the importance of creating opportunities for revisiting autobiographical narratives to inform practice. In addition, we point to the power of narrative as it relates to both the telling of stories about identity and as an analytic tool.
Why do speech and language therapists stay in, leave and (sometimes) return to the National Health Service (NHS)?
Authors: Loan‐Clarke John , Arnold John , Coombs Crispin , Bosley Sara , Martin Caroline
Published: March 2009

Background: Research into recruitment, retention and return of speech and language therapists in the National Health Service (NHS) is relatively limited, particularly in respect of understanding the factors that drive employment choice decisions.

Aims: To identify what factors influence speech and language therapists working in the NHS to stay, and consider leaving, but not do so. To identify what features of the NHS and alternative employers influence speech and language therapists to leave the NHS. To identify why some speech and language therapists return to the NHS after working elsewhere.

Methods & Procedures: A total of 516 male and female speech and language therapists, in three distinct groups (NHS stayers, leavers and returners) completed a questionnaire and gave responses to open‐ended questions regarding their perceptions of the NHS and other employers. Qualitative data analysis identified reasons why individuals stayed in, left or returned to the NHS employment, and what actions could be taken by management to facilitate retention and return.

Outcomes & Results: Stayers value job and pension security; professional development opportunities; the work itself; and professional support. Leavers not involved in childcare left because of workload/pressure/stress; poor pay; and not being able to give good patient care. Returners returned because of flexible hours; work location; professional development; and pension provision. Stayers and returners primarily wish to see more staff in the NHS, whereas leavers would return if there were more flexibility in work arrangements. Returners were particularly hostile towards Agenda for Change.

Conclusions & Implications: Whilst some preferences appear to require increased resources, others such as reducing bureaucracy and valuing professionals do not. The full impact of Agenda for Change has yet to be established. Predicted excess labour supply of allied health professionals and future structural changes present pressures but also possible opportunities for speech and language therapists.
Influence of gender and experience on the maximal instep soccer kick
Authors: Shan Gongbing
Published: March 2009

Although soccer is a popular sport worldwide, little work has been done to satisfy the increasing demand for quantitative research on female players. As a result, training programmes for female players are often taken directly from their male counterparts, without appropriate adaptations. In this study, I examine the influence of gender and experience on the maximal instep soccer kick among male and female college students, with equal numbers of novice and skilled players. The data collection equipment consisted of a synchronized system with VICON™ 3D motion capture (nine high‐speed cameras, 120 Hz) and NORAXON wireless electromyography. Results showed that trained male and female players have different techniques. After a powerful kick, males naturally follow through with a jump to dissipate residual leg momentum, whereas females avoid this airborne phase; instead, they counteract the momentum with upper‐body flexions. Skilled male players displayed a more powerful quasi whip‐like movement of the kicking leg and more explosive muscle work patterns (higher maximum and faster increase rate of muscle tension) than skilled females. During training, practitioners should pay special attention to repetitive injuries in small muscles like the adductor magnus. The differences observed may be important for the development of training programmes.
“The science of doping” revisited: Fallacies of the current anti‐doping regime
Authors: Pitsch Werner
Published: March 2009

Biomedical doping tests specifically, as well as doping test practises as a whole, have severe shortcomings which are based upon the fact that test procedures are in principle imperfect. With the help of Bayesian logic, it can be shown that the interpretation of doping test results is far from trivial with reference to individual athletes and single doping tests, but that these tests can reveal results which can be fairly dependable when it comes to estimating the prevalence of doping. Even if multiple tests are conducted and the samples are analyzed repeatedly for substance abuse, the need for positive A‐ and B‐sample analysis is a strong argument in assuming that positive‐tested athletes are guilty. However, this does not save an anti‐doping policy which relies on increasing numbers of doping tests all over the world from the problem of false positive tests, which becomes the more severe the better anti‐doping works in terms of lowering doping prevalence through deterrence. The considerations based on test theory and Bayesian logic lead to important ethical questioning of anti‐doping policies.
SLC26A9 is a constitutively active, CFTR-regulated anion conductance in human bronchial epithelia
Authors: Bertrand Carol A. , Zhang Ruilin , Pilewski Joseph M. , Frizzell Raymond A.
Published: March 2009

Human bronchial epithelial (HBE) cells exhibit constitutive anion secretion that is absent in cells from cystic fibrosis (CF) patients. The identity of this conductance is unknown, but SLC26A9, a member of the SLC26 family of CF transmembrane conductance regulator (CFTR)-interacting transporters, is found in the human airway and exhibits chloride channel behavior. We sought differences in the properties of SLC26A9 and CFTR expressed in HEK 293 (HEK) cells as a fingerprint to identify HBE apical anion conductances. HEK cells expressing SLC26A9 displayed a constitutive chloride current that was inhibited by the CFTR blocker GlyH-101 (71 ± 4%, 50 µM) and exhibited a near-linear current–voltage (I-V) relation during block, while GlyH-101–inhibited wild-type (wt)CFTR exhibited a strong inward-rectified (IR) I-V relation. We tested polarized HBE cells endogenously expressing either wt or ΔF508-CFTR for similar activity. After electrical isolation of the apical membrane using basolateral α-toxin permeabilization, wtCFTR monolayers displayed constitutive chloride currents that were inhibited by GlyH-101 (68 ± 6%) while maintaining a near-linear I-V relation. In the absence of blocker, the addition of forskolin stimulated a current increase having a linear I-V; GlyH-101 blocked 69 ± 7% of the current and shifted the I-V relation IR, consistent with CFTR activation. HEK cells coexpressing SLC26A9 and wtCFTR displayed similar properties, as well as forskolin-stimulated currents that exceeded the sum of those in cells separately expressing SLC26A9 or wtCFTR, and an I-V relation during GlyH-101 inhibition that was moderately IR, indicating that SLC26A9 contributed to the stimulated current. HBE cells from CF patients expressed SLC26A9 mRNA, but no constitutive chloride currents. HEK cells coexpressing SLC26A9 with ΔF508-CFTR also failed to exhibit SLC26A9 current. We conclude that SLC26A9 functions as an anion conductance in the apical membranes of HBE cells, it contributes to transepithelial chloride currents under basal and cAMP/protein kinase A–stimulated conditions, and its activity in HBE cells requires functional CFTR.
The analysis of desensitizing CNGA1 channels reveals molecular interactions essential for normal gating
Authors: Mazzolini Monica , Anselmi Claudio , Torre Vincent
Published: March 2009

The pore region of cyclic nucleotide–gated (CNG) channels acts as the channel gate. Therefore, events occurring in the cyclic nucleotide–binding (CNB) domain must be coupled to the movements of the pore walls. When Glu363 in the pore region, Leu356 and Thr355 in the P helix, and Phe380 in the upper portion of the S6 helix are mutated into an alanine, gating is impaired: mutant channels E363A, L356A, T355A, and F380A desensitize in the presence of a constant cGMP concentration, contrary to what can be observed in wild-type (WT) CNGA1 channels. Similarly to C-type inactivation of K+ channels, desensitization in these mutant channels is associated with rearrangements of residues in the outer vestibule. In the desensitized state, Thr364 residues in different subunits become closer and Pro366 becomes more accessible to extracellular reagents. Desensitization is also observed in the mutant channel L356C, but not in the double-mutant channel L356C+F380C. Mutant channels L356F and F380K did not express, but cGMP-gated currents with a normal gating were observed in the double-mutant channels L356F+F380L and L356D+F380K. Experiments with tandem constructs with L356C, F380C, and L356C+F380C and WT channels indicate that the interaction between Leu356 and Phe380 is within the same subunit. These results show that Leu356 forms a hydrophobic interaction with Phe380, coupling the P helix with S6, whereas Glu363 could interact with Thr355, coupling the pore wall to the P helix. These interactions are essential for normal gating and underlie the transduction between the CNB domain and the pore.
Elevations of intracellular calcium reflect normal voltage-dependent behavior, and not constitutive activity, of voltage-dependent calcium channels in gastrointestinal and vascular smooth muscle
Authors: McCarron John G. , Olson Marnie L. , Currie Susan , Wright Amanda J. , Anderson Kurt I. , Girkin John M.
Published: March 2009

In smooth muscle, the gating of dihydropyridine-sensitive Ca2+ channels may either be stochastic and voltage dependent or coordinated among channels and constitutively active. Each form of gating has been proposed to be largely responsible for Ca2+ influx and determining the bulk average cytoplasmic Ca2+ concentration. Here, the contribution of voltage-dependent and constitutively active channel behavior to Ca2+ signaling has been studied in voltage-clamped single vascular and gastrointestinal smooth muscle cells using wide-field epifluorescence with near simultaneous total internal reflection fluorescence microscopy. Depolarization (−70 to +10 mV) activated a dihydropyridine-sensitive voltage-dependent Ca2+ current (ICa) and evoked a rise in [Ca2+] in each of the subplasma membrane space and bulk cytoplasm. In various regions of the bulk cytoplasm the [Ca2+] increase ([Ca2+]c) was approximately uniform, whereas that of the subplasma membrane space ([Ca2+]PM) had a wide range of amplitudes and time courses. The variations that occurred in the subplasma membrane space presumably reflected an uneven distribution of active Ca2+ channels (clusters) across the sarcolemma, and their activation appeared consistent with normal voltage-dependent behavior. Indeed, in the present study, dihydropyridine-sensitive Ca2+ channels were not normally constitutively active. The repetitive localized [Ca2+]PM rises (“persistent Ca2+ sparklets”) that characterize constitutively active channels were observed rarely (2 of 306 cells). Neither did dihydropyridine-sensitive constitutively active Ca2+ channels regulate the bulk average [Ca2+]c. A dihydropyridine blocker of Ca2+ channels, nimodipine, which blocked ICa and accompanying [Ca2+]c rise, reduced neither the resting bulk average [Ca2+]c (at −70 mV) nor the rise in [Ca2+]c, which accompanied an increased electrochemical driving force on the ion by hyperpolarization (−130 mV). Activation of protein kinase C with indolactam-V did not induce constitutive channel activity. Thus, although voltage-dependent Ca2+ channels appear clustered in certain regions of the plasma membrane, constitutive activity is unlikely to play a major role in [Ca2+]c regulation. The stochastic, voltage-dependent activity of the channel provides the major mechanism to generate rises in [Ca2+].
Risk Factors for Fecal Colonization With Multiple Distinct Strains ofEscherichia coliAmong Long-Term Care Facility Residents
Authors: Lautenbach Ebbing , Tolomeo Pam , Black Nicole , Maslow Joel N.
Published: March 2009

Of 49 long-term care facility residents, 21 (43%) were colonized with 2 or more distinct strains ofEscherichia coli.There were no significant risk factors for colonization with multiple strains ofE. coli.These results suggest that future efforts to efficiently identify the diversity of colonizing strains will be challenging.
GS2: an efficiently computable measure of GO-based similarity of gene sets
Authors: Ruths Troy , Ruths Derek , Nakhleh Luay
Published: March 2009

Motivation: The growing availability of genome-scale datasets has attracted increasing attention to the development of computational methods for automated inference of functional similarities among genes and their products. One class of such methods measures the functional similarity of genes based on their distance in the Gene Ontology (GO). To measure the functional relatedness of a gene set, these measures consider every pair of genes in the set, and the average of all pairwise distances is calculated. However, as more data becomes available and gene sets used for analysis become larger, such pair-based calculation becomes prohibitive.

Results: In this article, we propose GS2 (GO-based similarity of gene sets), a novel GO-based measure of gene set similarity that is computable in linear time in the size of the gene set. The measure quantifies the similarity of the GO annotations among a set of genes by averaging the contribution of each gene's GO terms and their ancestor terms with respect to the GO vocabulary graph. To study the performance of our method, we compared our measure with an established pair-based measure when run on gene sets with varying degrees of functional similarities. In addition to a significant speed improvement, our method produced comparable similarity scores to the established method. Our method is available as a web-based tool and an open-source Python library.

Availability: The web-based tools and Python code are available at: http://bioserver.cs.rice.edu/gs2.

Contact:  troy.ruths@rice.edu
Using multi-data hidden Markov models trained on local neighborhoods of protein structure to predict residue–residue contacts
Authors: Björkholm Patrik , Daniluk Pawel , Kryshtafovych Andriy , Fidelis Krzysztof , Andersson Robin , Hvidsten Torgeir R.
Published: March 2009

Motivation:Correct prediction of residue–residue contacts in proteins that lack good templates with known structure would take ab initio protein structure prediction a large step forward. The lack of correct contacts, and in particular long-range contacts, is considered the main reason why these methods often fail.

Results: We propose a novel hidden Markov model (HMM)-based method for predicting residue–residue contacts from protein sequences using as training data homologous sequences, predicted secondary structure and a library of local neighborhoods (local descriptors of protein structure). The library consists of recurring structural entities incorporating short-, medium- and long-range interactions and is general enough to reassemble the cores of nearly all proteins in the PDB. The method is tested on an external test set of 606 domains with no significant sequence similarity to the training set as well as 151 domains with SCOP folds not present in the training set. Considering the top 0.2 · L predictions (L=sequence length), our HMMs obtained an accuracy of 22.8% for long-range interactions in new fold targets, and an average accuracy of 28.6% for long-, medium- and short-range contacts. This is a significant performance increase over currently available methods when comparing against results published in the literature.

Availability:  http://predictioncenter.org/Services/FragHMMent/

Contact:  torgeir.hvidsten@plantphys.umu.se

Supplementary information:  Supplementary data are available at Bioinformatics online.
Investing in Interagency Training to Safeguard Children: An Act of Faith or an Act of Reason?
Authors: Charles Marian , Horwath Jan
Published: March 2009

Since the 1970s, interagency training has been considered crucial for developing effective collaborative practice, initially in relation to child protection, and latterly, to safeguarding children's welfare. Charting the history of interagency training in England, this paper aims to demonstrate how, despite limited attention being paid to its evaluation, the role of training has expanded in terms of both content and target audience. This raises questions about the evidence base upon which investment in interagency training is founded. Drawing on the limited literature and experiences of interagency trainers, the authors question whether this investment is an act of faith or reason. They conclude that a belief in the value of training different disciplines together persists, despite little being known about the way in which interagency training improves practice.
Association of self‐reported alcohol use and hospitalization for an alcohol‐related cause in Scotland: a record‐linkage study of 23 183 individuals
Authors: McDonald Scott A. , Hutchinson Sharon J. , Bird Sheila M. , Graham Lesley , Robertson Chris , Mills Peter R. , Hayes Peter , Dillon John F. , Goldberg David J.
Published: March 2009

Aims  To investigate the extent to which self‐reported alcohol consumption level in the Scottish population is associated with first‐time hospital admission for an alcohol‐related cause.

Design  Observational record‐linkage study.

Setting  Scotland, 1995–2005.

Participants  A total of 23 183 respondents aged 16 and over who participated in the 1995, 1998 and 2003 Scottish Health Surveys, followed‐up via record‐linkage from interview date until 30 September 2005.

Measurements  Rate of first‐time hospital admission with at least one alcohol‐related diagnosis. Cox proportional hazards regression analysis was applied to estimate the relative risk of first‐time hospitalization with an alcohol‐related condition associated with usual alcohol consumption level (1–7, 8–14, 15–21, 22–35, 36–49, 50+ units/week and ex‐drinker, compared with <1 unit per week).

Findings  Of the SHS participants, 527 were hospitalized for an alcohol‐related cause during 135 313 person‐years of follow‐up [39 first admissions per 10 000 person‐years, 95% confidence interval (CI) 36–42]. Alcohol‐related hospitalization rates were considerably higher for males (61/10 000 person‐years, 95% CI 54–67) than for females (22/10 000 person‐years, 95% CI 18–26). Compared with the lowest alcohol consumption category (<1 unit per week), the relative risk of first‐time alcohol‐related admission increased with reported consumption: age‐adjusted hazard ratios ranged from 3 (1–5) for 1–7 units/week to 19 (10–37) for 50+ units/week (males); and from 2 (1–3) for 1–7 units/week to 28 (14–56) for 50+ units/week (females). After adjusting for age and usual alcohol consumption, the relative risk of first‐time alcohol‐related admission remained significantly higher for males reporting binge drinking and for both males and females residing in the most deprived localities.

Conclusions  Moderate and higher levels of usual alcohol consumption and binge drinking are serious risk factors for alcohol‐related hospitalization in the Scottish population. These findings contribute to our understanding of the relationship between alcohol intake and alcohol‐related morbidity.
A computerized harm minimization prevention program for alcohol misuse and related harms: randomized controlled trial
Authors: Vogl Laura , Teesson Maree , Andrews Gavin , Bird Kevin , Steadman Bronwyn , Dillon Paul
Published: March 2009

Aims Hazardous alcohol use is a leading cause of death among adolescents and young adults world‐wide, yet few effective prevention interventions exist. This study was the first to examine a computerized harm minimization intervention to reduce alcohol misuse and related harms in adolescents.

Design Cluster randomized controlled trial of a six‐session curriculum‐integrated harm minimization prevention program. The intervention was delivered by computer in the form of a teenage drama, which provided education through alcohol‐related scenarios to which young people could relate.

Setting Schools in Australia.

Participants A total of 1466 year 8 students (13 years) from 16 high schools in Australia were allocated randomly to a computerized prevention program (n = 611, eight schools) or usual classes (n = 855, eight schools).

Measurements Change in knowledge, alcohol use, alcohol‐related harms and alcohol expectancies.

Findings A computerized prevention program was more effective than usual classes in increasing alcohol‐related knowledge of facts that would inform safer drinking choices and decreasing the positive social expectations which students believed alcohol may afford. For females it was effective in decreasing average alcohol consumption, alcohol‐related harms and the frequency of drinking to excess (more than four standard drinks; 10 g ethanol). For males the behavioural effects were not significant.

Conclusions A harm minimization approach is effective in educating young people about alcohol‐related risks and is effective in reducing risky drinking and harms among girls. Reduction of problems among boys remains a challenge.
Soluble human leucocyte antigen‐G and interleukin‐10 levels in isocyanate‐induced asthma
Authors: Mapp C. E. , Ferrazzoni S. , Rizzo R. , Miotto D. , Stignani M. , Boschetto P. , Maestrelli P. , Baricordi O. R.
Published: March 2009

Background
We previously reported that in moderate‐to‐severe asthma there is a deficit of IL‐10 secretion that could prevent the production of soluble HLA‐G (sHLA‐G), a non‐classical human leucocyte antigen class I molecule with tissue‐protective properties in inflammatory responses.

Objective
Our objective was to investigate the production of sHLA‐G and the secretion of IL‐10 by peripheral blood mononuclear cells (PBMCs) in asthma induced by isocyanates and to compare the results with those obtained in non‐occupational allergic asthma.

Method
sHLA‐G and IL‐10 were measured by ELISA in the culture supernatants of unstimulated or lipopolysaccharide (LPS)‐stimulated PBMCs obtained from 20 subjects with isocyanate asthma, 16 asymptomatic subjects exposed to isocyanates, 18 subjects with non‐occupational allergic asthma, and 26 healthy control subjects.

Results
Occupational exposure to isocyanates was associated with high baseline levels of secretion of IL‐10 by PBMCs, whether or not the exposed subjects had asthmatic symptoms. However, spontaneous production of sHLA‐G by PBMC was significantly higher in subjects with isocyanate asthma compared with asymptomatic‐exposed controls. In contrast, PBMCs from subjects with non‐occupational allergic asthma produced sHLA‐G only after LPS stimulation.

Conclusions
sHLA‐G production and IL‐10 secretion are influenced by workplace exposure to isocyanates and by development of asthma. The different behaviour of both sHLA‐G and IL‐10 in asthma induced by isocyanates compared with non‐occupational allergic asthma suggests a heterogeneous biological role for HLA‐G molecules and for IL‐10, a key cytokine of immune and inflammatory responses.
Genetic and environmental contributions to allergen sensitization in a Chinese twin study
Authors: Liu X. , Zhang S. , Tsai H‐J , Hong X. , Wang B. , Fang Y. , Liu X. , Pongracic J. A. , Wang X.
Published: March 2009

Background
Allergic disease is on the rise worldwide. Effective prevention of allergic disease requires comprehensive understanding of the factors that contribute to its intermediate phenotypes, such as sensitization to common allergens.

Objective
To estimate the degree of genetic and environmental contributions to sensitization to food and aeroallergens.

Methods
Sensitization was defined as a positive skin prick test to an allergen. We calculated the zygosity‐specific concordance rates and odds ratios (ORs) for sensitization to food and aeroallergens in 826 Chinese twin pairs [472 monozygotic (MZ) and 354 dizygotic (DZ)] aged 12–28 years. We also applied structural equation modelling procedures to estimate genetic and environmental influences on sensitization.

Results
The concordance rates and risk of sensitization in one twin given the presence vs. the absence of sensitization in the other twin were higher in MZ twins than those in DZ twins. However, a large number of MZ twins were discordant in sensitization to common allergens. These observations suggest both genetic and environmental factors influence sensitization. Consistently, the estimated heritability and individual environmental components of the liability to sensitization ranged from 0.51 to 0.68 and 0.32 to 0.49, respectively, based on the best‐fitted structural equation model. We also observed high phenotypic correlations between sensitization to two aeroallergens (cockroach and dust mite: 0.83) and two food allergens (peanut and shellfish: 0.58), but only moderate correlations for the pairs between sensitization to a food and an aeroallergen (0.31–0.46). The shared genetic and environmental factors between paired sensitizations contribute to the observed correlations.

Conclusion
We demonstrated that sensitization to common food and aeroallergens were influenced by both genetic and environmental factors. Moreover, we found that paired allergen sensitizations might share some common sets of genes and environmental factors. This study underscores the need to further delineate unique and/or pleiotropic genetic and environmental factors for allergen sensitization.
Tree mortality in the African Sahel indicates an anthropogenic ecosystem displaced by climate change
Authors: Maranz Steven
Published: March 2009

Aim Widespread reports of disappearing tree species and senescing savanna parklands in the Sahel have generated a vigorous debate over whether climate change or severe human and livestock pressure is principally responsible. Many of the tree taxa in decline are closely associated with human settlement and farming, suggesting that the parkland ecosystem may not be a natural vegetation assemblage. The aim of this study is to assess the possibility that human activities promoted the spread of taxa with edible fruit into dry Sudano‐Sahelian areas during high‐rainfall periods in the climate cycle.

Location West African savannas (Mali, Burkina Faso, Ghana, Togo, Benin).

Methods Cultivated savanna parklands and adjacent forests and transitional landscapes were inventoried at 27 sites in five countries. All trees with basal diameters > 10 cm were counted within 500‐m2belt transects. Species composition and abundance were contrasted between three landscape classes to assess the degree of influence exerted by traditional human management. Twentieth century rainfall data were averaged for two sets of weather stations encompassing the north–south range of typical parkland tree species. Rainfall trends were used to evaluate the putative impact of climate change on edible and/or succulent fruit species at the northern limit of the parkland savanna zone.

Results Species composition and spatial distribution data indicate that the parkland ecosystem is significantly shaped by human activities. Indigenous land management favours edible‐fruit‐yielding taxa from the wetter Sudanian and Guinean vegetation zones over Sahelian species. Rainfall isohyets at the northern range limits of parkland species shifted southwards in the late 20th century, crossing the critical 600‐mm mean annual rainfall threshold for Sudanian flora. Relict vegetation and historical records indicate that the Sudanian parkland system extended in the past to near 15° N latitude in middle West Africa, compared with 13.5° N today.

Main conclusions The current loss of mesic trees in the Sudano‐Sahel zone appears to be driven by the sharp drop in rainfall since the 1960s, which has effectively stranded anthropogenically distributed species beyond their rainfall tolerance limits.
On the general dynamic model of oceanic island biogeography
Authors: Fattorini Simone
Published: March 2009

Aim  To investigate the biological meaning of equations used to apply the general dynamic model (GDM) of oceanic island biogeography proposed by R. J. Whittaker, K. A. Triantis and R. J. Ladle.

Location  Analyses are presented for 17 animal groups living on the Aeolian Islands, a volcanic archipelago in the central Mediterranean, near Sicily.

Methods  In addition to the mathematical implementation of the GDM proposed by Whittaker, Triantis and Ladle, and termed here logATT2 (, where S is species number or any other diversity metric, t is island age, A is island area, and a, b, c and d are fitted parameters), a new implementation based on the Arrhenius equation of the species–area relationship (SAR) is investigated. The new model (termed powerATT2) is: . For logATT2 and powerATT2 models, equations were developed to calculate (1) the expected number of species at equilibrium (i.e. when the island has reached maturity) per unit area (Seq), and (2) the time required to obtain this value (teq). Whereas the intercept in the Gleason model (S = C + z log A) or the coefficient of the Arrhenius power model (S = CAz) of the SAR can be considered measures of the expected number of species per unit area, this is not the case for the parameter a of the ATT2 models. However, values of Seq can be used for this purpose. The index of ‘colonization ability’ (CAB), calculated as the ratio , may provide a measure of the mean number of species added per unit area per unit time.

Results  Both ATT2 models fitted most of the data well, but the powerATT2 model was in most cases superior. Equilibrial values of species richness (Seq) varied from c. 3 species km−2 (reptiles) to 100 species km−2 (mites). The fitted curves for the powerATT2 model showed large variations in d, from 0.03 to 3. However, most groups had values of d around 0.2–0.4, as commonly observed for the z‐values of SARs modelled by a power function. Equilibration times ranged from about 170,000 years to 400,000 years. Mites and springtails had very high values of CAB, thus adding many more species per unit area per unit time than others. Reptiles and phytophagous scarabs showed very low values, being the groups that added fewest species per unit area per unit time.

Main conclusions  Values of equilibrial species richness per unit area are influenced by species biology (e.g. body size and ecological specialization). Theoretical and empirical evidence suggests that higher immigration rates should increase the z‐values of the Arrhenius model. Thus, in the same archipelago, groups with larger z‐values should be characterized by higher dispersal ability. Results obtained here for the parameter d conform to this prediction.
Canopy closure shapes clonal diversity and fine‐scale genetic structure in the dioecious understorey perennial Mercurialis perennis
Authors: Vandepitte Katrien , Roldán‐Ruiz Isabel , Leus Leen , Jacquemyn Hans , Honnay Olivier
Published: March 2009

The degree of canopy closure can shape the dynamics of understorey plant populations that rely on clonal and sexual recruitment. Populations are expected to undergo declines in clonal diversity under conditions where recruitment from seed is temporally and spatially restricted. Localized seedling recruitment in clonal populations may also affect spatial genetic structure due to the clumping of genetically related genets.

Our major objective was to determine the effect of the degree of canopy closure on clonal diversity and spatial genetic structure in the rhizomatous, dioecious forest perennial Mercurialis perennis. As the distribution of the male and female shoots has been shown to be influenced by canopy openings, we paid special attention to the mediating role of the varying sex ratio.

We used genome‐wide AFLP markers to fingerprint six populations of M. perennis along a light penetration gradient.

The proportion of male shoots in a population increased from 0.51 to 0.81 and male genet diversity decreased from 0.72 to 0.21 with increasing site illumination, in agreement with earlier reports of superior male growth in canopy openings. The most illuminated population, with the highest proportion of male shoots, was dominated by a few outsized, largely aggregated male clones (largest clone spreading over 10 m).

Overall clonal diversity (G/N: 0.31–0.74; mean: 0.52) and evenness strongly declined in well‐lit sites, suggesting reduced sexual recruitment and the vast vegetative spread of a few locally well‐adapted male genets under canopy gaps.

Fine‐scale genetic structure among genets was significant within all populations, but its degree tended to increase with an increased proportion of male shoots and reduced clonal diversity. Very localized recruitment due to a low seed dispersal capacity combined with the aggregated distribution of large gender‐specific clones likely incurred this pattern.

Synthesis. Forest management practices such as the cutting and removal of trees and the establishment of paths decreased the degree of canopy closure. Many understorey herb populations flourish in these canopy gaps, reflected in a higher clonal diversity. We demonstrated, however, that increased illumination negatively affects genotypic and genetic diversity in the dioecious understorey herb M. perennis.
Neither genetic nor observational data alone are sufficient for understanding sex‐biased dispersal in a social‐group‐living species
Authors: HARRIS T. R. , CAILLAUD D. , CHAPMAN C. A. , VIGILANT L.
Published: March 2009

Complex sex‐biased dispersal patterns often characterize social‐group‐living species and may ultimately drive patterns of cooperation and competition within and among groups. This study investigates whether observational data or genetic data alone can elucidate the potentially complex dispersal patterns of social‐group‐living black and white colobus monkeys (Colobus guereza, ‘guerezas’), or whether combining both data types provides novel insights. We employed long‐term observation of eight neighbouring guereza groups in Kibale National Park, Uganda, as well as microsatellite genotyping of these and two other neighbouring groups. We created a statistical model to examine the observational data and used dyadic relatedness values within and among groups to analyse the genetic data. Analyses of observational and genetic data both supported the conclusion that males typically disperse from their natal groups and often transfer into nearby groups and probably beyond. Both data types also supported the conclusion that females are more philopatric than males but provided somewhat conflicting evidence about the extent of female philopatry. Observational data suggested that female dispersal is rare or nonexistent and transfers into neighbouring groups do not occur, but genetic data revealed numerous pairs of closely related adult females among neighbouring groups. Only by combining both data types were we able to understand the complexity of sex‐biased dispersal patterns in guerezas and the processes that could explain our seemingly conflicting results. We suggest that the data are compatible with a scenario of group dissolution prior to the start of this study, followed by female transfers into different neighbouring groups.
Natural selection influences AFLP intraspecific genetic variability and introgression patterns in Atlantic eels
Authors: GAGNAIRE P. A. , ALBERT V. , JÓNSSON B. , BERNATCHEZ L.
Published: March 2009

Investigating patterns of genetic variation in hybridizing species provides an opportunity to understand the impact of natural selection on intraspecific genetic variability and interspecific gene exchange. The Atlantic eels Anguilla rostrata and A. anguilla each occupy a large heterogeneous habitat upon which natural selection could differentially shape genetic variation. They also produce viable hybrids only found in Iceland. However, the possible footprint of natural selection on patterns of genetic variation within species and introgressive hybridization in Icelandic eels has never been assessed. We revisited amplified fragment length polymorphism data collected previously using population genomics and admixture analyses to test if (i) genetic variation could be influenced by non‐neutral mechanisms at both the intra‐ and interspecific levels, and if (ii) selection could shape the spatio‐temporal distribution of Icelandic hybrids. We first found candidate loci for directional selection within both species. Spatial distributions of allelic frequencies displayed by some of these loci were possibly related with the geographical patterns of life‐history traits in A. rostrata, and could have been shaped by natural selection associated with an environmental gradient along European coasts in A. anguilla. Second, we identified outlier loci at the interspecific level. Non‐neutral introgression was strongly suggested for some of these loci. We detected a locus at which typical A. rostrata allele hardly crossed the species genetic barrier, whereas three other loci showed accelerated patterns of introgression into A. anguilla in Iceland. Moreover, the level of introgression at these three loci increased from the glass eel to the yellow eel stage, supporting the hypothesis that differential survival of admixed genotypes partly explains the spatio‐temporal pattern of hybrid abundance previously documented in Iceland.
Chloroplast DNA phylogeography suggests a West African centre of origin for the baobab,Adansonia digitataL. (Bombacoideae, Malvaceae)
Authors: POCK TSY JEAN‐MICHEL LEONG , LUMARET ROSELYNE , MAYNE DIANA , VALL ABDALLAHI OULD MOHAMED , ABUTABA YAHIA I. M. , SAGNA MAURICE , RAOSETA SOAHARIN’NY ONY RAKOTONDRALAMBO , DANTHU PASCAL
Published: March 2009

The African baobab (Adansonia digitataL.) is an emblematic, culturally important, and physically huge tropical tree species whose natural geographical distribution comprises most of tropical Africa, but also small patches of southern Arabia, and several Atlantic and Indian Ocean islands surrounding the African continent, notably including Madagascar. We analysed the polymerase chain reaction–restriction fragment length polymorphism of five chloroplast DNA fragments obtained from 344 individuals ofA. digitatacollected from 74 populations covering the entire extant distribution range of the species. Our goal was to reconstruct the phylogeographical history of the species and, if possible, to identify its centre of origin, which has been a subject of controversy for many decades. We identified five haplotypes whose distribution is clearly geographically structured. Using several species ofAdansoniaand of closely related genera as outgroups, the haplotypes showed a clear phylogeographical pattern of three groups. Two are phylogenetically related to the outgroup taxa, and are distributed in West Africa. The third group is substantially more differentiated genetically from outgroup species, and it corresponds to southern and eastern Africa, Arabia and the Indian Ocean islands, including Madagascar. According to our results, the tetraploidA. digitata, or its diploid progenitor, probably originated in West Africa and migrated subsequently throughout the tropical parts of that continent, and beyond, by natural and human‐mediated terrestrial and overseas dispersal.
Unwinding the structure and function of the archaeal MCM helicase
Authors: Sakakibara Nozomi , Kelman Lori M. , Kelman Zvi
Published: March 2009

During chromosomal DNA replication, the replicative helicase unwinds the duplex DNA to provide the single‐stranded DNA substrate for the polymerase. In archaea, the replicative helicase is the minichromosome maintenance (MCM) complex. The enzyme utilizes the energy of ATP hydrolysis to translocate along one strand of the duplex and unwind the complementary strand. Much progress has been made in elucidating structure and function since the first report on the biochemical properties of an archaeal MCM protein in 1999. We now know the biochemical and structural properties of the enzyme from several archaeal species and some of the mechanisms by which the enzyme is regulated. This review summarizes recent studies on the archaeal MCM protein and discusses the implications for helicase function and DNA replication in archaea.
Association between single nucleotide polymorphisms of surfactant protein D and allergic rhinitis in Chinese patients
Authors: Deng Y.‐Q. , Tao Z.‐Z. , Kong Y.‐G. , Xiao B.‐K. , Chen S.‐M. , Xu Y. , Wang Y. , He Q.
Published: March 2009

The development of allergic rhinitis is considered to be determined by the interaction between genetic and environmental factors. Surfactant protein D (SP‐D) has been proposed to offer protection against allergenic challenge at various levels in allergic responses. The present study aimed to investigate whether polymorphisms within the SFTPD gene (Met11Thr, Ala160Thr, and Ser270Thr) are associated with allergic rhinitis. Genotyping of SFTPD polymorphisms was performed using the pyrosequencing method. The study population comprised 216 patients with allergic rhinitis and 84 normal controls. The frequency of 11Thr/Thr genotype and Thr allele in the patient group was significantly higher than that in the control group after applying Bonferroni corrections (P = 0.007 and P = 0.006, respectively). Our subjects with the 11Thr/Thr genotype are more susceptible to allergic rhinitis. There were no significant differences between the patient group and the control group for frequencies of genotypes and alleles in either Ala160Thr or Ser270Thr single nucleotide polymorphisms (P > 0.05). No significant associations could be detected between any of these three SFTPD gene polymorphisms and the skin prick test response (P > 0.05). Meanwhile, there was a lack of association between the three loci and the levels of serum total immunoglobulin E (P > 0.05). In summary, our results suggest that the Met11Thr polymorphism in SP‐D plays a major role in the genetic predisposition to allergic rhinitis in Chinese adult population, whereas the other two SP‐D polymorphisms displayed no significant association with allergic rhinitis.
HLA‐B*27 subtypes in Northern and Northeastern Thais, Karens, and Bamars determined by a high‐resolution PCR‐SSP technique
Authors: Duangchanchot M. , Puapairoj C. , Romphruk A. , Kongmaroeng C. , Leelayuwat C. , Romphruk A. V.
Published: March 2009

Human leukocyte antigens (HLA), class I, are a group of antigens expressed on most nucleated cell surfaces. They transport endogenous peptides to the cell surface for recognition by T‐cell receptors. Their functions are involved in immune responses. Many diseases are associated with HLA alleles, especially HLA‐B*27 that is strongly associated with ankylosing spondylitis (AS). HLA‐B*27 consists of 42 subtypes. Different subtypes of HLA‐B*27 were reported in different ethnic groups of AS patients. In this study, a high‐resolution polymerase chain reaction–sequence‐specific primer technique has been developed to define all the HLA‐B*27 subtypes with a total of 29 primer mixtures. Two of the primer mixes were used to detect the HLA‐B*27‐specific group, and 27 primer mixes were used to identify 42 subtypes (B*2701–B*2721 and B*2723–B*2743). The HLA‐B*27‐group‐specific primers have been tested in unrelated healthy subjects; 846 Northeastern Thais (NET), 334 Northern Thais (NT), 264 Karens, and 310 Bamars. Sixty‐three NET (phenotype frequency, PF = 7.4%), 24 NT (PF = 7.1%), 5 Karens (PF = 1.8%), and 12 Bamars (PF = 3.9%) were positive for HLA‐B*27. Only B*2704 was found in Karens, whereas B*2704, B*2705/37/39, B*2706, and B*2707 were found in NET and NT. In Bamars, B*2704, B*2705/37/39, B*2706, and B*2725 were found. The distribution of HLA‐B*27 subtypes was compared with other studies in Asian and Caucasian populations. Significant differences of the distribution of HLA‐B*27 subtypes were found in most of the populations. This study established a simple technology for HLA‐B*27 subtyping and provided basic information for anthropology and further studies in disease associations.
Trade‐off between steady and unsteady swimming underlies predator‐driven divergence inGambusia affinis
Authors: LANGERHANS R. B.
Published: March 2009

Differences in predation intensity experienced by organisms can lead to divergent natural selection, driving evolutionary change. Western mosquitofish (Gambusia affinis) exhibit larger caudal regions and higher burst‐swimming capabilities when coexisting with higher densities of predatory fish. It is hypothesized that a trade‐off between steady (constant‐speed cruising; important for acquiring resources) and unsteady (rapid bursts and turns; important for escaping predators) locomotion, combined with divergent selection on locomotor performance (favouring steady swimming in high‐competition scenarios of low‐predation environments, but unsteady swimming in high‐predation localities) has caused such phenotypic divergence. Here, I found that morphological differences had a strong genetic basis, and low‐predation fish required less hydromechanical power during steady swimming, leading to increased endurance. I further found individual‐level support for cause‐and‐effect relationships between morphology, swimming kinematics and endurance. Results indicate that mosquitofish populations inhabiting low‐predation environments have evolved increased steady‐swimming abilities via stiffer bodies, larger anterior body/head regions, smaller caudal regions and greater three‐dimensional streamlining.
Sex Recognition via Chemical Cues in the Sex‐Role‐Reversed Gulf Pipefish (Syngnathus scovelli)
Authors: Ratterman Nicholas L. , Rosenthal Gil G. , Jones Adam G.
Published: March 2009

Sexual selection theory predicts that members of the choosy sex, usually females, should employ multiple sensory systems to obtain information about potential mates. Such predictions should also apply to systems in which sexual selection acts most strongly on females (i.e. sex‐role‐reversed species), and males of these taxa should be the individuals employing multiple cues to assess female attractiveness. Very little work has been directed toward mate choice involving multiple sensory systems in sex‐role‐reversed taxa, but fishes of the family Syngnathidae (pipefishes, seahorses, and sea dragons) provide an excellent opportunity to contribute to this research enterprise. While much is known about visual communication in pipefish, the role of chemical communication has not been investigated. Using dichotomous choice tests, we found that male, but not female, Gulf pipefish attended to chemical cues of opposite sex conspecifics. Given that males distinguished sex on the basis of chemical cues, we also tested whether males could assess female body size, an important trait with respect to mate choice in pipefish, on the basis of chemical cues alone. When given the choice between chemical cues produced by large vs. small females, males exhibited no preference. Our results suggest that male pipefish can use chemical cues to distinguish between males and females but not to differentiate females of different body size.