bluuebunny/crossref_metadata_2025 huggingface dataset:
Embryonic exposure to corticosterone modifies the juvenile stress response, oxidative stress and telomere length
Authors: Haussmann Mark F. , Longenecker Andrew S. , Marchetto Nicole M. , Juliano Steven A. , Bowden Rachel M.
Published: November 2011

Early embryonic exposure to maternal glucocorticoids can broadly impact physiology and behaviour across phylogenetically diverse taxa. The transfer of maternal glucocorticoids to offspring may be an inevitable cost associated with poor environmental conditions, or serve as a maternal effect that alters offspring phenotype in preparation for a stressful environment. Regardless, maternal glucocorticoids are likely to have both costs and benefits that are paid and collected over different developmental time periods. We manipulated yolk corticosterone (cort) in domestic chickens (Gallus domesticus) to examine the potential impacts of embryonic exposure to maternal stress on the juvenile stress response and cellular ageing. Here, we report that juveniles exposed to experimentally increased cortin ovohad a protracted decline in cort during the recovery phase of the stress response. All birds, regardless of treatment group, shifted to oxidative stress during an acute stress response. In addition, embryonic exposure to cort resulted in higher levels of reactive oxygen metabolites and an over-representation of short telomeres compared with the control birds. In many species, individuals with higher levels of oxidative stress and shorter telomeres have the poorest survival prospects. Given this, long-term costs of glucocorticoid-induced phenotypes may include accelerated ageing and increased mortality.
Fitness consequences of plants growing with siblings: reconciling kin selection, niche partitioning and competitive ability
Authors: File Amanda L. , Murphy Guillermo P. , Dudley Susan A.
Published: November 2011

Plant studies that have investigated the fitness consequences of growing with siblings have found conflicting evidence that can support different theoretical frameworks. Depending on whether siblings or strangers have higher fitness in competition, kin selection, niche partitioning and competitive ability have been invoked. Here, we bring together these processes in a conceptual synthesis and argue that they can be co-occurring. We propose that these processes can be reconciled and argue for a trait-based approach of measuring natural selection instead of the fitness-based approach to the study of sibling competition. This review will improve the understanding of how plants interact socially under competitive situations, and provide a framework for future studies.
Evaluation of the minimum energy hypothesis and other potential optimality criteria for human running
Authors: Miller Ross H. , Umberger Brian R. , Hamill Joseph , Caldwell Graham E.
Published: November 2011

A popular hypothesis for human running is that gait mechanics and muscular activity are optimized in order to minimize the cost of transport (CoT). Humans running at any particular speed appear to naturally select a stride length that maintains a low CoT when compared with other possible stride lengths. However, it is unknown if the nervous system prioritizes the CoT itself for minimization, or if some other quantity is minimized and a low CoT is a consequential effect. To address this question, we generated predictive computer simulations of running using an anatomically inspired musculoskeletal model and compared the results with data collected from human runners. Three simulations were generated by minimizing the CoT, the total muscle activation or the total muscle stress, respectively. While all the simulations qualitatively resembled real human running, minimizing activation predicted the most realistic joint angles and timing of muscular activity. While minimizing the CoT naturally predicted the lowest CoT, minimizing activation predicted a more realistic CoT in comparison with the experimental mean. The results suggest a potential control strategy centred on muscle activation for economical running.
Plant establishment and invasions: an increase in a seed disperser combined with land abandonment causes an invasion of the non-native walnut in Europe
Authors: Lenda Magdalena , Skórka Piotr , Knops Johannes M. H. , Moroń Dawid , Tworek Stanisław , Woyciechowski Michał
Published: November 2011

Successful invasive species often are established for a long time period before increasing exponentially in abundance. This lag phase is one of the least understood phenomena of biological invasions. Plant invasions depend on three factors: a seed source, suitable habitat and a seed disperser. The non-native walnut,
Juglans regia
, has been planted for centuries in Central Europe but, until recently, has not spread beyond planted areas. However, in the past 20 years, we have observed a rapid increase in walnut abundance, specifically in abandoned agricultural fields. The dominant walnut disperser is the rook,
Corvus frugilegus
. During the past 50 years, rooks have increased in abundance and now commonly inhabit human settlements, where walnut trees are planted. Central Europe has, in the past few decades, experienced large-scale land abandonment. Walnut seeds dispersed into ploughed fields do not survive, but when cached into ploughed and then abandoned fields, they successfully establish. Rooks preferentially cache seeds in ploughed fields. Thus, land-use change combined with disperser changes can cause rapid increase of a non-native species, allowing it to become invasive. This may have cascading effects on the entire ecosystem. Thus, species that are non-native and not invasive can become invasive as habitats and dispersers change.
Prevalence of human papillomavirus in mobile tongue cancer with particular reference to young patients
Authors: Kabeya Masayuki , Furuta Reiko , Kawabata Kazuyoshi , Takahashi Sugata , Ishikawa Yuichi
Published: November 2011

The carcinogenetic role of human papillomavirus (HPV) in mobile tongue cancer remains unclear because of conflicting results reported in the literature. This disparity is likely to be due to variations in the samples and methods used. Furthermore, despite a tendency for increased prevalence of mobile tongue cancer in young adults, only a few reports specifically in young patients have been published. In the present study on 32 patients, including six in their 20s, we genotyped the prevalence of HPV using a highly sensitive detection tool in fresh‐frozen samples from surgical specimens and a novel detection device with electrochemical DNA chip and loop‐mediated isothermal amplification. In addition, we confirmed HPV prevalence by in situ hybridization and immunohistochemistry for the p16INK4a protein, regarded as a biomarker of HPV‐associated cancers. The frequency of 13 genotypes of high‐risk HPV was 0/32 (0%), which was further confirmed by in situ hybridization. Overexpression of p16INK4a protein was observed in six of the 32 patients (19%), with four (67%) also overexpressing p53. Because there is usually a lack of p53 overexpression in HPV‐associated cancer, it is unlikely that p16INK4a protein overexpression is correlated with HPV infection. Consequently, it is unlikely that HPV infection plays an important role in mobile tongue carcinogenesis, in particular in young adults. In addition, our data suggest that the overexpression of p16INK4a protein is not an appropriate biomarker for HPV association in mobile tongue carcinogenesis. (Cancer Sci 2012; 103: 161–168)
A validation study of the CEMACH recommended modified early obstetric warning system (MEOWS)*
Authors: Singh S. , McGlennan A. , England A. , Simons R.
Published: November 2011

The 2003–2005 Confidential Enquiry into Maternal and Child Health report recommended the introduction of the modified early obstetric warning system (MEOWS) in all obstetric inpatients to track maternal physiological parameters, and to aid early recognition and treatment of the acutely unwell parturient. We prospectively reviewed 676 consecutive obstetric admissions, looking at their completed MEOWS charts for triggers and their notes for evidence of morbidity. Two hundred patients (30%) triggered and 86 patients (13%) had morbidity according to our criteria, including haemorrhage (43%), hypertensive disease of pregnancy (31%) and suspected infection (20%). The MEOWS was 89% sensitive (95% CI 81–95%), 79% specific (95% CI 76–82%), with a positive predictive value 39% (95% CI 32–46%) and a negative predictive value of 98% (95% CI 96–99%). There were no admissions to the intensive care unit, cardio respiratory arrests or deaths during the study period. This study suggests that MEOWS is a useful bedside tool for predicting morbidity. Adjustment of the trigger parameters may improve positive predictive value.
The influence of pre‐admission hypoglycaemic therapy on cardiac morbidity and mortality in type 2 diabetic patients undergoing major non‐cardiac surgery: a prospective observational study*
Authors: Bolliger D. , Seeberger M. D. , Lurati Buse G. , Christen P. , Seeberger E. , Ruppen W. , Filipovic M.
Published: November 2011

It remains unclear whether type 2 diabetics treated with either insulin or oral hypoglycaemic agents have the same incidence of cardiac morbidity and mortality after major non‐cardiac surgery. We prospectively studied 360 type 2 diabetic patients undergoing major non‐cardiac surgery of which 105 were treated with insulin only, 171 were treated with oral hypoglycaemics only and 84 were treated with a combination of insulin and oral hypoglycaemics. All‐cause mortality after 30 days and after 12 months was highest in the insulin (10% and 26%) and lowest in the oral hypoglycaemics group (2% and 13%; p = 0.02 and 0.007, respectively). Insulin treatment was independently associated with increased mortality after 30 days (hazard ratio 3.93; 95% CI 1.22–12.64; p = 0.022) and 12 months (hazard ratio 2.03; 95% CI 1.16–3.58; p = 0.014) after multivariate adjustment for age, sex and the revised cardiac risk index (insulin treatment excluded). The increased mortality in insulin‐treated diabetic patients may be due to a more progressive disease state in these patients rather than the treatment modality itself.
Inbreeding in the Thoroughbred horse
Authors: Binns M. M. , Boehler D. A. , Bailey E. , Lear T. L. , Cardwell J. M. , Lambert D. H.
Published: November 2011

Changes in the inbreeding coefficient, F, in the Thoroughbred horse over the past 45 years have been investigated by genotyping 467 Thoroughbred horses (born between 1961 and 2006) using the Illumina Equine SNP50 bead chip, which comprises 54 602 SNPs uniformly distributed across the equine genome. The Spearman rank correlation coefficient, r, between the year of birth and F was estimated. The results indicate that inbreeding in Thoroughbreds has increased over the past 40 years, with r = 0.24, P < 0.001 demonstrating that there is a highly significant, though relatively weak correlation between the year of birth and inbreeding coefficients. Interestingly, the majority of the increase in inbreeding is post‐1996 and coincides with the introduction of stallions covering larger numbers of mares.
Parenting children with neurodevelopmental disorders and/or behaviour problems
Authors: Garner R. E. , Arim R. G. , Kohen D. E. , Lach L. M. , MacKenzie M. J. , Brehaut J. C. , Rosenbaum P. L.
Published: November 2011

Background  Parenting behaviours influence child well‐being and development. However, much of the research on parenting behaviours and their correlates has focused on caregivers of healthy, typically developing children. Relatively less is known about the parenting behaviours of caregivers of children with chronic health conditions.

Objective  To examine and compare three parenting behaviours (positive interactions, consistency and ineffective parenting) among caregivers of children with neurodevelopmental disorders and/or externalizing behaviour problems, before and after accounting for child and family socio‐demographic characteristics.

Methods  Participants (n= 14 226) were drawn from the National Longitudinal Survey of Children and Youth, a long‐term study of Canadian children that follows their development and well‐being from birth to early adulthood. Children (and their caregivers) were divided into four groups according to the presence of a neurodevelopmental disorder (NDD; n= 815), the presence of an externalizing behaviour problem (EBP; n= 1322), the presence of both conditions (BOTH; n= 452) or neither of these conditions (NEITHER; n= 11 376).

Results  Caregivers of children in the NEITHER group reported significantly higher positive interaction scores and lower ineffective parenting behaviours than caregivers of children in any of the other three groups. Caregivers of children in the EBP and BOTH groups reported similar levels of consistency, but significantly lower levels than caregivers of NDD or NEITHER children. These associations largely remained after accounting for child and family socio‐demographic characteristics, with two exceptions: caregivers' reports of positive interactions were no longer significantly associated with child's NDD and BOTH conditions.

Conclusions  Parenting children with multiple health conditions can be associated with less positive, less consistent and more ineffective parenting behaviours. Understanding the factors that are associated with the challenges of caring for these children may require additional research attention.
Shyness in late childhood: relations with attributional styles and self‐esteem
Authors: Chan S. M. , Wong A. K. Y.
Published: November 2011

Background  Shyness in late childhood is related to social and psychological problems. The present study examined the relations among shyness, attributional styles and self‐esteem. It was hypothesized that self‐esteem mediated the effects of attributional styles on shyness.

Methods  Self‐reported data on degree of shyness, attributional styles and self‐esteem were obtained from 326 Chinese children with mean age of 10.85 years.

Results  It was found that positive attributional styles predicted shyness in the negative direction and the effects were fully mediated by self‐esteem, and negative attributional styles predicted shyness in the positive direction both directly and through self‐esteem.

Conclusion  The results imply that how children attribute positive and negative outcomes affect both self‐esteem and shyness. It is suggested that practitioners should conduct attribution‐retraining workshops for shy children and help teachers and parents learn how to mitigate negative attributional style and foster positive attributional styles in children.
The effect of filleting and ice application on the quality and safety of Atlantic bonito (Sarda sarda) at refrigerated storage
Authors: Koral Serkan , Köse Sevim
Published: November 2011

Filleting effect of refrigerated bonito with and without ice on the quality changes and food safety was investigated. Significant variations occurred (P < 0.05) in sensory, chemical and microbiological values amongst groups. The best sensory results were found for filleted bonito with ice (FBRI) with a shelf‐life of 13 days. While sensory values decreased significantly during storage, opposite situation occurred for both chemical and microbiological results (P < 0.05). The lowest total volatile basic nitrogen value was also observed with FBRI and was within the acceptable levels for 15 days as 17.86 mg 100 g−1. All samples contained acceptable trimethylamine levels for 15 days despite unacceptable sensory values after certain days. Although filleting seemed to increase the lipid oxidation, ice application resulted in lowering thiobarbituric acid content. Histamine results closely supported sensory values in terms of legally permitted levels usually by set FDA. While WBR contained histamine value over EU permitted level as 113.78 ppm on the 7th day, the value for FBRI was 56.13 ppm on the 15th day. Histamine‐forming bacteria counts supported histamine formation in most groups, while total bacteria counts were in agreement with sensory results. This study suggests that using ice and filleting can improve shelf‐life of bonito stored at refrigerated temperatures in terms of food quality and safety.
Similarity and difference among rainforest fruit‐feeding butterfly communities in Central and South America
Authors: DeVries Philip J. , Alexander Laura G. , Chacon Isidro A. , Fordyce James A.
Published: November 2011

1. Documenting species abundance distributions in natural environments is critical to ecology and conservation biology. Tropical forest insect faunas vary in space and time, and these partitions can differ in their contribution to overall species diversity.

2. In the Neotropics, the Central American butterfly fauna is best known in terms of general natural history, but butterfly community diversity is best documented by studies on South American fruit‐feeding butterflies. Here, we present the first long‐term study of fruit‐feeding nymphalid species diversity from Central America and provide a unique comparison between Central and South American butterfly communities.

3. This study used 60 months of sampling among multiple spatial and temporal partitions to assess species diversity in a Costa Rican rainforest butterfly community. Abundance distributions varied significantly at the species and higher taxonomic group levels, and canopy and understorey samples were found to be composed of distinct species assemblages.

4. Strong similarities in patterns of species diversity were found between this study and one from Ecuador; yet, there was an important difference in how species richness was distributed in vertical space. In contrast to the Ecuadorian site, Costa Rica had significantly higher canopy richness and lower understorey richness.

5. This study affirms that long‐term sampling is vital to understanding tropical insect species abundance distributions and points to potential differences in vertical structure among Central and South American forest insect communities that need to be explored.
Weed risk assessment: a way forward or a waste of time?
Authors: Hulme Philip E.
Published: November 2011

1. Many alien weeds pose significant environmental and/or economic threats across the globe, and methods to assess the potential risk of species introductions are key components in the management of plant invasions. Three broad approaches have been adopted in weed risk assessment: quantitative statistical models, semi‐quantitative scoring and qualitative expert assessment. Yet, the effectiveness of these different approaches is rarely evaluated. By bringing together perspectives drawn from statistics, complexity theory, bioeconomics and cognitive psychology, this review presents the first interdisciplinary appraisal of whether weed risk assessment is a valuable tool in the management of plant invasions.

2. Problems in obtaining an objective measure of the hazards posed by weeds, challenges of predicting complex hierarchical and nonlinear systems, difficulties in quantifying uncertainty and variability, as well as cognitive biases in expert judgement, all limit the utility of current risk assessment approaches. The accuracy of weed risk assessment protocols is usually insufficient, given inherent low base‐rates even when the costs and benefits of decisions are taken into account, and implies that the predictive value of weed risk assessment is questionable.

3. Current practices could be improved to address consistent hazard identification, encompass a hierarchy of spatio‐temporal scales, incorporate uncertainty, generate realistic base‐rates, and train risk assessors to limit cognitive biases. However, such refinements may still fail to predict weed risks any better than a knowledge of prior invasion history and quality of climate match.

4. Alternative approaches include scenario planning that seeks qualitative inputs regarding hypothetical events to facilitate long‐range planning using multiple alternatives each explicit in their treatment of uncertainty. This represents a change from prevention towards adaptive management where the difficulty in prediction is acknowledged and investment targets early detection, mitigation and management.

5. Synthesis and applications. Scenario planning may be particularly suitable for weeds as they can be rapidly surveyed and have sufficiently long lag phases between naturalisation and invasion that early detection is often feasible. If integrated with assessments of ecosystem vulnerability to invasion and interventions to improve ecosystem resilience, it would deliver a robust post‐border approach to invasive plant management. This approach would address threats from new introductions as well as ‘sleeper weeds’ already present in a region.
Abundance and diversity of wild bees along gradients of heavy metal pollution
Authors: Moroń Dawid , Grześ Irena M. , Skórka Piotr , Szentgyörgyi Hajnalka , Laskowski Ryszard , Potts Simon G. , Woyciechowski Michał
Published: November 2011

1. Wild bees are one of the most important groups of pollinators in the temperate zone. Therefore, population declines have potentially negative impacts for both crop and wildflower pollination. Although heavy metal pollution is recognized to be a problem affecting large parts of the European Union, we currently lack insights into the effects of heavy metals on wild bees.

2. We investigated whether heavy metal pollution is a potential threat to wild bee communities by comparing (i) species number, (ii) diversity and (iii) abundance as well as (iv) natural mortality of emerging bees along two independent gradients of heavy metal pollution, one at Olkusz (OLK), Poland and the other at Avonmouth (AVO), UK. We used standardized nesting traps to measure species richness and abundance of wild bees, and we recorded the heavy metal concentration in pollen collected by the red mason bee Osmia rufa as a measure of pollution.

3. The concentration of cadmium, lead and zinc in pollen collected by bees ranged from a background level in unpolluted sites [OLK: 1·3, 43·4, 99·8 (mg kg−1); AVO: 0·8, 42·0, 56·0 (mg kg−1), respectively] to a high level on sites in the vicinity of the OLK and AVO smelters [OLK: 6·7, 277·0, 440·1 (mg kg−1); AVO: 9·3, 356·2, 592·4 (mg kg−1), respectively].

4. We found that with increasing heavy metal concentration, there was a steady decrease in the number, diversity and abundance of solitary, wild bees. In the most polluted sites, traps were empty or contained single occupants, whereas in unpolluted sites, the nesting traps collected from 4 to 5 species represented by up to ten individuals. Moreover, the proportion of dead individuals of the solitary bee Megachile ligniseca increased along the heavy metal pollution gradient at OLK from 0·2 in uncontaminated sites to 0·5 in sites with a high concentration of pollution.

5. Synthesis and applications. Our findings highlight the negative relationship between heavy metal pollution and populations of wild bees and suggest that increasing wild bee richness in highly contaminated areas will require special conservation strategies. These may include creating suitable nesting sites and sowing a mixture of flowering plants as well as installing artificial nests with wild bee cocoons in polluted areas. Applying protection plans to wild pollinating bee communities in heavy metal‐contaminated areas will contribute to integrated land rehabilitation to minimize the impact of pollution on the environment.
Microclimate and vegetation function as indicators of forest thermodynamic efficiency
Authors: Norris Catherine , Hobson Peter , Ibisch Pierre L.
Published: November 2011

1. Resilient and functional landscapes are essential for climate change adaptation. Thermodynamic theory has been applied increasingly to ecological studies to understand ecosystem resilience and integrity. Resilient ecosystems have complex structure and greater levels of biomass and functional diversity, which act to enhance the degradation of solar energy. Forests that exhibit these characteristics express thermodynamic efficiency through a greater capacitance effect that promotes cooler surface temperatures under extreme weather conditions.

2. With forest disturbance, complex structures and functional linkages are simplified, reducing the capacity of the system to degrade energy. Such changes can lead to dysfunctional ecosystem states, impaired provision of ecosystem services and a weakened resilience.

3. This study has applied indicators based on thermodynamic theory to a chronosequence of forest ecosystems in the UK, Germany and Ukraine. Surface temperatures were measured to test thermodynamic theories relating to energy degradation and temperature moderation. Grime’s CSR model was applied to plant data to compare functional complexity in vegetation between stands.

4. Old‐growth woodlands are shown to attenuate surface temperature more effectively than native species plantations. Consistently lower temperatures were observed in European old‐growth forests with high proportions of biomass when compared to managed stands of similar species composition, suggesting a greater efficiency of energy degradation in complex forest ecosystems, particularly at higher temperatures.

5. Analysis of plant species data using Grime’s CSR model indicated that old‐growth forests ordinate towards competitive and stress‐tolerant communities in contrast to intensively managed forests, which had a greater proportion of generalist and ruderal species. High CSR functional scores were associated with moderated temperature extremes.

6. Synthesis and applications. Our results suggest an important thermodynamic basis for conservation in the context of climate change. Conservation practice and management policy, which is based on preserving ecosystem complexity and function, can aid in mitigating the effects of extreme temperatures, enhancing vital services such as climate regulation, primary production and water retention. Old‐growth forests have a significant climate mitigation role alongside other recognised ecosystem services such as carbon sequestration.
Predicting species vulnerability with minimal data to support rapid risk assessment of fishing impacts on biodiversity
Authors: Le Quesne Will J.F. , Jennings Simon
Published: November 2011

1. Large‐bodied species are especially vulnerable to fishing in mixed fisheries. Their effective conservation requires predictions of sensitivity and exposure to fishing mortality, but such predictions are hard to make when the population dynamics of most of these species have not been described.

2. We present a method for assessing sensitivity and conservation management reference points using widely available life‐history data. The method allows the sensitivity of all fish species in a community to be assessed in relation to conservation‐ and yield‐based fishery reference points.

3. Knowledge of sensitivity is used to (i) rank species by sensitivity, (ii) conduct a risk assessment to identify species potentially vulnerable to current fishing pressure and (iii) examine potential trade‐offs between fishery catches and the conservation status of sensitive species.

4. The method is applied to the Celtic Sea bottom‐dwelling fish community. For the species present, conservation threshold fishing mortalities ranged from 0·05 per year for the most sensitive large elasmobranchs to over 1 per year for small teleosts. The assessment predicts that current levels of fishing mortality may place all the elasmobranchs and over a quarter of the teleosts below conservation reference points.

5. Depending on the relative mortality rates affecting commercially targeted species and species of conservation concern, up to 65% of the potential yield‐per‐recruit of commercially important species may have to be forgone to reduce fishing mortality below conservation limit reference points for the most sensitive species.

6. Synthesis and applications.The method presented provides a clear objective procedure to construct ranked species sensitivity lists that can inform management, monitoring and research. The Celtic Sea case study demonstrated that limiting fishing pressure on key commercial stocks to meet fisheries production targets may be insufficient to guarantee the persistence of more sensitive species. Management actions that effectively decouple the mortality rates on commercial species and ‘conservation’ species are likely to be required to make progress in relation to conservation objectives. The method would support rapid assessment of sensitivity to fishing in many regions around the world as only taxonomic lists and estimates of body size are required.
Biogeographical modules and island roles: a comparison of Wallacea and the West Indies
Authors: Carstensen Daniel W. , Dalsgaard Bo , Svenning Jens‐Christian , Rahbek Carsten , Fjeldså Jon , Sutherland William J. , Olesen Jens M.
Published: November 2011

Aim In order to advance our understanding of the assembly of communities on islands and to elucidate the function of different islands in creating regional and subregional distribution patterns, we identify island biogeographical roles on the basis of the distribution of the islands’ biota within the archipelago. We explore which island characteristics determine island biogeographical roles. Furthermore, we identify biogeographical subregions, termed modules.

Location Wallacea in Indonesia, and the West Indies in the Caribbean Sea.

Methods We use a network approach to detect island biogeographical roles and avian biogeographical modules. To designate the biogeographical role of an island, each island is assigned two coordinates,landr. The position of an island inl–rspace characterizes its role, namely as peripheral, connector, module hub, or network hub. Island characteristics are tested as predictors oflandr.

Results Both Wallacea and the West Indies were found to be significantly modular and divided into four biogeographical modules. The four modules identified within Wallacea each contain all existing island roles, whereas no module in the West Indies represents all possible roles. Island area and elevation appeared to be the most important determinants of an island’slscore, while measurements of isolation essentially determined therscore.

Main conclusions In both Wallacea and the West Indies, the geographic structuring into biogeographical modules corresponds well with our knowledge of past connections and contemporary factors. In both archipelagos, large, mountainous islands are identified as hubs and are thus responsible for faunal coherence within modules (module hubs) and across the entire archipelago (network hubs). We thus interpret these as source islands for the surrounding islands in their module (module hubs) or for the entire archipelago (network hubs). Islands positioned marginally in their module and distant from the mainland are identified as connectors or network hubs, behaving as sinks and stepping stones for dispersing species. Modularity and predictors of biogeographical roles are similar for Wallacea and the West Indies, whereas the build‐up of biogeographical modules and the assortment of roles depend on the spatial constellation of islands in each archipelago.
Isolation and gene flow: inferring the speciation history of European house mice
Authors: DUVAUX LUDOVIC , BELKHIR KHALID , BOULESTEIX MATTHIEU , BOURSOT PIERRE
Published: November 2011

Inferring the history of isolation and gene flow during species differentiation can inform us on the processes underlying their formation. Following their recent expansion in Europe, two subspecies of the house mouse (Mus musculus domesticus and Mus musculus musculus) have formed a hybrid zone maintained by hybrid incompatibilities and possibly behavioural reinforcement, offering a good model of incipient speciation. We reconstruct the history of their divergence using an approximate Bayesian computation framework and sequence variation at 57 autosomal loci. We find support for a long isolation period preceding the advent of gene flow around 200 000 generations ago, much before the formation of the European hybrid zone a few thousand years ago. The duration of the allopatric episode appears long enough (74% of divergence time) to explain the accumulation of many post‐zygotic incompatibilities expressed in the present hybrid zone. The ancient contact inferred could have played a role in mating behaviour divergence and laid the ground for further reinforcement. We suggest that both subspecies originally colonized the Middle East from the northern Indian subcontinent, domesticus settling on the shores of the Persian Gulf and musculus on those of the Caspian Sea. Range expansions during interglacials would have induced secondary contacts, presumably in Iran, where they must have also interacted with Mus musculus castaneus. Future studies should incorporate this possibility, and we point to Iran and its surroundings as a hot spot for house mouse diversity and speciation studies.
Nutrition and division of labor: Effects on foraging and brain gene expression in the paper wasp Polistes metricus
Authors: DAUGHERTY T. H. F. , TOTH A. L. , ROBINSON G. E.
Published: November 2011

Deeply conserved molecular mechanisms regulate food‐searching behaviour in response to nutritional cues in a wide variety of vertebrates and invertebrates. Studies of the highly eusocial honey bee have shown that nutritional physiology and some conserved nutrient signalling pathways, especially the insulin pathway, also regulate the division of labour between foraging and non‐foraging individuals. Typically, lean workers leave the nest to forage for food, and well‐nourished workers perform tasks inside the nest. Here we provide the first direct test of whether similar mechanisms operate in a primitively eusocial insect in an independently evolved social lineage, the paper wasp Polistes metricus. We found that food deprivation caused reduced lipid stores and higher levels of colony and individual foraging. Individuals with greatly reduced lipid stores foraged at extremely elevated levels. In addition, brain expression of several foraging‐related genes was influenced by food deprivation, including insulin‐like peptide 2 (ilp2). Together with previous findings, our results demonstrate that nutrition regulates foraging division of labour in two independently evolved social insect lineages (bees and wasps), despite large differences in social organization. Our results also provide additional support for the idea that nutritional asymmetries among individuals, based on differences in nutritional physiology and expression of conserved nutrient signalling genes in the brain, are important in the division of labour in eusocial societies.
Interspecific hybridization increases MHC class II diversity in two sister species of newts
Authors: NADACHOWSKA‐BRZYSKA KRYSTYNA , ZIELIŃSKI PIOTR , RADWAN JACEK , BABIK WIESŁAW
Published: November 2011

Our understanding of the evolutionary mechanisms generating variation within the highly polymorphic major histocompatibility complex (MHC) genes remains incomplete. Assessing MHC variation across multiple populations, of recent and ancient divergence, may facilitate understanding of geographical and temporal aspects of variation. Here, we applied 454 sequencing to perform a large‐scale, comprehensive analysis of MHC class II in the closely related, hybridizing newts, Lissotriton vulgaris (Lv) and Lissotriton montandoni (Lm). Our study revealed an extensive (299 alleles) geographically structured polymorphism. Populations at the southern margin of the Lv distribution, inhabited by old and distinct lineages (southern Lv), exhibited moderate MHC variation and strong population structure, indicating little gene flow or extensive local adaptation. Lissotriton vulgaris in central Europe and the northern Balkans (northern Lv) and almost all Lm populations had a high MHC variation. A much higher proportion of MHC alleles was shared between Lm and northern Lv than between Lm and southern Lv. Strikingly, the average pairwise FST between northern Lv and Lm was significantly lower than between northern and southern Lv for MHC, but not for microsatellites. Thus, high MHC variation in Lm and northern Lv may result from gene flow between species. We hypothesize that the interspecific exchange of MHC genes may be facilitated by frequency‐dependent selection. A marginally significant correlation between the MHC and microsatellite allelic richness indicates that demographic factors may have contributed to the present‐day pattern of MHC variation, but unequivocal signatures of adaptive evolution in MHC class II sequences emphasize the role of selection on a longer timescale.
The genetic basis of evolution, adaptation and speciation
Authors: McNIVEN VANDA T. K. , LeVASSEUR‐VIENS HÉLÈNE , KANIPPAYOOR RACHELLE L. , LATURNEY MEGHAN , MOEHRING AMANDA J.
Published: November 2011

A primary question in biology concerns the genetic basis of the evolution of novel traits, often in response to environmental changes, and how this can subsequently cause species isolation. This topic was the focus of the symposium on the Genetics of Speciation and Evolution at the annual meeting of the Canadian Society for Ecology and Evolution, held in Banff in May 2011. The presentations revealed some of the rapid advances being made in understanding the genetic basis of adaptation and speciation, as well as the elegant interplay between an organism’s genetic complement and the environment that organism experiences.
Hybrid swarm between divergent lineages of mule deer (Odocoileus hemionus)
Authors: LATCH EMILY K. , KIEREPKA ELIZABETH M. , HEFFELFINGER JAMES R. , RHODES OLIN E.
Published: November 2011

Studies of hybrid zones have revealed an array of evolutionary outcomes, yet the underlying structure is typically characterized as one of three types: a hybrid zone, a hybrid swarm or a hybrid taxon. Our primary objective was to determine which of these three structures best characterizes a zone of hybridization between two divergent lineages of mule deer (Odocoileus hemionus), mule deer and black‐tailed deer. These lineages are morphologically, ecologically and genetically distinct, yet hybridize readily along a zone of secondary contact between the east and west slopes of the Cascade Mountains (Washington and Oregon, USA). Using microsatellite and mitochondrial DNA, we found clear evidence for extensive hybridization and introgression between lineages, with varying degrees of admixture across the zone of contact. The pattern of hybridization in this region closely resembles a hybrid swarm; based on data from 10 microsatellite loci, we detected hybrids that extend well beyond the F1 generation, did not detect linkage disequilibrium at the centre of the zone and found that genotypes were associated randomly within the zone of contact. Introgression was characterized as bidirectional and symmetric, which is surprising given that the zone of contact occurs along a sharp ecotone and that lineages are characterized by large differences in body size (a key component of mating success). Regardless of the underlying mechanisms promoting hybrid swarm maintenance, it is clear that the persistence of a hybrid swarm presents unique challenges for management in this region.
An activation domain of plasmid R1 TraI protein delineates stages of gene transfer initiation
Authors: Lang Silvia , Kirchberger Paul C. , Gruber Christian J. , Redzej Adam , Raffl Sandra , Zellnig Guenther , Zangger Klaus , Zechner Ellen L.
Published: November 2011

Bacterial conjugation is a form of type IV secretion that transports protein and DNA to recipient cells. Specific bacteriophage exploit the conjugative pili and cell envelope spanning protein machinery of these systems to invade bacterial cells. Infection by phage R17 requires F‐like pili and coupling protein TraD, which gates the cytoplasmic entrance of the secretion channel. Here we investigate the role of TraD in R17 nucleoprotein uptake and find parallels to secretion mechanisms. The relaxosome of IncFII plasmid R1 is required. A ternary complex of plasmid oriT, TraD and a novel activation domain within the N‐terminal 992 residues of TraI contributes a key mechanism involving relaxase‐associated properties of TraI, protein interaction and the TraD ATPase. Helicase‐associated activities of TraI are dispensable. These findings distinguish for the first time specific protein domains and complexes that process extracellular signals into distinct activation stages in the type IV initiation pathway. The study also provided insights into the evolutionary interplay of phage and the plasmids they exploit. Related plasmid F adapted to R17 independently of TraI. It follows that selection for phage resistance drives not only variation in TraA pilins but diversifies TraD and its binding partners in a plasmid‐specific manner.
Localization and activity of the calcineurin catalytic and regulatory subunit complex at the septum is essential for hyphal elongation and proper septation in Aspergillus fumigatus
Authors: Juvvadi Praveen Rao , Fortwendel Jarrod R. , Rogg Luise E. , Burns Kimberlie A. , Randell Scott H. , Steinbach William J.
Published: November 2011

Calcineurin, a heterodimer composed of the catalytic (CnaA) and regulatory (CnaB) subunits, plays key roles in growth, virulence and stress responses of fungi. To investigate the contribution of CnaA and CnaB to hyphal growth and septation, ΔcnaB and ΔcnaAΔcnaB strains of Aspergillus fumigatus were constructed. CnaA colocalizes to the contractile actin ring early during septation and remains at the centre of the mature septum. While CnaB's septal localization is CnaA‐dependent, CnaA's septal localization is CnaB‐independent, but CnaB is required for CnaA's function at the septum. Catalytic null mutations in CnaA caused stunted growth despite septal localization of the calcineurin complex, indicating the requirement of calcineurin activity at the septum. Compared to the ΔcnaA and ΔcnaB strains, the ΔcnaAΔcnaB strain displayed more defective growth and aberrant septation. While three Ca2+‐binding motifs in CnaB were sufficient for its association with CnaA at the septum, the amino‐terminal arginine‐rich domains (16‐RRRR‐19 and 44‐RLRKR‐48) are dispensable for septal localization, yet required for complete functionality. Mutation of the 51‐KLDK‐54 motif in CnaB causes its mislocalization from the septum to the nucleus, suggesting it is a nuclear export signal sequence. These findings confirm a cooperative role for the calcineurin complex in regulating hyphal growth and septation.
Influence of gastric acid on gastric emptying and gastric distension‐induced pain response in rats – effects of famotidine and mosapride
Authors: Keto Y. , Hirata T. , Takemoto Y. , Yamano M. , Yokoyama T.
Published: November 2011

Background  Gastroduodenal acidification has been reported to aggravate upper abdominal discomfort and pain that are symptoms suffered by functional dyspepsia (FD) patients. Delayed gastric emptying and hypersensitivity to gastric distension (GD) contribute importantly to the pathophysiology of FD.

Methods  In the present study, we determined the influence of pentagastrin‐stimulated endogenous gastric acid on gastric emptying and GD‐induced pain responses using rat model systems. Moreover, we evaluated the effects of famotidine and mosapride on changes in gastric emptying and the GD‐induced pain response to gastric acid hypersecretion. Gastric emptying was measured by excretion of glass beads that had been intragastrically administered with a liquid nutrient, and gastric pain response was evaluated by observing whether a GD‐induced increase in mean blood pressure occurred.

Key Results  Pentagastrin (2 mg kg−1, s.c.) which markedly and continuously stimulated gastric acid secretion, significantly delayed and enhanced respectively, gastric emptying and pain compared with saline‐injected groups. Oral famotidine (0.1–3 mg kg−1) and mosapride (0.3–3 mg kg−1) administration in a dose‐dependent manner accelerated the delay of gastric emptying. Furthermore, famotidine (0.3–3 mg kg−1) significantly alleviated the aggravation of the GD‐induced pain response, but mosapride (10 mg kg−1) did not.

Conclusions & Inferences  We established rat models to evaluate the effect of gastric acid hypersecretion on gastric emptying and the GD‐induced pain response. In these models, acid hypersecretion delayed gastric emptying and aggravated the pain response. Furthermore, we showed that famotidine ameliorated both delayed gastric emptying and gastric hypersensitivity, whereas mosapride only improved delayed gastric emptying.
Multiple dolomitization events along the Pozalagua Fault (Pozalagua Quarry, Basque–Cantabrian Basin, Northern Spain)
Authors: SWENNEN RUDY , DEWIT JULIE , FIERENS ELS , MUCHEZ PHILIPPE , SHAH MUMTAZ , NADER FADI , HUNT DAVID
Published: November 2011

The Pozalagua Quarry in the Basque–Cantabrian Basin of northern Spain exposes a unique set of fault‐associated dolomites that can be studied on a decametre scale. The dolomites developed along the Pozalagua Fault system in slope‐deposited limestones of Albian age. Following marine phreatic diagenesis, the limestones were subject to meteoric karst formation. The resulting cavities were filled either by angular limestone fragments in a black clay‐rich matrix, or by cave floor/pond (now dolomitized) sediments. The subsequent diagenetic history reflects repeated periods of fracturing, fluid expulsion, dissolution and cementation. Contrasting fluid pulses resulted in the formation of a network of hydrothermal karst and the subsequent development of coarse‐crystalline calcite cement, zebra dolomite, recrystallized coarse‐crystalline dolomite, elongated blue–grey coarse‐crystalline dolomite cement in the open fault and, finally, coarse‐crystalline saddle dolomite. Decimetre‐size reworked host‐rock fragments present in the latter two dolomite phases probably reflect roof collapse fragments of a cave system that developed along the Pozalagua Fault system. However, there are also metre‐scale host‐rock fragments that apparently ‘float’ in the coarse‐crystalline saddle dolomites, implying that either fragment assimilation was a widespread process or violent expulsion of fluids occurred along the Pozalagua Fault system. The presence of pre‐dolomite and post‐dolomite stylolites, parallel to bedding, supports a linkage between the diagenetic events and the Late Albian tectonism that affected the region.
Associations between technical quality of diabetes care and patient experience
Authors: Arah Onyebuchi A. , Roset Bastiaan , Delnoij Diana M. J. , Klazinga Niek S. , Stronks Karien
Published: November 2011

Aims  It has long been held that high‐quality care has both technical and interpersonal aspects. The nature and strength of any association between both aspects remain poorly explored. This study investigated the associations between diabetes patients’ reports of receiving recommended care (as measures of technical quality) and their experience and ratings (as measures of interpersonal care).

Methods  Using data from a cross section of 3096 patients with diabetes nested within 24 diabetes‐care‐networks, we conducted multilevel regression analysis of the relationships between nine indicators of receiving care recommended in practice guidelines and: six scales of patient experience and global ratings of general practitioner, nurses, and overall diabetes care.

Results  On average, reporting having received recommended care was associated with reporting better patient experience and ratings. The extent and frequencies of these associations varied across the different care processes. Receiving foot examination, physical activity advice, smoking status check, eye examination, and HbA1c testing, but not nutritional advice, urine, cholesterol or blood pressure checks, were statistically associated with better patient experience and global ratings. Those who received HbA1c testing rated their overall care 1.002 points higher (95% confidence interval: 0.726–1.278) on a scale of 0–10 than those who did not.

Conclusions  Higher self‐reported technical quality of care in diabetes appears to be frequently but not always associated with better experiences and ratings. It is possible that the former leads to the latter and/or that both share a common cause within providers. Both care aspects do not seem interchangeable during performance assessment.