bluuebunny/crossref_metadata_2025 huggingface dataset:
A south‐to‐north biogeographic hypothesis for Andean speciation: evidence from the lizard genus Proctoporus (Reptilia, Gymnophthalmidae)
Authors: Doan Tiffany M.
Published: June 2010

Aim  The lizard genus ProctoporusTschudi, 1845 was used as a model to test the South‐to‐North Speciation Hypothesis (SNSH) for species groups occurring in the Andes Mountains of South America. This hypothesis proposes that speciation of high Andean taxa followed a south‐to‐north pattern, generally coinciding with the progression of final uplift of the Andes. According to SNSH, a phylogenetic hypothesis of relationships of a taxonomic group occurring in the high Andes would show a branching pattern in which the southernmost species diverged first, followed by the more northern species, and so on in a northerly pattern.

Location  The central and northern Andes Mountains in South America.

Methods A phylogenetic hypothesis was reconstructed for all species of the lizard genus Proctoporus by examining the external morphology of 341 individuals. This phylogeny was then examined to determine monophyly of the genus, distribution patterns of species groups, and congruence with SNSH.

Results  The genus Proctoporus did appear to be monophyletic and, therefore, it was valid to use this group to assess SNSH. The southernmost species were found to be the most basal, which was consistent with SNSH. The species occurring in the northern Andes did not exactly match the SNSH prediction. The Venezuelan and Trinidadian species did appear to be highly derived, as predicted by the hypothesis, but the Ecuadorian and Colombian species did not form a particular pattern in relation to the hypothesis.

Main conclusions  The SNSH does appear to have predictive power with regard to large‐scale distribution patterns. The finer‐scale patterns of speciation in the Andes, however, appear to be a more complex phenomenon that cannot be fully explained by a simple hypothesis. It is important to have a testable hypothesis in hand with which to compare data from disparate species groups. The incorporation of phylogenetic data of other high Andean taxa with similar distribution patterns is necessary to determine the full utility of SNSH in explaining evolutionary patterns in the Andes of South America.
The palaeoxylological record of Metapodocarpoxylon libanoticum (Edwards) Dupéron‐Laudoueneix et Pons and the Gondwana Late Jurassic–Early Cretaceous continental biogeography
Authors: Philippe M. , Cuny G. , Bamford M. , Jaillard E. , Barale G. , Gomez B. , Ouaja M. , Thévenard F. , Thiébaut M. , Von Sengbusch P.
Published: June 2010

Aim  Vertebrates, palynomorphs and leaf floras each give a different picture of continental biogeography of Northern Gondwana during the Middle Jurassic–Early Cretaceous interval. A new biogeographical marker is required to get a clearer picture.

Location  Northern part of the Gondwana during the Middle Jurassic–Early Cretaceous interval.

Methods  Comparisons and correlations of wood data from the literature and new material.

Results  We have selected Metapodocarpoxylon Dupéron‐Laudoueneix et Pons because it has a restricted distribution, temporally and geographically; it is a well‐defined Mesozoic fossil wood monospecific genus, and there are wide‐ranging data on its distribution.

Conclusions  Metapodocarpoxylon distribution draws a clear latitudinal belt extending from Lebanon westward to Peru. Climate being the main factor of plant distribution at a global scale, the Metapodocarpoxylon area probably underlines a climatic belt. This has several implications, for example, choosing among different Global Circulation Models or discussing dinosaur distribution.
Regionalization of the avifauna of the Baja California Peninsula, Mexico: a parsimony analysis of endemicity and distributional modelling approach
Authors: Rojas‐Soto Octavio R. , Alcántara‐Ayala Othón , Navarro Adolfo G.
Published: June 2010

Aim To analyse the distributional patterns of the Baja California Peninsula's resident avifauna, and to generate a regionalization based on a method that uses a parsimony analysis (parsimony analysis of endemicity, PAE) of point data and modelled potential distributions.

Location The Baja California Peninsula, Mexico.

Methods A data base was constructed containing records of 113 species of resident terrestrial birds present in the Baja California Peninsula. Records and localities were obtained from the literature and from specimens housed in scientific collections world‐wide. Raw data points and potential distribution maps obtained using the software Genetic Algorithms for Rule‐set Prediction (GARP), were analysed with PAE.

Results The data base consisted of 4164 unique records (only one combination of species/locality) belonging to 113 terrestrial resident bird species, in a total of 809 localities. From the point distribution matrix, the analysis generated 500 equally parsimonious trees, from which a strict consensus cladogram with 967 steps was obtained. The cladogram shows a basal polytomy and some geographical correspondence of a few resolved groups obtained in the analysis. These results do not allow the recognition of areas defined by avifaunistic associations. From the potential distribution matrix, the analysis generated 501 equally parsimonious trees, and a strict consensus cladogram of 516 steps was obtained. The cladogram shows a higher resolution because of the number of resolved groups with better geographical correspondence and therefore regions are well‐defined.

Main conclusions The correspondence of some groupings of species suggest their validity as areas with biogeographical (historical and/or ecological) meaning. This regionalization in the Baja California avifauna seems to be consistent with previous regionalizations for other groups. Hence, PAE is a useful tool for area categorization if reliable point records and prediction tools are available. Our results suggest that the geographical definition is much better using potential data generated by GARP, particularly when they are contrasted with the results from point data. Thus, this is an excellent alternative for developing biogeographical studies, as well as for improving the use of data from scientific collections and other sources of biodiversity information.
Marine nematode deep‐sea biodiversity – hyperdiverse or hype?
Authors: Lambshead P. John D. , Boucher Guy
Published: June 2010

Nematodes have been identified as a potentially hyperdiverse group and the deep sea as a potentially hyperdiverse environment (i.e. > 1 million species). A large‐scale data set from the equatorial central Pacific is used to estimate regional diversity with results that challenge this view; regional diversity is higher in some coastal waters despite lower sample diversity in coastal waters than in the deep sea. The data suggests a paradigm where the deep sea has modest regional diversity, despite high local diversity through patch dynamics, because similar patches in a similar habitat are repeated for considerable distances. Disturbance in shallow water dominates over patch‐dynamic mechanisms reducing local diversity but regional diversity is high because of the close packing of multiple habitats within a single region.

 The Pacific data are also used to demonstrate the pitfalls of extrapolating from local to global diversity. There is no reason to conclude that nematodes are less diverse than other benthic groups, indeed where direct comparison is possible the Nematoda appear to be as diverse as the Polychaeta, the most diverse macrofaunal taxon. This analysis is not consistent with the hypothesis that either marine nematodes or the deep‐sea benthos are hyperdiverse raising the question whether any environment or metazoan taxon has more than a million species.
The Indochinese–Sundaic faunal transition at the Isthmus of Kra: an analysis of resident forest bird species distributions
Authors: Hughes Jennifer B. , Round Philip D. , Woodruff David S.
Published: June 2010

Aim  To establish the geographical position of the biogeographical transition between Indochinese and Sundaic faunas using distributional data for the best‐documented taxon, the birds.

Methods  Distributional data of 544 resident forest and forest edge bird species of Thailand and the Thai–Malay peninsula were examined at 45 sites spanning 15° of latitude from northern‐most Thailand to the southern peninsular Malaysia. Sites were grouped into 23 degree or half‐degree latitudinal zones and avifaunal similarity coefficients were calculated between each zone.

Results  A Mantel test revealed a significant transition between northern Indochinese and southern Sundaic (Indomalay) avifauna assemblages just north of the Isthmus of Kra (10°30′ N). Northern and southern range limits of 152 species (> 269 species and subspecies combined) lie between 11° and 13° N.

Main conclusions  This transition between zoogeographical subregions is not coincident with the widely recognized transition between floristic provinces which is traditionally placed 400–500 km further south at the Kangar–Pattani line, but is associated with a change from wet seasonal evergreen dipterocarp rain forest to mixed moist deciduous forest north of the Isthmus of Kra in the northern Thai–Malay peninsula. Climatological and ecological factors associated with the distribution of forest types today are reviewed and it is hypothesized that the avian transition tracks the northern phytogeographical boundary. Palaeogeographical factors, including hypothetical Neogene seaways, which may account for the historical development of both phytogeographical and avifaunal transitions are also described.
CFTR-Adenylyl Cyclase I Association Responsible for UTP Activation of CFTR in Well-Differentiated Primary Human Bronchial Cell Cultures
Authors: Namkung Wan , Finkbeiner Walter E. , Verkman A. S.
Published: June 2010

Chloride secretion by airway epithelial cells is defective in cystic fibrosis (CF). The conventional paradigm is that CFTR is activated through cAMP and protein kinase A (PKA), whereas the Ca2+-activated chloride channel (CaCC) is activated by Ca2+agonists like UTP. We found that most chloride current elicited by Ca2+agonists in primary cultures of human bronchial epithelial cells is mediated by CFTR by a mechanism involving Ca2+activation of adenylyl cyclase I (AC1) and cAMP/PKA signaling. Use of selective inhibitors showed that Ca2+agonists produced more chloride secretion from CFTR than from CaCC. CFTR-dependent chloride secretion was reduced by PKA inhibition and was absent in CF cell cultures. Ca2+agonists produced cAMP elevation, which was blocked by adenylyl cyclase inhibition. AC1, a Ca2+/calmodulin-stimulated adenylyl cyclase, colocalized with CFTR in the cell apical membrane. RNAi knockdown of AC1 selectively reduced UTP-induced cAMP elevation and chloride secretion. These results, together with correlations between cAMP and chloride current, suggest that compartmentalized AC1–CFTR association is responsible for Ca2+/cAMP cross-talk. We further conclude that CFTR is the principal chloride secretory pathway in non-CF airways for both cAMP and Ca2+agonists, providing a novel mechanism to link CFTR dysfunction to CF lung disease.
Epigenetic Modification Affecting Expression of Cell Polarity and Cell Fate Genes to Regulate Lineage Specification in the Early Mouse Embryo
Authors: Parfitt David-Emlyn , Zernicka-Goetz Magdalena
Published: June 2010

Formation of inner and outer cells of the mouse embryo distinguishes pluripotent inner cell mass (ICM) from differentiating trophectoderm (TE). Carm1, which methylates histone H3R17 and R26, directs cells to ICM rather that TE. To understand the mechanism by which this epigenetic modification directs cell fate, we generated embryos with in vivo–labeled cells of different Carm1 levels, using time-lapse imaging to reveal dynamics of their behavior, and related this to cell polarization. This shows that Carm1 affects cell fate by promoting asymmetric divisions, that direct one daughter cell inside, and cell engulfment, where neighboring cells with lower Carm1 levels compete for outside positions. This is associated with changes to the expression pattern and spatial distribution of cell polarity proteins: Cells with higher Carm1 levels show reduced expression and apical localization of Par3 and a dramatic increase in expression of PKCII, antagonist of the apical protein aPKC. Expression and basolateral localization of the mouse Par1 homologue, EMK1, increases concomitantly. Increased Carm1 also reduces Cdx2 expression, a transcription factor key for TE differentiation. These results demonstrate how the extent of a specific epigenetic modification could affect expression of cell polarity and fate-determining genes to ensure lineage allocation in the mouse embryo.
Forced Homo- and Heterodimerization of All gp130-Type Receptor Complexes Leads to Constitutive Ligand-independent Signaling and Cytokine-independent Growth
Authors: Suthaus Jan , Tillmann Anna , Lorenzen Inken , Bulanova Elena , Rose-John Stefan , Scheller Jürgen
Published: June 2010

Naturally ligand independent constitutively active gp130 variants were described to be responsible for inflammatory hepatocellular adenomas. Recently, we genetically engineered a ligand-independent constitutively active gp130 variant based on homodimerization of Jun leucine zippers. Because also heterodimeric complexes within the gp130 family may have tumorigenic potential, we seek to generate ligand-independent constitutively active heterodimers for all known gp130-receptor complexes based on IL-15/IL-15Rα-sushi fusion proteins. Ligand-independent heterodimerization of gp130 with WSX-1, LIFR, and OSMR and of OSMR with GPL led to constitutive, ligand-independent STAT1 and/or STAT3 and ERK1/2 phosphorylation. Moreover, these receptor combinations induced transcription of the STAT3 target genes c-myc and Pim-1 and factor-independent growth of stably transduced Ba/F3-gp130 cells. Here, we establish the IL-15/IL-15Rα-sushi system as a new system to mimic constitutive and ligand-independent activation of homo- and heterodimeric receptor complexes, which might be applicable to other heterodimeric receptor families. A mutated IL-15 protein, which was still able to bind the IL-15Rα-sushi domain, but not to β- and γ-receptor chains, in combination with the 2A peptide technology may be used to translate our in vitro data into the in vivo situation to assess the tumorigenic potential of gp130-heterodimeric receptor complexes.
Bimodal, Reciprocal Regulation of Fibroblast Growth Factor Receptor 1 Promoter Activity by BTEB1/KLF9 during Myogenesis
Authors: Mitchell Darrion L. , DiMario Joseph X.
Published: June 2010

Expression of the gene encoding fibroblast growth factor receptor 1 (FGFR1) and subsequent FGFR1-mediated cell signaling controls numerous developmental and disease-related processes. The transcriptional regulation of the FGFR1 gene is central to these developmental events and serves as a molecular model for understanding transcriptional control of growth factor receptor genes. The FGFR1 promoter is activated in proliferating myoblasts via several Sp1-like binding elements. These elements display varying levels of activation potential, suggesting that unique protein-DNA complexes coordinate FGFR1 gene expression via each of these sites. The Krüppel-like factor, BTEB1/KLF9, was expressed in both proliferating myoblasts and differentiated myotubes in vitro. The BTEB1 protein was nuclear-localized in both cell types. BTEB1 activated the FGFR1 promoter via interaction with the Sp1-like binding site located at −59 bp within the FGFR1 promoter. FGFR1 gene expression is down-regulated during myogenic differentiation, and FGFR1 promoter activity is correspondingly reduced. This reduction in FGFR1 promoter activity was attributable to BTEB1 interaction with the same Sp1-like binding site located at −59 bp in the FGFR1 promoter. Therefore, BTEB1 is capable of functioning as a transcriptional activator and repressor of the same promoter via the same DNA-binding element and demonstrates a novel, bimodal role of BTEB1 during myogenesis.
A support vector machine model for the prediction of proteotypic peptides for accurate mass and time proteomics
Authors: Webb-Robertson Bobbie-Jo M. , Cannon William R. , Oehmen Christopher S. , Shah Anuj R. , Gurumoorthi Vidhya , Lipton Mary S. , Waters Katrina M.
Published: June 2010

Motivation: The standard approach to identifying peptides based on accurate mass and elution time (AMT) compares profiles obtained from a high resolution mass spectrometer to a database of peptides previously identified from tandem mass spectrometry (MS/MS) studies. It would be advantageous, with respect to both accuracy and cost, to only search for those peptides that are detectable by MS (proteotypic).

Results: We present a support vector machine (SVM) model that uses a simple descriptor space based on 35 properties of amino acid content, charge, hydrophilicity and polarity for the quantitative prediction of proteotypic peptides. Using three independently derived AMT databases (Shewanella oneidensis, Salmonella typhimurium, Yersinia pestis) for training and validation within and across species, the SVM resulted in an average accuracy measure of ∼0.83 with an SD of <0.038. Furthermore, we demonstrate that these results are achievable with a small set of 13 variables and can achieve high proteome coverage.

Availability:  http://omics.pnl.gov/software/STEPP.php

Contact:  bj@pnl.gov

Supplementary information:  Supplementary data are available at Bioinformatics online.
A Bayesian approach using covariance of single nucleotide polymorphism data to detect differences in linkage disequilibrium patterns between groups of individuals
Authors: Clark Taane G. , Campino Susana G. , Anastasi Elisa , Auburn Sarah , Teo Yik Y. , Small Kerrin , Rockett Kirk A. , Kwiatkowski Dominic P. , Holmes Christopher C.
Published: June 2010

Motivation: Quantifying differences in linkage disequilibrium (LD) between sub-groups can highlight genetic regions or sites under selection and/or associated with disease, and may have utility in trans-ethnic mapping studies.

Results: We present a novel pseudo Bayes factor (PBF) approach that assess differences in covariance of genotype frequencies from single nucleotide polymorphism (SNP) data from a genome-wide study. The magnitude of the PBF reflects the strength of evidence for a difference, while accounting for the sample size and number of SNPs, without the requirement for permutation testing to establish statistical significance. Application of the PBF to HapMap and Gambian malaria SNP data reveals regional LD differences, some known to be under selection.

Availability and implementation: The PBF approach has been implemented in the BALD (Bayesian analysis of LD differences) C++ software, and is available from http://homepages.lshtm.ac.uk/tgclark/downloads

Contact:  taane.clark@lshtm.ac.uk
Traditional Japanese Kampo Medicine: Clinical Research between Modernity and Traditional Medicine—The State of Research and Methodological Suggestions for the Future
Authors: Watanabe Kenji , Matsuura Keiko , Gao Pengfei , Hottenbacher Lydia , Tokunaga Hideaki , Nishimura Ko , Imazu Yoshihiro , Reissenweber Heidrun , Witt Claudia M.
Published: June 2010

The Japanese traditional herbal medicine, Kampo, has gradually reemerged and 148 different formulations (mainly herbal extracts) can be prescribed within the national health insurance system. The objective of this article is to introduce Kampo and to present information from previous clinical studies that tested Kampo formulae. In addition, suggestions on the design of future research will be stated. The literature search was based on a summary, up until January 2009, by the Japanese Society of Oriental Medicine and included only those trials which were also available in either Pubmed or ICHUSHI (Japan Medical Abstracts Society). We included 135 studies, half of these studies (n = 68) used a standard control and 28 a placebo control. Thirty‐seven trials were published in English [all randomized controlled trials (RCTs)] and the remaining articles were in Japanese only. The sample size for most studies was small (two‐third of the studies included less than 100 patients) and the overall methodological quality appeared to be low. None of the studies used Kampo diagnosis as the basis for the treatment. In order to evaluate Kampo as a whole treatment system, certain aspects should be taken into account while designing studies. RCTs are the appropriate study design to test efficacy or effectiveness; however, within the trial the treatment could be individualized according to the Kampo diagnosis. Kampo is a complex and individualized treatment with a long tradition, and it would be appropriate for further research on Kampo medicine to take this into account.
Distribution of deep-water corals of the Flemish Cap, Flemish Pass, and the Grand Banks of Newfoundland (Northwest Atlantic Ocean): interaction with fishing activities
Authors: Murillo F. J. , Durán Muñoz P. , Altuna A. , Serrano A.
Published: June 2010

Murillo, F. J., Durán Muñoz, P., Altuna, A., and Serrano, A. 2011. Distribution of deep-water corals of the Flemish Cap, Flemish Pass, and the Grand Banks of Newfoundland (Northwest Atlantic Ocean): interaction with fishing activities. – ICES Journal of Marine Science, 68: 319–332. The distribution of deep-water corals of the Flemish Cap, Flemish Pass, and the Grand Banks of Newfoundland is described based on bycatch from Spanish/EU bottom trawl groundfish surveys between 40 and 1500 m depth. In all, 37 taxa of deep-water corals were identified in the study area: 21 alcyonaceans (including the gorgonians), 11 pennatulaceans, 2 solitary scleractinians, and 3 antipatharians. The greatest diversity of coral species was on the Flemish Cap. Corals were most abundant along the continental slope, between 600 and 1300 m depth. Soft corals (alcyonaceans), sea fans (gorgonians), and black corals (antipatharians) were most common on bedrock or gravel, whereas sea pens (pennatulaceans) and cup corals (solitary scleractinians) were found primarily on mud. The biomass of deep-water corals in the bycatches was highest in previously lightly trawled or untrawled areas, and generally low in the regularly fished grounds. The information derived from bottom-trawl bycatch records is not sufficient to map vulnerable marine ecosystems (VMEs) accurately, but pending more detailed habitat mapping, it provides a valuable indication of the presence/absence of VMEs that can be used to propose the candidate areas for bottom fishery closures or other conservation measures.
History and dynamics of the overexploitation of the blackspot sea bream (Pagellus bogaraveo) in the Bay of Biscay
Authors: Lorance Pascal
Published: June 2010

Lorance, P. 2011. History and dynamics of the overexploitation of the blackspot sea bream (Pagellus bogaraveo) in the Bay of Biscay. – ICES Journal of Marine Science, 68: 290–301. The blackspot sea bream (Pagellus bogaraveo) used to be a major species in the landings from the Bay of Biscay up to the early 1980s. Nowadays, it is only a minor bycatch. Up to the mid-1970s, more than 15 000 t of blackspot sea bream were landed annually in Spanish and French ports. Thereafter, catches declined sharply from 1975 to 1985 and have stayed at low levels ever since. Here, the full history of the fishery collapse is described, using time-series of landings dating back to the early 1900s. Fishing mortalities of the main demersal stocks (hake, anglerfish, sole) were in the range 0.2–0.5 during the last 30 years. It is likely that the blackspot sea bream stock was exploited at a similar level, which is shown here to be unsustainable. The blackspot sea bream is highly sensitive to overfishing because of its protandrous hermaphroditism, with late first maturity (8 years) as females and rather low productivity. According to a yield-per-recruit model, the biomass of fecund females (BFF) is reduced to <20% of virgin BFF for a fishing mortality around 0.2. A dynamic model assuming a simple stock–recruitment relationship fitted to the reconstructed landings explained the collapse, with estimated fishing mortalities never exceeding 0.5.
Maternal presence and environmental enrichment affect food neophobia of piglets
Authors: Oostindjer Marije , Muñoz Julia Mas , Van den Brand Henry , Kemp Bas , Bolhuis J. Elizabeth
Published: June 2010

Young omnivores show food neophobia in order to avoid the potential harmful effects of ingesting unfamiliar food items. We investigated whether the presence of the mother and an enriched rearing environment would reduce food neophobia in piglets. A mother may provide information on suitable food types to include in the diet, whereas an enriched environment may stimulate behavioural development and reduce reactivity towards novel stimuli (including food). Five barren-reared or enriched-reared piglets per litter were exposed to two novel food items in the presence, and the other five per litter in the absence, of the mother in a 7 min test. Maternal presence reduced food neophobia profoundly as reflected in a reduced latency to touching the food, a higher proportion of piglets sampling the two different food items and a higher intake. Latency to touch the food, however, was affected by maternal presence more strongly for barren-reared piglets than for enriched-reared piglets, and in the absence of the sow, consumption of one novel food type and time spent in the feeding area were higher for enriched-reared piglets.

Environmental enrichment does have the potential to reduce food neophobia, but the presence of the mother during the encounter with novel food seems more efficient in decreasing food neophobia of piglets.
Short signalling distances make plant communication a soliloquy
Authors: Heil Martin , Adame-Álvarez Rosa M.
Published: June 2010

Plants respond to attack by herbivores or pathogens with the release of volatile organic compounds. Neighbouring plants can receive these volatiles and consecutively induce their own defence arsenal. This ‘plant communication’, however, appears counterintuitive when it benefits independent and genetically unrelated receivers, which may compete with the emitter. As a solution to this problem, a role for volatile compounds in within-plant signalling has been predicted. We used wild-type lima bean (
Phaseolus lunatus
) to quantify under field conditions the distances over which volatile signals move, and thereby determine whether these cues will mainly trigger resistance in other parts of the same plant or in independent plants. Independent receiver plants exhibited airborne resistance to herbivores or pathogens at maximum distances of 50 cm from a resistance-expressing emitter. In undisturbed clusters of lima bean, over 80 per cent of all leaves that were located around a single leaf at this distance were other leaves of the same plant, whereas this percentage dropped below 50 per cent at larger distances. Under natural conditions, resistance-inducing volatiles of lima bean move over distances at which most leaves that can receive the signal still belong to the same plant.
The craniomandibular mechanics of being human
Authors: Wroe Stephen , Ferrara Toni L. , McHenry Colin R. , Curnoe Darren , Chamoli Uphar
Published: June 2010

Diminished bite force has been considered a defining feature of modernHomo sapiens, an interpretation inferred from the application of two-dimensional lever mechanics and the relative gracility of the human masticatory musculature and skull. This conclusion has various implications with regard to the evolution of human feeding behaviour. However, human dental anatomy suggests a capacity to withstand high loads and two-dimensional lever models greatly simplify muscle architecture, yielding less accurate results than three-dimensional modelling using multiple lines of action. Here, to our knowledge, in the most comprehensive three-dimensional finite element analysis performed to date for any taxon, we ask whether the traditional view that the bite ofH. sapiensis weak and the skull too gracile to sustain high bite forces is supported. We further introduce a new method for reconstructing incomplete fossil material. Our findings show that the human masticatory apparatus is highly efficient, capable of producing a relatively powerful bite using low muscle forces. Thus, relative to other members of the superfamily Hominoidea, humans can achieve relatively high bite forces, while overall stresses are reduced. Our findings resolve apparently discordant lines of evidence, i.e. the presence of teeth well adapted to sustain high loads within a lightweight cranium and mandible.
Adaptations in humans for assessing physical strength from the voice
Authors: Sell Aaron , Bryant Gregory A. , Cosmides Leda , Tooby John , Sznycer Daniel , von Rueden Christopher , Krauss Andre , Gurven Michael
Published: June 2010

Recent research has shown that humans, like many other animals, have a specialization for assessing fighting ability from visual cues. Because it is probable that the voice contains cues of strength and formidability that are not available visually, we predicted that selection has also equipped humans with the ability to estimate physical strength from the voice. We found that subjects accurately assessed upper-body strength in voices taken from eight samples across four distinct populations and language groups: the Tsimane of Bolivia, Andean herder-horticulturalists and United States and Romanian college students. Regardless of whether raters were told to assess height, weight, strength or fighting ability, they produced similar ratings that tracked upper-body strength independent of height and weight. Male voices were more accurately assessed than female voices, which is consistent with ethnographic data showing a greater tendency among males to engage in violent aggression. Raters extracted information about strength from the voice that was not supplied from visual cues, and were accurate with both familiar and unfamiliar languages. These results provide, to our knowledge, the first direct evidence that both men and women can accurately assess men's physical strength from the voice, and suggest that estimates of strength are used to assess fighting ability.
Iron defecation by sperm whales stimulates carbon export in the Southern Ocean
Authors: Lavery Trish J. , Roudnew Ben , Gill Peter , Seymour Justin , Seuront Laurent , Johnson Genevieve , Mitchell James G. , Smetacek Victor
Published: June 2010

The iron-limited Southern Ocean plays an important role in regulating atmospheric CO
2
levels. Marine mammal respiration has been proposed to decrease the efficiency of the Southern Ocean biological pump by returning photosynthetically fixed carbon to the atmosphere. Here, we show that by consuming prey at depth and defecating iron-rich liquid faeces into the photic zone, sperm whales (
Physeter macrocephalus
) instead stimulate new primary production and carbon export to the deep ocean. We estimate that Southern Ocean sperm whales defecate 50 tonnes of iron into the photic zone each year. Molar ratios of C
export
∶Fe
added
determined during natural ocean fertilization events are used to estimate the amount of carbon exported to the deep ocean in response to the iron defecated by sperm whales. We find that Southern Ocean sperm whales stimulate the export of 4 × 10
5
tonnes of carbon per year to the deep ocean and respire only 2 × 10
5
 tonnes of carbon per year. By enhancing new primary production, the populations of 12 000 sperm whales in the Southern Ocean act as a carbon sink, removing 2 × 10
5
tonnes more carbon from the atmosphere than they add during respiration. The ability of the Southern Ocean to act as a carbon sink may have been diminished by large-scale removal of sperm whales during industrial whaling.
Neural control of behavioural choice in juvenile crayfish
Authors: Liden William H. , Phillips Mary L. , Herberholz Jens
Published: June 2010

Natural selection leads to behavioural choices that increase the animal's fitness. The neuronal mechanisms underlying behavioural choice are still elusive and empirical evidence connecting neural circuit activation to adaptive behavioural output is sparse.

We exposed foraging juvenile crayfish to approaching shadows of different velocities and found that slow-moving shadows predominantly activated a pair of giant interneurons, which mediate tail-flips that thrust the animals backwards and away from the approaching threat. Tail-flips also moved the animals farther away from an expected food source, and crayfish defaulted to freezing behaviour when faced with fast-approaching shadows. Under these conditions, tail-flipping, an ineffective and costly escape strategy was suppressed in favour of freezing, a more beneficial choice. The decision to freeze also dominated in the presence of a more desirable resource; however, the increased incentive was less effective in suppressing tail-flipping when paired with slow-moving visual stimuli that reliably evoked tail-flips in most animals. Together this suggests that crayfish make value-based decisions by weighing the costs and benefits of different behavioural options, and they select adaptive behavioural output based on the activation patterns of identifiable neural circuits.
Gene expression regulation and lineage evolution: the North and South tale of the hybrid polyploidSqualius alburnoidescomplex
Authors: Pala Irene , Schartl Manfred , Brito Miguel , Vacas Joana Malta , Coelho Maria Manuela
Published: June 2010

The evolution of hybrid polyploid vertebrates, their viability and their perpetuation over evolutionary time have always been questions of great interest. However, little is known about the impact of hybridization and polyploidization on the regulatory networks that guarantee the appropriate quantitative and qualitative gene expression programme. TheSqualius alburnoidescomplex of hybrid fish is an attractive system to address these questions, as it includes a wide variety of diploid and polyploid forms, and intricate systems of genetic exchange. Through the study of genome-specific allele expression of seven housekeeping and tissue-specific genes, we found that a gene copy silencing mechanism of dosage compensation exists throughout the distribution range of the complex. Here we show that the allele-specific patterns of silencing vary within the complex, according to the geographical origin and the type of genome involved in the hybridization process. In southern populations, triploids ofS. alburnoidesshow an overall tendency for silencing the allele from the minority genome, while northern population polyploids exhibit preferential biallelic gene expression patterns, irrespective of genomic composition. The present findings further suggest that gene copy silencing and variable expression of specific allele combinations may be important processes in vertebrate polyploid evolution.
The influence of tidal cycles and freshwater inflow on the distribution and movement of an estuarine resident fish Acanthopagrus butcheri
Authors: Sakabe R. , Lyle J. M.
Published: June 2010

Movement patterns and habitat utilization by black bream Acanthopagrus butcheri (Sparidae), an estuarine resident species, were investigated using acoustic telemetry in a small estuary on the east coast of Tasmania, Australia. Thirty‐four adult A. butcheri were tracked for periods of up to 187 days between August 2005 and January 2006. Although able to tolerate a wide range of salinities, the fish spent most of the time within the upper and middle regions of the estuary, where brackish conditions dominated. The species exhibited extensive movements linked to tidal cycles, with small‐scale upstream movements during incoming tides and downstream movements during out going tides. The extent of these movements was positively correlated with the tidal height difference between consecutive tidal peaks and troughs. Freshwater inflows and resultant changes in salinity also significantly influenced distribution and movement patterns. Fish moved downstream during the periods of heavy inflows, returning upstream as salinities increased to c. >10. During the peak of spawning period (November to December) fish moved into the upper region of the estuary, where they aggregated to spawn. Periodic increases in freshwater discharge, however, resulted in fish leaving the spawning grounds and moving downstream. Towards the end of the spawning season (January), the fish became more dispersed throughout the entire estuarine system.
Comparison of the Intersurgical SolusTM laryngeal mask airway and the i‐gel supralaryngeal device
Authors: Amini S. , Khoshfetrat M.
Published: June 2010

We compared the performance of the Intersurgical SolusTM laryngeal mask airway (LMA) with that of the i‐gel in 120 patients of ASA physical status during general anaesthesia with respect to oropharyngeal leak pressure, peak airway pressure, airway manipulation, insertion time, fibreoptic view, ventilatory parameters, and peri‐operative complications. After receiving a standardised induction of anaesthesia, either a Solus LMA (60 patients) or an i‐gel (60 patients) was inserted. One hundred and fifteen patients completed the study. The leak pressure was significantly higher in the LMA group than the i‐gel group (mean (SD) 22.7 (7.7) cmH2O vs 19.3 (7.1) cmH2O; p = 0.02). A better fibreoptic view of the larynx was obtained in patients in the LMA group (p = 0.02) compared to those in the i‐gel group and less airway manipulation was required in the LMA group (p < 0.01). Both devices have good performance with very low peri‐operative complications. However, the Solus LMA provides a better oropharyngeal seal, provides a better fibreoptic view, and requires less manipulation to secure the airway than the i‐gel.
The dispersal and deposition of hydrochorous plant seeds in drainage ditches
Authors: SOOMERS HESTER , WINKEL DEBORAH N. , DU YUN , WASSEN MARTIN J.
Published: June 2010

1. Surface water is an important dispersal vector for wetland plant species. However, most previous studies on hydrochory (i.e. water dispersal) have focused on ecosystems with relatively rapid water flow. Therefore, there is a need to study such dispersal in slow‐flowing or stagnant waterbodies, such as drainage ditches, which might act as dispersal corridors between habitat patches.

2. To gain insight into the mechanisms by which seeds are transported in drainage ditches, the effect of the velocity of wind and water on the rate of transport of floating seeds of three wetland species (Carex pseudocyperus L., Iris pseudacorus L. and Sparganium erectum L.) was investigated. Furthermore, in release and retrace experiments with painted C. pseudocyperus seeds, a number of factors potentially determining the probability of seed deposition were investigated.

3. Net wind speed was found to be the main factor determining the rate at which seeds are transported in drainage ditches. No relation between water flow at middepth in the ditches and seed transport was found. Wind speed and flow at the water surface were positively related. The effect of wind speed on the rate of transport of floating seeds was greater for S. erectum seeds, because a greater ratio of their volume protrudes from the water, than for C. pseudocyperus and I. pseudacorus seeds.

4. The principal factors that determine seed deposition were aquatic plant cover, ditch slope and indentations in the ditch bank. Seeds changed direction if the wind direction changed, or if there was a bend in the ditch. The final pattern of deposition was related to mean net wind speed. Mean transport distance after 2 days varied between 34 and 451 m.

5. Unlike in rivers, seed transport in ditches was determined by wind speed and direction, enabling multidirectional seed dispersal. We conclude that in slow‐flowing waters, wind is a more important driver for hydrochorous seed transport than the flow of water. This sheds a new light on hydrochory and has important consequences for the management of otherwise fragmented wetland remnants.
Functional explanations for variation in bark thickness in tropical rain forest trees
Authors: Paine Charles Eliot Timothy , Stahl Clément , Courtois Elodie A. , Patiño Sandra , Sarmiento Carolina , Baraloto Christopher
Published: June 2010

1. The complex structure of tree bark reflects its many functions, which include structural support as well as defence against fire, pests and pathogens. Thick bark, however, might limit respiration by the living tissues of the trunk. Nevertheless, little research has addressed community‐level variation in bark thickness, and to the best of our knowledge, no one has tested multiple hypotheses to explain variation in bark thickness.

2. We conducted an extensive survey of bark thickness within and among species of trees in the tropical rain forests of French Guiana. Trunk bark thickness increased by 1·2 mm per 10 cm increase in stem diameter, and varied widely at all taxonomic levels. Mean trunk bark thickness was 4·5 mm (range: 0·5–29 mm), which was less that found in two Amazonian rain forests in previous studies. This survey of bark thickness should be of use for forest management since tree survival through fire is strongly predicted by bark thickness.

3. We combined the survey data with multiple datasets to test several functional hypotheses proposed to explain variation in bark thickness. We found bark to provide an average of 10% of the flexural rigidity of tree stems, which was substantially less than that found in the only other study of bark stiffness. Bark thickness was uncorrelated with species’ association with fire‐prone habitats, suggesting that the influence of fire on bark thickness does not extend into moist Forests. There was also little evidence that bark thickness is affected by its function as a defence against herbivory. Nor was there evidence that thick bark limits trunk respiration.

4. A re‐analysis of previously collected anatomical data indicated that variation in rhytidome (non‐conducting outer bark) thickness explains much of the variation in overall bark thickness. As rhytidome is primarily involved in protecting the living tissues of the trunk, we suggest that bark thickness is driven mostly by its defensive function.

5. Functional explanations for the variation in bark thickness were not clear‐cut. Nevertheless, this study provides a foundation for further investigation of the functional bases of bark in tropical trees.
Quantifying restoration success and recovery in a metal‐polluted stream: a 17‐year assessment of physicochemical and biological responses
Authors: Clements William H. , Vieira Nicole K. M. , Church Stanley E.
Published: June 2010

1. Evaluating the effectiveness of stream restoration is often challenging because of the lack of pre‐treatment data, narrow focus on physicochemical measures and insufficient post‐restoration monitoring. Even when these fundamental elements are present, quantifying restoration success is difficult because of the challenges associated with distinguishing treatment effects from seasonal variation, episodic events and long‐term climatic changes.

2. We report results of one of the most comprehensive and continuous records of physical, chemical and biological data available to assess restoration success for a stream ecosystem in North America. Over a 17 year period we measured seasonal and annual changes in metal concentrations, physicochemical characteristics, macroinvertebrate communities, and brown trout Salmo trutta populations in the Arkansas River, a metal‐contaminated stream in Colorado, USA.

3. Although we observed significant improvements in water quality after treatment, the effectiveness of restoration varied temporally, spatially and among biological response variables. The fastest recovery was observed at stations where restoration eliminated point sources of metal contamination. Recovery of macroinvertebrates was significantly delayed at some stations because of residual sediment contamination and because extreme seasonal and episodic variation in metal concentrations prevented recolonization by sensitive species.

4. Synthesis and applications. Because recovery trajectories after the removal of a stressor are often complex or nonlinear, long‐term studies are necessary to assess restoration success within the context of episodic events and changes in regional climate. The observed variation in recovery among chemical and biological endpoints highlights the importance of developing objective criteria to assess restoration success. Although the rapid response of macroinvertebrates to reduced metal concentrations is encouraging, we have previously demonstrated that benthic communities from the Arkansas River remained susceptible to other novel anthropogenic stressors. We suggest that the resistance or resilience of benthic macroinvertebrate communities to novel stressors may be effective indicators of restoration success that can account for the non‐additive (e.g. synergistic) nature of compound perturbations.
Variation in the effects of vertebrate grazing on fire potential between grassland structural types
Authors: Leonard Steve , Kirkpatrick Jamie , Marsden‐Smedley Jonathan
Published: June 2010

1. Vegetation fires can have major social, economic and ecological consequences. Research into fire behaviour has aimed to give managers greater ability to predict and control fires. Fire and grazing are important and interacting disturbances in grasslands. Fire is known to widely affect grazing patterns, but the effects of grazing on the incidence of fire are less well known. There have been few tests of the idea that ‘grazing reduces blazing’, which has popular and political currency in some countries. This study addresses the hypothesis that grazing affects fire potential in native grasslands.

2. Paired grazed and ungrazed quadrats were established at five lawn and five tussock grassland sites. Fuel load, percentage dead fuel and the number of days sustaining fires where possible were compared between treatments.

3. In lawn grasslands, grazing markedly reduced fire potential through the removal of plant biomass and by preventing the vegetation escaping into the unpalatable and flammable tussock state. Grazing led to increased fire potential in tussock grasslands where animals selectively removed live shoots, leaving a high proportion of dead fuel.

4. The difference in flammability responses to grazing between lawn and tussock grassland appeared to be due to differences in palatability that in turn may relate to soil fertility and the constancy of intense grazing. These differences mean that grazing lawns and tussock grasslands are likely to be subject to differing disturbance regimes. This association between disturbance regime and vegetation structural type suggests that lawns and tussock grasslands represent alternative stable states within the grassland ecosystem.

5. Synthesis and applications. Grazing is only likely to reduce the probability of fire where the bulk of the vegetation consists of potential food for grazing animals. It is likely that the negative relationship between vegetation palatability and fire potential applies to grasslands generally and possibly to many other vegetation types. Grassland managers may need to manipulate disturbance regimes in order to maintain vegetation structural heterogeneity and thereby promote landscape‐scale biodiversity.