bluuebunny/crossref_metadata_2025 huggingface dataset:
The transient coupled thermo-piezoelectric response of a functionally graded piezoelectric hollow cylinder to dynamic loadings
Authors: Babaei M. H. , Chen Z. T.
Published: December 2009

The transient, coupled thermo-piezoelectric response of a functionally graded, radially polarized hollow cylinder under dynamic axisymmetric loadings was investigated in the present paper. To take into account the simultaneous coupling of displacement, temperature and electric fields as well as non-Fourier heat conduction effect, the Chandrasekharaiah theory of generalized thermo-piezoelectricity was employed. Except thermal relaxation time which was taken to be constant, profiles of all other material properties follow a volume-fraction-based rule with different non-homogeneity indices for each property. To solve three governing coupled partial differential equations, the Galerkin finite-element method was used in the Laplace domain. To restore time, a numerical scheme was employed for the Laplace inversion. When the cylinder was exposed to a highly transient thermal loading, effects of the non-homogeneity index and thermal relaxation time on the results were investigated.
Female giant panda (
Ailuropoda melanoleuca
) chirps advertise the caller's fertile phase
Authors: Charlton Benjamin D. , Keating Jennifer L. , Rengui Li , Huang Yan , Swaisgood Ronald R.
Published: December 2009

Although female mammal vocal behaviour is known to advertise fertility, to date, no non-human mammal study has shown that the acoustic structure of female calls varies significantly around their fertile period. Here, we used a combination of hormone measurements and acoustic analyses to determine whether female giant panda chirps have the potential to signal the caller's precise oestrous stage (fertile versus pre-fertile). We then used playback experiments to examine the response of male giant pandas to female chirps produced during fertile versus pre-fertile phases of the caller's reproductive cycle. Our results show that the acoustic structure of female giant panda chirps differs between fertile and pre-fertile callers and that male giant pandas can perceive differences in female chirps that allow them to determine the exact timing of the female's fertile phase. These findings indicate that male giant pandas could use vocal cues to preferentially associate and copulate with females at the optimum time for insemination and reveal the likely importance of female vocal signals for coordinating reproductive efforts in this critically endangered species.
Cuttlefish dynamic camouflage: responses to substrate choice and integration of multiple visual cues
Authors: Allen Justine J. , Mäthger Lydia M. , Barbosa Alexandra , Buresch Kendra C. , Sogin Emilia , Schwartz Jillian , Chubb Charles , Hanlon Roger T.
Published: December 2009

Prey camouflage is an evolutionary response to predation pressure. Cephalopods have extensive camouflage capabilities and studying them can offer insight into effective camouflage design. Here, we examine whether cuttlefish,
Sepia officinalis
, show substrate or camouflage pattern preferences. In the first two experiments, cuttlefish were presented with a choice between different artificial substrates or between different natural substrates. First, the ability of cuttlefish to show substrate preference on artificial and natural substrates was established. Next, cuttlefish were offered substrates known to evoke three main camouflage body pattern types these animals show: Uniform or Mottle (function by background matching); or Disruptive. In a third experiment, cuttlefish were presented with conflicting visual cues on their left and right sides to assess their camouflage response. Given a choice between substrates they might encounter in nature, we found no strong substrate preference except when cuttlefish could bury themselves. Additionally, cuttlefish responded to conflicting visual cues with mixed body patterns in both the substrate preference and split substrate experiments. These results suggest that differences in energy costs for different camouflage body patterns may be minor and that pattern mixing and symmetry may play important roles in camouflage.
Zebra finches exhibit speaker-independent phonetic perception of human speech
Authors: Ohms Verena R. , Gill Arike , Van Heijningen Caroline A. A. , Beckers Gabriel J. L. , ten Cate Carel
Published: December 2009

Humans readily distinguish spoken words that closely resemble each other in acoustic structure, irrespective of audible differences between individual voices or sex of the speakers. There is an ongoing debate about whether the ability to form phonetic categories that underlie such distinctions indicates the presence of uniquely evolved, speech-linked perceptual abilities, or is based on more general ones shared with other species. We demonstrate that zebra finches (
Taeniopygia guttata
) can discriminate and categorize monosyllabic words that differ in their vowel and transfer this categorization to the same words spoken by novel speakers independent of the sex of the voices. Our analysis indicates that the birds, like humans, use intrinsic and extrinsic speaker normalization to make the categorization. This finding shows that there is no need to invoke special mechanisms, evolved together with language, to explain this feature of speech perception.
Ecological and evolutionary factors in dental morphological diversification among modern human populations from southern South America
Authors: Bernal Valeria , Perez S. Ivan , Gonzalez Paula N. , Diniz-Filho José Alexandre Felizola
Published: December 2009

The knowledge of processes involved in morphological variation requires the integrated analysis of evolutionary and ecological factors. Here, we investigate the factors responsible for dental variation among human populations from southern South America. The aim of this work is to test the correspondence of dental size and shape variation with geographical, molecular (i.e. mtDNA) and ecological (i.e. climate, diet and food preparation) variables employing comparative phylogenetic methods, which have not previously been extensively applied at a within-species level. The results of the Procrustes analysis show a significant association of shape variables with molecular distance and geography, whereas dental size is not associated with molecular or geographical distances among groups. Phylogenetic generalized least-squares analysis, which takes into account the evolutionary autocorrelation among populations, shows a significant relationship between dental size variation and diet, while temperature and pottery do not correspond with dental size or shape. Specifically, groups with diets rich in carbohydrates, as well as the maritime hunter-gatherers, have the smallest teeth. In summary, our results support ecological factors as the dominant factor on dental size diversification in this region, while evolutionary relationships account for variation in dental shape.
High-model abundance may permit the gradual evolution of Batesian mimicry: an experimental test
Authors: Kikuchi David W. , Pfennig David W.
Published: December 2009

In Batesian mimicry, a harmless species (the ‘mimic’) resembles a dangerous species (the ‘model’) and is thus protected from predators. It is often assumed that the mimetic phenotype evolves from a cryptic phenotype, but it is unclear how a population can transition through intermediate phenotypes; such intermediates may receive neither the benefits of crypsis nor mimicry. Here, we ask if selection against intermediates weakens with increasing model abundance. We also ask if mimicry has evolved from cryptic phenotypes in a mimetic clade. We first present an ancestral character-state reconstruction showing that mimicry of a coral snake (
Micrurus fulvius
) by the scarlet kingsnake (
Lampropeltis elapsoides
) evolved from a cryptic phenotype. We then evaluate predation rates on intermediate phenotypes relative to cryptic and mimetic phenotypes under conditions of both high- and low-model abundances. Our results indicate that where coral snakes are rare, intermediate phenotypes are attacked more often than cryptic and mimetic phenotypes, indicating the presence of an adaptive valley. However, where coral snakes are abundant, intermediate phenotypes are not attacked more frequently, resulting in an adaptive landscape without a valley. Thus, high-model abundance may facilitate the evolution of Batesian mimicry.
Effect of temperature on the gastric evacuation in sprat Sprattus sprattus
Authors: Bernreuther M. , Temming A. , Herrmann J.‐P.
Published: December 2009

Gastric evacuation of groups of juvenile (mean 63 mm total length, LT, 0·283 g dry mass, MD) sprat Sprattus sprattus feeding on brine shrimp Artemia sp. nauplii was studied at six temperatures (7·5, 10, 13, 16, 19·5 and 21·5° C) in the laboratory. Gastric evacuation was best described with a general model: , with St = stomach content at time t, S0 = stomach content at time 0, t = time , R, B = constants. The shape parameter was estimated as B = 0·668. For comparison with other studies, an exponential model was fitted also to the data. The evacuation constant (R) of the general gastric evacuation model increased exponentially with temperature between 7·5 and 16° C. The slope of the increase was reduced between 16 and 19·5° C and a slight decrease was observed between 19 and 21·5° C. Additionally, the effect of mean MD (range 0·286 – 1·025 g) was examined. A simple power function ( ) described the influence of predator mass on exponential evacuation constant with C = 0·503. The results of this investigation were integrated into a consumption model for the calculation of daily rations of S. sprattus: , with T = ambient temperature (°C) and of field stomach contents (g dry) individually raised to the power of 0·668.
The effect of different kinds of electrolyte and non‐electrolyte solutions on the survival rate and morphology of zebrafish Danio rerio embryos
Authors: Lahnsteiner F.
Published: December 2009

The effect of electrolyte and non‐electrolyte solutions on the survival and on the morphology of zebrafish Danio rerio embryos was investigated. Embryos in different ontogenetic stages were incubated in electrolyte (NaCl, KCl, MgCl2 and CaCl2) and non‐electrolyte solutions [sucrose and polyvinylalcohol (PVA)] of different concentrations for 5 – 15 min. The embryos were hatched to the long‐pec stage and the effective concentrations which caused a 50% decrease in embryo development (EC50) were determined. The morphometric changes, which were caused by the test solutions, were measured. Ion channel blockers were used to see if active ion transport played a role for embryo survival. Finally, dechorionated embryos were exposed to the test solutions to get indications about the importance of chorion and perivitelline space. For 12 hours post fertilization (hpf) embryos and a 15 min exposure period, EC50 was highest for MgCl2 (1·60 mol l−1), followed by sucrose (0·73 mol l−1), NaCl (0·49 mol l−1), KCl (0·44 mol l−1), CaCl2 (0·43 mol l−1) and PVA [0·0005 mol l−1 (2·2%)]. EC50 were lower for early embryonic stages than for advanced stages for all solutions with exception of MgCl2 and sucrose. At the EC50, MgCl2 and CaCl2 solutions did not induce morphometric changes. NaCl and sucrose solutions induced reversible morphometric changes, which were compensated within 10 min. Only the EC50 of KCl and PVA solutions induced permanent morphometric changes, which could not be compensated. Incubation of embryos in electrolyte and non‐electrolyte solutions together with ouabain (blocker of Na+– K+ ATPase), HgCl3 (dose‐dependent inhibition of aquaporine channels), verapamil (inhibition of calcium and magnesium uptake) and amiloride (inhibition of sodium uptake) significantly decreased the per cent of embryos developing to the long‐pec stage in comparison to the same solutions without blockers. Ouabain and HgCl3 also induced morphometric changes. For dechorionated embryos the survival rates in water and in the different test solutions were similar to untreated embryos.
Spawning dynamics and biomass estimates of an anchovy Engraulis australis population in contrasting gulf and shelf environments
Authors: Dimmlich W. F. , Ward T. M. , Breed W. G.
Published: December 2009

The spawning biomass of Australian anchovy Engraulis australis in gulf and shelf waters of South Australia was compared using the daily egg production method (DEPM). The total survey area was 128 700 km2 with recorded spawning areas in gulf and shelf waters of 4898 and 44 618 km2, respectively. High egg densities in the warm, shallow gulf waters were produced by small, young (<1 year old) E. australis that spawned relatively small batches of eggs (c. 855) approximately every 3 days. In cooler, deeper shelf waters, where larger, older E. australis are found, lower egg densities occurred despite individuals producing much larger batches of eggs (c. 15 572) approximately every 7 days. In shelf waters, the highest densities were recorded at inshore sampling stations. Spawning appeared to peak between 0000 and 0100 hours. Females were more abundant than males in samples from both gulf and shelf waters with sex ratios of 0·61 and 0·56, respectively. The spawning biomass of E. australis in shelf waters was 101 522 t, whereas the estimate for gulf waters was 25 374 t. Due to the differences in mean size of the spawning females, however, c. 6 × 109E. australis were present in each region. The results support the hypothesis that variability in habitat conditions may directly influence E. australis reproduction. A large reserve of young fish in the relatively stable gulf environment may increase the resilience of the E. australis population in South Australia to unfavourable interannual changes in offshore environmental conditions.
Evaluation of a non‐invasive tagging system for laboratory studies using three‐spined sticklebacksGasterosteus aculeatus
Authors: Webster M. M. , Laland K. N.
Published: December 2009

A non‐invasive tagging system for individual identification of three‐spined sticklebacksGasterosteus aculeatuswas evaluated. The tags were easily detectedviavideo, and tagged and non‐tagged fish did not differ in terms of growth, activity levels or shoaling behaviour.
Effect of turbulence on feeding intensity and survival of Japanese flounder Paralichthys olivaceus pelagic larvae
Authors: Oshima M. , Kato Y. , Masuda R. , Kimura S. , Yamashita Y.
Published: December 2009

Three‐day rearing experiments were conducted to study the effect of turbulence on the feeding intensity and survival of pelagic larvae of Japanese flounder Paralichthys olivaceus. Four levels of turbulence as control (10−7·2 m2 s−3), low (10−6·2 m2 s−3), mid (10−5·6 m2 s−3) and high (10−5·0 m2 s−3) were set by changing the flow rate of water pumped through pipes set on the bottom of the tanks. In B‐stage larvae, defined as having buds of elongated dorsal fin rays, the feeding intensity and growth were higher in the low and mid turbulence levels, while survival was highest in the control level. Most of the larvae surviving in the control level, however, were judged to be in a seriously starved condition leading to subsequent high mortality. Because the three‐day span of the rearing experiments was thought to be a little shorter than the periods before starvation‐induced, high mortality occurs. In contrast, for D‐stage larvae, their feeding and growth were optimal in the control and low levels. Feeding was more adversely affected in the high level for D‐stage larvae compared with B‐stage larvae. This is probably due to the compressed body shape and elongated dorsal fin rays of D‐stage larvae, which may be more strongly affected by turbulence and, as a consequence, the larval feeding behaviour such as pursuit and capture of prey organisms becomes less efficient than in lower turbulence. Considering the vertical distribution of B and D‐stage larvae in the oceanic water column, the optimum turbulence level range found in the present study corresponded to a wind speed of 7–10 m s−1. Therefore, moderate weather conditions of this wind speed range are considered to potentially enhance survival of early larval stages of P. olivaceus.
Interactions between immunocompetence, somatic condition and parasitism in the chubLeuciscus cephalusin early spring
Authors: Poisot T. , ŠImková A. , Hyršl P. , Morand S.
Published: December 2009

Relationships between immunocompetence, somatic condition, parasitism and water temperature in a wild population of chubLeuciscus cephaluswere investigated. The effects of a rapid temperature increase in early spring were studied for both sexes as water temperature affects immunocompetence. Investment in gonads and activity of mucus lysozyme were negatively correlated; lysozyme activity decreased as temperature increased. No correlations were found between lysozyme activity and parasitism or intensity of infection by monogeneans, the most abundant metazoan parasite group inL. cephalus. There was a positive correlation, however, between respiratory burst intensity and parasitism. Indices of investment in gonads and spleen were correlated, showing that energetic reserves allowed either investment in gonads and spleen, or that spleen investment, even if often used in other studies in immunoecology, was not always a significant indicator of immunocompetence during this period. This last proposition is supported by the lack of correlation between spleen investment and other factors linked to immunocompetence.
Restoring depleted coral‐reef fish populations through recruitment enhancement: a proof of concept
Authors: Heenan A. , Simpson S. D. , Meekan M. G. , Healy S. D. , Braithwaite V. A.
Published: December 2009

To determine whether enhancing the survival of new recruits is a sensible target for the restorative management of depleted coral‐reef fish populations, settlement‐stage ambon damsel fish Pomacentrus amboinensis were captured, tagged and then either released immediately onto small artificial reefs or held in aquaria for 1 week prior to release. Holding conditions were varied to determine whether they affected survival of fish: half the fish were held in bare tanks (non‐enriched) and the other half in tanks containing coral and sand (enriched). Holding fish for this short period had a significantly positive effect on survivorship relative to the settlement‐stage treatment group that were released immediately. The enrichment of holding conditions made no appreciable difference on the survival of fish once released onto the reef. It did, however, have a positive effect on the survival of fish while in captivity, thus supporting the case for the provision of simple environmental enrichment in fish husbandry. Collecting and holding settlement‐stage fish for at least a week before release appear to increase the short‐term survival of released fish; whether it is an effective method for longer‐term enhancement of locally depleted coral‐reef fish populations will require further study.
Observations on the seasonal breeding biology and fine structure of the egg surface in the white piranha Serrasalmus brandtii from the São Francisco River basin, Brazil
Authors: Honorato‐Sampaio K. , Santos G. B. , Bazzoli N. , Rizzo E.
Published: December 2009

In the Juramento Reservoir, south‐eastern Brazil, the white piranha Serrasalmus brandtii showed a prolonged reproductive season, with evidence for multiple spawning and a reproductive peak associated with seasonal rains. The egg surface exhibited a honeycomb‐like pore canal arrangement and an adhesive apparatus surrounding the micropyle. Electron microscopic analysis suggests a role for the micropylar cell and neighbouring follicular cells in secretion of substances for egg attachment.
Migratory behaviour and survival rates of wild northern Atlantic salmon Salmo salar post‐smolts: effects of environmental factors
Authors: Davidsen J. G. , Rikardsen A. H. , Halttunen E. , Thorstad E. B. , ØKland F. , Letcher B. H. , Skarðhamar J. , Næsje T. F.
Published: December 2009

To study smolt behaviour and survival of a northern Atlantic salmon Salmo salar population during river descent, sea entry and fjord migration, 120 wild S. salar were tagged with acoustic tags and registered at four automatic listening station arrays in the mouth of the north Norwegian River Alta and throughout the Alta Fjord. An estimated 75% of the post‐smolts survived from the river mouth, through the estuary and the first 17 km of the fjord. Survival rates in the fjord varied with fork length (LF), and ranged from 97·0 to 99·5% km−1. On average, the post‐smolts spent 1·5 days (36 h, range 11–365 h) travelling from the river mouth to the last fjord array, 31 km from the river mouth. The migratory speed was slower (1·8 LF s−1) in the first 4 km after sea entry compared with the next 27 km (3·0 LF s−1). Post‐smolts entered the fjord more often during the high or ebbing tide (70%). There was no clear diurnal migration pattern within the river and fjord, but most of the post‐smolts entered the fjord at night (66%, 2000–0800 hours), despite the 24 h daylight at this latitude. The tidal cycle, wind‐induced currents and the smolts' own movements seemed to influence migratory speeds and routes in different parts of the fjord. A large variation in migration patterns, both in the river and fjord, might indicate that individuals in stochastic estuarine and marine environments are exposed to highly variable selection regimes, resulting in different responses to environmental factors on both temporal and spatial scales. Post‐smolts in the northern Alta Fjord had similar early marine survival rates to those observed previously in southern fjords; however, fjord residency in the north was shorter.
Feeding ecology of pelagic fish larvae and juveniles in slope waters of the Gulf of Mexico
Authors: Wells R. J. D. , Rooker J. R.
Published: December 2009

Stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) were used to investigate feeding patterns of larval and early juvenile pelagic fishes in slope waters of the Gulf of Mexico. Contribution of organic matter supplied to fishes and trophic position within this pelagic food web was estimated in 2007 and 2008 by comparing dietary signatures of the two main producers in this ecosystem: phytoplankton [based on particulate organic matter (POM)] and Sargassum spp. Stable isotope ratios of POM and pelagic Sargassum spp. were significantly different from one another with δ13C values of POM depleted by 3–6‰ and δ15N values enriched by 2 relative to Sargassum spp. Stable isotope ratios were significantly different among the five pelagic fishes examined: blue marlin Makaira nigricans, dolphinfish Coryphaena hippurus, pompano dolphinfish Coryphaena equiselis, sailfish Istiophorus platypterus and swordfish Xiphias gladius. Mean δ13C values ranged almost 2 among fishes and were most depleted in I. platypterus. In addition, mean δ15N values ranged 4–5 with highest mean values found for both C. hippurus and C. equiselis and the lowest mean value for M. nigricans during both years. Increasing δ13C or δ15N with standard length suggested that shifts in trophic position and diet occurred during early life for several species examined. Results of a two‐source mixing model suggest approximately an equal contribution of organic matter by both sources (POM = 55%; pelagic Sargassum spp. = 45%) to the early life stages of pelagic fishes examined. Contribution of organic matter, however, varied among species, and sensitivity analyses indicated that organic source estimates changed from 2 to 13% for a δ13C fractionation change of ±0·25‰ or a δ15N fractionation change of ± 1·0‰ relative to original fractionation values.
Risk‐taking behaviour variation over time in sea bassDicentrarchus labrax: effects of day–night alternation, fish phenotypic characteristics and selection for growth
Authors: Millot S. , Bégout M.‐L. , Chatain B.
Published: December 2009

Differences in bold and shy personality on sea bassDicentrarchus labraxwere investigated between a population (wild) produced from wild‐brood fish and a population (selected) produced from selected‐brood fish. During the experiment (112 days), fish were reared under self‐feeding condition to characterize the feeding behaviour of each individual fish. Three risk‐taking tests (T1, T2 and T3 of 24 h with day–night alternation) were carried out at > 1 month intervals on 180 fish of each strain in order to monitorD. labraxbehaviour over time and in relation to the light:dark period. A risk‐taking score was evaluatedviaa preference choice between a safe zone (without food) and a risky zone (potentially with food) by recording the number and the duration of individual passages through an opening in an opaque divider. Results showed that fish performed passages preferentially during the night period and that wild fish were generally bolder than selected fish during T1 and T2 but showed a decrease in risk taking during T3, contrary to selected fish which showed a constant increase in their risk‐taking behaviour. The phenotypic characteristics of the bold fish were different in the two strains: wild bold fish were the smallest within the wild strain and selected bold fish presented the higher growth rate within the selected strain. For both strains, these bold fish were also generally characterized by a high feed‐demand activity. Fish hunger state thus seemed to be the highest motivation for risk‐taking behaviour under the present conditions. Furthermore, behavioural variations over tests such as higher risk taking (number of passages) and faster exploratory responses (higher score emergence) could be interpreted as relevant indicators of the learning process and habituation. According to the results, however, no real difference in coping strategy between strains could be observed at this first stage of domestication and selection.
Coronary vascular volume remodelling in rainbow troutOncorhynchus mykiss
Authors: Simonot D. L. , Farrell A. P.
Published: December 2009

The 34% increase in relative ventricular mass (Mrv) resulting from chronic anaemia (induced by an intraperitoneal injection of phenylhydrazine hydrochloride) was accompanied by a 117% increase in coronary vascular volume of diploid rainbow troutOncorhynchus mykiss. Coronary vascular volume of normocythemic triploid fish was similar to that of normocythemic diploid fish despite a largerMrv. These observations, in combination with previous studies, suggest that the vascularity of compact myocardium inO. mykisscan vary independently ofMrv.
Methods for estimating detection efficiency and tracking acoustic tags with mobile transect surveys
Authors: Melnychuk M. C. , Christensen V.
Published: December 2009

Mobile transect surveys were conducted for 5 years in a deep fjord looking for weak acoustic tags, most of which were in dead fishes lying on the seabed. Detection efficiencies were quantified because inferences about fish presence were made from tag detection data but a considerable proportion of tags were not detected. Methods for assessing transect widths using cumulative probabilities of measured perpendicular distances from blind transect lines to triangulated tag locations are described. Three methods for estimating detection efficiencies are presented: fitting attenuation functions to perpendicular distance data, simultaneous use of two receiver systems and test tag surveys. Several factors that influenced these detection efficiencies and ranges are shown, including boat speed, depth of tag, tag type, different hydrophone–receiver systems and variation among individual hydrophones and receivers of the same model. The trade‐off between detection efficiency per unit area and area swept is discussed, which is largely based on boat speed during transects. Finally, several methods are suggested for increasing decoding efficiencies in mobile tracking studies when tags are heard but are difficult to decode.
Preliminary examination of oxidative stress in juvenile spring Chinook salmon Oncorhynchus tshawytscha of wild origin sampled from transport barges
Authors: Welker T. L. , Congleton J. L.
Published: December 2009

Migrating juvenile wild Chinook salmon Oncorhynchus tshawytscha, collected and loaded onto transport barges at Lower Granite Dam on the Snake River, were sampled from barges at John Day Dam, 348 km downstream, at 5 day intervals beginning in late April and ending in late May. An increase in lipid peroxidation and decrease in vitamin E in liver were observed from early to late in the barge transportation season. These changes seemed unrelated to changes in plasma cortisol or corresponding glucose levels, which declined from early to late in the season, or the concentration of n‐3 highly unsaturated fatty acid (HUFA) concentrations in tissue but may be related to water temperature, which increased during the transport season, or other changes associated with the parr–smolt transformation.
Reproductive parasitism: male and female responses to conspecific and heterospecific intrusions at spawning in a mouth‐brooding cichlid Ophthalmotilapia ventralis
Authors: Haesler M. P. , Lindeyer C. M. , Taborsky M.
Published: December 2009

A rare form of alternative reproductive behaviour without simultaneous parasitic spawning was observed in Ophthalmotilapia ventralis, a lekking mouth‐brooding cichlid from Lake Tanganyika. Floater males attempted to sneak opportunistically into the territory to actively court the female, while the owner (bourgeois male) defended the territory against other potential intruders. Floater males had more body fat than territory owners and generally higher condition factors. In field experiments, the response of bourgeois males and courted females was tested towards floaters and egg predators (a catfish Synodontis multipunctatus) present in the territories. Territory owners responded aggressively particularly to floaters, and female responsiveness to bourgeois male courtship tended to decline when floaters were present. The potential influence of reproductive parasitism on sexual selection in mouth‐brooding cichlids is discussed.
Continued decline in tree euphorbias (Euphorbia tetragona and E. triangularis) on the Great Fish River Reserve, Eastern Cape, South Africa
Authors: Lent Peter C. , Eshuis Henk , Van Krimpen Ralph , De Boer Willem F.
Published: December 2009

A dramatic decline averaging 43% over a 4‐year period has occurred in tree Euphorbia (Euphorbia tetragona and Euphorbia triangularis) populations on the Great Fish River Reserve, South Africa. These changes are evident from data gathered by general vegetation monitoring methods as well as from a focused study of four tree Euphorbia populations. The decline from 2003 to 2007 was more marked for E. triangularis than for E. tetragona and was accompanied by a general absence of seedlings and a reduced presence of younger age classes of both species, decreasing the proportion of younger trees in the populations. The role of megaherbivores, specifically the black rhinoceros, in these changes is well established. However, the impact of baboon activity, leading to damage to tree crowns and upper branches, is also substantial, especially on E. triangularis populations. Damaged crowns were recorded significantly more often for E. triangularis than for E. tetragona, and the damage frequency increased with decreasing tree height. Thus, our work provides the first evidence that these two closely related Euphorbia species may be affected differently by herbivory.
Late Crohn’s disease patients present an increase in peripheral Th17 cells and cytokine production compared with early patients
Authors: VENY M. , ESTELLER M. , RICART E. , PIQUÉ J. M. , PANÉS J. , SALAS A.
Published: December 2009

Aliment Pharmacol Ther 31, 561–572

Background  Th1 and Th17 cells have been implicated in Crohn’s disease (CD) pathophysiology and may play a role in disease persistence.

Aim  To determine Th1 and Th17 responses in intestine and peripheral blood of early (<32 weeks since initial symptoms) and late (>2 years) CD patients.

Methods  Cytokine mRNA in intestinal biopsies was determined by RT‐PCR. Cytokine concentration in culture was measured by ELISA and cytokine‐producing cells were identified by intracellular staining.

Results  The inflamed mucosa showed significantly increased IL‐17 mRNA levels compared with non‐inflamed areas, both in early and late CD patients. However, only patients with late (n = 12), but not early (n = 9), active disease showed increased IL‐17 production, as well as a significantly higher percentage of IL‐17+CD4+ cells in blood, compared with controls (n = 12) or patients in remission (n = 13). Moreover, cultured peripheral CD4+ cells from late active CD patients presented significantly higher percentages of IL‐17+, IL‐22+ and IFN‐γ+ and a significantly increased production of IL‐17 and IL‐22, but not IFN‐γ+.

Conclusions  Increased IL‐17 gene transcription is common to early and late CD mucosa. However, exacerbated Th17 responses in the peripheral blood appear only in late disease. We propose that this population may constitute a mechanism of perpetuating the disease.
The influence of common gene variants of the xenobiotic receptor (PXR) in genetic susceptibility to intrahepatic cholestasis of pregnancy
Authors: CASTAÑO G. , BURGUEÑO A. , FERNÁNDEZ GIANOTTI T. , PIROLA C. J. , SOOKOIAN S.
Published: December 2009

Aliment Pharmacol Ther 31, 583–592

Background  The xenobiotic nuclear pregnane X receptor is implicated in many physiological pathways and diseases, including bile acid detoxification and cholestasis.

Aim  To estimate the contribution of common gene variants of the xenobiotic receptor (pregnane X receptor, PXR) to genetic susceptibility to intrahepatic cholestasis of pregnancy.

Methods  A total of 101 intrahepatic cholestasis of pregnancy patients and 171 healthy pregnant women in the third trimester of their pregnancies were included. Four tag single nucleotide polymorphisms (SNPs) (rs12488820 C/T, rs2472671 C/T, rs2461823 A/G, and rs1054191 A/G) encompassing 36 kb in chromosome 3, with a minor allele frequency ≥0.10 and representing 33 polymorphic sites were genotyped. Besides these, three additional SNPs (rs3814057, rs6785049, and rs7643645) were included because they showed previous evidence of functionality.

Results  Genotypic test for single SNPs showed that rs2461823 genotypes were significantly associated with intrahepatic cholestasis of pregnancy (P < 0.0069), OR per G allele: 1.44, 95% CI: 1.01–2.05, P < 0.042. The Cochran‐Armitage test for trend and the allelic test showed a significant association with disease status (P < 0.04 and 0.03 respectively), G being the risk allele. A positive association between rs2461823 and ALT, AST, and bilirubin concentrations was observed. Neonate birth weight adjusted by the Capurro index was significantly associated with rs2461823 (P < 0.05); the proportion of the total variation attributed to rs2461823 genotypes was 7.8%.

Conclusion  Common PXR polymorphisms may contribute to the genetic susceptibility to intrahepatic cholestasis of pregnancy.
No simple fix for fixation errors: cognitive processes and their clinical applications
Authors: Fioratou E. , Flin R. , Glavin R.
Published: December 2009

Fixation errors occur when the practitioner concentrates solely upon a single aspect of a case to the detriment of other more relevant aspects. These are well recognised in anaesthetic practice and can contribute significantly to morbidity and mortality. Improvement in patient safety may be assisted by development and application of countermeasures to fixation errors. Cognitive psychologists use ‘insight problems’ in a laboratory setting, both to induce fixation and to explore strategies to escape from fixation. We present some results from a series of experiments on one such insight problem and consider applications that may have relevance to anaesthetic practice.
Micro‐scale structure in the chemistry and biology of a shallow lake
Authors: BARKER TOM , IRFANULLAH HASEEB MD. , MOSS BRIAN
Published: December 2009

1. Repeat sampling in daytime within a lily (Nuphar lutea) bed and in open water showed distinct heterogeneities in the three‐dimensional distributions of water chemistry and planktonic organisms on centimetre to decimetre scales.

2. Vertical gradients of physico‐chemical variables that did not exist at dawn developed during the day in both sites, as available nutrients were released from the sediments and were consumed towards the surface.

3. Distributions of algal standing crop suggest limitation by both nutrients and grazing.

4. Marked variability in distributions may question the assumptions often made about the homogeneity of plankton and available nutrient distributions in open water and in macrophyte stands of shallow lakes. Although simple sampling regimes for monitoring of water quality may be adequate for many purposes, they miss a fine structure in the water that is inherently interesting in understanding the underlying processes of plankton function.
Analysis of variance with unbalanced data: an update for ecology & evolution
Authors: Hector Andy , Von Felten Stefanie , Schmid Bernhard
Published: December 2009

1. Factorial analysis of variance (anova) with unbalanced (non‐orthogonal) data is a commonplace but controversial and poorly understood topic in applied statistics.

2. We explain thatanovacalculates the sum of squares for each term in the model formula sequentially (type I sums of squares) and show howanovatables ofadjustedsums of squares are composite tables assembled from multiple sequential analyses. A differentanovais performed for each explanatory variable or interaction so that each term is placed last in the model formula in turn and adjusted for the others.

3. The sum of squares for each term in the analysis can be calculated after adjusting only for the main effects of other explanatory variables (type II sums of squares) or, controversially, for both main effects and interactions (type III sums of squares).

4. We summarize the main recent developments and emphasize the shift away from the search for the ‘right’anovatable in favour of presenting one or more models that best suit the objectives of the analysis.
Phylogeography and ecological niche modelling of the New Zealand stick insect Clitarchus hookeri (White) support survival in multiple coastal refugia
Authors: Buckley Thomas R. , Marske Katharine , Attanayake Dilini
Published: December 2009

Aim  Increasing our understanding of the effects of the Last Glacial Maximum (LGM) and determining the location of refugia requires studies on widely distributed species with dense sampling of populations. We have reconstructed the biogeographic history of Clitarchus hookeri (White), a widespread species of New Zealand stick insect that exhibits geographic parthenogenesis, using phylogeographic analysis and ecological niche modelling.

Location  New Zealand.

Methods  We used DNA sequence data from the mitochondrial cytochrome c oxidase subunit I gene to reconstruct phylogenetic relationships among haplotypes from C. hookeri and two undescribed Clitarchus species. We also used distribution data from our own field surveys and museum records to reconstruct the geographic distribution of C. hookeri during the present and the LGM, using ecological niche modelling.

Results  The ecological niche models showed that the geographic distribution of C. hookeri has expanded dramatically since the LGM. Our model predicted large areas of suitable LGM habitat in upper North Island, and small patches along the east coast of South Island. The phylogeographic analysis shows that populations in the northern half of North Island contain much higher levels of genetic variation than those from southern North Island and South Island, and is congruent with the ecological niche model. The distribution of bisexual populations is also non‐random, with males completely absent from South Island and very rare in southern North Island.

Main conclusions  During the LGM C. hookeri was most likely restricted to several refugia in upper North Island and one or more smaller refugia along the east coast of South Island. The unisexual populations predominate in post‐glacial landscapes and are clearly favoured in the recolonization of such areas. Our study exemplifies the utility of integrating ecological niche modelling and phylogeographic analysis.
The determinants of land snail diversity along a tropical elevational gradient: insularity, geometry and niches
Authors: Liew Thor‐Seng , Schilthuizen Menno , bin Lakim Maklarin
Published: December 2009

Aim  We investigated the patterns of species richness in land snails and slugs along a tropical elevational gradient and whether these patterns correlate with area, elevation, geographic constraints, and productivity. We did so both at the scale at which land snail population processes take place and at the coarser scale of elevational zones.

Location  Mount Kinabalu (4096 m) and the adjacent Mount Tambuyukon (2588 m) in Kinabalu Park, Sabah, Malaysian Borneo.

Methods  We used an effort‐controlled sampling protocol to determine land snail and slug species richness in 142 plots of 0.04 ha at elevations ranging from 570 to 4096 m. Extents of elevational ranges were determined by interpolation, extended where appropriate at the lower end with data from lowlands outside the study area. We used regression analysis to study the relationships between species density and richness on the one hand and elevation and area on the other. This was done for point data as well as for data combined into 300‐m elevational intervals.

Results  Species density (based on the individual samples) showed a decline with elevation. Elevational range length profiles revealed that range lengths are reduced at greater elevations and that a Rapoport effect is absent. Diversity showed a mild mid‐domain effect on Kinabalu, but not on Tambuyukon. When the data were combined into 300‐m elevational intervals, richness correlated more strongly with elevation than with area. Ecomorphospace was seen to shrink with increasing elevation.

Main conclusions  The elevational species richness patterns show the combined effects of (1) reduced niche diversity at elevations with lower productivity and (2) historical events in which the upward migration of lowland species as well as the speciation of highland endemics took place.
Noninvasive methods for assessment of airway inflammation in occupational settings
Authors: Quirce S. , Lemière C. , De Blay F. , Del Pozo V. , Gerth Van Wijk R. , Maestrelli P. , Pauli G. , Pignatti P. , Raulf‐Heimsoth M. , Sastre J. , Storaas T. , Moscato G.
Published: December 2009

To cite this article: Quirce S, Lemière C, de Blay F, del Pozo V, Gerth Van Wijk R, Maestrelli P, Pauli G, Pignatti P, Raulf‐Heimsoth M, Sastre J, Storaas T, Moscato G. Noninvasive methods for assessment of airway inflammation in occupational settings. Allergy 2010; 65: 445–458.

The present document is a consensus statement reached by a panel of experts on noninvasive methods for assessment of airway inflammation in the investigation of occupational respiratory diseases, such as occupational rhinitis, occupational asthma, and nonasthmatic eosinophilic bronchitis. Both the upper and the lower airway inflammation have been reviewed and appraised reinforcing the concept of ‘united airway disease’ in the occupational settings. The most widely used noninvasive methods to assess bronchial inflammation are covered: induced sputum, fractional exhaled nitric oxide (FeNO) concentration, and exhaled breath condensate. Nasal inflammation may be assessed by noninvasive approaches such as nasal cytology and nasal lavage, which provide information on different aspects of inflammatory processes (cellular vs mediators). Key messages and suggestions on the use of noninvasive methods for assessment of airway inflammation in the investigation and diagnosis of occupational airway diseases are issued.
Do individuals in better condition survive for longer? Field survival estimates according to male alternative reproductive tactics and sex
Authors: MUNGUÍA‐STEYER R. , CÓRDOBA‐AGUILAR A. , ROMO‐BELTRÁN A.
Published: December 2009

There is a gap in terms of the supposed survival differences recorded in the field according to individual condition. This is partly due to our inability to assess survival in the wild. Here we applied modern statistical techniques to field‐gathered data in two damselfly species whose males practice alternative reproductive tactics (ARTs) and whose indicators of condition in both sexes are known. In Paraphlebia zoe, there are two ART: a larger black‐winged (BW) male which defends mating territories and a smaller hyaline‐winged (HW) male that usually acts as a satellite. In this species, condition in both morphs is correlated with body size. In Calopteryx haemorrhoidalis, males follow tactics according to their condition with males in better condition practicing a territorial ART. In addition, in this species, condition correlates positively with wing pigmentation in both sexes. Our prediction for both species was that males practicing the territorial tactic will survive less longer than males using a nonterritorial tactic, and larger or more pigmented animals will survive for longer. In P. zoe, BW males survived less than females but did not differ from HW males, and not necessarily larger individuals survived for longer. In fact, size affected survival but only when group identity was analysed, showing a positive relationship in females and a slightly negative relationship in both male morphs. For C. haemorrhoidalis, survival was larger for more pigmented males and females, but size was not a good survival predictor. Our results partially confirm assumptions based on the maintenance of ARTs. Our results also indicate that female pigmentation, correlates with a fitness component – survival – as proposed by recent sexual selection ideas applied to females.
Cryptic female choice via sperm dumping favours male copulatory courtship in a spider
Authors: PERETTI A. V. , EBERHARD W. G.
Published: December 2009

Males of many animals perform ‘copulatory courtship’ during copulation, but the possible reproductive significance of this behaviour has seldom been investigated. In some animals, including the spiderPhysocyclus globosus(Pholcidae), the female discards sperm during or immediately following some copulations. In this study, we determined which of several variables associated with copulation correlated with paternity success inP. globosuswhen two males mate with a single female. Then, by determining which of these variables also correlated with sperm dumping, we inferred which variables may affect paternity via the mechanism of sperm dumping. Male abdomen vibration (a copulatory courtship behaviour) and male genitalic squeezing both correlated with both paternity and sperm dumping; so, these traits may be favoured by biased sperm dumping. Biased sperm dumping may also be the mechanism by which possible cryptic female choice favours another male trait that was the subject of a previous study, responsiveness to female stridulation.
Mixed infections may promote diversification of mutualistic symbionts: why are there ineffective rhizobia?
Authors: FRIESEN M. L. , MATHIAS A.
Published: December 2009

While strategy variation is a key feature of symbiotic mutualisms, little work focuses on the origin of this diversity. Rhizobia strategies range from mutualistic nitrogen fixers to parasitic nonfixers that hoard plant resources to increase their own survival in soil. Host plants reward beneficial rhizobia with higher nodule growth rates, generating a trade‐off between reproduction in nodules and subsequent survival in soil. However, hosts might not discriminate between strains in mixed infections, allowing nonfixing strains to escape sanctions. We construct an adaptive dynamics model of symbiotic nitrogen‐fixation and find general situations where symbionts undergo adaptive diversification, but in most situations complete nonfixers do not evolve. Social conflict in mixed infections when symbionts face a survival–reproduction trade‐off can drive the origin of some coexisting symbiont strategies, where less mutualistic strains exploit benefits generated by better mutualists.