bluuebunny/crossref_metadata_2025 huggingface dataset:
Sex allocation predicts mating rate in a simultaneous hermaphrodite
Authors: Janicke Tim , Schärer Lukas
Published: September 2009

Sexual selection theory for separate-sexed animals predicts that the sexes differ in the benefit they can obtain from multiple mating. Conventional sex roles assume that the relationship between the number of mates and the fitness of an individual is steeper in males compared with females. Under these conditions, males are expected to be more eager to mate, whereas females are expected to be choosier. Here we hypothesize that the sex allocation, i.e. the reproductive investment devoted to the male versus female function, can be an important predictor of the mating strategy in simultaneous hermaphrodites. We argue that within-species variation in sex allocation can cause differences in the proportional fitness gain derived through each sex function. Individuals should therefore adjust their mating strategy in a way that is more beneficial to the sex function that is relatively more pronounced. To test this, we experimentally manipulated the sex allocation in a simultaneously hermaphroditic flatworm and investigated whether this affects the mating behaviour. The results demonstrate that individuals with a more male-biased sex allocation (i.e. relatively large testes and small ovaries) are more eager to mate compared with individuals with a more female-biased sex allocation (i.e. relatively small testes and large ovaries). We argue that this pattern is comparable to conventional gender roles in separate-sexed organisms.
Anthropoid
versus
strepsirhine status of the African Eocene primates
Algeripithecus
and
Azibius
: craniodental evidence
Authors: Tabuce Rodolphe , Marivaux Laurent , Lebrun Renaud , Adaci Mohammed , Bensalah Mustapha , Fabre Pierre-Henri , Fara Emmanuel , Gomes Rodrigues Helder , Hautier Lionel , Jaeger Jean-Jacques , Lazzari Vincent , Mebrouk Fateh , Peigné Stéphane , Sudre Jean , Tafforeau Paul , Valentin Xavier , Mahboubi Mahammed
Published: September 2009

Recent fossil discoveries have demonstrated that Africa and Asia were epicentres for the origin and/or early diversification of the major living primate lineages, including both anthropoids (monkeys, apes and humans) and crown strepsirhine primates (lemurs, lorises and galagos). Competing hypotheses favouring either an African or Asian origin for anthropoids rank among the most hotly contested issues in paleoprimatology. The Afrocentric model for anthropoid origins rests heavily on the >45 Myr old fossil
Algeripithecus minutus
from Algeria, which is widely acknowledged to be one of the oldest known anthropoids. However, the phylogenetic position of
Algeripithecus
with respect to other primates has been tenuous because of the highly fragmentary fossils that have documented this primate until now. Recently recovered and more nearly complete fossils of
Algeripithecus
and contemporaneous relatives reveal that they are not anthropoids. New data support the idea that
Algeripithecus
and its sister genus
Azibius
are the earliest offshoots of an Afro–Arabian strepsirhine clade that embraces extant toothcombed primates and their fossil relatives.
Azibius
exhibits anatomical evidence for nocturnality.
Algeripithecus
has a long, thin and forwardly inclined lower canine alveolus, a feature that is entirely compatible with the long and procumbent lower canine included in the toothcomb of crown strepsirhines. These results strengthen an ancient African origin for crown strepsirhines and, in turn, strongly challenge the role of Africa as the ancestral homeland for anthropoids.
Community monopolization: local adaptation enhances priority effects in an evolving metacommunity
Authors: Urban Mark C. , De Meester Luc
Published: September 2009

The diversity and composition of biological communities might often depend on colonization history because early colonists can exclude future colonists through a priority effect. These priority effects, which have been observed across a wide variety of ecosystems, often arise because early colonists have sufficient time to use available resources efficiently and subsequently withhold them from invaders. Here, we explore the extent to which rapid local adaptive evolution contributes to the pervasiveness of these priority effects. Using an individual-based simulation, we show that early colonization allows the descendants of colonists to adapt to novel conditions and reduce the establishment success of an initially ecologically equivalent competing species. Our model predicts that slight differences in colonization timing and adaptive capacity between species can substantially alter the dynamics and diversity of communities. We also show that priority effects and gene flow can generate a novel mechanism for the expansion and retraction of species distributions in a metacommunity. Our results suggest that local adaptation combined with stochastic colonization events can obscure direct relationships between species distributions and environmental gradients. Given the increasing recognition of rapid, microgeographic evolution in natural populations, we expect that evolutionary priority effects could affect the structure and dynamics of many natural metacommunities.
Outbreak and persistence of opportunistic symbiotic dinoflagellates during the 2005 Caribbean mass coral ‘bleaching’ event
Authors: LaJeunesse Todd C. , Smith Robin T. , Finney Jennifer , Oxenford Hazel
Published: September 2009

Reef corals are sentinels for the adverse effects of rapid global warming on the planet's ecosystems. Warming sea surface temperatures have led to frequent episodes of bleaching and mortality among corals that depend on endosymbiotic micro-algae (
Symbiodinium
) for their survival. However, our understanding of the ecological and evolutionary response of corals to episodes of thermal stress remains inadequate. For the first time, we describe how the symbioses of major reef-building species in the Caribbean respond to severe thermal stress before, during and after a severe bleaching event. Evidence suggests that background populations of
Symbiodinium trenchi
(
D1a
) increased in prevalence and abundance, especially among corals that exhibited high sensitivity to stress. Contrary to previous hypotheses, which posit that a change in symbiont occurs subsequent to bleaching,
S. trenchi
increased in the weeks leading up to and during the bleaching episode and disproportionately dominated colonies that did not bleach. During the bleaching event, approximately 20 per cent of colonies surveyed harboured this symbiont at high densities (calculated at less than 1.0% only months before bleaching began). However, competitive displacement by homologous symbionts significantly reduced
S. trenchi
's prevalence and dominance among colonies after a 2-year period following the bleaching event. While the extended duration of thermal stress in 2005 provided an ecological opportunity for a rare host-generalist symbiont, it remains unclear to what extent the rise and fall of
S. trenchi
was of ecological benefit or whether its increased prevalence was an indicator of weakening coral health.
Troglomorphism, trichobothriotaxy and typhlochactid phylogeny (Scorpiones, Chactoidea): more evidence that troglobitism is not an evolutionary dead‐end
Authors: Prendini Lorenzo , Francke Oscar F. , Vignoli Valerio
Published: September 2009

The scorpion family TyphlochactidaeMitchell, 1971is endemic to eastern Mexico and exclusively troglomorphic. Six of the nine species in the family are hypogean (troglobitic), morphologically specialized for life in the cave environment, whereas three are endogean (humicolous) and comparably less specialized. The family therefore provides a model for testing the hypotheses that ecological specialists (stenotopes) evolve from generalist ancestors (eurytopes) and that specialization (in this case to the cavernicolous habitat) is an irreversible, evolutionary dead‐end that ultimately leads to extinction. Due to their cryptic ecology, inaccessible habitat, and apparently low population density, Typhlochactidae are very poorly known. The monophyly of these troglomorphic scorpions has never been rigorously tested, nor has their phylogeny been investigated in a quantitative analysis. We test and confirm their monophyly with a cladistic analysis of 195 morphological characters (142 phylogenetically informative), the first for a group of scorpions in which primary homology of pedipalp trichobothria was determined strictly according to topographical identity (the “placeholder approach”). The phylogeny of Typhlochactidae challenges the conventional wisdom that ecological specialization (stenotopy) is unidirectional and irreversible, falsifying Cope’s Law of the unspecialized and Dollo’s Law of evolutionary irreversibility. Troglobitism is not an evolutionary dead‐end: endogean scorpions evolved from hypogean ancestors on more than one occasion.

© The Willi Hennig Society 2009.
Molecular markers associated with lymph node metastasis in pancreatic ductal adenocarcinoma by genome‐wide expression profiling
Authors: Hirono Seiko , Yamaue Hiroki , Hoshikawa Yutaka , Ina Shinomi , Tani Masaji , Kawai Manabu , Ushijima Masaru , Matsuura Masaaki , Saiki Yuriko , Saiura Akio , Yamamoto Junji , Miki Yoshio , Noda Tetsuo
Published: September 2009

Lymph node metastasis (LNM) is the most important prognostic factor in patients undergoing surgical resection of pancreatic ductal adenocarcinoma (PDAC). In this study, we aimed to identify molecular markers associated with LNM in PDAC using genome‐wide expression profiling. In this study, laser microdissection and genome‐wide transcriptional profiling were used to identify genes that were differentially expressed between PDAC cells with and without LNM obtained from 20 patients with PDAC. Immunohistochemical staining was used to confirm the clinical significance of these markers in an additional validation set of 43 patients. In the results, microarray profiling identified 46 genes that were differently expressed between PDAC with and without LNM with certain significance. Four of these biomarkers were validated by immunohistochemical staining for association with LNM in PDAC in an additional validation set of patients. In 63 patients with PDAC, significant LNM predictors in PDAC elucidated from multivariate analysis were low expression of activating enhancer binding protein 2 (AP2α) (P = 0.012) and high expression of mucin 17 (MUC17) (P = 0.0192). Furthermore, multivariate analysis revealed that AP2α‐low expression and MUC17‐high expression are independent prognostic factors for poor overall survival (P = 0.0012, 0.0001, respectively). In conclusion, AP2α and MUC17 were independent markers associated with LNM of PDAC. These two markers were also associated with survival in patients with resected PDAC. We demonstrate that AP2α and MUC17 may serve as potential prognostic molecular markers for LNM in patients with PDAC. (Cancer Sci 2009)
Computer‐delivered interventions to reduce college student drinking: a meta‐analysis
Authors: Carey Kate B. , Scott‐Sheldon Lori A. J. , Elliott Jennifer C. , Bolles Jamie R. , Carey Michael P.
Published: September 2009

Aims  This meta‐analysis evaluates the efficacy of computer‐delivered interventions (CDIs) to reduce alcohol use among college students.

Methods  We included 35 manuscripts with 43 separate interventions, and calculated both between‐group and within‐group effect sizes for alcohol consumption and alcohol‐related problems. Effects sizes were calculated for short‐term (≤5 weeks) and long‐term (≥6 weeks) intervals. All studies were coded for study descriptors, participant characteristics and intervention components.

Results  The effects of CDIs depended on the nature of the comparison condition: CDIs reduced quantity and frequency measures relative to assessment‐only controls, but rarely differed from comparison conditions that included alcohol‐relevant content. Small‐to‐medium within‐group effect sizes can be expected for CDIs at short‐ and long‐term follow‐ups; these changes are less than or equivalent to the within‐group effect sizes observed for more intensive interventions.

Conclusions  CDIs reduce the quantity and frequency of drinking among college students. CDIs are generally equivalent to alternative alcohol‐related comparison interventions.
Reactivity to images in health and irritable bowel syndrome
Authors: CARRUTHERS H. R. , MORRIS J. , TARRIER N. , WHORWELL P. J.
Published: September 2009

Background  We have been using a medical artist to record and paint the images patients have of their irritable bowel syndrome (IBS) and have hypothesized that the reaction to such images might differ in health and IBS, which could have practical implications for future research.

Aim  To examine reactivity to images in health and IBS.

Methods  Twelve paintings of IBS were shown to 70 patients to determine the four most evocative images. The spontaneous response to these images and four ‘non‐IBS painful’ and four neutral paintings was assessed in another 100 IBS patients and 100 controls. The prompted reaction in terms of whether an image evoked the notion of pain, bloating or discomfort and to what degree was also recorded.

Results  Four images depicting bloating and pain scored the highest. These IBS images triggered significantly different reactivity between patients and controls in terms of their spontaneous and prompted responses. Even ‘non‐IBS painful’ and neutral images resulted in exaggerated and frequently significantly different responses in patients than in controls.

Conclusions  Visual hypersensitivity appears to be another manifestation of the tendency of IBS patients to react adversely to a variety of endogenous and exogenous stimuli. Identifying how individuals relate to different images might also give useful insights into understanding gastrointestinal symptoms.
Recombination is suppressed over a large region of the rainbow trout Y chromosome
Authors: Phillips R. B. , DeKoning J. J. , Ventura A. B. , Nichols K. M. , Drew R. E. , Chaves L. D. , Reed K. M. , Felip A. , Thorgaard G. H.
Published: September 2009

The previous genetic mapping data have suggested that most of the rainbow trout sex chromosome pair is pseudoautosomal, with very small X‐specific and Y‐specific regions. We have prepared an updated genetic and cytogenetic map of the male rainbow trout sex linkage group. Selected sex‐linked markers spanning the X chromosome of the female genetic map have been mapped cytogenetically in normal males and genetically in crosses between the OSU female clonal line and four different male clonal lines as well as in outcrosses involving outbred OSU and hybrids between the OSU line and the male clonal lines. The cytogenetic maps of the X and Y chromosomes were very similar to the female genetic map for the X chromosome. Five markers on the male maps are genetically very close to the sex determination locus (SEX), but more widely spaced on the female genetic map and on the cytogenetic map, indicating a large region of suppressed recombination on the Y chromosome surrounding the SEX locus. The male map is greatly extended at the telomere. A BAC clone containing the SCAR (sequence characterized amplified region) Omy‐163 marker, which maps close to SEX, was subjected to shotgun sequencing. Two carbonyl reductase genes and a gene homologous to the vertebrate skeletal ryanodine receptor were identified. Carbonyl reductase is a key enzyme involved in production of trout ovarian maturation hormone. This brings the number of type I genes mapped to the sex chromosome to six and has allowed us to identify a region on zebrafish chromosome 10 and medaka chromosome 13 which may be homologous to the distal portion of the long arm of the rainbow trout Y chromosome.
Multiple maternal origins of native modern and ancient horse populations in China
Authors: Lei C. Z. , Su R. , Bower M. A. , Edwards C. J. , Wang X. B. , Weining S. , Liu L. , Xie W. M. , Li F. , Liu R. Y. , Zhang Y. S. , Zhang C. M. , Chen H.
Published: September 2009

To obtain more knowledge of the origin and genetic diversity of domestic horses in China, this study provides a comprehensive analysis of mitochondrial DNA (mtDNA) D‐loop sequence diversity from nine horse breeds in China in conjunction with ancient DNA data and evidence from archaeological and historical records. A 247‐bp mitochondrial D‐loop sequence from 182 modern samples revealed a total of 70 haplotypes with a high level of genetic diversity. Seven major mtDNA haplogroups (A–G) and 16 clusters were identified for the 182 Chinese modern horses. In the present study, nine 247‐bp mitochondrial D‐loop sequences of ancient remains of Bronze Age horse from the Chifeng region of Inner Mongolia in China (c.4000–2000abp) were used to explore the origin and diversity of Chinese modern horses and the phylogenetic relationship between ancient and modern horses. The nine ancient horses carried seven haplotypes with rich genetic diversity, which were clustered together with modern individuals among haplogroups A, E and F. Modern domestic horse and ancient horse data support the multiple origins of domestic horses in China. This study supports the argument that multiple successful events of horse domestication, including separate introductions of wild mares into the domestic herds, may have occurred in antiquity, and that China cannot be excluded from these events. Indeed, the association of Far Eastern mtDNA types to haplogroup F was highly significant using Fisher’s exact test of independence (P = 0.00002), lending support for Chinese domestication of this haplogroup. High diversity and all seven mtDNA haplogroups (A–G) with 16 clusters also suggest that further work is necessary to shed more light on horse domestication in China.
Molecular analysis of carbohydrate N‐acetylgalactosamine 4‐O sulfotransferase 8 (CHST8) as a candidate gene for bovine spongiform encephalopathy susceptibility
Authors: Morina R. , Knorr C. , Haase B. , Leeb T. , Seuberlich T. , Zurbriggen A. , Brem G. , Schütz E. , Brenig B.
Published: September 2009

Endogenous prion proteins (PrP) play the central role in the pathogenesis of transmissible spongiform encephalopathies. The carbohydrate N‐acetylgalactosamine 4‐O sulfotransferase 8 (CHST8) promotes the conversion of the cellular PrPC into the pathogenic PrPd. Six sequence variants within the CHST8 gene were identified by comparative sequencing and genotyped for a sample of 623 animals comprising bovine spongiform encephalopathy (BSE)‐affected and healthy control cows representing German Fleckvieh (German Simmental), German Holstein (Holstein‐Friesian) and Brown Swiss. Significant differences in the allele, genotype and haplotype frequencies between BSE‐affected and healthy cows indicate an association of sequence variant g.37254017G>T with the development of the disease in Brown Swiss cattle.
Revisiting infant growth prior to childhood onset type 1 diabetes
Authors: Kharagjitsingh A. V. , De Ridder M. A. J. , Roep B. O. , Koeleman B. P. C. , Bruining G. J. , Veeze H. J.
Published: September 2009

Objective  Accelerated early growth prior to childhood type 1 diabetes onset is associated with an increased risk for type 1 diabetes (T1D). We aimed to study early growth, correcting for the previously neglected confounder of familial effects.

Design  Infant growth was studied in a retrospective family case‐control study of diabetic children in which siblings acted as matched familial controls allowing correction for confounders related to family particulars.

Patients  Weight and height data were collected from 213 juvenile onset type 1 diabetic children and their 255 healthy siblings. Growth in the first 4 years of life was studied using repeated measurement. The degree of early overgrowth was correlated with age of clinical onset.

Results  Birth weight and length did not differ between later diabetic children and their siblings. In the first year of life, weight standard deviation score (SDS) differed between patients and sibs (P = 0·0001). After the first year, both diabetic children and sibs showed parallel enhanced weight and height gain SDS until age 4 years. Earlier onset diabetes was associated with a higher weight SDS at 6 months of age.

Conclusion  In this family case‐control study the association of increased growth with development of T1D is limited to the first year of life implying that increased growth beyond the first year can be attributed to familial growth patterns, rather than predisposition to T1D per se. Age at disease onset correlated with increased weight in the first 6 months of life, indicating importance of features very early in life on later development of T1D.
Recurrence detection in differentiated thyroid cancer patients with elevated serum level of antithyroglobulin antibody: special emphasis on using 18F‐FDG PET/CT
Authors: Seo Ji Hyoung , Lee Sang Woo , Ahn Byeong‐Cheol , Lee Jaetae
Published: September 2009

Objective  A clinical challenge is presented by differentiated thyroid cancer (DTC) patients who show increased serum antithyroglobulin antibody (TgAb) level with undetectable thyroglobulin (Tg) and negative radioiodine whole body scan (I‐WBS). The aim of this study is to investigate the recurrence in DTC patients with elevated TgAb by using 18F‐FDG PET/CT (PET/CT) in addition to I‐WBS and neck ultrasonography (USG).

Subjects and design  A total of 276 TgAb+ patients were enrolled. Recurrence was assessed and compared between TgAb+ and TgAb‐ patients. TgAb+ patients were further categorized into two groups of 35–140 U/ml (Group A) and 140 U/ml or greater (Group B), according to receiver operating characteristic (ROC) curve analysis. Tumoural status was evaluated regarding the TgAb positivity and the degree of increase of TgAb.

Results  Thirty‐seven (13·4%) of 276 TgAb+ patients were finally diagnosed with recurrence, compared with 21 (13·5%) of 156 TgAb‐ patients (P = 0·987). There was a correlation between TgAb level and recurrence (P = 0·032). Recurrence was more common in Group B than Group A (27·8% and 9·9%, respectively, P = 0·001). Recurrence was found in 37·5% of 24 TgAb+/Tg‐ patients who showed a gradually increasing tendency in serial measurements of TgAb. Sixteen cervical foci (21·1%) missed on neck USG and 17 lesions (22·4%) located outside the neck were additionally detected with PET/CT in TgAb+ patients.

Conclusions  TgAb plays a complementary role to Tg in the detection of recurrence of DTC. Tumour recurrence was more frequent in patients with elevated TgAb level over 140 U/ml or a trend toward increasing levels. PET/CT could provide additional information to I‐WBS and neck USG in detecting tumour recurrence in patients with elevated TgAb.
How should we treat patients with low serum thyrotropin concentrations?
Authors: Mitchell Anna L. , Pearce Simon H. S.
Published: September 2009

Subclinical hyperthyroidism (SH) is defined by a low serum thyrotropin (TSH) concentration in the presence of normal levels of free thyroxine (FT4) and free triiodothyronine (FT3). However, it is helpful to distinguish between those with a detectable but low TSH value (in the 0·1–0·4 mU/l range) and those with a fully suppressed TSH (<0·1 mU/l), and we suggest the designation of grade I and grade II SH, respectively. Together, these patterns of thyroid function tests are found in 1–3% of the elderly population, and are associated with significant morbidity and mortality in longitudinal epidemiological surveys. There are a number of causes for this picture, which include endogenous thyroid disease, drug effects and concomitant nonthyroidal illness. Treatments commonly employed in the management of thyrotoxicosis are effective at correcting the biochemical abnormalities of SH but have not been shown to improve clinical outcome or symptoms. There is little good quality evidence available to guide the assessment or management of these patients. This review summarizes the clinical significance of SH and aims to provide guidance about whether we should treat patients with low serum TSH concentrations.
Foliage‐age mixing within balsam fir increases the fitness of a generalist caterpillar
Authors: JOHNS ROB , QUIRING DAN T. , LAPOINTE RENÉE , LUCAROTTI CHRISTOPHER J.
Published: September 2009

1. Manipulative field studies were carried out to evaluate the foliage age preference–performance relationship for an extreme generalist herbivore, the whitemarked tussock moth (Orygia leucostigma Smith) (Lepidoptera: Lymantriidae), within balsam fir [Abies balsamea (L.) Mill].

2. Field surveys indicated that early instar caterpillars fed almost exclusively on young (i.e. current‐year) foliage, whereas late instars caterpillars fed on both young and mature (i.e. 1‐ and 2‐year‐old) foliage.

3. Survival of early instar caterpillars was highest in treatments where current‐year and/or 1‐year old foliage were available, but decreased significantly on older foliage. In contrast, late instar caterpillars had the highest survival when allowed to feed on all age classes of foliage, whereas potential fecundity was highest for late instars that fed on young foliage.

4. Overall, caterpillars had 32–65% higher fitness when able to feed on all rather than just one age class of foliage.

5. These results support both the ‘complementary diet' hypothesis, which states that dietary mixing of different‐aged foliage can increase nutrient uptake and/or dilute harmful secondary plant chemicals, and the ‘ontogeny’ hypothesis, which attributes changes in diet to changes in the nutritional needs and/or tolerance to plant defences of juvenile insects as they develop.
Testing the host‐finding ability of a monophagous caterpillar in the field
Authors: BIERZYCHUDEK PAULETTE , WARNER KATY A. , MCHUGH ANNE , THOMAS LAURA
Published: September 2009

1. Relatively few studies of the host‐finding ability of specialised, phytophagous insects involve direct observations of individual insects moving among intact hosts and non‐hosts. Information from such studies can inform the design of restoration programmes for species of conservation concern.

2. The movement of caterpillars of the threatened Oregon silverspot butterfly,Speyeria zerene hippolyta(Edwards) (Lepidoptera: Nymphalidae) was studied in the field in cleared arenas with 10 cm radii. Caterpillars were placed in the centre, surrounded by three individuals of their host,Viola adunca, and three different non‐host individuals, separated by bare ground. In a second experiment, second instars were placed between a host and a non‐host, 3–6 cm away. Caterpillars were observed to determine if they walked to their host more often than expected by chance.

3. Caterpillars walked to vegetation significantly more often than expected by chance. They did not, however, reach their hosts more often than expected, based on plant availability.

4. It is concluded thatS. z. hippolytacaterpillars can distinguish vegetation from bare ground from 10 cm away. There is no evidence that they can distinguish their host plant from other herbaceous species at distances of 3 cm.
Sexual selection did not contribute to the evolution of male lifespan under curtailed age at reproduction in a seed beetle
Authors: MAKLAKOV ALEXEI A. , FRICKE CLAUDIA
Published: September 2009

1. Sexual selection is a powerful evolutionary force that is hypothesised to play an important role in the evolution of lifespan. Here we test for the potential contribution of sexual selection to the rapid evolution of male lifespan in replicated laboratory populations of the seed beetle, Callosobruchus maculatus.

2. For 35 generations, newly hatched virgin male beetles from eight different populations were allowed to mate for 24 h and then discarded. Sexual selection was removed in half of these populations by enforcing random monogamy.

3. Classic theory predicts that because of sexual competition, males from sexually selected lines would have higher age‐specific mortality rates and shorter lifespan than males from monogamous lines.

4. Alternatively, condition‐dependent sexual selection may also favour genes that have positive pleiotropic effects on lifespan and ageing.

5. Males from all eight populations evolved shorter lifespans compared with the source population. However, there was no difference in lifespan between males from populations with or without sexual selection. Thus, sexual selection did not contribute to the evolution of male lifespan despite the fact that such evolution did occur in our study populations.
Sequences of sex allocation and mortality in clutches of Metaphycus parasitoids of soft scale insects and the prevalence of all‐female broods
Authors: KAPRANAS APOSTOLOS , WAJNBERG ERIC , LUCK ROBERT F.
Published: September 2009

1. In many gregarious or quasi‐gregarious parasitoids that experience local mate competition, precise sex ratios with low variance are observed. Precise sex ratios can be achieved by laying male and female eggs in non‐random sequences.

2. Developmental mortality can also alter sex ratios of emerging offspring, and subsequently influence sex ratio optima.

3. The present study investigates sex allocation by Metaphycus flavus Howard, M. luteolus Timberlake, and M. angustifrons Compere (Hymenoptera: Encyrtidae), endoparasitoids of soft scale insects, in the laboratory.

4. All three Metaphycus species had precise secondary sex ratios when parasitising brown soft scale, Coccus hesperidum, L. in the laboratory. Moreover, we documented that all three species lay fertilised (= female) eggs first followed by unfertilised (= male) eggs at the end of the oviposition bout. However, there were significant differences in sex allocation sequences among species.

5. Mortality rates of eggs allocated within an oviposition bout also varied considerably, indicating that there is a significant interspecific variation in sequence position‐specific mortality.

6. Using a stochastic Monte Carlo simulation approach, we provide evidence that the incidence of all‐female broods in these parasitoid wasps appears mainly due to developmental mortality and not due to decisions by the ovipositing female. In two species the prevalence of all‐female broods was independent of clutch size, contrary to what is expected from theory. The influence of mortality on optimal sex allocation in these parasitoids is discussed.
Density‐dependent polyphenism and geographic variation in size among two populations of lubber grasshoppers (Romalea microptera)
Authors: JANNOT JASON E. , KO ALEXANDER E. , HERRMANN DUSTIN L. , SKINNER LAURA , BUTZEN EMILY , AKMAN OLCAY , JULIANO STEVEN A.
Published: September 2009

1. Density‐dependent phase polyphenism occurs when changes in density during the juvenile stages result in a developmental shift from one phenotype to another. Density‐dependent phase polyphenism is common among locusts (Orthoptera: Acrididae).

2. Previously, we demonstrated a longitudinal geographic cline in adult body size (western populations = small adults; eastern populations = large adults) in the eastern lubber grasshopper (Romalea microptera) in south Florida. As lubbers are confamilial with locusts, we hypothesised that the longitudinal size cline was partly due to density‐dependent phase polyphenism.

3. We tested the effect of density, population, and density×population interaction on life‐history traits (pronotum length, mass, cumulative development time, growth rate) of, and proportion surviving to, each of the five instars and the adult stage in a 2 × 3 factorial laboratory experiment with two lubber populations, each reared from hatchling to adult at three different densities.

4. The effect of density on life history and survival was independent of the effects of population on life history and survival. Higher densities led to larger adult sizes (pronotum, mass) and lower survivorship. The western population had smaller adult masses, fewer cumulative days to the adult stage, and higher survivorship than the eastern population.

5. Our data suggest that lubber grasshoppers exhibit density‐dependent phase polyphenism initiated by the physical presence of conspecifics. However, the plastic response of adult size to density observed in the laboratory is not consistent with the relationship between phenotypes and adult density in the field. Genetic differences between populations observed in the laboratory could contribute to size and life‐history differences among lubber populations in the field.
Perish legally and ecologically: the ineffectiveness of the minimum landing sizes in the Mediterranean Sea
Authors: STERGIOU K. I. , MOUTOPOULOS D. K. , ARMENIS G.
Published: September 2009

Abstract  Minimum landing size (MLS) is one technical measure used to manage fisheries with the aim of allowing enough juveniles to survive and spawn. In this study the practical and ecological efficiency of the MLSs set by European Union (Regulation 1967/2006) and Greek legislation for 13 fish species caught with five gears in the Ionian Sea was tested using length measurements from 22 382 individuals. The percentage of individuals with lengths smaller than MLS was estimated. In addition, MLSs were compared against length at 50% maturity (L50) and the percentages of individuals caught per species and gear with lengths smaller than the L50 were also estimated. The mean percentage of individuals caught with lengths smaller than MLS ranged from 5.9% for longliners to 42.6% for beach‐seiners, showing the practical inefficiency of this measure. In addition, all MLS were smaller than the corresponding L50 and L50 − SE values and across species the mean percentage of the immature individuals caught was very high, ranging from 55% for longliners to 92% for beach‐seiners, indicating that the vast majority of the individuals caught did not have the chance to spawn even once. Thus, the existing MLSs are ecologically inefficient for sustainable management.
Diurnal stream habitat use of juvenile Atlantic salmon, brown trout and rainbow trout in winter
Authors: JOHNSON J. H. , DOUGLASS K. A.
Published: September 2009

Abstract  The diurnal winter habitat of three species of juvenile salmonids was examined in a tributary of Skaneateles Lake, NY to compare habitat differences among species and to determine if species/age classes were selecting specific habitats. A total of 792 observations were made on the depth, velocity, substrate and cover (amount and type) used by sympatric subyearling Atlantic salmon, subyearling brown trout and subyearling and yearling rainbow trout. Subyearling Atlantic salmon occurred in shallower areas with faster velocities and less cover than the other salmonid groups. Subyearling salmon was also the only group associated with substrate of a size larger than the average size substrate in the study reach during both winters. Subyearling brown trout exhibited a preference for vegetative cover. Compared with available habitat, yearling rainbow trout were the most selective in their habitat use. All salmonid groups were associated with more substrate cover in 2002 under high flow conditions. Differences in the winter habitat use of these salmonid groups have important management implications in terms of both habitat protection and habitat enhancement.
A Bayesian approach to estimating Atlantic salmon fry densities using a rapid sampling technique
Authors: DAUPHIN G. , PREVOST E. , ADAMS C. E. , BOYLAN P.
Published: September 2009

Abstract  Removal sampling by electric fishing is widely used for assessing fish population size. As it is manpower consuming, less‐demanding techniques have been proposed to increase the number of sites covered with the same human resources. These techniques essentially provide relative abundance measures. To be used for absolute abundance estimation, they need to be inter‐calibrated with another method such as removal sampling. Here, hierarchical Bayesian modelling framework is used for this inter‐calibration because it allows an estimate of absolute abundance from abundance index data alone while accounting for the main sources of uncertainty. It is applied to a 0+ juvenile Atlantic salmon, Salmo salar L. data set from 21 sites on the River Faughan, Northern Ireland. A positive relationship was found between the abundance index (number of fish caught in 5 min of actual electric fishing) and the density. The estimates from the index of abundance alone are fairly imprecise, but still allow differentiation of contrasting levels of fish density.
Riverine and early marine survival of stocked salmon smolts, Salmo salar L., descending the Testebo River, Sweden
Authors: SERRANO I. , RIVINOJA P. , KARLSSON L. , LARSSON S.
Published: September 2009

Abstract  A combination of radio and acoustic telemetry was used to monitor the out‐migration of hatchery‐reared Atlantic salmon, Salmo salar L., in the River Testebo, its estuary and coastal system. As with many other Baltic rivers, the hydropower regulated River Testebo once had a self‐sustaining salmon population that is now extinct. Substantial losses of smolts in the river (48–69%) and inner part of the estuary (43–47%) were found, but after leaving the estuary, the success of post‐smolts moving out of the Bay was sufficiently high (83–89%) to conclude that habitat within the bay is not a factor limiting initial marine survival. The results suggest that hatchery‐based recovery of a wild salmon population in the river will not be successful unless other actions, such as habitat improvement, are included.
Relationship between fire, climate oscillations, and drought in British Columbia, Canada, 1920–2000
Authors: MEYN ANDREA , TAYLOR STEPHEN W. , FLANNIGAN MIKE D. , THONICKE KIRSTEN , CRAMER WOLFGANG
Published: September 2009

Climate oscillations such as El Niño–Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) are known to affect temperature and precipitation regimes and fire in different regions of the world. Understanding the relationships between climate oscillations, drought, and area burned in the past is required for anticipating potential impacts of regional climate change and for effective wildfire‐hazard management. These relationships have been investigated for British Columbia (BC), Canada, either as part of national studies with coarse spatial resolution or for single ecosystems. Because of BC's complex terrain and strong climatic gradients, an investigation with higher spatial resolution may allow for a spatially complete but differentiated picture. In this study, we analyzed the annual proportion burned–climate oscillation–drought relationships for the province's 16 Biogeoclimatic Ecosystem Classification (BEC) zones. Analyses are based on a digital, spatially explicit fire database, climate oscillation indices, and monthly precipitation and temperature data with a spatial resolution of 400 m for the period 1920–2000. Results show that (1) fire variability is better related to summer drought than to climate oscillations, and that (2) fire variability is most strongly related to both, climate oscillations and summer drought in southeastern BC. The relationship of area burned and summer drought is strong for lower elevations in western BC as well. The influence of climate oscillations on drought is strongest and most extensive in winter and spring, with higher indices being related to drier conditions. Winter and spring PDO and additive winter and spring PDO+ENSO indices show BC's most extensive significant relationship to fire variability. Western BC is too wet to show a moisture deficit in summer that would increase annual area burned due to teleconnections.
Conservation management approaches to protecting the capacity for corals to respond to climate change: a theoretical comparison
Authors: BASKETT MARISSA L. , NISBET ROGER M. , KAPPEL CARRIE V. , MUMBY PETER J. , GAINES STEVEN D.
Published: September 2009

Multiple anthropogenic impacts, including bleaching from climate change‐related thermal stress, threaten coral reefs. Protecting coral capacity to respond to the increase in future thermal stress expected with climate change can involve (1) protecting coral reefs with characteristics indicative of greater resistance and resilience to climate change, and (2) reducing other anthropogenic impacts that are more likely to reduce coral resistance and resilience to climate change. Here, we quantitatively compare possible priorities and existing recommendations for protecting coral response capacity to climate change. Specifically, we explore the relative importance of the relevant dynamics, processes, and parameters in a size‐structured model of coral and zooxanthellae ecological and evolutionary dynamics given projected future thermal stress. Model results with varying initial conditions indicate that protecting diverse coral communities is critical, and protecting communities with higher abundances of more thermally tolerant coral species and symbiont types secondary, to the long‐term maintenance of coral cover. A sensitivity analysis of the coral population size in each size class and the total coral cover with respect to all parameter values suggests greater relative importance of reducing additional anthropogenic impacts that affect coral–macroalgal competition, early coral life history stages, and coral survivorship (compared with reproduction, growth, and shrinkage). Finally, model results with temperature trajectories from different locations, with and without connectivity, indicate that protection of, and connectivity to, low‐thermal‐stress locations may enhance the capacity for corals to respond to climate change.
Assessment of the progression of haemophilic arthropathy in children
Authors: PERGANTOU H. , PLATOKOUKI H. , MATSINOS G. , PAPAKONSTANTINOU O. , PAPADOPOULOS A. , XAFAKI P. , PETRATOS D. , ARONIS S.
Published: September 2009

Summary.  Arthropathy is considered as an irreversible and progressive complication in patients with haemophilia, even in children on prophylaxis. To estimate the progression of haemophilic arthropathy, 85 joints of 24 boys with severe (n = 18) and moderate (n = 6) haemophilia (A: 22, B: 2) were investigated with clinical examination, X‐rays and magnetic resonance imaging (MRI) at two time periods (time 0 and 1). Patients’ age at time 0 was 10.5 ± 3.6 years and time elapsed to time 1 was 3.8 ± 1.4 years. At time 0: all investigated joints had more than three bleeds. Sixteen boys were on secondary prophylaxis for 5.4 ± 2.8 years. Clinical score (a modification of World Federation of Haemophilia’s scale): 2.0 ± 3.6, X‐ray score (Pettersson): 2.1 ± 2.8, MRI score (Denver): 4.5 ± 3.8. After the first evaluation, prophylaxis was intensified in 11 children and initiated in four. At time 1: clinical score: 1.5 ± 3.1, X‐ray: 1.7 ± 2.7, MRI score: 5.1 ± 4.1. On average, the clinical and X‐ray scores showed a significant improvement (26% and 40% of the joints respectively, P < 0.01) and the number of haemarthroses evidenced a threefold reduction from time 0 to 1 (P < 0.01), findings that could be associated with the modification of prophylaxis after time 0. MRI findings showed deterioration in 34% of the joints. Conversely, 14 joints (16.5%) with mild or moderate synovitis without cartilage degradation at time 0 showed an improvement at time 1. The information carried by the three scales could be divided into information shared by the three scores and information specific to each score, thus giving a more complete picture of joint damage caused by bleedings.
Application of fluoride iontophoresis to improve remineralization
Authors: KIM H. E. , KWON H. K. , KIM B. I.
Published: September 2009

Summary  Iontophoresis is generally used to maximize the therapeutic action of drugs in medicine. This technique can be used to improve the remineralization effect of topical fluoride applications in dentistry. The aim of this study was to compare the remineralization effect of fluoride iontophoresis (FI) with the conventional fluoride application (CFA) method in vitro. Sixty bovine enamel specimens were divided into three groups: no fluoride treatment, CFA and FI. Fluoride was applied to the demineralized specimens for 4 min in each experimental group. The types of fluoride system used for application were 1·23% acidulated phosphate fluoride gel (12 300 p.p.m. F, pH 3·5) and 2% sodium fluoride solution (9050 p.p.m. F, pH 7) in the experimental groups. All the specimens were then placed in a remineralizing solution for 24 h. This cycle was repeated five times. An iontophoresis device (0·4 mA, 12 V) was used in the FI groups. The efficacy of this technique was evaluated by measuring changes in the surface microhardness and lesion depth of the specimens using confocal laser scanning microscope (CLSM). Data were analysed using anova and Tukey’s post hoc test (P < 0·05). Although the FI groups showed higher ΔVHN than the CFA groups, there were no significant differences between these fluoride application methods (P > 0·05). When the lesion depth was measured using CLSM imaging, there was also no significant difference between the FI and CFA groups (P > 0·05). In conclusion, FI was not significantly superior to CFA in terms of the remineralization effect.
Activity pattern of swallowing‐related muscles, food properties and body position in normal humans
Authors: INAGAKI D. , MIYAOKA Y. , ASHIDA I. , YAMADA Y.
Published: September 2009

Summary  Activity patterns of the swallowing‐related muscles were examined in normal subjects at different four body positions during swallowing of foods with different textural properties. Surface electromyograms were recorded from two muscle groups, the anterior tongue and suprahyoid muscles. The TP technique we developed was applied to the electromyograms for quantitative analysis of the activity patterns. Three test foods were prepared by dissolving 2·0% (low), 5·7% (middle) and 9·1% (high concentration) of a thickening agent into distilled water. Each subject was delivered randomly, one of the test foods to swallow at one of the four body positions i.e. horizontal supine, 30° inclined, 60° inclined and upright. In this study, T50 values were calculated in activity data of the two muscle groups, and the T50 values were statistically examined analysis of variance with a linear model including four fixed effects of ‘concentrations’, ‘body positions’, ‘subjects’ and ‘sessions’. Three major findings obtained were that (i) the activity pattern of the anterior tongue was altered from a decrementing discharge pattern to an incrementing discharge pattern by shifting from the upright to the horizontal supine position, (ii) the activity pattern of the suprahyoid muscles was altered from a decrementing discharge pattern to an incrementing discharge pattern by shifting from the low concentration food to the higher ones and (iii) two subgroups were detected in subjects with the significant effects of ‘concentrations’ and ‘body positions’. These findings lead a conclusion that activity patterns of the swallowing‐related muscles are affected by food properties and body positions.
Sowing (and mapping) the wild oats
Authors: LEGER ELIZABETH A.
Published: September 2009

Both ecological and molecular methods have been applied to the study of locally adapted populations. WhileClausenet al. (1940)were the pioneers of field transplant studies, the work of Robert Allardet al. on the invasive speciesAvena barbatais a classic example of using molecular evidence to infer adaptation via correlation of particular alleles with environmental gradients. In a new study published in this issue of Molecular Ecology,Latta (2009)combines ecological methods (reciprocal environment studies) with quantitative genetic techniques (recombinant inbred lines and quantitative trait analysis) to provide new evidence for local adaptation within this well known system. The conclusions are orthogonal to the original hypothesis, and instead, provide evidence that factors other than local adaptation were likely responsible for the historically observed patterns. This new evidence suggests that one ecotype is generally more fit than the other in both a moist and a dry environment, and accordingly, it appears to be increasing in frequency in historically surveyed populations.