bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of human disturbance on California sea lions during the breeding season
Authors: Holcomb K. , Young J. K. , Gerber L. R. 
Published: July 2009

AbstractCalifornia sea lions Zalophus californianus occupy 26 islands in the Gulf of California (GoC), Mexico. Although human presence is prohibited on these islands without a government permit, the law is not enforced and tourism to the islands is increasing. Tourists, along with local fishermen, often come ashore to get close to the animals, which may disrupt behaviors critical for reproduction. In this paper, we report the results of an experimental study on the behavioral effects of human disturbance on California sea lions in the GoC. To document effects, we recorded sea lion behavior immediately before and in 10‐min intervals for up to an hour after experimental human disturbance. Our results showed few behavioral responses of sea lions to human disturbance. Adult females and juveniles demonstrated immediate responses, but these were not consistent between years, apparent an hour after disturbance, or evident across other age and sex classes. These results suggest that California sea lions may be resilient to human disturbance and a possible flagship species for ecotourism, but further studies of the physiological and population‐level effects of human disturbance are needed.
Genomic Convergence of Genome‐wide Investigations for Complex Traits
Authors: Kitsios Georgios D. , Zintzaras Elias 
Published: July 2009

SummaryGenome‐wide investigations for identifying the genes for complex traits are considered to be agnostic in terms of prior assumptions for the responsible DNA alterations. The agreement of genome‐wide association studies (GWAS) and genome‐wide linkage scans (GWLS) has not been explored to date. In this study, a genomic convergence approach of GWAS and GWLS was implemented for the first time in order to identify genomic loci supported by both methods. A database with 376 GWLS and 102 GWAS for 19 complex traits was created. Data regarding the location and statistical significance for each genetic marker were extracted from articles or web‐based databases. Convergence was quantified as the proportion of significant GWAS markers located within linked regions. Convergence was variable (0–73.3%) and was found to be significantly higher than expected by chance only for two of the 19 phenotypes. Seventy five loci of interest were identified, which being supported by independent lines of evidence, could merit prioritization in future investigations. Although convergence is supportive of genuine effects, lack of agreement between GWLS and GWAS is also indicative that these studies are designed to answer different questions and are not equally well suited for deciphering the genetics of complex traits.
Analysis of intraindividual and intraspecific variation in semicircular canal dimensions using high‐resolution x‐ray computed tomography
Authors: Welker Kelli L. , Orkin Joseph D. , Ryan Timothy M. 
Published: July 2009

AbstractThe semicircular canal system tracks head rotation and provides sensory input for the reflexive stabilization of gaze and posture. The purpose of this study was to investigate the intraspecific and intraindividual variation in the size of the three semicircular canals. The right and left temporal bones were extracted from 31 individuals of the short‐tailed shrew (Blarina brevicauda) and scanned on a high‐resolution x‐ray computed tomography system. The radius of curvature was calculated for each of the three semicircular canals for each side. Paired t‐tests and independent sample t‐tests indicated no significant differences in canal size between the right and left canals of the same individuals or between those of males and females of the same species. Pearson product moment correlation analyses demonstrated that there was no significant correlation between canal size and body mass in this sample.
Dimensions of forelimb muscles in orangutans and chimpanzees
Authors: Oishi Motoharu , Ogihara Naomichi , Endo Hideki , Ichihara Nobutsune , Asari Masao 
Published: July 2009

AbstractEight forelimbs of three orangutans and four chimpanzees were dissected and the muscle mass, fascicle length and physiological cross‐sectional area (PCSA) of all forelimb muscles were systematically recorded to explore possible interspecies variation in muscle dimensions. Muscle mass and PCSA were divided by the total mass and total PCSA of the entire forelimb muscles for normalization. The results indicate that the mass and PCSA ratios of the monoarticular elbow flexors (M. brachialis and M. brachioradialis) are significantly larger in orangutans. In contrast, the mass ratios of the biarticular muscles in the upper arm (the short head of M. biceps brachii and the long head of M. triceps brachii) are significantly larger in chimpanzees. For the rotator cuff muscles, the force‐generating capacity of M. subscapularis is significantly larger in orangutans, whereas the opposite rotator cuff muscle, M. infraspinatus, is larger in chimpanzees. These differences in forelimb muscle dimensions of the two species may reflect functional specialization for their different positional and locomotor behaviors.
Psychological vulnerability in children next‐born after stillbirth: a case–control follow‐up study
Authors: Turton Penelope , Badenhorst William , Pawlby Susan , White Sarah , Hughes Patricia 
Published: July 2009

Background:  Case studies and anecdotal accounts suggest that perinatal loss may impact upon other children in the family, including those born subsequent to loss. However, there is a dearth of systematically collected quantitative data on this potentially vulnerable group.Methods:  Case‐controlled follow‐up of 52 mothers with history of stillbirth with their next‐born children aged 6–8 years, and 51 control mother–child dyads. Previously reported baseline data included maternal antenatal and postnatal psychological assessment, and infant security of attachment at 12 months. Follow‐up assessments included maternal psychiatric and socio‐demographic data, mother and teacher‐rated scales of the child’s strengths and difficulties, child IQ, observer‐rated mother–child interaction and maternal reports of child health.Results:  There were no significant between‐group differences in child cognitive or health assessments, or in teacher‐rated child difficulties. However, mothers with history of stillbirth (the index group) reported increased child difficulties, in particular peer problems, and more adverse interaction was observed in respect of higher levels of maternal criticism of the child’s actions, more overall controlling behaviour by the mother, a less harmonious emotional atmosphere and a lower level of maternal engagement with the child. Some of these effects appeared to be mediated by maternal perinatal psychological symptoms and family breakdown.Conclusions:  This study provides no evidence to suggest that siblings born after stillbirth are clinically at risk but does lend empirical support to clinical reports that such children are seen by their mothers as having problems and that they are exposed to less optimal interaction with their mothers. Possible interpretations of these findings are discussed in the context of theoretical accounts of ‘replacement child’ and ‘vulnerable child’ syndromes.
Dispersed versus gregarious nesting strategies in the mason bee Chalicodoma siculum
Authors: Hefetz A. , Tengo J. 
Published: July 2009

Chalicodoma siculum (Rossi) is a mason bee that usually nests in dispersed sites, constructing spherical mud nests on twigs or hemispherical nests on hard surfaces. Under favourable conditions it may nest in aggregations of several hundred bees. At the nesting aggregation, nest usurpation often occurs, either by the laying of eggs in finished but unsealed cells, by opening a sealed cell and replacing its egg, or by taking over an unfinished cell. Mutual construction and provisioning of a single cell by several females was also often observed. Because participant bees display extreme aggression in prolonged disputes over cell ownership, these interactions can be regarded as competitive rather than cooperative. Moreover, since the total investment in such cells is not different from that in cells located in dispersed sites, the female that actually manages to lay an egg gains by participating in a cell under construction.We discuss the advantages of nesting in aggregations vs. the risks of being usurped, as selective forces underlying nesting behaviour of bees.
The influence of variation in larval period on adult cranial diversity in Pelobates fuscus (Anura: Pelobatidae)
Authors: Smirnov S. V. 
Published: July 2009

The timing and sequence of cranial ossification was studied in Pelobates fuscus tadpoles differing in the rate of their larval development. Laboratory‐reared animals, obtained from one egg mass, were examined. Some of the tadpoles metamorphosed during the first summer (normally developing tadpoles), whereas others prolonged the timing of their larval development into a second year or even later (slowly developing tadpoles). In slowly developing tadpoles the timing and sequence of cranial ossification differ in many respects from those occurring in normally developing tadpoles. Thus (a) ossification of some bones commences earlier and (b) there are some anachronisms in the sequence of ossification. As a whole, different cranial elements respond differently to prolongation of larval development. Bones which arise early in normal ontogeny (parasphenoid, frontoparietals, prootics, exoccipitals and interparietal) have a lengthened period of morphological differentiation and growth when larval development is prolonged. Consequently they show hypermorphosis in the adult with a profound effect on adult cranial morphology. Other ossifications, whose origin and growth are associated with the final metamorphic event (the transformation of the larval into the adult jaw mechanism), show no evident changes in the timing of their origin relative to somatic development.Another mechanism for altering adult morphology in animals with prolonged larval development results from the dissociation between somatic and sexual development. While somatic development in slowly developing tadpoles is very retarded and their external morphology may show no change during a large part of the larval stage, the generative system continues to develop. This situation produces tadpoles with premetamorphic somatic morphology but with almost mature generative organs. These tadpoles retain the ability to metamorphose and consequently they may transform into sexually mature animals with juvenile (early postmetamorphic) somatic morphology, i.e. into neotenic animals. In some specimens early‐originating cranial bones may be hypermorphosed whereas cranial elements normally arising in late metamorphic stages, or after metamorphosis is complete, are subject to paedomorphic reduction and under‐development.It is concluded that wide individual variation in the rate of larval development may account, at least in part, for the occurrence of intraspecific variability in anuran cranial morphology (e.g. in Pelobates syriacus).
Breeding energetics and food requirements of gentoo penguins (Pygoscelis papua) at Heard and Macquarie Islands
Authors: Gales R. , Green B. , Libke J. , Newgrain K. , Pembertion D. 
Published: July 2009

The food and energy requirements of breeding gentoo penguins (Pygoscelis papua) were studied at Heard and Macquaric Islands by means of isotope turnover techniques.The food consumption rates of chicks were measured at various stages of growth, providing estimates of the total food provided by adults to rear a chick to fledging.The energy expenditures of attending adults were also measured at different stages of chick‐rearing, allowing the total energy costs associated with breeding to be established for a pair of adults and at the population level on both islands. We estimate the total annual energy budget of a 6·2 kg breeding gentoo penguin to be 1517 MJ which is equivalent to the consumption of 292 kg prey.
Patterns of territory size and defence level in rural and urban tawny owl (Strix aluco) populations
Authors: Galeotti Paolo 
Published: July 2009

The effect of different variables on the territory size and defence level of tawny owl (Strix aluco L.) populations was studied in two habitats: mixed farmland (1976–1978) and town (1986–1988). Territory size was determined by plotting the position of territorial challenges (hoots) of males which were individually recognizable in most cases. No differences were found in size, defence, number of competitors and biomass between territories in farmland and in town, but territories in town were more fragmented and showed a larger nearest neighbour distance. Size of rural territories was adequately predicted both by some structural habitat features and food supplies, while size of urban territories was affected only by habitat structure and by years of territory occupancy. No effect on territory size by competing neighbours was found in either habitat, thus confirming that behavioural interactions between the owners of territories and potential settlers prevent a decrease of territory size.Defence level of urban territories was affected by 'social’variables (nearest neighbour distance and years of occupancy), structural variables (percentage of poplar grove and diversity), and food supply, while in rural territories only structural variables (fragmentation or natural vegetation) and food supplies affected defence level.This was due to different settlement tactics in the two areas, depending on the extent and quality of suitable habitat.
The ontogenetic shift in thermoregulatory behaviour of newt larvae: testing the ‘enemy‐free temperatures’ hypothesis
Authors: Smolinský R. , Gvoždík L. 
Published: July 2009

AbstractGrowth and development affect life‐history traits, and consequently organismal fitness. The inevitable increase in body size during ontogeny is associated with changes in both resource use and predation risk, which results in the ontogenetic shift in habitat preferences. In this study, we examined whether the shift in preferred body temperatures (Tps) of newt larvae Triturus alpestris increases the Tps deviation of the most vulnerable stages (after hatching and during metamorphosis) from the Tps range of their main predator, dragonfly larvae Aeshna cyanea– the ‘predator‐free temperatures’ hypothesis. Analyses of thermoregulatory behaviour in the laboratory thermal gradient showed that freshly hatched newt larvae maintained lower water temperatures than larvae in later stages, whose Tps largely fell into the Tps range of dragonfly larvae. With respect to the thermal quality of natural habitat, the anti‐predator effectiveness of the Tps shift decreased during development. Water temperatures in natural habitats were located largely below the preferred body temperature range of both newt and dragonfly larvae, which limits their potential thermal niche partitioning. We conclude that factors other than predator avoidance drive the ontogenetic Tps shift in our model system.
Evolutionary pathways to self‐fertilization in a tristylous plant species
Authors: Barrett Spencer C. H. , Ness Rob W. , Vallejo‐Marín Mario 
Published: July 2009

SummaryEvolutionary transitions from outcrossing to selfing occur commonly in heterostylous genera. The morphological polymorphisms that characterize heterostyly provide opportunities for different pathways for selfing to evolve. Here, we investigate the origins and pathways by which selfing has evolved in tristylousEichhornia paniculataby providing new evidence based on morphology, DNA sequences and genetic analysis. The primary pathway from outcrossing to selfing involves the stochastic loss of the short‐styled morph (S‐morph) from trimorphic populations, followed by the spread of selfing variants of the mid‐styled morph (M‐morph). However, the discovery of selfing variants of the long‐styled morph (L‐morph) in Central America indicates a secondary pathway and distinct origin for selfing. Comparisons of multi‐locus nucleotide sequences from 27 populations sampled from throughout the geographical range suggest multiple transitions to selfing. Genetic analysis of selfing variants of the L‐ and M‐morphs demonstrates recessive control of the loss of herkogamy, although the number of factors appears to differ between the forms. Early stages in the establishment of selfing involve developmental instability in the formation of flowers capable of autonomous self‐pollination. The relatively simple genetic control of herkogamy reduction and frequent colonizing episodes may often create demographic conditions favouring transitions to selfing inE. paniculata.
Correlates of mental health disorders among children with hearing impairments
Authors: FELLINGER JOHANNES , HOLZINGER DANIEL , SATTEL HERIBERT , LAUCHT MANFRED , GOLDBERG DAVID 
Published: July 2009

Aim  The aim of this study was to elucidate factors related to the high rate of mental health disorders seen in those with impaired hearing, including social factors and audiological measures.Method  A representative sample of 95 pupils (47 females, 48 males; mean age 11y 1mo, range 6y 5mo to 16y, SD 2y 7mo) with hearing impairments of at least 40dB and normal non‐verbal intelligence (IQ 97.5, SD 19.5), was assessed audiologically and with a structured clinical interview giving both current and lifetime diagnoses, and the Strengths and Difficulties Questionnaire. Detailed social information was gathered from parents and teachers.Results  Point and lifetime prevalence rates for any psychiatric disorder (32.6%; 45.3%) and depression (7.4%; 26.3%) were higher than in general population samples and not related to the degree of hearing loss. There was a relation between having a lifetime diagnosis and the child’s ability to be understood within the family (25.6% vs 7.7%, odds ratio 4.12 [1.2–14.1], p=0.02). Internalizing mental health disorders were between three and six times more likely in those who had been teased, maltreated by classmates, or isolated.Interpretation  We conclude that the increased risk of depression in those who have been teased, isolated, or maltreated is not peculiar to deafness, but the ability to make oneself understood is, and is modestly related (r=0.22–0.34) to the probability of these adverse experiences.
Serotonin released from amacrine neurons is scavenged and degraded in bipolar neurons in the retina
Authors: Ghai Kanika , Zelinka Christopher , Fischer Andy J. 
Published: July 2009

AbstractThe neurotransmitter serotonin is synthesized in the retina by one type of amacrine neuron but accumulates in bipolar neurons in many vertebrates. The mechanisms, functions and purpose underlying serotonin accumulation in bipolar cells remain unknown. Here, we demonstrate that exogenous serotonin transiently accumulates in a distinct type of bipolar neuron. KCl‐mediated depolarization causes the depletion of serotonin from amacrine neurons and, subsequently, serotonin is taken‐up by bipolar neurons. The accumulation of endogenous and exogenous serotonin by bipolar neurons is blocked by selective reuptake inhibitors. Exogenous serotonin is specifically taken‐up by bipolar neurons even when serotonin‐synthesizing amacrine neurons are destroyed; excluding the possibility that serotonin diffuses through gap junctions from amacrine into bipolar neurons. Further, inhibition of monoamine oxidase A prevents the degradation of serotonin in bipolar neurons, suggesting that monoamine oxidase A is present in these neurons. However, the vesicular monoamine transporter 2 is present only in amacrine cells suggesting that serotonin is not transported into synaptic vesicles and reused as a transmitter in the bipolar neurons. We conclude that the serotonin‐accumulating bipolar neurons perform glial functions in the retina by actively transporting and degrading serotonin that is synthesized in neighboring amacrine cells.
Hypothalamic neuronal histamine signaling in the estrogen deficiency‐induced obesity
Authors: Gotoh Koro , Masaki Takayuki , Chiba Seiichi , Higuchi Keiko , Kakuma Tetsuya , Shimizu Hiroyuki , Mori Masatomo , Sakata Toshiie , Yoshimatsu Hironobu 
Published: July 2009

AbstractMenopause is one of the triggers that induce obesity. Estradiol (E2), corticotropin‐releasing hormone (CRH), and hypothalamic neuronal histamine are anorexigenic substances within the hypothalamus. This study examined the interactions among E2, CRH, and histamine during the regulation of feeding behavior and obesity in rodents. Food intake was measured in rats after the treatment of E2, α‐fluoromethyl histidine, a specific suicide inhibitor of histidine decarboxylase that depletes hypothalamic neuronal histamine, or CRH antagonist. We measured food intake and body weight in wild‐type mice or mice with targeted disruption of the histamine receptors (H1‐R) knockout (H1KO mice). Furthermore, we investigated CRH content and histamine turnover in the hypothalamus after the E2 treatment or ovariectomy (OVX). We used immunohistochemical staining for estrogen receptors (ERs) in the histamine neurons. The E2‐induced suppression of feeding was partially attenuated in rats pre‐treated with α‐fluoromethyl histidine or CRH antagonist and in H1KO mice. E2 treatment increased CRH content and histamine turnover in the hypothalamus. OVX increased food intake and body weight, and decreased CRH content and histamine turnover in the hypothalamus. In addition, E2 replacement reversed the OVX‐induced changes in food intake and body weight in wild‐type mice but not in H1KO mice. Immunohistochemical analysis revealed ERs were expressed on histamine neurons and western blotting analysis and pre‐absorption study confirmed the specificity of ER antiserum we used. These results indicate that CRH and hypothalamic neuronal histamine mediate the suppressive effects of E2 on feeding behavior and body weight.
HumanS‐adenosylhomocysteine hydrolase: common gene sequence variation and functional genomic characterization
Authors: Feng Qiping , Keshtgarpour Mani , Pelleymounter Linda L. , Moon Irene , Kalari Krishna R. , Eckloff Bruce W. , Wieben Eric D. , Weinshilboum Richard M. 
Published: July 2009

AbstractS‐Adenosylhomocysteine hydrolase (AHCY) is the only mammalian enzyme known to catalyze the hydrolysis ofS‐adenosylhomocysteine. We have used a genotype‐to‐phenotype strategy to study this important enzyme by resequencingAHCYin 240 DNA samples from four ethnic groups. Thirty‐nine polymorphisms were identified – 28 of which were novel. Functional genomic studies for wild type AHCY and the three variant allozymes identified showed that two variant allozymes had slight, but significant decreases in enzyme activity, but with no significant differences in levels of immunoreactive protein. Luciferase reporter gene assays for common 5′‐flanking region haplotypes revealed that one haplotype with a frequency of ∼2% in Caucasian‐American subjects displayed a decreased ability to drive transcription. The variant nucleotide at 5′‐flanking region single nucleotide polymorphism (SNP) (−34) in that haplotype altered the DNA‐protein binding pattern during electrophoresis mobility shift assay. Finally, an AHCY genotype‐phenotype association study for expression in lymphoblastoid cells identified four SNPs that were associated with decreased expression. For the IVS6 (intervening sequence 6, i.e., intron 6) G56 > C SNP among those four, electrophoresis mobility shift assay showed that a C > G nucleotide change resulted in an additional shifted band. These results represent a step toward understanding the functional consequences of common genetic variation inAHCYfor the regulation of neurotransmitter, drug and macromolecule methylation.