bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sexual selection and the evolution of secondary sexual traits: sex comb evolution inDrosophila
Authors: Snook Rhonda R. , Gidaszewski Nelly A. , Chapman Tracey , Simmons Leigh W. 
Published: March 2013

AbstractSexual selection can drive rapid evolutionary change in reproductive behaviour, morphology and physiology. This often leads to the evolution of sexual dimorphism, and continued exaggerated expression of dimorphic sexual characteristics, although a variety of other alternative selection scenarios exist. Here, we examined the evolutionary significance of a rapidly evolving, sexually dimorphic trait, sex comb tooth number, in twoDrosophilaspecies. The presence of the sex comb in bothD. melanogasterandD. pseudoobscurais known to be positively related to mating success, although little is yet known about the sexually selected benefits of sex comb structure. In this study, we used experimental evolution to test the idea that enhancing or eliminating sexual selection would lead to variation in sex comb tooth number. However, the results showed no effect of either enforced monogamy or elevated promiscuity on this trait. We discuss several hypotheses to explain the lack of divergence, focussing on sexually antagonistic coevolution, stabilizing selection via species recognition and nonlinear selection. We discuss how these are important, but relatively ignored, alternatives in understanding the evolution of rapidly evolving sexually dimorphic traits.
Ecomorphology of the African felid ensemble: The role of the skull and postcranium in determining species segregation and assembling history
Authors: Morales M. M. , Giannini N. P. 
Published: March 2013

AbstractMorphology of extant felids is regarded as highly conservative. Most previous studies have focussed on skull morphology, so a vacuum exists about morphofunctional variation in postcranium and its role in structuring ensembles of felids in different continents. The African felid ensemble is particularly rich in ecologically specialized felids. We studied the ecomorphology of this ensemble using 31 cranial and 93 postcranial morphometric variables measured in 49 specimens of all 10 African species. We took a multivariate approach controlling for phylogeny, with and without body size correction. Postcranial and skull + postcranial analyses (but not skull‐only analyses) allowed for a complete segregation of species in morphospace. Morphofunctional factors segregating species included body size, bite force, zeugopodial lengths and osteological features related to parasagittal leg movement. A general gradient of bodily proportions was recovered: lightly built, long‐legged felids with small heads and weak bite forces vs. the opposite. Three loose groups were recognized: small terrestrial felids, mid‐to‐large sized scansorial felids and specialized Acinonyx jubatus and Leptailurus serval. As predicted from a previous study, the assembling of the African felid ensemble during the Plio‐Pleistocene occurred by the arrival of distinct felid lineages that occupied then vacant areas of morphospace, later diversifying in the continent.
The coevolution of long‐term pair bonds and cooperation
Authors: Song Z. , Feldman M. W. 
Published: March 2013

AbstractThe evolution of social traits may not only depend on but also change the social structure of the population. In particular, the evolution of pairwise cooperation, such as biparental care, depends on the pair‐matching distribution of the population, and the latter often emerges as a collective outcome of individual pair‐bonding traits, which are also under selection. Here, we develop an analytical model and individual‐based simulations to study the coevolution of long‐term pair bonds and cooperation in parental care, where partners play a Snowdrift game in each breeding season. We illustrate that long‐term pair bonds may coevolve with cooperation when bonding cost is below a threshold. As long‐term pair bonds lead to assortative interactions through pair‐matching dynamics, they may promote the prevalence of cooperation. In addition to the pay‐off matrix of a single game, the evolutionarily stable equilibrium also depends on bonding cost and accidental divorce rate, and it is determined by a form of balancing selection because the benefit from pair‐bond maintenance diminishes as the frequency of cooperators increases. Our findings highlight the importance of ecological factors affecting social bonding cost and stability in understanding the coevolution of social behaviour and social structures, which may lead to the diversity of biological social systems.
Adaptive latitudinal cline of photoperiodic diapause induction in the parasitoid Nasonia vitripennis in Europe
Authors: Paolucci S. , van de Zande L. , Beukeboom L. W. 
Published: March 2013

AbstractLiving in seasonally changing environments requires adaptation to seasonal cycles. Many insects use the change in day length as a reliable cue for upcoming winter and respond to shortened photoperiod through diapause. In this study, we report the clinal variation in photoperiodic diapause induction in populations of the parasitoid wasp Nasonia vitripennis collected along a latitudinal gradient in Europe. In this species, diapause occurs in the larval stage and is maternally induced. Adult Nasonia females were exposed to different photoperiodic cycles and lifetime production of diapausing offspring was scored. Females switched to the production of diapausing offspring after exposure to a threshold number of photoperiodic cycles. A latitudinal cline was found in the proportion of diapausing offspring, the switch point for diapause induction measured as the maternal age at which the female starts to produce diapausing larvae, and the critical photoperiod for diapause induction. Populations at northern latitudes show an earlier switch point, higher proportions of diapausing individuals and longer critical photoperiods. Since the photoperiodic response was measured under the same laboratory conditions, the observed differences between populations most likely reflect genetic differences in sensitivity to photoperiodic cues, resulting from local adaptation to environmental cycles. The observed variability in diapause response combined with the availability of genomic tools for N. vitripennis represent a good opportunity to further investigate the genetic basis of this adaptive trait.
Endolimax piscium sp. nov. (Amoebozoa), causative agent of systemic granulomatous disease of cultured sole, Solea senegalensis Kaup
Authors: Constenla M , Padrós F , Palenzuela O 
Published: March 2013

AbstractA new amoeba species pathogenic for Senegalese sole is described based on ultrastructural analysis and SSU rDNA phylogenetic inference. The parasite presents round to ovoid trophozoites (<5 μm) with a high degree of intracellular simplification. No mitochondria were observed, but mitosome‐like organelles were present. No cysts could be detected. Phylogenetic analysis confirmed the Senegalese sole parasite as an amitochondriate Archamoeba related to Endolimax nana and Iodamoeba spp., and we tentatively describe it as a new species in the genus Endolimax, Endolimax piscium. However, the genetic distance with E. nana is quite large, with only 60% pairwise identity between both SSU rDNA genotypes. Although the overall topology of the Archamoebae cladograms containing E. piscium was consistent, the support for the branching of Endolimax spp. relative to its closest neighbours was variable, being higher with distance or parsimony‐based inference methods than with ML or Bayesian trees. The use of stringent alignment sampling masks also caused instability and reduced support for some branches, including the monophyly of Endolimax spp. in the most conservative data sets. The characterization of other Archamoebae parasitizing fish could help to clarify the status of E. piscium and to interpret the large genetic distance observed between Endolimax species.
Association Between Intraoperative Blood Transfusions and Early Postoperative Delirium in Older Adults
Authors: Behrends Matthias , DePalma Glen , Sands Laura , Leung Jacqueline 
Published: March 2013

ObjectivesTo determine whether intraoperative blood transfusion, a known trigger and amplifier of inflammation, is an independent risk factor for early postoperative delirium (POD), an acute state of confusion with fluctuating consciousness and inattention after surgery, in older adults undergoing surgery.DesignSecondary analysis using a database created for a prospective cognitive outcomes study.SettingUniversity hospital.ParticipantsFour hundred seventy‐two individuals aged 65 and older undergoing major noncardiac surgery.MeasurementsPerioperative data were examined for association with POD on the first postoperative day. Multivariable logistic regression analysis was conducted to determine whether intraoperative blood transfusion independently predicts POD after adjusting for covariates known to be associated with onset of delirium and blood transfusions.ResultsOne hundred thirty‐seven individuals (29%) developed delirium on the first postoperative day. The multivariable logistic regression model identified age, sex, history of central nervous system disorder, preoperative cognitive dysfunction, and pain, as well as blood transfusions, as independent risk factors for POD. Intraoperative administration of more than 1,000 mL of red blood cells (RBCs) was the strongest predictor of POD on the first postoperative day (odds ratio = 3.68; 95% confidence interval = 1.32–10.94; P < .001).ConclusionIntraoperative blood transfusion of more than 1,000 mL of RBCs increases the risk of delirium on the first postoperative day in older adults undergoing noncardiac surgery.
Majority Shareholder Ownership and Real Earnings Management: Evidence from Korea
Authors: Goh Jaimin , Lee Ho‐Young , Lee Jung‐Wha 
Published: March 2013

AbstractThis article examines the influence of majority shareholder ownership on real earnings management. It investigates whether there is a conflict between or an alignment of majority and minority shareholders' interests. If majority shareholders' interests are aligned with those of minority shareholders, a greater majority shareholder ownership lowers real earnings management. On the other hand, if they are not aligned, majority shareholders' attempts to exploit minority shareholders will increase real earnings management. This study does not find a systematic relationship between majority shareholder ownership and real earnings management. However, real earnings management significantly decreases in the upward earnings management incentive bracket as majority shareholder ownership increases. This occurs primarily because majority shareholders are more sensitive to upward real earnings management, which has a negative effect on future performance. These results suggest that the larger the ownership of majority shareholders, the more they play a positive role in mitigating real earnings management. This positive role is only effective in the post‐Asian economic crisis period. These results may suggest that the economic crisis in Korea helped majority shareholders more conscious of the long‐term costs of real earnings management. These findings support the convergence‐of‐interests hypothesis, providing evidence by investigating real earnings management instead of accruals‐based earnings management.
Progression in multiple sclerosis is associated with low endogenous NCAM
Authors: Gnanapavan Sharmilee , Ho Peggy , Heywood Wendy , Jackson Sam , Grant Donna , Rantell Khadija , Keir Geoff , Mills Kevin , Steinman Lawrence , Giovannoni Gavin 
Published: March 2013

AbstractMultiple sclerosis (MS) is a CNS disorder characterized by demyelination and neurodegeneration. Although hallmarks of recovery (remyelination and repair) have been documented in early MS, the regenerative capacity of the adult CNS per se remains uncertain with the wide held belief that it is either limited or non‐existent. The neural cell adhesion molecule (NCAM) is a cell adhesion molecule that has been widely implicated in axonal outgrowth, guidance and fasciculation. Here, we used in vitro and in vivo of MS to investigate the role of NCAM in disease progression. We show that in health NCAM levels decrease over time, but this occurs acutely after demyelination and remains reduced in chronic disease. Our findings suggest that depletion of NCAM is one of the factors associated with or possibly responsible for disease progression in MS.
Open knot‐tying skills: Resident skills assessed
Authors: van Empel Pieter J. , Verdam Mathilde G. E. , Huirne Judith A. , Bonjer H. Jaap , Meijerink W. Jeroen , Scheele Fedde 
Published: March 2013

AbstractAimOpen knot‐tying and suturing skills are fundamental surgical skills, founding many alternative knot‐tying techniques. It is therefore mandatory for residents to possess adequate basic open knot‐tying skills. The aim of this study was to compare an objective assessment of open knot‐tying skills by residents to a resident's own estimation of his or her knot‐tying skills, before and after a knot‐tying course.Material and MethodsA prospective observational cohort study was performed. At baseline level, after 1 training day in the Advanced Suturing Course (ASC) in the Netherlands and Belgium and after 6 weeks of autonomous practice (i.e. self‐practice), 99 residents' open knot‐tying skills were objectively evaluated using the Objective Structured Assessment of Technical Skills (OSATS). The resident's own confidence in these skills was also evaluated.ResultsThe ASC substantially and significantly improved residents' knot‐tying skills according to the OSATS between baseline and post‐measurement. The observed improvement after 1 training day decreased after 6 weeks of autonomous practice. Self‐confidence increased directly after the training program and was maintained 6 weeks later. Residents having completed the first 3 years of residency displayed an overall greater self‐confidence than residents not having completed the first 3 years of residency, although the increase in self‐confidence was significantly larger in the latter after 6 weeks' autonomous training.ConclusionThere is a divergence between residents' objectified open knot‐tying skills and self‐confidence in these skills. The ASC improved open knot‐tying skills according to the OSATS, however this improvement decreased after a 6‐week period of autonomous practice. Self‐confidence, in contrast, was maintained or increased. Further research is needed to correlate validated training programs with clinical outcomes and to determine whether residents' open knot‐tying skills and self‐confidence are retained beyond 1 year.
A comparative immunohistochemical and immunophenotypical study on lymphocytes expression in patients affected by oral lichen planus
Authors: Lorenzini Guido , Viviano Massimo , Chisci Elettra , Chisci Glauco , Picciotti Maria 
Published: March 2013

BackgroundOral lichen planus (OLP) is an immune‐mediated mucocutaneous disease of uncertain aetiology. OLP has many manifestations: reticular, erosive, atrophic, plaque like, papular, bullous, with unique etiopathogenetic working. The purpose of this study is to find a link between different clinical types of lichen and the alterations of lymphocytes on peripheral blood and oral mucosa.Materials and MethodsA total of 21 patients were enrolled in this study. The mean age of patients was 53.82 years, between 31 and 78 years. OLP Diagnosis was afterwards confirmed by histopathology. Selected patients underwent to clinical evaluation, lesion characterization, incisional biopsy, samples histological analysis, peripheral blood collection. Blood specimens were submitted to cell count determination with differential, characterization of populations and circulating lymphocyte subpopulations using monoclonal antibodies in flow cytometry. Referring to the clinical presentation of lesions, patients were divided in two groups: red lesions (RL) and white lesions (WL) and compared with an age‐matched control group.ResultsThe results of the immunophenotypic study showed correlation between WL and the expression of CD19 lymphocytes (r = 0.693, P = 0.0005). The results of immunohistochemical study performed on histological specimens showed a significant correlation between RL group and expression of all lymphocyte tested (CD3 r = 0.722 P = 0.0002, CD4 r = 0.579 P = 0.0060, CD56 r = 0.513 P = 0.0173, CD8 r = 0.548 P = 0.0102).ConclusionsWe assume there is the responsibility of the expression of lymphocytes, not only type but also as quantity, in determining RL or WL manifestation of OLP. Circulating lymphocytes may have a role, too.
Is prophylactic atropine necessary during ketamine sedation in children?
Authors: Chong Jin Ho , Chew So‐phia , Ang Angelina Su Yin 
Published: March 2013

AimTo quantify clinically significant hypersalivation and other adverse events requiring intervention, with and without the use of atropine during ketamine use, using a consensus‐based, standardised terminology.MethodsThis was a retrospective study based on paediatric patients who received ketamine for procedures done at the children's emergency department from July 2010 to September 2010. Patients who were given atropine were compared with patients who were not given atropine with regard to clinically significant hypersalivation. All other side effects of ketamine (airway, respiratory, cardiovascular, neurological and gastrointestinal side effects) were documented.ResultsTwo out of the 164 (1.2%) patients who received atropine and 1 out of the 119 (0.8%) patients who did not receive atropine had desaturation (odds ratio (OR) 1.5; 95% CI 0.1–16.3). These three patients were all under 5 years old (P = 0.3) and had airway malalignment requiring repositioning. None had hypersalivation requiring intervention. Two out of 164 (1.2%) who received atropine and 3 out of 119 (2.5%) who did not receive atropine had vomiting (OR 0.5; CI 0.1–2.9). One patient who vomited did not receive atropine and was given ondansetron. The others had delayed discharges following a longer period of observation in the unit.ConclusionsThere was no clinically significant hypersalivation in children given ketamine sedation, with or without the coadministration of atropine. Ketamine is a relatively safe drug for use in children with few intervention‐based side effects.
Negative ion chemistry in the coma of comet 1P/Halley
Authors: Cordiner M. A. , Charnley S. B. 
Published: March 2013

AbstractNegative ions (anions) were identified in the coma of comet 1P/Halley during in situ Electron Electrostatic Analyzer measurements performed by the Giotto spacecraft in 1986. These anions were detected with masses in the range 7–110 amu, but with insufficient mass resolution to permit unambiguous identification. We present details of a new chemical‐hydrodynamic model for the coma of comet Halley that includes—for the first time—atomic and molecular anions, in addition to a comprehensive hydrocarbon chemistry. Anion number densities are calculated as a function of radius in the coma, and compared with the Giotto results. Important anion production mechanisms are found to include radiative electron attachment, polar photodissociation, dissociative electron attachment, and proton transfer. The polyyne anions C4H−and C6H−are found to be likely candidates to explain the Giotto anion mass spectrum in the range 49–73 amu. TheCN−anion probably makes a significant contribution to the mass spectrum at 26 amu. Larger carbon‐chain anions such as C8H−can explain the peak near 100 amu provided there is a source of large carbon‐chain‐bearing molecules from the cometary nucleus.
A search for amino acids and nucleobases in the Martian meteorite Roberts Massif 04262 using liquid chromatography‐mass spectrometry
Authors: Callahan Michael P. , Burton Aaron S. , Elsila Jamie E. , Baker Eleni M. , Smith Karen E. , Glavin Daniel P. , Dworkin Jason P. 
Published: March 2013

AbstractThe investigation into whether Mars contains signatures of past or present life is of great interest to science and society. Amino acids and nucleobases are compounds that are essential for all known life on Earth and are excellent target molecules in the search for potential Martian biomarkers or prebiotic chemistry. Martian meteorites represent the only samples from Mars that can be studied directly in the laboratory on Earth. Here, we analyzed the amino acid and nucleobase content of the shergottite Roberts Massif (RBT) 04262 using liquid chromatography‐mass spectrometry. We did not detect any nucleobases above our detection limit in formic acid extracts; however, we did measure a suite of protein and nonprotein amino acids in hot‐water extracts with high relative abundances of β‐alanine and γ‐amino‐n‐butyric acid. The presence of only low (to absent) levels of several proteinogenic amino acids and a lack of nucleobases suggest that this meteorite fragment is fairly uncontaminated with respect to these common biological compounds. The distribution of straight‐chained amine‐terminal n‐ω‐amino acids in RBT 04262 resembled those previously measured in thermally altered carbonaceous meteorites (Burton et al. 2012; Chan et al. 2012). A carbon isotope ratio of −24‰ ± 6‰ for β‐alanine in RBT 04262 is in the range of reduced organic carbon previously measured in Martian meteorites (Steele et al. 2012). The presence of n‐ω‐amino acids may be due to a high temperature Fischer‐Tropsch‐type synthesis during igneous processing on Mars or impact ejection of the meteorites from Mars, but more experimental data are needed to support these hypotheses.
Is local selection so widespread in river organisms? Fractal geometry of river networks leads to high bias in outlier detection
Authors: Fourcade Yoan , Chaput‐Bardy Audrey , Secondi Jean , Fleurant Cyril , Lemaire Christophe 
Published: March 2013

AbstractIdentifying local adaptation is crucial in conservation biology to define ecotypes and establish management guidelines. Local adaptation is often inferred from the detection of loci showing a high differentiation between populations, the so‐called FST outliers. Methods of detection of loci under selection are reputed to be robust in most spatial population models. However, using simulations we showed that FST outlier tests provided a high rate of false‐positives (up to 60%) in fractal environments such as river networks. Surprisingly, the number of sampled demes was correlated with parameters of population genetic structure, such as the variance of FSTs, and hence strongly influenced the rate of outliers. This unappreciated property of river networks therefore needs to be accounted for in genetic studies on adaptation and conservation of river organisms.