bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of CHI3L1 and MASP2 as a biomarker pair for liver cancer through integrative secretome and transcriptome analysis
Authors: Wang Jun , Gao Feng , Mo Fan , Hong Xu , Wang Hongyang , Zheng Shusen , Lin Biaoyang
Published: April 2009

Hepatocellular carcinoma (HCC) is the fifth most frequent neoplasm with more than 500 000 new cases diagnosed yearly. Novel liver cancer biomarkers are needed. By tandem mass spectrometry, we analyzed the secretomes of 12 individual paired samples of liver cancer and adjacent normal tissues and identified 1528 proteins with >2 unique peptide hits. The false discovery rate was 3.4%. Using spectral counting, we found 87 proteins in the HCC group and 86 proteins in the normal group that showed fivefold overexpression. These proteins provided a rich source of biomarker candidates. We presented a novel paradigm in combining biomarkers that include an up‐regulated cancer biomarker and a down‐regulated organ‐enriched marker, and identified chitinase‐3‐like protein 1(CHI3L1) and mannan‐binding lectin serine peptidase 2 (MASP2) as the top biomarker pair for HCC diagnosis using integrative transcriptomics and proteomics analysis. Using ELISA assays, we further evaluated this biomarker pair in a separate cohort of 25 serum samples of liver cancer patients and 15 age‐matched normal controls. The combined marker pair (YKL40/MASP2 ratio) performed better than either marker alone with an AUC of 0.97 for liver cancer diagnosis. Further validation of the biomarker pair in HCC patients versus disease controls and independent cohorts is warranted.
The incidence and management of siaolocele after parotidectomy
Authors: Witt Robert L.
Published: April 2009

Objectives

(1) To determine if a postparotidectomy sialocele occurs at a higher incidence with a partial superficial parotidectomy compared with a near‐complete parotidectomy and (2) to determine if needle aspiration versus observation yield more persistent sialoceles beyond 1 month.

Study Design

A single‐surgeon, single‐institution case series with a chart review.

Methods

Comparing 100 consecutive partial superficial parotidectomy procedures and 20 consecutive near‐total parotidectomy procedures for formation of a postoperative sialocele. Patients were evaluated at 1 week and 1 month postoperatively. The first 18 sialoceles were treated with one or more needle aspirations. The last 21 sialoceles were treated with observation.

Results

There were 39 sialoceles in the partial superficial parotidectomy group (39/100, 39%) and none in the near‐total parotidectomy group (0/20, 0%) (P < 0.05). All sialoceles resolved by the end of the first postoperative month whether aspirated or not aspirated.

Conclusions

Sialoceles are common postpartial superficial parotidectomy, and they did not occur after near‐total parotidectomy. Sialoceles can generally be treated by observation with an expectation of resolution within 1 month.
Diet and feeding of the musky octopus, Eledone moschata, in the northern Adriatic Sea
Authors: Krstulović Šifner Svjetlana , Vrgoč Nedo
Published: April 2009

This paper presents data on the diet of the musky octopus, Eledone moschata, caught with bottom-trawl nets in the northern Adriatic Sea from October 2001 to June 2003. A total of 1226 stomachs were examined, out of which 34.8% were empty. Several indices were used to describe the diet of the species. Crustaceans were found to be the most important prey category and their remains occurred in 65.0% of stomachs with food. Fish and cephalopods were present in 37.8% and 21.8% of stomachs, respectively. Differences in food composition between smaller and larger individuals were observed. In specimens with mantle lengths up to 80 mm crustaceans dominated, occurring in 79.4% of examined stomachs. Important prey categories of the larger specimens (>80 mm) were crustaceans, fish and cephalopods. No significant differences in the diet between males and females were found. Cannibalism occurred only occasionally and at larger sizes. Seasonal changes in the diet were observed, but seasonality did not seem to be a limiting factor in the feeding intensity of the species. Results indicate that the observed differences in the diet composition and feeding dynamics of the musky octopus are primarily due to the animals' changes in size.
Reconsidering the Ad Hominem
Authors: Johnson Christopher M.
Published: April 2009

Ad hominem arguments are generally dismissed on the grounds that they are not attempts to engage in rational discourse, but are rather aimed at undermining argument by diverting attention from claims made to assessments of character of persons making claims. The manner of this dismissal however is based upon an unlikely paradigm of rationality: it is based upon the presumption that our intellectual capacities are not as limited as in fact they are, and do not vary as much as they do between rational people. When we understand rationality in terms of intellectual virtues, however, which recognize these limitations and provide for the complexity of our thinking, ad hominem considerations can sometimes be relevant to assessing arguments.
Do antipsychotic drugs affect brain structure? A systematic and critical review of MRI findings
Authors: Navari S. , Dazzan P.
Published: April 2009

Background

The potential effects of antipsychotic drugs on brain structure represent a key factor in understanding neuroanatomical changes in psychosis. This review addresses two issues: (1) do antipsychotic medications induce changes in total or regional human brain volumes and (2) do such effects depend on antipsychotic type?

Method

A systematic review of studies reporting structural brain magnetic resonance imaging (MRI) measures: (1) directly in association with antipsychotic use; and (2) in patients receiving lifetime treatment with antipsychotics in comparison with drug-naive patients or healthy controls. We searched Medline and EMBASE databases using the medical subject heading terms: ‘antipsychotics’ AND ‘brain’ AND (MRI NOT functional). The search included studies published up to 31 January 2007. Wherever possible, we reported the effect size of the difference observed.

Results

Thirty-three studies met our inclusion criteria. The results suggest that antipsychotics act regionally rather than globally on the brain. These volumetric changes are of a greater magnitude in association with typical than with atypical antipsychotic use. Indeed, there is evidence of a specific effect of antipsychotic type on the basal ganglia, with typicals specifically increasing the volume of these structures. Differential effects of antipsychotic type may also be present on the thalamus and the cortex, but data on these and other brain areas are more equivocal.

Conclusions

Antipsychotic treatment potentially contributes to the brain structural changes observed in psychosis. Future research should take into account these potential effects, and use adequate sample sizes, to allow improved interpretation of neuroimaging findings in these disorders.
The Competitive Road to Proportional Representation
Authors: Calvo Ernesto
Published: April 2009

One of the most noteworthy political regularities in the early twentieth century was the shift away from majoritarian electoral rules in Western Europe. The conventional wisdom suggests that proportional representation (PR) was introduced by elites who believed that under the existing majoritarian rules (simple plurality, block-vote, two-ballot rules) they would soon lose power to rapidly growing socialist parties. But this does not explain why many electoral reforms were carried out in countries with weak or nonexistent socialist parties. The author shows that increasing the number of parties distorts the seat-vote properties of electoral rules to a larger degree than previously anticipated. Under increasing party competition, electoral regimes display larger partisan biases than those observed in two-party races and crowd out minority parties that have territorially dispersed constituencies in favor of minority parties that have territorially concentrated constituencies. Using a dynamic Bayesian model for seats and votes, the author measures the partisan biases brought about by the expansion of voting rights in the late nineteenth century to explain the drive to reform majoritarian electoral systems.
“We Thought You Would Be White”: Race and Gender in
Fieldwork
Authors: Henderson Frances B.
Published: April 2009

After an exhausting 22-hour trip from St. Louis, I landed in Maputo,
Mozambique, alone, for the first time in July 2003 to begin my
dissertation research on women and women's organizations in
Mozambique since democratization. I spent an hour talking to a young
man who was returning home (to Maputo) from Brazil. Seeing it as an
opportunity to practice my Portuguese with someone who spoke
English, I did not realize that an hour had passed and my “welcoming
party” still had not arrived. The young man and I switched from
Portuguese to English as he began telling me the “cool places to
hang out and get a drink” in Maputo. I had no idea who was coming to
pick me up as I was armed only with the information that it was my
in-country advisor's brother who would be there. As this young man
and I were talking someone came up to me and asked, “Are you
Frances?” With a sigh of relief, I said yes, and he replied, “I was
here all of the time and I did not realize that you were here until
I heard you speaking English with this young man. I did not
recognize you; we thought you would be white.”
Connections between plasma sheet transport, Region 2 currents, and entropy changes associated with convection, steady magnetospheric convection periods, and substorms
Authors: Lyons Larry R. , Wang Chih‐Ping , Gkioulidou Matina , Zou Shasha
Published: April 2009

Here we describe how energy‐dependent magnetic drift in the presence of a pressure gradient in the direction of the drift leads to a divergence of perpendicular particle flux, and that this violates conservation of flux tube particle content. We address how, within the plasma sheet, this divergence of particle flux should be expected to lead simultaneously to the divergence of perpendicular current that drives the Region 2 (R2) current system and to significant violation of entropy conservation. The modeling results of Wang et al. (2004b) show that the above violation of entropy conservation due to magnetic drift, when taken together with magnetic field stretching, offers a resolution to the pressure crises question. On the basis of our argument that the same energy‐dependent magnetic drift effect leads to the perpendicular divergence that drives the R2 field‐aligned current system and the violation of entropy conservation, we suggest that the existence of the R2 current system can by itself be viewed as a signature of violation of entropy conservation. Finally, we propose that observational evidence suggests that an enhanced rate of entropy reduction and R2 currents resulting from particle divergence within the vicinity of the Harang reversal may be a critical aspect of the substorm expansion phase.
Exploring the Geophysical Signatures of Microbial Processes: AGU Chapman Conference on Biogeophysics; Portland, Maine, 13–16 October 2008
Authors: Slater Lee , Atekwana Estella
Published: April 2009

Geophysical methods have the potential to detect and characterize microbial growth and activity in subsurface environments over different spatial and temporal scales. Recognition of this potential has resulted in the development of a new subdiscipline in geophysics called “biogeophysics,” a rapidly evolving Earth science discipline that integrates environmental microbiology, geomicrobiology, biogeochemistry, and geophysics to investigate interactions that occur between the biosphere (microorganisms and their products) and the geosphere. Biogeophysics research performed over the past decade has confirmed the potential for geophysical techniques to detect microbes, microbial growth/biofilm formation, and microbe‐mineral interactions.

The unique characteristics of geophysical data sets (e.g., noninvasive data acquisition, spatially continuous properties retrieved) present opportunities to explore geomicrobial processes outside of the laboratory, at unique spatial scales unachievable with microbiological techniques, and possibly in remote environments such as the deep ocean. In response to this opportunity, AGU hosted a Chapman Conference with a mission to bring together geophysicists, biophysicists, geochemists, geomicrobiologists, and environmental microbiologists conducting multidisciplinary research with potential impact on biogeophysics in order to define the current state of the science, identify the critical questions facing the community, and generate a road map for establishing biogeophysics as a critical subdiscipline of Earth science research.
Acyl-homoserine lactone-mediated cross talk among epiphytic bacteria modulates behavior of Pseudomonas syringae on leaves
Authors: Dulla Glenn F J , Lindow Steven E
Published: April 2009

The leaf surface harbors a host of bacterial epiphytes that are capable of influencing the quorum sensing (QS) system of the plant pathogen Pseudomonas syringae pv. syringae (Pss). Pss uses QS to regulate expression of genes conferring extracellular polysaccharide production, motility and factors contributing to virulence to plants. About 7% of bacterial epiphytes isolated in this study produce the Pss cognate signal, 3-oxohexanoyl-homoserine lactone (3OC6HSL), often in amounts more than 10-fold higher than Pss. Premature induction of QS in Pss by these 3OC6HSL-producing epiphytes suppressed swarming motility and subsequent disease of the leaf. Co-inoculation of 3OC6HSL-producing strains with Pss reduced the number of lesions when inoculated together onto leaves compared with that of plants inoculated with Pss alone. Strains in which 3OC6HSL accumulation was quenched by expression of an N-acyl-homoserine lactonase did not decrease disease when co-inoculated with Pss. Disease incidence caused by a nonmotile mutant of Pss was not affected by 3OC6HSL-producing bacteria, suggesting that exogenous 3OC6HSL signal that altered the motility of Pss was responsible for reducing the apparent virulence of this pathogen. Thus, considerable cross talk involving exogenous 3OC6HSL occurs on leaves and this process can be exploited for disease control.
Renner–Teller effect in linear tetra-atomic molecules. I. Variational method including couplings between all degrees of freedom on six-dimensional potential energy surfaces
Authors: Jutier L. , Léonard C. , Gatti F.
Published: April 2009

For electronically degenerate states of linear tetra-atomic molecules, a new method is developed for the variational treatment of the Renner–Teller and spin-orbit couplings. The approach takes into account all rotational and vibrational degrees of freedom, the dominant couplings between the corresponding angular momenta as well as the couplings with the electronic and electron spin angular momenta. The complete rovibrational kinetic energy operator is expressed in Jacobi coordinates, where the rovibrational angular momenta ĴN have been replaced by Ĵ−L̂ez−Ŝ and the spin-orbit coupling has been described by the perturbative term ASO×L̂ez⋅Ŝz. Attention has been paid on the electronic wave functions, which require additional phase for linear tetra-atomic molecules. Our implemented rovibrational basis functions and the integration of the different parts of the total Hamiltonian operator are described. This new variational approach is tested on the electronic ground state X Π2u of HCCH+ for which new six-dimensional potential energy surfaces have been computed using the internally contracted multireference configuration interaction method and the cc-pV5Z basis set. The calculated rovibronic energies and their comparisons with previous theoretical and experimental works are presented in the next paper.
HCN polymers characterized by solid state NMR: Chains and sheets formed in the neat liquid
Authors: Mamajanov Irena , Herzfeld Judith
Published: April 2009

Hydrogen cyanide polymerizes readily under a variety of conditions and significant prebiotic roles have been suggested for these polymers due to the abundance of HCN in universe. However, the structures of HCN polymers have been more speculative than grounded in experimental data. Here we show that C13 and N15 solid state NMR spectra of polymers formed in neat HCN are inconsistent with the previously proposed structures and suggest instead that the polymers are formed by simple monomer addition, first in head-to-tail fashion to form linear, conjugated chains, and then laterally to form saturated two-dimensional networks. This interpretation of the NMR spectra finds support in other information about the polymerization of neat HCN, including the presence of free radicals. As expected from the literature, formation of the HCN tetramer, diaminomaleonitrile, is also observed, but only when the reaction is catalyzed exclusively by base and then in crystalline form.
HCN polymers characterized by SSNMR: Solid state reaction of crystalline tetramer (diaminomaleonitrile)
Authors: Mamajanov Irena , Herzfeld Judith
Published: April 2009

The HCN tetramer, diaminomaleonitrile, crystallizes in sheets with amine and nitrile groups of neighboring molecules in close proximity. This suggests the possibility of relatively facile acid-base addition to form a protopeptide polymer. We find that moderate heating under argon indeed results in an unmistakable reaction, with the abrupt transformation of pale crystallites to shrunken dark particles that become electrically conductive upon doping with iodine. Since nearly a quarter of the mass is lost in the process and the released gas condenses, polymerizes, and reacts with aqueous AgNO3 like HCN, it seems likely that the dark solid is a polymer of HCN trimer. C13 and N15 solid state NMR spectra show the formation of new N–C bonds, and entirely different functional groups from those observed in polymers formed by liquid HCN. These include three different types of nitrogen functionalities and an absence of saturated carbon or nitrile. The observed chemical shifts, optical properties, and electrical conductivity are consistent with polymers of HCN trimer that have undergone cyclization to form poly-[aminoimidazole].
Patterned media with composite structure for writability at high areal recording density
Authors: Sbiaa Rachid , Aung Kyaw Oo , Piramanayagam S. N. , Tan Ei-Leen , Law Randall
Published: April 2009

Writability in bit-patterned media (BPM) is a critical issue for high areal densities. In this study, magnetization reversal for multilayer of (Co/Pd) nanodots was investigated using magnetic force microscopy. We observed an increase of more than 15 times in switching field (Hsw) in BPM over that of continuous films. An exchange coupled structure made of a thin Co layer with in-plane magnetization and high perpendicular anisotropy layer of (Co/Pd) multilayer to reduce the switching field is proposed. When the Co layer is thinner than 2 nm, its magnetization is aligned perpendicular to the film plane due to the exchange coupling with the 15 nm thick (Co/Pd) multilayer. The thin Co layer helps in reducing the Hsw of (Co/Pd) by almost 50% and also its distribution by 57% as measured from remanence magnetization.
Anisotropic intracule densities and electron correlation in H2: A quantum Monte Carlo study
Authors: Per Manolo C. , Russo Salvy P. , Snook Ian K.
Published: April 2009

We derive efficient quantum Monte Carlo estimators for the anisotropic intracule and extracule densities. These estimators are used in conjunction with an accurate explicitly correlated wave function to investigate the bond-length dependence of electron correlation effects in the ground-state H2 molecule. It is shown that the localized increase in the magnitude of the correlation energy as the bond is stretched is accompanied by highly anisotropic correlation effects. In addition, we find a small long-range part of the Coulomb hole, which is present even at the equilibrium bond length.
Global and local characterization of turbulent and chaotic structures in a dipole-confined plasma
Authors: Grierson B. A. , Worstell M. W. , Mauel M. E.
Published: April 2009

When the neutral density increases sufficiently, plasma confined by a magnetic dipole field exhibits a transition to a high density, quasisteady state with complex turbulent behaviors. Experiments using the collisionless terrella experiment [B. Levitt, D. Maslovsky, and M. Mauel, Phys. Plasmas 9, 2507 (2002)] used statistical tools and fast imaging to understand this turbulent state with respect to both global and local paradigms. Globally, the whole-plasma dynamics are observed using a unique high-speed imaging diagnostic that views the time-varying spatial structure of the polar current density. The biorthogonal decomposition for multiple space-time points is used to decompose the measured plasma dynamics into spatial and temporal mode functions. The dominant modes are long wavelength and radially broad with amplitudes and phases that are chaotic. The potential fluctuations are also found to be dominated by low azimuthal mode numbers. Locally, multipoint and multiple-time bispectral quantities are computed and used to estimate the linear dispersion and nonlinear structure coupling of a broadband of interacting fluctuations. The spectral power transfer is found to be from small to large scale in an inverse energy cascade. The energy spectrum displays a k−3 power law consistent with the enstrophy cascade in two-dimensional turbulence. In all cases, the fluctuations appear interchangelike and consistent with two-dimensional electrostatic interchange mixing. To the best of our knowledge, this is the first time when both local and global dynamics of turbulent interchange structures have been simultaneously measured in a strongly magnetized plasma.
Synthesis and thermoelectric properties of type-VIII germanium clathrates Sr8AlxGayGe46−x−y
Authors: Sasaki Yuta , Kishimoto Kengo , Koyanagi Tsuyoshi , Asada Hironori , Akai Koji
Published: April 2009

Nominal Sr8AlxGa16−xGe30 samples with x=6, 8, and 10 crystallized in the type-VIII clathrate structure (I4¯3m, No. 217), while the sample with x=4 crystallized in the type-I clathrate structure (Pm3¯n, No. 223). While a large number of the type-I thermoelectric clathrates exist, only three type-VIII clathrates of Ba8Ga16Sn30, Eu8Ga16Ge30, and Sr8AlxGa16−xSi30 had been synthesized before. The type-VIII Sr8AlxGayGe46−x−y samples (6≤x≤7 and 10≤y≤11) with various carrier concentrations were prepared to investigate their thermoelectric properties. They exhibited the temperature dependences of electrical conductivities and the Seebeck coefficients typical of n type degenerate semiconductors, which almost depended on their carrier concentrations systematically. A relatively large dimensionless figure-of-merit ZT of 0.56 at 800 K was obtained for the type-VIII Sr8Al6.3Ga10.3Ge29.4 sample with a carrier concentration of 3.0×1020 cm−3. This ZT value is comparable to that of 0.62 at 800 K for the type-I Sr8Ga16.5Ge29.5 clathrate. The type-VIII clathrate had a smaller effective mass, a higher mobility, and a higher lattice thermal conductivity than those of the type-I clathrate. The difference in transport properties between the type-I and type-VIII clathrates is also discussed.
Origin of electric dipoles formed at high-k/SiO2 interface
Authors: Kita Koji , Toriumi Akira
Published: April 2009

A model for the physical origin of the dipole formed at high-k/SiO2 interface is proposed. In our model, an areal density difference of oxygen atoms at high-k/SiO2 interface is considered as an intrinsic origin of the dipole formation. The oxygen movement from higher-oxygen-density side to a lower-oxygen-density one will determine the direction of interface dipole. The bonding energy relaxation at the interface explains why the oxygen density difference is the driving force of the oxygen movement. Our model enables the prediction of the dipole directions for candidate gate dielectrics, including those so far not reported.
Mechanism for top-down control of working memory capacity
Authors: Edin Fredrik , Klingberg Torkel , Johansson Pär , McNab Fiona , Tegnér Jesper , Compte Albert
Published: April 2009

Working memory capacity, the maximum number of items that we can transiently store in working memory, is a good predictor of our general cognitive abilities. Neural activity in both dorsolateral prefrontal cortex and posterior parietal cortex has been associated with memory retention during visuospatial working memory tasks. The parietal cortex is thought to store the memories. However, the role of the dorsolateral prefrontal cortex, a top-down control area, during pure information retention is debated, and the mechanisms regulating capacity are unknown. Here, we propose that a major role of the dorsolateral prefrontal cortex in working memory is to boost parietal memory capacity. Furthermore, we formulate the boosting mechanism computationally in a biophysical cortical microcircuit model and derive a simple, explicit mathematical formula relating memory capacity to prefrontal and parietal model parameters. For physiologically realistic parameter values, lateral inhibition in the parietal cortex limits mnemonic capacity to a maximum of 2–7 items. However, at high loads inhibition can be counteracted by excitatory prefrontal input, thus boosting parietal capacity. Predictions from the model were confirmed in an fMRI study. Our results show that although memories are stored in the parietal cortex, interindividual differences in memory capacity are partly determined by the strength of prefrontal top-down control. The model provides a mechanistic framework for understanding top-down control of working memory and specifies two different contributions of prefrontal and parietal cortex to working memory capacity.
The Iranian Economy in the Twentieth Century: A Global Perspective
Authors: Esfahani Hadi Salehi , Pesaran M. Hashem
Published: April 2009

This paper examines the transformation of the Iranian economy through the twentieth century within a global context. At the start of that century, the Iranian economy had long remained stagnant, poor, and largely agrarian, with a marginal role in the world economy. By the turn of the twenty-first century, Iran had transformed into a complex and relatively large economy with important consequences for the economies of the Middle East and other parts of the world. While the initial conditions and the evolution of domestic institutions and resources played major roles in the pace and nature of that transformation, relations with the rest of the world had crucial influences as well. This paper focuses on the latter forces, while taking account of their interactions with domestic factors in shaping the particular form of economic development in Iran. We study the ways in which the development of the Iranian economy has been affected by international price movements and by the ebbs and flows of trade, investment, and economic growth in the rest of the world. In considering these effects, we also analyze the role of domestic political economy factors and policies in enhancing or hindering the ability of domestic producers to respond to external challenges and opportunities.
Mrpl36 Is Important for Generation of Assembly Competent Proteins during Mitochondrial Translation
Authors: Prestele Martin , Vogel Frank , Reichert Andreas S. , Herrmann Johannes M. , Ott Martin
Published: April 2009

The complexes of the respiratory chain represent mosaics of nuclear and mitochondrially encoded components. The processes by which synthesis and assembly of the various subunits are coordinated remain largely elusive. During evolution, many proteins of the mitochondrial ribosome acquired additional domains pointing at specific properties or functions of the translation machinery in mitochondria. Here, we analyzed the function of Mrpl36, a protein associated with the large subunit of the mitochondrial ribosome. This protein, homologous to the ribosomal protein L31 from bacteria, contains a mitochondria-specific C-terminal domain that is not required for protein synthesis per se; however, its absence decreases stability of Mrpl36. Cells lacking this C-terminal domain can still synthesize proteins, but these translation products fail to be properly assembled into respiratory chain complexes and are rapidly degraded. Surprisingly, overexpression of Mrpl36 seems to even increase the efficiency of mitochondrial translation. Our data suggest that Mrpl36 plays a critical role during translation that determines the rate of respiratory chain assembly. This important function seems to be carried out by a stabilizing activity of Mrpl36 on the interaction between large and small ribosomal subunits, which could influence accuracy of protein synthesis.
Social structure influences extra-pair paternity in socially monogamous mammals
Authors: Cohas Aurélie , Allainé Dominique
Published: April 2009

Using the genetic estimates of paternity available for 22 species of socially monogamous mammals, we investigated the impact of the social structure and of the type of pair bonding on the interspecific variations of extra-pair paternity rates. To this purpose, we classified species in three categories of social structure—solitary, pair or family-living species—and in two categories of pair bonding—intermittent or continuous. We show that interspecific variations of extra-pair paternity rates are better explained by the social structure than by the type of pair bonding. Species with intermittent and continuous pair bonding present similar rates of extra-pair paternity, while solitary and family-living species present higher extra-pair paternity rates than pair-living species. This can be explained by both higher male–male competition and higher female mate choice opportunities in solitary and family-living species than in pair-living species.
A tiger cannot change its stripes: using a three-dimensional model to match images of living tigers and tiger skins
Authors: Hiby Lex , Lovell Phil , Patil Narendra , Kumar N. Samba , Gopalaswamy Arjun M. , Karanth K. Ullas
Published: April 2009

The tiger is one of many species in which individuals can be identified by surface patterns. Camera traps can be used to record individual tigers moving over an array of locations and provide data for monitoring and studying populations and devising conservation strategies. We suggest using a combination of algorithms to calculate similarity scores between pattern samples scanned from the images to automate the search for a match to a new image. We show how using a three-dimensional surface model of a tiger to scan the pattern samples allows comparison of images that differ widely in camera angles and body posture. The software, which is free to download, considerably reduces the effort required to maintain an image catalogue and we suggest it could be used to trace the origin of a tiger skin by searching a central database of living tigers' images for matches to an image of the skin.
Sexually antagonistic genetic variance for fitness in an ancestral and a novel environment
Authors: Delcourt Matthieu , Blows Mark W. , Rundle Howard D.
Published: April 2009

The intersex genetic correlation for fitness

, a standardized measure of the degree to which male and female fitness covary genetically, has consequences for important evolutionary processes, but few estimates are available and none have explored how it changes with environment. Using a half-sibling breeding design, we estimated the genetic (co)variance matrix (
G
) for male and female fitness, and the resulting

, in
Drosophila serrata
. Our estimates were performed in two environments: the laboratory yeast food to which the population was well adapted and a novel corn food. The major axis of genetic variation for fitness in the two environments, accounting for 51.3 per cent of the total genetic variation, was significant and revealed a strong signal of sexual antagonism, loading negatively in both environments on males but positively on females. Consequently, estimates of

were negative in both environments (−0.34 and −0.73, respectively), indicating that the majority of genetic variance segregating in this population has contrasting effects on male and female fitness. The possible strengthening of the negative

in this novel environment may be a consequence of no history of selection for amelioration of sexual conflict. Additional studies from a diverse range of novel environments will be needed to determine the generality of this finding.
Independent colonization of multiple urban centres by a formerly forest specialist bird species
Authors: Evans Karl L. , Gaston Kevin J. , Frantz Alain C. , Simeoni Michelle , Sharp Stuart P. , McGowan Andrew , Dawson Deborah A. , Walasz Kazimierz , Partecke Jesko , Burke Terry , Hatchwell Ben J.
Published: April 2009

Urban areas are expanding rapidly, but a few native species have successfully colonized them. The processes underlying such colonization events are poorly understood. Using the blackbirdTurdus merula, a former forest specialist that is now one of the most common urban birds in its range, we provide the first assessment of two contrasting urban colonization models. First, that urbanization occurred independently. Second, that following initial urbanization, urban-adapted individuals colonized other urban areas in a leapfrog manner. Previous analyses of spatial patterns in the timing of blackbird urbanization, and experimental introductions of urban and rural blackbirds to uncolonized cities, suggest that the leapfrog model is likely to apply. We found that, across the western Palaearctic, urban blackbird populations contain less genetic diversity than rural ones, urban populations are more strongly differentiated from each other than from rural populations and assignment tests support a rural source population for most urban individuals. In combination, these results provide much stronger support for the independent urbanization model than the leapfrog one. If the former model predominates, colonization of multiple urban centres will be particularly difficult when urbanization requires genetic adaptations, having implications for urban species diversity.
Sex-specific timing of mate searching and territory prospecting in the nightingale: nocturnal life of females
Authors: Roth Tobias , Sprau Philipp , Schmidt Rouven , Naguib Marc , Amrhein Valentin
Published: April 2009

Formal models have shown that diel variation in female mate searching is likely to have profound influence on daily signalling routines of males. In studies on acoustic communication, the temporal patterns of the receivers' signal evaluation should thus be taken into account when investigating the functions of signalling. In bird species in which diel patterns of signalling differ between males singing to defend a territory or to attract a mate, the diel patterns of mate and territory prospecting are suggested to depend on the sex of the prospector. We simulated newly arriving female nightingales (
Luscinia megarhynchos
) by translocating radio-tagged females to our study site. The mate-searching females prospected the area mostly at night, visiting several singing males. The timing of female prospecting corresponded to the period of the night when the singing activity of unpaired males was higher than that of paired males. In contrast to females, territory searching males have been shown to prospect territories almost exclusively during the dawn chorus. At dawn, both paired and unpaired males sang at high rates, suggesting that in contrast to nocturnal singing, dawn singing is important to announce territory occupancy to prospecting males. In the nightingale, the sex-specific timing of prospecting corresponded to the differential signalling routines of paired and unpaired males. The temporal patterns in the behaviour of signallers and receivers thus appear to be mutually adapted.
Birth season glucocorticoids are related to the presence of infants in sifaka (
Propithecus verreauxi
)
Authors: Brockman Diane K. , Cobden Amy K. , Whitten Patricia L.
Published: April 2009

The responses of plural breeding mammals to environmental stressors are little understood in free-ranging populations, but recent studies of singular breeders suggest that ecological factors and social milieu influence the variable physiological stress responses observed among individuals. Our previous studies examining faecal glucocorticoid (fGC)–behaviour interactions in plural breeding male sifaka (
Propithecus verreauxi
) show that fGC elevations coincide with specific dispersal events, particularly the eviction of subordinates by resident alpha males. This study examined the utility of fGC assays for assessing the stress responses of male sifaka to demographic changes in the population during the birth season. Analyses were based on 889 faecal samples collected over five birth seasons from 124 adult males residing in 55 different groups at Beza Mahafaly, Madagascar. Results show that fGC levels in males are unrelated to age, residence, group stability or rank, but are significantly and positively correlated with the presence of infants, annual elevations in weekly mean fGC concentrations in males paralleling increasing numbers of infants born annually in the population. These data are the first to show that in seasonal plural breeding species such as sifaka, elevated fGC in males reflects specific events related to reproduction rather than states or social context during the birth season.
Predation risk as a driving force for phenotypic assortment: a cross-population comparison
Authors: Croft D.P. , Darden S.K. , Ruxton G.D.
Published: April 2009

Frequency-dependent predation has been proposed as a general mechanism driving the phenotypic assortment of social groups via the ‘oddity effect’, which occurs when the presence of odd individuals in a group allows a predator to fixate on a single prey item, increasing the predator's attack-to-kill ratio. However, the generality of the oddity effect has been debated and, previously, there has not been an ecological assessment of the role of predation risk in driving the phenotypic assortment of social groups. Here, we compare the levels of body length assortment of social groups between populations of the Trinidadian guppy (Poecilia reticulata) that experience differences in predation risk. As predicted by the oddity effect hypothesis, we observe phenotypic assortment by body length to be greater under high predation risk. However, we found that a number of low-predation populations were also significantly assorted by body length, suggesting that other mechanisms may have a role to play.
Coevolution of diet and prey-specific venom activity supports the role of selection in snake venom evolution
Authors: Barlow Axel , Pook Catharine E. , Harrison Robert A. , Wüster Wolfgang
Published: April 2009

The processes that drive the evolution of snake venom variability, particularly the role of diet, have been a topic of intense recent research interest. Here, we test whether extensive variation in venom composition in the medically important viper genus
Echis
is associated with shifts in diet. Examination of stomach and hindgut contents revealed extreme variation between the major clades of
Echis
in the proportion of arthropod prey consumed. The toxicity (median lethal dose, LD
50
) of representative
Echis
venoms to a natural scorpion prey species was found to be strongly associated with the degree of arthropod feeding. Mapping the results onto a novel
Echis
phylogeny generated from nuclear and mitochondrial sequence data revealed two independent instances of coevolution of venom toxicity and diet. Unlike venom LD
50
, the speed with which venoms incapacitated and killed scorpions was not associated with the degree of arthropod feeding. The prey-specific venom toxicity of arthropod-feeding
Echis
may thus be adaptive primarily by reducing venom expenditure. Overall, our results provide strong evidence that variation in snake venom composition results from adaptive evolution driven by natural selection for different diets, and underscores the need for a multi-faceted, integrative approach to the study of the causes of venom evolution.
Juvenile salmon with high standard metabolic rates have higher energy costs but can process meals faster
Authors: Millidine K.J. , Armstrong J.D. , Metcalfe N.B.
Published: April 2009

Basal or standard metabolic rate (SMR) has been found to exhibit substantial intraspecific variation in a range of taxa, but the consequences of this variation are little understood. Here we explore how SMR is related to the energy cost of processing food, known as apparent specific dynamic action or the heat increment of feeding. Using juvenile Atlantic salmonSalmo salar, we show that fishes with a higher SMR had a higher peak and a greater total energy expenditure when digesting a given size of meal. However, the duration over which their metabolism was elevated after consuming the meal was shorter. The greater energy costs they incur for processing food may be related to their assimilation efficiency. These relationships are likely to have implications for feeding strategies and growth rates, since individuals with a higher SMR have higher routine costs of living but recover more quickly following feeding and so may have a greater potential for processing food.
Matrilocal residence is ancestral in Austronesian societies
Authors: Jordan Fiona M. , Gray Russell D. , Greenhill Simon J. , Mace Ruth
Published: April 2009

The nature of social life in human prehistory is elusive, yet knowing how kinship systems evolve is critical for understanding population history and cultural diversity. Post-marital residence rules specify sex-specific dispersal and kin association, influencing the pattern of genetic markers across populations. Cultural phylogenetics allows us to practise ‘virtual archaeology’ on these aspects of social life that leave no trace in the archaeological record. Here we show that early Austronesian societies practised matrilocal post-marital residence. Using a Markov-chain Monte Carlo comparative method implemented in a Bayesian phylogenetic framework, we estimated the type of residence at each ancestral node in a sample of Austronesian language trees spanning 135 Pacific societies. Matrilocal residence has been hypothesized for proto-Oceanic society (ca3500 BP), but we find strong evidence that matrilocality was predominant in earlier Austronesian societiesca5000–4500 BP, at the root of the language family and its early branches. Our results illuminate the divergent patterns of mtDNA and Y-chromosome markers seen in the Pacific. The analysis of present-day cross-cultural data in this way allows us to directly address cultural evolutionary and life-history processes in prehistory.
Flight costs of long, sexually selected tails in hummingbirds
Authors: Clark Christopher James , Dudley Robert
Published: April 2009

The elongated tails adorning many male birds have traditionally been thought to degrade flight performance by increasing body drag. However, aerodynamic interactions between the body and tail can be substantial in some contexts, and a short tail may actually reduce rather than increase overall drag. To test how tail length affects flight performance, we manipulated the tails of Anna's hummingbirds (Calypte anna) by increasing their length with the greatly elongated tail streamers of the red-billed streamertail (Trochilus polytmus) and reducing their length by removing first the rectrices and then the entire tail (i.e. all rectrices and tail covert feathers). Flight performance was measured in a wind tunnel by measuring (i) the maximum forward speed at which the birds could fly and (ii) the metabolic cost of flight while flying at airspeeds from 0 to 14 m s−1. We found a significant interaction effect between tail treatment and airspeed: an elongated tail increased the metabolic cost of flight by up to 11 per cent, and this effect was strongest at higher flight speeds. Maximum flight speed was concomitantly reduced by 3.4 per cent. Also, removing the entire tail decreased maximum flight speed by 2 per cent, suggesting beneficial aerodynamic effects for tails of normal length. The effects of elongation are thus subtle and airspeed-specific, suggesting that diversity in avian tail morphology is associated with only modest flight costs.
Why do winners keep winning? Androgen mediation of winner but not loser effects in cichlid fish
Authors: Oliveira Rui F. , Silva Ana , Canário Adelino V.M.
Published: April 2009

Animal conflicts are influenced by social experience such that a previous winning experience increases the probability of winning the next agonistic interaction, whereas a previous losing experience has the opposite effect. Since androgens respond to social interactions, increasing in winners and decreasing in losers, we hypothesized that socially induced transient changes in androgen levels could be a causal mediator of winner/loser effects. To test this hypothesis, we staged fights between dyads of size-matched males of the Mozambique tilapia (Oreochromis mossambicus). After the first contest, winners were treated with the anti-androgen cyproterone acetate and losers were supplemented with 11-ketotestosterone. Two hours after the end of the first fight, two contests were staged simultaneously between the winner of the first fight and a naive male and between the loser of first fight and another naive male. The majority (88%) of control winners also won the second interaction, whereas the majority of control losers (87%) lost their second fight, thus confirming the presence of winner/loser effects in this species. As predicted, the success of anti-androgen-treated winners in the second fight decreased significantly to chance levels (44%), but the success of androgenized losers (19%) did not show a significant increase. In summary, the treatment with anti-androgen blocks the winner effect, whereas androgen administration fails to reverse the loser effect, suggesting an involvement of androgens on the winner but not on the loser effect.
Monitoring surgical performance: an application to total hip replacement
Authors: Biau David J. , Milet Alexandre , Thévenin Fabrice , Anract Philippe , Porcher Raphaël
Published: April 2009

Rationale, aims and objectives  Inadequate surgical implantation of a hip replacement may result in decreased patient satisfaction and reduced implant survival. The objective was to monitor surgical performance in hip replacement.

Method  The study took place at a teaching centre. All primary total hip replacements were prospectively included in the series. For each hip replacement, intraoperative technical errors, cup and stem fixation and position, and postoperative complications were recorded. If all items rated were correct, the procedure was considered as correct. The Cumulative Sums (CUSUM) test was used to monitor the performance of the centre. A 90% proportion of successful procedures was considered as adequate performance and a 75% proportion of successful procedures was deemed as inadequate performance. Meetings were conducted to discuss the results of monitoring.

Results  Eighty‐three total hip replacements were monitored. Overall, 28 procedures (34%) were considered inadequate. The most potent reasons for inadequate performance were cup positioning and stem fixation. The CUSUM test signalled after the second procedure that performance was inadequate. After the first meeting, despite an improvement was seen, the CUSUM test raised an alarm indicating inadequate performance. The study was stopped after the second meeting because of funding reasons before it could be demonstrated that performance had reached the desired level.

Conclusion  This study has demonstrated that implementing a dedicated system to monitor surgical performance in a teaching hospital improves the quality of implantation of total hip replacements. Nonetheless, the target of ninety percent of adequate primary total hip replacement could not be reached and efforts should be continued.