bluuebunny/crossref_metadata_2025 huggingface dataset:
Asymptotic dispersion for two‐dimensional highly heterogeneous permeability fields under temporally fluctuating flow
Authors: de Dreuzy J.‐R. , Carrera J. , Dentz M. , Le Borgne T.
Published: December 2011

Temporal fluctuations of water flux have been investigated as a mechanism that strongly enhances transverse dispersion in heterogeneous media. Unfortunately, most results have been obtained by linear stochastic theories on permeability fields of limited variability. Worse, results are inconsistent regarding the impact of fluctuations on longitudinal dispersion, which motivates our work to find the effect of temporal velocity fluctuations on macrodispersion. We perform numerical Monte Carlo simulations for highly variable permeability fields of up to 800 correlation lengths. We find that fluctuations longitudinal to the main flow direction hardly modify macrodispersion because they do not alter the flow lines. Fluctuations transverse to the main flow direction not only increase transverse dispersion, which is well known, but also reduce the longitudinal macrodispersion in a significant and consistent way, which contradicts previous findings. The reduction of the longitudinal dispersion is comparable to the increase of transverse dispersion. Most surprisingly, for high heterogeneity, temporal fluctuations cause total (longitudinal plus transverse) macrodispersion to drop with respect to the steady state one. Enhancement of the transverse macrodispersion comes from both the increase of the transverse velocity variability and Lagrangian correlation. Reduction of the longitudinal macrodispersion results from the reduction of the Lagrangian correlation of the longitudinal velocity. That is, temporal fluctuations reduce longitudinal spreading both by breaking the fastest velocity paths on the plume front and by letting solute bypass the low‐permeability zones that tend to block or trap the solute in steady state flow conditions.
Primärprävention des Schlaganfalls – Was ist neu?
Authors: Poppert H. , Sander K. , Etgen T. , Sander D.
Published: December 2011

Trotz der Fortschritte im Bereich der Akutbehandlung und Sekundärprävention des Schlaganfalls, stellt dieser weiterhin die wichtigste Ursache für dauernde Behinderung und die zweithäufigste Todesursache weltweit dar. Die wesentlichen Risikofaktoren für den Schlaganfall sind gut bekannt und können in nichtveränderbare (z. B. Alter, Geschlecht, genetische Prädisposition) und modifizierbare (z. B. Hypertonus, Nikotin, Diabetes) unterteilt werden. Die INTERSTROKE-Studie zeigte, dass 5 Faktoren (anamestischer Hypertonus oder Blutdruck >160/90 mm Hg, Rauchen, Taille-Hüft-Quotient, Ernährung und Bewegungsmangel) insgesamt 83,4% des Schlaganfallrisikos erklären. In der vorliegenden Übersichtsarbeit werden aktuelle Entwicklungen der Primärprävention des Schlaganfalls dargestellt. Dazu gehören die Bedeutung der Blutdruckvariabilität, neue Daten zu Statinen und Antithrombotika, die Therapie der asymptomatischen Karotistenose sowie der Stellenwert nichtmedikamentöser Maßnahmen im Rahmen einer „Lifestyle“-Modifikation.
Impurity effects in quasiparticle spectrum of high-Tc superconductors (Review Article)
Authors: Pogorelov Yu. G. , Santos M. C. , Loktev V. M.
Published: December 2011

The revision is made of Green function methods that describe the dynamics of electronic quasiparticles in disordered superconducting systems with d-wave symmetry of order parameter. Various types of impurity perturbations are analyzed within the simplest T-matrix approximation. The extension of the common self-consistent T-matrix approximation (SCTMA) to the so-called group expansions in clusters of interacting impurity centers is discussed and hence the validity criteria for SCTMA are established. A special attention is paid to the formation of impurity resonance states and localized states near the characteristic points of energy spectrum, corresponding to nodal points on the Fermi surface.
Soliton states in mesoscopic two-band-superconducting cylinders
Authors: Kuplevakhsky S. V. , Omelyanchouk A. N. , Yerin Y. S.
Published: December 2011

In the framework of the Ginzburg-Landau approach, we present a self-consistent theory of specific soliton states in mesoscopic (thin-walled) two-band-superconducting cylinders in external parallel magnetic fields. Such states arise in the presence of “Josephson-type” interband coupling, when phase winding numbers are different for each component of the superconducting order parameter. We evaluate the Gibbs free energy of the system up to second-order terms in a certain dimensionless parameter ɛ≈Lm/Lk≪1, where Lm and Lk are the magnet and kinetic inductance, respectively. We derive the complete set of exact soliton solutions. These solutions are thoroughly analyzed from the viewpoint of both local and global (thermodynamic) stability. In particular, we show that rotational-symmetry-breaking caused by the formation of solitons gives rise to a zero-frequency rotational mode. Although soliton states prove to be thermodynamically metastable, the minimal energy gap between the lowest-lying single-soliton states and thermodynamically stable zero-soliton states can be much smaller than the magnetic Gibbs free energy of the latter states, provided that intraband “penetration depths” differ substantially and interband coupling is weak. The results of our investigation may apply to a wide class of mesoscopic doubly-connected structures exhibiting two-band superconductivity.
X-ray fluorescence from a model liquid/liquid solvent extraction system
Authors: Bu Wei , Hou Binyang , Mihaylov Miroslav , Kuzmenko Ivan , Lin Binhua , Meron Mati , Soderholm L. , Luo Guangming , Schlossman Mark L.
Published: December 2011

X-ray fluorescence near total reflection (XFNTR) is measured from the liquid/liquid interface between dodecane and an ErCl3 aqueous solution by monitoring L shell Er emission lines. A custom sample cell is used to minimize absorption of the fluorescence x-rays that pass through dodecane on their way to the detector. The Er3+ concentration near the interface is related to the fluorescence intensity by a scale factor that is extracted by fitting the incident-angle dependent Er Lα emission line intensities for different ErCl3 bulk concentrations. As an application, we present the use of XFNTR to monitor the growth of interfacial crud in a model solvent extraction system consisting of an interface between a dodecane solution of bis(2-ethylhexyl) phosphate (HDEHP) and an ErCl3 aqueous solution.
Governing factors in stress response of nanoparticle films on water surface
Authors: Kim Kyungil , Leahy Brian D. , Dai Yeling , Shpyrko Oleg , Soltau Janet S. , Pelton Matthew , Meron Mati , Lin Binhua
Published: December 2011

The mechanical properties of self-assembled silver nanoparticle (Ag-NP) films at the air-liquid interface are studied using both visible light optics and x-ray scattering techniques. The response of such films to compression is compared with results from previously studied gold nanoparticle (Au-NP) films, showing many similarities, along with significant differences. Possible factors governing the stress response of nanoparticle films are discussed.
Analysis on the spectra and synchronous radiated electric field observation of cloud-to-ground lightning discharge plasma
Authors: Cen Jianyong , Yuan Ping , Qu Haiyan , Zhang Tinglong
Published: December 2011

According to the spectra of cloud-to-ground (CG) lightning discharge plasma captured by a slit-less spectrograph and the information of synchronous radiated electric field, the temperatures, the total intensity of spectra, the peak value of current and its action integral of discharge plasma channel have been calculated. Furthermore, the correlativity of these parameters has been analyzed for the first time. The results indicate that the total intensity of spectra has a positive correlation to the discharge current in different strokes of one CG lightning, and the temperature of discharge plasma is direct proportion to the action integral in the first return strokes of different lightning.
Effect of spanwise confinement on flag flutter: Experimental measurements
Authors: Doaré Olivier , Mano David , Carlos Bilbao Ludena Juan
Published: December 2011

The effect of spanwise clearance on the critical velocity for fluttering of a cantilevered plate in a channel flow is addressed experimentally. It is found that the critical velocity is influenced by the presence of the walls when the ratio between the clearance and the length of the plate C/L is less than 0.1 and slowly converges to the critical velocity predicted by models considering infinite span plates. These results are in good agreement with the predictions of a potential flow model taking into account spanwise confinement.
Relativistic electromagnetic flat top solitons and their stability
Authors: Sundar Sita , Das Amita , Saxena Vikrant , Kaw Predhiman , Sen Abhijit
Published: December 2011

The inclusion of ion response in the study of relativistically intense electromagnetic laser pulse propagation in plasma yields certain distinct varieties of single peak solitonic structures. A flat top slow moving structure (for which the various fields have a flat profile over a wide spatial range) is one such solution. A detailed characterization of these solutions along with the eigen spectrum of their formation in the parameter space has been presented. The evolution of this particular solution is studied in detail with the help of a coupled fluid Maxwell set of equations. The study shows that the flat top solution is unstable. The instability is characterized as the backward Brillouin instability for which the electron quiver velocity plays the role of the effective temperature.
Thermal ideality factor of hydrogenated amorphous silicon p-i-n solar cells
Authors: Kind R. , van Swaaij R. A. C. M. M. , Rubinelli F. A. , Solntsev S. , Zeman M.
Published: December 2011

The performance of hydrogenated amorphous silicon (a-Si:H) p-i-n solar cells is limited, as they contain a relatively high concentration of defects. The dark current voltage (JV) characteristics at low forward voltages of these devices are dominated by recombination processes. The recombination rate depends on the concentration of active recombination centers and the recombination efficacy of each of these centers. The first factor causes the ideality factor of the devices to be non-integer and to vary with voltage. The temperature dependence of the dark current can be expressed by its activation energy. For microcrystalline silicon solar cells the activation energy varies with voltage with a so-called thermal ideality factor of 2. This value was derived for devices with a spatially uniform defect distribution and reflects the recombination efficacy. Here we present results of a thickness series of a-Si:H p-i-n solar cells. We have matched the experimental curves with computer simulations, and show that the voltage-dependent ideality factor curve can be used to extract information on the cross sections for electron and hole capture. Also, the activation energy is used as a measure for the mobility gap, resulting in a mobility gap for a-Si:H of 1.69 eV. We find a thermal ideality factor close to 2 for all samples. This is explained with a theoretical derivation, followed by a comparison between the internal electric field strength and the spatial variation of the defect density in the intrinsic layer. The thermal ideality factor is shown to be insensitive to the defect distribution and the recombination profile in the device. It is, therefore, an appropriate parameter to characterize a-Si:H p-i-n devices, providing direct insight on the recombination efficacy.
Influence of strain on the electronic structure of the TbMnO3/SrTiO3 epitaxial interface
Authors: Venkatesan S. , Döblinger M. , Daumont C. , Kooi B. , Noheda B. , De Hosson J. T. M. , Scheu C.
Published: December 2011

Understanding the magnetotransport properties of epitaxial strained thin films requires knowledge of the chemistry at the interface. We report on the change in Mn electronic structure at the epitaxially strained TbMnO3/SrTiO3 interface. Scanning transmission electron microscopy shows an abrupt interface with a bright contrast, indicating the presence of misfit strain. Electron energy loss spectroscopy displays a chemical shift of the Mn L2,3 edge together with a high white line intensity ratio revealing a reduction in the nominal Mn oxidation state in the first 3–4 monolayers. These observations indicate misfit strain significantly changes the electronic structure at the interface.
Broadband polarization transformation via enhanced asymmetric transmission through arrays of twisted complementary split-ring resonators
Authors: Wei Zeyong , Cao Yang , Fan Yuancheng , Yu Xing , Li Hongqiang
Published: December 2011

This study proposes an ultrathin chiral metamaterial slab stacked with twisted complementary split-ring resonators (CSRRs) for highly efficient broadband polarization transformation. The polarization of linearly polarized electromagnetic waves can be rotated in a specific direction by passing it through such a slab having a thickness of about one-tenth the operational wavelength. Microwave experiments verified the theoretically predicted conversion efficiency of up to 96% covering a bandwidth of 24% of the central wavelength. CSRRs with circular symmetry provide increased interlayer coupling strength, which produces a high-efficiency broadband response and strong isolation of the original polarization.
Gain assisted nanocomposite multilayers with near zero permittivity modulus at visible frequencies
Authors: Rizza Carlo , Di Falco Andrea , Ciattoni Alessandro
Published: December 2011

We have fabricated a nano-laminate by alternating metal and gain medium layers, the gain dielectric consisting of a polymer incorporating optically pumped dye molecules. From standard reflection-transmission experiments, we show that, at a visible wavelength, both the real and the imaginary parts of the permittivity ε∥ attain very small values and we measure, at λ = 604 nm, |ε∥|=0.04 which is 21.5% smaller than its value in the absence of optical pumping. Our investigation thus proves that a medium with a permittivity with very small modulus, a key condition promising efficient subwavelength optical steering, can be actually synthesized.
Modeling of multilayer electrode performance in transverse electro-optic modulators
Authors: Zhu Minmin , Chen Xiliang , Du Zehui , Ma Jan
Published: December 2011

For some electro-optic (EO) modulators, lowering the driving voltage is necessary to reduce the power consumption of the modulators. There are four significant factors influencing the driving voltage of the EO modulators: geometrical parameters of wafer and electrodes, surface and embedded electrodes, material properties of wafer, and structure of modulators. Using the superposition method and surface charge technique, the electric fields, halfwave voltages, switching times and optical transmissions of EO modulators with two-layer, three-layer, and four-layer electrodes are calculated, respectively. It is found that the halfwave voltage decreases while the switching time increase slightly as the number of layers increases. Such study demonstrates that using multilayer electrodes is an effective technique of lowering the halfwave voltage, which may have implication of EO modulator design.
Pt/CdTe/Pt asymmetric nano-Schottky diodes from colloidal quantum dots
Authors: Khatei Jayakrishna , Rao K. S. R. Koteswara
Published: December 2011

We have fabricated nano-Schottky diodes of CdTe QDs with platinum metal electrodes in metal-semiconductor-metal planar configuration by drop-casting. The observed high value of ideality factor (13.3) of the diode was possibly due to the presence of defects in colloidal QDs. We observed asymmetry and non-linear nature of I-V characteristics between forward and reverse directions, which has been explained in terms of size distributions of quantum dots due to coffee ring effect.
Key Factors to Prepare Polyelectrolytes Showing Temperature-Sensitive Lower Critical Solution Temperature-type Phase Transitions in Water
Authors: Kohno Yuki , Ohno Hiroyuki
Published: December 2011

Tetrabutylphosphonium styrenesulfonate and its homopolymer showed a lower critical solution temperature-type phase transition in water. As the hydrophobicity of these monomeric and polymeric salts affects phase behaviour, the phase transition temperature of the polyelectrolyte was changed by the introduction of monomers having different alkyl chain length on the phosphonium cations.
The potential utility of rodents and other small mammals as indicators of ecosystem 'integrity' of South African grasslands
Authors: Avenant Nico
Published: December 2011

Context The expansive grassland biome is one of the most extensively transformed in South Africa, yet no strategy for monitoring its integrity is in place. A grassland health program, incorporating different ecosystem levels, was recently initiated. The suitability of three taxonomic groups as indicators has been tested so far: vegetation (by calculating an ecological index value, El), insects (using the South African grassland scoring system, SAGraSS) and small mammals (this study). All of these methods aim to be rapid and easy to perform. Whereas SAGraSS still needs further refinement, several factors already indicate the importance of including small mammal community parameters in integrity assessments. Aims This contribution reports on more than 12 years of results from various studies on small mammals in the Free State Grasslands, with the aim of exploring the utility of small mammal survey for assessment of ecosystem integrity. Methods The hypothesis was based on the outcomes of several short-term studies conducted in the grassland biome. Combining all previous results, this paper re-evaluates the parameters of trap success, species richness, diversity, evenness and individual species as bio-indicators. Key results By combining data from many sites and years, the effect of seasonal and inter-annual variations in habitat and population parameters was diminished, and a more general picture of small mammal community structure revealed. New insights were gleaned into the status of several indicator species. By providing a summary of small mammal community parameter scores and indices, the study establishes a benchmark for future small mammal assessments and monitoring. To be effective, small mammal surveys in the grassland biome of southern Africa should be carried out in autumn and early winter. Conclusions This study suggests that small mammal species richness and diversity decline with habitat degradation; that the generalist rodent Mastomys coucha dominates community numbers at low ecological integrity; that the number of specialist species increases towards ecological climax; and that specific species act as indicators during the successional process. Implications This study should benefit the monitoring, conservation and management of grassland ecosystems, make environmental impact assessments more effective, and identify new topics for ecological research.
Intraprotomer masking of third variable loop (V3) epitopes by the first and second variable loops (V1V2) within the native HIV-1 envelope glycoprotein trimer
Authors: Liu Li , Cimbro Raffaello , Lusso Paolo , Berger Edward A.
Published: December 2011

Within the trimeric HIV-1 envelope (Env) spike, the first and second variable loops (V1V2 region) and the third variable loop (V3) of the gp120 subunit play dual roles in antibody recognition, because they contain neutralization epitopes and also participate in epitope masking. The spatial relationships between V1V2 and V3 and the associated mechanisms of epitope masking remain unclear. Here we investigated interactions between these domains using two monoclonal antibodies recognizing distinct conserved linear epitopes that are subject to masking in the functional trimer, which limits their neutralizing activities. Using Env pseudotype virus infection assays, we found that deleting the V1V2 region greatly enhanced neutralization by both antibodies, leading us to consider two alternative models: V1V2 on one gp120 protomer masks V3 on the same protomer (intraprotomer or
cis
masking) versus on an adjacent protomer (interprotomer or
trans
masking). Our experimental approach exploited a previously described complementation system wherein two variant Envs harboring different inactivating mutations (one in gp120, the other in gp41) are coexpressed in the same cell; functional Env results only from cooperative interactions within mixed trimers, thereby enabling selective examination of mixed trimer activity. We introduced additional mutations that either promoted (V1V2 deletion, i.e., unmasking) or prevented (GPGR to GPGQ mutation, i.e., epitope destruction) interaction with the antibodies. The observed neutralization sensitivities of mixed trimers produced from various combinations of constructs support the intraprotomer (
cis
) model of V1V2 masking of V3 epitopes.
Similarity of genes horizontally acquired by
Escherichia coli
and
Salmonella enterica
is evidence of a supraspecies pangenome
Authors: Karberg Katherine A. , Olsen Gary J. , Davis James J.
Published: December 2011

Most bacterial and archaeal genomes contain many genes with little or no similarity to other genes, a property that impedes identification of gene origins. By comparing the codon usage of genes shared among strains (primarily vertically inherited genes) and genes unique to one strain (primarily recently horizontally acquired genes), we found that the plurality of unique genes in
Escherichia coli
and
Salmonella enterica
are much more similar to each other than are their vertically inherited genes. We conclude that
E. coli
and
S. enterica
derive these unique genes from a common source, a supraspecies phylogenetic group that includes the organisms themselves. The phylogenetic range of the sharing appears to include other (but not all) members of the Enterobacteriaceae. We found evidence of similar gene sharing in other bacterial and archaeal taxa. Thus, we conclude that frequent gene exchange, particularly that of genetic novelties, extends well beyond accepted species boundaries.
Sex, lies and thematising Irish
Authors: Kelly-Holmes Helen
Published: December 2011

Thematising Irish in the media reflects the complex and contradictory sociolinguistic and language-ideological situation in Ireland. This article explores some of that complexity by investigating a thread on an online discussion forum on the subject of the first ever party leaders’ debate in Irish that took place during the 2011 general election in Ireland. In the discussion thread, three particular discourses emerge: a “discourse of truth” about Irish as lacking both authority as a national language and authenticity as a minority language of a recognizable ethnic group; a discourse of “them and us”; involving a differentiation between “Irish speakers” and “non-Irish speakers”, largely based on notions of competence; and, finally, a newly emerging discourse of “sexy Irish”, which signals a commodification of Irish speakers as young, beautiful and mediatisable. The features of the forum and the online, real-time evolution of the discussion thread impact in a number of ways upon these discourses and ideologies. However, despite the possibilities afforded by the forum, which are utilized by posters for performing Irish in different ways, these everyday practices are effectively erased and invalidated by the prevailing discourses, which rely strongly on the notion of bilingualism as parallel and discrete monolingualisms.
Importance of breeding season and maternal investment in studies of sex-ratio adjustment: a case study using tree swallows
Authors: Baeta Renaud , Bélisle Marc , Garant Dany
Published: December 2011

The control of primary sex-ratio by vertebrates has become a major focus in biology in recent years. Evolutionary theory predicts that a differential effect of maternal characteristics on the fitness of sons and daughters is an important route, whereby selection is expected to favour a bias towards the production of one sex. However, despite experimental evidence for adaptive brood sex-ratio manipulation, support for this prediction remains a major challenge in vertebrates where inconsistencies between correlative studies are frequently reported. Here, we used a large dataset (2215 nestlings over 3 years) from a wild population of tree swallows (
Tachycineta bicolor
) and show that variations in breeding conditions affect female sex allocation in this species. Our results also suggest that such variation in sex allocation, owing to breeding season heterogeneity, modifies the relationships between maternal characteristics and maternal investment. Indeed, we detect a positive effect of maternal age on brood sex-ratio when age also affects offspring condition (in a low-quality breeding season). Our results indicate that including measures of both breeding season quality and maternal investment will help to better understand sex allocation patterns.
Using phylogenies in conservation: new perspectives
Authors: Rolland Jonathan , Cadotte Marc W. , Davies Jonathan , Devictor Vincent , Lavergne Sebastien , Mouquet Nicolas , Pavoine Sandrine , Rodrigues Ana , Thuiller Wilfried , Turcati Laure , Winter Marten , Zupan Laure , Jabot Franck , Morlon Hélène
Published: December 2011

The 2011 meeting of the European Ecological Federation took place in Ávila, Spain, from 26th September to 29th September. The French Ecological Society (SFE) and the Foundation for Research on Biodiversity (FRB) sponsored a session entitled ‘Evolutionary history, ecosystem function and conservation biology: new perspectives’. We report on the main insights obtained from this symposium.
Calcification rates and the effect of ocean acidification on Mediterranean cold-water corals
Authors: Maier C. , Watremez P. , Taviani M. , Weinbauer M. G. , Gattuso J. P.
Published: December 2011

Global environmental changes, including ocean acidification, have been identified as a major threat to scleractinian corals. General predictions are that ocean acidification will be detrimental to reef growth and that 40 to more than 80 per cent of present-day reefs will decline during the next 50 years. Cold-water corals (CWCs) are thought to be strongly affected by changes in ocean acidification owing to their distribution in deep and/or cold waters, which naturally exhibit a CaCO3saturation state lower than in shallow/warm waters. Calcification was measured in three species of Mediterranean cold-water scleractinian corals (Lophelia pertusa,Madrepora oculataandDesmophyllum dianthus) on-board research vessels and soon after collection. Incubations were performed in ambient sea water. The speciesM. oculatawas additionally incubated in sea water reduced or enriched in CO2.At ambient conditions, calcification rates ranged between −0.01 and 0.23% d−1. Calcification rates ofM. oculataunder variable partial pressure of CO2(pCO2) were the same for ambient and elevated pCO2(404 and 867 µatm) with 0.06 ± 0.06% d−1, while calcification was 0.12 ± 0.06% d−1when pCO2was reduced to its pre-industrial level (285 µatm). This suggests that present-day CWC calcification in the Mediterranean Sea has already drastically declined (by 50%) as a consequence of anthropogenic-induced ocean acidification.
A general model for effects of temperature on ectotherm ontogenetic growth and development
Authors: Zuo Wenyun , Moses Melanie E. , West Geoffrey B. , Hou Chen , Brown James H.
Published: December 2011

The temperature size rule (TSR) is the tendency for ectotherms to develop faster but mature at smaller body sizes at higher temperatures. It can be explained by a simple model in which the rate of growth or biomass accumulation and the rate of development have different temperature dependence. The model accounts for both TSR and the less frequently observed reverse-TSR, predicts the fraction of energy allocated to maintenance and synthesis over the course of development, and also predicts that less total energy is expended when developing at warmer temperatures for TSR and vice versa for reverse-TSR. It has important implications for effects of climate change on ectothermic animals.
Rapid phenotypic evolution during incipient speciation in a continental avian radiation
Authors: Campagna Leonardo , Benites Pilar , Lougheed Stephen C. , Lijtmaer Darío A. , Di Giacomo Adrián S. , Eaton Muir D. , Tubaro Pablo L.
Published: December 2011

Adaptive radiations have helped shape how we view animal speciation, particularly classic examples such as Darwin's finches, Hawaiian fruitflies and African Great Lakes cichlids. These ‘island’ radiations are comparatively recent, making them particularly interesting because the mechanisms that caused diversification are still in motion. Here, we identify a new case of a recent bird radiation within a continentally distributed species group; the capuchino seedeaters comprise 11Sporophilaspecies originally described on the basis of differences in plumage colour and pattern in adult males. We use molecular data together with analyses of male plumage and vocalizations to understand species limits of the group. We find marked phenotypic variation despite lack of mitochondrial DNA monophyly and few differences in other putatively neutral nuclear markers. This finding is consistent with the group having undergone a recent radiation beginning in the Pleistocene, leaving genetic signatures of incomplete lineage sorting, introgressive hybridization and demographic expansions. We argue that this apparent uncoupling between neutral DNA homogeneity and phenotypic diversity is expected for a recent group within the framework of coalescent theory. Finally, we discuss how the ecology of open habitats in South America during the Pleistocene could have helped promote this unique and ongoing radiation.
Purification, crystallization and preliminary X-ray diffraction of fluorescence recovery protein from Synechocystis PCC 6803
Authors: Liu Ting , Shuai Yingli , Zhou Honggang
Published: December 2011

Fluorescence recovery protein (FRP), which is encoded by the slr1964 gene in Synechocystis PCC 6803, plays a key role in the orange carotenoid protein-related photoprotective mechanism in cyanobacteria. As the crystal structure of FRP may provide information about the biological functions and mechanism of action of the protein, recombinant full-length FRP and a truncated form were overexpressed, purified and crystallized at 291 K using ethylene imine polymer as the precipitant. An FRP data set was collected to a resolution of 2.75 Å at low temperature (100 K). The crystal belonged to space group P41212, with unit-cell parameters a = b = 61.9, c = 160.7 Å, α = β = γ = 90°. Assuming that the asymmetric unit contains three molecules, the Matthews coefficient was calculated to be 2.1 Å3 Da−1.
Crystallization and preliminary X-ray structure analysis of human ribosomal protein L30e
Authors: Kawaguchi Akiko , Ose Toyoyuki , Yao Min , Tanaka Isao
Published: December 2011

Many functions have been reported for the eukaryotic ribosomal protein L30e. L30e makes several inter-subunit and intra-subunit interactions with protein or RNA components of the 80S ribosome. Yeast L30e has been shown to bind to its own transcript to autoregulate expression at both the transcriptional and the translational levels. Furthermore, it has been reported that mammalian L30e is a component of the selenocysteine-incorporation machinery by binding to the selenocysteine-insertion sequence on mRNA. As high-resolution crystal structures of mammalian L30e are not available, the purification, crystallization and X-ray structure analysis of human L30e are presented here.
The Demand for Non‐Audit Services and Auditor‐Client Relationships: Evidence from Swedish Small and Medium‐Sized Enterprises
Authors: Svanström Tobias , Sundgren Stefan
Published: December 2011

The joint provision of audit and non‐audit services by incumbent auditors has been intensively debated in the literature. The basic issue is that, while non‐audit services can impair auditor independence, knowledge spillovers from these services can reduce the audit cost. This is an important trade‐off for small and medium‐sized enterprises (SMEs) that depend on their auditors for non‐audit services. Using data from 322 Swedish SMEs, this study investigates the choice of purchasing non‐audit services from the incumbent auditor and other audit firms. We hypothesize, and find, that the length of the auditor‐client relationship is positively related to the purchase of non‐audit services from incumbent auditors. Also, we find a positive association between perceived quality of audit services and the likelihood of a client purchasing non‐audit services from the auditor. However, unlike studies of publicly traded companies, agency variables do not drive the purchase of non‐audit services by SMEs.
National survey of malignant mesothelioma and asbestos exposure in Japan
Authors: Gemba Kenichi , Fujimoto Nobukazu , Kato Katsuya , Aoe Keisuke , Takeshima Yukio , Inai Kouki , Kishimoto Takumi
Published: December 2011

In the present study, malignant mesothelioma (MM) cases in Japan were investigated retrospectively. We extracted records for 6030 cases of death due to MM between 2003 and 2008 to clarify the clinical features of MM, including its association with asbestos exposure (AE). Of all these cases, a clinical diagnosis of MM was confirmed for 929. The origin of MM included the pleura in 794 cases (85.5%), the peritoneum in 123 cases (13.2%), the pericardium in seven cases (0.8%), and the testicular tunica vaginalis in five cases (0.5%). The histological subtypes of MM included 396 epithelioid (55.9%), 154 sarcomatoid (21.7%), 126 biphasic (17.8%), and 33 cases (4.7%) classified as “other types”. Of all the MM cases, AE was indicated in 76.8% and pleural plaques were detected in 34.2%. The number of asbestos particles was determined in 103 cases of MM. More than 1000 asbestos particles per gram dried lung tissue were detected in 74.8% of cases and more than 5000 particles were detected in 43.7% of cases. We compared patient characteristics and the diagnostic procedures for MM before and after the “Kubota shock”. Compared with the early phase of this study (2003–2005), the median age at diagnosis of MM was higher, the number of cases without definite diagnosis of MM was lower, the proportion of cases diagnosed by thoracoscopy was higher, and the percentage of cases in which the occupational history was described in the medical records was significantly higher in the later phase (2006–2008). Our study confirmed that more than 70% of MM cases in Japan are associated with AE. The “Kubota shock” may affect some features pertaining to MM. (Cancer Sci 2012; 103: 483–490)
Very low rate and light smokers: smoking patterns and cessation‐related behaviour in England, 2006–11
Authors: Kotz Daniel , Fidler Jennifer , West Robert
Published: December 2011

Aims  There is a growing interest in very low rate [fewer than one cigarette per day (CPD)] and light (one to nine CPD) smokers and in some parts of the world their numbers appear to be increasing. This paper examined changes in prevalence over the past 5 years, cessation patterns, and smoking and demographic characteristics of very low rate, light and moderate‐to‐heavy (10+ CPD) smokers in England.

Design  Cross‐sectional and longitudinal data from aggregated monthly waves of a household survey: the Smoking Toolkit Study.

Setting  England.

Participants  A total of 23 245 smokers interviewed between November 2006 and May 2011 and 4147 who provided data at 6‐month follow‐up.

Measurements  We compared the demographic and smoking characteristics between the three groups of smokers at baseline, and the rate of attempts to quit, use of aids to cessation and success of quit attempts at follow‐up.

Findings  Very low rate smoking remained extremely rare (1.9% of smokers in 2006 to 2.8% in 2011), but light smoking became increasingly common (23.9–32.8%). Compared with moderate‐to‐heavy smokers, very low rate and light smokers were younger, more often female and from a higher socio‐economic background. They were more motivated to quit and enjoyed smoking less. During the 6‐month follow‐up period, light smokers, but not very low rate smokers, were more likely to attempt to quit than moderate‐to‐heavy smokers. When they tried to quit, very low rate and light smokers used aids to cessation less than moderate‐to‐heavy smokers but still used them to a substantial degree: 18%, 31% and 44% used over‐the‐counter nicotine replacement therapy in their most recent quit attempt for the three types of smoker, respectively. Even very low rate smokers had a substantial failure rate: 65% failed in their most recent quit attempt within 6 months.

Conclusions  Very low rate (fewer than one cigarette per day) and light (one to nine cigarettes per day) smokers in England are at least as motivated to quit as heavier smokers. Although they use cessation medication less than heavier smokers and are more likely to succeed, they still use such medication and fail in quit attempts to a substantial degree.
Vicariance divergence and gene flow among islet populations of an endemic lizard
Authors: RUNEMARK ANNA , HEY JODY , HANSSON BENGT , SVENSSON ERIK I.
Published: December 2011

Allopatry and allopatric speciation can arise through two different mechanisms: vicariance or colonization through dispersal. Distinguishing between these different allopatric mechanisms is difficult and one of the major challenges in biogeographical research. Here, we address whether allopatric isolation in an endemic island lizard is the result of vicariance or dispersal. We estimated the amount and direction of gene flow during the divergence of isolated islet populations and subspecies of the endemic Skyros wall lizard Podarcis gaigeae, a phenotypically variable species that inhabits a major island and small islets in the Greek archipelago. We applied isolation‐with‐migration models to estimate population divergence times, population sizes and gene flow between islet–mainland population pairs. Divergence times were significantly correlated with independently estimated geological divergence times. This correlation strongly supports a vicariance scenario where islet populations have sequentially become isolated from the major island. We did not find evidence for significant gene flow within P. g. gaigeae. However, gene‐flow estimates from the islet to the mainland populations were positively affected by islet area and negatively by distance between the islet and mainland. We also found evidence for gene flow from one subspecies (P. g. weigandi) into another (P. g. gaigeae), but not in the other direction. Ongoing gene flow between the subspecies suggests that even in this geographically allopatric scenario with the sea posing a strong barrier to dispersal, divergence with some gene flow is still feasible.
Case report of mammary analog secretory carcinoma of the parotid gland
Authors: Ito Shigemi , Ishida Eiichi , Skalova Alena , Matsuura Kazuto , Kumamoto Hiroyuki , Sato Ikuro
Published: December 2011

Mammary Analog Secretory Carcinoma (MASC) is a new entity of malignant salivary gland tumors that morphologically resembles mammary secretory carcinoma and carries the identical ETV6‐NTRK3 fusion gene. We report our first case of MASC in Japan occurring in the parotid gland of a 37‐year‐old female patient with a t (12; 15) (p13; q25) translocation. Histologically, the tumor was composed of monomorphic cuboidal cells with low‐grade vesicular nuclei and pale eosinophilic cytoplasm, and formed microcystic and tubular spaces with periodic acid‐Schiff‐positive secretion. Immunohistochemically, the tumor cells tested positive for cytokeratin, vimentin, and S‐100 protein. MASC is a morphological mimicker of acinic cell carcinoma, but is a distinct neoplasm characterized by a specific chromosomal translocation. An accumulation of similar case studies is mandatory in order to clarify biological behaviors.
A GEOLOGICAL PERSPECTIVE ON THE USE OF Pb ISOTOPES IN ARCHAEOMETRY
Authors: ALBARÈDE F. , DESAULTY A.‐M. , BLICHERT‐TOFT J.
Published: December 2011

Lead isotope ratios in ore bodies and magmatic rocks depend in a complex way on several a priori independent parameters, including the geological age of the tectonic province in which the ores and magmas formed and its U/Pb (μ) and Th/U (κ) ratios, two very sensitive parameters characteristic of metal sources. All these parameters are entangled in hard‐to‐read Pb isotopic ratios. With respect to the commonly used fingerprinting techniques, which rely on the comparison of raw isotope ratios, the main motivation for the present work is to provide a method for making geologically and geochemically educated guesses about metal provenance even in the absence of isotopic data on reference ores. It shows how to unscramble a geological model age and μ and κ information from isotopic measurements. This approach brings to light a new organization of the Pb isotope database and an untapped wealth of information that can be used for provenance studies and other archaeometric purposes. We provide expressions with which to calculate these parameters and, using literature data, demonstrate how Pb isotopes in ores and magmas define clear zones in the silver‐rich provinces of the Central Andes. We further show how the geological model age and μ and κ values fingerprint production areas in 16th–18th century silver coins minted in Mexico and South America. Finally, we use Pb isotopes to illustrate how the Reconquista of the Emirate of Granada (1482–91) and the seizure of the Betic silver mines are reflected in the silver coins of the Catholic Monarchs.
Mortality after temporal lobe epilepsy surgery
Authors: Seymour Nicola , Granbichler Claudia A. , Polkey Charles E. , Nashef Lina
Published: December 2011

Purpose:  To report mortality, after a longer interval, in a cohort of patients with drug‐resistant epilepsy treated by temporal lobe surgery between 1975 and 1995. A previous audit of these patients ending December 1, 1997 observed a standardized mortality ratio (SMR) of 4.5.

Methods:  We analyzed mortality in a cohort of 306 patients with temporal lobe epilepsy (TLE) who underwent temporal lobe resections between December 1, 1975 and December 1, 1995. Deaths occurring after December 1,1997 and until December 1, 2009 were evaluated. Medical records, death certificates, postmortem examination reports, coroner officer’s reports, and coroner’s inquest reports were sought, and causes of death were ascertained. Sudden unexpected death in epilepsy (SUDEP) cases were identified.

Key Findings:  In 3,569 person‐years of follow‐up 19 deaths occurred, [SMR 2.00, 95% confidence interval (CI) 1.27–3.13], 14 men (SMR 2.01, 95% CI 1.19–3.39) and 5 women (SMR 1.68, 95% CI 0.70–4.03). On analysis of subgroups, SMRs were significantly elevated in patients with mesial temporal sclerosis (MTS) (SMR 2.50, 95% CI 1.38–4.51), men with MTS (SMR 3.12, 95% CI 1.56–6.25), men with nonspecific lesions (SMR 2.68, 95% CI 1.00–7.09), and right‐sided resections in MTS (SMR 3.33, 95% CI 1.39–8.00). During follow‐up, six SUDEP cases were observed with a rate of 1/595 person‐years.

Significance:  In this cohort, the risk for premature death in patients undergoing TLE surgery decreased over time but remained above the standard population. Men had a slightly higher risk than women, as did right‐sided resections in MTS, confirming this observation in the original cohort. Although lower, the risk of SUDEP remained. Without up‐to‐date information on seizure outcome, we were unable to directly relate this to mortality.
The Acute Hemodynamic Response to LV Pacing within Individual Branches of the Coronary Sinus using a Quadripolar Lead
Authors: SHETTY ANOOP K. , DUCKETT SIMON G. , LIANG YING , KAPETANAKIS STAMATIS , GINKS MATTHEW , BOSTOCK JULIAN , CARR‐WHITE GERALD , RHODE KAWAL , RAZAVI REZA , RINALDI C. ALDO
Published: December 2011

Background:
 It is not clear whether there is a large difference in acute hemodynamic response (AHR) to left ventricle (LV) pacing in different regions of the same coronary sinus (CS) vein. Using the four electrodes available on a Quartet LV lead, we evaluated the AHR to pacing within individual branches of the CS.

Methods:
 An acute hemodynamic study was attempted in 20 patients. In each patient, we assessed AHR in a number of CS veins and along a significant proportion of each CS branch using three different bipolar configurations. We compared the AHR achieved when pacing using each different vector and also the highest AHR achieved in any position within the same patient with the lowest achieved in that patient.

Results
: Sixty‐four different CS positions in 19 patients were successfully assessed. No significant difference in AHR was found overall between the three vectors tested. The mean percentage difference in AHR between the CS branch vectors with the lowest and highest dP/dtmax was +6.5 ± 5.4% (P < 0.001). A much larger difference of +16.9 ± 6.1% (P < 0.001) was seen when comparing the highest and lowest AHR achieved using any vector in any position within the same patient.

Conclusion:
 A small difference in AHR is seen when pacing within the same branch of the CS compared to pacing in different branches in the same patient. This suggests that although the site of LV lead placement is important, the position within a CS branch is less important than choosing the right vein. (PACE 2012; 35:196–203)
Cardiac Arrhythmias and Sudden Unexpected Death in Epilepsy (SUDEP)
Authors: VELAGAPUDI POONAM , TURAGAM MOHIT , LAURENCE THOMAS , KOCHERIL ABRAHAM
Published: December 2011

Sudden unexpected death in epilepsy (SUDEP) is a major clinical problem in epilepsy patients in the United States, especially those with chronic, uncontrolled epilepsy. Several pathophysiological events contributing to SUDEP include cardiac arrhythmias, respiratory dysfunction, and dysregulation of systemic or cerebral circulation. There is a significant body of literature suggesting the prominent role of cardiac arrhythmias in the pathogenesis of SUDEP. There is evidence to say that long‐standing epilepsy can cause physiological and anatomical autonomic instability resulting in life‐threatening arrhythmias. Tachyarrhythmias, bradyarrhythmias, and asystole are commonly seen during ictal, interictal, and postictal phase in epilepsy patients. It is unclear if these rhythm disturbances need attention as some of them may be just benign findings. Evidence regarding prolonged cardiovascular monitoring or the benefit of pacemaker/defibrillator implantation for primary or secondary prevention in epilepsy patients is limited. Awareness regarding pathophysiology, cardiac effects, and management options of SUDEP will become useful in guiding more individualized treatment in the near future. (PACE 2011; 1–8)