bluuebunny/crossref_metadata_2025 huggingface dataset:
Atmospheric chemistry‐climate feedbacks
Authors: Raes Frank , Liao Hong , Chen Wei‐Ting , Seinfeld John H.
Published: June 2010

We extend the theory of climate feedbacks to include atmospheric chemistry. A change in temperature caused by a radiative forcing will include, in general, a contribution from the chemical change that is fed back into the climate system; likewise, the change in atmospheric burdens caused by a chemical forcing will include a contribution from the associated climate change that is fed back into the chemical system. The theory includes two feedback gains, Gche and Gcli. Gche is defined as the ratio of the change in equilibrium global mean temperature owing to long‐lived greenhouse gas radiative forcing, under full climate‐chemistry coupling, to that in the absence of coupling. Gcli is defined as the ratio of the change in equilibrium mean aerosol or gas‐phase burdens owing to chemical forcing under full coupling, to that in the absence of coupling. We employ a climate‐atmospheric chemistry model based on the Goddard Institute for Space Studies (GISS) GCM II', including tropospheric gas‐phase chemistry, sulfate, nitrate, ammonium, black carbon, and organic carbon. While the model describes many essential couplings between climate and atmospheric chemistry, not all couplings are accounted for, such as indirect aerosol forcing and the role of natural dust and sea salt aerosols. Guided by the feedback theory, we perform perturbation experiments to quantify Gche and Gcli. We find that Gche for surface air temperature is essentially equal to 1.00 on a planetary scale. Regionally, Gche is estimated to be 0.80–1.30. The gains are small compared to those of the physical feedbacks in the climate system (e.g., water vapor, and cloud feedbacks). These values for Gche are robust for the specific model used, but may change when using more comprehensive climate‐atmospheric chemistry models. Our perturbation experiments do not allow one to obtain robust values for Gcli. Globally averaged, the values range from 0.99 to 1.28, depending on the chemical species, while, in areas of high pollution, Gcli can be up to 1.15 for ozone, and as large as 1.40 for total aerosol. These preliminary values indicate a significant role of climate feedbacks in the atmospheric chemistry system.
Natural streamflow regime alterations: Damming of the Piave river basin (Italy)
Authors: Botter G. , Basso S. , Porporato A. , Rodriguez‐Iturbe I. , Rinaldo A.
Published: June 2010

A novel approach is proposed to estimate the natural streamflow regime of a river and to assess the extent of the alterations induced by dam operation related to anthropogenic (e.g., agricultural, hydropower) water uses in engineered river basins. The method consists in the comparison between the seasonal probability density function (pdf) of observed streamflows and the purportedly natural streamflow pdf obtained by a recently proposed and validated probabilistic model. The model employs a minimum of landscape and climate parameters and unequivocally separates the effects of anthropogenic regulations from those produced by hydroclimatic fluctuations. The approach is applied to evaluate the extent of the alterations of intra‐annual streamflow variability in a highly engineered alpine catchment of north‐eastern Italy, the Piave river. Streamflows observed downstream of the regulation devices in the Piave catchment are found to exhibit smaller means/modes, larger coefficients of variation, and more pronounced peaks than the flows that would be observed in the absence of anthropogenic regulation, suggesting that the anthropogenic disturbance leads to remarkable reductions of river flows, with an increase of the streamflow variability and of the frequency of preferential states far from the mean. Some structural limitations of management approaches based on minimum streamflow requirements (widely used to guide water policies) as opposed to criteria based on whole distributions are also discussed.
An ellipsoidal harmonic representation of Earth's lithospheric magnetic field to degree and order 720
Authors: Maus S.
Published: June 2010

While high‐degree models of the Earth's gravity potential have been inferred from measurements for more than a decade, corresponding geomagnetic models are difficult to produce. The primary challenge lies in the estimation of the magnetic potential, which is not completely determined by available field intensity measurements and cannot be computed by direct integration. Described here is the methodology behind the third generation of the National Geophysical Data Center's degree 720 magnetic model. Key issues are (1) the ellipsoidal harmonic representation of the magnetic potential, (2) the reduction of ambiguities by a suitable penalty function, and (3) the use of an iterative method to estimate the model coefficients. The NGDC‐720 model provides the lithospheric magnetic field vector at any desired location and altitude close to and above the Earth's surface. Anticipated uses are in geological and tectonic studies of the lithosphere, as a local correction for magnetic navigation and heading systems, and the calibration of ground, marine, airborne, and spaceborne magnetometers. The NGDC‐720 model is available at http://geomag.org/models/ngdc720.html and for long‐term archive at http://earthref.org/cgi‐bin/er.cgi?s=erda.cgi?n=989.
Geochemistry of clathrate‐derived methane in Arctic ocean waters
Authors: Elliott Scott , Reagan Matthew , Moridis George , Smith Philip Cameron
Published: June 2010

Alterations to the composition of seawater are estimated for microbial oxidation of methane from large polar clathrate destabilizations, which may arise in the coming century. Gas fluxes are taken from porous flow models of warming Arctic sediment. Plume spread parameters are then used to bracket the volume of dilution. Consumption stoichiometries for the marine methanotrophs are based on growth efficiency and elemental/enzyme composition data. The nutritional demand implied by extra CH4 removal is compared with supply in various high latitude water masses. For emissions sized to fit the shelf break, reaction potential begins at one hundred micromolar and falls to order ten a thousand kilometers downstream. Oxygen loss and carbon dioxide production are sufficient respectively to hypoxify and acidify poorly ventilated basins. Nitrogen and the monooxygenase transition metals may be depleted in some locations as well. Deprivation is implied relative to existing ecosystems, along with dispersal of the excess dissolved gas. Physical uncertainties are inherent in the clathrate abundance, patch size, outflow buoyancy and mixing rate. Microbial ecology is even less defined but may involve nutrient recycling and anaerobic oxidizers.
Effect of the solar wind proton entry into the deepest lunar wake
Authors: Nishino M. N. , Fujimoto M. , Saito Y. , Yokota S. , Kasahara Y. , Omura Y. , Goto Y. , Hashimoto K. , Kumamoto A. , Ono T. , Tsunakawa H. , Matsushima M. , Takahashi F. , Shibuya H. , Shimizu H. , Terasawa T.
Published: June 2010

We study effect of the solar wind (SW) proton entry deep into the near‐Moon wake that was recently discovered by the SELENE mission. Because previous lunar‐wake models are based on electron dominance, no effect of SW proton entry has been taken into account. We show that the type‐II entry of SW protons forms proton‐governed region (PGR) to drastically change the electromagnetic environment of the lunar wake. Broadband electrostatic noise found in the PGR is manifestation of electron two‐stream instability, which is attributed to the counter‐streaming electrons attracted from the ambient SW to maintain the quasi‐neutrality. Acceleration of the absorbed electrons up to ∼1 keV means a superabundance of positive charges of 10−5–10−7 cm−3 in the near‐Moon wake, which should be immediately canceled out by the incoming high‐speed electrons. This is a general phenomenon in the lunar wake, because PGR does not necessarily require peculiar SW conditions for its formation.
Sterol-regulatory-element-binding protein 1c mediates the effect of insulin on the expression of Cidea in mouse hepatocytes
Authors: Wang Rui , Kong Xingxing , Cui Anfang , Liu Xiaojun , Xiang Ruolan , Yang Yanli , Guan Youfei , Fang Fude , Chang Yongsheng
Published: June 2010

Members of the Cide [cell death-inducing DFFA (DNA fragmentation factor-α)-like effector] gene family have been reported to be associated with lipid metabolism. In the present study, we show that Cidea mRNA levels are markedly reduced by fasting and are restored upon refeeding in mouse livers. To elucidate the molecular mechanism, the promoter region of the mouse Cidea gene was analysed and a putative SRE (sterol-regulatory element) was identified. Studies using luciferase reporter constructs together with electrophoretic mobility-shift assays and chromatin immunoprecipitation confirmed the binding of SREBP-1c (SRE-binding protein 1c) to the putative SRE. Furthermore, adenovirus-mediated overexpression of SREBP-1c led to a dramatic increase in Cidea mRNA. In contrast with the induction of Cidea expression by insulin and TO901317 in wild-type mouse hepatocytes, the stimulatory effects were lost in hepatocytes prepared from SREBP-1c-null mice. Adenovirus-mediated overexpression of Cidea in hepatocytes promoted lipid accumulation and triacylglycerol (triglyceride) storage; however, knockdown of Cidea compromised the ability of SREBP-1c to stimulate lipid accumulation. Taken together, these results suggest that SREBP-1c directly mediates the effect of insulin on Cidea in hepatocytes and that Cidea, at least in part, mediates SREBP-1c-dependent lipid accumulation.
Prevalence and prognostic implications of active cytomegalovirus infection in patients with acute heart failure
Authors: Núñez Julio , Chilet Marifina , Sanchis Juan , Bodí Vicent , Núñez Eduardo , Miñana Gema , Tormo Nuria , Clari Maria A. , Pellicer Mauricio , Chorro Francisco J. , Llàcer Angel , Navarro David
Published: June 2010

AHF (acute heart failure) causes significant morbidity and mortality. Recent studies have postulated that the expression of inflammatory mediators, such as cytokines and chemokines, plays an important role in the development and progression of heart failure. A pro-inflammatory state has been postulated as a key factor in triggering CMV (cytomegalovirus) reactivation. Therefore we sought to determine the prevalence of active CMV infection in immunocompetent patients admitted for AHF and to quantify the association with the risk of the combined end point of death or AHF readmission. A total of 132 consecutive patients admitted for AHF were enrolled in the present study. Plasma CMV DNAaemia was assessed by qRT-PCR (quantitative real-time PCR), and cytokine measurements in plasma were performed by ELISA. Clinical data were evaluated by personnel blinded to CMV results. The independent association between active CMV infection and the end point was determined by Cox regression analysis. During a median follow-up of 120 [IQR (interquartile range), 60–240] days, 23 (17.4%) deaths, 34 (24.2%) readmissions for AHF and 45 (34.1%) deaths/readmissions for AHF were identified. Plasma CMV DNAaemia occurred in 11 (8.3%) patients, albeit at a low level (<100 copies/ml). The cumulative rate of the composite end point was higher in patients with CMV DNAaemia (81.8 compared with 29.8%; P<0.001). After adjusting for established risk factors, the occurrence of CMV DNAaemia was strongly associated with the clinical end point [hazard ratio = 4.39 (95% confidence interval, 2.02–9.52); P<0.001]. In conclusion, active CMV infection occurs, although uncommonly, in patients with AHF, and may be a marker of disease severity.
Modeling of the effective work function instability in metal/high-κ dielectric stacks
Authors: Fet A. , Häublein V. , Bauer A. J. , Ryssel H. , Frey L.
Published: June 2010

This paper discusses the effective work function instability in high-κ-based MOS gate stacks, which occurs after high temperature (1070 °C) processing. Theories which have been put forward to explain this effect are discussed and unified to a consistent phenomenological model. The Vfb roll-off effect is also discussed and can be described by the model.
Stability of the various crystallographic phases of the multiferroic (1−x)BiFeO3–xPbTiO3 system as a function of composition and temperature
Authors: Bhattacharjee Shuvrajyoti , Pandey Dhananjai
Published: June 2010

In this report, we have studied the stability of various crystallographic phases of (1−x)BiFeO3–xPbTiO3 as a function of composition and temperature. The structure of BF-xPT is reconfirmed to be tetragonal and monoclinic in the P4mm and Cc space groups for x>0.31 and 0.10≤x≤0.27, whereas the two phases coexist in the morphotropic phase boundary (MPB) region 0.27<x<0.31. A recent proposition of an orthorhombic phase in the MPB region has been ruled out comprehensively. From the high temperature powder x-ray diffraction (XRD) data it is shown that the MPB in this system is tilted towards the tetragonal side, a unique feature among the family of PbTiO3 based MPB systems. We have established accurately the room temperature phase diagram for this solid solution. By comparing the observed bond lengths between oxygen and other cations, obtained from Rietveld analysis of the room temperature powder XRD data with expected ionic bond lengths, we have shown that the very high c/a ratio in the tetragonal phase of this system is linked with the covalency effects for bonding between both A and B site cations with oxygen.
Measuring D(d,p)T fusion reactant energy spectra with Doppler shifted fusion products
Authors: Boris D. R. , Kulcinski G. L. , Santarius J. F. , Donovan D. C. , Piefer G. R.
Published: June 2010

Deuterium fusion reactant energy spectra have been measured using a diagnostic that records the Doppler shift imparted to charged particle fusion products of the D(d,p)T reaction by the center-of-mass velocity of the deuterium reactants. This diagnostic, known as the fusion ion Doppler shift diagnostic (FIDO) measures fast deuterium energy spectra in the inertial electrostatic confinement (IEC) experiment at the University of Wisconsin–Madison {Santarius et al. [Fusion Sci. Technol. 47, 1238 (2005)]}, a device to confine high energy light ions in a spherically symmetric, electrostatic potential well. This article details the first measurements of the fusion reactant energy spectra in an IEC device as well as the design and principles of operation of the FIDO diagnostic. Scaling of reactant energy spectra with a variety of experimental parameters have been explored.
Interaction between static magnetic islands and interchange modes in a straight heliotron plasma with high resistivity
Authors: Saito Kinya , Ichiguchi Katsuji , Ohyabu Nobuyoshi
Published: June 2010

Fundamental mechanism of the nonlinear interaction between static magnetic islands generated by an external field and a resistive interchange mode is investigated in a straight heliotron plasma with high resistivity by using a numerical method based on the reduced magnetohydrodynamics equations. The behavior of the magnetic islands is examined at the steady state after the nonlinear saturation of the interchange mode. The width and the phase of the magnetic islands are changed by the mode evolution. These changes are almost determined by the linear combination of the two perturbed poloidal magnetic fluxes, the flux imposed externally and the flux attributed to the interchange mode, in spite of the fact that the changes result from the nonlinear process. It is also obtained that the amount of the local change of the pressure at the resonant surface in the saturation state depends on the phase of the static magnetic islands.
Magnetic X-points, edge localized modes, and stochasticity
Authors: Sugiyama L. E. , Strauss H. R.
Published: June 2010

Edge localized modes (ELMs) near the boundary of a high temperature, magnetically confined toroidal plasma represent a new type of nonlinear magnetohydrodynamic (MHD) plasma instability that grows through a coherent plasma interaction with part of a chaotic magnetic field. Under perturbation, the freely moving magnetic boundary surface with an X-point splits into two different limiting asymptotic surfaces (manifolds), similar to the behavior of a hyperbolic saddle point in Hamiltonian dynamics. Numerical simulation using the extended MHD code M3D shows that field-aligned plasma instabilities, such as ballooning modes, can couple to the “unstable” manifold that forms helical, field-following lobes around the original surface. Large type I ELMs proceed in stages. Initially, a rapidly growing ballooning outburst involves the entire outboard side. Large plasma fingers grow well off the midplane, while low density regions penetrate deeply into the plasma. The magnetic field becomes superficially stochastic. A secondary inboard edge instability causes inboard plasma loss. The plasma gradually relaxes back toward axisymmetry, with diminishing cycles of edge instability. Poloidal rotation of the interior and edge plasma may be driven. The magnetic tangle constrains the early nonlinear ballooning, but may encourage the later inward penetration. Equilibrium toroidal rotation and two-fluid diamagnetic drifts have relatively small effects on a strong MHD instability. Intrinsic magnetic stochasticity may help explain the wide range of experimentally observed ELMs and ELM-free behavior in fusion plasmas, as well as properties of the H-mode and plasma edge.
Evidence of electron conductivity in polysilanes and its implications in design of ultraviolet emitting devices
Authors: Deepak  , Banerjee Niladri , Seki Shu
Published: June 2010

Polysilanes are thought to be primarily hole conducting. Consequently, poor efficiency of a polysilane based light emitting diode is explained on the basis of propensity of the charge carriers to nonradiatively recombine near the cathode. We fabricated a single layer device based on poly(n-octylphenylsilane) with a calcium cathode. This device, however, cannot be analyzed on the basis of a single carrier (hole) transport and the device, unexpectedly, exhibits an injection limited current, though no barrier to hole injection exists. Simulation based analysis reveals bipolar transport, with electron mobility much greater than the hole mobility. This now also makes polysilane electron transport layers possible. In addition, we establish that the time-of-flight measured mobilities in polysilanes may not be relevant to electronic devices, which employ much thinner layers. Based on these observations, the basis for device design is revised. Accordingly, a N, N-diphenyl-N, N-bis(1-naphthyl)(1,1-biphenyl)-4,4 diamine layer is inserted between the polysilane and cathode, in which a lowered electron injection barrier allows current to increase by ten times and electroluminescent quantum efficiency by eight times. Simulation of the current in the device shows that increase in current is originating from at least ten-fold increase in electron concentration. An alternative method employing bathocuproine for blocking holes, however, is not found useful in the case of polysilanes.
Evaluation of GeO desorption behavior in the metal/GeO2/Ge structure and its improvement of the electrical characteristics
Authors: Oniki Yusuke , Koumo Hideo , Iwazaki Yoshitaka , Ueno Tomo
Published: June 2010

The relation between germanium monoxide (GeO) desorption and either improvement or deterioration in electrical characteristics of metal/GeO2/Ge capacitors fabricated by thermal oxidation has been investigated. In the metal/GeO2/Ge stack, two processes of GeO desorption at different sites and at different temperatures were observed by thermal desorption spectroscopy measurements. The electrical characteristics of as-oxidized metal/GeO2/Ge capacitors shows a large flat-band voltage shift and minority carrier generation due to the GeO desorption from the GeO2/Ge interface during oxidation of Ge substrates. On the other hand, the electrical properties were drastically improved by a postmetallization annealing at low temperature resulting in a metal catalyzed GeO desorption from the top interface.
Self-compensation of optical damage in reduced nominally pure LiNbO3 crystals
Authors: Kostritskii S. M. , Aillerie M. , Sevostyanov O. G.
Published: June 2010

Optical damage dynamics was investigated in as-grown, chemically reduced and oxidized nominally pure LiNbO3, as well as in iron-doped LiNbO3 crystals. The self-arranged partial compensation of the optical damage for focused low-power 644-nm-laser beams was discovered in chemically reduced LiNbO3 crystals. During first stage of experiment, when the usual fast rise of the optical damage occurs, the transmitted power decreases from an initial to minimal value due to photorefractive defocusing, while the steady-state is achieved only after the long-term exposure, when a sequent slow increase in the transmitted power, indicating on self-compensation of the optical damage, is observed. It has been established, that this effect is caused by temperature gradient due to the inhomogeneous light-induced heating within small illuminated area of a bulk crystal. The electron–hole competition in photoinduced charge carriers transport upon influence of inhomogeneous temperature field, the secondary and tertiary pyroelectric effects are shown to be responsible for most important peculiarities of the self-compensation dynamics.
Magnetic metal cladding gives better attenuation in small waveguides operating at high microwave frequencies than nonmagnetic metals
Authors: Livesey K. L. , Camley R. E.
Published: June 2010

We calculate the attenuation in microwave waveguides comprising a thin film of dielectric SiO2 sandwiched by copper or iron films. We show that in a frequency range between roughly 63 and 73 GHz, using iron gives lower losses by up to 7.5 dB/cm compared with copper. This is in the region of so-called antiresonance where the effective skin depth of ferromagnetic iron diverges.
Effect of doping and counterdoping on high-pressure phase transitions of silicon
Authors: Guo J. J. , Pan D. , Yan X. Q. , Fujita T. , Chen M. W.
Published: June 2010

The influence of dopants and counterdopants on high-pressure phase transitions of silicon was investigated by high-pressure Raman microscopy. A small amount of dopants were found to dramatically influence the high pressure stability of silicon. The combination of doping and counterdoping provides an effective way to manipulate the critical pressures of the phase transitions, which offers unique insights on atomic mechanisms of high pressure phase transitions of Si.
Dispersal of suspended sediments and nutrients in the Great Barrier Reef lagoon during river-discharge events: conclusions from satellite remote sensing and concurrent flood-plume sampling
Authors: Brodie Jon , Schroeder Thomas , Rohde Ken , Faithful John , Masters Bronwyn , Dekker Arnold , Brando Vittorio , Maughan Mirjam
Published: June 2010

Intense wet-season rainfall in January 2005 caused rivers in the Mackay–Whitsunday region of Queensland, Australia, to produce large discharges to the Great Barrier Reef (GBR) lagoon. The regional land use is dominated by sugarcane cultivation, beef grazing and urban uses. The high nutrient (nitrogen and phosphorus) fluxes from these land uses via river runoff produced a massive phytoplankton bloom in the GBR lagoon, which, after 9 days, had spread 150 km offshore. The plume and algal bloom surrounded inner-shelf reefs of the GBR such as Brampton Island Reef and its spread was tracked with a variety of satellite sensors including MODIS, SeaWiFS and Landsat over the 9-day period. The ability to be able to access imagery from a large number of satellite sensors allowed almost daily estimates of the extent of plume to be made, despite periods of cloud. Analysis of water samples from the plume revealed elevated (2–50 times higher) concentrations of Chlorophyll a (and hence phytoplankton biomass), up to 50 times higher than in non-flood conditions, nutrients (2–100 times higher) and herbicide residues (10–100 times higher) compared with GBR lagoon waters in non-discharge conditions. The concentration data from the samples and estimated exposure periods from the satellite images allowed estimates of the exposure of GBR marine ecosystems (coral reefs, the pelagic community, seagrass beds and mangrove forests) to the terrestrial contaminants to be made.
Life history and reproduction of two abundant mysids (Mysidacea: Mysidae) in an intermittently open New Zealand estuary
Authors: Lill Adrian W. T. , Lal Aparna , Closs Gerard P.
Published: June 2010

Mysids typically form a large proportion of the hyperbenthic faunal biomass in estuaries and are central to the functioning of estuarine food webs. The population dynamics, annual life histories and reproductive effort of two common temperate estuarine mysids, Tenagomysis chiltoni and T. novae-zealandiae, are described in the intermittently open Kaikorai Lagoon, New Zealand. Mysids were sampled by night, monthly from September 2003 to September 2004. Both species completed their life cycles in the lagoon. There was an apparent spatial separation of breeding populations, with T. chiltoni prevalent in the upper lagoon and T. novae-zealandiae dominating the lower lagoon. Densities were lowest in late winter and peaked in late summer/early autumn for both species. Both species exhibited multivoltine life cycles, with breeding peaks occurring in October 2003, December 2003 and February/March 2004 for T. novae-zealandiae, and October/November 2003 and February/March 2004 for T. chiltoni. Breeding strategy for both species varied over the year with the adult size, brood size and the reproductive effort of both T. novae-zealandiae and T. chiltoni all being highest in spring. The life histories of both T. novae-zealandiae and T. chiltoni in the Kaikorai Lagoon are comparable to life histories described for other temperate estuarine mysid species in large open estuaries, and were not significantly modified to cope with the unpredictable demands of life in an intermittent estuary.
Fish and sessile assemblages associated with wind-turbine constructions in the Baltic Sea
Authors: Andersson Mathias H. , Öhman Marcus C.
Published: June 2010

Offshore wind farms are being built at a high rate around the world to meet the demand for renewable energy. We studied fish and sessile communities on and around offshore wind-turbine foundations in the southern Baltic Sea, 7 years after construction, using visual census techniques to determine how fish, sessile-invertebrate and algal communities are affected by the introduction of such structures. Fish assemblages were dominated by two-spotted gobies (Gobiusculus flavescens) that were found in large shoals in close association with the vertical surface. At the seabed, close to the foundation, the black goby (Gobius niger) was recorded in large numbers. The most obvious difference in fish densities was found between wind-power foundations extending through the entire water column and the surrounding open waters. Fouling assemblages on the vertical foundation surfaces and at the seabed just below differed from those at the seabed further away by having higher coverage of blue mussel (Mytilus edulis) and less algal growth. The results from the present study suggest that the introduction of offshore wind turbines in marine waters could have a positive effect on fish numbers and the presence of sessile invertebrates.
Fish dispersal in a seasonal wetland: influence of anthropogenic structures
Authors: Hohausová Eva , Lavoy Richard J. , Allen Micheal S.
Published: June 2010

Knowledge of fish dispersal routes when exploiting temporary habitat is important for understanding the ecology of species and for designing and conducting conservation and land-management activities. We evaluated fish dispersal in a network of seasonal habitats and a permanent fish source (a lake) in a subtropical wetland, in Florida, sampled biweekly from May 2002 to May 2003. Fish dispersal routes were influenced by (1) local physical conditions, (2) anthropogenic alterations and (3) fish species and size. Fish from the source dispersed into 9 of the 25 seasonal sites evaluated, via temporarily formed dispersal corridors between the source and the sites. Low connection depths along the corridors were a key factor, allowing small-bodied species (e.g. Gambusia holbrooki, Elassoma evergladei) to travel farther than large-bodied fish (e.g. Erimyzon sucetta, Lepomis macrochirus). Fish travelled distances of 0.7–4 km. Anthropogenic structures both enhanced (ditches, sand roads) and blocked (a railroad, soil dumps) fish dispersal routes. We demonstrated extensive opportunistic use by fish of seasonal wetlands. Our results indicated that anthropogenic alterations to the landscape can provide habitat for native fish and also allow dispersal of non-native fish and thus should be implemented with care.
Using DNA barcodes to connect adults and early life stages of marine fishes from the Yucatan Peninsula, Mexico: potential in fisheries management
Authors: Valdez-Moreno Martha , Vásquez-Yeomans Lourdes , Elías-Gutiérrez Manuel , Ivanova Natalia V. , Hebert Paul D. N.
Published: June 2010

Barcoding has proven a useful tool in the rapid identification of all life stages of fish species. Such information is of critical importance for fisheries management and conservation, especially in high-diversity regions, such as Mexico’s marine waters, where more than 2200 species occur. The present study reports the barcode analysis of 1392 specimens from the Yucatan Peninsula, corresponding to 610 adults and juveniles, 757 larvae and 25 eggs, representing 181 species (179 teleosts and 2 rays), 136 genera and 74 families. Barcoding results revealed major range extensions and overlooked taxa, including three sympatric species of Albula (one likely undescribed) and a new taxon of Floridichthys. In total, six species of eggs and 34 species of larvae were identified through their barcode match with adults. These cases enabled the first discrimination of the larvae of four species of Eucinostomus, and new information about spawning locality and time was obtained from egg records for the hogfish, Lachnolaimus maximus, which is one of the most commercially important species in the Mexican Caribbean. Also, barcodes revealed mistakes in species recognition during a sport-fish contest. In the future, barcodes will help avoid similar errors and protect rare or endangered species, and will aid regulation of fisheries quotas.
Variability of epifaunal assemblages associated with native and invasive macroalgae
Authors: Gestoso Ignacio , Olabarria Celia , Troncoso Jesús S.
Published: June 2010

Marine macroalgae harbour abundant and diverse assemblages of epifauna. Patterns of distribution and abundance of epifauna, which are often variable in space and time, differ markedly among macroalgae species. Non-indigenous seaweeds may alter composition and structure of epifaunal assemblages and therefore harbour different assemblages from those associated with native macroalgae. In this study, we analysed the epifaunal assemblages associated with the native algae Bifurcaria bifurcata and the invasive alga Sargassum muticum on the southern part of the Galician coast (north-west Spain). In particular, we tested the hypothesis that there were differences in the epifaunal assemblages associated with the native and invasive algae. We used a hierarchical spatial sampling design to identify if these differences were consistent over space and time. Results indicated that there were significant differences between epifaunal assemblages associated with both algae. The fact that such differences were, in general, consistent at different spatial scales suggests that biological factors related to the specific habitat might play a more important role than physical factors as determinants of epifaunal distribution. This study also showed that S. muticum seems to supply a new and additional habitat for the native epifauna, contributing to increases in the spatial and temporal variability of epifaunal assemblages.
Cerebral cavernous malformation protein CCM1 inhibits sprouting angiogenesis by activating DELTA-NOTCH signaling
Authors: Wüstehube Joycelyn , Bartol Arne , Liebler Sven S. , Brütsch René , Zhu Yuan , Felbor Ute , Sure Ulrich , Augustin Hellmut G. , Fischer Andreas
Published: June 2010

Cerebral cavernous malformations (CCM) are frequent vascular abnormalities caused by mutations in one of the
CCM
genes. CCM1 (also known as KRIT1) stabilizes endothelial junctions and is essential for vascular morphogenesis in mouse embryos. However, cellular functions of CCM1 during the early steps of the CCM pathogenesis remain unknown. We show here that CCM1 represents an antiangiogenic protein to keep the human endothelium quiescent. CCM1 inhibits endothelial proliferation, apoptosis, migration, lumen formation, and sprouting angiogenesis in primary human endothelial cells. CCM1 strongly induces DLL4-NOTCH signaling, which promotes AKT phosphorylation but reduces phosphorylation of the mitogen-activated protein kinase ERK. Consistently, blocking of NOTCH activity alleviates CCM1 effects. ERK phosphorylation is increased in human CCM lesions. Transplantation of CCM1-silenced human endothelial cells into SCID mice recapitulates hallmarks of the CCM pathology and serves as a unique CCM model system. In this setting, the multikinase inhibitor Sorafenib can ameliorate loss of CCM1-induced excessive microvascular growth, reducing the microvessel density to levels of normal wild-type endothelial cells. Collectively, our data suggest that the origin of CCM lesions is caused by perturbed Notch signaling-induced excessive capillary sprouting, which can be therapeutically targeted.
Anderson localization makes adiabatic quantum optimization fail
Authors: Altshuler Boris , Krovi Hari , Roland Jérémie
Published: June 2010

Understanding NP-complete problems is a central topic in computer science (NP stands for nondeterministic polynomial time). This is why adiabatic quantum optimization has attracted so much attention, as it provided a new approach to tackle NP-complete problems using a quantum computer. The efficiency of this approach is limited by small spectral gaps between the ground and excited states of the quantum computer’s Hamiltonian. We show that the statistics of the gaps can be analyzed in a novel way, borrowed from the study of quantum disordered systems in statistical mechanics. It turns out that due to a phenomenon similar to Anderson localization, exponentially small gaps appear close to the end of the adiabatic algorithm for large random instances of NP-complete problems. This implies that unfortunately, adiabatic quantum optimization fails: The system gets trapped in one of the numerous local minima.
“Yugoslavia in 1989 and after”: a comment
Authors: Kanin David B.
Published: June 2010

V.P. (Chip) Gagnon, Jr. (2004, 2010) has provided a useful corrective to what he has called the “Myth of Ethnic War,” the notion that what was Yugoslavia was torn apart by primeval communal hatreds. He is not alone in this. Maria Todorova's variation on Edward Said's “Orientalism” take on the same question, and edited volumes put together by Dušan Bjelić and Obrad Savić and by Raymond Detrez and Pieter Plas have also attacked the problem posed when public intellectuals and politicians paint a crude caricature of Balkan history. The readers of this journal no doubt have their own favorites when it comes to the sport of bashing this particular myth.
Repetition Priming across Distinct Contexts: Effects of Lexical Status, Word Frequency, and Retrieval Test
Authors: Coane Jennifer H. , Balota David A.
Published: June 2010

Repetition priming, the facilitation observed when a target is preceded by an identity prime, is a robust phenomenon that occurs across a variety of conditions. Oliphant (1983), however, failed to observe repetition priming for targets embedded in the instructions to an experiment in a subsequent lexical decision task. In the present experiments, we examined the roles of priming context (list or instructions), target lexicality, and target frequency in both lexical decision and episodic recognition performance. Initial encoding context did not modulate priming in lexical decision or recognition memory for low-frequency targets or nonwords, whereas context strongly modulated episodic recognition for high-frequency targets. The results indicate that priming across contexts is sensitive to the distinctiveness of the trace and the reliance on episodic retrieval mechanisms. These results also shed light on the influence of event boundaries, such that priming occurs across different events for relatively distinct (low-frequency) items.
Cognitive Control in Cued Task Switching with Transition Cues: Cue Processing, Task Processing, and Cue–Task Transition Congruency
Authors: Van Loy Björn , Liefooghe Baptist , Vandierendonck André
Published: June 2010

We investigated the processes underlying performance during cued task switching with transition cues. To this end, transition cueing and explicit cueing were compared in a design controlling for sequential effects in the two preceding trials in order to further examine the contribution of cue processes, task processes, and cue–task transition congruency during transition cueing. The study confirmed that the task-switch cost in transition cueing is larger than the task-switch cost in explicit cueing and showed that this larger switch cost is mainly due to cue processing. We also successfully decomposed performance in transition cueing into cue processing, task processing, and cue–task transition congruency on both a theoretical (Experiment 1) and an empirical basis (Experiments 2–3). Our empirical dissociation also demonstrates that cue–task transition congruency affects performance during both cue processing and task processing. We discuss the importance of our findings in relation to the different theories on task switching.
The HPV Vaccination Strategy: Could Male Vaccination Have a Significant Impact?
Authors: Brown V. , White K. A. J.
Published: June 2010

We investigate the potential success of the human papilloma virus (HPV) vaccine, taking into consideration possible waning immunity and the influence of behavioural parameters. We use a compartmental, population‐level ordinary differential equation (ODE) model. We find the effective reproductive value for HPV, , which measures the threshold for infection outbreak in a population that is not entirely susceptible, together with infection prevalence. We study the effects of different parameters on both of these quantities. Results show that waning immunity plays a large part in allowing infection to persist. The proportion of the population not sexually active when vaccination occurs affects , as does the rate at which individuals become sexually active. In several cases, infection persists as a result of an infection reservoir in the male cohort. To explore this further, we introduce male vaccination and find the conditions for which vaccination of males could be considered appropriate.
Multiscale Estimation of Cell Kinetics
Authors: Jean Larry W. , Suchorolski Martin T. , Jeon Jihyoun , Luebeck E. Georg
Published: June 2010

We introduce a methodology based on the Luria–Delbrück fluctuation model for estimating the cell kinetics of clonally expanding populations. In particular, this approach allows estimation of the net cell proliferation rate, the extinction coefficient and the initial (viable) population size. We present a systematic approach based on spatial partitioning, which captures the local fluctuations of the number and sizes of individual clones. However, partitioning introduces measurement error by inflating the number of clones, which is dependent on time and the degree of cell migration. We perform various in silico experiments to explore the properties of the estimators and we show that there exists a direct relationship between precision and observation time. We also explore the trade‐off between the measurement error and the estimation accuracy. By exploring different scales of cellular fluctuations, from the entire population down to those of individual clones, we show that this methodology is useful for inferring important parameters in neoplastic progression.
“A Constitutional Conveyance of Intelligence, Public and Private”: The Post Office, the Business of Printing, and the American Revolution
Authors: Adelman Joseph M.
Published: June 2010

This essay argues that American printers motivated by a deep commercial interest in fast and effective communication worked to overturn the British imperial postal service in 1774 and 1775. Printers enlisted merchants and members of the revolutionary elite, who also relied on long-distance communication through the post office for their own commercial and political purposes, to provide financial and political support. In making their case, printers mobilized a broad array of political ideology and imagery already familiar to colonists during the decade-long imperial crisis, emphasizing the political necessity of replacing the imperial institution. At the same time, they uncontroversially asserted that a new American post office would safeguard their precarious commercial ventures. The essay therefore demonstrates that printers were not “mere mechanics” but actively shaped the political debates leading to the American Revolution as part of a process that scholars have recently highlighted in a work on the economic and commercial influences on the Revolution. Furthermore, it grants the post office its due as part of the Habermasian public sphere; although understudied, the post office—both as a physical space and as a network through which information could travel—was a crucial means by which Americans developed a national infrastructure for political communications. Exploring the overthrow of the British post office, and the creation of an American post office, reveals an understudied but crucial episode to explain the symbiosis between politics and commerce during the American Revolutionary era.
Aetiological factors contributing to the development of primary laryngeal aspergillosis in immunocompetent patients
Authors: Liu Yong-Cai , Zhou Shui-Hong , Ling Ling
Published: June 2010

Primary laryngeal aspergillosis is extremely rare, especially in an immunocompetent host. It is commonly found as part of a systemic infection involving the respiratory system in immunocompromised people. Two cases of laryngeal aspergillosis with no systemic extension and no generalized immune deficiency are presented here. We report what is to the best of our knowledge only the second case of Aspergillus infection in a vocal cord cyst. Aspergillus species were identified in tissue sections and confirmed by PCR studies. We present a literature review of laryngeal aspergillosis cases and discuss predisposing factors, clinical presentation, histopathology, PCR, diagnosis and treatment of Aspergillus laryngitis. The known aetiological causes of the disease are increasing and include iatrogenic factors, vocal abuse, vocal-fold cysts and occupational factors, and immunocompetent patients are susceptible to these predisposing factors.
Phylogeographical particularity of the Mycobacterium tuberculosis Beijing family in South Korea based on international comparison with surrounding countries
Authors: Kang Hee Yoon , Wada Takayuki , Iwamoto Tomotada , Maeda Shinji , Murase Yoshiro , Kato Seiya , Kim Hee Jin , Park Young Kil
Published: June 2010

To understand the domestic population structure ofMycobacterium tuberculosisclinical isolates in the Republic of Korea, we genotypically analysed 80 isolates obtained from various geographical origins in the country. Of these, 64 (80.0 %) isolates were identified as Beijing family strains. It is particularly interesting that their phylogenetic classification, based on the ancient/modern separation and the presence/absence of the genomic region RD181, revealed a majority of the ancient (RD181+) subfamily in the population. The 15 loci of variable number of tandem repeat(s) of mycobacterial interspersed repetitive units (15-MIRU-VNTR) were also analysed. Combination with the previous VNTR data reported from surrounding countries revealed that the topology of the minimum spanning tree was linked tightly not to the geographical origins of the patients but to the phylogenetic characteristics of the isolates. These results show that the phylogeographical distribution of theM. tuberculosisBeijing family around far-eastern Asia could be estimated using international accumulation and comparison of VNTR genotyping data.
Identification of a bacterial di-haem cytochrome c peroxidase from Methylomicrobium album BG8
Authors: Karlsen O. A. , Larsen Ø. , Jensen H. B.
Published: June 2010

The nucleotide sequence of an open reading frame (corB) downstream of the copper-repressible CorA-encoding gene of the methanotrophic bacterium Methylomicrobium album BG8 was obtained by restriction enzyme digestion and inverse PCR. The amino acid sequence deduced from this gene showed significant sequence similarity to the surface-associated di-haem cytochrome c peroxidase (SACCP) previously isolated from Methylococcus capsulatus (Bath), including both c-type haem-binding motifs. Homology analysis placed this protein, phylogenetically, within the subfamily containing the M. capsulatus SACCP of the bacterial di-haem cytochrome c peroxidase (BCCP) family of proteins. Immunospecific recognition confirmed synthesis of the M. album CorB as a protein non-covalently associated with the outer membrane and exposed to the periplasm. corB expression is regulated by the availability of copper ions during growth and the protein is most abundant in M. album when grown at a low copper-to-biomass ratio, indicating an important physiological role of CorB under these growth conditions. corB was co-transcribed with the gene encoding CorA, constituting a copper-responding operon, which appears to be under the control of a σ
54-dependent promoter. M. album CorB is the second isolated member of the recently described subfamily of the BCCP family of proteins. So far, these proteins have only been described in methanotrophic bacteria.
Identification of bistable populations of Porphyromonas gingivalis that differ in epithelial cell invasion
Authors: Suwannakul S. , Stafford G. P. , Whawell S. A. , Douglas C. W. I.
Published: June 2010

Bistable populations of bacteria give rise to two or more subtypes that exhibit different phenotypes. We have explored whether the periodontal pathogen Porphyromonas gingivalis exhibits bistable invasive phenotypes. Using a modified cell invasion assay, we show for the first time that there are two distinct subtypes within a population of P. gingivalis strains NCTC 11834 and W50 that display differences in their ability to invade oral epithelial cells. The highly invasive subtype invades cells at 10–30-fold higher levels than the poorly invasive subtype and remains highly invasive for approximately 12–16 generations. Analysis of the gingipain activity of these subtypes revealed that the highly invasive type had reduced cell-associated arginine-specific protease activity. The role of Arg-gingipain activity in invasion was verified by enhancement of invasion by rgpAB mutations and by inclusion of an Arg-gingipain inhibitor in invasion assays using wild-type bacteria. In addition, a population of ΔrgpAB bacteria did not contain a hyperinvasive subtype. Screening of the protease activity of wild-type populations of both strains identified high and low protease subtypes which also showed a corresponding reduction or enhancement, respectively, of invasive capabilities. Microarray analysis of these bistable populations revealed a putative signature set of genes that includes oxidative stress resistance and iron transport genes, and which might be critical to invasion of or survival within epithelial cells.