bluuebunny/crossref_metadata_2025 huggingface dataset:
Framing and Claiming: Contemporary Globalization and “Going Out” in China's Rhetoric towards Latin America
Authors: Strauss Julia C.
Published: March 2012

China's increasing, and increasingly visible, engagement in Latin America has led to a variety of analyses, many based on either international relations notions of realism or international political economy precepts of trade. Rather than seeing China's rhetoric on its relations with Latin America as fluff that conceals a harder reality, this article takes rhetoric seriously as a device of “framing and claiming”: a way in which political elites in China interpret the fast-changing developing world and China's place in it. The article explores how political elites have understood the sources of China's own domestic development and then projected those notions on to other parts of the developing world, through earlier “fractal” logics of development whereby each state repeats one model of development in its own way and a currently dominant “division of labour” logic that posits one integrated model of development whereby complementarity and comparative advantage hold sway. The article concludes with a comparison of China's relations with Peru and Brazil, suggesting that China's bilateral relations with Brazil indicate a newer, emerging rhetoric of global partnership based on equality.
Great Men and Large Numbers: Undertheorising a History of Mass Killing
Authors: KÜHNE THOMAS
Published: March 2012

Scholarship is not only about gaining new insights or establishing accurate knowledge but also about struggling for political impact and for market shares – shares of public or private funds, of academic jobs, of quotations by peers, and of media performances. Timothy Snyder'sBloodlandsfights for recentring contemporary European history.1No longer, his new book implies, should the centre of that history be Germany, which initiated two world wars and engaged with three genocides; even less should the centre be Western Europe, which historians for long have glorified as the trendsetter of modernity; and the Soviet Union, or Russia, does not qualify as ‘centre’ anyway. Introducing ‘to European history its central event’ (p. 380) means to focus on the eastern territories of Europe, the landsbetweenGermany and Russia, which, according to Snyder, suffered more than any other part from systematic, politically motivated, mass murder in the twentieth century. The superior victimhood of the ‘bloodlands’ is a numerical one. Fourteen million people, Jewish and non-Jewish, in the territories of what is today most of Poland, the Ukraine, Belarus, western Russia, and the Baltic States did not become just casualties of war but victims of deliberate mass murder. Indeed, this is ‘a very large number’ (p. 411), one that stands many comparisons: ten million people perished in Soviet and German concentration camps (as opposed to the Nazi death camps, which were located within the ‘bloodlands’), 165,000 German Jews died during the Holocaust (p. ix), and even the number of war casualties most single countries or territories counted in the Second World War was smaller.
The Establishment of Bolshevik Power in the Crimea and the Construction of a Multinational Soviet State: Organisation, Justification, Uncertainties
Authors: DUFAUD GRÉGORY
Published: March 2012

The autonomous Soviet republic of the Crimea was established in October 1921 as part of the Russian Federative Republic. A few months later came the announcement that the new republic was to be ‘tatarised’, in accordance with a policy which was already being implemented in other territories but which was not systematised, in the form of ‘indigenisation’, until 1923. This article examines how the Bolsheviks imposed their authority in the Crimea. It analyses the dealings and negotiations among the principal actors in both Moscow and the Crimea, and traces the establishment of rules and agreements. It also examines the uncertainties and anxieties that troubled the Crimean Communist Party when the enthusiasm of some Crimean communists for indigenisation rapidly led to suspicions of nationalism. This article, written from the periphery, throws light on the construction of a multinational Soviet state by focusing on the actors and their actions.
Velocity dependence of shear‐induced permeability associated with frictional behavior in fault zones of the Nankai subduction zone
Authors: Tanikawa Wataru , Mukoyoshi Hideki , Tadai Osamu , Hirose Takehiro , Tsutsumi Akito , Lin Weiren
Published: March 2012

We measured frictional properties and permeability of core materials from the megasplay fault zone (site C0004) and the frontal thrust (site C0007) in the shallow part of the Nankai subduction zone. Permeability was measured before and after 7.9 m slip displacement at high (1.05 m/s) and low velocities (0.013 m/s) under normal stresses of 1.5 MPa using the rotary‐shear apparatus, from which we estimated the shear‐induced permeability change in an experimental fault gouge prepared from core material. Gouge permeability (10−18 m2) decreased after sliding for wet gouge and increased for dry gouge. The high‐velocity friction test under wet conditions yielded a smaller reduction in permeability than the low‐velocity test, whereas the opposite trend was observed in dry conditions. We attribute the differences in permeability to the effects of thermal/mechanical pore pressurization upon shear‐induced compaction. Symmetric boudin structures may represent evidence of hydrofracturing induced by pore fluid pressurization. The large friction coefficient of the megasplay fault material in the slow and wet friction tests is explained by homogeneous shear deformation and higher permeability that promotes faster shear‐induced compaction. The similarity in post‐shear permeability for the gouges from the both faults may account for the similar friction coefficients in high‐velocity friction, assuming that the pore fluid pressurization process controls high‐velocity frictional behavior. This velocity dependence on friction suggests that a large dynamic stress drop is expected for the megasplay fault, implying that large slip displacement followed by a giant tsunami is plausible when a rupture from depth propagates to the megasplay fault.
Shallow oceanic crust: Full waveform tomographic images of the seismic layer 2A/2B boundary
Authors: Christeson Gail L. , Morgan Joanna V. , Warner Michael R.
Published: March 2012

We present results of full‐waveform tomographic inversions of four profiles acquired over young intermediate‐ and fast spreading rate oceanic crust. The mean velocity‐depth functions from our study include a 0.25–0.30 km‐thick low‐velocity, low‐gradient region beneath the seafloor overlying a 0.24–0.28‐km‐thick high‐gradient region; together these regions compose seismic layer 2A. Mean layer 2A interval velocities are 3.0–3.2 km/s. The mean depth to the layer 2A/2B boundary is 0.49–0.54 km, and mean velocities within the upper 0.25 km of layer 2B are 4.7–4.9 km/s. Previous velocity analyses of the study areas using 1‐D ray tracing underestimate the thickness of the high‐gradient region at the base of layer 2A. We observe differences in the waveform inversion velocity models that correspond to imaging of the layer 2A event; regions with a layer 2A event have higher velocity gradients at the base of layer 2A. Intermittent high velocities, which we interpret as massive flows, are observed in the waveform inversion velocity models at 0.05–0.10 km below the seafloor (bsf) over 10–25% of the intermediate‐spreading profiles and 20–45% of the fast spreading profiles. The high‐gradient region located 0.25–0.54 km bsf at the base of layer 2A may be associated with an increased prevalence of massive flows, the first appearance of dikes (lava‐dike transition zone), or with increased crack sealing by hydrothermal products. The upper portion of layer 2B, which begins at 0.49–0.54 km bsf, may correspond to sheeted dikes or the top of the transition zone of lavas and dikes.
Upper‐mantle earthquakes beneath the Arafura Sea and south Aru Trough: Implications for continental rheology
Authors: Sloan R. A. , Jackson J. A.
Published: March 2012

The extent and controls of long‐term elastic strength and seismicity in the upper continental lithospheric mantle (UCLM) are controversial topics in continental tectonics. One key issue is the scarcity of UCLM earthquakes, even where the UCLM is likely to be colder than 600°C. The rarity of these earthquakes could be because the UCLM generally relatively hydrous causing it to deform aseismically even when colder than 600°C, unless it is deforming at exceptionally high strain rates. Alternatively, the UCLM could be relatively anhydrous, and potentially seismogenic at temperatures below 600°C; in which case the rarity of UCLM earthquakes may be because areas where the UCLM is colder than 600°C have such a thick seismogenic layer, and such a cool mantle root, that they deform exceptionally slowly. The identification and study of UCLM earthquakes allows us to distinguish between these possibilities. Here we show that two earthquakes occurred in the UCLM beneath the epicontinental Arafura Sea. Both earthquakes occurred where the UCLM is probably cooler than 600°C and one of these earthquakes lies ∼25 km below the Moho in an region where there is no evidence of unusually high strain rates. There at least, it is probable that the UCLM is relatively anhydrous, and seismogenic at temperatures below 600°C. We also find evidence that regions where the UCLM is colder than 600°C also have a seismogenic lower crust. This results in a single, extremely strong layer comprising the entire crust and the UCLM down to the 600°C isotherm.
Tidal triggering of low frequency earthquakes near Parkfield, California: Implications for fault mechanics within the brittle‐ductile transition
Authors: Thomas A. M. , Bürgmann R. , Shelly D. R. , Beeler N. M. , Rudolph M. L.
Published: March 2012

Studies of nonvolcanic tremor (NVT) have established the significant impact of small stress perturbations on NVT generation. Here we analyze the influence of the solid earth and ocean tides on a catalog of ∼550,000 low frequency earthquakes (LFEs) distributed along a 150 km section of the San Andreas Fault centered at Parkfield. LFE families are identified in the NVT data on the basis of waveform similarity and are thought to represent small, effectively co‐located earthquakes occurring on brittle asperities on an otherwise aseismic fault at depths of 16 to 30 km. We calculate the sensitivity of each of these 88 LFE families to the tidally induced right‐lateral shear stress (RLSS), fault‐normal stress (FNS), and their time derivatives and use the hypocentral locations of each family to map the spatial variability of this sensitivity. LFE occurrence is most strongly modulated by fluctuations in shear stress, with the majority of families demonstrating a correlation with RLSS at the 99% confidence level or above. Producing the observed LFE rate modulation in response to shear stress perturbations requires low effective stress in the LFE source region. There are substantial lateral and vertical variations in tidal shear stress sensitivity, which we interpret to reflect spatial variation in source region properties, such as friction and pore fluid pressure. Additionally, we find that highly episodic, shallow LFE families are generally less correlated with tidal stresses than their deeper, continuously active counterparts. The majority of families have weaker or insignificant correlation with positive (tensile) FNS. Two groups of families demonstrate a stronger correlation with fault‐normal tension to the north and with compression to the south of Parkfield. The families that correlate with fault‐normal clamping coincide with a releasing right bend in the surface fault trace and the LFE locations, suggesting that the San Andreas remains localized and contiguous down to near the base of the crust. The deep families that have high sensitivity to both shear and tensile normal stress perturbations may be indicative of an increase in effective fault contact area with depth. Synthesizing our observations with those of other LFE‐hosting localities will help to develop a comprehensive understanding of transient fault slip below the “seismogenic zone” by providing constraints on parameters in physical models of slow slip and LFEs.
‘Candidatus Thermochlorobacter aerophilum:’ an aerobic chlorophotoheterotrophic member of the phylum Chlorobi defined by metagenomics and metatranscriptomics
Authors: Liu Zhenfeng , Klatt Christian G , Ludwig Marcus , Rusch Douglas B , Jensen Sheila I , Kühl Michael , Ward David M , Bryant Donald A
Published: March 2012

An uncultured member of the phylum Chlorobi, provisionally named ‘Candidatus Thermochlorobacter aerophilum’, occurs in the microbial mats of alkaline siliceous hot springs at the Yellowstone National Park. ‘Ca. T. aerophilum’ was investigated through metagenomic and metatranscriptomic approaches. ‘Ca. T. aerophilum’ is a member of a novel, family-level lineage of Chlorobi, a chlorophototroph that synthesizes type-1 reaction centers and chlorosomes similar to cultivated relatives among the green sulfur bacteria, but is otherwise very different physiologically. ‘Ca. T. aerophilum’ is proposed to be an aerobic photoheterotroph that cannot oxidize sulfur compounds, cannot fix N2, and does not fix CO2 autotrophically. Metagenomic analyses suggest that ‘Ca. T. aerophilum’ depends on other mat organisms for fixed carbon and nitrogen, several amino acids, and other important nutrients. The failure to detect bchU suggests that ‘Ca. T. aerophilum’ synthesizes bacteriochlorophyll (BChl) d, and thus it occupies a different ecological niche than other chlorosome-containing chlorophototrophs in the mat. Transcription profiling throughout a diel cycle revealed distinctive gene expression patterns. Although ‘Ca. T. aerophilum’ probably photoassimilates organic carbon sources and synthesizes most of its cell materials during the day, it mainly transcribes genes for BChl synthesis during late afternoon and early morning, and it synthesizes and assembles its photosynthetic apparatus during the night.
Spatial and temporal dynamics of the microbial community in the Hanford unconfined aquifer
Authors: Lin Xueju , McKinley James , Resch Charles T , Kaluzny Rachael , Lauber Christian L , Fredrickson James , Knight Rob , Konopka Allan
Published: March 2012

Pyrosequencing analysis of 16S rRNA genes was used to study temporal dynamics of groundwater bacteria and archaea over 10 months within three well clusters separated by ∼30 m and located 250 m from the Columbia River on the Hanford Site, WA. Each cluster contained three wells screened at different depths ranging from 10 to 17 m that differed in hydraulic conductivities. Representative samples were selected for analyses of prokaryotic 16S and eukaryotic 18S rRNA gene copy numbers. Temporal changes in community composition occurred in all nine wells over the 10-month sampling period. However, there were particularly strong effects near the top of the water table when the seasonal rise in the Columbia River caused river water intrusion at the top of the aquifer. The occurrence and disappearance of some microbial assemblages (such as Actinobacteria ACK-M1) were correlated with river water intrusion. This seasonal impact on microbial community structure was greater in the shallow saturated zone than deeper zone in the aquifer. Spatial and temporal patterns for several 16S rRNA gene operational taxonomic units associated with particular physiological functions (for example, methane oxidizers and metal reducers) suggests dynamic changes in fluxes of electron donors and acceptors over an annual cycle. In addition, temporal dynamics in eukaryotic 18S rRNA gene copies and the dominance of protozoa in 18S clone libraries suggest that bacterial community dynamics could be affected not only by the physical and chemical environment but also by top-down biological control.
Embryo losses in sheep during short-term nutritional supplementation
Authors: Viñoles C. , Glover K. M. M. , Paganoni B. L. , Milton J. T. B. , Martin G. B.
Published: March 2012

To test whether a nutritional supplement fed from 6 days before until 15 days after insemination reduces progesterone concentrations and increases embryo losses, Merino ewes were artificially inseminated (Day 0). Control ewes (n = 116) were not supplemented whereas Lupin6 ewes (n = 112) were supplemented with 500 g lupin grain daily for 6 days before insemination, and Lupin6+15 ewes (n = 122) from 6 days before until 15 days after insemination. There were no major differences between treatment groups in progesterone concentrations over the first 17 days of pregnancy. Embryo losses over Days 10–17 were lower in the Lupin6+15 than in the Control and Lupin6 groups, but the opposite occurred from Day 17–30. The concentrations of insulin and IGF-I were higher in Lupin6+15 ewes on Days 5, 12 and 17, compared with Lupin6 and Control ewes, while leptin concentrations decreased by Day 17 in the Lupin6+15 group. We conclude that feeding ewes for 15 days after mating improved embryo survival, which was associated with an increase in the concentrations of metabolic hormones and lower progesterone concentrations. However, the decrease in leptin concentrations promoted by the interruption of supplementation seems be linked to increased embryo mortality up to Day 30.
Global dimming and brightening - evidence and agricultural implications.
Authors: Wild M. , Roesch A. , Ammann C.
Published: March 2012

There is growing observational evidence that the level of sunlight received at the Earth's surface is not stable over the years but undergoes substantial decadal changes. These changes, known popularly as global dimming and brightening, are related to anthropogenic air pollution, as well as changes for cloudiness. Here, we summarize the evidence and discuss the implications of these variations in biospheric growth in general and agricultural applications in particular. Emphasis is placed on implications for forest canopies, grassland and agricultural crop production. Yet not only the total amount of sunlight that the biosphere receives is important but also the relative portion of the direct and diffuse light. Increasing air pollution and cloudiness can alter this partitioning towards a higher relative portion of diffuse light, in addition to a reduction in the total amount of sunlight. This diffuse light can enhance photosynthesis, particularly in tall and dense vegetation canopies, as it is distributed more effectively within the canopy compared with direct solar radiation, which is only accessible to the outermost (sunlit) layers. Here, we conclude that the growth of tall canopies such as forests or crop fields may be favoured under global dimming conditions owing to the enhanced diffuse light, despite the overall reduction in the total amount of sunlight. On the other hand, under the same dimming conditions, the yield of grassland, with its shallow open canopy, may be reduced, as it has little benefit from the enhanced diffuse fraction, while suffering from a loss in the total amount of sunlight for photosynthesis. Variations in solar radiation therefore may have largely varying effects on agricultural production depending on the structure of the crop canopy.
Estimation of Tag Shedding and Reporting Rates for Lake Erie Jaw-Tagged Walleyes
Authors: Vandergoot Christopher S. , Brenden Travis O. , Thomas Michael V. , Einhouse Donald W. , Cook H. Andrew , Turner Mark W.
Published: March 2012

Since 1990, walleyes Sander vitreus in Lake Erie have been tagged annually with jaw tags to better understand the population dynamics and ecological characteristics of individual spawning populations. Although the data collected from this tagging program have been used for a variety of management purposes (e.g., estimating migration patterns, stock intermixing, and mortality rates), there has been only cursory examination of the shedding and reporting rates associated with the program. We used double tagging and high-reward tagging experiments to estimate tag shedding and reporting rates for jaw-tagged walleyes in Lake Erie. Double tagging of walleyes with jaw and passive integrated transponder (PIT) tags suggested that the tagging method and tagging agency contributed to the observed variability in both immediate (within 21 d of tagging) retention and chronic jaw tag shedding rates. Agency-specific model-averaged estimates of immediate tag retention ranged from 95% to 99%. For chronic shedding, model-averaged instantaneous rates (annual) ranged from 0.07 to 0.28. Jaw tag reporting rates, estimated via releases of high-reward tags in 1990 and 2000, varied among tagging years, tagging basins, and commercial and recreational fisheries. In general, tag reporting rates were higher for the recreational fishery (range, 33–55%) than for the commercial fishery (10–17%), and the reporting rates for both fisheries and tagging basins were found to have declined between 1990 and 2000. Uncertainty in the tag reporting rates was greater for the recreational fishery than for the commercial fishery. Our findings will benefit management of the economically important Lake Erie walleye fisheries by providing managers with robust tag shedding and reporting rate estimates, providing more reliable estimates of important dynamic rates (e.g., fishing and natural mortality) by correcting the long-term jaw tagging data set for these previously unaccounted for biases.

Received September 13, 2011; accepted November 30, 2011
Graphene formed on SiC under various environments: comparison of Si-face and C-face
Authors: Srivastava N , He Guowei , Luxmi  , Mende P C , Feenstra R M , Sun Yugang
Published: March 2012

The morphology of graphene on SiC {0 0 0 1} surfaces formed in various environments including ultra-high vacuum, 1 atm of argon and 10−6–10−4 Torr of disilane is studied by atomic force microscopy, low-energy electron microscopy and Raman spectroscopy. The graphene is formed by heating the surface to 1100–1600 °C, which causes preferential sublimation of the Si atoms. The argon atmosphere or the background of disilane decreases the sublimation rate so that a higher graphitization temperature is required, thus improving the morphology of the films. For the (0 0 0 1) surface, large areas of monolayer-thick graphene are formed in this way, with the size of these areas depending on the miscut of the sample. Results on the

surface are more complex. This surface graphitizes at a lower temperature than for the (0 0 0 1) surface and consequently the growth is more three-dimensional. In an atmosphere of argon the morphology becomes even worse, with the surface displaying markedly inhomogeneous nucleation, an effect attributed to unintentional oxidation of the surface during graphitization. Use of a disilane environment for the

surface is found to produce improved morphology, with relatively large areas of monolayer-thick graphene.
The structure of graphene grown on the SiC

surface
Authors: Hicks J , Shepperd K , Wang F , Conrad E H
Published: March 2012

Graphene grown on the SiC

surface is unique. Unlike graphene grown on the (0 0 0 1) surface, graphene grown on the

surface has higher electron mobilities and an unusual non-Bernal stacking. Its different electronic properties are associated with its stacking and the graphene–SiC interface. In this paper we discuss what is known about the structure of this material. In particular we will discuss the ordering in this material and how it is related to the interface structure. We update new ideas about the interface and stacking and contrast it with works from other groups. New evidence for how Si is removed from the interface is also given that provides some insight into the growth process and shows that graphene nucleation is not confined to screw dislocations. This has important implications for the viability of patterned graphene growth.
Structure and stability of the interface between graphene and 6H-SiC(0 0 0 −1) (3 × 3): an STM and ab initio study
Authors: Hiebel F , Magaud L , Mallet P , Veuillen J-Y
Published: March 2012

We examine in detail the structure and evolution upon annealing of the SiC(3 × 3) reconstruction which is known to be present at the interface between the SiC–C face substrate and the graphene layer for samples prepared in high vacuum. We use ab initio calculations to test the validity of proposed or classical structural models in comparison with scanning tunnelling microscopy (STM) images. We analyse the electronic structure of the bare surface and detect interface states which can pin the surface Fermi level. From a comparison of the signal coming from the bare and graphene-covered SiC(3 × 3) reconstruction we propose that the transparency of the graphene in high-bias STM images results from an enhancement of the local density of states of the interface plane by the graphene layer. We discuss the thermal stability of the SiC(3 × 3) surface, and show that it transforms more easily into the SiC(2 × 2)C reconstruction in the graphene-covered region than for the bare surface. This evolution generates both structural and electronic heterogeneities at the interface.
Effective theory of rotationally faulted multilayer graphene—the local limit
Authors: Kindermann M , First P N
Published: March 2012

Interlayer coupling in rotationally faulted graphene multilayers breaks the local sublattice-symmetry of the individual layers. Earlier we have presented a theory of this mechanism, which reduces to an effective Dirac model with space-dependent mass in an important limit. It thus makes a wealth of existing knowledge available for the study of rotationally faulted graphene multilayers. Agreement of this theory with a recent experiment in a strong magnetic field was demonstrated. Here we explore some of the predictions of this theory for the system in zero magnetic field at large interlayer bias, when it becomes local in space. We use that theory to illuminate the physics of localization and velocity renormalization in twisted graphene layers.
Model and simulations of the epitaxial growth of graphene on non-planar 6H–SiC surfaces
Authors: Ming Fan , Zangwill Andrew
Published: March 2012

We study step flow growth of epitaxial graphene on 6H–SiC using a one-dimensional kinetic Monte Carlo model. The model parameters are effective energy barriers for the nucleation and propagation of graphene at the SiC steps. When the model is applied to graphene growth on vicinal surfaces, a strip width distribution is used to characterize the surface morphology. Additional kinetic processes are included to study graphene growth on SiC nano-facets. Our main result is that the original nano-facet is fractured into several nano-facets during graphene growth. This phenomenon is characterized by the angle at which the fractured nano-facet is oriented with respect to the basal plane. The distribution of this angle across the surface is found to be related to the strip width distribution for vicinal surfaces. As the terrace propagation barrier decreases, the fracture angle distribution changes continuously from two-sided Gaussian to one-sided power law. Using this distribution, it will be possible to extract energy barriers from experiments and interpret the growth morphology quantitatively.
Toroidal velocity shear Kelvin–Helmholtz instabilities in strongly rotating tokamak plasmas
Authors: Chapman I.T. , Brown S. , Kemp R. , Walkden N.R.
Published: March 2012

Strong sheared toroidal flows are predicted to drive parallel velocity shear Kelvin–Helmholtz oscillations unstable in spherical tokamak plasmas. Numerical simulations that include rotation in the equilibrium suggest that future spherical tokamaks will have an upper limit in uni-directional injected neutral beam heating in order to keep the sheared toroidal rotation below the critical level for the onset of the global parallel velocity shear Kelvin–Helmholtz instability.
cPLA2α and EHD1 interact and regulate the vesiculation of cholesterol-rich, GPI-anchored, protein-containing endosomes
Authors: Cai Bishuang , Caplan Steve , Naslavsky Naava
Published: March 2012

The lipid modifier phospholipase A2 catalyzes the hydrolysis of phospholipids to inverted-cone–shaped lysophospholipids that contribute to membrane curvature and/or tubulation. Conflicting findings exist regarding the function of cytosolic phospholipase A2 (cPLA2) and its role in membrane regulation at the Golgi and early endosomes. However, no studies addressed the role of cPLA2 in the regulation of cholesterol-rich membranes that contain glycosylphosphatidylinositol-anchored proteins (GPI-APs). Our studies support a role for cPLA2α in the vesiculation of GPI-AP–containing membranes, using endogenous CD59 as a model for GPI-APs. On cPLA2α depletion, CD59-containing endosomes became hypertubular. Moreover, accumulation of lysophospholipids induced by a lysophospholipid acyltransferase inhibitor extensively vesiculated CD59-containing endosomes. However, overexpression of cPLA2α did not increase the endosomal vesiculation, implying a requirement for additional factors. Indeed, depletion of the “pinchase” EHD1, a C-terminal Eps15 homology domain (EHD) ATPase, also induced hypertubulation of CD59-containing endosomes. Furthermore, EHD1 and cPLA2α demonstrated in situ proximity (<40 nm) and interacted in vivo. The results presented here provide evidence that the lipid modifier cPLA2α and EHD1 are involved in the vesiculation of CD59-containing endosomes. We speculate that cPLA2α induces membrane curvature and allows EHD1, possibly in the context of a complex, to sever the curved membranes into vesicles.
IDSA Clinical Practice Guideline for Acute Bacterial Rhinosinusitis in Children and Adults
Authors: Chow Anthony W. , Benninger Michael S. , Brook Itzhak , Brozek Jan L. , Goldstein Ellie J. C. , Hicks Lauri A. , Pankey George A. , Seleznick Mitchel , Volturo Gregory , Wald Ellen R. , File Thomas M.
Published: March 2012

Evidence-based guidelines for the diagnosis and initial management of suspected acute bacterial rhinosinusitis in adults and children were prepared by a multidisciplinary expert panel of the Infectious Diseases Society of America comprising clinicians and investigators representing internal medicine, pediatrics, emergency medicine, otolaryngology, public health, epidemiology, and adult and pediatric infectious disease specialties. Recommendations for diagnosis, laboratory investigation, and empiric antimicrobial and adjunctive therapy were developed.
Interobserver Variability in the Interpretation of Colon Manometry Studies in Children
Authors: Sood Manu R. , Mousa Hayat , Tipnis Neel , Di Lorenzo Carlo , Werlin Steven , Fernandez Sergio , Liem Olivia , Simpson Pippa , Rudolph Colin
Published: March 2012

Objectives:

The aim of the present study was to evaluate the variability in interpretation of colon manometry (CM) in children.

Methods:

Fifty‐seven colon motility studies were independently reviewed by 5 observers. Each observer was required to report on the colonic motility during fasting, after administration of a meal, and after bisacodyl stimulation. They were also asked to comment whether CM study was normal or abnormal and whether in their opinion the postprandial recording provided clinically useful information.

Results:

The median (range) agreement regarding the presence of high‐amplitude propagating contractions (HAPC) was 83% (80%–92%). The interpretation of gastrocolonic response produced the most inconsistent results with median (range) agreemnet of 64% (53%–95%). The postprandial period was reported to be useful in only 3% to 24% of the studies. The median (range) agreement regarding the overall interpretation of the study being either normal or abnormal was 87% (83%–90%).

Conclusions:

The most easily recognizable contraction pattern during CM is the high‐amplitude propagating contractions. Visual interpretation of the gastrocolonic response produces the most inconsistent results and maximum variability. Abbreviated CM studies without the postprandial period or routine calculation of the motility index to evaluate gastrocolonic response can help make colon manometries more objective and reliable.
Identifying individual DNA species in a complex mixture by precisely measuring the spacing between nicking restriction enzymes with atomic force microscope
Authors: Reed Jason , Hsueh Carlin , Lam Miu-Ling , Kjolby Rachel , Sundstrom Andrew , Mishra Bud , Gimzewski J. K.
Published: March 2012

We discuss a novel atomic force microscope-based method for identifying individual short DNA molecules (<5000 bp) within a complex mixture by measuring the intra-molecular spacing of a few sequence-specific topographical labels in each molecule. Using this method, we accurately determined the relative abundance of individual DNA species in a 15-species mixture, with fewer than 100 copies per species sampled. To assess the scalability of our approach, we conducted a computer simulation, with realistic parameters, of the hypothetical problem of detecting abundance changes in individual gene transcripts between two single-cell human messenger RNA samples, each containing roughly 9000 species. We found that this approach can distinguish transcript species abundance changes accurately in most cases, including transcript isoforms which would be challenging to quantitate with traditional methods. Given its sensitivity and procedural simplicity, our approach could be used to identify transcript-derived complementary DNAs, where it would have substantial technical and practical advantages versus established techniques in situations where sample material is scarce.
Brownian motion or Lévy walk? Stepping towards an extended statistical mechanics for animal locomotion
Authors: Gautestad Arild O.
Published: March 2012

Animals moving under the influence of spatio-temporal scaling and long-term memory generate a kind of space-use pattern that has proved difficult to model within a coherent theoretical framework. An extended kind of statistical mechanics is needed, accounting for both the effects of spatial memory and scale-free space use, and put into a context of ecological conditions. Simulations illustrating the distinction between scale-specific and scale-free locomotion are presented. The results show how observational scale (time lag between relocations of an individual) may critically influence the interpretation of the underlying process. In this respect, a novel protocol is proposed as a method to distinguish between some main movement classes. For example, the ‘power law in disguise’ paradox—from a composite Brownian motion consisting of a superposition of independent movement processes at different scales—may be resolved by shifting the focus from pattern analysis at one particular temporal resolution towards a more process-oriented approach involving several scales of observation. A more explicit consideration of system complexity within a statistical mechanical framework, supplementing the more traditional mechanistic modelling approach, is advocated.
Next‐generation small RNA sequencing for microRNAs profiling in Apis mellifera: comparison between nurses and foragers
Authors: Liu F. , Peng W. , Li Z. , Li W. , Li L. , Pan J. , Zhang S. , Miao Y. , Chen S. , Su S.
Published: March 2012

MicroRNAs (miRNAs) are endogenous small non‐coding RNAs regulating gene expression in animals and plants. To find some differentially expressed miRNAs that may be associated with age‐dependent behavioural changes in honey bees (Apis mellifera), we applied next‐generation high‐throughput sequencing technology to detect small RNAs in nurses and foragers. Our results showed that both nurses and foragers had a complicated small RNA population, and the length of small RNAs varied, 22 nucleotides being the predominant length. Combining deep sequencing and bioinformatic analysis, we discovered that nine known miRNAs were significantly different between nurses and foragers (P < 0.01; absolute value of fold‐change ≥1). Some of their target genes were related to neural function. Moreover, 67 novel miRNAs were identified in nurses and foragers. Ame‐miR‐31a and ame‐miR‐13b were further validated using quantitative reverse‐transcription PCR assays. The present study provides new information on the miRNA abundance of honey bees, and enhances our understanding of miRNA function in the regulation of honey bee development.
Kisspeptin‐Immunoreactivity Changes in a Sex‐ and Hypothalamic‐Region‐Specific Manner Across Rat Postnatal Development
Authors: Desroziers E. , Mikkelsen J. D. , Duittoz A. , Franceschini I.
Published: March 2012

Kisspeptins are potent secretagogues of gonadotrophin‐releasing hormone, playing a key role in puberty onset. These peptides are produced by distinct neuronal populations of the hypothalamus located in the rostral periventricular area of the third ventricle (RP3V) and arcuate nucleus (ARC). The present immunohistochemical study aimed to determine the spatiotemporal onset of kisspeptin‐immunoreactivity (‐IR) in the neonatal hypothalamus of male and female rats and to evaluate changes in kisspeptin‐IR around puberty. Kisspeptin‐IR cells and fibres could be detected from the day of birth in the ARC of both males and females. At this stage, only females displayed some kisspeptin‐IR fibres in the RP3V. From postnatal day 7 to adulthood, males displayed lower levels of kisspeptin‐IR than females in both regions. During infancy, kisspeptin‐IR fibre density in the female decreased in the ARC, whereas it increased in the RP3V. A sex‐independent decline in RP3V kisspeptin‐IR fibre density was observed in the juvenile, followed by a peripubertal increase in RP3V and ARC kisspeptin‐IR. These peripubertal increases in kisspeptin‐IR occurred at different timings dependent on sex and region. In females specifically, the increase in kisspeptin‐IR fibre density occurred first in the ARC and later in the RP3V under constant levels of circulating oestradiol. In conclusion, the present study highlights the expression of hypothalamic kisspeptins soon after birth, as well as the neonatal establishment of a strong and persisting sex difference in ARC kisspeptin‐IR in rats. Moreover, a female‐specific desynchronisation of the ARC and RP3V was observed with respect to the increase in kisspeptin‐IR fibre density around puberty, which was not related to peripubertal variations in circulating oestradiol.
Allopregnanolone Protects Against Dopamine‐Induced Striatal Damage After In Vitro Ischaemia via Interaction at GABAA Receptors
Authors: Knight S. R. , Davidson C. , Young A. M. J. , Gibson C. L.
Published: March 2012

Sex steroid hormones, such as progesterone, have been shown to display neuroprotective properties after various models of central nervous system injury, including cerebral ischaemia, although the mechanism(s) of action remain largely undetermined. Allopregnanolone, an active progesterone metabolite, may explain some of the protective actions of progesterone. We utilised an in vitro model of ischaemia to evaluate the neuroprotective potential of allopregnanolone and examine its interaction at the GABAA receptor, which is hypothesised to be its main neuroprotective mechanism. In adult male mouse coronal caudate slices exposed to oxygen glucose deprivation (OGD), we measured aspects of OGD‐induced dopamine release, which is neurotoxic during ischaemia, using fast cyclic voltammetry and also assessed tissue viability. The GABAA agonist, muscimol, displayed a neuroprotective profile in terms of delaying the OGD‐evoked dopamine efflux (P < 0.05) and reducing the amount of dopamine released after OGD (P < 0.05). Allopregnanolone, at a concentration of 10−6 m, also displayed a neuroprotective profile because it significantly reduced the amount of dopamine efflux (P < 0.05) and reduced the loss of viable tissue after OGD compared to slices exposed to vehicle during OGD (P < 0.05). However, the effect of 10−6 m allopregnanolone on dopamine efflux was prevented in the presence of bicuculline, a competitive GABAA receptor antagonist. These results describe the use of an in vitro model of ischaemia with respect to determining that allopregnanolone is neuroprotective during the acute phase of ischaemia, and also demonstrate that such actions are dependent, at least in part, upon interaction at the GABAA receptor.
Strigolactone analogues induce suicidal seed germination of Striga spp. in soil
Authors: KGOSI R L , ZWANENBURG B , MWAKABOKO A S , MURDOCH A J
Published: March 2012

Kgosi RL, Zwanenburg B, Mwakaboko AS & Murdoch AJ (2012). Strigolactone analogues induce suicidal seed germination of Striga spp. in soil. Weed Research52, 197–203.

Striga hermonthica and Striga asiatica are obligate root parasites that cause serious problems in the production of staple cereal crops in Africa. Because of the high levels of infestation, there is an urgent need to control these weeds. A potentially useful control option is depletion of the soil seed bank by suicidal germination, which involves germination of the seeds in the absence of host plants. Suicidal germination is often mentioned in the literature, but not considered realistic, because of the alleged untimely decomposition of the stimulants in the soil, despite the fact that some encouraging results were reported around 1980. The alleged instability has prevented active research in this direction for the past 20–25 years. Five newly designed synthetic germination stimulants were investigated as candidates for suicidal germination. An important issue is the persistence of these stimulants in soil. Packets with Striga spp. seeds were put in pots with soil and then treated with aqueous solutions of the stimulants. All five compounds induced germination under these conditions, with percentages varying between 18% and 98% depending on stimulant and species. There were no noticeable signs of decomposition of the stimulants. The best performing stimulant is derived from 1‐tetralone. We conclude that synthetic strigolactones analogues have excellent prospects for use in combating parasitic weeds. Further testing will be needed to evaluate whether such prospects can be realised in the field.
A review of the worldwide prevalence of vitiligo in children/adolescents and adults
Authors: Krüger Christian , Schallreuter Karin Uta
Published: March 2012

Background  Vitiligo is an acquired, idiopathic, and worldwide common depigmentation disorder with an estimated prevalence from 0.1 to 8%. These numbers are based on clinical population studies and field research examining inhabitants of geographically enclosed areas. Our aim was to collect all available data on the prevalence of vitiligo in the general population, paying particular attention to children/adolescent groups and adults.

Materials and methods  Screening of available literature and online databases using several key words.

Results  We found more than 50 studies that used several methods and subgroups of the general population. The prevalence of vitiligo ranges from 0.06 to 2.28%, whereas this was 0.0–2.16% in children/adolescents populations.

Conclusions  The often cited prevalence of 8% could not be confirmed after excluding clinical patient populations. Accordingly, the worldwide prevalence of vitiligo ranges between 0.5 and 2%.
Overall mortality after radical nephrectomy in patients aged over 80 years with renal cancer: A retrospective study on preoperative prognostic factors
Authors: Brassart Elena , Lebdai Souhil , Berger Julien , Traore Sory , Bernhard Jean‐Christophe , Fardoun Tarek , Muller Guillaume , Patard Jean‐Jacques , Azzouzi Abdel Rahmène , Bigot Pierre
Published: March 2012

Objectives:  To evaluate the overall survival postnephrectomy for renal cancer for patients aged over 80 years, and to identify preoperative prognostic factors that might influence therapeutic strategies.

Methods:  In a retrospective study in five French departments of urology, 179 patients aged over 80 years with renal cell carcinoma underwent radical nephrectomy between 1990 and 2011. The following data were collected: age, sex, body mass index, Charlson Comorbidity Index, American Society of Anesthesiology class, Eastern Cooperative Oncology Group Performance Status, type of surgery, period of follow‐up, survival, death etiology, symptoms, Fuhrman grade and tumor–nodes–metastasis stage.

Results:  After a 29.6‐month follow up, 89 patients (49.7%) died. Death etiologies were: cancer for 46 (52%) patients, immediate or distant perioperative complications for five patients (6%) and three patients (3%) respectively, cardiovascular disease for 16 patients (18%), other cancers for three patients (3%) and unknown for 16 patients (18%). In a multivariate analysis, T‐stage, M‐stage and Charlson Comorbidity Index were identified as independent prognostic factors. Patients were divided into three groups (good, intermediate and bad prognosis) with significantly different survivals of 91, 36 and 22 months (P < 0.0001), respectively.

Conclusions:  Preoperative data, including T‐stage, M‐stage and Charlson Comorbidity Index represent significant independent prognostic factors for survival for patients aged over 80 years. These data might help the clinician in selecting the most suitable candidates for radical nephrectomy among elderly patients with renal cancer.
Root dynamics influence tree–grass coexistence in an Australian savanna
Authors: FEBRUARY E. C. , COOK G. D. , RICHARDS A. E.
Published: March 2012

Both resource and disturbance controls have been invoked to explain tree persistence among grasses in savannas. Here we determine the extent to which competition for available resources restricts the rooting depth of both grasses and trees, and how this may influence nutrient cycling under an infrequently burned savanna near Darwin, Australia. We sampled fine roots <2 mm in diameter from 24 soil pits under perennial as well as annual grasses and three levels of canopy cover. The relative proportion of C3 (trees) and C4 (grasses) derived carbon in a sample was determined using mass balance calculations. Our results show that regardless of the type of grass both tree and grass roots are concentrated in the top 20 cm of the soil. While trees have greater root production and contribute more fine root biomass grass roots contribute a disproportional amount of nitrogen and carbon to the soil relative to total root biomass. We postulate that grasses maintain soil nutrient pools and provide biomass for regular fires that prevent forest trees from establishing while savanna trees, are important for increasing soil N content, cycling and mineralization rates. We put forward our ideas as a hypothesis of resource‐regulated tree–grass coexistence in tropical savannas.