bluuebunny/crossref_metadata_2025 huggingface dataset:
Pan-African metamorphic and magmatic rocks of the Khanka Massif, NE China: further evidence regarding their affinity
Authors: ZHOU JIAN-BO , WILDE SIMON A. , ZHAO GUO-CHUN , ZHANG XING-ZHOU , ZHENG CHANG-QING , WANG HU , ZENG WEI-SHUN
Published: February 2010

The Khanka Massif is a crustal block located along the eastern margin of the Central Asian Orogenic Belt (CAOB) and bordered to the east by Late Jurassic–Early Cretaceous circum-Pacific accretionary complexes of the Eastern Asian continental margin. It consists of graphite-, sillimanite- and cordierite-bearing gneisses, carbonates and felsic paragneisses, in association with various orthogneisses. Metamorphic zircons from a sillimanite gneiss from the Hutou complex yield a weighted mean206Pb/238U age of 490 ± 4 Ma, whereas detrital zircons from the same sample give ages from 934–610 Ma. Magmatic zircon cores in two garnet-bearing granite gneiss samples, also collected from the Hutou complex, yield weighted mean206Pb/238U ages of 522 ± 5 Ma and 515 ± 8 Ma, whereas their metamorphic rims record206Pb/238U ages of 510–500 Ma. These data indicate that the Hutou complex in the Khanka Massif records early Palaeozoic magmatic and metamorphic events, identical in age to those in the Mashan Complex of the Jiamusi Massif to the west. The older zircon populations in the sillimanite gneiss indicate derivation from Neoproterozoic sources, as do similar rocks in the Jiamusi Massif. These data confirm that the Khanka Massif has a close affinity with other major components of the CAOB to the west of the Dun-Mi Fault. Based on these results and previously published data, the Khanka Massif is therefore confirmed as having formed a single crustal entity with the Jiamusi (and possibly the Bureya) massif since Neoproterozoic time.
The ventilated filling box containing a vertically distributed source of buoyancy
Authors: COOPER PAUL , HUNT GARY R.
Published: February 2010

This paper describes the fluid mechanics within a box containing a vertical plane distributed source of buoyancy. A theoretical analysis is presented that models the development of plumes from such sources in an unconfined ambient of uniform density. Two extensions are considered. The first concerns a sealed box and the second involves the more general situation where the box is ventilated by openings at top and bottom. In the sealed box the stratification develops in much the same way as for a ‘filling box’ containing a single-point source of buoyancy on the floor. An initial front descends from the ceiling of the box and an asymptotic stratification eventually develops which is continuous in the vertical direction. In the case of the ventilated box it is found that a complex stratification develops where one or more horizontal intrusions are formed by detachment of the plume/boundary layer from the vertically distributed source where the buoyancy of the plume is less than, or equal to, that of the stratified ambient at a given height. Experimental results are presented to demonstrate the validity of the theory. The findings are relevant to both forced and naturally ventilated buildings containing non-adiabatic vertical surfaces.
Almost limiting short-crested gravity waves in deep water
Authors: OKAMURA MAKOTO
Published: February 2010

We investigate the properties of almost limiting short-crested gravity waves with harmonic resonance for various incident angles. When the incident angle is less than 47.5°, the enclosed crest angle in non-resonant limiting waves is 90°, which corresponds to that in standing waves. In contrast, when the incident angle exceeds 47.5°, the enclosed crest angle in non-resonant limiting waves is 120°, which corresponds to that in two-dimensional progressive waves. The enclosed crest angle is 90° in resonant limiting waves for all incident angles. The crest becomes flatter than the trough in resonant limiting waves if the fundamental mode has a different sign from its harmonic resonant mode. Bifurcation of short-crested waves is also investigated.
A serological study ofDirofilaria immitisin feral cats in Grenada, West Indies
Authors: Fernandez C. , Chikweto A. , Mofya S. , Lanum L. , Flynn P. , Burnett J.P. , Doherty D. , Sharma R.N.
Published: February 2010

A study to determine the seroprevalence ofDirofilaria immitiswas carried out in feral cats in Grenada. Of the 137 feral cats tested for circulating antibodies (IgG; lateral-flow immunoassay) and circulating antigens (Ag; enzyme-linked immunosorbent assay), 8% (95% confidence interval (CI) 3.5–12.5%) were antibody positive and 5.1% (95% CI 1.4–8.8%) were antigen positive. No significant difference between cats aged>1 to 4 years and cats less than 1 year of age was found (P>0.05, χ2). There was also no significant difference (P>0.05, χ2) between male and female cats.Dirofilaria immitisprevalence is relatively high in the feral cat population of Grenada. Evidence ofD. immitisinfection in feral cats coupled with the endemic nature of heartworm disease in dogs in Grenada leads us to suggest the introduction of heartworm prophylaxis in cats. To the authors' knowledge, this serological evidence of heartworm infection in feral cats in Grenada is the first report from the Caribbean region.
Complete congenital third branchial fistula with left-sided, recurrent, suppurative thyroiditis
Authors: Madana J , Yolmo D , Gopalakrishnan S , K Saxena S
Published: February 2010

Objective:

We report an extremely rare case of a complete congenital third branchial arch fistula in a nine-year-old boy.

Method:

A case report and a review of the English literature concerning third branchial arch fistula of congenital origin are presented.

Results:

A nine-year-old boy presented with a history of a small opening in the middle third of the anterior neck since birth, with recurrent surrounding swelling. There was no history of surgical drainage or spontaneous rupture. Computed tomography with contrast injection into the external cervical opening revealed a patent tract from the neck skin to the base of the pyriform sinus. Complete excision of the tract up to the pyriform sinus with left hemithyroidectomy was performed. Follow up at 22 months showed no recurrence.

Conclusion:

To our knowledge, this case represents a very rare occurrence of the congenital variety of complete third branchial arch fistula at an unusual site. This case indicates that third branchial arch fistula can be complete, and may present in the anterior neck, an unusual site. In such cases, computed tomography fistulography and injection of dye into the pyriform sinus enables intra-operative delineation of the tract.
Density and distribution patterns of the endangered speciesPinna nobiliswithin aPosidonia oceanicameadow in the Gulf of Oristano (Italy)
Authors: Coppa S. , Guala I. , de Lucia G.A. , Massaro G. , Bressan M.
Published: February 2010

Pinna nobilisis an endemic bivalve of the Mediterranean Sea. In the last decadesP. nobilispopulations have declined drastically due to increasing anthropogenic pressure and it has been declared a protected species since 1992. Despite the need for conservation, knowledge of the ecology and monitoring of the main populations ofP. nobilisare limited. This study considered a population living within aPosidonia oceanicameadow in the Gulf of Oristano (western Mediterranean, Italy). The study area, about 150 hectares, part of which is included within a Marine Protected Area and a Site of Community Importance, was subdivided in 3 sub-areas. The percentage cover of different habitat types (P. oceanica, dead matte and sand) in each sub-area was measured and meadow features (substrate coverage, matte compactness and shoot density) characterized. The hypotheses of differences in density, percentage of dead individuals, population structure, shell burial level and orientation ofP. nobilis, were investigated according to sub-areas and to habitat type. The spatial distribution was patchy, and the habitat type resulted a key factor in determining both density and distribution. A strong edge effect was demonstrated: more than half of the observed individuals colonized theP. oceanicaborder. Matte compactness and shoot density were found to affect the density and distribution ofP. nobilis. Shell burial level and percentage of dead individuals varied with sub-areas and habitat types. Size distribution was bimodal and common shell orientation was observed in two sub-areas. These results contribute to increase the knowledge of population ecology of this species and to provide useful information for implementing conservation policies.
Nilpotent-by-abelian Lie algebras of type FPm
Authors: GROVES J. R. J. , KOCHLOUKOVA DESSISLAVA H.
Published: February 2010

Let L be a finitely generated Lie algebra which is a split extension of a free nilpotent Lie algebra N by a finite dimensional abelian Lie algebra. Let V denote the quotient of N by its commutator subalgebra; we can regard V as a module for L/N. We discuss the relationship between the homological finiteness properties of V and those of L. In particular, we show that if L has type FPm and N has class c then V is 1 + c(m − 1)-tame (equivalently, the (1 + c(m − 1))th tensor power of V is finitely generated under the diagonal action of L/N).
Prevalence and clinical correlations of genetic subtypes ofGiardia lambliain an urban setting
Authors: BREATHNACH A. S. , McHUGH T. D. , BUTCHER P. D.
Published: February 2010

The clinical significance of different genetic subtypes or assemblages ofGiardia lambliais uncertain. Cases of giardiasis in south-west London between 1999 and 2005 were studied, comparing molecular-typing results with clinical and epidemiological findings from routine surveillance. We identified 819 cases, of whom 389 returned surveillance questionnaires. A subset of 267 faecal samples was submitted for typing by sequencing of the triose phosphate isomerase (tpi) and ribosomal RNA genes, and/or a separate duplex PCR of thetpigene. Typing was successful in 199 (75%) samples by at least one of the molecular methods. Assemblage A accounted for 48 (24%) samples and Assemblage B for 145 (73%); six (3%) were mixed. Both assemblages had similar seasonality, age distribution and association with travel. Clinical features were available for 59 successfully typed cases: both assemblages caused similar illness, but Assemblage A was significantly more frequently associated with fever than Assemblage B.
The use of a new virtual cohort study design to investigate an outbreak ofE. coliO157 linked to a supermarket delicatessen
Authors: McCARTNEY G. , COWDEN J. , MURRAY S. , AHMED S.
Published: February 2010

In outbreaks of foodborne disease associated with retail outlets, the outlet often closes as a precaution before the specific food vehicle has been identified. Suspect food vehicles may be named as part of general control measures. A conventional case-control study cannot be performed because both cases and potential controls are likely to be aware of the hypothesis and therefore potentially biased. Modern sales recording systems in many food retail outlets may provide a basis for constructing a virtual cohort and allow a statistical inference to be made about various possible vehicles of infection. In 2007, an outbreak ofE. coliO157 infection in Paisley, Scotland, was linked to cooked meat from a supermarket delicatessen using descriptive epidemiology. Construction of a virtual cohort allowed a relative risk and confidence interval to be estimated which supported the hypothesis of cooked beef topside being the vehicle of infection. This novel method could be valuable in the investigation of future outbreaks.
Trichinella infection in a hunting community in East Greenland
Authors: MØLLER L. N. , KOCH A. , PETERSEN E. , HJULER T. , KAPEL C. M. O. , ANDERSEN A. , MELBYE M.
Published: February 2010

Trichinella nativa infection (trichinellosis) is highly prevalent in Arctic wildlife, but the human burden of trichinellosis in present-day Greenland is unknown. The study aimed to determine Trichinella seroprevalence in an eastern Greenlandic hunting community and to evaluate risk factors for seropositivity. Overall, 998 inhabitants aged ⩾10 years in the Ammassalik municipality were tested for Trichinella-specific IgG antibodies. Background information was obtained from questionnaires. Seropositivity was 1·4% in persons aged <40 years and increased to >12% in those aged ⩾60 years. Older age, occupation as hunter or fisherman, and consumption of polar bear meat significantly increased the risk of Trichinella seropositivity. The seropositivity age pattern probably reflects changes in dietary preferences, but could also reflect mandatory meat inspection since 1966. However, preventive measures against Trichinella infection should be strengthened in Greenland.
Counting Matchings and Tree-Like Walks in Regular Graphs
Authors: WANLESS IAN. M.
Published: February 2010

The number of closed tree-like walks in a graph is closely related to the moments of the roots of the matching polynomial for the graph. Thus, by counting these walks up to a given length it is possible to find approximations for the matching polynomial. This approach has been used in two separate problems involving asymptotic enumerations of 1-factorizations of regular graphs. Nevertheless, a systematic way to count the required walks had not previously been found.

In this paper we give an algorithm to count closed tree-like walks in a regular graph up to a given length. For smallm, this provides expressions for the number ofm-matchings in the graph in terms of the numbers of copies of certain small subgraphs that appear in the graph. The simplest of these expressions were already known, having been rediscovered by numerous authors usingad hocmethods. We offer the first general method for producing the expressions. We also find generating functions that isolate the contribution from the simplest kind of subgraph – namely a single cycle of arbitrary length.
Associations between being overweight, variability in heart rate, and well-being in the young men
Authors: Schmid Klaus , Schönlebe Jana , Drexler Hans , Mueck-Weymann Michael
Published: February 2010

Abnormalities of the autonomic nervous system have been repeatedly shown in hypertension. We studied the associations between being overweight, blood pressure, cardiac vagal tone as measured by variability in heart rate, and well-being in a large cohort of young men. We hypothesised an inverse correlation between body mass index and the variability in heart rate. Further, we assessed systolic and diastolic blood pressure as traditional indicators of cardiovascular risk. Exclusion criteria were the use of drugs or pharmaceuticals. The following data from 786 men with a mean age of 19.4 years (standard deviation = 1.4, with a range from 16 to 24 years) were analysed in a cross-sectional study: body mass index, sleep duration, sporting activities, psychological well-being, blood pressure, heart rate, and variability in heart rate. Despite the young age of the men in this study, increased values for the body mass index were already associated with a shift in sympathovagal balance trending towards sympathetic dominance. There was also a significant positive correlation between body mass index and systolic and diastolic blood pressure. A multiple stepwise regression analysis showed that significant factors, which were associated with variability in heart rate, were body mass index and sporting activities. In addition, sporting activity and sleep duration had a significant positive impact on psychological well-being. Even in young men, being overweight is associated with increased cardiovascular risk, especially an increased sympathetic and/or lowered cardiovascular tone and increased blood pressure. Our study gives additional motivation for the early prevention and treatment of obesity in childhood and adolescence.
OPTIMAL MONETARY POLICY UNDER PARAMETER UNCERTAINTY IN A SIMPLE MICROFOUNDED MODEL
Authors: Kurozumi Takushi
Published: February 2010

This paper examines optimal monetary policy under uncertainty about fundamental parameters of a dynamic stochastic general-equilibrium model. In contrast to previous studies, a microfoundation of the model leads this uncertainty to generate uncertainty not only about the transmission of monetary policy but also about the transmission of shocks and about a social welfare loss function. In the presence of such uncertainty, this paper finds conditions under which optimal discretionary policy responds to shocks more aggressively than in the absence of the uncertainty. These conditions depend crucially on the persistence of shocks and the magnitude of policy multipliers. To obtain the conditions, taking proper account of uncertainty about the transmission of shocks and about the welfare loss function is of crucial importance.
Carbon and nitrogen cycle dynamics in the O‐CN land surface model: 2. Role of the nitrogen cycle in the historical terrestrial carbon balance
Authors: Zaehle S. , Friend A. D. , Friedlingstein P. , Dentener F. , Peylin P. , Schulz M.
Published: February 2010

Global‐scale results of the new O‐CN terrestrial biosphere model coupling the carbon (C) and nitrogen (N) cycles show that the model produces realistic estimates of present‐day C and N stocks and fluxes, despite some regional biases. N availability strongly affects high‐latitude foliage area and foliage N, limiting vegetation productivity and present‐day high‐latitude net C uptake. Anthropogenic N deposition is predicted to have increased net primary productivity due to increases in foliage area and foliage N, contributing 0.2–0.5 Pg C yr−1 to the 1990s global net C uptake. While O‐CN's modeled global 1990s terrestrial net C uptake (2.4 Pg C yr−1) is similar to the estimate not accounting for anthropogenic N inputs and N dynamics (2.6 Pg C yr−1), its latitudinal distribution and the sensitivity of the terrestrial C balance to its driving factors are substantially altered by N dynamics, with important implications for future trajectories of the global carbon cycle.
Statistical properties of groundwater noble gas paleoclimate models: Are they robust and unbiased estimators?
Authors: Sun Tie , Hall Chris M. , Castro Maria Clara
Published: February 2010

Noble gas paleoclimate reconstructions from noble gas concentrations in groundwater have the promise of providing absolute paleotemperature information, but difficulties in modeling measured noble gas concentrations with simple models have led to a number of competing noble gas temperature (NGT) schemes being developed. These different models make different assumptions about the size and nature of the noble gas air‐saturated water and excess air (EA) components within groundwater, and they yield significantly different NGT values (∼5°C). We use four different NGT models (unfractionated air, closed system equilibration (CE), oxygen depletion, and gas diffusion relaxation) to examine seven published noble gas data sets and find that although different NGT models produce records that are offset with respect to temperature and excess air, the amount of variation of fitted temperature and excess air values within a given record is surprisingly consistent between fitting methods. By using the NGT methods on 5000 synthetically produced data for each model, we show that all but the closed system equilibrium or CE model of Aeschbach‐Hertig et al. (2000) are unbiased estimators, with the CE model tending to overestimate both NGT and the EA component. However, despite offsets in NGT and EA, all four models agree remarkably well when estimating temperature differences, confirming the pattern seen with real data, and this suggests that temperature variations derived from NGT data are quite robust. Patterns of misfit of noble gases are shown for both synthetic and real data, which help to provide diagnostic tools for assessing the appropriateness of different NGT methods for different noble gas data sets.
Paleointensity determination using anhysteretic remanence and saturation isothermal remanence
Authors: Yu Yongjae
Published: February 2010

Determining the strength of ancient planetary magnetic field is pivotal to understanding the evolution of planets and asteroids in the solar system. While the Thellier‐type double heating technique provides the most faithful field strength information for rocks carrying a thermoremanent magnetization (TRM), many extraterrestrial rock samples respond unfavorably to heat treatment. The present study systematically examined the two well‐known normalization techniques that avoid any heating by comparing the ratios of TRM/anhysteretic remanent magnetization (ARM) and TRM/saturation isothermal remanent magnetization (SIRM). Both the ratios of TRM/ARM and TRM/SIRM are dependent on the grain size as well as the volume concentration of magnetite. The remanence ratios also were found to increase as the alternating field increased during demagnetization for fine‐grained magnetite. A new calibration relation of 2.60 ± 1.32 for the TRM/ARM and of (3.62 ± 1.28) × 10−2 for the TRM/SIRM was defined for an external field of 50 μT. The TRM/SIRM is superior to TRM/ARM because the former showed less dispersion in the grain size dependence, the volume concentration dependence, and the stability against AF demagnetization. In addition, the standard error of the mean for the TRM/SIRM ratio was smaller than that for the TRM/ARM ratio. Thus, whenever heating is inapplicable, the SIRM method seems to be a better choice than the ARM method. However, it should be emphasized that the uncertainty of TRM/ARM and TRM/SIRM is still nearly an order of magnitude larger than that of the high‐fidelity Thellier estimation and thus must be limited in use only when samples are irreversibly altered during heating. In practice, the best approach is to carry out both ARM and SIRM methods and check whether the two estimations agree within the uncertainties.
On the mechanism of formation of depositional remanent magnetization
Authors: Shcherbakov Valeriy , Sycheva Natalia
Published: February 2010

Coagulation of particles into aggregates during their settling in an aqueous solution is numerically simulated with regard to Brownian motion, Van der Waals and Stokes's forces, gravitation, and magnetostatic interactions. Clusters obtained have a fractal structure with the average fractal dimension d = 1.83. Magnetic grains do not group until their concentration exceeds at least a few percent. The deposition process obeys a scaling principle: the sizes of clusters arriving at the bottom of a basin do not change if the product of the basin depth H and the concentration of initial material c0 is constant. Attempts at numerical simulations of laboratory redeposition experiments are made. Good agreement between numerical simulations and experimental results by van Vreumingen (1993) demonstrates that the modeling algorithm is based on reasonable physical assumptions. The magnetization of a flocculating suspension is defined by at least seven parameters, which characterize magnetic and nonmagnetic particles, as well as the aqueous medium. This multiparametric dependence hinders estimations of paleofield intensity by the redeposition method because it is practically impossible to reproduce natural conditions in the laboratory. Flocculation influences the magnetization intensity of the settling suspension at concentrations c0 typical for redeposition experiments or natural sedimentation in lakes and shallow seas. Flocculation is of minor importance for deep oceanic regions because of their extremely low sedimentation rate. However, factors like small‐scale turbulence and biotic processes are not taken into account by the model and may require modification of these conclusions. Also, a simple model of pDRM acquisition based on elastic and plastic properties of sediment slurry is proposed.
Magnitude of the Hall fields during magnetic reconnection
Authors: Le A. , Egedal J. , Daughton W. , Drake J. F. , Fox W. , Katz N.
Published: February 2010

In situ observation of the Earth's magnetosphere has identified Hall magnetic fields as a key signature of collisionless magnetic reconnection. The inflow portion of the reconnection diffusion region is further characterized by strong electron pressure anisotropy. These two features are tightly linked in a quantitative model, which is verified using fully kinetic simulations. The model predicts the Hall field strength and the maximum electron pressure anisotropy as functions of the upstream ratio of electron fluid and magnetic pressures.
Continental Transform Basins: Why Are They Asymmetric?
Authors: Seeber Leonardo , Sorlien Christopher , Steckler Michael , Cormier Marie‐Helene
Published: February 2010

Continental transforms constitute only a few of the world's plate boundaries and do not produce the largest earthquakes. Yet they are the tectonic underpinning of some of the most attractive and densely populated coastal environments. As a result, they have disproportionally contributed to catastrophic earthquakes. The most recent example is the M = 7.0 earthquake that struck Haiti on 12 January 2010, killing at least 100,000 people, by some reports.

Because of concern for their earthquakes, continental transforms–particularly California's San Andreas Fault and Turkey's North Anatolian fault–have been intensely studied. Nonetheless, the link between the largest and most dangerous earthquakes and fault segments along transforms remains elusive. A better understanding of the structural singularities bounding these segments, particularly the subsurface nature of basins along transform faults, may clarify why some of them stop earthquake ruptures while others do not.
Synthesis and characterization of a tin(ii) bis(phosphinoyl)methanediide complex: a stannavinylidene derivative
Authors: Guo Jiayi , Lau Kai-Chung , Xi Hong-Wei , Lim Kok Hwa , So Cheuk-Wai
Published: February 2010

A novel tin(ii) bis(phosphinoyl)methanediide compound3has been synthesized by the reaction of1with two equivalents of [Sn{N(SiMe3)2}2] in refluxing toluene. X-Ray crystallography and DFT calculations show that compound3has a >CSn: skeleton.
Dynamic supramacromolecular self-assembly: deformable polymer fabricated nanostructures through a host-controlled approach
Authors: Yan Qiang , Yuan Jinying , Kang Yan , Yin Yingwu
Published: February 2010

Adjusting the molar ratio between α-CD and copolymer can induce supramacromolecular complexes to dynamically and reversibly self-tune their fabrication from micelles to cylinders to vesicles to sheets like “living” assemblies.
Novel insights into mannitol metabolism in the fungal plant pathogen Botrytis cinerea
Authors: Dulermo Thierry , Rascle Christine , Billon-Grand Geneviève , Gout Elisabeth , Bligny Richard , Cotton Pascale
Published: February 2010

In order to redefine the mannitol pathway in the necrotrophic plant pathogen Botrytis cinerea, we used a targeted deletion strategy of genes encoding two proteins of mannitol metabolism, BcMTDH (B. cinerea mannitol dehydrogenase) and BcMPD (B. cinerea mannitol-1-phosphate dehydrogenase). Mobilization of mannitol and quantification of Bcmpd and Bcmtdh gene transcripts during development and osmotic stress confirmed a role for mannitol as a temporary and disposable carbon storage compound. In order to study metabolic fluxes, we followed conversion of labelled hexoses in wild-type and ΔBcmpd and ΔBcmtdh mutant strains by in vivo NMR spectroscopy. Our results revealed that glucose and fructose were metabolized via the BcMPD and BcMTDH pathways respectively. The existence of a novel mannitol phosphorylation pathway was also suggested by the NMR investigations. This last finding definitively challenged the existence of the originally postulated mannitol cycle in favour of two simultaneously expressed pathways. Finally, physiological and biochemical studies conducted on double deletion mutants (ΔBcmpdΔBcmtdh) showed that mannitol was still produced despite a complete alteration of both mannitol biosynthesis pathways. This strongly suggests that one or several additional undescribed pathways could participate in mannitol metabolism in B. cinerea.
Bioinformatic and experimental survey of 14-3-3-binding sites
Authors: Johnson Catherine , Crowther Sandra , Stafford Margaret J. , Campbell David G. , Toth Rachel , MacKintosh Carol
Published: February 2010

More than 200 phosphorylated 14-3-3-binding sites in the literature were analysed to define 14-3-3 specificities, identify relevant protein kinases, and give insights into how cellular 14-3-3/phosphoprotein networks work. Mode I RXX(pS/pT)XP motifs dominate, although the +2 proline residue occurs in less than half, and LX(R/K)SX(pS/pT)XP is prominent in plant 14-3-3-binding sites. Proline at +1 is rarely reported, and such motifs did not stand up to experimental reanalysis of human Ndel1. Instead, we discovered that 14-3-3 interacts with two residues that are phosphorylated by basophilic kinases and located in the DISC1 (disrupted-in-schizophrenia 1)-interacting region of Ndel1 that is implicated in cognitive disorders. These data conform with the general findings that there are different subtypes of 14-3-3-binding sites that overlap with the specificities of different basophilic AGC (protein kinase A/protein kinase G/protein kinase C family) and CaMK (Ca2+/calmodulin-dependent protein kinase) protein kinases, and a 14-3-3 dimer often engages with two tandem phosphorylated sites, which is a configuration with special signalling, mechanical and evolutionary properties. Thus 14-3-3 dimers can be digital logic gates that integrate more than one input to generate an action, and coincidence detectors when the two binding sites are phosphorylated by different protein kinases. Paired sites are generally located within disordered regions and/or straddle either side of functional domains, indicating how 14-3-3 dimers modulate the conformations and/or interactions of their targets. Finally, 14-3-3 proteins bind to members of several multi-protein families. Two 14-3-3-binding sites are conserved across the class IIa histone deacetylases, whereas other protein families display differential regulation by 14-3-3s. We speculate that 14-3-3 dimers may have contributed to the evolution of such families, tailoring regulatory inputs to different physiological demands.
Increased plasma concentrations of anterior gradient 2 protein are positively associated with ovarian cancer
Authors: Edgell Tracey A. , Barraclough Dong L. , Rajic Antonio , Dhulia Janu , Lewis Kate J. , Armes Jane E. , Barraclough Roger , Rudland Philip S. , Rice Gregory E. , Autelitano Dominic J.
Published: February 2010

Ovarian cancer is often asymptomatic and is diagnosed at an advanced stage with poor survival rates, thus there is an urgent need to develop biomarkers for earlier detection of ovarian cancer. In the present study, we demonstrate for the first time that the previously reported metastasis-inducing protein AGR2 (anterior gradient protein 2) can be detected in the blood of ovarian cancer patients. Using a newly developed ELISA, we show significantly increased concentrations of AGR2 protein in plasma from cancer patients relative to normal controls. Plasma AGR2 concentrations were highest in stages II and III ovarian cancer patients and were similarly elevated in patients with both serous and non-serous tumours. The identification of elevated plasma concentrations of AGR2 may provide a useful biomarker to aid in the discrimination of normal and ovarian cancer patients particularly when used in combination with CA125.
First-principles calculations of Fe-doped monolayer C60 on h-BN/Ni(111) surface
Authors: Li Lan , Wu Yu-Ning , Cheng Hai-Ping
Published: February 2010

We have used large-scale first-principles calculations based on density functional theory to investigate the structure, energetics, electronic, and magnetic structures of Fen-doped C60 monolayers supported by h-BN monolayer-covered Ni(111) surfaces. A systematic study of n-dependent physical properties has been performed (n=1–4,15). Binding energies on Fe atoms to the Fen−1–C60 complex have been calculated for n=1–4 after a thorough configuration search and structural optimization. The binding energy, electron charge transfer (from Fen to C60), and magnetic moment all increase monotonically as functions of n. The electron charge transfer, ranging from ∼1e− to 5e−, is from the spin minority population. This leads to a situation in which the net spin of the C60 molecule aligns with the spin minority and the magnetic moment in C60 is opposite to the total magnetic moment of the system. For n=2, a competing antiferromagnetic state has been found. In this state, the net spin of the system as well as the C60 is zero. Density of states and projected density of states analysis indicate that the system becomes metallic upon metal doping regardless its magnetic state. In addition, we have also performed calculations with the Hubbard U term (DFT+U) for two systems, n=4 and 15, to investigate possible gap opening near the Fermi surface.
Distance-controlled scattering in a plasmonic trap
Authors: Huang Lina , Martin Olivier J. F.
Published: February 2010

Light scattered by a dielectric object when it is trapped in the field of a plasmonic nanostructure is studied theoretically and experimentally using both dielectric spheres and S. cerevisiae cells. A dramatic enhancement of the scattered light is observed for short separation distances between scatterer and plasmonic trap. It is shown that this effect can serve to selectively image cells after their immobilization and distinguish them from a turbid background. The high sensitivity of the scattered light to the separation distance and lateral displacement also provides additional insights in the configuration of the cell within the trap.
Microwave breakdown in waveguide filters, numerical simulation, and comparison to experiments
Authors: Frigui K. , Baillargeat D. , Catherinot A. , Bila S. , Verdeyme S. , Puech J. , Pacaud D.
Published: February 2010

Microwave breakdowns in output multiplexer filters, boarded on telecommunications satellites, can affect the device and damage it. During tests at atmospheric pressure, these breakdowns are generally initiated in the vicinity of a noble metal coated frequency adjustment screw. A modeling of the microwave breakdown ignition is developed taking into account the thermoelectronic emission from the screw and the noble metal atom vaporization. The influence of field strength is particularly investigated to predict the breakdown delay after the application of the microwave power. Then, a specific structure has been designed and built and a dedicated measurement procedure has been proposed. As it will be shown, the test structure experimental behavior agrees well with the theoretical one. Finally, the results given by the numerical modeling of microwave breakdown are compared to the measurements performed in a five-pole filter of an output multiplexer.
Reversible optical nonreciprocity in periodic structures with liquid crystals
Authors: Miroshnichenko Andrey E. , Brasselet Etienne , Kivshar Yuri S.
Published: February 2010

We demonstrate how to achieve reversible nonreciprocal optical response in a periodic photonic structure with a pair of defects, one of them being a nonlinear liquid crystal defect layer. The twin defect structure is symmetric at low intensity and becomes asymmetric above an intensity threshold that corresponds to the optical reordering of the liquid crystal. We show that nonreciprocal effects can be reversed by changing the wavelength as a consequence of the wavelength dependent light localization at the defect mode inside the structure.
Dielectric-loaded surface plasmon polariton waveguides on a finite-width metal strip
Authors: Grandidier J. , des Francs G. Colas , Markey L. , Bouhelier A. , Massenot S. , Weeber J.-C. , Dereux A.
Published: February 2010

We investigate the guiding properties of a dielectric-loaded surface plasmon polariton waveguide on a finite-width metal strip. The guided mode is characterized by leakage radiation microscopy for different metal strip widths. We show a strong mode attenuation for metal strip widths below 1.75 μm at telecom wavelength λ=1.55 μm. We estimate the minimal width using numerical methods and propose an original interpretation. Good agreement with the measured data is achieved. The determination of this critical width is a prerequisite for designing miniaturized plasmonics devices.
Enhanced photothermal therapy assisted with gold nanorods using a radially polarized beam
Authors: Kang Hong , Jia Baohua , Li Jingliang , Morrish Dru , Gu Min
Published: February 2010

We report on the use of a radially polarized beam for photothermal therapy of cancer cells labeled with gold nanorods. Due to a three-dimensionally distributed electromagnetic field in the focal volume, the radially polarized beam is proven to be a highly efficient laser mode to excite gold nanorods randomly oriented in cancer cells. As a result, the energy fluence for effective cancer cell damage is reduced to one fifth of that required for a linearly polarized beam, which is only 9.3% of the medical safety level.
Quantum confinement effect on the vacancy-induced spin polarization in carbon, silicon, and germanium nanoparticles: Density functional analysis
Authors: Zhang Zhenkui , Dai Ying , Huang Baibiao , Whangbo Myung-Hwan
Published: February 2010

Density functional calculations were carried out to examine the vacancy-induced spin polarization in diamond, silicon, and germanium nanoparticles and the magnetic coupling between the vacancy-induced defect states in those nanoparticles. Our calculations show that the vacancy-induced defect states are spin-polarized in diamond nanoparticles regardless of their size but this happens in silicon and germanium nanoparticles only when their size is small, which is in reasonable agreement with the experimentally observed magnetic behaviors. The vacancy-induced defect states on adjacent vacancies prefer to couple ferromagnetically in C nanoparticles but antiferromagnetically in Si and Ge nanoparticles.
Effect of the local hydrogen bonding network on the reorientational and translational dynamics in supercritical water
Authors: Skarmoutsos Ioannis , Guardia Elvira
Published: February 2010

Molecular dynamics simulations have been performed in a wide range of densities along a near critical isotherm of supercritical water in order to reveal the interconnection between the local hydrogen bonding (HB) network and several related dynamic properties. The results obtained have revealed a significant slowing down of reorientational dynamics of the water molecules as the value of the number of hydrogen bond per molecule increases and this is reflected on the increase in the reorientational correlation times. The calculated reorientational times exhibit also an increasing trend by increasing the bulk density, and this effect is more pronounced in the case of the first-order Legendre reorientational correlation functions. A clear nonlinear dependence of the librational mode frequencies of the water molecules on the augmented local density around them has also been revealed. This result could be regarded as an additional support of experimental observations suggesting the use of a nonlinear relation when analyzing the density dependence of spectroscopic peak frequencies in order to extract information about local density augmentation in supercritical fluids. The HB dynamics have been also investigated, revealing a plateau in the calculated HB lifetimes at intermediate and higher liquidlike densities and a small increase at low, gaslike densities.
Raman scattered photon transmission through a single nanoslit
Authors: Chen Chang , Clemente Francesca , Kox Ronald , Lagae Liesbet , Maes Guido , Borghs Gustaaf , Van Dorpe Pol
Published: February 2010

We demonstrate excitation and detection of Raman scattering of a silicon substrate through a 15 nm gold nanoslit. Along with the nanoslit, a plasmonic cavity is fabricated to optimize optical transmission through the slit. Using a polarization analysis we prove that the plasmons enhanced transmission is responsible for the detection of the Raman scattered photons of the silicon substrate through the nanoslit. The optical cavity between the nanoslit and the Si substrate further enhances this backward photon transmission. This opens up prospects for new tools for near-field Raman spectroscopy and sub-wavelength measurements.
Nanometer-scale dielectric constant of Ge quantum dots using apertureless near-field scanning optical microscopy
Authors: Ogawa Y. , Minami F. , Abate Yohannes , Leone Stephen R.
Published: February 2010

Tip-enhanced near-field scattering images of Ge quantum dots (QDs) with 20–40 nm height and 220–270 nm diameter grown on a Si substrate have been observed with a spatial resolution of 15 nm. Changing the wavelength of the incident light, the contrast of the images is reversed. It is found that the scattering intensity is caused by the dielectric constants of the materials under the probe. By changing the wavelength of the incident light, we have obtained information about the dielectric constant dispersion of single Ge QDs.
A direct comparison of single-walled carbon nanotubes and quantum-wells based subpicosecond saturable absorbers for all optical signal regeneration at 1.55 μm
Authors: Nong H. , Gicquel M. , Bramerie L. , Perrin M. , Grillot F. , Levallois C. , Maalouf A. , Loualiche S.
Published: February 2010

Subpicosecond optical transmission experiments are used to compare saturable absorber (SA) based on bundled single-walled carbon nanotubes (SWNT) and iron-doped InGaAs/InP epitaxial multiple quantum wells (MQW) at 1.55 μm telecom wavelength. The SA key parameters (contrast ratio, saturation fluence, and recovery time) relevant for high speed all optical signal regeneration (AOSR) are extracted from the normalized differential transmission (NDT). Although both SA exhibit good contrast ratios, SWNT show a full signal recovery as well as a much faster response time than MQW. This original work on SA shows that SWNT are excellent candidates for future low cost AOSR.
Coating geometries of metals on single-walled carbon nanotubes
Authors: He Yu , Zhang Jinyu , Wang Yan , Yu Zhiping
Published: February 2010

This paper studies the coating geometries of metals on single-walled carbon nanotubes (SWNTs) on the basis of the nucleation theory and wetting theory. The metal surface energy, cohesion energy, diffusion barrier, and metal-SWNT interfacial energy are calculated using first-principles calculation. Metals including Fe, Al, Au, Pd, Ni, and Ti are considered. For Ti, Ni, and Pd, low metal-SWNT interfacial energies and high diffusion barriers are responsible for forming continuous or quasicontinuous layers on the SWNT surface. In contrast, Al and Au have small diffusion barriers and poor SWNT surface wetting, thus they tend to aggregate and form large clusters. Although the binding energy between Fe and SWNTs is large, due to the large cohesion energy and poor wetting, Fe may form isolated clusters. All results are in good agreement with experimental observations.
Full implementation and benchmark studies of Mukherjee’s state-specific multireference coupled-cluster ansatz
Authors: Das Sanghamitra , Mukherjee Debashis , Kállay Mihály
Published: February 2010

The state-specific multireference coupled-cluster (SS-MRCC) ansatz developed by Mukherjee and co-workers [J. Chem. Phys. 110, 6171 (1999)] has been implemented by means of string-based techniques. The implementation is general and allows for using arbitrary complete active spaces of any spin multiplicity and arbitrarily high excitations in the cluster operators. Several test calculations have been performed for single- and multiple-bond dissociations of molecular systems. Our experience shows that convergence problems are encountered when solving the working equations of the SS-MRCC in the case the weight of one or more reference functions tends to take on very small values. This is system specific and cannot yet be handled in a black-box fashion. The problem can be obviated by either dropping all the cluster amplitudes from the corresponding model functions with coefficients below a threshold or by a regularization procedure suggested by Tikhonov or a combination of both. In the current formulation the SS-MRCC is not invariant with respect to transformation of active orbitals among themselves. This feature has been extensively explored to test the degree of accuracy of the computed energies with both pseudocanonical and localized active orbitals. The performance of the method is assessed by comparing the results with the corresponding full configuration interaction (CI) values with the same set of orbitals (correlated and frozen). Relative efficacies of CI methods such as MRCI singles and doubles with the same active space and size-extensivity corrected ones such as MR averaged coupled pair functional and MR averaged quadratic CC have also been studied. Allied full-fledged CC methods have also been employed to see their relative performance vis-à-vis the SS-MRCC. These latter methods are the complete-active-space-inspired single-reference (SR) CC based SS theory and the single-root MR Brillouin–Wigner CC. Our benchmark results indicate that the performance of the SS-MRCC is generally quite good for localized active orbitals. The performance with the pseudocanonical orbitals, however, is sometimes not as satisfactory as for the localized orbitals.
Tunable self-organization of nanocomposite multilayers
Authors: Chen C. Q. , Pei Y. T. , Shaha K. P. , De Hosson J. Th. M.
Published: February 2010

In this letter we report the controlled growth and microstructural evolution of self-assembled nanocomposite multilayers that are induced by surface ion-impingement. The nanoscale structures together with chemical composition, especially at the growing front, have been investigated with high-resolution transmission electron microscopy. Concurrent ion impingement of growing films produces an amorphous capping layer 3 nm in thickness where spatially modulated phase separation is initiated. It is shown that the modulation of multilayers as controlled by the self-organization of nanocrystallites below the capping layer, can be tuned through the entire film.
Electrical failure in blends of chemically identical, soft thermoplastic elastomers with different elastic stiffness
Authors: Kollosche Matthias , Kofod Guggi
Published: February 2010

Investigations on the effect of stiffness on breakdown strength in polymer materials are typically performed indirectly by variation of temperature. Here, the stiffness is varied directly using blends of chemically identical, physically crosslinking elastomers, thus avoiding possible temperature-induced variations in electric and ionic conductivity. Avoiding a chemically crosslinking system rules out variations due to crosslinkers or initiators. Measurements were carried out with a hemispherical indenter resting on a slab of the material with constant load. A theory recently proposed by Zhao and Suo was adapted to the experimental conditions and found to apply well, with no free fitting parameters.
Reaction rate in reversible A↔B reaction-diffusion processes
Authors: Sinder M. , Sokolovsky V. , Pelleg J.
Published: February 2010

The reversible A↔B reaction-diffusion process, where species A and B are initially mixed and diffuse with different diffusion coefficients, is usually simulated in the framework of the quasiequilibrium approximation. In this paper the reaction rate of such process is investigated. It is shown that despite the fact that a reaction-diffusion process is considered as the quasiequilibrium process the contribution of the reaction in changes of the species concentration is comparable with the diffusion contribution. Moreover, the ratio of the reaction to diffusion contributions is independent of time and coordinate. Using published experimental data the reaction rate and its profile are calculated.