bluuebunny/crossref_metadata_2025 huggingface dataset:
Holocene Glacier Fluctuations in the Peruvian Andes Indicate Northern Climate Linkages
Authors: Licciardi Joseph M. , Schaefer Joerg M. , Taggart Jean R. , Lund David C.
Published: September 2009

Togetherness

Two of the most important questions in paleoclimatology are, how are the climates of the Northern and Southern Hemispheres linked, and what are the roles of the high latitudes and the tropics in driving and transmitting climate changes? Past investigations have concentrated on the study of large, rapid climate changes like deglaciations or the Younger Dryas because they are the easiest ones to see and to date.

Licciardi
et al.

(p.
1677
) expand the scope of these investigations by determining precise cosmogenic isotope ages for glacial moraines formed in the Peruvian Andes during the Holocene (the last 11,000 years). The precision of these data reveals a broad correlation between Peruvian glacial advances and climate in the North Atlantic region, revealing important climate linkages between the tropics and higher latitudes.
Distribution of Mid-Latitude Ground Ice on Mars from New Impact Craters
Authors: Byrne Shane , Dundas Colin M. , Kennedy Megan R. , Mellon Michael T. , McEwen Alfred S. , Cull Selby C. , Daubar Ingrid J. , Shean David E. , Seelos Kimberly D. , Murchie Scott L. , Cantor Bruce A. , Arvidson Raymond E. , Edgett Kenneth S. , Reufer Andreas , Thomas Nicolas , Harrison Tanya N. , Posiolova Liliya V. , Seelos Frank P.
Published: September 2009

Martian Impact

Impact craters form frequently on Mars, exposing material that would otherwise remain hidden below the surface.

Byrne
et al.

(p.
1674
) identified mid-latitude craters that formed over the last few years, imaged them in great detail with a camera on board the Mars Reconnaissance Orbiter, and monitored subsequent changes. The craters excavated buried water ice, which was later seen sublimating away. In addition, some craters might have excavated completely through the ice. The observations are consistent with models and other observations that suggest water ice should be stable decimeters to about 1 meter below the martian surface at latitudes poleward of about 40°; and suggest that, in the recent past, Mars had a wetter atmosphere than at present.
Chloroquine Transport via the Malaria Parasite’s Chloroquine Resistance Transporter
Authors: Martin Rowena E. , Marchetti Rosa V. , Cowan Anna I. , Howitt Susan M. , Bröer Stefan , Kirk Kiaran
Published: September 2009

Malaria Chloroquine Resistance Transporter

Malaria is one of the most deadly infectious diseases in the world today, and the emergence and spread of chloroquine-resistant parasites has been a disaster for world health. The Chloroquine Resistance Transporter (PfCRT) was originally identified because mutations in this protein confer chloroquine resistance in the human malaria parasite,
Plasmodium falciparum
. However, the mechanism by which they do so has been the subject of ongoing debate.

Martin
et al.

(p.
1680
) have now succeeded in expressing PfCRT at the surface of
Xenopus laevis
oocytes, establishing a robust and reproducible heterologous system for the study of this protein. The resistance-conferring form of the protein mediates the transport of chloroquine, whereas wild-type PfCRT does not. Thus, as suspected, chloroquine resistance in the malaria parasite indeed arises as a result of the transport of the drug via mutant PfCRT.
Reversible Reactions of Ethylene with Distannynes Under Ambient Conditions
Authors: Peng Yang , Ellis Bobby D. , Wang Xinping , Fettinger James C. , Power Philip P.
Published: September 2009

Tin Two-Step

Doubly and triply bonded carbon compounds have a well-studied tendency to link up with one another and form rings. The rates of these reactions and their relative susceptibilities to acceleration by heat versus light are encapsulated in the decades-old Woodward-Hoffmann rules. More recently, alkene and alkyne analogs have been prepared with heavier elements such as silicon and tin substituted for carbon.

Peng
et al.

(p.
1668
; see the Perspective by

Sita

) have now discovered that two distannynes (compounds with triply bonded tins) react readily with ethylene to form cycloadducts, with tin-carbon σ bonds taking the place of C-C and Sn-Sn π bonds. These products, characterized spectroscopically and crystallographically, are only loosely bound at room temperature, easily reverting to their multiply bonded precursors on gentle heating.
Coordinatively Unsaturated Al
3+
Centers as Binding Sites for Active Catalyst Phases of Platinum on γ-Al
2
O
3
Authors: Kwak Ja Hun , Hu Jianzhi , Mei Donghai , Yi Cheol-Woo , Kim Do Heui , Peden Charles H. F. , Allard Lawrence F. , Szanyi Janos
Published: September 2009

Bonding Oxides and Metals

The binding of noble metals that can act as catalysts to metal oxides that are reducible is assumed to occur at the exposed cation of the oxide. For nonreducable oxides such as aluminum oxide, it is not so obvious how the metal can bind strongly.

Kwak
et al.

(p.
1670
) used a combination of high-resolution transmission electron microscopy and solid-state magic-angle spinning nuclear magnetic resonance to study the anchoring of platinum at high and low loadings on alumina. At the surface, the Al
3+
ions were penta-coordinated. Density functional calculations support a model in which the cation binds three oxygen atoms in the alumina and two from platinum oxide.
Simulating Multifunctional Structures
Authors: Phillpot Simon R. , Sinnott Susan B.
Published: September 2009

More powerful computers and better algorithms are making it possible to probe and engineer the atomic-level properties of nanostructures.
Detection of Adsorbed Water and Hydroxyl on the Moon
Authors: Clark Roger N.
Published: September 2009

Lunar Water

The Moon has been thought to be primarily anhydrous, although there has been some evidence for accumulated ice in permanently shadowed craters near its poles (see the Perspective by

Lucey

, published online 24 September). By analyzing recent infrared mapping by Chandrayaan-1 and Deep Impact, and reexamining Cassini data obtained during its early flyby of the Moon,

Pieters
et al.

(p.
568
, published online 24 September),

Sunshine
et al.

(p.
565
, published online 24 September), and

Clark
et al.

(p.
562
, published online 24 September) reveal a noticeable absorption signal for H
2
O and OH across much of the surface. Some variability in water abundance is seen over the course of the lunar day. The data imply that solar wind is depositing and/or somehow forming water and OH in minerals near the lunar surface, and that this trapped water is dynamic.
Temporal and Spatial Variability of Lunar Hydration As Observed by the Deep Impact Spacecraft
Authors: Sunshine Jessica M. , Farnham Tony L. , Feaga Lori M. , Groussin Olivier , Merlin Frédéric , Milliken Ralph E. , A’Hearn Michael F.
Published: September 2009

Lunar Water

The Moon has been thought to be primarily anhydrous, although there has been some evidence for accumulated ice in permanently shadowed craters near its poles (see the Perspective by

Lucey

, published online 24 September). By analyzing recent infrared mapping by Chandrayaan-1 and Deep Impact, and reexamining Cassini data obtained during its early flyby of the Moon,

Pieters
et al.

(p.
568
, published online 24 September),

Sunshine
et al.

(p.
565
, published online 24 September), and

Clark
et al.

(p.
562
, published online 24 September) reveal a noticeable absorption signal for H
2
O and OH across much of the surface. Some variability in water abundance is seen over the course of the lunar day. The data imply that solar wind is depositing and/or somehow forming water and OH in minerals near the lunar surface, and that this trapped water is dynamic.
Revising the AP Biology Curriculum
Authors: Wood William B.
Published: September 2009

Major, welcome changes to the AP biology curriculum raise questions about implementation and assessment.
Election Heats Up Nuclear Debate
Authors: Vogel Gretchen
Published: September 2009

A nearly 3-decade-old telex message regarding the scientific evaluation of a disposal site for highly radioactive nuclear waste in Germany has become a prominent issue in the campaign leading up to Sunday's national elections.
Investigation of outpatients referred to a chemical pathologist with potential pseudohyperkalaemia
Authors: Kapoor A K , Ravi A , Twomey P J
Published: September 2009

Background:

Pseudohyperkalaemia is when the in vitro blood potassium concentration is artefactually raised while the in vivo concentration is normal. With unexplained hyperkalaemia, pseudohyperkalaemia needs to be excluded to avoid unnecessary and potentially detrimental therapy. There are numerous causes, but no systematic approach for the investigation of outpatients with potential pseudohyperkalaemia exists in the literature.

Aims:

To evaluate the in-house protocol.

Methods:

Patients referred for investigation of potential pseudohyperkalaemia underwent an outpatient based protocol which is designed to determine whether the cause was due to delayed blood separation, clotting, centrifugation or a haematological abnormality.

Results:

32 patients with serum potassium of 5.5–7.1 mmol/l were referred. All patients had pseudohyperkalaemia; the most frequent causes were full blood count (FBC) abnormalities (28%), time >4 hours from sampling to centrifugation (28%) and sample clotting (25%). Anaemia was more likely to be found in male patients.

Conclusion:

Before a problem can be treated, it must be confirmed and its aetiology identified. A systematic approach to investigate potential pseudohyperkalaemia has been presented. This confirmed the clinician’s suspicion of pseudohyperkalaemia and in the majority of patients the aetiology was also identified. The use of serum and plasma potassium with an FBC in the initial investigation will identify whether clotting or a haematological abnormality is the cause in about half of the cases. Assay of whole-blood potassium is less important as centrifugation is a rare cause. Time to centrifugation is likely to play a major part in the majority of the remaining cases.
α1-Antitrypsin deficiency: best clinical practice
Authors: Kalsheker N A
Published: September 2009

α1-Antitrypsin (AAT), a 52 kDa plasma protein, is produced mainly in the liver. It is the most abundant circulatingserineproteinaseinhibitor (serpin). It has also previously been called protease inhibitor to reflect its function as a general inhibitor of serine proteases. Its main physiological role is to inhibit neutrophil elastase and it contributes to the innate immune system as an anti-inflammatory protein. Severe AAT deficiency is most prevalent in northern Europeans affecting about 1 in 3000 of the population. AAT deficiency predisposes individuals who smoke to developing pulmonary emphysema in the fourth–fifth decade of adult life and to childhood cirrhosis in about 10% of cases, with the initial presentation being prolonged neonatal jaundice. The mean interval from presentation with symptoms to diagnosis in adults is about 8 years. The condition is under-recognised and under-diagnosed. The only effective current treatment for the severe liver disease that occurs in childhood currently is liver transplantation. Replacement therapy with purified AAT from human plasma is being used in clinical practice for the lung disease though it is not known whether this influences the outcome of this chronic condition. The liver pathology arises from intracellular polymerisation of mutant protein, and attenuation of polymerisation is a potential target for therapy.
The role of laboratory processing in determining diagnostic conclusiveness of breast fine needle aspirations: conventional smearing versus a monolayer preparation
Authors: Wauters C A P , Kooistra B , Strobbe L J A
Published: September 2009

Aim:

To compare breast fine needle aspiration (FNA) specimens prepared by conventional smearing (CS) versus monolayer preparation (MP), with respect to the conclusiveness of the cytopathological diagnosis.

Methods:

From 1992 to 1996, aspirators prepared aspirates themselves by direct smearing onto 2–4 slides. From 1999 to 2003, aspirate preparation was performed in the laboratory, creating a MP, using a Hettich cytocentrifuge. FNA diagnoses were categorised into inadequate (C1), benign (C2), atypical (C3), suspicious for malignancy (C4) and malignant (C5). The reference standard constituted histological follow-up. A conclusive FNA diagnosis was defined as C2 in lesions benign on follow-up and C5 in lesions malignant on histology.

Results:

From 1992 to 1996, 692 aspirates were processed by CS, whereas from 1999 to 2003, 1301 aspirates were processed by MP. More FNA were ultrasound-guided in the MP group (85.6% versus 21.5%, p<0.001). When compared with CS, MP-prepared FNA had conclusive diagnoses significantly more often (72.8% versus 58.5%, p<0.001). This effect remained significant when corrected for the difference in ultrasound guidance (adjusted odds ratio 1.7, 95% confidence interval 1.3 to 2.2, p<0.001), and was larger for malignant lesions than for benign lesions (51.7% versus 79.9%, p<0.001).

Conclusion:

Patients presenting with breast lesions can more often be offered a same-day, conclusive cytopathological diagnosis when FNA are prepared by a manual MP processing technique.
BCL2gene aberration as an IPI-independent marker for poor outcome in non-germinal-centre diffuse large B cell lymphoma
Authors: Obermann E C , Csato M , Dirnhofer S , Tzankov A
Published: September 2009

Aim:

Diffuse large B cell lymphoma (DLBCL) is the most common lymphoid malignancy in the western hemisphere, and is characterised by a highly variable outcome that impedes individual risk assessment. Lacking reliable biomarkers, the international prognostic index (IPI) has been the most reliable factor to predict survival and stratify patients for therapy. The aim of this study was to investigate the frequency and potential prognostic role ofBCL2aberrations on the chromosomal level and the protein level in a large DLBCL collective.

Methods:

Fluorescence in situ hybridisation (FISH) with commercially available dual-colour break-apart probes and immunohistochemistry were used to assessBCL2gene abnormalities and bcl2 protein expression on validated tissue microarrays containing 224 well-characterised cases of primary DLBCL.

Results:

FISH analysis ofBCL2revealed a break in 40/215 cases (19%) and a gain in 66/171 (39%) cases. OnlyBCL2gains correlated with bcl2 protein expression (p = 0.001). Presence of anyBCL2gene abnormality, particularly gains, correlated independently of the IPI with a significantly worse prognosis in DLBCL of non-germinal centre (non-GC) phenotype as opposed to DLBCL of non-GC type without this genetic alteration (p = 0.003). DLBCL of germinal centre phenotype did not show this association.

Conclusions:

Cases of DLBCL of the non-GC type withBCL2gene aberration are accompanied by a significantly worse prognosis as opposed to cases without such gene abnormalities. It may be helpful to assesBCL2gene abnormalities by FISH in addition to assessing established parameters for individual risk estimation in DLBCL.
EXPLORING TRANS-PLANCKIAN PHYSICS AND THE CURVATURE EFFECT BY THE PRIMORDIAL POWER SPECTRUM WITH WMAP FIVE-YEAR DATA
Authors: REN JIE , ZHANG HONG-GUANG , MENG XIN-HE
Published: September 2009

The vacuum inflation with a boundary condition specified at a short distance scale in a generally primeval nonflat universe, and implications of the correspondingly modified primordial power spectrum via the WMAP data are investigated. We obtain a general form of the modified primordial power spectrum including the effects of both the possibly new physics scale and the spatial curvature. The modulation of the primordial power spectrum due to new physics is of the order H/Λ, where H is the Hubble parameter during inflation and Λ is the new physics scale which is key to inflation, while the modulation from the curvature effect is of the order K/k2, where K is the spatial curvature before inflation and k is the comoving wave number. We also find that a closed universe before inflation is favored by WMAP five-year data.
REVISITING THE MODIFIED STAROBINSKY MODEL WITH A COSMOLOGICAL CONSTANT
Authors: PELINSON ANA
Published: September 2009

The Starobinsky model is a natural inflationary scenario in which inflation arises due to quantum effects of the massless matter fields. A modified version of the Starobinsky (MSt) model takes the masses of matter fields and the cosmological constant, Λ, into account. The equations of motion become much more complicated; however, approximate analytic and numeric solutions are possible. In the MSt model, inflation starts due to the supersymmetric (SUSY) particle content of the underlying theory, and the transition to the radiation-dominated epoch occurs due to the relatively heavy s-particles decoupling. For Λ = 0 the inflationary solution is stable until the last stage, just before decoupling. In the present paper we generalize this result for Λ ≠ 0, since Λ should be nonvanishing at the SUSY scale. We also take into account the radiative corrections to Λ. The main result is that the inflationary solution of the MSt model remains robust and stable.
ON THE X-RAY PROPERTIES OF H2O MASER HOST GALAXIES
Authors: GUO QIAN , ZHANG JIANG-SHUI , FAN JUN-HUI
Published: September 2009

All galaxies beyond the Magellanic clouds with detected H 2 O maser emission so far are investigated and their X-ray observations are collected in detail to probe the X-ray properties of this special kind of galaxies. The soft excess and the strong iron emission line are commonly presented in their X-ray spectrum. Similar to the spectra of normal Seyfert 2 galaxies, the X-ray soft components are usually explained well by two alternative models or their combination: the absorbed power law model and the thermal emission model. The hard X-ray continua are usually flat, which should be caused by the increase of the reflection component, with the increase of the absorbing material density. Modeling their X-ray spectra shows that high absorbing column density is prevalent in our H 2 O megamaser host AGNs. Further, we investigate a possible relation between the iron line emission and the nuclear X-ray emission. It shows no significant correlation between the equivalent width (EW) of the neutral Fe Kα emission line (~ 6.4 keV) and the intrinsic nuclear X-ray luminosity. However, one trend appears clearly — the EW of the iron line decreases with the increase of the observed X-ray luminosity for our H 2 O maser galaxies. We also estimate the accretion rate of H 2 O maser host AGNs and the results show that maser galaxies may have a higher accretion rate than nonmaser Seyfert galaxies. In addition, possible relations between the EW of the iron line with the accretion rate and the central black hole mass are investigated and no significant trend of correlation can be found between them.
HELICAL MAGNETIC FIELDS FROM INFLATION
Authors: CAMPANELLI LEONARDO
Published: September 2009

We analyze the generation of seed magnetic fields during de Sitter inflation considering a noninvariant conformal term in the electromagnetic Lagrangian of the form [Formula: see text], where I(ϕ) is a pseudoscalar function of a nontrivial background field ϕ. In particular, we consider a toy model that could be realized owing to the coupling between the photon and either a (tachyonic) massive pseudoscalar field or a massless pseudoscalar field nonminimally coupled to gravity, where I follows a simple power law behavior I(k,η) = g/(-kη)β during inflation, while it is negligibly small subsequently. Here, g is a positive dimensionless constant, k the wave number, η the conformal time, and β a real positive number. We find that only when β = 1 and 0.1 ≲ g ≲ 2 can astrophysically interesting fields be produced as excitation of the vacuum, and that they are maximally helical.
CHAPLYGIN ELECTRON GAS MODEL
Authors: RADINSCHI I. , RAHAMAN F. , KALAM M. , CHAKRABORTY K.
Published: September 2009

We provide a new electromagnetic mass model admitting the Chaplygin gas equation of state. We investigate three specializations, the first characterized by a vanishing effective pressure, the second provided with a constant effective density and the third described by a constant effective pressure p0. For these specializations we will discuss the models assuming that [Formula: see text], where σ, σ0, λ and s represent the charge density of the spherical distribution, the charge density at the center of the system, the metric potential and a constant, respectively. In addition, for specialization I, we have found the isotropic coordinate as well as the Kretschmann scalar for a particular case, and for specialization III two special scenarios have been studied.
QUASINORMAL MODES AND STABILITY OF A FIVE-DIMENSIONAL DILATONIC BLACK HOLE
Authors: LÓPEZ-ORTEGA A.
Published: September 2009

We exactly calculate the quasinormal frequencies of the electromagnetic and Klein–Gordon perturbations propagating in a five-dimensional dilatonic black hole. Furthermore, we exactly find the quasinormal frequencies of the massive Dirac field. Using these results we study the linear stability of this black hole. We compare our results for the quasinormal frequencies and for the linear stability of the five-dimensional black hole with those already published.
ARBITRAGE SMOOTHING IN FITTING A SEQUENCE OF YIELD CURVES
Authors: BEKKER PAUL A. , BOUWMAN KEES E.
Published: September 2009

Empirical modeling of the yield curve is often inconsistent with absence of arbitrage. In fact, many parsimonious models, like the popular Nelson-Siegel model, are inconsistent with absence of arbitrage. In other cases, arbitrage-free models are often used in inconsistent ways by recalibrating parameters that are assumed constant. For these cases, this paper introduces an arbitrage smoothing device to control arbitrage errors that arise in fitting a sequence of yield curves. The device is applied to the US term structure for the family of Nelson-Siegel curves. It is shown that the arbitrage smoothing device contributes to parameter stability and smoothness.
SIMULTANEOUS CALIBRATION TO A RANGE OF PORTFOLIO CREDIT DERIVATIVES WITH A DYNAMIC DISCRETE-TIME MULTI-STEP MARKOV LOSS MODEL
Authors: WALKER MICHAEL B.
Published: September 2009

This article describes a dynamic discrete-time multi-step Markov model for the losses experienced by a given credit portfolio, and develops a method for the simultaneous calibration of the model to all available relevant market prices (for CDO's, forward-start CDO's, options on CDO's, leveraged super-senior tranches with loss triggers, etc.) established on a given day. The implementation is via an efficient linear programming procedure, and examples are given. The approach represents an extension of previous work (Walker, 2005, 2006; Torresetti et al., 2006) on the static loss-surface model to a model containing the necessary underlying dynamics.
ASYMPTOTICS OF CANONICAL AND SATURATED RNA SECONDARY STRUCTURES
Authors: CLOTE PETER , KRANAKIS EVANGELOS , KRIZANC DANNY , SALVY BRUNO
Published: September 2009

It is a classical result of Stein and Waterman that the asymptotic number of RNA secondary structures is 1.104366 · n-3/2 · 2.618034n. In this paper, we study combinatorial asymptotics for two special subclasses of RNA secondary structures — canonical and saturated structures. Canonical secondary structures are defined to have no lonely (isolated) base pairs. This class of secondary structures was introduced by Bompfünewerer et al., who noted that the run time of Vienna RNA Package is substantially reduced when restricting computations to canonical structures. Here we provide an explanation for the speed-up, by proving that the asymptotic number of canonical RNA secondary structures is 2.1614 · n-3/2 · 1.96798n and that the expected number of base pairs in a canonical secondary structure is 0.31724 · n. The asymptotic number of canonical secondary structures was obtained much earlier by Hofacker, Schuster and Stadler using a different method.

Saturated secondary structures have the property that no base pairs can be added without violating the definition of secondary structure (i.e. introducing a pseudoknot or base triple). Here we show that the asymptotic number of saturated structures is 1.07427 · n-3/2 · 2.35467n, the asymptotic expected number of base pairs is 0.337361 · n, and the asymptotic number of saturated stem-loop structures is 0.323954 · 1.69562n, in contrast to the number 2n - 2 of (arbitrary) stem-loop structures as classically computed by Stein and Waterman. Finally, we apply the work of Drmota to show that the density of states for [all resp. canonical resp. saturated] secondary structures is asymptotically Gaussian. We introduce a stochastic greedy method to sample random saturated structures, called quasi-random saturated structures, and show that the expected number of base pairs is 0.340633 · n.
ITERATIVE TWO-PASS ALGORITHM FOR MISSING DATA IMPUTATION IN SNP ARRAYS
Authors: SINOQUET CHRISTINE
Published: September 2009

Though nowadays high-throughput genotyping techniques' quality improves, missing data still remains fairly common. Studies have shown that even a low percentage of missing SNPs is detrimental to the reliability of down-stream analyses such as SNP-disease association tests. This paper investigates the potentiality for improving the accuracy of an SNP inference method based on the algorithm formerly designed by Roberts and co-workers (NPUTE, 2007). This initial algorithm performs a single scan of an SNP array, inferring missing SNPs in the context of sliding windows. We have first designed a variant, KNNWinOpti, which fully exploits backward and forward dependencies between the overlapping windows and thus restores the genuine dependency of inference upon direction scanning. Our major contribution, algorithm SNPShuttle, therefore iterates bi-directional scanning to predict SNP values with more confidence. We have run simulations on realistic benchmarks built after the high resolution map of mouse strains published by the Perlegen Project. For each of the 20 mouse chromosomes and for missing data percentage varying in range 5%–30%, SNPShuttle has always been shown to increase yet high KNNWinOpti's accuracies.
A NOTE ON THE CALCULATION OF N-STATISTICS
Authors: ALMUDEVAR ANTHONY
Published: September 2009

A class of statistics suitable for testing against equality of multivariate distributions is described by Klebanov and co-workers in 2007. Referred to as N-statistics, their discriminating ability is based on various forms of distance kernels in ℝd, the intention being to capture distinct forms of deviation from equality. This makes them particularly suitable for large-scale genomic screening applications, in which such variety of alternatives can be anticipated. One of these kernels, denoted as L4, introduces weighting by directional densities, hence the evaluation of L4 requires integration on the unit sphere in ℝd. In this note we introduce a methodology for the evaluation of integrals related to L4. It is shown that for a class of directional densities including, but not limited to, the uniform density L4 reduces to Euclidean distance. For other cases, the methodology permits a direct interpretation of L4 in terms of the directional weighting.
INVESTIGATION OF SEISMIC DAMAGE OF CABLE-STAYED BRIDGES WITH DIFFERENT CONNECTION CONFIGURATION
Authors: LI HUI , LIU JINLONG , OU JINPING
Published: September 2009

In this paper, the seismic behaviors of three cable-stayed bridges with different structural systems including Rigid System (RS), Floating System (FS) and Passive Energy Dissipation System (PEDS) are studied. The results show that the seismic behaviors of these bridges are so different even under the same earthquake. Based on damage analysis of the towers, failure modes of the three different systems are concluded. For RS, the bottom of the middle tower is a vulnerable region, implying that the failure mainly focuses here and plastic hinge forms under earthquake. The FS is damaged most severely, in which the edge tower has a larger damage index than that of middle tower. While the seismic responses of PEDS decrease dramatically compared to FS due to the incorporation of viscous dampers and the damage indices for all towers are small. The seismic damage condition between the middle tower and the edge tower can be adjusted by changing the damping coefficient of the viscous damper.
A PERFORMANCE-BASED SEISMIC DESIGN METHODOLOGY FOR STEEL BRIDGE SYSTEMS
Authors: USAMI TSUTOMU , GE HANBIN
Published: September 2009

This paper outlines a performance-based seismic design methodology for steel bridge systems. Two kinds of menus are proposed. The first is the displacement-based evaluation method which compares the response displacement with the ultimate displacement, and the second is the strain-based evaluation method which compares the response strain and the ultimate strain. Moreover, the seismic required performance matrix for bridge structures and soundness matrix for members are presented and discussed.
INTEGRATED SIMULATION FOR EARTHQUAKE HAZARD AND DISASTER PREDICTION
Authors: HORI MUNEO , OGUNI KENJI , ICHIMURA TSUYOSHI
Published: September 2009

This paper presents the integrated simulation for earthquake hazard and disaster prediction. The earthquake hazard simulation takes advantage of the macro-micro analysis method which estimates strong ground motion with high spatial and temporal resolution. The earthquake disaster simulation calculates seismic responses for all structures in a target area by inputting synthesized strong ground motion to a structure analysis method which is plugged into the system; a suitable analysis method, linear or non-linear, is chosen depending on the type of the structure. The results of all simulations are visualized so that government officials and residents can share common recognition of possible earthquake hazard and disaster. Two examples of this integrated earthquake simulations are presented; one is made by plugging nonlinear structure analysis methods into the system, and the other is made for an actual city, the computer model of which is constructed with the help of available geographical information systems.
Apatite thermochronology in modern geology
Authors: Lisker F. , Ventura B. , Glasmacher U. A.
Published: September 2009

Fission-track and (U–Th–Sm)/He thermochronology on apatites are radiometric dating methods that refer to thermal histories of rocks within the temperature range of 40°–125 °C. Their introduction into geological research contributed to the development of new concepts to interpreting time-temperature constraints and substantially improved the understanding of cooling processes within the uppermost crust. Present geological applications of apatite thermochronological methods include absolute dating of rocks and tectonic processes, investigation of denudation histories and long-term landscape evolution of various geological settings, and basin analysis.
Focused erosion in the Alps constrained by fission-track ages on detrital apatites
Authors: Malusà Marco G. , Zattin Massimiliano , Andò Sergio , Garzanti Eduardo , Vezzoli Giovanni
Published: September 2009

Fission-track dating on detrital apatites from modern sands of the Po Delta is used for a provenance study of sediments in the Po River basin. Analysed samples show a fission-track grain-age distribution characterized by two prominent peaks at 7.7 Ma and 17 Ma. The youngest peak accounts for 46% of the total population of dated grains. This young component in the grain-age distribution is consistent with bedrock cooling ages observed in the Western Alps between the External Massifs and the Houiller unit, as well as in the Lepontine dome of the Central Alps and in the Miocene foredeep units of the Apennines, that overall represent only 12% of the orogenic source area. Results suggest that most of the sediment load in the last 10
2
–10
5
years was supplied by focused erosion of relatively small areas that experienced short-term erosion rates one order of magnitude higher than in the rest of the belt.
Exhumation of the Sierra de Cameros (Iberian Range, Spain): constraints from low-temperature thermochronology
Authors: Del Río P. , Barbero L. , Stuart F. M.
Published: September 2009

We present new fission-track and (U–Th)/He data from apatite and zircon in order to reconstruct the exhumation of the Sierra de Cameros, in the northwestern part of Iberian Range, Spain. Zircon fission-track ages from samples from the depocentre of the basin were reset during the metamorphic peak at approximately 100 Ma. Detrital apatites from the uppermost sediments retain fission-track age information that is older than the sediment deposition age, indicating that these rocks have not exceeded 110 °C. Apatites from deeper in the stratigraphic sequence of the central part of the basin have fission-track ages of around 40 Ma, significantly younger than the stratigraphic age, recording the time of cooling after peak metamorphic conditions. Apatite (U–Th)/He ages in samples from these sediments are 31–40 Ma and record the last period of cooling during Alpine compression. The modelled thermal history derived from the uppermost sediments indicates that the thermal pulse associated with peak metamorphism was rapid, and that the region has cooled continuously to the present. The estimated palaeogeothermal gradient is around 86 °C km
−1
and supports a tectonic model with a thick sedimentary fill (
c
. 8 km) and explains the origin of the low-grade metamorphism observed in the oldest sediments.
Thermal and denudation history of the Lusatian Block (NE Bohemian Massif, Germany) as indicated by apatite fission-track data
Authors: Ventura Barbara , Lisker Frank , Kopp Jürgen
Published: September 2009

The Lusatian Block in eastern Germany is part of the Variscan Bohemian Massif. It is located at the intersection of two regional fault–thrust systems that have been controlling the regional geological and landscape evolution since at least late Mesozoic times, the Elbe Fault System and the Eger Graben. Although the Lusatian Block has traditionally been described as a morphological high throughout the Mesozoic, timing, style and amount of denudation have not yet been quantified. Apatite fission-track (AFT) analysis of basement rocks yields ages varying between approximately 70 and 95 Ma, with mean track-lengths ranging from 13.6 to 14.1 µm. Thermal history modelling of the AFT data points to a minimum denudation of 3 km of the Lusatian Block in the Late Cretaceous. Onset of denudation can be related to transpression along the Lusatian Thrust as a main element of the Elbe Fault System. Moreover, the thermal history models provide tentative evidence for a second cooling–denudation event, which affected Lusatia in the late Palaeogene. This final denudation of at least 1 km probably occurred as a far-field response to the uplift of the northern shoulder of the Cenozoic Eger Graben.
Steady-state exhumation pattern in the Central Andes – SE Peru
Authors: Ruiz G. M. H. , Carlotto V. , Van Heiningen P. V. , Andriessen P. A. M.
Published: September 2009

The Western Cordillera of SE Peru is part of the Central Andes and is situated to the west of the Eastern Andes from which it is separated by the northern termination of the Altiplano – the Inter-Andean Valley. It is a volcanic–volcano-detrital chain that developed in the Palaeogene, and is characterized by a 4000 m-high mean altitude whose origin is poorly constrained. We selected a vertical profile in the region of Abancay to trace the record the evolving uplift and erosion history of the Andean orogen. Fission-track data on both apatite and zircon crystals were completed on plutonic rocks of the Tertiary Andahuaylas–Yauri batholith. Ages ranged between 24 and 14 Ma, and 38 and 30 Ma, respectively. Thermal modelling was completed for the whole profile and does not, like age–altitude relationships, show evidence of any clear disruption of the exhumation paths since 38 Ma either by sedimentary burial and/or rapid exhumation. One of the noteworthy aspects of the data is that exhumation was steady at a rate of 0.17 km Ma
−1
from the late Eocene until at least the middle Miocene (38–14 Ma). The uplift of the Western Cordillera was thus probably steady for this period with sedimentary deposition restricted to the present-day Altiplano and Inter-Andean Valley regions.
Improving constraints on apatite provenance: Nd measurement on fission-track-dated grains
Authors: Carter A. , Foster G. L.
Published: September 2009

Detrital thermochronology is commonly used to locate source and improve the understanding of a region's long-term development. Provenance detrital age data typically comprise a number of distinct age modes representing contributions from a number of different sources. For methods such as apatite fission track (FT) this can present a challenge in that direct assignment of age modes to particular lithological or tectono-stratigraphic units is rarely possible, particularly when ancient orogenic sediments are examined. A new approach described here is based on measuring Nd isotopic data on single apatites by laser ablation ICPMS where the
143
Nd/
144
Nd ratios are diagnostic of grain source. By combining Nd isotopic measurement with apatite FT analysis it is possible to link detrital apatite FT ages to specific rock unit sources. The methodology and wider benefits of this new approach are discussed using examples from the Himalaya and Andaman Islands.
Calibration and comparison of etching techniques for apatite fission-track thermochronology
Authors: Murrell G. R. , Sobel E. R. , Carrapa B. , Andriessen P.
Published: September 2009

Understanding time–temperature histories using apatite fission-track thermochronology involves sample preparation, analysis and then thermal modelling using an appropriate annealing algorithm. A subtle point in this sequence is ascertaining that the sample preparation utilized is compatible with the methodology used in obtaining the data for constructing the annealing data set. This issue is important if one wishes to utilize the relatively new multikinetic annealing algorithm of Ketcham
et al.
that is implemented in their AFTSolve and HeFTy models which is based on a different etching recipe than those previously used. A preliminary calibration step involves comparing published etch pit diameters for a suite of samples with those analysed by an operator. Results show that the operator can reliably reproduce the calibration data set. We then report a laboratory experiment using samples from Finland and Spain that compares the results obtained using two different etching methodologies (7% nitric acid with qualitative etching conditions and 5.5 M nitric acid at constant conditions). The two raw data sets yield variable results. Comparing the two etching methodologies reveals the influence of this procedure on the kinetic parameter
D
par
.
Convective heat transfer in a steeply dipping fault zone and its impact on the interpretation of fission-track data - a modelling study
Authors: Timar-Geng Zoltan , Henk Andreas , Wetzel Andreas
Published: September 2009

The effects of convective heat transfer by hydrothermal fluid flow on fission-track (FT) thermochronology are studied using numerical modelling techniques. Parameter studies are carried out on two-dimensional crustal segments with a steeply dipping fault zone exposed to constant denudation to evaluate the relative importance of different variables, including denudation rate as well as hydraulic and material properties. Time–temperature histories of particle points are calculated in the vicinity and also a few kilometres away of the fault zone. These time–temperature paths are then used in a forward-modelling approach to determine the expected FT cooling ages and track-length distributions.

Modelling results indicate that hydrothermal fluid flow can significantly disturb the background conductive thermal state of the upper crust, and the interpretation of FT data using a steady-state geothermal gradient can result in erroneous denudation rates that overestimate the true erosion rates by more than 80%. A pattern of highly varied FT cooling ages from samples at the same elevation does not necessarily ask for differential tectonic movements, instead it can be generated by deep circulation of groundwater within a few million years (Ma). Denudation rates inferred from FT cooling age–elevation plots are likewise inaccurate in a hydrothermally active area because the important assumption about closure temperature isotherms being horizontal or at a constant depth below the surface is not met.
What perturbs isotherms? An assessment using fission-track thermochronology and thermal modelling along the Gotthard transect, Central Alps
Authors: Glotzbach C. , Spiegel C. , Reinecker J. , Rahn M. , Frisch W.
Published: September 2009

Interpretation of low-temperature thermochronological data usually relies on assumptions on the shape of isotherms. Recently, a number of thermal modelling approaches investigate and predict the theoretical influence of topography on isotherms. The application and proof of these predictions is not well confirmed by measured data. Here we present apatite fission-track (AFT) data from samples collected along the Gotthard road tunnel and its corresponding surface line to test these predictions. AFT ages broadly cluster around 6 Ma along the tunnel. No correlation of tunnel ages with superimposed topography is seen, which means that topography-induced perturbation of isotherms under given boundary conditions (topographic wavelength 12 km; relief 1.5 km; exhumation rate 0.45 km Ma
−1
) can be neglected for the interpretation of AFT ages. Thus, in areas characterized by similar topographies and exhumation rates, apparent exhumation rates deduced from the age–elevation relationship (AER) of AFT data need no correction for topography-induced perturbation of isotherms. Three-dimensional (3D) numerical thermal modelling was carried out incorporating thermally relevant parameters and mechanisms, such as topography, geology, thermal conductivities and heat production. Modelling reveals a strong influence on the shape of isotherms caused by spatially variable thermal parameters, especially heat production rates. Therefore, not only topography has to be considered for interpreting low-temperature thermochronological data, but also other parameters like heat production rates.

Supplementary material:
1. Electron microprobe analyses, 2. Topography and model extend, 3. Model parameters are all available online at
http://www.geolsoc.org.uk/SUP18380
.
TLR3-mediated NF-κB signaling in human esophageal epithelial cells
Authors: Lim Diana M. , Narasimhan Sneha , Michaylira Carmen Z. , Wang Mei-Lun
Published: September 2009

Despite its position at the front line against ingested pathogens, very little is presently known about the role of the esophageal epithelium in host innate immune defense. As a key player in the innate immune response, Toll-like receptor (TLR) signaling has not been well characterized in human esophageal epithelial cells. In the present study, we investigated the inflammatory response and signaling pathways activated by TLR stimulation of human esophageal cells in vitro. Using quantitative RT-PCR, we profiled the expression pattern of human TLRs 1–10 in primary esophageal keratinocytes (EPC2), immortalized nontransformed esophageal keratinocytes (EPC2-hTERT), and normal human esophageal mucosal biopsies and found that TLRs 1, 2, 3, and 5 were expressed both in vivo and in vitro. Using the cytokine IL-8 as a physiological read out of the inflammatory response, we found that TLR3 is the most functional of the expressed TLRs in both primary and immortalized esophageal epithelial cell lines in response to its synthetic ligand polyinosinic polycytidylic acid [poly(I:C)]. Through reporter gene studies, we show that poly(I:C)-induced NF-κB activation is critical for the transactivation of the IL-8 promoter in vitro and that nuclear translocation of NF-κB occurs at an early time point following poly(I:C) stimulation of esophageal epithelial cells. Importantly, we also show that poly(I:C) stimulation induces the NF-κB-dependent esophageal epithelial expression of TLR2, leading to enhanced epithelial responsiveness of EPC2-hTERT cells to TLR2 ligand stimulation, suggesting an important regulatory role for TLR3-mediated NF-κB signaling in the innate immune response of esophageal epithelial cells. Our findings demonstrate for the first time that TLR3 is highly functional in the human esophageal epithelium and that TLR3-mediated NF-κB signaling may play an important regulatory role in esophageal epithelial homeostasis.
Effect of meal volume and calorie load on postprandial gastric function and emptying: studies under physiological conditions by combined fiber-optic pressure measurement and MRI
Authors: Kwiatek Monika A. , Menne Dieter , Steingoetter Andreas , Goetze Oliver , Forras-Kaufman Zsofia , Kaufman Elad , Fruehauf Heiko , Boesiger Peter , Fried Michael , Schwizer Werner , Fox Mark R.
Published: September 2009

This study assessed the effects of meal volume (MV) and calorie load (CL) on gastric function. MRI and a minimally invasive fiber-optic recording system (FORS) provided simultaneous measurement of gastric volume and pressure changes during gastric filling and emptying of a liquid nutrient meal in physiological conditions. The gastric response to 12 iso-osmolar MV-CL combinations of a multinutrient drink (MV: 200, 400, 600, 800 ml; CL: 200, 300, 400 kcal) was tested in 16 healthy subjects according to a factorial design. Total gastric volume (TGV) and gastric content volume (GCV = MV + secretion) were measured by MRI during nasogastric meal infusion and gastric emptying over 60 min. Intragastric pressure was assessed at 1 Hz by FORS. The dynamic change in postprandial gastric volumes was described by a validated three-component linear exponential model. The stomach expanded with MV, but the ratio of GCV:MV at t0 diminished with increasing MV ( P < 0.01). Postprandial changes in TGV followed those of GCV. Intragastric pressure increased with MV, and this effect was augmented further by CL ( P = 0.02); however, the absolute pressure rise was <4 mmHg. A further postprandial increase of gastric volumes was observed early on before any subsequent volume decrease. This “early” increase in GCV was greater for smaller than larger MV ( P < 0.01), indicating faster initial gastric emptying of larger MV. In contrast, volume change during filling and in the early postprandial period were unaffected by CL. In the later postprandial period, gastric emptying rate continued to be more rapid with high MVs ( P < 0.001); however, at any given volume, gastric emptying was slowed by higher CL ( P < 0.001). GCV half-emptying time decreased with CL at 18 ± 6 min for each additional 100-kcal load ( P < 0.001). These findings indicate that gastric wall stress (passive strain and active tone) provides the driving force for gastric emptying, but distal resistance to gastric outflow regulates further passage of nutrients. The distinct early phase of gastric emptying with relatively rapid, uncontrolled passage of nutrients into the small bowel, modulated by meal volume but not nutrient composition, ensures that the delivery of nutrients in the later postprandial period is related to the overall calorie load of the meal.