bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Invasiveness Between Laparoscopy‐Assisted Total Gastrectomy and Open Total Gastrectomy
Authors: Kawamura Hideki , Yokota Ryoichi , Homma Shigenori , Kondo Yukifumi
Published: September 2009

Background

Because only a few studies have been performed to date on the invasiveness of laparoscopy‐assisted total gastrectomy (LATG) compared with open total gastrectomy (OTG), the minimal invasiveness of LATG has been unclear.

Methods

The OTG cohort contained 35 cases, which were performed from April 2003 to October 2005. The LATG cohort contained 46 cases, which were performed from November 2005 to November 2008. Postoperative changes over time in various parameters relating to minimal invasiveness were evaluated. We used the Wong‐Baker FACES Pain Rating Scale to evaluate pain. Vital signs and a face scale were analyzed using daily maximum values on postoperative days (POD) 1–7. A hematological examination was performed on the preoperative day and POD 1, 4, 7, and 10. The number of days until oxygen saturation level (SaO2) was 95% or more in room air was used to evaluate respiratory function.

Results

Significantly lower pain scores were obtained in the LATG group on POD 1, 4, 5, and 7. There was a significantly lower body temperature in the LATG group on POD 7. A significantly lower white blood cell count was revealed for LATG patients on POD 10, and for C‐reactive protein on POD 1. Significantly higher serum total protein values were observed in the LATG group on POD 1, 4, and 7. Significantly lower blood sugar level was found in the LATG group on POD 4 and 7. The number of days until SaO2 was 95% or more in room air was significantly fewer in the LATG group.

Conclusions

LATG seems to be a less invasive procedure than OTG.
Comparison of Four Staging Systems of Lymph Node Metastasis in Gastric Cancer
Authors: Zhang Ming , Zhu Guanyu , Ma Yan , Xue Yingwei
Published: September 2009

Background

The classification of lymph node metastasis in patients with gastric cancer is still controversial. Our aim was to evaluate the relative merits of four staging systems of lymph node metastasis.

Methods

In our study, the nodal status was classified according to the 5th edition of the tumor node metastasis (TNM) system, the Japanese Classification of Gastric Carcinoma (JCGC), the ratio of metastatic lymph nodes, and the size of the largest metastatic lymph node. Each staging system was scored as good (+2), fair (+1), or poor (0) with respect to the theoretical value (extent of the anatomical lymphatic tumor spread), convenience (simplicity), surgical applicability (extent of lymph node dissection), and prognostic value (ability to predict survival rate).

Results

In the multivariate analysis including the four staging systems and other potential prognostic factors, stepwise Cox regression revealed that the ratio of metastatic lymph nodes was the most independent prognostic factor. The TNM, ratio, and size systems were convenient because they had no consideration for the location of the tumor and lymph node. Although the JCGC system had advantages in theoretical value and surgical application, it was most optional due to the complexity of the system.

Conclusions

Although all different staging systems are comparable, the metastatic lymph node ratio system is convenient, reproducible, and has the highest ability to predict survival.
Incidental Gallbladder Carcinoma Diagnosed During or After Laparoscopic Cholecystectomy
Authors: Zhang Wei‐Jie , Xu Gui‐Fang , Zou Xiao‐Ping , Wang Wei‐Bing , Yu Jun‐Chi , Wu Guo‐Zhong , Lu Chun‐Lei
Published: September 2009

Background

Gallbladder carcinoma (GC) is a highly lethal neoplasm. With the increase of cholecystectomies since the wide acceptance of laparoscopic cholecystectomy (LC), the incidental diagnosis of gallbladder carcinoma is more frequent. The aim of the present study was to report our experience with GC diagnosed during or after the performance of LC.

Methods

A total of 10,466 LCs were carried out from January 1999 to December 2007 in our hospital. Records of patients with incidental carcinoma were collected and analyzed retrospectively.

Results

Of all the patients, 20 (0.19%) were histopathologically diagnosed as having a GC. There were 4 men and 16 women; the median age in this group was 65.7 years (range: 37–81 years).The depth of cancer invasion was: pTis (4 cases), pT1a (2 cases), pT1b (2 cases), pT2 (6 cases), pT3 (4 cases), and pT4 (2 cases). The sensitivity and specificity of intraoperatively frozen section examination were 83.3 and 100%, respectively. Patients with in situ, pT1a and pT1b tumors underwent LC only, and there were no recurrences. The survival rate between patients with GC diagnosed during or after LC showed no difference; it was dependent on the depth of cancer invasion.

Conclusions

The survival with incidental GC is related to stage, and it validates that a carefully performed LC is adequate treatment for carcinoma in situ, and stage 1a and b cancer. A frozen section examination was helpful but did not provide a definitive diagnosis. Meticulous techniques during LC, including retrieval of the gallbladder in a retrieval bag, may prevent port‐site recurrence and intraperitoneal dissemination.
Nanoscale Visualization of Elastic Inhomogeneities at TiN Coatings Using Ultrasonic Force Microscopy
Authors: Hidalgo JA , Montero-Ocampo C , Cuberes MT
Published: September 2009

Ultrasonic force microscopy has been applied to the characterization of titanium nitride coatings deposited by physical vapor deposition dc magnetron sputtering on stainless steel substrates. The titanium nitride layers exhibit a rich variety of elastic contrast in the ultrasonic force microscopy images. Nanoscale inhomogeneities in stiffness on the titanium nitride films have been attributed to softer substoichiometric titanium nitride species and/or trapped subsurface gas. The results show that increasing the sputtering power at the Ti cathode increases the elastic homogeneity of the titanium nitride layers on the nanometer scale. Ultrasonic force microscopy elastic mapping on titanium nitride layers demonstrates the capability of the technique to provide information of high value for the engineering of improved coatings.
Kinetic Study of the Prooxidant Effect of α‐Tocopherol. Hydrogen Abstraction from Lipids by α‐Tocopheroxyl Radical
Authors: Ouchi Aya , Ishikura Masaharu , Konishi Kensuke , Nagaoka Shin‐ichi , Mukai Kazuo
Published: September 2009

A kinetic study of the prooxidant effect of α‐tocopherol was performed. The rates of allylic hydrogen abstraction from various unsaturated fatty acid esters (ethyl stearate 1, ethyl oleate 2, ethyl linoleate 3, ethyl linolenate 4, and ethyl arachidonate 5) by α‐tocopheroxyl radical in toluene were determined, using a double‐mixing stopped‐flow spectrophotometer. The second‐order rate constants (kp) obtained are <1 × 10−2 M−1s−1 for 1, 1.90 × 10−2 M−1s−1 for 2, 8.33 × 10−2M−1s−1 for 3, 1.92 × 10−1 M−1s−1 for 4, and 2.43 × 10−1M−1s−1 for 5 at 25.0 °C. Fatty acid esters 3, 4, and 5 contain two, four, and six –CH2– hydrogen atoms activated by two π‐electron systems (–C=C–CH2–C=C–). On the other hand, fatty acid ester 2 has four –CH2– hydrogen atoms activated by a single π‐electron system (–CH2–C=C–CH2–). Thus, the rate constants, kabstr/H, given on an available hydrogen basis are kp/4 = 4.75 × 10−3M−1s−1 for 2, kp/2 = 4.16 × 10−2 M−1s−1 for 3, kp/4 = 4.79 × 10−2M−1s−1 for 4, and kp/6 = 4.05 × 10−2M−1s−1 for 5. The kabstr/H values obtained for 3, 4, and 5 are similar to each other, and are by about one order of magnitude higher than that for 2. From these results, it is suggested that the prooxidant effect of α‐tocopherol in edible oils, fats, and low‐density lipoproteins may be induced by the above hydrogen abstraction reaction.
Variation of grain nitrogen content in relation with grain yield in old and modern Spanish wheats grown under a wide range of agronomic conditions in a Mediterranean region
Authors: ACRECHE M. M. , SLAFER G. A.
Published: September 2009

Wheat yield and grain nitrogen concentration (GNC; mg N/g grain) are frequently negatively correlated. In most growing conditions, this is mainly due to a feedback process between GNC and the number of grains/m2. In Mediterranean conditions, breeders may have produced cultivars with conservative grain set. The present study aimed at clarifying the main physiological determinants of grain nitrogen accumulation (GNA) in Mediterranean wheat and to analyse how breeding has affected them. Five field experiments were carried out in north-eastern Spain in the 2005/06 and 2006/07 growing seasons with three cultivars released at different times and an advanced line. Depending on the experiment, source-sink ratios during grain filling were altered by reducing grain number/m2 either through pre-anthesis shading (unshaded control or 0·75 shading only between jointing and anthesis) or by directly trimming the spikes after anthesis and before the onset of the effective grain filling period (un-trimmed control or spikes halved 7–10 days after anthesis). Grain nitrogen content (GN content; mg N/grain) decreased with the year of release of the genotypes. As the number of grains/m2 was also increased by breeding there was a clear dilution effect on the amount of nitrogen allocated to each grain. However, the increase in GN content in old genotypes did not compensate for the loss in grain nitrogen yield (GNY) due to the lower number of grains/m2. GN content of all genotypes increased (increases ranged from 0·13 to 0·40 mg N/grain, depending on experiment and genotype) in response to the post-anthesis spike trimming or pre-anthesis shading. The degree of source-limitation for GNA increased with the year of release of the genotypes (and thus with increases in grain number/m2) from 0·22 (mean of the four manipulative experiments) in the oldest cultivar to 0·51 (mean of the four manipulative experiments) in the most modern line. It was found that final GN content depended strongly on the source-sink ratio established at anthesis between the number of grains set and the amount of nitrogen absorbed at this stage. Thus, Mediterranean wheat breeding that improved yield through increases in grain number/m2 reduced the GN content by diluting a rather limited source of nitrogen into more grains. This dilution effect produced by breeding was further confirmed by the reversal effect produced by grain number/m2 reductions due to either pre-anthesis shading or post-anthesis spike trimming.
Early response to antidepressant treatment in bulimia nervosa
Authors: Sysko R. , Sha N. , Wang Y. , Duan N. , Walsh B. T.
Published: September 2009

Background

Bulimia nervosa (BN) is a serious psychiatric disorder characterized by frequent episodes of binge eating and inappropriate compensatory behavior. Numerous trials have found that antidepressant medications are efficacious for the treatment of BN. Early response to antidepressant treatment, in the first few weeks after medication is initiated, may provide clinically useful information about an individual's likelihood of ultimately benefitting or not responding to such treatment. The purpose of this study was to examine the relationship between initial and later response to fluoxetine, the only antidepressant medication approved by the US Food and Drug Administration (FDA) for the treatment of BN, with the goal of developing guidelines to aid clinicians in deciding when to alter the course of treatment.

Method

Data from the two largest medication trials conducted in BN (n=785) were used. Receiver operating characteristic (ROC) curves were constructed to assess whether symptom change during the first several weeks of treatment was associated with eventual non-response to fluoxetine at the end of the trial.

Results

Eventual non-responders to fluoxetine could be reliably identified by the third week of treatment.

Conclusions

Patients with BN who fail to report a ⩾60% decrease in the frequency of binge eating or vomiting at week 3 are unlikely to respond to fluoxetine. As no reliable relationships between pretreatment characteristics and eventual response to pharmacotherapy have been identified for BN, early response is one of the only available indicators to guide clinical management.
Prognostic value of cognitive functioning for global functional recovery in first-episode schizophrenia
Authors: González-Blanch C. , Perez-Iglesias R. , Pardo-García G. , Rodríguez-Sánchez J. M. , Martínez-García O. , Vázquez-Barquero J. L. , Crespo-Facorro B.
Published: September 2009

Background

It has become widely accepted that cognitive deficits in schizophrenia are related to functional outcome. However, it remains to be seen whether these associations are relevant for predicting which cases will have a global functional recovery. In this study, we attempt to determine whether global functional recovery (integrating social and occupational outcomes) after first-episode schizophrenia (FES) can be predicted by cognitive variables.

Method

A total of 131 FES patients with functional deficits (n=97) and functional recovery (n=34) as determined at 1-year follow-up were examined. Neuropsychological, sociodemographic, pre-morbid and clinical data at baseline were analysed using independent groups comparisons and a logistic regression method.

Results

Sustained attention and negative symptoms emerged as significant predictors of good global functional outcome. Although the model revealed a high accuracy (91%) in the classification of patients with functional deficits, it was unacceptably low (26%) in the classification of patients with global functional recovery.

Conclusions

The limitations found in the prediction of a favourable global functional outcome may well be an indication for a need to address the role of other factors not commonly included in longitudinal studies of long-term outcomes in schizophrenia.
LEARNING, COMMITMENT, AND MONETARY POLICY
Authors: Waters George A.
Published: September 2009

This paper examines a class of interest rate rules that respond to public expectations and to lagged variables and considers varying levels of commitment that correspond to varying degrees of response to lagged output. Under commitment the policymaker adjusts the nominal rate with lagged output to impact public expectations. Within this class of rules, I provide a condition for nonexplosive and determinate solutions. Expectational stability obtains for any nonnegative response to lagged output. Simulation results show that modified commitment is best under least-squares learning. However, in the presence of parameter uncertainty and/or measurement error in the policymaker's data on public expectations, the best policy is one of partial commitment, where the response to lagged output is less than under modified commitment. The case for partial commitment is strengthened if the gain parameter in the learning mechanism is high, which can be interpreted as the use of few lags by public agents in the formation of expectations or as an indication of low credibility of the policymaker. The appointment of a conservative central banker ameliorates these concerns about modified commitment.
ABATEMENT TECHNOLOGY ADOPTION UNDER UNCERTAINTY
Authors: Pommeret Aude , Schubert Katheline
Published: September 2009

New technology has been credited with solving environmental problems by mitigating the effects of pollutants. We construct a general equilibrium model in which abatement technology is a real option and pollution's (negative) amenity value alters both risk aversion and the intertemporal elasticity of substitution. We derive the tax scheme such that in a decentralized economy agents adopt the abatement technology at the time that is socially optimal. We show that the higher the greenness of preferences, the earlier the adoption and the higher the optimal tax rate. We also obtain that adoption is fostered by uncertainty if the effective intertemporal elasticity of substitution is large enough, but is not affected by uncertainty if this elasticity is low. Moreover, the optimal tax rate, which only exists if the effective intertemporal elasticity of substitution is high, is an increasing function of uncertainty.
ON THE RELATION BETWEEN GROSS OUTPUT– AND VALUE ADDED–BASED PRODUCTIVITY MEASURES: THE IMPORTANCE OF THE DOMAR FACTOR
Authors: Balk Bert M.
Published: September 2009

In this paper I consider the relation between gross output– and value added–based total factor productivity (TFP) measures. It appears that, without any (micro-)economic theory being required, a conditional relationship between TFP indices can be derived, in which the Domar factor plays an important role. At the same time it turns out that gross output– and value added–based TFP indicators (difference-type measures) always coincide. In the Divisia index framework and maintaining the classical assumptions (profit maximization and a production technology that exhibits globally constant returns to scale), it appears that both TFP indices measure technological change, albeit in a dual way. In establishing this result, no separability assumptions are involved. Both indices are in general path-dependent. Path independence of the gross output–based TFP index requires that the technology exhibit Hicks input neutrality, whereas path independence of the value added–based TFP index requires Hicks value-added neutrality. These two concepts of neutrality are, however, not dual.
MEASUREMENT ERROR IN MONETARY AGGREGATES: A MARKOV SWITCHING FACTOR APPROACH
Authors: Barnett William A. , Chauvet Marcelle , Tierney Heather L. R.
Published: September 2009

This paper compares the different dynamics of the simple-sum monetary aggregates and the Divisia monetary aggregate indices over time, over the business cycle, and across high and low inflation and interest-rate phases. Although traditional comparisons of the series sometimes suggest that simple-sum and Divisia monetary aggregates share similar dynamics, there are important differences around turning points that cannot be evaluated by their average behavior. We use a factor model with a regime-switching model that separates the common movements underlying the monetary aggregate indices from idiosyncratic variations in each series. We find that the major differences between the simple-sum aggregates and Divisia indices occur around the beginnings and ends of recessions and during some high-interest-rate phases. We note the inferences' policy relevance, which is particularly dramatic at the broadest (M3) level of aggregation. Indeed, as Belongia [Journal of Political Economy, 104 (5) (1996), 1065–1083] has observed in this regard, “measurement matters.”
MEASURING THE IMPACT OF FINANCIAL INTERMEDIATION: LINKING CONTRACT THEORY TO ECONOMETRIC POLICY EVALUATION
Authors: Townsend Robert M. , Urzua Sergio S.
Published: September 2009

We study the impact that financial intermediation can have on productivity through the alleviation of credit constraints in occupation choice and/or an improved allocation of risk, using both static and dynamic structural models as well as reduced-form OLS and IV regressions. Our goal in this paper is to bring these two strands of the literature together. Even though, under certain assumptions, IV regressions can accurately recover the true model-generated local average treatment effect, this is quantitatively different, in order of magnitude and even sign, from other policy impact parameters (e.g., ATE and TT). We also show that laying out clearly alternative models can guide the search for instruments. On the other hand, adding more margins of decision, that is, occupation choice and intermediation jointly, or adding more periods with promised utilities as key state variables, as in optimal multiperiod contracts, can cause the misinterpretation of IV as the causal effect of interest.
Arc Basalt Simulator version 2, a simulation for slab dehydration and fluid‐fluxed mantle melting for arc basalts: Modeling scheme and application
Authors: Kimura Jun‐Ichi , Hacker Bradley R. , van Keken Peter E. , Kawabata Hiroshi , Yoshida Takeyoshi , Stern Robert J.
Published: September 2009

Convergent margin magmas typically have geochemical signatures that include elevated concentrations of large‐ion lithophile elements; depleted heavy rare earth elements and high field strength elements; and variously radiogenic Sr, Pb, and Nd isotopic compositions. These have been attributed to the melting of depleted mantle peridotite by the fluxing of fluids or melts derived from subducting oceanic crust. High Mg # basalts and high Mg # andesites are inferred to make up the bulk of subduction‐related primary magmas and may be generated by fluid or melt fluxing of mantle peridotite. The difference in contributions from the subducted slab found among various arcs appears to be mostly controlled by thermal structure. Cold slabs yield fluids, and hot slabs yield melts. Recent experimental studies and thermodynamic models better constrain the phase petrology of the slab components during prograde metamorphism and melting, mantle wedge melting, and mantle slab melt reaction. Experimental results also constrain the behavior of many elements in these processes. In addition, geodynamic models allow increasingly realistic, quantitative modeling of the temperature and pressure in the subducted slab and mantle wedge. These developments together enable generation of forward models to explain arc magma geochemistry. The Arc Basalt Simulator (ABS) version 2 (ABS2) uses an Excel® spreadsheet‐based calculator to predict the partitioning of incompatible element and Sr‐Nd‐Pb isotopic composition in a slab‐derived fluid and in arc basalt magma generated by an open system fluid‐fluxed melting of mantle wedge peridotite. The ABS2 model is intended to simulate high Mg # basalt geochemistry in relatively cold subduction zones. The modeling scheme of ABS2 is presented and is applied to primitive arc magmas.
A three‐dimensional, multispecies, comprehensive MHD model of the solar wind interaction with the planet Venus
Authors: Terada N. , Shinagawa H. , Tanaka T. , Murawski K. , Terada K.
Published: September 2009

We present our newly developed numerical model of the solar wind interaction with the planet Venus. The model solves three‐dimensional, 10‐ion‐species magnetohydrodynamic (MHD) equations using a total variation diminishing monotonic upstream scheme for conservation laws, which is implemented on an unstructured grid system. These equations describe the dynamics of both the solar wind and the planetary ionosphere. An excellent performance of the model is verified by comparing our numerical results with the existing numerical and observational data. In particular, profiles of the magnetic field, number densities, velocity, and transterminator flux of ionospheric plasma are shown to reproduce the observational findings. A main goal of this paper is to present the numerical model and its performance for the general dynamics and structures of the solar wind interaction with the ionosphere of Venus.
Three‐dimensional boundary integral modeling of spontaneous earthquake sequences and aseismic slip
Authors: Lapusta Nadia , Liu Yi
Published: September 2009

Fault processes involve complex patterns of seismic events and aseismic slip. This work develops a three‐dimensional (3‐D) methodology for simulating long‐term history of spontaneous seismic and aseismic slip on a vertical planar strike‐slip fault subjected to slow tectonic loading. Our approach reproduces all stages of earthquake cycles, from accelerating slip before dynamic instability, to rapid dynamic propagation of earthquake rupture, to postseismic slip, and to interseismic creep, including aseismic transients. We use the developed 3‐D methodology to study interaction of fault slip with a small patch of higher normal stress over long‐term slip history. For uniform initial prestress, dynamic rupture is significantly affected by the stronger patch in the first simulated event but not in subsequent ones. The change in behavior is due to redistribution of shear stress by prior slip, which demonstrates that distributions of fault strength and stress are related and illustrates the importance of simulating long slip histories even in studies of dynamic rupture. Despite no long‐term effect on dynamic rupture, the small patch of higher normal stress influences nucleation processes and hence long‐term slip patterns in the model. Comparison of the fully dynamic simulations and a widely used quasi‐dynamic approach shows that the quasi‐dynamic approach modifies long‐term slip patterns in addition to resulting in much smaller slip velocities and rupture speeds during dynamic events. We show that the response of quasi‐dynamic formulations with reduced radiation damping terms can be scaled to match the results of the standard quasi‐dynamic formulation and hence cannot improve the comparison.
Coseismic thermal pressurization can notably prolong earthquake recurrence intervals on weak rate and state friction faults: Numerical experiments using different constitutive equations
Authors: Mitsui Yuta , Hirahara Kazuro
Published: September 2009

We add a new perspective to component factors of earthquake cyclicity, namely coseismic thermal pressurization (TP) within fluid‐saturated fault zones, which is pore fluid pressurization caused by frictional heating. By using a single degree of freedom system with a rate‐ and state‐dependent friction law, we show that the short‐lived TP can prolong earthquake recurrence intervals. This lengthening effect can operate even without any notable shear heating in weak faults. Moreover, if the maximum increase in temperature is above a certain level, the permeability rather than the maximum temperature becomes important for the lengthening effect. Lower permeability causes longer recurrence intervals. By contrast, narrower slip zones (more pronounced heating) do not simply prolong recurrence intervals, although they entail higher dynamic undershoot and energy radiation. These features do not depend on whether the assumed evolution law is the Ruina law or the Dieterich law. However, our results indicate that if the degree of TP changes for each earthquake, the ideal time‐predictable model for earthquake cycles can be applicable only in the case of faults obeying the Ruina law. Furthermore, on the basis of the above‐mentioned dependence of the interval on the permeability, we point out that it is necessary to measure the permeability rather than the slip zone thickness (or the increase in temperature) in order to estimate the TP effect on long‐term earthquake cycles. Although it is currently difficult to measure the permeability under ground, measurements should be performed in the light of the importance of permeability in the prediction of future seismic hazards.
Scavenging in weakly electrified saturated and subsaturated clouds, treating aerosol particles and droplets as conducting spheres
Authors: Zhou Limin , Tinsley Brian A. , Plemmons Abigail
Published: September 2009

The effects of electric charge on collision rate coefficients for scavenging of aerosol particles by droplets are evaluated, as appropriate to weak electrification conditions in clouds. Variations in charges on droplets and particles in clouds are proportional to the flow of current in the global electric circuit through gradients in resistivity, which are determined by gradients in droplet concentration and humidity. We obtain the collision rate coefficients by “trajectory model” calculations for spherical aerosol particles and droplets using the exact electrical force equation, with its long‐range repulsion and short‐range attraction, interacting with drag, inertia, and phoretic forces. The use of the exact electric force gives rate coefficients up to a factor of two greater than previous image charge calculations for particles in the “Greenfield Gap”. Rate coefficients for scavenging by Brownian diffusion are obtained by the analytic expression for “flux model” calculations. Rate coefficients for combined effects of electric and phoretic scavenging are given, as appropriate for scavenging of droplets evaporating to residual particles while temporarily retaining the original droplet charge. For particles of radii below about 0.1 μm and with charges typical of residues of freshly evaporated droplets, the long‐range repulsive electrical force reduces the collision rate coefficients below those for phoretic scavenging in subsaturated air and below the rates for Brownian scavenging. Time constants for scavenging of particles are given for selected values of droplet size, particle and droplet charges, and particle density, and the applications to observed effects in the atmosphere are discussed.
Determination of surface‐wave phase velocities across USArray from noise and Aki's spectral formulation
Authors: Ekström Göran , Abers Geoffrey A. , Webb Spahr C.
Published: September 2009

We use expressions for the cross‐correlation of stochastic surface waves originally derived by Aki (1957) to develop an algorithm for determining inter‐station phase‐velocity measurements from continuous seismic data. In the frequency domain, the cross correlation of azimuthally isotropic noise is described by a Bessel function, and we associate zeros in the observed spectrum with zeros of the Bessel function to obtain phase‐velocity estimates at discrete frequencies. Phase velocities derived in this way at several frequencies are joined to form a dispersion curve, which is then sampled to obtain phase‐velocity estimates at arbitrary frequencies. We collect a set of dispersion curves for more than 30,000 station pairs of the transportable component of USArray, and derive Rayleigh wave phase‐velocity maps at periods of 12 and 24 s for the western United States. The spectral method lends itself well to automation, and avoids limitations at short inter‐station distances associated with time‐domain methods.
Cold filamentary intensification and oceanic surface convergence lines
Authors: McWilliams J. C. , Colas F. , Molemaker M. J.
Published: September 2009

The reflectance images of the oceanic surface are full of surfactant lines created by surface velocity convergences, with typical line spacings of 0.1–10 km, i.e., in the submesoscale range. Here we propose a dynamical explanation by the process of filamentary intensification that shrinks the transverse scale of rectilinear surface temperature extrema at a super‐exponential rate by the action of horizontal deformation flows associated with mesoscale eddies. This process is analogous to deformation‐induced frontogenesis with sharpening temperature gradients accelerated by its ageostrophic secondary circulation. In the particular case of cold filaments, the shrinking rate, surface convergence, and downwelling are especially strong because of the configuration of ageostrophic acceleration. This behavior is demonstrated theoretically with idealized two‐dimensional solutions and illustrated in a realistic regional circulation simulation near Peru.
Thermal evolution of Mercury: Effects of volcanic heat‐piping
Authors: Multhaup K.
Published: September 2009

A 1D thermal evolution model of Mercury is presented. It accounts for stagnant lid convection, mantle differentiation and inner core growth. Early MESSENGER results indicate that—contrary to prior conclusions drawn from Mariner 10 imagery—volcanism has indeed played a significant role in Mercury's past. To study the effects of mantle heat bypassing the stagnant lid by means of volcanic heat‐piping, contrasting end‐member models are considered. Results show how break‐down of mantle convection and onset of inner core growth are influenced by the mode of heat removal. Structural models of present day Mercury are presented. Their dependence on the core sulphur contents predominates that on the choice of mantle heat removal. However, the latter clearly controls the timing of thermal history events.
Transient convection in upper lake sediments produced by internal seiching
Authors: Kirillin Georgiy , Engelhardt Christof , Golosov Sergey
Published: September 2009

We present the first evidence of free convection development in lake sediments caused by seiche oscillations. Appearance of the pore water convection is manifested by increase in the upward heat flux during periodical seiche‐driven upwelling of cold deep water over the bottom slope. The dimensionless convective heat flux scales favorably with the square root of the Rayleigh Number, suggesting an intermediate character of the convective flow between the Rayleigh‐Benard free convection in fluid and the Horton‐Rogers‐Lapwood convection in porous media. According to the scaling analysis, the seiche‐induced pore water convection could intensify up to 1000 times the dissolved matter exchange between lake sediment and water column. Among lake processes that can be significantly affected by the transient convection in sediments are the nutrients cycle, the water‐sediments exchange of dissolved gases and the benthic microbial activity.
Electron and proton heating by solar wind turbulence
Authors: Breech B. , Matthaeus W. H. , Cranmer S. R. , Kasper J. C. , Oughton S.
Published: September 2009

Previous formulations of heating and transport associated with strong magnetohydrodynamic (MHD) turbulence are generalized to incorporate separate internal energy equations for electrons and protons. Electron heat conduction is included. Energy is supplied by turbulent heating that affects both electrons and protons and is exchanged between them via collisions. Comparison to available Ulysses data shows that a reasonable accounting for the data is provided when (1) the energy exchange timescale is very long and (2) the deposition of heat due to turbulence is divided, with 60% going to proton heating and 40% into electron heating. Heat conduction, determined here by an empirical fit, plays a major role in describing the electron data.
Properties of Ganymede's magnetosphere inferred from improved three‐dimensional MHD simulations
Authors: Jia Xianzhe , Walker Raymond J. , Kivelson Margaret G. , Khurana Krishan K. , Linker Jon A.
Published: September 2009

We describe a three‐dimensional single‐fluid MHD simulation of Ganymede's magnetosphere that accords extremely well with the Galileo particles and fields measurements. Major improvements to our previously published model involve the modification of the inner boundary condition and the implementation of an anomalous resistivity model. The improved model couples the moon's ionosphere (with finite Pedersen conductance) with the magnetosphere self‐consistently. The previous model applied only in the limit of unreasonably high ionospheric conductivity. We illustrate in detail the global convection pattern inferred from the new model and demonstrate some features of the convection that differ from that of the Earth's magnetosphere because Ganymede lacks a corotation electric field. Our new model does a better job of reproducing magnetic field and plasma observations from multiple Galileo passes, which sampled different external conditions and different regions of the magnetosphere. In particular, for a critical upstream pass (G8) during which the Galileo spacecraft entered onto closed field lines, the simulated magnetosphere provides an excellent fit to the measurements without the need for tuning the spacecraft trajectory. In comparison with the plasma measurements of the G2 flyby, our model also yields good agreement with the Galileo PLS observations and supports the conclusion reached by Vasyliūnas and Eviatar (2000) that the observed ionospheric outflow consists of oxygen ions. For constant external conditions, dynamic variations associated with magnetic reconnection on timescales of the order of tens of seconds are found over a large region near the magnetopause in the simulations. Future applications of our model, such as test particle tracing and investigating the behavior of the cross polar cap potential under different external and ionospheric conditions, will provide a more comprehensive understanding of Ganymede's magnetospheric environment.
Seasonal characteristics of the relationship between daily precipitation intensity and surface temperature
Authors: Berg P. , Haerter J. O. , Thejll P. , Piani C. , Hagemann S. , Christensen J. H.
Published: September 2009

Past studies have argued that the intensity of extreme precipitation events should increase exponentially with temperature. This argument is based on the principle that the atmospheric moisture holding capacity increases according to the Clausius‐Clapeyron equation and on the expectation that precipitation formation should follow accordingly. We test the latter assumption by investigating to what extent a relation with temperature can be observed intraseasonally in present‐day climate. For this purpose, we use observed and simulated daily surface temperature and precipitation over Europe. In winter a general increase in precipitation intensity is indeed observed, while in summer we find a decrease in precipitation intensity with increasing temperature. We interpret these findings by making use of model results where we can distinguish separate precipitation types and investigate the moisture content in the atmosphere. In winter, the Clausius‐Clapeyron relationship sets a limit to the increase in the large‐scale precipitation with increasing temperature. Conversely, in summer the availability of moisture, and not the atmosphere's capacity to hold this moisture, is the dominant factor at the daily timescale. For convective precipitation, we find a peak like structure which is similar for all subregions, independent of the mean temperature, contrary to large‐scale precipitation which has a more monotonic dependence on temperature.
Evidence for the origin of layered deposits in Candor Chasma, Mars, from mineral composition and hydrologic modeling
Authors: Murchie Scott , Roach Leah , Seelos Frank , Milliken Ralph , Mustard John , Arvidson Raymond , Wiseman Sandra , Lichtenberg Kimberly , Andrews‐Hanna Jeffrey , Bishop Janice , Bibring Jean‐Pierre , Parente Mario , Morris Richard
Published: September 2009

New results from the Compact Reconnaissance Imaging Spectrometer for Mars and High Resolution Imaging Science Experiment and Context Imager cameras on Mars Reconnaissance Orbiter provide insights into the origin of interior layered deposits in Valles Marineris from analysis of a thick, well‐exposed section in western Candor Chasma. Most of the deposit is dominated spectrally by nanophase ferric oxide like that found in the globally distributed eolian dust, with the addition of a prevalent component of monohydrated sulfates. A rippled mantle containing both pyroxene and monohydrated sulfate emanates from discrete layers, which are interpreted as interbedded basaltic sand. Ferric minerals are observed in most of the sulfate‐rich layers, and locally a coarse‐grained grayer component has been concentrated from the layers by sorting. Polyhydrated sulfates are concentrated in discrete layers high in the section, implying chasma‐scale changes in brine chemistry during formation of the layered deposits. Hydrological models were constructed in order to assess whether evaporite deposition from groundwater discharge could have trapped eolian sediments to form the observed deposits. The predicted thickness and extent of the evaporite‐trapped sediment is consistent with the distribution of interior layered deposits in Candor Chasma as well as in other chasmata of Valles Marineris. In this scenario, eolian dust and sand were trapped and lithified by evaporites formed by evaporation of groundwater discharge that was highly localized within the chasmata. Sulfates precipitated in the resulting saline conditions, and diagenetic alteration formed crystalline ferric minerals including hematite. This model links the layered deposits in Valles Marineris and those in Meridiani Planum to a common regional process.
Meta‐analysis in evidence‐based orthodontics
Authors: Papadopoulos MA
Published: September 2009

Structured Abstract

Author – Papadopoulos MA

Objective – In the last 10 years, health sciences literature has seen a significant increase in papers that report findings of meta‐analyses. Meta‐analysis overcomes the weakness of conventional narrative literature review. Moreover, it has established itself as a significant tool in clinical research and evidence‐based medicine. But despite its station in the field, it is not without controversy. The aim of this paper is to present the main controversies that surround meta‐analyses and to discuss the most important issues of conduct and reporting of results derived from these studies.

Results – Controversial issues include the ability of the investigators to combine studies that differ in important aspects; such as study populations, experimental designs and quality controls, and the like. It has been argued that selection bias could exist. Thus, it is common for the results of meta‐analyses to be contradictory. As any other statistical procedure or analytical approach, meta‐analyses too can be misused or abused. Misleading results could be avoided if certain basic principles are followed in the conduct of a meta‐analysis. In particular, attention should be given to: (a) the methods of literature search for the studies to be included in the analysis, (b) the measures taken to reduce or eliminate bias, (c) the inclusion and exclusion criteria of the individual studies from the analysis, (d) how the data will be extracted from the literature, and (e) how the data will be analyzed statistically.

Conclusion – Reports of meta‐analytical studies carried out with the above parameters in mind yield a more objective appraisal of the evidence, and a more precise estimate of the treatment effect.
Effects of the headgear‐activator Teuscher appliance in the treatment of class II division 1 malocclusion: a geometric morphometric study
Authors: Singh GD , Thind BS
Published: September 2009

Structured Abstract

Authors – Singh GD, Thind BS

Objectives – To test the hypothesis that there are no gender differences in the outcomes of patients with class II malocclusion treated with the headgear‐activator Teuscher appliance (HATA).

Design – Retrospective, longitudinal

Setting and Sample Population – Puerto Rico and Scotland, UK. Thirty‐one patients requiring correction of class II division 1 malocclusions.

Experimental Variable – Male and female patients treated using HATA.

Outcome Measures – Mean pre‐ and post‐treatment parameters derived from cephalometry subjected to t‐tests, and finite‐element scaling analysis (FESA), which localizes and quantifies differences between mean pre‐ and post‐treatment configurations.

Results – Post‐treatment, cephalometry showed that for both males and females, angle SNA decreased, SNB increased, and lower facial heights increased significantly (p < 0.01). For the female post‐treatment configuration, FESA revealed large size increases (≈20%) located in the inter‐maxillary region, the ramus and mandibular body, and around the nasal and mental regions. Conversely, the lip region was diminished (≈20%). Similarly, male post‐treatment showed size increases located in the inter‐maxillary region that extended into the nasal region and the mandibular body (≈10–15%), and around the chin (15%). The lip region was diminished (≈5%).

Conclusion – In the attainment of a normal occlusion, both male and female patients treated for class II malocclusions using HATA exhibit antero‐posterior restraint of the maxilla, improvements in the mandible maintaining facial height, and lip changes commensurate with improvements in the soft tissue profile.
Plasmacytoid and conventional dendritic cells are early producers of IL‐12 inNeospora caninum‐infected mice
Authors: Teixeira Luzia , Botelho Ana Sofia , Mesquita Sandro Dá , Correia Alexandra , Cerca Filipe , Costa Renata , Sampaio Paula , Castro António Gil , Vilanova Manuel
Published: September 2009

Neospora caninumis a coccidian parasite causative of clinical infections in a wide range of animal hosts. The maturation and activation of splenic conventional dendritic cells (cDCs) and plasmacytoid dendritic cells (pDCs) were studied here in BALB/c mice challenged intraperitoneal withN. caninumtachyzoites. The number of cDCs was found to decrease in the spleen of the infected mice 12 h and 2 days after the parasitic challenge, whereas at day 5 after infection it was significantly above that of mock‐infected controls. In contrast, the number of splenic pDCs did not change significantly on infection. In the infected mice, both cell subtypes displayed an activated phenotype with upregulation of costimulatory and MHC class II molecules. This stimulatory effect was more marked at the earliest assessed time point after infection, 12 h, when a clear increase in the frequency of cDCs (CD8α+and CD8α−) and pDCs producing interleukin‐12 (IL‐12) was also observed.N. caninumtachyzoites could be observed by confocal microscopy associated with sorted DCs. Overall, these results present the first evidence that both cDCs and pDCs mediatein vivothe innate immune response toN. caninuminfection through the production of IL‐12, a key cytokine for host resistance to neosporosis.
Nucleic-acid-binding properties of the C2-L1Tc nucleic acid chaperone encoded by L1Tc retrotransposon
Authors: Heras Sara R. , Thomas M. Carmen , Macias Francisco , Patarroyo Manuel E. , Alonso Carlos , López Manuel C.
Published: September 2009

It has been reported previously that the C2-L1Tc protein located in the Trypanosoma cruzi LINE (long interspersed nuclear element) L1Tc 3′ terminal end has NAC (nucleic acid chaperone) activity, an essential activity for retrotransposition of LINE-1. The C2-L1Tc protein contains two cysteine motifs of a C2H2 type, similar to those present in TFIIIA (transcription factor IIIA). The cysteine motifs are flanked by positively charged amino acid regions. The results of the present study show that the C2-L1Tc recombinant protein has at least a 16-fold higher affinity for single-stranded than for double-stranded nucleic acids, and that it exhibits a clear preference for RNA binding over DNA. The C2-L1Tc binding profile (to RNA and DNA) corresponds to a non-co-operative-binding model. The zinc fingers present in C2-L1Tc have a different binding affinity to nucleic acid molecules and also different NAC activity. The RRR and RRRKEK [NLS (nuclear localization sequence)] sequences, as well as the C2H2 zinc finger located immediately downstream of these basic stretches are the main motifs responsible for the strong affinity of C2-L1Tc to RNA. These domains also contribute to bind single- and double-stranded DNA and have a duplex-stabilizing effect. However, the peptide containing the zinc finger situated towards the C-terminal end of C2-L1Tc protein has a slight destabilization effect on a mismatched DNA duplex and shows a strong preference for single-stranded nucleic acids, such as C2-L1Tc. These results provide further insight into the essential properties of the C2-L1Tc protein as a NAC.