bluuebunny/crossref_metadata_2025 huggingface dataset:
Termination of a 6 year ridge‐spreading event observed using a seafloor seismic network on the Endeavour Segment, Juan de Fuca Ridge
Authors: Weekly Robert T. , Wilcock William S. D. , Hooft Emilie E. E. , Toomey Douglas R. , McGill Paul R. , Stakes Debra S.
Published: February 2013

We present automatically determined epicenters and magnitudes for 36,523 earthquakes recorded along the Endeavour segment between August 2003 and October 2006 using a local ocean‐bottom seismometer (OBS) network. The catalog is dominated by two swarm sequences in January and February 2005 in the vicinity of the Endeavour overlapping spreading center, which included earthquakes in West Valley, the northern portion of the Endeavour segment, southwest Endeavour Valley, and the Endeavour vent fields. These swarms are attributed to volcanism including a dike intrusion on the northern Endeavour in February 2005 and smaller diking events on the propagating tip of the West Valley segment in both swarms. The dike on the northern Endeavour propagated to the south, which is inconsistent with magma sourced from the axial magma chamber beneath the elevated central portion of the segment. Following the swarms, seismic activity on the Endeavour segment decreased on average to ~15% of pre‐swarm values and almost ceased at the segment ends. We infer that a 6 year non‐eruptive event that started with a swarm in 1999 and finished with the 2005 swarms ruptured the entire segment and relieved plate‐spreading stresses. The inferred coupling between the 1999 and 2005 events, the observation of extensive precursory activity prior to the 2005 swarms, and the interaction between seismically active regions during the swarms is consistent with static triggering with delays influenced by viscoelastic relaxation, hydraulic diffusion, and magma withdrawal and replenishment.
New insights into the 2012 Emilia (Italy) seismic sequence through advanced numerical modeling of ground deformation InSAR measurements
Authors: Tizzani P. , Castaldo R. , Solaro G. , Pepe S. , Bonano M. , Casu F. , Manunta M. , Manzo M. , Pepe A. , Samsonov S. , Lanari R. , Sansosti E.
Published: February 2013

We provide new insights into the two main seismic events that occurred in 2012 in the Emilia region, Italy. We extend the results from previous studies based on analytical inversion modeling of GPS and RADARSAT‐1 InSAR measurements by exploiting RADARSAT‐2 data. Moreover, we benefit from the available large amount of geological and geophysical information through finite element method (FEM) modeling implemented in a structural‐mechanical context to investigate the impact of known buried structures on the modulation of the ground deformation field. We find that the displacement pattern associated with the 20 May event is consistent with the activation of a single fault segment of the inner Ferrara thrust, in good agreement with the analytical solution. In contrast, the interpretation of the 29 May episode requires the activation of three different fault segments and a block roto‐translation of the Mirandola anticline. The proposed FEM‐based methodology is applicable to other seismic areas where the complexity of buried structures is known and plays a fundamental role in the modulation of the associated surface deformation pattern.
Thermal enhancement of gas transfer velocity of CO2 in an Amazon floodplain lake revealed by eddy covariance measurements
Authors: Polsenaere Pierre , Deborde Jonathan , Detandt Guillaume , Vidal Luciana O. , Pérez Marcela A. P. , Marieu Vincent , Abril Gwenaël
Published: February 2013

In November 2011, the partial pressures of carbon dioxide (pCO2) in water and air in a floodplain lake of the Amazon River in Brazil were 800 ± 75 and 387 ± 8 ppmv, respectively. Turbulent CO2 fluxes from the lake measured with eddy covariance ranged from 0.05 to 2.2 µmol m−2 s−1. The corresponding gas transfer velocities k600 ranged from 1.3 to 31.6 cm h−1, averaging 12.2 ± 6.7 cm h−1. At moderate to high wind speed, k600 increased with wind speed, with values above parameterizations for other lake ecosystems. During the prevailing tropical low wind speed (below 2.7 m s−1) and high insolation conditions, unexpected high k600 values (up to 20 cm h−1) were obtained and correlated with latent heat and sensible heat fluxes. In Amazonian open lakes, owing to long quiescent periods of low wind speed but extremely high daytime insolation and heat fluxes, thermal enhancement makes time‐integrated gas transfer velocities four to five times higher than those computed from classic wind parameterization.
Orbital radar, imagery, and atmospheric modeling reveal an aeolian origin for Abalos Mensa, Mars
Authors: Brothers T. C. , Holt J. W. , Spiga A.
Published: February 2013

Icy deposits surrounding Planum Boreum, Mars, contain crucial information for deciphering paleoclimate and past geologic processes at the martian north pole. One such deposit, Abalos Mensa, is an enigmatic wedge of material located near the ~ 1 km high Rupes Tenuis. Its unique location and lobate morphology have fostered formation hypotheses that assume either fluvial or aeolian erosion of a once‐larger ice deposit. The aeolian scenario posed previously requires impact shielding of ancient basal unit material to provide an erosional remnant which seeds later deposition, while the fluvial hypotheses invoke cryovolcanism beneath the younger north polar layered deposits (NPLD) and associated outflow to erode the adjacent chasmata. Here we combine newly available radar sounding data, high‐resolution imagery, digital elevation models, and atmospheric modeling to examine internal structure and infer both the mechanisms for, and timing of, Abalos Mensa formation. From this integrative approach, we conclude that Abalos Mensa formed as a distinct feature via atmospheric deposition following erosion of Rupes Tenuis and grew concurrently with the rest of Planum Boreum as the NPLD accumulated. The required processes are consistent with those observed today: no exotic phenomena (cryovolcanism, fluvial activity, or impact shielding) appear necessary to explain the formation of Abalos Mensa.
Iron speciation in aerosol dust influences iron bioavailability over glacial‐interglacial timescales
Authors: Spolaor A. , Vallelonga P. , Cozzi G. , Gabrieli J. , Varin C. , Kehrwald N. , Zennaro P. , Boutron C. , Barbante C.
Published: February 2013

Iron deposition influences primary production and oceanic sequestration of atmospheric carbon dioxide (CO2). Iron has two oxidation states, Fe(II) and Fe(III), with Fe(II) being more soluble and available for oceanic phytoplankton uptake. The past proportions of soluble iron in aerosol dust remain unknown. Here we present iron speciation (Fe2+ and Fe3+) in the Antarctic Talos Dome ice core over millennial time scales. We demonstrate that iron speciation over the last 55 kyr is linked to increasing quantities of fine dust (FD) (0.7–5 µm) and intensified long‐range dust transport. We propose that Fe(II) and Fe2+ production is principally enhanced in FD by photoreduction, although pH and organic complexation may also contribute to the speciation dynamics. During the Last Glacial Maximum, Fe2+ concentrations in dust increased by up to seven times more than interglacial levels, while Fe3+ only doubled. Cold and dusty climatic periods may increase the percentage of biologically available Fe(II) and Fe2+ deposited in the nutrient‐limited Southern Ocean, allowing greater phytoplankton uptake and perhaps increased CO2 drawdown.
The metalloproteinase ADAMTS1: A comprehensive review of its role in tumorigenic and metastatic pathways
Authors: de Arao Tan Izza , Ricciardelli Carmela , Russell Darryl L.
Published: February 2013

As it was first characterized in 1997, the ADAMTS (A Disintegrin and Metalloprotease with ThromboSpondin motifs) metalloprotease family has been associated with many physiological and pathological conditions. Of the 19 proteases belonging to this family, considerable attention has been devoted to the role of its first member ADAMTS1 in cancer. Elevated ADAMTS1 promotes pro‐tumorigenic changes such as increased tumor cell proliferation, inhibited apoptosis and altered vascularization. Importantly, it facilitates significant peritumoral remodeling of the extracellular matrix environment to promote tumor progression and metastasis. However, discrepancy exists, as several studies also depict ADAMTS1 as a tumor suppressor. This article reviews the current understanding of ADAMTS1 regulation and the consequence of its dysregulation in primary cancer and ADAMTS1‐mediated pathways of cancer progression and metastasis.
FUNCTIONAL ANALYSIS AND TREATMENT OF PROBLEM BEHAVIOR IN EARLY EDUCATION CLASSROOMS
Authors: Greer Brian D. , Neidert Pamela L. , Dozier Claudia L. , Payne Steven W. , Zonneveld Kimberley L. M. , Harper Amy M.
Published: February 2013

We conducted functional analyses (FA) with 4 typically developing preschool children during ongoing classroom activities and evaluated treatments that were based on FA results. Results of each child's FA suggested social‐positive reinforcement functions, and differential reinforcement of alternative behavior plus time‐out was effective in decreasing problem behavior and increasing appropriate behavior. We discuss the utility of classroom‐based FAs and potential compromises to experimental control.
U6 promoter‐enhanced GlnUAG suppressor tRNA has higher suppression efficacy and can be stably expressed in 293 cells
Authors: Koukuntla Ramesh , Ramsey William J. , Young Won‐Bin , Link Charles J.
Published: February 2013

Background

Almost one‐third of all human genetic diseases are the result of nonsense mutations that can result in truncated proteins. Nonsense suppressor tRNAs (NSTs) were proposed as valuable tools for gene therapy of genetic diseases caused by premature termination codons (PTCs). Although various strategies have been adapted aiming to increase NST expression and efficacy, low suppression efficacies of NSTs and toxicity associated with stable expression of suppressor tRNAs have hampered the development of NST‐mediated gene therapy.

Methods

We have employed the U6 promoter to enhance Gln‐Amber suppressor tRNA (GlnUAG) expression and to increase PTC suppression in mammalian cells. In an attempt to study the toxic effects of NSTs, a stable 293 cell line constitutively expressing a U6 promoter‐enhanced GlnUAG tRNA was established. To examine whether any proteomic changes occurred in cells that constitutively express suppressor tRNA, whole cell proteins from cells with and without any suppressor tRNA expression were analyzed.

Results

The data obtained suggest that U6 promoter‐enhanced GlnUAG tRNAs have higher suppression efficacies than multimers of the same suppressor tRNA without a U6 promoter. Proteomic analysis of cells constitutively expressing the GlnUAG suppressor tRNA indicates that stable expression of NSTs may not lead to significant read through of normal cellular proteins.

Conclusions

Because most tRNAs have cell‐specific differential expression, this technique will enable the expression of different kinds of suppressor tRNAs in various cell types at high, functionally relevant levels. The techniques developed in the present study may contribute to the further development of suppressor tRNA‐mediated gene therapy. Copyright © 2013 John Wiley & Sons, Ltd.
Estimating total horizontal aeolian flux within shrub‐invaded groundwater‐dependent meadows using empirical and mechanistic models
Authors: Vest Kimberly R. , Elmore Andrew J. , Kaste James M. , Okin Gregory S. , Li Junran
Published: February 2013

Wind erosion is a significant environmental problem that removes soil resources from sensitive ecosystems and contributes to air pollution. In regions of shallow groundwater, friable (puffy) soils are maintained through capillary action, surface evaporation of solute‐rich soil moisture, and protection from mobilization by groundwater‐dependent grasses and shrubs. When a reduction in vegetation cover occurs through any disturbance process, there is potential for aeolian transport and dust emission. We find that as mean gap size between vegetation elements scaled by vegetation height increases, total horizontal aeolian sediment flux increases and explains 58% of the variation in total horizontal aeolian sediment flux. We also test a probabilistic model of wind erosion based on gap size between vegetation elements scaled by vegetation height (the Okin model), which predicts measured total horizontal aeolian sediment flux more closely than another commonly used model based on the average plant area observed in profile (Raupach model). The threshold shear velocity of bare soil appears to increase as gap size between vegetation elements scaled by vegetation height increases, reflecting either surface armoring or reduced interaction between the groundwater capillary zone and surface sediments. This work advances understanding of the importance of measuring gap size between vegetation elements scaled by vegetation height for empirically estimating Q and for structuring process‐based models of desert wind erosion in groundwater‐dependent vegetation.
Influence of lithology on hillslope morphology and response to tectonic forcing in the northern Sierra Nevada of California
Authors: Hurst Martin D. , Mudd Simon M. , Yoo Kyungsoo , Attal Mikael , Walcott Rachel
Published: February 2013

Many geomorphic studies assume that bedrock geology is not a first‐order control on landscape form in order to isolate drivers of geomorphic change (e.g., climate or tectonics). Yet underlying geology may influence the efficacy of soil production and sediment transport on hillslopes. We performed quantitative analysis of LiDAR digital terrain models to examine the topographic form of hillslopes in two distinct lithologies in the Feather River catchment in northern California, a granodiorite pluton and metamorphosed volcanics. The two sites, separated by <2 km and spanning similar elevations, were assumed to have similar climatic histories and are experiencing a transience in landscape evolution characterized by a propagating incision wave in response to accelerated surface uplift c. 5 Ma. Responding to increased incision rates, hillslopes in granodiorite tend to have morphology similar to model predictions for steady state hillslopes, suggesting that they adjust rapidly to keep pace with the incision wave. By contrast, hillslopes in metavolcanics exhibit high gradients but lower hilltop curvature indicative of ongoing transient adjustment to incision. We used existing erosion rate data and the curvature of hilltops proximal to the main channels (where hillslopes have most likely adjusted to accelerated erosion rates) to demonstrate that the sediment transport coefficient is higher in granodiorite (8.8 m2ka−1) than in metavolcanics (4.8 m2ka−1). Hillslopes in both lithologies get shorter (i.e., drainage density increases) with increasing erosion rates.
Tibetan Plateau precipitation as depicted by gauge observations, reanalyses and satellite retrievals
Authors: Tong Kai , Su Fengge , Yang Daqing , Zhang Leilei , Hao Zhenchun
Published: February 2013

The European Centre for Medium‐range Weather Forecasts (ECMWF) reanalysis ERA‐40, ERA‐Interim, University of Washington (UW) data, APHRODITE's Water Resources (APHRODITE), and Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) precipitation estimates are compared with each other and with the corrected gauge observations over the Tibetan Plateau (TP) at both basin and plateau scales. The ERA‐40 generally can capture the broad spatial and temporal distributions in the gauge‐based precipitation estimates over the TP. However, the ERA‐40 shows little agreement with the gauge‐based precipitation in annual variations for the years before 1979. The anticipated improvements in the ERA‐Interim precipitation relative to ERA‐40 have not been realized in this study. It greatly overestimates the Corrected‐China Meteorological Administration (CMA) (by 74–290%) and other datasets, although the ERA‐Interim has a better correspondence than ERA‐40 with the Corrected‐CMA data at both annual and monthly scales among the selected basins. All the products can detect the large‐scale precipitation regime, including the monsoon‐dominated precipitation in summer and the westerly‐wind‐induced precipitation in winter. The Corrected‐CMA and APHRODITE estimates generally show decreasing trends in summer and increasing trends in spring and winter precipitation during 1961–2007 at both basin and plateau scales. However, the Corrected‐CMA shows larger values in trends and more cases with significance than the APHRODITE, suggesting the effects of the undercatch corrections on the precipitation trends. The use of precipitation derived from current reanalysis projects is less preferable for hydrology analysis than the TP observational data at basin scales. However, using gauge‐based precipitation datasets as hydrologic model forcings should be careful in the river basins where gauge station network is spare, such as in the Yarlung zangbo river basin. Satellite products still hold a great potential for providing high‐resolution precipitation information in remote regions such as the western TP, although more evaluations are needed on the feasibility of satellite precipitation products on the TP where the topography is complex and rainfall rate is highly variable.
What Cost Knowledge Management? The Example of Infosys
Authors: Kimble Chris
Published: February 2013

The term knowledge management (KM) first came to prominence in the late 1990s. Although initially dismissed as a fad, KM continues to be featured in articles concerning business productivity and innovation. And yet, clear‐cut examples that demonstrate the success of KM are few and far between. A brief examination of the history of KM explores the reasons for this and looks at some of the assumptions about what KM can achieve. A subsequent analysis of the experiences of Infosys with KM shows that for KM to be successful, organizational leaders need to engage in a continuous process of modification and maintenance. Although KM initiatives can be made to yield worthwhile returns over an extended period, there are often substantial ongoing costs associated with them. © 2013 Wiley Periodicals, Inc.
Is Your Organization Addicted to Outsourcing?
Authors: Rieley James B. , Lyon Angus
Published: February 2013

Managers challenged to reduce expenses may find a solution in identifying the part of the business that costs more than it is delivering and then contracting with an external organization to provide the same services for less money. Sometimes the results are as planned, but when the decision to outsource is made without considering the full spectrum of factors that led the organization to consider outsourcing in the first place, the decision to cut in‐house staff and take on outside help can have serious unplanned consequences, and even lead to a counterproductive cycle of costly outsourcing engagements. © 2013 Wiley Periodicals, Inc.
To Prevent Attrition in Business Process Outsourcing, Focus on People
Authors: Thaly Priya , Sinha Vinita
Published: February 2013

Addressing the high rate of attrition that has long plagued business process outsourcing (BPO) enterprises has become essential in light of the sector's expansion across numerous industries around the world. A study of one Indian BPO enterprise revealed that many of the factors that contribute to attrition can be offset by an organizational focus on people. On the basis of their findings, the researchers offer numerous strategies for improving employee retention without compromising business processes. Managers in any sector can apply these suggestions to help ensure the continued growth and success of their organizations. © 2013 Wiley Periodicals, Inc.
Hybrid femtosecond/picosecond coherent anti‐Stokes Raman scattering for high‐speed CH4/N2 measurements in binary gas mixtures
Authors: Engel Sascha R. , Miller Joseph D. , Dedic Chloe E. , Seeger Thomas , Leipertz Alfred , Meyer Terrence R.
Published: February 2013

Hybrid femtosecond/picosecond (fs/ps) vibrational coherent anti‐Stokes Raman scattering was demonstrated for high‐speed, in‐situ measurements of CH4/N2 mole fractions in binary gas mixtures with temporal nonresonant suppression. A single broadband, 100‐fs laser source was used to simultaneously excite CH4 and N2 vibrational Raman transitions, characterized by a spectral separation of ~584 cm−1, followed by frequency‐domain detection with a time‐delayed ps probe pulse. In this manner, the temporal evolution of the nonresonant background and vibrational wavepackets of CH4 and N2 could be evaluated to maximize signal and minimize interferences. A typical accuracy of ~95% was achieved for experimental CH4 mole fractions between 0.02 and 0.70, and a precision of ~4% was achieved by maximizing relative excitation energy through induced chirp in the pump and Stokes pulses. It was further shown that mole‐fraction measurements were not affected by variations in bi‐molecular broadened linewidths over a wide range of mixture fractions. Copyright © 2013 John Wiley & Sons, Ltd.
Spectroscopic investigation on the structural modifications induced by radical stress on oligopeptides for tissue engineering
Authors: Di Foggia M. , Torreggiani A. , Taddei P. , Dettin M. , Tinti A.
Published: February 2013

EAK16 (AEAEAKAKAEAEAKAK) and seven alternating polar/hydrophobic oligopeptides (derived from EAK16 by primary structure modifications) were tested for their resistance to free radical attack, in view of their possible use as biomimetic coatings of biomedical devices; in fact, oxidative radical stress, mainly due to hydroxyl radicals (•OH), is a common physiological condition occurring under acute or chronic inflammatory response. •OH radicals, mimicking an endogenous radical stress, were generated by gamma‐radiolysis of water solutions. IR and Raman spectroscopies were used to investigate the damages induced by free radicals on the oligopeptides, in particular on their folding and inter‐chain interactions.

Some oligopeptides, i.e. EAK16 (pept1), pept3 (obtained by K → O substitution), pept5 (A → Abu substitution), pept7 (insertion at the N‐terminus of the RGD sequence), and pept8 (RGD insertion and “scrambling” of the sequence) were not severely affected by the treatment and retained their prevalent structure (i.e. α‐helix for pept8 and β‐sheet for the others). The other peptides, i.e. pept2 (obtained by E → D substitution), pept4 (E → D and K → O substitutions) and pept6 (A → Y substitution), showed significant conformational changes (i.e. increase in the α‐helix content) upon irradiation. In pept2 and pept4, modifications in hydrophobic and ionic interactions were observed; the latter were mainly ascribed to the decarboxylation of acidic amino acids. In pept6, the main target of the •OH attack was Tyr, as deduced by the strong variations observed in Tyr bands both in IR and Raman spectra.

This study may contribute to gain insight into the different biological performances of the EAK16‐derived peptides and to identify the most adequate materials usable for bone regeneration. Copyright © 2013 John Wiley & Sons, Ltd.
Strengthening protections for human subjects: Proposed restrictions on the publication of transplant research involving prisoners
Authors: Valapour Maryam , Paulson Kristin M. , Hilde Alisha
Published: February 2013

Publication is one of the primary rewards in the academic research community and is the first step in the dissemination of a new discovery that could lead to recognition and opportunity. Because of this, the publication of research can serve as a tacit endorsement of the methodology behind the science. This becomes a problem when vulnerable populations that are incapable of giving legitimate informed consent, such as prisoners, are used in research. The problem is especially critical in the field of transplant research, in which unverified consent can enable research that exploits the vulnerabilities of prisoners, especially those awaiting execution. Because the doctrine of informed consent is central to the protection of vulnerable populations, we have performed a historical analysis of the standards of informed consent in codes of international human subject protections to form the foundation for our limit and ban recommendations: (1) limit the publication of transplant research involving prisoners in general and (2) ban the publication of transplant research involving executed prisoners in particular. Liver Transpl 19:362–368, 2013. © 2013 AASLD.
Offer patterns of nationally placed livers by donation service area
Authors: Lai Jennifer C. , Feng Sandy , Vittinghoff Eric , Roberts John P.
Published: February 2013

We previously reported that national liver distribution is highly concentrated in 6 US centers, and this raises the possibility of expedited placement. Therefore, we evaluated all national offers of nationally placed livers (n=1625) to adult wait-list candidates from February 2005 to January 2010. We developed a model to predict national utilization pathways; pathways exceeding the best-fit linear unbiased predictions by ≥3 standard errors were defined as preferred. All 51 donation service areas (DSAs) placed 1 or more livers nationally, but the percentage per DSA ranged from 1% to 36%. Of 2830 possible national DSA-center pathways, 87% were used. Five hundred eighty livers (36%) were accepted on the first national offer. Four DSAs accounted for 47% of first-national-offer livers, and 44% of these were accepted by a single center. In comparison with first-offer livers using nonpreferred pathways, first offers along a preferred pathway were offered to fewer status 1 candidates (19% versus 61%) and had lower median Model for End-Stage Liver Disease (MELD) scores (22 versus 36, P<0.001). In conclusion, DSA placement patterns of national livers vary widely, with 4 DSAs exporting a high proportion of national livers on the first national offer to non–status 1 candidates with MELD scores less than their local transplant MELD scores. Although this practice may facilitate liver placement, it raises the possibility of expedience trumping patient need. Here we propose changes to the national liver distribution system that will help to balance equity, efficiency, and transparency. Liver Transpl 19:404–410, 2013. © 2013 AASLD.
Treatment strategy for recurrent hepatocellular carcinoma: Salvage transplantation, repeated resection, or radiofrequency ablation?
Authors: Chan Albert C. Y. , Chan See Ching , Chok Kenneth S. H. , Cheung Tan To , Chiu Dai Wing , Poon Ronnie T. P. , Fan Sheung Tat , Lo Chung Mau
Published: February 2013

The objective of this study was to evaluate the efficacy of salvage liver transplantation (SLT), repeated hepatic resection (RR), and repeated radiofrequency ablation (rRFA) for patients with postoperative tumor recurrence. The optimal treatment strategy for patients with recurrent hepatocellular carcinoma (HCC) remains unclear. From January 1993 to September 2009, 532 patients underwent either hepatic resection or radiofrequency ablation (RFA) for HCC within the Milan criteria. In all, 219 patients experienced intrahepatic recurrence, and 87 were selected for SLT (n=19), RR (n=24), or rRFA (n=44). Their clinicopathological data were reviewed, and their survival outcomes were assessed with Kaplan-Meier methods. Seventy-four of 220 patients (33.6%) developed recurrent HCC within the Milan criteria. The median Model for End-Stage Liver Disease (MELD) scores for SLT, RR, and rRFA were 10.7, 7.2, and 8.3, respectively (P<0.001). The 1-, 3-, and 5-year tumor-free survival rates were 68.4%, 57.9%, and 57.9%, respectively, for SLT; 69.7%, 49.3%, and 49.3%, respectively, for RR; and 40.0%, 19.8%, and 10.6%, respectively, for rRFA (P=0.001). For recurrent HCC within the Milan criteria, the 1-, 3-, and 5-year tumor-free survival rates for SLT were all 60%; the corresponding rates were 70.2%, 48.0%, and 48.0% for RR and 41.0%, 20.3%, and 10.9% for RFA (P=0.004). After adjustments of the MELD score, the 5-year survival rates for SLT, RR, and rRFA were 50.0%, 48.0%, and 11.4%, respectively (P=0.003). A subgroup analysis showed that SLT and RR led to comparable survival outcomes, but both treatments led to significantly better survival outcomes than rRFA (P<0.001). In conclusion, SLT is an efficacious treatment for patients with recurrent HCC and should be considered when RR is not feasible. Liver Transpl 19:411–419, 2013. © 2013 AASLD.
Erythrocytosis after liver transplantation: The experience of a university hospital
Authors: Cordone Gabriella , Zingone Fabiana , Cardillo Giuseppe , Martinelli Vincenzo , Pugliese Novella , Pellegrini Lucienne , Ciacci Carolina , Parrilli Gianpaolo
Published: February 2013

The prevalence and causes of erythrocytosis after liver transplantation have never been studied, even though this condition is known to predispose patients to thrombosis leading to graft failure or death. Erythrocytosis after orthotopic liver transplantation (OLT) can be defined as an increase in the red cell mass >125% in patients without a pre-OLT history of this condition. The study population was composed of 96 patients: 33 had undergone transplantation for a hepatitis B virus (HBV) infection (18 had a hepatitis D virus coinfection), 43 had undergone transplantation for a hepatitis C virus infection, 9 had undergone transplantation for alcohol abuse, and 11 had undergone transplantation for other causes [autoimmune liver disease (6), Wilson's syndrome (1), or cryptogenetic liver cirrhosis (4)]. Idiopathic erythrocytosis was reported in 11 male patients with a history of HBV infection. Patients with the diagnosis of erythrocytosis underwent phlebotomy every 3 weeks until the hematocrit level reached 45%, and this was repeated if the level exceeded 49%, so no patient presented with cardiovascular accidents during the follow-up. In conclusion, a history of HBV infection, male sex, and hepatitis B immune globulin therapy are all possible cofactors for an increased risk of erythrocytosis in OLT patients. Liver Transpl 19:420–424, 2013. © 2013 AASLD.
Director of anesthesiology for liver transplantation: Existing practices and recommendations by the united network for organ sharing
Authors: Mandell Susan M. , Pomfret Elizabeth A. , Steadman Randall , Hirose Ryutaro , Reich David J. , Schumann Roman , Walia Ann
Published: February 2013

A new Organ Procurement and Transplantation Network/United Network for Organ Sharing bylaw recommends that all centers appoint a director of liver transplant anesthesia with a uniform set of criteria. We obtained survey data from the Liver Transplant Anesthesia Consortium so that we could compare existing criteria for a director in the United States with the current recommendations. The data set included responses from adult academic liver transplant programs before the new bylaw. The respondent rates were within statistical limits to exclude sampling bias. All centers had a director of liver transplant anesthesia. The criteria varied between institutions, and the data suggest that the availability of resources influenced the choice of criteria. The information suggests that the criteria used in the new bylaw reflect existing practices. The bylaw plays an important role in supporting emerging leadership roles in liver transplant anesthesia and brings greater uniformity to the directorship position. Liver Transpl 19:425–430, 2013. © 2013 AASLD.
Technical aspects and outcomes of living donor liver transplantation for pediatric patients with situs inversus
Authors: Vincenzi Rodrigo , Seda-Neto Joao , da Fonseca Eduardo Antunes , Ketzer Bernardo Mazzini , Benavides Marcel , Cândido Helry Lopes , Porta Gilda , Miura Irene Kazue , Pugliese Renata , Danesi Vera Baggio , Guimaraes Teresa Cristina , Porta Adriana , Borges Cristian Barbieri , Kondo Mario , Chapchap Paulo
Published: February 2013

The vascular anomalies encountered in patients with biliary atresia associated with polysplenia syndrome and situs inversus (SI) demand technical refinements when liver transplantation is being performed. The available data describing the technique used in living donor liver transplantation (LDLT) in this population are limited; the short vascular stumps of the donor's liver can impart additional technical difficulties during vascular reconstruction. Here we describe our experience with 9 children with biliary atresia and SI who underwent LDLT. In our series, the retrohepatic vena cava was absent for 7 patients, 7 had a preduodenal portal vein (PV), and 4 had a variant arterial anatomy. The donor's left hepatic vein was anastomosed to the confluence of the recipient's 3 hepatic veins in 7 patients. Vascular grafts were used for PV reconstruction in 3 cases. A left lateral segment graft was used in all but 1 patient who needed a graft reduction. All grafts were placed in the upper left abdomen. There were no vascular complications after transplantation. All patients were alive and well at a median follow-up of 55 months. In conclusion, LDLT can be successfully performed in pediatric patients with SI. Complex vascular anomalies associated with the use of partial liver grafts obtained from living donors are not associated with an increased occurrence of vascular complications. Liver Transpl 19:431–436, 2013. © 2013 AASLD.
Excellent quality of life after liver transplantation for patients with perihilar cholangiocarcinoma who have undergone neoadjuvant chemoradiation
Authors: Murad Sarwa Darwish , Heimbach Julie K. , Gores Gregory J. , Rosen Charles B. , Benson Joanne T. , Kim Ray W.
Published: February 2013

Patients with perihilar cholangiocarcinoma (CCA) undergoing neoadjuvant chemoradiation followed by liver transplantation (LT) have excellent survival. However, little is known about their quality of life (QOL). We assessed the QOL of these patients and compared it to the QOL of patients who underwent transplantation for other liver diseases. From 1993 to 2010, 129 CCA patients underwent LT, and 93 (72%) were alive as of November 2010. All recipients were sent a previously validated QOL questionnaire composed of disease-specific QOL metrics (liver disease symptoms, Karnofsky score, health perception, and index of well-being) and generic QOL metrics [Short Form 36 (SF-36) and European Quality of Life (EuroQol)]. These recipients were compared to 110 transplant recipients with other liver diseases (excluding hepatitis C). Among the recipients with CCA, the response rate was 85% (n = 79). Patients with CCA did significantly better on liver disease symptoms (3.3 versus 3.2, P = 0.05), the Karnofsky score (90.8 versus 86.6, P = 0.03), the SF-36 Physical Functioning domain (52.0 versus 46.3, P < 0.001), and the EuroQol Mobility category (10% versus 33%, P = 0.001), and they rated their overall health better in comparison with non-CCA patients (85.9 versus 80.7, P = 0.02). CCA patients scored consistently higher on all other domains, albeit without significant differences. The observed differences in QOL remained unchanged when adjustments were made for demographic factors, including the level of education. In conclusion, patients who underwent neoadjuvant chemoradiation followed by LT for perihilar CCA reported excellent QOL that was equal to or better than that of recipients with other liver diseases. These results are important in light of the continued debate about the feasibility of this aggressive treatment in patients with perihilar CCA. Liver Transpl 19:521–528, 2013. © 2013 AASLD.
Binding Mechanism of Inhibitors to CDK5/p25 Complex: Free Energy Calculation and Ranking Aggregation Analysis
Authors: Wu Qiong , Kang Hong , Tian Chuan , Huang Qi , Zhu Ruixin
Published: February 2013

Cyclin‐dependent kinase‐5 (CDK5) plays an indispensable role in the central nervous system. Competitive inhibition of the ATP‐binding pocket of CDK5 is involved in fighting with neurodegenerative diseases, diabetes, tumors, inflammations etc. To better design ATP‐binding competitive inhibitors, the binding mechanism of three important inhibitors of kinases, (R)‐roscovitine (RRC), aloisine‐A (ALH) and indirubin‐3′‐oxime (IXM), together with their receptor CDK5, were studied by molecular dynamics simulations. The H‐bond analysis demonstrated that a strong bond was formed between the CO or NH groups in the backbone of Cys83 and the N or NH groups on the nitrogen‐containing ring of inhibitors. These hydrogen bonds significantly increase the binding and inhibitory efficiency. The free energy analysis show that the order of predicted binding affinities of these three inhibitors toward CDK5/p25 is IXM>ALH>RRC, which is consistent with the experimental data. Besides the hydrogen bond formation, the van der Waals interactions between residues Ile10, Val18, and Leu133 of CDK5 and inhibitors were discovered to constitute another substantial component of their binding mode. Worth mentioning is that the conformational turnover of the inhibitor RRC was observed during the course of molecular dynamics simulations. We believe that this is the reason why RRC has the lower H‐bond occupancy and binding affinity than the other two inhibitors. Furthermore, during the analysis of the per‐residue decomposition, the ranking aggregation method was firstly employed to rank the contribution of different residues. The results demonstrated that the top five residues in the active pocket of CDK5 were Cys83, Leu133, Ile10, Phe82, and Glu81, which is in good agreement with the results of H‐bond analysis and binding free energy analysis. These findings should provide insights into the inhibition mechanism of the CDK5/p25 complex and be useful for the rational design of novel ATP‐binding competitive inhibitors in the near future.
Error estimate in a finite volume approximation of the partial asymptotic domain decomposition
Authors: Panasenko Grigory , Viallon Marie‐Claude
Published: February 2013

The method of asymptotic partial domain decomposition has been proposed for partial differential equations set in rod structures, depending on a small parameter. It reduces the dimension of the problem (or simplifies it in another way) in the main part of the domain keeping the initial formulation in the remaining part and prescribing the asymptotically precise conditions on the interface. This paper is devoted to the finite volume implementation of the method of asymptotic partial domain decomposition. We consider a model problem in a thin domain (its thickness is a small parameter). We obtain an error estimate, expressed in terms of the small parameter and the step of the mesh. Copyright © 2013 John Wiley & Sons, Ltd.
Dependence of the solution of a semi‐discrete von Mises equation with respect to the pressure for an inverse problem
Authors: Plantié Laurent
Published: February 2013

We study precisely the solution of a semi‐discrete von Mises problem with known pressure to generalize a method for an inverse problem: the problem with known displacement. We prove the boundedness of the diffusive term, the uniqueness and the continuity of the solution with respect to the pressure and a coercivity property. However, the estimate of the diffusive term is not sharp enough for the inverse problem. We highlight a special behaviour of this term due to the combination of the nonlinearity with the degeneracy of the diffusion coefficient. Copyright © 2013 John Wiley & Sons, Ltd.
Multiple solutions for a Robin‐type differential inclusion problem involving the p(x)‐Laplacian
Authors: Ge Bin , Zhou Qing‐Mei
Published: February 2013

In this paper, we obtain the existence of at least two nontrivial solutions for a Robin‐type differential inclusion problem involving p(x)‐Laplacian type operator and nonsmooth potentials. Our approach is variational, and it is based on the nonsmooth critical point theory for locally Lipschitz functions. Copyright © 2013 John Wiley & Sons, Ltd.
Stability of the determination of the surface impedance of an obstacle from the scattering amplitude
Authors: Bellassoued Mourad , Choulli Mourad , Jbalia Aymen
Published: February 2013

We prove a stability estimate of logarithmic type for the inverse problem consisting in the determination of the surface impedance of an obstacle from the scattering amplitude. We present a simple and direct proof, which is essentially based on an elliptic Carleman inequality. Copyright © 2013 John Wiley & Sons, Ltd.
Bandwidth improvement of a broadband PIFA for multiple mobile services
Authors: Gómez‐Villanueva R. , Linares‐y‐Miranda R. , Jardón‐Aguilar H.
Published: February 2013

A new very broadband planar inverted‐F antenna (PIFA) operating from 1.64 to 8.62 GHz with S11 < −10 dB is presented. The antenna has a volume of 4 × 2 × 1 cm3 and exhibits adequate radiation characteristics. It has the largest wideband reported for a PIFA‐type antenna and can be used for services such as DCS, PCS, LTE, WiMAX, WLAN, and Bluetooth. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:886–890, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27409
Compact cascaded quadruplet bandpass filter using artificial magnetic resonators
Authors: Lee Tae‐Hak , Baik Jung‐Woo , Kim Youngsik
Published: February 2013

A compact cascaded quadruplet (CQ) bandpass filter (BPF) using artificial magnetic resonators is proposed in this letter.An artificial magnetic resonator, which has a negative effective permeability at the resonant frequency, consists of a shorted spiral structure. The negative‐mu characteristics are extracted from the simulation result of the scattering parameters in a fictitious rectangular waveguide. Compared with the open‐loop resonators that are usually used to construct conventional CQ‐BPFs, the proposed artificial magnetic resonator achieves about an 80% size reduction ratio. The measured insertion and return losses at a center frequency of 2.14 GHz are approximately 1.83 dB and 21 dB, respectively. The group delay is less than 0.81 ns in the W‐CDMA passband. The full‐wave simulation results are in good agreement with the measurement results. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:883–886, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27410
Vivaldi antenna impedance bandwidth dependence on stripline to bilateral slotline transition
Authors: Bancroft Randy , Chou Ri‐Chee
Published: February 2013

The Vivaldi Antenna is known to have a theoretically unlimited instantaneous frequency bandwidth.Vivaldi design geometry which uses an open circuit stub stripline to bilateral slotline transition is the limiting factor of this design. It is shown that a shorted stub transition increases the bandwidth toward the theoretical limit. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:937–941, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27413
Shared aperture dual band dual polarization microstrip patch antenna
Authors: Sharma Devendra Kumar , Kulshrestha Sanjeev , Chakrabarty S. B. , Jyoti Rajeev
Published: February 2013

This article presents the design and development of a new type of wideband shared aperture dual band dual microstrip polarization patch antenna (MPA) operating at L&S band. In this configuration, square ring shaped radiating element at L band and square shaped patch printed on different dielectric substrate layers housed within the square ring at S‐band has been used. The probe fed feeding mechanism is employed to get wide bandwidth performance at both bands. The measured 10‐dB return loss bandwidth is 28.3% at L band and 29.4% at S‐band. The simulated and measured antenna parameters of this antenna are in excellent agreement. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:917–922, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27414
Frequency tuning and miniaturization of square microstrip antenna embedded with “T”‐shaped defected ground structure
Authors: Chakraborty Ujjal , Chowdhury S.K. , Bhattacharjee A.K.
Published: February 2013

Study of the effect of “T”‐shaped defected ground structure (DGS) on frequency tuning and size reductions of a square microsrtrip antenna in comparison with square conventional and slit added compact patches are presented. Parametric analysis of the DGS shows that the resonant frequency of the proposed antenna can be tuned from 3.188 GHz down to 1.80 GHz with more than 4% fractional bandwidth. A significant size reduction of about 80% is achieved. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:869–872, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27417
A 24/77‐GHz SiGe BiCMOS transmitter chipset for automotive radar
Authors: Giammello Vittorio , Ragonese Egidio , Palmisano Giuseppe
Published: February 2013

This article presents a 24/77‐GHz transmitter chipset for automotive radar sensors implemented in a 160/175‐GHz fT/fmax SiGe BiCMOS technology. The chipset adopts a dual‐band architecture consisting of a 24‐GHz section for ultra‐wideband short‐range radar operation, which is also exploited to drive the 77‐GHz long‐range radar transmitter front‐end. The proposed design adopts a single 24‐GHz frequency synthesizer to implement both radar operation modes. The transmitter chipset is able to deliver a maximum output power of 3 dBm and 12 dBm at 24 GHz and 77 GHz, respectively. The 24‐GHz transmitter demonstrates to operate with pulse widths of 0.5 ns and 1 ns in compliance with the transmission mask designed by ETSI. The 77‐GHz transmitter exhibits a power gain of 20 dB, an output power of 12 dBm, and an output referred 1‐dB compression point of 9.5 dBm, while drawing 155 mA from a 2.5‐V supply voltage. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:782–786, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27425
High efficiency reflectarray using smooth tapering in phase pattern on antenna surface
Authors: Maddahali Mohsen , Forooraghi Keyvan
Published: February 2013

In this article, a novel method is introduced to design a high efficiency and broadband reflectarray.Several techniques will be introduced for designing wideband reflectarray. First, by using fractal ring unit cell with 700° phase range; second, by smoothing phase tapering on reflectarray surface; and finally, by finding the optimum free reference phase and f/D ratio. Using these ideas, a 625 element array prototype of 25 × 25 cm2 dimensions with 1 dB gain bandwidth of 12% and radiation efficiency close to 66% at 10 GHz is simulated and tested. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:747–753, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27427
Triple‐band CMOS voltage‐controlled oscillator
Authors: Jang Sheng‐Lyang , Chen Yao‐Tsu , Chang Chia‐Wei , Juang Miin‐Horng
Published: February 2013

A low‐phase noise triple‐band voltage‐controlled oscillator (VCO) is proposed and it consists of a triple‐resonance LC resonator and a cross‐coupled switching transistor pair. In the proposed VCO that uses the triple‐resonance LC‐resonator, band switching is achieved by tuning the varactors in the resonator without using lossy switches in the resonator path. The triple‐resonance LC resonator comprises a parallel‐tuned LC resonator and two series resonant resonators. The proposed VCO has been implemented with the TSMC 0.18 μm 1P6M CMOS technology and the core power consumption is 3.12 mW at the dc drain–source bias of 0.8 V. The VCO can generate differential signals in the frequency range of 6.651∼7.146 GHz, 5.607∼5.941 GHz, and 3.15 GHz∼3.483 GHz. The die area of the triple‐band VCO is 0.684 × 0.754 mm2. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:737–740, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27431
Design and characterization of microfluidic housing effects on coplanar waveguide microfluidic delay line performance
Authors: Murray Casey , Franklin Rhonda R.
Published: February 2013

A fluid and its housing are integrated on a coplanar waveguide circuit surface, realizing a variable delay line. Performance tradeoffs for different fluidic housing shapes are investigated. Simulation and measurement results for two circuits are shown with the housing filled with air or de‐ionized water. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:789–793, 2013; View this article online at wileyonlinelibrary.com. DOI: 10.1002/mop.27434