bluuebunny/crossref_metadata_2025 huggingface dataset:
Severe muscle depletion in patients on the liver transplant wait list: Its prevalence and independent prognostic value
Authors: Tandon Puneeta , Ney Michael , Irwin Ivana , Ma Mang M. , Gramlich Leah , Bain Vincent G. , Esfandiari Nina , Baracos Vickie , Montano-Loza Aldo J. , Myers Robert P.
Published: June 2012

As detected by cross-sectional imaging, severe muscle depletion, which is termed sarcopenia, holds promise for prognostication in patients with cirrhosis. Our aims were to describe the prevalence and predictors of sarcopenia in patients with cirrhosis listed for liver transplantation (LT) and to determine its independent prognostic significance for the prediction of waiting-list mortality. Adults listed for LT who underwent abdominal computed tomography/magnetic resonance imaging within 6 weeks of activation were retrospectively identified. The exclusions were hepatocellular carcinoma, acute liver failure, prior LT, and listing for multivisceral transplantation or living related LT. Sixty percent of the 142 eligible patients were male, the median age was 53 years, and the median Model for End-Stage Liver Disease (MELD) score at listing was 15. Forty-one percent were sarcopenic; sarcopenia was more prevalent in males versus females (54% versus 21%, P < 0.001) and increased with the Child-Pugh class (10% for class A, 34% for class B, and 54% for class C, P = 0.007). Male sex, the dry-weight body mass index (BMI), and Child-Pugh class C cirrhosis (but not the MELD score) were independent predictors of sarcopenia. Sarcopenia was an independent predictor of mortality (hazard ratio = 2.36, 95% confidence interval = 1.23-4.53) after adjustments for age and MELD scores. In conclusion, sarcopenia is associated with increased waiting-list mortality and is poorly predicted by subjective nutritional assessment tools such as BMI and subjective global assessment. If this is validated in larger studies, the objective assessment of sarcopenia holds promise for prognostication in this patient population. Liver Transpl 18:1209–1216, 2012. © 2012 AASLD.
Evolution of nonalcoholic fatty liver disease recurrence after liver transplantation
Authors: Patil Deepa T. , Yerian Lisa M.
Published: June 2012

Nonalcoholic steatohepatitis (NASH) is the progressive form of nonalcoholic fatty liver disease (NAFLD) and is the fourth most common indication for liver transplantation. Risk factors for NAFLD can persist and even worsen after liver transplantation. However, the risk and significance of NAFLD recurrence remain unclear. Reported posttransplant NAFLD and NASH recurrence rates vary widely across studies. There is little information detailing the histological evolution of NAFLD recurrence, and the long-term natural history of NAFLD recurrence is unclear. In this review, we summarize the findings of studies on the prevalence of recurrent NAFLD and its risk factors in the posttransplant setting, and we explore reasons for the discrepant reported recurrence rates. On the basis of currently available data, the relatively low rates of advanced fibrosis and NAFLD-associated graft loss and the comparability of the survival rates for these patients and patients undergoing transplantation for other diseases suggest that although NAFLD or NASH can recur, the clinical significance of disease recurrence for graft or patient survival may be small. Liver Transpl 18:1147–1153, 2012. © 2012 AASLD.
Computational Insights into ADAMTS4, ADAMTS5 and MMP13 Inhibitor Selectivity
Authors: Filomia Federico , Saxena Puneet , Durante Caterina , de Rienzo Francesca , Cocchi Marina , Menziani Maria Cristina
Published: June 2012

The results obtained by means of Molecular Dynamics simulations and Multiway Explorative Data Analysis on ADAMTS4, ADAMTS5 and MMP13 complexed with Marimastat and two cis‐1(S)2(R)‐amino‐2‐indanol ligands suggest that determinant characteristics for ligand binding and selectivity among the three enzymes are to be found in the different protein conformation flexibility. Moreover, the role of the TS‐domain in the inhibitor binding to ADAMTS enzymes has been investigated for the first time in this work. The results obtained suggest that the influence of the TS‐domain on the S1′ loop fluctuations of ADAMTS4 and ADAMTS5 could be exploited for the design of therapeutics for chronic osteoarthritis diseases.
Large global well‐posedness of the three‐dimensional magneto‐hydrodynamic equations with the initial data of the type ‘v + w’
Authors: Han Jinsheng
Published: June 2012

We study the Cauchy problem of the three‐dimensional, incompressible magneto‐hydrodynamic equations with full velocity dissipation and magnetic diffusion. We prove the global well‐posedness of the magneto‐hydrodynamic equations due to some particular initial data of the type ‘ v + w’, which may be large in the corresponding critical space. We provide two kinds of results, and they do not contain each other. Copyright © 2012 John Wiley & Sons, Ltd.
Balanced multiwavelets with optimum time–frequency resolution
Authors: Li Baobin , Li Dengfeng
Published: June 2012

Balanced multiwavelets with optimum time–frequency resolution are discussed in this paper, which are balanced of at least one order and at same time possess the optimum time–frequency resolution. On the basis of lattice structure of causal FIR lossless systems, some balanced with optimum time–frequency resolution are constructed. Copyright © 2012 John Wiley & Sons, Ltd.
Some normality criteria of function families concerning shared values
Authors: Yuan Wenjun , Li Zhirong , Lin Jianming
Published: June 2012

In this paper, we study the normality of families of meromorphic functions concerning shared values. We consider mainly whether a family meromorphic functions is normal in D, if (i) for every pair of functions f and g in , f(k) − afn and g(k) − agn share the value b, and (ii) f has no zero of multiplicity less than k in D for every function , where a and b are two finite complex numbers such that a ≠ 0, n ≥ k + 3 and k ≥ 2 are two positive integers. An example shows that the condition (ii) in our results is best possible. Copyright © 2012 John Wiley & Sons, Ltd.
Longitudinal rotating frame relaxation time measurements in infarcted mouse myocardium in vivo
Authors: Musthafa Haja‐Sherief N. , Dragneva Galina , Lottonen Line , Merentie Mari , Petrov Lyubomir , Heikura Tommi , Ylä‐Herttuala Elias , Ylä‐Herttuala Seppo , Gröhn Olli , Liimatainen Timo
Published: June 2012

Longitudinal relaxation time in the rotating frame (T1ρ) was measured using continuous wave irradiation in normal and infarcted mouse myocardium in vivo. Significant increase in T1ρ was found after 7 days of infarction when compared with reference myocardium or in myocardium before infarction. Cine MRI and histology were performed to verify the severity of infarction. The time course of T1ρ in the infarct fits better with granulation and scar tissue formation than necrosis and edema. The results of the study show that T1ρ could potentially be a noninvasive quantitative marker for tissue remodeling after ischemic damage. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
An adaptive multiscale method for crack propagation and crack coalescence
Authors: Holl M. , Loehnert S. , Wriggers P.
Published: June 2012

This work presents a new multiscale technique for the efficient simulation of crack propagation and crack coalescence of macrocracks and microcracks. The fully adaptive multiscale method is able to capture localization effect mesh independently. By modeling macrocracks and microcracks, the extended finite element method offers an accurate solution and captures cracks and their propagation without changing the mesh topology. Propagating and coaliting cracks of different length scales can therefore be easily modeled and updated during the computation process. Hence, the presented method is an efficient and accurate option for modeling cracks of different length scales. This is demonstrated in several numerical examples showing the interaction of microcracks and macrocracks. Copyright © 2012 John Wiley & Sons, Ltd.
Repairing unstructured triangular mesh intersections
Authors: McLaurin David , Marcum David , Remotigue Mike , Blades Eric
Published: June 2012

Computational analysis and design has become a fundamental part of product research, development, and manufacturing in aerospace, automotive, and other industries. In general, the success of the specific application depends heavily on the accuracy and consistency of the computational model used. The aim of this work is to reduce the time needed to prepare geometry for volume grid generation. This will be accomplished by developing tools that semi‐automatically repair discrete data. Providing another level of automation to the process of repairing large, complex problems in discrete data will significantly accelerate the grid generation process. The developed algorithms are meant to offer a semi‐automated solution to a complicated geometrical problem — specifically discrete mesh intersection.

The intersection‐repair strategy presented here focuses on repairing the intersection in‐place as opposed to rediscretizing the intersecting geometries. Combining robust, efficient methods of detecting intersections and then repairing intersecting geometries in‐place produces a significant improvement over techniques used in current literature. The result of this intersection process is a nonintersecting geometry that is free of duplicate and degenerate geometry. Results are presented showing the accuracy and consistency of the intersection repair tool. Copyright © 2012 John Wiley & Sons, Ltd.
Was the Dog Locally Domesticated in the Danube Gorges? Morphometric Study of Dog Cranial Remains From Four Mesolithic–Early Neolithic Archaeological Sites by Comparison With Contemporary Wolves
Authors: Dimitrijević V. , Vuković S.
Published: June 2012

In this article, we test a hypothesis about local dog domestication in the Danube Gorges of the central Balkans in the course of the Mesolithic period. Morphometric features of dog mandibles and teeth from Mesolithic–Early Neolithic sites of Vlasac, Padina, Lepenski Vir, and Hajdučka Vodenica have been analysed and compared with recent wolves from the central Balkans. Decrease in size and changes in proportions of dog's dental features were tracked diachronically. We identified specimens which manifested mixed wolf/dog features. Such specimens originate from the Early Mesolithic contexts, the time when a decrease in size began. On the basis of this pattern, we suggest that dog domestication may have taken place in the Danube Gorges during the Early Mesolithic (ca 9500–7500 cal. bc). The reduction of size continued throughout Late Mesolithic (ca 7500–6300 cal. bc), but there were still individuals that might be regarded as ‘transitional’ in comparison with wolves on account of their size, and a distinct difference in size between wolves and dogs did not develop. Accordingly, if local domestication was in progress here, the domestication process might have lasted for more than just few generations and even several millennia. Copyright © 2012 John Wiley & Sons, Ltd.
A comprehensive view on stabilities and reactivities of triarylmethyl cations (tritylium ions)
Authors: Horn Markus , Mayr Herbert
Published: June 2012

By combining conventional photometric and conductimetric methods with stopped‐flow techniques, we were able to investigate ionization rate constants of trityl bromides, chlorides, and carboxylates in aqueous acetonitrile in a reactivity range from 10−5 to 103 s−1. In this way, it became possible to compare ionization processes yielding tritylium ions which differ by 21 units in pKR+, corresponding to 120 kJ mol−1 in free energy. Analysis of such far‐reaching correlations provided new insights into several aspects of organic reactivity. We observed (i) the change of solvolysis mechanisms from SN1 reactions without and with common ion return, (ii) reactions where formation and consumption of the carbocations could be observed visually, (iii) solvolyses where the ionization step is almost complete before the reaction with water becomes significant, and (iv) ionizations that yield solutions of persistent carbocations. The continuous change from reactions with carbocation‐like transition states to reactions with transition states of little carbocation character caused large variations of Winstein–Grunwald m values. Values of m = 0.2 for ionization processes show that low values of m do not necessarily imply SN2 reactions. Although the 4,4′,4″‐trimethoxytritylium ion reacts more than 1000 times faster with water than the 4‐dimethylaminotritylium ion and has a pKR+ value that is more negative by three units, both carbocations are formed with almost equal rates by ionization of the corresponding acetates in aqueous acetonitrile. This comparison again illustrates that electrofugality is not simply the inverse of electrophilicity and presents a challenge for further study of the importance of intrinsic barriers. Copyright © 2012 John Wiley & Sons, Ltd.
Demonstrating the psychometric properties of a problem‐related distress screener in a community sample of 319 cancer survivors
Authors: Miller Melissa F. , Buzaglo Joanne S. , Clark Karen L. , Loscalzo Matthew J. , Kennedy Victoria , Taylor Julie , Dougherty Kasey Ryan , Golant Mitch
Published: June 2012

Objective

The purpose was to test the psychometric properties of a 36‐item community‐based problem‐related distress screening tool, among 319 cancer survivors recruited across 14 affiliates of the Cancer Support Community.

Methods

Internal reliability was estimated using Cronbach's alpha coefficient. Test–retest reliability was assessed using the intra‐class correlation coefficient (ICC). Concurrent validity was determined by correlations with the Functional Assessment of Cancer Therapy‐General Well‐Being Scale (FACT‐G), the Center for Epidemiologic Studies Depression Scale (CES‐D), and the Distress Thermometer (DT) and receiver operating characteristic (ROC) curve analysis using the CES‐D (≥16) and DT (≥4) as the criterion. Non‐parametric analysis of variance was used to establish discriminant validity.

Results

The distress screener demonstrated high internal consistency (Cronbach's alpha = 0.91) and strong test–retest reliability (ICC ≥ 0.75). Summary scores of the distress screener correlated substantially with the FACT‐G (R2 = 0.58, p < 0.001), CES‐D (R2 = 0.48, p < 0.001), and DT (R2 = 0.35, p < 0.001) indicating strong concurrent validity and were able to discriminate groups of clinical relevance. ROC analyses showed a cutoff score of 8 for problem items rated ≥3 had optimal sensitivity and specificity relative to the CES‐D and DT.

Conclusions

The distress screener shows strong psychometric properties and can be considered a valuable community‐based instrument to screen for psychological distress related to social, emotional, physical, and other patient‐related symptoms and problems. This study is the first to address the chasm between hospital and community‐based screening by validating a community‐based instrument and has begun to demonstrate the feasibility of screening in the community. Copyright © 2012 John Wiley & Sons, Ltd.
Robotic‐assisted treatment of celiac artery compression syndrome: report of a case and review of the literature
Authors: Meyer Mark , Gharagozloo Farid , Nguyen Duy , Tempesta Barbara , Strother Eric , Margolis Marc
Published: June 2012

Background

The surgical management of celiac artery compression syndrome (CACS) is controversial. Controversies include the appropriate surgical technique, the surgical approach, and the utility of postoperative stents. The literature is reviewed, and a case of CACS is presented in which a robotic‐assisted division of the median arcuate ligament (MAL) was performed.

Methods

Robotic‐assisted treatment of celiac artery syndrome was carried out using six (five 1 cm and one 2 cm) abdominal incisions. The robotic device was used to expose the aorta and celiac artery and divide the median arcuate ligament.

Results

Postoperatively, the patient's postprandial abdominal pain subsided. On 16 month follow‐up, the patient was doing well, tolerated an unrestricted diet without symptoms, and exhibited weight gain.

Conclusion

This case is the second reported in the literature and demonstrates that the robotic approach to division of the MAL is feasible, safe, and efficacious. Copyright © 2012 John Wiley & Sons, Ltd.
Teaching the nature of science through scientific errors
Authors: Allchin Douglas
Published: June 2012

Error in science is a prime occasion to teach the nature of science, especially the central feature of tentativeness. Error types also reflect corresponding methodologies of science, critical for practicing science and (in a context of scientific literacy) analyzing its claims. Effective efforts in teaching about error will ideally be informed by earlier educational perspectives and a schema for inventorying and organizing error types. Approaches using student‐directed inquiry have limits, whereas guided‐inquiry historical case studies seem appropriate vehicles. On a larger scale, one may also envision a prospective learning progression on successively deeper understandings of error in science. Sample case studies and opportunities for further reading are identified. © 2012 Wiley Periodicals, Inc. Sci Ed96:904–926, 2012
Unplanned adaptations before breaking the blind
Authors: Posch Martin , Proschan Michael A.
Published: June 2012

Occasionally, things go so wrong in a clinical trial that a change must be made. For example, the originally planned primary outcome may be measured completely unreliably. Is there any recourse? One may still be able to salvage the trial using a permutation test if a change is made before breaking the treatment blind. The solution is not a panacea; we discuss the limitations and legitimate grounds for criticism. Still, when it is needed, the procedure is preferable to rigid adherence to a design that makes no sense. Published 2012. This article is a US Government work and is in the public domain in the USA.
New Techniques to Detect the Suitable Time to Close the Tap Hole of a Blast Furnace
Authors: Ruiz‐Bustinza Iñigo , Antoranz Juan Carlos , Mochón Javier , Rodriguez Daniel , Parra Roberto , Verdeja Luis Felipe , Martin Ramón
Published: June 2012

The closing of a BF tap hole, as a final end to an optimum pig iron and slag tapping contained in the hearth, is an operation that requires the plant operator's complex background to recognize the instant in which the tap hole must be closed; this way avoiding dangerous phenomena relating to whistlinga. In this paper, two systems are described – which may act concurrently – of advisement to the plant's operator in order to warn him of when he must close the tap hole. One of them is based in the processing of the EMF probe signals, which measure the electromotive force between two points of the hearth shell. These probes are welded to the BF shell under study and are located on top and underneath the respective tap hole. The second system uses image treatment of pig iron and slag flow casting coming out of the tap hole in this hostile environment.
A Germanate Compound Constructed from Dissymmetric Ge7 Chains and Metal Complexes
Authors: Ren Xiaoyan , Li Yi , Shao Lang , Yu Jihong , Xu Ruren
Published: June 2012

Abstract. A novel germanate compound, |[Ni(dien)2]3(H2O)3|[Ge7O13F5]2(designated JU‐85, dien = diethylenetriamine), was solvothermally synthesized. The structure of JU‐85 was determined by single‐crystal X‐ray diffraction and further characterized by powder X‐ray diffraction, inductively coupled plasma, infrared spectroscopy, elemental analysis, and thermogravimetric analysis. JU‐85 has dissymmetric chains constructed from diagonally linked Ge7 building units and various Ni(dien)22+ complexes formed in situ during the synthesis. Compared with its structural analogue, FJ‐6, JU‐85 contains less complex cations and different host‐guest assembly. Besides the diagonal linkage in JU‐85, other dissymmetric linkages of Ge7 building units were enumerated, which could be used as the stereogenic centers for the design of novel chiral germanate compounds.
Proving termination of nonlinear command sequences
Authors: Babić Domagoj , Cook Byron , Hu Alan J. , Rakamarić Zvonimir
Published: June 2012

We describe a simple and efficient algorithm for proving the termination of a class of loops with nonlinear assignments to variables. The method is based on divergence testing for each variable in the cone-of-influence of the loop’s condition. The analysis allows us to automatically prove the termination of loops that cannot be handled using previous techniques. We also describe a method for integrating our nonlinear termination proving technique into a larger termination proving framework that depends on linear reasoning.
Selecting the best targeted agent in first‐line treatment of unresectable liver metastases from colorectal cancer: does the bench have the answers?
Authors: Benhaim L. , Loupakis F. , LaBonte M.J. , Lenz H.J.
Published: June 2012

For physicians facing patients with organ‐limited metastases from colorectal cancer, tumor shrinkage and sterilization of micrometastatic disease is the main goal, giving the opportunity for secondary surgical resection. At the same time, for the majority of patients who will not achieve a sufficient tumor response, disease control remains the predominant objective. Since FOLFOX or FOLFIRI have similar efficacies, the challenge is to define which could be the most effective targeted agent (anti‐EGFR or anti‐VEGF) to reach these goals. Therefore, a priori molecular identification of patients that could benefit from anti‐EGFR or anti‐VEGF monoclonal antibodies (i.e. the currently approved targeted therapies for metastatic colorectal cancer) is of critical importance. In this setting, the KRAS mutation status was the first identified predictive marker of response to anti‐EGFR therapy. Since it has been demonstrated that tumors with KRAS mutation do not respond to anti‐EGFR therapy, KRAS status must be determined prior to treatment. Thus, for KRAS wild‐type patients, the choices that remain are either anti‐VEGF or anti‐EGFR. In this review, we present the most updated data from translational research programs dealing with the identification of biomarkers for response to targeted therapies.
Application of Green Commercial Surfactant in Preparing Purely Acrylic Latex via Semi‐continuous Seeded Emulsion Polymerization
Authors: Chen Lijun
Published: June 2012

Nonylphenol ethoxylates (NPEOs) are widely used as surfactants for emulsion polymerization and for post adding stabilization for latex applications in formulations with high filler content. However, NPEOs are bioaccumulative and persistent in the environment while nonylphenol, the breakdown product of NPEs, is an endrocrine disruptor. Therefore, it has been recommended to ban technical processes using NPEOs as surfactants. The acrylic polymer latex was prepared via semi‐continuous seeded emulsion polymerization of butyl acrylate and methyl methacrylate in water phase initiated with potassium persulfate when nonylphenol ethoxylates are replaced with alkyl polyglycoside (APG) surfactants. The structure of the resultant acrylic polymer latex is confirmed with Fourier transform infrared spectroscopy spectrum. Differential scanning calorimetry confirms that the resultant latex is a kind of random copolymer and the consistency among the chain segment is fairly good. Influences of amount of APG on the properties of the resultant latex and its film were investigated. Results show that the particle size of the latex is decreased with the increase of the amount of APG. And the ionic stability of latex is also improved with the increase of the amount of APG. However, the water‐resistance of the film of the latex is decreased with the increase of the amount of APG.
On the Edge: Britain and the European Union
Authors: Donnelly Brendan
Published: June 2012

British negotiating tactics at the European Council of December 2011 were the predictable outcome of the underlying approach to the EU of the present British government and particularly of its largest component, the Conservative Party. Recent years have seen a consolidation of hostility in the UK towards the EU, both at the public and the political level. A referendum on British membership is in the medium term a real possibility, with no certainty as to its outcome. British attitudes towards the EU may change over time in a more favourable direction. Any such change will require concerted political action and leadership, which have hitherto been lacking.
The space of 4-ended solutions to the Allen–Cahn equation in the plane
Authors: Pacard Frank , Kowalczyk Michał , Liu Yong
Published: June 2012

We are interested in entire solutions of the Allen–Cahn equation

\mathrm{\Delta }u−F^{′}(u) = 0

which have some special structure at infinity. In this equation, the function

F

is an even, double well potential. The solutions we are interested in have their zero set asymptotic to 4 half oriented affine lines at infinity and, along each of these half affine lines, the solutions are asymptotic to the one dimensional heteroclinic solution: such solutions are called

4

-ended solutions

. The main result of our paper states that, for any

\theta \in (0,\pi / 2)

, there exists a

4

-ended solution of the Allen–Cahn equation whose zero set is at infinity asymptotic to the half oriented affine lines making the angles

θ

,

\pi −\theta

,

\pi + \theta

and

2\pi −\theta

with the

x

-axis. This paper is part of a program whose aim is to classify all

2k

-ended solutions of the Allen–Cahn equation in dimension

2

, for

k⩾2

.
The Stokes conjecture for waves with vorticity
Authors: Varvaruca Eugen , Weiss Georg S.
Published: June 2012

We study stagnation points of two-dimensional steady gravity free-surface water waves with vorticity.

We obtain for example that, in the case where the free surface is an injective curve, the asymptotics at any stagnation point is given either by the “Stokes corner flow” where the free surface has a
corner of
120°, or the free surface ends in a
horizontal cusp
, or the free surface is
horizontally flat
at the stagnation point. The cusp case is a new feature in the case with vorticity, and it is not possible in the absence of vorticity.

In a second main result we exclude horizontally flat singularities in the case that the vorticity is 0 on the free surface. Here the vorticity may have infinitely many sign changes accumulating at the free surface, which makes this case particularly difficult and explains why it has been almost untouched by research so far.

Our results are based on calculations in the original variables and do not rely on structural assumptions needed in previous results such as isolated singularities, symmetry and monotonicity.
A mathematical formulation of the random phase approximation for crystals
Authors: Cancès Eric , Stoltz Gabriel
Published: June 2012

This works extends the recent study on the dielectric permittivity of crystals within the Hartree model [E. Cancès, M. Lewin, Arch. Ration. Mech. Anal. 197 (1) (2010) 139–177] to the time-dependent setting. In particular, we prove the existence and uniqueness of the nonlinear Hartree dynamics (also called the random phase approximation in the physics literature), in a suitable functional space allowing to describe a local defect embedded in a perfect crystal. We also give a rigorous mathematical definition of the microscopic frequency-dependent polarization matrix, and derive the macroscopic Maxwell–Gauss equation for insulating and semiconducting crystals, from a first order approximation of the nonlinear Hartree model, by means of homogenization arguments.
Well-posedness of the Hele–Shaw–Cahn–Hilliard system
Authors: Wang Xiaoming , Zhang Zhifei
Published: June 2012

We study the well-posedness of the Hele–Shaw–Cahn–Hilliard system modeling binary fluid flow in porous media with arbitrary viscosity contrast but matched density between the components. For initial data in

H^{s}

,

s > \frac{d}{2} + 1

, the existence and uniqueness of solution in

C([0,T];H^{s}) \cap L^{2}(0,T;H^{s + 2})

that is global in time in the two dimensional case (

d = 2

) and local in time in the three dimensional case (

d = 3

) are established. Several blow-up criterions in the three dimensional case are provided as well. One of the tools that we utilized is the Littlewood–Paley theory in order to establish certain key commutator estimates.
Structural and SAXS analysis of the budding yeast SHU‐complex proteins
Authors: She Zhun , Gao Zeng-Qiang , Liu Ying , Wang Wen-Jia , Liu Guang-Feng , Shtykova Eleonora V. , Xu Jian-Hua , Dong Yu-Hui
Published: June 2012

PSY3
and
CSM2

bind
by X‐ray crystallography (
View interaction
)
PSY3
,
CSM2
,
Shu 1
and
Shu 2

physically interact
by
x ray scattering
(View interaction)
Uncertainties in the assessment of the isotopic composition of surface fluxes: A direct comparison of techniques using laser‐based water vapor isotope analyzers
Authors: Good Stephen P. , Soderberg Keir , Wang Lixin , Caylor Kelly K.
Published: June 2012

The isotopic composition of surface fluxes is a key environmental tracer currently estimated with a variety of methods, including: Keeling mixing models, the flux‐gradient technique, and eddy covariance. We present a direct inter‐comparison of these three methods used to estimate the isotopic ratio of water vapor in surface fluxes (δET) over half‐hour periods, with a focus on the statistical uncertainty of each method We develop expressions for a function of instrument precision, sample size, and atmospheric conditions. Uncertainty estimators are validated with high frequency (1 Hz) data from multiple configurations of commercial off‐axis integrated cavity output spectroscopy (ICOS) systems. We find measurement techniques utilizing the high frequency capabilities of ICOS system outperform those methods where a single average of the isotopic composition is obtained at each height, with improvements attributed to large sample counts and increased variation in observed concentrations. Analytically, and with supporting data, we show that over 30 minute periods the Keeling plot and flux‐gradient techniques produce nearly identicalδET and values, while eddy covariance calculations always introduce more uncertainty given the same high frequency data. This additional uncertainty is proportional to the reciprocal of the correlation coefficient between vertical wind speed and water vapor mixing ratio. Finally, given the inverse relationship between δET uncertainties and the range of water vapor observed, we propose that experimental designs should attempt to maximize both sample count and the coefficient of variation in atmospheric water vapor.
The effects of transverse bed topography variations in ice‐flow models
Authors: Sergienko O. V.
Published: June 2012

A suite of ice‐flow models is subject to a performance test designed to investigate treatment of flow over variable basal topography. Using transfer functions developed by Gudmundsson (2003) and numerical models of various complexity, this study demonstrates that a widely used flowband model has strong limitations associated with its underlying assumptions, and thus should be applied only in specific geometrical settings. Its performance can be significantly improved by using the laterally averaged basal topography instead of centerline topography. In applications where spatial variability of flow fields is important, hybrid ice‐flow models can be a viable alternative to flowband models. In addition, analysis of horizontal distributions of the various ice‐flow characteristics (e.g., surface elevation, velocity, and horizontal stress components) shows that field observations that focus on assessing these parameters only along the centerline of ice flow could be misleading. These results also suggest that such spatial variability needs to be taken into account when designing field surveys of ice flow.
New insights into the nation's carbon storage potential
Authors: Warwick Peter D. , Zhu Zhiliang
Published: June 2012

Carbon sequestration is a method of securing carbon dioxide (CO2) to prevent its release into the atmosphere, where it contributes to global warming as a greenhouse gas. Geologic storage of CO2 in porous and permeable rocks involves injecting high‐pressure CO2 into a subsurface rock unit that has available pore space. Biologic carbon sequestration refers to both natural and anthropogenic processes by which CO2 is removed from the atmosphere and stored as carbon in vegetation, soils, and sediments.
Open access to geophysical data sets requires community responsibility
Authors: Pritchard Matt , Owen Susan , Anandakrishnan Sridhar , Holt William , Bennett Richard , La Femina Peter , Jansma Pamela , MacGregor Ian , Raymond Carol , Schwartz Susan , Stein Seth , Miller Meghan
Published: June 2012

In our increasingly digital age, access to data is becoming faster and easier. This has many positive consequences for scientific discovery, but it also presents challenges for protecting the data collectors and ensuring proper citation (e.g., M. A. Parsons et al.,Eos, 91(34), 297, doi:10.1029/2010EO340001). These issues have been concerns of UNAVCO's staff and those involved in the governance of UNAVCO as they crafted a new open data policy that became effective on 2 March 2012. UNAVCO is a nonprofit consortium of 177 university and research institutions from around the world. Founded in 1984 as the University Navstar Consortium and formally incorporated in 2001 as UNAVCO, Inc., the organization facilitates the collection and archiving of geodetic data (http://www.unavco.org).
Cardenas receives, 2011 Early Career Hydrologic Sciences Award: Citation
Authors: Wilson John L.
Published: June 2012

Meinhard Bayani Cardenas received the 2011 Early Career Hydrologic Sciences Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award is for significant early career contributions to hydrologic science.
Swift receives 2011 Ocean Sciences Award: Citation
Authors: Aagaard Knut
Published: June 2012

James H. Swift received the 2011 Ocean Sciences Section Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award is given in recognition of outstanding and long‐standing service to the ocean sciences.
Swift receives 2011 Ocean Sciences Award: Response
Authors: Swift James H.
Published: June 2012

James H. Swift received the 2011 Ocean Sciences Section Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award is given in recognition of outstanding and long‐standing service to the ocean sciences.
Plasma conditions at Saturn's magnetopause
Authors: Balcerak Ernie
Published: June 2012

Magnetized planets, including Earth and Saturn, are surrounded by a magnetosphere, a magnetic bubble that generally repels the solar wind. Magnetic reconnection—the breaking and rejoining of magnetic field lines—occurs at Earth's magnetopause (the boundary of the magnetosphere), allowing solar wind energy to enter the magnetosphere. At Earth, magnetic reconnection is the main driver of magnetosphere dynamics. At Saturn's magnetopause, however, spacecraft have found limited evidence for magnetic reconnection to date. Theory suggests that magnetic reconnection is more likely to happen when the ratio of plasma pressure to magnetic field pressure, known as plasma beta, is lower.
Steady convection keeps Earth's magnetic field in balance
Authors: Schultz Colin
Published: June 2012

The onslaught of the solar wind on the Sun‐facing side of Earth's magnetic field causes terrestrial magnetic field lines to break through magnetic reconnection. The persistent pressure of the solar wind pulls the field lines and the associated plasma around to the magnetotail on Earth's nightside, where magnetic reconnection occurs once again to form the plasma sheet region. This uneven distribution creates a pressure gradient that drives nightside plasma back toward the planet. The Earthward transport of this nightside magnetospheric plasma is known to occur in one of two ways: as a magnetic substorm or as steady magnetospheric convection (SMC). Substorms include acute inflows that cause plasma to pile up in the inner magnetosphere and have been tied to the onset of aurorae. SMC, on the other hand, has been proposed as a mechanism for rebalancing the plasma gradient established between the day and night sides of Earth's magnetic field. Kissinger et al. compiled 14 years of magnetic field and plasma observations to study how plasma flows and magnetospheric conditions differ between SMC events and substorms.
New constraints on European glacial freshwater releases to the North Atlantic Ocean
Authors: Eynaud Frédérique , Malaizé Bruno , Zaragosi Sébastien , de Vernal Anne , Scourse James , Pujol Claude , Cortijo Elsa , Grousset Francis E. , Penaud Aurélie , Toucanne Samuel , Turon Jean‐Louis , Auffret Gérard
Published: June 2012

During the late Quaternary, both external and internal forcings have driven major climatic shifts from glacial to interglacial conditions. Nonlinear climatic steps characterized the transitions leading to these extrema, with intermediate excursions particularly well expressed in the dynamics of the Northern Hemisphere cryosphere. Here we document the impact of these dynamics on the north‐eastern North Atlantic Ocean, focussing on the 35–10 ka interval. Sea‐surface salinities have been reconstructed quantitatively based on two independent methods from core MD95‐2002, recovered from the northern Bay of Biscay adjacent to the axis of the Manche paleoriver outlet and thus in connection with proximal European ice sheets and glaciers. Quantitative reconstructions deriving from dinocyst and planktonic foraminiferal analyses have been combined within a robust chronology to assess the amplitude and timing of hydrological changes in this region. Our study evidences strong pulsed freshwater discharges which may have impacted the North Atlantic Meridional Overturning Circulation.
Regional extent of the large coseismic slip zone of the 2011 Mw 9.0 Tohoku‐Oki earthquake delineated by on‐fault aftershocks
Authors: Kato Aitaro , Igarashi Toshihiro
Published: June 2012

Since the 2011 Tohoku‐Oki earthquake, many fault source models have been constructed using a variety of data, such as teleseismic, strong ground motion, geodetic, and tsunami recordings. However, questions remain as to how far the associated large‐slip zone extended along the plate interface during the rupture. Here we delineate the outer edge of this large‐slip zone in detail, based on the sharp density contrast observed for interplate, repeating, and down‐dip compressional earthquakes induced by the Tohoku‐Oki mainshock. The seismicity rate of interplate earthquakes changed significantly after the mainshock, probably as a result of stress perturbations by the large‐slip, and here we use this information as qualitative constraints in constructing our model. The model that we present for the large‐slip zone of the Tohoku‐Oki earthquake incorporates the main features of previously proposed fault source models, and also the observed fine‐scale heterogeneities of fault slip associated with this event. It is important to highlight that the outer edge of this large‐slip zone shows a remarkably complex shape. In particular, it is narrow and elongate southward along the ~35 km iso‐depth contour of the plate boundary offshore of Fukushima and Ibaraki. This southward elongate slip zone corresponds to down‐dip regions that appear to have produced higher relative levels of short‐period seismic radiation.
Simulated winter circulation types in the North Atlantic and European region for preindustrial and glacial conditions
Authors: Hofer D. , Raible C. C. , Merz N. , Dehnert A. , Kuhlemann J.
Published: June 2012

Winter circulation types under preindustrial and glacial conditions are investigated and used to quantify their impact on precipitation. The analysis is based on daily mean sea level pressure fields of a highly resolved atmospheric general circulation model and focuses on the North Atlantic and European region. We find that glacial circulation types are dominated by patterns with an east‐west pressure gradient, which clearly differs from the predominantly zonal patterns for the recent past. This is also evident in the frequency of occurrence of circulation types when projecting preindustrial circulation types onto the glacial simulations. The elevation of the Laurentide ice sheet is identified as a major cause for these differences. In areas of strong precipitation signals in glacial times, the changes in the frequencies of occurrence of the circulation types explain up to 60% of the total difference between preindustrial and glacial simulations.
High‐fidelity paleointensity determination from historic volcanoes in Japan
Authors: Yu Yongjae
Published: June 2012

Providing high‐fidelity paleointensity estimates is pivotal to identify temporal fluctuation of ancient geomagnetic field. Despite abundance of available paleointensity data in Japan, only dozen of them satisfy modern standards with systematic alteration checks. High‐fidelity paleointensity estimates were obtained from historic andesitic lavas collected from Mt. Aso (Ojodake, ≈700 BC), Mt. Kirishima (Iwoyama, AD 1768; Ohachi, AD 1235), and Mt. Sakurajima (An‐ei, AD 1779; Nabeyama, AD 764–766). Variation of geomagnetic field intensity is distinctively different from the prediction of global models (ARCH3k.1, CALS3k.3, CALS3k.4, CALS7k.2, and CALS10k.1b) for the past 4000 years in Japan. The compilation of high‐fidelity Thellier data set in Japan showed two obvious high intensities at AD 590–765 and AD 1330–1435 and one low intensity at ≈700 BC. These time intervals with anomalous high/low intensities are nearly identical to three of the four potential archeomagnetic jerks recognized from the European archeomagnetic data, implying that the archeomagnetic jerks were global (or at least northern hemispheric) features. To improve the poor representation of regional geomagnetic field variation with respect to the global model prediction, more high‐fidelity paleointensity determinations are required in East Asia.
Subglacial melt channels and fracture in the floating part of Pine Island Glacier, Antarctica
Authors: Vaughan David G. , Corr Hugh F. J. , Bindschadler Robert A. , Dutrieux Pierre , Gudmundsson G. Hilmar , Jenkins Adrian , Newman Thomas , Vornberger Patricia , Wingham Duncan J.
Published: June 2012

A dense grid of ice‐penetrating radar sections acquired over Pine Island Glacier, West Antarctica has revealed a network of sinuous subglacial channels, typically 500 m to 3 km wide, and up to 200 m high, in the ice‐shelf base. These subglacial channels develop while the ice is floating and result from melting at the base of the ice shelf. Above the apex of most channels, the radar shows isolated reflections from within the ice shelf. Comparison of the radar data with acoustic data obtained using an autonomous submersible, confirms that these echoes arise from open basal crevasses 50–100 m wide aligned with the subglacial channels and penetrating up to 1/3 of the ice thickness. Analogous sets of surface crevasses appear on the ridges between the basal channels. We suggest that both sets of crevasses were formed during the melting of the subglacial channels as a response to vertical flexing of the ice shelf toward the hydrostatic condition. Finite element modeling of stresses produced after the formation of idealized basal channels indicates that the stresses generated have the correct pattern and, if the channels were formed sufficiently rapidly, would have sufficient magnitude to explain the formation of the observed basal and surface crevasse sets. We conclude that ice‐shelf basal melting plays a role in determining patterns of surface and basal crevassing. Increased delivery of warm ocean water into the sub‐ice shelf cavity may therefore cause not only thinning but also structural weakening of the ice shelf, perhaps, as a prelude to eventual collapse.
Inflammatory Cytokines in Experimental and Human Stroke
Authors: Lambertsen Kate Lykke , Biber Knut , Finsen Bente
Published: June 2012

Inflammation is a hallmark of stroke pathology. The cytokines, tumor necrosis factor (TNF), interleukin (IL)-1, and IL-6, modulate tissue injury in experimental stroke and are therefore potential targets in future stroke therapy. The effect of these cytokines on infarct evolution depends on their availability in the ischemic penumbra in the early phase after stroke onset, corresponding to the therapeutic window (<4.5 hours), which is similar in human and experimental stroke. This review summarizes a large body of literature on the spatiotemporal and cellular production of TNF, IL-1, and IL-6, focusing on the early phase in experimental and human stroke. We also review studies of cytokines in blood and cerebrospinal fluid in stroke. Tumor necrosis factor and IL-1 are upregulated early in peri-infarct microglia. Newer literature suggests that IL-6 is produced by microglia, in addition to neurons. Tumor necrosis factor- and IL-1-producing macrophages infiltrate the infarct and peri-infarct with a delay. This information is discussed in the context of suggestions that neuronal sensitivity to ischemia may be modulated by cytokines. The fact that TNF and IL-1, and suppossedly also IL-6, are produced by microglia within the therapeutic window place these cells centrally in potential future stroke therapy.
Targeted Disruption of Organic Cation Transporter 3 (Oct3) Ameliorates Ischemic Brain Damage through Modulating Histamine and Regulatory T Cells
Authors: Zhu Pengxiang , Hata Ryuji , Ogasawara Masahito , Cao Fang , Kameda Kenji , Yamauchi Kohei , Schinkel Alfred H , Maeyama Kazutaka , Sakanaka Masahiro
Published: June 2012

The organic cation transporters OCT1, 2, and 3 (SLC22A1-3) have been implicated in the elimination of biogenic amines such as histamine. Among them, OCT3 was identified as an uptake-2 transporter, responsible for clearance of histamine. Because increasing evidence suggests the involvement of histamine in cerebral ischemia, we investigated the effects of targeted disruption of organic cation transporter-3 (Oct3) on the severity of ischemic brain damage. Transient focal ischemia for 1 hour was induced by occlusion of the middle cerebral artery (MCA) of homozygous Oct3-deficient mice and their wild-type (Wt) littermates. Although targeted disruption of Oct3 did not affect physiological parameters after MCA occlusion, this disruption significantly increased histamine content in the ischemic cortex and significantly reduced the infarct volume after cerebral ischemia. Furthermore, targeted disruption of Oct3 prevented the reduction of regulatory T-cell proportion after cerebral ischemia while this disruption did not affect Th1 and Th2 cells proportions after ischemia. Since repeated administration of L-histidine (a precursor of histamine) to Wt mice also showed the same effects, our observations suggested that OCT3 is the molecule responsible for clearance of ischemia-induced histamine in the brain and targeted disruption of Oct3 ameliorated ischemic brain damage through an increase in regulatory T cells.