bluuebunny/crossref_metadata_2025 huggingface dataset:
A review of decellurization methods caused by an urgent need for quality control of cell‐free extracellular matrix' scaffolds and their role in regenerative medicine
Authors: Kawecki Marek , Łabuś Wojciech , Klama‐Baryla Agnieszka , Kitala Diana , Kraut Malgorzata , Glik Justyna , Misiuga Marcelina , Nowak Mariusz , Bielecki Tomasz , Kasperczyk Aleksandra
Published: February 2017

The natural extracellular matrix (ECM),thanks to its specific properties (e.g., collagenous lattice, a reservoir of growth factors, ECM‐cell anchoring areas, an optimal pH and CO2),ensures an optimal microenvironment for homeostatic and regenerative cell development. In the context of regenerative medicine, ECM is a lair for residual and infiltrative cells. The aim of the clinical usage of cell‐free ECM scaffolds is the enhancement of tissue regeneration with possible minimization of an adverse host reaction on allogeneic or xenogeneic biomaterial. Thus, the objective of decellularization is to obtain acellular grafts characterized by optimal biological properties, such as a lack of remaining cellular elements (e.g., cell membrane phospholipids and proteins, nucleic acids, mitochondria), lack of immunogenicity, lack of calcification promotion and lack of cytotoxicity (e.g., in unrinsed detergents). Furthermore, cell‐free ECM scaffolds should present the optimal mechanical and structural properties that may ensure the biocompatibility of the graft. The maintenance of the ultrastructure composition of the ECM is one of the most important goals of decellularization. All physical, chemical, and biological methods proposed (used separately or in combination to extract cells from tissues/organs) are not 100% effective in cell removal and always cause a disruption of the ECM texture, as well as a probable loss of important structure components. Although cell‐free ECM scaffolds are generally classified as medical devices, there are no widely accepted or legally defined criteria for quality control/evaluation methods of obtained matrices. Such criteria must be provided. Some of them have been proposed in this manuscript. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 909–923, 2018.
Slip interface imaging based on MR‐elastography preoperatively predicts meningioma–brain adhesion
Authors: Yin Ziying , Hughes Joshua D. , Glaser Kevin J. , Manduca Armando , Van Gompel Jamie , Link Michael J. , Romano Anthony , Ehman Richard L. , Huston John
Published: February 2017

Purpose

To investigate the ability of slip interface imaging (SII), a recently developed magnetic resonance elastography (MRE)‐based technique, to predict the degree of meningioma–brain adhesion, using findings at surgery as the reference standard.

Materials and Methods

With Institutional Review Board approval and written informed consent, 25 patients with meningiomas >2.5 cm in maximal diameter underwent preoperative SII assessment. Intracranial shear motions were introduced using a soft, pillow‐like head driver and the resulting displacement field was acquired with an MRE pulse sequence on 3T MR scanners. The displacement data were analyzed to determine tumor–brain adhesion by assessing intensities on shear line images and raw as well as normalized octahedral shear strain (OSS) values along the interface. The SII findings of shear line images, OSS, and normalized OSS were independently and blindly correlated with surgical findings of tumor adhesion by using the Cohen's κ coefficient and chi‐squared test.

Results

Neurosurgeons categorized the surgical plane as extrapial (no adhesion) in 15 patients, mixed in four, and subpial (adhesion) in six. Both shear line images and OSS agreed with the surgical findings in 18 (72%) cases (fair agreement, κ = 0.37, 95% confidence interval [CI]: 0.05–0.69), while normalized OSS was concordant with the surgical findings in 23 (92%) cases (good agreement, κ = 0.86, 95% CI: 0.67–1). The correlation between SII predictions (shear line images, OSS, and normalized OSS) and the surgical findings were statistically significant (chi‐squared test, P = 0.02, P = 0.02, and P < 0.0001, respectively).

Conclusion

SII preoperatively evaluates the degree of meningioma–brain adhesion noninvasively, allowing for improved prediction of surgical risk and tumor resectability.

Level of Evidence: 1

Technical Efficacy: Stage 1

J. Magn. Reson. Imaging 2017;46:1007–1016.
Combining soil and tree‐stem flux measurements and soil gas profiles to understand CH4 pathways in Fagus sylvatica forests
Authors: Maier Martin , Machacova Katerina , Lang Friederike , Svobodova Kateřina , Urban Otmar
Published: February 2017

Quantifying and understanding fluxes of methane (CH4) and carbon dioxide (CO2) in natural soil–plant–atmosphere systems are crucial to predict global climate change. Wetland herbaceous species or tree species at waterlogged sites are known to emit large amounts of CH4. Upland forest soils are regarded as CH4 sinks and tree species like upland beech are not known to significantly emit CH4. Yet, data are scarce and this assumption needs to be tested.

We combined measurements of soil–atmosphere and stem–atmosphere fluxes of CO2 and CH4, and soil gas profiles to assess the contribution of the different ecosystem compartments at two upland beech forest sites in Central Europe in a case study. Soil was a net CH4 sink at both sites, though emissions were detected consistently from beech stems at one site. Although stem emissions from beech stems were high compared to known fluxes from other upland tree species, they were substantially lower compared to the strong CH4 sink of the soil. Yet, we observed extraordinarily large CH4 emissions from one beech tree that was 140% of the CH4 sink of the soil. The soil gas profile at this tree indicated CH4 production at a soil depth > 0.3 m, despite the net uptake of CH4 consistently observed at the soil surface. Field soil assessment showed strong redoximorphic color patterns in the adjacent soil and supports this evaluation. We hypothesize that there is a transport link between the soil and stem via the root system representing a preferential transport mechanism for CH4 despite the fact that beech roots usually do not bear aerenchyma. The high mobility of gases requires a holistic view on the soil–plant–atmosphere system. Therefore, we recommend including field soil assessment and soil gas profiles measurements when investigating soil–atmosphere and stem–atmosphere fluxes to better understand the sources of gases and their transport mechanisms.
The utility of the musculocutaneous anterolateral thigh flap in pharyngolaryngeal reconstruction in the high‐risk patient
Authors: Ooi Adrian S.H. , Teven Chad M. , Inbal Amir , Chang David W.
Published: February 2017

BACKGROUND AND OBJECTIVES

Prior radiotherapy leads to increased wound complication rates for microsurgical reconstruction of pharyngolaryngeal (PL) defects. Incorporating vastus lateralis muscle together with anterolateral thigh flap (ALT) skin in defect reconstruction is useful in protecting vital structures and reinforcing irradiated neck skin and suture lines. This study shows the utility of the musculocutaneous ALT (MC ALT) in PL reconstruction in previously irradiated patients.

METHODS

A single‐surgeon, retrospective chart review of all patients with defects of the PL region where an MC ALT was used for reconstruction from February 2014 to May 2016. The harvest of the MC ALT is described.

RESULTS

Thirteen consecutive patients underwent reconstruction with a MC ALT flap. All 13 patients had received previous radiotherapy. PL defects included five partial, five subtotal, and three total. There was a 100% flap survival rate with five early recipient site complications including three fistulas, one neck abscess, and one partial muscle necrosis. Three patients (23%) developed strictures requiring dilatation, two of whom had received post‐reconstruction radiotherapy.

CONCLUSIONS

The use of the MC ALT for reconstruction of PL defects should be considered to mitigate the negative effects of prior irradiation and provide a back‐up plan in instances where complications occur.
Overcoming the divide between ataxias and spastic paraplegias: Shared phenotypes, genes, and pathways
Authors: Synofzik Matthis , Schüle Rebecca
Published: February 2017

Autosomal‐dominant spinocerebellar ataxias, autosomal‐recessive spinocerebellar ataxias, and hereditary spastic paraplegias have traditionally been designated in separate clinicogenetic disease classifications. This classification system still largely frames clinical thinking and genetic workup in clinical practice. Yet, with the advent of next‐generation sequencing, phenotypically unbiased studies have revealed the limitations of this classification system. Various genes (eg, SPG7, SYNE1, PNPLA6) traditionally rooted in either the ataxia or hereditary spastic paraplegia classification system have now been shown to cause ataxia on the one end of the disease continuum and hereditary spastic paraplegia on the other. Other genes such as GBA2 and KIF1C were almost simultaneously published as both a hereditary spastic paraplegia and an ataxia gene. The variability and fluidity of observed phenotypes along the ataxia‐spasticity spectrum warrants a rethinking of the traditional classification system. We propose to replace this divisive diagnosis‐driven ataxia and hereditary spastic paraplegia classification system by a descriptive, unbiased approach of modular phenotyping. This approach is also open to expansion of the phenotype beyond ataxia and spasticity, which often occur as part of broader multisystem neuronal dysfunction. The concept of a continuous ataxia‐spasticity disease spectrum is further supported by ataxias and hereditary spastic paraplegias sharing not only overlapping phenotypes and underlying genes, but also common cellular pathways and disease mechanisms. This suggests a shared vulnerability of cerebellar and corticospinal neurons for common pathophysiological processes. It might be this mechanistic overlap that drives their clinical overlap. A mechanistically inspired classification system will help to pave the way for mechanism‐based strategies for drug development. © 2017 International Parkinson and Movement Disorder Society
Validating the ability of the discontinuous deformation analysis method to model normal P‐wave propagation across rock fractures
Authors: Gong Wenjun , Wang Yunsheng , Ning Youjun , Luo Yonghong , Wang Yujie
Published: February 2017

The effects of fractures on wave propagation problems are increasingly abstracting the attention of scholars and engineers in rock engineering field. This study aims to fully validate the ability of discontinuous deformation analysis (DDA) to model normal P‐wave propagation across rock fractures. The effects of a single fracture and multiple parallel fractures are all tested. The results indicate that DDA can accurately reflect the fracture effects, including the fractures stiffness, the fracture spacing and the fracture number, and the effects of incident wave frequency on one‐dimensional P‐wave propagation problems. Thus, DDA is able to deal well with normal incident P‐wave propagation problems. Copyright © 2017 John Wiley & Sons, Ltd.
Extended RF shimming: Sequence‐level parallel transmission optimization applied to steady‐state free precession MRI of the heart
Authors: Beqiri Arian , Price Anthony N. , Padormo Francesco , Hajnal Joseph V. , Malik Shaihan J.
Published: February 2017

Cardiac magnetic resonance imaging (MRI) at high field presents challenges because of the high specific absorption rate and significant transmit field (B1+) inhomogeneities. Parallel transmission MRI offers the ability to correct for both issues at the level of individual radiofrequency (RF) pulses, but must operate within strict hardware and safety constraints. The constraints are themselves affected by sequence parameters, such as the RF pulse duration and TR, meaning that an overall optimal operating point exists for a given sequence. This work seeks to obtain optimal performance by performing a ‘sequence‐level’ optimization in which pulse sequence parameters are included as part of an RF shimming calculation. The method is applied to balanced steady‐state free precession cardiac MRI with the objective of minimizing TR, hence reducing the imaging duration. Results are demonstrated using an eight‐channel parallel transmit system operating at 3 T, with an in vivo study carried out on seven male subjects of varying body mass index (BMI). Compared with single‐channel operation, a mean‐squared‐error shimming approach leads to reduced imaging durations of 32 ± 3% with simultaneous improvement in flip angle homogeneity of 32 ± 8% within the myocardium.
Create ADA‐compliant learning experiences for all students
Authors: Sutton Halley
Published: February 2017

ANAHEIM, Calif. — With distance learning options at an all‐time high, creating online course design that is both pedagogically sound and accessible for all students is at a premium. Key to that goal is understanding the difference between providing accessible content and providing accommodations and knowing how an institution can meet both needs. In a session at the annual Educause conference, Sheryl Burgstahler, director of accessible technology services at the University of Washington; and Martin LaGrow, senior academic consultant from Ellucian, shared strategies to create Americans with Disabilities Act–compliant course design and learn from common problems with specific inaccessible technology that institutions face when creating online course content.
Use rubrics to assess professional and workplace learning
Authors: Sutton Halley
Published: February 2017

CHICAGO — How do you grant your adult learners credit for the work they may have done in the workforce, while ensuring that your academic standards are met? In a session at the Council for Adult and Experiential Learning annual conference, Jeanine Nagrod, director of the Office for Assessment of Professional and Workplace Learning at Thomas Edison State University; and Regina Riccioni, previous director of that office and current dean of allied sciences at Union County College, shared the assessment guide that TESU created based on these needs, as well as samples of rubrics to construct your own professional and workplace learning credit evaluation system.
Students Speak/Resources
Authors: Sutton Halley
Published: February 2017

Students Speak

For‐profit certification offers empowerment and challenges

Resources

Competency‐based education better for workplace

For‐profit, nonprofit students score the same

Vet benefits completely fund for‐profits
Hansen solubility parameter: from polyethylene and poly(vinyl acetate) homopolymers to ethylene–vinyl acetate copolymers
Authors: Camacho Javier , Díez Eduardo , Díaz Ismael , Ovejero Gabriel
Published: February 2017

The Hansen solubility parameters (HSPs) of two ethylene–vinyl acetate (EVA) copolymers (with 18 and 33 wt% of vinyl acetate) and their corresponding homopolymers (polyethylene, PE, and poly(vinyl acetate), PVAc) have been studied at various temperatures, employing the previously obtained Flory–Huggins parameters. From these latter values, a procedure based on the Hansen solubility spheres theory was employed to determine the HSPs, as well as the radius of interaction. The procedure was validated with literature data, with deviations of around 3%. The HSP values (dispersion, polar and association terms, respectively, all in MPa1/2) at 333.15 K are 14.84, −3.88 and 1.78 for PE, 17.65, −1.24 and 2.76 for EVA410 (with 18 wt% of vinyl acetate), 17.52, 0.15 and 3.61 for EVA460 (with 33 wt% of vinyl acetate) and 19.45, 10.59 and 5.76 for PVAc. The main characteristic of the obtained HSP values is that the high polar term of PVAc tends to increase the solubility character of the pure PE, and thus the EVA copolymers, allowing them to solubilize dispersion and polar compounds. Finally, it was also demonstrated that it is possible to predict the HSPs of EVA copolymers using the vinyl acetate content and the HSPs of pure PE and PVAc as input data. © 2017 Society of Chemical Industry
Relative protein quantification and accessible biology in lung tumor proteomes from four LC‐MS/MS discovery platforms
Authors: Stewart Paul A. , Fang Bin , Slebos Robbert J. C. , Zhang Guolin , Borne Adam L. , Fellows Katherine , Teer Jamie K. , Chen Y. Ann , Welsh Eric , Eschrich Steven A. , Haura Eric B. , Koomen John M.
Published: February 2017

Discovery proteomics experiments include many options for sample preparation and MS data acquisition, which are capable of creating datasets for quantifying thousands of proteins. To define a strategy that would produce a dataset with sufficient content while optimizing required resources, we compared (1) single‐sample LC‐MS/MS with data‐dependent acquisition to single‐sample LC‐MS/MS with data‐independent acquisition and (2) peptide fractionation with label‐free (LF) quantification to peptide fractionation with relative quantification of chemically labeled peptides (sixplex tandem mass tags (TMT)). These strategies were applied to the same set of four frozen lung squamous cell carcinomas and four adjacent tissues, and the overall outcomes of each experiment were assessed. We identified 6656 unique protein groups with LF, 5535 using TMT, 3409 proteins from single‐sample analysis with data‐independent acquisition, and 2219 proteins from single‐sample analysis with data‐dependent acquisition. Pathway analysis indicated the number of proteins per pathway was proportional to the total protein identifications from each method, suggesting limited biological bias between experiments. The results suggest the use of single‐sample experiments as a rapid tissue assessment tool and digestion quality control or as a technique to maximize output from limited samples and use of TMT or LF quantification as methods for larger amounts of tumor tissue with the selection being driven mainly by instrument time limitations. Data are available via ProteomeXchange with identifiers PXD004682, PXD004683, PXD004684, and PXD005733.
Sensitivity of the 2014 Pentecost storms over Germany to different model grids and microphysics schemes
Authors: Barthlott Christian , Mühr Bernhard , Hoose Corinna
Published: February 2017

At Pentecost 2014, following a period of hot weather, northwestern Germany was affected by a series of severe convective storms leading to fatalities and significant damage from strong winds, heavy precipitation, hail, and lightning. We present convection‐permitting numerical simulations for 2 days of this event (8 and 9 June) using the COnsortium for Small‐scale MOdeling (COSMO) model. Whereas a control run in a nearly operational configuration successfully reproduced the convective events of the first day, it failed to adequately reproduce the events of the second day. To further assess the predictability of this event, sensitivity studies with an enlarged model domain, finer horizontal and vertical grid spacing, and a double‐moment microphysics scheme were performed. Results show that enlarging the model domain improved the results over France and the Netherlands by better resolving deep convection and secondary cell initiation in that area, but the model failed to simulate deep convection over Germany. The increase of model resolution from 2.8 km to 2.2 and 1 km had minor effects only. However, the errors of accumulated precipitation were diminished independently of the model domain and grid resolution on the first day when using the double‐moment microphysics scheme. A better result for 9 June was obtained by using later initialization times (0300 and 0600 UTC instead of 0000 UTC). The control run initialized at 0000 UTC produced one cell, which decayed while travelling over the Netherlands. In contrast, the runs initialized later produced thunderstorms over Germany as well, due to outflow triggering or cell splitting. Finally, different cloud condensation nuclei (CCN) assumptions revealed a systematic relationship for condensate amounts of cloud water, rain and ice with increasing CCN. However, the evaporation of raindrops at lower levels led to a non‐systematic response of accumulated precipitation to CCN. In addition, grid spacing effects on aerosol–cloud interactions were assessed.
Electrochemical analysis of molybdate conversion coating on hot‐dip galvanized steel in various growth stages
Authors: Zhang Shuang‐hong , Yang Bo , Kong Gang , Lu Jin‐tang
Published: February 2017

The electrochemical behavior of molybdate conversion coatings in various growth stages was investigated by electrochemical impedance spectroscopy and equivalent circuits. The chemical composition and microstructure were characterized by SEM/energy dispersive spectroscopy, atomic force microscopy, and AES. Neutral salt spray tests complemented the information. The results indicated that the growth process of the molybdate conversion coating was accompanied by the growth of micro cracks, consisting of three stages: in the early and middle stages, the protective property of the coatings increased with increasing treatment time and then decreased when the cracks developed in the last stage. On the basis of the observation of the microstructure and the analysis of the electrochemical impedance spectra of the coatings in various stages, a simplified growth process model of the molybdate conversion coating on hot‐dip galvanized steel was created. Copyright © 2017 John Wiley & Sons, Ltd.
Effect of surface treatment of UHMWPE fiber on mechanical and impact fracture behavior of PTFE/POM composites
Authors: He Runqin , Niu Fenglian , Chang Qiuxiang
Published: February 2017

Ultra‐high‐molecular‐weight polyethylene (UHMWPE) fiber was treated to reinforce the polytetrafluoroethylene/polyoxymethylene (PTFE/POM), and the mechanical properties of surface‐treated UHMWPE were investigated. Scanning electron microscopy was utilized to study the fracture surfaces of UHMWPE/POM/PTFE composites. Experimental results showed that the surface treatment of UHMWPE fiber effectively improves the mechanical property of POM/PTFE composites. Scanning electron microscopy studies indicated that surface modification could improve the interfacial adhesion of POM/PTFE composites. And the dispersion of UHMWPE in POM/PTFE composites was also improved after the surface modification. Copyright © 2017 John Wiley & Sons, Ltd.
Evaluation of vehicular dynamic effects for the life cycle fatigue design of short‐span bridges
Authors: Zhang Wei , Wu Mengxue , Zhu Jin
Published: February 2017

Dedicated to Prof. Dr. Akimitsu Kurita on his 70th birthday

In current bridge design codes or specifications, the dynamic effects of vehicles are considered by using a dynamic amplification factor (DAF) or dynamic load allowance (IM). However, a DAF is defined based on the ratio of the maximum dynamic load responses to the static load responses, and it is more appropriate for maximum value‐based strength design. For fatigue design, stress cycles other than the maximum stress ranges could contribute to fatigue damage accumulations. Meanwhile, on the capacity side, a reduction in fatigue strength due to structural deterioration, which is related to local environmental conditions, including temperature, humidity, etc., could introduce more uncertainties into structural safety and reliability evaluation. However, such multiple stress range effects and structural deterioration are not included in current bridge fatigue design. To evaluate the vehicular dynamic effects for the life cycle fatigue design of short‐span bridges, the present study proposes a new dynamic amplification factor for life cycle bridge fatigue design (DALC), which is defined as the ratio of the life cycle nominal live load stress range to the maximum static stress range. In contrast to other traditionally defined dynamic factors, the newly defined DALC includes information about both the structural loading and the structural capacity. Therefore, the multiple stress cycles from vehicle‐induced vibrations and the structural deteriorations from road surface conditions and corrosion of structural members are included. Parametric studies of DALC were carried out for multiple parameters and variables in the bridge's design life cycle, for instance, possible faulting days in each year, fatigue strength exponent, corrosion parameters and corrosion level. The stochastic properties and uncertainties from these variables are also considered in the DALC calculation.
Evaluation of cracks in an offshore crane runway girder
Authors: Wardenier Jaap , de Vries Peter , Timmermann Gerrit
Published: February 2017

This paper deals with the evaluation of fatigue cracks in a box type radial crane runway girder with full penetration welds between the web and flange. After 20 years of service fatigue cracks were observed which were initiated in the flange at the toe of the full penetration weld with the web. The observed cracks in the crane runway girder vary in length from a few mm to 330 mm with a summation of the lengths of all observed cracks being 750 mm, on a total length of 56000 mm, thus being only 1.3 %.

The investigation consists of the fatigue analysis described in this paper and additional experimental investigations with scale tests of approximately 1:2 on equivalent I sections with a concentrated load and with a line load to investigate whether cracks stop when they have grown through the residual tensile stress field. For this analyzed crane runway girder with multi‐layered full penetration welds and with small cracks at the weld toes in the flange, based on EN 1993‐6 the damage would be 1.0 for a design class 98 which is not far from the ”class“ 92 found by Kuhlmann et al, [1] for tests with rolling wheels, however, related to weld failures from the root of not fully penetrated fillet welds in combination with crack initiations at the weld toe.
Design and construction of the complex steel structure for the Amager Bakke waste‐to‐energy plant
Authors: Hauptenbuchner Johannes
Published: February 2017

Amager Bakke (English: Amager slope) is the name of Copenhagen's new waste‐to‐energy‐plant located on the Amager peninsula. Once finished, it will be one of the largest incinerators in northern Europe and will be used for the combined production of district heat and electricity. On top of the waste‐to‐energy plant there will be a landscaped park featuring artificial ski slopes and a viewing platform. The support structure is mainly formed by a steelwork. The model‐based design and construction of the complex, three‐dimensional steel structure proved to be a challenging task for all the engineers and companies involved.
Self‐assembly of Renewable Nano‐sized Triterpenoids
Authors: Bag Braja Gopal , Majumdar Rakhi
Published: February 2017

Studies on plant metabolites have gained renewed interest in recent years because these can serve as renewable chemicals for the development of a sustainable society. Among various plant secondary metabolites, terpenoids constitute the major component and triterpenoids are the 30C subset of it. In recent years, triterpenoids have drawn the attention of scientific community due to many of its potential and realized applications in medicine, drug delivery, thermochromic materials, pollutant capture, catalysis, liquid crystals, etc. In this personal review, we have discussed our computational results carried out on sixty representative naturally occurring triterpenoids demonstrating that all the triterpenoids are renewable functional nano‐entities. Study of the self‐assembly of several triterpenoids such as betulin, betulinic acid, oleanolic acid, glycyrrhetinic acid and arjunolic acid and their derivatives in different liquids have also been discussed. Moreover, the utilization of the resulting supramolecular architectures such as vesicles, spheres, flowers and fibrillar networks of nano‐ to micrometer dimensions and gels have also been discussed in the perspective of green, renewable and nanos.
Online FERPA tutorials: Push back on nondisclosure
Authors: Rainsberger Richard
Published: February 2017

What's so different about writing a recommendation letter for a student who is planning to enroll at another college? Don't you need the student's written consent to do this? Well, no … but you can't go wrong if you get the student's consent in writing. As I mentioned last month, you can write a recommendation letter that includes nondirectory information (e.g., grades and GPA) without written consent if you have evidence that the student is planning to enroll at another college (34 CFR §99.31(a)(2)). That means the student has submitted an admissions application to College B.
Plan a memorable commencement that reflects your institution
Authors: Hope Joan
Published: February 2017

How can you plan and carry out a memorable commencement ceremony? Five‐inch binders that let you keep track of every detail help. A creative team and help from across the institution are also critical.
Water quality and UK agriculture: challenges and opportunities
Authors: Holden Joseph , Haygarth Philip M. , Dunn Nicola , Harris Jim , Harris Robert C. , Humble Ann , Jenkins Alan , MacDonald Jannette , McGonigle Dan F. , Meacham Theresa , Orr Harriet G. , Pearson Phillippa L. , Ross Martin , Sapiets Alison , Benton Tim
Published: February 2017

There are high aspirations for environmental water quality targets in the UK, but requirements for significant growth in agricultural production to meet both food security objectives and provide viable livelihoods for farmers make these hard to achieve. Significant water quality challenges are related to nutrients, pesticides, pharmaceuticals, pathogens, sediments and habitat alteration. To facilitate the challenges posed, there is a need for predictive, spatially distributed models to be developed that encompass the key aspects of agriculture and water management in order to inform future policy and organizations with an interest in land management. Additionally, there needs to be recognition from policy makers that different solutions are needed in different agri‐water systems and that it often takes many years or decades for policies to have a sustained water quality impact. Long‐term support for research infrastructure and the scientific skills base is required to enable measurement and data analysis necessary to inform decision making. Farmers need clearly articulated information on the issues and potential solutions on which to make informed management decisions regarding water. There are existing solutions to some problems and this knowledge needs to be effectively disseminated with appropriate incentives for implementation to have maximum impact. Greater collaboration between researchers, industry, and policy makers, with the necessary framework to deliver effective joint working, is urgently needed. There is also a need for a wider societal understanding of the land–water system and the various ways in which society pays (and might pay in the future) for the real value of water. WIREs Water 2017, 4:e1201. doi: 10.1002/wat2.1201

This article is categorized under:

Water and Life > Stresses and Pressures on Ecosystems

Science of Water > Water Quality
Global employment and social trends
Authors: Kühn Stefan , Milasi Santo , Horne Richard , Yoon Sheena
Published: February 2017

Against the backdrop of a rather disappointing economic performance in 2016 and the below‐trend outlook for 2017, Chapter 1 assesses the ability of the economy to (i) generate a sufficient number of jobs, (ii) improve the quality of employment for those with a job, and (iii) ensure that the gains of growth are shared in an inclusive manner. The chapter also discusses the policy efforts needed to overcome structural impediments to growth, including inequality.
Relating trace refinement and linearizability
Authors: Smith Graeme , Winter Kirsten
Published: February 2017

In the late 1980’s, Back extended the notion of stepwise refinement of sequential systems to concurrent systems. By doing so he provided a definition of what it means for a concurrent system to be correct with respect to an abstract (potentially sequential) specification. This notion of refinement, referred to as
trace refinement
, was also independently proposed by Abadi and Lamport and has found widespread acceptance and application within the refinement community. Around the same time as Back’s work, Herlihy and Wing proposed
linearizability
as the correctness notion for concurrent objects. Linearizability has also found widespread acceptance being regarded as the standard notion of correctness for concurrent objects in the concurrent-algorithms community. In this paper, we provide a formal link between trace refinement and linearizability. This allows us to compare the two correctness conditions. Our comparisons show that trace refinement implies linearizability, but that linearizability does not imply trace refinement in general. However, linearizability does imply trace refinement under certain conditions. These conditions relate to (i) the fact that trace refinement can be used to prove both safety and liveness properties, whereas linearizability can only be used to prove safety properties, and (ii) the fact that trace refinement depends on the identification of when operations in the implementation are observed to occur. We discuss the consequences of these differences in the context of verifying concurrent objects.
Wavefront direction and cycle length affect left atrial electrogram amplitude
Authors: Iso Kazuki , Watanabe Ichiro , Kogawa Rikitake , Okumura Yasuo , Nagashima Koichi , Takahashi Keiko , Watanabe Ryuta , Arai Masaru , Ohkubo Kimie , Nakai Toshiko , Hirayama Atsushi , Nikaido Mizuki
Published: February 2017

Background

The relationship between atrial electrogram (EGM) characteristics in atrial fibrillation (AF) and those in sinus rhythm (SR) are generally unknown. The activation rate and direction may affect EGM characteristics. We examined characteristics of left atrial (LA) EGMs obtained during pacing from different sites.

Methods

The study included 10 patients undergoing pulmonary vein isolation for AF. Atrial EGMs were recorded from a 64‐pole basket catheter placed in the LA, and bipolar EGM amplitudes from the distal electrode pair (1–2) and proximal electrode pair (6–7) from 8 splines were averaged. The high right atrium (HRA), proximal coronary sinus (CSp), and distal coronary sinus (CSd) were paced at 600 ms and 300 ms.

Results

When the LA voltage at SR was ≥1.5 mV, bipolar voltages of the HRA were greater than those of the CSp, which were greater than those of the CSd, regardless of the pacing cycle length. The shorter pacing cycle length resulted in a reduction of the LA EGM voltage at sites of SR voltage ≥1.5 mV, but no significant difference was seen at sites where the SR EGM amplitude was between >0.5 and <1.5 mV. No significant differences were seen in intra‐basket conduction times between pacing cycle lengths of 600 ms and 300 ms at any pacing site.

Conclusion

The rate and direction‐dependent reduction of the amplitude of atrial EGMs may explain, in part, the voltage discordance during SR and AF.
Magnetotelluric sounding in the Western Transbaikalia segment of the Central Asian fold belt
Authors: Pospeeva E.V. , Potapov V.V. , Vitte L.V.
Published: February 2017

This paper presents the results of magnetotelluric (MT) studies performed within the Western Transbaikalia segment of the Central Asian fold belt along the Selenga River delta–Krasnyi Chikoi Village profile. The data are interpreted using the results of recent geological, petrological, geothermal, tectonic, and geochronological studies of the Mongolia-Transbaikalian part of the Central Asian fold belt, including large heterochronous igneous provinces and zones. The studies have shown that the investigated area has a complex geologic and tectonic structure produced by extensive rifting leading to the formation of large crustal blocks and by intense magmatic fluid activity along deep fault zones. The investigated profile is characterized by a combination of blocks with different types of geoelectric section—mountain ranges and intermontane basins separated by long-lived deep fault zones.
Stratigraphy and ecostratigraphic distribution of foraminiferal morphogroups from the Upper Jurassic of the Makar’yev section (Unzha River, Volga River basin)
Authors: Colpaert C. , Nikitenko B.L. , Khafaeva S.N.
Published: February 2017

Investigation of the Upper Callovian to Lower Kimmeridgian microfossils from the Makar’yev reference section (Unzha River, East European Platform) has been carried out. The section is characterized by ammonite debris and abundant associations of benthic and planktic foraminifers. It is a perfect object for stratigraphic and paleoecological researches. The biostratigraphic distribution of foraminifers from the Makar’yev section allows one to identify standard foraminifera zones of the East European Platform, as well as to upgrade some of them. The analysis of vertical and lateral ammonites and foraminiferal distribution, completed with lithostratigraphy, has precised the stratigraphic volume and position of boundaries of several lithological units.

An improved stratigraphic scheme for the Kostroma area of the Moscow Depression is proposed. Analysis of the composition, structure, and dynamic changes of the foraminiferal assemblages has been performed. The morphofunctional analysis of foraminiferal genera has for the first time identified how foraminiferal morphogroups differing in their life style and feeding strategy varied with short-term paleoenvironmental changes. These morphogroup changes allow establishing four ecostratigraphic levels. These paleoecological data have been calibrated along with geochemical factors. They have shown a crisis of foraminiferal association during the Late Oxfordian and Early Kimmeridgian. A similar crisis has also been discovered in the north of Siberia, which may be an argument for its global distribution. The analysis of the taxonomic composition and the density of foraminiferal associations, in parallel with the structure of the association, has revealed a succession of transgressive and regressive events during the Late Callovian–Early Kimmeridgian. It allows the typification of each assemblage in relation with each event and underlines the occurrence of second-order sea-level fluctuations (middle part of the Middle Oxfordian and the earliest Kimmeridgian).
Neotectonics and seismicity of Erzurum pull-apart basin, East Turkey
Authors: Koçyigit A. , Canoglu M.C.
Published: February 2017

The study area is the Erzurum pull-apart basin located in the East Anatolian Tectonic Block (EATB), which is under the control of a strike-slip neotectonic regime since the beginning of Quaternary. The Quaternary Erzurum pull-apart basin is an about 1–30 km wide, 90 km long and actively growing strike-slip depression. It is bounded by the Erzurum–Dumlu sinistral strike-slip fault zone to the east-southeast, by the Askale sinistral strike-slip fault zone to the north-northwest, and by the Basköy–Kandilli reverse fault zone and the N–S-trending Ilica oblique-slip normal fault set to the west. The Erzurum pull-apart basin was evolved by the deformation and subdivision of an E–W-trending older intermontane basin. The new basin has a 0.5 km thick, flat-lying (undeformed) and uconsolidated fill, which overlies, with an angular unconformitry, the deformed (folded and faulted) basement rocks of pre-Quaternary age. Basin fill consists of coarser-grained marginal facies (fault terrace, fan, fan-apron and superimposed fan deposits) and finer-grained depocentral facies represented by flood plain to organic material-rich marsh deposits. All gradations are seen among these lithofacies.

The seismicity of the Erzurum pull-apart basin is quite high. The magnitude of the peak earthquake to be sourced from the active faults (e.g., the Erzurum fault) is about Mw = 7.0. This was proved by both the historical and recent earthquakes. Numerous settlements in the size of a large city (e.g., Erzurum), county, town and small villages with a total population of over 766,000 are located in and along the active fault-bounded margins of the Erzurum pull-apart basin. They are under the threat of destructive earthquakes to be sourced from the margin-boundary faults. Therefore, based on both the active fault parameters and the water-saturated basin fill, a large-scale earthquake hazard map has to be prepared. This map has to be used in both the earthquake hazard to risk analyses and the redesign of city planning and all type of constructions in Erzurum and other settlements in this region.
Age of the Jombolok lava field (East Sayan): evidence from dendrochronology and radiocarbon dating
Authors: Arzhannikov S.G. , Ivanov A.V. , Arzhannikova A.V. , Demonterova E.I. , Jolivet M. , Voronin V.I. , Buyantuev V.A. , Oskolkov V.A.
Published: February 2017

Dendrochronology and radiocarbon dating, with reference to remote sensing, digital elevation modeling, geological, and geomorphological data, provide new age constraints for the Jombolok lava field in the East Sayan Mountains (Siberia). The Jombolok lava field originated in the latest Late Pleistocene and underwent at least four phases of volcanic activity recorded in lava flows. Two earliest phases followed shortly one after another more than 13 kyr ago. The third phase corresponding to eruptions of Kropotkin volcano can be timed only relatively. The fourth phase has been dated by dendrochronology and AMS 14C of well-preserved wood buried under the youngest lava which occurs among older lavas near the Jombolok River mouth. The age of this activity is bracketed between the death of trees caused by eruptions 1268–928 years ago and the beginning of new tree growth on the surface of the most recent lavas 900 years ago.
The evolution of planets. Venus as the Earth’s probable future
Authors: Dobretsov N.L.
Published: February 2017

The general evolution of planets in the Solar System is discussed with a focus on the structure and history of Venus compared with the Earth. The history of the planets of the terrestrial group has been similar and included at least six correlated stages. Many common features the terrestrial planets shared in their early and late evolution have been due to their common origin from the protoplanetary gas-and-dust nebula and plume magmatism widespread on all the planets of the terrestrial group. The characteristic features of the structure and evolution of Venus are most brightly manifested in the specific composition of its atmosphere and of plume magmatism. Venus, with its surface as hot as 450 °C and the near-surface pressure of 92–93 bars, has a hot and dense atmosphere 93 times that of the Earth in mass. Most of its atmospheric mass (99%) belongs to the 65-km thick troposphere consisting of CO2 (96.5%) and N2 (3.5%). The upper troposphere includes a 25–30 km thick cloud layer composed mainly of sulfuric acid droplets, water vapor, and SO2. At a height of 49.58 km, the clouds approach the conditions of the terrestrial surface and might be hospitable to bacterial life. Volcanism, the most active and widespread process of Venusian geology, maintains continuous SO2 emission. There are diverse volcanic edifices on Venus, which are most often large and are similar to the Earth’s plume-related volcanoes. The evolution before 1 Ga, as well as the share and the role of alkaline rocks and carbonatites among its volcanics, are among the most debatable issues about Venus. Being located closer to the Sun, Venus cooled down more slowly and less intensely than the Earth after the primary accretion. In the Proterozoic, it began heating and reached its present state at ~ 1 or 2 Ga. In the future, as the Sun becomes a red giant, the Earth is predicted to begin heating up in 500–600 Myr to reach the temperature of present Venus in about 1.5 Gyr.
Integral representation of nonconvex functionals defined on measures
Authors: Bouchitté G. , Buttazzo G.
Published: February 2017

We show that every functional which is defined on the space

\mathcal M(\Omega,\mathbf R^n)

of all

\mathbf R^n

valued measures with bounded variation on

Ω

, and which is local and sequentially weakly

\ast

lower semicontinuous, can be represented in a suitable integral form.

Représentation intégrale de fonctionnelles nonconvexes définies sur des mesures
. – Une formule de représentation intégrale est établie pour toute fonctionnelle définie sur l’espace

\mathcal M(\Omega,\mathbf R^n)

des mesures boréliennes sur

Ω

à valeurs dans

\mathbf R^n

, qui est locale et séquentiellement semicontinue inférieurement pour la topologie

\ast

faible.
The nonrelativistic limit of the nonlinear Dirac equation
Authors: Najman B.
Published: February 2017

It is proved that there exist solutions of the nonlinear Dirac equation, smooth in time, on a time interval which is independent of

c

. Moreover after multiplication by a phase factor (dependent on

c

) these solutions converge to the solution of a coupled system of nonlinear Schrödinger type equations.

La limite non relativistique de l’équation de Dirac non linéaire
. − On montre qu’existent des solutions de l’équation de Dirac non linéaire, régulières en temps, sur un intervalle en temps indépendant de

c

. En plus, après la multiplication avec un facteur de phase (

c

-dépendant) ces solutions convergent vers la solution d’un système couplé d’équations du type Schrödinger non linéaire.
Periodic solutions of Hamiltonian systems of 3-body type
Authors: Bahri A. , Rabinowitz P.H.
Published: February 2017

We study the question of the existence of periodic solutions of Hamiltonian systems of the form:

\"q + \mathrm{V}_{q}\left(t,\:q\right) = 0\qquad \text{where }\:\mathrm{V} = \sum \limits_{1\:≦\:i\: \neq \:j}^{3}\mathrm{V}_{ij}\left(t,\:q_{i}−q_{j}\right)
\tag{✶}

with

\mathrm{V}(t, ξ)

T-periodic in

t

and singular at

ξ = 0

. Under hypotheses on

\mathrm{V}

of 3-body type, we prove that the functional corresponding to (✶) has an unbounded sequence of critical points provided that the singularity of

\mathrm{V}

at 0 is strong enough.
Extension de fonctions de type positif et entropie associée. Cas multidimensionnel
Authors: Seghier A.
Published: February 2017

In an earlier note [7] we gave simple conditions which were sufficient for the effective reconstruction of spectral densities. Clearly the natural setting for these results is the problem of the extension of positive type in the multidimensionnal case [6]. Further analysis, in this framework, of the results mentionned above shows that they are applicable to the phase problem in cristallography. Illustrative examples of such extensions are given.

Nous avons donné dans une précédente note [7] des conditions suffisantes simples pour la reconstruction effective de densités spectrales. Il s’avère que le cadre naturel de ces résultats est le problème de l’extension de fonctions de type positif dans le cadre multidimensionnel [6]. Une analyse plus poussée, dans ce cadre, des résultats mentionnés ci-dessus, montre qu’ils sont applicables au problème de phases en cristallographie.