bluuebunny/crossref_metadata_2025 huggingface dataset:
A geochemical and geophysical reappraisal to the significance of the recent unrest at Campi Flegrei caldera (Southern Italy)
Authors: Moretti Roberto , De Natale Giuseppe , Troise Claudia
Published: February 2017

Volcanic unrest at calderas involves complex interaction between magma, hydrothermal fluids, and crustal stress and strain. Campi Flegrei caldera (CFc), located in the Naples (Italy) area and characterized by the highest volcanic risk on Earth for the extreme urbanization, undergoes unrest phenomena involving several meters of uplift and intense shallow microseismicity since several decades. Despite unrest episodes display in the last decade only moderate ground deformation and seismicity, current interpretations of geochemical data point to a highly pressurized hydrothermal system. We show that at CFc, the usual assumption of vapor‐liquid coexistence in the fumarole plumes leads to largely overestimated hydrothermal pressures and, accordingly, interpretations of elevated unrest. By relaxing unconstrained geochemical assumptions, we infer an alternative model yielding better agreement between geophysical and geochemical observations. The model reconciles discrepancies between what observed (1) for two decades since the 1982–1984 large unrest, when shallow magma was supplying heat and fluids to the hydrothermal system, and (2) in the last decade. Compared to the 1980's unrest, the post‐2005 phenomena are characterized by much lower aquifers overpressure and magmatic involvement, as indicated by geophysical data and despite large changes in geochemical indicators. Our interpretation points out a model in which shallow sills, intruded during 1969–1984, have completely cooled, so that fumarole emissions are affected now by deeper, CO2‐richer, magmatic gases producing the modest heating and overpressure of the hydrothermal system. Our results have important implications on the short‐term eruption hazard assessment and on the best strategies for monitoring and interpreting geochemical data.
Impacts of off‐fault plasticity on fault slip and interaction at the base of the seismogenic zone
Authors: Nevitt Johanna M. , Pollard David D.
Published: February 2017

Direct observations of faults exhumed from midcrustal depths indicate that distributed inelastic deformation enhances fault slip and interaction across steps. Constrained by field measurements, finite element models demonstrate that the slip distribution for a fault in a Mises elastoplastic continuum differs significantly from that of a linear elastic model fault. Lobes of plastic shear strain align with fault tips and effectively lengthen the fault, resulting in greater maximum slip and increased slip gradients near fault tips. Additionally, distributed plastic shear strain facilitates slip transfer between echelon fault segments. Fault arrays separated by contractional steps, which are subjected to greater mean normal stress and Mises equivalent stress, produce greater maximum slip than do those separated by extensional steps (with no fractures). These results provide insight into fault behavior at the base of the seismogenic zone, with implications for rupture dynamics of discontinuous faults.
Modeling the ionospheric prereversal enhancement by using coupled thermosphere‐ionosphere data assimilation
Authors: Chen Chia‐Hung , Lin Charles , Chen Wei‐Han , Matsuo Tomoko
Published: February 2017

We report that assimilating total electron content (TEC) into a coupled thermosphere‐ionosphere model by using the ensemble Kalman filter results in improved specification and forecast of eastward prereversal enhancement (PRE) electric field (E field). Through data assimilation, the ionospheric plasma density, thermospheric winds, temperature, and compositions are adjusted simultaneously. The improvement of duskside PRE E field calculation over the prior state is achieved primarily by intensification of eastward neutral wind. The improved E field calculation promotes a stronger plasma fountain and deepens the equatorial trough. As a result, the horizontal gradients of Pedersen conductivity and eastward wind are increased due to greater zonal electron density gradient and smaller ion drag at dusk, respectively. Such modifications provide preferable conditions and obtain a strengthened PRE magnitude closer to the observation. The adjustment of PRE E field is enabled through self‐consistent thermosphere and ionosphere coupling processes captured in the model. This study suggests that the PRE E field that is critical in driving the evening equatorial plasma instability could be better forecasted by assimilation of TECs in the 10 min cycling.
Theory connecting nonlocal sediment transport, earth surface roughness, and the Sadler effect
Authors: Schumer Rina , Taloni Alessandro , Furbish David Jon
Published: February 2017

Earth surface evolution, like many natural phenomena typified by fluctuations on a wide range of scales and deterministic smoothing, results in a statistically rough surface. We present theory demonstrating that scaling exponents of topographic and stratigraphic statistics arise from long‐time averaging of noisy surface evolution rather than specific landscape evolution processes. This is demonstrated through use of “elastic” Langevin equations that generically describe disturbance from a flat earth surface using a noise term that is smoothed deterministically via sediment transport. When smoothing due to transport is a local process, the geologic record self organizes such that a specific Sadler effect and topographic power spectral density (PSD) emerge. Variations in PSD slope reflect the presence or absence and character of nonlocality of sediment transport. The range of observed stratigraphic Sadler slopes captures the same smoothing feature combined with the presence of long‐range spatial correlation in topographic disturbance.
Nonlinear fundamental and harmonic cyclotron resonant scattering of radiation belt ultrarelativistic electrons by oblique monochromatic EMIC waves
Authors: Wang Geng , Su Zhenpeng , Zheng Huinan , Wang Yuming , Zhang Min , Wang Shui
Published: February 2017

Cyclotron resonant scattering by electromagnetic ion cyclotron (EMIC) waves has been considered to be responsible for the rapid loss of radiation belt high‐energy electrons. For parallel‐propagating EMIC waves, the nonlinear character of cyclotron resonance has been revealed in recent studies. Here we present the first study on the nonlinear fundamental and harmonic cyclotron resonant scattering of radiation belt ultrarelativistic electrons by oblique EMIC waves on the basis of test particle simulations. Higher wave obliquity produces stronger nonlinearity of harmonic resonances but weaker nonlinearity of fundamental resonance. Compared to the quasi‐linear prediction, these nonlinear resonances yield a more rapid loss of electrons over a wider pitch angle range. In the quasi‐linear regime, the ultrarelativistic electrons are lost in the equatorial pitch angle range αeq<75°, nearly independent of wave normal angle ψ. In contrast, the upper pitch angle cutoff of nonlinear losses tends to increase with the wave normal angle increasing, which is about αeq=82° at ψ = 0° and αeq>87.5° at ψ = 20° and 40°. At the resonant pitch angles αeq<75°, the difference between quasi‐linear and nonlinear loss timescales tends to decrease with the wave normal angle increasing. At ψ = 0° and 20°, the nonlinear electron loss timescale is 10% shorter than the quasi‐linear prediction; at ψ = 40°, the difference in loss timescales is reduced to <5%.
Global view of the E region irregularity and convection velocities in the high‐latitude Southern Hemisphere
Authors: Forsythe Victoriya V. , Makarevich Roman A.
Published: February 2017

Occurrence of the E region plasma irregularities is investigated using two Super Dual Auroral Radar Network (SuperDARN) South Pole (SPS) and Zhongshan (ZHO) radars that sample the same magnetic latitude deep within the high‐latitude plasma convection pattern but from two opposite directions. It is shown that the SPS and ZHO velocity distributions and their variations with the magnetic local time are different, with each distribution being asymmetric; i.e., a particular velocity polarity is predominant. This asymmetry in the E region velocity distribution is associated with the bump‐on‐tail of the distribution near the nominal ion acoustic speed Cs that is most likely due to the Farley‐Buneman instability (FBI) echoes or an inflection point of the distribution below nominal Cs that is most likely due to the gradient drift instability echoes. In contrast, the distribution of the convection velocity component was found to be symmetric, i.e., with no bump‐on‐tail or an inflection point, but with a bias (i.e., uniform shift) toward a particular polarity. It is demonstrated that the asymmetry in the convection pattern between the eastward and westward zonal components is unexpectedly strong, with the westward zonal component being predominant, especially at lower latitudes, while also exhibiting a strong interplanetary magnetic field By dependence. The observations are consistent with the notion that the asymmetry in the E region velocity distribution is highly sensitive to the bias in the convection component caused by the zonal convection component asymmetry and that the bump‐on‐tail or inflection point features may also depend on the irregularity height and the presence of strong density gradients modifying the FBI threshold value.
Can tide dominance be inferred from the point bar pattern of tidal meandering channels?
Authors: Tambroni N. , Luchi R. , Seminara G.
Published: February 2017

We performed 2‐D numerical simulations of flow and bed topography in a channel consisting of a sequence of tidal meanders connected to a tidal sea at one end and closed at the other end. Our main goal was to investigate whether the location of point bars relative to the bend apex is correlated with the character of the local flow field, i.e., its flood or ebb dominance. Validation of the model was achieved performing a comparison with results of laboratory observations. Simulations did reproduce the observed evolution of the laterally averaged bed profile toward an equilibrium configuration characterized by the classical landward aggrading trend typical of straight tidal channels with the formation of a shore at the landward end. The presence of meanders led to small amplitude spatial oscillations of the profile on the meander scale. The bar pattern developed when the morphology was far from equilibrium, such that the sediment transport was sufficiently intense to drive significant morphodynamic perturbations. Numerical results did show conclusively that the key factor controlling the phase of the point bar pattern relative to curvature is the flood‐ or ebb‐dominant character of the basic flow field. More precisely, ebb/flood dominance led to point bars located seaward/landward relative to the bend apex. Moreover, two almost symmetrical long lobes that trailed away from the meander apex in both the ebb and flood directions formed in the transition region where the flow field shifts from flood into ebb dominant.
Ecohydrological interactions within “fairy circles” in the Namib Desert: Revisiting the self‐organization hypothesis
Authors: Ravi Sujith , Wang Lixin , Kaseke Kudzai Farai , Buynevich Ilya V. , Marais Eugene
Published: February 2017

Vegetation patterns such as rings, bands, and spots are recurrent characteristics of resource‐limited arid and semiarid ecosystems. One of the most recognizable vegetation patterns is the millions of circular patches, often referred to as “fairy circles,” within the arid grassland matrix extending over hundreds of kilometers in the Namib Desert. Several modeling studies have highlighted the role of plant‐soil interactions in the formation of these fairy circles. However, little is known about the spatial and temporal variabilities of hydrological processes inside a fairy circle. In particular, a detailed field assessment of hydrological and soil properties inside and outside the fairy circles is limited. We conducted extensive measurements of infiltration rate, soil moisture, grass biometric, and sediment grain‐size distribution from multiple circles and interspaces in the Namib Desert. Our results indicate that considerable heterogeneity in hydrological processes exists within the fairy circles, resulting from the presence of coarser particles in the inner bare soil areas, whereas concentration of fine soil occurs on the vegetated edges. The trapping of aeolian and water‐borne sediments by plants may result in the observed soil textural changes beneath the vegetation, which in turn, explains the heterogeneity in hydrological processes such as infiltration and runoff. Our investigation provides new insights and experimental data on the ecohydrological processes associated with fairy circles, from a less studied location devoid of sand termite activity within the circles. The results seem to provide support to the “self‐organization hypothesis” of fairy circle formation attributed to the antiphase spatial biomass‐water distributions.
Decoupling of coral skeletal δ13C and solar irradiance over the past millennium caused by the oceanic Suess effect
Authors: Deng Wenfeng , Chen Xuefei , Wei Gangjian , Zeng Ti , Zhao Jian‐xin
Published: February 2017

Many factors influence the seasonal changes in δ13C levels in coral skeletons; consequently, the climatic and environmental significance of such changes is complicated and controversial. However, it is widely accepted that the secular declining trend of coral δ13C over the past 200 years reflects the changes in the additional flux of anthropogenic CO2 from the atmosphere into the surface oceans. Even so, the centennial‐scale variations, and their significance, of coral δ13C before the Industrial Revolution remain unclear. Based on an annually resolved coral δ13C record from the northern South China Sea, the centennial‐scale variations of coral δ13C over the past millennium were studied. The coral δ13C and total solar irradiance (TSI) have a significant positive Pearson correlation and coupled variation during the Medieval Warm Period and Little Ice Age, when natural forcing controlled the climate and environment. This covariation suggests that TSI controls coral δ13C by affecting the photosynthetic activity of the endosymbiotic zooxanthellae over centennial timescales. However, there was a decoupling of the coral skeletal δ13C and TSI during the Current Warm Period, the period in which the climate and environment became linked to anthropogenic factors. Instead, coral δ13C levels have a significant Pearson correlation with both the atmospheric CO2 concentration and δ13C levels in atmospheric CO2. The correlation between coral δ13C and atmospheric CO2 suggests that the oceanic 13C Suess effect, caused by the addition of increasing amounts of anthropogenic 12CO2 to the surface ocean, has led to the decoupling of coral δ13C and TSI at the centennial scale.
Estimating bed shear stress from remotely measured surface turbulent dissipation fields in open channel flows
Authors: Johnson E. D. , Cowen E. A.
Published: February 2017

Synoptic information on bed shear stress is necessary in predicting the transport of sediments and environmental contaminants in rivers and open channels. Existing methods of estimating bed shear stress typically involve measuring vertical profiles of streamwise velocity or Reynolds stress and taking advantage of the logarithmic or the constant stress region, respectively, to determine friction velocity and subsequently, bed shear stress. While effective, these methods yield local measurements of bed shear stress only. Direct measurements of bed shear stress can also be obtained through measurements with a drag plate. However, this method yields average shear stress information over the area of the plate and is impractical for large‐scale implementation in the field.

Here we present a method capable of providing continuous synoptic measurements of bed shear stress over a large field‐of‐view. A series of Large‐Scale Particle Image Velocimetry (LSPIV) and Acoustic Doppler Velocimetry (ADV) measurements were made in a variety of flows generated in a wide‐open channel facility. Turbulent dissipation is calculated on the free surface from the 2‐D LSPIV results and is correlated with near‐surface ADV measurements of turbulent dissipation in the water column. The ADV results are consistent with the Nezu (1977) established relationship for the vertical variation of turbulent dissipation in the water column. Knowledge of the correlation between free‐surface and near‐surface dissipation values coupled with Nezu's (1977) relationship allow a robust and accurate estimate of friction velocity to be made and subsequently, shear stress at the bed can be estimated.
Improving probabilistic prediction of daily streamflow by identifying Pareto optimal approaches for modeling heteroscedastic residual errors
Authors: McInerney David , Thyer Mark , Kavetski Dmitri , Lerat Julien , Kuczera George
Published: February 2017

Reliable and precise probabilistic prediction of daily catchment‐scale streamflow requires statistical characterization of residual errors of hydrological models. This study focuses on approaches for representing error heteroscedasticity with respect to simulated streamflow, i.e., the pattern of larger errors in higher streamflow predictions. We evaluate eight common residual error schemes, including standard and weighted least squares, the Box‐Cox transformation (with fixed and calibrated power parameter λ) and the log‐sinh transformation. Case studies include 17 perennial and 6 ephemeral catchments in Australia and the United States, and two lumped hydrological models. Performance is quantified using predictive reliability, precision, and volumetric bias metrics. We find the choice of heteroscedastic error modeling approach significantly impacts on predictive performance, though no single scheme simultaneously optimizes all performance metrics. The set of Pareto optimal schemes, reflecting performance trade‐offs, comprises Box‐Cox schemes with λ of 0.2 and 0.5, and the log scheme (λ = 0, perennial catchments only). These schemes significantly outperform even the average‐performing remaining schemes (e.g., across ephemeral catchments, median precision tightens from 105% to 40% of observed streamflow, and median biases decrease from 25% to 4%). Theoretical interpretations of empirical results highlight the importance of capturing the skew/kurtosis of raw residuals and reproducing zero flows. Paradoxically, calibration of λ is often counterproductive: in perennial catchments, it tends to overfit low flows at the expense of abysmal precision in high flows. The log‐sinh transformation is dominated by the simpler Pareto optimal schemes listed above. Recommendations for researchers and practitioners seeking robust residual error schemes for practical work are provided.
A parametric approach for simultaneous bias correction and high‐resolution downscaling of climate model rainfall
Authors: Mamalakis Antonios , Langousis Andreas , Deidda Roberto , Marrocu Marino
Published: February 2017

Distribution mapping has been identified as the most efficient approach to bias‐correct climate model rainfall, while reproducing its statistics at spatial and temporal resolutions suitable to run hydrologic models. Yet its implementation based on empirical distributions derived from control samples (referred to as nonparametric distribution mapping) makes the method's performance sensitive to sample length variations, the presence of outliers, the spatial resolution of climate model results, and may lead to biases, especially in extreme rainfall estimation. To address these shortcomings, we propose a methodology for simultaneous bias correction and high‐resolution downscaling of climate model rainfall products that uses: (a) a two‐component theoretical distribution model (i.e., a generalized Pareto (GP) model for rainfall intensities above a specified threshold u*, and an exponential model for lower rainrates), and (b) proper interpolation of the corresponding distribution parameters on a user‐defined high‐resolution grid, using kriging for uncertain data. We assess the performance of the suggested parametric approach relative to the nonparametric one, using daily raingauge measurements from a dense network in the island of Sardinia (Italy), and rainfall data from four GCM/RCM model chains of the ENSEMBLES project. The obtained results shed light on the competitive advantages of the parametric approach, which is proved more accurate and considerably less sensitive to the characteristics of the calibration period, independent of the GCM/RCM combination used. This is especially the case for extreme rainfall estimation, where the GP assumption allows for more accurate and robust estimates, also beyond the range of the available data.
Heat and water transport in soils and across the soil‐atmosphere interface: 1. Theory and different model concepts
Authors: Vanderborght Jan , Fetzer Thomas , Mosthaf Klaus , Smits Kathleen M. , Helmig Rainer
Published: February 2017

Evaporation is an important component of the soil water balance. It is composed of water flow and transport processes in a porous medium that are coupled with heat fluxes and free air flow. This work provides a comprehensive review of model concepts used in different research fields to describe evaporation. Concepts range from nonisothermal two‐phase flow, two‐component transport in the porous medium that is coupled with one‐phase flow, two‐component transport in the free air flow to isothermal liquid water flow in the porous medium with upper boundary conditions defined by a potential evaporation flux when available energy and transfer to the free airflow are limiting or by a critical threshold water pressure when soil water availability is limiting. The latter approach corresponds with the classical Richards equation with mixed boundary conditions. We compare the different approaches on a theoretical level by identifying the underlying simplifications that are made for the different compartments of the system: porous medium, free flow and their interface, and by discussing how processes not explicitly considered are parameterized. Simplifications can be grouped into three sets depending on whether lateral variations in vertical fluxes are considered, whether flow and transport in the air phase in the porous medium are considered, and depending on how the interaction at the interface between the free flow and the porous medium is represented. The consequences of the simplifications are illustrated by numerical simulations in an accompanying paper.
Lead‐Free Organic–Inorganic Hybrid Perovskites for Photovoltaic Applications: Recent Advances and Perspectives
Authors: Shi Zejiao , Guo Jia , Chen Yonghua , Li Qi , Pan Yufeng , Zhang Haijuan , Xia Yingdong , Huang Wei
Published: February 2017

Organic–inorganic hybrid halide perovskites (e.g., MAPbI3) have recently emerged as novel active materials for photovoltaic applications with power conversion efficiency over 22%. Conventional perovskite solar cells (PSCs); however, suffer the issue that lead is toxic to the environment and organisms for a long time and is hard to excrete from the body. Therefore, it is imperative to find environmentally‐friendly metal ions to replace lead for the further development of PSCs. Previous work has demonstrated that Sn, Ge, Cu, Bi, and Sb ions could be used as alternative ions in perovskite configurations to form a new environmentally‐friendly lead‐free perovskite structure. Here, we review recent progress on lead‐free PSCs in terms of the theoretical insight and experimental explorations of the crystal structure of lead‐free perovskite, thin film deposition, and device performance. We also discuss the importance of obtaining further understanding of the fundamental properties of lead‐free hybrid perovskites, especially those related to photophysics.
A Low Resistance Calcium/Reduced Titania Passivated Contact for High Efficiency Crystalline Silicon Solar Cells
Authors: Allen Thomas G. , Bullock James , Jeangros Quentin , Samundsett Christian , Wan Yimao , Cui Jie , Hessler‐Wyser Aïcha , De Wolf Stefaan , Javey Ali , Cuevas Andres
Published: February 2017

Recent advances in the efficiency of crystalline silicon (c‐Si) solar cells have come through the implementation of passivated contacts that simultaneously reduce recombination and resistive losses within the contact structure. In this contribution, low resistivity passivated contacts are demonstrated based on reduced titania (TiOx) contacted with the low work function metal, calcium (Ca). By using Ca as the overlying metal in the contact structure we are able to achieve a reduction in the contact resistivity of TiOx passivated contacts of up to two orders of magnitude compared to previously reported data on Al/TiOx contacts, allowing for the application of the Ca/TiOx contact to n‐type c‐Si solar cells with partial rear contacts. Implementing this contact structure on the cell level results in a power conversion efficiency of 21.8% where the Ca/TiOx contact comprises only ≈6% of the rear surface of the solar cell, an increase of 1.5% absolute compared to a similar device fabricated without the TiOx interlayer.
Adams–Oliver syndrome review of the literature: Refining the diagnostic phenotype
Authors: Hassed Susan , Li Shibo , Mulvihill John , Aston Christopher , Palmer Susan
Published: February 2017

The Adams–Oliver syndrome (AOS) is defined as aplasia cutis congenita (ACC) with transverse terminal limb defects (TTLD). Frequencies of associated anomalies are not well characterized. Six causative genes have been identified: ARHGAP31, DOCK6, EOGT, RBPJ, NOTCH1, and DLL4. We review 385 previously described individuals (139 non‐familial and 246 familial probands and family members) and add clinical data on 13 previously unreported individuals with AOS. In addition to ACC and TTLD, the most commonly associated anomalies included a wide variety of central nervous system (CNS) anomalies and congenital heart defects each seen in 23%. CNS anomalies included structural anomalies, microcephaly, vascular defects, and vascular sequelae. CNS migration defects were common. Cutis marmorata telangiectasia congenita (CMTC) was found in 19% of the study population and other vascular anomalies were seen in 14%. Hemorrhage was listed as the cause of death for five of 25 deaths reported. A relatively large number of non‐familial probands were reported to have hepatoportal sclerosis with portal hypertension and esophageal varices. Non‐familial probands were more likely to have additional anomalies than were familial probands. The data reported herein provide a basis for refining the diagnostic features of AOS and suggest management recommendations for probands newly diagnosed with AOS. © 2017 Wiley Periodicals, Inc.
The utility of alpha‐fetoprotein screening in Beckwith–Wiedemann syndrome
Authors: Duffy Kelly A. , Deardorff Matthew A. , Kalish Jennifer M.
Published: February 2017

Beckwith–Wiedemann syndrome (BWS) is one of the most common cancer predisposition disorders. As a result, BWS patients receive tumor screening as part of their clinical management. Until recently, this screening has been employed uniformly across all genetic and epigenetic causes of BWS, including the utilization of ultrasonography to detect abdominal tumors and alpha‐fetoprotein (AFP) to detect hepatoblastoma. The advancements in our understanding of the genetics and epigenetics leading to BWS has evolved over time, and has led to the development of genotype/phenotype correlations. As tumor risk appears to correlate with genetic and epigenetic causes of BWS, several groups have proposed alterations to tumor screening protocols based on the etiology of BWS, with the elimination of AFP as a screening measure and the elimination of all screening measures in BWS patients with loss of methylation at the KCNQ1OT1:TSS‐DMR 2 (IC2). There are many challenges to this suggestion, as IC2 patients may have additional factors that contribute to risk of hepatoblastoma including fetal growth patterns, relationship with assisted reproductive technologies, and the regulation of the IC2 locus. © 2017 Wiley Periodicals, Inc.
Cardiovascular autonomic dysfunction in Ehlers–Danlos syndrome—Hypermobile type
Authors: Hakim Alan , O'Callaghan Chris , De Wandele Inge , Stiles Lauren , Pocinki Alan , Rowe Peter
Published: February 2017

Autonomic dysfunction contributes to health‐related impairment of quality of life in the hypermobile type of Ehlers–Danlos syndrome (hEDS). Typical signs and symptoms include tachycardia, hypotension, gastrointestinal dysmotility, and disturbed bladder function and sweating regulation. Cardiovascular autonomic dysfunction may present as Orthostatic Intolerance, Orthostatic Hypotension, Postural Orthostatic Tachycardia Syndrome, or Neurally Mediated Hypotension. The incidence, prevalence, and natural history of these conditions remain unquantified, but observations from specialist clinics suggest they are frequently seen in hEDS. There is growing understanding of how hEDS‐related physical and physiological pathology contributes to the development of these conditions. Evaluation of cardiovascular symptoms in hEDS should include a careful history and clinical examination. Tests of cardiovascular function range from clinic room observation to tilt‐table assessment to other laboratory investigations such as supine and standing catecholamine levels. Non‐pharmacologic treatments include education, managing the environment to reduce exposure to triggers, improving cardiovascular fitness, and maintaining hydration. Although there are limited clinical trials, the response to drug treatments in hEDS is supported by evidence from case and cohort observational data, and short‐term physiological studies. Pharmacologic therapy is indicated for patients with moderate‐severe impairment of daily function and who have inadequate response or tolerance to conservative treatment. Treatment in hEDS often requires a focus on functional maintenance. Also, the negative impact of cardiovascular symptoms on physical and psycho‐social well‐being may generate a need for a more general evaluation and on‐going management and support. © 2017 Wiley Periodicals, Inc.
Moderne Anorganische Aerogele
Authors: Ziegler Christoph , Wolf André , Liu Wei , Herrmann Anne‐Kristin , Gaponik Nikolai , Eychmüller Alexander
Published: February 2017

Der Begriff Aerogel beschreibt im Wesentlichen eine besondere geometrische Struktur der Materie, die materialunabhängig ist und keinem speziellen Syntheseverfahren unterliegt. Grundsätzlich können daher Aerogele aus unzähligen Materialien bestehen, wodurch die Anwendungsmöglichkeiten nahezu unbegrenzt sind. Dasselbe trifft auf Nanopartikel zu. Diese werden ebenso durch ihre geometrischen Eigenschaften definiert. In den letzten Jahrzehnten standen daher nanoskalige Materialien im Fokus der Forschung, und es entwickelten sich mögliche Anwendungen in vielen naturwissenschaftlichen Bereichen. Heute ist eine Vielzahl an Metall‐, Halbleiter‐, Oxid‐ und anderen Nanopartikeln durch kolloidale Synthesen zugänglich. Dennoch ist es für eine Anwendung oft notwendig, dass diese Materialien zuvor in makroskopische Strukturen angeordnet werden. Dieser Aufsatz gibt eine ausführliche Übersicht über die Entwicklung, die die Welt der kolloidalen Nanopartikel und der Aerogele miteinander vereint. Ermöglicht wurde dies durch die kontrollierte Destabilisierung der vorab gebildeten Nanopartikel, die zu einer Anordnung der Nanopartikel zu einem dreidimensionalen, makroskopischen Netzwerk führt. Dieses revolutionäre Konzept verleiht die Möglichkeit, präzise kontrollierte Nanopartikel als Grundbausteine für makroskopische, poröse Strukturen mit einstellbaren Eigenschaften zu nutzen.
Modern Inorganic Aerogels
Authors: Ziegler Christoph , Wolf André , Liu Wei , Herrmann Anne‐Kristin , Gaponik Nikolai , Eychmüller Alexander
Published: February 2017

Essentially, the term aerogel describes a special geometric structure of matter. It is neither limited to any material nor to any synthesis procedure. Hence, the possible variety of materials and therefore the multitude of their applications are almost unbounded. In fact, the same applies for nanoparticles. These are also just defined by their geometrical properties. In the past few decades nano‐sized materials have been intensively studied and possible applications appeared in nearly all areas of natural sciences. To date a large variety of metal, semiconductor, oxide, and other nanoparticles are available from colloidal synthesis. However, for many applications of these materials an assembly into macroscopic structures is needed. Here we present a comprehensive picture of the developments that enabled the fusion of the colloidal nanoparticle and the aerogel world. This became possible by the controlled destabilization of pre‐formed nanoparticles, which leads to their assembly into three‐dimensional macroscopic networks. This revolutionary approach makes it possible to use precisely controlled nanoparticles as building blocks for macroscopic porous structures with programmable properties.
Heparin versus bivalirudin for non‐primary percutaneous coronary intervention: A post‐Hoc analysis of the CPORT‐E trial
Authors: Czarny Matthew J. , Hwang Chao‐Wei , Naiman Daniel Q. , Lemmon Cynthia C. , Hasan Rani K. , Wang Thomas , Aversano Thomas
Published: February 2017

Objectives

To compare bivalirudin to heparin during non‐primary percutaneous coronary intervention (PCI).

Background

The optimal anticoagulant to support PCI remains uncertain.

Methods

We performed a propensity score‐based analysis comparing clinical outcomes of patients receiving heparin to those receiving bivalirudin during non‐primary PCI.

Results

Of 18,867 patients in the Cardiovascular Patient Outcomes Research Team Non‐Primary PCI (CPORT‐E) trial, we selected 7,913 patients undergoing non‐staged PCI of whom 57.3% received heparin and 42.7% received bivalirudin. In‐hospital myocardial infarction occurred in 4.4% of patients receiving bivalirudin and 3.0% of patients receiving heparin (relative risk [RR] 1.5, 95% confidence interval [CI] 1.1–2.1, P = 0.022); this difference persisted at 6 weeks (5.0% vs. 3.6%, RR 1.4, 95% CI 1.0–1.8, P = 0.041). There was no difference in all‐cause mortality either in‐hospital (0.2% vs. 0.1% for heparin vs. bivalirudin, P = 0.887) or at 6 weeks (0.5% vs. 0.7%, P = 0.567). In‐hospital bleeding requiring transfusion occurred in 0.9% of patients receiving bivalirudin and 1.9% of patients receiving heparin (RR 0.4, 95% CI 0.3–0.7, P <0.001), but there was no difference at 6 weeks (2.7% for heparin vs. 1.9% for bivalirudin, RR 0.7, 95% CI 0.5–1.0, P = 0.062).

Conclusions

In patients undergoing non‐primary PCI at hospitals without on‐site cardiac surgery, bivalirudin was associated with a decreased risk of in‐hospital bleeding requiring transfusion and an increased risk of in‐hospital MI compared to heparin. © 2017 Wiley Periodicals, Inc.
Diastereoselective Radical‐Type Cyclopropanation of Electron‐Deficient Alkenes Mediated by the Highly Active Cobalt(II) Tetramethyltetraaza[14]annulene Catalyst
Authors: Chirila Andrei , Gopal Das Braja , Paul Nanda D. , de Bruin Bas
Published: February 2017

A new protocol for the catalytic synthesis of cyclopropanes using electron‐deficient alkenes is presented, which is catalysed by a series of affordable, easy to synthesise and highly active substituted cobalt(II) tetraaza[14]annulenes. These catalysts are compatible with the use of sodium tosylhydrazone salts as precursors to diazo compounds in one‐pot catalytic transformations to afford the desired cyclopropanes in almost quantitative yields. The reaction takes advantage of the metalloradical character of the Co complexes to activate the diazo compounds. The reaction is practical and fast, and proceeds from readily available starting materials. It does not require the slow addition of diazo reagents or tosylhydrazone salts or heating and tolerates many solvents, which include protic ones such as MeOH. The CoII complexes derived from the tetramethyltetraaza[14]annulene ligand are easier to prepare than cobalt(II) porphyrins and present a similar catalytic carbene radical reactivity but are more active. The reaction proceeds at 20 °C in a matter of minutes and even at −78 °C in a few hours. The catalytic system is robust and can operate with either the alkene or the diazo reagent as the limiting reagent, which inhibits the dimerisation of diazo compounds totally. The protocol has been applied to synthesise a variety of substituted cyclopropanes. High yields and selectivities were achieved for various substrates with an intrinsic preference for trans cyclopropanes.
The Synergistic Effect to Promote the Direct Conversion of Bioethanol into Isobutene over Ternary Multifunctional CrxZnyZrzOn Catalysts
Authors: Liu Feng , Men Yong , Wang Jinguo , Huang Xiaoxiong , Wang Yuanqiang , An Wei
Published: February 2017

A significant beneficial effect of introducing chromium over mesoporous Cr1Zn1Zr8On oxide composite catalysts was observed in the upgrading and direct conversion of bioethanol into isobutene (ETIB), and a 38 % enhancement in the selectivity (yield) to isobutene was observed relative to that observed with its binary Zn1Zr8On counterpart. Two critical factors were related to the surface properties of this catalyst: a proper surface acid/base balance and favorable redox properties dictated the selectivity to isobutene. Through combined experimental and theoretical efforts, synergistic effects of redox‐active Crδ+ in promoting the dehydrogenation of ethanol were elucidated and therefore the production of isobutene. This work provides a guide for the rational design of efficient catalysts for a highly active and selective cascade ETIB reaction, for which the relative strengths of the redox/acid and base/acid sites of the catalyst serve as catalytic descriptors.
Methanesulfonyl Chloride Decomposition as a Key Step for Low‐Temperature Methane Conversions
Authors: Kang Shujuan , Zhou Wei , Ma Qisheng , Zhang Qianwen , Chen Guanyi , Tang Yongchun
Published: February 2017

The presence of SO2 in methane (CH4) halogenation/chlorination to form methanesulfonyl chloride (CH3SO2Cl, MSC), followed by catalytic decomposition of MSC to produce methyl chloride (CH3Cl) could effectively prevent deeper reactions of CH3Cl to improve the product selectivity. A number of catalytic systems capable of highly selectively decomposing MSC are studied experimentally. Molecular modeling based on density functional theory (DFT) calculations suggest a bimolecular nucleophilic substitution SN2 reaction mechanism for the catalytic MSC decomposition reaction. The order of activation energies of different catalytic systems agrees with the laboratory observations.
Associations of High‐Dose Melphalan Pharmacokinetics and Outcomes in the Setting of a Randomized Cryotherapy Trial
Authors: Cho YK , Sborov DW , Lamprecht M , Li J , Wang J , Hade EM , Gao Y , Tackett K , Williams N , Benson DM , Efebera YA , Rosko AE , Devine SM , Poi M , Hofmeister CC , Phelps MA
Published: February 2017

High‐dose melphalan followed by autologous stem cell transplantation remains the standard of care for eligible patients with multiple myeloma, but disease response and toxicity, including severe mucositis, varies among patients. Our randomized trial investigated duration of cryotherapy (2 and 6 h) for reduction of mucositis prevalence and severity and explored factors associated with variability in pharmacokinetics and outcomes from melphalan therapy. The results demonstrate that 2‐h is at least as effective as 6‐h cryotherapy in decreasing severe mucositis. From a population pharmacokinetic model, we identified that fat‐free mass, hematocrit, and creatinine clearance were significant covariates, as reported previously. Furthermore, we observed the rs4240803 SLC7A5 polymorphism was significantly associated with pharmacokinetic variability, and pharmacokinetics was associated with both mucositis and neutropenia. However, melphalan exposure was not associated with progression‐free or overall survival in our dataset. These findings contribute to ongoing efforts to personalize melphalan dosing in transplant patients.
Lessons Learned: Transfer of the High‐Definition Circulating Tumor Cell Assay Platform to Development as a Commercialized Clinical Assay Platform
Authors: Kuhn P , Keating SM , Baxter GT , Thomas K , Kolatkar A , Sigman CC
Published: February 2017

Planning and transfer of a new technology platform developed in an academic setting to a start‐up company for medical diagnostic product development may appear daunting and costly in terms of complexity, time, and resources. In this review we outline the key steps taken and lessons learned when a technology platform developed in an academic setting was transferred to a start‐up company for medical diagnostic product development in the interest of elucidating development toolkits for academic groups and small start‐up companies starting on the path to commercialization and regulatory approval.
Synthesis Optimization, Shaping, and Heat Reallocation Evaluation of the Hydrophilic Metal–Organic Framework MIL‐160(Al)
Authors: Permyakova Anastasia , Skrylnyk Oleksandr , Courbon Emilie , Affram Maame , Wang Sujing , Lee U‐Hwang , Valekar Anil H. , Nouar Farid , Mouchaham Georges , Devic Thomas , De Weireld Guy , Chang Jong‐San , Steunou Nathalie , Frère Marc , Serre Christian
Published: February 2017

The energy‐storage capacities of a series of water‐stable porous metal–organic frameworks, based on high‐valence metal cations (Al3+, Fe3+, Cr3+, Ti4+, Zr4+) and polycarboxylate linkers, were evaluated under the typical conditions of seasonal energy‐storage devices. The results showed that the microporous hydrophilic Al‐dicarboxylate MIL‐160(Al) exhibited one of the best performances. To assess the properties of this material for space‐heating applications on a laboratory pilot scale with an open reactor, a new synthetic route involving safer, greener conditions was developed. This led to the production of MIL‐160(Al) on a 400 g scale, before the material was shaped into pellets through a wet‐granulation method. The material exhibited a very high energy‐storage capacity for a physical‐sorption material (343 Wh kg−1), which is in full agreement with the predicted value.
Howler monkey foraging ecology suggests convergent evolution of routine trichromacy as an adaptation for folivory
Authors: Melin Amanda D. , Khetpal Vishal , Matsushita Yuka , Zhou Kaile , Campos Fernando A. , Welker Barbara , Kawamura Shoji
Published: February 2017

Primates possess remarkably variable color vision, and the ecological and social factors shaping this variation remain heavily debated. Here, we test whether central tenants of the folivory hypothesis of routine trichromacy hold for the foraging ecology of howler monkeys. Howler monkeys (genus Alouatta) and paleotropical primates (Parvorder: Catarrhini) have independently acquired routine trichromacy through fixation of distinct mid‐ to long‐wavelength‐sensitive (M/LWS) opsin genes on the X‐chromosome. The presence of routine trichromacy in howlers, while other diurnal neotropical monkeys (Platyrrhini) possess polymorphic trichromacy, is poorly understood. A selective force proposed to explain the evolution of routine trichromacy in catarrhines—reliance on young, red leaves—has received scant attention in howlers, a gap we fill in this study. We recorded diet, sequenced M/LWS opsin genes in four social groups of Alouatta palliata, and conducted colorimetric analysis of leaves consumed in Sector Santa Rosa, Costa Rica. For a majority of food species, including Ficus trees, an important resource year‐round, young leaves were more chromatically conspicuous from mature leaves to trichromatic than to hypothetical dichromatic phenotypes. We found that 18% of opsin genes were MWS/LWS hybrids; when combined with previous research, the incidence of hybrid M/LWS opsins in this species is 13%. In visual models of food discrimination ability, the hybrid trichromatic phenotype performed slightly poorer than normal trichromacy, but substantially better than dichromacy. Our results provide support for the folivory hypothesis of routine trichromacy. Similar ecological pressures, that is, the search for young, reddish leaves, may have driven the independent evolution of routine trichromacy in primates on separate continents. We discuss our results in the context of balancing selection acting on New World monkey opsin genes and hypothesize that howlers experience stronger selection against dichromatic phenotypes than other sympatric species, which rely more heavily on cryptic foods.
Long‐term consistency in spatial patterns of primate seed dispersal
Authors: Heymann Eckhard W. , Culot Laurence , Knogge Christoph , Noriega Piña Tony Enrique , Tirado Herrera Emérita R. , Klapproth Matthias , Zinner Dietmar
Published: February 2017

Seed dispersal is a key ecological process in tropical forests, with effects on various levels ranging from plant reproductive success to the carbon storage potential of tropical rainforests. On a local and landscape scale, spatial patterns of seed dispersal create the template for the recruitment process and thus influence the population dynamics of plant species. The strength of this influence will depend on the long‐term consistency of spatial patterns of seed dispersal. We examined the long‐term consistency of spatial patterns of seed dispersal with spatially explicit data on seed dispersal by two neotropical primate species, Leontocebus nigrifrons and Saguinus mystax (Callitrichidae), collected during four independent studies between 1994 and 2013. Using distributions of dispersal probability over distances independent of plant species, cumulative dispersal distances, and kernel density estimates, we show that spatial patterns of seed dispersal are highly consistent over time. For a specific plant species, the legume Parkia panurensis, the convergence of cumulative distributions at a distance of 300 m, and the high probability of dispersal within 100 m from source trees coincide with the dimension of the spatial–genetic structure on the embryo/juvenile (300 m) and adult stage (100 m), respectively, of this plant species. Our results are the first demonstration of long‐term consistency of spatial patterns of seed dispersal created by tropical frugivores. Such consistency may translate into idiosyncratic patterns of regeneration.
Myocardial fibrosis: biomedical research from bench to bedside
Authors: Gyöngyösi Mariann , Winkler Johannes , Ramos Isbaal , Do Quoc‐Tuan , Firat Hüseyin , McDonald Kenneth , González Arantxa , Thum Thomas , Díez Javier , Jaisser Frédéric , Pizard Anne , Zannad Faiez
Published: February 2017

Myocardial fibrosis refers to a variety of quantitative and qualitative changes in the interstitial myocardial collagen network that occur in response to cardiac ischaemic insults, systemic diseases, drugs, or any other harmful stimulus affecting the circulatory system or the heart itself. Myocardial fibrosis alters the architecture of the myocardium, facilitating the development of cardiac dysfunction, also inducing arrhythmias, influencing the clinical course and outcome of heart failure patients. Focusing on myocardial fibrosis may potentially improve patient care through the targeted diagnosis and treatment of emerging fibrotic pathways. The European Commission funded the FIBROTARGETS consortium as a multinational academic and industrial consortium with the primary aim of performing a systematic and collaborative search of targets of myocardial fibrosis, and then translating these mechanisms into individualized diagnostic tools and specific therapeutic pharmacological options for heart failure. This review focuses on those methodological and technological aspects considered and developed by the consortium to facilitate the transfer of the new mechanistic knowledge on myocardial fibrosis into potential biomedical applications.