bluuebunny/crossref_metadata_2025 huggingface dataset:
Treating Sample Covariances for Use in Strongly Coupled Atmosphere‐Ocean Data Assimilation
Authors: Smith Polly J. , Lawless Amos S. , Nichols Nancy K.
Published: December 2017

Strongly coupled data assimilation requires cross‐domain forecast error covariances; information from ensembles can be used, but limited sampling means that ensemble derived error covariances are routinely rank deficient and/or ill‐conditioned and marred by noise. Thus, they require modification before they can be incorporated into a standard assimilation framework. Here we compare methods for improving the rank and conditioning of multivariate sample error covariance matrices for coupled atmosphere‐ocean data assimilation. The first method, reconditioning, alters the matrix eigenvalues directly; this preserves the correlation structures but does not remove sampling noise. We show that it is better to recondition the correlation matrix rather than the covariance matrix as this prevents small but dynamically important modes from being lost. The second method, model state‐space localization via the Schur product, effectively removes sample noise but can dampen small cross‐correlation signals. A combination that exploits the merits of each is found to offer an effective alternative.
The Diversity of Cloud Responses to Twentieth Century Sea Surface Temperatures
Authors: Silvers Levi G. , Paynter David , Zhao Ming
Published: December 2017

Low‐level clouds are shown to be the conduit between the observed sea surface temperatures (SST) and large decadal fluctuations of the top of the atmosphere radiative imbalance. The influence of low‐level clouds on the climate feedback is shown for global mean time series as well as particular geographic regions. The changes of clouds are found to be important for a midcentury period of high sensitivity and a late century period of low sensitivity. These conclusions are drawn from analysis of amip‐piForcing simulations using three atmospheric general circulation models (AM2.1, AM3, and AM4.0). All three models confirm the importance of the relationship between the global climate sensitivity and the eastern Pacific trends of SST and low‐level clouds. However, this work argues that the variability of the climate feedback parameter is not driven by stratocumulus‐dominated regions in the eastern ocean basins, but rather by the cloudy response in the rest of the tropics.
Pressure‐Driven Poiseuille Flow: A Major Component of the Torque‐Balance Governing Pacific Plate Motion
Authors: Stotz I. L. , Iaffaldano G. , Davies D. R.
Published: December 2017

The Pacific Plate is thought to be driven mainly by slab pull, associated with subduction along the Aleutians‐Japan, Marianas‐Izu‐Bonin, and Tonga‐Kermadec trenches. This implies that viscous flow within the sub‐Pacific asthenosphere is mainly generated by overlying plate motion (i.e., Couette flow) and that the associated shear stresses at the lithosphere's base are resisting such motion. Recent studies on glacial isostatic adjustment and lithosphere dynamics provide tighter constraints on the viscosity and thickness of Earth's asthenosphere and, therefore, on the amount of shear stress that asthenosphere and lithosphere mutually exchange, by virtue of Newton's third law of motion. In light of these constraints, the notion that subduction is the main driver of present‐day Pacific Plate motion becomes somewhat unviable, as the pulling force that would be required by slabs exceeds the maximum available from their negative buoyancy. Here we use coupled global models of mantle and lithosphere dynamics to show that the sub‐Pacific asthenosphere features a significant component of pressure‐driven (i.e., Poiseuille) flow and that this has driven at least 50% of the Pacific Plate motion since, at least, 15 Ma. A corollary of our models is that a sublithospheric pressure difference as high as ±50 MPa is required across the Pacific domain.
Ice Stream Slowdown Will Drive Long‐Term Thinning of the Ross Ice Shelf, With or Without Ocean Warming
Authors: Campbell Adam J. , Hulbe Christina L. , Lee Choon‐Ki
Published: December 2017

As time series observations of Antarctic change proliferate, it is imperative that mathematical frameworks through which they are understood keep pace. Here we present a new method of interpreting remotely sensed change using spatial statistics and apply it to the specific case of thickness change on the Ross Ice Shelf. First, a numerical model of ice shelf flow is used together with empirical orthogonal function analysis to generate characteristic patterns of response to specific forcings. Because they are continuous and scalable in space and time, the patterns allow short duration observations to be placed in a longer time series context. Second, focusing only on changes that are statistically significant, the synthetic response surfaces are used to extract magnitude and timing of past events from the observational data. Slowdown of Kamb and Whillans Ice Streams is clearly detectable in remotely sensed thickness change. Moreover, those past events will continue to drive thinning into the future.
Attributable Human‐Induced Changes in the Likelihood and Magnitude of the Observed Extreme Precipitation during Hurricane Harvey
Authors: Risser Mark D. , Wehner Michael F.
Published: December 2017

Record rainfall amounts were recorded during Hurricane Harvey in the Houston, Texas, area, leading to widespread flooding. We analyze observed precipitation from the Global Historical Climatology Network with a covariate‐based extreme value statistical analysis, accounting for both the external influence of global warming and the internal influence of El Niño–Southern Oscillation. We find that human‐induced climate change likely increased the chances of the observed precipitation accumulations during Hurricane Harvey in the most affected areas of Houston by a factor of at least 3.5. Further, precipitation accumulations in these areas were likely increased by at least 18.8% (best estimate of 37.7%), which is larger than the 6–7% associated with an attributable warming of 1°C in the Gulf of Mexico and Clausius‐Clapeyron scaling. In a Granger causality sense, these statements provide lower bounds on the impact of climate change and motivate further attribution studies using dynamical climate models.
Changes in the Mechanisms Causing Rapid Drought Cessation in the Southeastern United States
Authors: Maxwell Justin T. , Knapp Paul A. , Ortegren Jason T. , Ficklin Darren L. , Soulé Peter T.
Published: December 2017

The synoptic processes that end droughts are poorly understood, yet have significant climatological implications. Here we examined the spatiotemporal patterns of rapid drought cessation (RDC) in the southeastern United States during the1979–2013 warm season (April–November) for three storm types: Frontal, Tropical, and Air mass. We defined RDC as a 1 month shift in soil moisture sufficient to alleviate an existing drought. We found that 73% of all warm‐season droughts were ended by RDC events and the three storm‐type groups ended droughts over similar spatial areas. Frontal storms were the most frequent mechanism for RDC events, yet their occurrences significantly decreased and were negatively related to increases in Northern Hemisphere air temperatures. Projected future warming in the Northern Hemisphere suggests a continued decline in the frequency and relative contribution of Frontal storms as RDC events, potentially influencing the timing and spatial scale of drought cessation in the southeastern U.S.
Catalytic Enantioselective Povarov Reactions of Ferrocenecarbaldehyde‐Derived Imines – Brønsted Acid Catalysis at Parts‐Per‐Million Level Loading
Authors: Stevanović Dragana , Bertuzzi Giulio , Mazzanti Andrea , Fochi Mariafrancesca , Bernardi Luca
Published: December 2017

Despite the broad interest in ferrocene containing compounds, ferrocenyl substrates have been employed in catalytic asymmetric settings only sporadically. Herein, catalytic asymmetric Povarov reactions with ferrocenecarbaldehyde‐derived N‐aryl imines are presented. This study demonstrates that the stereoelectronic properties of ferrocenyl imines do not preclude their engagement in enantioselective phosphoric acid catalysis: cycloadducts derived from benzyl N‐vinylcarbamate were obtained in good yields and nearly enantiopure form using 0.1 mol% of a standard Brønsted acid catalyst. Furthermore, it is shown that specific optimisation with some substrates allowed to lower the catalyst loading up to 10–20 parts‐per‐million, an unprecedented value for phosphoric acid catalysts. Such low loading protocol could be applied to a preparative scale reaction, and to imines derived from arylaldehydes.

magnified image
Synthesis of Ni nanoparticles with controllable magnetic properties by atmospheric pressure microplasma assisted process
Authors: Lin Liangliang , Li Sirui , Hessel Volker , Starostin Sergey A. , Lavrijsen R. , Zhang Wei
Published: December 2017

An atmospheric pressure microplasma technique is demonstrated for the gas phase synthesis of Ni nanoparticles by plasma‐assisted nickelocene dissociation at different conditions. The dissociation process and the products are characterized by complementary analytical methods to establish the relationship between operational conditions and product properties. The innovation is to show proof‐of‐principle of a new synthesis route which offers access to less costly and less poisonous reactant, a higher quality product, and a simple, continuous and pre/post treatment‐free manner with chance for fine‐tuning “in‐flight.” Results show that Ni nanoparticles with controllable magnetic properties are obtained, in which flexible adjustment of product properties can be achieved by tuning operational parameters. At the optimized condition only fcc Ni nanoparticles are formed, with saturation magnetization value of 44.4 mAm2/g. The upper limit of production rate for Ni nanoparticles is calculated as 4.65 × 10−3 g/h using a single plasma jet, but the process can be scaled‐up through a microplasma array design. In addition, possible mechanisms for plasma‐assisted nickelocene dissociation process are discussed. © 2017 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 64: 1540–1549, 2018
Desktop NMR and Its Applications From Materials Science To Organic Chemistry
Authors: Blümich Bernhard , Singh Kawarpal
Published: December 2017

NMR spectroscopy is an indispensable method of analysis in chemistry, which until recently suffered from high demands for space, high costs for acquisition and maintenance, and operational complexity. This has changed with the introduction of compact NMR spectrometers suitable for small‐molecule analysis on the chemical workbench. These spectrometers contain permanent magnets giving rise to proton NMR frequencies between 40 and 80 MHz. The enabling technology is to make small permanent magnets with homogeneous fields. Tabletop instruments with inhomogeneous fields have been in use for over 40 years for characterizing food and hydrogen‐containing materials by relaxation and diffusion measurements. Related NMR instruments measure these parameters in the stray field outside the magnet. They are used to inspect the borehole walls of oil wells and to test objects nondestructively. The state‐of‐the‐art of NMR spectroscopy, imaging and relaxometry with compact instruments is reviewed.
What Function Is Optimal for CCSD(T) Complete Basis Extrapolation for OH Stretching Potential of Water Molecules?
Authors: Yang Mino
Published: December 2017

A procedure to calculate the complete basis set limits of electronic energy of water molecules is developed based on two levels of extrapolation scheme. A three‐point fitting scheme with the energies computed at the levels of basis function, aug‐cc‐pVXZ for X = 4–6, is employed to obtain accurate energies of a monomer and a dimer of water. Three extrapolation functions considered in this article are found to work excellently to give accurate Hartree–Fock (HF) energies of water molecules. However, the three functions give slightly different values up to 1–2 mHartree for the complete basis limit of electronic correlation energy. The best performing extrapolating function for the five‐point fitting scheme with a larger set of basis functions for X = 2–6 has been determined aiming for the extrapolation from the lowest two levels of basis sets, double and triple zeta basis functions. For this purpose, an exponential function is suggested for HF energy while an exponential function with a square root exponent is suggested for electronic correlation energy. The optimal exponents of the two functions have been determined.
Kirmse–Doyle‐ and Stevens‐Type Rearrangements of Glutarate‐Derived Oxonium Ylides
Authors: Skrobo Benedikt , Schlörer Nils E. , Neudörfl Jörg‐M. , Deska Jan
Published: December 2017

A novel chemoenzymatic synthetic cascade enables the preparation of densely decorated tetrahydrofuran building blocks. Here, the lipase‐catalyzed desymmetrization of 3‐alkoxyglutarates renders highly enantioenriched carboxylic acid intermediates, whose subsequent activation and oxonium ylide rearrangement by means of rhodium or copper complexes furnishes functionalized O‐heterocycles with excellent diastereoselectivity. The two‐step protocol offers a streamlined and flexible synthesis of tetrahydrofuranones bearing different benzylic, allylic or allenylic side chains with full control over multiple stereogenic centers.
Controllable Syntheses of MOF‐Derived Materials
Authors: Zou Kang‐Yu , Li Zuo‐Xi
Published: December 2017

Metal–organic frameworks (MOFs), as an important kind of porous inorganic‐organic hybrid materials with inherent outstanding physicochemistry characteristics, can be widely applied as versatile precursors for the facile preparation of functional MOF‐derived materials. However, there are plenty of sophisticated factors during the synthetic process, which is far from reaching the goal of effectively controlling the nature of MOF‐derived materials (such as the composition, morphology and surface area). Therefore, it is urgently necessary to develop regular protocols and concepts for controllable syntheses of MOF‐derived materials. In this minireview, we mainly summarize and analyze complicated factors in the fabrication of MOF‐derived materials according to recently reported literatures, and this provides a new insight into the rational design and syntheses of MOF‐derived materials.
Customizing Photoredox Properties of PXX‐based Dyes through Energy Level Rigid Shifts of Frontier Molecular Orbitals
Authors: Sciutto Andrea , Fermi Andrea , Folli Andrea , Battisti Tommaso , Beames Joseph M. , Murphy Damien M. , Bonifazi Davide
Published: December 2017

Here we describe the synthesis of electron‐rich PXX derivatives in which the energy levels of the excited states have been rigidly shifted through the insertion of imide groups. This has allowed the development of a new series of oxygen‐doped photoredox‐active chromophores with improved oxidizing and reducing properties. Capitalizing on the dehalogenation of organic halides as a model reaction, we could investigate the photooxidative and photoreductive potential of these molecules in model chemical transformations. Depending on the substrate, solvent and dye the reaction mechanism can follow different paths. This prompted us to consider the first chemoselective transformation protocol, in which two different C−Br bonds could be chemoselectively reacted through the sequential photoactivation of two different colorants.
Travel distance and stereotactic body radiotherapy for localized prostate cancer
Authors: Mahal Brandon A. , Chen Yu‐Wei , Sethi Roshan V. , Padilla Oscar A. , Yang David D. , Chavez Janice , Muralidhar Vinayak , Hu Jim C. , Feng Felix Y. , Hoffman Karen E. , Martin Neil E. , Spratt Daniel E. , Yu James B. , Orio Peter F. , Nguyen Paul L.
Published: December 2017

BACKGROUND

Definitive stereotactic body radiotherapy (SBRT) represents an emerging and debated treatment option for patients with prostate cancer, with potential economic savings and reports of short‐term efficacy since 2006. The current study sought to define national trends in definitive prostate SBRT use and determine whether patterns vary by travel distance for treatment.

METHODS

The National Cancer Data Base identified 181,544 men with localized prostate cancer who were treated with definitive external beam radiotherapy from 2004 through 2012. Joinpoint regression analyzed definitive prostate SBRT trends over time, whereas multivariable logistic regression defined the odds for its receipt by travel distance for treatment.

RESULTS

Definitive prostate SBRT use increased from 1.8% in 2004 to 5.9% in 2012 (P for trend <.0001), with a joinpoint for increased use noted in 2006 (P<.0001). Higher SBRT use was found to be associated with longer travel distance for treatment, younger age, white race, more affluent zip code of residence, academic treatment center, favorable disease characteristics, and fewer comorbidities (all P<.0001). Compared with travel distances <25 miles for treatment, travel distances of 25 to 50 miles and >50 miles were associated with increasing adjusted odds of receipt of definitive prostate SBRT (1.63 [95% confidence interval, 1.51‐1.76] and 2.35 [95% confidence interval, 2.14‐2.57], respectively; both P < .0001).

CONCLUSIONS

Definitive prostate SBRT use increased more than 3‐fold since 2004, with a significant increase in use coinciding with early reports of short‐term efficacy. Long‐distance travel for treatment was associated with greater than twice the odds of receipt of definitive prostate SBRT compared with short‐distance travel, suggesting that treatment decisions with unknown long‐term clinical implications may be strongly driven by sociodemographic factors. Cancer 2018;124:1141‐9. © 2017 American Cancer Society.
The Role of Normative CSR‐Promoting Institutions in Stimulating CSR Disclosures in Developing Countries
Authors: Ali Waris , Frynas Jedrzej George
Published: December 2017

This paper provides evidence that CSR (corporate social responsibility) forums and networks such as the United Nations Global Compact Local Network (UNGC), non‐governmental organizations (NGOs) such as the World Wide Fund (WWF) for Nature, and CSR standards such as International Organization for Standardization (ISO) 14000 play a significant role in driving CSR disclosure, using data from publicly quoted companies in Pakistan. The role of CSR‐promoting institutions in enhancing capacity can provide a key explanation for the previously noted differences in disclosure patterns between developed and developing countries, on the one hand, and the improved disclosure in developing countries linked to the development of such institutions, on the other. Academically, this research demonstrates the vital importance of CSR‐promoting institutions, and the related normative isomorphism logics, for CSR disclosure in lower‐income countries, which have previously been assumed to largely lack such institutions. In practical terms, the significant relationship between CSR‐promoting institutions and CSR disclosure suggests that we need stronger policies to encourage the development of such institutions. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment
Magnetic Field‐Enhanced 4‐Electron Pathway for Well‐Aligned Co3O4/Electrospun Carbon Nanofibers in the Oxygen Reduction Reaction
Authors: Zeng Zheng , Zhang Tian , Liu Yiyang , Zhang Wendi , Yin Ziyu , Ji Zuowei , Wei Jianjun
Published: December 2017

The sluggish reaction kinetics of the oxygen reduction reaction (ORR) has been the limiting factor for fuel energy utilization, hence it is desirable to develop high‐performance electrocatalysts for a 4‐electron pathway ORR. A constant low‐current (50 μA) electrodeposition technique is used to realize the formation of a uniform Co3O4 film on well‐aligned electrospun carbon nanofibers (ECNFs) with a time‐dependent growth mechanism. This material also exhibits a new finding of mT magnetic field‐induced enhancement of the electron exchange number of the ORR at a glassy carbon electrode modified with the Co3O4/ECNFs catalyst. The magnetic susceptibility of the unpaired electrons in Co3O4 improves the kinetics and efficiency of electron transfer reactions in the ORR, which shows a 3.92‐electron pathway in the presence of a 1.32 mT magnetic field. This research presents a potential revolution of traditional electrocatalysis by simply applying an external magnetic field on metal oxides as a replacement for noble metals to reduce the risk of fuel‐cell degradation and maximize the energy output.
Use of split‐free nano‐liquid chromatography–mass spectrometry/high resolution mass spectrometry interface to improve the detection of α‐cobratoxin in equine plasma for doping control
Authors: Bailly‐Chouriberry Ludovic , Garcia Patrice , Cormant Florence , Loup Benoit , Popot Marie‐Agnès , Bonnaire Yves
Published: December 2017

Cobra (Naja naja kaouthia) venom contains a toxin called α‐cobratoxin (α‐Cbtx) containing 71 amino acids (MW 7821 Da) with a reported analgesic power greater than morphine. In 2013, the first analytical method for the detection of α‐Cbtx in equine plasma was developed by Bailly‐Chouriberry et al, allowing the confirmation of the presence of α‐Cbtx at low concentrations (1–5 ng/mL or 130–640 fmol/mL) in plasma samples. To increase the method sensitivity and therefore to improve the detection of α‐Cbtx in post‐administration plasma samples, a nano‐liquid chromatography–mass spectrometry/high resolution mass spectrometry (nLC–MS/HRMS) method was developed. This new method allowed us to confirm the presence of α‐Cbtx in plasma samples spiked at 100 pg/mL (12.8 fmol/mL) and the detection of α‐Cbtx was obtained in plasma samples collected 72 hours post‐administration (50 pg/mL or 6.4 fmol/mL) which was defined as the limit of detection (LOD). The presented method is 20‐fold more sensitive compared to the method previously described.
Is Didymosphenia geminata an introduced species in New Zealand? Evidence from trends in water chemistry, and chloroplast DNA
Authors: Kilroy Cathy , Novis Phil
Published: December 2017

Defining the geographic origins of free‐living aquatic microorganisms can be problematic because many such organisms have ubiquitous distributions, and proving absence from a region is practically impossible. Geographic origins become important if microorganisms have invasive characteristics. The freshwater diatom Didymosphenia geminata is a potentially ubiquitous microorganism for which the recent global expansion of nuisance proliferations has been attributed to environmental change. The changes may include declines in dissolved reactive phosphorus (DRP) to low levels (e.g., <2 mg/m3) and increases in dissolved inorganic nitrogen (DIN) to >10 mg/m3 because both these nutrient conditions are associated with nuisance proliferations of D. geminata. Proliferations of D. geminata have been observed in South Island, New Zealand, since 2004. We aimed to address the ubiquity hypothesis for D. geminata in New Zealand using historical river water nutrient data and new molecular analyses. We used 15 years of data at 77 river sites to assess whether trends in DRP or DIN prior to the spread of D. geminata were consistent with a transition from a rare, undetected, species to a nuisance species. We used new sequences of chloroplast regions to examine the genetic similarity of D. geminata populations from New Zealand and six overseas locations. We found no evidence for declines in DRP concentrations since 1989 that could explain the spread of proliferations since 2004. At some affected sites, lowest DRP occurred before 2004. Trends in DIN also did not indicate enhanced suitability for D. geminata. Lack of diversity in the chloroplast intergenic regions of New Zealand populations and populations from western North America is consistent with recent dispersal to New Zealand. Our analyses did not support the proposal that D. geminata was historically present in New Zealand rivers. These results provide further evidence countering proposals of general ubiquity in freshwater diatoms and indicate that, as assumed in 2004, D. geminata is a recent arrival in New Zealand.
Prolonged dry periods between rainfall events shorten the growth period of the resurrection plant Reaumuria soongorica
Authors: Zhang Zhengzhong , Shan Lishan , Li Yi
Published: December 2017

The resurrection plant Reaumuria soongorica is widespread across Asia, southern Europe, and North Africa and is considered to be a constructive keystone species in desert ecosystems, but the impacts of climate change on this species in desert ecosystems are unclear. Here, the morphological responses of R. soongorica to changes in rainfall quantity (30% reduction and 30% increase in rainfall quantity) and interval (50% longer drought interval between rainfall events) were tested. Stage‐specific changes in growth were monitored by sampling at the beginning, middle, and end of the growing season. Reduced rainfall decreased the aboveground and total biomass, while additional precipitation generally advanced R. soongorica growth and biomass accumulation. An increased interval between rainfall events resulted in an increase in root biomass in the middle of the growing season, followed by a decrease toward the end. The response to the combination of increased rainfall quantity and interval was similar to the response to increased interval alone, suggesting that the effects of changes in rainfall patterns exert a greater influence than increased rainfall quantity. Thus, despite the short duration of this experiment, consequences of changes in rainfall regime on seedling growth were observed. In particular, a prolonged rainfall interval shortened the growth period, suggesting that climate change‐induced rainfall variability may have significant effects on the structure and functioning of desert ecosystems.
Minimum area thresholds for rattlesnakes and colubrid snakes on islands in the Gulf of California, Mexico
Authors: Meik Jesse M. , Makowsky Robert
Published: December 2017

We expand a framework for estimating minimum area thresholds to elaborate biogeographic patterns between two groups of snakes (rattlesnakes and colubrid snakes) on islands in the western Gulf of California, Mexico. The minimum area thresholds for supporting single species versus coexistence of two or more species relate to hypotheses of the relative importance of energetic efficiency and competitive interactions within groups, respectively. We used ordinal logistic regression probability functions to estimate minimum area thresholds after evaluating the influence of island area, isolation, and age on rattlesnake and colubrid occupancy patterns across 83 islands. Minimum area thresholds for islands supporting one species were nearly identical for rattlesnakes and colubrids (~1.7 km2), suggesting that selective tradeoffs for distinctive life history traits between rattlesnakes and colubrids did not result in any clear advantage of one life history strategy over the other on islands. However, the minimum area threshold for supporting two or more species of rattlesnakes (37.1 km2) was over five times greater than it was for supporting two or more species of colubrids (6.7 km2). The great differences between rattlesnakes and colubrids in minimum area required to support more than one species imply that for islands in the Gulf of California relative extinction risks are higher for coexistence of multiple species of rattlesnakes and that competition within and between species of rattlesnakes is likely much more intense than it is within and between species of colubrids.
Mapping multi‐scale vascular plant richness in a forest landscape with integrated LiDARand hyperspectral remote‐sensing
Authors: Hakkenberg C. R. , Zhu K. , Peet R. K. , Song C.
Published: December 2017

The central role of floristic diversity in maintaining habitat integrity and ecosystem function has propelled efforts to map and monitor its distribution across forest landscapes. While biodiversity studies have traditionally relied largely on ground‐based observations, the immensity of the task of generating accurate, repeatable, and spatially‐continuous data on biodiversity patterns at large scales has stimulated the development of remote‐sensing methods for scaling up from field plot measurements. One such approach is through integrated LiDARand hyperspectral remote‐sensing. However, despite their efficiencies in cost and effort, LiDAR‐hyperspectral sensors are still highly constrained in structurally‐ and taxonomically‐heterogeneous forests ‐ especially when species’ cover is smaller than the image resolution, intertwined with neighboring taxa, or otherwise obscured by overlapping canopy strata. In light of these challenges, this study goes beyond the remote characterization of upper canopy diversity to instead model total vascular plant species richness in a continuous‐cover North Carolina Piedmont forest landscape. We focus on two related, but parallel, tasks. First, we demonstrate an application of predictive biodiversity mapping, using nonparametric models trained with spatially‐nested field plots and aerial LiDAR‐hyperspectral data, to predict spatially‐explicit landscape patterns in floristic diversity across seven spatial scales between 0.01–900 m2. Second, we employ bivariate parametric models to test the significance of individual, remotely‐sensed predictors of plant richness to determine how parameter estimates vary with scale. Cross‐validated results indicate that predictive models were able to account for 15–70% of variance in plant richness, with LiDAR‐derived estimates of topography and forest structural complexity, as well as spectral variance in hyperspectral imagery explaining the largest portion of variance in diversity levels. Importantly, bivariate tests provide evidence of scale‐dependence among predictors, such that remotely‐sensed variables significantly predict plant richness only at spatial scales that sufficiently subsume geolocational imprecision between remotely‐sensed and field data, and best align with stand components including plant size and density, as well as canopy gaps and understory growth patterns. Beyond their insights into the scale‐dependent patterns and drivers of plant diversity in Piedmont forests, these results highlight the potential of remotely‐sensible essential biodiversity variables for mapping and monitoring landscape floristic diversity from air‐ and space‐borne platforms.
Cardiovascular magnetic resonance imaging and clinical performance of somatostatin receptor positron emission tomography in cardiac sarcoidosis
Authors: Pizarro Carmen , Kluenker Folke , Dabir Darius , Thomas Daniel , Gaertner Florian C. , Essler Markus , Grohé Christian , Nickenig Georg , Skowasch Dirk
Published: December 2017

Aims

Cardiac affection constitutes a major limiting condition in systemic sarcoidosis. The primary objective of this study was to investigate the persistence rate of cardiac sarcoid involvement by cardiovascular magnetic resonance (CMR) imaging in patients diagnosed with cardiac sarcoidosis (CS). Moreover, we examined the additional insights into myocardial damage's characteristics gained by somatostatin receptor scintigraphy.

Methods and results

In a pilot study, we had previously identified cardiac involvement—diagnosed by CMR imaging—to be present in 29 of 188 patients (15.4%) with histologically proven, extra‐CS. Out of these initial 29 CS‐positive patients, 27 patients (49.9 ± 11.8 years, 59.3% male) were presently re‐examined and underwent a second CMR study and complementary standard clinical testing. Somatostatin receptor scintigraphy using the ligand 68Ga‐DOTATOC was additionally performed when clinically indicated (17 patients). Within a median follow‐up period of 2.6 years, none of the initial 29 patients deceased or experienced aborted sudden cardiac death. However, two patients developed third‐degree atrioventricular block that required device therapy. Among the 27 re‐examined CS patients, pathological CMR findings persisted in 14 of 27 patients (51.9%). CS remission was primarily due to a resolution of acute inflammatory processes. 68Ga‐DOTATOC positron emission tomography/computed tomography (PET/CT) identified one patient with regions of raised tracer uptake that concorded with acute inflammatory changes, as assessed by CMR; this patient received no immunosuppressive medication at the time of PET/CT execution.

Conclusions

Within follow‐up, CS persisted in barely half the patients, and the patients were not afflicted with cardiac death. Additional 68Ga‐DOTATOC PET/CT allowed for visualization of acute myocardial inflammation.
Synthesis of Trifluoromethyl Tetrafluoro‐λ6‐sulfanyl‐Substituted Alkenes, Ketones, and Acids: Polar Hydrophobic Building Blocks
Authors: Ikeda Akari , Zhong Linbin , Savoie Paul R. , von Hahmann Cortney N. , Zheng Wei , Welch John T.
Published: December 2017

The trifluoromethyl tetrafluoro‐λ6‐sulfanyl (CF3SF4) group is both extraordinarily lipophilic and profoundly electron withdrawing, properties associated with polar hydrophobicity. Utilization of the CF3SF4 group to prepare novel materials or biologically active agents will not be possible without new methods for the synthesis of aliphatic CF3SF4‐substituted building blocks. To advance those studies, trichloromethanesulfenyl chloride was conveniently converted to trans‐trifluoromethyl tetrafluoro‐λ6‐sulfanyl chloride (CF3SF4Cl) by oxidative chlorofluorination. Triethylborane‐promoted addition reactions of trans‐CF3SF4Cl to substituted olefins and alkynes yielded a variety of new materials. Those addition products were subsequently transformed to CF3SF4‐substituted carboxylic acids, CF3SF4‐substituted ketones, and a CF3SF4‐substituted aldehyde.
The improvement of numerical modeling in the solution of incompressible viscous flow problems using finite element method based on spherical Hankel shape functions
Authors: Farmani Sajedeh , Ghaeini‐Hessaroeyeh Mahnaz , Javaran Saleh Hamzehei
Published: December 2017

In this paper, the finite element method with new spherical Hankel shape functions is developed for simulating 2‐dimensional incompressible viscous fluid problems. In order to approximate the hydrodynamic variables, the finite element method based on new shape functions is reformulated. The governing equations are the Navier‐Stokes equations solved by the finite element method with the classic Lagrange and spherical Hankel shape functions. The new shape functions are derived using the first and second kinds of Bessel functions. In addition, these functions have properties such as piecewise continuity. For the enrichment of Hankel radial basis functions, polynomial terms are added to the functional expansion that only employs spherical Hankel radial basis functions in the approximation. In addition, the participation of spherical Bessel function fields has enhanced the robustness and efficiency of the interpolation. To demonstrate the efficiency and accuracy of these shape functions, 4 benchmark tests in fluid mechanics are considered. Then, the present model results are compared with the classic finite element results and available analytical and numerical solutions. The results show that the proposed method, even with less number of elements, is more accurate than the classic finite element method.
Neonatal mouse cortical but not isogenic human astrocyte feeder layers enhance the functional maturation of induced pluripotent stem cell‐derived neurons in culture
Authors: Lischka Fritz W. , Efthymiou Anastasia , Zhou Qiong , Nieves Michael D. , McCormack Nikki M. , Wilkerson Matthew D. , Sukumar Gauthaman , Dalgard Clifton L. , Doughty Martin L.
Published: December 2017

Human induced pluripotent stem (iPS) cell‐derived neurons and astrocytes are attractive cellular tools for nervous system disease modeling and drug screening. Optimal utilization of these tools requires differentiation protocols that efficiently generate functional cell phenotypes in vitro. As nervous system function is dependent on networked neuronal activity involving both neuronal and astrocytic synaptic functions, we examined astrocyte effects on the functional maturation of neurons from human iPS cell‐derived neural stem cells (NSCs). We first demonstrate human iPS cell‐derived NSCs can be rapidly differentiated in culture to either neurons or astrocytes with characteristic cellular, molecular and physiological features. Although differentiated neurons were capable of firing multiple action potentials (APs), few cells developed spontaneous electrical activity in culture. We show spontaneous electrical activity was significantly increased by neuronal differentiation of human NSCs on feeder layers of neonatal mouse cortical astrocytes. In contrast, co‐culture on feeder layers of isogenic human iPS cell‐derived astrocytes had no positive effect on spontaneous neuronal activity. Spontaneous electrical activity was dependent on glutamate receptor‐channel function and occurred without changes in INa, IK, Vm, and AP properties of iPS cell‐derived neurons. These data demonstrate co‐culture with neonatal mouse cortical astrocytes but not human isogenic iPS cell‐derived astrocytes stimulates glutamatergic synaptic transmission between iPS cell‐derived neurons in culture. We present RNA‐sequencing data for an immature, fetal‐like status of our human iPS cell‐derived astrocytes as one possible explanation for their failure to enhance synaptic activity in our co‐culture system.
Impact of fear of falling and fall history on disability incidence among older adults: Prospective cohort study
Authors: Makino Keitaro , Makizako Hyuma , Doi Takehiko , Tsutsumimoto Kota , Hotta Ryo , Nakakubo Sho , Suzuki Takao , Shimada Hiroyuki
Published: December 2017

Objective

Fear of falling (FOF) is a major health problem for older adults, present not just in fallers, but also nonfallers. This study examined the impact of FOF and fall history on disability incidence among community‐dwelling older adults from a prospective cohort study.

Methods

A total of 5104 older adults living in community settings participated in baseline assessment and were followed up for about 4 years (median 52 mo, range 49‐55 mo). At baseline, participants were assessed the presence of FOF and their fall history, and divided into 4 groups: Fall (−) FOF (−), Fall (+) FOF (−), Fall (−) FOF (+), and Fall (+) FOF (+). Disability incidence was defined as national long‐term care insurance certification for personal support or care.

Results

During the follow‐up period, 429 participants (9.9%) were newly certified as having a disability and needing personal support for long‐term care insurance. Fall (−) FOF (+) group and Fall (+) FOF (+) group showed a significantly higher risk of disability incidence than Fall (−) FOF (−) group even after adjusting for covariates (Fall (−) FOF (+): hazard ratio 1.28, 95% confidence interval, 1.01‐1.62, Fall (+) FOF (+): hazard ratio 1.44, 95% confidence interval, 1.05‐1.98).

Conclusions

Fear of falling could be a simple and useful predictor of disability incidence in community‐dwelling older adults. Identifying and decreasing fall risk factors may prevent fall‐related injuries, but excessive FOF may be associated with increased risk of disability incidence.
Behavior‐driven arc expression is reduced in all ventral hippocampal subfields compared to CA1, CA3, and dentate gyrus in rat dorsal hippocampus
Authors: Chawla M. K. , Sutherland V. L. , Olson K. , McNaughton B. L. , Barnes C. A.
Published: December 2017

Anatomical connectivity and lesion studies reveal distinct functional heterogeneity along the dorsal–ventral axis of the hippocampus. The immediate early gene Arc is known to be involved in neural plasticity and memory and can be used as a marker for cell activity that occurs, for example, when hippocampal place cells fire. We report here, that Arc is expressed in a greater proportion of cells in dorsal CA1, CA3, and dentate gyrus (DG), following spatial behavioral experiences compared to ventral hippocampal subregions (dorsal CA1 = 33%; ventral CA1 = 13%; dorsal CA3 = 23%; ventral CA3 = 8%; and dorsal DG = 2.5%; ventral DG = 1.2%). The technique used here to obtain estimates of numbers of behavior‐driven cells across the dorsal–ventral axis, however, corresponds quite well with samples from available single unit recording studies. Several explanations for the two‐ to‐threefold reduction in spatial behavior‐driven cell activity in the ventral hippocampus can be offered. These include anatomical connectivity differences, differential gain of the self‐motion signals that appear to alter the scale of place fields and the proportion of active cells, and possibly variations in the neuronal responses to non‐spatial information within the hippocampus along its dorso‐ventral axis.
Ageing in India: Financial hardship from health expenditures
Authors: Lee Ting‐Hsuan J. , Saran Indrani , Rao Krishna D.
Published: December 2017

India's rapidly ageing population raises concerns about the burden of health care payments among older individuals who may have both limited income and greater health care needs. Using a nationally representative household survey, we investigate the association between age and financial hardship due to health expenditures. We find that both the probability of experiencing health problems and mean total out‐of‐pocket health expenditures increase with age. Second, the probability of households experiencing catastrophic health expenditures increases with each additional member aged 60 and above—33% of households with one 60+ member and 38% of households with 2 or more 60+ members experienced catastrophic health expenditures, compared to only 20% in households with all members under the age of 60 years. Lastly, we show that individuals aged 60 and above had a much higher probability of becoming impoverished as a result of health expenditures—the probability of impoverishment for 60+ individuals was 3 percentage points higher than for individuals under the age of 60. Overall, around 4.8% of the older population, representing 4.1 million people, fell into poverty. The results suggest that there is an urgent need for public investments in financial protection programs for older people in India.
Determining hydrological regimes in an agriculturally used tropical inland valley wetland in Central Uganda using soil moisture, groundwater, and digital elevation data
Authors: Gabiri Geofrey , Diekkrüger Bernd , Leemhuis Constanze , Burghof Sonja , Näschen Kristian , Asiimwe Immaculate , Bamutaze Yazidhi
Published: December 2017

Inadequate knowledge exists on the distribution of soil moisture and shallow groundwater in intensively cultivated inland valley wetlands in tropical environments, which are required for determining the hydrological regime. This study investigated the spatial and temporal variability of soil moisture along 4 hydrological positions segmented as riparian zone, valley bottom, fringe, and valley slope in an agriculturally used inland valley wetland in Central Uganda. The determined hydrological regimes of the defined hydrological positions are based on soil moisture deficit calculated from the depth to the groundwater table. For that, the accuracy and reliability of satellite‐derived surface models, SRTM‐30m and TanDEM‐X‐12m, for mapping microscale topography and hydrological regimes are evaluated against a 5‐m digital elevation model (DEM) derived from field measurements. Soil moisture and depth to groundwater table were measured using frequency domain reflectometry sensors and piezometers installed along the hydrological positions, respectively. Results showed that spatial and temporal variability in soil moisture increased significantly (p < .05) towards the riparian zone; however, no significant difference was observed between the valley bottom and riparian zone. The distribution of soil hydrological regimes, saturated, near‐saturated, and nonsaturated regimes does not correlate with the hydrological positions. This is due to high spatial and temporal variability in depth to groundwater and soil moisture content across the valley. Precipitation strongly controlled the temporal variability, whereas microscale topography, soil properties, distance from the stream, anthropogenic factors, and land use controlled the spatial variability in the inland valley. TanDEM‐X DEM reasonably mapped the microscale topography and thus soil hydrological regimes relative to the Shuttle Radar Topography Mission DEM. The findings of the study contribute to improved understanding of the distribution of hydrological regimes in an inland valley wetland, which is required for a better agricultural water management planning.
Parenting as a moderator of the effects of cumulative risk on children's social–emotional adjustment and academic readiness
Authors: Ruberry Erika J. , Klein Melanie R. , Kiff Cara J. , Thompson Stephanie F. , Lengua Liliana J.
Published: December 2017

This study examined whether parenting moderated the association between cumulative risk and preschool children's adjustment problems, social competence, and academic readiness. The sample consisted of 306 families representing the full range of income, with 29% at or near poverty and 28% lower income. Cumulative risk and observed maternal parenting behaviours were assessed when the children were 36–40 months, and teachers rated outcomes at 63–68 months. Greater cumulative risk was more strongly related to higher adjustment problems when scaffolding was low and unrelated when it was high, suggesting a protective effect. Consistent limit setting was associated with higher academic readiness regardless of risk level and at low levels of risk it was associated with the highest levels of social competence. A pattern potentially indicating differential effectiveness emerged for warmth, such that, at lower levels of risk, higher warmth was associated with better outcomes, but at higher levels of risk, it was associated with higher levels of problems and poorer social competence and academic readiness. Results suggest that buffering effects of particular parenting behaviours, both alone and in combination, may be context‐specific.

Highlights

This study examined whether parenting moderated the association between cumulative risk and preschool children's social–emotional adjustment outcomes.

Parental warmth, consistent limit‐setting and scaffolding conditioned the relations between risk and child outcomes, yet some of the patterns were unexpected.

Further work is needed to confirm whether effective parenting behaviors differ across risk contexts and if these can buffer children from developing adjustment problems.
Mechanoactivation of the angiotensin II type 1 receptor induces β‐arrestin‐biased signaling through Gαi coupling
Authors: Wang Jialu , Hanada Kenji , Gareri Clarice , Rockman Howard A.
Published: December 2017

Ligand activation of the angiotensin II type 1 receptor (AT1R), a member of the G protein‐coupled receptor (GPCR) family, stimulates intracellular signaling to mediate a variety of physiological responses. The AT1R is also known to be a mechanical sensor. When activated by mechanical stretch, the AT1R can signal via the multifunctional adaptor protein β‐arrestin, rather than through classical heterotrimeric G protein pathways. To date, the AT1R conformation induced by membrane stretch in the absence of ligand was thought to be the same as that induced by β‐arrestin‐biased agonists, which selectively engage β‐arrestin thereby preventing G protein coupling. Here, we show that in contrast to the β‐arrestin‐biased agonists TRV120023 and TRV120026, membrane stretch uniquely promotes the coupling of the inhibitory G protein (Gαi) to the AT1R to transduce signaling. Stretch‐triggered AT1R‐Gαi coupling is required for the recruitment of β‐arrestin2 and activation of downstream signaling pathways, such as EGFR transactivation and ERK phosphorylation. Our findings demonstrate additional complexity in the mechanism of receptor bias in which the recruitment of Gαi is required for allosteric mechanoactivation of the AT1R‐induced β‐arrestin‐biased signaling.