bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproductive success of Whiskered TernChlidonias hybridain eastern Spain in relation to water level variation
Authors: Ortiz Lledó Álvaro , Vidal Mateo Javier , Urios Moliner Vicente
Published: April 2018

Background

A study on the Whiskered TernChlidonias hybridawas carried out between 2002 and 2009 in wetlands of eastern Spain to evaluate how water level fluctuation affects its reproductive success (hatching, fledgling and breeding success). This species is catalogued as Vulnerable in Spain and has an unfavorable conservation status in Europe.

Methods

Our study includes 18 sampling areas from five wetlands, covering a total of 663 nests, 1,618 eggs, 777 nestlings and 225 fledglings. The colonies were visited at least twice per week in breeding period. The number of eggs and/or nestlings present in each nest were annotated each time the colonies were visited with the aim to compare the evolution of these parameters with time. Hatching success was calculated as the proportion of egg that hatched successfully. Fledgling success and breeding success were calculated as the proportion of chicks that fledged successfully and the proportion of eggs that produced fledglings. We used the Kruskal–Wallis test to analyze the differences in the dependent variables hatching, fledgling and breeding success among the wetlands and the sampling areas. We explored the relationship between the different reproductive success with the average fluctuation rate and the anchoring depth of nests, using statistics of the linear regression.

Results

It was observed that the reproductive success varied significantly in the interaction among the different categories of water level fluctuation and the different areas (using the Kruskal–Wallis test). Our records showed that pronounced variations in water level destroyed several nests, which affected the Whiskered Tern reproductive success. Considering all events that occurred in 18 areas, the mean (±SD) of nests, eggs and nestlings that were lost after water level fluctuations were of 25.60 ± 21.79%, 32.06 ± 27.58% and 31.91 ± 21.28% respectively, also including the effects of rain and predation.

Discussion

Unfavorable climatic events, such as strong wind, rain or hail, also caused the loss of nests, eggs and nestlings, even when wetland water levels remained constant. The influence of the anchorage depth of the nest and the water level fluctuation rate were analyzed and did not provide statistically significant results. It was not possible to establish a clear pattern on these latter variables, so further studies are needed to obtain more significant results. We propose to undertake similar studies in wetlands where the water level can be regulated, with the range of nest anchorage depth on the emergent vegetation being between 30 and 60 cm, which could improve the reproductive success in this kind of habitats. As recommendation, in water level controlled wetlands (that use sluices), it should not vary more than ±6 cm in a short time (1–2 days) once the nests are established since it negatively affects their reproductive success.
Growth Score: a single metric to define growth in 96-well phenotype assays
Authors: Cuevas Daniel A. , Edwards Robert A.
Published: April 2018

High-throughput phenotype assays are a cornerstone of systems biology as they allow direct measurements of mutations, genes, strains, or even different genera. High-throughput methods also require data analytic methods that reduce complex time-series data to a single numeric evaluation. Here, we present the Growth Score, an improvement on the previous Growth Level formula. There is strong correlation between Growth Score and Growth Level, but the new Growth Score contains only essential growth curve properties while the formula of the previous Growth Level was convoluted and not easily interpretable. Several programs can be used to estimate the parameters required to calculate the Growth Score metric, including ourPMAnalyzerpipeline.
Herencia e innovación en el Diccionario militar portátil (1822) de Fernández Mancheño
Authors:   Universidad de Murcia (España), Sánchez Orense Marta
Published: April 2018

En el presente trabajo nos proponemos rastrear la huella del Diccionario militar (1749) de Raimundo Sanz, el primer representante en lengua española de esta variedad lexicográfica especial, en el Diccionario militar portátil (1822) de José Fernández Mancheño, compuesto en la centuria siguiente, con el fin de calibrar cuánta de su terminología responde más bien a herencias que a la innovación propia. Constituirá igualmente nuestro objetivo verificar las influencias mutuas de tipo semántico, además de las concernientes a la marcación empleada para la restricción del uso de los términos. Gracias a nuestro análisis contrastivo, se obtienen varias conclusiones, entre las que destacan, primero, que la innovación en el caso de Fernández Mancheño respecto a su inmediato predecesor consiste, curiosamente, en recurrir a la terminología bélica de épocas pasadas y, segundo, que son la marcación y las definiciones los elementos microestructurales en los que más se aprecia el avance realizado por Fernández Mancheño respecto a Sanz.
Rechazar una invitación y negarse a una petición: procedimientos de atenuación discursiva empleados en las respuestas escritas de alumnas de español como lengua extranjera en Estados Unidos
Authors:   Universidad de Almería (España), Rodríguez Muñoz Francisco J. , Níkleva Dimitrinka G. ,   Universidad de Granada (España)
Published: April 2018

Este artículo se propone analizar los procedimientos de atenuación discursiva que utilizan 52 alumnas de español como lengua extranjera de Estados Unidos. A partir de un cuestionario, se recogieron las respuestas en relación con dos funciones comunicativas presentes en el Plan curricular del Instituto Cervantes. En la primera, las participantes tenían que declinar la invitación de un amigo, en tanto que en la segunda, debían responder a la petición de un desconocido negándose a su cumplimiento. Aunque, inicialmente, se suponía que una mayor distancia social implicaría un mayor número de recursos de atenuación en el plano enunciativo, los resultados sugieren que existen otros factores que impiden la confirmación de dicha hipótesis. Con todo, se presentan diferencias en la cantidad y el tipo de mecanismos atenuadores vinculados a ambas funciones en dos niveles intermedios de dominio de español (uno entre A2 y B1, y otro entre B1 y B2).
Elegant Surface of CoNi Alloys toward Efficient Magnetorheological Performances Realized with Carbon Quantum Dots
Authors: Zhang Wen Ling , Qu Fengcheng , Tian Yu , Choi Hyoung Jin , Deng Li , Liu Jingquan , Tian Jinmi , Liu Hao
Published: April 2018

Designing and fabricating a rational surface architecture is one of the critical factors to achieve desirable physical and chemical properties and still remains an immense challenge. Herein, a series of CoNi‐based hierarchical microspheres with different surface morphologies, including litchi‐like, seed‐of‐plane‐tree‐like, and waxberry‐like shapes, are obtained via surface nucleation of carbon quantum dots (CQDs) with different concentrations in liquid polyol. Microstructure investigations suggest that all the CoNi microspheres are uniformly with enhanced surface roughness with the increasing concentration of CQDs. This study provides insight into the surface dominant magnetorheological (MR) behaviors of these CoNi‐based suspensions. Taking both the synergistic benefits of paramagnetic CoNi microspheres and surface architecture, the resulting CoNi microspheres exhibit enhanced interparticle friction for enhancing their MR effects compared with smooth surface microspheres, opening up the possible mechanism for revealing the MR effect. Moreover, this facile strategy can be extended as an effective path to achieve high‐performance MR behaviors for engineering applications.
Visible‐Light‐Driven Conversion of Alcohols into Iodide Derivatives with Iodoform
Authors: Zhao Yubao , Antonietti Markus
Published: April 2018

A cost‐effective, straightforward, and environmentally benign alcohol iodination procedure with broad substrate scope is reported herein. In this reaction system, visible light and iodoform are employed as the energy source and iodination reagent, respectively. The reaction begins with the homolytic fission of the C–I bond in iodoform induced by visible‐light irradiation, producing active radicals. The following steps involve radical trapping by DMF (dimethylformamide), nucleophilic substitution, Vilsmeier‐type reagent formation, and the final iodination of the alcohol. The excellent performance of the model reaction in the flow photoreactor demonstrates the potential of this system for practical application.
Trophic specialization and morphological divergence between two sympatric species in Lake Catemaco, Mexico
Authors: Ornelas‐García Claudia Patricia , Córdova‐Tapia Fernando , Zambrano Luis , Bermúdez‐González María Pamela , Mercado‐Silva Norman , Mendoza‐Garfias Berenit , Bautista Amando
Published: April 2018

The association of morphological divergence with ecological segregation among closely related species could be considered as a signal of divergent selection in ecological speciation processes. Environmental signals such as diet can trigger phenotypic evolution, making polymorphic species valuable systems for studying the evolution of trophic‐related traits. The main goal of this study was to analyze the association between morphological differences in trophic‐related traits and ecological divergence in two sympatric species, Astyanax aeneus and A. caballeroi, inhabiting Lake Catemaco, Mexico. The trophic differences of a total of 70 individuals (35 A. aeneus and 35 A. caballeroi) were examined using stable isotopes and gut content analysis; a subset of the sample was used to characterize six trophic and six ecomorphological variables. In our results, we recovered significant differences between both species in the values of stable isotopes, with higher values of δ15N for A. caballeroi than for A. aeneus. Gut content results were consistent with the stable isotope data, with a higher proportion of invertebrates in A. caballeroi (a consumption of invertebrates ten times higher than that of A. aeneus, which in turn consumed three times more vegetal material than A. caballeroi). Finally, we found significant relationship between ecomorphology and stable isotopes (r = .24, p < .01), hence, head length, preorbital length, eye diameter, and δ15N were all positively correlated; these characteristics correspond to A. caballeroi. While longer gut and gill rakers, deeper bodies, and vegetal material consumption were positively correlated and corresponded to A. aeneus. Our results are consistent with the hypothesis that morphological divergence in trophic‐related traits could be associated with niche partitioning, allowing the coexistence of closely related species and reducing interspecific competition.
Knowledge, attitude, and beliefs on epilepsy among adults in Erute South, Lira District, Uganda
Authors: Kiwanuka Frank , Anyango Olyet Carolyne
Published: April 2018

Objective

To assess the knowledge, attitudes, and beliefs of adults on epilepsy in Erute South County, Lira District, Uganda.

Methods

A cross‐sectional study was conducted in rural Erute South County. Two hundred seventeen of 220 randomly selected adults 18 years or older participated in the study. A standardized self‐administered questionnaire (Attitudes towards persons with Epilepsy “ATPE”) was used for data collection. Protocol approval was sought from International Health Sciences University, and informed consent was obtained from participants at all times.

Results

Two hundred seventeen of 220 invited community members completed the study. Females comprised the majority 51.6%.. Most of the respondents had a low level of knowledge on epilepsy. The mean ATPE scale knowledge score was 4.57 (standard deviation [SD] = 3.24) of a maximum score of 11. The male respondents almost had mean knowledge scores almost equal to their female counterparts (4.23, SD = 2.48; 4.51, SD = 2.54, respectively). Most respondents had negative attitudes toward epilepsy, with a mean ATPE attitude score of 73.2 (SD = 2.11) of a possible maximum score of 126. The mean attitude scores for the male and female respondents were 58.18 (SD = 4.23) and 86.62 (SD = 5.23), respectively. Most respondents had negative beliefs such as attributing epilepsy to supernatural spirits, heredity, and preference of traditional medicine and healers to conventional medicine as a treatment for epilepsy. A significant number of respondents expressed sympathetic feelings toward people living with epilepsy, specifically tolerance and kindness to those living with epilepsy.

Significance

Findings could benefit policymakers, the district health team, researchers, community members, affected families, and people with epilepsy in designing awareness strategies. Knowledge on epilepsy could improve the quality of life and care for people living with epilepsy, through reducing misconceptions and stigmatization in the communities where they live.
Assessment of Advanced Liver Fibrosis and the Risk for Hepatic Decompensation in Patients With Congestive Hepatopathy
Authors: Lemmer Alexander , VanWagner Lisa B. , Ganger Daniel
Published: April 2018

Congestive hepatopathy (CH) arises from chronically elevated right‐sided heart pressures transmitted to the liver by passive venous congestion. Over time, CH can lead to hepatic bridging fibrosis, decompensated cirrhosis, and hepatocellular carcinoma. Currently, there are no evidence‐based guidelines to direct appropriate screening or management of patients with CH, partly because of the inability of current clinical tools (serum tests, imaging studies, liver stiffness measurements, and liver biopsy) to accurately estimate hepatic fibrosis or the risk for hepatic decompensation. The Model for End‐Stage Liver Disease excluding international normalized ratio (MELD‐XI) score is the only validated serum‐based test to predict clinical outcomes in CH. Noninvasive liver stiffness measurements are proving to be of minimal utility as all patients with CH have elevated values that currently cannot differentiate between congestion and fibrosis. In addition, fibrosis staging by liver biopsy is difficult to standardize because of heterogeneous collagen deposition in CH. Moreover, liver biopsy results have little predictive value for post–heart transplant hepatic outcomes in patients with CH. Evaluating liver nodules and masses is also complicated in CH as the finding of delayed venous washout in nodules is not specific for hepatocellular carcinoma in the background of a congested liver, and these lesions may require biopsy to confirm the diagnosis. The lack of effective clinical tools for predicting liver fibrosis and liver function suggests the need for the development of novel biomarkers in patients with CH to assist in the management of this complicated disease. (Hepatology 2018; 00:000‐000).
Recent Development in Recognition of and Assistance to Foreign Insolvency Representatives Under the Hong Kong Common Law
Authors: Li Xiaolin , Tu Guangjian
Published: April 2018

Although Hong Kong has neither enacted nor launched any plan to enact a statute addressing cooperation and assistance on cross‐border insolvency matters, recently, a unique Hong Kong approach dealing with recognition and assistance in cross‐border insolvency is gradually forming under common law. Thanks to the efforts made by the Companies Court of the Hong Kong High Court, insolvency representatives appointed in the place of incorporation of the debtors may, firstly, be accorded a certain degree of automatic recognition and cooperation based on traditional private international law rules without going through a recognition procedure and, secondly, be recognized and granted active assistance under principle of universalism at common law. With regard to the limits of this common law power, the court has referred to but not strictly followed the British Privy Council's decision in Singularis Holdings Limited v. PricewaterhouseCoopers (Singularis) and instead followed the previous approach in Cambridge Gas Transport Corp v. Official Committee of Unsecured Creditors (of Navigator Holdings PLC and others) (Cambridge Gas). The Companies Court also attempted to simplify and facilitate the application and grant of this common law recognition and assistance through a series of innovations. Copyright © 2018 INSOL International and John Wiley & Sons, Ltd.
Asking ‘Why’ in AI: Explainability of intelligent systems – perspectives and challenges
Authors: Preece Alun
Published: April 2018

Recent rapid progress in machine learning (ML), particularly so‐called ‘deep learning’, has led to a resurgence in interest in explainability of artificial intelligence (AI) systems, reviving an area of research dating back to the 1970s. The aim of this article is to view current issues concerning ML‐based AI systems from the perspective of classical AI, showing that the fundamental problems are far from new, and arguing that elements of that earlier work offer routes to making progress towards explainable AI today.
Werner transition‐metal complex (WTMC)‐mediated mild and efficient chemo‐selective acylation of phenols and anilines under solvent‐free condition
Authors: Sarief Abdulla , Haque SK Manirul , Feroze Syed Mudabbir , Arifuddin Mohammed
Published: April 2018

Werner‐type transition‐metal complexes (WTMC) such as [Co(NH3)5Cl]Cl2, Cu[(NH3)4]SO4, Mn(acac)3, Ni[(NH3)6]Cl2, Ni[(en)3]S2O3, and Hg[Co(SCN)4] efficiently promote the chemoselective acetylation of phenols and anilines under solvent‐free condition. The results of this study clearly shows that the optimal condition for the acetylation of anilines/phenols (1 mmol) (2a–r) with acetic anhydride (1.2 mmol) in the presence of WTMC (1 mmol) and two drops of H3PO4 on heating for 10 min under solvent‐free condition gives the corresponding acetanilides/phenyl acetate (3a–r) in good to excellent yield. Furthermore, the method is simple, efficient, chemoselective, and eco‐friendly under solvent‐free condition for the acetylation of anilines and phenols promoted by WTMC by using acetic anhydrate as the acetylating agent. The simple preparation of the catalyst, easy procedure of the acetylation reaction, and simple work‐up indicate the importance of WTMC for such reactions.
Stoichiometry of carbon, nitrogen, and phosphorus through the freshwater pipe
Authors: Maranger Roxane , Jones Stuart E. , Cotner James B.
Published: April 2018

The “freshwater pipe” concept has improved our understanding of freshwater carbon (C) cycling, however, it has rarely been applied to macronutrients such as nitrogen (N) or phosphorus (P). Here, we synthesize knowledge of the processing of C, N, and P together in freshwaters from land to the ocean. We compared flux estimates into and out of the N and P “pipes” and showed the net removal rates of N and P by inland waters were less than those for C. The C : N : P stoichiometry of inland water inputs vs. exports differed due to large respiratory C and N losses, and efficient P burial in inland waters. Residence time plays a critical role in the processing of these elements through the pipe, where higher water residence times from streams to lakes results in substantial increases in C : N, C : P, and N : P ratios.
Neuromuscular ultrasound of the brachial plexus: A standardized approach
Authors: Baute Vanessa , Strakowski Jeffrey A. , Reynolds Jon W. , Karvelas Kristopher R. , Ehlers Paul , Brenzy Kevin J. , Li Zhongyu J. , Cartwright Michael S.
Published: April 2018

Reliable assessment of brachial plexus disorders can be challenging due to the complexity of the anatomy and variation of potential pathology. Electrodiagnostic testing can be both uncomfortable for the patient and inconclusive. Ultrasound can serve as a complement to clinical assessment, electrodiagnostic testing, and other imaging modalities. This study describes a systematic approach for performing neuromuscular ultrasound for suspected pathology in the brachial plexus. The literature regarding techniques for brachial plexus ultrasound was reviewed. A team composed of specialists in neurology, physiatry, anesthesiology, orthopedic surgery, and vascular surgery used this as the basis for describing standardized techniques for performing brachial plexus ultrasound. Four standard views, along with other supplemental views, are described for the evaluation of the brachial plexus. An illustrative case is presented. Ultrasound is a high‐resolution point of care diagnostic tool that allows assessment of structural pathology affecting the brachial plexus. Muscle Nerve 58: 618–624, 2018
Large‐eddy simulation of a warm‐air advection episode in the summer Arctic
Authors: Sotiropoulou Georgia , Tjernström Michael , Savre Julien , Ekman Annica M. L. , Hartung Kerstin , Sedlar Joseph
Published: April 2018

While there is an increasing scientific interest in the role of advection of warm and moist air into the Arctic, there is little understanding of the interactive processes between the advected air, boundary‐layer clouds and turbulence during such events and almost all studies refer to winter conditions. We use large‐eddy simulation (LES) to investigate these processes for an extreme warm‐air advection episode observed during summer 2014. The results indicate that moisture advection is the critical factor for cloud formation; shutting off this supply resulted in cloud dissipation, regardless of heat advection being present or not. The dissipation of the cloud reduced the surface energy budget by up to 37 W/m2. Advection of heat suppresses cloud‐driven mixing through enhancement of the atmospheric stability. Turning off the large‐scale heat transport therefore resulted in a somewhat optically thicker cloud, on average increasing the liquid water path by ∼10 g/m2. The results showed little sensitivity to a number of assumptions and simplifications in the LES set‐up, such as the prescribed cloud condensation nuclei concentration, friction velocity, surface albedo and the available moisture above the cloud layer.
Near-horizon extremal geometries: coadjoint orbits and quantization
Authors: Javadinezhad R. , Oblak B. , Sheikh-Jabbari M. M.
Published: April 2018

Abstract

The NHEG algebra is an extension of Virasoro introduced in [arXiv:1503.07861]; it describes the symplectic symmetries of (n + 4)-dimensional Near Horizon Extremal Geometries with SL(2, ℝ) × U(1)
n+ 1 isometry. In this work we construct the NHEG group and classify the (coadjoint) orbits of its action on phase space. As we show, the group consists of maps from an n-torus to the Virasoro group, so its orbits are bundles of standard Virasoro coadjoint orbits over T

n
. We also describe the unitary representations that are expected to follow from the quantization of these orbits, and display their characters. Along the way we show that the NHEG algebra can be built from u(1) currents using a twisted Sugawara construction.
Gauge contribution to the 1/NF expansion of the Yukawa coupling beta function
Authors: Kowalska Kamila , Sessolo Enrico Maria
Published: April 2018

Abstract

We provide a closed analytical form for the gauge contribution to the beta function of a generic Yukawa coupling in the limit of large N

F
, where N

F
is the number of heavy vector-like fermions charged under an abelian or non-abelian gauge group. The resummed expression is finite and for the abelian case presents a pole at the same location as for the corresponding gauge beta function. When applied to new physics scenarios characterized by large Yukawa couplings, the contribution calculated here can cure their pathological UV behavior and make the couplings asymptotically free.
From spinning primaries to permutation orbifolds
Authors: de Mello Koch Robert , Rabambi Phumudzo , Van Zyl Hendrik J. R.
Published: April 2018

Abstract

We carry out a systematic study of primary operators in the conformal field theory of a free Weyl fermion. Using SO(4, 2) characters we develop counting formulas for primaries constructed using a fixed number of fermion fields. By specializing to particular classes of primaries, we derive very explicit formulas giving the generating functions for the number of primaries in these classes. We present a duality map between primary operators in the fermion field theory and polynomial functions. This allows us to construct the primaries that were counted. Next we show that these classes of primary fields correspond to polynomial functions on certain permutation orbifolds. These orbifolds have palindromic Hilbert series.
Particle acceleration in explosive relativistic reconnection events and Crab Nebula gamma-ray flares
Authors: Lyutikov Maxim , Komissarov Serguei , Sironi Lorenzo , Porth Oliver
Published: April 2018

We develop a model of gamma-ray flares of the Crab Nebula resulting from the magnetic reconnection events in a highly magnetised relativistic plasma. We first discuss physical parameters of the Crab Nebula and review the theory of pulsar winds and termination shocks. We also review the principle points of particle acceleration in explosive reconnection events [Lyutikov et al., J. Plasma Phys., vol. 83(6), p. 635830601 (2017a); J. Plasma Phys., vol. 83(6), p. 635830602 (2017b)]. It is required that particles producing flares are accelerated in highly magnetised regions of the nebula. Flares originate from the poleward regions at the base of the Crab’s polar outflow, where both the magnetisation and the magnetic field strength are sufficiently high. The post-termination shock flow develops macroscopic (not related to the plasma properties on the skin-depth scale) kink-type instabilities. The resulting large-scale magnetic stresses drive explosive reconnection events on the light-crossing time of the reconnection region. Flares are produced at the initial stage of the current sheet development, during the X-point collapse. The model has all the ingredients needed for Crab flares: natural formation of highly magnetised regions, explosive dynamics on the light travel time, development of high electric fields on macroscopic scales and acceleration of particles to energies well exceeding the average magnetic energy per particle.
Size-based termination of higher-order rewriting
Authors: BLANQUI FRÉDÉRIC
Published: April 2018

We provide a general and modular criterion for the termination of simply typed λ-calculus extended with function symbols defined by user-defined rewrite rules. Following a work of Hughes, Pareto and Sabry for functions defined with a fixpoint operator and pattern matching, several criteria use typing rules for bounding the height of arguments in function calls. In this paper, we extend this approach to rewriting-based function definitions and more general user-defined notions of size.
Geochemical and Microstructural Signals in Giant ClamTridacna maximaRecorded Typhoon Events at Okinotori Island, Japan
Authors: Komagoe Taro , Watanabe Tsuyoshi , Shirai Kotaro , Yamazaki Atsuko , Uematu Mitsuo
Published: April 2018

To validate the usability of the giant clam shell as a recorder of short‐term environmental changes such as typhoons, we collected a liveTridacna maximafrom Okinotori Island, Japan, on 15 June 2006. Growth increment thickness, stable isotope ratio (δ18Oshell, δ13Cshell), and the barium/calcium ratio (Ba/Ca) in theT. maximashell sample were measured and compared to Okinotori Island instrumental environmental data. In the outer layer of the shell sample, there were 365 ± 6 growth increments per year, as estimated by the δ18Oshellprofile compared with sea surface temperature. The growth increments in the specimen were formed daily, and thus, we can determine the date of the sampling points of δ18Oshell, δ13Cshelland the Ba/Ca ratio by counting growth increments. After typhoon approach, there is a decrease in increment thickness and some disturbed growth increments. The positive peaks in the shell Ba/Ca ratio and δ18Oshellcorresponded to lower sea surface temperature caused by typhoons. These results indicated that the microstructural and geochemical record inTridacna maximashells could be useful for detecting past typhoon events.
Societal Impacts Collection Continues to Grow
Authors: Lunn Jenny , Wooden Paige
Published: April 2018

There have been further additions to the highly successful “Earth and Space Science is Essential for Society” collection of commentaries.
Honoring Earth and Space Scientists
Authors:   AGU
Published: April 2018

AGU members and others in the news.
Snapshots of March for Science Signs Across the Globe
Authors: Cartier Kimberly
Published: April 2018

From chemical puns and censorship to the spectrum of awesome and a touch of magic, signs at this year’s events showcased the science marchers’ creativity and passion…and a bit of humor.
Export of Strongly Diluted Greenland Meltwater From a Major Glacial Fjord
Authors: Beaird Nicholas L. , Straneo Fiammetta , Jenkins William
Published: April 2018

The Greenland Ice Sheet has been, and will continue, losing mass at an accelerating rate. The influence of this anomalous meltwater discharge on the regional and large‐scale ocean could be considerable but remains poorly understood. This uncertainty is in part a consequence of challenges in observing water mass transformation and meltwater spreading in coastal Greenland. Here we use tracer observations that enable unprecedented quantification of the export, mixing, and vertical distribution of meltwaters leaving one of Greenland's major glacial fjords. We find that the primarily subsurface meltwater input results in the upwelling of the deep fjord waters and an export of a meltwater/deepwater mixture that is 30 times larger than the initial meltwater release. Using these tracer data, the vertical structure of Greenland's summer meltwater export is defined for the first time showing that half the meltwater export occurs below 65 m.
A Mechanism of Land Degradation in Turf‐Mantled Slopes of the Tibetan Plateau
Authors: Okin Gregory S. , D'Odorico Paolo , Liu Jianquan
Published: April 2018

Kobresia pygmaea meadows are typical of Tibetan Plateau landscapes in the 3,000 to 5,500 m elevation range and constitute the most extensive alpine ecosystem in the world. Kobresia pygmaea forms turf mats that stabilize the surface and shelter the underlying soils from water erosion. Large tracts of the Plateau, however, exhibit signs of ongoing degradation of the turf and erosion of the underlying soil. Despite the crucial role played by K. pygmaea turf mats in the stabilization of the headwaters of major Asian rivers, the mechanisms responsible for their degradation remain poorly investigated. Here we develop a process‐based model of land degradation of Tibetan Plateau slopes, which accounts for (i) turf cracking, (ii) water flow concentration in the cracks, (iii) crack widening by scouring, and (iv) sheet‐flow erosion. As expected, soil erosion increases with the slope and drainage area (hence the observation of stronger erosion in relatively steep downhill sites). Model simulations indicate that with a sensible set of parameters representative of soil and hydrologic conditions in the region, Tibetan Plateau landscapes are vulnerable to turf mat degradation and soil erosion. As soon as polygonal cracks develop, water flow widens them until the landscape is completely barren. At this point sheet flow eventually erodes the mineral soil leaving behind a highly degraded landscape.
The Role of Tectonic Stress in Triggering Large Silicic Caldera Eruptions
Authors: Cabaniss Haley E. , Gregg Patricia M. , Grosfils Eric B.
Published: April 2018

We utilize 3‐D temperature‐dependent viscoelastic finite element models to investigate the mechanical response of the host rock supporting large caldera‐size magma reservoirs (volumes >102 km3) to local tectonic stresses. The mechanical stability of the host rock is used to determine the maximum predicted repose intervals and magma flux rates that systems may experience before successive eruption is triggered. Numerical results indicate that regional extension decreases the stability of the roof rock overlying a magma reservoir, thereby promoting early‐onset caldera collapse. Alternatively, moderate amounts of compression (≤10 mm/year) on relatively short timescales (<104 years) increases roof rock stability. In addition to quantifying the affect of tectonic stresses on reservoir stability, our models indicate that the process of rejuvenation and mechanical failure is likely to take place over short time periods of hundreds to thousands of years. These findings support the short preeruption melt accumulation timescales indicated by U series disequilibrium studies.
Monitoring the Vertical Distribution of Rainfall‐Induced Strain Changes in a Landslide Measured by Distributed Fiber Optic Sensing With Rayleigh Backscattering
Authors: Kogure Tetsuya , Okuda Yudai
Published: April 2018

Distributed fiber optic sensing with Rayleigh backscattering, which has been recognized as a novel technique for measuring differences in temperature or strain, was adopted in a borehole to a depth of 16 m in an actual landslide to detect a vertical profile of strain changes. Strain changes were measured every 6 hr from 19 June 2017 to 18 October 2017 with a spatial resolution of 10 cm and strain resolution of 1.87 με. The measurements provided a clear‐cut vertical profile of the strain changes caused by rainfalls that cannot be detected by conventional methods. The results show that there are two types of deformation in the landslide mass: (1) sliding at the boundary between tuff and mudstone and (2) creep in mudstone layers. Activation of deeper sections of the landslide by heavy rainfalls has also been detected.
Simple Physical Model for the Probability of a Subduction‐ Zone Earthquake Following Slow Slip Events and Earthquakes: Application to the Hikurangi Megathrust, New Zealand
Authors: Kaneko Yoshihiro , Wallace Laura M. , Hamling Ian J. , Gerstenberger Matthew C.
Published: April 2018

Slow slip events (SSEs) have been documented in subduction zones worldwide, yet their implications for future earthquake occurrence are not well understood. Here we develop a relatively simple, simulation‐based method for estimating the probability of megathrust earthquakes following tectonic events that induce any transient stress perturbations. This method has been applied to the locked Hikurangi megathrust (New Zealand) surrounded on all sides by the 2016 Kaikoura earthquake and SSEs. Our models indicate the annual probability of a M≥7.8 earthquake over 1 year after the Kaikoura earthquake increases by 1.3–18 times relative to the pre‐Kaikoura probability, and the absolute probability is in the range of 0.6–7%. We find that probabilities of a large earthquake are mainly controlled by the ratio of the total stressing rate induced by all nearby tectonic sources to the mean stress drop of earthquakes. Our method can be applied to evaluate the potential for triggering a megathrust earthquake following SSEs in other subduction zones.
Convection Enhances Mixing in the Southern Ocean
Authors: Sohail Taimoor , Gayen Bishakhdatta , Hogg Andrew McC.
Published: April 2018

Mixing efficiency is a measure of the energy lost to mixing compared to that lost to viscous dissipation. In a turbulent stratified fluid the mixing efficiency is often assumed constant at η = 0.2, whereas with convection it takes values closer to 1. The value of mixing efficiency when both stratified shear flow and buoyancy‐driven convection are active remains uncertain. We use a series of numerical simulations to determine the mixing efficiency in an idealized Southern Ocean model. The model is energetically closed and fully resolves convection and turbulence such that mixing efficiency can be diagnosed. Mixing efficiency decreases with increasing wind stress but is enhanced by turbulent convection and by large thermal gradients in regions with a strongly stratified thermocline. Using scaling theory and the model results, we predict an overall mixing efficiency for the Southern Ocean that is significantly greater than 0.2 while emphasizing that mixing efficiency is not constant.
Crevasse Splays Versus Avulsions: A Recipe for Land Building With Levee Breaches
Authors: Nienhuis Jaap H. , Törnqvist Torbjörn E. , Esposito Christopher R.
Published: April 2018

Natural‐levee breaches can not only initiate an avulsion but also, under the right circumstances, lead to crevasse splay formation and overbank sedimentation. The formative conditions for crevasse splays are not well understood, yet such river sediment diversions form an integral part of billion‐dollar coastal restoration projects. Here we use Delft3D to investigate the influence of vegetation and soil consolidation on the evolution of a natural‐levee breach. Model simulations show that crevasse splays heal because floodplain aggradation reduces the water surface slope, decreasing water discharge into the flood basin. Easily erodible and unvegetated floodplains increase the likelihood for channel avulsions. Denser vegetation and less potential for soil consolidation result in small crevasse splays that are not only efficient sediment traps but also short‐lived. Successful crevasse splays that generate the largest land area gain for the imported sediment require a delicate balance between water and sediment discharge, vegetation root strength, and soil consolidation.
Obesity exacerbates colitis-associated cancer via IL-6-regulated macrophage polarisation and CCL-20/CCR-6-mediated lymphocyte recruitment
Authors: Wunderlich Claudia M. , Ackermann P. Justus , Ostermann Anna Lena , Adams-Quack Petra , Vogt Merly C. , Tran My-Ly , Nikolajev Alexei , Waisman Ari , Garbers Christoph , Theurich Sebastian , Mauer Jan , Hövelmeyer Nadine , Wunderlich F. Thomas
Published: April 2018

Colorectal cancer (CRC) is one of the most lethal cancers worldwide in which the vast majority of cases exhibit little genetic risk but are associated with a sedentary lifestyle and obesity. Although the mechanisms underlying CRC and colitis-associated colorectal cancer (CAC) remain unclear, we hypothesised that obesity-induced inflammation predisposes to CAC development. Here, we show that diet-induced obesity accelerates chemically-induced CAC in mice via increased inflammation and immune cell recruitment. Obesity-induced interleukin-6 (IL-6) shifts macrophage polarisation towards tumour-promoting macrophages that produce the chemokine CC-chemokine-ligand-20 (CCL-20) in the CAC microenvironment. CCL-20 promotes CAC progression by recruiting CC-chemokine-receptor-6 (CCR-6)-expressing B cells and γδ T cells via chemotaxis. Compromised cell recruitment as well as inhibition of B and γδ T cells protects against CAC progression. Collectively, our data reveal a function for IL-6 in the CAC microenvironment via lymphocyte recruitment through the CCL-20/CCR-6 axis, thereby implicating a potential therapeutic intervention for human patients.
Exercise induces new cardiomyocyte generation in the adult mammalian heart
Authors: Vujic Ana , Lerchenmüller Carolin , Wu Ting-Di , Guillermier Christelle , Rabolli Charles P. , Gonzalez Emilia , Senyo Samuel E. , Liu Xiaojun , Guerquin-Kern Jean-Luc , Steinhauser Matthew L. , Lee Richard T. , Rosenzweig Anthony
Published: April 2018

Loss of cardiomyocytes is a major cause of heart failure, and while the adult heart has a limited capacity for cardiomyogenesis, little is known about what regulates this ability or whether it can be effectively harnessed. Here we show that 8 weeks of running exercise increase birth of new cardiomyocytes in adult mice (~4.6-fold). New cardiomyocytes are identified based on incorporation of 15N-thymidine by multi-isotope imaging mass spectrometry (MIMS) and on being mononucleate/diploid. Furthermore, we demonstrate that exercise after myocardial infarction induces a robust cardiomyogenic response in an extended border zone of the infarcted area. Inhibition of miR-222, a microRNA increased by exercise in both animal models and humans, completely blocks the cardiomyogenic exercise response. These findings demonstrate that cardiomyogenesis can be activated by exercise in the normal and injured adult mouse heart and suggest that stimulation of endogenous cardiomyocyte generation could contribute to the benefits of exercise.
Global profiling of protein–DNA and protein–nucleosome binding affinities using quantitative mass spectrometry
Authors: Makowski Matthew M. , Gräwe Cathrin , Foster Benjamin M. , Nguyen Nhuong V. , Bartke Till , Vermeulen Michiel
Published: April 2018

Interaction proteomics studies have provided fundamental insights into multimeric biomolecular assemblies and cell-scale molecular networks. Significant recent developments in mass spectrometry-based interaction proteomics have been fueled by rapid advances in label-free, isotopic, and isobaric quantitation workflows. Here, we report a quantitative protein–DNA and protein–nucleosome binding assay that uses affinity purifications from nuclear extracts coupled with isobaric chemical labeling and mass spectrometry to quantify apparent binding affinities proteome-wide. We use this assay with a variety of DNA and nucleosome baits to quantify apparent binding affinities of monomeric and multimeric transcription factors and chromatin remodeling complexes.
Blocking negative effects of senescence in human skin fibroblasts with a plant extract
Authors: Lämmermann Ingo , Terlecki-Zaniewicz Lucia , Weinmüllner Regina , Schosserer Markus , Dellago Hanna , de Matos Branco André Dargen , Autheried Dominik , Sevcnikar Benjamin , Kleissl Lisa , Berlin Irina , Morizot Frédérique , Lejeune Francois , Fuzzati Nicola , Forestier Sandra , Toribio Alix , Tromeur Anaïs , Weinberg Lionel , Higareda Almaraz Juan Carlos , Scheideler Marcel , Rietveld Marion , El Ghalbzouri Abdoel , Tschachler Erwin , Gruber Florian , Grillari Johannes
Published: April 2018

There is increasing evidence that senescent cells are a driving force behind many age-related pathologies and that their selective elimination increases the life- and healthspan of mice. Senescent cells negatively affect their surrounding tissue by losing their cell specific functionality and by secreting a pro-tumorigenic and pro-inflammatory mixture of growth hormones, chemokines, cytokines and proteases, termed the senescence-associated secretory phenotype (SASP). Here we identified an extract from the plant Solidago virgaurea subsp. alpestris, which exhibited weak senolytic activity, delayed the acquisition of a senescent phenotype and induced a papillary phenotype with improved functionality in human dermal fibroblasts. When administered to stress-induced premature senescent fibroblasts, this extract changed their global mRNA expression profile and particularly reduced the expression of various SASP components, thereby ameliorating the negative influence on nearby cells. Thus, the investigated plant extract represents a promising possibility to block age-related loss of tissue functionality.
In vitro synthesis of gene-length single-stranded DNA
Authors: Veneziano Rémi , Shepherd Tyson R. , Ratanalert Sakul , Bellou Leila , Tao Chaoqun , Bathe Mark
Published: April 2018

Single-stranded DNA (ssDNA) increases the likelihood of homology directed repair with reduced cellular toxicity. However, ssDNA synthesis strategies are limited by the maximum length attainable, ranging from a few hundred nucleotides for chemical synthesis to a few thousand nucleotides for enzymatic synthesis, as well as limited control over nucleotide composition. Here, we apply purely enzymatic synthesis to generate ssDNA greater than 15 kilobases (kb) using asymmetric PCR, and illustrate the incorporation of diverse modified nucleotides for therapeutic and theranostic applications.
Overactive autophagy is a pathological mechanism underlying premature suture ossification in nonsyndromic craniosynostosis
Authors: Qiu Shanshan , Wang Jing , Huang Siqi , Sun Shouqing , Zhang Zhen , Bao Nan
Published: April 2018

Nonsyndromic craniosynostosis (NSC) is the most common craniosynostosis with the primary defect being one or more fused sutures. In contrast to syndromic craniosynostosis, the etiopathogenesis of NSC is largely unknown. Here we show that autophagy, a major catabolic process required for the maintenance of bone homeostasis and bone growth, is a pathological change associated with NSC. Using calvarial suture mesenchymal cells (SMCs) isolated from the fused and unfused sutures of NSC patients, we demonstrate that during SMC differentiation, the level of the autophagosomal marker LC3-II increases as osteogenic differentiation progresses, particularly at differentiation day 7, a stage concurrent with mineralization. In fused SMCs, autophagic induction was more robust than that in unfused SMCs, which consequently led to enhanced mineralized nodule formation. Perturbation of autophagy with rapamycin or wortmannin promoted or inhibited the ossification of SMCs, respectively. Our findings suggest that autophagy is essential for the osteogenic differentiation of SMCs and that overactive autophagy is a molecular abnormality underlying premature calvarial ossification in NSC.
Store-operated Ca2+ entry is activated by every action potential in skeletal muscle
Authors: Koenig Xaver , Choi Rocky H , Launikonis Bradley S
Published: April 2018

Store-operated calcium (Ca2+) entry (SOCE) in skeletal muscle is rapidly activated across the tubular system during direct activation of Ca2+ release. The tubular system is the invagination of the plasma membrane that forms junctions with the sarcoplasmic reticulum (SR) where STIM1, Orai1 and ryanodine receptors are found. The physiological activation of SOCE in muscle is not defined, thus clouding its physiological role. Here we show that the magnitude of a phasic tubular system Ca2+ influx is dependent on SR Ca2+ depletion magnitude, and define this as SOCE. Consistent with SOCE, the influx was resistant to nifedipine and BayK8644, and silenced by inhibition of SR Ca2+ release during excitation. The SOCE transient was shaped by action potential frequency and SR Ca2+ pump activity. Our results show that SOCE in skeletal muscle acts as an immediate counter-flux to Ca2+ loss across the tubular system during excitation-contraction coupling.
Quantitative analysis of steel samples by laser-induced-breakdown spectroscopy with wavelet-packet-based relevance vector machines
Authors: Xie Shichen , Xu Tao , Niu Guanghui , Liao Wenlong , Lin Qinyu , Duan Yixiang
Published: April 2018

Laser-induced breakdown spectroscopy (LIBS) has been gradually adopted as a quantitative technique for metallurgy analysis in recent years.
Highly labeled methylene blue-ds DNA silica nanoparticles for signal enhancement of immunoassays: application to the sensitive detection of bacteria in human platelet concentrates
Authors: Bonnet Romaric , Farre Carole , Valera Lionel , Vossier Ludivine , Léon Fanny , Dagland Typhaine , Pouzet Agnès , Jaffrézic-Renault Nicole , Fareh Jeannette , Fournier-Wirth Chantal , Chaix Carole
Published: April 2018

A nanoparticle-based electrochemical immunoassay for bacteria detection in platelet concentrates.
Excitation-wavelength-dependent photoluminescence of silicon nanoparticles enabled by adjustment of surface ligands
Authors: Shen Xiao-Bin , Song Bin , Fang Bei , Jiang Ai-Rui , Ji Shun-Jun , He Yao
Published: April 2018

Rational introduction of surface ligands leads to the production of SiNPs with excitation-wavelength-dependent fluorescence.
Phosphorus anionic redox activity revealed by operando P K-edge X-ray absorption spectroscopy on diphosphonate-based conversion materials in Li-ion batteries
Authors: Schmidt Sebastian , Sallard Sébastien , Borca Camelia , Huthwelker Thomas , Novák Petr , Villevieille Claire
Published: April 2018

When cycling diphosphonate-based organic–inorganic hybrid materials as negative battery electrodes, specific charges exceeding the maximum for a metal redox reaction are recorded.
Absorbed hydrogen enhances the catalytic hydrogenation activity of Rh-based nanocatalysts
Authors: Morfin Franck , Blondeau Lucie , Provost Karine , Malouche Abdelmalek , Piccolo Laurent , Zlotea Claudia
Published: April 2018

A Rh hydride (RhHx) nanocatalyst shows enhanced catalytic hydrogenation activity as compared to its metal counterpart (Rh).