bluuebunny/crossref_metadata_2025 huggingface dataset:
Forest stand productivity derived from site conditions: an assessment of old Douglas-fir stands (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) in Central Europe
Authors: Eckhart Tamara , Pötzelsberger Elisabeth , Koeck Roland , Thom Dominik , Lair Georg J. , van Loo Marcela , Hasenauer Hubert
Published: February 2019

Key message

Douglas-fir growth correlates with the climate, the soil moisture regime, and the soil nutrient status, reflecting a broad physiological amplitude. Even though planting this non-native tree species is suggested as a viable strategy to improve adaptiveness of European forests to a more extreme climate and to assure future productivity, the expected temperature increase may induce a decline in forest stand productivity for Douglas-fir in already warm and dry regions.

Context

Tree species selection is one of the most important forest management decisions to enhance forest productivity and stand stability on a given site. Douglas-fir (Pseudotsuga menziesii(Mirb.) Franco var.menziesii), a non-native species from north-western America, is seen as an important additional species option for adapting Central European forests to a changing climate.

Aims

This study assesses Douglas-fir forest productivity derived from site conditions. We investigate climatic and physico-chemical soil characteristics and productivity of 28 mature Douglas-fir stands growing on siliceous, as well as carbonate bedrock material in southern Germany and north-eastern Austria.

Methods

The importance of climatic and physico-chemical soil characteristics was analyzed with the machine learning methodRandom Forests.

Results

The results show that Douglas-fir growth correlates with climate, soil moisture, and soil nutrient availability derived from ten climatic and physico-chemical soil parameters.

Conclusion

The broad pH optimum between 4.5 and 7.2 reflects the broad physiological amplitude of Douglas-fir, and no significant differences were detectable between carbonate and siliceous bedrock. We also conclude that climate change may induce a forest stand productivity decline, because lower productivity with the highest mean summer temperature across our study range was observed at the warmest sites in Eastern Austria.
Price limits under incomplete preference information based on almost stochastic dominance
Authors: Jahnke Hermann , Martini Jan Thomas , Wiens Tobias
Published: February 2019

We derive price limits as decision aids for identifying favorable and unfavorable contracts from the perspective of a selling firm in face of uncertain outcomes. The analysis is based on the concept of almost stochastic dominance to incorporate incomplete information about the decision-maker’s preferences. The main challenges to use this concept in practice are to define and limit the required preference
information and to demonstrate the performance of the resulting price limits. We propose price limits that are suitable for a wide range of applications, in particular services. While their information requirements vary, all price limits refer to the same type of aggregate information about marginal utilities and risk aversion. In the scenario with the lowest requirements, the preference information shrinks to a single number which is easy to approximate and to communicate. A comprehensive numerical study featuring fixed-price contracts shows that the incomplete preference information may lead to substantial improvements of the price limits over the situation of no preference information. We also discuss determinants and caveats
of these improvements. For instance, the improvements increase with decreases of the decision-maker’s risk sensitivity and may differ substantially in magnitude between the lower and the upper price limit.
Economic Impacts of Business Continuity on an Outbreak of Highly Pathogenic Avian Influenza in Minnesota Egg Laying Operations
Authors: Thompson Jada M. , Pendell Dustin L. , Boyer Tim , Patyk Kelly A. , Malladi Sasidhar , Weaver J. Todd
Published: February 2019

Animal disease outbreaks can cause disruptions in domestic and international markets. Business continuity aims to provide a proactive approach to alleviate some of these negative effects on consumers, producers, and agribusinesses. Using a partial equilibrium model of the U.S. egg industry, the economic impacts of business continuity during an epidemiological simulated disease event are modeled. Results show total welfare losses can be reduced by allowing permitted movement during an outbreak given a specified level of biosecurity. Understanding the potential market responses business continuity can have on the market may lead to reductions in the negative implications of a disease event.
Dynamics of thin liquid films on vertical cylindrical fibres
Authors: Ji H. , Falcon C. , Sadeghpour A. , Zeng Z. , Ju Y. S. , Bertozzi A. L.
Published: February 2019

Recent experiments on thin films flowing down a vertical fibre with varying nozzle diameters present a wealth of new dynamics that illustrate the need for more advanced theory. We present a detailed analysis using a full lubrication model that includes slip boundary conditions, nonlinear curvature terms and a film stabilization term. This study brings to focus the presence of a stable liquid layer playing an important role in the full dynamics. We propose a combination of these physical effects to explain the observed velocity and stability of travelling droplets in the experiments and their transition to isolated droplets. This is also supported by stability analysis of the travelling wave solution of the model.
A theory of magnetic-like fields for viscoelastic fluids
Authors: Vieu Thibault , Mutabazi Innocent
Published: February 2019

We formulate the Oldroyd-B model for viscoelastic fluids in terms of magnetic-like fields obeying a set of equations analogous to Maxwell’s equations. In the limit of infinite relaxation time for the polymer, the polymeric stress tensor can be identified with the Maxwell stress tensor of a magnetic field. Away from this asymptotic case, the stress tensor of the polymer cannot be decomposed in terms of a tensor product of a magnetic field any more and several theoretical issues arise. We show that the analogy between the Oldroyd-B model and Maxwell’s equations can still be rigorously extended provided that one defines three magnetic-like fields obeying Maxwell’s equations with magnetic currents and charges. This solves the theoretical caveats and leads to a better understanding of the viscoelastic instability. In particular, we evidence a gauge symmetry which unifies some previous works, and we investigate several gauge choices. As an illustration we apply our method to viscoelastic Taylor–Couette flow but this theory of ‘viscoelastic fields’ is general and may be useful in a large variety of viscoelastic flows. The present study may also be of interest from the electromagnetic point of view, as it provides real systems possessing magnetic-like charges (monopoles) and currents.
Drag reduction and instabilities of flows in longitudinally grooved annuli
Authors: Moradi H. V. , Floryan J. M.
Published: February 2019

The primary and secondary laminar flows in annuli with longitudinal grooves and driven by pressure gradients have been analysed. There exist geometric configurations reducing pressure losses in primary flows in spite of an increase of the wall wetted area. The parameter ranges when such flows exist have been determined using linear stability theory. Two types of secondary flows have been identified. The first type has the form of the classical travelling waves driven by shear and modified by the grooves. The axisymmetric waves dominate for sufficiently large radii of the annuli while different spiral waves dominate for small radii. The secondary flow topology is unique in the former case and has the form of axisymmetric rings propagating in the axial direction. Topologies in the latter case are not unique, as spiral waves with left and right twists can emerge under the same conditions, resulting in flow structures varying from spatial rings to rhombic forms. The most intense motion of this type occurs near the walls. The second type of secondary flow has the form of travelling waves driven by inertial effects with characteristics very distinct from the shear waves. Its critical Reynolds number increases proportionally to $S^{-2}$, where $S$ denotes the groove amplitude, while the amplification rates increase proportionally to $S^{2}$. These waves exist only if $S$ is above a well-defined minimum and their axisymmetric forms dominate, with the most intense motion occurring near the annulus mid-section. Geometries that give preference to the latter waves have been identified. It is shown that the drag-reducing topographies stabilize the classical travelling waves; these waves are driven by viscous shear, so reduction of this shear decreases their amplification. The same topographies destabilize the new waves; these waves are driven by an inviscid mechanism associated with the formation of circumferential inflection points, and an increase of the groove amplitude increases their amplification. The flow conditions when the presence of grooves can be ignored, i.e. the annuli can be treated as being hydraulically smooth, have been determined.
Travelling wave solutions on an axisymmetric ferrofluid jet
Authors: Doak A. , Vanden-Broeck J.-M.
Published: February 2019

We consider a potential flow model of axisymmetric waves travelling on a ferrofluid jet. The ferrofluid coats a copper wire, through which an electric current is run. The induced azimuthal magnetic field magnetises the ferrofluid, which in turn stabilises the well known Plateau–Rayleigh instability seen in axisymmetric capillary jets. This model is of interest because the stabilising mechanism allows for axisymmetric magnetohydrodynamical solitary waves. A numerical scheme capable of computing steady periodic, solitary and generalised solitary wave solutions is presented. It is found that the solution space for the model is very similar to that of the classical problem of two-dimensional gravity–capillary waves.
Lagrangian network analysis of turbulent mixing
Authors: Iacobello Giovanni , Scarsoglio Stefania , Kuerten J. G. M. , Ridolfi Luca
Published: February 2019

A temporal complex network-based approach is proposed as a novel formulation to investigate turbulent mixing from a Lagrangian viewpoint. By exploiting a spatial proximity criterion, the dynamics of a set of fluid particles is geometrized into a time-varying weighted network. Specifically, a numerically solved turbulent channel flow is employed as an exemplifying case. We show that the time-varying network is able to clearly describe the particle swarm dynamics, in a parametrically robust and computationally inexpensive way. The network formalism enables us to straightforwardly identify transient and long-term flow regimes, the interplay between turbulent mixing and mean flow advection and the occurrence of proximity events among particles. Thanks to their versatility and ability to highlight significant flow features, complex networks represent a suitable tool for Lagrangian investigations of turbulent mixing. The present application of complex networks offers a powerful resource for Lagrangian analysis of turbulent flows, thus providing a further step in building bridges between turbulence research and network science.
Two Punic inscriptions from Roman Tripolitania
Authors: Elmayer Abdulhafid F.
Published: February 2019

This article provides the edition and commentary of two Punic inscriptions of Roman imperial date from inland areas of Tripolitania. One is the first edition of a Punic funerary text written in Latin script from Bani Walid in the Werfalla district. The other is a discussion offering an alternative interpretation of two architectural blocks bearing a fragmentary dedication that were recovered from the vicinity of the mausoleum of Gasr Doga in the Tarhuna district. Both texts shed new light on aspects of the cultural dynamics of Libyco-Punic culture under Roman rule.
FACTORS OF CARMICHAEL NUMBERS AND AN EVEN WEAKER -TUPLES CONJECTURE
Authors: WRIGHT THOMAS
Published: February 2019

One of the open questions in the study of Carmichael numbers is whether, for a given$R\geq 3$, there exist infinitely many Carmichael numbers with exactly$R$prime factors. Chernick [‘On Fermat’s simple theorem’,Bull. Amer. Math. Soc.45(1935), 269–274] proved that Dickson’s$k$-tuple conjecture would imply a positive result for all such$R$. Wright [‘Factors of Carmichael numbers and a weak$k$-tuples conjecture’,J. Aust. Math. Soc.100(3) (2016), 421–429] showed that a weakened version of Dickson’s conjecture would imply that there are an infinitude of$R$for which there are infinitely many such Carmichael numbers. In this paper, we improve on our 2016 result by weakening the required conjecture even further.
First isolation of Leishmania infantum by blood culture in bovines from endemic area for canine visceral leishmaniasis
Authors: Paixão-Marques Mirian dos Santos , Alves-Martin Maria Fernanda , Guiraldi Lívia Maísa , dos Santos Wesley José , de Lemos Fábio Almeida , Sánchez Gabriela Pacheco , Richini-Pereira Virginia Bodelão , Lucheis Simone Baldini
Published: February 2019

Leishmaniasis is considered a parasitic disease that still causes serious consequences for mankind, because it presents a high mortality rate worldwide. Considered multi-hosts, the parasites of the genus Leishmania are able of infecting a wide variety of animal species. The dog was considered the main source of infection of visceral leishmaniasis (VL), in the urban area. However, the role of other animal species in the epidemiological cycle of the disease, such as cattle, remains unclear. Therefore, the aim of the present study was to evaluate the occurrence of Leishmania spp. in 100 bovines (Bos taurus) from an area endemic for canine VL, using blood culture and molecular analysis. By the sequencing analysis, one sample showed 100% similarity with Leishmania infantum. The results provide the first case of L. infantum isolation in one bovine from the periurban areas of Bauru, state of São Paulo, Brazil.
Restricted completion of sparse partial Latin squares
Authors: Andrén Lina J. , Casselgren Carl Johan , Markström Klas
Published: February 2019

Ann×npartial Latin squarePis calledα-dense if each row and column has at mostαnnon-empty cells and each symbol occurs at mostαntimes inP. Ann×narrayAwhere each cell contains a subset of {1,…,n} is a (βn,βn, βn)-array if each symbol occurs at mostβntimes in each row and column and each cell contains a set of size at mostβn. Combining the notions of completing partial Latin squares and avoiding arrays, we prove that there are constantsα,β> 0 such that, for every positive integern, ifPis anα-densen×npartial Latin square,Ais ann×n (βn, βn, βn)-array, and no cell ofPcontains a symbol that appears in the corresponding cell ofA, then there is a completion ofPthat avoidsA; that is, there is a Latin squareLthat agrees withPon every non-empty cell ofP, and, for eachi,jsatisfying 1 ≤i,j≤n, the symbol in position (i,j) inLdoes not appear in the corresponding cell ofA.
The frequency of asymptomatic urinary system abnormalities in children detected with cineurography imaging during angiocardiography
Authors: Oral Orcun , Toprak Muhammet Hamza Halil , Uysal Fahrettin , Bostan Ozlem Mehtap , Cil Ergun
Published: February 2019

Introduction

Diagnostic and interventional catheter angiography of the heart is frequently used in paediatric cardiology. It is also possible to detect urinary system anomalies with cineurography images that may be obtained during angiocardiography. In this study, the aim was to determine the frequency, distribution, and properties of urinary system anomalies accompanying heart diseases, and to find out the effectiveness of cineurographic images in detecting the urinary system anomalies.

Methods

The cineurographic images of 2022 children who had undergone angiocardiography between 1995 and 2015 were retrospectively examined.

Results

Urinary system anomalies were detected in 261 of the 2022 cases (12.9%). Of these 261 cases, 148 were males (56.7%), whereas 113 were females (43.3%). Among the heart diseases, the group most accompanied by urinary system anomalies was the non-cyanotic left-to-right shunted heart diseases, which was detected in 120 (39.1%) patients. Pelvicalyceal ectasia was the most common urinary system anomaly encountered and was detected in 89 patients (34.1%). Of the urinary system anomalies cases, 94 detected by cineurography were determined to be clinically severe. When the effectiveness of the cineurography was evaluated using the ultrasonography records of the patients, it was found to have 63.8% accuracy.

Conclusion

Many of the patients with CHDs concomitantly have urinary system anomalies. It is possible to determine asymptomatic urinary system anomalies using cineurographic imaging during angiocardiography. This may lead to earlier treatments and improved prognosis for the patients, thus making it possible to prevent potential future problems.
Association between left ventricular ejection fraction and Kawasaki disease shock syndrome
Authors: Qiu Huixian , Li Chen , He Yuee , Weng Fengfeng , Shi Hongying , Pan Lulu , Guo Yuping , Zhang Yuanhai , Wu Rongzhou , Chu Maoping
Published: February 2019

Objective

This study was performed to explore the clinical features of Kawasaki disease shock syndrome and analyse the association between the left ventricular ejection fraction and Kawasaki disease shock syndrome.

Methods

We retrospectively reviewed the medical records of all consecutive inpatients with Kawasaki disease at Wenzhou Medical University Second Affiliated Hospital and Yuying Children’s Hospital in Wenzhou, China from January 2009 to December 2016. We compared the clinical characteristics, laboratory data, and left ventricular ejection fraction between patients with and without Kawasaki disease shock syndrome and analysed the effect of the left ventricular ejection fraction on Kawasaki disease shock syndrome under different clinical conditions of Kawasaki disease.

Results

In total, 1147 patients were diagnosed with Kawasaki disease. Of these 1147 patients, 17 were diagnosed with Kawasaki disease shock syndrome; 68 patients admitted to the hospital at the same time, ±2 weeks, with Kawasaki disease but without Kawasaki disease shock syndrome served as the control group. Compared with the control group, the Kawasaki disease shock syndrome group had a significantly higher incidence of coronary artery lesions, cardiac troponin I concentration, N-terminal prohormone of brain natriuretic peptide concentration, neutrophil count and ratio, alanine aminotransferase concentration, aspartate aminotransferase concentration, and C-reactive protein concentration and a significantly lower platelet count, serum albumin concentration, and left ventricular ejection fraction. A low left ventricular ejection fraction was associated with Kawasaki disease shock syndrome under different conditions of Kawasaki disease.

Conclusion

Among patients with Kawasaki disease, cardiac injury is more likely in those with Kawasaki disease shock syndrome than without, and a low left ventricular ejection fraction may be associated with the development of Kawasaki disease shock syndrome.
Compact low-cost substrate integrated waveguide fed antenna for 122 GHz radar applications
Authors: Frank Martin , Lurz Fabian , Weigel Robert , Koelpin Alexander
Published: February 2019

This paper describes the design and characterization of a compact substrate integrated waveguide (SIW) fed antenna for the 122 GHz industrial, scientific, and medical band. The use of a single RO4350B substrate layer and the SIW feeding ensure a low-cost fabrication. Two versions of the antenna are presented differing in antenna gain and size. For measurement purpose, a transition from rectangular waveguide to SIW is introduced. Measurements of the radiation pattern have been performed and show good agreement with the numerical results for both antennas and an antenna gain up to 7.14 dBi.
May-Thurner syndrome – Are we aware enough?
Authors: Mako Katalin , Puskas Attila
Published: February 2019

Summary. Iliac vein compression syndrome (May-Thurner syndrome – MTS) is an anatomically variable clinical condition in which the left common iliac vein is compressed between the right common iliac artery and the underlying spine. This anatomic variant results in an increased incidence of left iliac or iliofemoral vein thrombosis. It predominantly affects young women in the second or third decades of life with preponderance during pregnancy or oral contraceptive use. Although MTS is rare, its true prevalence is underestimated but it can be a life-threatening condition due to development of pulmonary embolism (PE). In this case based review the authors present three cases of MTS. All patients had been previously confirmed with PE, but despite they were admitted to hospital, diagnosed and correctly treated for PE and investigated for thrombophilia, the iliac vein compression syndrome was not suspected or investigated. With this presentation the authors would like to emphasize that MTS is mostly underdiagnosed, and it needs to be ruled out in left iliofemoral vein thrombosis in young individuals.
Reactive Transport Modeling Applied to Ni Laterite Ore Deposits in New Caledonia: Role of Hydrodynamic Factors and Geological Structures in Ni Mineralization
Authors: Myagkiy Andrey , Golfier Fabrice , Truche Laurent , Cathelineau Michel
Published: February 2019

This study is devoted to understanding the impact of topography and hydrodynamics on the formation of high‐grade supergene nickel deposits. The investigation proposes a new conceptual mineralization model that describes the formation of various exceptionally Ni‐enriched hot spots observed in lateritic profiles. Numerical analysis of the effects of local hydrodynamics on deposits formation is performed by means of PHREEQC geochemical simulator and COMSOL Multiphysics software. These are coupled through an iCP Java interface that allows to code their level of interaction and facilitates the exchange of parameters. The model developed extends the currently existing geochemical formulation of nickeliferous laterite formation from peridotite carried out in 1‐D and is additionally capable of simulating mass solute transport and geochemical processes within complex fractured‐porous systems. The simulations improve our understanding of metal enrichment in saprolite and bedrock zones. It was shown that, although the initial development of nickel lateritic ores takes a few million years, they are prone to relatively quick leaching and subsequent redistribution of Ni when the topography changes in response to tectonic processes. The latter leads to the formation of rich nickel deposits at the bottom of the slope, mostly due to leaching of the saprolite material. In addition to the role of changes in topography, the critical impact of fractures and fracture networks on metal mobility and distribution was identified. The model developed provides significant insight into the distribution of mineral resources, in particular Ni deposits, and can be of great help for future mineral prospecting in industry.
Vertical Axis Rotation Across the Eastern Mono Basin and West‐Central Walker Lane Revealed by Paleomagnetic Data From the Jack Springs Tuff
Authors: Petronis M. S. , Zebrowski P. J. , Shields S. F. , Pluhar C. J. , Lindeman J. R.
Published: February 2019

The mid‐Miocene Jack Springs Tuff (JST) outcrops from the Bodie Hills of eastern California into the western Mina Deflection, Nevada. Distal outcrops of the JST occur northwest of Mono Lake, CA, on a minimally rotated structural block. This provides a reference location for our paleomagnetic study to estimate relative vertical‐axis rotation. A new 40Ar/39Ar age places the eruption of the JST at 12.114 ± 0.006 Ma. Anisotropy of magnetic susceptibility data, once corrected for local tilt and vertical axis rotation, yields a mean imbrication that trends 178°. The probable source of the JST is located in the Huntoon Valley/Queens Valley region. Eighteen paleomagnetic sites constrain mid‐Miocene to recent vertical axis rotation within the region. All sites are discordant to the reference location with variable amounts of clockwise vertical axis rotation ranging from 25° to 104°. We hypothesize that a previously unrecognized early phase of deformation occurred that predates the deformation in the central Mina Deflection. These new data support the hypothesis that transtensional faulting associated with North American and Pacific plate interaction transferred deformation across the Mono Basin region that was partially accommodated by vertical axis rotation. By late Miocene, deformation had stepped east developing the Silver Peak‐Lone Mountain detachment system followed by the structures that presently define the central Mina deflection. This study further demonstrates that deformation occurred east of the Sierra Nevada Mountains at the latitude of the Mono Basin in western‐most Nevada, a region previously thought to be undeformed in terms of clockwise vertical axis rotation.
Global Ensemble Forecast System (GEFS) Predictions of Days 1–15 U.S. Tornado and Hail Frequencies
Authors: Gensini Vittorio A. , Tippett Michael K.
Published: February 2019

U.S. severe convective storms have grown to represent a 10 billion dollar annual peril for the insurance industry, and their accurate prediction remains a challenging task. This study examines days 1–15 severe convective storm predictions from the Global Ensemble Forecast System (GEFS). GEFS forecasts are based on the Supercell Composite Parameter and verified against spatially smoothed tornado and hail reports over the periods 1 March to 31 May 2016–2017. Skill is analyzed for deterministic forecasts (ensemble mean Supercell Composite Parameter exceeding specified thresholds) and probabilistic forecasts (fraction of ensemble members exceeding specified thresholds). Deterministic forecasts of tornado and hail activities are statistically more skillful than a random no‐skill reference to days 9 and 12, respectively. Probabilistic forecasts are skillful relative to climatological no‐skill reference to day 9 for tornado and day 12 for hail activity. These results provide a useful baseline for further improvement of tornado and hail forecasts at these ranges.
Coupled North Atlantic Subdecadal Variability in CMIP5 Models
Authors: Martin Thomas , Reintges Annika , Latif Mojib
Published: February 2019

The interaction between the atmosphere, specifically the North Atlantic Oscillation, and the North Atlantic Ocean circulation on subdecadal time scale is analyzed in a subset of models participating in the Coupled Model Intercomparison Project phase 5. From preindustrial control runs of at least 500‐year length, we derive anomaly patterns in the atmospheric and ocean circulation and of air‐sea heat exchange. All models simulate a distinct dipolar oceanic overturning anomaly at the subdecadal time scale, with centers at 30°N and 55°N. The dipolar overturning anomaly goes along with marked anomalies in the North Atlantic sea surface temperature and gyre circulation. Lag‐regression analyses demonstrate, with relatively small ensemble spread, how the atmosphere and the ocean circulation interact. The dipolar anomalies in the overturning are forced by North Atlantic Oscillation‐related wind stress curl anomalies. Anomalous surface heat fluxes in concert with anomalous vertical motions drive a meridional dipolar heat content anomaly in the upper ocean, and it is this dipolar heat content anomaly which carries the coupled system from one phase of the subdecadal cycle to the other by reversing the tendencies in the overturning circulation. The coupled subdecadal variability derived from the Coupled Model Intercomparison Project phase 5 models is characterized by three elements: a wind‐driven part steering the dipolar overturning anomaly, surface heat flux anomalies that support a heat buildup in the subpolar gyre region, and the heat storage memory which is instrumental in the phase reversal of the North Atlantic Oscillation.
Subsurface Sediment Mobilization in the Southern Chryse Planitia on Mars
Authors: Brož P. , Hauber E. , van de Burgt I. , Špillar V. , Michael G.
Published: February 2019

The southern part of the smooth plain of Chryse Planitia on Mars hosts a large population of kilometer‐sized (from ~0.2 to ~20 km) landforms spread over a wide area. Based on the investigation of a small part of this area, Komatsu et al. (2016, https://doi.org/10.1016/j.icarus.2015.12.032) proposed that the edifices may be the result of the subsurface sediment mobilization. We mapped the full extent of these landforms within Chryse Planitia and performed a morphological and spatial analysis in an attempt to further test this hypothesis. We identified a total number of 1,318 of these objects, which we grouped into five different morphological classes. The edifices can be observed over an area of 700,000 km2 near the termini of the large outflow channels, Ares, Simud, and Tiu Valles, with a nonrandom spatial distribution. The features are clustered and anticorrelated to the ancient highlands, which form erosional remnants shaped by the outflow events. This suggests a genetic link between the distribution of the edifices and the presence of the sedimentary deposits on which they are superposed. Such distribution is consistent with the previous notion that subsurface sediment mobilization may be the mechanism for their formation and is less consistent with the alternative igneous volcanic hypothesis. We also propose a scenario in which the large morphologic variability can be explained by variations of the water content within the ascending mud and by variations in the effusion rates. The edifices may represent one of the most prominent fields of sedimentary volcanism detected on Mars.
Hourly Aerosol Assimilation of Himawari‐8 AOT Using the Four‐Dimensional Local Ensemble Transform Kalman Filter
Authors: Dai Tie , Cheng Yueming , Suzuki Kentaroh , Goto Daisuke , Kikuchi Maki , Schutgens Nick A. J. , Yoshida Mayumi , Zhang Peng , Husi Letu , Shi Guangyu , Nakajima Teruyuki
Published: February 2019

The next‐generation geostationary satellite Himawari‐8 has a much higher observation frequency of the aerosol field than polar‐orbiting satellites. Aerosol analyses with a geostationary satellite can advance our understanding of the rapid spatiotemporal evolution of aerosols, which is especially critical for studies of air pollution and its mechanisms. We present a one‐monthlong hourly aerosol analysis using an aerosol data assimilation based on the local ensemble Kalman filter (LETKF), Himawari‐8‐retrieved hourly aerosol optical thicknesses (AOTs), and a global model named Non‐hydrostatic Icosahedral Atmospheric Model coupled with an aerosol model named Spectral Radiation Transport Model for Aerosol Species (NICAM‐SPRINTARS). To assimilate asynchronous observations and avoid frequent switching between the assimilation and ensemble aerosol forecasts, the LETKF is also extended to the four‐dimensional LETKF (4D‐LETKF). The hourly aerosol analyses are evaluated with both the assimilated Himawari‐8 AOTs and independent Moderate Resolution Imaging Spectroradiometer (MODIS)‐ and AErosol RObotic NETwork (AERONET)‐retrieved AOTs. All evaluations show that the assimilations positively affect the model performances and produce simulated AOTs that are closer to the observations. The analyses correctly reduce the significantly positive biases and root‐mean‐square errors of the control experiment, especially over East China and Australia. Our results also show that hourly aerosol analyses with more frequent Himawari‐8 observations are superior to those using the polar satellite MODIS observations. The performances among the LETKF and 4D‐LETKF experiments are generally not so different, but the computational load of the 4D‐LETKF is much lighter than that of the LETKF.
Microbial residence time is a controlling parameter of the taxonomic composition and functional profile of microbial communities
Authors: Mansfeldt Cresten , Achermann Stefan , Men Yujie , Walser Jean-Claude , Villez Kris , Joss Adriano , Johnson David R , Fenner Kathrin
Published: February 2019

A remaining challenge within microbial ecology is to understand the determinants of richness and diversity observed in environmental microbial communities. In a range of systems, including activated sludge bioreactors, the microbial residence time (MRT) has been previously shown to shape the microbial community composition. However, the physiological and ecological mechanisms driving this influence have remained unclear. Here, this relationship is explored by analyzing an activated sludge system fed with municipal wastewater. Using a model designed in this study based on Monod-growth kinetics, longer MRTs were shown to increase the range of growth parameters that enable persistence, resulting in increased richness and diversity in the modeled community. In laboratory experiments, six sequencing batch reactors treating domestic wastewater were operated in parallel at MRTs between 1 and 15 days. The communities were characterized using both 16S ribosomal RNA and non-target messenger RNA sequencing (metatranscriptomic analysis), and model-predicted monotonic increases in richness were confirmed in both profiles. Accordingly, taxonomic Shannon diversity also increased with MRT. In contrast, the diversity in enzyme class annotations resulting from the metatranscriptomic analysis displayed a non-monotonic trend over the MRT gradient. Disproportionately high abundances of transcripts encoding for rarer enzymes occur at longer MRTs and lead to the disconnect between taxonomic and functional diversity profiles.
Convergent gain and loss of genomic islands drive lifestyle changes in plant-associated Pseudomonas
Authors: Melnyk Ryan A , Hossain Sarzana S , Haney Cara H
Published: February 2019

Host-associated bacteria can have both beneficial and detrimental effects on host health. While some of the molecular mechanisms that determine these outcomes are known, little is known about the evolutionary histories of pathogenic or mutualistic lifestyles. Using the model plant Arabidopsis, we found that closely related strains within the Pseudomonas fluorescens species complex promote plant growth and occasionally cause disease. To elucidate the genetic basis of the transition between commensalism and pathogenesis, we developed a computational pipeline and identified genomic islands that correlate with outcomes for plant health. One island containing genes for lipopeptide biosynthesis and quorum-sensing is required for pathogenesis. Conservation of the quorum-sensing machinery in this island allows pathogenic strains to eavesdrop on quorum signals in the environment and coordinate pathogenic behavior. We found that genomic loci associated with both pathogenic and commensal lifestyles were convergently gained and lost in multiple lineages through homologous recombination, possibly constituting an early step in the differentiation of pathogenic and commensal lifestyles. Collectively this work provides novel insights into the evolution of commensal and pathogenic lifestyles within a single clade of host-associated bacteria.
Author Correction: Increasing the bactofection capacity of a mammalian expression vector by removal of the f1 ori
Authors: Johnson Síle A. , Ormsby Michael J. , McIntosh Anne , Tait Stephen W. G. , Blyth Karen , Wall Daniel M.
Published: February 2019

This Article was originally published under Nature Research’s License to Publish, but has now been made available under a [CC BY 4.0] license. The PDF and HTML versions of the Article have been modified accordingly.
Mmu-miR-185 depletion promotes osteogenic differentiation and suppresses bone loss in osteoporosis through the Bgn-mediated BMP/Smad pathway
Authors: Cui Qi , Xing Jinhao , Yu Miao , Wang Yue , Xu Jian , Gu Yajuan , Nan Xu , Ma Wenping , Liu Hao , Zhao Hongshan
Published: February 2019

MicroRNAs (miRs) play an essential role in the regulation of bone formation and homeostasis. miR-185 has been reported to negatively regulate osteogenesis in vitro. However, whether it has an impact on in vivo bone homeostasis remains unknown. Here, we demonstrated that primary osteoblasts and mesenchymal stem cells derived from miR-185-knockout (KO) mice exhibited enhanced osteogenesis. Further, we constructed an ovariectomized mouse model to investigate the role of miR-185 during osteoporosis. Micro-computed tomography revealed an increased bone volume in KO compared to wild-type mice 6 weeks after surgery, indicating redundant bone formation after miR-185 depletion. Dual-luciferase reporter assays identified biglycan (Bgn), which promotes bone formation through the BMP/Smad pathway, as the direct target of miR-185. Taken together, these findings indicate that blocking miR-185 expression increases bone formation during osteoporosis, which may partly occur through the regulation of Bgn expression and BMP/Smad signaling.
The companion of cellulose synthase 1 confers salt tolerance through a Tau-like mechanism in plants
Authors: Kesten Christopher , Wallmann Arndt , Schneider René , McFarlane Heather E. , Diehl Anne , Khan Ghazanfar Abbas , van Rossum Barth-Jan , Lampugnani Edwin R. , Szymanski Witold G. , Cremer Nils , Schmieder Peter , Ford Kristina L. , Seiter Florian , Heazlewood Joshua L. , Sanchez-Rodriguez Clara , Oschkinat Hartmut , Persson Staffan
Published: February 2019

Microtubules are filamentous structures necessary for cell division, motility and morphology, with dynamics critically regulated by microtubule-associated proteins (MAPs). Here we outline the molecular mechanism by which the MAP, COMPANION OF CELLULOSE SYNTHASE1 (CC1), controls microtubule bundling and dynamics to sustain plant growth under salt stress. CC1 contains an intrinsically disordered N-terminus that links microtubules at evenly distributed points through four conserved hydrophobic regions. By NMR and live cell analyses we reveal that two neighboring residues in the first hydrophobic binding motif are crucial for the microtubule interaction. The microtubule-binding mechanism of CC1 is reminiscent to that of the prominent neuropathology-related protein Tau, indicating evolutionary convergence of MAP functions across animal and plant cells.
Active Control of the Spoof Plasmon Propagation in Time Varying and Non-reciprocal Metamaterial
Authors: Ourir A. , Fink M.
Published: February 2019

We present an efficient concept based on time varying and non reciprocal metamaterials to achieve an active control of the spoof plasmon (SP) propagation at sub-wavelength scale. An experimental demonstration of non-reciprocal guiding device based on split ring resonator is proposed as an application of this concept in the microwave regime. We show that this device is able to blue-shift the propagated SP waves and to achieve an active steering of these SPs at sub-wavelength scale by controlling the modulation frequency of the time varying metamaterial. This approach could be extended plainly to infrared and optical regimes by considering suitable technologies.
A variety of hydrogenotrophic enrichment cultures catalyse cathodic reactions
Authors: Saheb-Alam Soroush , Persson Frank , Wilén Britt-Marie , Hermansson Malte , Modin Oskar
Published: February 2019

Biocathodes where living microorganisms catalyse reduction of CO2 can potentially be used to produce valuable chemicals. Microorganisms harbouring hydrogenases may play a key role for biocathode performance since H2 generated on the electrode surface can act as an electron donor for CO2 reduction. In this study, the possibility of catalysing cathodic reactions by hydrogenotrophic methanogens, acetogens, sulfate-reducers, denitrifiers, and acetotrophic methanogens was investigated. The cultures were enriched from an activated sludge inoculum and performed the expected metabolic functions. All enrichments formed distinct microbial communities depending on their electron donor and electron acceptor. When the cultures were added to an electrochemical cell, linear sweep voltammograms showed a shift in current generation close to the hydrogen evolution potential (−1 V versus SHE) with higher cathodic current produced at a more positive potential. All enrichment cultures except the denitrifiers were also used to inoculate biocathodes of microbial electrolysis cells operated with H+ and bicarbonate as electron acceptors and this resulted in current densities between 0.1–1 A/m2. The microbial community composition of biocathodes inoculated with different enrichment cultures were as different from each other as they were different from their suspended culture inoculum. It was noteworthy that Methanobacterium sp. appeared on all the biocathodes suggesting that it is a key microorganism catalysing biocathode reactions.
The AAA+ protease ClpXP can easily degrade a 31 and a 52-knotted protein
Authors: Sivertsson Elin M. , Jackson Sophie E. , Itzhaki Laura S.
Published: February 2019

Knots in proteins are hypothesized to make them resistant to enzymatic degradation by ATP-dependent proteases and recent studies have shown that whereas ClpXP can easily degrade a protein with a shallow 31 knot, it cannot degrade 52-knotted proteins if degradation is initiated at the C-terminus. Here, we present detailed studies of the degradation of both 31- and 52-knotted proteins by ClpXP using numerous constructs where proteins are tagged for degradation at both N- and C-termini. Our results confirm and extend earlier work and show that ClpXP can easily degrade a deeply 31-knotted protein. In contrast to recently published work on the degradation of 52-knotted proteins, our results show that the ClpXP machinery can also easily degrade these proteins. However, the degradation depends critically on the location of the degradation tag and the local stability near the tag. Our results are consistent with mechanisms in which either the knot simply slips along the polypeptide chain and falls off the free terminus, or one in which the tightened knot enters the translocation pore of ClpXP. Results of experiments on knotted protein fusions with a highly stable domain show partial degradation and the formation of degradation intermediates.
NMR structures and mutational analysis of the two peptides constituting the bacteriocin plantaricin S
Authors: Ekblad Bie , Kristiansen Per Eugen
Published: February 2019

The structure of the individual peptides of the two-peptide bacteriocin plantaricin S, an antimicrobial peptide produced by a Lactobacillus plantarum strain, has been determined in DPC micelles. The two peptides of plantaricin S, Pls-α and Pls-β, form an α-helix from and including residue 8 to 24 with a less structured region around residue 16-19 and an amphiphilic α-helix from and including residue 7 to 23, respectively. Activity assays on single amino acid-substituted GxxxG and GxxxG-like motifs show that substituting the Ser and Gly residues in the G9xxxG13 motif in Pls-α and the S17xxxG21 motif in Pls-β reduced or drastically reduced the antimicrobial activity. The two-peptide bacteriocin muricidin contains GxxxG-like motifs at similar positions and displays 40-50% amino acid identity with plantaricin S. Activity assays of combinations of the peptides that constitute the bacteriocins plantaricin S and muricidin show that some combinations are highly active. Furthermore, sequence alignments show that the motifs important for plantaricin S activity align with identical motifs in muricidin. Based on sequence comparison and activity assays, a membrane-inserted model of plantaricin S in which the two peptides are oriented antiparallel relative to each other and where the GxxxG and GxxxG-like motifs important for activity come close in space, is proposed.
Emergence of supercontraction in regenerated silkworm (Bombyx mori) silk fibers
Authors: Pérez-Rigueiro José , Madurga Rodrigo , Gañán-Calvo Alfonso M. , Elices Manuel , Guinea Gustavo V. , Tasei Yugo , Nishimura Akio , Matsuda Hironori , Asakura Tetsuo
Published: February 2019

The conditions required for the emergence of supercontraction in regenerated silkworm (Bombyx mori) silk fibers are assessed through an experimental approach that combines the spinning of regenerated fibers with controlled properties and their characterization by 13C solid-state nuclear magnetic resonance (NMR). Both supercontracting and non-supercontracting regenerated fibers are produced using the straining flow spinning (SFS) technique from 13C labeled cocoons. The short-range microstructure of the fibers is assessed through 13C CP/MAS in air and 13C DD/MAS in water, and the main microstructural features are identified and quantified. The mechanical properties of the regenerated fibers and their microstructures are compared with those of natural silkworm silk. The combined analysis highlights two possible key elements as responsible for the emergence of supercontraction: (1) the existence of an upper and a lower limit of the amorphous phase compatible with supercontraction, and (2) the existence of two ordered phases, β-sheet A and B, which correspond to different packing arrangements of the protein chains.
The Density of Cell Nuclei at the Materno-Fetal Exchange Barrier is Sexually Dimorphic in Normal Placentas, but not in IUGR
Authors: Barapatre Nirav , Haeussner Eva , Grynspan David , Schmitz Christoph , Edler von Koch Franz , Frank Hans-Georg
Published: February 2019

Placental sexual dimorphism is of special interest in prenatal programming. Various postnatal diseases with gender dependent incidence, especially neuropsychiatric disorders like schizophrenia and autism spectrum disorders, have prenatal risk factors established. However, the functional relevance of placental microarchitecture in prenatal programming is poorly investigated, mainly due to a lack of statistically efficient methods. We hypothesized that the recently established 3D microscopic analysis of villous trees would be able to identify microscopic structural correlates of human placental sexual dimorphism. We analyzed the density of cell nuclei of villous trophoblast, i.e. the materno-fetal exchange barrier, in placentas from term pregnancies. The cell nuclei were grouped into proliferative and non-proliferative nuclei by detection of a proliferation marker (PCNA). Normal female placentas showed a higher density of non-proliferating nuclei (PCNA-negative) in villous trophoblast than normal male placentas. The density of PCNA-negative cell nuclei was higher in placentas of pregnancies with intrauterine growth retardation (IUGR) than in control placentas. The data of the present study shows that the density of non-proliferative cell nuclei in the syncytial layer of villous trophoblast is influenced by fetal sex and by IUGR, while proliferation remains unchanged. A novel concept of post-fusion regulation of syncytial structure and function is proposed.