bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimating site-specific optimum air temperature and assessing its effect on the photosynthesis of grasslands in mid- to high-latitudes
Authors: Chang Qing , Xiao Xiangming , Wu Xiaocui , Doughty Russell , Jiao Wenzhe , Bajgain Rajen , Qin Yuanwei , Wang Jie
Published: January 2020

The effect of air temperature on photosynthesis is important for the terrestrial carbon cycle. The optimum air temperature for photosynthesis is one of the major parameters in data-driven and process-based photosynthesis models that estimate the gross primary production (GPP) of vegetation under a changing climate. To date, most models use the biome-specific optimum air temperature (

T

o
p
t
−
b

) parameter. To what degree will the site-specific optimum air temperature (

T

o
p
t
−
s

) affect GPP simulation results remains unclear. In this study, we estimated

T

o
p
t
−
s

by using GPP data from 11 grassland eddy flux tower sites (GPPEC) and satellite vegetation indices (NDVI and EVI). We found that T
opt-s parameter values estimated from EVI have good consistency with those from GPPEC at individual sites. We also evaluated the effects of site-specific and biome-specific optimum air temperature parameters on grassland photosynthesis. The results showed that the use of

T

o
p
t
−
s

in the Vegetation Photosynthesis Model improved to various degrees in both daily and annual GPP estimates in those grassland flux tower sites. Our results highlight the necessity and potential for the use of

T

o
p
t
−
s

in terrestrial GPP models, especially in those situations with large temperature variation (heatwave and cold spill events).
Sub-national variability of wind power generation in complex terrain and its correlation with large-scale meteorology
Authors: Pickering Bryn , Grams Christian M , Pfenninger Stefan
Published: January 2020

The future European electricity system will depend heavily on variable renewable generation, including wind power. To plan and operate reliable electricity supply systems, an understanding of wind power variability over a range of spatio-temporal scales is critical. In complex terrain, such as that found in mountainous Switzerland, wind speeds are influenced by a multitude of meteorological phenomena, many of which occur on scales too fine to capture with commonly used meteorological reanalysis datasets. Past work has shown that anticorrelation at a continental scale is an important way to help balance variable generation. Here, we investigate systematically for the first time the possibility of balancing wind variability by exploiting anticorrelation between weather patterns in complex terrain. We assess the capability for the Consortium for Small-scale Modeling (COSMO)-REA2 and COSMO-REA6 reanalyses (with a 2 and 6 km horizontal resolution, respectively) to reproduce historical measured data from weather stations, hub height anemometers, and wind turbine electricity generation across Switzerland. Both reanalyses are insufficient to reproduce site-specific wind speeds in Switzerland’s complex terrain. We find however that mountain-valley breezes, orographic channelling, and variability imposed by European-scale weather regimes are represented by COSMO-REA2. We discover multi-day periods of wind electricity generation in regions of Switzerland which are anticorrelated with neighbouring European countries. Our results suggest that significantly more work is needed to understand the impact of fine scale wind power variability on national and continental electricity systems, and that higher-resolution reanalyses are necessary to accurately understand the local variability of renewable generation in complex terrain.
Synthesis of WS2/CNT hybrid nanoparticles for fabrication of hybrid aluminum matrix nanocomposite
Authors: Vaziri Hossein Salehi , Shokuhfar Ali , Afghahi Seyyed Salman Seyyed
Published: January 2020

In this study, a simple, safe and cost-effective method was developed for fabricating the tungsten disulfide/carbon nanotube (WS2/CNT) hybrid nanoparticles via chemical vapor deposition (CVD) process. Hybrid nanoparticles used for reinforcing the aluminum matrix. The hybrid nanocomposites were prepared by powder metallurgy processing and consolidated by the Hot-Pressing process. The chemical composition and morphology of the WS2/CNT hybrid particles were studied by x-ray diffraction (XRD), filed emission scanning electron microscopy (FESEM), Raman spectra, Fourier-transform infrared spectroscopy (FTIR) and thermo gravimetric analysis (TGA). The results proved that the uniform, pure and tubular WS2/ CNT hybrid nanoparticles were produced and WS2 nanoparticles were decorated the CNT surface successfully. Optical microscopy (OM) and FESEM used for characterization of the microstructure of hybrid nanocomposite, indicate a good distribution of hybrid nanoparticles in the aluminum matrix. Maximum values of relative density, hardness and compressive strength were measured for sample with WS2/CNT ratio of 1:1. A relative density of more than 99.5% was obtained for this sample. Hardness and compressive strength were improved by 43% and 60% compared with pure aluminum respectively.
High performance Fe–N–C oxygen reduction electrocatalysts by solid-phase preparation of metal–organic frameworks
Authors: Hou Bingxue , Wang Cheng Cheng , Tang Rui , Zhang Qi , Cui Xumei
Published: January 2020

Iron-nitrogen-carbon (Fe–N–C) compounds have been regarded as efficient and non-precious metal electrocatalysts for oxygen reduction reaction (ORR). The environmentally friendly preparation of Fe–N–C electrocatalysts is desirable but still challenging. Here, several Fe–N–C catalysts incorporated by ZIF-8 has been simply prepared by solid state reaction method. Fe–N–C containing 2% mole percentage Fe electrocatalysts fired at 900 °C exhibited superior intrinsic activities in oxygen saturated-0.1 M KOH for ORR with half wave potential of 0.831 V (versus RHE), comparable with Pt/C from JM (0.838 V). It also exhibited higher stability than those of Pt–C in alkaline condition. The higher intrinsic ORR activity and remarkable stability can be due to the more dispersed Fe–Nx active sites, which indicate that Fe–N–C by 2% mole percentage Fe electrocatalyst is an excellent alternative electrocatalyst for energy applications.
Cu(II) and Gd(III) doped boehmite nanostructures: a comparative study of electrical property and thermal stability
Authors: Roy Shubham , Bardhan Souravi , Chanda Dipak Kr , Maity Anupam , Ghosh Saheli , Mondal Dhananjoy , Singh Subhankar , Das Sukhen
Published: January 2020

The present article reports the effect of transition (Cu2+) and rare earth metal (Gd3+) ion doping on structural, microstructural and electrical properties of boehmite nanoparticles. Rietveld refinement is adopted here to refine the x-ray diffractograms for further analyzing the microstructural details and their alteration due to the incorporation of foreign cations. This is probably the first time when dielectric properties of these doped boehmite samples having been reported herein. These samples show remarkably high dielectric constant values which corroborate that doping enhances the microstrain values inside the orthorhombic structure and results in higher crystallographic defects. Enhancement in defect sites causes the augmentation of relative permittivity and ac conductivity. Temperature stability has also been enhanced significantly in our Cu-doped sample. The present study enables us to determine a relationship between crystalline deformation and electrical properties of nanomaterials which may be highly beneficial in fabricating cost-effective energy harvesting devices.
High-temperature mechanical properties of cast Al–Si–Cu–Mg alloy by combined additions of cerium and zirconium
Authors: Bevilaqua William Lemos , Stadtlander Antonio Ricardo , Froehlich Andre Ronaldo , Lemos Guilherme Vieira Braga , Reguly Afonso
Published: January 2020

The main aim of this work is to investigate the effects of combinative Ce and Zr additions (0.3 wt% Ce + 0.16 wt% Zr; 0.3 wt% Ce + 0.27 wt% Zr and 0.3 wt% Ce + 0.36 wt% Zr) on the microstructure and mechanical properties in cast Al–Si–Cu–Mg alloy. The microstructures features were investigated by optical microscope, scanning electron microscope and hardness measurements. The microstructural analysis has shown that the increase of Ce and Zr contents increases the volume fraction of intermetallics formed during the solidification leading to grain refinement and changes in silicon morphology of the as-cast microstructure. The intermetallics formed do not dissolve during the solution heating treatment (T6). The mechanical behavior at room and high temperatures (175, 210, 245 and 275 °C) was determined from uniaxial tensile tests. The high thermal stability of Al–Si–Cu–La–Ce and Al–Si–Zr–Ti–Mg phases found in microstructure, in particular for the alloy containing 0.3 wt% Ce + 0.27 wt% Zr, is responsible for the increase to 6.7% and 5.1% the ultimate strength at 210 °C and 275 °C respectively, compared with the standard alloy.
Automatic phase space generation for Monte Carlo calculations of intensity modulated particle therapy
Authors: Wang Qianxia , Zhu Cong , Bai Xuemin , Deng Yu , Schlegel Nicki , Adair Antony , Chen Zhi , Li Yongqiang , Moyers Michael , Yepes Pablo
Published: January 2020

Monte Carlo (MC) is generally considered as the most accurate dose calculation tool for particle therapy. However, a proper description of the beam particle kinematics is a necessary input for a realistic simulation. Such a description can be stored in phase space (PS) files for different beam energies. A PS file contains kinetic information such as energies, positions and travelling directions for particles traversing a plane perpendicular to the beam direction. The accuracy of PS files plays a critical role in the performance of the MC method for dose calculations. A PS file can be generated with a set of parameters describing analytically the beam kinematics. However, determining such parameters can be tedious and time consuming. Thus, we have developed an algorithm to obtain those parameters automatically and efficiently. In this paper, we presented such an algorithm and compared dose calculations using PS automatically generated for the Shanghai Proton and Heavy Ion Center (SPHIC) with measurements. The gamma-index for comparing calculated depth dose distributions (DDD) with measurements are above 96.0% with criterion 0.6%/0.6 mm. For each single energy, the mean difference percentage between calculated lateral spot sizes at 5 different locations along beam direction and measurements are below 3.5%.
Generalized matrix spectral factorization and quasi-tight framelets with a minimum number of generators
Authors: Diao Chenzhe , Han Bin
Published: January 2020

As a generalization of orthonormal wavelets in

L
2

(

R

)

L_2({\mathbb {R}})

, tightframelets (also called tight wavelet frames) are of importance in wavelet analysis and applied sciences due to their many desirable properties in applications such as image processing and numerical algorithms. Tight framelets are often derived from particular refinable functions satisfying certain stringent conditions. Consequently, a large family of refinable functions cannot be used to construct tight framelets. This motivates us to introduce the notion of a quasi-tight framelet, which is a dual framelet but behaves almost like a tight framelet. It turns out that the study of quasi-tight framelets is intrinsically linked to the problem of the generalized matrix spectral factorization for matrices of Laurent polynomials. In this paper, we provide a systematic investigation on the generalized matrix spectral factorization problem and compactly supported quasi-tight framelets. As an application of our results on generalized matrix spectral factorization for matrices of Laurent polynomials, we prove in this paper that from any arbitrary compactly supported refinable function in

L
2

(

R

)

L_2({\mathbb {R}})

, we can always construct a compactly supported one-dimensional quasi-tight framelet having the minimum number of generators and the highest possible order of vanishing moments. Our proofs are constructive and supplemented by step-by-step algorithms. Several examples of quasi-tight framelets will be provided to illustrate the theoretical results and algorithms developed in this paper.
Harmonic symmetries for Hermitian manifolds
Authors: Wilson Scott
Published: January 2020

Complex manifolds with compatible metric have a naturally defined subspace of harmonic differential forms that satisfy Serre, Hodge, and conjugation duality, as well as hard Lefschetz duality. This last property follows from a representation of

s
l

(
2
,

C

)

\mathfrak {sl}(2,\mathbb {C})

, generalizing the well-known structure on the harmonic forms of compact Kähler manifolds. Some topological implications are deduced.
Multiparameter singular integrals on the Heisenberg group: uniform estimates
Authors: Vitturi Marco , Wright James
Published: January 2020

We consider a class of multiparameter singular Radon integral operators on the Heisenberg group

H

1

{\mathbb H}^1

where the underlying submanifold is the graph of a polynomial. A remarkable difference with the euclidean case, where Heisenberg convolution is replaced by euclidean convolution, is that the operators on the Heisenberg group are always

L
2

L^2

bounded. This is not the case in the euclidean setting where

L
2

L^2

boundedness depends on the polynomial defining the underlying surface. Here we uncover some new, interesting phenomena. For example, although the Heisenberg group operators are always

L
2

L^2

bounded, the bounds are not uniform in the coefficients of polynomials with fixed degree. When we ask for which polynomials uniform

L
2

L^2

bounds hold, we arrive at the same class where uniform bounds hold in the euclidean case.
On the congruence kernel of isotropic groups over rings
Authors: Stavrova A.
Published: January 2020

Let

R
R

be a connected noetherian commutative ring, and let

G
G

be a simply connected reductive group over

R
R

of isotropic rank

≥
2

\ge 2

. The elementary subgroup

E
(
R
)

E(R)

of

G
(
R
)

G(R)

is the subgroup generated by

U

P
+

(
R
)

U_{P^+}(R)

and

U

P
−

(
R
)

U_{P^-}(R)

, where

U

P
±

U_{P^\pm }

are the unipotent radicals of two opposite parabolic subgroups

P
±

P^\pm

of

G
G

. Assume that

2
∈

R
×

2\in R^\times

if

G
G

is of type

B
n

,

C
n

,

F
4

,

G
2

B_n,C_n,F_4,G_2

and

3
∈

R
×

3\in R^\times

if

G
G

is of type

G
2

G_2

. We prove that the congruence kernel of

E
(
R
)

E(R)

, defined as the kernel of the natural homomorphism

E
(
R
)

^

→

E
(
R
)

¯

\widehat {E(R)}\to \overline {E(R)}

between the profinite completion of

E
(
R
)

E(R)

and the congruence completion of

E
(
R
)

E(R)

with respect to congruence subgroups of finite index, is central in

E
(
R
)

^

\widehat {E(R)}

. In the course of the proof, we construct Steinberg groups associated to isotropic reducive groups and show that they are central extensions of

E
(
R
)

E(R)

if

R
R

is a local ring.
Smoothly embedding Seifert fibered spaces in 𝑆⁴
Authors: Issa Ahmad , McCoy Duncan
Published: January 2020

Using an obstruction based on Donaldson’s theorem, we derive strong restrictions on when a Seifert fibered space

Y
=
F
(
e
;

p
1

q
1

,
…
,

p
k

q
k

)

Y = F(e; \frac {p_1}{q_1}, \ldots , \frac {p_k}{q_k})

over an orientable base surface

F
F

can smoothly embed in

S
4

S^4

. This allows us to classify precisely when

Y
Y

smoothly embeds provided

e
>
k

/

2

e > k/2

, where

e
e

is the normalized central weight and

k
k

is the number of singular fibers. Based on these results and an analysis of the Neumann-Siebenmann invariant

μ
¯

\overline {\mu }

, we make some conjectures concerning Seifert fibered spaces which embed in

S
4

S^4

. Finally, we also provide some applications to doubly slice Montesinos links, including a classification of the smoothly doubly slice odd pretzel knots up to mutation.
The Cohen-Macaulay property in derived commutative algebra
Authors: Shaul Liran
Published: January 2020

By extending some basic results of Grothendieck and Foxby about local cohomology to commutative DG-rings, we prove new amplitude inequalities about finite DG-modules of finite injective dimension over commutative local DG-rings, complementing results of Jørgensen and resolving a recent conjecture of Minamoto. When these inequalities are equalities, we arrive at the notion of a local-Cohen-Macaulay DG-ring. We make a detailed study of this notion, showing that much of the classical theory of Cohen-Macaulay rings and modules can be generalized to the derived setting, and that there are many natural examples of local-Cohen-Macaulay DG-rings. In particular, local Gorenstein DG-rings are local-Cohen-Macaulay. Our work is in a non-positive cohomological situation, allowing the Cohen-Macaulay condition to be introduced to derived algebraic geometry, but we also discuss extensions of it to non-negative DG-rings, which could lead to the concept of Cohen-Macaulayness in topology.
Invited Commentary: Methods for Estimating Effects of Minimum Wages on Health
Authors: Leigh J Paul
Published: January 2020

Economists have been researching effects of minimum wages on unemployment, poverty, income inequality, and educational attainment for over 60 years. Epidemiologists have only recently begun researching minimum wages even though unemployment through education are central topics within social epidemiology. Buszkiewicz et al. (Am J Epidemiol. 2021;190(1):21–30) offer a welcome addition to this nascent literature. A commanding advantage of Buszkiewicz et al.’s study over others is its distinction between a “likely affected” group comprised of workers with ≤12 years of schooling versus “not likely affected” groups with ≥13 years of schooling. But there are disadvantages, common to other studies. Buszkiewicz et al. use cross-sectional data; they include the self-employed as well as part-time and part-year workers in their treatment groups. Their definitions of affected groups based on education create samples with 75% or more of workers who earn significantly above minimum wages; definitions are not based on wages. Inclusion of workers not subject to (e.g., self-employed) or affected by minimum wages biases estimates toward the null. Finally, within any minimum wage data set, it is the state—not federal—increases that account for the lion’s share of increases and that form the natural experiments; however, state increases can occur annually whereas the development of chronic diseases might take decades.
Towards intercrop ideotypes: non-random trait assembly can promote overyielding and stability of species proportion in simulated legume-based mixtures
Authors: Louarn Gaëtan , Barillot Romain , Combes Didier , Escobar-Gutiérrez Abraham
Published: January 2020

Backgrounds and Aims

A major challenge when supporting the development of intercropping systems remains the design of efficient species mixtures. The ecological processes that sustain overyielding of legume-based mixtures compared to pure crops are well known, but their links to plant traits remain to be unravelled. A common assumption is that enhancing trait divergence among species for resource acquisition when assembling plant mixtures should increase species complementarity and improve community performance.

Methods

The Virtual Grassland model was used to assess how divergence in trait values between species on four physiological functions (namely light and mineral N acquisition, temporal development, and C–N use efficiency) affected overyielding and mixture stability in legume-based binary mixtures. A first step allowed us to identify the model parameters that were most important to interspecies competition. A second step involved testing the impact of convergent and divergent parameter (or trait) values between species on virtual mixture performance.

Results

Maximal overyielding was achieved in cases where trait values were divergent for the physiological functions controlling N acquisition and temporal development but convergent for light interception. It was also found that trait divergence should not affect competitive abilities of legume and non-legumes at random. Indeed, random trait combinations frequently led to reduced mixture yields when compared to a perfectly convergent neutral model. Combinations with the highest overyielding also tended to be associated with mixture instability and decreasing legume biomass proportion. Achieving both high overyielding and mixture stability was only found to be possible under low or moderate N levels, using combinations of traits adapted to each environment.

Conclusions

No simple assembly rule based on trait divergence could be confirmed. Plant models able to infer plant–plant interactions can be helpful for the identification of major interaction traits and the definition of ideotypes adapted to a targeted intercropping system.
Parameter estimation for functional–structural plant models when data are scarce: using multiple patterns for rejecting unsuitable parameter sets
Authors: Wang Ming , White Neil , Hanan Jim , He Di , Wang Enli , Cribb Bronwen , Kriticos Darren J , Paini Dean , Grimm Volker
Published: January 2020

Background and Aims

Functional–structural plant (FSP) models provide insights into the complex interactions between plant architecture and underlying developmental mechanisms. However, parameter estimation of FSP models remains challenging. We therefore used pattern-oriented modelling (POM) to test whether parameterization of FSP models can be made more efficient, systematic and powerful. With POM, a set of weak patterns is used to determine uncertain parameter values, instead of measuring them in experiments or observations, which often is infeasible.

Methods

We used an existing FSP model of avocado (Persea americana ‘Hass’) and tested whether POM parameterization would converge to an existing manual parameterization. The model was run for 10 000 parameter sets and model outputs were compared with verification patterns. Each verification pattern served as a filter for rejecting unrealistic parameter sets. The model was then validated by running it with the surviving parameter sets that passed all filters and then comparing their pooled model outputs with additional validation patterns that were not used for parameterization.

Key Results

POM calibration led to 22 surviving parameter sets. Within these sets, most individual parameters varied over a large range. One of the resulting sets was similar to the manually parameterized set. Using the entire suite of surviving parameter sets, the model successfully predicted all validation patterns. However, two of the surviving parameter sets could not make the model predict all validation patterns.

Conclusions

Our findings suggest strong interactions among model parameters and their corresponding processes, respectively. Using all surviving parameter sets takes these interactions into account fully, thereby improving model performance regarding validation and model output uncertainty. We conclude that POM calibration allows FSP models to be developed in a timely manner without having to rely on field or laboratory experiments, or on cumbersome manual parameterization. POM also increases the predictive power of FSP models.
Towards completing understanding of genome size characters in plants. A commentary on: ‘Genome size and endopolyploidy evolution across the moss phylogeny’
Authors: Duckett Jeff
Published: January 2020

Major differences between moss and vascular plant genome sizes have major implications for stomatal biology whilst an absence of endopolyploidy in Sphagnum is most probably related to the unique development of the capitulum.
Benefits of an anti-parasite treatment are influenced by within-brood size variation in Tree Swallows (Tachycineta bicolor)
Authors: Griebel Ilsa A , Dawson Russell D
Published: January 2020

In all animals, susceptibility to parasites can differ among individuals. Young, nest-bound birds are exposed to a diversity of nest-dwelling ectoparasites that typically feed on their blood. Within broods, hatching asynchrony creates size hierarchies that result in morphological and physiological variation among nest mates, and susceptibility to parasites also may vary predictably with this size hierarchy. Our objective was to use a broad-spectrum, anti-parasite drug, ivermectin (IVM), to treat individual nestling Tree Swallows (Tachycineta bicolor) and assess how nestling susceptibility to parasites varied both within and among broods. Broods were either assigned to an IVM group, where half of the nestlings in a brood received IVM injections and half received control injections of pure sesame oil, or to a control group, where all nestlings received oil injections. We found that the IVM treatment reduced parasite loads for broods as a whole, thereby benefiting all nestlings in IVM broods and suggesting our treatment resulted in herd immunity. Specifically, nestlings from IVM broods had higher hemoglobin concentrations, regardless of whether they received injections with IVM or oil, and greater fledging success, than nestlings from control broods. On the contrary, IVM treatment did not strongly affect nestling morphology, with only marginal effects on the growth rate of ninth primary feathers, and the effects of the treatment on 2 other morphological traits depending on temporal factors. Variation in size within broods, however, influenced the chance of an individual fledging, which increased with relative size within a brood, but only under lower parasite loads (i.e. IVM broods). By experimentally manipulating nestling susceptibility to parasites, we have demonstrated variation in nestling response to an anti-parasite treatment both within and among broods, and future studies should investigate the underlying mechanism for why certain nestlings along the brood size hierarchy are more susceptible to parasites.
Bone histology yields insights into the biology of the extinct elephant birds (Aepyornithidae) from Madagascar
Authors: Chinsamy Anusuya , Angst Delphine , Canoville Aurore , Göhlich Ursula B
Published: January 2020

Given that the biology of the recently extinct aepyornithids is poorly understood, we undertook a histological study of 29 skeletal elements of adult and juvenile specimens of Aepyornithidae, i.e. Aepyornis maximus, Aepyornis hildebrandti and Vorombe titan, in addition to a group of taxonomically unidentifiable juvenile Aepyornithiformes. Comparative analysis of the histology of the different skeletal elements showed that although the femur retained a good record of growth during early ontogeny, the tibiotarsus provided the best record of growth. Our data showed that, like other insular birds and their extant relative, the kiwi, Aepyornithidae experienced protracted growth. We also found that intracortical remodelling began early in ontogeny and continued throughout their lives, becoming more extensive throughout the compacta with age, albeit more restricted to the perimedullary region in the femora. We also deduced that the different skeletal elements experienced variable amounts of intracortical remodelling, which was most likely to be related to biomechanical constraints, size of the element and ontogenetic age. Additionally, we documented the occurrence of an unusual endosteal tissue within the large perimedullary erosional spaces of a femur of A. maximus. Overall, our study provided a lot of new information about the life history of these giant, recently extinct ratites.
Commensalism outweighs phylogeographical structure in its effect on phenotype of a Sudanian savanna rodent
Authors: Mikula Ondřej , Nicolas Violaine , Boratyński Zbyszek , Denys Christiane , Dobigny Gauthier , Fichet-Calvet Elisabeth , Gagaré Sama , Hutterer Rainer , Nimo-Paintsil Shirley Cameron , Olayemi Ayodeji , Bryja Josef
Published: January 2020

The murid rodent Praomys daltoni is widespread in Sudanian savanna and woodlands of West Africa, and previous study of mitochondrial DNA variability suggested that it encompasses the phenotypically (small, grey-bellied) and ecologically (commensal) distinct form, Praomys derooi. Here, we comprehensively examined the genetic and morphological diversity within the complex. Six mitochondrial lineages showed a fine-scale phylogeographical pattern, whereas delimitation based on nuclear loci pooled four of them into a single widespread unit. A newly discovered lineage from southern Mauritania stands apart from the rest of the complex and might represent an unrecognized species. At the same time, the internal position of P. derooi (C2 mitochondrial lineage) was confirmed by the multilocus analysis. The magnitude of genetic distances between major phylogeographical lineages was typical for interspecific divergence in other clades of Praomys, despite the little differences among them in morphology (skull and upper molar row shapes). The most pronounced morphological shift was associated with a transition to commensalism, especially in P. derooi, but also in other lineages. This makes the whole complex a suitable model for the study of phenotypic novelty, the evolution of commensalism and conditions for ecological speciation.
On Quantifying Water Quality Benefits of Healthy Soils
Authors: Zimnicki Thomas , Boring Timothy , Evenson Grey , Kalcic Margaret , Karlen Douglas L , Wilson Robyn S , Zhang Yao , Blesh Jennifer
Published: January 2020

Despite decades of research demonstrating links between many agricultural practices and water quality, the ability to predict water quality on the basis of changes in soil health remains severely limited. By better understanding how soil health affects downstream water quality, researchers and policymakers could prioritize different conservation practices while exploring more innovative soil health management strategies. Focusing on the Great Lakes region, we describe the value and challenges of different approaches to linking soil health and water quality, specifically applying nitrogen and phosphorus mass balances and adapting simulation models to better incorporate changing soil health conditions. We identify critical research needs, including paying greater attention to a broad suite of conservation practices and to biological indicators of soil health. We also discuss key barriers to farmer adoption of conservation practices from field to national scales, highlighting that improved scientific understanding alone is insufficient to drive widespread change.
Comparative floral development reveals novel aspects of structure and diversity of flowers in Cannabaceae
Authors: Leme Flávia M , Schönenberger Jürg , Staedler Yannick M , Teixeira Simone P
Published: January 2020

Species of Cannabaceae are wind pollinated, have inconspicuous and reduced flowers that are pistillate, staminate and apparently perfect on the same individual or on different individuals, with a single-whorled perianth and a pseudomonomerous gynoecium. Our objective is to understand the developmental processes that lead to such a reduced flower morphology and polygamy in Cannabis sativa, Celtis iguanaea and Trema micrantha. Floral buds and flowers were processed for surface, histological examinations and 3D reconstructions of vasculature. The single-whorled perianth is interpreted as a calyx because the organs are robust, have a broad base, an acute apex and quincuncial aestivation and are opposite the stamens. Petals are absent from inception. The dicliny is established at different development stages: stamens or carpels are absent from inception (Cannabis sativa), initiated and aborted during early (Trema micrantha, before sporo/gametogenesis) or late (Celtis iguanaea, after sporo/gametogenesis) development. Furthermore, in all species studied the carpels are congenitally united and the pseudomonomerous nature of the gynoecium is confirmed. Glandular trichomes are distributed on the bracts, sepals, anther connective and receptacle. Special floral features shared by species of Cannabaceae include precocious ovule development and sepals that are each vascularized by one bundle. The reduced flowers of Cannabaceae are the result of the absence from inception and/or abortion of organs and even of a whole whorl at different developmental stages, which were probably selected in response to pressures exerted by the similar pollination mechanism.
Floral morphology and morphogenesis in Sanguisorba (Rosaceae): flower diversification despite petal reduction and spatial constraints
Authors: Wang Jun-Ru , Wang Xi , Su Na , Li Qiu-Jie , Zhang Xiao-Hui , Ma Yue-Ping , Zhao Liang , Ginefra Toni João Felipe , De Craene Louis Ronse
Published: January 2020

Most Rosaceae flowers are pentamerous and have petals, but subtribe Sanguisorbinae have small tetramerous (or trimerous) flowers without petals, and their floral morphology and morphogenesis remain poorly known. We investigated the floral development of three Sanguisorba spp. using scanning electron microscopy to clarify the relationship between floral development and mature flowers, with emphasis on floral constraints affecting reduction of petals, diversity of androecial patterns and the development of the gynoecium and ovule, and to clarify the pollination mechanisms in the absence of petals. All species have botryoids, with numerous flowers initiated acropetally, and the maturation of flowers follows different directions. All flowers are tetramerous and sepals emerge pairwise. No petal primordia appear. Antesepalous stamens are initiated in a pairwise manner; only S. hakusanensis has a second whorl. The ovary appears inferior by development of a cystiform hypanthium. There is only one ovule with a single integument by reduction of the inner. The space occupied by the larger sepals forces the stamens to develop sequentially. Our data demonstrate that petals are basically absent and that there is a possible shift of pollination mechanisms in Sanguisorba among the mainly wind-pollinated Sanguisorbinae, as both anemophilous and entomophilous characters are found in this genus.
Differential effects of deep brain stimulation and levodopa on brain activity in Parkinson’s disease
Authors: Mueller Karsten , Urgošík Dušan , Ballarini Tommaso , Holiga Štefan , Möller Harald E , Růžička Filip , Roth Jan , Vymazal Josef , Schroeter Matthias L , Růžička Evžen , Jech Robert
Published: January 2020

Levodopa is the first-line treatment for Parkinson’s disease, although the precise mechanisms mediating its efficacy remain elusive. We aimed to elucidate treatment effects of levodopa on brain activity during the execution of fine movements and to compare them with deep brain stimulation of the subthalamic nuclei. We studied 32 patients with Parkinson’s disease using functional MRI during the execution of finger-tapping task, alternating epochs of movement and rest. The task was performed after withdrawal and administration of a single levodopa dose. A subgroup of patients (n = 18) repeated the experiment after electrode implantation with stimulator on and off. Investigating levodopa treatment, we found a significant interaction between both factors of treatment state (off, on) and experimental task (finger tapping, rest) in bilateral putamen, but not in other motor regions. Specifically, during the off state of levodopa medication, activity in the putamen at rest was higher than during tapping. This represents an aberrant activity pattern probably indicating the derangement of basal ganglia network activity due to the lack of dopaminergic input. Levodopa medication reverted this pattern, so that putaminal activity during finger tapping was higher than during rest, as previously described in healthy controls. Within-group comparison with deep brain stimulation underlines the specificity of our findings with levodopa treatment. Indeed, a significant interaction was observed between treatment approach (levodopa, deep brain stimulation) and treatment state (off, on) in bilateral putamen. Our functional MRI study compared for the first time the differential effects of levodopa treatment and deep brain stimulation on brain motor activity. We showed modulatory effects of levodopa on brain activity of the putamen during finger movement execution, which were not observed with deep brain stimulation.
Phylogenetic Analysis Indicates a Longer Term Presence of the Globally Distributed H58 Haplotype of Salmonella Typhi in Southern India
Authors: Pragasam Agila Kumari , Pickard Derek , Wong Vanessa , Dougan Gordon , Kang Gagandeep , Thompson Andrew , John Jacob , Balaji Veeraraghavan , Mutreja Ankur
Published: January 2020

Background

Typhoid fever caused by Salmonella Typhi is a major public health concern in low-/middle-income countries. A recent study of 1900 global S. Typhi indicated that South Asia might be the site of the original emergence of the most successful and hypervirulent clone belonging to the 4.3.1 genotype. However, this study had limited samples from India.

Methods

We analyzed 194 clinical S. Typhi, temporal representatives from those isolated from blood and bone marrow cultures in southern India, over 26 years (1991–2016). Antimicrobial resistance (AMR) testing was performed for most common clinical agents. Whole-genome sequencing and SNP-level analysis was conducted. Comparative genomics of Vellore isolates was performed to infer transmission and AMR events.

Results

We identified multidrug-resistance (MDR)–associated clade 4.3.1 as the dominant genotype. We detected 4.3.1 S. Typhi as early as 1991, the earliest to be reported form India, and the majority were fluoroquinolone resistant and not MDR. MDR was not detected at all in other genotypes circulating in Vellore. Comparison with global S. Typhi showed 2 Vellore subgroups (I and II) that were phylogenetically highly related to previously described South Asia (subgroup I, II) and Southeast Asia (subgroup II) clades.

Conclusions

4.3.1 S. Typhi has dominated in Vellore for 2 decades. Our study would assist public health agencies in better tracking of transmission and persistence of this successful clade in India and globally. It informs clinicians of the AMR pattern of circulating clone, which would add confidence to their prophylactic/treatment decision making and facilitate efficient patient care.
Technical Characteristics of Curriculum-Based Measurement With Students Who Are Deaf
Authors: Lam Elizabeth A , Rose Susan , McMaster Kristen L
Published: January 2020

This study compared the reliability and validity of student scores from paper–pencil and e-based assessments using the “maze” and “silent reading fluency” (SRF) tasks. Forty students who were deaf and hard of hearing and reading between the second and fifth grade reading levels and their teachers (n = 21) participated. For maze, alternate form reliability coefficients obtained from correct scores and correct scores adjusted for guessing ranged from r = .61 to .84 (ps < .01); criterion-related validity coefficients ranged from r = .33 to .67 (most ps < .01). For SRF, reliability coefficients obtained from correct scores ranged from r = .50 to .75 (ps < .01); validity ranged from r = .25 to .72. Differences between student performance on paper–pencil and e-based conditions were generally non-significant for maze; significant differences between conditions for SRF favored the paper–pencil condition. Findings suggest that maze holds promise, with inconclusive results for SRF.
Game changer? A sporting indication to implant a left atrial appendage closure device in a rugby player with atrial fibrillation: a case report
Authors: Briosa e Gala Andre , Cox Andrew , Pope Michael , Betts Timothy
Published: January 2020

Background

Caring for athletes with cardiac disease requires an approach that caters to the specific needs of the athlete.

Case summary

A 27-year-old professional rugby player was admitted with decompensated heart failure and atrial fibrillation (AF). Transthoracic echocardiogram showed features in keeping with a dilated cardiomyopathy with severe left ventricular (LV) systolic impairment. He made good progress on evidence-based heart failure medication and his LV systolic function returned to normal. He failed to maintain sinus rhythm with cardioversion and remained in persistent AF. He then suffered a transient ischaemic attack despite appropriate anticoagulation. At 1-year follow-up, he was asymptomatic and against medical advice continued to play competitive rugby whilst taking rivaroxaban. He subsequently underwent implantation with a percutaneous left atrial appendage occlusion device, allowing him to discontinue anticoagulation, reduce his bleeding risk and resume his career, whilst simultaneously lowering the thromboembolic risk.

Discussion

Counselling should include different management options aimed at minimizing the risks to athletes if they to return to competitive sports. Left atrial appendage occlusion devices are a suitable AF-related stroke prevention strategy in athletes competing in full-contact sports.
Seasonal variation of epiphytic bacteria in the phyllosphere of Gingko biloba, Pinus bungeana and Sabina chinensis
Authors: Bao Lijun , Gu Likun , Sun Bo , Cai Wenyang , Zhang Shiwei , Zhuang Guoqiang , Bai Zhihui , Zhuang Xuliang
Published: January 2020

Phyllosphere harbors diverse microorganisms, which influence plant growth and health. In order to understand the extent to which environmental factors affect epiphytic microbial communities, we characterized microbial communities on leaves of three separate tree species present on the college campus, and also present within a forest park over two seasons. Quantitative PCR analysis showed the quantity of 16S rRNA genes was lower in May compared with October, while the abundances of functional genes (nifH and bacterial amoA genes) were extremely high in May. High-throughput sequencing revealed a large variation in the diversity and composition of bacterial and diazotrophic communities over the two seasons, and showed the abundance of functional genera, such as Nocardioides, Bacillus and Zoogloea were significantly elevated in May. In addition, xenobiotic biodegradation pathways of bacterial communities were clearly elevated in May. Network analysis showed the correlations between phyllospheric bacteria in May were more complex than that in October and showed greater negative correlations. These results were consistent in all tree species in this study. This study showed that phyllospheric bacteria varied greatly in different seasons, which implies that different growing seasons should be considered in the exploitation of the interactions between phyllospheric microorganisms and host plants.
Patterns of local, intercontinental and interseasonal variation of soil bacterial and eukaryotic microbial communities
Authors: De Gruyter Johan , Weedon James T , Bazot Stéphane , Dauwe Steven , Fernandez-Garberí Pere-Roc , Geisen Stefan , De La Motte Louis Gourlez , Heinesch Bernard , Janssens Ivan A , Leblans Niki , Manise Tanguy , Ogaya Romà , Löfvenius Mikaell Ottosson , Peñuelas Josep , Sigurdsson Bjarni D , Vincent Gaëlle , Verbruggen Erik
Published: January 2020

Although ongoing research has revealed some of the main drivers behind global spatial patterns of microbial communities, spatio-temporal dynamics of these communities still remain largely unexplored. Here, we investigate spatio-temporal variability of both bacterial and eukaryotic soil microbial communities at local and intercontinental scales. We compare how temporal variation in community composition scales with spatial variation in community composition, and explore the extent to which bacteria, protists, fungi and metazoa have similar patterns of temporal community dynamics. All soil microbial groups displayed a strong correlation between spatial distance and community dissimilarity, which was related to the ratio of organism to sample size. Temporal changes were variable, ranging from equal to local between-sample variation, to as large as that between communities several thousand kilometers apart. Moreover, significant correlations were found between bacterial and protist communities, as well as between protist and fungal communities, indicating that these microbial groups change in tandem, potentially driven by interactions between them. We conclude that temporal variation can be considerable in soil microbial communities, and that future studies need to consider temporal variation in order to reliably capture all drivers of soil microbiome changes.
The influence of diet on the microbiota of live-feed rotifers (Brachionus plicatilis) used in commercial fish larviculture
Authors: Turgay Emre , Steinum Terje Marken , Eryalçın Kamil Mert , Yardımcı Remziye Eda , Karataş Süheyla
Published: January 2020

Live-feed is indispensable to commercial fish larviculture. However, high bacterial loads in rotifers could pose a biosecurity risk. While this may be true, live-feed associated bacteria could also be beneficial to fish larvae through improved feed utilization or pathogen inhibition following host microbiota modification. The study objective was to elucidate the largely unexplored microbiota of rotifers propagated on five different diets through bacterial community profiling by 16S rRNA gene amplicon sequencing. Investigated rotifer samples had a median observed alpha-diversity of 338 ± 87 bacterial species. Alpha- and Gamma-Proteobacteria dominated the rotifer microbiota followed by members of classes Flavobacteriia, Cytophagia, Mollicutes, Phycisphaerae and Bacteroidia. Different diets significantly altered the bacterial communities associated with rotifers according to PERMANOVA test results and beta dispersion calculations. A common core rotifer microbiome included 31 bacterial species present in relative abundances over 0.01%. We discuss the functional role of some microbiome members. Our data suggested the presence of several known fish pathogens in stock rotifers. However, we found no evidence for increased loads of these presumptive taxa in propagated live-feed rotifers during this field trial.
Mapping of Eastern North Atlantic Ocean seismicity from Po/So observations at a mid-aperture seismological broad-band deep sea array
Authors: Krüger Frank , Dahm Torsten , Hannemann Katrin
Published: January 2020

A mid-aperture broad-band test array (OBS array DOCTAR) was deployed from June 2011 to April 2012 about 100 km north of the Gloria fault in the Eastern North Atlantic in about 5000 m water depth. In addition arrays were installed on Madeira Island and in western Portugal mainland. For the first time in the Eastern North Atlantic, we recorded a large number of high frequency Po and So waves from local and regional small and moderate earthquakes (ML < 4). An incoherent beamforming method was adapted to scan continuous data for such Po and So arrivals applying a sliding window waveform migration and frequency–wavenumber technique. We identify about 320 Po and 1550 So arrivals and compare the phase onsets with the ISC catalogue (ISC 2015) for the same time span. Up to a distance of 6° to the DOCTAR stations all events listed in the ISC catalogue could be associated to Po and So phases. Arrivals from events in more than 10° distance could be identified only in some cases. Only few Po and/or So arrivals were detected for earthquakes from the European and African continental area, the continental shelf regions and for earthquakes within or northwest of the Azores plateau. Unexpectedly, earthquake clusters are detected within the oceanic plates north and south of the Gloria fault and far from plate boundaries, indicating active intraplate structures. We also observe and locate numerous small magnitude earthquakes on the segment of the Gloria fault directly south of DOCTAR, which likely coincides with the rupture of the 25 November 1941 event. Local small magnitude earthquakes located beneath DOCTAR show hypocentres up to 30 km depth and strike-slip focal mechanisms. A comparison with detections at temporary mid-aperture arrays on Madeira and in western Portugal shows that the deep ocean array performs much better than the island and the continental array regarding the detection threshold for events in the oceanic plates.

We conclude that sparsely distributed mid-aperture seismic arrays in the deep ocean could decrease the detection and location threshold for seismicity with ML < 4 in the oceanic plate and might constitute a valuable tool to monitor oceanic plate seismicity.