bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic exchange interactions in monolayer CrI3 from many-body
wavefunction calculations
Authors: Pizzochero Michele , Yadav Ravi , Yazyev Oleg V 
Published: April 2020

Abstract
The marked interplay between the crystalline, electronic, and magnetic structure of
atomically thin magnets has been regarded as the key feature for designing next-generation
magneto-optoelectronic devices. In this respect, a detailed understanding of the microscopic
interactions underlying the magnetic response of these crystals is of primary importance. Here,
we combine model Hamiltonians with multireference configuration interaction wavefunctions to
accurately determine the strength of the spin couplings in the prototypical single-layer magnet
CrI3. Our calculations identify the (ferromagnetic) Heisenberg exchange interaction
J = −1.44 meV as the dominant term, being the inter-site magnetic
anisotropies substantially weaker. We also find that single-layer CrI3 features an
out-of-plane easy axis ensuing from a single-ion anisotropy A = −0.10
meV, and predict g-tensor in-plane components

g

x
x

=

g

y
y

=
1.90

and out-of-plane component
g

zz
= 1.92. In addition, we assess
the performance of a dozen widely used density functionals against our accurate correlated
wavefunctions calculations and available experimental data, thereby establishing reference
results for future first-principles investigations. Overall, our findings offer a firm
theoretical ground to recent experimental observations.
Influence of boric anhydride reinforcement on mechanical properties and abrasive wear of nylon 6
Authors: Randhawa Kawaljit Singh , Patel Ashwin D 
Published: April 2020

Abstract
To investigate the influence of boric anhydride (B2O3) on mechanical properties of nylon 6, tensile, hardness and impact test were carried out. Average tensile strength along with percentage elongation and modulus of elasticity has been calculated and plotted in this paper. Rockwell hardness and Izod impact tests were carried out to identify the hardness and toughness of materials. Boric anhydride used in this research was limited to less than 10 wt% of nylon 6 matrix material and was 2 wt%, 4 wt% and 8 wt%. Abrasion resistance of pure nylon 6 and composites was measured as weight loss due to abrasion. For the characterization of nylon 6 and its composites, Thermo-gravimetric analysis (TGA) and x-ray diffraction (XRD) were carried out. In results, it was found that the boric anhydride reinforcement increased the tensile strength and abrasion resistance when used up to 2 wt% in the nylon 6 matrix. Hardness found to be continually increased as the boric anhydride reinforcement percentage increased. The crystallinity of nylon 6 was little affected due to fillers and was found minimum for the 4 wt% boric anhydride reinforced nylon 6 composites. It was also found that the elastic modulus, Rockwell hardness and tensile strength, abrasion resistance show good correlations which are discussed in the discussion section.
Effect of different reduction rates on the near-interfacial structure of pressed 304/Q235 composite plate
Authors: Wang Shun , Zhao Guanghui , Li Yugui , Juan Li , Song Yaohui 
Published: April 2020

Abstract
The 304 stainless steel/Q235 composite plate was pressed at 1200 °C using a 500-ton hydraulic testing machine at a reduction rate of 25%, 30%, 35%, and 40% respectively. The microstructure of the composite plate was analyzed by means of scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The results showed that the black matter at the interface was the oxide of Mn and Si, and during the compression deformation process, the partial oxide film and the linear inclusions were crushed and extruded into fine particles. Small grains of different sizes appeared on the composite interface, and this deformation made the Q235 carbon steel and the 304 stainless steel on both sides of the composite interface show a coordinated deformation tendency when the reduction rate reached 35%. The whole process showed that the deformed carbon steel was first deformed, and the hard-to-deform stainless steel began to be deformed at a certain point, and then they were both further deformed together.
Structure and electronic properties of closed-ring defects in epitaxial graphene
Authors: Chen Yan , Li Meng-Chen , Wang Qi-Ming , Wang Guo-Sheng , Wei Xin , Song Guo-Feng , Kong Xiang-Mu , Xu Yun , Liu Ying 
Published: April 2020

Abstract
A number of past studies have focused on point and line defects in graphene epitaxially grown on SiC substrates. However, few studies have investigated closed-ring defects formed within grain boundary loops. The present study addresses this issue by applying low-temperature scanning tunneling microscopy/spectroscopy to investigate the atomic structures of closed-ring defects in graphene epitaxially grown on 4H-SiC, and to evaluate their effects on the electron state density. The results indicate that the orientations of the graphene lattice inside and outside of grain boundary loop structures are rotated uniformly by an angle of 30° relative to each other, suggesting that closed-ring defects are highly ordered and are mainly composed of clusters of pentagon-heptagon carbon rings and highly ordered pentagon-heptagon chains. In addition, the spectroscopy results reveal for the first time that the density of electron states inside a closed-ring defect is strongly localized and position-dependent. Moreover, these closed-ring defects can eliminate intervalley scattering while maintaining intravalley scattering. These findings are not only helpful for contributing to a deeper understanding of the effects of closed-ring defects in graphene, but also present a potentially useful valley-filtering mechanism for charge carries that can be applied to the practical development of all-electric valley-based devices.
Phase space analysis of quantum transport in electronic nanodevices
Authors: Datseris George , Fleischmann Ragnar 
Published: April 2020

Abstract
Electronic transport in nanodevices is commonly studied theoretically and numerically within the Landauer-Büttiker formalism: a device is characterized by its scattering properties to and from reservoirs connected by perfect semi-infinite leads, and transport quantities are derived from the scattering matrix. In some respects, however, the device becomes a ‘black box’ as one only analyses what goes in and out. Here we use the Husimi function as a complementary tool for quantitatively understanding transport in graphene nanodevices. It is a phase space representation of the scattering wavefunctions that allows to link the scattering matrix to a more semiclassical and intuitive description and gain additional insight in to the transport process. In this article we use the Husimi function to analyze some of the fascinating electronic transport properties of graphene, Klein tunneling and intervalley scattering, in two exemplary graphene nanodevices. By this we demonstrate the usefulness of the Husimi function in electronic nanodevices and present novel results e.g. on Klein tunneling outside the Dirac regime and intervalley scattering at a pn-junction and a tilted graphene edge.
Burkholder’s function and a weighted 𝐿² bound for stochastic integrals
Authors: Bañuelos Rodrigo , Brzozowski Michał , Osȩkowski Adam 
Published: April 2020

Let

X
X

be a continuous-path martingale and let

Y
Y

be a stochastic integral, with respect to

X
X

, of some predictable process with values in

[
−
1
,
1
]

[-1,1]

. We provide an explicit formula for Burkholder’s function associated with the weighted

L
2

L^2

bound

‖
Y

‖

L
2

(
W
)

≲
[
w

]

A
2

‖
X

‖

L
2

(
W
)

.

\begin{equation*} \|Y\|_{L^2(W)}\lesssim [w]_{A_2}\|X\|_{L^2(W)}. \end{equation*}
What might but must not be
Authors: Finlay Stephen , Lennertz Benjamin 
Published: April 2020

AbstractWe examine an objection to analysing the epistemic ‘might’ and ‘may’ as existential quantifiers over possibilities. Some claims that a proposition “might” be the case appear felicitous although, according to the quantifier analysis, they are necessarily false, since there are no possibilities in which the proposition is true. We explain such cases pragmatically, relying on the fact that ‘might’-sentences are standardly used to convey that the speaker takes a proposition as a serious option in reasoning. Our account explains why it makes sense to utter these sentences despite their being literally false and why their falsity is easily missed.
Reconstruction of plasmids by shotgun sequencing from environmental DNA: which bioinformatic workflow?
Authors: Hilpert Cécile , Bricheux Geneviève , Debroas Didier 
Published: April 2020

AbstractPlasmids play important roles in microbial evolution and also in the spread of antibiotic resistance. Plasmid sequences are extensively studied from clinical isolates but rarely from the environment with a metagenomic approach focused on the plasmid fraction referred to as the plasmidome. A clear challenge in this context is to define a workflow for discriminating plasmids from chromosomal contaminants existing in the plasmidome. For this purpose, we benchmarked existing tools from assembly to detection of the plasmids by reference-free methods (cBar and PlasFlow) and database-guided approaches. Our simulations took into account short-reads alone or combined with moderate long-reads like those actually generated in environmental genomics experiments. This benchmark allowed us to select the best tools for limiting false-positives associated to plasmid prediction tools and a combination of reference-guided methods based on plasmid and bacterial databases.
Boosting the accuracy of protein secondary structure prediction through nearest neighbor search and method hybridization
Authors: Krieger Spencer , Kececioglu John 
Published: April 2020

Abstract

Motivation
Protein secondary structure prediction is a fundamental precursor to many bioinformatics tasks. Nearly all state-of-the-art tools when computing their secondary structure prediction do not explicitly leverage the vast number of proteins whose structure is known. Leveraging this additional information in a so-called template-based method has the potential to significantly boost prediction accuracy.

Method
We present a new hybrid approach to secondary structure prediction that gains the advantages of both template- and non-template-based methods. Our core template-based method is an algorithmic approach that uses metric-space nearest neighbor search over a template database of fixed-length amino acid words to determine estimated class-membership probabilities for each residue in the protein. These probabilities are then input to a dynamic programming algorithm that finds a physically valid maximum-likelihood prediction for the entire protein. Our hybrid approach exploits a novel accuracy estimator for our core method, which estimates the unknown true accuracy of its prediction, to discern when to switch between template- and non-template-based methods.

Results
On challenging CASP benchmarks, the resulting hybrid approach boosts the state-of-the-art Q8 accuracy by more than 2–10%, and Q3 accuracy by more than 1–3%, yielding the most accurate method currently available for both 3- and 8-state secondary structure prediction.

Availability and implementation
A preliminary implementation in a new tool we call Nnessy is available free for non-commercial use at http://nnessy.cs.arizona.edu.
Hopper: a mathematically optimal algorithm for sketching biological data
Authors: DeMeo Benjamin , Berger Bonnie 
Published: April 2020

Abstract

Motivation
Single-cell RNA-sequencing has grown massively in scale since its inception, presenting substantial analytic and computational challenges. Even simple downstream analyses, such as dimensionality reduction and clustering, require days of runtime and hundreds of gigabytes of memory for today’s largest datasets. In addition, current methods often favor common cell types, and miss salient biological features captured by small cell populations.

Results
Here we present Hopper, a single-cell toolkit that both speeds up the analysis of single-cell datasets and highlights their transcriptional diversity by intelligent subsampling, or sketching. Hopper realizes the optimal polynomial-time approximation of the Hausdorff distance between the full and downsampled dataset, ensuring that each cell is well-represented by some cell in the sample. Unlike prior sketching methods, Hopper adds points iteratively and allows for additional sampling from regions of interest, enabling fast and targeted multi-resolution analyses. In a dataset of over 1.3 million mouse brain cells, Hopper detects a cluster of just 64 macrophages expressing inflammatory genes (0.004% of the full dataset) from a Hopper sketch containing just 5000 cells, and several other small but biologically interesting immune cell populations invisible to analysis of the full data. On an even larger dataset consisting of ∼2 million developing mouse organ cells, we show Hopper’s even representation of important cell types in small sketches, in contrast with prior sketching methods. We also introduce Treehopper, which uses spatial partitioning to speed up Hopper by orders of magnitude with minimal loss in performance. By condensing transcriptional information encoded in large datasets, Hopper and Treehopper grant the individual user with a laptop the analytic capabilities of a large consortium.

Availability and implementation
The code for Hopper is available at https://github.com/bendemeo/hopper. In addition, we have provided sketches of many of the largest single-cell datasets, available at http://hopper.csail.mit.edu.
Interactions of circulating estradiol and progesterone on changes in endometrial area and pituitary responsiveness to GnRH†
Authors: Motta Jessica C L , Madureira Guilherme , Silva Lucas O , Alves Rodrigo L O R , Silvestri Mayara , Drum Jéssica N , Consentini Carlos E C , Prata Alexandre B , Pohler Ky G , Wiltbank Milo C , Sartori Roberto 
Published: April 2020

Abstract
Changes in circulating progesterone (P4) and estradiol (E2) during proestrus produce dynamic changes in endometrial function and pituitary release of gonadotropins. Independent and combined effects of P4 and E2 on endometrium and pituitary were evaluated. In a preliminary study, an exogenous hormone model of proestrus was created by removal of corpus luteum and follicles ≥5 mm followed by gradual removal of intravaginal P4 implants during 18 h and treatment with increasing doses of estradiol benzoate during 48 h to mimic proestrus using high E2 (n = 9) or low E2 (n = 9). Decreased P4, increased E2, and increased endometrial area (EA) simulated proestrus in high-E2 cows and this was used subsequently. The main experiment used a 2 × 2 factorial design with: high E2 and low P4 (n = 11); high E2 and high P4 (n = 11); low E2 and high P4 (n = 11); low E2 and low P4 (n = 10). At 48 h, gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) and follicle stimulating hormone (FSH) release was determined. Variables were analyzed using PROCMIXED of Statistical Analysis System. The EA increased dramatically during 48 h only in high-E2 and low-P4 cows. For FSH, high-E2 cows had greater area under the curve (AUC) and FSH peak after GnRH than low E2, with mild negative effects of high P4. For LH, concentration at peak and AUC were 2-fold greater in high E2 compared to low-E2 groups, with low P4 also 2-fold greater than high-P4 groups. Thus, maximal changes in uterus and pituitary during proestrus depend on both low P4 and high E2, but different physiologic responses are regulated differently by E2 and P4. Changes in endometrium depend on low P4 and high E2, whereas GnRH-induced FSH secretion primarily depends on high E2, and GnRH-induced LH secretion is independently increased by high E2 or reduced by high P4.
Disentangling relationships between the amphi-AdriaticEuphorbia spinosaand Balkan endemicE. glabriflora(Euphorbiaceae)
Authors: Stevanoski Ivana , Kuzmanović Nevena , Dolenc Koce Jasna , Schönswetter Peter , Frajman Božo 
Published: April 2020

AbstractThe Mediterranean region is one of the 25 biodiversity hotspots, with several species distributed on both sides of the Adriatic Sea, i.e. on the Apennine and the Balkan Peninsulas. One of these is Euphorbia spinosa, distributed in the coastal regions of the Ligurian, Tyrrhenian, Ionian and Adriatic Seas, whereas its closest relative, E. glabriflora, occurs in continental regions of the western and southern Balkan Peninsula, mostly on serpentine substrates. They differ morphologically, but transitional forms resembling E. glabriflora can be found within the range of E. spinosa and in the overlapping areas of both species, and phylogenetic relationships between them remain unclear. Using nuclear ribosomal ITS sequences, we here show that these two species form a monophyletic group closely related to the E. acanthothamnos alliance, but the relationships between them remain unresolved. Also, amplified fragment length polymorphism (AFLP) fingerprints are weakly structured, but indicate a north-west to south-east trend in genetic differentiation and two main genetic groups; however, these are not entirely congruent with morphological species boundaries. In addition, morphometric analyses indicate only weak differentiation between the taxa, mostly due to occurrence of morphologically transitional forms in contact areas between the two genetic groups. Based on our results we propose to treat both taxa as subspecies of E. spinosa and provide a taxonomic treatment with descriptions. Finally, based on the high genetic variability on the Balkan Peninsula, we hypothesize a trans-Adriatic dispersal from the Balkans to the Apennine Peninsula, probably during the Pleistocene. This is in line with previous studies of different plants with amphi-Adriatic distributions, with the exception that in E. spinosa the distributions on both peninsulas are of similar size, whereas in most other cases the distribution area on the Balkan Peninsula is larger than on the Apennine Peninsula.
Hindlimb motor responses to unilateral brain injury: spinal cord encoding and left-right asymmetry
Authors: Zhang Mengliang , Watanabe Hiroyuki , Sarkisyan Daniil , Andersen Marlene Storm , Nosova Olga , Galatenko Vladimir , Carvalho Liliana , Lukoyanov Nikolay , Thelin Jonas , Schouenborg Jens , Bakalkin Georgy 
Published: April 2020

AbstractMechanisms of motor deficits (e.g. hemiparesis and hemiplegia) secondary to stroke and traumatic brain injury remain poorly understood. In early animal studies, a unilateral lesion to the cerebellum produced postural asymmetry with ipsilateral hindlimb flexion that was retained after complete spinal cord transection. Here we demonstrate that hindlimb postural asymmetry in rats is induced by a unilateral injury of the hindlimb sensorimotor cortex, and characterize this phenomenon as a model of spinal neuroplasticity underlying asymmetric motor deficits. After cortical lesion, the asymmetry was developed due to the contralesional hindlimb flexion and persisted after decerebration and complete spinal cord transection. The asymmetry induced by the left-side brain injury was eliminated by bilateral lumbar dorsal rhizotomy, but surprisingly, the asymmetry after the right-side brain lesion was resistant to deafferentation. Pancuronium, a curare-mimetic muscle relaxant, abolished the asymmetry after the right-side lesion suggesting its dependence on the efferent drive. The contra- and ipsilesional hindlimbs displayed different musculo-articular resistance to stretch after the left but not right-side injury. The nociceptive withdrawal reflexes evoked by electrical stimulation and recorded with EMG technique were different between the left and right hindlimbs in the spinalized decerebrate rats. On this asymmetric background, a brain injury resulted in greater reflex activation on the contra- versus ipsilesional side; the difference between the limbs was higher after the right-side brain lesion. The unilateral brain injury modified expression of neuroplasticity genes analysed as readout of plastic changes, as well as robustly impaired coordination of their expression within and between the ipsi- and contralesional halves of lumbar spinal cord; the effects were more pronounced after the left side compared to the right-side injury. Our data suggest that changes in the hindlimb posture, resistance to stretch and nociceptive withdrawal reflexes are encoded by neuroplastic processes in lumbar spinal circuits induced by a unilateral brain injury. Two mechanisms, one dependent on and one independent of afferent input may mediate asymmetric hindlimb motor responses. The latter, deafferentation resistant mechanism may be based on sustained muscle contractions which often occur in patients with central lesions and which are not evoked by afferent stimulation. The unusual feature of these mechanisms is their lateralization in the spinal cord.
Sclera Recognition Based on Efficient Sclera Segmentation and Significant Vessel Matching
Authors: Xu Dong , Dong Wei , Zhou Han 
Published: April 2020

Abstract
The visible blood vein in sclera has unique characteristics for each person, and it can be captured in visible light conditions. Therefore, the sclera vessels have been used as an important feature to improve the performance of identification recognition systems, for example, mobile payment and phone encryption system. But recent studies show that unsatisfactory sclera segmentation and tedious matching process are the two critical issues to degrade the performance of sclera identification system. In this paper, we propose a robust sclera recognition system with high accuracy and efficiency. First, a novel sclera segmentation method that provides adaptive threshold is proposed. Second, we have designed an improved vessels enhancement method based on the local grey distribution and local texture information, and least square linearization and moment invariants are utilized to extract features. Finally, an efficient matching strategy is put forward based on the detected significant vessels. The experimental results on one database with images captured in colour illumination prove that the proposed sclera recognition method has an obvious improvement regarding efficiency and accuracy over other sclera recognition systems.
Public-Key Encryption In The Standard Model Against Strong Leakage Adversary
Authors: Alawatugoda Janaka 
Published: April 2020

Abstract
Over the years, security against adaptively chosen-ciphertext attacks (CCA2) is considered as the strongest security definition for public-key encryption schemes. With the uprise of side-channel attacks, new security definitions are proposed, addressing leakage of secret keys together with the standard CCA2 definition. Among the new security definitions, security against continuous and after-the-fact leakage-resilient CCA2 can be considered as the strongest security definition, which is called as security against (continuous) adaptively chosen-ciphertext leakage attacks (continuous CCLA2). In this paper, we present a construction of a public-key encryption scheme, namely LR-PKE, which satisfies the aforementioned security definition. The security of our public-key encryption scheme is proven in the standard model, under decision BDH assumption. Thus, we emphasize that our public-key encryption scheme LR-PKE is (continuous) CCLA2-secure in the standard model. For our construction of LR-PKE, we have used a strong one-time signature scheme and a leakage-resilient refreshing protocol as underlying building blocks. The leakage bound is $0.15n\log p -1$ bits per leakage query, for a security parameter $k$ and a statistical security parameter $n$, such that $\log p \geq k$ and $n$ is a function of $k$. It is possible to see that LR-PKE is efficient enough to be used for real-world usage.