bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plane algebraic curves in fancy balls
Authors: Kruzhilin N. G. , Orevkov S. Yu. 
Published: November 2020

Abstract
Boileau and Rudolph [1] called an oriented link

in the 3-sphere a

-boundary if it can be realized as the intersection of an algebraic curve

in

and the boundary of a smooth embedded closed 4-ball

. They showed that some links are not

-boundaries. We say that

is a strong

-boundary if

is connected. In particular, all quasipositive links are strong

-boundaries.
In this paper we give examples of non-quasipositive strong

-boundaries and non-strong

-boundaries. We give a complete classification of (strong)

-boundaries with at most five crossings.
The Diophantine problem in the classical matrix groups
Authors: Myasnikov A. G. , Sohrabi M. 
Published: November 2020

Abstract
In this paper we study the Diophantine problem in the classical matrix groups

,

,

and

,

, over an associative ring

with identity. We show that if

is one of these groups, then the Diophantine problem in

is polynomial-time equivalent (more precisely, Karp equivalent) to the Diophantine problem in

. When

we assume that

is commutative. Similar results hold for

and

provided

has no zero divisors (for

the ring

is not assumed to be commutative).
On a spectral sequence for the action of the Torelli group of genus

on the complex of cycles
Authors: Gaifullin A. A. 
Published: November 2020

Abstract
The Torelli group of a closed oriented surface

of genus

is the subgroup

of the mapping class group

consisting of all mapping classes that act trivially on the homology of

. One of the most intriguing open problems concerning Torelli groups is the question of whether the group

is finitely presented. A possible approach to this problem relies on the study of the second homology group of

using the spectral sequence

for the action of

on the complex of cycles. In this paper we obtain evidence for the conjecture that

is not finitely generated and hence

is not finitely presented. Namely, we prove that the term

of the spectral sequence is not finitely generated, that is, the group

remains infinitely generated after taking quotients by the images of the differentials

and

. Proving that it remains infinitely generated after taking the quotient by the image of

would complete the proof that

is not finitely presented.
The Fermat-Steiner problem in the space of compact subsets of

endowed with the Hausdorff metric
Authors: Galstyan A. Kh. , Ivanov A. O. , Tuzhilin A. A. 
Published: November 2020

Abstract
The Fermat-Steiner problem consists in finding all points in a metric space

at which the sum of the distances to fixed points

of

attains its minimum value. This problem is studied in the metric space

of all nonempty compact subsets of the Euclidean space

, and the

are pairwise disjoint finite sets in

. The set of solutions of this problem (which are called Steiner compact sets) falls into different classes in accordance with the distances to the

. Each class contains an inclusion-greatest element and inclusion-minimal elements (a maximal Steiner compact set and minimal Steiner compact sets, respectively). We find a necessary and sufficient condition for a compact set to be a minimal Steiner compact set in a given class, provide an algorithm for constructing such compact sets and find a sharp estimate for their cardinalities. We also put forward a number of geometric properties of minimal and maximal compact sets. The results obtained can significantly facilitate the solution of specific problems, which is demonstrated by the well-known example of a symmetric set

, for which all Steiner compact sets are asymmetric. The analysis of this case is significantly simplified due to the technique developed.
Bibliography 16 titles.
Distance metrics for ranked evolutionary trees
Authors: Kim Jaehee , Rosenberg Noah A. , Palacios Julia A. 
Published: November 2020

SignificanceRooted binary trees inferred from molecular sequence data provide information about the evolutionary history of populations and species. We introduce metrics on ranked tree shapes and ranked genealogies, in which the shape and temporal branching order in a tree are considered, but not the taxon labels. Our metrics enable quantification of evolutionary differences, assessment of tree uncertainty, and construction of statistical summaries of a tree distribution. They are computationally efficient and particularly useful for comparing phylodynamics of infectious diseases involving heterochronous samples and for comparative analyses of organisms that live in different geographic regions.
Forest and woodland replacement patterns following drought-related mortality
Authors: Batllori Enric , Lloret Francisco , Aakala Tuomas , Anderegg William R. L. , Aynekulu Ermias , Bendixsen Devin P. , Bentouati Abdallah , Bigler Christof , Burk C. John , Camarero J. Julio , Colangelo Michele , Coop Jonathan D. , Fensham Roderick , Floyd M. Lisa , Galiano Lucía , Ganey Joseph L. , Gonzalez Patrick , Jacobsen Anna L. , Kane Jeffrey Michael , Kitzberger Thomas , Linares Juan C. , Marchetti Suzanne B. , Matusick George , Michaelian Michael , Navarro-Cerrillo Rafael M. , Pratt Robert Brandon , Redmond Miranda D. , Rigling Andreas , Ripullone Francesco , Sangüesa-Barreda Gabriel , Sasal Yamila , Saura-Mas Sandra , Suarez Maria Laura , Veblen Thomas T. , Vilà-Cabrera Albert , Vincke Caroline , Zeeman Ben 
Published: November 2020

SignificanceForests are experiencing growing risks of drought-induced mortality in a warming world. Yet, ecosystem dynamics following drought mortality remain unknown, representing a major limitation to our understanding of the ecological consequences of climate change. We provide an emerging picture of postdrought ecological trajectories based on field indicators of forest dynamics. Replacement patterns following mortality indicate limited short-term persistence of predrought dominant tree species, highlighting the potential for major ecosystem reorganization in the coming decades. The great variability of the observed dynamics within and among species reinforces the primary influence of drought characteristics and ecosystem legacies, modulated by land use, management, and past disturbances, on ongoing drought-related species turnover and their potential implications for future forest biodiversity and ecosystem services.
Early evidence for mounted horseback riding in northwest China
Authors: Li Yue , Zhang Chengrui , Taylor William Timothy Treal , Chen Liang , Flad Rowan K. , Boivin Nicole , Liu Huan , You Yue , Wang Jianxin , Ren Meng , Xi Tongyuan , Han Yifu , Wen Rui , Ma Jian 
Published: November 2020

Significance
This study provides insights into the emergence and adoption of equestrian technologies in China. Analysis of ancient horse bones from Shirenzigou and Xigou in eastern Xinjiang demonstrates that pastoralists along China’s northwest frontier practiced horseback riding and mounted archery by the fourth century BCE. This region may have played a key role in the initial spread of equestrian technologies from the Altai region into the heartland of China’s early settled states, where they eventually facilitated the rise of the first united empires in China and triggered extensive social, political, and economic exchanges between China and its neighbors on the Eurasian Steppes.
Mechanical injuries of neurons induce tau mislocalization to dendritic spines and tau-dependent synaptic dysfunction
Authors: Braun Nicholas J. , Yao Katherine R. , Alford Patrick W. , Liao Dezhi 
Published: November 2020

Significance
Athletes and soldiers exposed to repeated traumatic brain injuries have increased risk of developing chronic traumatic encephalopathy (CTE), which is a neurodegenerative disease characterized by tangled deposits of the protein tau in the brain and loss of cognitive function. This study provides the first experimental evidence showing that mechanical stretching of neurons induces tau to be mislocalized to dendritic spines where it causes synaptic dysfunction. This cross-disciplinary study utilizes computational modeling, imaging, and electrophysiology to unravel a cellular framework for how tau phosphorylation mediates trauma-induced synaptic dysfunction, highlighting the essential role of tau in functional deficits caused by traumatic brain injury.
β-Catenin signaling dynamics regulate cell fate in differentiating neural stem cells
Authors: Rosenbloom Alyssa B. , Tarczyński Marcin , Lam Nora , Kane Ravi S. , Bugaj Lukasz J. , Schaffer David V. 
Published: November 2020

Significance
Stem cells in the adult brain undergo a weeks-long differentiation process to become new neurons. During this process, the stem cell continuously senses differentiation cues, which fluctuate over a wide range of physiological timescales. However, how differentiation can proceed reliably despite these fluctuations is poorly understood. We use light-activatable control of the neurogenic β-catenin signal to probe how adult neurogenesis responds to fluctuations in differentiation cues. We discovered that β-catenin dynamics strongly influence cell-fate decisions. Surprisingly, while a sustained signal resulted in neurogenesis, transient signals induced cell death. Our results may provide an explanation for the cell death that is commonly observed during adult neurogenesis and may also illuminate a quality control mechanism for correcting errors during neurogenesis.
Role of inner solvation sheath within salt–solvent complexes in tailoring electrode/electrolyte interphases for lithium metal batteries
Authors: Ren Xiaodi , Gao Peiyuan , Zou Lianfeng , Jiao Shuhong , Cao Xia , Zhang Xianhui , Jia Hao , Engelhard Mark H. , Matthews Bethany E. , Wu Haiping , Lee Hongkyung , Niu Chaojiang , Wang Chongmin , Arey Bruce W. , Xiao Jie , Liu Jun , Zhang Ji-Guang , Xu Wu 
Published: November 2020

Significance
Rechargeable lithium metal batteries are promising next-generation high-energy-density energy storage systems. However, their applications have been greatly impeded by the instabilities of electrolytes toward both highly reductive lithium metal anode and high-voltage cathodes. Here, we use localized high-concentration electrolytes to investigate the fundamental correlation between the battery performance and the electrolyte solvation chemistry and its profound electrode/electrolyte interphase properties. Experimental and theoretical analyses reveal an intriguing general rule that the strong interactions between the salt and the solvent in the inner solvation sheath within the salt–solvent complexes promote their intermolecular proton/charge-transfer reactions, dictate the properties of the electrode/electrolyte interphases, and then influence the battery performances. These findings can shed light for rational electrolyte design for various battery systems.
Hedgehog pathway activation through nanobody-mediated conformational blockade of the Patched sterol conduit
Authors: Zhang Yunxiao , Lu Wan-Jin , Bulkley David P. , Liang Jiahao , Ralko Arthur , Han Shuo , Roberts Kelsey J. , Li Anping , Cho Wonhwa , Cheng Yifan , Manglik Aashish , Beachy Philip A. 
Published: November 2020

Significance
Precise manipulation of Hedgehog pathway activity holds great value for biological research and clinical applications, but pathway agonists amenable to engineering have been lacking. We selected a nanobody that potentially targets the conformational changes of the Hedgehog receptor Patched1 and demonstrated that this nanobody potently activates the pathway in vivo. This nanobody can serve as the basis for mechanistic studies of Hedgehog pathway activation and for potential therapeutic applications. Our method may further apply to the investigation of other related transporters in the Resistance-Nodulation-Division superfamily.
Echolocating bats accumulate information from acoustic snapshots to predict auditory object motion
Authors: Salles Angeles , Diebold Clarice Anna , Moss Cynthia F. 
Published: November 2020

Significance
Research on visual tracking of moving stimuli has contributed to our understanding of sensory-guided behaviors; however, the processes that support auditory object tracking in natural three-dimensional environments remain largely unknown. This is important, not only to diverse groups of animals, but also to humans that rely on hearing to track objects in their environment. For visually impaired individuals, hearing is paramount for auditory object tracking and navigation, and in recent years, mobility training programs for the blind include instruction on echolocation using tongue clicks. In this work, we provide conclusive demonstration that echolocating bats use predictive strategies to track moving auditory objects, which can inform future comparative work on auditory motion processing.
Antibody-mediated activation of the FGFR1/Klothoβ complex corrects metabolic dysfunction and alters food preference in obese humans
Authors: Baruch Amos , Wong Chin , Chinn Leslie W. , Vaze Anjali , Sonoda Junichiro , Gelzleichter Thomas , Chen Shan , Lewin-Koh Nicholas , Morrow Linda , Dheerendra Suresh , Boismenu Richard , Gutierrez Johnny , Wakshull Eric , Wilson Maria E. , Arora Puneet S. 
Published: November 2020

SignificanceFibroblast growth factor 21 (FGF21) controls metabolic organ homeostasis and eating behavior via FGF receptor 1/Klothoβ (FGFR1/KLB) complexes. Here we show that a bispecific anti-FGFR1/KLB agonist antibody, BFKB8488A, mimics the actions of FGF21 in monkeys and humans. BFKB8488A induced marked weight loss in obese monkeys while elevating expression of FGFR1 target genes in adipose tissue. A clinical study in overweight human participants demonstrated that a single dose of BFKB8488A caused transient body weight reduction, sustained improvement in cardiometabolic parameters, and a trend toward reduction in preference for sweet taste and carbohydrate intake. These data suggest that antibody-mediated activation of the FGFR1/KLB complex in humans recapitulates the effects of FGF21 and can be used as therapy for obesity-related metabolic defects.
Mechanically superior matrices promote osteointegration and regeneration of anterior cruciate ligament tissue in rabbits
Authors: Mengsteab Paulos Y. , Otsuka Takayoshi , McClinton Aneesah , Shemshaki Nikoo Saveh , Shah Shiv , Kan Ho-Man , Obopilwe Elifho , Vella Anthony T. , Nair Lakshmi S. , Laurencin Cato T. 
Published: November 2020

Significance
This paper describes a mechanically superior matrix that enhances the osteointegration and regeneration of ACL tissue in a rabbit model. We show that bone marrow aspirate concentrate enhances the presence of cuboidal cells that are reminiscent of ACL fibroblasts and chondrocytes, a sign of enhanced regeneration. This paper also demonstrates that the combinatorial application of FGF-2 and FGF-8 in the knee joint suppresses inflammation by reducing adipokine secretion. The incorporation of nondegradable PET fibers into the PLLA bioengineered ACL matrix showed improved strength retention after implantation. We report the strongest matrix to date in a rabbit ACL reconstruction model, which is a promising step toward the clinical translation of an off-the-shelf ligament for orthopedic applications.
Essential role of the linear ubiquitin chain assembly complex and TAK1 kinase in A20 mutant Hodgkin lymphoma
Authors: Song Zhihui , Wei Wei , Xiao Wenming , Al-Saleem Essel D. , Nejati Reza , Chen Liqi , Yin Jiejing , Fabrizio Joseph , Petrus Michael N. , Waldmann Thomas A. , Yang Yibin 
Published: November 2020

Significance
Hodgkin lymphoma (HL) is the most common (6,000 to 7,000 new cases per year) lymphoma subtype in young adulthood. Our study is the first effort to investigate the deep mechanisms underlying the recurrent A20 mutations in HL based on results from a high-throughput ubiquitin regulator-focused CRISPR library screen. Our results reveal the essential role of the linear-ubiquitination E3 ligase LUBAC and protein kinase TAK1 in the oncogenic NF-κB signaling that characterizes HL, leading to improved understanding of the molecular circuitry that drives the pathology of HL. The therapeutic potential of targeting this pathway was tested using a highly specific TAK1 small-molecule inhibitor, which is an approach that can provide intervention strategies for targeted therapy in this disease.
In situ sprayed NIR-responsive, analgesic black phosphorus-based gel for diabetic ulcer treatment
Authors: Ouyang Jiang , Ji Xiaoyuan , Zhang Xingcai , Feng Chan , Tang Zhongmin , Kong Na , Xie Angel , Wang Junqing , Sui Xinbing , Deng Liu , Liu Younian , Kim Jong Seung , Cao Yihai , Tao Wei 
Published: November 2020

Significance
How to achieve effective treatment of diabetic ulcer (DU) is still a major challenge in the clinic. Herein, we propose an effective strategy to perfectly address all the problems faced in the treatment of DU. A near-infrared–responsive black phosphorus-based sprayed fibrin gel capable of alleviating pain, eliminating bacteria, reducing inflammation, and promoting angiogenesis is developed. The promoting wound healing and pain relief effects in the diabetic mouse ulcer model indicate this gel is a valuable wound dressing for effective treatment of DU and other advanced wounds. We anticipate that this therapeutic strategy may be generalized for treating other disorders such as chronic inflammation and infections.
Lifshitz transition underlying the metamagnetic transition of UPt3
Authors: McCollam A , Fu Mingxuan , Julian S R 
Published: November 2020

Abstract
Comparing quantum oscillation measurements, dc magnetoresistance measurements, and Fermi surfaces obtained from LDA calculations, we argue that the metamagnetic transition of UPt3, which occurs at an applied field μ
◦
H

M
∼ 20 T, coincides with a Lifshitz transition at which an open orbit on the band 2 hole-like Fermi surface becomes closed for one spin direction. At low field, proximity of the Fermi energy to this particular van Hove singularity may have implications for the superconducting pairing potential of UPt3. In our picture the magnetization comes from non-linear spin-splitting of the heavy fermion bands. In support of this, we show that the non-linear field dependence of a particular quantum oscillation frequency can be fitted by assuming that the corresponding extremal Fermi surface area is proportional to the magnetization. In addition, below H

M
, we find in our LDA calculations a new, non-central orbit on band 1, whose non-linear behaviour explains a field-dependent frequency recently observed in magnetoacoustic quantum oscillation measurements.
Hysteretic magnetoresistance in nanowire devices due to stray fields induced by micromagnets
Authors: Jiang Y , de Jong E J , van de Sande V , Gazibegovic S , Badawy G , Bakkers E P A M , Frolov S M 
Published: November 2020

Abstract
We study hysteretic magnetoresistance in InSb nanowires due to stray magnetic fields from CoFe micromagnets. Devices without any ferromagnetic components show that the magnetoresistance of InSb nanowires commonly exhibits either a local maximum or local minimum at zero magnetic field. Switching of microstrip magnetizations then results in positive or negative hysteretic dependence as conductance maxima or minima shift with respect to the global external field. Stray fields are found to be in the range of tens of millitesla, comparable to the scale over which the nanowire magnetoresistance develops. We observe that the stray field signal is similar to that obtained in devices with ferromagnetic contacts (spin valves). We perform micromagnetic simulations which are in reasonable agreement with the experiment. The use of locally varying magnetic fields may bring new ideas for Majorana circuits in which nanowire networks require control over field orientation at the nanoscale.
First demonstration of high current canted-cosine-theta coils with Bi-2212 Rutherford cables
Authors: Garcia Fajardo L , Shen T , Wang X , Myers C , Arbelaez D , Bosque E , Brouwer L , Caspi S , English L , Gourlay S , Hafalia A , Martchevskii M , Pong I , Prestemon S 
Published: November 2020

Abstract
Future high energy physics colliders could benefit from accelerator magnets based on high-temperature superconductors, which may reach magnetic fields of up to 45 T at 4.2 K, twice the field limit of the two Nb-based superconductors. Bi2Sr2CaCu2O8-x (Bi-2212) is the only high-T
c cuprate material available as a twisted, multifilamentary and isotropic round wire. However, it has been hitherto unclear how an accelerator magnet can be fabricated from Bi-2212 round wires and whether high field quality can be achieved. This paper reports on the first demonstration of high current Bi-2212 coils using Rutherford cable based on a canted-cosine-theta (CCT) design and an overpressure processing heat treatment. Two Bi-2212 CCT coils, BIN5a and BIN5b, were made from a nine-strand Rutherford cable. Their electromagnetic design is identical, but they were fabricated differently: both coils underwent heat treatment in their aluminum–bronze mandrels, but unlike BIN5a that was impregnated with epoxy in its reaction mandrel, the conductor of BIN5b was transferred to a 3D printed Accura Bluestone mandrel after the heat treatment, a process attempted here for the first time, and was not impregnated. BIN5a reached a peak current of 4.1 kA with a self-field of 1.34 T in the bore. This corresponds to a wire engineering current density (J
e) of 912 A mm−2, which is two times that of BIN2-IL, a previous Bi-2212 CCT coil fabricated at LBNL, which used a six-around-one cable processed with the conventional 1 bar pressure melt processing. On the other hand, BIN5b reached 3.1 kA. The coils exhibited no quench training. All the quenches were thermal runaways that occurred at the same location. In addition, we report on the field quality and ramp-dependent hysteresis measurements taken during the test of BIN5a at 4.2 K. Overall, our results demonstrate that the CCT technology is a route that should be further investigated for making high field, potentially quench training free dipole magnets with Bi-2212 cables.
Continuous narrowband lasing with coherently driven V-level atoms
Authors: Hotter Christoph , Plankensteiner David , Ritsch Helmut 
Published: November 2020

Abstract
Simultaneous strong coherent pumping of the two transitions of a V-level atom with very different decay rates has been predicted to create almost perfect inversion on the narrower transition. Using the example of the blue and red transitions in Strontium we show that for suitable operating conditions the corresponding resonant gain can be used to continuously operate a laser on the narrow transition. In particular, for a strong detuning of the pump field with respect to the narrow transition, coherent laser emission occurs close to the bare atomic transition frequency exhibiting only a negligible contribution from coherent pump light scattered into the lasing mode. Calculations of the cavity output spectrum show that the resulting laser linewidth can get much smaller than the bandwidth of the pump light and even the natural linewidth of the narrow atomic transition. Its frequency is closely tied to the atomic transition frequency for properly chosen atom numbers. Simulations including atomic motion show Doppler cooling on the strong transition with minor motion heating on the lasing transition, so that continuous laser operation in the presence of a magneto-optical trap should be possible with current experimental technology.