bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coherent narrow-linewidth optical frequency synthesis across the optical telecommunication band
Authors: Yang Honglei , Zhang Shengkang , Zhao Weinan , Zhang Li 
Published: April 2020

Broadband, coherent narrow-linewidth optical frequency synthesis is of crucial importance in dual-comb interferometric measurement. Here we present a detailed description of the construction and performance characterization of a hertz-level linewidth coherent optical frequency synthesizer across the optical telecommunication band. A narrow-linewidth cavity-stabilized laser at 1565.00 nm is built and coherently transferred through a fiber link with an additional fractional frequency instability of

2.0

×

10

−
16

at 1 s averaging time. Broadband, coherent optical frequency synthesis is then achieved by steering one mode of a laser frequency comb with the transferred optical frequency oscillation. By beating with a 1542.14 nm ultra-stable cavity-stabilized laser, the evaluated fractional frequency stability and absolute linewidth of the nearest synthesized optical oscillation are

3.5

×

10

−
15

at 1 s averaging time and 1.8 Hz, respectively. According to the ultra-low-noise feature of the utilized laser frequency comb of

4.7

×

10

−
17

at 1 s averaging time, the synthesized optical frequency oscillations could maintain the high coherence across the comb’s output bandwidth.
Demonstration of using two aperture pairs combined with multiple-mode receivers and MIMO signal processing for enhanced tolerance to turbulence and misalignment in a 10  Gbit/s QPSK FSO link
Authors: Song Haoqian , Li Long , Pang Kai , Zhang Runzhou , Zou Kaiheng , Zhao Zhe , Du Jing , Song Hao , Liu Cong , Cao Yinwen , Willner Ari N. , Almaiman Ahmed , Bock Robert , Lynn Brittany , Tur Moshe , Willner Alan E. 
Published: April 2020

We utilize aperture diversity combined with multiple-mode receivers and multiple-input-multiple-output (MIMO) digital signal processing (DSP) to demonstrate enhanced tolerance to atmospheric turbulence and spatial misalignment in a 10 Gbit/s quadrature-phase-shift-keyed (QPSK) free-space optical (FSO) link. Turbulence and misalignment could cause power coupling from the fundamental Gaussian mode into higher-order modes. Therefore, we detect power from multiple modes and use MIMO DSP to enhance the recovery of the original data. In our approach, (a) each of multiple transmitter apertures transmits a single fundamental Gaussian beam carrying the same data stream, (b) each of multiple receiver apertures detects the signals that are coupled from the fundamental Gaussian beams to multiple orbital angular momentum (OAM) modes, and (c) MIMO DSP is used to recover the data over multiple modes and receivers. Our simulation shows that the outage probability could be reduced from

>

0.1

to

<

0.01

. Moreover, we experimentally demonstrate the scheme by transmitting two fundamental Gaussian beams carrying the same data stream and recovering the signals on OAM modes 0 and

+

1

at each receiver aperture. We measure an up to

∼

10

d
B

power-penalty reduction for a bit error rate (BER) at the 7% forward error correction limit for a 10 Gbit/s QPSK signal.
Rapid acquisition of broadband two-dimensional electronic spectra by continuous scanning with conventional delay lines
Authors: Spencer Austin P. , Chen Lin X. 
Published: April 2020

A passively phase-stable, broadband (

∼

7

f
s

,

>

2000

c
m

−
1

) two-dimensional (2D) electronic spectroscopy apparatus that achieves rapid acquisition rates by continuously—rather than step-wise—scanning the Fourier-transform dimension is demonstrated for the first time, to the best of our knowledge. This is made possible through use of a partially common path interferometer design in which the coherence time

τ

is sampled in a “rotating frame.” Rapid, continuous scanning of

τ

increases the duty cycle of signal collection, rejects the majority of excitation pulse scatter, and enables the measurement of a complete 2D spectrum in 92 ms, which minimizes the influence of pulse intensity and delay fluctuations on the 2D spectrum. In practice, these improvements make possible the acquisition of hundreds of 2D spectra in tens of minutes, which opens the door to dense sampling of ultrafast relaxation dynamics and to generating extremely broadband 3D Fourier-transform spectra.
Creating a three-dimensional surface with antireflective properties by using femtosecond-laser Bessel-beam-assisted thermal oxidation
Authors: Li Xiaowei , Xu Zhijie , Jiang Lan , Shi Yaoming , Wang Andong , Huang Lingling , Wei Qunshuo 
Published: April 2020

Metal surfaces with low reflectance have received considerable attention for their great optical, electrical, and thermal properties. However, the difficulty in achieving low reflectance on curved metal surfaces has hindered their practical applications. We propose a rapid and flexible method for processing a three-dimensional surface with antireflective properties. A Bessel beam created using an axicon is employed to generate ripple structures on the curved surface, thereby assisting subsequent thermal oxidation. Ripple structures coated with oxide semiconductor nanowires are then processed on a Cu substrate, thus further reducing reflectance. Antireflective properties with a minimum reflectance of less than 0.015 at a wavelength of 500–1200 nm could be achieved by using this method. This presented approach reduces dimensionality in laser processing, subsequently improving processing efficiency, and provides a foundation for the practical application of metal antireflective surfaces.
The US, China and Huawei Debate on 5G Telecom Technology: Global Apprehensions and the Indian Scenario
Authors: Jaisal E.K. 
Published: April 2020

AbstractAdvancements in connectivity and telecommunications have redefined the ways people access information and services. The 5th Generation of telecom technology which is set to open up new avenues and opportunities have but stirred up a series of escalating tensions between two mighty powers in global politics- the US and China. While 5G offers an array of options for global trade and co-operation to flourish, it has generated counter-intuitive results, at least temporarily, with the US adopting a protectionist standpoint to contain the Chinese dominance in the telecom sector, citing security concerns. The US lobbying against Chinese vendors, particularly Huawei, has generated uncertainty among countries on the adoption and deployment of equipment provided by the firm. The paper attempts to comprehend the issues revolving around Huawei, its extent of influence, the global impact of US sanctions and to explore the ways forward for countries like India.
Structural Variant in Mitochondrial-Associated Gene (MRPL3) Induces Adult-Onset Neurodegeneration with Memory Impairment in the Mouse
Authors: Cahill Lindsay S. , Cameron Jessie M. , Winterburn Julie , Macos Patrick , Hoggarth Johnathan , Dzamba Misko , Brudno Michael , Nutter Lauryl M. J. , Sproule Thomas J. , Burgess Robert W. , Henkelman R. Mark , Sled John G. 
Published: April 2020

An impediment to the development of effective therapies for neurodegenerative disease is that available animal models do not reproduce important clinical features such as adult-onset and stereotypical patterns of progression. Usingin vivomagnetic resonance imaging and behavioral testing to study male and female decrepit mice, we found a stereotypical neuroanatomical pattern of progression of the lesion along the limbic system network and an associated memory impairment. Using structural variant analysis, we identified an intronic mutation in a mitochondrial-associated gene (Mrpl3) that is responsible for the decrepit phenotype. While the function of this gene is unknown, embryonic lethality inMrpl3knock-out mice suggests it is critical for early development. The observation that a mutation linked to energy metabolism precipitates a pattern of neurodegeneration via cell death across disparate but linked brain regions may explain how stereotyped patterns of neurodegeneration arise in humans or define a not yet identified human disease.SIGNIFICANCE STATEMENTThe development of novel therapies for adult-onset neurodegenerative disease has been impeded by the limitations of available animal models in reproducing many of the clinical features. Here, we present a novel spontaneous mutation in a mitochondrial-associated gene in a mouse (termed decrepit) that results in adult-onset neurodegeneration with a stereotypical neuroanatomical pattern of progression and an associated memory impairment. The decrepit mouse model may represent a heretofore undiagnosed human disease and could serve as a new animal model to study neurodegenerative disease.
Intracellular Calcium Responses Encode Action Potential Firing in Spinal Cord Lamina I Neurons
Authors: Harding Erika K. , Boivin Bruno , Salter Michael W. 
Published: April 2020

Maladaptive plasticity of neurons in lamina I of the spinal cord is a lynchpin for the development of chronic pain, and is critically dependent on intracellular calcium signaling. However, the relationship between neuronal activity and intracellular calcium in these neurons is unknown. Here we combined two-photon calcium imaging with whole-cell electrophysiology to determine how action potential firing drives calcium responses within subcellular compartments of male rat spinal cord lamina I neurons. We found that single action potentials generated at the soma increase calcium concentration in the somatic cytosol and nucleus, and these calcium responses invade dendrites and dendritic spines by active backpropagation. Calcium responses in each compartment were dependent on voltage-gated calcium channels, and somatic and nuclear calcium responses were amplified by release of calcium from ryanodine-sensitive intracellular stores. Grouping single action potential-evoked calcium responses by neuron type demonstrated their presence in all defined types, as well as a high degree of similarity in calcium responses between neuron types. With bursts of action potentials, we found that calcium responses have the capacity to encode action potential frequency and number in all compartments, with action potential number being preferentially encoded. Together, these findings indicate that intracellular calcium serves as a readout of neuronal activity within lamina I neurons, providing a unifying mechanism through which activity may regulate plasticity, including that seen in chronic pain.SIGNIFICANCE STATEMENTDespite their critical role in both acute pain sensation and chronic pain, little is known of the fundamental physiology of spinal cord lamina I neurons. This is especially the case with respect to calcium dynamics within these neurons, which could regulate maladaptive plasticity observed in chronic pain. By combining two-photon calcium imaging and patch-clamp electrophysiological recordings from lamina I neurons, we found that action potential firing induces calcium responses within the somatic cytosol, nucleus, dendrites, and dendritic spines of lamina I neurons. Our findings demonstrate the presence of actively backpropagating action potentials, shifting our understanding of how these neurons process information, such that calcium provides a mechanism for lamina I neurons to track their own activity.
An Epilepsy-Associated SV2A Mutation Disrupts Synaptotagmin-1 Expression and Activity-Dependent Trafficking
Authors: Harper Callista B. , Small Christopher , Davenport Elizabeth C. , Low Darryl W. , Smillie Karen J. , Martínez-Mármol Ramón , Meunier Frédéric A. , Cousin Michael A. 
Published: April 2020

The epilepsy-linked geneSV2A, has a number of potential roles in the synaptic vesicle (SV) life cycle. However, how loss of SV2A function translates into presynaptic dysfunction and ultimately seizure activity is still undetermined. In this study, we examined whether the first SV2A mutation identified in human disease (R383Q) could provide information regarding which SV2A-dependent events are critical in the translation to epilepsy. We utilized a molecular replacement strategy in which exogenous SV2A was expressed in mouse neuronal cultures of either sex, which had been depleted of endogenous SV2A to mimic the homozygous human condition. We found that the R383Q mutation resulted in a mislocalization of SV2A from SVs to the plasma membrane, but had no effect on its activity-dependent trafficking. This SV2A mutant displayed reduced mobility when stranded on the plasma membrane and reduced binding to its interaction partner synaptotagmin-1 (Syt1). Furthermore, the R383Q mutant failed to rescue reduced expression and dysfunctional activity-dependent trafficking of Syt1 in the absence of endogenous SV2A. This suggests that the inability to control Syt1 expression and trafficking at the presynapse may be key in the transition from loss of SV2A function to seizure activity.SIGNIFICANCE STATEMENTSV2A is a synaptic vesicle (SV) protein, the absence or dysfunction of which is linked to epilepsy. However, the series of molecular events that result in this neurological disorder is still undetermined. We demonstrate here that the first human mutation in SV2A identified in an individual with epilepsy displays reduced binding to synaptotagmin-1 (Syt1), an SV protein essential for synchronous neurotransmitter release. Furthermore, this mutant cannot correct alterations in both Syt1 expression and trafficking when expressed in the absence of endogenous SV2A (to mimic the homozygous human condition). This suggests that the inability to control Syt1 expression and trafficking may be key in the transition from loss of SV2A function to seizure activity.
BRAG2a Mediates mGluR-Dependent AMPA Receptor Internalization at Excitatory Postsynapses through the Interaction with PSD-95 and Endophilin 3
Authors: Fukaya Masahiro , Sugawara Takeyuki , Hara Yoshinobu , Itakura Makoto , Watanabe Masahiko , Sakagami Hiroyuki 
Published: April 2020

Brefeldin A-resistant ArfGEF 2 (BRAG2) [or Iqsec1 (IQ motif and Sec7 domain-containing protein 1)] is a guanine nucleotide exchange factor for ADP ribosylation factor 6 (Arf6), a small GTPase implicated in the membrane trafficking between the plasma membrane and endosomes. BRAG2 regulates Arf6-dependent endocytosis of AMPA receptors (AMPARs) through the direct interaction during the hippocampal long-term depression. However, the molecular mechanism by which the BRAG2–Arf6 pathway links AMPARs to the endocytic machinery remains elusive. Herein, using mouse brains of both sexes, we demonstrated that BRAG2a, an alternative isoform with a long C-terminal insert containing a proline-rich domain and type I PDZ-binding motif, was selectively localized to the excitatory postsynaptic density (PSD). Using yeast two-hybrid screening, we identified PSD-95 and endophilin 1/3 as BRAG2a-binding partners in the brain. The interaction with PSD-95 was required for synaptic targeting of BRAG2a. In cultured hippocampal neurons, stimulation of group I metabotropic glutamate receptors (mGluRs) increased the interaction of BRAG2a with endophilin 3 and concomitant Arf6 activation in a time-dependent manner. Knockdown of BRAG2 in cultured hippocampal neurons blocked the mGluR-dependent decrease in surface AMPAR levels, which was rescued by introducing wild-type BRAG2a, but not wild-type BRAG2b or BRAG2a mutants lacking the ability to activate Arf6 or to interact with endophilin 3 or PSD-95. Further postembedding immunoelectron microscopic analysis revealed the preorganized lateral distribution of BRAG2a, Arf6, and endophilin 3 for efficient endocytosis at the postsynaptic membrane. Together, the present findings unveiled a novel molecular mechanism by which BRAG2a links AMPARs to the clathrin-dependent endocytic pathway through its interaction with PSD-95 and endophilin 3.SIGNIFICANCE STATEMENTBRAG2/Iqsec1 is a GDP/GTP exchange factor for ADP ribosylation factor 6 (Arf6), a small GTPase implicated in the membrane trafficking between the plasma membrane and endosomes, and regulates Arf6-dependent endocytosis of AMPARs through direct interaction during hippocampal long-term depression, one of the mechanisms of synaptic plasticity related to learning and memory. However, the molecular mechanism by which the BRAG2–Arf6 pathway links AMPARs to the endocytic machinery remains elusive. Here, we identified isoform-specific mechanisms of BRAG2-mediated AMPAR internalization. We demonstrated that the interaction of BRAG2a isoform with PSD-95 and endophilin 3 was required for the mGluR-dependent decrease in surface AMPARs in hippocampal neurons. These results unveiled a novel molecular mechanism by which BRAG2 links AMPARs to the clathrin-mediated endocytic machinery at postsynaptic sites.
Allen, Jones and Hall: Black Social Entrepreneurship During the Early Republic
Authors: Forrest Donovan 
Published: April 2020

In the years after the Revolutionary War, the cities of Philadelphia, Pennsylvania and Boston, Massachusetts saw a dramatic increase in the social entrepreneurship of African- Americans. The prevalent disenfranchisement of African-Americans in the era of the early Republic, the signing of the Declaration of Independence while most Blacks were enslaved and denied their basic right to life, liberty, and their pursuit of happiness, created an American society filled with discrimination and injustice. In the midst of hypocrisy, Black men rose to the occasion and founded organizations that provided Blacks with a sense of identity, comfort, and support.
Nickel Allergic Contact Dermatitis: Identification, Treatment, and Prevention
Authors: Silverberg Nanette B. , Pelletier Janice L. , Jacob Sharon E. , Schneider Lynda C. ,   SECTION ON DERMATOLOGY, SECTION ON ALLERGY AND IMMUNOLOGY, Cohen Bernard , Horii Kimberly A. , Kristal Leonard , Maguiness Sheilagh M. , Tollefson Megha Mathakia , Weinstein Miriam G. , Wright Teresa S. , Yan Albert C. , Matsui Elizabeth C. , Bird John A. , Davis Carla McGuire , Hernandez-Trujillo Vivian Pilar , Orange Jordan S. , Pistiner Michael , Wang Julie 
Published: April 2020

Nickel is a ubiquitous metal added to jewelry and metallic substances for its hardening properties and because it is inexpensive. Estimates suggest that at least 1.1 million children in the United States are sensitized to nickel. Nickel allergic contact dermatitis (Ni-ACD) is the most common cutaneous delayed-type hypersensitivity reaction worldwide. The incidence among children tested has almost quadrupled over the past 3 decades. The associated morbidities include itch, discomfort, school absence, and reduced quality of life. In adulthood, individuals with Ni-ACD may have severe disabling hand eczema. The increasing rate of Ni-ACD in children has been postulated to result from early and frequent exposure to metals with high amounts of nickel release (eg, as occurs with ear piercing or with products used daily in childhood such as toys, belt buckles, and electronics).To reduce exposure to metal sources with high nickel release by prolonged and direct contact with human skin, Denmark and the European Union legislated a directive several decades ago with the goal of reducing high nickel release and the incidence of Ni-ACD. Since then, there has been a global reduction in incidence of Ni-ACD in population-based studies of adults and studies of children and young adults being tested for allergic contact dermatitis. These data point to nickel exposure as a trigger for elicitation of Ni-ACD and, further, provide evidence that legislation can have a favorable effect on the economic and medical health of a population.This policy statement reviews the epidemiology, history, and appearances of Ni-ACD. Examples of sources of high nickel release are discussed to highlight how difficult it is to avoid this metal in modern daily lives. Treatments are outlined, and avoidance strategies are presented. Long-term epidemiological interventions are addressed. Advocacy for smarter nickel use is reviewed. The American Academy of Pediatrics supports US legislation that advances safety standards (as modeled by the European Union) that protect children from early and prolonged skin exposure to high–nickel-releasing items. Our final aim for this article is to aid the pediatric community in developing nickel-avoidance strategies on both individual and global levels.
Market integration among foreign exchange rate movements in central and eastern European countries
Authors: Hung Ngo Thai 
Published: April 2020

AbstractThis study focuses on the level of interdependence across the Central and Eastern European (CEE) foreign exchange markets (Hungary, Poland, the Czech Republic, Romania and Croatia) from September 2008 to September 2017, using the return spillover measure proposed by Diebold and Yilmaz (2009; 2012). We mainly find a bidirectional volatility spillover among these assets and the cross-market linkages in the CEE region have become stronger over time. Furthermore, the Czech exchange market has a significant influence on the rest of the foreign exchange markets. The total spillover remained very high over the periods 2010–2012 and 2015–2017, despite the noteworthy fluctuations in other periods. These results would also be useful for portfolio managers, policy makers and speculative traders to develop exploitable strategies, by providing knowledge of the transmission mechanisms of the volatility of foreign exchange markets. The results may support the distribution of assets in a financial portfolio, especially after financial integration.
Rights Statement Selection Tool
Authors: Galson Gabriel , Karl Brandy 
Published: April 2020

Through the standardized rights statements it provides, RightsStatements.org allows institutions to clearly communicate the copyright status of digitized cultural heritage works, promoting their reuse. However, it can be tricky for institutions to determine correct statement usage through the site without additional context. The Rights Statement Selection Tool [bit.ly/RSSTOOL] is an interactive infographic that serves to visually explain the statement selection workflow, allowing a copyright novice to identify the correct statement through decision tree alone. This legal tool lets cultural heritage institutions assign rights statement review work to non-experts, potentially increasing the number of items that can be evaluated. It’s meant to be integrated into cataloging workflows: clickable links lead to each statement’s URI page, and it can be viewed in a browser alongside the RightsStatements.org site. The Tool serves as a complete visual reference to the statements: each is covered and explained. It aggregates relevant resources and serves as a structural bridge between related copyright status determination charts and Creative Commons charts. Donation agreements–often a source of confusion for rights statements reviewers–are covered as well. The Tool is, by design, as agnostic to national law as possible. The US-centered copyright status determination charts that feed into it (such as the Hirtle and Sunstein charts) could easily be swapped for resources reflecting other countries’ national law; the RightsStatements.org logic that it covers would remain unchanged, and so would the chart. As the RightsStatements.org standard goes global, this tool can be translated, adapted, and re-used beyond the US.