bluuebunny/crossref_metadata_2025 huggingface dataset:
Reinforcements, production techniques and property analysis of AA7075 matrix composites − a critical review
Authors: B.S. Sowrabh , B.M. Gurumurthy , Y.M. Shivaprakash , Sharma Sathya Shankara
Published: December 2021

Aluminium alloy based metal matrix composites are being extensively used in the aerospace, automobile, defense, marine and electronic industries owing to their excellent strength, high resistance to wear, corrosion and better thermal stability. Many investigators have explored different aluminium alloy series composites, like heat treatable AA2024, AA6061 and AA7075 since the properties of these matrix alloys can be easily tailor made to suite specific application due to easy processability and heat treatability. AA7075 alloy matrix is predominantly being used, as it exhibits high ultimate tensile strength, resistance to corrosion and fatigue in the group. In the current review work, attention is focused to present types of reinforcing materials used, benefits of reinforcement hybridization, methods employed for composite production and critical property analysis, with conclusions of experimentation and the suggested prospective applications of AA7075 composites. Due to good castability and moldability variety of processing techniques in solid, semisolid and liquid states are possible. As matrix alloy, low processing temperature, ability to accommodate reinforcements and adoptability to different reinforcing techniques, it is easy to obtain optimal properties as per the application. AA7075 with small addition of copper is paved the path in the field of electronic and military applications due to high thermal and electrical conductance. Even pure metal addition & magnesium with copper facilitate good weldability, plasticity and corrosion resistance. Due to the flexibility in accommodating carbide and oxide compound reinforcements in the matrix, this matrix composite widens versatility limit due to excellent hardness and wear resistance. CNT and graphite reinforcements to this aluminium series matrix are marked as ultra-high precision components in defense field.
Fifth Metacarpal Neck Fractures: Outcome-influencing Factors
Authors: Pereira Catarina , Ribau Ana , Barbosa Tiago , Rodrigues Filipe , Catelas Diogo , Neves Pedro
Published: December 2021

Introduction Fifth metacarpal neck fractures are extremely common, but there is still no consensus regarding the ideal course of treatment.

Volar angulation and shortening are decisive factors; however, there is still controversy about the cut-off values that translate into worse clinical results.

The present study aims to answer these questions in order to provide additional data to aid in the clinical practice and decision making.

Materials and Methods A retrospective study evaluated patients with fifth metacarpal fractures treated between 2013 and 2018. A total of 133 patients were included, with an average follow-up of 2 months. Surgery was performed in 21 patients, and 112 were treated conservatively. The radiological assessment of volar anguation and shortening was based in the first and last radiographs of the follow-up. The patients were contacted and submited to a questionnaire that included the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) score and subjective evaluations of pain (Visual Analogue Scale, VAS), hand strength, stiffness and finger mobility, and cosmetic result.

Results Surgery was more successful in reducing angulation than the conservative treatment, achieving more anatomic final values for angulation and shortening (p < 0.05). On the other hand, surgery seems to be associated with a higher notion of limited finger mobility (p = 0.02).

Among patients treated conservatively, inicial angulations > 60° and final angulations > 50° were associated with worse cosmetic results (p = 0,039). Final shortening > 4 mm translated into a higher notion of stiffness and limited finger mobility (p = 0.034).

More advanced age showed a correlation with higher scores on the VAS (p = 0.023) and QuickDASH (p < 0,001). Female patients (p = 0.02) were also associated with higher VAS scores. The overall satisfaction rate was of 97%.

Conclusion Although globally the functional outcome of these fractures is very good, the present study reports several factors that should be considered when treating fifth metacarpal neck fractures.
Mental health changes and the willingness to take risks
Authors: Li Lu , Richter Andreas , Steinorth Petra
Published: December 2021

Utilizing the longitudinal SOEP data representative of the German population, we find that mental health shocks significantly decrease the willingness to take risks. We also find that mental health improvements increase the willingness to take risks significantly. Our findings are relevant for better understanding the economic decision making of the large number of individuals with mental health issues.
Impact of Artificial Intelligence on HR practices in the UAE
Authors: Singh Abhilasha , Shaurya Apurva
Published: December 2021

Social trends and information technology are creating pressure, resulting in organizations being forced to update and recreate themselves. Against this backdrop there is an increasing trend to adopt artificial intelligence technologies. This study aims to explore and investigate the effect of Artificial Intelligence (AI) on Human Resources (HR) practices in UAE companies with the help of mixed-method design. A mixed-method design was applied to explore and test the research questions. Semi-structured interviews and survey were conducted, respectively for both the study designs. AI and HR personnel were approached as sample participants for this study. Thematic analysis and PLS-SEM (Partial least squares path modeling) were used to analyze the data, respectively. Positive and significant effects of planned training and development process (0.231→0.021), tactical performance appraisal and integration of AI (0.719→0.000), and integration of AI and efficient HR practices (0.204→0.131) were shown. The moderating role of ease of use on integration of AI and efficient HR practices was negative and insignificant. AI plays an essential role in shifting the HR functions to enter the digitization era. The types of businesses and abilities require some activities such as training and development due to the increased use of technology.
The risks of invisibilization of populations and places in environment-migration research
Authors: Borderon Marion , Best Kelsea B. , Bailey Karen , Hopping Doug L. , Dove Mackenzie , Cervantes de Blois Chelsea L.
Published: December 2021

Recent years have seen an increase in the use of secondary data in climate adaptation research. While these valuable datasets have proven to be powerful tools for studying the relationships between people and their environment, they also introduce unique oversights and forms of invisibility, which have the potential to become endemic in the climate adaptation literature. This is especially dangerous as it has the potential to introduce a double exposure where the individuals and groups most likely to be invisible to climate adaptation research using secondary datasets are also the most vulnerable to climate change. Building on significant literature on invisibility in survey data focused on hard-to-reach and under-sampled populations, we expand the idea of invisibility to all stages of the research process. We argue that invisibility goes beyond a need for more data. The production of invisibility is an active process in which vulnerable individuals and their experiences are made invisible during distinct phases of the research process and constitutes an injustice. We draw on examples from the specific subfield of environmental change and migration to show how projects using secondary data can produce novel forms of invisibility at each step of the project conception, design, and execution. In doing so, we hope to provide a framework for writing people, groups, and communities back into projects that use secondary data and help researchers and policymakers incorporate individuals into more equitable climate planning scenarios that “leave no one behind.”
Г-L intervalley separation and electron mobility in GaAsSb grown on InP: Transport comparison with the GaInAs and GaInAsSb alloys
Authors: Bolognesi C. R. , Ostinelli O. J. S.
Published: December 2021

GaAs0.51Sb0.49 is lattice-matched to InP and finds electron transport applications in base or absorber layers in high-speed heterostructure bipolar transistors or photodiodes, because its staggered (“type-II”) band alignment with InP favors electron injection across abrupt heterojunctions. Little remains known about electron transport properties and band structure details of GaAsxSb1−x near x = 0.5. Particularly, based on the Γ-L intervalley separation in binary constituents (ΔΓL = 84 meV in GaSb and 290 meV in GaAs at 300 K), interpolation suggests a low Γ-L separation in GaAs0.51Sb0.49 before considering energy gap bowing effects. To gain insight into electron transport in GaAs0.51Sb0.49, we characterized experimental Hall electron mobilities vs carrier concentration at 300 and 77 K in n-type GaAs0.51Sb0.49, Ga0.47In0.53As, and Ga0.76In0.24As0.67Sb0.33 alloys nearly matched to InP. In marked contrast to the other two alloys, GaAs0.51Sb0.49 exhibits a sharp rise in 77 K electron mobility, which evidences L-valley de-population for lower electron concentrations. A two-band transport analysis reveals a Γ-L valley separation ΔΓL = 91 meV at 77 K, significantly lower than values recommended in the literature. Based on the reported temperature variations of ΔΓL in GaAs and GaSb, 84 < ΔΓL < 95 meV is expected at 300 K. The corresponding GaAsxSb1−x L-valley bowing parameter is cL = 1.63 eV, significantly higher than the 1.1–1.2 eV recommended in the literature. In contrast to GaAsxSb1−x, GaInAsSb grown on InP displays a strong alloy scattering, which limits its low-temperature electron mobility.
High-efficiency circularly polarized green light emission from GaN-based laser diodes integrated with GaN metasurface quarterwave plate
Authors: Wang Miao , Lin Yu , Yi Jue-Min , Li De-Yao , Liu Jian-Ping , Cao Bing , Wang Chin-Hua , Wang Jian-Feng , Xu Ke
Published: December 2021

We demonstrated high efficient circularly polarized emission from the InGaN/GaN quantum well green laser diode (LD) integrated with GaN metasurface quarterwave plates. Optical properties of the nanoscale thin GaN nanograting metasurface were numerically studied and optimized for a quarter-wave plate. The fabricated nanogratings then were integrated on the emission facet of the LD. Both conversion efficiency and the polarization state of the device were measured, and the conversion efficiency is around 80% while the degree of circular polarization is maintained around 0.99. Our results of achieving a high degree of polarization and a high conversion efficiency at the integrated LD device pay the way for multi-functional applications in bio-imaging, submarine optical communication, quantum communication, and holographic display.
Two-dimensional lifetime-based kHz surface temperature measurement technique using phosphor thermometry
Authors: Cai Tao , Han Jeongmin , Kim Mirae , Kim Kyung Chun
Published: December 2021

A kHz phosphor thermometry technique was developed for contactless two-dimensional measurements with Mg4FGeO6: Mn4+ utilizing its rise and decay of the phosphorescence. Different from the traditional method that phosphorescence rises when the decay is complete, high-frequency excitation light was applied in this study, which causes a rise of phosphorescence with an incomplete decay of phosphorescence. This eventually causes the phosphor to emit a waveform signal. Experimental results show that this phosphorescence waveform signal is stable and only affected by temperature when the excitation conditions are fixed. A calibration curve can then be obtained by calculating the ratio of the crests and troughs of the phosphorescence signal. This study shows that the developed method has high precision and is easy to operate for two-dimensional high-frequency temperature measurement.
Bias-dependent tunneling anisotropic magnetoresistance in antiferromagnetic Pd-doped FeRh-based junctions
Authors: Han L. , Chen X. Z. , Li X. L. , Zhang J. , Feng J. F. , Li F. , Song C. , Pan F.
Published: December 2021

We report the bias-dependent tunneling anisotropic magnetoresistance (TAMR) in antiferromagnetic α′-Fe(Rh0.98Pd0.02)/MgO/γ-Fe(Rh0.98Pd0.02) junctions. The TAMR effect is driven by the antiferromagnetic-ferromagnetic phase transition of α′-Fe(Rh0.98Pd0.02) and concomitantly large variation of the density of states (DOS) near the Fermi level. It exhibits polarity reversion behavior with increasing bias voltage, i.e., negative and positive polarities for low and high bias voltages, respectively. Such bias-dependent TAMR is comprehended by first-principle calculations, where a crossing point and subsequent magnitude-reversion emerge between the DOS of antiferromagnetic and ferromagnetic phases of α′-Fe(Rh0.98Pd0.02). Harnessing the tunneling behavior by a feasible bias voltage in an antiferromagnet-based junction is a frontier of great promise in antiferromagnet spintronics.
Controlling the polarization of chiral dipolar emission with a spherical dielectric nanoantenna
Authors: Yao Kan , Zheng Yuebing
Published: December 2021

Circularly polarized light (CPL) carrying spin angular momentum is crucial to many applications, such as quantum computing, optical communication, novel displays, and biosensing. Nonetheless, the emission from chiral molecules contains comparable CPL components with opposite handedness, resulting in low levels of CPL overall with a small dissymmetry factor and fixed handedness consistent with the handedness of the molecules. Nanoantennas have proved to be useful tools for controlling the emission properties of quantum emitters. In particular, dielectric resonators support electric and magnetic modes, which implies unparalleled opportunities to interact with chiral molecules whose emission originates from both electric and magnetic dipole transitions. In this work, we theoretically study the effects of a spherical dielectric nanoantenna on the directionality and polarization of emission from a chiral molecule. With exact analytical solutions based on generalized Mie theory, we show that directional chiral light emission and nontrivial polarization modulation, such as handedness reversal or chirality enhancement, can be achieved simultaneously for a chiral dipole tangentially coupled with a silicon nanosphere. The influence of the relative strength and orientation between the electric and magnetic dipole moments is also discussed. Our results suggest a new approach to controlling chiral dipolar emission and could benefit the development of chiral light sources.
An improved deep learning-based algorithm for 3D reconstruction of vacuum arcs
Authors: Wang Zhenxing , Pan Yangbo , Zhang Wei , Li Haomin , Geng Yingsan , Wang Jianhua , Sun Liqiong
Published: December 2021

Extensive attempts have been made to enable the application of deep learning to 3D plasma reconstruction. However, due to the limitation on the number of available training samples, deep learning-based methods have insufficient generalization ability compared to the traditional iterative methods. This paper proposes an improved algorithm named convolutional neural network-maximum likelihood expectation maximization-split-Bergman (CNN-MLEM-SB) based on the combination of the deep learning CNN and an iterative algorithm known as MLEM-SB. This method uses the prediction result of a CNN as the initial value and then corrects it using the MLEM-SB to obtain the final results. The proposed method is verified experimentally by reconstructing two types of vacuum arcs with and without transverse magnetic field (TMF) control. In addition, the CNN and the proposed algorithm are compared with respect to accuracy and generalization ability. The results show that the CNN can effectively reconstruct the arcs between a pair of disk contacts, which has specific distribution patterns: its structural similarity index measurement (SSIM) can reach 0.952. However, the SSIM decreases to 0.868 for the arc between a pair of TMF contacts, which is controlled by the TMF and has complex distribution patterns. Compared with the CNN reconstruction method, the proposed algorithm can achieve a higher reconstruction accuracy for any arc shape. Compared with the iterative algorithm, the proposed algorithm’s reconstruction efficiency is higher by 38.24% and 35.36% for the vacuum arc between the disk and the TMF contacts, respectively.
Hybridizing piezoelectric and electromagnetic mechanisms with dynamic bistability for enhancing low-frequency rotational energy harvesting
Authors: Fang Shitong , Xing Juntong , Chen Keyu , Fu Xinlei , Zhou Shengxi , Liao Wei-Hsin
Published: December 2021

This Letter proposes a rotational energy harvester with hybrid piezoelectric and electromagnetic mechanisms and dynamic bistability. It consists of a piezoelectric stack with a force magnification frame and two connected springs, and two electromagnetic coils with inner impact stoppers. On the one hand, the hybrid energy transduction is applied in the gravity-based rotational energy harvester to enhance the energy output. On the other hand, the dynamic bistability by utilizing the centrifugal force is proposed to improve low-frequency performances. Simulation and experiments demonstrate that the proposed harvester starts to exhibit the bistability as the rotational frequency is increased from zero with subsequent interwell, chaotic, and intrawell motions, among which the interwell motions can increase the peak power from piezoelectric and electromagnetic parts by 24.99% and 57.41%, respectively. Specifically, the maximum total output power in experiments is measured to be 2.98 mW at 7.5 Hz and the spring stiffness of 4200 N/m. Moreover, the total power and frequency bandwidth are both higher but broader/narrower with a higher spring stiffness or impact distance, respectively.
Characteristics of 1520 nm InGaAs multijunction laser power converters
Authors: Wang An-Cheng , Sun Yu-Run , Yu Shu-Zhen , Yin Jia-Jing , Zhang Wei , Wang Jun-Sheng , Fu Qiu-Xue , Han Yan-Hui , Qin Jie , Dong Jian-Rong
Published: December 2021

Eight-junction In0.53Ga0.47As laser power converters (LPCs) designed for converting the laser energy around 1520 nm are demonstrated with a maximum room-temperature (RT) conversion efficiency of 36.9 ± 0.9% at 53.9 W/cm2. Subcell photocurrents of the LPC are extracted from current steps in wide-voltage-range I–V curves, and the current mismatching degree (Cm) at RT is determined to be ∼5%. Temperature dependence of the Cm of the InGaAs LPC confirms that the LPC reaches its minimal Cm around RT. Finally, the LPCs are characterized under different temperatures and laser powers, and the temperature coefficients of the open circuit voltage and conversion efficiency are fitted to be −12 mV/K and −0.155%abs/K, respectively. The experimental results show the potential of In0.53Ga0.47As multijunction LPCs for applications in free space and fiber-based long distance laser power transmission.
Anomalous suppressed thermal conductivity in CuInTe2 under pressure
Authors: Li Yongheng , Liu Junyan , Wang Xueyun , Hong Jiawang
Published: December 2021

Pressure is an effective way to improve the thermoelectric performance by optimizing the electronic transport property. However, the increase in the thermal conductivity under pressure limits the improvement of thermoelectric properties. Here, based on the first-principles calculation and phonon Boltzmann transport equations, we find the unusual negative relation between the thermal conductivity and pressure in CuInTe2, i.e., its thermal conductivity along the c direction surprisingly decreases by 49% with applying the pressure from 0 to 7.7 GPa. This anomalous phenomenon mainly originates from remarkably enhanced phonon scattering rates under pressure due to dramatically softened transverse acoustic phonons and low energy optical phonons, which provide more phonon–phonon scattering channels. Our findings reveal the mechanism of decrease in the lattice thermal conductivity under pressure, which could be used for further improvement in the thermoelectric performance synergetically in the presence of pressure.
Modeling the cholesteric pitch of apolar cellulose nanocrystal suspensions using a chiral hard-bundle model
Authors: Chiappini Massimiliano , Dussi Simone , Frka-Petesic Bruno , Vignolini Silvia , Dijkstra Marjolein
Published: December 2021

Cellulose nanocrystals (CNCs) are naturally sourced elongated nanocolloids that form cholesteric phases in water and apolar solvents. It is well accepted that CNCs are made of bundles of crystalline microfibrils clustered side-by-side, and there is growing evidence that each individual microfibril is twisted. Yet, the origin of the chiral interactions between CNCs remains unclear. In this work, CNCs are described with a simple model of chiral hard splinters, enabling the prediction of the pitch using density functional theory and Monte Carlo simulations. The predicted pitch P compares well with experimental observations in cotton-based CNC dispersions in apolar solvents using surfactants but also with qualitative trends caused by fractionation or tip sonication in aqueous suspensions. These results suggest that the bundle shape induces an entropy-driven chiral interaction between CNCs, which is the missing link in explaining how chirality is transferred from the molecular scale of cellulose chains to the cholesteric order.
Thermodynamics of concentration vs flux control in chemical reaction networks
Authors: Avanzini Francesco , Esposito Massimiliano
Published: December 2021

We investigate the thermodynamic implications of two control mechanisms of open chemical reaction networks. The first controls the concentrations of the species that are exchanged with the surroundings, while the other controls the exchange fluxes. We show that the two mechanisms can be mapped one into the other and that the thermodynamic theories usually developed in the framework of concentration control can be applied to flux control as well. This implies that the thermodynamic potential and the fundamental forces driving chemical reaction networks out of equilibrium can be identified in the same way for both mechanisms. By analyzing the dynamics and thermodynamics of a simple enzymatic model, we also show that while the two mechanisms are equivalent at steady state, the flux control may lead to fundamentally different regimes where systems achieve stationary growth.
An active dendritic tree can mitigate fan-in limitations in superconducting neurons
Authors: Primavera Bryce A. , Shainline Jeffrey M.
Published: December 2021

Superconducting electronic circuits have much to offer with regard to neuromorphic hardware. Superconducting quantum interference devices (SQUIDs) can serve as an active element to perform the thresholding operation of a neuron's soma. However, a SQUID has a response function that is periodic in the applied signal. We show theoretically that if one restricts the total input to a SQUID to maintain a monotonically increasing response, a large fraction of synapses must be active to drive a neuron to threshold. We then demonstrate that an active dendritic tree (also based on SQUIDs) can significantly reduce the fraction of synapses that must be active to drive the neuron to threshold. In this context, the inclusion of a dendritic tree provides dual benefits of enhancing computational abilities of each neuron and allowing the neuron to spike with sparse input activity.
Heralded single-pixel imaging with high loss-resistance and noise-robustness
Authors: Kim Junghyun , Jeong Taek , Lee Su-Yong , Kim Duk Y. , Kim Dongkyu , Lee Sangkyung , Ihn Yong Sup , Kim Zaeill , Jo Yonggi
Published: December 2021

Imaging with non-classically correlated photon-pairs takes advantages over classical limits in terms of sensitivity and a signal-to-noise ratio. However, it is still a challenge to achieve a strong resilience to background noise and losses for practical applications. In this work, we present heralded single-pixel imaging that is remarkably robust against bright background noise and severe signal losses. Using a strong temporal correlation between a photon-pair and joint measurement-based imaging method, we achieve the suppression of noise up to 1000 times larger than the signal and also demonstrate the correlation-induced SNR enhancement factor of over 200 against 70 times larger noise and a 90% signal loss compared to non-time-gated classical imaging. Our work enables correlated imaging with a highly scalable photon capacity.
Site-specific, genotypic and temporal variation in photosynthesis and its related biochemistry in wheat (
Authors: Dehigaspitiya Prabuddha , Milham Paul , Martin Anke , Ash Gavin , Gamage Dananjali , Holford Paul , Seneweera Saman
Published: December 2021

Photosynthesis in wheat (Triticum aestivum L.) pericarps may contribute appreciably to wheat grain yield. Consequently, we investigated the temporal variation of traits related to photosynthesis and sucrose metabolism in the pericarps and flag leaves of three wheat genotypes, Huandoy, Amurskaja 75 and Greece 25, which are reported to differ in expression of genes related to the C4 pathway in wheat grain. Significant site-specific, genotypic and temporal variation in the maximum carboxylation rate (Vcmax) and maximum rates of electron transport (Jmax) (biological capacity of carbon assimilation) were observed early in ontogeny that dissipated by late grain filling. Although the transcript abundance of rbcS and rbcL in flag leaves was significantly higher than in the pericarps, in line with their photosynthetic prominence, both organ types displayed similar expression patterns among growth stages. The higher N concentrations in the pericarps during grain enlargement suggest increased Rubisco; however, expression of rbcS and rbcL indicated the contrary. From heading to 14 days post-anthesis, wheat pericarps exhibited a strong, positive correlation between biological capacity for carbon assimilation and expression of key genes related to sucrose metabolism (SPS1, SUS1 and SPP1). The strong correlation between spike dry weight and the biological capacity for carbon assimilation along with other findings of this study suggest that metabolic processes in wheat spikes may play a major role in grain filling, total yield and quality.
Corrigendum 1 (published 22 Oct 2021) to: What does it mean to be for a Place?
Authors: Borrelle Stephanie B. , Koch Jonathan B. , McDonough MacKenzie Caitlin , Ingeman Kurt E. , McGill Bonnie M. , Lambert Max R. , Belason Anat M. , Dudney Joan , Chang Charlotte H. , Teffer Amy K. , Wu Grace C.
Published: December 2021

Indigenous knowledge is a multilayered knowledge system that can effectively manage global ecosystem and biodiversity conservation. Conservation is an applied discipline with the goal of preserving the world's biodiversity and ecosystems. However, settler–coloniser conservation practices often fail to fully examine how settler–coloniser epistemologies are centred at the expense of Indigenous conservation praxis. Evaluating how conservation practices outside of an Indigenous lens can become more inclusive and just is a critical area for research and reflection. We draw on our own experiences as early-career researchers working towards anticolonial, just and inclusive approaches to conservation science and practice by discussing what it means to be for a Place. We believe that a non-Indigenous conservationist who is for a Place advocates for inclusive stewardship with Indigenous Peoples and other marginalised communities to conserve species and ecosystems and the connections that bind communities to their landscapes. As an example of how settler–coloniser conservation practitioners can be for a Place, we discuss writing a policy statement in 2019 on behalf of the Society for Conservation Biology opposing the construction of the Thirty Meter Telescope on the summit of Mauna Kea, Hawai‘i. We describe the thought process behind our policy statement and provide examples of other actions for conservation researchers and practitioners working to be for a Place. We aim to provide our colleagues, particularly those trained in settler–coloniser conservation practices, an opportunity to identify more just practices for the Places we aspire to conserve.
Genomic basis of fishing-associated selection varies with population density
Authors: Crespel Amélie , Schneider Kevin , Miller Toby , Rácz Anita , Jacobs Arne , Lindström Jan , Elmer Kathryn R. , Killen Shaun S.
Published: December 2021

Significance

Fisheries-associated selection is recognized as one of the strongest potential human drivers of contemporary evolution in natural populations. The results of this study show that while simulated commercial fishing techniques consistently remove fish with traits associated with growth, metabolism, and social behavior, the specific genes under fishing selection differ depending on the density of the targeted population. This finding suggests that different fish populations of varying sizes will respond differently to fishing selection at the genetic level. Furthermore, as a population is fished over time, the genes under selection may change as the population diminishes. This could have repercussions on population resilience. This study highlights the importance of selection but also environmental and density effects on harvested fish populations.
Health benefits of decreases in on-road transportation emissions in the United States from 2008 to 2017
Authors: Choma Ernani F. , Evans John S. , Gómez-Ibáñez José A. , Di Qian , Schwartz Joel D. , Hammitt James K. , Spengler John D.
Published: December 2021

Significance

Despite decades of reductions in vehicle emissions in the United States, their impacts remain large, and the offsetting effects of different factors on benefits achieved in recent years are not well understood. We assess benefits from 2008 to 2017 on a fine spatial resolution using the latest epidemiological evidence and emissions inventories. We find that regulation continues to yield large benefits: $270 (190 to 480) billion in 2017 from reduced PM
2.5
-attributable mortality and greenhouse gas emissions. Traffic-related PM
2.5
-attributable mortality would have been 2.4 times as large in 2017 if vehicles had still been emitting at 2008 levels, accounting for most benefits. Urban passenger light-duty vehicles have become increasingly important, and major health gains require more stringent policies to curb their emissions.
Competitive dynamics underlie cognitive improvements during sleep
Authors: Chen Pin-Chun , Niknazar Hamid , Alaynick William A. , Whitehurst Lauren N. , Mednick Sara C.
Published: December 2021

Significant

Sleep facilitates both long-term episodic memory consolidation and short-term working memory functioning. However, the mechanism by which the sleeping brain performs both complex feats and which sleep features are associated with these processes remain unclear. Using a pharmacological approach, we demonstrate that long-term and working memory are served by distinct offline neural mechanisms and that these mechanisms are mutually antagonistic. We propose a sleep switch model in which the brain toggles between the two memory processes via a complex interaction at the synaptic, systems, and mechanistic level with implications for research on cognitive disturbances observed in neurodegenerative disorders such as Alzheimer’s and Parkinson's disease, both of which involve the decline of sleep.
Historical redlining and cardiovascular health: The Multi-Ethnic Study of Atherosclerosis
Authors: Mujahid Mahasin S. , Gao Xing , Tabb Loni P. , Morris Colleen , Lewis Tené T.
Published: December 2021

Significance

How structural racism contributes to the disproportionate burden of cardiovascular disease risk on minoritized groups in the United States is understudied. This study examined the impact of historical redlining, a government-sanctioned and racially discriminatory policy, and present-day cardiovascular health (CVH). Results suggested that living in historically redlined neighborhoods was associated with CVH only among Black participants and that within this group, living in a neighborhood with better social environment quality weakened but did not fully attenuate this association. These findings suggest that, similar to the institution of slavery, redlining is one manifestation of structural racism that drives health outcomes today. This work underscores the necessity to investigate structural racism as a root cause of racial/ethnic health inequities.
The US COVID-19 Trends and Impact Survey: Continuous real-time measurement of COVID-19 symptoms, risks, protective behaviors, testing, and vaccination
Authors: Salomon Joshua A. , Reinhart Alex , Bilinski Alyssa , Chua Eu Jing , La Motte-Kerr Wichada , Rönn Minttu M. , Reitsma Marissa B. , Morris Katherine A. , LaRocca Sarah , Farag Tamer H. , Kreuter Frauke , Rosenfeld Roni , Tibshirani Ryan J.
Published: December 2021

Significance

The US COVID-19 Trends and Impact Survey (CTIS) has operated continuously since April 6, 2020, collecting over 20 million responses. As the largest public health survey conducted in the United States to date, CTIS was designed to facilitate detailed demographic and geographic analyses, track trends over time, and accommodate rapid revision to address emerging priorities. Using examples of CTIS results illuminating trends in symptoms, risks, mitigating behaviors, testing, and vaccination in relation to evolving high-priority policy questions over 12 mo of the pandemic, we illustrate the value of online surveys for tracking patterns and trends in COVID outcomes as an adjunct to official reporting, and showcase unique insights that would not be visible through traditional public health reporting.
High-impact rare genetic variants in severe schizophrenia
Authors: Zoghbi Anthony W. , Dhindsa Ryan S. , Goldberg Terry E. , Mehralizade Aydan , Motelow Joshua E. , Wang Xinchen , Alkelai Anna , Harms Matthew B. , Lieberman Jeffrey A. , Markx Sander , Goldstein David B.
Published: December 2021

Significance

In this study, we found that selecting individuals with extremely severe forms of schizophrenia led to a significantly improved ability to detect disease-associated rare variants. The high prevalence of rare variant risk factors in individuals with severe, extremely treatment-resistant schizophrenia suggests future clinical opportunities for risk prediction, prognostic stratification, and genetic counseling. These findings have implications for the design of future genetic studies in schizophrenia and highlight a strategy to reduce phenotypic heterogeneity and improve gene discovery efforts in other neuropsychiatric disorders.
Fractalkine-induced microglial vasoregulation occurs within the retina and is altered early in diabetic retinopathy
Authors: Mills Samuel A. , Jobling Andrew I. , Dixon Michael A. , Bui Bang V. , Vessey Kirstan A. , Phipps Joanna A. , Greferath Ursula , Venables Gene , Wong Vickie H. Y. , Wong Connie H. Y. , He Zheng , Hui Flora , Young James C. , Tonc Josh , Ivanova Elena , Sagdullaev Botir T. , Fletcher Erica L.
Published: December 2021

Significance

This work identifies a role for microglia, the innate immune cells of the CNS, in the local control of the retinal vasculature and identifies deficits early in diabetes. Microglia contact neurons and vasculature and express several vasoactive agents. Activation of microglial fractalkine-Cx3cr1 signaling leads to capillary constriction and blocking the renin-angiotensin system (RAS) with candesartan abolishes microglial-mediated vasoconstriction in the retina. In early diabetes, reduced retinal blood flow is coincident with capillary constriction, increased microglial–vessel association, loss of microglial–capillary regulation, and altered microglial expression of the RAS pathway. While candesartan restores retinal capillary diameter early in diabetes, targeting of microglial–vascular regulation is required to prevent coincident dilation of large retinal vessels and reduced retinal blood flow.
hox
gene expression predicts tetrapod-like axial regionalization in the skate,
Leucoraja erinacea
Authors: Criswell Katharine E. , Roberts Lucy E. , Koo Eve T. , Head Jason J. , Gillis J. Andrew
Published: December 2021

Significance

The tetrapod vertebral skeleton is subdivided into distinct regions that are determined by spatial expression of
Hox
genes in the early embryo. Fishes are thought to lack comparable regionalization, but the relationship between anatomy and
hox
expression has not been tested beyond tetrapods. By comparing vertebral morphology with embryonic
hox
expression in a cartilaginous fish, the skate (
Leucoraja erinacea
), we found that the skate vertebral column is regionalized, with regional transitions predicted by embryonic
hox
gene expression patterns. This discovery points to an origin of nested
hox
gene expression and
hox
-based vertebral regionalization at the common ancestor of jawed vertebrates.
“P2RY8-son” break of tolerance promotes SLE
Authors: Tusseau Maud , Belot Alexandre
Published: December 2021

In this issue of JEM, He et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20211004) associate novel P2RY8 genetic variants to lupus, expanding the field of monogenic autoimmunity. The authors demonstrate that P2RY8 prevents the expansion of DNA-reactive B cells by restraining B cell mobility and activation within the germinal center.
APMP key comparison report of air kerma for 137Cs (APMP.RI(I)-K5)
Authors: Kim I J , Yi C-Y , Díaz N C , Wang S-W , Lin Y-C , Zhang Y , Li D , Kurosawa T , Saito N
Published: December 2021

Main text

The APMP/TCRI Dosimetry Working Group performed the APMP.RI(I)-K5 key comparison of the air kerma for 137Cs in 2014. Five national metrology institutes (NMIs) took part in the comparison. Two commercial ionization chambers were used as transfer instruments and circulated among the participants. The results showed that the maximum difference between the participants and the Bureau International des Poids et Mesures, evaluated using the comparison data of the linking laboratories of the Korea Research Institute of Standards and Science and the National Metrology Institute of Japan, was less than 0.5% within the expanded uncertainty. This comparison supports the equivalence of the calibration capabilities of the participating laboratories. The results predate the publication of ICRU report 90, therefore, the revision of the data reflecting the effects of the ICRU report 90 on the degrees of equivalences of the participant laboratories is presented in Appendix C.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Report on the AFRIMETS.M. F-S1 supplementary force comparison for 10 kN and 100 kN
Authors: Bangi Josephat Obwoge , Seidel Mark , Kimetto David , Kumme Rolf , Rotich Henry , Röske Dirk
Published: December 2021

Main text

This bilateral comparison of Force Standard Machines (FSM) named AFRIMETS.M. F-S1 was carried out in the force range from 1 kN to 100 kN between Physikalisch-Technische Bundesanstalt (PTB) of Germany as the pilot laboratory and Kenya Bureau of Standards (KEBS) of Kenya as the participant laboratory. KEBS had already participated in the APMP.M. F-K2 key comparison where measurements were made only at 50 kN and 100 kN force steps. Therefore, this bilateral comparison was planned to thoroughly compare the KEBS FSM and the PTB Deadweight Machines in wider force steps than those of the APMP.M. F-K2 key comparison and thus it had no corresponding key-comparisons values to be linked to at that time. PTB provided two force transducers for the supplementary comparison with 10 kN and 100 kN nominal capacities. The comparison method called "DKD" procedure was used. This procedure has already been used in several comparisons in Germany and other countries. The purpose to this comparison is to give support to the uncertainty claims for KEBS and will be used to determine the Calibration and Measurement Capability (CMC). In addition, this comparison will provide metrological proof of the application for a CMC entry in the BIPM Key Comparison Database (KCDB). This report describes the scheme and results of the comparison.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Lorentzian quantum cosmology goes simplicial
Authors: Dittrich Bianca , Gielen Steffen , Schander Susanne
Published: December 2021

We employ the methods of discrete (Lorentzian) Regge calculus for analysing Lorentzian quantum cosmology models with a special focus on discrete analogues of the no-boundary proposal for the early universe. We use a simple four-polytope, a subdivided four-polytope and shells of discrete three-spheres as triangulations to model a closed universe with cosmological constant, and examine the semiclassical path integral for these different choices. We find that the shells give good agreement with continuum results for small values of the scale factor and in particular for finer discretisations of the boundary three-sphere, while the simple and subdivided four-polytopes can only be compared with the continuum in certain regimes, and in particular are not able to capture a transition from Euclidean geometry with small scale factor to a large Lorentzian one. Finally, we consider a closed universe filled with dust particles and discretised by shells of three-spheres. This model can approximate the continuum case quite well. Our results embed the no-boundary proposal in a discrete setting where it is possibly more naturally defined, and prepare for its discussion within the realm of spin foams.
Non-melt selective enhancement of crystalline structure in molybdenum thin films using femtosecond laser pulses
Authors: Sharif Ayesha , Farid Nazar , Wang Mingqing , Vijayaraghavan Rajani K , Choy Kwang-Leong , McNally Patrick J , O’Connor Gerard M
Published: December 2021

It is challenging to crystalize a thin film of higher melting temperature when deposited on a substrate with comparatively lower melting point. Trading such disparities in thermal properties between a thin film and its substrate can significantly impede material processing. We report a novel solid-state crystallization process for annealing of high melting point molybdenum thin films. A systematic investigation of laser induced annealing from single pulse to high pulse overlapping is reported upon scanning at fluences lower than the threshold required for the damage/ablation of molybdenum thin films. The approach allows better control of the grain size by changing the applied laser fluence. Atomic force microscopy surface morphology and x-ray diffraction (XRD) analysis reveal significant improvements in the average polycrystalline grain size after laser annealing; the sheet resistance was reduced by 19% of the initial value measured by a Four-point probe system. XRD confirms the enlargement of the single crystal grain size. No melting was evident, although a change in the close packing, shape and size of nanoscale polycrystalline grains is observed. Ultrashort laser induced crystallinity greatly enhances the electrical properties; Hall measurements reinforced that the overall carrier concentration increases after scanning at different laser fluences. The proposed method, based on the aggregation and subsequent growth of polycrystalline and single crystal-grains, leading to enhanced crystallization, has potential to be applicable in thin film processing industry for their wide applications.
Accurate PIV measurement on slip boundary using single-pixel algorithm
Authors: Li Hongyuan , Cao Yufan , Wang Xiangyu , Wan Xia , Xiang Yaolei , Yuan Huijing , Lv Pengyu , Duan Huiling
Published: December 2021

To accurately measure the near-wall flow by particle image velocimetry (PIV) is a big challenge, especially for the slip boundary condition. Apart from high-precision measurements, an appropriate PIV algorithm is important to resolve the near-wall velocity profile. In our study, the single-pixel algorithm is employed to calculate the near-wall flow, which is demonstrated to be capable of accurately resolving the flow velocity near the slip boundary condition. Based on synthetic particle images, the advantages of the single-pixel algorithm are manifested in comparison with the conventional window-correlation algorithm. In particular, the single-pixel algorithm has higher spatial resolution and accuracy, and lower systematic error and random error for the case of the slip boundary condition. Furthermore, for experimental verification, micro-PIV measurements are conducted over a liquid–gas interface, and the single-pixel algorithm is successfully applied to the calculation of near-wall velocity under the slip boundary condition, especially negative slip velocity. The current work demonstrates the advantages of the single-pixel algorithm in analyzing complex flows under the slip boundary condition, such as in drag reduction, wall skin-friction evaluation, and near-wall vortex structure measurement.
Angle-dependent effects in DLS measurements of polydisperse particles
Authors: Jin Lin , Jarand Curtis W , Brader Mark L , Reed Wayne F
Published: December 2021

Dynamic light scattering (DLS) is widely used for analyzing biological polymers and colloids. Its application to nanoparticles in medicine is becoming increasingly important with the recent emergence of prominent lipid nanoparticle (LNP)-based products, such as the SARS-CoV-2 vaccines from Pfizer, Inc.-BioNTech (BNT162b2) and Moderna, Inc. (mRNA-1273). DLS plays an important role in the characterization and quality control of nanoparticle-based therapeutics and vaccines. However, most DLS instruments have a single detection angle θ, and the amplitude of the scattering vector, q, varies among them according to the relationship q = (4πn/λ
0) sin(θ/2), where λ
0 is the laser wavelength. Results for identical, polydisperse samples among instruments of varying q yield different hydrodynamic diameters, because, as particles become larger they scatter less light at higher q, so that higher-q instruments will under-sample large particles in polydisperse populations, and report higher z-average diffusion coefficients, and hence smaller effective hydrodynamic diameters than lower-q instruments. As particle size reaches the Mie regime the scattering envelope manifests angular maxima and minima, and the monotonic decrease of average size versus q is lost. The discrepancy among instruments of different q is hence fundamental, and not merely technical. This work examines results for different q-value instruments, using mixtures of monodisperse latex sphere standards, for which experimental measurements agree well with computations, and also polydisperse solutions of physically-degraded LNPs, for which results follow expected trends. Mie effects on broad unimodal populations are also considered. There is no way to predict results between two instruments with different q for samples of unknown particle size distributions. Initial analysis of the polydispersity index among different instruments shows a technical difference due to method of autocorrelation analysis, in addition to the fundamental q-effect.