Showing papers by "York University published in 2022"

The 2021 flexible and printed electronics roadmap

Abstract: Author(s): Bonnassieux, Y; Brabec, CJ; Cao, Y; Carmichael, TB; Chabinyc, ML; Cheng, KT; Cho, G; Chung, A; Cobb, CL; Distler, A; Egelhaaf, HJ; Grau, G; Guo, X; Haghiashtiani, G; Huang, TC; Hussain, MM; Iniguez, B; Lee, TM; Li, L; Ma, Y; Ma, D; McAlpine, MC; Ng, TN; Osterbacka, R; Patel, SN; Peng, J; Peng, H; Rivnay, J; Shao, L; Steingart, D; Street, RA; Subramanian, V; Torsi, L; Wu, Y | Abstract: This roadmap includes the perspectives and visions of leading researchers in the key areas of flexible and printable electronics. The covered topics are broadly organized by the device technologies (sections 1–9), fabrication techniques (sections 10–12), and design and modeling approaches (sections 13 and 14) essential to the future development of new applications leveraging flexible electronics (FE). The interdisciplinary nature of this field involves everything from fundamental scientific discoveries to engineering challenges; from design and synthesis of new materials via novel device design to modelling and digital manufacturing of integrated systems. As such, this roadmap aims to serve as a resource on the current status and future challenges in the areas covered by the roadmap and to highlight the breadth and wide-ranging opportunities made available by FE technologies.

Lives saved and hospitalizations averted by COVID-19 vaccination in New York City: a modeling study.

Abstract: Background Following the start of COVID-19 vaccination in New York City (NYC), cases have declined over 10-fold from the outbreak peak in January 2020, despite the emergence of highly transmissible variants. We evaluated the impact of NYC's vaccination campaign on saving lives as well as averting hospitalizations and cases. Methods We used an age-stratified agent-based model of COVID-19 to include transmission dynamics of Alpha, Gamma, Delta and Iota variants as identified in NYC. The model was calibrated and fitted to reported incidence in NYC, accounting for the relative transmissibility of each variant and vaccination rollout data. We simulated COVID-19 outbreak in NYC under the counterfactual scenario of no vaccination and compared the resulting disease burden with the number of cases, hospitalizations and deaths reported under the actual pace of vaccination. Findings We found that without vaccination, there would have been a spring-wave of COVID-19 in NYC due to the spread of Alpha and Delta variants. The COVID-19 vaccination campaign in NYC prevented such a wave, and averted 290,467 (95% CrI: 232,551 - 342,664) cases, 48,076 (95% CrI: 42,264 - 53,301) hospitalizations, and 8,508 (95% CrI: 7,374 - 9,543) deaths from December 14, 2020 to July 15, 2021. Interpretation Our study demonstrates that the vaccination program in NYC was instrumental to substantially reducing the COVID-19 burden and suppressing a surge of cases attributable to more transmissible variants. As the Delta variant sweeps predominantly among unvaccinated individuals, our findings underscore the urgent need to accelerate vaccine uptake and close the vaccination coverage gaps. Funding This study was supported by The Commonwealth Fund.

Face masks disrupt holistic processing and face perception in school-age children

Abstract: Face perception is considered a remarkable visual ability in humans that is subject to a prolonged developmental trajectory. In response to the COVID-19 pandemic, mask-wearing has become mandatory for adults and children alike. Recent research shows that mask-wearing hinders face recognition abilities in adults, but it is unknown if the same holds true in school-age children in whom face perception is not fully developed. Here we tested children (n = 72, ages 6-14 years old) on the Cambridge Face Memory Test - Kids (CFMT-K), a validated measure of face perception performance. Faces were presented with or without masks and across two orientations (upright/inverted). The inclusion of face masks led to a profound deficit in face perception abilities. This decrement was more pronounced in children compared to adults, but only when task difficulty was adjusted across the two age groups. Additionally, children exhibited reliable correlations between age and the CFMT-K score for upright faces for both the mask and no-mask conditions. Finally, as previously observed in adults, children also showed qualitative differences in the processing of masked versus non-masked faces. Specifically, holistic processing, a hallmark of face perception, was disrupted for masked faces as suggested by a reduced face-inversion effect. Together, these findings provide evidence for substantial quantitative and qualitative alterations in the processing of masked faces in school-age children.

A probabilistic framework for integrating sentence-level semantics via BERT into pseudo-relevance feedback

Abstract: Existing pseudo-relevance feedback (PRF) methods often divide an original query into individual terms for processing and select expansion terms based on the term frequency, proximity, position, etc. This process may lose some contextual semantic information from the original query. In this work, based on the classic Rocchio model, we propose a probabilistic framework that incorporates sentence-level semantics via Bidirectional Encoder Representations from Transformers (BERT) into PRF. First, we obtain the importance of terms at the term level. Then, we use BERT to interactively encode the query and sentences in the feedback document to acquire the semantic similarity score of a sentence and the query. Next, the semantic scores of different sentences are summed as the term score at the sentence level. Finally, we balance the term-level and sentence-level weights by adjusting factors and combine the terms with the top-k scores to form a new query for the next-round processing. We apply this method to three Rocchio-based models (Rocchio, PRoc2, and KRoc). A series of experiments are conducted based on six official TREC data sets. Various evaluation indicators suggest that the improved models achieve a significant improvement over the corresponding baseline models. Our proposed models provide a promising avenue for incorporating sentence-level semantics into PRF, which is feasible and robust. Through comparison and analysis of a case study, expansion terms obtained from the proposed models are shown to be more semantically consistent with the query.

The Number Densities and Stellar Populations of Massive Galaxies at 3 < z < 6: A Diverse, Rapidly Forming Population in the Early Universe

Abstract: Abstract We present the census of massive (log( M * / M ⊙ ) > 11) galaxies at 3 < z < 6 identified over the COSMOS/UltraVISTA Ultra-Deep field stripes: consisting of ≈100 and ≈20 high-confidence candidates at 3 < z < 4 and 4 < z < 6, respectively. The 3 < z < 4 population is comprised of post-starburst, UV-star-forming, and dusty star-forming galaxies in roughly equal fractions, while UV-star-forming galaxies dominate at 4 < z < 6 . We account for various sources of biases in the spectral energy distribution (SED) modeling, finding that the treatment of emission line contamination is essential for understanding the number densities and mass growth histories of massive galaxies at z > 3. The significant increase in observed number densities at z ∼ 4 (> × 5 in ≲600 Myr) implies that this is the epoch at which log( M * / M ⊙ ) > 11 galaxies emerge in significant numbers, with stellar ages (≈500–900 Myr) indicating rapid formation epochs as early as z ∼ 7. Leveraging ancillary multiwavelength data sets, we perform panchromatic SED modeling to constrain the total star formation activity of the sample. The star formation activity of the sample is generally consistent with being on the star formation main sequence at the considered redshifts, with ≈15%–25% of the population showing evidence of suppressed star formation rates, indicating that quenching mechanisms are already at play by z ∼ 4. We stack the available Hubble Space Telescope imaging, confirming their compact nature ( r e ≲ 2.2 kpc), consistent with expected sizes of high- z star-forming galaxies. Finally, we discuss how our results are in-line with the early formation epochs and short formation timescales inferred from the fossil records of the most massive galaxies in the universe.

Time‐dependent changes in autophagy, mitophagy and lysosomes in skeletal muscle during denervation‐induced disuse

Abstract: Deficits in skeletal muscle mitochondrial content and quality are observed following denervation-atrophy. This is due to alterations in the biogenesis of new mitochondria as well as their degradation via mitophagy. The regulation of autophagy and mitophagy over the course of denervation (Den) remains unknown. Further, the time-dependent changes in lysosome content, the end-stage organelle for mitophagy, remain unexplored. Here, we studied autophagic as well as mitophagic pre-lysosomal flux in subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria from rat muscle subjected to Den for 1, 3 or 7 days. We also assessed flux at 1 day post-denervation in transgenic mt-keima mice. Markers of mitochondrial content were reduced at 7 days following Den, and Den further resulted in rapid decrements in mitochondrial respiration, along with increased ROS emission. Pre-lysosomal autophagy flux was upregulated at 1 and 3 days post-Den but was reduced compared to time-matched sham-operated controls at 7 days post-Den. Similarly, pre-lysosomal mitophagy flux was enhanced in SS mitochondria as early as 1 and 3 days of Den but decreased in both SS and IMF subfractions following 7 days of Den. Lysosome protein content and transcriptional regulators TFEB and TFE3 were progressively enhanced with Den, an adaptation designed to enhance autophagic capacity. However, evidence for lysosome dysfunction was apparent by 7 days, which may limit degradation capacity. This may contribute to an inability to clear dysfunctional mitochondria and increased ROS signalling, thereby accelerating muscle atrophy. Thus, therapeutic targeting of lysosome function may help to maintain autophagy and muscle health during conditions of muscle disuse or denervation. Key points Denervation is an experimental model of peripheral neuropathies as well as muscle disuse, and it helps us understand some aspects of the sarcopenia of ageing. Muscle disuse is associated with reduced mitochondrial content and function, leading to metabolic impairments within the tissue. Although the processes that regulate mitochondrial biogenesis are understood, those that govern mitochondrial breakdown (i.e. mitophagy) are not well characterized in this context. Autophagy and mitophagy flux, measured up to the point of the lysosome (pre-lysosomal flux rates), were increased in the early stages of denervation, along with mitochondrial dysfunction, but were reduced at later time points when the degree of muscle atrophy was highest. Denervation led to progressive increases in lysosomal proteins to accommodate mitophagy flux, yet evidence for lysosomal impairment at later stages may limit the removal of dysfunctional mitochondria, stimulate reactive oxygen species signalling, and reduce muscle health as denervation time progresses.

Stable Quasi‐Solid‐State Aluminum Batteries

Abstract: Nonaqueous rechargeable aluminum batteries (RABs) of low cost and high safety are promising for next-generation energy storage. With the presence of ionic liquid (IL) electrolytes, their high moisture sensitivity and poor stability would lead to critical issues in liquid RABs, including undesirable gas production, irreversible activity loss, and an unstable electrode interface, undermining the operation stability. To address such issues, herein, a stable quasi-solid-state electrolyte is developed via encapsulating a small amount of an IL into a metal-organic framework, which not only protects the IL from moisture, but creates sufficient ionic transport network between the active materials and the electrolyte. Owing to the generated stable states at both positive-electrode-electrolyte and negative-electrode-electrolyte interfaces, the as-assembled quasi-solid-state Al-graphite batteries deliver specific capacity of ≈75 mA h g-1 (with positive electrode material loading ≈9 mg cm-2 , much higher than that in the conventional liquid systems). The batteries present a long-term cycling stability beyond 2000 cycles, with great stability even upon exposure to air within 2 h and under flame combustion tests. Such technology opens a new platform of designing highly safe rechargeable Al batteries for stable energy storage.

Boosting Continuous‐Wave Laser‐Driven Nonlinear Photothermal White Light Generation by Nanoscale Porosity

Abstract: The irradiation of an optically absorptive medium by a continuous-wave (CW) near-infrared (NIR) laser can result in a spectral continuum emission covering both the visible and NIR regions, which is attractive for applications as continuum light sources in diverse fields. It is shown here that this NIR-laser-driven light emission can be effectively modulated with nanoscale architecture in the medium. By using porous silica as the model matrix and Yb3+ ions as the photothermally active centers, up to 100 folds increment in NIR-laser-induced emission intensity and dramatic decrease in threshold excitation density are demonstrated. It is observed that the emission intensity exhibits a strong nonlinear dependence on the power of the NIR excitation laser, featuring clear excitation power thresholds. Based on combined numerical simulation and spectral and temperature measurements, the improved broadband emission and photothermal nonlinearity are interpreted by enhanced optical energy localization around the laser spot that results in boosting the photon-to-photon conversion efficiency. The use of the nonlinear photothermal emission process as a broadband NIR light source, which could be exploited for applications including NIR spectroscopy, imaging, and sensing, is further demonstrated as a proof-of-concept.

Global population dynamics of a single species structured with distinctive time-varying maturation and self-limitation delays

Abstract: <p style='text-indent:20px;'>We consider the classical Nicholson's blowflies model incorporating two distinctive time-varying delays. One of the delays corresponds to the length of the individual's life cycle, and another corresponds to the specific physiological stage when self-limitation feedback takes place. Unlike the classical formulation of Nicholson's blowflies equation where self-regulation appears due to the competition of the productive adults for resources, the self-limitation of our considered model can occur at any developmental stage of an individual during the entire life cycle. We aim to find sharp conditions for the global asymptotic stability of a positive equilibrium. This is a significant challenge even when both delays are held at constant values. Here, we develop an approach to obtain a sharp and explicit criterion in an important situation where the two delays are asymptotically apart. Our approach can be also applied to the non-autonomous Mackey-Glass equation to provide a partial solution to an open problem about the global dynamics.</p>

An obesogenic diet impairs uncoupled substrate oxidation and promotes whitening of the brown adipose tissue in rats

Abstract: Brown adipose tissue (BAT) is rich in mitochondria containing uncoupling protein 1 (UCP1), and dissipates energy through thermogenesis. However, even though BAT mass and its UCP1 content increase in rodents chronically fed a high-fat sucrose-enriched (HFS) diet, marked expansion of adiposity still occurs in these animals, suggesting insufficient BAT-mediated HFS diet-induced thermogenesis. Thus, the objective of this study was to investigate the metabolic and molecular mechanisms that regulate BAT thermogenesis in HFS-induced obesity. To accomplish this, rats were fed either a standard chow or HFS diet for 8 weeks. Subsequently, glucose and fatty acid metabolism and the molecular mechanisms underlying these processes were assessed in freshly isolated primary BAT adipocytes. Despite increasing BAT mass and its UCP1 content, the HFS diet reduced uncoupled glucose and palmitate oxidation in BAT adipocytes. It also markedly diminished tyrosine hydroxylase content and lipolysis in these cells. Conversely, glucose uptake, lactate production, glycerol incorporation into lipids, palmitate incorporation into triacylglycerol (TAG), phosphoenolpyruvate carboxykinase and glycerol kinase levels, and lipoprotein lipase and cluster of differentiation 36 gene expression were increased. In summary, a HFS diet enhanced glyceroneogenesis and shifted BAT metabolism toward TAG synthesis by impairing UCP1-mediated substrate oxidation and by enhancing fatty acid esterification in intact brown adipocytes. These adaptive metabolic responses to chronic HFS feeding attenuated BAT thermogenic capacity and favoured the development of obesity. Key points Despite increasing brown adipose tissue (BAT) mass and levels of thermogenic proteins such as peroxisome proliferator-activated receptor γ coactivator 1α, carnitine palmitoyltransferase 1B and uncoupling protein 1 (UCP1), an obesogenic high-fat sucrose-enriched (HFS) diet attenuated uncoupled glucose and fatty acid oxidation in brown adipocytes. Brown adipocytes diverted glycerol and fatty acids toward triacylglycerol (TAG) synthesis by elevating the cellular machinery that promotes fatty acid uptake along with phosphoenolpyruvate carboxykinase and glycerol kinase levels. The HFS diet increased glucose uptake that supported lactate production and provided substrate for glyceroneogenesis and TAG synthesis in brown adipocytes. Impaired UCP-1-mediated thermogenic capacity and enhanced TAG storage in BAT adipocytes were consistent with reduced adipose triglyceride lipase and tyrosine hydroxylase levels in HFS diet-fed animals.

Hydroxyl-anchored covalent organic crown-based polymers for CO₂ fixation into cyclic carbonates under mild conditions

Abstract: A series of covalent organic crown-based polymers coordinated with KI exhibit high activity. The synergetic effect plays an important role in accelerating the reaction rate.

Assessing Inequities in COVID-19 Vaccine Roll-Out Strategy Programs: A Cross-Country Study Using a Machine Learning Approach

Abstract: After the start of the COVID-19 pandemic and its spread across the world, countries have adopted containment measures to stop its transmission, limit fatalities, and relieve hospitals from straining and overwhelming conditions imposed by the virus. Many countries implemented social distancing and lockdown strategies that negatively impacted their economies and the psychological wellbeing of their citizens, even though they contributed to saving lives. Recently approved and available, COVID-19 vaccines can provide a really viable and sustainable option for controlling the pandemic. However, their uptake represents a global challenge due to vaccine hesitancy and logistic-organizational hurdles that have made its distribution stagnant in several developed countries despite several appeals by the media, policy- and decision-makers, and community leaders. Vaccine distribution is also a concern in developing countries, where there is a scarcity of doses. The objective of the present study was to set up a metric to assess vaccination uptake and identify national socio-economic factors influencing this indicator. We conducted a cross-country study. We first estimated the vaccination uptake rate across countries by fitting a logistic model to reported daily case numbers. Using the uptake rate, we estimated the vaccine roll-out index. Next, we used Random Forest, an "off-the-shelf" machine learning algorithm, to study the association between vaccination uptake rate and socio-economic factors. We found that the mean vaccine roll-out index is 0.016 (standard deviation 0.016), with a range between 0.0001 (Haiti) and 0.0829 (Mongolia). The top four factors associated with the vaccine roll-out index are the median per capita income, human development index, percentage of individuals who have used the internet in the last three months, and health expenditure per capita. The still-ongoing COVID-19 pandemic has shed light on the disparity in vaccine adoption across low- and high-income countries, which represents a global public health challenge. We must pave the way for universal access to vaccines and other approved treatments, regardless of demographic structures and underlying health conditions. Income disparity remains, instead, an important cause of vaccine inequity, which restricts the functioning of the global vaccine allocation framework and, thus, the ending of the pandemic. Stronger mechanisms are needed to foster countries' political willingness to promote vaccine and drug access equity in a globalized society where future pandemics and other global health crises can be anticipated.

What is that I hear? An interdisciplinary review and research agenda for non‐native accents in the workplace

Abstract: Speaking with a non-native English accent at work is a prevalent global phenomenon. Yet, our understanding of the impact of having a non-native accent at work is limited, in part because research on accents has been multidisciplinary, fragmented, and difficult for scholars to access and synthesize. To advance research on accents in the workplace, we provide an interdisciplinary and integrative review of research on non-native accents drawing from the communications, social psychology, and organizational sciences literatures. First, we briefly review the dominant approaches taken in each literature. Second, we organize and integrate extant research findings using a 2 × 2 framework that incorporates the two main theoretical perspectives used to explain the effects of accents—stereotypes and processing fluency—and the two primary categories of workplace outcomes examined—interpersonal (i.e., others' evaluations of speakers with non-native accents, such as hiring recommendations) and intrapersonal (i.e., non-native-accented speakers' own evaluations and experiences, such as sense of belonging). To facilitate future research, we end by articulating a research agenda including theoretical and methodological expansions related to the study of accents, identifying critical moderators, adopting an intersectional approach, and studying group-level and potential positive effects of speaking with non-native accents.

Practical recommendations for considering culture, race, and ethnicity in personality psychology

Abstract: Personality science is the study of the individual. It aims to understand what makes people similar to others, different from some, and unique to themselves. However, there is room for research in personality to more thoughtfully consider culture, race, and ethnicity in order to better understand individual differences in people’s patterns of thinking, feeling, and behaving. High impact personality journals rarely include such factors into the interpretation of results, and cross-cultural and ethnic minority publications are limited within the discipline. This article offers a brief, non-exhaustive overview of how culture, race, and ethnicity are examined in relation to personality, showing that: (1) social structures continue to be neglected in the research, (2) we can learn from research being conducted in neighboring areas, and (3) valuable work is already being done within personality psychology. We offer recommendations that emphasize community based participatory research methods, combined etic-emic approaches, and contextualizing research findings to improve the consideration of culture, race, and ethnicity in personality research.

Assetization and the ‘new asset geographies’

Abstract: An asset is both a resource and property, in that it generates income streams with its sale price based on the capitalization of those revenues. Although an asset's income streams can be financially sliced up, aggregated, and speculated upon across highly diverse geographies, there still has to be something underpinning these financial operations. Something has to generate the income that a political economic actor can lay claim to through a property or other right, entailing a process of enclosure, rent extraction, property formation, and capitalization. Geographers and other social scientists are producing a growing literature illustrating the range of new (and old) asset classes created by capitalists in their search for revenue streams, for which we argue assetization is a necessary concept to focus on the moment of enclosure and rent extraction. It is a pressing task for human geographers to unpack the diverse and contingent ‘asset geographies’ entailed in this assetization process. As a middle range concept and empirical problematic, we argue that assetization is an important focal point for wider debates in human geography by focusing attention on the moment of enclosure, rent extraction, and material remaking of society which the making of a financial asset implies.

Climate change-accelerated ocean biodiversity loss &amp; associated planetary health impacts

Abstract: A planetary health perspective views human health as a function of the interdependent relationship between human systems and the natural systems in which we live. The planetary health impacts of climate change induced ocean biodiversity loss are little understood. Based on a systematic literature review, we summarize how climate change-induced ocean warming, acidification, and deoxygenation affect ocean biodiversity and their resulting planetary health impacts. These impacts on the planets’ natural and human systems include biospheric and human consequences for ecosystem services, food and nutrition security, human livelihoods, biomedical and pharmaceutical research, disaster risk management, and for organisms pathogenic to humans. Understanding the causes and effects of climate change impacts on the ocean and its biodiversity and planetary health is crucial for taking preventive, restorative and sustainable actions to ensure ocean biodiversity and its services. Future courses of action to mitigate climate change-related ocean biodiversity loss to support sound planetary health are discussed.