bluuebunny/crossref_metadata_2025_split huggingface dataset:
Roles of oxygen level and hypoxia-inducible factor signaling pathway in cartilage, bone and osteochondral tissue engineering
Authors: Fu Lei , Zhang Liwen , Zhang Xin , Chen Linxin , Cai Qing , Yang Xiaoping 
Published: January 2021

Abstract
The repair and treatment of articular cartilage injury is a huge challenge of orthopedics. Currently, most of the clinical methods applied in treating cartilage injuries are mainly to relieve pains rather than to cure them, while the strategy of tissue engineering is highly expected to achieve the successful repair of osteochondral defects. Clear understandings of the physiological structures and mechanical properties of cartilage, bone and osteochondral tissues have been established, but the understanding of their physiological heterogeneity still needs further investigation. Apart from the gradients in the micromorphology and composition of cartilage-to-bone extracellular matrixes, an oxygen gradient also exists in natural osteochondral tissue. The response of hypoxia-inducible factor (HIF)-mediated cells to oxygen would affect the differentiation of stem cells and the maturation of osteochondral tissue. This article reviews the roles of oxygen level and HIF signaling pathway in the development of articular cartilage tissue, and their prospective applications in bone and cartilage tissue engineering. The strategies for regulating HIF signaling pathway and how these strategies finding their potential applications in the regeneration of integrated osteochondral tissue are also discussed.
Biomatrix from goat-waste in sponge/gel/powder form for tissue engineering and synergistic effect of nanoceria
Authors: Singh Hemant , Purohit Shiv Dutt , Bhaskar Rakesh , Yadav Indu , Bhushan Sakchi , Gupta Mukesh Kumar , Gautam Sneh , Showkeen Muzamil , Mishra Narayan Chandra 
Published: January 2021

Abstract
For tissue engineering (TE), decellularized matrices gained huge potential as they consist of natural biomolecules which help in cell attachment and proliferation. Among various animal tissues, goat tissue has gained least attention in spite of the fact that goat tissue is less susceptible to disease transmission as compared to cadaveric porcine and bovine tissue. In this study, goat small intestine submucosa (G-SIS) was isolated from goat small intestine (G-SI), a waste from goat-slaughterhouse, and decellularized to obtain decellularized G-SIS (DG-SIS) biomatrix in the form of powder, gel and sponge form, so that it can be used for healing various types of wounds. Further, nanoceria (NC), owing to its free radical scavenging, anti-inflammatory, antibacterial and angiogenic properties, was incorporated in the DG-SIS in to fabricate DG-SIS/NC nanobiocomposite scaffold, which may exhibit synergistic effects to accelerate tissue regeneration. The scaffolds were found to be hydrophilic, biodegradable, haemocompatible, biocompatible, antibacterial and showed free radical scavenging capability. The scaffold containing NC concentration (500 µg ml−1) depicted highest cell (fibroblast cells) adhesion, MTT activity and free radical scavenging as compared to the DG-SIS and other nanobiocomposite scaffolds. Thus, DG-SIS/NC3 (NC with concentration 500 µg ml−1) scaffold could be a potential scaffold biomaterial for skin TE application.
Assessment of complex subsurface redox structures for sustainable development of agriculture and the environment
Authors: Hansen Birgitte , Voutchkova Denitza D , Sandersen Peter B E , Kallesøe Anders , Thorling Lærke , Møller Ingelise , Madsen Rasmus B , Jakobsen Rasmus , Aamand Jens , Maurya Pradip , Kim Hyojin 
Published: January 2021

Abstract
Cost-efficient targeted nitrogen (N) regulation of agriculture with low impact on the environment is the new N regulation paradigm. It requires detailed knowledge on the geological and geochemical conditions of the subsurface that is crucial for assessing the nitrate flowpaths and reduction processes. An integral part of this is analysis of the subsurface redox structures to determine the locations of nitrate reduction. This knowledge has so far not been easy to access because of lacking technology. Here we present a new concept consisting of integration and interpretation of data from the geophysical towed transient electromagnetic method, borehole information on lithology, sediment colour descriptions, geochemistry and groundwater chemistry. The concept is demonstrated in three small first-order hydrological catchments. National GIS screening analyses show that the new concept is highly needed in large parts of Denmark where the redox structures are complicated e.g. in marine landscape types and in glacial moraine landscapes but less needed in areas dominated by homogeneous meltwater plains. Providing subsurface knowledge for locally targeted N regulation of agriculture is paramount in many developed countries with intensive agriculture to lower the environmental impact, and it could also be critical in developing countries to support sustainable economic and environmental development.
Richness patterns of endemic and threatened conifers in south-west China: topographic-soil fertility explanation
Authors: Dakhil Mohammed A , Li Jiangrong , Pandey Bikram , Pan Kaiwen , Liao Ziyan , Olatunji Olusanya Abiodun , Zhang Lin , Eid Ebrahem M , Abdelaal Mohamed 
Published: January 2021

Abstract
Understanding the relationships between species richness patterns and environment constitutes a key issue in biogeography and conservation strategies. To our knowledge, this is the first integrative study that incorporates soil and human-influence data into species richness modelling. Our aims were to (a) estimate the richness patterns of four conifers groups (all conifers species, endemics, threatened, and endemic-threatened species) in south-west China, (b) assess the relative importance of environmental predictors (energy, water, climate, topography, and soil) and the human-influence on the conifers richness patterns and (c) identify hotspot ecoregions, nature reserves, or important plant areas as priority conservation areas. Generalized linear models and hierarchical partitioning were used by correlating 8962 distributional records of 97 conifer species with different environmental drivers. Results indicated that central Sichuan, northern Sichuan, northern Yunnan, and the southern areas of the Hengduan mountains were identified as distinct centres of conifers richness in China. Topographic heterogeneity and soil fertility were the strongest drivers of conifer richness patterns, while climate, energy, water, and human drivers were contributed to a lower degree. The identified conifers’ important areas were mostly located outside of the existing nature reserves but inside the ecoregions. Our findings emphasize that incorporating soil data into spatial modelling provides great insights for the conservation of conifers species. We recommend conservationists to use soil variables and other environmental data to generate a comprehensive understanding of the key drivers underlying the patterns of conifer diversity and distribution.
Climate change, aeroallergens, and the aeroexposome
Authors: Beggs Paul J 
Published: January 2021

Abstract
Allergic diseases are a major public health problem globally and are increasing. The impacts of climate change on aeroallergens such as pollen and fungal spores and allergic respiratory diseases such as allergic asthma and allergic rhinitis have been considered since the early years of climate change and human health research, and exploration of this topic has accelerated over the past decade or so. This review examines the impacts of climate change on aeroallergens, including interactions with air pollutants, and the resulting impacts on allergic respiratory diseases. It discusses mitigation and adaptation in this context. It does this with a focus on advances over the last 2 years (2019 and 2020) to highlight research at the frontier of this field. It also explores the growing recognition of the need for a more holistic and integrated approach to environmental monitoring and exposure and presents the concept of the aeroexposome as a frame through which these impacts of climate change and responses to them could be viewed moving forward. As the evidence of impacts of climate change on aeroallergen production and atmospheric concentration, seasonality, distribution, and allergenicity mounts, crucial research demonstrating the resulting impacts on health outcomes such as aeroallergen sensitisation prevalence, asthma emergency department visits, and asthma hospitalisations is now emerging. It is vital that the momentum of the last decade continue with research to fill the many gaps that remain in our knowledge of this complex topic—refining analytical techniques, broadening the geographical coverage (to include, for example, the Southern Hemisphere), and more explicitly exploring the impacts of climate change on indoor aeroallergens.
Flood evacuation during pandemic: a multi-objective framework to handle compound hazard
Authors: Tripathy Shrabani S , Bhatia Udit , Mohanty Mohit , Karmakar Subhankar , Ghosh Subimal 
Published: January 2021

Abstract
The evacuation of the population from flood-affected regions is a non-structural measure to mitigate flood hazards. Shelters used for this purpose usually accommodate a large number of flood evacuees for a temporary period. Floods during a pandemic result in a compound hazard. Evacuations under such situations are difficult to plan as social distancing is nearly impossible in the highly crowded shelters. This results in a multi-objective problem with conflicting objectives of maximizing the number of evacuees from flood-prone regions and minimizing the number of infections at the end of the shelter’s stay. To the best of our knowledge, such a problem is yet to be explored in literature. Here we develop a simulation-optimization framework, where multiple objectives are handled with a max–min approach. The simulation model consists of an extended Susceptible—Exposed—Infectious—Recovered—Susceptible model. We apply the proposed model to the flood-prone Jagatsinghpur district in the state of Odisha, India. We find that the proposed approach can provide an estimate of people required to be evacuated from individual flood-prone villages to reduce flood hazards during the pandemic. At the same time, this does not result in an uncontrolled number of new infections. The proposed approach can generalize to different regions and can provide a framework to stakeholders to manage conflicting objectives in disaster management planning and to handle compound hazards.
Data-related and methodological obstacles to determining associations between temperature and COVID-19 transmission
Authors: Dong Zhaomin , Fan Xiarui , Wang Jiao , Mao Yixin , Luo Yueyun , Tang Song 
Published: January 2021

Abstract
More and more studies have evaluated the associations between ambient temperature and coronavirus disease 2019 (COVID-19). However, most of these studies were rushed to completion, rendering the quality of their findings questionable. We systematically evaluated 70 relevant peer-reviewed studies published on or before 21 September 2020 that had been implemented from community to global level. Approximately 35 of these reports indicated that temperature was significantly and negatively associated with COVID-19 spread, whereas 12 reports demonstrated a significantly positive association. The remaining studies found no association or merely a piecewise association. Correlation and regression analyses were the most commonly utilized statistical models. The main shortcomings of these studies included uncertainties in COVID-19 infection rate, problems with data processing for temperature, inappropriate controlling for confounding parameters, weaknesses in evaluation of effect modification, inadequate statistical models, short research periods, and the choices of research areal units. It is our viewpoint that most studies of the identified 70 publications have had significant flaws that have prevented them from providing a robust scientific basis for the association between temperature and COVID-19.
The relationship between land surface temperature and artificial impervious surface fraction in 682 global cities: spatiotemporal variations and drivers
Authors: Yang Qiquan , Huang Xin , Yang Jie , Liu Yue 
Published: January 2021

Abstract
The artificial impervious surface (AIS) counts among the most important components of the urban surface, and understanding how temperature changes with the AIS fraction (AISF) is crucial for urban ecology and sustainability. Considering the high heterogeneity among existing local studies, this study systematically analyzed the relationship between land surface temperature (LST) and AISF in 682 global cities. The LST–AISF relation was quantified by the coefficient (δLST, ΔLST/ΔAISF) of a linear regression model, which measures the LST change by 1 unit (1%) increase in AISF. The LST was acquired from the Moderate Resolution Imaging Spectroradiometer (MODIS) daily products during 2014–2016, while the AISF was calculated as the proportion of AIS in each MODIS pixel according to the high-resolution Global Artificial Imperious Area (GAIA) product in 2015. Major results can be summarized as follows: (a) LST shows an increasing trend along AISF gradients (positive δLST) in most cities, with annually average daytime and nighttime δLST of 0.0219 (0.0205, 0.0232) °C/% (values in parenthesis define the 95% confidence interval, hereinafter) and 0.0168 (0.0166, 0.0169) °C/%, respectively, for global cities. (b) Daytime δLST varies substantially among cities, with generally stronger values in tropical and temperate cities, but weaker or even negative values in arid cities; while at night, cities located in the cold climate zone tend to have larger δLST. (c) The LST–AISF relation is also season-dependent, characterized by a greater δLST in warm months, especially for cities located in temperate and cold climate zones. (d) Driver analyses indicate that changes in surface biophysical properties, including vegetation conditions and albedo, are main contributors to the spatiotemporal variation of daytime and nighttime δLST, respectively. These results help us to get a quantitative and systematic understanding of the climatic impacts of urbanization.
Elevation-dependent warming in the Eastern Siberian Arctic
Authors: Miller James R , Fuller John E , Puma Michael J , Finnegan Joseph M 
Published: January 2021

Abstract
There is evidence for elevation-dependent warming (EDW) in many mountainous regions, including the Alps, Rockies, and Tibetan Plateau, all of which are in mid latitudes. Most studies finding evidence of EDW indicate that both recent decadal and future projected warming rates are greater at higher elevations. In this study, we examine the roles of Arctic amplification and elevation on future warming rates in winter and summer in eastern Siberia (50–70° N; 80–180° E). This region includes four major river basins that flow into the Arctic Ocean (the Yenisei, Lena, Indigirka, and Kolyma) and intersects with mountain ranges in northern Mongolia and eastern Siberia. We analyze projected 21st century temperature projections using a six-member ensemble of the National Center for Atmospheric Research (NCAR) Community Climate System Model (CCSM4) with a radiative forcing of 8.5 W m−2. Projected warming rates in winter for the 21st century are dominated by Arctic amplification, which leads to significantly larger warming rates at higher latitudes, with latitudinal gradients of about 0.16 °C degree−1 latitude. In summer, the latitudinal gradient is near zero (0.02 °C degree−1 of latitude). Within specific latitude bands, we also find EDW. However, unlike most mid-latitude locations where warming rates are greater at higher elevations, we find that future warming rates are smaller at higher elevations for this high-latitude region, particularly during winter, with statistically significant rates varying between −0.70 °C km−1 and −2.46 °C km−1 for different 5° latitude bands. The decrease in warming rates with elevation in winter at the highest latitudes is primarily attributed to strong inversions and changes in the lapse rate as free-air temperatures warm at slower rates than surface temperatures. In summer, the elevation dependence is much weaker than in winter but still statistically significant and negative in all but the most northern latitude band with values ranging between −0.10 °C km−1 and −0.56 °C km−1.
Accelerated decline of summer Arctic sea ice during 1850–2017 and the amplified Arctic warming during the recent decades
Authors: Cai Qiongqiong , Wang Jia , Beletsky Dmitry , Overland James , Ikeda Moto , Wan Liying 
Published: January 2021

Abstract
The 168 year trends of summer (July–September) sea ice area (SIA) variations in six Arctic regions during 1850–2017 are analyzed. SIA has been significantly decreasing in most Arctic regions since 1850. The rate of retreat for the period of 1948–2017 accelerated multi-fold. For the nearly four decades since 1979, most Arctic regions are experiencing the highest reduction rate. Besides the increasing surface air temperature, the key drivers to the accelerated summer Arctic sea ice decline are found to be the combined global warming and the regional Arctic warming exerted simultaneously by the Arctic Oscillation, North Atlantic Oscillation, Atlantic Multidecadal Oscillation and Pacific Decadal Oscillation during the last several decades. The dynamical and thermodynamical warming, driven by the internal variability of the teleconnection patterns, occurred in the last several decades, in particular on the multidecadal timescales. This leads to Arctic amplification that accelerates the positive ice/ocean albedo feedback loop, resulting in accelerating summer sea ice decline.
Kicked rotor with attosecond pulse train
Authors: Mašović D R 
Published: January 2021

Abstract
The kicked rotor (KR) is one of the basic models in connection with chaos and quantum chaos. A possible application of an attosecond pulse train as a kicking field in the KR is theoretically examined for the first time. This version of the KR is denoted as an atto-KR. It seems to be the most realistic version of the KR because it takes into account the real form of the kicking field as it appears in the experiments. The atto-KR is investigated from the classical and the quantum aspects. In the classical case, a new map instead of the Chirikov standard map is proposed. It may be useful in appropriate experiments with the classical chaos. In the quantum case, the atto-KR gives satisfactory results. Phenomena such as dynamical localization and quantum resonances appear in the undisturbed form. It may be also used for examining the influence of the quantum effects on classical chaos and diffusion.
Universal reductions and solitary waves of weakly nonlocal defocusing nonlinear Schrödinger equations
Authors: Koutsokostas G N , Horikis T P , Kevrekidis P G , Frantzeskakis D J 
Published: January 2021

Abstract
We study asymptotic reductions and solitary waves of a weakly nonlocal defocusing nonlinear Schrödinger (NLS) model. The hydrodynamic form of the latter is analyzed by means of multiscale expansion methods. To the leading-order of approximation (where only the first of the moments of the response function is present), we show that solitary waves, in the form of dark solitons, are governed by an effective Boussinesq/Benney–Luke (BBL) equation, which describes bidirectional waves in shallow water. Then, for long times, we reduce the BBL equation to a pair of Korteweg–de Vries (KdV) equations for right- and left-going waves, and show that the BBL solitary wave transforms into a KdV soliton. In addition, to the next order of approximation (where both the first and second moment of the response function are present), we find that dark solitons are governed by a higher-order perturbed KdV (pKdV) equation, which has been used to describe ion-acoustic solitons in plasmas and water waves in the presence of higher-order effects. The pKdV equation is approximated by a higher-order integrable system and, as a result, only insubstantial changes in the soliton shape and velocity are found, while no radiation tails (in this effective KdV picture) are produced.
Selective and robust time-optimal rotations of spin systems
Authors: Ansel Quentin , Glaser Steffen J , Sugny Dominique 
Published: January 2021

Abstract
We study the selective and robust time-optimal rotation control of several spin-1/2 particles with different offset terms. For that purpose, the Pontryagin maximum principle is applied to a model of two spins, which is simple enough for analytic computations and sufficiently complex to describe inhomogeneity effects. We find that selective and robust controls are respectively described by singular and regular trajectories. Using a geometric analysis combined with numerical simulations, we determine the optimal solutions of different control problems. Selective and robust controls can be derived analytically without numerical optimization. We show the optimality of several standard control mechanisms in Nuclear Magnetic Resonance, but new robust controls are also designed.
Fast and simple quantum state estimation
Authors: Contreras Daniel Uzcátegui , Senno Gabriel , Goyeneche Dardo 
Published: January 2021

Abstract
We present an iterative method to solve the multipartite quantum state estimation problem. We demonstrate convergence for any informationally complete set of generalized quantum measurements in every finite dimension. Our method exhibits fast convergence in high dimensions and strong robustness under the presence of realistic errors both in state preparation and measurement stages. In particular, for mutually unbiased bases and tensor product of generalized Pauli observables it converges in a single iteration.
Diversity of coniferous species and communities under natural and anthropogenic conditions on islands of Primorsky Region
Authors: Kiselyova A G 
Published: January 2021

Abstract
Coniferous stands perform environment-forming, protective, indicative, recreational and other functions. The islands in the northern part of the Sea of Japan (Primorsky Region, Russia) are inhabited by eight species of gymnosperms belonging to three families and five genera: Abies holophylla Maxim., Abies nephrolepsis (Trautv.ex Maxim.) Maxim., Picea ajanensis Fisch. ex Carrière, Pinus densiflora Siebold & Zucc., Pinus koraiensis Siebold & Zucc. Juniperus davurica Pall., Juniperus rigida Siebold & Zucc., Taxus cuspidata Siebold & Zucc. Populations of Taxus cuspidata survive under natural conditions on Naumov and Petrov islands; communities of Pinus densiflora – on Vkhodnye, Sibiryakov, and Antipenko islands; natural plantations of Abies holophylla – on Stenin and Sibiryakov islands; elfinwoods of Juniperus davurica – on Skaly Kreyser Islands. Under anthropogenic conditions, coniferous species are rare or sporadic. The islands of the Pacific region from the subtropics to the boreal zone are home to 35 species of conifers, 11 genera and 4 families. The most common coniferous species on the Pacific islands are Taxus cuspidata and Pinus pumila. Two groups of islands: one comprising Sakhalin and the Kuril Islands as well as other embracing islands of the Bering Sea and the northern part of the Sea of Okhotsk, are identified based on similarity in coniferous species composition. For conservation and restoration of communities with the participation of coniferous species, attention should be given to both large tracts of coniferous plantations and small populations.