bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Rasch model analysis to analyse students’ mastery of concept on newton law
Authors: Rosiqoh R , Suhendi E
Published: January 2021

The objective of this research was to describe the concept mastery of the tenth year students in the learning topic of Newton Law by using Rasch model analysis. This was a case study research by applying group post-test only research design. There were 30 students taken as a sample consisting of 6 male students and 24 female students with an average age of 15 to 16 years. There were 20 items of multiple-choice tests used in this research (r = 0.88). The result of analysis by using Rasch model such as person fit order where there were 8 students with the outfit mean-square score out of the limit. The students “18P” code is categorized as not smart students because they were not able to solve the easiest problems of the test but they could solve more difficult problems. Generally, the percentage of the students’ mastery of concept mastery was categorized as low.
The students’ Physics Problem Solving Skills in basic physics course
Authors: Sutarno S , Putri D H , Risdianto E , Satriawan M , Malik A
Published: January 2021

One important skill that can support the success of learning physics for students is problem solving skills. This study explores the level of Physics Problem Solving Skills (PPSS) of 54 first semester students (11 men and 43 women, age range 16-18 years) in basic physics course in the science and physics education study program at Universitas Bengkulu, Indonesia. In the first lecture, students learn the concept of one-dimensional motion includes uniformly accelerated motion and vertical motion, but the lecturer does not provide examples of problems and how to solve them. In the second lecture, students learn the concept of Newton’s Law and its application, and the lecturer gives examples of problems and stages to solve them, however the lecturer does not emphasize that these stages are important procedures in solving physical problems. At the end of each lesson, students are given an essay Physics Problem Solving Skills test. Based on an analysis of student answers, it is known that in general the student PPSS level is still in the novice and transition categories. This indicates the importance of developing and implementing basic physics lecture programs that are able to promote students’ higher-order thinking skills including physics problem solving skills.
Difficulties of pre-service physics teacher to desain and implement inquiry learning
Authors: Hendri M , Syarkowi A , Rasmi D P
Published: January 2021

This research aims to describe the difficulties of the pre-service teacher in designing and implementing inquiry learning in senior high school. A case study design was used for this research. Three pre-service teachers were interviewed and observed to determine the distressing point. This research finds all of the respondents started to design learning inquiry from finding some examples of the inquiry learning process in the internet or senior thesis report and imitated that in their lesson plan. This reflected they had the problem of a doubt what the inquiry process looks like. Along with their self-research about inquiry process illustrations, some of them tried to get the clue in the published article on the internet. It took several weeks to self-analyse what they found on the internet. The majority of problems of this is lack of English understanding. For the implementation process, most of them were able to run the teaching but all of them had a problem with applying the assessment process. Most of them thought the assessment process was just in the formative assessment, not along with the learning process. This research also concludes if they still have much lack of knowledge in desingning inqury learning and lack skill in guiding the students in inquiry learning using guided questions.
Ethnoscience analysis of “lemang bamboo” Sumatera traditional food
Authors: Jufrida J , Basuki F R , Oksaputra M F , Fitaloka O
Published: January 2021

Lemang bamboo is a Sumatera traditional food made from glutinous rice that cooked in bamboo. Melemang is one of the Jambi community traditions that has been passed down for generations. This study aims to analyze science concepts and map basic competencies that can be integrated with the process of making lemang bamboo. This research was a qualitative research through ethno science studies. The research subjects were lemang sellers in Muaro Jambi and Batanghari city. Data collected through interviews and observations. Data were analyzed descriptively and reconstructed into scientific knowledge. The results of this study indicate that indigenous knowledge about the process of making lemang bamboo which can be reconstructed into scientific knowledge. The concept of science found in the process of making lemang bamboo were measurement, classification of living things, temperature and heat. The process of making lemang bamboo can be used as a source of learning science.
Development of learning in conservation education subject based on the natural resources potency in the Taman Wisata Alam Bengkulu City
Authors: Aswin P , Lestari D D , Karyadi B
Published: January 2021

The aims of this study is to develop conservation education based on the potential of natural resources in the city of Bengkulu to improve scientific writing skills. This type of research is research and development (analysis, design, development). The steps of research are exploring of Taman Wisata Alam (TWA) as area conservation, collecting data of each ecosystem, identifying of biodiversity, make a map of potency TWA area, designing of material teaching. The results of this study are: 1) There is a coastal forest ecosystem that has vegetation types of trees, shrubs, bushes, grass, fungi, pteridophyte, and bryophyte; 2) Mapping the potential of conservation have coastal, swamp, and mangrove 3) Teaching materials developed from potential TWA conservation areas have introduction of TWA, instructions for students to exploring area conservation, guide activity of writing article based on the exploration experience of conservation area. The conclusion of this research is that research can be developed by utilizing the potential of conservation areas and designing teaching materials that guide students to practice writing.
Development of module of medicinal plants for the subject of organic chemistry in natural materials to stimulate metacognitive skills of students Tadris IPA IAIN Bengkulu
Authors: Lismeiriza L , Karyadi B , Ruyani A , Sundaryono A , Listiono A E
Published: January 2021

This research aims to develop a module of medicinal plants for the subject of organic chemistry in natural materials to stimulate the metacognitive skills of students Tadris IPA IAIN Bengkulu. The research method Refers to the steps of Research and Development. The research is Began by analyzing the needs of the subject of organic chemistry in natural and plant materials that are Often used by Bengkulu people as medicines to be used as learning resources in the form of modules. The trial of the module was limited to 16 students of the fourth semester in the IAIN Bengkulu, Natural Sciences Study Program. The results Showed that the metacognitive skills of students using the medicinal herbs module varied greatly. Student metacognitive skills are mostly good (50%), very good (6%), satisfactory (6%), and less (38%). The ability of students in the planning aspect has developed well while the aspects of monitoring, evaluating, and revising have not developed well (enough). This local potential medicinal plant module is Able to stimulate the metacognitive abilities of the fourth semester of students, Tadris natural sciences Study Program, IAIN Bengkulu viewed from the classical values.
A simplified computational model of possible hydrodynamic interactions between respiratory and swimming-related water flows in labriform-swimming fishes
Authors: Leung David B , Eldredge Jeff D , Gordon Malcolm S
Published: January 2021

Hydrodynamic interactions in bony fishes between respiratory fluid flows leaving the opercular openings and simultaneous flows generated by movements of downstream pectoral fins are both poorly understood and likely to be complex. Labriform-swimming fishes that swim primarily by moving only their pectoral fins are good subjects for these studies. We performed a computational fluid dynamics investigation of a simplified 2D model of these interactions based on previously published experimental observations of both respiratory and pectoral fin movements under both resting and slow, steady swimming conditions in two similar labriform swimmers: the bluegill sunfish (L. macrochirus) and the largemouth bass (M. salmoides). We carried out a parametric study investigating the effects that swimming speed, strength of opercular flow and phase difference between the pectoral fin motion and the opercular opening and closing have on the thrust and sideslip forces generated by the pectoral fins during both the abduction and adduction portions of the fin movement cycle. We analyzed pressure distributions on the fin surface to determine physical differences in flows with and without opercular jets. The modeling indicates that complex flow structures emerge from the coupling between the opercular jets and vortex shedding from pectoral fins. The jets from the opercular openings appear to exert significant influence on the forces generated by the fins; they are potentially significant in the maneuverability of at least some labriform swimmers. The numerical simulations and the analysis establish a framework for the study of these interactions in various labriform swimmers in a variety of flow regimes. Similar situations in groups of fishes using other swimming modes should also be investigated.
Biodegradable JDBM coating stent has potential to be used in the treatment of benign biliary strictures
Authors: Guo Lili , Yu Lanting , Zhao Qiuyan , Gong Xiaoyuan , Xie Haoran , Yuan Guangyin , Li Baiwen , Wan Xinjian
Published: January 2021

In our previous study, to find out the optimal alloy suitable for biliary surgery, magnesium alloy Jiao Da Bio-magnesium (denoted as JDBM) alloy, Zn–3Cu alloys, and their respective coating (MgF2–PDLLA) products were produced for our research. We found that JDBM seems to be a potential material for clinical biliary stent application due to its uniform degradation and good compatibility. In order to apply the JDBM alloy to treat benign bile duct stricture, our group prepared the bare JDBM and its coating product into finished stents by mesh weaving carving technology and conducted the mechanical property tests, degradation tests and biocompatibility tests. During the mechanical property tests, we found the bare JDBM stent was more suitable than titanium alloy stent when applies to the bile duct, and the coating of the JDBM coating stent has no effect on its mechanical properties. Our in vitro and in vivo experiments revealed that the degradation rate of the JDBM coating stent is lower than that of the JDBM stent, and both stents were biosafe. Thus, there is promise for JDBM coating stents for the treatment of benign biliary strictures.
Capability of core-sheath polyvinyl alcohol–polycaprolactone emulsion electrospun nanofibrous scaffolds in releasing strontium ranelate for bone regeneration
Authors: Abdollahi Boraei Seyyed Behnam , Nourmohammadi Jhamak , Bakhshandeh Behnaz , Dehghan Mohammad Mehdi , Gholami Hossein , Gonzalez Zoilo , Sanchez-Herencia Antonio Javier , Ferrari Begona
Published: January 2021

Core-sheath nanofibrous scaffolds from polyvinyl alcohol (PVA)–strontium ranelate (SrR)–Polycaprolactone (PCL) were prepared by water in oil electrospinning method. Thus, PCL (the oil phase) was used as the shell part and a mixture of PVA and SrR (the water phase) was inserted in the core. The amounts of SrR was varied from 0 to 15 wt.% Mussel-inspired dopamine-gelatin coating was done on the nanofibrous to improve their hydrophilicity and cellular attachment. The effect of the SrR content on morphology, mechanical, physicochemical, in vitro release behaviors, and biological properties as well as in vivo bone regeneration was investigated. Morphological observations revealed that continuous nanofibers with a core/shell structure were successfully obtained and the fibers diameter increased as the SrR content rose. X-ray diffraction (XRD) analysis revealed that SrR was molecularly distributed in the nanofibers and increasing the amount of the SrR decreased the crystallinity of the nanofibers. Moreover, the SrR release was regulated through the mechanism of Fickian diffusion and it was assumed as fast as possible in the samples with higher SrR content. The mesenchymal stem cell culturing showed improved cell proliferation by adding SrR and accelerating the expression of ALP, Runx2, Col I, and OCN genes. Besides, the SrR-loaded nanofibers improved bone formation of calvarial defects in a rat model as revealed by in vivo investigations.
Light-assisted therapy for biofilm infected micro-arc oxidation TiO2 coating on bone implants
Authors: Han Xiang , Zhang Guannan , Chai Maozhou , Zhang Xiangyu
Published: January 2021

Implant-associated infections is a main factor leading to the failure of titanium (Ti) implants. Micro-arc oxidation is a convenient and effective technique to form a biocompatible metal (Ag+, Cu2+ and Zn2+) ions-doped TiO2 coatings to combat bacterial infections. However, compared with the sterilization by metal ions, light-triggered antibacterial therapies have accepted more attention due to its higher antibacterial efficiency and security. Although TiO2 is an excellent photocatalyst, it can be triggered by ultraviolet light due to the wide band gap. Herein, molybdenum disulfide (MoS2) modified TiO2 coating was fabricated on Ti by a hybrid process of micro-arc oxidation and hydrothermal treatment. The hybrid coating exhibits excellent antibacterial activity under the irradiation of 808 nm near-infrared light because of the synergistic antibacterial effects of reactive oxygen species and hyperthermia, and Staphylococcus aureus (S. aureus) biofilm can be eradicated within 15 min both in vivo and in vitro. Furthermore, collagen decorated on the surface of the hybrid coating can improve the proliferation, adhesion and spreading of MC3T3-E1 osteoblasts.
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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Validation of the efficiency of using solar energy resources for autonomous power supply of the trans-border area between Russia and Mongolia
Authors: Ivanova I Yu , Khalgaeva N A
Published: January 2021

The study provides an analysis of the state of the electric power supply in the trans-border area of Baikal-Khövsgöl. We identified the problems of power supply and the presence of decentralized consumers. The analysis of indicators of solar energy resources of the area from both Mongolia and Russia sides was based on various data sources. The NASA data of solar radiation incident on the different surfaces was selected for further calculations and zoning of the area. We evaluated the economic feasibility of the construction of the solar power plant (SPP) serving tourism infrastructure facilities with a capacity of 10 to 100 persons located on the northern coast of Lake Khövsgöl, which are provided with electricity from diesel power plants (DPP). The research used an iterative express method for determining the optimal power of a SPP for autonomous power supply, developed by the authors. The criterion for optimality is the minimum ratio of capital investment in a SPP and the cost of substituted fuel at a DPP. The research findings attest to the fact that the introduction of the SPP for stand-alone electric power supply seems to be economically viable for both stationary and mobile facilities. Undiscounted payback periods resulted from the diesel fuel substitution range from 2.5 to 6 years.
The roadside infrastructure development: a geographical view
Authors: Bogdanov V N , Dugarova G B
Published: January 2021

The roadside infrastructure has begun to form recently and is accompanied by different problems. These problems are common to many Russian regions, in particular Irkutsk Oblast. In this article, the authors share their experience in studying roadside infrastructure with the aim to improve the existing network and rational placement of new objects as well as prospects for developing roadside infrastructure in Russia as a whole. This publication is a continuation of our long-term research and the scientific novelty consists in the generalization of the results and comparison of various foreign models of road infrastructure development. In this study, we used the methods developed and tested in our previous works. This study is one of the first in Irkutsk Oblast, and the accumulated material can serve as a basis for creating a comprehensive scheme for the optimal placement of roadside infrastructure. We identified the main factors and problems of the roadside infrastructure development, made mathematical calculations, and compiled original thematic maps. As a result of the study, we came to the conclusion that the Irkutsk Oblast that has a rich natural, socioeconomic, and energetic potential can be a good testing ground for the successful application of the existing foreign roadside service development systems (European or North American).
Trends in vegetation cover dynamics in the Russian part of the Amur River basin in relation to the economic development of the territory
Authors: Kryukova M V , Schlothgauer S D
Published: January 2021

This work presents the research results in condition and trends in the vegetation cover of the Amur River basin resulting from economic activities. The economic activity impact is assessed both directly and indirectly. Vulnerability of the vegetation cover in the Amur Region is determined according various factors: ecotone position, unstable living environment; relict nature of plant taxa and communities and low degree of adaptation; insularity of relicts, endemic taxa and communities. Risk factors for the plant cover of the Amur Region include large-scale fires, continuous plowing of lands, forest cuttings, construction of hydraulic facilities (hydro-electric stations and reservoirs), expansion of road infrastructure, mining of non-ferrous metals, etc. The effects of development on the Amur Region territory include discontinuity of the habitats of many relict and endemic species, increase of the pattern structure of their spatial distribution and formation of isolated, unstable populations, decrease in the floral and regional ecological diversity of biogeocenoses, synantropization, unification of the vegetation cover, transformation and destruction of historically established ecosystems, habitats and increasing environmental risks. Four types of ecological state are identified: catastrophic, critical, stressed and satisfactory. The identified zones of catastrophic and critical ecological states of the vegetation cover are confined to the most developed southern parts of the Amur Region and urban agglomerations. Most of the Amur River basin features stressed and satisfactory ecological states, the preservation of which is facilitated by the inaccessibility of these territories.
Efficiency of using timber processing waste for heat supply of the city of Baikalsk
Authors: Khan V V , Gubiy E V , Dekanova N P
Published: January 2021

The heat supply problem of the city of Baikalsk isconsidered. The most environmentally friendly solution of this problem is using of the timber, which was felled during forest sanitation outside the Anchuk village. Environmental friendliness and other advantages of the biofuel are the main reason of using this type of heat source. This article presents comparative analysis of the production and delivery costs of the fuel wood chips and pellets for Baikalsk. Pressed fuel wood chips and chips with standard bulk density are considered. The levelized cost of heat, unit cost and capital costs are used as indicators of the economic efficiency of pellets and fuel wood chips. According to the results of all three economic indicators, pressed fuel chips proved to be most effective type of heat source than others. Unit cost and LCOH are roughly the same for pellets and for pressed fuel chips. However, the capital costs of production and transportation of the pellets are almost 50% higher than for pressed chips. Thereby, it is preferable to choose pressed fuel wood chips burning for economic reasons of the reducing transportation expenses.
Issues of protection of the Lake Baikal legal regime
Authors: Orlova I I , Bekker Yu L
Published: January 2021

Conceptual provisions of the Federal law “On protection of Lake Baikal”, adopted in 1999, have never been disputed during the last 20 years: legal regime primarily of the central ecological zone is supported by regulatory acts, the state ecological expertise is in place. Current ecological crisis of ecosystem, actual failure of the approved target federal projects, ecological catastrophe threats due to possible technological consequences of delay in the Baikal paper plant waste liquidation are consequences of lack of scientific cover in program action projects, as well as refusal of preliminary open discussion on possibility of legislative and other initiatives with regard to Baikal. In the sphere of scientific support of measures on the Lake Baikal preservation the following points are suggested: 1. Scientific research is to be included into the Russian national scientific projects as a mandatory stage of formation and implementation of state regulation measures. 2. Normative setting of requirements of mandatory scientific expertise for projects that can significantly impact the Lake Baikal preservation. 3. Institution of “Expertise of the Russian Academy of Sciences” is to be used for expert assessment of the most significant projects in the sphere of the Lake Baikal protection.
RAS expertise for assurance of consistency of solutions to applied problems and results of fundamental researches
Authors: Bekker Yu L , Orlova I I
Published: January 2021

Nowadays the main institution for exclusion of contradictions between the results of fundamental and applied problems can be the RAS expertise of big development projects, launched by the state and business. Such status is set in the Russian legislature as an indicator of expertise of highest qualification, scientific justification and exclusion of conflict of interests. Moreover, lack of disputing instruments allows to count on effectiveness of use of this institution in sphere of nature management and formation of “green” economy. A methodology of conduction of the RAS expertise for proposals on liquidation of accumulated environmental damage, done by the JSC “Baikalsky PPM”, in the context of technical feasibility and compliance with requirements of legal regime of Lake Baikal. Principal conditions of these expert works are: inclusion of the RAS Expertise into complex of measures on scientific support of realization of Russia’s national development goals; an organization that requests expertise of technical solutions of the affiliated parties cannot be a customer; compliance with common requirements of completeness and quality of information; competitiveness of expertise process; expertise procedure has to be supported by several levels of results’ verification keeping the confidentiality of information on experts’ identities and their executed work.
Methods for mapping information on the structure and dynamics of geosystems of mountains of the Baikal region
Authors: Sedykh S A
Published: January 2021

The paper presents the results of the ecological study, with the analysis of landscapes and mapping of the area of the testing ground. The testing ground is located in the Eastern Transbaikalia, covering the part of the central part of Primorskii Range and sourth-eastern macroslope of this mountain range (having an easterly aspect for the Primorskii Range). For the analysis of the structure of geosystems and the estimation of disturbance, the basic geosystem approach is applied to modern geoinformation-cartographic and remote methods. Based on V.B. Sochava’s theory of geosystems it is assumed for use in processing and ordering a large volume of information. In the paper we analyzed the regional background and main factors of the landscape differentiation of the study areas. The pyrogenic impact, which increased by the 21st century and caused the transformation of the natural structure of the Baikal mountains, caused the need to improve the methods of mapping the geosystems of topological level, their dynamics, landscape-forming processes and individual local phenomena. We identified negative digressions of geosystems for the period 1989-2019 at the experimental site, when 42% of 100 km2 of natural systems of highlands, mountain-taiga middle mountains and lowmountain-slope forests were lost.