Modern Walking Robots: A Brief Overview

In this review, we would like to present some of the most interesting modern designs of walking robots: bipedal, quadropedal, hexopedal, and octopods. Their advantages and disadvantages are highlighted. It has been determined that structures with eight or more limbs are ineffective due to high level of electricity consumption. The use of more than six number of legs does not give noticeable advantages in profile cross-country ability or maneuverability, however, it allows to reduce the forces and moments of inertia forces due to decrease in mode coefficient (ratio of time spent by propulsor in support to time of entire step), and, consequently, smoother leg movements in swing phase

A pan-Arctic initiative on the spatial and temporal dynamics of Arctic coasts

Permafrost coasts make up roughly one third of all coasts worldwide. Their erosion leads to the release of previously locked organic carbon, changes in ecosystems and the destruction of cultural heritage, infrastructure and whole communities. Since rapid environmental changes lead to an intensification of Arctic coastal dynamics, it is of great importance to adequately quantify current and future coastal changes. However, the remoteness of the Arctic and scarcity of data limit our understanding of coastal dynamics at a pan-Arctic scale and prohibit us from getting a complete picture of the diversity of impacts on the human and natural environment. In a joint effort of the EU project NUNATARYUK and the NSF project PerCS-Net, we seek to close this knowledge gap by collecting and analyzing all accessible high-resolution shoreline position data for the Arctic coastline. These datasets include geographical coordinates combined with coastal positions derived from archived data, surveying data, air and space born remote sensing products, or LiDAR products. The compilation of this unique dataset will enable us to reach unprecedented data coverage and will allow us a first insight into the magnitude and trends of shoreline changes on a pan-Arctic scale with locally highly resolved temporal and spatial changes in shoreline dynamics. By comparing consistently derived shoreline change data from all over the Arctic we expect that the trajectory of coastal change in the Arctic becomes evident. A synthesis of some initial results will be presented in the 2020 Arctic Report Card on Arctic Coastal Dynamics. This initiative is an ongoing effort – new data contributions are welcome

Chronicles of nature calendar, a long-term and large-scale multitaxon database on phenology

We present an extensive, large-scale, long-term and multitaxon database on phenological and climatic variation, involving 506,186 observation dates acquired in 471 localities in Russian Federation, Ukraine, Uzbekistan, Belarus and Kyrgyzstan. The data cover the period 1890-2018, with 96% of the data being from 1960 onwards. The database is rich in plants, birds and climatic events, but also includes insects, amphibians, reptiles and fungi. The database includes multiple events per species, such as the onset days of leaf unfolding and leaf fall for plants, and the days for first spring and last autumn occurrences for birds. The data were acquired using standardized methods by permanent staff of national parks and nature reserves (87% of the data) and members of a phenological observation network (13% of the data). The database is valuable for exploring how species respond in their phenology to climate change. Large-scale analyses of spatial variation in phenological response can help to better predict the consequences of species and community responses to climate change.Peer reviewe

Phenological shifts of abiotic events, producers and consumers across a continent

Ongoing climate change can shift organism phenology in ways that vary depending on species, habitats and climate factors studied. To probe for large-scale patterns in associated phenological change, we use 70,709 observations from six decades of systematic monitoring across the former Union of Soviet Socialist Republics. Among 110 phenological events related to plants, birds, insects, amphibians and fungi, we find a mosaic of change, defying simple predictions of earlier springs, later autumns and stronger changes at higher latitudes and elevations. Site mean temperature emerged as a strong predictor of local phenology, but the magnitude and direction of change varied with trophic level and the relative timing of an event. Beyond temperature-associated variation, we uncover high variation among both sites and years, with some sites being characterized by disproportionately long seasons and others by short ones. Our findings emphasize concerns regarding ecosystem integrity and highlight the difficulty of predicting climate change outcomes. The authors use systematic monitoring across the former USSR to investigate phenological changes across taxa. The long-term mean temperature of a site emerged as a strong predictor of phenological change, with further imprints of trophic level, event timing, site, year and biotic interactions.Peer reviewe

Dynamics of Low-Lying Sandy Coast of the Gydan Peninsula, Kara Sea, Russia, Based on Multi-Temporal Remote Sensing Data

The retreat rates of Arctic coasts have increased in recent decades at many sites, and an essential part of coasts considered accumulative before have turned erosional due to global climate changes and construction in the coastal zone. In this paper, we study a 7 km long coastal section of the western Gydan Peninsula in a new construction area. Based on the interpretation of multi-temporal satellite imagery, we assessed coastal dynamics in distinct periods from 1972 to 2020. We analyzed the geological structure of the coast as well as changes in hydrometeorological parameters with time, and considering the human impact, we proposed the main drivers of spatial and temporal variations of coastal dynamics. The studied low-lying sandy accumulative marine terrace was more or less stable in the period before construction (1972–2014). However, with the area’s development, the coast dynamics changed drastically: in 2014–2017, three-quarters of the studied area experienced retreat, and the average retreat rate amounted to 5.8 m/yr, up to 28.5 m/yr near the construction sites. We relate this coastal erosion intensification to human impact combined with the growth of hydrometeorological forcing. Although coastal erosion slowed down after 2017, the retreat trend remained. In the coming years, with Arctic climate warming, erosion of the studied coast will continue

Microbial community structure of activated sludge in treatment plants with different wastewater compositions

Activated sludge (AS) plays a crucial role in the treatment of domestic and industrial wastewater. AS is a biocenosis of microorganisms capable of degrading various pollutants, including organic compounds, toxicants and xenobiotics. We performed 16S rRNA gene sequencing of AS and incoming sewage in three wastewater treatment plants (WWTPs) responsible for processing sewage with different origins: municipal wastewater, slaughterhouse wastewater, and refinery sewage. In contrast to incoming wastewater, the taxonomic structure of AS biocenosis was found to become stable in time, and each WWTP demonstrated a unique taxonomic pattern. Most pathogenic microorganisms (Streptococcus, Trichococcus, etc.) and inductors of AS bulking and flocculation (Comamonadaceae, Flavobacteriaceae, etc.), which are abundantly represented in incoming sewage, were significantly decreased in AS of all WWTPs, except for the slaughterhouse wastewater, which was rich in organic matter. Here we present a novel approach enabling the prediction of the metabolic potential of bacterial communities based on their taxonomic structures and MetaCyc database data. We developed a software application, XeDetect, to implement this approach. Using XeDetect, we found that the metabolic potential of the three bacterial communities clearly reflected the substrate composition. We revealed that the microorganisms responsible for AS flocculation and bulking (abundant in AS of slaughterhouse wastewater) played a leading role in the degradation of substrates such as fatty acids, amino acids, and other bioorganic compounds. Moreover, we discovered that the chemical, rather than the bacterial composition of the incoming wastewater was the main factor in AS structure formation. XeDetect (freely available: https://sourceforge.net/projects/xedetect) represents a novel powerful tool for the analysis of the metabolic capacity of bacterial communities. The tool will help to optimize bioreactor performance and avoid some most common technical problems

A Spatially Detailed Projection of Environmental Conditions in the Arctic Initiated by Climate Change

The environmental conditions of the Arctic are vulnerable to the effects of climate change. We focus on the territory of the Yamalo-Nenets Autonomous Okrug (YaNAO). The objective of this study is to project mid-21st century climate-driven changes in the state of climate and the natural environment in the YaNAO. For this purpose, the CMIP6 data models with the climate change scenario SSP5-8.5 were used. Climate change directly affects the statistics of extreme events and climatically driven phenomena, such as frosts and thaws, as well as avalanches and slush flows. Climate change causes changes in the Arctic environment, primarily due to permafrost degradation, leading to important modifications in events such as mudflows, cryogenic landslides, abrasion, erosion, suffusion, frost heave, solifluction, thermokarst, and others. In some cases, the intensity and area of these processes increase, such as heaving processes and thermokarst becoming more active by 2050. In other cases, the solifluction processes decrease in the south part of the YaNAO due to the discontinuous or sporadic permafrost distribution. Projected climatic changes will inevitably lead to the restructuring of the geosystems in YaNAO, creating risks for infrastructure in economically active territories

Biocides with Controlled Degradation for Environmentally Friendly and Cost-Effective Fecal Sludge Management

Didecyldimethylammonium chloride (DDAC) and polyhexamethylene guanidine (PHMG) exhibit high antimicrobial activity and are widely used as biocidal agents in chemical toilet additives for the management of fecal sludge (FS). Disposal of such biocide-treated FS to a wastewater treatment plant (WWTP) is a major environmental problem. It is possible to reduce environmental damage through the use of biocidal agents, which easily decompose after performing their main biocidal functions. In this work, it is proposed to use the fact of a gradual increase in pH of FS from the initial 7.5 to 9.0–10.0 due to the decomposition of urea. Six biocidal compounds were selected that are capable of rapidly degrading in an alkaline environment and one that naturally degrades upon prolonged incubation. Four of them: bronopol (30 mg/L), DBNPA (500 mg/L), Sharomix (500 mg/L), and sodium percarbonate (6000 mg/L) have shown promise for environmentally friendly management of FS. In selected dosage, they successfully reduced microbial activity under both aerobic and anaerobic conditions and are cost-effective. After 10 days of incubation, degradation of the biocide occurred as measured by biological oxygen demand (BOD5) in biocide-treated FS. Such FS can be discharged to WWTP without severe damage to the activated sludge process, the need for dilution and additional procedures to neutralize toxicity