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This study examines the impact of fire incidents on wildlife and habitats in the western oak forests of Iran (Zagros region). These forests are globally recognized for their exceptional biodiversity but are frequently threatened by wildfires. To achieve this, the study uses the space–time scan statistics permutation (STSSP) model to identify areas with a higher frequency of fires. The study also analyzes the effects of fires on the Zagros forests from 2000 to 2021 using remote-sensing MODIS data. Also, to understand the elements at risk of fire, burned areas were assessed based on the richness of vertebrate species, determined by the distribution of 88 vertebrate species. The results show that the annual fire rate in the Zagros forests is 76.2 (fire occurrences per year), calculated using the Poisson distribution. Findings show the highest fire rates are found in the northwest and a part of the south of the Zagros. The northwest of the Zagros also has the largest number of single fires and clusters, indicating a wide spatial distribution of fire in these regions. On the other side, it was unexpectedly found that these regions have the richest number of species and higher habitat value. The results demonstrate a significant correlation between the value of the habitat and the extent of burned areas (p < 0.05). The study also reveals that the greatest impact of fires is on small vertebrates. The overlap of frequent fire spots with the richest regions of Zagros oak forests in terms of vertebrate diversity emphasizes the need for strategic forest risk reduction planning, especially in these priority zones. [ABSTRACT FROM AUTHOR]

The intense Siberian wildfires in the summer of 2019 had devastating effects. Here the dynamics of these wildfires is described taking into consideration the legal act that determines modern forest management in Russia -- the Forest Code-2006. This changed the approach to wildfire management in Russia by introducing control zones, where authorities can legally ignore wildfires due to their inaccessibility or remoteness from firefighting infrastructure. Remote sensing and open reports show that most wildfires (60--98%, depending on the day) in Siberia in 2019 were in control zones. Notably, the largest percentages were recorded during the crucial phases of the wildfires, including their rapid spread in June (97--98%) and during the peak from on 2 August (96%), when 3,012,082 of 3,134,128 hectares were on fire. The decision not to fight these wildfires was debatable given the considerable social concerns expressed online during the peak of the wildfires, which later resulted in civic petitions in favour of fighting wildfires more efficiently in Siberia. Based on previous reports by experts there is an urgent need to incorporate a more scientific approach in defining control zones in Siberia, to balance the current economic and socioenvironmental considerations. Otherwise, the control zones of Russian forests (occupying 48% of Russia's and 11% of the global forest area, respectively) will remain a critical blind spot in climate change mitigation plans that aim to utilize Siberia's carbon sequestration potential. [ABSTRACT FROM AUTHOR]

Based on the photocurrent model, we theoretically investigate the terahertz (THz) radiation in gas plasma driven by monochromatic chirp laser pulse. It is shown that the trajectories of the ionized electrons can be controlled effectively and can form a larger net residual current in a chirped field. As a result, the radiated THz yield can be dramatically improved by nearly more than two orders of magnitude than that of few-cycle chirp-free laser field. Furthermore, with the THz yield dependence on the laser intensity, wavelength and pulse width of the drivers carefully investigated, some noticeable differences between chirped field and chirp-free pulse are observed. [ABSTRACT FROM AUTHOR]

Predicting wildfire spread behavior is an extremely important task for many countries. On a small scale, it is possible to ensure constant monitoring of the natural landscape through ground means. However, on the scale of large countries, this becomes practically impossible due to remote and vast forest territories. The most promising source of data in this case that can provide global monitoring is remote sensing data. Currently, the main challenge is the development of an effective pipeline that combines geospatial data collection and the application of advanced machine learning algorithms. Most approaches focus on short-term fire spreading prediction and utilize data from unmanned aerial vehicles (UAVs) for this purpose. In this study, we address the challenge of predicting fire spread on a large scale and consider a forecasting horizon ranging from 1 to 5 days. We train a neural network model based on the MA-Net architecture to predict wildfire spread based on environmental and climate data, taking into account spatial distribution features. Estimating the importance of features is another critical issue in fire behavior prediction, so we analyze their contribution to the model’s results. According to the experimental results, the most significant features are wind direction and land cover parameters. The F1-score for the predicted burned area varies from 0.64 to 0.68 depending on the day of prediction (from 1 to 5 days). The study was conducted in northern Russian regions and shows promise for further transfer and adaptation to other regions. This geospatial data-based artificial intelligence (AI) approach can be beneficial for supporting emergency systems and facilitating rapid decision-making. [ABSTRACT FROM AUTHOR]

This study investigated the effect of trimethylgallium flow rate on the structural and photoelectronic properties of β-Ga2O3 films grown on α-Al2O3 (0001) substrates using MOVPE method. As the source flow rate gradually decreased from 7.2 mol/min to 3.6 mol/min, the films gradually changes from polycrystalline to a single epitaxial orientation, and the epitaxial relationships between the film and the substrate were β-Ga2O3 ( 2 - 01) ∥α-Al2O3 (0001) and β-Ga2O3 [010] ∥α-Al2O3 < 1 - 010>. The film thickness was reduced from 767.4 to 329.2 nm and the surface root-mean-square roughness decreased from 18.1 to 5.84 nm. The average transmittance in the visible range increased from 81.2 to 83.4%, and the optical bandgap width increased from 4.80 to 4.95 eV. The prepared MSM-structured photodetectors (PDs) could continuously switch response to 254 nm UV light, and the PD prepared at 7.2 mol/min source flow rate had a maximum photo current of 1405.2 nA. However, the PD prepared under the condition of 3.6 mol/min had the lowest dark current, the highest photo-dark current ratio, shorter fast response time, and a good retention characteristic. [ABSTRACT FROM AUTHOR]

Spatiotemporal analysis provides valuable insights into spatial variations through time series of outgoing longwave radiation (OLR) in a seismically active region. This study investigates the relationship between the anomalous variations in OLR associated with the earthquake preparation process for earthquakes (Mw > 6.0) in the Sumatra region radius of 75 km from 1993 to 2012 concerning the 26 December 2004 Sumatra–Andaman Islands earthquake. To explore the spatiotemporal characteristics of OLR, the grid comprising 11° × 11° was considered for a 12-month time period preceding the earthquake. The spatial distribution of the anomalous OLR flux is investigated over and around the epicentral region to indicate a region's earthquake preparation process. The entire spatial extent is categorized into two leagues, "Macro dimension League" (MaDL) and "Micro dimension League" (MiDL). To facilitate the comparison of different grid dimensions, the OLR values of the grids are normalized. The authors inferred that the anomalous variations observed in MiDL are more predominant than in other regions, mainly 1–3 months before earthquakes. These anomalous variations may serve as precursory signals manifesting as a thermal release near and over the epicentral region. It might indicate the earthquake preparation process over the seismically vulnerable regions with a magnitude greater than 6.0 Mw. Hence, the study suggests that the anomalous changes in OLR could be considered as a precursor in earthquake precursory studies, at least in this confined study region. [ABSTRACT FROM AUTHOR]

Coastal zones supporting diurnal shelf waves near the South Kuril Islands were determined based on the analysis of small-scale amplitude and phase variations of diurnal O1 and K1 tidal waves estimated from along-track TOPEX/Poseidon altimetry data. The amplitudes and phases of these waves were revealed not only along the original tracks (1992–2002), but also along those shifted by half the intertrack distance (2002–2005). This made it possible to more accurately determine the zone supporting diurnal shelf waves. It was found that diurnal shelf waves in the form of baroclinic coastal trapped modes strongly influence tidal motions on the oceanic shelf of Urup and Iturup islands. Two wavelengths fit in this section of the shelf (one pair of quasi-stationary eddies is localized on the shelf of Urup Island and a second one on the shelf of Iturup Island). This is an unexpected result, as barotropic shelf modes usually form one pair of eddies (for example, on the northeastern shelf of Sakhalin Island, on the northern shelf of Hokkaido Island and on the oceanic shelf of the North Kuril Islands). We found that the zone of K1 and O1 tidal waves start from Chirpoi Island, which means that shelf waves are generated as a result of the diffraction of a large-scale Kelvin tidal wave in the deep Bussol Strait. The existence of the lower frequency O1 tidal shelf wave was found not only on the shelf of Urup and Iturup islands, but also on the shelf of Shikotan Island, which is consistent with the earlier results of Yefimov and Rabinovich (1980). Diurnal shelf waves cause significant increases in the O1 and K1 amplitudes on the coast of Iturup Island (especially at its southern part) and on Urup Island in comparison with the open ocean, and produce strong instrumentally-observed diurnal tidal currents in these regions. Baroclinic diurnal shelf (coastal trapped) waves also contribute to vertical movements, forcing water temperature variations at sufficiently great depths, which can have a significant impact on the living conditions of benthic communities. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs), are porous crystalline structures comprising of metal ions or clusters intricately linked with organic entities, displaying topological diversity and effortless chemical flexibility. These characteristics render them apt for multifarious applications such as adsorption, separation, sensing, and catalysis. Predominantly, the distinctive properties and prospective utility of MOFs are discerned post-manufacture or extrapolation from theoretically conceived models. For empirical researchers unfamiliar with hypothetical structure development, the meticulous crystal engineering of a high-performance MOF for a targeted application via a bottom-up approach resembles a gamble. For example, the precise pore limiting diameter (PLD), which determines the guest accessibility of any MOF cannot be easily inferred with mere knowledge of the metal ion and organic ligand. This limitation in bottom-up conceptual understanding of specific properties of the resultant MOF may contribute to the cautious industrial-scale adoption of MOFs. Consequently, in this study, we take a step towards circumventing this limitation by designing a new tool that predicts the guest accessibility—a MOF key performance indicator—of any given MOF from information on only the organic linkers and the metal ions. This new tool relies on clustering different MOFs in a galaxy-like social network, MOFGalaxyNet, combined with a Graphical Convolutional Network (GCN) to predict the guest accessibility of any new entry in the social network. The proposed network and GCN results provide a robust approach for screening MOFs for various host–guest interaction studies. [ABSTRACT FROM AUTHOR]

Employing the isothermal molecular dynamics and the embedded atom method, we simulated melting of metallic nanoparticles (Au, Ag, Cu, Ni, and Pb ones). In more detail, the results for Au and Ag nanoparticles are presented and discussed. At first, we analyzed the behavior of the temperature dependences for the potential (cohesive) term into the specific (per atom) internal energy and for the degree of crystallinity in the course of heating nanoparticles. We have found that the results obtained for nanoparticles of about 4 and 8 nm in size (containing 2093 and 20,113 atoms, respectively) demonstrate the continuous melting. Employing the dependence of the specific potential energy on the distance to the nanoparticle center of mass and the common neighbor analysis, we showed that the continuous melting occurs via the surface pre-melting mechanism. Then, we evaluated the self-diffusion coefficient in the surface disordered layers of Au and Ag nanoparticles and found that our results agree in order of magnitude (10−9 m2/s) with the values of the self-diffusion coefficient for the bulk Au and Ag melts at the corresponding bulk melting temperatures. Finally, combining in our molecular dynamics experiments continuous heating Au nanoparticles with annealing them at some constant selected temperatures, we have shown that the liquid nucleation and growth mechanism should be most adequate to the melting behavior of metallic nanoparticles. [ABSTRACT FROM AUTHOR]

Defects created in lightly Sn-doped (2 × 1016 cm−3) (010)-oriented bulk β-Ga2O3 implanted with 1.2 MeV, 3 × 1015 cm−2 197Au+ ions before and after treatment in hydrogen plasmas at 330 °C were studied by X-ray measurements, Rutherford backscattering spectra, capacitance–voltage, current–voltage, admittance spectra and deep level transient spectroscopy. Au implantation creates defects that produce total depletion of carriers in the top 1.5 µm and introduces electron traps with energy levels at Ec-0.7 eV, Ec-1.05 eV, Ec-0.45 eV, and deep acceptors with optical ionization thresholds near 1.3 eV, 2.3 eV and 3.1 eV, similar to the centers dominating the spectra of deep traps in β-Ga2O3. Hydrogen plasma treatment greatly enhances the photocurrent and photo-capacitance and decreases the width of the insulating layer produced by Au implantation. The results can be explained by hydrogen passivation of the triply charged Ga vacancies and doubly charged split Ga vacancies acceptors in the implanted region, returning part of this region to n-type conductivity. [ABSTRACT FROM AUTHOR]

Bird diversity research in this area has revealed that the eastern Himalaya mountain range, south slopes, and mid-lower altitude areas have higher levels of bird diversity than the western Himalaya mountain range, north slopes, and high-altitude areas, respectively (Acharya I et al i . The results of most studies on the altitude gradient distribution of birds carried out in the Himalaya mountain area showed that the abundance of birds firstly increased and then decreased with the change of altitude and that the areas with the highest abundance were generally in the range of 2000-3000 m (Acharya I et al i . However, the survey can generally reflect the changing trend of bird abundance in the large Mount Everest altitude gradient, which will help to understand the condition of birds at extremely high altitudes. The species and abundance of birds in the high altitude area of Mount Everest decreased sharply with the increase of altitude. [Extracted from the article]

We have accurately recalculated the embedding functions for Pt and Pd in the frames of the basic embedded atom method (EAM) scheme primarily developed by Daw and Baskes. The main motivation behind such a problem is that some later EAM parameterizations inadequately predict for Pd a higher melting temperature than for Pt. So, other results obtained by employing these parameterizations are also called into question. Our numerically calculated EAM functions for Pt and Pd were verified theoretically and in molecular dynamics simulations of bulk Pt and Pd phases as well as of Pt, Pd, and binary Pt–Pd nanoparticles. In particular, bulk densities in the solid and liquid states, temperatures and heats of melting, and bulk moduli of Pt and Pd were evaluated. Besides, the elastic constants C 11 , C 12 , and C 44 were theoretically recalculated. All the verification results at least satisfactorily agree with the available experimental data. One of the advantages of our embedding functions is that they are suitable for atomistic simulations of Pt- and Pd-based alloys as well. In particular, our embedding functions quite adequately predict segregation of Pd atoms to the surface of binary Pt–Pd nanoparticles. [ABSTRACT FROM AUTHOR]

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Background The North Caucasus is an extensive region with a multitude of landscapes and high biological diversity. Amongst various ecosystems, the xerophytic sub-Mediterranean forests of the Abrau Peninsula (Utrish State Nature Reserve) and its vicinity are unique but have been poorly studied. The diversity of diatoms in North Caucasian ecosystems have been studied partially and only little information is available about their presence and distribution on the Abrau Peninsula. Here, we present a comprehensive check-list of diatoms sampled during a July 2021 field campaign. Samples were collected in 67 sites, including 39 permanent streams, 21 temporal (puddles) and seven permanent waterbodies. Results of the current study contribute to improving the knowledge about diatoms in the north-western Caucasus and its sub-Mediterranean ecosystems in particular. [ABSTRACT FROM AUTHOR]

Sialic acid is a terminal component of carbohydrate chains of glycoproteins and glycolipids. The present study estimated total sialic acid (TSA) and its ratio with total proteins (TP), in serum and saliva of preeclampsia. The study further investigated the association of these parameters with clinical variables of disease progression. 50 preeclampsia patients (32 mild preclampsia and 18 severe preeclampsia cases) and 50 pregnant controls were included in the study. Serum and salivary free sialic acid, protein bound sialic acid and TP were measured spectrophotometrically. Serum and salivary TSA and its ratio with TP were calculated. There was a significant increase in serum TSA and its ratio with TP in preeclampsia compared to the controls. The increase reflected with the severity of the disease. Serum TSA and TSA/TP showed a significant positive correlation with blood pressure, proteinuria and a significant negative correlation with infant birth weight. In saliva, there was no statistical difference between TSA in preeclampsia and controls. Salivary TSA/TP increased significantly in preeclampsia. However the increase was not in accordance to the disease severity. Salivary TSA and TSA/TP were not significantly associated with any of the clinical parameters of disease progression. Significant increase in seum TSA reflects the disturbance in sialyation of serum proteins in preeclampsia, that could not be depicted in the saliva of these patients. Disturbance in serum protein sialyation is further exaggerated with the severity of the disease. Serum TSA and TSA/TP and not the respective salivary parameters, could serve as useful indicators in assessment of clinical progression of the disease. [ABSTRACT FROM AUTHOR]

The work is devoted to the study of the mechanical properties of porous ceramics based on diatomite, which has high porosity, adsorption capacity, weak thermal and acoustic conductivity, refractoriness and acid resistance. Based on the morphological analysis of the samples, the numerical value of the sample's porosity was determined. The mechanical properties of the samples were determined by static and dynamic loading methods. The values of static and dynamic elastic moduli of the samples were experimentally measured. The research results showed that, for the material under consideration, at the initial stages of compression processes, the processes of elastic deformation are mainly realized with the subsequent transition to the region of plastic deformation. It was also found that for highly porous samples in the elastic deformation region, the manifestation of pressing processes is possible. In this work, the study of the dependence of the dynamic modulus of porous diatomite ceramics on porosity was carried out: a decrease in elastic moduli was recorded with an increase in the material porosity. A decrease in material porosity after deformation is found. [ABSTRACT FROM AUTHOR]

Many researchers have recognized the long distance teleconnections between El Niño–Southern Oscillation (ENSO) events and some other processes in the global climate system happening in areas often very far from the equatorial zone of the Pacific Ocean. In this paper we investigate similar links between ENSO and extratropical processes taken in their whole set. For this goal we compute differences between the sea-level pressure and the near-surface air (sea surface) temperature global fields which correspond to either El Niño or La Niña events observed since the end of the XIX century and up to the beginning of the XXI century. As a result, we establish that an integrity exists of ENSO and the extratropical teleconnections such as North Atlantic Oscillation (NAO), Arctic Oscillation (AO), the Northern Hemisphere annular (NHA) mode as well as the Pacific–North American (PNA) pattern, and their analogs in the Southern Hemisphere in the interannual timescale. Named this integrity the Global Atmospheric Oscillation (GAO), we define two representative indices of GAO, and investigate the temporal dynamics of these indices. This investigation reveals that GAO's extratropical components may be real irrespective of ENSO while the latter accompanies GAO in all cases. Moreover, in view of a general eastward propagation of the GAO as a spatial structure, some its extratropical components show changes of their features prior the El Niño (La Niña) begins to form. Using these features as fingerprints of the forthcoming evolution of ENSO, we define another GAO index for the El Niño prediction with the lead-time of about 1 year. At last, we establish that some of the CMIP5-models reproduce GAO reasonably well. [ABSTRACT FROM AUTHOR]

The review-and-analytical article deals with the interrelation between demographic transition and national security. The focus is on the countries of the former Soviet Union. It proves that along with two traditional approaches of population policy, i.e. prevention and overcoming of negative consequences of demographic transition, measures of adjustment to demographic change are acquiring increasing importance. [ABSTRACT FROM AUTHOR]

At the start of the third millennium, new opportunities have arisen in biogeographical research, namely in the generalisation, visualisation and cross-spectrum analysis of biological and geographical information and in the compilation of biogeographical maps and innovative models for regions that differ in the availability of distribution data. These tasks include long-term monitoring of plants and animals which are in danger of extinction, geographical analysis of biodiversity distribution and development of effective wildlife conservation strategies for specific regions. The studies of the Department of Biogeography of Moscow University on geography and biodiversity conservation are based on long-term field expeditions. The examples of the Asian Subarctic Mountains, the steppes of Central Kazakhstan and the urbanised north-west of Russia are used to illustrate Russian approaches to the use of biogeographical monitoring for the identification of priority areas for biodiversity conservation. The species populations of the higher plants and vertebrates listed in the Red Books have been considered as the basic units of biodiversity. [ABSTRACT FROM AUTHOR]

Maturation is one of the most important life history traits that influences on many ecological characteristics of animals. This study aimed to describe the indirect distinguish of first reproduction and habitat shift (transition from the pelagic to benthic environment), using the width of translucent and annuluses of the pectoral fin spine of two sturgeon species, Persian sturgeon, Acipenser persicus, and starry sturgeon, Acipenser stellatus. Interpretation of growth bands in pectoral fin sections was done objectively using direct reading of thin sections and image analysis. The results showed that changes in the profiles of translucent and annuluses occurred at the time of habitat shift and first reproduction. Females of both sturgeons move to the deeper waters earlier than males, which can be considered as strategy for the prolonged gonad development of female individuals. Estimated age at maturity for A. persicus (9 years for female and 7 years for male) was higher than A. stellatus (7 years for female and 6 years for male), which coincide with abrupt reduction in annuli width. Marks of habitat shift and first reproduction in the pectoral fin spine are species-specific characters and enable life history traits to be identified. [ABSTRACT FROM AUTHOR]

Information on the occurrence, spatial distribution and morphometric characteristics of Antarctic icebergs is needed in a large number of applications including navigation, heat and freshwater balance calculations, biochemistry of the ocean and climatology. Using over 60 000 ship observations of icebergs in the Southern Ocean collected since the end of the 1940s we have produced a detailed map of the distribution of Antarctic icebergs as well as maps of related statistics including the standard deviation, minimum and maximum values of the iceberg concentration and the probability of iceberg-free observations. The study incorporated small and medium-sized icebergs with a length of <10 nautical miles. Most observations were taken during the warm period of the year, from December to April. It is shown that the iceberg distribution across the Southern Ocean is determined by the location of calving regions and peculiarities of the atmospheric circulation and ocean currents. Iceberg concentration data combined with information on the iceberg size and shape distribution have been used to evaluate the area-integrated characteristics of Antarctic icebergs. The instantaneous number of icebergs in the Southern Ocean was estimated as 132 269 with an uncertainty of 7%. The area and volume of icebergs were equal correspondingly to 55 805 km2 and 16 893 km3 with uncertainties of 32–33%. [ABSTRACT FROM AUTHOR]

White sturgeon (Acipenser transmontanus) support an active fishery in the Columbia River, but there is poor reproductive success within the impounded sections. The poor reproductive success has been attributed to hydroelectric development; however, water pollution could be a significant factor. White sturgeon plasma, liver, and gonad samples were collected from four Columbia River locations and a California aquaculture facility. Total length and weight of the fish were measured, and plasma samples were analyzed for testosterone (T), 11-ketotestosterone (KT), 17β-estradiol (E2), and vitellogenin. Liver samples were analyzed for chlorinated pesticides and polychlorinated biphenyls, ethoxyresorufin-O-deethylase (EROD) activity and histopathology. Gonads were examined histologically to assess sexual maturity and characterize any lesions. Significant differences by location existed for p,p′-DDE, EROD activity, and condition factor. Plasma T was negatively correlated with p,p′-DDE in males and females, and plasma KT was negatively correlated in males. These data indicate that pollutants could be adversely affecting white sturgeon in the Columbia River basin. [ABSTRACT FROM AUTHOR]