Optimizing the use of water resources of mountain rivers of the Greater Caucasus (case study on the Gudyalchay river)

The aim of the thesis is to study and propose effective solutions to the management of the Greater Caucasus River, in the example of the Gudyalchay river. The Greater Caucasus rivers are mainly spring-fed rivers, which come from the high mountainous areas. High water periods coincide with intense snowmelts observed mostly in early April, while low flows come in late August or early September. Water resources of the target region are mostly used for irrigation and drinking water, which is mostly required late summer months. This pattern requires effectively optimizing the water resources in the river of the Greater Caucasus. In most cases, it is proposed to regulate the flow of the river to solve this problem. However, flow regulation in parallel leads to the loss of very valuable ecosystems. These ecosystem services include mostly cultural and regulating services, such as the provision of spawning grounds for migrating fish, as well as tourism. In this study, methods and techniques are used to determine the years in which the impact of human economic activity on river flow began. These methods are based on comparing the flow of disturbing rivers with the flow of rivers with a natural regime of precipitation in the basin. Based on observations of natural flow, the dependence of river flow on the main flow-generating factors is studied, and the analytical relationship between these factors and the flow is found. Then, due to these dependencies, the natural flow is calculated for the period of anthropogenic factors on the flow and is quantified based on the difference between the flow observed with the natural flow. Using the multiplicity correlation between precipitation and temperature, the change in flow was quantified based on possible precipitation and temperature changes. According to the given formulas, it is possible to determine the impact of climate change on both, non-seasonal and annual flows. New proposals have been made to calculate the total evaporation from the river basins. The average multi-year value of evaporation from river basins was found based on these proposals. The effect of evaporation and solubility on the river flow was determined by hydrographs. The importance of snow waters in the nutrition of Gudyalchay, Damiraparanchay, Gusarchay, Agsuchay, Balakenchay and Goychay rivers was noted. The formula for calculating the natural flow according to water balance methods is given

Helicity conservation by flow across scales in reconnecting vortex links and knots

The conjecture that helicity (or knottedness) is a fundamental conserved quantity has a rich history in fluid mechanics, but the nature of this conservation in the presence of dissipation has proven difficult to resolve. Making use of recent advances, we create vortex knots and links in viscous fluids and simulated superfluids and track their geometry through topology-changing reconnections. We find that the reassociation of vortex lines through a reconnection enables the transfer of helicity from links and knots to helical coils. This process is remarkably efficient, owing to the antiparallel orientation spontaneously adopted by the reconnecting vortices. Using a new method for quantifying the spatial helicity spectrum, we find that the reconnection process can be viewed as transferring helicity between scales, rather than dissipating it. We also infer the presence of geometric deformations that convert helical coils into even smaller scale twist, where it may ultimately be dissipated. Our results suggest that helicity conservation plays an important role in fluids and related fields, even in the presence of dissipation

Palladium-templated subcomponent self-assembly of macrocycles, catenanes, and rotaxanes.

The reaction of 2,6-diformylpyridine with diverse amines and Pd(II) ions gave rise to a variety of metallosupramolecular species, in which the Pd(II) ion is observed to template a tridentate bis(imino)pyridine ligand. These species included a mononuclear complex as well as [2+2] and [3+3] macrocycles. The addition of pyridine-containing macrocyclic capping ligands allows for topological complexity to arise, thereby enabling the straightforward preparation of structures that include a [2]catenane, a [2]rotaxane, and a doubly threaded [3]rotaxane.This work was underwritten by the Marie Curie Academic-Industrial Initial Training Network on Dynamic Molecular Nanostructures (DYNAMOL) of the European Union’s Seventh Framework Programme (FP7) and the UK Engineering and Physical Sciences Research Council (EPSRC). We thank the Cambridge Chemistry NMR service for experimental assistance, Diamond Light Source (UK) for synchrotron beamtime on I19 (MT7984), and the EPSRC National Crystallography Service for X-ray data collection.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/anie.20140616

Investigation of SARS-Cov-2 Infection in Domestic Animals

Concerned with the COVID-19 pandemic, the study of this disease in animals has got a great scientific importance in clarifying the information about the source and circulation of the infection. The study aimed to investigate the source of infection of domestic animals (dog, cat, cattle, sheep, goat and poultry) with SARS-CoV-2, as well as to identify susceptible animal species and ways of transmission of the virus. Observations were made on the animals selected for the study, from which nasopharyngeal and oropharyngeal smears were taken for PCR, and blood samples were taken for enzyme-linked immunosorbent assay (ELISA). The experimental part of the study was carried out in veterinary clinics, animal shelters and farms. Dogs and cats are kept in animal shelters and examined in veterinary clinics, as well as cattle, sheep, goats and poultry grown on various farms, were involved in the study. Antibodies to SARS-CoV-2 were detected in 11 of 645 samples taken from animals whose clinical signs of COVID-19 disease were initially observed or whose owners were exposed to the disease. Based on the results of the study, monitoring the dynamics of the spread of SARSCoV- 2 among animals is of great scientific and practical importance in preventing this process

Metallosupramolecular self-assembly of a universal 3-ravel

In the realm of supramolecular chemistry, a small number of intricately interwoven structures that bridge the boundaries between art and science have been reported. These motifs, which typically form on the nanometre scale, display both considerable beauty and complexity. However, the generation of new topologies of this type has remained a very significant synthetic challenge. Here, we describe the synthesis of a discrete highly intertwined metallosupramolecular assembly based on a universal 3-ravel motif—a topology as yet unprecedented in supramolecular chemistry. The exotic, 20-component, [Fe8L12] ravel entanglement may be considered as a 'branched knot', with individual molecules displaying either left- or right-handed chirality. The formation of this cluster was demonstrated by single-crystal and powder X-ray diffraction. The arrangement is stabilized by a favourable combination of π–π interactions and Nature's tendency to minimize voids in molecular architectures

Helicity within the vortex filament model

Kinetic helicity is one of the invariants of the Euler equations that is associated with the topology of vortex lines within the fluid. In superfluids, the vorticity is concentrated along vortex filaments. In this setting, helicity would be expected to acquire its simplest form. However, the lack of a core structure for vortex filaments appears to result in a helicity that does not retain its key attribute as a quadratic invariant. By defining a spanwise vector to the vortex through the use of a Seifert framing, we are able to introduce twist and henceforth recover the key properties of helicity. We present several examples for calculating internal twist to illustrate why the centreline helicity alone will lead to ambiguous results if a twist contribution is not introduced. Our choice of the spanwise vector can be expressed in terms of the tangential component of velocity along the filament. Since the tangential velocity does not alter the configuration of the vortex at later times, we are able to recover a similar equation for the internal twist angle to that of classical vortex tubes. Our results allow us to explain how a quasi-classical limit of helicity emerges from helicity considerations for individual superfluid vortex filaments

Novel R-roscovitine NO-donor hybrid compounds as potential pro-resolution of inflammation agents

AbstractNeutrophils play a pivotal role in the pathophysiology of multiple human inflammatory diseases. Novel pharmacological strategies which drive neutrophils to undergo programmed cell death (apoptosis) have been shown to facilitate the resolution of inflammation. Both the cyclin-dependent kinase inhibitor (CDKi) R-roscovitine and nitric oxide (NO) have been shown to enhance apoptosis of neutrophils and possess pro-resolution of inflammation properties. In order to search for new multi-target pro-resolution derivatives, here we describe the design, synthesis and investigation of the biological potential of a small series of hybrid compounds obtained by conjugating R-roscovitine with two different NO-donor moieties (compounds 2, 9a, 9c). The synthesized compounds were tested as potential pro-resolution agents, with their ability to promote human neutrophil apoptosis evaluated. Both compound 9a and 9c showed an increased pro-apoptotic activity when compared with either R-roscovitine or structurally related compounds devoid of the ability to release NO (des-NO analogues). Inhibition of either NO-synthase or soluble guanylate cyclase did not affect the induction of apoptosis by the R-roscovitine derivatives, similar to that reported for other classes of NO-donors. In contrast the NO scavenger PTIO prevented the enhanced apoptosis seen with compound 9a over R-roscovitine. These data show that novel compounds such as CDKi–NO-donor hybrids may have additive pro-resolution of inflammation effects

Discovering privileged topologies of molecular knots with self-assembling models

Despite the several available strategies to build complex supramolecular constructs, only a handful of different molecular knots have been synthesised so far. Here, in response to the quest for further designable topologies, we use Monte Carlo sampling and molecular dynamics simulations, informed by general principles of supramolecular assembly, as a discovery tool for thermodynamically and kinetically accessible knot types made of helical templates. By combining this approach with the exhaustive enumeration of molecular braiding patterns applicable to more general template geometries, we find that only few selected shapes have the closed, symmetric and quasi-planar character typical of synthetic knots. The corresponding collection of admissible topologies is extremely restricted. It covers all known molecular knots but it especially includes a limited set of novel complex ones that have not yet been obtained experimentally, such as 10124 and 15n41185, making them privileged targets for future self-assembling experiments