Charge carrier transport in PbS films doped with iodine.

The results of the measurements of electrical and Hall resistivities on polycrystalline PbS films doped with iodine obtained through hydrochemical deposition are presented. The analysis of the temperature dependence of resistivity points out the crossover from the hopping mechanism due to thermal delocalization in the impurity band to the variable range hopping mechanism. The increase in the iodine content in the films leads to an increase in the impurity ionization energy. It has been established that the temperature dependence of resistivity over a wide temperature range obeys the inverse Arrhenius law, which is characteristic of disordered polycrystalline films with different sizes and orientations of crystallites relative to the substrate, as confirmed by AFM topography, Raman spectra and X-ray diffraction measurements. We found that the type of charge carrier changes from electrons to holes with an increase in the iodine content. Additionally, for a wide range of iodine doping, the concentration of charge carriers is low, indicating the possible occurrence of a self-compensation mechanism due to the formation of impurity defects.

Effect of Salinity on Reproduction and Fatty Acid Profile of the Microalga Nitzschia сf. thermaloides.

The microalga Nitzschia cf. thermaloides was found in reservoirs of mud volcanoes in eastern Crimea. The species was observed to have a wide range of halotolerance and, in particular, to be capable of vegetative reproduction within a substrate salinity range of 0-110‰. The effect of salinity on the fatty acid (FA) profile was for the first time studied in N. cf. thermaloides. The quantitative and qualitative FA composition remained unchanged regardless of salinity, suggesting maintenance of a stable compacted membrane structure, which probably contributes to the species adaptation to salinity. Saturated FAs accounted for a major portion of total FAs, and the species was therefore assumed to provide a potentially valuable source of saturated FAs for biotechnology and an alternative raw material for biofuel.

Fatty Acid Composition of Total Lipids in Atlantic Salmon Salmo salar L. Parr and Smolts Reared in Aquaculture at Various Lighting Regimes.

Continuous artificial lighting (24LD) was introduced experimentally in the standard technology to grow salmon juveniles in a southern region (Republic of North Ossetia-Alania) and its effect on fatty acid (FA) composition of total lipids in muscles and the liver was assessed in parr and smolts of the Atlantic salmon Salmo salar L. Changes in the key FA were observed in the FA spectrum of fish, indicating that smoltification was complete and that smolts were ready for new habitat conditions. Thus the content of polyunsaturated FAs (PUFAs) significantly increased as a result of an increase in (n-3) PUFAs, and, in particular, marine-type 22:6(n-3), and high values were observed for (n-3)/(n-6) and 22:6(n-3)/18:3(n-3) PUFA ratios. The most significant changes were detected in muscles. In all experimental groups, a decrease in saturated FAs (SFAs) and an increase in total lipid unsaturation was attributed primarily to PUFAs, while monounsaturated FAs (MUFAs) decreased along with SFAs. The experimental data on the lipid and FA composition in salmon juveniles and a higher proportion of smolts in the test groups indicated that smoltification was the most successful in groups with continuous lighting and 24-h feeding and a natural regime of lighting and feeding.

Phospholipid Composition of Fingerlings of Atlantic Salmon Salmo salar during Growth and Development in Aquaculture: The Effect of Different Lighting and Feeding Regimes.

The effect of different feeding and lighting regimes (natural and continuous) on the phospholipid composition of Atlantic salmon fingerlings reared in commercial aquaculture in the summer-autumn period in North Ossetia-Alania was studied. Qualitative and quantitative determination of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, lysophosphatidylcholine, sphingomyelin was performed by high-performance liquid chromatography. A decrease (September-November) in the content of the studied phospholipids in fingerlings decreased, which should be considered primarily as a biochemical adaptation of development and preparation of juveniles for the upcoming smoltification. The effects of lighting and feeding regime on phospholipid composition were found mainly in the fish reared under constant lighting and 24/7 feeding and the fish reared under natural light and feeding during daylight hours. However, the observed changes were not specific to a particular experimental group of fish in the framework of this study.

The influence of iodide addition on the composition, morphology, crystal structure, and semiconductor and photoelectric properties of PbS films.

The concentration conditions for the deposition of lead sulfide and hydroxide in a citrate-ammonia reaction system by varying the pH value and the concentration of the ammonium iodide dopant are calculated. Kinetic studies of the process of conversion of lead salt into sulfide by varying the concentration of NH4I in solution within the range of 0.0-0.4 M show an inhibitory effect of ammonium iodide, which reduces the constant of the effective rate of the conversion process by almost 20 times. Thin films of lead sulfide with a thickness of 100 to 650 nm are synthesized by chemical bath deposition in the presence of NH4I on sitall and glass substrates. The introduction of NH4I into the reaction mixture decreases the size of crystallites forming the films and increases the fraction of nanoparticles to 17%. The films deposited during 90 min contain 48.5-51.7 at% of lead, 47.4-47.9 at% of sulfur, and up to 3.7 at% of iodine; the content of iodine can reach 17.1 at% in the initial period of deposition (after 20 min of deposition). The calculated fractal dimension of the surface of the iodine-doped PbS(I) films (Dc = 2.04-2.14) corresponds to the process of film formation by the cluster-cluster aggregation mechanism with small sticking probability (reaction-limited cluster aggregation model (RLCA)). According to the X-ray diffraction data, the PbS(I) films have a cubic structure of the NaCl (B1) type; an increase in the concentration of NH4I in the solution results in an increase in the lattice parameter from 0.59315(1) to 0.59442(3) nm, which is probably due to the substitution of sulfur ions for iodine ones. According to optical studies, the introduction of ammonium iodide into the reaction mixture leads to a shift of the absorption edge to the high-energy region and the appearance of an additional (impurity) band. The PbS films deposited in the presence of NH4I do not require additional photosensitization operations and show a relatively high volt-watt sensitivity to IR radiation at anomalously small values of the time constant.

Antimicrobial Activity of Lipid Extracts of Echinoderms in the Nhatrang Bay (South China Sea).

The obtained results on the study of the antimicrobial activity of lipid extracts of tissues of starfishes Linckia laevigata and Culcita novaeguineae and sea urchin Diadema setosum collected in the Nhatrang Bay (South China Sea) against nosocomial strains of Klebsiella pneumoniae, Enterococcus faecium, Escherichia coli, Pseudomonas aeruginosa, Candida sp., Streptococcus pyogenes, and Staphylococcus aureus are presented. The effect of the investigated extracts on Gram-positive, Gram-negative microorganisms, as well as yeast of the genus Candida, was determined. It was found that lipid extracts of echinoderms of the Nhatrang Bay exhibit the highest antimicrobial activity against the Gram-positive microorganisms, namely Streptococcus pyogenes.

Comparative Study of Lipid Content in Leptoclinus maculatus Postlarvae from Kongsfjord and Rjipfjord, Svalbard Archipelago.

A comparative study of lipid profile of the daubed shanny Leptoclinus maculatus postlarvae from fjords of different domains (arctic-boreal Kongsfjord and high-arctic Rjipfjord) of Svalbard Archipelago waters in summer was performed. A more efficient accumulation of lipids in the fishes from Kongsfjord compared to Rjipfjord due to triacylglycerols and wax esters was established. These differences may be related mainly to the trophic conditions of the habitat (species composition, abundance, and availability of food items). The higher level of cholesterol esters than wax esters at the L1 stage of development of the daubed shanny postlarvae compared to older fishes pointed to their active feeding mainly on phytoplankton. The differences in the content of certain classes of phospholipids may indicate adaptive changes at the level of biomembranes, contributing to the maintenance of cell homeostasis in response to abiotic environmental factors, and reflect their additional intake with food at the early stages of fish development.

A nonlinear evolution of the structure, morphology, and optical properties of PbS-CdS films with cadmium nitrate in the reaction mixture.

Herein, we describe the nonlinear processes for the formation of thin films of the PbS-CdS system using chemical bath deposition with a gradual change in the cadmium nitrate content in the reaction mixture. The morphology of films was studied via scanning electron microscopy and atomic force microscopy. The mechanism for the formation of thin-film compounds can be considered as cluster-particle aggregation (diffusion-limited aggregation). X-ray diffraction confirmed the formation of single-phase layers of substitutional B1-type CdxPb1-xS solid solutions (space group Fm3[combining macron]m) when the concentration of cadmium nitrate in the reaction bath increased up to [Cd(NO3)2] = 0.08 M. The maximum cadmium content in CdxPb1-xS solid solutions was determined to be x = 0.094. At the concentration of [Cd(NO3)2] = 0.10 M, a two-phase film was formed, where the film consisted of crystallites of cubic CdxPb1-xS with x = 0.071 (lower compared to the film obtained at [Cd(NO3)2] = 0.08 M) and fine-crystalline hexagonal B4-type Cd1-δS (space group P63mc). The texture of grains forming films was observed; where a predominant orientation with the (111) plane along substrate in PbS changed to the (200) plane in CdxPb1-xS films, the portion of (200) oriented grains increased with an increase in cadmium nitrate content up to [Cd(NO3)2] = 0.08 M, and at 0.10 M of cadmium nitrate, a radical change in the type of texture to the (111) type occurred. The concentration [Cd(NO3)2] = 0.10 M is called the critical concentration, where under this condition, the deposition process occurs due to the excess Gibbs energy. The higher cadmium content x in films determined by the energy-dispersive X-ray analysis and Auger spectroscopy compared with that estimated from the crystal lattice parameter is associated with the presence of an additional amorphous CdS phase formed as a sublayer distributed in intercrystalline spaces and island formations. Optical studies showed a nonlinear change in the band gap (Eg) of obtained films from 0.53 to 0.76 eV, whereas at the critical cadmium salt concentration (0.10 M), two crystalline phases with Eg equal to 0.73 and 2.47 eV were observed.

Lipid Status of Gray Whales Eschrichtius robustus in the Piltun Feeding Area.

For the first time, the relationship of lipid and fatty acid composition with individual, gender and age characteristics of the gray whale Eschrichtius robustus in the Piltun feeding area is shown using the methods of biochemical analysis.

Pseudokabatana alburnus n. gen. n. sp., (Microsporidia) from the liver of topmouth culter Culter alburnus (Actinopterygii, Cyprinidae) from China.

We describe the type species of a novel genus of microsporidian parasite, Pseudokabatana alburnus n. gen. n. sp., infecting the liver of topmouth culter, Culter alburnus Basilewsky, 1855, from Lake Poyang off Xingzi county, Jiangxi Province, China. The parasite elicits formation of spherical xenomas of up to 1.2 mm in diameter containing all observed life stages from early merogonal plasmodia to mature spores contained within the cytoplasm of host hepatocytes. Merogonal plasmodia existed in direct contact with the host cytoplasm and contained up to 20 visible nuclei. Plasmotomy of the multinucleate plasmodium led to formation of uninucleate cells in which the nucleus underwent further division to form bi-nucleate presporonts, sporonts (defined by cells with a thickened endospore) and eventually sporoblasts (containing pre-cursors of the spore extrusion apparatus). Mature spores were pyriform and monokaryotic, measuring 2.3 ± 0.19 µm long and 1.3 ± 0.10 µm wide. Spores possessed a bipartite polaroplast and 5-6 coils of a polar filament, in a single rank. The obtained partial SSU rRNA gene sequence, 1383 bp in length, did not match any of microsporidia available in GenBank. SSU rDNA-based phylogenetic analysis indicated a new taxon branching with Kabatana rondoni, a parasite infecting the skeletal muscle of Gymnorhamphichthys rondoni from the Amazon River. Due to different host and tissue tropism, the novel taxon did not fit the diagnostic criteria for the genus Kabatana. Further, based on SSU rDNA-inferred phylogenetic analyses, different ultrastructural features of developmental stages, and ecological considerations, a new genus Pseudokabatana and type species Pseudokabatana alburnus n. sp. was erected for the parasite in topmouth culter.

Morphological and molecular characterization of a new cyprinid gall bladder-infecting Chloromyxum species, Chloromyxum peleci sp. n. (Myxozoa: Chloromyxidae), from Pelecus cultratus (L.) in Russia.

Extensive sampling to get rich data is very important to resolve the current taxonomic problem of Chloromyxum genus and elucidate the nature phylogenetic relationships among congeneric species. During the parasitological survey of cyprinid fish in Gulf of Finland off the coast of St. Petersburg, a new Chloromyxum species, named as Chloromyxum peleci sp. n., was found to infect the gall bladder of sichel, Pelecus cultratus (L.). Here, we provided the morphological, ultrastructural, and molecular features to describe it. Infection was represented by mono- or disporic plasmodia and mature free-floating spores in the gall bladder. Mature spores are typical of freshwater Chloromyxum species, spherical or subspherical in lateral view, measuring 8.8 ± 0.5 µm (7.4-9.5) in length, 7.8 ± 0.3 µm (7.0-8.8) in width, and 7.5 ± 0.4 µm (6.8-8.2) in thickness. Spores have a cog-like appearance in apical view for sutural ridge, and eight to ten widely spaced extrasutural ridges per valve protrude from the spore valve margin. The surface ridge patterns of the new species are similar with those of Chloromyxum auratum and Chloromyxum cristatum, with some branching. Four polar capsules of slightly unequal in two pairs were oval in apical view and pyriform in side view, locating at the anterior end of the spores. Polar filaments coil with four to five turns. The obtained almost full length of 18S ribosomal DNA (rDNA) of Ch. peleci sp. n. does not match any sequences available in GenBank but was most closely related to that of Chloromyxum fluviatile (97.9%). Phylogenetic analysis indicated that Ch. peleci sp. n. clustered in a Chloromyxum subclade infecting the gall bladder of freshwater teleost, with robust nodal support. However, Chloromyxum sensu lato infecting gall bladder of freshwater teleost was again proved to be polyphyletic. The possible evolutionary history of Chloromyxum morphotype of Chloromyxum sensu lato was discussed based on the rDNA-referred phylogeny. This is the second Chloromyxum species from sichel.

[Henneguya wolinensis (Myxosporea: Myxobolidae), a new for Russian fauna parasite from the perch Perca fluviatilis L.].

The infection of the perch Perea fluviatilis L. with myxosporean Henneguya wolinensis Romuk-Wodoracki, 1990 has been detected. This is the second finding of this parasite after its original descriptin and the first for Russia. Plasmodium of this species develops in the epidermis under scales throughout the body causing the formation of white cysts up to 1 mm. Spores are fusiform, large, their average length constitutes 25.5 µm without the caudal appendages and 62 µm with them. Slight morphological differences in spore structure comparing to original description have been revealed.

Morphological and molecular characterization of Myxobolus mucosus sp. n. (Myxosporea: Myxobolidae) with basifilamental sporulation in two cyprinid fishes, Rutilus rutilus (L.) and Leuciscus leuciscus (L.) in Russia.

A new Myxobolus species, Myxobolus mucosus sp. n., was found in the basifilamental location of roach, Rutilus rutilus, and common dace, Leuciscus leuciscus, during the investigation of fish myxosporean fauna in Finnish Bay of Baltic Sea and Lake Ladoga in 2014. Plasmodia from the two hosts share similar morphometric and morphological features which are whitish and slightly elongated oval and measured 300-500 µm in diameter. Mature spores of M. mucosus sp. n. are ellipsoidal in frontal view and lemon shaped in sutural view, measuring 13.6 ± 0.62 (12.8-14.2) µm in length, 10.7 ± 0.51 (10.3-11.4) µm in width, 7.8 ± 0.41 (7.2-8.3) µm in thickness and 13.0 ± 0.89 (11.5-14.2) µm in length, 10.8 ± 0.77 (10.2-11.5) µm in width, 7.7 ± 0.52 (7.3-8.0) µm in thickness from roach and common dace, respectively. Polar capsules were pyriform, equal in size, converging anteriorly, with 5.9 ± 0.22 (5.7-6.3) µm in length and 3.9 ± 0.3 (3.5-4.1) µm in width and 5.6 ± 0.38 (5.1-6.2) µm in length and 3.8 ± 0.24 (3.5-4.0) µm in width from roach and common dace, respectively. Spore valves are relatively thin, symmetrical, and smooth. The most remarkable morphological character of this new Myxobolus species is the distinct mucous envelope, surrounding the full myxospore valves, up to 25 and 32 µm, respectively, in roach and common dace. The partial 18S ribosomal DNA (rDNA) sequence variation of myxospores from two hosts is very tiny (below 0.8 %) but significantly differing from all available sequences of myxosporeans in GenBank. Therefore, it can be concluded that this myxosporean from these two closely related cyprinids are conspecific by combining morphological characteristics, tissue specificity, and molecular data. Phylogenetic analysis showed that this newly described species cluster with several gill-infecting Myxobolus species from cyprinid fish inhabiting in Eastern Europe.

Supplemental description and molecular characterization of Myxobolus miyarii Kudo, 1919 (Myxosporea: Myxobolidae) infecting intestine of Amur catfish (Silurus asotus).

Myxobolus miyairii Kudo, 1919 was first reported from the intestines of the Amur catfish (Silurus asotus) in Japan and then in China and Russia, but with incomplete description. During the investigation of fish myxosporean diversity in Poyang Lake, the biggest lake along the Yangtze River, China, two Amur catfish highly infected with M. miyairii in the intestine wall were sampled. So, the complete description of this species with morphological and molecular data was presented here. A large number of whitish, round or ellipsoidal pseudocysts 0.32-0.78 mm in diameter could be found in the external intestinal wall after dissecting the infected fish. Mature spores of M. miyairii were elongated and ellipsoidal in the frontal view and narrow fusiform in the lateral view, with a slightly pointed anterior end and a bluntly rounded posterior end and measured 13.3 ± 0.49 (12.5-14.7) µm × 6.6 ± 0.27 (6.2-7.4) µm × 5.0 ± 0.26 (4.4-5.7) µm in size. Spore surface was smooth and two spore valves symmetrical, with a thin and straight sutural ridge. Interestingly, two types of caudal appendage (single or bifurcated) were occasionally present on the posterior end of some spores which has not previously been reported. The two equal pyriform polar capsules measured 6.5 ± 0.30 (6.2-7.5) µm long and 1.9 ± 0.14 (1.5-2.3) µm wide and situated at the anterior end of the spore. Polar filaments coiled with eight to nine turns, perpendicularly to the longitudinal axis of the polar capsules. Histopathological analysis showed that the plasmodium developed in the circular muscle layer of intestinal wall of Amur catfish, but no obvious inflammatory responses were observed. Phylogenetic analysis based on the partial 18S small subunit ribosomal DNA sequences indicates that M. miyairii cluster within a clade of Siluriforme-infecting Henneguya species with the support of a high bootstrap value, but also evolutionarily independent from the Henneguya clade infecting the epithelium of fish of the Ictaluridae family. Additionally, Myxobolus species reported with caudal processes dispersed within the Henneguya-Myxobolus clade.

[THE MICROSPORIDIUM GLUGEA GASTEROSTEI VORONIN 1974 (MICROSPORIDIA: MARINOSPORIDIA) FROM THE THREE-SPINED STICKLEBACK GASTEROSTEUS ACULEATUS (ACTINOPTERYGII: GASTEROSTEIFORMES) AS AN INDEPENDENT SPECIES].

The microsporidium Glugea gasterostei from the three-spined stickleback Gasterosteus aculeatus was described as an independent species basing upon morphological and ecological traits of the parasite (Voronin, 1974), further supported by ultrastructural characters of its spores (Voronin, 1983). During the revision of microsporidia of the genus Glugea (Canning, Lom, 1986; Lom, 2002), the validity of this species was doubted and it was synonymized with G. anomala. Nevertheless, the molecular phylogenetic analysis performed in the present study showed the unique molecular haplotype of small subunit rRNA gene of G. gasterostei (Genbank accession number KM977990) and its close relatedness to G. anomala, G. atherinae and G. hertwigi (sequence similarity of 99.7 %). One of typical characters of G. gasterostei, as opposed to G. anomala, is the formation of xenomas on inner tissues and not on the surface of infected fishes. This feature is retained even after the infection of different host species. Taken together, these data confirm the validity of G. gasterostei as a separate species among closely related taxa that had diverged comparatively recently.

[THE DESCRIPTION OF MYXOBOLUS PELECICOLA SP. NOV. (MYXOZOA: MYXOBOLIDAE) FROM PELECUS CULTRATUS (CYPRINIFORMES, CYPRINIDAE)].

Morphological study of myxosporean parasites Myxobolus pelecicola sp. n. from Pele- cus cultratus (L., 1758), is presented. Presporogenic stage not observed. Polysporous, el- lipsoidal. plasmodia up to 1.2 mm in length and 0.1 to 0.4 mm in width develop in the ske- letal musculature. Mature spores elongate oval or oval form in frontal view, lens-shaped in sutural view. Length of spores 16.5 ± 0.83 (14.9-18.0), width 12.1 ± 0.63 (11.6-13.3) (n = 50), thickness 7.8 ± 0.3 (7.4-8.3) µm (n = 10). Polar capsules pyriform, unequal, length of large 8.0 ± 0.44 (7.5-8.8), small 7.6 ± 0.26 (7.2-7.8), width of large 4.5 ± 0.22 (4.2-4.7), small 4.0 ± 0.21 (3.8-4.3) µm. Five to 6 distinct filament coils oriented obli- quely to capsule length, found in polar capsule. The length of extruded (in water) filament up to 130 µm. Large, but indistinct triangular intercapsular appendix present in spores. Single rodlet inclusion is very often observed in the posterior part of spore. Mucous enve- lope is absent. The type host of Myxobolus pelecicola sp. n. is sabrefish Pelecus cultratus (L., 1758). Type locality: Finnish Bay (60°05' N 29°55' E) and Ladoga lake (60°07' N 32°19' E), Russia.

[On the methods of investigation of the actinosporean development phase of myxosporidians].

The paper describes the techniques of the actinospores investigation under field and laboratory conditions. The methylene blue solution for staining of actinospore processes and estimating of daughter cells of sporoplasm is proposed.

[On the methods of investigation of the actinosporean developmental phase of myxosporidians].

The paper describes the techniques of the actinospores investigation under field and laboratory conditions. The methylene blue solution for staining of actinospore processes and estimating of daughter cells of sporoplasm is proposed.

[A new microsporidian species Glugea mesocotti sp. n. (Microsporidia:Glugeidae) from Mesocottus haitej (Scorpaeniformes:Cottidae)].

A new microsporidian parasite of a freshwater fish Mesocottus haitej from the Amur River basin of Russia is described using light microscopy. The numerous whitish xenomas, round or oval, up to 3.0 mm large were found to be located in subcutaneous tissue of the body and mouth cavity, in the intestine and other internal organs. The formol fixed spores are elongate oval, measuring 4.8 (4.5-5.0) x 2.3 (2.2-2.5) microm in a wet smears. Posterior vacuole occupies about half of the spores. Sporophorous vesicles measuring up to 13 microm contain a great number of spores.