On genetic differentiation of the Pacific cod <Emphasis Type="Italic">Gadus macrocephalus</Emphasis> tilesius, 1810 (Gadiformes: Gadidae)

The variability of the Gmo3, Gmo34, Gmo35, and Pgmo32 DNA microsatellite loci in Pacific cod Gadus macrocephalus samples from different areas of the North Pacific was analyzed. The data obtained show that Pacific cod from the southern Kuril Islands significantly differs from the populations of the Bering Sea, the Sea of Okhotsk, and the coastal waters of Canada (the microsatellite loci Gmo3 and Pgmo32 bear the highest differentiating capacity). Despite the significant geographical remoteness of these areas from one another, the above three Pacific cod populations exhibit a high degree of similarity (I = 0.997–0.999).     

A nanoparticle in plasma

Charge and energy fluxes onto a nanoparticle under conditions typical of laboratory plasmas are investigated theoretically. Here, by a nanoparticle is meant a grain the size of which is much smaller than both the electron Larmor radius and Debye length and the thermionic emission from which is not limited by the space charge. Under conditions at which thermionic emission plays an important role, the electric potential and temperature T _p of a nanoparticle are determined by solving a self-consistent set of equations describing the balance of energy and charge fluxes onto the nanoparticle. It is shown that, when the degree of plasma ionization exceeds a critical level, the potential of the nanoparticle and the energy flux onto it increase with increasing nanoparticle temperature, so that, starting from a certain temperature, the nanoparticle potential becomes positive. The critical degree of ionization starting from which the potential of a nanoparticle is always positive is determined as a function of the plasma density and electron temperature. The nanoparticle temperature T _p corresponding to the equilibrium state of a positively charged nanoparticle is found as a function of the electron density for different electron temperatures.     

Death of ouabain-treated renal epithelial cells: evidence for p38 MAPK-mediated Na i + /K i + -independent signaling

Recent studies demonstrate that cytotoxic actions of ouabain and other cardiotonic steroids (CTS) on renal epithelial cells (REC) are triggered by their interaction with the Na⁺,K⁺-ATPase α-subunit but not the result of inhibition of Na⁺,K⁺-ATPase-mediated ion fluxes and inversion of the [Na⁺]_i/[K⁺]_i ratio. This study examined the role of mitogen-activated protein kinases (MAPK) in the death of ouabain-treated REC. Exposure of C7-MDCK cells that resembled principal cells from canine kidney to 3 μM ouabain led to phosphorylation of p38 without significant impact on phosphorylation of ERK and JNK MAPK. Maximal increment of p38 phosphorylation was observed at 4 h followed by cell death at 12 h of ouabain addition. In contrast to ouabain, neither cell death nor p38 MAPK phosphorylation were affected by elevation of the [Na⁺]_i/[K⁺]_i ratio triggered by Na⁺,K⁺-ATPase inhibition in K⁺-free medium. p38 phosphorylation was noted in all other cell types exhibiting death in the presence of ouabain, such as intercalated cells from canine kidney and human colon rectal carcinoma cells. We did not observe any action of ouabain on p38 phosphorylation in ouabain-resistant smooth muscle cells from rat aorta and endothelial cells from human umbilical vein. Both p38 phosphorylation and death of ouabain-treated C7-MDCK cells were suppressed by p38 inhibitor SB 202190 but were resistant to its inactive analogue SB 202474. Our results demonstrate that death of CTS-treated REC is triggered by Na_i⁺,K_i⁺—independent activation of p38 MAPK.     

Otolith Shape Analysis as a Tool for Species Identification and Studying the Population Structure of Different Fish Species

An analysis and a comparison of the methods of geometric morphometrics as applied to fish species identification and to studies on the population structure of fish stocks based on peculiarities of the otolith shape are performed. A review of the geometric morphometric methods used in studies on fish otoliths is provided. The results of our own research on possible utilization of elliptical Fourier analysis for species identification are also described.     

The secreted protein Noggin4 is an activator of the Wnt/PCP-signaling pathway

The protein Noggin4 of the African clawed frog Xenopus laevis has been shown to act as a modulator of the “noncanonical” Wnt/PCP-signaling pathway that plays an important role in the regulation of cell motility. Induction of disturbances in the expression of Noggin4 led to the activation of Wnt/PCP-pathway and the related anomalies of early embryonic development. The Noggin4 protein can bind the Wnt11 protein that normally contributes to the activation of the Wnt/PCP-pathway and of enhancing the activator effect of this protein in luciferase assays. Thus, Noggin4 can be used as a tool for specific experimental regulation of the activity of the Wnt/PCP pathway.     

Comparative characteristic of sablefish Anoplopoma fimbria in catches with passive and active fishing gear in the northwestern Pacific ocean

According to materials of trap, long-line, and trawl fishing, specific features of distribution of sablefish Anoplopoma fimbria and some of its biological characteristics in Pacific waters off the southeastern coast of Kamchatka, continental slope of the western part of the Bering Sea, Shirshov Underwater Ridge, and off the Commander Islands are considered. Maximum density concentrations according to data of trap fishing was noted along southeastern coast of Kamchatka and the data of trawl fishing indicated most frequent catches in the western part of the Bering Sea in the area of Koryak coast up to Cape Navarin. The pattern of vertical distribution in different areas considerably differs. The magnitude of trap catches in different areas is different and determined by the type of trap and the period of soaking. The size composition, fatness, and the sex ratio are different in catches of different fishing gear and differ between regions. On the whole, in Russian Far Eastern waters, females mature in mass at a body length of 71 cm and males at 57 cm.     

Specific features of distribution,ecology, and dynamics of catches of blotched snailfish Crystallichthys mirabilis (Liparidae) in Pacific waters off the northern Kuril Islands and southeastern Kamchatka

Based on materials of 1992–2002, data on the spatial-bathymetric distribution and size-age composition of blotched snailfish Crystallichthys mirabilis and species accompanying it in catches in Pacific waters off the northern Kuril Islands and southeastern Kamchatka are presented. This relatively large representative of the family Liparidae (maximum length in catches 50 cm, body weight 2150 g) is found throughout the examined area in the depth interval of 76–755 m at near-bottom temperature of ?1.2 to +4.2°C. Maximum catches (over 200–500 individuals or 180–280 kg per hour trawling) year round are recorded off the southeastern extremity of Kamchatka, from the oceanic side of the Shumshu and Paramushir islands and on the beam of the Fourth Kuril Strait in the bathymetric range of 151–350 m. The magnitude of its catches in the examined area is subjected to interannual, seasonal, and diurnal dynamics.     

Age and growth of the Pacific halibut <Emphasis Type="Italic">Hippoglossus stenolepis</Emphasis> and the size-age composition of its catches in the North-Western part of the Pacific Ocean

The results of investigation are discussed on age and growth of the Pacific halibut Hippolglossus stenolepis, as well as size-age composition of its catches in three regions of the North-Western Pacific—in Navarin area of the Bering Sea, in Pacific waters on the Northern Kurils and south-eastern Kamchatka, of the Southern Kurils—from the end of the last century. The growth rate of Pacific halibut is similar in all three regions in spite of their considerable geographic remoteness. No significant differences in the growth rate of males and females in these regions, as well as no significant interannual differences in growth of specimens caught in Pacific waters off the Northern Kurils and south-eastern Kamchatka in 1996–2000, are found. Comparison of the present-day size-age composition and that in the beginning-middle of the last century revealed their considerable similarity.