A computer-aided framework for subsurface identification of white shark pigment patterns

Subsurface video footage can be used as a successful identification tool for various marine organisms; however, processing of such information has proven challenging. This study tests the use of automated software to assist with photo-identification of the great white shark Carcharodon carcharias in the region of Gansbaai, on the south coast of South Africa. A subsurface photo catalogue was created from underwater video footage. Single individuals were identified by using pigmentation patterns. From this catalogue, two images of the head for each individual were inserted into automated contour-recognition software (Interactive Individual Identification System Beta Contour 3.0). One image was used to search the database, the other served as a reference image. Identification was made by means of a contour, assigned using the software to the irregular border of grey and white on the shark's head. In total, 90 different contours were processed. The output provided ranks, where the first match would be a direct identification of the individual. The method proved to be accurate, in particular for high-quality images where 88.24% and 94.12%, respectively, were identified by two independent analysts as first match, and with all individuals identified within the top 10 matches. The inclusion of metadata improved accuracy and precision, allowing identification of even low-quality images.     

Definition of the Pechora basin geographical and hydrological characteristics using GIS technology

This paper describes approaches to hydrological calculations using GIS technology by an example of the Pechora basin. A digital model of the river basin is applied to automatically outline watersheds of the river and its tributaries and to determine the areas and coordinates of the centers of drainage basins of hydrological posts. Original hydrological data are interpolated and hydrological characteristics are calculated. The calculated values are compared with the earlier published data obtained by traditional methods.     

Some peculiarities of holocene processes in Western SiberiaZur holozängeschichte der westsibirischen torfmooreQuelques singuliarités des processus holocènes sur le territoire de la Sibérie occidentale

The authors deal with problems of the origin of peat in the territory of the West Siberian Lowland where Holocene processes are sufficiently widespread to be representative of this world-wide phenomenon. Here, for example, are found the most extensive peat bogs of the Earth. The authors deal with the stratigraphy of these peat bogs and the reconstruction of Holocene conditions in the West Siberian Lowland. The development of peat bogs has considerably modified landscape features since the retreat of the last glaciation, i.e., during the last 10,000 to 11,000 years. The peat bogs began to develop simultaneously in thousands of depressions after the ice cover had melted. Later they merged into vast peaty bog regions. Without any intervention by man the peat bogs will cover all of Western Siberia in the course of several thousands of years. The development of extensive peat bogs is due to an irregular advance of floods on Siberian rivers which leads to a rise in the water level on tributaries of great rivers and to a retardation of the discharge of flood waves In the conclusion the authors point to the problems of economic use of swampy regions and to questions of land reclamation that must be answered before economic use of the territory (mainly in connection with extensive oil and gas deposits in these regions) can be fully effective.     

盐生植物萌发期对盐胁迫和干旱胁迫的适应研究进展

目前我国盐渍土地面积较大,尤其是青藏高原的盐渍地,常伴有干旱、半干旱的生境,导致植物不易生长,生态环境日渐恶劣,这种生态现状亟待解决。盐生植物具有一定的耐盐性和耐旱性,是改善盐渍地的首选植物,种子的活力决定了种子萌发的情况,多数学者为改善严峻的生态环境开始了盐生植物引种的研究。测定种子活力有直接方法和间接方法,大多数学者采用的是直接方法,即在实验室模拟一定条件直接测定萌发率。本文简述了盐生植物的概况、制造胁迫的主要方法以及检测种子活力的指标,综述了近年来各位学者对盐爪爪、白刺等具有代表性的22种盐生植物在种子萌发期的耐盐性以及抗旱性的相关研究,为改善盐渍地的生态环境、提升盐渍地的生产量提供了理论依据。     

Long-term variability in the hydrochemical regime of the Manych-Chograi hydrological system

Data collected from the scientific literature and field studies carried out by the specialists from the Azov Branch of the Murmansk Institute of Marine Biology and from the Southern Scientific Center in July and August of 2004 are used to confirm the further salinization of the Manych-Gudilo Lake. The aforesaid salinization was accompanied by a change in the water state index, caused by an increase in the salinity of inflowing water, which determines the water-and-salt budget of the lake.     

On the asymmetry of selected Fraunhofer lines

An analysis is made of the asymmetry of Fraunhofer lines observed with the double-pass monochromator of the horizontal solar telescope ASU-5 of the Main Astronomical Observatory of the Ukrainian Academy of Sciences. The conclusion is that the character of macromotion in the radial direction varies with height; in a tangential direction the motions at different depths are homogeneous. The asymmetry of weak lines is due to convection rather than to wave motions.     

First finding of Archaeopteridaceae wood in the Upper Devonian deposits of the Middle Timan Region

Stem remains of Archaeopteridaceae with a well-preserved anatomical structure were firstly found in the Upper Devonian deposits of the Middle Timan Region. The wood was studied under SEM and REM and was identified as Callixylon trifilievii Zalessky. Previous findings of Archaeopteridaceae in the northern part of European Russia and some taxonomic problems of the species were discussed.