1,657 research outputs found
On the structure of the seminal receptacle in cyclopids (Copepoda, Cyclopoida). [Translation from: Informatsionnyi Byulleten Biologiya Vnutrennikh Vod (6) 26-31, 1970.]
The seminal bag, or seminal receptacle, forms a characteristic organ of cyclopids, serving for retention of the sperms discharged from the spermatophores. The structure of the seminal receptacle, more precisely its form, is fairly widely used in diagnosis and undoubtedly can be more widely applied in the systematics of the group. Within the limits of the family Cyclopidae it is possible to distinguish crustaceans with three basic types of seminal bag. The differences consist of the position which this organ occupies in the genital segment. of one species, we carried out a series of observations on its formation in ontogenesis and during the life of the adult stage. As material for observation the study used laboratory cultures of three species; Acanthocyclops americanus (Marsh) from the plankton of the Moscow River, Cyclops vicinus Uljan and Mesocyclops leuckarti Glaus from the plankton of the channel section of the upper part of the Gorkovsk reservoir. The author concluded that the irreversibility of the changes in the seminal receptacle presents the possibility of utilising this structure as one of the indicators of the growth of the individual
DEVELOPMENT OF AN OCCUPATIONAL SAFETY MANAGEMENT SYSTEM BASED ON THE PROCESS APPROACH
The article discusses the relevance and possibility of using the process approach in the development and implementation of occupational safety management systems based on GOST 12.0.230-2007, which is the main document in this area for all industrial enterprises and organisations of the Russian Federation. The system of occupational safety management in the organisation is considered taking into account all its internal communications and input-output parameters. It is shown that the process approach used in the design of the occupational safety management system in the organisation, allows categorising the list of works (processes), participants, resources (responsible, performers, documents, etc.), the control and correction processes.
The methodological substantiation of the process approach to the design of the occupational safety management system in the organisation is given, the basic issues of its applicability are considered. A context diagram of the process of an occupational safety management system is drawn in the IDEF0 graphical notation by means of the SADT structural analysis technology. The decomposition of the context diagram to the required levels of detail is presented and the balance factor of the models is calculated
Spurious trend switching phenomena in financial markets
The observation of power laws in the time to extrema of volatility, volume
and intertrade times, from milliseconds to years, are shown to result
straightforwardly from the selection of biased statistical subsets of
realizations in otherwise featureless processes such as random walks. The bias
stems from the selection of price peaks that imposes a condition on the
statistics of price change and of trade volumes that skew their distributions.
For the intertrade times, the extrema and power laws results from the format of
transaction data
Large Angle Hadron Correlations from Medium-Induced Gluon Radiation
Final state medium-induced gluon radiation in ultradense nuclear matter is
examined and shown to favor large angle emission when compared to vacuum
bremsstrahlung due to the suppression of collinear gluons. Perturbative
expression for the contribution of its hadronic fragments to the back-to-back
particle correlations is derived. It is found that in the limit of large jet
energy loss gluon radiation determines the yield and angular distribution of |
Delta phi | > Pi/2 di-hadrons to transverse momenta pT2 of the associated
particles. Clear transition from enhancement to suppression of the away-side
hadron correlations is established at moderate pT2 and its experimentally
accessible features are predicted versus the trigger particle momentum pT1.Comment: 5 pages, 3 figures. Figures 1 and 2 and some of the text revised.
Footnote added. As published in Phys. Lett.
Particle Ratios, Equilibration, and the QCD Phase Boundary
We discuss the status of thermal model descriptions of particle ratios in
central nucleus-nucleus collisions at ultra-relativistic energy. An alternative
to the
``Cleymans-Redlich'' interpretation of the freeze-out trajectory is given in
terms of the total baryon density. Emphasis is placed on the relation between
the chemical equilibration parameters and the QCD phase boundary. Furthermore,
we trace the essential difference between thermal model analyses of data from
collisions between elementary particles and from heavy ion collisions as due to
a transition from local strangeness conservation to percolation of strangeness
over large volumes, as occurs naturally in a deconfined medium.
We also discuss predictions of the thermal model for composite particle
production.Comment: Contribution to SQM2001 Conference, submitted to J. Phys.
Determination of polycyclic aromatic hydrocarbons in soil by gas chromatography - mass-spectrometry
Для определения полициклических ароматических углеводородов (ПАУ) в почве наиболее перспективным представляется метод газовой хроматографии с масс-спектрометрическим детектированием (ГХ-МС). В работе изучены оптимальные условия и предложен алгоритм пробоподготовки образцов почвы с последующей идентификацией и измерением концентрации данных экотоксикантов в них указанным методом. Установлено, что из трёх исследованных экстрагентов (гексан, хлористый метилен, изопропанол), наиболее подходящим для извлечения ПАУ ожидаемо является гексан. Рабочее время экстракции составило 1 час при температуре 68 °С (температура кипения гексана). Степень извлечения - 97 %. Сокращено число используемых реактивов (высокотоксичные или дорогостоящие растворители и стандарты) и расширен диапазон определяемых содержаний ПАУ по сравнению с существующими нормативными документами за счет сканирования по ионам с массами, соответствующим массам молекулярных ионов нафталина ( m/z = 128), фенантрена и антрацена ( m/z = 178) и пирена ( m/z = 202). Погрешность определения полициклических ароматических углеводородов составляет не более 10 %. Применимость и проверка правильности предлагаемой методики определения ПАУ в почвах продемонстрирована на образцах, отобранных в районах г. Томска с различной экологической нагрузкой.Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic toxicants that accumulate well in soil. Several different techniques for qualitative and quantitative determination of PAHs exist today, but all of them have their drawbacks outlined in the present article. Therefore, a new methodology was developed for qualitative and quantitative determination of PAHs in soil by gas chromatography with mass spectrometric detection (GC-MS). It includes stages of sample preparation and analysis. The selection of optimal conditions for the identification of PAHs was carried out on four light PAHs (naphthalene, phenanthrene, anthracene and pyrene), as they have relatively low levels of carcinogenicity. The developed method is highly sensitive (detection limit of PAHs is 2∙10⁻³ µg/kg), fast and convenient for routine analyses. The range of concentrations of PAHs, which allows defining this technique as quite wide range (from 2 ng/kg to 4 mg/kg), was determined using the real samples of soil that had been selected in the city of Tomsk regions with different environmental pressures. The obtained experimental data allowed detecting and explaining some predictabilities of accumulation of PAHs in soils. In particular, the dependence of the concentration of PAHs from the environmental pressure in a certain area was demonstrated
Functional classification of proteins based on projection of amino acid sequences: application for prediction of protein kinase substrates
<p>Abstract</p> <p>Background</p> <p>The knowledge about proteins with specific interaction capacity to the protein partners is very important for the modeling of cell signaling networks. However, the experimentally-derived data are sufficiently not complete for the reconstruction of signaling pathways. This problem can be solved by the network enrichment with predicted protein interactions. The previously published <it>in silico </it>method PAAS was applied for prediction of interactions between protein kinases and their substrates.</p> <p>Results</p> <p>We used the method for recognition of the protein classes defined by the interaction with the same protein partners. 1021 protein kinase substrates classified by 45 kinases were extracted from the Phospho.ELM database and used as a training set. The reasonable accuracy of prediction calculated by leave-one-out cross validation procedure was observed in the majority of kinase-specificity classes. The random multiple splitting of the studied set onto the test and training set had also led to satisfactory results. The kinase substrate specificity for 186 proteins extracted from TRANSPATH<sup>® </sup>database was predicted by PAAS method. Several kinase-substrate interactions described in this database were correctly predicted. Using the previously developed ExPlain™ system for the reconstruction of signal transduction pathways, we showed that addition of the newly predicted interactions enabled us to find the possible path between signal trigger, TNF-alpha, and its target genes in the cell.</p> <p>Conclusions</p> <p>It was shown that the predictions of protein kinase substrates by PAAS were suitable for the enrichment of signaling pathway networks and identification of the novel signaling pathways. The on-line version of PAAS for prediction of protein kinase substrates is freely available at <url>http://www.ibmc.msk.ru/PAAS/</url>.</p
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