5,145 research outputs found

    Genetske strukturne populacije brgljuna (Engraulis encrasicolus Linnaeus, 1758) (Osteichthyes: Engraulide) iz Mediterana i Atlantskog oceana

    Get PDF
    Muscle proteins of the European anchovy Engraulis encrasicolus L. were analyzed using starch gel electrophoresis and isoelectric focusing on thin polyacrylamide ampholine gel. Twenty-two protein loci were analyzed and polymorphism was found in six of them. Based on genetic-biochemical data, we hypothesize that there are two anchovy subspecies, European and African. The former inhabits the Atlantic Ocean, the Mediterranean coast of Europe, and the Aegean, Marmora, Black, and Azov Seas. The latter is found in the Cape Blank region of the Atlantic Ocean and, probably, along the northwestern part of the African coast. The Aegean anchovy consists of hybrid populations, resulting from introgressive hybridization between the European and the African populations. No evidence for subspecies differentiation between the populations from the European coast of the Mediterranean and the Atlantic Ocean was found. Genetic distances between the Azov and Black Sea populations show that the former probably entered the Black Sea during the Karangad period and the latter during the last connection of the Black Sea to the Mediterranean. The genetic distance between the Black Sea anchovy and the Azov anchovy shows that they could be specified as two different populations. Probably some earlier subspecies differences disappeared as a result of introgressive hybridization.Analizirani su mišićni proteini europskog brgljuna (Engraulis encrasicolus L.) upotrebom škrobno gelne elektroforeze i izoelektričnog fokusiranja na tankom poliakrilamidnom gelu. Analizirana su 22 proteinska položaja i kod šestorice je dobiven polimorfizam. Postavljena je hipoteza na osnovi genetsko-biokemijskih podataka da postoje 2 podvrste brgljuna: europska i afrička. Prva naseljava Mediteran, mediteranske obale Europe, te Egejsko, Mramorno, Crno i Azovsko more. Druga je nađena u području Cape Blank u Atlantskom oceanu i vjerojatno uzduž sjeverozapadnog dijela afričke obale. Egejski brgljun se sastoji od hibridnih populacija koje su rezultat introgresivne hibridizacije. Nema uvida u diferencijaciju podvrsta između populacija s europske obale Mediterana i Atlantskog oceana. Genetske udaljenosti između populacija Azovskog i Crnog mora ukazuju da je prva ušla u Crno more tijekom karangadskog razdoblja, a druga tijekom zadnje veze Crnog mora i Mediterana. Genetska udaljenost između brgljuna iz Crnog mora i brgljuna iz Azovskog mora upućuje na to da se mogu razlikovati različite populacije. Vjerojatno su neke razlike u podvrstama nastale kao rezultat introgresivne hibridizacije

    Multi-Parametric Rigid and Flexible, Low-Cost, Disposable Sensing Platforms for Biomedical Applications

    Get PDF
    The measurement of Na+, K+ and H+ is essential in medicine and plays an important role in the assessment of tissue ischemia. Microfabrication, inkjet- and screen-printing can be used for solid contact ion selective electrodes (ISE) realization; these, however, can be non-standardized, costly and time consuming processes. We present the realization of ISEs on post-processed electrodes fabricated via standardized printed circuit board (PCB) manufacturing techniques. In vitro results are presented from two rigid platforms (32 ISEs) for liquid sample dip-stick measurements and two flexible platforms (6 and 32 ISEs) for post-surgical intestinal tissue monitoring, each with a common reference electrode (RE). These are combined with optimized tetrapolar bioimpedance sensors for tissue ischemia detection. Both electroless and hard gold PCB finishes are examined. Apart from the electroless rigid platform, the rest demonstrated comparable and superior performance, with the pH sensors demonstrating the greatest deviation; the flexible hard gold platform achieved a sensitivity 4.6 mV/pH and 49.2 mV/pH greater than the electroless flexible and rigid platforms, respectively. The best overall performance was achieved with the hard gold flexible platform with sensitivities as large as 73.4 mV/pH, 56.3 mV/log [Na+], and 57.4 mV/log [K+] vs. custom REs on the same substrate. Simultaneous measurements of target analytes is demonstrated with test solutions and saliva samples. The results exhibit superior performance to other PCB-based pH sensors, demonstration of Na+ and K+ PCB-based sensors with comparable performance to potentiometric sensors fabricated with other techniques, paving the way towards mass-produced, low-cost, disposable, multi-parametric chemical sensing diagnostic platforms

    Modest-2: A Summary

    Get PDF
    This is a summary paper of MODEST-2, a workshop held at the Astronomical Institute ``Anton Pannekoek'' in Amsterdam, 16-17 December 2002. MODEST is a loose collaboration of people interested in MOdelling DEnse STellar systems, particularly those interested in modelling these systems using all the available physics (stellar dynamics, stellar evolution, hydrodynamics and the interplay between the three) by defining interfaces between different codes. In this paper, we summarize 1) the main advances in this endeavour since MODEST-1; 2) the main science goals which can be and should be addressed by these types of simulations; and 3) the most pressing theoretical and modelling advances that we identified.Comment: Accepted by New Astronom

    Supernova Ia: a Converging Delayed Detonation Wave

    Get PDF
    A model of a carbon-oxygen (C--O) presupernova core with an initial mass 1.33 M_\odot, an initial carbon mass fraction 0.27, and with an average mass growth-rate 5 x 10^{-7} M_\odot/yr due to accretion in a binary system was evolved from initial central density 10^9 g/cm^3, and temperature 2.05 x 10^8 K through convective core formation and its subsequent expansion to the carbon runaway at the center. The only thermonuclear reaction contained in the equations of evolution and runaway was the carbon burning reaction 12C + 12C with an energy release corresponding to the full transition of carbon and oxygen (with the same rate as carbon) into 56Ni. As a parameter we take \alpha_c - a ratio of a mixing length to the size of the convective zone. In spite of the crude assumptions, we obtained a pattern of the runaway acceptable for the supernova theory with the strong dependence of its duration on \alpha_c. In the variants with large enough values of \alpha_c=4.0 x 10^{-3} and 3.0 x 10^{-3} the fuel combustion occurred from the very beginning as a prompt detonation. In the range of 2.0 x 10^{-3} >= \alpha_c >= 3.0 x 10^{-4} the burning started as a deflagration with excitation of stellar pulsations with growing amplitude. Eventually, the detonation set in, which was activated near the surface layers of the presupernova (with m about 1.33 M_\odot) and penetrated into the star down to the deflagration front. Excitation of model pulsations and formation of a detonation front are described in detail for the variant with \alpha_c=1.0 x 10^{-3}.Comment: 13 pages, 11 figures, to appear in Astronomy Letter

    Hierarchy of Conservation Laws of Diffusion--Convection Equations

    Full text link
    We introduce notions of equivalence of conservation laws with respect to Lie symmetry groups for fixed systems of differential equations and with respect to equivalence groups or sets of admissible transformations for classes of such systems. We also revise the notion of linear dependence of conservation laws and define the notion of local dependence of potentials. To construct conservation laws, we develop and apply the most direct method which is effective to use in the case of two independent variables. Admitting possibility of dependence of conserved vectors on a number of potentials, we generalize the iteration procedure proposed by Bluman and Doran-Wu for finding nonlocal (potential) conservation laws. As an example, we completely classify potential conservation laws (including arbitrary order local ones) of diffusion--convection equations with respect to the equivalence group and construct an exhaustive list of locally inequivalent potential systems corresponding to these equations.Comment: 24 page
    corecore