55,856 research outputs found
Determination of dissolved oxygen in water with leukoberbelin-blue I. A quick Winkler method. [Translation from: Z.analyt.Chem. 262 97-99, 1972.]
The reaction of Mn(II) with water-dissolved oxygen, to a higher manganese hydroxide in an alkaline medium, as with the longstanding classic Winkler method, is the first step in the method described here. The assumption for faultless results by the conventional and modified Winkler method is clean water, which contains no organic substances by Mn(III) or Mn(IV). In many cases, however, eg. in river and lake-water tests, it can be seen with the naked eye that after some time the originally brown-coloured precipitate of manganese hydroxide becomes more and more colourless. Oxygen content was analysed in the water samples and evaluated by raising the amount of the leuko-base and giving the corresponding dilution of the colouring matter solution formed still higher oxygen contents can be measured
Pushing for answers: is myosin V directly involved in moving mitochondria?
In budding yeast, the actin-based class V myosin motors, Myo2 and Myo4, transport virtually all organelles from mother to bud during cell division. Until recently, it appeared that mitochondria may be an exception, with studies showing that the Arp2/3 complex is required for their movement. However, several recent studies have proposed that Myo2 has a direct involvement in mitochondria inheritance. In this issue, Altmann et al. (Altmann, K., M. Frank, D. Neumann, S. Jakobs, and B. Westermann. 2008. J. Cell Biol. 181:119–130) provide the strongest support yet that Myo2 and its associated light chain Mlc1 function directly and significantly in both mitochondria–actin interactions and in the movement of mitochondria from mother to bud. The conflicting functions of Arp 2/3 and Myo2 may be reconciled by the existence of multiple pathways involved in mitochondrial transport
Toric rings, inseparability and rigidity
This article provides the basic algebraic background on infinitesimal
deformations and presents the proof of the well-known fact that the non-trivial
infinitesimal deformations of a -algebra are parameterized by the
elements of cotangent module of . In this article we focus on
deformations of toric rings, and give an explicit description of in
the case that is a toric ring.
In particular, we are interested in unobstructed deformations which preserve
the toric structure. Such deformations we call separations. Toric rings which
do not admit any separation are called inseparable. We apply the theory to the
edge ring of a finite graph. The coordinate ring of a convex polyomino may be
viewed as the edge ring of a special class of bipartite graphs. It is shown
that the coordinate ring of any convex polyomino is inseparable. We introduce
the concept of semi-rigidity, and give a combinatorial description of the
graphs whose edge ring is semi-rigid. The results are applied to show that for
, is not rigid while for , is
rigid. Here is the complete bipartite graph with one
edge removed.Comment: 33 pages, chapter 2 of the Book << Multigraded Algebra and
Applications>> 2018, Springer International Publishing AG, part of Springer
Natur
Statistics of Extreme Values in Time Series with Intermediate-Term Correlations
It will be discussed the statistics of the extreme values in time series
characterized by finite-term correlations with non-exponential decay.
Precisely, it will be considered the results of numerical analyses concerning
the return intervals of extreme values of the fluctuations of resistance and
defect-fraction displayed by a resistor with granular structure in a
nonequilibrium stationary state. The resistance and defect-fraction are
calculated as a function of time by Monte Carlo simulations using a resistor
network approach. It will be shown that when the auto-correlation function of
the fluctuations displays a non-exponential and non-power-law decay, the
distribution of the return intervals of extreme values is a stretched
exponential, with exponent largely independent of the threshold. Recently, a
stretched exponential distribution of the return intervals of extreme values
has been identified in long-term correlated time series by Bunde et al. (2003)
and Altmann and Kantz (2005). Thus, the present results show that the stretched
exponential distribution of the return intervals is not an exclusive feature of
long-term correlated time series.Comment: 6 pages, 7 figures, conference paper, in Noise and Stochastics in
Complex Systems and Finance, ed. by J. Kertez, S. Bornhold, R. N. Mantegna,
Procs. of SPIE, vol. 6601, 19, 200
\u3ci\u3eAltmann v. Austria\u3c/i\u3e and the Retroactivity of the Foreign Sovereign Immunities Act
In Republic of Austria v. Altmann, the U.S. Supreme Court decided that the Foreign Sovereign Immunities Act of 1976 (FSIA) generally applies to claims based on events that occurred before the Statute\u27s enactment. To decide the retroactivity question, the Court had occasion to consider the essential nature of foreign sovereign immunity: is it merely a procedural immunity providing foreign states with present protection from the inconvenience and indignity of a lawsuit, or is it something more than that? The Court\u27s examination of this question was brief and unsatisfying. Its analysis would have been enriched by a recognition that foreign sovereign immunity is regulated not just by federal statute, but also by principles of customary international law that the federal statute sought, in large part, to codify. Among the authorities the Court did consider, it found support for the proposition that foreign sovereign immunity is a procedural immunity and also for the proposition that foreign sovereign immunity is an immunity from substantive liability. Viewing these authorities as contradictory, the Court concluded that the retroactivity issue had to be resolved on other grounds. This brief article maintains that the relevant authorities are not contradictory. They are consistent with the conclusion that foreign states enjoy both a procedural and a substantive immunity, a possibility that the Court appears to have overlooked
- …