746 research outputs found
Research Notes : United States : Cultivar identification by isozyme analysis
The purpose of this survey is to build a multiple enzyme system which may provide many biochemical characters to fingerprint cultivars. A total of 751 lines and cultivars of Glycine max have been screened for their enzyme zymogram types by using the technique of slab-gel electrophoresis (see Chiang, 1985; Doong, 1986; Gorman, 1983; Gorman and Kiang, 1977, 1978; Kiang and Gorman, 1983, for method). For 367 named cultivars, the zymogram types of eight enzymes and one seed protein (Ti) are listed in Table 1. Except for several cultivars, two of the eight enzymes, ADH and LAP, listed in Table 1 were mainly classified by Gorman (1983)
Life histories determine divergent population trends for fishes under climate warming
Most marine fish species express life-history changes across temperature gradients, such as faster growth, earlier maturation, and higher mortality at higher temperature. However, such climate-driven effects on life histories and population dynamics remain unassessed for most fishes. For 332 Indo-Pacific fishes, we show positive effects of temperature on body growth (but with decreasing asymptotic length), reproductive rates (including earlier age-at-maturation), and natural mortality for all species, with the effect strength varying among habitat-related species groups. Reef and demersal fishes are more sensitive to temperature changes than pelagic and bathydemersal fishes. Using a life table, we show that the combined changes of life histories upon increasing temperature tend to facilitate population growth for slow life-history populations, but reduce it for fast life-history ones. Within our data, lower proportions (25-30%) of slow life-history fishes but greater proportions of fast life-history fishes (42-60%) show declined population growth rates under 1 °C warming. Together, these findings suggest prioritizing sustainable management for fast life-history species
The Initial Mass Function as given by the fragmentation
The dichotomy between a universal mass function (IMF) and a variable IMF
which depends on local physical parameters characterises observational and
theoretical stellar astronomy. In this contribution the available distributions
of probability are briefly reviewed. The physical nature of two of them, gamma
variate and lognormal, is then explained once the framework of the
fragmentation is introduced. Interpolating techniques are then applied to the
sample of the first 10 pc and to the open cluster NGC6649: in both cases
lognormal distribution produces the best fit. The three power law function has
also been investigated and visual comparison with an artificially generated
sample of 100000 stars suggests that the variations in the spectral index are
simply due to the small number of stars available in the observational sample.
In order to derive the sample of masses, a new formula that allows us to
express the mass as a function of the absolute magnitude and (B-V) for MAIN V,
GIANTS III and SUPERGIANTS I is derived.Comment: 6 pages 9 figure
Cell size distribution in a random tessellation of space governed by the Kolmogorov-Johnson-Mehl-Avrami model: Grain size distribution in crystallization
The space subdivision in cells resulting from a process of random nucleation
and growth is a subject of interest in many scientific fields. In this paper,
we deduce the expected value and variance of these distributions while assuming
that the space subdivision process is in accordance with the premises of the
Kolmogorov-Johnson-Mehl-Avrami model. We have not imposed restrictions on the
time dependency of nucleation and growth rates. We have also developed an
approximate analytical cell size probability density function. Finally, we have
applied our approach to the distributions resulting from solid phase
crystallization under isochronal heating conditions
Communications Biophysics
Contains research objectives and reports on two research projects
Path-integral analysis of fluctuation theorems for general Langevin processes
We examine classical, transient fluctuation theorems within the unifying
framework of Langevin dynamics. We explicitly distinguish between the effects
of non-conservative forces that violate detailed balance, and non-autonomous
dynamics arising from the variation of an external parameter. When both these
sources of nonequilibrium behavior are present, there naturally arise two
distinct fluctuation theorems.Comment: 24 pages, one figur
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