Dynamic and steady state characteristics of the rabbit gastrocnemius muscle determined in series measurements

1. Within the range of the given conditions of measuring static and dynamic properties of the rabbit gastrocnemius muscle the following results were obtained: a) the dependence of the maxima of isotonic shortening upon the relative length of the muscle at constant load is linear; b) the parameters of the non-linear dependence of the passive elastic force of the muscle upon its relative length (measured in series) were identified using asymptotic regression; c) the time course of isotonic contractions (at an interval from 0 to 0.3 s after the beginning of stimulation) could be satisfactorily approximated by responses of a linear system to a step-function; d) the time course of isometric contractions (at an interval from 0 to 0.3 s after the beginning of stimulation) could be closely approximated by responses of a linear system to a step-function. 2. The time constants of isotonic and isometric contractions were determined as the parameters of the corresponding linear systems. 3. The maximum rates of the isometric and isotonic contractions were determined as maxima of the first derivatives of the responses of the corresponding models. 4. The experimental set-up made it possible to compare the values of the parameters concomitantly followed at various muscle lengths and at various loads.     

SuperSAGE analysis of the <Emphasis Type="Italic">Nicotiana attenuata</Emphasis> transcriptome after fatty acid-amino acid elicitation (FAC): identification of early mediators of insect responses

Background  

Plants trigger and tailor defense responses after perception of the oral secretions (OS) of attacking specialist lepidopteran larvae. Fatty acid-amino acid conjugates (FACs) in the OS of the Manduca sexta larvae are necessary and sufficient to elicit the herbivory-specific responses in Nicotiana attenuata, an annual wild tobacco species. How FACs are perceived and activate signal transduction mechanisms is unknown.     

Die Apogamie bei Aspidium remotum Al. Br.

Ohne ZusammenfassungMit 2 Textabbildungen und Tafel I–X.     

Zweiter Beitrag zur Flora Montenegro's

Ohne Zusammenfassung     

The effect of light on the growth rate of intertidal Acropora pulchra (Brook) from Phuket,Thailand, lat. 8°N

Series of apices of Acropora pulchra from an intertidal reef at Phuket, Thailand, were grown at different depths in the sea, and the length growth was monitored at 12–24 h intervals with laser diffraction. The growth rates of actively growing apices were normally distributed and showed a high variability, with an average coefficient of variation of 58%. There was a highly significant difference in average growth rate between adjacent colonies. A significant linear relationship was found between irradiance and length growth, with a saturating level at 300–400 Wm^-2. At 1000 Wm^-2 length growth was significantly reduced. Under normal daylight conditions, day and night growth rates were equal.     

A determination key to the structural types of seattered green using the air multispectral photography

Scattered green was studied in Czechoslovakia by means of the air multispectral photography and of the field observation. According to various repartition and canopy 19 structural types of seattered green were derived.