Now showing items 31-40 of 330
An idealized concept of the true cladistic character
(Elsevier, 1975-04)
Estimating evolutionary relationships is basic to the objectives of systematics. Comparative data, structured as taxonomic characters, are usually the essential considerations on which such estimates are founded. Some ...
Effects of hypoxia on the distribution of calcium in arterial smooth muscle cells of rats and swine
(Springer-Verlag, 1975-03)
Exposure to hypoxia caused an increase in the hematocrit and right heart weight of experimental rats, but did not affect calcium-45 uptake by pulmonary arterial smooth muscle cells. However, autoradiographic studies showed ...
Inverse relationship between galactokinase activity and 2-deoxygalactose resistance in Chinese hamster ovary cells
(Kluwer Academic Publishers-Plenum Publishers; Plenum Publishing Corporation ; Springer Science+Business Media, 1978-11)
Galactokinase activity is reduced in 12 independent clones of Chinese hamster ovary cells resistant to 2-deoxygalactose. The frequency of resistant colonies is increased with chemical mutagens. The resistant phenotype is ...
The epidermis and sensory organs of Dugesia tigrina (Turbellaria: Tricladida)
(Springer-Verlag, 1978-10)
The epidermis of D. tigrina was examined using the scanning electron microscope. Both dorsal and ventral surfaces are extremely irregular in contour, as well as being permeated by large numbers of pores. Cilia are restricted ...
Opposing actions of Ca++ and ATP plus Mg++ in controlling the kynurenine aminotransferase activity of isolated rat kidney mitochondria
(Elsevier, 1977-03-21)
A new method of monitoring changes in the permeability of the mitochondrial inner membrane to substrates, based on mitochondrial kynurenine aminotransferase activity, is applied in this study of a requirement for Ca++ for ...
The location of highly repetitious DNA in the somatic chromosomes of Drosophila melanogaster
(Springer-Verlag, 1978-01)
In situ hybridization of Drosophila melanogaster somatic chromosomes has been used to demonstrate the near exact correspondence between the location of highly repetitious DNA and classically defined constitutive heterochromatin. ...
Development of a photosynthesis model with an emphasis on ecological applications
(Springer-Verlag, 1976-06)
In this paper, a description of photosynthesis in a single leaf is developed that separates physiological sub-processes and that is practical to apply as an ecological tool. Temperature dependencies are emphasized with the ...
Genetic variation in the carbonic anhydrase isozymes of macaque monkeys. I. The radioimmunosorbent assay
(Kluwer Academic Publishers-Plenum Publishers; Plenum Publishing Corporation ; Springer Science+Business Media, 1973-02)
A radioimmunosorbent technique is described which is capable of independently detecting both isozymes of carbonic anhydrase, CA I and CA II, in concentrations as low as 1 ng/ml. The technique is used to quantitate the ...
Innervation of free muscle grafts in the rat in the absence of mechanical trauma to surrounding muscles or nerves
(Elsevier, 1976-09-01)
Soleus muscles in the rat were freely grafted alongside a normal soleus muscle in the absence of mechanical trauma to any of the surrounding muscles or motor nerves. The object of this experiment was to determine whether ...
Kynurenine metabolism in rats: Some hormonal factors affecting enzyme activities
(Elsevier, 1975-07-15)
The effects of certain long-term hormonal treatments of male and female rats on the activities of several enzymes involved in kynurenine synthesis and degradation were determined to further rationalize previously observed ...