A Critical Study of Sensor Element Diffusion Porometers

Improvements in the design, calibration, and method of use ofsensor element diffusion porometers are described and the difficultiescaused by non-isothermal conditions during the use of theseporometers are discussed.     

The Minimum Intercellular-Space Carbon-dioxide Concentration in Leaves of the Palm Phoenix reclinata

Leaves of Phoenix reclinata respond both to high temperatureand to water-strain with sudden and marked increase in theirminimum intercellular-space carbon-dioxide concentration. Theleaves of Phoenix reclinata which had been grown in the opencountry did not suffer a significant after-effect from beingexposed to experimentally imposed water-strain.     

Analysis of the mitochondrial genome of Schistocerca gregaria gregaria (Orthoptera: Acrididae)

In the present study, we present the full sequence of the mitochondrial genome of the African desert locust Schistocerca gregaria gregaria. The size of 15625 bp reported matches very well with mitochondrial genomes of other Orthopteriodea. The mitochondrial genome comprises 13 protein‐coding genes, two ribosomal RNAs and 22 t‐RNAs with two t‐RNA (trnD and trnK) rearrangements that are typical for the taxon Caelifera. We compared the sequence with 12 mitochondrial genes of Schistocerca gregaria flaviventris and Schistocerca americana and used some of these data to construct phylogenetic trees, which confirm the close relationship between the two subspecies S. g. flaviventris and S. g. gregaria. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 296–305.     

The evolution of avian mating systems: a phylogenetic analysis of male and female polygamy and length of pair bond

A phylogenetic analysis of the evolution of mating systems in birds was made, based on the phylogeny of Sibley and Ahlquist. Both the mating behaviour and the social behaviour of species were classified for males and females, according to (1) the frequency of mated individuals in a species having several mates in a breeding season compared to those having one mate (the mating pattern), and (2) whether there is a bond between males and females, and in case of there being a bond, to the length of the bond. Non-passerines are extensively analysed, whereas we only give a survey of the situation in passerines. In non-passerine birds, the number of inferred transitions from monogamy to polygamy are 15 for females and 16–23 for males. Almost all transitions between different states of mating pattern are to higher states of polygamy. Our analyses also show a concentration of transitions to polygamy and short bonds, respectively, in the two monophyletic groups of Struthionidae-Anatidae and Pteroclidae-Laridae.     

Melanins in IGR 1 Melanoma Cells

Information on the composition of melanins is obtained by analysis both of 4-amino-3-hydroxyphenylalanine (AHP) after hydriodic acid degradation and of pyrrole-2,3,5-tricarboxylic acid (PTCA) after potassium permanganate oxidation. Analysis of thiazole-4,5-dicarboxylic acid (TDCA) and pyrrole-2,3-dicarboxylic acid (PDCA) after permanganate oxidation, provides additional information on the composition, TDCA on pheomelanin residues, and PDCA on indolic residues without carboxy groups. Using model melanins formed from dopa and cysteinyldopa in different proportions, we found the TDCA/(PTCA+PDCA) ratio to yield a reliable estimate of the relative proportions of pheomelanin and eumelanin. The PDCA/PTCA ratio reflects the relationship between indole residues with and without carboxy groups. We have analyzed degradation products from cultures of IGR 1, an extensively studied melanoma cell line. Cell cultures were harvested after 2, 4, and 7 days. Culture media were changed after 2 days in all series, and also after 4 days in one series harvested at 7 days. Cells without medium change had seven times the amount of melanin found in cultures with medium change. The PDCA/PTCA ratio decreased with increasing amounts of melanin. With increased melanization, eumelanin is increased relatively more than pheomelanin. The cell content of 5-S-cysteinyldopa (5-S-CD) was similar in all cultures, while 6-hydroxy-5-methoxyindole-2-carboxylic acid (6H5MICA), a eumelanin precursor metabolite, was found in increased amounts of media of heavily pigmented cultures.     

Enzyme Activity Pattern and Mitochondrio-cytoplasmic Relations in Protozoa. Comparative Study of Tetrahymena pyriformis, Allogromia laticollaris, and Labyrinthula coenocystis

SYNOPSIS. Enzyme activity patterns were determined in Tetrahymena pyriformis, Allogromia laticollaris , and Labyrinthula coenocystis. The activities of enzymes belonging to certain metabolic pathways (glycolysis, fatty acid oxidation, tricarboxylic acid cycle) had constant proportions in each species, whereas their absolute levels differed. The activities of intramitochondrial enzymes were compared with the mitochondrial to total cytoplasmic volume ratio. Despite the very different fine structure of the mitochondria in the 3 protozoa, there was good correlation between the activities of citric acid cycle enzymes and the mitochondrial volume.