Extensive variation in synonymous substitution rates in mitochondrial genes of seed plants

Background  

It has long been known that rates of synonymous substitutions are unusually low in mitochondrial genes of flowering and other land plants. Although two dramatic exceptions to this pattern have recently been reported, it is unclear how often major increases in substitution rates occur during plant mitochondrial evolution and what the overall magnitude of substitution rate variation is across plants.     

On feeding and nutrition in Fungiacava eilatensis (Bivalvia, Mytilidae), a commensal living in fungiid corals

The enlarged inhalant siphon of Fungiacava eilatensis opens into the coelenteron of species of fungiid corals with which it lives in commensal association. Material consisting of mucus, zooxanthellae, nematocysts, plankton and inorganic matter, is taken exclusively from the coelenteron. The very mobile foot possibly assists in food collection and in the removal of pseudofaeces; but, with large ctenidia, the bivalve is a typical ciliary feeder. Experiments with labelled zooxanthellae reveal that these are taken into the gut of Fungiacava with subsequent metabolic incorporation of products derived from them. The other prime source of food must be phytoplankton carried in with the feeding currents of the coral, itself carnivorous so that there is no competition for food between commensal and host. The Fungia zooxanthella– Fungiacava association operates as a "Troika" the productivity of which is autoregulated in proportion to the number of bivalves present. The inorganic wastes of the bivalve (as well as those of the coral) are utilized by the zooxanthellae, resultant increase in the algal component becoming available as food to the bivalve. Losses in the cycle are balanced by intake of exogenous food.     

Auditory segregation of competing voices: absence of effects of FM or AM coherence.

Four experiments sought evidence that listeners can use coherent changes in the frequency or amplitude of harmonics to segregate concurrent vowels. Segregation was not helped by giving the harmonics of competing vowels different patterns of frequency or amplitude modulation. However, modulating the frequencies of the components of one vowel was beneficial when the other vowel was not modulated, provided that both vowels were composed of components placed randomly in frequency. In addition, staggering the onsets of the two vowels, so that the amplitude of one vowel increased abruptly while the amplitude of the other was stationary, was also beneficial. Thus, the results demonstrate that listeners can group changing harmonics and can segregate them from stationary harmonics, but cannot use coherence of change to separate two sets of changing harmonics.     

Squamous cell carcinoma and lichen sclerosus et atrophicus of the prepuce.

Two cases of squamous cell carcinoma of the prepuce arising on balanitis xerotica obliterans are described. This event is unusual and not well known. The surgical treatment was a wide circumcision in which the prepuce and part of the shaft skin were removed, performing as well a decortication of the glans base. This technique seemed to be satisfactory in removing the carcinoma and obtaining a definite improvement in the clinical picture of balanitis xerotica obliterans as well.     

Population analysis of minor hemoglobin fractions. I. Hemoglobin A2]

The inhabitants of 7 isolated villages (of different nationalities) and of 5 panmictic populations were studied. Populational and segregation analyses of Hb A2 in 3036 normal and 150 heterozygous individuals for beta- and delta beta-thalassemia were carried out. The Hb A2 levels in some populations are established to deviate from the normal distribution. Bimodal dependency of the levels of Hb A2 distribution is demonstrated, which suggests the existance of heterogenous subpopulations by the Hb A2 level. The segregation analysis has revealed distinct genetic determination of Hb A2 levels. There was a good correlation between Hb A2 and Hb F values (r=-0.82).