The Ophryoglenina includes two families of histophagous ciliates, the Ophryoglenidae and the Ichthyophthiriidae. The organelle of Lieberkühn is the only feature that unambiguously establishes these ...two families as members of a monophyletic group. This organelle is a reniform cortical structure found in the oral cavity. Careful re-examination of the trophont of Ophryoglena sp. and the theront of Ichthyophthirius multifiliis has demonstrated similarities in their organelles of Lieberkühn. These include its placement between oral polykinetids 1 and 2, its being overlain by cytoplasmic ridges of cortical alveoli, its reniform shape, and the extreme density of the main body of the organelle. These organelles are homologous by the criteria of position and structural similarity. The suborder Ophryoglenina is corroborated as a monophyletic taxon.
Nine artificial ponds each subjected to one of three experimental treatments of organic enrichment exhibited no significant differences in mean concentration of dissolved nitrate, nitrite, ammonia or ...phosphate. Phytoplankton communities were dominated by Chlorophyta. Communities differed considerably in population size and in pattern of fluctuation among ponds treated similarly. Population variations generally were not correlated with nutrient variations. Development of large algal populations began concurrently with sharp increases (25 μg/liter or more) in nitrate concentration in some ponds. In zoo-plankton communities a shift occurred in dominant forms from rotifers in June, to cladocera in July, and copepods in August. In general, algal species diversity (H̄) was not positively correlated with nutrient concentrations. Redundancy (R) was closely parallel in the ponds. Among ponds supporting very large algal populations, only one exhibited consistently high R values for that period. The expected inverse relation between P/R ratio and H̄ among autotrophic communities was not observed. The correlation coefficient for these two parameters was -.09. Vertical mixing of algal communities in all ponds was indicated by comparison of surface and deeper samples.
Phonetic coding in dyslexics and normal readers Hall, James W.; Ewing, Audrey; Tinzmann, Margaret B. ...
Bulletin of the Psychonomic Society,
04/1981, Letnik:
17, Številka:
4
Journal Article
Odprti dostop
Normal (N = 15, grades 3 & 4) & severely deficient readers (N = 8, aged 15 to 40) recalled rhyming & nonrhyming letter strings; both groups performed poorly. It is argued that these results offer no ...support for the phonetic code deficiency hypothesis proposed by D. Shankweiler et al ("The Speech Code and Learning to Read," Journal of Experimental Psychology: Human Learning and Memory, 1979, 5, 531-545). 1 Table, 3 References. Modified HA
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