Irrigation and Community in the Central Peruvian Highlands

Irrigation in Quinua is an adaptation of high altitude agriculture, and its regulation and celebration are significant aspects of the political and ritual life of the community. Comparative data suggest that similar relationships are widespread in Peru. The information from Quinua is used to illuminate the water needs of Huari, an important archaeological site located in the community. The significance of the data for the hydraulic hypothesis of Wittfogel and Steward is discussed.     

Protein Synthesis and Differentiation During Pulmonate Development

An analysis of the changing patterns of protein synthesis duringearly development of Lymnaea palustris has been undertaken.An examination of the ingestion of capsule fluid protein suggeststhat after gastrulation 30 to 65% of the total embryo proteinis undigested food protein. Starch gel electrophoresis revealsa sudden increase in the number of hydrolases from four to twenty-siximmediately following the trochophore stage with the latterbeing present also in adult organs. Studies reported here andelsewhere demonstrate rhythmic changes in uridine incorporationduring early cleavage which peaks at the trochophore stage.Continuous treatment of embryos with 50 to 100µ.g of actinomycin-D(AMD) starting at the 2-cell stage slowed development throughthe trochophore stage but did not prevent normal larval organdevelopment. This AMD application reduced ³H uridine incorporationmore than 90% but did not appreciably alter the pattern of totalor ¹⁴C leucine pulse labeled peptides on sodium dodecyl sulfate(SDS) ultrathin slab electrophoresis gels. However, pronouncedand numerous changes in the patterns of both labeled and unlabeledpeptides were observed during development through 4 days withthe most notable alterations occurring at the 2.5 post-gastrulastage. This was true in normal and continuously treated AMDembryos. The morphological and biochemical data suggest Lymnaeaearly development is controlled by stable maternal messengerRNA.     

Pulmonary aspiration in preschool children with cystic fibrosis

Pulmonary aspiration of gastric refluxate (PAGR) has been demonstrated in association with pulmonary inflammation in school aged children with Cystic Fibrosis (CF). We sought to determine if similar findings were present in preschool children. Pepsin was measured in Broncho-alveolar lavage (BAL) fluid collected from clinically stable preschool children with CF and controls. Elevated pepsin levels were found in a subgroup of children with CF, but this was not found to be associated with pulmonary infection, pulmonary inflammation or respiratory or gastrointestinal symptoms.     

Revision of the Zone 13 graptolite biostratigraphy in the Marathon, Texas, standard succession and its bearing on Upper Ordovician graptolite biogeography

One of the long-standing problems in North American graptolite biostratigraphy is the distinct differences in assemblages of post-Climacograptus bicornis age between the classical graptolite sequences in the New York - Quebec and Marathon, west Texas, regions. These have been attributed either to faunal provincialism or to the presence of a major hiatus between the Woods Hollow and Maravillas formations in Texas. New collections from the key Marathon Picnic Grounds section contain diagnostic Late Ordovician graptolites that confirm the existence of a major stratigraphic gap below the Maravillas Formation. The lower Maravillas Formation (Zone 13) has a Late Ordovician, low-diversity Pacific Province graptolite fauna that includes the biostratigraphically diagnostic species Climacograptus nevadensis, C. tubuliferus, Orthograptus fastigatus and Dicellograptus ornatus. Zone 13 graptolite assemblages from the Marathon region correlate with the C. tubuliferus to D. ornatus zones in the Trail Creek, Idaho, succession, the Ea4-Bo2 interval in Victoria, the O. fastigatus Zone in the Canadian Arctic Islands, the O. quadrimucronatus to D. ornatus zones of the Canadian Cordillera, and the D. complanatus to D. anceps zones in Scotland. The hiatus between the Woods Hollow and Maravillas formations spans an interval corresponding to at least the Eal Ea3 interval in Australia, the C. americanus to upper A. manitoulinensis zones in the New York - Quebec succession, and the D. clingani and P. linearis zones in Scotland. These results agree with the magnitude of the hiatus previously indicated by conodont biostratigraphy. Late Ordovician graptolite distribution patterns in North America can be explained by an extension of Cooper, Fortey & Lindholm's (1991; Lethaia 24) Lower Ordovician graptolite biofacies model into the Upper Ordovician, which incorporates both lateral water-mass specificity and depth stratification. Using this model, we recognize in Laurentia two separate biofacies among tropical-zone Late Ordovician Pacific Province graptolite faunas, a cosmopolitan Oceanic biofacies, and a cratonic Laurentian biofacies. The lower Maravillas Formation graptolite fauna is clearly part of the Oceanic biofacies, whereas the coeval Appalachian faunas represent the Laurentian biofacies. □Graptolites, Ordovician, biostratigraphy, Texas, biofacies, biogeography.     

Phylogenetic Relationships of the Nassulida Within the Phylum Ciliophora Inferred from the Complete Small Subunit rRNA Gene Sequences of Furgasonia blochmanni, Obertrumia georgiana, and Pseudomicrothorax dubius

ABSTRACT. Using comparisons of complete small subunit rRNA sequences from the ciliated protozoans Furgasonia blochmanni, Obertrumia georgiana , and Pseudomicrothorax dubius we inferred the phylogenetic position of the Nassulida (Class Nassophorea) within the Ciliophora. In distance matrix analyses the Nassulida share a common ancestry with the colpodean ciliate Colpoda inflata. Distance matrix and parsimony methods convincingly demonstrate that the Nassulida plus Colpodida are members of a complex ciliate assemblage that also includes the oligohymenophorans and phyllopharyngeans. These phylogenetic inferences are largely congruent with recent analyses of 23S-like rRNA gene sequences and morphogenetic features. Groups traditionally thought to represent ancestral lineages now appear as highly derived ciliates. In contrast, heterotrichs which were considered to represent a highly evolved group, diverge at the base of the ciliates.