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Cretaceous sediments are disconformably overlain by Pliocene sediments along the banks of Greens Mill Run, Greenville, North Carolina, located in the central coastal plain. The Cretaceous sediments, composed of glauconitic sand and clay, have previously been informally considered part of the Maastrichtian Peedee Formation. The Pliocene sediments are assigned to the Yorktown Formation and consist of shelly, muddy sand overlain with a gradational contact by shell-poor, muddy sand. Foraminifera are abundant in the Cretaceous unit and are dominated by the planktic foraminifera Guembelitria cretacea. Low planktic foraminiferal diversity, the absence of single and double-keeled species, the dominance of planktic over benthic foraminifera, and the occurrence of glauconite and phosphorite grains indicates a middle neritic environment. The age of the Cretaceous unit is late Campanian (Zone CC22c), as indicated by the co-occurrence of the calcareous nannofossils Reinhardtites levis and Reinhardtites anthophorus. For this reason, we assign these deposits to the Donoho Creek Formation of the Black Creek Group rather than to the lithologically similar and younger Peedee Formation. Benthic foraminifera dominate the lower part of the Yorktown Formation, are similar to those from the Rushmere Member of the Yorktown Formation in the southern Salisbury Embayment, and indicate deposition in an inner to middle neritic environment. Phosphorite peloids and intraclasts are likely reworked from underlying strata and suggest wave ravinement and deposition during transgression, which is further supported by a fining upward trend. The upper part of the Yorktown Formation exposure, characterized by abundant molds of small bivalves and barren of foraminifera, represents the Morgarts Beach Member. Sedimentological data are consistent with foraminiferal data as far as expected depositional energy. A restricted inner neritic or estuarine environment is indicated. [ABSTRACT FROM AUTHOR]

The pathogenic protozoan Tritrichomonas foetus F2 contains seven genes which encode cysteine proteinases. The enzymes are similar to cathepsin-L. The greatest structural similarity exists between the TFCP7 and TFCP8 genes while the least similarity is between the TFCP3 and TFCP9 genes. Multiple copies of the TFCP3 gene are present while the other genes have single copies. The TFCP8 gene shows the greatest transcription while the TFCP4 gene shows the least transcription. Other isolates have different gene expressions but TFCP8 encodes the main enzyme.

Conventional procedures help isolate and identify seven DNA molecules encoding different cysteine proteinase (CP) from the pathogenic protozoon Trichomonas vaginalis. Characterization of four clones shows that TvCP1 and TvCP2 are full length and TvCP3 and TvCP4 are slightly less than full length. Amino acid sequence analysis helps compare these species with each other and T. vaginalis gene products belonging to cathepsin L/cathepsin H/papain branch of the papain superfamily. Southern analysis shows that TvCP4 gene is a multiple-copy and the three others are single-copy, and that all four sequences have similar-sized, single abundant transcripts, suggesting a common evolutionary origin for these four CPs.

Geological investigations of Herndon Bay, a Carolina bay in the Coastal Plain of North Carolina (USA), provide evidence for rapid basin scour and migration during Marine Isotope Stage (MIS) 3 of the late Pleistocene. LiDAR data show a regressive sequence of sand rims that partially backfill the remnant older portions of the bay, with evidence for basin migration more than 600 meters to the northwest. Basin migration was punctuated by periods of stability and construction of a regressive sequence of sand rims with basal muddy sands incorporated into the oldest rims. Single grain OSL ages place the initial formation of each sand rim from oldest to most recent as ca. 36.7 +/- 4.1, 29.6 +/- 3.1, and 27.2 +/- 2.8 ka. These ages indicate that migration and rim construction was coincident with MIS 3 through early MIS 2, a time of rapid oscillations in climate. The fact that Carolina bay basins can migrate, yet maintain their characteristic shape and orientation, demonstrates that Carolina bays are oriented lakes that evolved over time through lacustrine and eolian processes. This research also indicates that Carolina bays can respond rapidly during periods of climatic transition such as Dansgaard-Oeschger or Heinrich events. [ABSTRACT FROM AUTHOR]