Two Pleistocene nonglacial units underlie eolian deposits of the last glaciation in the southern part of the Nushagak lowland, a major Quaternary basin in southwestern Alaska. The Flounder Flat ...complex, the lower of the two units, consists mainly of deposits of tundra lakes. Pollen and beetle data suggest a somewhat mesic graminoid tundra without significant birch and ericaceous shrubs and a climate colder than present. The overlying Etolin complex includes organic silt, nonwoody peat, and associated inorganic sediments that accumulated in swales and on lower slopes. Lowermost peaty silt of the Etolin complex locally contains pollen spectra indicative of birch-shrub tundra and beetle assemblages characteristic of mesic-to-wet habitats broadly similar to those of the Holocene tundra. Evidence for full-interglacial climates, however, is ambiguous. Stratigraphically higher samples from the Etolin complex suggest a colder-than-modern graminoid tundra with local mesic-to-wet habitats but restricted shrub cover. Radiocarbon and paleoecological data suggest at least partial correlation of the Etolin complex with the middle Wisconsin (Boutellier) nonglacial interval, mostly >38,000 yr BP.
Improvements in the design of modern scanning electron microscopes (SEM) and new methods of specimen preparation incorporating chemical removal of the cytosol and cytoskeleton, now make it possible ...to view cells and their organelles in three dimensions (3D) at high magnification. In this experiment, high resolution SEM (HRSEM) utilizing new methods of tissue preparation was used to study the intracellular structures of the mouse ileum. In addition, in vivo intestinal perfusion was used to further enhance cellular preservation. Using these modifications it was possible to visualize, in 3D, the fine structure of intestinal epithelial cells and intracellular organelles such as the nucleus, mitochondria, endoplasmic reticulum, and Golgi complex, as well as microvilli and cell membrane. Whole mitochondria appeared as irregularly shaped organelles which contained tubular cristae. Plate-like cristae were not observed. The brush border was found to be closely packed array of cylindrical projections. The extensive folding and structural intricacy of lateral cell membranes between absorptive cells could only be appreciated by viewing this tissue with 3D HRSEM. The use of HRSEM to study 3D ultrastructure of cells and their organelles will improve our understanding of the structure-function relationships in both the healthy and diseased gastrointestinal tract.
HD 3167 is a bright (V = 8.9), nearby KO star observed by the NASA K2 mission (EPIC 220383386), hosting two small, short-period transiting planets. Here we present the results of a multi-site, ...multi-instrument radial-velocity campaign to characterize the HD 3167 system. The masses of the transiting planets are 5.02 +/- 0.38 M-circle plus for HD 3167 b, a hot super-Earth with a likely rocky composition (rho(b) = 5.6(-1.43)(+2.15) g cm(-3)), and 9.80(-1.24)(+1.30) M-circle plus for HD 3167 c, a warm sub-Neptune with a likely substantial volatile complement (rho(c) = 1.97(-0.59)(+0.94) g cm(-3)). We explore the possibility of atmospheric composition analysis and determine that planet c is amenable to transmission spectroscopy measurements, and planet b is a potential thermal emission target. We detect a third, non-transiting planet, HD 3167 d, with a period of 8.509 +/- 0.045 d (between planets b and c) and a minimum mass of 6.90 +/- 0.71 M-circle plus. We are able to constrain the mutual inclination of planet d with planets b and c: we rule out mutual inclinations below 1.degrees 3 because we do not observe transits of planet d. From 1.degrees 3 to 40 degrees, there are viewing geometries invoking special nodal configurations, which result in planet d not transiting some fraction of the time.
A 98.8% response rate was achieved in a follow-up study of a community based health survey. The follow-up methodology used in contacting the residents of 1700 households in a suburban upper-middle ...class community is presented. Study subjects, who were predominantly white, older adults, participated in the original health survey during 1972 and 1973. When the follow-up study was conducted three years later to determine the vital status of study participants, 30% of the households had moved. Follow-up response of two sets of mailings totaled 76.1%. An additional 12.1% response was obtained by calling residents at their last known address. The final 10.5% of the contacted households were located by intensive telephone tracing. A wide variety of sources of information, both local and non-local, were used to locate these "hard to trace" households. They were different from all other contacted households with respect to mobility rate, household size, and death rate. A 15.5% underestimate of the three-year death rate would have occurred if the hard to trace group had not been contacted. These results emphasize the importance of complete follow-up in prospective studies.
