3,320 research outputs found
Effiziente Synthese makrocyclischer Kohlenwasserstoffe mit Durchmessern im Nanometerbereich
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108614/1/19921040715_ftp.pd
Workshop on the Martian Northern Plains: Sedimentological, Periglacial, and Paleoclimatic Evolution
Papers that have been accepted for presentation at the Workshop on the Martian Northern Plains: Sedimentological, Periglacial, and Paleoclimatic Evolution, on 12-14 Aug. 1993 in Fairbanks, Alaska are included. Topics covered include: hydrological consequences of ponded water on Mars; morphological and morphometric studies of impact craters in the Northern Plains of Mars; a wet-geology and cold-climate Mars model: punctuation of a slow dynamics approach to equilibrium; the distribution of ground ice on Mars; and stratigraphy of the Martian Northern Plains
Magellan stereo images and Venusian geology
Areas of Venus imaged by Magellan radar with multiple viewing conditions provide unique data that will contribute to the solution of venusian geologic problems and provide a basis for quantitative comparison of venusian landforms with those on other planetary bodies. Three sets of images with different viewing conditions have been acquired: (1) left-looking with variable incidence angles (cycle 1 profile), (2) right-looking with nearly constant incidence angles (cycle 2 profile), and (3) left-looking with variable incidence angles that are almost always smaller than those in (1) (cycle 3 profiles). The unique data provided by paired images of the same scene with different incidence angles arises from image displacements caused by the relief of individual landforms at scales comparable to the ground-range and azimuth resolutions of the images. There are two aspects of the data: (1) Stereopsis achieved by simultaneous viewing of paired left-looking images of the same scene permits three-dimensional perception and interpretation of the morphologies of landforms at resolutions much finer than the altimetry footprints. (2) Measurements of differences of image displacements (parallax) on paired images with known imaging geometries provide quantitative estimates of the relief and shapes of landforms. The potential scientific contributions of the data can be grouped into two interrelated classes: (A) geologic mapping, analysis, and interpretation and (B) topical studies that involve topographic measurements. Stereopsis, without quantitative measurements, enhances geologic mapping, analysis, and interpretation of the rock units of Venus to a degree that cannot be overestimated. In geologic mapping, assemblages of landforms, assessments of backscatter and variations in backscatter, and fine-scale topography are used to define and characterize geologic map units that represent laterally continuous deposits or rock units. Stereopsis adds the important dimension of local relief for characterization of geologic units at a scale that is not possible with Magellan altimetry or products derived from the altimetry. Relative ages of the geologic units are determined using the well-known principles of superposition and intersection. Here, the perception of relief is invaluable because superposition relations among the geological units are more readily and clearly established. The recognition of folds, faults, and fault systems, regardless of their orientations, is facilitated with stereopsis so that sequences of deformation of the geologic units can be determined and structural analyses vastly improved. Shapes of landforms are readily perceived so that they can be properly interpreted. The end result of the mapping, analyses, and interpretations is a geologic history of Venus that includes the sequences of formation and deformation of various geologic units. Measurements of relief at the finest scale possible are necessary for numerous topical studies. Standard altimetry will provide the necessary information on the relief of most large landforms, but it tends to underestimate the relief of small landforms and distorts their shapes. Although special processing of the altimeter echoes improves the estimates of the relief and shapes of some landforms, there are uncertainties in the interpretations of the echoes. Examples of topical studies requiring measurements of relief are given
Iodine-promoted decomposition of 1-aryl-3,3-dialkyltriazenes: A mild method for the synthesis of aryl iodides
Iodine promoted decomposition of 1-aryl-3,3-dialkyltriazenes in organic solvents is shown to give high yields of the corresponding aryl iodides under extremely mild conditions. The presence of iodine greatly accelerates the reaction in both iodoalkanes as well as in non-iodinated solvents.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31431/1/0000349.pd
Brown· Midrib Sorghum Silage for Midlactation Dairy Cows
Brown midrib sorghum silage was compared with alfalfa, corn, and normal sorghum silages for its effect on performance, ruminal metabolism, and digestive kinetics of Holstein dairy cows in midlactation. Twelve cows averaging 90 ± 5 DIM were assigned to one of four diets in replicated 4 X 4 Latin squares with 4-wk periods. Additionally, 3 ruminally fistulated cows (95 ± 20 DIM) were assigned to the same diets in a 3x 4 Youden square for measurement of ruminal characteristics. Diets were fed as isonitrogenous TMR that contained 65% silage (OM basis). The DMl was greater for the corn and brown midrib sorghum (4% of BW/d) than for the alfalfa and normal sorghum diets (3.4% of BW/d). The brown midrib sorghum supported FCM production that was similar to that of cows on corn and alfalfa diets (25.8 kg/d), but cows fed normal sorghum produced less milk and fewer milk components. Source of silage had no effect on eating time, but rumination was least for the alfalfa.diet.. Ruminal pH and ammonia concentrations were similar for all diets. Total VFA concentrations were greatest for the corn and brown midrib sorghum diets. The brown midrib sorghum had greater in situ extent of ruminal NDF digestion than did the normal sorghum, which agreed with in vitro data. The brown midrib sorghum used in this experiment supported FCM production similar to the corn and alfalfa silages commonly fed to dairy cows in midlactation
Brown· Midrib Sorghum Silage for Midlactation Dairy Cows
Brown midrib sorghum silage was compared with alfalfa, corn, and normal sorghum silages for its effect on performance, ruminal metabolism, and digestive kinetics of Holstein dairy cows in midlactation. Twelve cows averaging 90 ± 5 DIM were assigned to one of four diets in replicated 4 X 4 Latin squares with 4-wk periods. Additionally, 3 ruminally fistulated cows (95 ± 20 DIM) were assigned to the same diets in a 3x 4 Youden square for measurement of ruminal characteristics. Diets were fed as isonitrogenous TMR that contained 65% silage (OM basis). The DMl was greater for the corn and brown midrib sorghum (4% of BW/d) than for the alfalfa and normal sorghum diets (3.4% of BW/d). The brown midrib sorghum supported FCM production that was similar to that of cows on corn and alfalfa diets (25.8 kg/d), but cows fed normal sorghum produced less milk and fewer milk components. Source of silage had no effect on eating time, but rumination was least for the alfalfa.diet.. Ruminal pH and ammonia concentrations were similar for all diets. Total VFA concentrations were greatest for the corn and brown midrib sorghum diets. The brown midrib sorghum had greater in situ extent of ruminal NDF digestion than did the normal sorghum, which agreed with in vitro data. The brown midrib sorghum used in this experiment supported FCM production similar to the corn and alfalfa silages commonly fed to dairy cows in midlactation
Interfacial Mechanophore Activation Using Laser-Induced Stress Waves
A new methodology is developed to activate and characterize mechanochemical transformations at a solid interface. Maleimideâanthracene mechanophores covalently anchored at a fused silicaâpolymer interface are activated using laser-induced stress waves. Spallation-induced mechanophore activation is observed above a threshold activation stress of 149 MPa. The retro [4+2] cycloaddition reaction is confirmed by fluorescence microscopy, XPS, and ToF-SIMS measurements. Control experiments with specimens in which the mechanophore is not covalently attached to the polymer layer exhibit no activation. In contrast to activation in solution or bulk polymers, whereby a proportional increase in mechanophore activity is observed with applied stress, interfacial activation occurs collectively with spallation of the polymer film
An Automated Image-Based Method for Rapid Analysis of Chlamydia Infection as a Tool for Screening Antichlamydial Agents
This is the published version. Copyright American Society for MicrobiologyA major limitation in the identification of novel antichlamydial compounds is the paucity of effective methods for large-scale compound screening. The immunofluorescence assay is the preferred approach for accurate quantification of the intracellular growth of Chlamydia. In this study, an immunofluorescence image-based method (termed image-based automated chlamydial identification and enumeration [iBAChIE]) was customized for fully automated quantification of Chlamydia infection using the freely available open-source image analysis software program CellProfiler and the complementary data exploration software program CellProfiler Analyst. The method yielded enumeration of different species and strains of Chlamydia highly comparably to the conventional manual methods while drastically reducing the analysis time. The inhibitory capability of established antichlamydial activity was also evaluated. Overall, these data support that iBAChIE is a highly effective tool for automated quantification of Chlamydia infection and assessment of antichlamydial activities of molecules. Furthermore, iBAChIE is expected to be amenable to high-throughput screening studies for inhibitory compounds and fluorescently labeled molecules to study host-pathogen interactions
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