Mouse RC/BTB2, a Member of the RCC1 Superfamily, Localizes to Spermatid Acrosomal Vesicles

Mouse RC/BTB2 is an unstudied protein of the RCC1 (Regulator of Chromosome Condensation) superfamily. Because of the significant remodeling of chromatin that occurs during spermiogenesis, we characterized the expression and localization of mouse RC/BTB2 in the testis and male germ cells. The Rc/btb2 gene yields two major transcripts: 2.3 kb Rc/btb2-s, present in most somatic tissues examined; and 2.5 kb Rc/btb2-t, which contains a unique non-translated exon in its 5′-UTR that is only detected in the testis. During the first wave of spermatogenesis, Rc/btb2-t mRNA is expressed from day 8 after birth, reaching highest levels of expression at day 30 after birth. The full-length protein contains three RCC1 domains in the N-terminus, and a BTB domain in the C-terminus. In the testis, the protein is detectable from day 12, but is progressively up-regulated to day 30 and day 42 after birth. In spermatids, some of the protein co-localizes with acrosomal markers sp56 and peanut lectin, indicating that it is an acrosomal protein. A GFP-tagged RCC1 domain is present throughout the cytoplasm of transfected CHO cells. However, both GFP-tagged, full-length RC/BTB2 and a GFP-tagged BTB domain localize to vesicles in close proximity to the nuclear membrane, suggesting that the BTB domain might play a role in mediating full-length RC/BTB2 localization. Since RCC1 domains associate with Ran, a small GTPase that regulates molecular trafficking, it is possible that RC/BTB2 plays a role in transporting proteins during acrosome formation

Occurance and Movement of Ground Water in Austin Chalk and Eagle Ford and Ozan Formations at the Superconducting Super Collider (SSC) Site, Ellis County, Texas

This report defines hydrologic properties and describes rates and modes of groundwater flow in weathered and unweathered Austin Chalk and Ozan (lower Taylor Marl) and Eagle Ford Formations at the Superconducting Super Collider (SSC) site in Ellis County, Texas. Fractures probably are the primary conduit of groundwater flow in these formations because unfractured bedrock has low hydraulic conductivity. Distribution and fabric of detrital versus authigenic clays, rather than total clay content, influence the mechanical properties and log-response character of chalk and marl. The middle Austin Chalk typically has lower fracture intensity and abundance, greater ductility, lower porosity, and lower average hydraulic conductivity than the upper and lowermost Austin. Precipitation over upland drainage divides percolates into the ground and moves downward through the soil zone and weathered bedrock to the water table. Water levels in both weathered and unweathered bedrock generally mimic topography, reflecting a dynamic balance between the rate of recharge from precipitation and rates of discharge by evapotranspiration, flow to springs and seeps, and pumping of wells. Groundwater percolates along vertical fractures and horizontal bedding-plane joints and through the more permeable sedimentary layers. Flow paths are generally eastward but bend toward discharge points in springs and seeps in the valley bottoms and stream banks. Vertical movement is retarded by unfractured, low-permeability beds. Only a small amount (<1 percent) of the groundwater moving through the surficial weathered bedrock moves downward into unweathered, low-permeability bedrock. Vertical circulation of groundwater in fractured zones locally is deep. At the eastern side of the SSC, groundwater moves downward from the Ozan into the Austin beneath the upland drainage divides but upward from the Austin through the Ozan beneath stream valleys.Bureau of Economic Geolog

High Interfacial Activity of Polymers &quot;Grafted through&quot; Functionalized Iron Oxide Nanoparticle Clusters

The mechanism by which polymers, when grafted to inorganic nanoparticles, lower the interfacial tension at the oil water interface is not well understood, despite the great interest in particle stabilized emulsions and foams. A simple and highly versatile free radical &quot;grafting through&quot; technique was used to bond high organic fractions (by weight) of poly(oligo(ethylene oxide) monomethyl ether methacrylate) onto iron oxide clusters, without the need for catalysts. In the resulting similar to 1 mu m hybrid particles, the inorganic cores and grafting architecture contribute to the high local concentration of grafted polymer chains to the dodecane/water interface to produce low interfacial tensions of only 0.003 w/v % (polymer and particle core). This &quot;critical particle concentration&quot; (CPC) for these hybrid inorganic/polymer amphiphilic particles to lower the interfacial tension by 36 mN/m was over 30-fold lower than the critical micelle concentration of the free polymer (without inorganic cores) to produce nearly the same interfacial tension. The low CPC is favored by the high adsorption energy (similar to 10(6) k(B)T) for the large similar to 1 mu m hybrid particles, the high local polymer concentration on the particles surfaces, and the ability of the deformable hybrid nanocluster cores as well as the polymer chains to conform to the interface. The nanocluster cores also increased the entanglement of the polymer chains in bulk DI water or synthetic seawater, producing a viscosity up to 35 000 cP at 0.01 s(-1), in contrast with only 600 cP for the free polymer. As a consequence of these interfacial and rheological properties, the hybrid particles stabilized oil-in-water emulsions at concentrations as low as 0.01 w/v %, with average drop sizes down to 30 mu m. In contrast, the bulk viscosity was low for the free polymer, and it did not stabilize the emulsions. The ability to influence the interfacial activity and rheology of polymers upon grafting them to inorganic particles, including clusters, may be expected to be broadly applicable to stabilization of emulsions and foams

The value of multiangle measurements for retrieving structurally and radiatively consistent properties of clouds, aerosols, and surfaces

Passive optical multiangle observations make possible the retrieval of scene structural characteristics that cannot be obtained with, or require fewer underlying assumptions than, single-angle sensors. Retrievable quantities include aerosol amount over a wide variety of surfaces (including bright targets); aerosol microphysical properties such as particle shape; geometrically-derived cloud-top heights and 3-D cloud morphologies; distinctions between polar clouds and ice; and textural measures of sea ice, ice sheets, and vegetation. At the same time, multiangle data are necessary for accurate retrievals of radiative quantities such as surface and top-of-atmosphere albedos, whose magnitudes are governed by structural characteristics of the reflecting media and which involve angular integration over intrinsically anisotropic intensity fields. Measurements of directional radiation streams also provide independent checks on model assumptions conventionally used in satellite retrievals, such as the application of 1-D radiative transfer theory, and provide data required to constrain more sophisticated, 3-D approaches. In this paper, the value of multiangle remote sensing in establishing physical correspondence and self-consistency between scene structural and radiative characteristics is demonstrated using simultaneous observations from instruments aboard NASA\u27s Terra satellite (MISR, CERES, ASTER, and MODIS). Illustrations pertaining to the remote sensing of clouds, aerosols, ice, and vegetation properties are presented

The Value of Multiangle Measurements for Retrieving Structurally and Radiatively Consistent Properties of Clouds, Aerosols, and Surfaces

Passive optical multiangle observations make possible the retrieval of scene structural characteristics that cannot be obtained with, or require fewer underlying assumptions than, single-angle sensors. Retrievable quantities include aerosol amount over a wide variety of surfaces (including bright targets); aerosol microphysical properties such as particle shape; geometrically-derived cloud-top heights and 3-D cloud morphologies; distinctions between polar clouds and ice; and textural measures of sea ice, ice heets, and vegetation. At the same time,multiangle data are necessary for accurate retrievals of radiative quantities such as surface and top-of-atmosphere albedos, whose agnitudes are governed by structural characteristics of the reflecting media and which involve angular integration over intrinsically anisotropic intensity fields. Measurements of directional radiation streams also provide independent checks on model ssumptions conventionally used in satellite retrievals, such as the application of 1-D radiative transfer theory, and provide data required to constrain more sophisticated, 3-D pproaches.In this paper, the value of multiangle remote sensing in establishing physical correspondence and self-consistency between scene structural and radiative characteristics is demonstrated using simultaneous observations from instruments board NASA’s Terra satellite (MISR,CERES, ASTER, and MODIS). Illustrations pertaining to the remote sensing of clouds, aerosols, ice, and vegetation properties are resented. D 2005 Elsevier Inc. All rights reserved.JRC.H.3-Global environement monitorin