1,210 research outputs found

    Use of remote sensing techniques for geological hazard surveys in vegetated urban regions

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    The feasibility of using aerial photography for lithologic differentiation in a heavily vegetated region is investigated using multispectral imagery obtained from LANDSAT satellite and aircraft-borne photography. Delineating and mapping of localized vegetal zones can be accomplished by the use of remote sensing because a difference in morphology and physiology results in different natural reflectances or signatures. An investigation was made to show that these local plant zones are affected by altitude, topography, weathering, and gullying; but are controlled by lithology. Therefore, maps outlining local plant zones were used as a basis for lithologic map construction

    Impacts of dreissenid mussel invasions on chlorophyll and total phosphorus in 25 lakes in the USA

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94854/1/fwb.12050.pd

    Delineation of geological problems for use in urban planning

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    Activities of the University of Alabama in support of state and local planning commissions are reported. Demonstrations were given of the various types of remotely sensed images available from U-2, Skylab, and LANDSAT; and their uses and limitations were discussed. Techniques to be used in determining flood prone areas were provided for environmental studies. A rapid, inexpensive method for study was developed by which imagery is copied on 35 mm film and projected on existing topographic maps for measuring delta volume and growth

    Electrostatics in wind-blown sand

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    Wind-blown sand, or "saltation," is an important geological process, and the primary source of atmospheric dust aerosols. Significant discrepancies exist between classical saltation theory and measurements. We show here that these discrepancies can be resolved by the inclusion of sand electrification in a physically based saltation model. Indeed, we find that electric forces enhance the concentration of saltating particles and cause them to travel closer to the surface, in agreement with measurements. Our results thus indicate that sand electrification plays an important role in saltation.Comment: 4 journal pages, 5 figures, and supplementary material. Article is in press at PR

    N4WBP5A (Ndfip2), a Nedd4-interacting protein, localizes to multivesicular bodies and the Golgi, and has a potential role in protein trafficking

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    N4WBP5A (Ndfip2) belongs to an evolutionarily conserved group of Nedd4-interacting proteins with two homologues in mammalian species. We have previously shown that N4WBP5A expression in Xenopus oocytes results in increased cell-surface expression of the epithelial sodium channel. N4WBPs are characterized by one or two amino terminal PPxY motifs and three transmembrane domains. Here we show that both PPxY motifs of N4WBP5A mediate interaction with WW domains of Nedd4 and that N4WBP5A can physically interact with the WW domains of several Nedd4-family proteins. N4WBP5A is ubiquitinated and ubiquitination does not significantly affect the turnover of N4WBP5A protein. Ubiquitination of N4WBP5A is enhanced by Nedd4 and Nedd4-2 expression. N4WBP5A localizes to the Golgi, vesicles associated with the Golgi complex and to multivesicular bodies. We show that the ectopic expression of N4WBP5A inhibits receptor-mediated endocytosis of labelled epidermal growth factor. N4WBP5A overexpression inhibits accumulation of EGF in large endocytic/lysosomal vesicles suggestive of a role for N4WBP5A in protein trafficking. We propose that N4WBP5A acts as an adaptor to recruit Nedd4 family ubiquitin-protein ligases to the protein trafficking machinery.Linda M. Shearwin-Whyatt, Darren L. Brown, Fiona G. Wylie, Jennifer L. Stow and Sharad Kuma

    DATA REPORT

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    INTRODUCTION Ocean Drilling Program (ODP) Leg 116 cored the distal part of the Bengal Fan at three closely spaced sites (717-719). The recovered sediments consisted dominantly of turbidites that varied in thickness between a few centimeters and 2 m or more. A number of different facies have been identified in the sequence and are described by Stow et al. (this volume). Representative examples of these facies types were selected and sampled for grain-size analysis. The results of these analyses are tabulated in this data report. METHODS Sediment samples of approximately 2-g dry weight were placed in 50-cm 3 beakers and disaggregated in a solution of 10% Calgon. To assist in complete disaggregation of the sediment, an ultrasonic probe was used for approximately 2 min. on each sample. Suspended sample concentrations were of the order of 20 g/L. The prepared suspensions were stored in 150-cm 3 plastic bottles. The grain-size analyses were performed by laser diffraction using Malvern particle sizers, models 35OOD and 2600C. The principles of particle-size analysis by laser diffraction are described by The Malvern laser-sizers consist of a laser source, beam expander, sample chamber, focusing lens, ring detector, and a microcomputer. In this study each analysis used a 100-mm focal length focusing lens yielding data consisting of 15 size classes between 1.9 and 188 µm. A percentage of sample outside of this range above and below these limits is also given. The grain-size distribution was computed using the model-independent program option. The sample suspension is introduced into a small ultrasonic tank from which the suspension is continuously pumped through the sample chamber in the path of the laser. The main attraction of laser diffraction analysis for this study was the relatively small sample size required for analysis. Only 2-5 cm 3 of the prepared suspensions are required for each analysis. Several repeat analyses can therefore be performed even on very small original samples. An additional advantage is the speed with which analyses can be performed, generally about 10 min per sample. For many of the samples, duplicate or triplicate analyses were performed to test the reproducibility of the results. 1 Cochran, J. R., Stow, D.A.V., et al., 1990. Proc. ODP, Sci. Results, 116: College Station, TX (Ocean Drilling Program)

    Patterns of Vertebrate Diversity and Protection in Brazil

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    Most conservation decisions take place at national or finer spatial scales. Providing useful information at such decision-making scales is essential for guiding the practice of conservation. Brazil is one of the world’s megadiverse countries, and consequently decisions about conservation in the country have a disproportionate impact on the survival of global biodiversity. For three groups of terrestrial vertebrates (birds, mammals, and amphibians), we examined geographic patterns of diversity and protection in Brazil, including that of endemic, small-ranged, and threatened species. To understand potential limitations of the data, we also explored how spatial bias in collection localities may influence the perceived patterns of diversity. The highest overall species richness is in the Amazon and Atlantic Forests, while the Atlantic Forest dominates in terms of country endemics and small-ranged species. Globally threatened species do not present a consistent pattern. Patterns for birds were similar to overall species richness, with higher concentrations of threatened species in the Atlantic Forest, while mammals show a more generalized pattern across the country and a high concentration in the Amazon. Few amphibians are listed as threatened, mostly in the Atlantic Forest. Data deficient mammals occur across the country, concentrating in the Amazon and southeast Atlantic Forest, and there are no data deficient birds in Brazil. In contrast, nearly a third of amphibians are data deficient, widespread across the country, but with a high concentration in the far southeast. Spatial biases in species locality data, however, possibly influence the perceived patterns of biodiversity. Regions with low sampling density need more biological studies, as do the many data deficient species. All biomes except the Amazon have less than 3% of their area under full protection. Reassuringly though, rates of protection do correlate with higher biodiversity, including higher levels of threatened and small-ranged species. Our results indicate a need for expanded formal protection in Brazil, especially in the Atlantic forest, and with an emphasis on fully protected areas
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