The paddlefish (Polyodon spathula) is a primitive fish that is found in several large rivers of the Mississippi River drainage. The status of paddlefish populations in these large rivers is debatable due to several factors including habitat loss, contaminants and commercial fishing (Sparrowe 1986; Gundersen and Pearson 1992). The roe of female paddlefish is used to make domestic caviar and comm...

This article examines the impact of the New York court decision, Rivers v. Katz, which in June 1986 dramatically changed the state procedure for responding to involuntarily committed psychiatric patients who formally refused psychopharmacologic treatment. The court rejected the medically administered review process that had been used to respond to involuntarily committed psychiatric patients wh...

Here we provide global estimates of the seasonal flux of sediment, on a river-by-river basis, under modern and prehuman conditions. Humans have simultaneously increased the sediment transport by global rivers through soil erosion (by 2.3 +/- 0.6 billion metric tons per year), yet reduced the flux of sediment reaching the world's coasts (by 1.4 +/- 0.3 billion metric tons per year) because of re...

Erosion by flowing water is one of the major forces shaping the surface of Earth. Studies in the last decade have shown, in particular, that the drainage region of rivers, where water is collected, exhibits scale invariant features characterized by exponents that are the same for rivers around the world. Here we show that from the data obtained by the MOLA altimeter of the Mars Global Surveyor ...

Contents 1. Introduction 2. Primary stage of the occurrence of river systems 3. Development of rivers in the Paleozoic 4. Change of hydrography in the Mesozoic 5. Modification of river systems in the Cenozoic 6. Water balance change of the river basins in the Mesozoic-Cenozoic 7. Features of dynamics of the hydrographic network and channel deformations 8. Hydrography and water resources of the ...

We have used a variety of approaches to introduce quantitative concepts into our introductory geology classes, some of which rely on using case studies of local rivers to improve student interest and appreciation of quantitative methods in scientific problem solving. Fortunately, there are rivers in most parts of the country, so these approaches are easily transferable and applicable in many ar...

In this paper, we dene the concepts of compatibility between twofuzzy subsets on Q, the set of states of a max- min general fuzzy automatonand transitivity in a max-min general fuzzy automaton. We then construct auniform structure on Q, and dene a topology on it. We also dene the conceptof semi-uniform structures on a nonempty set X and construct a semi-uniformstructure on the set of states of ...

The direct and secondary effects of rapidly changing climate caused large rivers draining the Atlantic passive margin to incise quickly into bedrock beginning about 35,000 years ago. Measured in samples from bedrock fluvial terraces, 10-beryllium shows that both the Susquehanna and Potomac Rivers incised 10- to 20-meter-deep gorges along steep, convex lower reaches during the last glacial cycle...

Taking into account the importance of Lake Sevan and Lake Sevan basin’s rivers for Armenian economy, the main goals of our investigations were the documentation of water quality and the biodiversity of invertebrates developed in Lake Sevan basin’s rivers and selected tributaries. Moderately satisfied ecological condition for the biodiversity of Lake Sevan basin’s rivers has been established, an...

Mountain landscapes have dynamic climates that, together with tectonic processes, influence their topographic evolution. Spatial and temporal variations in rainfall are ubiquitous these settings as orographic precipitation patterns evolve climate change topography. Despite important implications such changes for river incision, is understudied. Here, we investigate how pattern should affect bot...