Lehigh University

About: Lehigh University is a education organization based out in Bethlehem, Pennsylvania, United States. It is known for research contribution in the topics: Catalysis & Fracture mechanics. The organization has 12684 authors who have published 26550 publications receiving 770061 citations.

Linking planktonic diatoms and climate change in the large lakes of the Yellowstone ecosystem using resource theory

Abstract: Resource-based physiology of the eight important planktonic diatom species in the large lakes of the Yellowstone region can be used to explain their relative abundances and seasonal changes. The diatoms are ranked along resource ratio gradients according to their relative abilities to grow under limitation by Si, N, P, and light. Hypotheses based on resource physiology can be integrated with observations on seasonal changes in diatom assemblages to explain the present distributions of diatoms and to test the causal factors proposed to explain diatom distributions over the Holocene. Knowledge of the limnology of these lakes and process-oriented physiology provide the basis for a more detailed interpretation of the paleorecord and a firmer basis for landscape-level transfer functions for fine-scale climate reconstruction.

Development and Validation of the Academic Competence Evaluation Scales

Abstract: The purpose of this study was to clarify the construct of academic competence and develop a valid teacher rating instrument to assess this construct. A 95-item pilot scale, the Academic Competence Evaluation Scales (ACES), was developed to assess the theoretical components (i.e., academic skills, study skills, academic motivation, interpersonal skills, and academic self-concept) hypothesized to contribute to the construct of academic competence. The ACES was administered to 56 teachers who rated 300 students in Grades 1 through 6. To explore convergent and discriminant validity, 13 teachers completed ratings of social skills, problem behaviors, and academic competence (as measured by the Social Skills Rating System; SSRS) for 60 students. In addition, 32 students completed the Iowa Test of Basic Skills (ITBS), a popular measure of academic achievement. Teacher feedback, item Importance ratings, item-ITBS correlations, and the results of an exploratory factor analysis were used to eliminate 35 items from t...

Synchronous anatexis, metamorphism, and rapid denudation at Nanga Parbat (Pakistan Himalaya)

Abstract: The Nanga Parbat-Haramosh massif of the western Himalaya is a north-trending half-window of Indian crust that provides spectacular exposures of Precambrian basement gneisses that have been overprinted by Himalayan metamorphism. We report here petrologic data and U/Pb dates on zircon and monazite which document that Nanga Parbat gneisses underwent a Pliocene-Pleistocene episode of high-grade metamorphism and anatexis during an interval in which the Nanga Parbat massif was undergoing rapid denudation at mean rates of ∼5 mm/yr. We speculate that by initiating decompression melting, this denudation may be at least partly responsible for the anatexis and high-grade metamorphism.

Blocking and Routing Discrete Solitons in Two-Dimensional Networks of Nonlinear Waveguide Arrays

Abstract: It is shown that discrete solitons can be navigated in two-dimensional networks of nonlinear waveguide arrays. This can be accomplished via vector interactions between two classes of discrete solitons: signals and blockers. Discrete solitons in such two-dimensional networks can exhibit a rich variety of functional operations, e.g., blocking, routing, logic functions, and time gating.

A framework for understanding Latent Semantic Indexing (LSI) performance

Abstract: In this paper we present a theoretical model for understanding the performance of Latent Semantic Indexing (LSI) search and retrieval application. Many models for understanding LSI have been proposed. Ours is the first to study the values produced by LSI in the term by dimension vectors. The framework presented here is based on term co-occurrence data. We show a strong correlation between second-order term co-occurrence and the values produced by the Singular Value Decomposition (SVD) algorithm that forms the foundation for LSI. We also present a mathematical proof that the SVD algorithm encapsulates term co-occurrence information.