A Stream Calculus of Bottomed Sequences for Real Number Computation

AbstractA calculus XPCF of 1⊥-sequences, which are infinite sequences of {0,1,⊥} with at most one copy of bottom, is proposed and investigated. It has applications in real number computation in that the unit interval I is topologically embedded in the set Σ⊥,1ω of 1⊥-sequences and a real function on I can be written as a program which inputs and outputs 1⊥-sequences. In XPCF, one defines a function on Σ⊥,1ω only by specifying its behaviors for the cases that the first digit is 0 and 1. Then, its value for a sequence starting with a bottom is calculated by taking the meet of the values for the sequences obtained by filling the bottom with 0 and 1. The validity of the reduction rule of this calculus is justified by the adequacy theorem to a domain-theoretic semantics. Some example programs including addition and multiplication are shown. Expressive powers of XPCF and related languages are also investigated

Cyclic AMP modulation and its effects on chemo-resistant colon cancer cell proliferation and survival

One of the major problems associated with colorectal cancer is resistance to cytotoxic chemotherapeutic agents. New strategies are therefore required to inhibit colon cancer proliferation and survival. Here I use modulators of cAMP pathways, including inhibitors of phosphodiesterase 4 (PDE4) enzymes, which are under clinical development for other disease states, to inhibit the breakdown of cAMP and to assess the effects of raising intracellular cAMP on colon cancer proliferation and survival. I found that some chemo-resistant cancer cells are addicted to keeping low cAMP in PDE4 regulated compartments, and modulation of this pool causes G1/S-phase arrest and apoptosis. I also show that PDE4 controlled cAMP negatively regulates the PI 3-Kinase/Akt pathway, which some cells are addicted to for survival. Furthermore, I investigated the expression and role of PDE4 enzymes in metastatic colon cancer cells and assessed the effects of modulating their expression on survival. Also, I used a clinically relevant analogue of forskolin, an agonist of adenylyl cyclase, to examine the general effect on growth of epithelial cancer cell lines. This work might provide new strategies for the treatment of advanced colon cancer

Program and Abstracts of the Annual Meeting of the Georgia Academy of Science, 2012

The annual meeting of the Georgia Academy of Science took place March 23-34, 2012, at Kennesaw State University, Kennesaw, Georgia. Presentations were provided by members of the Academy who represented the following sections: I. Biological Sciences II Chemistry III. Earth & Atmospheric Sciences IV. Physics, Mathematics, Computer Science, Engineering & Technology V. Biomedical Sciences VI. Philosophy & History of Science VII. Science Education VIII. Anthropology

Women in Science 2012

The summer of 2012 saw the number of students seeking summer research experiences with a faculty mentor reaching record levels. In total, 179 students participated in the Summer Undergraduate Research Fellows (SURF) program, involving 59 faculty mentor-advisors, representing all of the Clark Science Center’s fourteen departments and programs.https://scholarworks.smith.edu/clark_womeninscience/1011/thumbnail.jp

What Is Cognitive Psychology?

What Is Cognitive Psychology? identifies the theoretical foundations of cognitive psychology—foundations which have received very little attention in modern textbooks. Beginning with the basics of information processing, Michael R. W. Dawson explores what experimental psychologists infer about these processes and considers what scientific explanations are required when we assume cognition is rule-governed symbol manipulation. From these foundations, psychologists can identify the architecture of cognition and better understand its role in debates about its true nature. This volume offers a deeper understanding of cognitive psychology and presents ideas for integrating traditional cognitive psychology with more modern fields like cognitive neuroscience.Publishe

Stochastic and deterministic models for dense granular flow

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2008.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 245-254).Granular materials such as sand or gravel surround us everyday and yet remain poorly understood. In this thesis, two models are developed for dense granular flow, each capable of predicting flows with accuracy in multiple environments. The models are based on differing perspectives of grain-level dynamics, with one deriving flow from a stochastic mechanism and the other from a deterministic deformation law. The Stochastic Flow Rule (SFR): This work models granular flow as a sequence of localized collective grain displacements. As in the Spot Model for drainage (Bazant 2001), grain clusters move as dictated by "spots" which travel through the material as biased random-walkers. The SFR derives spot motion directly from the material stresses, thus generalizing and extending the Spot Model beyond drainage to any quasi-2D geometry with a computable stress field. Limit-State Mohr-Coulomb Plasticity is used to approximate the stress profile in a slow flowing granular assembly. The SFR then describes quantitatively how to convert the slip-line field and stresses into the necessary parameters to fully define a spot's random trajectory through the material and generate a steady flow profile. Results are compared to known flow data. Nonlinear Granular Elasto-Plasticity: This work models granular deformation at the meso-scale as a deterministic consequence of the local stresses and state parameters. Recently proposed models for granular elasticity (Jiang and Liu 2003) and plastic flow (Jop et al. 2006) are combined into one universal granular continuum law, capable of predicting both flowing regions and stagnant zones simultaneously in any arbitrary 3D flow geometry.(cont.) The unification is performed by first motivating physically, and then implementing a Kroner-Lee elasto-plastic decomposition. The model is then numerically solved in multiple geometries and results are compared to experiments and discrete simulations.by Kenneth Norman Kamrin.Ph.D

Aeronautical engineering: A special bibliography, supplement 44

This special bibliography lists 249 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1974

The deep space network

The objectives, functions, and organization of the Deep Space Network are summarized along with deep space station, ground communication, and network operations control capabilities. Mission support of ongoing planetary/interplanetary flight projects is discussed with emphasis on Viking orbiter radio frequency compatibility tests, the Pioneer Venus orbiter mission, and Helios-1 mission status and operations. Progress is also reported in tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations