2,695 research outputs found
Ch. 22 Linking Electoral and Partisan Participation [pre-print] from The Oxford Handbook of Political Participation
VLSI Performance Comparison of Banyan and Crossbar Communications Networks
The performance characteristics of banyan and crossbar communications networks are compared in a VLSI environment where it is assumed that the entire network resides on a single VLSI chip. A high level model of the space (area) and time (delay) requirements for these networks is developed and relative performance comparisons are made based on space-time product measure. The results differed significantly from those obtained with more traditional analyses which are usually based on switch aggregate comparisons. These analyses usually lead to the banyan as being the preferable network due to the N log2 N (for banyan) versus N^2 (for crossbar) switch growth. The conclusion of this path is that using a space-time product performance measure, and roughly current technology parameters. Under these conditions the crossbar is probably preferable due to its greater conceptual and implementation simplicity
Studying the interplay of party support and turnout [pre=print]
This chapter builds on earlier work (Franklin 2022) that explored the mechanism tying party choice at the individual level to election-level turnout rates. It employs CSES surveys from 28 countries over the course of 3 to 5 elections. It builds on past findings that used error correction models to confirm the role of negative feedback in maintaining equilibrium rates of party support; and elaborates on a parallel mechanism that helps to maintain an equilibrium level of turnout, through voter reactions to evolving levels of electoral competition. The chapter treats voter turnout, voterparty policy congruence, and party support as aspects of a single dynamic process at the party and birthyear-cohort levels, also helping to validate the dynamic account of turnout processes suggested in earlier work
Online appendix for “Studying the interplay of party support and turnout; Chapter 5 in The Problem of Governing: essays for Richard Rose edited by Michael Keating, Ian McAllister, Edward Page and Guy Peters. London: Palgrave Macmillan
Investigation of aerobic and anaerobic microflora and volatile fatty acids in the jejunum, ileum, and cecum of the weanling pig
Experiment 1. The purpose of this experiment was to characterize aerobic and anaerobic microflora, volatile fatty acids (VFA) , pH, dry matter, and lactate (L+ and D-) concentrations in the jejunum, ileum, and cecum of pigs weaned at 17 or 24 d of age. Pigs were surgically fitted with T-cannulas in either the jejunum, ileum, or cecum at approximately 14 d of age. After a 3 d recovery period, pigs were randomly assigned a weaning age and intestinal and fecal contents were sampled at 17, 20, 24, 27, 31, and 34 d of age. Noncannulated littermates were also sacrificed at weaning with intestinal, fecal, and blood samples taken to determine effects of carmulation. No differences (P \u3e .05) were noted in serum cortisol or microbial populations between cannulated and noncannulated pigs. Dry matter percentage and pH levels were higher (P \u3c .05) in the cecum than in the ileum or jejunum. Unweaned pigs maintained higher (P \u3c .05) lactobacilli populations than weaned pigs; however, populations declined (P \u3c .05) in both groups postweaning. Fecal populations of E. coli and lactobacilli declined (P \u3c .05) postweaning; whereas, fecal bifidobacteria populations increased (P \u3c .05) regardless of weaning age. VFA levels were higher (P \u3c .05) in the cecum versus the jejunum or ileum and lactate (L+) tended (P \u3c .07) to be higher in the jejunum and ileum versus the cecum. Weaning and weaning age were determined to have significant effects on microflora and VFA concentrations.
Experiment 2. The purpose of this experiment was to investigate the effect of dietary galactose on aerobic and anaerobic microflora, volatile fatty acids (VFA), pH, dry matter, and lactate (L+ and D-) concentrations in the ileum and cecum of weanling pigs. Pigs were surgically fitted with T-carmulas in either the ileum or cecum at approximately 14 d of age. After a 4 d recovery period, pigs were weaned at 18 d of age and randomly assigned either a control or treatment diet.The control diet was a phase starter diet based on corn starch and the treatment diet was similar except for galactose replacing a portion (13%) of the corn starch. The diets were mixed with water and offered twice daily. Intestinal and fecal samples were obtained at 18,21, 25,28, 32, and 35 d of age. Digesta pH increased (P \u3c .05) following weaning regardless of collection site. Dry matter percentage was higher (P \u3c .01) in cecal contents compared to ileal contents. Galactose did not affect populations of microflora or VFA concentrations, except for a tendency (P \u3c .08) to prolong E. coli populations postweaning and to decrease acetate production. Lactate (L+) concentrations were greater (P \u3c .05) in ileal versus cecal contents. Results indicate that galactose fed at this level incurs only minimal changes in microflora and VFA concentrations in the ileum and cecum of weanling pigs
NCUBE User Activity Academic Year 1988/89
This document summarizes usage and activities associated with the NCUBE computer system. The system is located within the Computer and Communications Research Center on the 3rd floor of Bryan Hall, School of Engineering and Applied Science, Washington University, St. Louis, Missouri. We begin with a brief review of the machine\u27s hardware characteristics and then proceed to reviewing user activities
A PCR-Based Method of Detection and Differentiation of K88 Escherichia coli
The objective of this study was to develop a Polymerase Chain Reaction (PCR)-based method to detect and differentiate between Escherichia coli possessing genes for the expression of three antigenic variants of the fimbrial adhesin K88 (K88ab, K88ac, and K88ad). Five primers were designed that allowed detection of K88 E. coli, regardless of antigenic variant, as well as the separate detection of ab, ac, and ad variants. Primers AM005 and AM006 were 21 base-pair oligomers that corresponded to a region of the K88 operon that is common to all 3 antigenic variants. Primers MF007, MF008, and MF009 were 24 base-pair oligomers that matched variable regions specific to ab, ac, and ad variants, respectively. Using primers AM005 and AM006, a PCR product was obtained that corresponded to a 764 base-pair region within the large structural subunit of the K88 operon common to all 3 antigenic variants. Primer AM005 used with either MF007, MF008, or MF009 produced PCR products approximately 500 base-pairs in length from within the large structural subunit of the K88 operon of the 3 respective antigenic variants. Fragments were identified by rates of migration on a 1% agarose gel relative to each other as well as to fragments derived from BstEII-digested lambda DNA. This PCR-based method compared well with ELISA and Western Blot tests for the ability to differentiate between the antigenic variants. K88 E. coli were differentiated from among laboratory strains and detected in ileal samples taken from cannulated pigs challenged with a known K88 variant. K88 E. coli were also detected from fecal swabs taken from newly weaned pigs, thus confirming that this PCR-based test could provide a convenient clinical assay for the detection of K88 E. coli. Detection and differentiation of K88 E. coli using general and specific primers were successful. PCR methods of detection should permit identification of K88 antigenic variants regardless of the level of expression of the antigen
Estimating Tropical Forest Structure Using a Terrestrial Lidar
Forest structure comprises numerous quantifiable biometric components and characteristics, which include tree geometry and stand architecture. These structural components are important in the understanding of the past and future trajectories of these biomes. Tropical forests are often considered the most structurally complex and yet least understood of forested ecosystems. New technologies have provided novel avenues for quantifying biometric properties of forested ecosystems, one of which is LIght Detection And Ranging (lidar). This sensor can be deployed on satellite, aircraft, unmanned aerial vehicles, and terrestrial platforms. In this study we examined the efficacy of a terrestrial lidar scanner (TLS) system in a tropical forest to estimate forest structure. Our study was conducted in January 2012 at La Selva, Costa Rica at twenty locations in a predominantly undisturbed forest. At these locations we collected field measured biometric attributes using a variable plot design. We also collected TLS data from the center of each plot. Using this data we developed relative vegetation profiles (RVPs) and calculated a series of parameters including entropy, Fast Fourier Transform (FFT), number of layers and plant area index to develop statistical relationships with field data.We developed statistical models using a series of multiple linear regressions, all of which converged on significant relationships with the strongest relationship being for mean crown depth (r2 = 0.88, p \u3c 0.001, RMSE = 1.04 m). Tree density was found to have the poorest significant relationship (r2 = 0.50, p \u3c 0.01, RMSE = 153.28 n ha-1). We found a significant relationship between basal area and lidar metrics (r2 = 0.75, p \u3c 0.001, RMSE = 3.76 number ha-1). Parameters selected in our models varied, thus indicating the potential relevance of multiple features in canopy profiles and geometry that are related to field-measured structure. Models for biomass estimation included structural canopy variables in addition to height metrics. Our work indicates that vegetation profiles from TLS data can provide useful information on forest structure
Performance Evaluation of Hierarchical Simulation Systems
Simulation needs for design analysis, verification, and testing have become increasingly important as integrated circuit size and complexity have grown. One technique for dealing with this problem is to utilize hierarchical modeling and simulation methods. This paper presents an analysis of hierarchical simulation systems in terms of two performance measures; the number of statements required for describing a system, and the simulation system execution time associated with a given hierarchical system representation. A model of hierarchical simulation system performance is developed. The performance of the hierarchical simulator, lsim2, is examined through its use on the set of benchmark circuits and the results discussed in light of model predictions
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