Evidence for intact semantic representations in patients with frontal lobe lesions.

Patients with frontal lobe lesions and control participants were assessed on 2 tests of semantic knowledge. In the triadic comparison task, participants were shown all possible triplets of 12 animal names and judged which 2 of each triplet were most alike. In the ordered similarity task, participants rank ordered animals in terms of their similarity to a target animal. For both tasks, semantic structure-- derived from multidimensional scaling techniques-- revealed similar representations in patients with frontal lobe lesions and control participants. Additional pathfinder analyses also produced networks that did not differ between groups. These patients exhibited intact semantic knowledge despite deficits on tests of free recall and verbal fluency that involved the same semantic category and exemplars. Thus, intact representation of semantic knowledge in frontal patients stands in contrast to their marked deficits in strategic retrieval of semantic knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exploring Variability and Performance in a Sub-200-mV Processor

In this study, we explore the design of a subthreshold processor for use in ultra-low-energy sensor systems. We describe an 8-bit subthreshold processor that has been designed with energy efficiency as the primary constraint. The processor, which is functional below V_dd=200 mV, consumes only 3.5 pJ/inst at V_dd=350 mV and, under a reverse body bias, draws only 11 nW at V_dd=160 mV. Process and temperature variations in subthreshold circuits can cause dramatic fluctuations in performance and energy consumption and can lead to robustness problems. We investigate the use of body biasing to adapt to process and temperature variations. Test-chip measurements show that body biasing is particularly effective in subthreshold circuits and can eliminate performance variations with minimal energy penalties. Reduced performance is also problematic at low voltages, so we investigate global and local techniques for improving performance while maintaining energy efficiency.     

Affinity Studies of Hemicyanine Derived Water Soluble Colorimetric Probes with Reactive Oxygen/Nitrogen/Sulfur Species

Peroxynitrite (ONOO^-) is an essential endogenous reactive oxygen species (ROS) generated in mitochondria under various pathological and physiological conditions. An increase in its level in mitochondria is related to numerous diseases. Herein, we report a series of hemicyanine-derived water-soluble colorimetric probes ( 1 – 4 ) and the reactivity of which was studied with various reactive oxygen, nitrogen, and sulfur species. Probes 1 – 4 are formed by conjugating 1,2,3,3-tetramethyl-3H-indolium iodide and 4-hydroxybenzaldehyde or its derivatives through an alkene linkage formed by the Knoevenagel reaction. Oxidative cleavage of the electron-rich double bond of the conjugated hemicyanine dye revealed a discerning affinity of probe 3 towards peroxynitrite among all reactive oxygen species. The rapid change in color of 3 provides a sensitive and selective method for detecting peroxynitrite with a low detection limit of 180 nM. Notably, the water solubility of the probe displays excellent performance for the selective detection of peroxynitrite among ROS and reactive nitrogen (RNS)/sulfur species (RSS). UV-vis, ¹H NMR, and ¹³C NMR spectroscopic data and results from theoretical calculations provide further information on the interaction of peroxynitrite with probe 3 .     

Evaluation of a real-time PCR assay quantifying the ruminal pool size and duodenal flow of protozoal nitrogen

We have recently developed a real-time polymerase chain reaction (PCR) assay to quantify copies of the genes encoding protozoal 18S rRNA. The assay includes procedures for isolating and concentrating protozoal cells from the rumen for use as a standard to convert 18S rRNA gene copies to a biomass basis. The current objectives were to 1) determine the degree of reduction of bacterial contamination in the protozoal standard, 2) determine if protozoal standards derived from ruminal fluid are appropriate for predicting duodenal flows, and 3) evaluate the assay's determined values for protozoal N in the rumen and flowing to the duodenum compared with independent measurements. Our protozoal collection method reduced non-associated bacterial contamination by 33-fold, the contamination of which could otherwise significantly bias RNA (microbial marker) and N percentages of concentrated protozoal fractions. Based on denaturing gradient gel electrophoresis, the use of protozoal cells isolated from ruminal fluid appears appropriate for use in quantitative assays determining protozoal N flow postruminally. Using real-time PCR, protozoal N was determined to be 4.8 and 12.7% of the rumen microbial N pool and 5.9 and 11.9% of the duodenal flow of microbial N on diets containing low (16%) or high (21%) forage neutral detergent fiber, respectively, which were comparable with independent measures and expectations.     

Assessment of iron bioavailability from twenty elite late‐maturing tropical maize varieties using an in vitro digestion/Caco‐2 cell model

An in vitro digestion/Caco‐2 cell model was used to assess iron bioavailability of twenty elite late‐maturing tropical maize varieties grown in three diverse agroecologies in West and Central Africa (WCA). Kernel‐iron concentration of the varieties, averaged across locations, varied from 19.2 to 24.4 mg kg^?1, while mean kernel‐zinc concentration ranged between 19.4 and 24.6 mg kg^?1. Significant differences in iron bioavailability were observed among varieties, but the environment had no significant effect. Mean bioavailable iron ranged between 14% below and 43% above the reference control variety, TZB‐SR. Variety DMR‐LSR‐Y with the highest concentrations of kernel‐iron and ‐zinc of 24–25 mg kg^?1 across the three locations had a similar quantity of bioavailable iron as the reference control, TZB‐SR. In the long run this variety could be potentially effective in reducing iron deficiency because of its high kernel‐iron. The most promising varieties were Mid‐altitude STR synthetic and ACR91SUWAN‐1‐SRC1. They had kernel‐iron and ‐zinc levels of 22–24 mg kg^?1 and bioavailable iron 24–36% higher than the reference control, TZB‐SR. Additional research is necessary to determine if the increases in kernel‐iron concentration and bioavailable iron observed in this study can significantly improve the iron status of individuals in WCA at risk for iron deficiency. Copyright © 2004 Society of Chemical Industry     

The Analysis of the Lubrication Condition and Friction Losses of a Single Acting Cross Head Guide Shoe of a Low Speed Cross Head Diesel Engine: Part II — A Practical Model for the Determination of the Oil Film Thickness

The cross head guide shoe plate of a large diesel engine operates under a large normal force which presses it against the rails between which it executes both axial and transverse motion. In order to ensure the safe operation of an unconventional bearing such as the guide shoe system of the cross head engine, an algorithm that can be used to predict accurately the oil film thickness that can be achieved for all the engine's operating regimes, is invaluable. A solution of the three dimensional form of Reynolds differential equation can provide the requisite oil film thickness. However, with even the availability of very fast computers and large computer storage capacity this solution for a large axial bearing such as the guide shoe becomes impractical in terms of computation time and computer core requirements. This paper describes alternative simplified algorithm for accurate prediction of the oil film thickness developed in the guide shoe bearing at different operating regimes of the engine.     

A simple method for on-chip, sub-femto Farad interconnectcapacitance measurement

In this letter, a sensitive and simple technique for parasitic interconnect capacitance measurement and extraction is presented. This on-chip technique is based upon an efficient test structure design that utilizes only two transistors in addition to the unknown interconnect capacitance to be characterized. No reference capacitor is needed. The measurement itself is also simple; only a dc current meter is required. Furthermore, the extraction methodology employs a self-checking algorithm to verify that the extracted capacitance value is consistent and accurate. The technique is demonstrated by extracting the capacitance of a single crossover between a Metal 1 line and a Metal 2 of 0.44 fF. The resolution limit is dominated by the matching of the minimum sized transistors used for the test structure. We estimate this resolution limit to be about 0.03 fF     

Variability in nanometer CMOS: Impact, analysis, and minimization

Variation is a significant concern in nanometer-scale CMOS due to manufacturing equipment being pushed to fundamental limits, particularly in lithography. In this paper, we review recent work in coping with variation, through both improved analysis and optimization. We describe techniques based on integrated circuit manufacturing, circuit design strategies, and mathematics and statistics. We then go on to discuss trends in this area, and a future technology outlook with an eye towards circuit and CAD-solutions to growing levels of variation in underlying device technologies.     

Long-term follow-up of an EORTC randomized prospective trial comparing intravesical bacille Calmette-Guérin-RIVM and mitomycin C in superficial bladder cancer. EORTC GU Group and the Dutch South East Cooperative Urological Group. European Organisation for Research and Treatment of Cancer Genito-Urinary Tract Cancer Collaborative Group

Posterior laryngeal clefts (PLCs) are described in the literature as rare laryngeal abnormalities. The authors believe type I clefts are much more common than previously reported. In two busy pediatric tertiary care centers, such clefts are the second most common congenital laryngeal finding at rigid endoscopy, second only to laryngomalacia. PLCs frequently present with symptomatology that can be attributed to other common disease processes and are often undiagnosed unless the surgeon maintains a high index of suspicion and specifically examines the posterior glottis by palpation during microlaryngoscopy. This report presents a series of 41 patients with type I PLCs, reviews their subtle and often confusing presenting signs and symptoms, and describes a simple yet reliable method of diagnosis.     

Surveillance for geographic and secular trends in congenital syphilis--United States, 1983-1991

PROBLEM/CONDITION: CDC monitors trends in the occurrence of congenital syphilis (CS) in the United States by using surveillance data sent from state and local health departments. Comparisons of data from this surveillance system with data from the Division of Sexually Transmitted Diseases/HIV Prevention and the Birth Defects Monitoring Program (BDMP) can be used to assess the potential effects of changes in case finding and reporting practices on these trends. REPORTING PERIOD COVERED: This report covers CS surveillance in the United States for the years 1983-1991. DESCRIPTION OF SYSTEM: Cases of CS among infants < 1 year of age and primary and secondary (P&S) syphilis among women are reported quarterly to CDC. The BDMP is a CDC national surveillance system that samples hospital discharge data on U.S. births. RESULTS: During the period 1983-1991, 12,151 CS cases were reported. Before 1988, regional CS incidence increased 35%-131% annually. Larger increases occurred in the Northeast (578%) in 1989 and in the South (178%), Midwest (244%), and West (777%) in 1990. Within regions, these larger increases were temporally related to increases in P&S syphilis in women and changes to a more sensitive CS case definition. INTERPRETATION: CS incidence has increased since 1983 in all regions of the United States. Increases since 1988 reflect both changes in surveillance reporting practices--the surveillance case definition for CS was changed in 1988 and further revised in 1989--and a true increase in incidence. ACTIONS TAKEN: These data indicate where CS prevention efforts need to be targeted. To facilitate reporting of CS cases, CDC has developed a) a shorter form for reporting cases of CS after 1991 and b) a software package for use by state and local health departments to enter and analyze CS data.