2,786 research outputs found
The Impact of Pictorial Display on Operator Learning and Performance
The effects of pictorially displayed information on human learning and performance of a simple control task were investigated. The controlled system was a harmonic oscillator and the system response was displayed to subjects as either an animated pendulum or a horizontally moving dot. Results indicated that the pendulum display did not effect performance scores but did significantly effect the learning processes of individual operators. The subjects with the pendulum display demonstrated more vertical internal models early in the experiment and the manner in which their internal models were tuned with practice showed increased variability between subjects
Legal Ethics
The most important event in legal ethics in the past year was the adoption of Florida\u27s Rules of Professional Conduct (hereinafter referred to as the Florida Rules or Rules )
γ-Zeins are essential for endosperm modification in quality protein maize
Essential amino acids like lysine and tryptophan are deficient in corn meal because of the abundance of zein storage proteins that lack these amino acids. A naturalmutant, opaque 2 (o2) causes reduction of zeins,anincreaseofnonzeinproteins,andas a consequence, adoubling of lysine levels.However, o2’s soft inferior kernels precluded its commercial use. Breeders subsequently overcame kernel softness, selectingseveral quantitative loci (QTLs), called o2modifiers,without losing the high-lysine trait. These maize lines are known as “quality protein maize” (QPM). One of the QTLs is linked to the 27-kDa γ-zein locus on chromosome 7S. Moreover, QPM lines have 2- to 3-fold higher levels of the 27-kDa γ-zein, but the physiological significance of this increase is not known. Because the 27- and 16-kDa γ-zein genes are highly conserved in DNA sequence, we introduced a dominant RNAi transgene into a QPM line (CM105Mo2) to eliminate expression of them both. Elimination of γ-zeins disrupts endosperm modification by o2 modifiers, indicating their hypostatic action to γ-zeins. Abnormalities in protein body structure and their interaction with starch granules in the F1 with Mo2/+; o2/o2; γRNAi/+ genotype suggests that γ-zeins are essential for restoring protein body density and starch grain interaction in QPM. To eliminate pleiotropic effects caused by o2, the 22-kDa α-zein, γ-zein, and β-zein RNAis were stacked, resulting in protein bodies forming as honeycomb-like structures. We are unique in presenting clear demonstration that γ-zeins play a mechanistic role in QPM, providing a previously unexplored rationale for molecular breeding
Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study
This is the final version of the article. Available from BioMed Central via the DOI in this record.BACKGROUND: Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affected methemoglobin levels during pregnancy. We also examined whether differences in water use practices existed among pregnant women based on household drinking water source of private vs. public supply. METHODS: A longitudinal study of 357 pregnant women was conducted. Longitudinal regression models were used to examine changes and predictors of the change in methemoglobin levels over the period of gestation. RESULTS: Pregnant women showed a decrease in methemoglobin levels with increasing gestation although <1% had levels above the physiologic normal of 2% methemoglobin, regardless of the source of their drinking water. The multivariable analyses did not show a statistically significant association between methemoglobin levels and the estimated nitrate intake from tap water among pregnant women around 36 weeks gestation (β = 0.046, p = 0.986). Four women had tap water nitrate levels above the MCL of 10 mg/L. At enrollment, a greater proportion of women who reported using water treatment devices were private wells users (66%) compared to public system users (46%) (p < 0.0001). Also, a greater proportion of private well users (27%) compared to public system users (13%) were using devices capable of removing nitrate from water (p < 0.0001). CONCLUSION: Pregnant women potentially exposed to nitrate levels primarily below the MCL for drinking water were unlikely to show methemoglobin levels above the physiologic normal. Water use practices such as the use of treatment devices to remove nitrates varied according to water source and should be considered in the assessment of exposure to nitrates in future studies
Cruise Report: EX-17-11 Gulf of Mexico 2017 (ROV and Mapping)
From November 29, 2017 to December 21, 2017, the NOAA Office of Ocean Exploration and Research (OER) and partners conducted a telepresence-enabled ocean exploration expedition on NOAA Ship Okeanos Explorer to collect critical baseline data and information and to improve knowledge about unexplored and poorly understood deepwater areas of the Gulf of Mexico. The Gulf of Mexico 2017 (EX-17-11) expedition was part of a series of expeditions between 2017 and 2018 that explored deepwater areas in the Gulf of Mexico. During 23 days at sea, 17 remotely operated vehicle (ROV) dives were completed off the Western Florida Escarpment and in the central and western Gulf of Mexico. Over 93 hours of ROV bottom time were logged at depths between 300 and 2,321 meters. Over 20,000 square kilometers of seafloor were mapped. A total of 138 biological and 11 geological samples were collected. The expedition gathered over 280,000 live video views worldwide and the OER website received over 35,600 views. A core onshore science team of over 80 participants from around the world collaborated and supported real-time ocean exploration science. The data associated with this expedition have been archived and are publicly available through the NOAA Archives
Natural enemies of Myzocallis coryli (Hom.: Aphididae) in Oregon hazelnut orchards
Fifty-five species of aphidophagous predators were found in a survey of the hazelnut orchards of western Oregon. Important predators of the filbert aphid, Myzocallis coryli (Goetze), include: Adalia bipunctata (L.), Cycloneda polita Csy. (Coleoptera: Coccinellidae); Deraeocoris brevis (Uhler) (Hemiptera: Miridae); and species of Hemerobius and Chrysopa (Neuroptera: Hemerobiidae and Chrysopidae).One parasitoid, Mesidiopsis sp. (Hymenoptera: Aphelinidae) was found to attack the aphid. In addition, one pathogenic fungus, Triplosporium fresenii (Nowakowski) Batko (Entomophthorales: Entomophthoraceae) was found to cause an epizootic in an orchard with a high aphid density
CN and HCN in Dense Interstellar Clouds
We present a theoretical investigation of CN and HCN molecule formation in
dense interstellar clouds. We study the gas-phase CN and HCN production
efficiencies from the outer photon-dominated regions (PDRs) into the opaque
cosmic-ray dominated cores. We calculate the equilibrium densities of CN and
HCN, and of the associated species C+, C, and CO, as functions of the
far-ultraviolet (FUV) optical depth. We consider isothermal gas at 50 K, with
hydrogen particle densities from 10^2 to 10^6 cm^-3. We study clouds that are
exposed to FUV fields with intensities 20 to 2*10^5 times the mean interstellar
FUV intensity. We assume cosmic-ray H2 ionization rates ranging from 5*10^-17
s^-1, to an enhanced value of 5*10^-16 s^-1. We also examine the sensitivity of
the density profiles to the gas-phase sulfur abundance.Comment: Accepted for publication in ApJ, 33 pages, 8 figure
Commentary: the role of cytologic analysis of voided urine in the work-up of asymptomatic microhematuria
Microscopic hematuria is a common finding in patients presenting to both primary care doctors as well as urologists. Sources of microscopic hematuria include infection, stones, inflammatory disorders as well as cancer of the genitourinary tract, particularly urothelial cancer. A primary focus in the urologic workup of hematuria is to rule out cancer. This is done using radiographic studies as well as procedures such as cystoscopy and bladder biopsy. As the authors state in their article titled "The utility of serial urinary cytology in the initial evaluation of the patient with microscopic hematuria", cytologic analysis of voided urine, though attractive due to its noninvasive nature, has been found to have the neither the sensitivity, cost-effectiveness, nor the ease of administration necessary to replace more invasive diagnostics in the evaluation of microscopic hematuria
Rotation Measure Synthesis of Galactic Polarized Emission with the DRAO 26-m Telescope
Radio polarimetry at decimetre wavelengths is the principal source of
information on the Galactic magnetic field. The diffuse polarized emission is
strongly influenced by Faraday rotation in the magneto-ionic medium and
rotation measure is the prime quantity of interest, implying that all Stokes
parameters must be measured over wide frequency bands with many frequency
channels. The DRAO 26-m Telescope has been equipped with a wideband feed, a
polarization transducer to deliver both hands of circular polarization, and a
receiver, all operating from 1277 to 1762 MHz. Half-power beamwidth is between
40 and 30 arcminutes. A digital FPGA spectrometer, based on commercially
available components, produces all Stokes parameters in 2048 frequency channels
over a 485-MHz bandwidth. Signals are digitized to 8 bits and a Fast Fourier
Transform is applied to each data stream. Stokes parameters are then generated
in each frequency channel. This instrument is in use at DRAO for a Northern sky
polarization survey. Observations consist of scans up and down the Meridian at
a drive rate of 0.9 degree per minute to give complete coverage of the sky
between declinations -30 degree and 90 degree. This paper presents a complete
description of the receiver and data acquisition system. Only a small fraction
of the frequency band of operation is allocated for radio astronomy, and about
20 percent of the data are lost to interference. The first 8 percent of data
from the survey are used for a proof-of-concept study, which has led to the
first application of Rotation Measure Synthesis to the diffuse Galactic
emission obtained with a single-antenna telescope. We find rotation measure
values for the diffuse emission as high as approximately 100 rad per square
metre, much higher than recorded in earlier work.Comment: Accepted for publication in The Astronomical Journa
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