11,697 research outputs found
A Study to Determine the Effectiveness of a Specialized Cooperative Food Service Course in the Hampton, Virginia Distributive Education Program
The purpose of this study was to determine the effectiveness of the Specialized Food Service course being taught at Pembroke High School through the Distributive Education program area
A Quality Audit of the Beef Industry
Quality, in the context it will be discussed here, includes all of the factors that affect value/desirability of U.S. slaughter cattle (steers/heifers slaughtered at 9 to 42 months of age, immediately following a period of 90 to 300 days of high-concentrate feeding) in terms of the value/desirability of their carcasses and dress-off/offal items
Lessons from the Canadian Cattle Industry for Developing the National Animal Identification System
The primary focus of animal identification programs, which are rapidly developing throughout the world, is to effectively respond to animal health emergencies that have the potential to cause devastating consequences to animal and public health. Additional benefits of an animal identification program include maintaining or expanding international trade, increased consumer confidence, and improved supply chain management. The primary objective of this paper is to provide a series of recommendations for the U.S. to consider as it continues to develop the National Animal Identification System. The secondary objective is to explain how some progressive operations, spanning all sectors of the live cattle and beef industry supply chain complex in Canada, have utilized the technology of the mandatory cattle identification program to improve management intensity.Animal Identification, Canadian Cattle Identification Agency, National Animal Identification System, Research and Development/Tech Change/Emerging Technologies, Q10, Q16,
The Polarized Spectrum of Apm 08279+5255
We report the discovery of significant linear polarization (p > 1%) in the
hyperluminous z=3.87 BALQSO APM~08279+5255. The polarization spectrum is
complex, with properties similar to those of other, lower redshift but more
highly polarized BALQSOs. The resonance emission lines are unpolarized while
the absorption troughs show polarization similar to or higher than the
continuum. In particular, an apparent increase of polarization in the trough
covering 1000-1030 angstroms (rest) supports the interpretation of this feature
as a broad absorption component associated with OVI/Ly_beta local to the QSO,
as opposed to an intervening damped Ly_alpha absorption system.
The elevated polarization in some of the absorption features implies that we
view the scattered (polarized) spectrum through a sightline with less absorbing
material than the direct spectrum. Therefore, the complex structure of the
polarization spectrum in this brilliant lensed BALQSO suggests that it will be
an important laboratory for studying the structure of QSOs at high redshift.Comment: 8 pages, 1 figure. Accepted for publication in The Astrophysical
Journal Letter
An Extraordinary Scattered Broad Emission Line in a Type 2 QSO
An infrared-selected, narrow-line QSO has been found to exhibit an
extraordinarily broad Halpha emission line in polarized light. Both the extreme
width (35,000 km/sec full-width at zero intensity) and 3,000 km/sec redshift of
the line centroid with respect to the systemic velocity suggest emission in a
deep gravitational potential. An extremely red polarized continuum and partial
scattering of the narrow lines at a position angle common to the broad-line
emission imply extensive obscuration, with few unimpeded lines of sight to the
nucleus.Comment: 4 pages, 1 figure, to appear in the Astrophysical Journal Letter
The Redox-Sensitive Transcriptional Activator OxyR Regulates the Peroxide Response Regulon in the Obligate Anaerobe Bacteroides fragilis
The peroxide response-inducible genes ahpCF, dps, and katB in the obligate anaerobe Bacteroides fragilis are
controlled by the redox-sensitive transcriptional activator OxyR. This is the first functional oxidative stress
regulator identified and characterized in anaerobic bacteria. oxyR and dps were found to be divergently
transcribed, with an overlap in their respective promoter regulatory regions. B. fragilis OxyR and Dps proteins
showed high identity to homologues from a closely related anaerobe, Porphyromonas gingivalis. Northern blot
analysis revealed that oxyR was expressed as a monocistronic 1-kb mRNA and that dps mRNA was approximately
500 bases in length. dps mRNA was induced over 500-fold by oxidative stress in the parent strain and
was constitutively induced in the peroxide-resistant mutant IB263. The constitutive peroxide response in strain
IB263 was shown to have resulted from a missense mutation at codon 202 (GAT to GGT) of the oxyR gene
[oxyR(Con)] with a predicted D202G substitution in the OxyR protein. Transcriptional fusion analysis revealed
that deletion of oxyR abolished the induction of ahpC and katB following treatment with hydrogen
peroxide or oxygen exposure. However, dps expression was induced approximately fourfold by oxygen exposure
in DoxyR strains but not by hydrogen peroxide. This indicates that dps expression is also under the control of
an oxygen-dependent OxyR-independent mechanism. Complementation of DoxyR mutant strains with wildtype
oxyR and oxyR(Con) restored the inducible peroxide response and the constitutive response of the ahpCF,
katB, and dps genes, respectively. However, overexpression of OxyR abolished the catalase activity but not katB
expression, suggesting that higher levels of intracellular OxyR may be involved in other physiological processes.
Analysis of oxyR expression in the parents and in DoxyR and overexpressing oxyR strains by Northern
blotting and oxyR*::xylB fusions revealed that B. fragilis OxyR does not control its own expression. Originally published Journal of Bacteriology, Vol. 182, No. 18, Sep. 200
Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk
Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens
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