3,588 research outputs found
Lower Bound on the Propagation Speed of Gravity from Gravitational Cherenkov Radiation
Recently, interesting 4-D Lorentz violating models have been proposed, in
which all particles have a common maximum velocity , but gravity propagates
(in the preferred frame) with a different maximum velocity . We
show that the case is very tightly constrained by the observation of
the highest energy cosmic rays. Assuming a galactic origin for the cosmic rays
gives a conservative bound of ; if the cosmic rays
have an extragalactic origin the bound is orders of magnitude tighter, of order
.Comment: 8 pages with 1 figure, JHEP style. References added, slight
(superficial) change
The influence of a school\u27s schedule on teaching practices and behaviors
In 1999 the teaching staff at Washington Township High School and the teaching staff at Upper Darby High School were asked to participate in a study of the influence of a school\u27s schedule on teaching practices and behaviors. This study investigates the classroom behaviors and practices of high school teachers both in a traditionally scheduled school and in a block scheduled school. This report presents the results of an analysis of a survey administered to a stratified random sample. The results of the survey were compiled manually and appear in tabular form. The analysis of the data reveals the frequency at which various teaching practices occur and the level of satisfaction experienced by the teachers in their particular schools. The analysis of the results of the teacher survey yields the following findings: Teachers in the 4/4 block schedule are slightly more likely to use a variety of teaching methods during each class period; they report greater satisfaction and enthusiasm about their school; they are more satisfied with the amount of planning time they have; and they report a greater desire to remain in their current schedule than the teachers in the traditional schedule
Provision of information to patients and relatives after traumatic brain injury : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Psychology at Massey University
It is estimated that Traumatic Brain Injury' (TBI) affects over 9000 people in New Zealand every year. This study aimed to describe the information and resources available to patients and their families after a TBI in New Zealand. A survey was sent to a sample of General Practitioners and hospital Emergency Departments asking about what information and other resources they had available for patients. Results showed that, of those who responded, all hospitals but less than half the General Practitioners had a patient information sheet on TBI. The quality of content and appearance of the leaflets was highly variable, but generally the presentation of the hospital information sheets was better. Individuals who had recently sustained a TBI and their relatives were also given a questionnaire about the information they received while in hospital and how satisfied they felt with it. Due to small numbers of respondents, no generalisations could be made from this part of the study
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The Photochemistry of <i>N</i>-Arylsulfonyl Amino Acids and Peptides
The photochemistry of arylsulfonamides has received continuing interest for the last four decades for three main reasons: 1) arylsulfonamides offer convenient acceptor properties for studying photo-induced electron transfer (PIET.) processes in chromophorically modified peptide models, 2) arylsulfonamides have potential as photoremovable protecting groups in organic synthesis, but this has so far remained largely unrealized, 3) arylsulfonamide pharmaceuticals are generally photolabile and photostability is an important consideration in the development of new drugs. We have studied a series of p-toluenesulfonyl amino acid derivatives and undertaken comprehensive product analysis to elucidate the photoproducts and identify common pathways of photodegradation. We found that the tosyl a-amino acids formed toluenesulfinic acid as a major photoproduct in conjunction with ammonia, carbon dioxide and a carbonyl compound. Upon changing the carboxylate to an ester or an amide, a Cɑ-H abstraction became the dominant process to give a carbonyl compound, toluenesulfinic acid and ammonia. These were also the major photoproducts with a tosyl ß-amino acid. A mechanism is proposed that involves an initial electron transfer (ET) from the carboxyl function to the sulfonyl moiety to give a biradical intermediate that could react to produce most of the observed products. Some differences in product distribution were found with different amino acid side-chains, although bulky aliphatic or sulfur containing side-chains produced little variation. A tyrosine derivative underwent side-chain cleavage, implying electron transfer from the side-chain rather than the carboxyl function. Peptide bond cleavages occurred in the majority of amide derivatives, which can also be explained by an electron transfer mechanism. The results showed that S-N cleavage to form the free amino acid moiety occurs in very poor yield due to a complex array of competing photoreactions. A photoyellowing was seen in many of the amide compounds which may be due to photochromism, a process that is consistent with our photo-induced electron transfer hypothesis
Geochemical Impacts From Permanganate Oxidation Based on Field Scale Assessments.
In situ chemical oxidation (ISCO) using permanganate is a technology for treatment of organic hazardous wastes. This research is a review of 30 permanganate (MnO4-) ISCO sites to determine whether there are long term impacts on groundwater quality due to the introduction of the oxidant into the subsurface. A second objective is to determine if manganese concentration can be predicted by trends in specific pre and postoxidation monitored parameters (i.e., pH and oxidation reduction potential (ORP)). The final objective is to identify the effects of site and design conditions on groundwater conditions postoxidation. Results indicate that (1) there are limited long term groundwater impacts due to oxidant introduction (i.e., water quality indicators begin to approach preoxidation levels by 2 years postoxidation), (2) manganese concentrations can be predicted and (3) site and design conditions have pronounced short term impacts on geochemical parameters (i.e., especially site media type, mass of oxidant injected, and initial ORP)
Detection and initial characterization of a bacteriocin inhibitory to Campylobacter jejuni
Given the current concerns regarding the use of antibiotics and chemical preservatives in animal husbandry, a naturally occurring antimicrobial peptide of bacterial origin (bacteriocin) that exhibits antagonist activity toward foodborne pathogens could provide a favorable alternative to these agents. The goal of this research was to identify one or more bacteriocins that might reduce the incidence of C. jejuni in poultry and poultry products, and thus enhance the safety of food products of poultry origin. Twelve bacteriocin-producing bacteria (producer organisms), which included eight Lactobacillus sp. strains, two Paenibacillus polymyxa strains, a Streptococcus salivarious and a Propionibacterium thoenii, were selected and screened against two wild type strains of C. jejuni (indicator organisms) via agar spot and well diffusion assays. Four organisms inhibited C. jejuni growth and were retained for further evaluation. Through inhibition tests with catalase and four proteases, the inhibitory substances were determined to be proteinaceous. The bacterium Paenibacillus polymyxa (ATCC 842) provided the most consistent inhibitory activity. The antimicrobial molecule produced by P. polymyxa was found to be a protein of molecular weight between 3000 and 5000 D, stable during extended storage at low temperature, stable to heat at 1210C, and optimally produced during incubation at 30-370C for 24 h in the pH range 6.0 to 7.4
A Disabled Student? In My Classroom?
The Act, P.L. 94-142, The Education of All Handicapped Children, calls for education of exceptional children in the least restrictive environment, often the regular classroom. Integration of the disabled into the classroom ends the physical isolation, rejection, and segregation of the special classes era. But total integration of the non-disabled and the disabled cannot occur without increased educational attitudinal changes toward the disabled. These changes involve awareness by teachers and non-disabled peers of the unique needs and abilities of the disabled, acceptance of them, and abandonment of prejudicial ideas about the disabled
Geochemical Impacts From Permanganate Oxidation Based on Field Scale Assessments.
In situ chemical oxidation (ISCO) using permanganate is a technology for treatment of organic hazardous wastes. This research is a review of 30 permanganate (MnO4-) ISCO sites to determine whether there are long term impacts on groundwater quality due to the introduction of the oxidant into the subsurface. A second objective is to determine if manganese concentration can be predicted by trends in specific pre and postoxidation monitored parameters (i.e., pH and oxidation reduction potential (ORP)). The final objective is to identify the effects of site and design conditions on groundwater conditions postoxidation. Results indicate that (1) there are limited long term groundwater impacts due to oxidant introduction (i.e., water quality indicators begin to approach preoxidation levels by 2 years postoxidation), (2) manganese concentrations can be predicted and (3) site and design conditions have pronounced short term impacts on geochemical parameters (i.e., especially site media type, mass of oxidant injected, and initial ORP)
Potential useability of an experimental 4-H career education manual
The purpose of this study was to explore the useability of an experimental 4-H Career Education Manual developed for Extension Supervisory District Five Counties in Tennessee. Specific objectives included the following: 1. To involve High School Counselors in getting their opinions as to whether or not the Experimental Manual might be useable as intended. 2. To involve 4-H Agents in District V counties in getting their opinions as to whether or not the Experimental Manual might be useable as intended. 3. To involve Grainger County Senior 4-H\u27ers who had participated in the series in getting their opinions as to whether or not the Experimental Manual might be useable as intended. 4. To involve a National Panel of 4-H Professionals in getting their opinions as to whether or not the Experimental Manual might be useable as intended. Major findings of the study include the following: 1. Eleven High School Counselor responses on 18 of 20 evaluative items indicated they felt the Manual was at least Somewhat Appropriate for its intended use. 2. Counselor responses indicated that 60% or more checked the Manual Very Appropriate on five items. 3. The 36 4-H Agent responses on all 20 evaluative Items indicated they felt the Manual was at least Somewhat Appropriate for its intended use. 4. Agent responses also indicated that 60% or more checked the Manual Very Appropriate on three items. 5. Responses from 11 4-H Club members indicated that they felt that the Manual was at least Somewhat Appropriate on all 20 evaluative items. 6. Sixty percent or more of the 4-H\u27ers checked the Manual Very Appropriate on six items. 7. Responses of four National Panel of 4-H Professionals indicated that they felt the Manual was at least Somewhat Appropriate on all 20 evaluative items. 8. National Panel of 4-H Professional responses further indicated that three-fourths felt the Manual Very Appropriate on nine criteria. 9. Respondents noted the difficulty of finding time to implement the activity. It was suggested that the Manual be used with older 4-H\u27ers (11th and 12th graders) rather than 9th and 10th graders. Respondents felt that careers in all areas of life should be discussed and more definite ideas given in deciding a career. It also was suggested that the Manual could be adapted for use specifically as a one-time seminar. It was implied that since the opinions of Counselors, Agents, 4-H members and the National Panel of 4-H Professionals were favorable that therefore they saw the Manual as being useable for the intended purpose. Recommendations were made for use of the Manual and for its further testing
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