Automated Source-Detector Positioner for Radiation Detection

The Nuclear Engineering Department at Virginia Commonwealth University has an unmet need for an automated source detector positioner for radiation detection experiments that are carried out in lab work. During radiation data collection in radiation detection systems it is of the utmost importance that radioactive samples are positioned and moved with the highest degree of precision possible. This high degree of precision allows for more meaningful data to be collected. The current methods employed by the Nuclear Engineering Department are not as accurate as they can be due to the fact the the current detection systems are manual. Furthermore they are aligned only by sight and have fixed shelving positions. The figure below is the solution to this issue: An automated Source-Detector Positioner for Radiation Detection. This detection system has been design to have a low tolerance so that radiation samples are always centered in the “Sample holder/clamp” over the radiation detector probe. Two stepper motors move along rods, lifting or lowering the sample holder to the desired position over the radiation detection probe. There is also an optional shielding component for the limitation of radiation emission that improves on the shelving method from previous devices. This is all supported with 3D printed rings and metal rods.https://scholarscompass.vcu.edu/capstone/1208/thumbnail.jp

Territorialization, science and the colonial state: the case of Highway 55 in Minnesota

This paper examines a recent conflict over the rerouting of Highway 55 in the city of Minneapolis, Minnesota. During a three-year struggle over the project, a group of indigenous people argued that the space where the highway would pass was sacred and of historical importance. We analyse a Cultural Resource Assessment prepared by a team of scientists that responded to these claims and cleared the way for the reroute. Our reading, which draws from the literatures of postcolonial studies and sociology of science, examines the way scientific claims are made to evaluate the sacredness of the site. We find that science works to produce the effect of state territorialization - or the iterative making of the space of the state - by placing ecological phenomena and indigenous testimony 'within' a non-sacred Minnesotan space

Drug use in Irish schools: a comparison with other countries.

Depending on what criteria one adopts, the most serious drug problem in Irish schools might be 'cigarettes' or 'alcohol' or one of the illegal substances. In order to decide on the seriousness of a drug problem, it is necessary not only to consider the numbers using the substance, but also to compare the findings longitudinally and cross-culturally. This article reported on a three-phase survey of the reported use of cigarettes, alcohol and illegal drugs by 3,000 randomly-selected second-level pupils aged between 12.5 and 18 years in the Dublin area. Twenty-four post-primary schools were involved, representing the full range of socio-economic backgrounds. A self-administered, anonymous questionnaire was used to gather information. The research results showed that over two-thirds of the sample had smoked a cigarette at one time in their lives, while over one-third had smoked in the previous month, and hence were defined as current smokers. When these findings were compared with other countries, the level of smoking among Irish school-goers was found to be 'extremely high'. With regard to drinking, almost two-thirds of those surveyed reported that they had ever consumed an alcoholic drink, and one-third of the sample said that they had felt drunk at least once. When these rates were compared with other countries, it was found that the levels of drinking in Ireland were mid-way between low-consumption countries like Israel and high-consumption countries like France. Regarding drugs, marijuana and glue or other inhalants were found to be the most frequently misused substances; about 13% of the sample reported that they had tried each of these at some time in their lives. The level of illegal drug use found in the present study, however, was judged to be low when compared with that in other countries

Electron Transfer in Cytochrome c Oxidase: The Rate of Electron Equillibration Between Cytochrome a and Copper A

Intramolecular electron transfer in partially reduced cytochrome c oxidase has been studied by means of perturbed equilibrium techniques. We have prepared a three electron reduced, CO inhibited form of the enzyme in which cytochrome a and copper A are partially reduced an in intramolecular redox equilibrium. When these samples were photolyzed using a nitrogen laser (0.6 µs, 1.0 mJ pulses) changes in absorbance at 598 nm and 830 nm were observed which are consistent with a fast electron from cytochrome a to copper A. The absorbance changes at 598 nm have an apparent rate of 17,200 ± 1,700 s-1 (1σ), at pH 7.0 and 25.5 °C. These changes were not observed in either the CO mixed valence or CO inhibited fully reduced forms of the enzyme. The rate is fastest at about pH 8.0, and falls off in either direction, and there is a small, but clear temperature dependence. The process was also observed in the cytochrome c -- cytochrome c oxidase high affinity complex. This rate is far faster than any rate measured or inferred previously for the cytochrome a -- copper A electron equilibration, but the interpretation of these results is hampered by the fact that the relaxation could only be followed during the time before CO became rebound to the oxygen binding site. The meaning of our our measured rate is discussed, along with other reported rates for this process. In addition, a temperature-jump experiment on the same system is discussed. We have also prepared a partially reduced, cyanide inhibited form of the enzyme in which cytochrome a, copper A and copper B are partially reduced and in redox equilibrium. Warming these samples produced absorbance changes at 605 nm which indicate that cytochrome a was becoming more oxidized, but there were no parallel changes in absorbance at 830 nm as would be expected if copper A was becoming reduced. We concluded that electrons were being redistributed from cytochrome a to copper B. The kinetics of the absorbance changes at 605 nm were investigated by temperature-jump methods. Although a rate could not be resolved, we concluded that the process must occur with an (apparent) rate larger than 10,000 s-1. During the course of the temperature-jump experiments, we also found that non-redox related, temperature dependent absorbance changes in fully reduced CO inhibited cytochrome c oxidase, and in the cyanide mixed valence enzyme, took place with an (apparent) rate faster that 30,000 s-1.</p

Forest management and wildfire risk in inland northwest

This brief reports the results of a mail survey of forest landowners in northeastern Oregon conducted in the fall of 2012 by the Communities and Forests in Oregon (CAFOR) Project at the University of Colorado and the University of New Hampshire in cooperation with Oregon State University College of Forestry Extension. The mail survey--a follow-up to a telephone survey conducted for the counties of Baker, Union, and Wallowa in the fall of 2011 -was administered to understand who constituted forest landowners in these three coun¬ties and their perceptions about forest management on both public and private land, as well as risks to forests in the area and the actions they have taken to reduce those risks. The respondents indicated that they perceive wildfire as the greatest threat to their lands, and they consider cooperation with neighbors as very or extremely important for land management. Forest landowners believe public lands are managed poorly and see a greater risk of wildfire occurring on neighboring public land than on their own land. Their opinions on land management are not strongly related to background factors or ideology (for example, gender, age, political party, wealth) but may be heavily influenced by personal experience with wildfire

Affidavit of identity, Marshall County, MS, 7 November 1840

https://egrove.olemiss.edu/aldrichcorr_b/1035/thumbnail.jp

Metabolic Comparison of Wild-Type and Transgenic Synechocystis PCC 6803 Cyanobacteria

The Calvin-Benson (CBB) cycle is an essential part of nature. This phenomenon allows carbon molecules in carbon dioxide from the atmosphere to be converted into useful energy in the form of sugars. Cyanobacteria are single-celled organisms capable of utilizing energy from sunlight to drive this cycle and are also readily engineered. In hopes of improving this cycle, we compared a wild-type version of the Synechocystis PCC6803 cyanobacteria to an engineered version overexpressing the enzyme FBA (fructose-biphosphate aldolase), called 70 glpX, to deduce how the overexpressing strain is able to be more photosynthetically efficient. To do this, comparative metabolomics were done to compare metabolite concentrations in order to identify differences between the two. It was found that the FBA enzyme in the 70 glpX contained increased metabolite concentrations at certain points in the CBB cycle when compared to the wild-type, causing an increase in the rate of photosynthesis. We can see that the substrate was higher at certain points, which may suggest a higher metabolic rate, explaining how the engineered version is better at carrying out photosynthesis

Drug use in Irish schools: A comparison with other countries

They have collaborated on several papers on drug use, attitude formation and research methodology. The present paper is based on the results of a three-phase survey of drug use in Dublin postprimary schools. What is the most serious drug problem in Irish schools in the late eighties? Depending on what criteria one adopts the answer might be &quot;cigarettes&quot;, or &quot;alcohol&quot;, or one of the illegal substances. What will become clear is that in order to decide on the seriousness of a drug problem, it is necessary to consider not only the numbers using the substance, but also the comparison with other times and other countries, the probability of addiction, the consequences to the individual involved, the effects on others in the family, etc. People value each of these criteria differently, with the result that the grounds for identifying the &quot;size&quot; of a drug problem (if indeed there is a problem at all) are many and varied. Unfortunately, the legal/illegal distinction does not help very much, since by some criteria (e.g. number of deaths caused) the &quot;legal&quot; substances cause most problems. THE DUBLIN SMOKING, ALCOHOL AND DRUGS STUDY The study on which the present paper is based, is a three-phase survey of the reported use of cigarettes, alcohol and illegal drugs by 3,000 randomly selected pupils in the greater Dublin area. Twenty-four post-primary schools were involved, representing the full range of socio-economic backgrounds. About two-thirds of the pupils were from secondary schools and about one-third were from community, comprehensive or vocational schools. As would be expected from such a sample, the vast majority of the respondents range in age from 12.5 to 18.0 years. The survey instruments consisted of self-administered questionnaires in which pupils anonymously completed items relating to their use of, attitudes towards and beliefs about smoking, alcohol and other drugs. The surveys were carried out by trained personnel from the Economic and Social Research Institute and normally the class teacher was absent from these sessions. The students were instructed not to put their names on the questionnaires and the instructions on the questionnaires reiterated the anonymous and confidential nature of the survey. Since the students did not put their names on the questionnaire and since many of the interesting questions involved linking a given respondent&apos;s answer at one phase to his or her answers at a different phase, it was essential to devise a method of matching questionnaires across phases. This was accomplished through the use of a self-generated code. Respondents supplied information that was unique to themselves specifically, date of birth, number of older brothers, number of older sisters, and first initial of mother&apos;s first name. On the basis of these characteristics, a computer programme matched the files across the phases, thus allowing the advantage of confidentiality, but without the drawbacks. RELIABILITY AND VALIDITY The reliability of the measures was assessed mainly through a measure of the extent to which the subjects&apos; reports of their use of a given substance correlated with their reports at the later testin

Architectural changes of the biceps femoris long head after concentric or eccentric training

Purpose: To determine i) the architectural adaptations of the biceps femoris long head (BFlf) following concentric or eccentric strength training interventions; ii) the time course of adaptation during training and detraining. Methods: Participants in this randomized controlled trial (control [n=28], concentric training group [n=14], eccentric training group [n=14], males) completed a 4-week control period, followed by 6 weeks of either concentric- or eccentric-only knee flexor training on an isokinetic dynamometer and finished with 28 days of detraining. Architectural characteristics of BFlf were assessed at rest and during graded isometric contractions utilizing two-dimensional ultrasonography at 28 days pre-baseline, baseline, days 14, 21 and 42 of the intervention and then again following 28 days of detraining. Results: BFlf fascicle length was significantly longer in the eccentric training group (p < 0.05, d range: 2.65 to 2.98) and shorter in the concentric training group (p < 0.05, d range: -1.62 to -0.96) after 42 days of training compared to baseline at all isometric contraction intensities. Following the 28-day detraining period, BFlf fascicle length was significantly reduced in the eccentric training group at all contraction intensities compared to the end of the intervention (p < 0.05, d range: -1.73 to -1.55). There was no significant change in fascicle length of the concentric training group following the detraining period. Conclusions: These results provide evidence that short term resistance training can lead to architectural alterations in the BFlf. In addition, the eccentric training-induced lengthening of BFlf fascicle length was reversed and returned to baseline values following 28 days of detraining. The contraction mode specific adaptations in this study may have implications for injury prevention and rehabilitation