Reaction of chromium(VI) with glutathione or with hydrogen peroxide: identification of reactive intermediates and their role in chromium(VI)-induced DNA damage.

The types of reactive intermediates generated upon reduction of chromium(VI) by glutathione or hydrogen peroxide and the resulting DNA damage have been determined. In vitro, reaction of chromium(VI) with glutathione led to formation of two chromium(V) complexes and the glutathione thiyl radical. When chromium(VI) was reacted with DNA in the presence of glutathione, chromium-DNA adducts were obtained, with no DNA strand breakage. The level of chromium-DNA adduct formation correlated with chromium(V) formation. Reaction of chromium(VI) with hydrogen peroxide led to formation of hydroxyl radical. No chromium(V) was detectable at 24 degrees C (297 K); however, low levels of the tetraperoxochromium(V) complex were detected at 77 K. Reaction of chromium(VI) with DNA in the presence of hydrogen peroxide produced significant DNA strand breakage and the 8-hydroxydeoxyguanosine adduct, whose formation correlated with hydroxyl radical production. No significant chromium-DNA adduct formation was detected. Thus, the nature of chromium(VI)-induced DNA damage appears to be dependent on the reactive intermediates, i.e. chromium(V) or hydroxyl radical, produced during the reduction of chromium(VI)

Chromium(VI) reduction by ascorbate: role of reactive intermediates in DNA damage in vitro.

Reaction of chromium(VI) with one equivalent of ascorbate was studied by electron paramagnetic resonance spectroscopy in the presence of 0.10 M 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) at room temperature in 0.10 M (N-[2-hydroxyethyl]piperazine-N'-[2-ethanesulfonic acid]) (HEPES) and 0.05 M tris(hydroxymethyl)aminomethane hydrochloride (Tris-HCl) buffers (pH 7.0 room temperature). Chromium(V), ascorbyl radical, and carbon-based DMPO-radical adducts were observed. A higher level of Cr(V) was observed in HEPES buffer and a higher level of the DMPO-radical adducts was observed in Tris-HCl buffer. Chromium-DNA binding studies were carried out in vitro for calf thymus DNA incubated with Cr(VI) and ascorbate in both buffers at 37 degrees C. Higher Cr-DNA binding was observed in HEPES buffer. DNA strand-break studies were carried out in vitro on pBR322 DNA incubated with Cr(VI) and ascorbate in both buffers at 37 degrees C. Higher percent nicking was observed in Tris-HCl buffer. Addition of DMPO decreased nicking levels in Tris-HCl buffer. These results suggest that free radicals are more reactive than Cr(V) in producing DNA strand breaks and that Cr(V) will react with DNA to produce Cr-DNA adducts. The fact that buffer affects the nature of the reactive intermediates produced upon reduction of Cr(VI) may be related to differences in intracellular metabolism of Cr(VI) and resulting DNA damage observed in various cell culture systems and animal tissues in vivo

Motivations and barriers to prosthesis users participation in physical activity, exercise and sport : a review of the literature

The UK will host the Paralympics in 2012 and the Commonwealth Games in 2014 showcasing the talents of elite athletes and aiming to inspire the population to become involved. However, low levels of physical activity (PA) are prevalent: only 40% of men and 28% of women meet the minimum UK recommendations. The limb absent population is no exception. To determine if people with limb amputations are participating in physical activity and sport; whether post-amputation activity levels match pre-amputation levels; and if there are motivations and barriers to participation. Study design: Literature review Five reviewers systematically search of peer reviewed and gray literature in seven bibliographic databases and the Cochrane Library. Results: Following rigorous elimination, 12 articles were finally included in the review and critically appraised. Four themes were identified: components, rehabilitation outcomes, body image and motivations and barriers to participation. People with limb absence are not participating in PA conducive to health benefits, and only a minority participate in exercise and sports. Participation following amputation does not mirror that of pre-amputation levels, and more barriers than motivations exist to adopting and maintaining a physically active lifestyle. This literature review aims to inform those involved in rehabilitation and ongoing care of those with limb absence about what motivates or precludes their participation in physical activity, exercise and sport. Such knowledge could be applied to improving health and well being in this population

Developing core sets for persons following amputation based on the International Classification of Functioning, Disability and Health as a way to specify functioning

Amputation is a common late stage sequel of peripheral vascular disease and diabetes or a sequel of accidental trauma, civil unrest and landmines. The functional impairments affect many facets of life including but not limited to: Mobility; activities of daily living; body image and sexuality. Classification, measurement and comparison of the consequences of amputations has been impeded by the limited availability of internationally, multiculturally standardized instruments in the amputee setting. The introduction of the International Classification of Functioning, Disability and Health (ICF) by the World Health Assembly in May 2001 provides a globally accepted framework and classification system to describe, assess and compare function and disability. In order to facilitate the use of the ICF in everyday clinical practice and research, ICF core sets have been developed that focus on specific aspects of function typically associated with a particular disability. The objective of this paper is to outline the development process for the ICF core sets for persons following amputation. The ICF core sets are designed to translate the benefits of the ICF into clinical routine. The ICF core sets will be defined at a Consensus conference which will integrate evidence from preparatory studies, namely: (a) a systematic literature review regarding the outcome measures of clinical trails and observational studies, (b) semi-structured patient interviews, (c) international experts participating in an internet-based survey, and (d) cross-sectional, multi-center studies for clinical applicability. To validate the ICF core sets field-testing will follow. Invitation for participation: The development of ICF Core Sets is an inclusive and open process. Anyone who wishes to actively participate in this process is invited to do so

Fracture geometry and orientation correlations in a fold-and-thrust structure in the Northern Apennines, Italy

Secondary permeability created by fractures is an interesting property regarding reservoir purposes. In the Umbria-Marche Apennines these fractures have been digitized using software named Digifract. The goal of this research is to correlate these fractures to the lithology, and their relative position regarding the two main structures found in the area; the Sibillini thrust and the Fiastrone anticline. The lithology found in this area consists out of Mesozoic carbonate formations, which in some cases contain marls and cherts, and a siliciclastic turbidite formation. Digifract is used to quantify and analyze fractures determining the fracture height, fracture density and fracture orientation. When present, cherts and marls act as fracture boundaries in the carbonate formations. When present in the siliciclastic turbidite formation, shale layers prevent the fractures from propagating. The fracture density in the formations increases as the bedding thickness decreases. Mainly because of their relative small bedding thicknesses the Maiolica Fm and the Scaglia Rossa Fm have the largest fracture density. The Laga Fm and the Calcare Massiccio Fm have the largest fracture heights. In the footwall of the Sibillini thrust a distinction can be made between a fault-controlled fracture zone and a fracture zone controlled by other stresses. The boundary between these zones in the footwall can be found between 150 and 225 meters of the fault. On the crest of the Fiastrone anticline the largest fracture density can be found regarding this structure, whereas the greatest fracture height is to be found on the limbs of the anticline.Geo-EngineeringGeoscience & EngineeringCivil Engineering and Geoscience

A method to assess the likelihood and magnitude of initial capital expenditure overruns of future gold mining projects using retrospective data analysis

In the mining industry the initial capital expenditure budgeted in the feasibility study is being overrun structurally. These capital expenditure overruns have long been recognised, yet no method is available predicting the probability a mining project will experience an overrun.This thesis introduces a method to assess the likelihood and magnitude of an initial capital expenditure overrun occurring for future gold mining projects. A database is populated with 65 gold mining projects that have experienced an overrun. For each project, 19 variables are described in the database that define the projects. The variables are analysed using individual variable analysis and multivariate regression analysis to investigate whether a correlation can be found between the variables and the initial capital expenditure overrun. Using the results of the individual variable analysis, a tool is developed to semi-quantify the risk a future gold mining project is exposed to regarding an initial capital expenditure overrun. The tool can visualise the risk a project is exposed to in a 2D risk matrix displaying the likelihood and magnitude of a possible overrun.For 16 of the 19 variables a possible correlation is found. The variables are grouped together, representing root causes with regards to the initial capital expenditure overrun. The database analysis suggests that relatively small gold mining projects experience a larger capital expenditure overrun than large gold mining projects. In addition, projects owned by relatively large companies tend to experience a larger capital expenditure overrun. Furthermore, projects where a low number of payback years or a high internal rate of return presented in the bankable feasibility study indicate a profitable project tend to experience a smaller capital expenditure overrun. Finally, the database suggests a correlation between the relative gold price and the capital expenditure overrun. Projects from which the bankable feasibility study was published when the gold price was relatively high, tend to experience initial capital expenditure overruns more frequent and with a larger magnitude. Using the correlations resulting from the database analysis, a predictive tool is successfully developed for which future gold mining projects can be assessed on initial capital expenditure overrun risk

The Union Soldier Monument Controversy at the Bentonville Battlefield State Historic Site

This thesis centers on a controversial monument initiative at the Bentonville Battlefield State Historic Site in Johnston County, North Carolina in 1994. The planned obelisk was to record the participation of the four Union Army corps that participated in the March 1865 battle. The sponsors of the memorial failed to anticipate, react or even comprehend the nature of the opposition to their project. Several prominent persons, including high appointed officials in the state government, played central roles in that opposition. In the end, the proposal was disapproved by the state authority, the North Carolina Historical Commission, by the narrowest of margins. With thoughtful consideration, proponents could have anticipated and minimized the outcry against their plan. As only one more commissioner's vote would have spelled success, a well-conceived campaign could have resulted in the subsequent placement of the commemorative piece. This thesis analyzes the actual objections of the dissidents. It dispels some historical errors and misconceptions of the time period. It relates the Southern experience, both during and since the end of the War Between the States, to opponents' predominant opinions. The ramifications of the state-wide collective memory and its impact on the outcome are explored in depth. Finally, a course of action is proposed which, had any or all of its recommendations been implemented, would have likely tipped the scale in favor of the monument. It is hoped that both public history students and professionals may glean important insight from this thesis to ensure the successful conclusion of their commemorative initiatives