Carbon Distribution in the Stiliwater Complex and Evolution of Vapor During Crystallization of Stillwater and Bushveld Magmas

The occurrence and distribution of carbon in the Stillwater Complex have been investigated. In mineralized troctolite and associated rocks of olivine-bearing zone I (OB I), carbon is present as graphitic material and calcite. The assemblage forsterite-antigorite-calcite-graphite and the petro graphic relations indicate equilibration of the carbon-rich phases during serpentinization. Typical OB I troctolite contains 500-1100 ppm wt. carbon, 40-70% of which is in calcite, whereas troctolite from higher stratigraphic positions generally contains 2 log units below that of the Ni-NiO oxygen buffer. Upon the appearance of graphite, the fluid evolved to a more hydrogen-rich composition by graphite precipitation and loss of oxygen to the surrounding silicate-oxide assemblage. Cooling of fluid to 25°C below the first appearance of graphite resulted in reduction in the fluid mass by >70%, thus concentrating chlorine, sulfur and other residual species in the intercumulus fluid and melt. The model explains the presence of chlor-apatite and the enrichment of graphite in the Bushveld Critical Zone and predicts that chlor-apatite-bearing Stillwater rocks were similarly enriched in graphite during crystallizatio

Fast shower simulation in the ATLAS calorimeter

The time to simulate pp collisions in the ATLAS detector is largely dominated by the showering of electromagnetic particles in the heavy parts of the detector, especially the electromagnetic barrel and endcap calorimeters. Two procedures have been developed to accelerate the processing time of electromagnetic particles in these regions: (1) a fast shower parameterisation and (2) a frozen shower library. Both work by generating the response of the calorimeter to electrons and positrons with Geant 4, and then reintroduce the response into the simulation at runtime. In the fast shower parameterisation technique, a parameterisation is tuned to single electrons and used later by simulation. In the frozen shower technique, actual showers from low-energy particles are used in the simulation. Full Geant 4 simulation is used to develop showers down to ~1 GeV, at which point the shower is terminated by substituting a frozen shower. Judicious use of both techniques over the entire electromagnetic portion of the ATLAS calorimeter produces an important improvement of CPU time. We discuss the algorithms and their performance in this paper

Sustainable development in the mining industry: Towards the development of tools for evaluating socioeconomic impact in the Canadian context

In spite of its economic outputs, the Canadian mining sector has suffered from several setbacks that have compromised its reputation. This has led many of its stakeholders to adopt a shift towards a new paradigm focused on sustainable development. In this review of the literature, we identify the impact that mining activities have had on various social, economic and environmental issues in Canadian society. We also survey the criteria and indicators included in various models that may be used to evaluate the adequacy of the transition of mines towards sustainable development. Finally, the strengths and weaknesses of eight tools that have been applied to the socioeconomic impact of mines are analysed. A clear vision of prospects for promoting sustainable development in Canadian mining emerges from this survey. Our analysis reveals important factors not given adequate consideration in the models used currently to evaluate and suggests opportunities to improve these evaluation tools through identification of more relevant criteria and indicators. The research undertaken should incite stakeholders to develop social and economic impact evaluation tools that are better adapted to the Canadian context

Pattern Analysis of Microtubule-Polymerizing and -Depolymerizing Agent Combinations as Cancer Chemotherapies

Subcellular distribution of mass can be analyzed by a technique that involves culturing cells on interferometers and digitizing their interference contours. Contour sampling resulted in 102 variables per cell, which were predictors of oncogenic transformation. Cell phenotypes can be deconstructed by use of latent factors, which represent the covariance of the real variables. The reversal of the cancertype phenotype by a combination of microtubule- stabilizing and -depolymerizing agents was described previously. The implications of these results have been explored by clinicians who treated patients with the combination of docetaxel and vinorelbine (Navelbine®). The current study was performed to determine the effects of different combinations on phenotype and in phases of the cell cycle other than mitosis. Combinations of paclitaxel with either colchicine, podophyllotoxin, nocodazole, or vinblastine caused phenotype reversal. Paclitaxel analogue, 7-deoxytaxol, by itself caused reversal. Factors #4, (filopodia), #5 (displacement and/or deep invaginations in the periphery), #8, and #12 took on values typical of normal cells, whereas the values of #7 (p21-activated kinase), and #13 (rounding up) shifted toward the cancer-type. All combinations altered microtubule arrangement at the cell edge. Delivery schedules and drug ratios used in clinical studies were subjected to analysis. Clinical response rates were better when the combination was not interspersed with a single agent (P=0.004). The results support the idea that efficacy depends upon simultaneous exposure to both agents, and suggest a novel mechanism for combination therapies. These therapies appear to restore in transformed cells some of the features of a contact-inhibited cell, and to impede progress through the cell cycle even when provided at nanomolar concentrations

Multi-criteria evaluation of the socioeconomic impact of mining in Canada from a sustainable development perspective: A theoretical model

The socioeconomic impact of mining in Canada has positive and negative aspects. Effective evaluation of its impact suffers from the inadequacy of the criteria and indicators chosen to measure its sustainability and the limitations of the current means used to minimize the subjectivity of expert judgments. Constraints associated with legislation and standards governing mining activities must also be considered. In this study, a theoretical model is proposed for evaluating the socioeconomic impact of mining in Canada. This model combines the multi-criteria analysis methods known as the analytic hierarchy process and fuzzy integrated judgment. Based on a simulation, the model is able to take into account the subjectivity of expert judgments. In addition to reducing this subjectivity and allowing measurement of sensitivity, the model provided an overview of the progress achieved by a mine during its transition towards sustainable development

HOXA3 Modulates Injury-Induced Mobilization and Recruitment of Bone Marrow-Derived Cells

The regulated recruitment and differentiation of multipotent bone marrow-derived cells (BMDCs) to sites of injury are critical for efficient wound healing. Previously we demonstrated that sustained expression of HOXA3 both accelerated wound healing and promoted angiogenesis in diabetic mice. In this study, we have used green fluorescent protein-positive bone marrow chimeras to investigate the effect of HOXA3 expression on recruitment of BMDCs to wounds. We hypothesized that the enhanced neovascularization induced by HOXA3 is due to enhanced mobilization, recruitment, and/or differentiation of BMDCs. Here we show that diabetic mice treated with HOXA3 displayed a significant increase in both mobilization and recruitment of endothelial progenitor cells compared with control mice. Importantly, we also found that HOXA3-treated mice had significantly fewer inflammatory cells recruited to the wound compared with control mice. Microarray analyses of HOXA3-treated wounds revealed that indeed HOXA3 locally increased expression of genes that selectively promote stem/progenitor cell mobilization and recruitment while also suppressing expression of numerous members of the proinflammatory nuclear factor κB pathway, including myeloid differentiation primary response gene 88 and toll-interacting protein. Thus HOXA3 accelerates wound repair by mobilizing endothelial progenitor cells and attenuating the excessive inflammatory response of chronic wounds

The Geant4-Based ATLAS Fast Electromagnetic Shower Simulation

We present a three-pronged approach to fast electromagnetic shower simulation in ATLAS. Parameterisation is used for high-energy, shower libraries for medium-energy, and an averaged energy deposition for very low-energy particles. We present a comparison between the fast simulation and full simulation in an ATLAS Monte Carlo production

Vertebral bone marrow fat, bone mineral density and diabetes : The Osteoporotic Fractures in Men (MrOS) study

Elevated vertebral bone marrow fat (BMF) among individuals with osteoporosis has been established in histomorphometric studies. Several studies have found a negative correlation between BMF and bone mineral density (BMD) at the spine in men and women across different age groups. Animal studies have also observed bone loss with increased BMF in mice with induced diabetes. Our study objective was to test the hypothesis that the association between BMF and BMD varies by diabetic status. We performed a cross-sectional study of 156 men aged 74-96years from the Osteoporotic Fractures in Men study at the Pittsburgh clinical site. All men had spine BMF scans using proton magnetic resonance spectroscopy and spine and hip BMD scans by dual-energy X-ray absorptiometry. BMF was expressed as lipid to "lipid+water" ratio (%). Men were considered diabetic if they self-reported a physician diagnosis of diabetes, diabetes medication or had a fasting glucose ≥126mg/dl. Men with diabetes (n=38) had a significantly higher spine BMF (58.9 vs. 54.6%, p=0.0035), spine BMD (1.20 vs. 1.10g/cm(2), P=0.007) and total hip BMD (1.00 vs. 0.94g/cm(2), p=0.04) than those without, while no differences were observed for body weight, body mass index or waist circumference. Pearson correlation tests showed no significant correlation of spine BMF with age or BMD in non-diabetics. Significant inverse correlations were observed between BMF and BMD (-0.30 for femoral neck and -0.39 for total hip) among diabetic men. In conclusion, men with diabetes had a higher BMF compared to non-diabetic men. The correlation between BMF and BMD differed by diabetes status. Further investigation of the association of diabetes with BMF and BMD may provide a better understanding of the high fracture rates among individuals with diabetes despite their higher BMD

Cell-Cycle Protein Expression in a Population-Based Study of Ovarian and Endometrial Cancers

Aberrant expression of cyclin-dependent kinase (CDK) inhibitors is implicated in the carcinogenesis of many cancers, including ovarian and endometrial cancers. We examined associations between CDK inhibitor expression, cancer risk factors, tumor characteristics, and survival outcomes among ovarian and endometrial cancer patients enrolled in a population-based case control study. Expression (negative vs. positive) of three CDK inhibitors (p16, p21, p27) and ki67 was examined with immunohistochemical staining of tissue microarrays. Logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for associations between biomarkers, risk factors, and tumor characteristics. Survival outcomes were available for ovarian cancer patients and examined using Kaplan-Meier plots and Cox proportional hazards regression. Among ovarian cancer patients (n=175), positive p21 expression was associated with endometrioid tumors (OR=12.22, 95% CI=1.45-102.78) and higher overall survival (log-rank p=0.002). In Cox models adjusted for stage, grade, and histology, the association between p21 expression and overall survival was borderline significant (hazard ratio=0.65, 95% CI=0.42-1.05). Among endometrial cancer patients (n=289), positive p21 expression was inversely associated with age (OR ≥ 65 years of age=0.25, 95% CI=0.07-0.84) and current smoking status (OR: 0.33, 95% CI 0.15, 0.72) compared to negative expression. Our study showed heterogeneity in expression of cell-cycle proteins associated with risk factors and tumor characteristics of gynecologic cancers. Future studies to assess these markers of etiological classification and behavior may be warranted