Development of a volatility and polarity separator (VAPS) for volatility- and polarity-resolved organic aerosol measurement

Discrepancies between modeled and measured atmospheric organic aerosol (OA) have highlighted the need for in situ instrumentation to better characterize the sources, formation mechanisms, and atmospheric evolution of ambient OA. We have developed the Volatility and Polarity Separator (VAPS) for hourly measurements of volatility- and polarity-resolved OA detected using high-resolution time-of-flight mass spectrometry (HR-ToF-MS). Here, atmospheric OA is inertially impacted onto a collection cell, material is transferred onto a short transfer line located inside a gas chromatography (GC) oven, the oven is heated to provide a first-dimension separation of volatility, then thermally pulsed through a short polar GC column for a second-dimension polarity separation, and finally detected by HR-ToF-MS. This novel instrument increases the mass throughput of ambient OA in comparison to traditional GC due to shorter transfer paths and passivated coatings. Molecular separation resolution is partially sacrificed for this increased mass recovery, but the high-resolution mass spectral data recovers information such as chemical classes and even some individual compounds along with elemental composition to determine aerosol oxidation states. Different techniques for interpreting and representing VAPS data are considered and its applicability to positive matrix factorization (PMF) analysis is demonstrated.

Copyright © 2016 American Association for Aerosol Research     

Numerical investigation into the effect of backfilling on coal pillar strength in highwall mining

This paper attempts to quantify the effect of backfilling on pillar strength in highwall mining using numerical modelling. Calibration against the new empirical strength formula for highwall mining was conducted to obtain the material parameters used in the numerical modelling. With the obtained coal strength parameters, three sets of backfill properties were investigated. The results reveal that the behavior of pillars varies with the type and amount of backfill as well as the pillar width to mining height ratio(w/h). In case of cohesive backfill, generally 75% backfill shows a significant increase in peak strength, and the increase in peak strength is more pronounced for the pillars having lower w/h ratios. In case of noncohesive backfill, the changes in both the peak and residual strengths with up to 92% backfill are negligible while the residual strength constantly increases after reaching the peak strength only when 100%backfill is placed. Based on the modelling results, different backfilling strategies should be considered on a case by case basis depending on the type of backfill available and desired pillar dimension.     

Antenatal steroids, condition at birth and respiratory morbidity and mortality in very preterm infants

The study purpose was to compare the effect of exercise training on serum lipid and apolipoprotein concentrations and the activities of intravascular enzymes related to lipid transport in previously untrained eumenorrheic, premenopausal (PRM) women (n = 21; mean age, 36 +/- 3 years) and estrogen-free postmenopausal (POM) women (n = 16; mean age, 68 +/- 8 years). Subjects trained at a progressive intensity and duration (50% to 75% maximal O2 consumption [VO2max], 200 to 300 kcal/session) 4 d/wk for 12 weeks. Before and after training, VO2max, body weight, relative body fat, and fasting blood samples were obtained following 2 weeks on a standardized diet designed to maintain body weight and during the early follicular stage for the PRM group. Blood samples were analyzed for serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), the cholesterol content of the HDL3 subfraction, apolipoprotein (apo)A-I and apoB, lipoprotein(a), and the activity of lecithin:cholesterol acyltransferase (LCAT). Total and hepatic triglyceride lipase activity (HTGLA) were determined from plasma samples obtained after heparin administration. The cholesterol content of the low-density lipoprotein (LDL) and HDL2 subfractions and endothelial-bound lipoprotein lipase activity (LPLA) were calculated. A two (group) x two (time) multivariate ANOVA (MANOVA), with repeated measures for time indicated that the exercise-induced changes in physiological measurements, serum lipid or apolipoprotein concentrations, or enzyme activities did not differ between groups. Serum concentrations of TC, LDL-C, and HDL3 cholesterol, TG, and apo A-I and apoB were higher in POM women compared with the PRM group (P < .05 for all). For the combined groups, body weight and relative body fat did not change with training, but VO2max increased an average of 18.5% (P < .05). LPLA, HTGLA, and LCAT activity were unaltered with exercise training. Except for a small but significant decrease in HDL-C (-5.5%) and an elevation in apoB (4.3%; P < .05 for both), the concentrations of serum lipids and apolipoproteins did not change over the training period. We conclude that in previously untrained women, menopausal status does not influence the exercise training response of serum lipids or apolipoproteins or activities of intravascular enzymes related to lipid transport.     

The good, the bad and the juggled: the new ethics of building materials

In much environmental analysis, architecture is reduced to a fraction of itself: the architectural-artefact-as-physical-object. Its symbolic and self-referential capacities, its aesthetic and spatial concerns ww- that which conventionally characterises it as 'design'- are dismissed as irrelevant to the crisis at hand. What 'meaning' architecture is permitted thus tends to be discussed in quantifiable terms: energy ratings, insulation values, etc. This data, however, only has meaning because it is contained within a larger hermeneutic framework, an ethical one. That is, buildings meeting certain environmental performance criteria are deemed ethically acceptable because they are taking into consideration the well-being of a larger community, whether that community is exclusively human, or inclusive of all life. This is a new definition of the ethical in architecture, new because what is conventionally viewed as a qualitative judgement is being considered in quantitative terms, with all the problems of interpretation inherent in such a direction.     

Hepatitis C virus transmission dynamics in injection drug users

Hepatitis C virus (HCV) presents several challenges to the development of prevention programs. HCV infection is persistent in up to 80% of cases, and viremic individuals may transmit infection to others. With 65-90% of injection drug users anti-HCV positive, a large reservoir of infection exists in most drug-injector populations. Studying the genetic variability of HCV infections could permit researchers to reconstruct chains of viral transmission in IDUs. However, the relationship of HCV to HIV epidemiology remains unclear and may depend on whether the proportions of infectious persons in the population are similar for both viruses.     

The fission yeast SPB component Cut12 links bipolar spindle formation to mitotic control

During fission yeast mitosis, the duplicated spindle pole bodies (SPBs) nucleate microtubule arrays that interdigitate to form the mitotic spindle. cut12.1 mutants form a monopolar mitotic spindle, chromosome segregation fails, and the mutant undergoes a lethal cytokinesis. The cut12(+) gene encodes a novel 62-kD protein with two predicted coiled coil regions, and one consensus phosphorylation site for p34(cdc2) and two for MAP kinase. Cut12 is localized to the SPB throughout the cell cycle, predominantly around the inner face of the interphase SPB, adjacent to the nucleus. cut12(+) is allelic to stf1(+); stf1.1 is a gain-of-function mutation bypassing the requirement for the Cdc25 tyrosine phosphatase, which normally dephosphorylates and activates the p34(cdc2)/cyclin B kinase to promote the onset of mitosis. Expressing a cut12(+) cDNA carrying the stf1.1 mutation also suppressed cdc25.22. The spindle defect in cut12.1 is exacerbated by the cdc25.22 mutation, and stf1.1 cells formed defective spindles in a cdc25.22 background at high temperatures. We propose that Cut12 may be a regulator or substrate of the p34(cdc2) mitotic kinase.     

Association between coronary heart disease and cancers of the breast, prostate, and colon

Coronary heart disease (CHD) and cancers of the breast, prostate, and colon are more common in industrialized countries than in the developing world, and to some degree, these conditions appear to share risk factors. To investigate whether there is an association between these cancers and a prior history of CHD, a hospital-based case-control study was conducted at Columbia-Presbyterian Medical Center in New York. The study was based on 252 breast cancer cases, 256 colorectal cancer cases, and 322 benign surgical controls, all of whom underwent biopsy or surgery between January 1989 and December 1992, and on 319 prostate cancer cases and 189 benign prostatic hypertrophy controls diagnosed between January 1984 and December 1986 (prior to widespread use of prostate-specific antigen screening). Medical records were reviewed on each, focusing on the preoperative anesthesia and surgical clearances. No association was found between a history of CHD and breast or colorectal cancer, but an elevated risk was found for prostate cancer (odds ratio, 2.00; 95% confidence interval, 1.18-3.39), using unconditional logistic regression with adjustment for appropriate confounders. No association was found between cigarette smoking and any of the three cancers. Aspirin use was protective for colorectal cancer (odds ratio, 0.35; 95% confidence interval, 0.17-0.73) but had no association with breast or prostate cancer. The study suggests that individuals with CHD are at elevated risk for prostate cancer but not breast or colorectal cancer. Etiological risk factors associated with CHD should be investigated with regard to prostate cancer. Patients with CHD may represent a high-risk group for prostate cancer and potential future targets for prostate cancer screening interventions.