Variation in Perthitic Microcline From a Zoned Pegmatite

Quantitative microscopic and chemical anaylses of 12 specimens of microcline, most of them perthitic, from the zoned Hugo pegmatite in the Black Hills near Keystone, South Dakota, have yielded data that can be used to estimate the temperatures of crystallization at successive stages in the formation of the pegmatite. The determined temperatures of crystallization range from 565°C in zone 3a, near the margin of the pegmatite, to 280°C in zone 7, the core

Stepped spillway model pressures characteristics, Susu Dam Malaysia

Susu Dam is an RCC Dam under construction in Peninsula Malaysia. The dam design has been carried out by SMEC International in its offices in Kuala Lumpur. The dam is some 90 m tall. The overfall stepped spillway provides for discharges to enter a hydraulic jump stilling basin for energy dissipation, prior to passing through a culvert under a roadway. The spillway was subject to hydraulic model testing at the Utah Water Research Laboratory of Utah State University (USA), at a length scale of 1:30. The hydraulic performance of the spillway design was evaluated up to the 4,700 m3/s Probable Maximum Flood (PMF) discharge (almost 1,000 L/s model scale). The spillway was tested through a number of configurations, prior to the development of the final arrangement. The purpose of the paper is to describe the modelling detail, and then focus on the flow behaviour at the stair-stepped spillway chute with 2.4 m high steps, in particular the piezometric pressures and transient pressures on the tread and riser of the steps. The spillway chute converged from ~100 m at the crest to 78 m at the bottom at entrance to the stilling basin; the unit discharge entering the stilling basin was ~ 60 m2/s for the PMF. Of particular interest was the occurrence of negative pressures on the steps, and the paper will describe the transients for several discharges from the AEP 1 in 1,000 up to the PMF; the results indicating very low pressures into a cavitation region. The design provides for an aerator across the spillway in order to counter the effects of possible cavitation. Results will be presented with and without the aerator operating. The paper provides useful design information for the hydraulic design of stepped spillways

Prognostic relevance of dynamic hyperinflation during cardiopulmonary exercise testing in adult patients with cystic fibrosis

AbstractBackgroundDynamic hyperinflation during cardiopulmonary exercise testing (CPET) in cystic fibrosis (CF) has not been well characterized, and little is known regarding its prevalence, risk factors and clinical associations.MethodsCPET data from 109 adult patients with mild-to-moderate CF was used, in this retrospective study, to characterize and determine the prevalence of dynamic hyperinflation, and evaluate its relationship with lung function and exercise tolerance, clinical symptoms, and prognosis over a two-year period.Results58% of patients responded to CPET with dynamic hyperinflation. These patients had significantly lower lung function (FEV1 66±19 versus 79±18%pred., p<0.01) and exercise tolerance (peak oxygen uptake 28.7±8.1 versus 32.9±6.1mL·kg−1·min−1, p=0.02), and experienced greater shortness of breath at peak exercise (7±3 versus 5±2 Modified Borg scale, p=0.04) compared to patients who responded without dynamic hyperinflation. Significant relationships between FEV1, FVC, FEV1/FVC, FEF25–75 and dynamic hyperinflation were shown (p<0.01; p=0.02; p<0.01; p<0.01, respectively). Dynamic hyperinflation was also significantly correlated with oxygen uptake, tidal volume, work-rate and shortness of breath at peak exercise (p=0.03; p<0.01; p<0.01; p=0.04, respectively). Responding to CPET with or without dynamic hyperinflation did not significantly predict FEV1 at 2years beyond the FEV1 at baseline (p=0.06), or increase the likelihood of experiencing a pulmonary exacerbation over a two-year period (p=0.24).ConclusionThe prevalence of dynamic hyperinflation during CPET in adult patients with mild-to-moderate CF is high, and is associated with reduced lung function and exercise tolerance, and increased exertional dyspnea. However, identifying dynamic hyperinflation during CPET had limited prognostic value for lung function and pulmonary exacerbation

Molecular consequences of cystic fibrosis transmembrane regulator (CFTR) gene mutations in the exocrine pancreas

Background and aims: We tested the hypothesis that the actual or predicted consequences of mutations in the cystic fibrosis transmembrane regulator gene correlate with the pancreatic phenotype and with measures of quantitative exocrine pancreatic function. Methods: We assessed 742 patients with cystic fibrosis for whom genotype and clinical data were available. At diagnosis, 610 were pancreatic insufficient, 110 were pancreatic sufficient, and 22 pancreatic sufficient patients progressed to pancreatic insufficiency after diagnosis. Results: We identified mutations on both alleles in 633 patients (85.3%), on one allele in 95 (12.8%), and on neither allele in 14 (1.9%). Seventy six different mutations were identified. The most common mutation was ΔF508 (71.3%) followed by G551D (2.9%), G542X (2.3%), 621+1G→T (1.2%), and W1282X (1.2%). Patients were categorized into five classes according to the predicted functional consequences of each mutation. Over 95% of patients with severe class I, II, and III mutations were pancreatic insufficient or progressed to pancreatic insufficiency. In contrast, patients with mild class IV and V mutations were consistently pancreatic sufficient. In all but four cases each genotype correlated exclusively with the pancreatic phenotype. Quantitative data of acinar and ductular secretion were available in 93 patients. Patients with mutations belonging to classes I, II, and III had greatly reduced acinar and ductular function compared with those with class IV or V mutations. Conclusion: The predicted or known functional consequences of specific mutant alleles correlate with the severity of pancreatic disease in cystic fibrosis.published_or_final_versio

Thermoanaerosceptrum fracticalcis gen. nov. sp. nov., a novel fumarate-fermenting microorganism from a deep fractured carbonate aquifer of the US Great Basin

Deep fractured rock ecosystems across most of North America have not been studied extensively. However, the US Great Basin, in particular the Nevada National Security Site (NNSS, formerly the Nevada Test Site), has hosted a number of influential subsurface investigations over the years. This investigation focuses on resident microbiota recovered from a hydrogeologically confined aquifer in fractured Paleozoic carbonate rocks at 863 – 923 m meters below land surface. Analysis of the microorganisms living in this oligotrophic environment provides a perspective into microbial metabolic strategies required to endure prolonged hydrogeological isolation deep underground. Here we present a microbiological and physicochemical characterization of a deep continental carbonate ecosystem and describe a bacterial genus isolated from the ecosystem. Strain DRI-13T is a strictly anaerobic, moderately thermophilic, fumarate-respiring member of the phylum Firmicutes. This bacterium grows optimally at 55°C and pH 8.0, can tolerate a concentration of 100 mM NaCl, and appears to obligately metabolize fumarate to acetate and succinate. Culture-independent 16S rRNA gene sequencing indicates a global subsurface distribution, while the closest cultured relatives of DRI-13T are Pelotomaculum thermopropionicum (90.0% similarity) and Desulfotomaculum gibsoniae (88.0% similarity). The predominant fatty acid profile is iso-C15:0, C15:0, C16:0 and C14:0. The percentage of the straight-chain fatty acid C15:0 is a defining characteristic not present in the other closely related species. The genome is estimated to be 3,649,665 bp, composed of 87.3% coding regions with an overall average of 45.1% G+C content. Strain DRI-13T represents a novel genus of subsurface bacterium isolated from a previously uncharacterized rock-hosted geothermal habitat. The characterization of the bacterium combined with the sequenced genome provides insights into metabolism strategies of the deep subsurface biosphere. Based on our characterization analysis we propose the name Thermoanaerosceptrum fracticalcis (DRI-13T = DSM 100382T = ATCC TSD-12T)

Dioxinlike properties of a trichloroethylene combustion-generated aerosol.

Conventional chemical analyses of incineration by-products identify compounds of known toxicity but often fail to indicate the presence of other chemicals that may pose health risks. In a previous report, extracts from soot aerosols formed during incomplete combustion of trichloroethylene (TCE) and pyrolysis of plastics exhibited a dioxinlike response when subjected to a keratinocyte assay. To verify this dioxinlike effect, the complete extract, its polar and nonpolar fractions, some containing primarily halogenated aromatic hydrocarbons, were evaluated for toxicity using an embryo assay, for antiestrogenicity using primary liver cell cultures, and for the ability to transform the aryl hydrocarbon receptor into its DNA binding form using liver cytosol in a gel retardation assay. Each of these assays detect dioxinlike effects. Medaka (Oryzias latipes) embryos and primary liver cell cultures of rainbow trout (Oncorhynchus mykiss) were exposed to concentrations of extract ranging from 0.05 to 45 micrograms/l. Cardiotoxicity with pericardial, yolk sac, and adjacent peritoneal edema occurred after exposure of embryos to concentrations of 7 micrograms/l or greater. These same exposure levels were associated with abnormal embryo development and, at the higher concentrations, death. Some of the fractions were toxic but none was as toxic as the whole extract. In liver cells, total cellular protein and cellular lactate dehydrogenase activity were not altered by in vitro exposure to whole extract (0.05-25 micrograms/l). However, induction of cytochrome P4501A1 protein and ethoxyresorufin O-deethylase activity occurred. In the presence of whole extract, estradiol-dependent vitellogenin synthesis was reduced. Of the fractions, only fraction 1 (nonpolar) showed a similar trend, although vitellogenin synthesis inhibition was not significant. The soot extract and fractions bound to the Ah receptor and showed a significantly positive result in the gel retardation/DNA binding test. Chemical analyses using GC-MS with detection limits for 2,3,7,8-tetrachlorodibenzo-p-dioxin and dibenzofuran in the picomole range did not show presence of these compounds. Our results indicate that other chemicals associated with TCE combustion and not originally targeted for analysis may also pose health risks through dioxinlike mechanisms

An international/multicentre report on patients with cystic fibrosis (CF) over the age of 40 years

AbstractBackgroundThe lifespan of patients with cystic fibrosis (CF) is increasing significantly. The objective of this international pilot study was to study the characteristics of these long-term survivors.MethodsFour centres with large CF clinics from London (UK), Minneapolis (USA), Toronto (Canada) and Verona (Italy) identified 366 patients who had survived 40years and longer.ResultsAt all centres males survived longer than females. There were more pancreatic sufficient patients in Verona (60%) and Toronto (40%) than in London (16%) and Minneapolis (21%). The percentage of ΔF508 homozygous patients varied between 47% in London and 45% in Minneapolis to only 26% in Toronto and 9% in Verona.Average FEV1 and BMI values of the surviving population appeared to stabilise after 40years of age. FEV1 was on average 12% higher in patients who were pancreatic sufficient (p > 0.0001). There was no difference in survival between the centres. The overall median survival after the age of 40 was 13years. The estimated annual death rate was approximately 3.4% from the age of 40–60years.ConclusionsSignificant numbers of patients are now surviving to 40years or more, and it is hoped that an in-depth study of these patients may identify the factors contributing to longer survival

The Role of Physical, Chemical, and Microbial Heterogeneity on the Field-Scale Transport and Attachment of Bacteria

A field-scale bacterial transport experiment was conducted at the Narrow Channel Focus Area of the South Oyster field site located in Oyster, Virginia. The goal of the field experiment was to determine the relative influence of subsurface heterogeneity and microbial population parameters on flow direction, velocity, and attachment of bacteria at the field scale. The field results were compared with results from laboratory-scale column experiments to develop a method for predicting field-scale bacterial transport. The field site is a shallow, sandy, unconfined, aerobic aquifer that has been characterized by geophysical, sedimentological, and hydrogeological methods. Comamonas sp. strain DA001 and a conservative tracer, bromide (Br), were injected into an area of high permeability for 12 hours. The Br and bacterial concentrations in the groundwater were monitored for 1 week at 192 sampling ports spaced over a 2-m vertical zone located from 0.5 to 7 m down-gradient of the injection well. The bacterial and Br plume was observed to move past 95 sampling ports. The densely characterized field site enabled the comparison of variations in DA001 transport to the aquifer properties. The velocity of the injected plume was correlated with geophysical estimates of hydraulic conductivity. The bacterial and Br plume appeared to follow flow paths not coincident with the hydraulic gradient but through a zone of higher permeability located off the flow axis. The amount of breakthrough of the bacteria was similar in both the high and low permeability layers with only a weak correlation between the observed hydraulic conductivity and amount of bacterial breakthrough. The uniformity in the observed attachment rates across varying grain sizes could be explained by heterogeneity of microbial properties within the single strain of injected bacteria. Application of colloid filtration theory to the field data indicated that variations in the microbial population were described by a lognormal distribution of the collision efficiency (a). Core-scale studies were used to predict the a distribution and field-scale transport distances of DA001. In sandy aquifers, physical heterogeneity may play a secondary role in controlling field-scale bacterial transport, and future research should focus on the microbial factors affecting transport