Effects of pH and Concentrations of Linoleic and Linolenic Acids on Extent and Intermediates of Ruminal Biohydrogenation in Vitro

Three experiments were conducted by in vitro incubations in ruminal fluid to investigate the effects of pH and amounts of linoleic and linolenic acids on the extent of their biohydrogenation, the proportions of conjugated linoleic acid (CLA) and trans-C18:1 as intermediates, and the ratio trans-10:trans-11 intermediates. The effects of pH and amount of linoleic acid were investigated in kinetic studies, and effects of the amount of linolenic acid were studied with 6-h incubations. With identical initial amounts of linoleic acid, its disappearance declined when the mean pH during incubation was under 6.0 compared with a mean pH over 6.5, and when the amount of linolenic acid increased from 10 to 180 mg/160-ml flask, suggesting an inhibition of the isomerization step of the biohydrogenation. Low pH decreased the ratio of trans-10:trans-11 intermediates. With initial amounts of linoleic acid increasing from 100 to 300 mg, the percentage of linoleic acid disappearance declined, but the amount that disappeared increased, without modification of the trans-10:trans-11 ratio, suggesting a maximal capacity of isomerization rather than an inhibition. Moreover, increasing initial linoleic acid resulted in high amounts of trans-C18:1 and an increase of C18:0 that was a linear function of time, suggesting a maximal capacity for the second reduction step of biohydrogenation. High amounts of initial linolenic acid did not affect the amounts of CLA, trans-C18:1, or the ratio trans-10:trans-11. Based on these experiments, a ruminal pH near neutrality with high amount of dietary linoleic acid should modulate the reactions of biohydrogenation in a way that supports CLA and trans-11C18:1 in the rumen

In Vitro Versus in Situ Ruminal Biohydrogenation of Unsaturated Fatty Acids from a Raw or Extruded Mixture of Ground Canola Seed/Canola Meal

Raw or extruded blends of ground canola seeds and canola meal were used to compare in vitro and in situ lag times and rates of disappearance due to ruminal biohydrogenation of unsaturated fatty acids. The in situ study resulted in higher lag times for biohydrogenation for polyunsaturated fatty acids and lower rates of biohydrogenation of unsaturated fatty acids than the in vitro study, so the in situ biohydrogenation of polyunsaturated fatty acids was not complete at 24 h of incubation. With both methods, rates of biohydrogenation of polyunsaturated fatty acids were higher than for cis-9C18:1. Extrusion did not affect the rate of biohydrogenation of cis-9C18:1, but resulted in higher rates of biohydrogenation of polyunsaturated fatty acids with higher proportions of trans intermediates of biohydrogenation at 4 h of incubation in vitro and at 8 h of incubation in situ. These results suggest that extrusion affects the isomerization of polyunsaturated fatty acids, rather than the hydrogenation steps. In conclusion, in vitro and in situ methods can both show differences of ruminal metabolism of unsaturated fatty acids due to processing, but the methods provide very different estimates of the rates of disappearance due to biohydrogenation

Oil & Gas Water Use in Texas: Update to the 2011 Mining Water Use Report

In Spring 2012, we undertook an update of the hydraulic fracturing sections of the TWDB-sponsored report titled “Current and Projected Water Use in the Texas Mining and Oil and Gas Industry” that we published in June 2011 (Nicot et al., 2011). The 2011 report provided estimated county-level water use in the oil and gas industry in 2008 and projections to 2060. This 2012 update was prompted by two main events: (1) a major shift of the oil and gas industry from gas to oil production, displacing production centers across the state and impacting county-level amounts; (2) rapid development of technological advances, resulting in more common reuse and in the ability to use more brackish water. The timely update was enabled by a faster than anticipated development, translating into abundant statistical data sets from which to derive projections, and by an increased willingness of the industry to participate in providing detailed information about water use in its operations. This document follows the same methodology as the 2011 report but differs from it in two ways. Our current update clearly distinguishes between water use and water consumption. The 2011 report does not include reuse from neighboring hydraulic fracturing jobs, recycling from other industry operations or other treatment plants, and use of brackish water. Our update also presents three scenarios: high, low, and most likely water use and consumption with a focus on water consumption. This update has been reviewed by the TWDB and should supersede oil and gas industry projections from the 2011 report.Bureau of Economic Geolog

Area of review: how large is large enough for carbon storage?

The Texas Gulf Coast is an attractive target for carbon storage. Stacked sand-shale layers provide large potential storage volumes and defense-in-depth leakage protection. However, multiple perforations resulting from intensive hydrocarbon exploration and production have weakened seal integrity in many favorable locations. If the ultimate goal of carbon storage is to isolate large volumes of CO2 for hundreds to thousands of years, plume migration will encounter inadequately completed wells miles away from the injection zone. Moreover, the detrimental impact of CO2 on cement could undermine the structural integrity of all contacted wells, although pressure effects subside quickly after injection. Even wells abandoned to current standards cannot be guaranteed leak-free in the long term. We describe spatial statistics extracted from the Texas RRC Well Bore database as applied to carbon storage. Although the Area of Review (AOR) has been traditionally defined by a fixed radius with the strong regulatory requirement that the injectate stays within the injection layer, buoyancy is a major characteristic of CO2 that introduces a third dimension into the Area of Review process. Using simple geological mapping to characterize structural traps, we determine the likely pathway and the contacted volume of a migrating plume. The latter can be as large as a fault compartment with dimensions of 20 km × 20 km. However, the contacted volume is ultimately a function of the total injected volume, and the specifics of each project should dictate the dimensions of the zone of endangering influence (ZEI). An option, viable for the Texas Gulf Coast, to reduce geologic uncertainty, to decrease the impact of wells, and to limit the amount of information to be collected, is to inject CO2 below the maximum penetration of most wells.Bureau of Economic Geolog

Oidium neolycopersici: Intra-specific variability inferred from AFLP analysis and relationship with closely related powdery mildew fungi infecting various plant species

Previous works indicated a considerable variation in the pathogenicity, virulence, and host range of Oidium neolycopersici isolates causing tomato powdery mildew epidemics in many parts of the world. In this study, rDNA internal transcribed spacer (ITS) sequences, and amplified fragment length polymorphism (AFLP) patterns were analyzed in 17 O. neolycopersici samples collected in Europe, North America, and Japan, including those which overcame some of the tomato major resistance genes. The ITS sequences were identical in all 10 samples tested and were also identical to ITS sequences of eight previously studied O. neolycopersici specimens. The AFLP analysis revealed a high genetic diversity in O. neolycopersici and indicated that all 17 samples represented different genotypes. This might suggest the existence of either a yet unrevealed sexual reproduction or other genetic mechanisms that maintain a high genetic variability in O. neolycopersici. No clear correlation was found between the virulence and the AFLP patterns of the O. neolycopersici isolates studied. The relationship between O. neolycopersici and powdery mildew anamorphs infecting Aquilegia vulgaris, Chelidonium majus, Passiflora caerulea, and Sedum alboroseum was also investigated. These anamorphs are morphologically indistinguishable from and phylogenetically closely related to O. neolycopersici. The cross-inoculation tests and the analyses of ITS sequences and AFLP patterns jointly indicated that the powdery mildew anamorphs collected from the above mentioned plant species all represent distinct, but closely related species according to the phylogenetic species recognition. All these species were pathogenic only to their original host plant species, except O. neolycopersici which infected S. alboroseum, tobacco, petunia, and Arabidopsis thaliana, in addition to tomato, in cross-inoculation tests. This is the first genome-wide study that investigates the relationships among powdery mildews that are closely related based on ITS sequences and morphology. The results indicate that morphologically indistinguishable powdery mildews that differed in only one to five single nucleotide positions in their ITS region are to be considered as different taxa with distinct host ranges

In situ ruminal biohydrogenation of fatty acids from extruded soybeans: effects of dietary adaptation and of mixing with lecithin or wheat straw

Kinetics and intermediates of biohydrogenation of fatty acids were investigated in situ using extruded soybeans, a blend of extruded soybeans and lecithin (99:1), or a blend of extruded soybeans plus wheat straw (66:34). Two dry dairy cows received successively a diet with added palmitic acid and a diet with added extruded soybeans, and assays were completed after a 3-week adaptation to each diet. Adaptation of the cows to dietary polyunsaturated fatty acids suppressed the lag time before the beginning of biohydrogenation. Adaptation of cows, and mixing straw with soybeans, increased the rate of biohydrogenation of C18:2 and C18:3, resulting in less C18:2 and C18:3, and more trans C18:1 and C18:0 in the in situ bags. Lecithin did not affect the kinetics of biohydrogenation or the profile of fatty acids in the in situ bags. Differences in the rate of biohydrogenation, and profile of residual fatty acids in the bags were observed between the two cows. Even with a mixture of soybeans and straw in cows receiving dietary polyunsaturated fatty acids, biohydrogenation was slower and resulted in higher proportions of trans-C18:1 than expected from results of literature in vivo. Resultsshow that the biohydrogenation in situ is slow, highly dependent on experimental conditions, and that the use of several cows, adapted to the test fat source before the assay is initiated, is necessary in order to obtain a reliable estimate of kinetics parameters

Monitoring Stray Natural Gas in Groundwater With Dissolved Nitrogen. An Example From Parker County, Texas

Concern that hydraulic fracturing and natural gas production contaminates groundwater requires techniques to attribute and estimate methane flux. Although dissolved alkane and noble gas chemistry may distinguish thermogenic and microbial methane, low solubility and concentration of methane in atmosphereâ equilibrated groundwater precludes the use of methane to differentiate locations affected by high and low flux of stray methane. We present a method to estimate stray gas infiltration into groundwater using dissolved nitrogen. Due to the high concentration of nitrogen in atmosphericâ recharged groundwater and low concentration in natural gas, dissolved nitrogen in groundwater is much less sensitive to change than dissolved methane and may differentiate groundwater affected high and low flux of stray natural gas. We report alkane and nitrogen chemistry from shallow groundwater wells and eight natural gas production wells in the Barnett Shale footprint to attribute methane and estimate mixing ratios of thermogenic natural gas to groundwater. Most groundwater wells have trace to nondetect concentrations of methane. A cluster of groundwater wells have greater than 10 mg/L dissolved methane concentrations with alkane chemistries similar to natural gas from the Barnett Shale and/or shallower Strawn Group suggesting that localized migration of natural gas occurred. Twoâ component mixing models constructed with dissolved nitrogen concentrations and isotope values identify three wells that were likely affected by a large influx of natural gas with gas:water mixing ratios approaching 1:5. Most groundwater wells, even those with greater than 10â mg/L methane, have dissolved nitrogen chemistry typical of atmosphereâ equilibrated groundwater suggesting natural gas:water mixing ratios smaller than 1:20.Plain Language SummaryHydraulic fracturing, horizontal drilling, and associated natural gas production have dramatically changed the energy landscape across America over the past 10 years. Along with this renaissance in the energy sector has come public concern that hydraulic fracturing may contaminate groundwater. In this study we measure the chemistry of dissolved gas from shallow groundwater wells located above the Barnett Shale natural gas play, a tight gas reservoir located west of the Dallasâ Fort Worth Metroplex. We compare groundwater chemistry results to natural gas chemistry results from nearby production wells. Most groundwater wells have trace to nondetectible concentrations of methane, consistent with no measurable infiltration of natural gas into shallow groundwater. A cluster of groundwater wells have greater than 10 mg/L dissolved methane concentrations with alkane chemistries similar to natural gas. Using dissolved nitrogen and alkane concentrations and their stable isotope ratios in combination with chemical mixing models, we conclude that natural gas transported from the shallower Strawn Group affected these groundwater wells rather than natural gas from the deeper Barnett Shale, which is the target of hydraulic fracturing in this area. These results suggest that hydraulic fracturing has not affected shallow groundwater drinking sources in this area.Key PointsDissolved nitrogen in groundwater provides a means to differentiate highâ and lowâ flux infiltration of stray gasNitrogen concentrations and isotope values may attribute natural gas sourcesPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146362/1/wrcr23523.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146362/2/wrcr23523_am.pd

Altered splicing of the BIN1 muscle-specific exon in humans and dogs with highly progressive centronuclear myopathy

Amphiphysin 2, encoded by BIN1, is a key factor for membrane sensing and remodelling in different cell types. Homozygous BIN1 mutations in ubiquitously expressed exons are associated with autosomal recessive centronuclear myopathy (CNM), a mildly progressive muscle disorder typically showing abnormal nuclear centralization on biopsies. In addition, misregulation of BIN1 splicing partially accounts for the muscle defects in myotonic dystrophy (DM). However, the muscle-specific function of amphiphysin 2 and its pathogenicity in both muscle disorders are not well understood. In this study we identified and characterized the first mutation affecting the splicing of the muscle-specific BIN1 exon 11 in a consanguineous family with rapidly progressive and ultimately fatal centronuclear myopathy. In parallel, we discovered a mutation in the same BIN1 exon 11 acceptor splice site as the genetic cause of the canine Inherited Myopathy of Great Danes (IMGD). Analysis of RNA from patient muscle demonstrated complete skipping of exon 11 and BIN1 constructs without exon 11 were unable to promote membrane tubulation in differentiated myotubes. Comparative immunofluorescence and ultrastructural analyses of patient and canine biopsies revealed common structural defects, emphasizing the importance of amphiphysin 2 in membrane remodelling and maintenance of the skeletal muscle triad. Our data demonstrate that the alteration of the muscle-specific function of amphiphysin 2 is a common pathomechanism for centronuclear myopathy, myotonic dystrophy, and IMGD. The IMGD dog is the first faithful model for human BIN1-related CNM and represents a mammalian model available for preclinical trials of potential therapies

Associations between ACTN3 and OPPERA pain-related genes in malocclusion

We have investigated an orthognathic surgery population to determine how variation in masticatory muscle gene expression and genotype plays a key role in development of both jaw-deformation malocclusion and temporomandibular joint disorders (TMD). A gene of particular interest is ACTN3 since the common R577X polymorphism results in α-actinin-3 protein loss, reduced myofiber Z-disc structural integrity in skeletal muscle and decreased osteoblast/osteoclast activity in bone formation. Secondly, since the prevalence of TMD in this population is quite high (30%) we sought to determine if genes related to pain processes─previously identified in the Orofacial Pain: Prospective Evaluation and Risk Assessment Study (OPPERA) were differentially expressed