Browsing by Subject "pH"
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Item Algal biofuels : the effect of salinity and pH on growth and lipid content of algae(2009-08) Gutierrez, Cesar Carlos; Marshall, Jill Ann; Sathasivan, Kanagasabapathi; Mehdy, Mona Cynthia, 1955-Supplies of nonrenewable fossil fuels are becoming more limited even as they continue to contribute to pollution and economic concerns. Alternative sources of energy must be developed that help minimize these problems. One potential source of energy is the production of biofuels from algae. Here we evaluate algae found in South Texas brackish water ponds used for aquaculture of fish as a possible source of biofuels. In particular, we examine the effects of salinity and pH on the growth and lipid content of the algae. Samples of algae from the ponds exhibited high levels of growth and lipid production at a salinity of 9 ppt and pH 7. These conditions are similar to the natural conditions of the ponds, indicating that they may be a good source of algal biofuels.Item Ambient pH signaling influences phosphate transport in Neurospora crassa(Texas A&M University, 2007-04-25) Kennedy, Patrick WadeIn the course of our efforts to resolve Pi transport mechanisms in the model fungus Neurospora crassa we identified a null mutant, par-1, that displays enhanced Pi transport activity specifically under alkaline growth conditions. The PAR-1 protein is related to PalF of Aspergillus nidulans, which is one component of an ambient pH signaling pathway that is conserved among fungi. A deletion mutant for the PacC homolog, another component of the same pathway, phenocopies par-1, demonstrating that a defect in pH signaling is responsible for the altered Pi transport activity. Our results indicate that pH signaling in N. crassa plays an important role in coordinating high and low affinity Pi transport in response to ambient pH, but through different mechanisms. Sulfate acquisition also is influenced by pH signaling, suggesting that this regulatory system has a broad role in nutrient uptake and homeostasis.Item AMPHIBIANS OF THE SOUTHERN GREAT PLAINS: HABITAT AND THE IMPACTS OF TEMPERATURE AND pH ON SURVIVAL(2013-05) Kissner, Jessica; Griffis-Kyle, Kerry; McIntyre, Nancy E.; Haukos, David A.; Wallace, Mark C.Global climate change has had an increasing role in the decline of amphibian populations due to direct (e.g. critical temperature thresholds) and indirect (e.g. temperature stress, spreading of disease, and habitat alteration and loss) effects of increasing atmospheric temperature. Due to the complexity of habitats needed to complete all of their life stages, amphibians are subject to stressors through a number of systems (e.g., water quality, climatic characteristics, and terrestrial habitat). Furthermore, habitat currently used by amphibians may become inhospitable due to indirect stressing effects of increased temperatures projected for the Southern Great Plains (SGP). To protect and manage for species at risk, we must first understand their basic community assemblages, distributions, habitat associations, and tolerances. Because little amphibian research has come from northeastern New Mexico, collecting data on these parameters will be a useful tool for future research and management in this area. The objectives of this study were to: (1) examine amphibian species presence, richness, an index of reproductive success, and larval growth in northeastern New Mexico and relate them to site-specific and landscape-level habitat characteristics and (2) identify environmental factors that may jeopardize population persistence in the future. After conducting field work, I determined an additional objective based on the current average high temperature (28.3°C) and pH ranges (4.9 to 9.4) I recorded: (3) to determine the effect of a 5.6°C increase in average summer temperature by 2090 (to 33.9°C) due to climate change on embryo and tadpole survival, the effects of pH 4.9 and 9.4 on embryo and tadpole survival, and the effects of the interactions between pH and temperature on embryo and tadpole survival. Over 2011 and 2012, I sampled each playa wetland 5 times over a 17-day sampling period after precipitation of >2cm using call, visual encounter, egg mass, dip net, and funnel trap surveys to examine the amphibian community. I also collected tadpole measurements throughout development to examine larval growth patterns. Water quality was sampled during each survey, and ArcMap was employed to determine landscape-level habitat features. I sampled 14 playa wetlands in northeastern New Mexico, detecting 7 amphibian species with a maximum species richness per playa of 4. I detected reproduction in 4-6 species (as Pelobatid tadpoles are difficult to identify to species), and larval growth in Anaxyrus cognatus, Pseudacris clarkii, and Pelobatid spp. was exponential up to age 17 days (all p < 0.01). I also documented the first New Mexico state record of Pseudacris clarkii (spotted chorus frog). Although I did not document any statistically significant associations between amphibian species presence, richness, or reproductive success and habitat characteristics, I observed a trend of no P. clarkii reproduction at the acidic sites (4.9-6.9) even though adults were present in playa wetlands with pH 4.9-9.4. Based on my field observations about amphibian natural history from 2011, I hypothesized that increased temperature due to global climate change in 2090 may influence the ability of anurans to survive in pH-stressed playas. I tested these hypotheses in the lab in order to strengthen my field-based inferences. In 2012, I performed a fully-factorial laboratory experiment using the 2011 pH extremes (4.9 and 9.4), 2011 current average temperature (28.3°C), and 2090 projected temperature (33.9°C ), with embryos from 3 pairs of wild-caught P. clarkii. The results of my experiment suggest that P. clarkii cannot successfully reproduce in water with high temperature (33.9°C), regardless of the pH conditions. Furthermore, survival to metamorphosis in acidic conditions (pH 4.9), regardless of temperature, is unlikely, findings consistent with both my field observations and laboratory results. Survival to metamorphosis in basic conditions (pH 9.4) is very low (9%), compared to survival at pH 7 (84 %) that other studies have documented. Based on my findings, an increase in summer temperature of 5.6°C over the next 70 years will likely cause mortality and extirpation of some amphibian species in the Southern Great Plains. My results demonstrate the threat to P. clarkii due to projected climate change and suggest that other amphibian species may also be vulnerable, particularly for anuran populations that are at the edge of their range such as Gastrophryne olivaea, a New Mexico state-endangered species. By combining field and laboratory techniques and coming to a similar conclusion, I have been able to provide conclusions about the effect of temperature and pH on amphibian survival and population persistence.Item Continuous fermentation of food scraps with constant pH control to produce carboxylic acids(2009-05-15) Coleman Jr., Stanley AlbertGlobal energy demands combined with environmental restrictions are fueling a move to alternative energy sources. Biofuels are formed from biomass; the MixAlco process is one such method. In this work, food scraps are explored as a potential feedstock to the MixAlco process. Batch fermentation with various temperatures, buffers, and pH control methods elucidated the behavior of food scraps during fermentation. The pH and reactor configuration were limiting factors when maximizing production. A fermentor was developed and tested with constant pH control. This resulted in elevated concentration (100 g/L) and selectivity (82%) of desired products. The fermentation resulted in elevated concentrations, but low conversion of solids. The undigested material may serve as a nutrient source for fermenting lignocellulosic feedstocks. Combining various nutrient sources with lignocellulose, such as bagasse, resulted in additional production and further conversion. Multiple nutrient sources were tested resulting in total acid concentration ranging from 20.2 to 34.5 g/L.Item Decreasing Variation in Cook Color of Ground Beef Patties Varying in Myoglobin and pH Using Acetic Acid and Hydrocolloid Solutions(2011-02-22) Aldredge, Teresa LynnThe objective was to examine the use of acetic acid (AA) with xanthan gum (XG) or konjac flour (KF) to reduce variation in cooked color of ground beef patties varying in myoglobin and pH. Beef clods were selected from carcasses of young (<24 months, Y) and mature (>48 months, M) animals. Within each age category, high (>6.0, H) and normal pH (5.3-5.7, N) clods were chosen. Ground beef was prepared from each maturity/pH combination and treatments applied at 12% of the meat block: control (mixed only), 0.5% AA, 0.25% XG/0.5% AA, or 0.125% KF/0.5% AA. Dry and moist cooking was performed in a convection oven to internal temperatures: 65.6 degrees C, 71.1 degrees C, and 76.7 degrees C. Patties were held at 76.7 degrees C for up to 240 min in dry and moist environments. Internal (assessed at 0, 120, and 240 min of holding) and external (assessed every 30 min, 0 to 240 min of holding) color evaluations (CIE L*a*b*, visual doneness, and pink scores) were conducted. Three replications were performed. The YN patties had the most done appearance internally and the highest denatured myoglobin percentage. Generally, the YH and MN patties had responses between YN and MH got most variables. The MH patties had the highest internal a* color space values, lowest degree of doneness scores and low percentage of denatured myoglobin. The YN patties responded normally to the different internal temperatures achieved during cooking. The YH, MN, and MH patties had increased doneness to 71.1 degrees C and plateaued between 71.1 degrees C to 76.7 degrees C. Visual degree of doneness decreased during moist holding and this was most evident in dry cook/moist held patties. Patties from MH meat were not affected by the treatments as much as the other meat types. The inclusion of AA, XG/AA, and KF/AA in patties made from YH and MN can effectively reduce visible redness and increase myoglobin denaturation in comparison to the control YN beef patties. These ingredients could be viable options to reduce the variation that pH or myoglobin content imparts on ground beef patty cooked color, but as seen in the MH meat, treatment additions were not effective for overcoming both pH and high myoglobin content.Item Experimental and mathematical investigation of dynamic availability of metals in sediment(2009-12) Hong, Yongseok; Reible, Danny D.; Kinney, Kerry A.Contaminated sediments are periodically subjected to resuspension processes during either storm events or due to dredging. In sediments, metals are often contained in insoluble low bioavailability forms. Upon resuspension, however, biogeochemical processes associated with the exposure to more oxic conditions may lead to transformation and release of the metals, giving rise to exposure and risk in the water column. Batch experiments suggested that oxidation of reduced species and corresponding pH decrease were the most importance processes controlling metals release upon sediment resuspension. A mathematical model was implemented to better understand the complex underlying biogeochemical reactions that affect metals release. The model described the metals dynamics and other inter-related important biogeochemical factors well and was successful at predicting the metals release from different sediment reported in the literature. Tidal and other cyclic variations in oxygen, pH and other relevant parameters in the overlying water may also lead to cyclic transformations and release of metals from surficial sediments. In simulated estuarine microcosm experiments, cyclic variations in pH and salinity due to freshwater/saltwater exchange were shown to lead to cyclic variations in metal release. Both pH and salinity were important factors controlling interstitial dissolved metals concentrations, however, in terms of freely dissolved metals concentrations, which have been considered to be more related with toxicity and bioavailability, pH was the single most important parameter. The mathematical model was extended to the conditions of the cyclic behavior in an estuary and successfully described metals release under such conditions. It is believed that the model can be used to predict the metals behavior in other sediments and conditions by model calibration with a similar experimental approach to that used in this study.Item Functional Properties and Utilization of High pH Beef(2010-10-12) Garcia, Lyda G.Two Texas fed beef and cow/bull packing plants were surveyed for high pH beef carcasses as well as the evaluation of functional properties of high pH beef in whole muscle beef jerky, frankfurters, and snack stick production. An estimated 42% of cow carcasses were of 6.0 muscle pH or greater as well as exhibiting darker, less red colored lean. Jerky high in pH from cow inside rounds resulted in the greatest percent moisture and least percent protein compared to other treatments. High pH cooked jerky were higher in (P < 0.05) pH and water activity and lower in percent fat and shear force values. In cooked jerky slices, fed-high resulted in the highest percent MPR and cook yield, but was the most tender. In contrast, fed-normal resulted in the least water activity, MPR and toughest jerky slices. In frankfurter production, emulsion stability and hydration values was highest for C (1.98mL) followed by 100H (3.37mL) that decreased as percent high pH decreased. As storage day increased, frankfurter pH decreased, especially by day 56 (5.67) where LAB and APC counts had reached a log of 6.0 indicative of spoilage by day 28 and became lighter and less red in color with minimal lipid oxidation. 100H was harder and less cohesive with trained panelists reported containing at least 50% high pH meat was harder. The pH and internal color of cooked snack sticks significantly increased and became lighter and redder as percent high pH meat increased. Even though water activity compared to a whole muscle dry product or an emulsified, water added product ranged from 0.85 to 0.86 (P > 0.05), minimal (P greater than 0.05) lipid oxidation occurred. 100N resulted in the least percentage of fat but 3% more (P less than 0.05) protein and highest shear force values. Overall, beef raw materials high in pH may be better suited in a semi-dry fermented product.Item Hyperactivated Motility of Stallion Spermatozoa(2013-12-02) Loux, Shavahn CIn vitro fertilization does not occur readily in the horse. Recent evidence suggests that this is due to failure to initiate hyperactivated motility in vitro; however, little is known about the induction of hyperactivated motility in equine sperm. In mice, hyperactivated motility requires the CatSper channel, a pH-gated calcium channel, therefore we investigated this channel and its related intracellular changes, alkalinization and calcium influx, in equine sperm. Motility was assessed by computer-assisted sperm motility analysis, andchanges in intracellular pH and calcium were determined via the calcium and pH-specific fluorescent probes, BCECF-AM, Fluo3-AMand Fluo4-AM. Additionally, a demembranated sperm model was developed to investigate the direct effect of major regulators of sperm motility on axonemal function. Increasing intracellular pH induced a rise in intracellular calcium, which was inhibited by the known CatSper blocker mibefradil, supporting the presence of a pH-gated calcium channel, presumably CatSper, in equine sperm. Hyperactivation was induced by treatment with high-pH medium, procaine and 4-aminopyridine. Hyperactivation was associated with moderately increased intracellular pH, but appeared inversely related to increases in intracellular calcium. Sperm treated with procaine in calcium-deficient media both maintained motility and underwent hyperactivation, suggesting that extracellular calcium was not required for hyperactivation. CATSPER1 protein was localized to the principal piece of equine sperm on immunocytochemistry. Analysis of the predicted equine CATSPER1 protein revealed species-specific differences in structure in the pH-sensor region. Demembranated equine sperm required ATP for reactivated motility, but did not require cAMP. Motility of demembranated equine sperm was not inhibited by elimination of calcium (chelation to below 20 pM). Excess calcium inhibited motility at concentrations lower than those reported in other species. Calcium-inhibited sperm arrested with a straight tail rather than in a curve, as seen with calcium arrest in other species. Hyperactivated-like motility was not induced at any pH or calcium concentration. Equine sperm were not inhibited by cadmium at concentrations that profoundly inhibit motility in demembranated sperm in other species. These findings indicate species-specific differences in calcium regulation of sperm motility which may relate directly to the inefficiency of functional capacitation of equine sperm under standard in vitro conditions.Item Improvement of Low Quality Meat Utilizing Functional Ingredients(2011-08-08) Booren, Betsy LynAlternative methods to reduce the variation caused by pale, soft, and exudative (PSE) and dark, firm, and dry (DFD) conditions in meat tissues need to be examined. The objective of this dissertation was to determine if functional ingredients, like hydrocolloids and bicarbonates, improved the quality of PSE and DFD meat. This was accomplished by examining the rheological characteristics of meat model systems and products after enhancement with hydrocolloids and bicarbonates ingredient solutions. These results will be used to formulate and manufacture either enhanced beef steaks, beef roasts, or frankfurters to test the efficacy of use to improve the quality of DFD or PSE meat. The flow behavior, steady-shear viscosity, and dynamic testing of hydrocolloid solutions were determined. Torsion Analysis (TA) and Texture Profile Analysis (TPA) were performed on PSE muscle tissue gel samples and frankfurters. Raw and cooked CIE color space values, pH, and sensory evaluation determination were made on meat gel samples, beef steaks, roast beef, and frankfurters. Hydroxypropyl methylcellulose (1.0%HPMC), methylcellulose (1.0%SGMC), and konjac flour (0.125%KF) were found to be Newtonian in behavior. The dynamic moduli of these ingredients were resistant to changes in ionic strength and were tested for viability in a meat model system. Potassium bicarbonate (KHCO) was a viable substitute for sodium bicarbonate. The synergistic effect of combining KHCO with hydrocolloids, salt and sodium phosphate (SP) improved the color, pH, and textural properties of PSE ground pork and frankfurters, but did not effect sensory characteristics. Acetic acid (AA), KF, and xanthan gum (XG) were added to beef steaks and bottom rounds to reduce the meat quality variation caused by high pH and animal age. The addition of AA and hydrocolloid treatments improved the color and pH of high pH muscles and did not appreciable affect shelf-life flavor of cooked roast beef. Solutions of AA, KF and XG were viable enhancement treatments for use in high pH beef bottom rounds to produce a fully cooked roast beef product.Item Low pH waters in the vicinity of Oak Hill Mine : a statistical evaluation of water quality(2014-08) Mercier, Lilith Joy; Sharp, John Malcolm, Jr.Lignite (brown coal) mine-mouth power plants supply a significance portion of electricity generated annually in Texas. Most lignite is produced from the Wilcox Group at surface mines located near a power plant. At the Oak Hill Mine, a lignite mine in the Sabine Uplift area of northeast Texas, the presence of low pH seeps has delayed the release of some portions of the reclaimed land from bond of some until all surface water bodies achieves a stable pH between 6 and 9. But this federal requirement may require an artificial elevation of surface water pH above the natural range for low volume, groundwater-fed surface water bodies in that region. The primary objective of this thesis is to determine whether the distribution of groundwater pH at Oak Hill Mine has become more acidic as a result of mining activity. This study shows that low pH (<6.0) groundwater was common within the mine permit area prior to mining activities; the 95% confidence interval for the median pH of overburden pre-disturbance (OP) wells is 4.7 to 4.8. This naturally occurring, low pH groundwater is produced by the weathering (oxidative dissolution) of pyrite in the Carrizo Sand and overburden Wilcox Group. Although low pH groundwater occurs naturally within the Oak Hill Mine permit area, groundwater pH has also decreased (groundwater has become more acidic) as a result of mining activities. The 95% confidence interval for the median pH of overburden reclamation (OR) wells is 4.1 to 4.2, indicating that mining activities has changed the median groundwater pH by approximately -0.5 standard units. Underburden groundwater is less acidic than overburden groundwater, but also becomes more acidic after mining activities. Underburden pre-disturbance (UP) groundwater has a median pH of 6.2 to 6.3 at the 95% confidence interval, whereas underburden reclamation (UR) groundwater has a median pH of 5.6 to 5.8 at the 95% confidence interval.Item Pyruvoyl dependent arginine decarboxylases from Chlamydiae and Crenarchaea(2008-12) Giles, Teresa Neelima; Graham, David E.Arginine decarboxylase is a key enzyme involved in the polyamine pathway of organisms. Pyruvoyl-dependent arginine decarboxylases are expressed in the form of proenzymes that self-cleave to form N-terminal [beta] and C-terminal [alpha] subunits generating an active pyruvoyl group at the [alpha] terminus. We have identified an archaeal homolog of a pyruvoyl-dependent arginine decarboxylase in Chlamydophila pneumoniae that could play a role in the persistence of the organism in the host. The recombinant enzyme showed highest activity at pH 3.4, which is the lowest optimum pH ever reported for a pyruvoyl dependent arginine decarboxylase. The proton-consuming decarboxylation raises intracellular pH, and thereby plays a role in acid-resistance. It could inhibit the pro-inflammatory nitric oxide synthase resulting in asymptomatic infection. A variant protein Thr⁵²Ser at the predicted cleavage site showed less pro-enzyme cleavage and activity compared to the wild-type. The homologs of arginine decarboxylase and flanking arginine-agmatine antiporter were also found in different biovariants of Chlamydia trachomatis. In the invasive L2 strain of C. trachomatis, the presence of a nonsense codon in the gene encoding arginine decarboxylase enzyme prevented the expression of an active enzyme. The variant protein with tryptophan replacing nonsense codon restored arginine decarboxylase activity. The non-invasive D strain of C. trachomatis had an intact arginine decarboxylase gene, but it was recombinantly expressed as a proenzyme that was uncleaved. The arginine-agmatine antiporters from both the strains were active and transported tritiated arginine into their cells. The polyamine pathway of the crenarchaeon Sulfolobus solfataricus uses arginine to make putrescine, but the organism lacks homologs of arginine decarboxylase. However, it has two paralogs of pyruvoyl dependent S-adenosylmethionine decarboxylase − SSO0536 and SSO0585. These enzymes were recombinantly expressed as pro-enzymes that self-cleaved into [beta] and [alpha] subunits. Even with a 47% amino acid sequence identity, the SSO0536 protein exhibited significant arginine decarboxylase activity whereas SSO0585 protein had significant S-adenosylmethionine decarboxylase activity. This is the first report of an S-adenosylmethionine decarboxylase enzyme showing alternative decarboxylase activity. The chimeric protein with the [alpha]-subunit of SSO0585 and [beta]-subunit of SSO0536 had arginine decarboxylase activity, suggesting that the residues responsible for substrate recognition are located in the amino terminus.Item Single and Multiple Heteroatom Incorporation in MFI Zeolites(2012-11-05) Garcia Vargas, NatalyZeolites are crystalline inorganic solids that are industrially used for adsorption, ion exchange and catalysis. As catalysts, they have been particularly successful in the hydrocarbon processing industry due to their unique activities and selectivities. Zeolites are mainly used in acid catalyzed reactions, but their catalytic functionality can be diversified through the incorporation of elements that are traditionally not part of their framework. The incorporation of various elements has been studied in recent decades resulting in zeolites with potential to perform different chemistries or improve catalytic performance in existing ones. However, many of these investigations have been conducted under conditions that do not necessarily represent realistic scenarios for industrial implementation. The main objective of this dissertation was to study the single and simultaneous framework incorporation of tin, boron, germanium and aluminum in MFI zeolites under synthesis conditions that are more in line with industrial preparations. These include the use of mixtures in alkaline media with high concentration of precursor species. The interest on tin resides on its potential for Lewis acid catalysis, while boron and germanium have potential for modulating acid strength and enhancing catalytic properties respectively. Three specific systems were studied: MFI zeolites with simultaneous incorporation of germanium and aluminum (i.e. Ge-Al-MFI zeolites), MFI zeolites with simultaneous incorporation of germanium and boron (i.e. B-Ge-MFI zeolites), and MFI zeolites with single incorporation of tin (i.e. Sn-MFI zeolites). Systematic synthesis experiments were coupled with extensive analytical characterization in order to assess how element incorporation and zeolite physicochemical properties are affected by synthesis conditions. In addition, the catalytic activity of Sn-MFI zeolites for the hydroxylation of phenol was studied. The general conclusion from this work is that framework incorporation of these elements is highly influenced by pH, mixture composition and the presence of sodium cations. Sodium cations are commonly included in industrial preparations through the use of sodium hydroxide, but they were found to negatively affect framework incorporation due to a tendency to form stable extra-framework impurities with the heteroatoms, especially germanium and tin. pH and mixture composition are particularly influential in controlling germanium and boron incorporation, while the incorporation of tin, its coordination environment and catalytic performance were found to depend on synthesis conditions as well as post-synthesis treatments.Item Spray carrier stability, plant mobility, and runoff potential of trifloxysulfuron(2009-06-02) Matocha, Mark AndrewTriflxysulfuron is a sulfonylurea herbicide developed for postemergence weed control in cotton, sugarcane, and turf. Greenhouse and laboratory studies were conducted at the Texas A&M University campus and at the USDA-ARS research facility in Stoneville, MS to: 1) quantify the dissipation of trifloxysulfuron in a spray tank at 0, 1, 3, 7, 14, and 21 d after mixing as influenced by pH of the spray carrier and evaluate the resulting effects on efficacy on Palmer amaranth (Amaranthus palmeri S. Wats); 2) determine the effect of spray carrier pH on absorption and translocation of radiolabeled trifloxysulfuron in Palmer amaranth and Texasweed (Caperonia palustris (L.) St. Hil.); 3) determine average edge-of-field concentrations, total mass losses, and fractional losses of trifloxysulfuron applied to cotton at the 5-leaf stage and to bare soil as influenced by simulated rainfall. The dissipation of trifloxysulfuron followed first-order kinetics. Calculated half-life values indicated that hydrolysis occurred more rapidly with the more acidic spray carriers with little or no difference between neutral and alkaline pH levels. Bioassay on Palmer amaranth showed no differences in plant dry weights due to pH level or dissipation time. The absorption of 14C-trifloxysulfuron was greater for Palmer amaranth than for Texasweed when averaged over time and pH. Altering pH did not affect the translocation of trifloxysulfuron in Palmer amaranth. In contrast, translocation of 14C-trifloxysulfuron in Texasweed increased in the order of pH 5 < pH 7 = pH 9. Cumulative trifloxysulfuron losses in runoff from cotton plots were 0.21 g ha-1 while losses from bare plots were 0.13 g ha-1. These values corresponded to fractional losses of 2.7% for cotton plots and 1.7% for bare plots of the total amount applied. These studies provide important information regarding the stability, plant uptake, and runoff potential of a commonly used sulfonylurea herbicide.Item The Heritability of Factors that Influence Tenderness in Beef Cattle(2010-12) Johnson, Paige A.; Miller, Markus F.; Moser, Dan; Thompson, Leslie D.; Johnson, Bradley J.; Jackson, Samuel P.The heritability, phenotypic correlations and genetic correlations of 63 factors were determined in this study. The traits studied (with their heritabilities and standard errors in parenthesis) included: days on feed (1.00 ± 0.116), longissimus muscle area (0.85 ± 0.183), marbling (0.83 ± 0.170), adjusted preliminary yield grade (0.61 ± 0.156), quality grade (0.59 ± 0.148), yield grade (0.56 ± 0.150), preliminary yield grade (0.48 ± 0.143), muscle score (0.44 ± 0.140), 21-day Warner-Bratzler Shear force (0.42 ± 0.148), 3-day initial juiciness (0.42 ± 0.148), hump height (0.40 ± 0.141), 7-day Warner-Bratzler Shear force (0.37 ± 0.147), 7-day initial tenderness (0.37 ± 0.140), 48-hour temperature (0.35 ± 0.121), lean color (0.34 ± 0.122), 14-day sustained tenderness (0.33 ± 0.135), 3-day initial tenderness (0.32 ± 0.131), 3-day sustained tenderness (0. 31 ± 0.129), 7-day sustained tenderness (0.31 ± 0.129), a* (0.29 ± 0.115), 3-hour temperature (0.29 ± 0.114), 14-day initial tenderness (0.28 ± 0.126), 14-day Warner-Bratzler Shear force (0.28 ± 0.121), b* (0.28 ± 0.120), final weight (0.26 ± 0.113), m-calpain (0.24 ± 0.195), 3-day overall mouthfeel (0.24 ± 0.119), 3-day Warner-Bratzler Shear force (0.23 ± 0.114), kidney, pelvic and heart fat (0.23 ± 0.107), temperament (0.23 ± 0.094), 3-day flavor intensity (0.22 ± 0.114), average daily gain (0.22 ± 0.105), 21-day initial tenderness (0.19 ± 0.110), frame score (0.19 ± .097), 21-day beef flavor (0.18 ± 0.110), 14-day overall mouthfeel (0.18 ± 0.107),14-day sustained juiciness (0.18 ± 0.105), μ-calpain (0.17 ± 0.197), 14-day initial juiciness (0.17 ± 0.104), lean firmness (0.17 ± 0.094), 21-day sustained tenderness (0.16 ± 0.108), 48-hour pH (0.16 ± 0.097), hot carcass weight (0.15 ± 0.091), 7-day overall mouthfeel (0.14 ± 0.097), 14-day beef flavor (0.12 ± 0.097), calpastatin (0.11 ± 0.095), 14-day flavor intensity (0.11 ± 0.094), 21-day flavor intensity (0.10 ± 0.087), lean texture (0.10 ± 0.086), initial weight (0.10 ± 0.078), L* (0.09 ± 0.087), 7-day flavor intensity (0.06 ± 0.081), 3-hour pH (0.06 ± 0.073), 3-day sustained juiciness (0.05 ± 0.081), heat ring (0.05 ± 0.061), 21-day overall mouthfeel (0.02 ± 0.076), 3-day beef flavor (0.01 ± 0.072), 7-day sustained juiciness (0.01 ± 0.062), 21-day sustained juiciness (0.00 ± 0.089), 7-day beef flavor (0.00 ± 0.080), sarcomere length (0.00 ± 0.075), 21-day initial juiciness (0.00 ± 0.072) and 7-day initial juiciness (0.00 ± 0.062). Phenotypic correlations and their respective p-values were determined and reported for all 3,969 relationships. Genetic correlations (n = 276) were determined for traits that were heritable including correlations for tenderness traits such as m-calpain activity, calpastatin activity, 48-hour pH, 48-hour carcass temperature, and marbling. Other genetic correlations studied included extensive sensory taste panel traits including 3-, 7- ,14- and 21-day initial tenderness, sustained tenderness, initial juiciness, sustained juiciness, flavor intensity, beef flavor and overall mouthfeel. The genetic correlations of color traits were also determined including Hunter colorimeter readings for a* and b*, as well as, subjective lean color scores. Other carcass traits studied using genetic correlations included lean texture, lean firmness, yield grade, hot carcass weight, and longissimus muscle area. Genetic correlations for 21-day Warner-Bratzler shear force, temperament, breed type and hump height were also determined.Item V-ATPase at the cell surface in highly metastatic Prostate Cancer cells(2010-12) Bermudez, Luis E.; Martinez-Zaguilan, Raul; Perez-Zoghbi, Jose; Filleur, StephanieProstatic adenocarcinoma is the second-leading cause of cancer death of men in the United States. According to the American Cancer Society, there are almost 218,000 new cases and 32,000 deaths every year due to prostate cancer. The major threat comes from progression of this cancer towards metastasis. The molecular mechanisms underlying the promotion of metastasis are unclear. Metastatic tumors are highly glycolytic in nature and they tend to undergo anaerobic metabolism. This leads to the production of lactic acid that could result in intracellular acidosis. To survive in this environment, cells regulate their pH by expressing several transporters. In this study we show that metastatic prostate cancer cells use a vital transport system that counteracts intracellular acidosis and promotes metastasis, i.e. plasma membrane Vacuolar H+-ATPases (pm-V-ATPases). V-ATPases are typically found in intracellular acidic compartments. We have previously shown that V-ATPases at the cell surface are involved in breast cancer metastasis, invasiveness, and drug resistance. In this study, we demonstrated that V-ATPases are localized at the cell surface in highly metastatic prostate cancer cells using immunocytochemistry. We also demonstrated that the mRNA levels of specific subunit isoforms of V-ATPase that targets the V-ATPase to the cell surface are increased in highly metastatic prostate cancer cells when compared to non-metastatic. We monitored the activity of V-ATPases in living cells by measuring proton fluxes and specific activity in isolated membrane fractions. We also demonstrated that inhibiting the V-ATPase enhances chemosensitivity in metastatic prostate cancer cells. These data indicate that V-ATPases at the cell surface are present in highly but not in poorly metastatic cells. This suggests that the V-ATPase is a novel molecular target to enhance the efficacy of chemotherapeutic drugs to alleviate the consequences of prostate cancer metastasis.