The class Cyanidiophyceae (the "cyanidia") includes three genera, the walled Cyanidium and Galdieria and the "naked" Cyandioschyzon. All of these algae are unicellular and asexual and live at high temperature and low pH. The cyanidia grow optimally at a pH of 2-3 but can tolerate a higher pH and lower their surrounding pH if it is above the optimal level. They can also tolerate high concentrations of potential toxins that are often found in their natural environments. This thesis shows that strains of cyanidia from Yellowstone National Park and other geographic locations have differing abilities to lower their surrounding pH and tolerate environmental toxins that are found in many environments in which they live. These unique characteristics of this class of algae allow them to be optimally adapted for life in extreme environments with few competitors. This thesis includes unpublished co-authored material.

Two experiments were conducted. In experiment 1, the objectives were: 1) to develop and evaluate the accuracy and precision of a new continuous ruminal pH measurement system 2) to determine the required frequency for pH electrode standardization and 3) to determine the effect of additional pre-partum concentrate when compared to NRC (2001) recommendations on post-partum ruminal acidosis in primiparous cows. Accuracy and precision of the Lethbridge Research Centre Ruminal pH measurement system (LRCpH) was determined by comparing LRCpH derived values against manual measurement. To determine the required frequency of electrode standardization, three treatments were imposed (24, 48, or 72 h of continuous measurement) and arranged in a repeated 3×3 Latin square design. The LRCpH accurately and precisely measured ruminal pH (repeated measures correlation coefficient = 0.97 and concordance correlation coefficient = 0.97 for 5-min averages). Changes in baseline mV readings for pH readings after 24, 48 or 72 h of ruminal incubation were not significantly different than zero, indicating that daily standardization of new electrodes was not essential. Using the LRCpH to measure ruminal pH overcomes animal mobility restrictions of previous systems. <p>In experiment 2, the effect of additional concentrate allocation during the pre-partum period was evaluated using 14 ruminally cannulated Holstein heifers. The heifers were assigned to one of two feeding regimes pre-calving: 1) control treatment or 2) an intensive high concentrate feeding treatment (HC). All cows received the same lactation diet post-partum. Ruminal pH was measured continuously from d -5 to d +5, and for 3-consecutive days starting on d +17 ± 1.2, d +37 ± 1.4, and d +58 ± 1.5 relative to parturition. Feeding additional concentrate pre-partum did not reduce post-partum ruminal acidosis. In fact, animals fed the HC treatment had more daily episodes of acute acidosis and lower dry matter intake and body condition score than animals fed the control treatment. Day relative to parturition affected the occurrence and severity of ruminal acidosis with a dramatic increase in ruminal acidosis after parturition. This study demonstrates that feeding addition concentrate pre-partum did not reduce post-partum acidosis which emphasized the need to develop and implement feeding strategies that reduce this risk.

Denna studie har utvärderat effekten hos tre fosforfällor med kalkstenskross med avseende på reduktion av totalfosfor och fosfat samt påverkan på vattnets pH. En kostnadsanalys utfördes för att beräkna effektiviteten uttryckt i kostnad per kg infångad fosfor. Fosforfällorna består av en 80-180 meter lång dikessektion i vilken en 0,5-1 meter djup bädd av krossad kalksten har placerats. Kalkens primära funktion är att binda till sig en del av det fosfat som finns löst i det genomflödande vattnet. En av fosforfällorna ligger i Hagbygärdedämmet i utkanten av Kalmar. Det tar emot dagvatten från Hagbygärdediket, som avvattnar de västra delarna av Kalmar tätort. De två andra ligger i Dunö och Bottorp, 3 respektive 10 km söder om Kalmar, och tar emot vatten från åkermark. För att utvärdera fosforfällornas effektivitet togs dagliga prover av vatten och flöde under en veckas tid för samtliga lokaler. För fosforfällan i Hagbygärdedämmet gjordes även en longitudinell mätning där vattenprover togs med jämna mellanrum under perioden 31/10 2012- 6/5 2013. Under denna period mättes även flödet vid tre tillfällen i samband med vattenprovtagningen. Resultatet från mätningarna tydde på en signifikant reduktion av fosfat för fosforfällan i Dunö. Fosforfällan i Hagbygärdedämmet uppvisade en signifikant reduktion av fosfat under den korta mätperioden och när samtliga mätningar betraktades, dock inte under den longitudinella mätningen allena. Överlag var reningsgraden låg för samtliga lokaler vilket ansågs kunna bero på otillräcklig kontakt mellan vattnet och kalken. Bara fosforfällan i Bottorp gav upphov till en signifikant effekt på vattnets pH trots att Dunö hade lägre pH på det inflödande vattnet. För Dunö och Bottorp betraktades dataunderlaget vara för knappt för att dra några säkra slutsatser från dessa resultat. Kostnadsanalysen, om än förenklad, visade att metoden kan vara ett bra ekonomiskt alternativ för infångning av fosfor ute i fält. Ett större dataunderlag erfordras dock för att säkerställa effekten. / The aim of this study has been to evaluate the effect of three phosphorus traps with respect to reduction of phosphorus and phosphate as well as the effect on pH of the treated water. A cost analysis has been performed in order to present the effectiveness as cost per kg entrapped phosphorus. The phosphorus traps consist of an 80-180 meter long ditch section in which a 0,5-1 meter thick bed of crushed limestone has been placed. The function of the limestone is primarily to adsorb some of the dissolved phosphate in the influent. One of the phosphorus traps is located in the Hagbygärde wetland on the outskirts of Kalmar. It receives storm water from the Hagbygärde ditch which drains the western parts of Kalmar city. The other two receive water from farmland and are located in Dunö and Bottorp, 3 and 10 km south of Kalmar respectively. In order to evaluate the effectiveness of the phosphorus traps, daily water samples and flow measurements were taken during one week. Also, a longitudinal study of the phosphorus trap in the Hagbygärde wetland was performed from 31/10 2012 to 6/5 2013. During this period water samples were taken periodically and at three of these instances water flow was measured as well. The results of these measurements indicated a significant reduction of phosphate for the phosphorus trap in Dunö. The phosphorus trap in the Hagbygärde wetland also showed a significant reduction of phosphate content during the shorter measuring period and when all measurements were included, although not when considering the longitudinal study alone. Overall, the reduction of phosphorus and phosphate were low in all cases which were attributed to inadequate contact between the water flow and the limestone. Only the phosphorus trap in Bottorp had a significant effect on water pH, despite that Dunö was the locality showing the lowest pH of the inflowing water. For Dunö and Bottorp, the datasets were regarded insufficient for making any certain conclusions based on these results. The cost analysis, albeit simplified, showed that this method could be a good financial option for capturing aqueous phosphate in the field, although more data is needed to ensure the results.

Two experiments were conducted. In experiment 1, the objectives were: 1) to develop and evaluate the accuracy and precision of a new continuous ruminal pH measurement system 2) to determine the required frequency for pH electrode standardization and 3) to determine the effect of additional pre-partum concentrate when compared to NRC (2001) recommendations on post-partum ruminal acidosis in primiparous cows. Accuracy and precision of the Lethbridge Research Centre Ruminal pH measurement system (LRCpH) was determined by comparing LRCpH derived values against manual measurement. To determine the required frequency of electrode standardization, three treatments were imposed (24, 48, or 72 h of continuous measurement) and arranged in a repeated 3×3 Latin square design. The LRCpH accurately and precisely measured ruminal pH (repeated measures correlation coefficient = 0.97 and concordance correlation coefficient = 0.97 for 5-min averages). Changes in baseline mV readings for pH readings after 24, 48 or 72 h of ruminal incubation were not significantly different than zero, indicating that daily standardization of new electrodes was not essential. Using the LRCpH to measure ruminal pH overcomes animal mobility restrictions of previous systems. <p>In experiment 2, the effect of additional concentrate allocation during the pre-partum period was evaluated using 14 ruminally cannulated Holstein heifers. The heifers were assigned to one of two feeding regimes pre-calving: 1) control treatment or 2) an intensive high concentrate feeding treatment (HC). All cows received the same lactation diet post-partum. Ruminal pH was measured continuously from d -5 to d +5, and for 3-consecutive days starting on d +17 ± 1.2, d +37 ± 1.4, and d +58 ± 1.5 relative to parturition. Feeding additional concentrate pre-partum did not reduce post-partum ruminal acidosis. In fact, animals fed the HC treatment had more daily episodes of acute acidosis and lower dry matter intake and body condition score than animals fed the control treatment. Day relative to parturition affected the occurrence and severity of ruminal acidosis with a dramatic increase in ruminal acidosis after parturition. This study demonstrates that feeding addition concentrate pre-partum did not reduce post-partum acidosis which emphasized the need to develop and implement feeding strategies that reduce this risk.

Reproduction de : Thèse de doctorat : Chimie à l'état solide : Le Mans : 2006. / Titre provenant de l'écran-titre. Bibliogr. en fin de chapitres.

The effect of pH on fiber and paper properties, during beating and sheet formation, was investigated for three different pulps. The pulps were pH adjusted to four different pH levels between 3 and 9. Isotropic laboratory sheet were made of both unbeaten and beaten pulps. The beaten neutral sulfite semi-chemical pulp and bleached softwood kraft pulp were affected by changes in pH; bleached softwood kraft pulp in a minor extent due to less fiber surface charges. Compared to the other pH levels, pH 3 showed a lower fiber surface charge, water retention value, tensile index, tensile stiffness index, compressive index and edge crush resistance index. SEM pictures showed a denser network at pH 9 than for pH 3. This was seen for both neutral sulphite semi-chemical and softwood kraft pulp. The unbeaten pulps and beaten bleached hardwood kraft pulp were not affected by changes in pH. SEM pictures showed no difference in the fiber network for bleached hardwood kraft pulp. A mill trial, with neutral sulphite semi-chemical pulp, at pH levels between pH 4.8 and pH 5.6 was completed. No significant difference was seen for any mechanical property.

Th. doct-ing.--Sci. et tech. en prod. vég. et qualité des produits--Toulouse--I.N.P., 1981. N°: 162.

The main aim of the thesis is to discover the significance of parameters of postmortal changes of game, on which we may well base for the further appraisal in practice. The theoretical part describes company for processing game, from which the samples for the experiment were taken. Furthermore, it incorporates the composition and the qualities of meat and the factors that affect the meat of game. A significant chapter describes postmortal processes and ways of meat spoilage. The experimental part of the thesis measures both the pH and ammoniac postmortal indicators. As for the experiment, the measurement was carried out on two groups of samples coming from the ham of wild boar. With regard to the results the indicators were proved to be measurable postmortal parameters by postmortal changes and consequent process ripening of meat. The figures between individual measurements increased, but the dependence on time cannot be made on grounds of the results. The figure of ammoniac increased during the measurement too, and we gained a concrete image of its content in the meat thanks to photometric method. The results were compared with the measurement of ammoniac of slaughter animals. For analysis volume of ammoniac in specimen of lean flesh was used traditional micro method according to Conway. More profound analysis ought to be made for the appraisal of postmortal indicators. Next interesting parametres for determination of significance postmortal changes could be also enzymatic substance.

No description available.

The role of cytoplasmic pH in guard cell signal transduction was investigated in epidermal strips of Commelina communis. The cytoplasmic pH of guard cells was measured by dual excitation ratio confocal laser scanning microscopy. Large transient alkalinisations occurred for up to 20 minutes both during closure, in response to ABA and calcium, and opening in response to IAA and fusicoccin. Therefore the direction of the pH change does not determine the direction stomatal movement in Commelina communis in contrast to previous reports in Paphiopedilum tonsum. Furthermore, CO₂ caused a slow acidification during stomatal closure, indicating that pore movements are not always associated with a transient cytoplasmic alkalinisation. The internal pH of guard cells was buffered by low concentrations of isobutyrate. Small reductions in stomatal closure in response to ABA and calcium were observed, however, responses to CO₂, IAA and fusicoccin were unaltered. High levels of isobutyrate stimulated wide stomatal opening for all stimuli. Therefore manipulation of cytoplasmic pH only give limited support in the case of ABA and calcium that cytoplasmic pH changes are either necessary for or modulate stomatal movements. The observed pH changes may therefore be a consequence of the mechanism underlying pore movement rather than genuine cytoplasmic signals per se, A model is described based on strong ion and weak acid chemistry which predicts that the observed pH transients result from changes in the concentrations of chloride and malate which charge balance the potassium fluxes during stomatal movements. No suitable fluorescent indicator was found to measure pH in either the apoplast or vacuole. However the volume of the guard cell lumen, vacuole, nucleus and chloroplast were directly measured during stomatal movements and the cytoplasmic volume was calculated. These volumes were used to re-calculate compartmental pH and ion concentrations from previous reports.