Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Xiaolei Zou, Florida State University, College of Arts and Sciences, Dept. of Meteorology. Title and description from dissertation home page (June 18, 2004). Includes bibliographical references.

Thesis (Ph. D.)--University of Rhode Island, 2003. / Typescript. Includes bibliographical references (v. 2, leaves 331-354).

Two experiments were conducted during the winters of 2012-13 (yr 1) and 2013-14 (yr 2), to evaluate 3 winter feeding systems: (i) field grazing standing whole plant corn (SC) cv. ‘DKC 26-25’ (yr 1, CP = 9.5%, TDN = 66.1%; yr 2, CP = 9%, TDN = 69.8%), (ii) field grazing swathed barley hay (SB) cv. ‘Ranger’ (yr 1, CP = 13.2%, TDN = 56.8%; yr 2, CP = 10%, TDN = 61.9% and (iii) barley hay bales fed in drylot pens (DL) cv. ‘Ranger’ (yr 1, CP = 13.1%, TDN = 53.2%; yr 2, CP = 8.2%, TDN = 55.2%). Forages were allocated on a 3-4 d interval in SC and SB systems. The specific objectives were to compare crop yield and agronomy, beef cow performance, reproductive efficiency and system costs in experiment 1 (EXP 1); and ruminal pH, SCFA and ammonia concentration in experiment 2 (EXP 2). In EXP 1, 60 dry, pregnant Black Angus cows (yr 1, 644 kg ± 72 kg; yr 2, 672 kg ± 66 kg) at mid-gestation, stratified by body weight (BW) were allocated to 1 of 3 replicated (n=2) winter grazing treatments for 77 d in yr 1 and 78 d in yr 2. Increases in rib fat were greater (P = 0.02) for SC cows compared to SB cows (1.6 vs 0.3 mm, respectively). Estimated DMI was lower (P < 0.01) for SC cows (9.1 kg/d) compared to SB and BH cows (14.3 and 13.0 kg/d, respectively) which did not differ (P > 0.05) from each other. Calves born to cows grazing SC were heavier (P ˂ 0.01) at birth compared to calves from SB and BH cows (43, 40 and 40 kg, respectively). Changes in cow BW and average daily gain (ADG) were lower (P < 0.01) and negative in year 2 (BW change, 23.8 and -4.9 kg; ADG, 0.3 and -0.1 kg for yr 1 and 2, respectively). The number of calves born in first 21 d was 44% higher (P < 0.01) in yr 1 compared to yr 2. Economic analysis revealed that total costs were greatest for BH ($2.75/cow/d) compared to SC and SB ($2.06 and $2.00 cow/d, respectively) systems. In EXP 2, 9 cannulated beef heifers were cycled through the 3 winter systems concurrently within EXP 1, in a replicated 3 × 3 Latin square design, for 63 d to evaluate effect of forage type and day of allocation on rumen fermentation. Results from EXP 2 indicated an increase (P < 0.01) in minimum pH of cannulated heifers from d 1 to d 3 of forage allocation in SC and SB systems. Lower (P < 0.01) minimum and mean pH and increased duration and area (P < 0.01) under pH 5.8 were observed in yr 2 in SC and yr 1 in SB. In yr 2, total SCFA, acetate and propionate concentration increased (P < 0.01) in SB heifers, but butyrate concentration increased (P < 0.05) in SC heifers compared to yr 1. Ruminal fermentation was unaffected (P > 0.05) by day of forage allocation and yr of study in BH system. Results from EXP 1 and EXP 2 suggest that both SC and SB systems are cost effective alternatives to BH system, and do not negatively affect cow reproductive performance following winter grazing. However, yearly differences in weather and seeding date of forages can have a profound effect on nutrient composition of forages, and can cause variations in cow performance and rumen metabolism during the period of extensive winter grazing.

Winter losses challenge the adoption of Miscanthus as a biomass crop in northern regions. This study was conducted to investigate the winter survival and yield potential of Miscanthus in Ontario. Twenty Miscanthus entries representing diploid M. sacchariflorus x M. sinensis hybrids, triploid M. x giganteus hybrids and diploid M. sinensis were established in 2008 at three locations in Ontario. First year winter survival ranged from 8-100% in Leamington, 0-100% in Elora and 0-89% in Kemptville. No difference in winter survival potential of the three species groups was observed in Leamington or Elora, but a diploid hybrid was significantly greater than all others in Kemptville. Establishment year culm height and basal circumference, and second year spring regrowth timing and biomass yield were associated with winter survival. Overall, winter severity increased from Leamington to Kemptville. The diploid hybrids were most winter hardy, followed by M. x giganteus types, followed by M. sinensis, though all had equivalent survival potential in Leamington and Elora. / Mendel Biotechnology

Winter flounder, Pleuronectes americanus, is being developed for aquaculture in Atlantic Canada. Since larval culture has been successful, research can now address problems at the juvenile stage such as weaning, diet and optimal growth environment. Weaning, a critical stage in culture of any flatfish species, is the switch from live food to an artificial diet. In a three month study, I was able to wean wild young-of-the year winter flounder from live, cultured Artemia onto dry food. Specific growth rates and food conversion indicated the artificial diet was a better food source than Artemia. In a second study, I was able to wean recently-metamorphosed winter flounder reared in the laboratory, onto two artificial diets which differed in price and lipid content. There was no difference between the inexpensive salmonid starter diet and the more costly Nippai diet on growth and survival. In a third study, I examined the effects of temperature and density on wild year 0 and 1 winter flounder reared on dry salmonid diet. There was no effect of density on growth and survival over the ranges tested. Greatest growth occurred at 15$ sp circ$C, although survival was highest at ambient temperature.

Collagenases were extracted from the skeletal muscle of winter flounder (Pseudopleuronectes americanus) with Tris-HCl buffer, pH 7.4, containing 5 mM CaCl$ sb2.$ The crude extract in the active form was purified by ammonium sulfate fractionation, followed by a succession of column chromatographic steps which included ion-exchange, immobilized metal affinity and size-exclusion in the Fast Protein Liquid Chromatography (FPLC) system. The trypsin-like and chymotrypsin-like activities of the crude extract diminished with purification. A comparative study of the collagenase fraction from ion-exchange chromatography (IEX-1) and the commercial collagenase fraction from Clostridium histolyticum indicated that the two enzymes were similar with respect to their response to temperature but differed with respect to their response to pH. The enzymes differed slightly in terms of their thermal and pH stabilities. The winter flounder collagenase fraction from size-exclusion chromatography (SEC) had a higher optimum pH temperature than the IEX-1 fraction as well as the commercial collagenase. However, both SEC and the IEX-1 extracts had the same optimum pH. The collagenase fraction from SEC had a slightly lower thermal stability than the IEX-1 fraction and the commercial collagenase. / The higher catalytic efficiency (V$ sb{ rm max}$/K$ sb{ rm m}$') and the lower $ Delta$G values for C. histolyticum collagenases showed that bacterial collagenases are better catalysts than winter flounder skeletal muscle collagenases for the PZ-peptide hydrolase reaction at 37$ sp circ$C and pH 7.1. / Zymography revealed the presence of two collagenase isoenzymes from the fish muscle, designated as WFC-1 and WFC-2 with molecular weights of 79,600 and 75,500, respectively. WFC-1 was separated from WFC-2 by electrophoretic blotting onto the PVDF membrane. The amino acid composition of WFC-1 and WFC-2 were closely related. / The fish collagenases were inhibited by metal chelators, EDTA and 1,10-phenanthroline suggesting that these enzymes are metalloproteases. The enzyme activity in the presence of EDTA and 1,10-phenanthroline were recovered upon addition of low levels of calcium and zinc ions, respectively. Higher levels of these metal ions inhibited the isoenzymes. 2-Mercaptoethanol and dithiothreitol were also effective inhibitors.

No description available.

Microclimates of various road weather stations in Devon were examined. Road surface temperatures were measured during various synoptic conditions. Data from the thermal mapping exercise conducted by Vaisala TMI were analysed and categorised as clear and calm, cloudy and windy, and a condition between the two extremes. Results indicate valleys to be relative cold spots in clear conditions, and high altitude stations are cold spots during cloudy conditions. A separate case study during the cold spell of February 1991 reinforced the conclusion and extended these views county wide. Coastal stations with surface winds were observed to be 1 to 3 deg.C warmer than inland stations. Reaction times, the delay in road temperature reaction due to synoptic change, showed for the most difficult forecasting scenario on the passage of a cold front, small reaction times (less than 30 minutes) at exposed sites when clear skies resulted, sheltered sites having a reaction time of up to 2 hours. Sheltered sites in valleys had the largest temperature drop due to cold air drainage. A surface climate model was used in retrospect to predict road surface temperatures at night, each station having its own characteristic exposure. Cloud change was estimated from satellite images. Results indicate predicted minimum temperature within 0.5 deg.C of observation. Real time forecasts were tried and an accuracy of 65% at this level was achieved. These results were equal or better than the existing &quot;Open Road&quot; forecasts.

The structure of macrobenthic communities was investigated in carbonate and transitional carbonate-terrigenous sediments of the Southern Gulf of Mexico (Campeche Bank). The aim was to assess the influence of natural disturbance represented by winter storms and river runoff and the putative influence of oil-related activities using a regional approach. At a scale of &gt; 100 km community composition of benthic macroinfauna was characterised as distinct assemblages within the carbonate and transitional sedimentary provinces controlled by natural disturbance. The carbonate assemblage was numerous and diverse influenced by a heterogeneous substratum. Winter storms had a severe impact with mortality probably resulting from abrasion and passive transport causing low values of number of taxa, abundance, biomass and diversity measurements. Conversely, on the transitional shelf a sequence of disturbance from river runoff and winter storms resulted in a general impoverished community due to fine sedimentation and sediment instability. Immediately after the rainy season, values of biological measures were low, but the severity of disturbance was contingent with depth. At a scale of 10s km within the transitional shelf, the combined effect from natural and anthropogenic disturbance caused extremely low values of biological measures within the so called oil exclusion zone. Despite the lack of adequate controls the effects of oil related activities were identified as severe reductions in macroinfauna densities and biomass resulting in a very simple community. Large spatial variability at this scale masks the temporal variation observed in other areas of the Campeche Bank and the relationship between biological measures and indicators of oil activities (Barium, Nickel and oil-hydrocarbons). Finally the increased variability resulting from the influence of oil activities interrupts the natural gradient of macroinfauna patterns across the shelf.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 56-65). Also available via the Internet.