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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Studies on bile and brain specializations in uranoscopid fish (Perciformes: Uranoscopidae)

Hsu, Jumg-chen 20 August 2010 (has links)
Stargazers (Uranoscopidae) have two specialized characters- large volume of bile and a small-size brain. To explain why stargazers need large volume of bile, two hypotheses were proposed: (1) a function of the bile of stargazers is acting as the sex pheromone, and (2) bile enhances calcium uptake efficiency. The brain volume was measured, and the volumes of each part of the brain were also measured. The elementary investigations indicate that the stargazers have larger bile volume ratio and smaller brain weight ratio than other fishes reported in the present studies. The bile volumes are no significant difference between the female stargazers and the male stargazers, the bile volumes showed no monthly difference. Besides, the number of olfactory epithelium and the neuron density of the telencephalon in stargazers were not more than other fishes, the function of sex pheromone of bile can not be confirmed. The cranium hardness, bone density, and calcium content in stargazers are significantly more than other fishes. Most fish uptake calcium by the gill and the intestine from seawater or food. However, stargazers often hide in the sand and wait for the prey for most of the time, less water flow through the gills are expected. Therefore stargazers possibly uptake calcium through the intestine. Efficiency of the bile to aid calcium uptake has to be examined by experiments. The paraffin histology has been taken in various parts of the brain. Crista cerebelli is the center for sensing mechanical vibration; the volume of stargazer¡¦s crista cerebelli is higher than other fishes. Stargazers have large saccular otolith compare to the whole brain. Studies on the lateral line and acoustic sense of stargazers are new research topics. Furthermore, decrease in brain size in stargazers is for the purpose of reducing the oxygen consumption, so as to hiding in the sand. Stargazers are one of the fisheries species on western Taiwan coast. However there are very few studies on the stargazers in Taiwan; we should understand more about them in order to protect and consume the stargazers in a better way.
82

Intraluminal Content is Required for the Maintenance of Antigrade Proluminal Movement of 3H-Androgens into Rat Caput Epididymal Tubules

MIYAKE, KOJI, TSUJI, YOSHIKAZU, HIBI, HATSUKI, YAMAMOTO, MASANORI 25 March 1994 (has links)
No description available.
83

Effects of copper on phosphorus utilization in Ulva fasciata Delile (Ulvales, Chlorophyta)

Huang, Ya-Ling 30 July 2002 (has links)
The effects of copper on growth and phosphorus (P) utilization were investigated in the marine chlorophyte Ulva fasciata Delile. Both the daily specific growth rate and tissue P contents decreased as increasing CuSO4 concentrations, while the contents of total tissue, intracellular and cell-wall Cu increased. Based on the relationship between daily specific growth rate and external CuSO4 concentrations, the upper limit of U. fasciata is 100 uM CuSO4. After 4-day exposure to varying CuSO4 concentrations, Pi uptake was inhibited. Analysis of P fraction in U. fasciata exposed to 100 uM CuSO4 shows that the Cu-induced decline in total tissue P contents is mainly due to a decrease in both soluble reactive P (i.e. Pi). Exposure to 100 uM of Cu caused the accumulation of total tissue Cu contents to a plateau and then rose again at day 3, and tissue P contents and daily specific growth rate decreased at day 4. IC50 (concentration of 50 % inhibition) of daily specific growth rate and tissue P contents are 9.8 and 37.8 uM of Cu concentration in the medium, respectively, and 0.76 and 1.44 mg¡Dg-1 DW for total tissue Cu contents, respectively. Overall, Cu causes Cu accumulation in intracellular space and cell wall and decrease of growth and P contents of U. fasciata partly via Pi uptake inhibition.
84

Simulation and Estimation of Organ Uptake in a Digital Mouse Phantom

Jimenez, Edward Steven January 2010 (has links)
The objective of this work is to estimate and simulate organ uptake variability and correlations using measured data from the FastSPECT II Single Photon Emission Computed Tomography (SPECT) imaging system. We will investigate various methods that attempt to determine organ-uptake within a set of organs in a digital phantom; these methods include Region-of-Interest, Gauss-Markov, Wiener, and Reconstruction Estimation algorithms. In addition to the estimators, we will also test whether moving the phantom with respect to the imaging system and gathering multiple images from different positions will improve the performance of our estimators. The variations and correlations in the object will be modeled using Gaussian distributions with first and second-order statistics known exactly. We will present a mathematical formulation of this model, in a texture-free context, as well as some results on image-quality assessment. The object model will be the MOBY digital mouse phantom; the 4-D MOBY Mouse Model is a digital phantom developed by Paul Segars\citep{moby}, which provides a useful digital model for nuclear-medicine and CT imaging.
85

Crop Phenology, Dry Matter Production, and Nutrient Uptake and Partitioning in Cantaloupe (Cucumis Melo L.) and Chile (Capsicum Annuum L.)

Soto-Ortiz, Roberto January 2008 (has links)
Currently, the information available concerning requirements for optimum crop growth and development, dry matter production, and nutrient uptake and partitioning for Cantaloupes and New Mexico chile type cultivars is limited. Such information is required to predict and identify critical stages of growth in order to develop efficient nutrient management programs for these crops. The goals of this dissertation are: 1) to obtain general irrigated cantaloupe and New Mexico chile plants development models as a function of heat units accumulated after planting (HUAP), and 2) to determine dry matter production and nutrient uptake and partitioning patterns of these crops as a function of HUAP. Four primary investigations are presented in this dissertation. In the first and second studies, plant development models for irrigated cantaloupe and New Mexico chile-type cultivars were obtained. For cantaloupe plants, early bloom occurred at 265 ± 47 HUAP, early fruit set at 381 ± 51 HUAP, early netting at 499 ± 63 HUAP, and physiological maturity at 746 ± 66 HUAP. For chile plants, first bloom occurred at 530 ± 141 HUAP, early bloom at 750 ± 170 HUAP, peak bloom at 1006 ± 145 HUAP, first green chile harvest at 1329 ± 120 HUAP, and red harvest stage at 1798 ± 58 HUAP. Also, these studies revealed that beyond the early netting stage (approximately 499 HUAP), cantaloupe fruits were the strongest sinks for dry matter accumulation. For chile plants, between the first green chile harvest and red chile harvest stages (approximately at 1550 HUAP), chile pods developed into stronger sinks for dry matter accumulation. The third and fourth investigations revealed that the period of maximum nutrient uptake coincides with that of maximum dry matter accumulation for both crops. The overall total nutrient uptake of N, P, K, Ca, Mg, S, B, Zn, Mn, Fe, and Cu for cantaloupe plants was 138, 21, 213, 132, 29, 28, 0.17, 0.20, 0.13, 2.0, and 0.06 kg ha⁻¹, for chile plants, the overall total nutrient was 216, 20, 292, 117, 56, 28, 0.31, 0.20, 0.31, 1.6 and 0.14 kg ha⁻¹ for these nutrients respectively.
86

Nitrogen Assimilation-Metabolism in Relation to Potassium Use in Cauliflower (Brassica oleracea var. botrytis)

Huang, Ruiping 25 November 2010 (has links)
A field trial and a greenhouse experiment were conducted to investigate the impacts of N and K nutrients on plant N/K assimilation, nitrate reductase activity (NRA), curd yield and quality of cauliflower cv. ‘Minuteman’. In the field study the treatments consisted of five N rates (0, 55, 110, 165 and 220 kg/ha) and three K rates (0, 25 and 50 kg/ha). In the greenhouse study the treatments were five levels of N (0, 16.5, 33, 50 and 66.5 mg/plant/day) using a modified Hoagland nutrition solution. In the field study the interaction of N/K rates was significant in cauliflower whole plant N/K uptake. Head N/K accumulation was 32-35% of plant total N/K uptake (8.0 g/plant), which was significantly correlated with head yield and size (P<0.05). Cauliflower NRA was associated with leaf/head sap NO3-N concentrations. It is suggested that nitrogen and potassium translocation is an important factor of cauliflower yield and quality.
87

Effective Optimization of Catalytic Hydrogenations Using a Rationally Designed Hydrogen Uptake System

Waldie, Fraser, D. Cole 03 February 2012 (has links)
This thesis examines the various aspects of catalytically deoxygenating biomass-derived feedstocks including the relevant catalyst materials, conditions and equipment. Preliminary investigations probed the ability of T316 SS, as a reactor material, to perform as an effective hydrogenation catalyst at temperatures above 100 oC, under reducing aqueous-acidic media. Additionally, an external apparatus was developed in order to facilitate the optimization of catalytic hydrogenations. The accuracy and applicability of this system was confirmed using the reduction of levulinic acid to γ-valerolactone. Accurate information pertaining to the quantity of hydrogen consumed was obtained in addition to in situ differential rates reaction allowing for the derivation of the integrated rate law. Subsequently, the newly designed uptake system was used to monitor, and effectively optimize, the deoxygenation of a series of complex furfural-derived substrates towards the attempted production of high-energy density fuels. Commercially available Pd/C and Ru/C catalysts were employed, unsuccessfully, under a variety of reaction conditions. / NSERC, Los Alamos National Laboratories, Ontario Innovation Trust
88

Torrefaction and Pelletization of Different Forms of Biomass of Ontario

Acharya, Bimal 02 May 2013 (has links)
The purpose of this study is to investigate the torrefaction and pelletization behavior, hydrophobicity, storage behavior, ash analysis on three different biomasses: one (willow pellets) from wood products, one (oat pellets) from agricultural products and one (poultry litter) from the non-lignocellulosic biomass products during the processes. Four different torrefaction temperatures from 200°C-300°C, at 10-60 minute residence times, 0%-2.4% oxygen concentration, were considered. Of these, 285°C for willow pellets, 270°C for oat pellets and 275°C for poultry litter were found to be optimum for hydrophobicity. Studies of XRD and SEM of biomass ash at 800°C, 900°C and 1000°C were also carried out. The aforementioned results indicate that torrefaction is a feasible alternative to improve energy properties of ordinary biomass and prevent moisture re-absorption during storage.
89

Broad line NMR imaging : applications to porous building materials and new developments in stray field imaging

Bohris, Alexander J. January 1999 (has links)
No description available.
90

Development of reference standards for cardiorespiratory fitness from Ball State University Adult Physical Fitness Program cohort

Kaufmann, Angela J. 20 July 2013 (has links)
To develop reference standards for cardiorespiratory fitness (CRF) from directly measured maximum oxygen consumption using the Ball State University Adult Physical Fitness Program (APFP) cohort. The APFP cohort is an open cohort of self-referred participants since 1971. From 3,212 individual participants, 2,642 male and 1,741 female (18-79 years) test files remained after exclusion criteria was met. Gender-specific age, physical activity (PA), body mass index (BMI), and smoking status CRF reference standards were developed. Men had greater mean CRF (35%) than women and consistently had greater mean CRF according to age, PA, BMI, and smoking status (p<.05). CRF was approximately 10% lower across each decade of age, and was greater with increasing PA compared to the sedentary group. Greater classes of BMI had lower CRF, and CRF was 5% greater in non-smokers compared to current smokers. A pooled CRF registry is recommended for a larger and more diverse cohort. / School of Physical Education, Sport, and Exercise Science

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