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Three experiments were conducted to evaluate the effects of dietary chitin and chitosan on growth, immune responses and resistance of grass prawn Penaeus monodon against white spot syndrome virus (WSSV) and Vibrio infections. In the first experiment, two levels (0.5¡B1 g/100g diet) of chitin and three levels (0.5¡B1¡B5 g/100g diet) of chitosan were evaluated. The results show that weight gain of the shrimp fed on diet containing no chitosan or the lowest level of chitosan (0.5 %) was higher than other groups. In the second experiment, four levels of chitosan (0¡B0.5¡B1¡B5 g/100g diet) were tested. Weight gains of the control (0 %) and 0.5 % chitosan groups were significantly (P<0.05) higher than the 0.1 and 1 % chitosan groups. Shrimp survival rate was not influenced by chitosan inclusion. The test shrimp of the first experiment were evaluated for their immune responses after dietary exposures. The results show that phenoloxidase activity and superoxide dismutase were not significantly different (P>0.05) among treatments. The production of superoxide anion in the 0.5 % chitin group was significantly (P<0.05) lower than the other groups at day 3 and 12. The last experiment evaluated the effectiveness of dietary chitosan against infection of WSSV and Vibrio damsela. Shrimp were fed for 20 days on test diets containing four levels of chitosan (0¡B0.5¡B1¡B5 g/100g diet) and then challenged by injection of WSSV or Vibrio solution. In the WSSV challenge, except at day 7, shrimp survivals were not different among treatments. At day 7, however, the survival rates of the shrimp fed the diet containing 0.1 or 1 % chitosan were significantly (P<0.05) higher than those of the other groups. When challenged with Vibrio damsela, there was no difference in shrimp survival among dietary treatments. The present study shows that dietary chitin and chitosan do not significantly enhance immune responses and disease resistance of juvenile P. monodon. Dietary incorporation of chitin or chitosan negatively affects shrimp growth.

Missense, nonsense, and frameshift mutations in the human anion exchanger 1 (AE1) have been associated with inherited distal renal tubular acidosis and hereditary spherocytosis. These two disorders are almost always mutually exclusive. However, we have recently found an unusual exception, i.e, a patient with complete distal renal tubular acidosis and severe hereditary spherocytosis. DNA sequencing revealed a novel mutation AE1 E522K (Band 3 Kaohsiung) combined with AE1 G701D mutation in this patient. We hypothesize these AE1 mutations cause these two disorders because of trafficking defect. To elucidate this hypothesis, we analyzed protein trafficking and subcellular location of AE1 and these mutants transfected into MDCK cells. Our results showed that they formed homodimers or heterodimers with each other. Homodimers of the wild-type and E522K mutant were localized at the plasma membrane, whereas the G701D mutant largely remained in the cytoplasm. On the other hand, heterodimers of either E522K or G701D and the wild-type AE1 were located in the plasma membrane, whereas E522K/G701D heterodimers remained in the cytoplasm. As for erythroid isoform of anion exchanger 1, analysis of protein trafficking and subcellular localization of the wild-type erythroid isoform of human anion exchanger 1 and these mutants transfected into k562 cells also showed that they can form homodimers or heterodimers with each other. Erythroid AE1 E522K/G701D cell-surface expression was significantly lower compared with WT homodimer expression. This result coincided with that erythroid AE1 of the patient¡¦s red cell membrane can be detected 28% that of normal control in immunoblotting. Our study shows that the compound E522K/G701D mutation of human anion exchanger 1 causes trafficking defects in kidney and red blood cell lines, and these may explain the complete distal renal tubular acidosis and hereditary spherocytosis of the patient.

The research presented herein explores three aspects of asymmetric catalysis: (1) the development of new catalytic enantioselective reactions, (2) the application of stereoselective catalysis to natural product total synthesis, and (3) the design and synthesis of new chiral catalysts. / Chemistry and Chemical Biology

The dissertation focuses on the recent discovery in supramolecular chemistry of novel macrocyclic compounds with NH and CH donor groups. Chapter 1 provides a brief overview of the anions under study, supramolecular chemistry, the relevant other anion receptors, as well as previous findings involving the use of CH donor groups as functional building blocks. Chapter 2, as the major focus of this dissertation, describes a pyrrolyl-based triazolophane, incorporating CH and NH donor groups, which acts as a receptor for the pyrophosphate anion in chloroform solution. It shows selectivity for this trianion, followed by HSO₄− > H₂PO₄− > Cl− > Br− (all as the corresponding tetrabutylammonium salts), with NH−anion interactions being more important than CH−anion interactions. In the solid state, the receptor binds the pyrophosphate anion in a clip-like slot via NH and CH hydrogen bonds. Chapter 3 describes a pyrrole–based triazolium–phane which has been prepared through “click” chemistry in moderate yield. It displays a high selectivity for tetrahedral oxyanions relative to various test monoanions and trigonal planar anions in mixed polar organic–aqueous solvent media. It was also found that the binding affinity and selectivity of the macrocycle to the anions are solvent dependent. Several crystal structures were solved. They confirm that the cationic macrocycle ring binds pyrophosphate and phosphate anions in the solid state. Finally, chapter 4 describes a novel 1,3,4-substituted 1,2,3-triazolium salt found to function as an effective precursor for the synthesis of structurally characterized cationic silver(I) and ruthenium(II) carbene complexes of overall 1:2 ligand-to-metal stoichiometry. The Ag(I) complex crystallized in the form of an eight silver atom containing cluster, whereas the Ru(II) complex proved to be a discrete species and was found to be capable of initiating the ring-opening metathesis polymerization of norbornene upon activation with (trimethylsilyl)diazomethane. / text

The Waimakariri-Avon River system is an important component of the Christchurch aquifer system and has been identified as one of, if not the, primary groundwater flow path. The Waimakariri-Avon River system is ideally suited to geochemical tracing of surface water- groundwater interaction and while many past studies have been undertaken to characterise this system, in terms of its geochemistry and physical hydrogeological components, there is still a large amount of uncertainty as to how long it takes for groundwater to flow from the Waimakariri River, through the Waimakariri-Avon River groundwater system, to the springs that feed the Avon River. The primary goals of this thesis were to; 1) Constrain the residence time of groundwater connecting the Waimakariri-Avon River groundwater system using stable oxygen and hydrogen isotopes and analysis of anionic concentrations of: chloride, fluoride, nitrate, nitrite, bromide and sulfate, 2) Provide additional evidence of a hydrological connection between the Waimakariri River and the Avon River systems, 3) Present observations of the stable isotopic and anionic response of surface water to rainfall events, 4) Identify stable isotopic and anionic surface water variation along the Waimakariri-Avon River system, and establish the reasons for these. This study presents the use of natural isotopic and anionic tracers to characterise the residence time of the groundwater that flows between the Waimakariri and Avon Rivers, by sampling surface water and meteoric water at sites that are part of the Waimakariri-Avon River system. 375 samples were collected from 10 surface water and 4 rainwater sites distributed across the Waimakariri-Avon River surface water-groundwater flow path between March 5th and August, 2014. Additionally the study provides further stable isotopic evidence of the connection between the Waimakariri and Avon Rivers, as well as presents the variability of surface water chemistry in response to rainfall events. Identification of isotopic and anionic variation along the Waimakariri-Avon River system, by surface water sampling, was also conducted to establish the probable causes of observed variations. This study found that the use of large rainfall events, as natural tracers, was not conclusive in establishing the groundwater residence time of the Waimakariri-Avon River system within the 4.5 month sampling period available. Surface water sampling provided further evidence in support of past studies that have determined an isotopic connection between the Waimakariri River and the Avon River with mean stable isotopic values for the Waimakariri River (-8.85‰ δ18O and-60.65 δD) and Avon River (-8.53‰ δ18O and -58.72 δD) being more similar than those of locally derived meteoric water (-5.48‰ δ18O and -35.13 δD). Observations of surface water chemistry variations thorough time determined and identified clear responses to rainfall events as deviations from baseline values, coinciding with rainfall events. Isotopic variation along the Waimakariri-Avon River system was shown to reflect Waimakariri River derived shallow groundwater with the contributions from rainwater increasing with increased proximity to the Avon River mouth. Anionic profiling of the Waimakariri-Avon River system identified increasing concentrations of chloride, nitrate, sulfate, nitrite and bromide, relative to the Waimakariri River, with increased proximity to the Avon River mouth. Fluoride concentrations were identified in lower concentration, relative to the Waimakariri River, with increased proximity to the Avon River mouth. Fluoride and nitrite concentrations were attributed predominantly, if not entirely, to an atmospheric source as mean concentrations were greater in meteoric waters by a factor of at least 2, compared to surface water samples. Chloride and bromide have been attributed to possible salt water mixing as a result of the interaction of upwelling deeper groundwater with the marine and estuarine sands beneath the upper unconfined aquifer, that act as a confining layer within the Christchurch aquifer system. Nitrate and sulfate concentrations have been attributed to potential fertilizer usage and past land-use impacts. A significant step-change increase in chloride, bromide, nitrate and sulfate concentrations was observed between the surface water sample sites at Avonhead Park and the University of Canterbury. The step-change coincides with the boundary of the upper confining layer within the Christchurch aquifer system, and explains the increases in chloride and bromide concentrations. It also suggests a widely distributed source area as concentrations do not become diluted at the Avon River site, at Hagley Park, , which would be expected from the addition of other tributaries, if they did not have similarly high chloride and bromide concentrations. The area between these two sites has also been identified by Environment Canterbury as potentially impacted by past agricultural land-use practices and may explain the increases in nitrate and sulfate concentrations.

The focus of the research presented in this thesis is the design, synthesis, and anion recognition properties of a structurally novel class of poly(amides) that incorporates the diaminocyclobutenedione (squaramide) group into the polymer backbone. In Chapter 1, a brief overview of different anion-responsive synthetic macromolecules is presented. Emphasis is placed on the wide structural diversity of the polymers, the mechanisms of their anion-induced responses, and features such as signal amplification, multivalency, and cooperative behavior that can be exploited productively in the context of anion recognition and sensing. Chapter 2 describes a new method for the regioselective preparation of squaramides, using Lewis acid-catalyzed condensations of diethyl squarate and different anilines. Zinc trifluoromethanesulfonate promotes efficient condensations of anilines with squarate esters, providing access to symmetrical and unsymmetrical squaramides in high yields from readily available starting materials. Colorimetric anion-sensing behavior and computational studies illustrating the enhanced hydrogen bond donor ability and acidity of squaramides in comparison to ureas are presented. In Chapter 3, the application of the synthetic method described above to the selective preparation of polysquaramides composed of 1,2-isomeric repeat units is described. The optical, thermal and aggregation properties of these materials are also discussed. Finally, Chapter 4 describes self-assembly properties as well as applications of these materials in the area of anion recognition and sensing. Incorporating an anion-binding squaramide group into a polymeric architecture results in drastic alterations in the selectivity and magnitude of its anion-induced response, resulting in a sensitive and discriminating turn-on fluorescence sensor for dihydrogenphosphate ions. This unusual behavior is the result of a cooperative, anion-triggered aggregation process that was further probed by dynamic light scattering (DLS), transmission electron microscopy (TEM) and laser confocal microscopy.

The focus of the research presented in this thesis is the design, synthesis, and anion recognition properties of a structurally novel class of poly(amides) that incorporates the diaminocyclobutenedione (squaramide) group into the polymer backbone. In Chapter 1, a brief overview of different anion-responsive synthetic macromolecules is presented. Emphasis is placed on the wide structural diversity of the polymers, the mechanisms of their anion-induced responses, and features such as signal amplification, multivalency, and cooperative behavior that can be exploited productively in the context of anion recognition and sensing. Chapter 2 describes a new method for the regioselective preparation of squaramides, using Lewis acid-catalyzed condensations of diethyl squarate and different anilines. Zinc trifluoromethanesulfonate promotes efficient condensations of anilines with squarate esters, providing access to symmetrical and unsymmetrical squaramides in high yields from readily available starting materials. Colorimetric anion-sensing behavior and computational studies illustrating the enhanced hydrogen bond donor ability and acidity of squaramides in comparison to ureas are presented. In Chapter 3, the application of the synthetic method described above to the selective preparation of polysquaramides composed of 1,2-isomeric repeat units is described. The optical, thermal and aggregation properties of these materials are also discussed. Finally, Chapter 4 describes self-assembly properties as well as applications of these materials in the area of anion recognition and sensing. Incorporating an anion-binding squaramide group into a polymeric architecture results in drastic alterations in the selectivity and magnitude of its anion-induced response, resulting in a sensitive and discriminating turn-on fluorescence sensor for dihydrogenphosphate ions. This unusual behavior is the result of a cooperative, anion-triggered aggregation process that was further probed by dynamic light scattering (DLS), transmission electron microscopy (TEM) and laser confocal microscopy.

Self-assembly is an efficient method for generating large numbers of structurally diverse catalysts for screening. In this work, the method of self-assembly was explored in the construction of bifunctional catalysts, from a chiral aminophosphine, 2-formylphenylboronic acid, and a (thio)urea-containing diol. These catalysts were evaluated by their effect on the asymmetric aza-Morita-Baylis-Hillman reaction. In the second half of this thesis, the hydrogen bonding abilities of different dithiosquaramides were analyzed. As thioureas have been shown to be stronger hydrogen bond donors than ureas, it was hypothesized that dithiosquaramides may also follow a similar trend. Affinities of corresponding squaramides and dithiosquaramides to chloride, sulfate, and tosylate were compared, as well as their abilities to catalyze the Freidel-Crafts alkylation between indole and trans-β-nitrostyrene.

No description available.