Studies were undertaken to investigate the presence of nitric oxide synthase (NOS; E.C. 1.14.13.39) activity in number of cnidarian species from shallow marine subtropical environments. Enzyme activity was assayed by measuring the conversion of 3H L-arginine to 3H L-citrulline (the citrulline assay). This assay was shown to be sufficiently sensitive for studies of this nature but was not optimised for use with cnidarian preparations. As a result, confidence in the accuracy of the generated assay results is limited. NOS activity was nevertheless demonstrated in the sea anemone A. pallida, in the zooxanthellae associated with A. pallida, Symbiodinium spp. and in five scleractinian coral species. Preliminary studies were conducted to characterise NOS from A. pallida. NOS activity of this species was shown to be predominantly cytosolic and basal rates of enzyme activity were determined to be 0.47 ±0 - 9.96 ±0.06 pmoles citrulline µg proteinˉ¹ minˉ¹. The biochemical signature of the enzyme is defined by an apparent Km of 132.9 µM L-arginine and an apparent V max of 17.7 pmoles citrulline µg proteinˉ¹ minˉ¹. The NOS enzyme from A. pallida was inhibited by the arginine analogue L-NMA with an apparent K1 of 1014 µM. Histochemical localisation of NOS activity by NADPH-diaphorase staining showed the enzyme to be present in the epidermal cells and at the extremities of the mesoglea. The hypothesis that NOS has potential as an innovative biochemical effect biomarker in cnidarian species was investigated with a number of experiments. NOS activity levels were determined in A. pallida previously dosed with sublethal concentrations of copper, fluoranthene or tributyltin-oxide. No clear evidence to support this hypothesis was provided by these studies. Morphological responses of A. pallida were monitored during exposure to contaminants, arginine analogues, a nitric oxide donor and a thermal regime that induced bleaching. Contraction of tentacles and body columns was a noted response to each of these exposures; individuals exposed to the most extreme concentrations of chemicals or the highest temperature tested typically elicited the most extreme contraction responses. Exposure of A. pallida to temperatures gradually increasing from 25 to 35°C over 10 days induced bleaching characterised by reduced zooxanthellae densities. NOS activity levels and antioxidant capacity, both expressed in terms of per unit protein, were increased in anemones exposed to temperatures of > 31 °C. NOS and FRAP activities expressed on a per anemone basis showed no clear change over the experimental period despite the substantial declines in host protein noted in anemones over the experimental period. These results indicate that FRAP and NOS activity levels were maintained over the course of the applied experimental thermal regime despite the occurrence of dramatic physiological changes. Taken together, these results suggest that NOS plays an important role in the biology of cnidarians, and that as such, the activity of this enzyme has the potential to be developed into a valuable biomarker for the evaluation of initial responses of key organisms in tropical and subtropical marine ecosystems to adverse conditions. However, these results also reveal that a more comprehensive knowledge of both the roles played by NO and the responsiveness of NOS to a range of potentially adverse stimuli is required to fulfil this potential.

Divergence structures associated with the spectrum of precipitating systems in the subtropics and midlatitudes are not well documented. A mesoscale model (MM5) is employed to quantify the relative importance different baroclinic environments have on divergence profiles for common storm types in southeast Texas, a subtropical region. Divergence profiles averaged over a 100 x 100 nested grid with 3-km grid spacing are calculated from the model-derived wind fields for each storm. The divergence profiles simulated for selected storms are consistent with those calculated from an S-band radar using the velocity-azimuth display (VAD) technique. Divergence profiles from well-modeled storms vary in magnitude and structure across the spectrum of baroclinicities and storm types common in southeast Texas. Barotropic storms more characteristic of the Tropics generate the most elevated divergence (and thus diabatic heating) structures with the largest magnitudes. As the degree of baroclinicity increases, stratiform area fractions increase while the levels of non-divergence (LNDs) decrease. However, some weakly baroclinic storms contain stratiform area fractions and divergence profiles with magnitudes and LNDs that are similar to barotropic storms, despite having lower tropopause heights and less deep convection. Additional convection forms after the passage of some of the modeled barotropic and weakly baroclinic storms that contain elevated divergence signatures, circumstantially suggesting that heating at upper-levels may cause diabatic feedbacks that help drive regions of persistent convection in the subtropics. Applying a two-dimensional stratiform-convective separation algorithm to MM5 reflectivity data generates realistic stratiform and convective divergence signals. Stratiform regions in barotropic storms contain thicker, more elevated mid-level convergence structures with larger magnitudes than strongly baroclinic storms, while weakly baroclinic storms have LNDs that fall somewhere in between with magnitudes similar to barotropic storms. Divergence profiles within convective regions typically become more elevated as baroclinicity decreases, although variations in magnitude are less coherent. These simulations suggest that MM5 adequately captures mass field perturbations within convective and stratiform regions, the latter of which produces diabatic feedbacks capable of generating additional convection. As a result, future research determining the climatological dynamic response caused by divergence profiles in MM5 may be feasible.

The growing human population threatens the many of the earth’s biological systems. In the last 600 years extinction rates risen from 1 extinction per million species per year (E/MSY) in the 1400’s to 50 E/MSY today. During this time period 1.5% of all known birds have gone extinct, because they could not adapt quickly enough to human mediated changes. The goal of this dissertation was to determine how urbanization and anthropogenic services needed to support urban areas impact cypress dome wetland aquatic insect and migratory bird populations that depend on them. In Central Florida cypress dome hydroperiods are driven by seasonal rainfall conditions and fill June and July with the onset of the Florida rainy season then begin drying beginning in October with the onset of the dry season. Some wetlands were strongly influenced by groundwater pumping and dried out quicker than others, a characteristic that reduced annual insect emergence. Decreased adult insect populations were associated with lower emergence rates early in the dry season led to lower utilization by insectivorous birds. Winter migratory birds significantly related with adult insect abundance during winter months (r = 0.578, p=0.049), and utilized this region at the peak in adult insect populations. Conversely, Neotropical migrants travel through the region during spring when insects are scarce, and adult insects began sharp decline suggesting that Neotropical migrants depleted populations possibly leading to interspecies competition. Neotropical migrants strongly avoided urban areas and declined by 70% in urban areas, which may contribute to declining Neotropical migratory bird populations as a lack in adequate stopover sites may limit entire species. If they are not able to adapt foraging patterns that utilize urban areas in Central Florida where urban development is increasing rabidly populations may continue to decline.

Mercury (Hg) is a global pollutant, yet Hg biomagnification, the increase in Hg with trophic level, remains poorly characterized in many regions, especially at subtropical latitudes. The present study assessed subtropical reservoirs of eastern China, which provided an opportunity to quantify Hg biomagnification under highly altered conditions that included high atmospheric Hg deposition, use of reservoirs for fisheries, manipulation of food webs through stocking and high fishing pressure, and increasing eutrophication. Despite China’s Hg emission and deposition rates that are among the highest worldwide, low fish Hg concentrations and Hg biomagnification rates were found; this was explained by food web structure and fish species characteristics. Stocked species occupied lower trophic levels and had significantly lower Hg concentrations relative to wild fishes. Evidence of decreased Hg concentrations with eutrophication (as indicated by chlorophyll-a) was observed, suggesting algal biodilution and/or somatic growth dilution. Relative to temperate lakes, zooplankton density dilution may also be causing reduced Hg concentrations in subtropical biota. Hydrogeomorphic features, such as water retention time and percent crop cover, explained Hg bioaccumulation factors and Hg concentrations at the base of the food web. Eutrophication and hydrogeomorphic features also influenced the bioavailability of selenium, which can protect against the toxicity of Hg at adequate concentrations, and the concentration of eicosapentaenoic acid, a beneficial fatty acid, in the planktivorous Bighead Carp (Hypophthalmichthys nobilis). This may indicate that the risk of exposure to the neurotoxicant methylmercury relative to benefits of fish consumption may increase with eutrophication in some fish species. Overall, the findings of this study suggest food web structure, eutrophication, and hydrogeomorphic features together explain low Hg concentrations in anthropogenically modified subtropical reservoirs in eastern China. / Thesis (Ph.D, Biology) -- Queen's University, 2014-07-01 11:35:12.637

Ten ring-width based chronologies from Nepal are described and the prospects for further dendroclimatic work there reviewed briefly. The initial results are encouraging, and more intensive subregional sampling is called for. All the cores examined showed distinct annual rings, and there was little evidence of double or missing rings, except juniper at some sites and in some Pinus roxburghii trees. Difficulty was encountered in dating Pinus wallichiana and Cupressus dumosa. Individual site chronologies of Cedros deodora, P. roxburghii and P. wallichiana were particularly promising, and of high elevation Abies spectabilis moderately so. Densitometric data are likely to be more useful for this species. The paucity of meteorological data in Nepal represents an obstacle to further dendroclimatic work there.

The "POWER - PLANT" deals with the rehabilitation of the former Central Power Conversion and Dale Schoeller (Nejedly I and III) in the village Libušín Mine. Will be newly designed for building the power plant technology with progressive fluidized bed boiler to biomass steam turbine with an output of 7 MW and absorption (trigeneration) unit producing heat, cooling and electricity, which also will function as a cooler primary circuits. The source of water for the power plant will not only former mining pit Nejedlý I which is currently flooded drinking water at about 12 ° C. This system uses high efficiency embedded fuel (biomass), which is ultimately required less. A greater proportion of electricity generated and part of the heat will be distributed to the public network. In most areas will be proposed publicly accessible greenhouses of steel-aluminum construction filled ETFE foil forming the heat insulating membrane filled with air. The reason is to create conditions for the cultivation of tropical and subtropical plants. Greenhouses will be connected to the absorption unit power (underground meanders through which water will circulate), the ventilation shaft mine and mine water - therefore it will be possible to manage the conditions of the internal environment of the building without the influence of the season and especially without mounting other technological devices. It will provide for cooperation with the absorption unit for cooling the primary circuit - therefore eliminating the need for cooling towers or fans. The project will build a detached departments of the Faculty of Mechanical Engineering in Prague - Institute of progressive technologies and systems for energy and the Faculty of Agronomy and Natural Resources CULS. The reason is to allow students and scientists actively and in practice mainly participate in the operation and especially the development of the issue. The public in the area besides themselves open to the greenhouses indoor and outdoor thermal swimming. Part of the entrance hall is a bistro and foremost lecture hall. The aim is decentralized botanical-energy complex of buildings that produce electricity, heat, cooling, and biomass, and creating recreational, educational and research conditions.