Würzburg, Universiẗat, Diss., 2007.

<p>Bronopol (2-brom-2nitropropan-1,3-diol) occurs in many products, for example cosmetics, medicines and industrial water systems. In this thesis Bronopol was investigated to see if it is an environmental problem in Sweden.</p><p>As a starting point two existing analysis methods was used to combine to one. The first one was suited for phenol analysis and the other one for Bronopol analysis. The combined method was optimized as far as possible, although this wasn’t achieved as hoped. The cause of this was due to errors beyond our explanation. Because of this problem the yield couldn’t be determined.</p><p>The water samples were taken from Tekniska Verken in Linköping, Sweden. It was two samples, one incoming and one outgoing sample from the waste water treatment plant. The samples were filtered and then they were passed through SPE columns. The samples were evaporated to dryness with N2. After this the samples were derivatizised with TMS and the following step was GC analysis with EC – detector.</p><p>Bronopol was detected in the incoming water sample.</p> / <p>Bronopol (2-brom-2nitropropan-1,3-diol) förekommer i dagens läge i en mängd olika produk-ter, allt från kosmetika till läkemedel samt inom industrier. I denna studie utreddes det om Bronopol i dagens läge är ett miljöproblem.</p><p>Som utgångspunkt i studien användes två olika metoder, den ena analysmetoden var anpassad för fenoler och den andra var anpassad för Bronopolanalys. Dessa två analysmetoder kombi-nerades till en metod för att analysera Bronopol. Därefter optimerades den på bästa möjliga sätt. Dock gick inte optimeringen så bra. På grund av fel som inte kunde förklaras kunde inget utbyte bestämmas i samband med analys av vattenproverna.</p><p>Vattenproverna togs från Tekniska Verken i Linköping och det var ett ingående samt ett utgå-ende vattenprov från avloppsreningsverket. Proverna filtrerades med Büchnertratt och Munk-tellfilter. Därefter fick proverna gå igenom SPE – kolonnen och sedan indunstades proverna till torrhet med N2. Innan proverna applicerades på SPE – kolonnerna konditionerades de med etylacetat, metanol samt surgjort vatten. Efter det analyserades proverna med gaskromatografi med en EC – detektor.</p><p>Bronopol detekterades i det ingående vattenprovet men inte i det utgående.</p>

Methylotrophs are aerobic bacteria that use methanol as a carbon and/or energy source. They are widespread but have not been extensively studied in marine environments. Seawater 14C tracer studies were combined with molecular biological cultivation- independent techniques (polymerase chain reactions using 16S rRNA and mxaF gene specific primers, 454 pyrosequencing) to investigate temporal and spatial variability in rates of microbial methanol utilisation and methylotrophic community composition in temperate coastal waters of the western English Channel, UK (WEC) and the Atlantic Ocean (Atlantic Meridional Transect 19). Microbial methanol dissimilation rates were, on average, thirteen times higher in waters of the WEC (0.65–11.2 nmol l-1h-1) than in open ocean waters of the Atlantic (0.01–1.7 nmol l-1h-1), with maximum rates found during winter months in the WEC. Highest methanol dissimilation rates in the Atlantic were measured in the north subtropical gyre of up to eight times higher than other Atlantic regions. Microbial methanol assimilation rates in the Atlantic Ocean (0.01–2.2 x10-2 nmol l-1h-1) were up to four times higher than those from the WEC (0.04–2.6 x10-2 nmol l-1h-1). Methanol assimilation rates from the WEC displayed seasonal maxima during summer, but showed methanol bacterial growth efficiency (BGEM) of <1% all year. Overall, assimilation rates were highest in the equatorial upwelling where BGEM reached 17%. Methanol assimilation rates showed a significant positive correlation with bacterial leucine incorporation in contrast to methanol dissimilation, which showed a negative relationship. Methanol dissimilation rates strongly correlated with the abundance of bacteria of the SAR11 clade, previously shown to utilise methanol as an energy source. The first basin scale approach using 454 pyrosequencing in the Atlantic revealed a remarkable increase in bacterial diversity in the nutrient limited southern gyre. Use of mxaF PCR primers also confirmed the ubiquitous presence of methylotrophic bacteria throughout the top 200m of the Atlantic Ocean.

No description available.

The environmental dynamics of the northern Benguela upwelling system was investigated primarily using a time series of mean, weekly satellite images of sea surface temperature (SST), and observed trends were related to patterns in the reproductive activity and recruitment success of the region's pilchard and anchovy stocks. Three main methods were used to look at environmental trends: overall and seasonal trends in the system's behaviour were derived from maps of mean SST and SST variability, charts of mean weekly SST per 0.5° latitude were constructed to show spatio-temporal variability in coastal upwelling activity, and standardised principal components analysis was employed to identify the major modes of spatial SST variability and to quantify the evolution of the system's spatial structure through time. Important new findings include the observation that interannual variability itself is largely due to interannual differences in conditions during February, March and April, and that longshore intrusions of warmer water from both ends of the system and onshore intrusions of oceanic water account for a large proportion of the system's temporal variability in spatial structure. Comparisons of clupeoid reproductive activity with environmental trends further confirms that spawning activity and anchovy larvae abundance tend to be greatest when upwelling activity is reduced and conditions are suitable for the retention of eggs and larvae. As regards recruitment variability, pilchard recruitment was found to have a generally positive relationship with SST conditions, whilst anchovy recruitment appeared to be favoured by cooler conditions than pilchard. Different 'domains' in the relationship between the system's spatial structure, as revealed by the principal components analysis, and inshore SSTs were found to correspond closely with differing levels of anchovy and pilchard recruitment between 1982 and 1987. Should these relationships hold when tested over more years, they might, in the future, provide a basis for predicting clupeoid recruitment success in the region.

Universiẗat, Diss.--Münster, 1999.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this study, two methods frequently used in the extraction of residues of pesticides in fruits and vegetables, the QuEChERS method and the mini-Luke method, were compared in order to optimize and validate these methods using quantification by GC×GC-μECD. This study was carried out for the pesticides bifenthrin, cyfluthrin, fenpropathrin, fenvalerate, esfenvalerate and permethrin cis and trans in tomato. In the QuEChERS method, 10 mL of acetonitrile containing 1% (v/v) of acetic acid was added to 10 g of sample. In the mini-Luke method, 30 mL of acetone, followed by 60 mL of a 1:1 (v/v) mixture of petroleum ether and dichloromethane were added to 10 g of sample. In the extraction method with acetonitrile, recoveries between 90.2 and 105.5% were obtained with RSD values lower than 8.7%, whereas, using the extraction method with acetone, the recoveries were between 86.2 and 110.8% with RSD values lower than 9.0%. In terms of limit of quantification (LOQ), the QuEChERS method presented values between 0.01 and 0.02 mg kg-1, considered more satisfactory than those obtained using the modified mini-Luke method (LOQ between 0.02 and 0.05 mg kg-1), where the value of LOQ found for cyfluthrin was above of the maximum limit of residues allowed by ANVISA, and therefore unsatisfactory. The r2 values from the analytical curves in the extract of the matrix were equal or higher than 0.9992 and 0.9955 for the modified QuEChERS method and the modified mini-Luke method, respectively, demonstrating that the modified QuEChERS method supplied more appropriate r2 values. Moreover, the QuEChERS method is a simpler procedure as it utilizes manual agitation and can be employed in any laboratory or in the field. Another important advantage of this method is the lower amount of solvent used. This study also showed that the GC×GC-μECD system using a modulator of double compressed air jet reduces costs and can be used in analyses of pyrethroid pesticides in tomato, with satisfactory values of LOD and LOQ, good precision and accuracy. / Nesse estudo comparou-se dois métodos bastante utilizados na extração de resíduos de pesticidas em frutas e vegetais, o método QuEChERS e o método mini-Luke, de modo a otimizar e validar estes métodos utilizando quantificação por GC×GC-μECD. Este estudo foi realizado para os pesticidas bifentrina, ciflutrina, fenpropatrina, fenvalerato, esfenvalerato e permetrina cis e trans em tomate. No método QuEChERS adicionou-se 10 mL de acetonitrila contendo 1% (v/v) de ácido acético em 10 g de amostra. No método mini-Luke adicionou-se 30 mL de acetona, seguidos de 60 mL da mistura 1:1 (v/v) de éter de petróleo e diclorometano em 10 g de amostra. Ao empregar-se o método de extração com acetonitrila obteve-se recuperações entre 90,2 e 105,5% com RSD menor que 8,7%, enquanto que, utilizando o método de extração com acetona, as recuperações ficaram entre 86,2 e 110,8% com RSD menor que 9,0%. Em termos de limite de quantificação (LOQ) o método QuEChERS modificado apresentou valores entre 0,01 e 0,02 mg kg-1, considerados mais satisfatórios que os obtidos pelo método mini-Luke modificado (LOQ entre 0,02 e 0,05 mg kg-1), sendo que, neste caso, o valor de LOQ encontrado para ciflutrina não foi satisfatório, pois está acima do limite máximo de resíduos permitido pela ANVISA. Com relação aos valores de r2 das curvas analíticas, percebeu-se que, utilizando o método QuEChERS modificado estes valores foram maiores ou iguais a 0,9992 e para o método mini-Luke modificado foram maiores ou iguais a 0,9955, ambos para as curvas no extrato da matriz, demonstrando, portanto, que o método QuEChERS modificado forneceu valores de r2 mais apropriados. Além disso, o método QuEChERS mostrou ser um procedimento mais simples por utilizar agitação manual, podendo ser aplicado em qualquer laboratório ou a campo. Outra vantagem importante deste método é a menor quantidade de solvente utilizado. Este estudo mostrou também que o sistema GC×GC-μECD com modulador de duplo jato de ar comprimido possibilita a redução dos custos da análise e que esta combinação pode ser utilizada em análises de pesticidas piretróides em tomate, pois obteve-se valores satisfatórios de LOD e LOQ, com boa precisão e exatidão.

Ocean chemistry has oscillated throughout Earth history to favour the dominant non-biogenic polymorph of calcium carbonate (CaCO3) to be either calcite or aragonite (Sandberg, 1983). Throughout the Phanerozoic these oscillations have occurred to facilitate aragonite-dominant conditions three times and calcite-dominant conditions twice. These aragonite-calcite seas conditions have previously been viewed as a global phenomenon where conditions fluctuate over time, but not in space, and represent the main environmental context in which the evolution of CaCO3 biomineralisation has occurred (Stanley and Hardie, 1998). CaCO3 is one of the most widely distributed minerals in the marine environment, occurring throughout geological history, both biogenically and non-biogenically (Lowenstam and Weiner, 1989). Marine non-biogenic precipitates are commonly found as carbonate ooids, sedimentary cements and muds (Nichols, 2009). Biogenic CaCO3 is formed via biomineralisation in calcifying organisms (Lowenstam and Weiner, 1989; Allemand et al., 2004), and is much more abundant than the non-biogenic forms. Although CaCO3 is abundant, it only accounts for a small proportion of the global carbon budget. Biogenic CaCO3 is representative of a larger proportion of the global carbon budget than non-biogenically formed CaCO3 (Berelson et al., 2007). The main driving force controlling the precipitation of CaCO3 polymorphs is the Mg:Ca molar ratio of seawater (Morse et al., 2007). However, other parameters such as temperature (Burton and Walter, 1984; Morse et al, 1997; Balthasar and Cusack, 2015), pCO2 (Lee and Morse, 2010), and SO4 (Morse et al., 2007) are also known to influence CaCO3 polymorph formation but are often overlooked in the context of aragonite-calcite seas. Fluctuations in these parameters of Mg:Ca ratio, SO42+ and pCO2 of seawater have been suggested to cause shifts in original composition of non-biogenic marine carbonates, and in turn viewed as the main driving mechanisms facilitating the switch between aragonite and calcite dominance (Morse et al., 1997; Lee and Morse, 2010; Bots et al., 2011). Specifically the influence of temperature is important because it is likely to result in aragonite-calcite sea conditions to vary spatially (Balthasar and Cusack, 2015). Today marine temperatures are changing across the latitudes due to environmental factors. Global CO2 levels have increased significantly since industrialisation (Doney et al., 2009), with 33% entering the oceans and reducing pH (Raven et al., 2005) accelerating climate change (IPCC, 2013) and influencing marine calcification (Fitzer et al., 2014a; 2015b; Bach, 2015; Zhao et al., 2017). Strong links between the carbon cycle and climate change observed in the rock record give evidence that environmental changes such as pCO2 and global warming have impacts on calcification and marine biota (Hönish et al., 2012). The first objective was to determine the influence of Mg:Ca ratio, temperature and water movement on the first-formed precipitates of non-biogenic CaCO3 precipitation yielded via a continuous addition technique experiments (Chapter 3). CaCO3 precipitation was induced by continuously adding bicarbonate to a bulk solution of known Mg:Ca ratio (1,2 or 3), and fixed salinity of 35 (practical salinity scale), at 20°C and 30ºC in still conditions, and then repeated with the solution being shaken at 80rpm mimicking more natural marine conditions. The mineralogy and crystal morphology of precipitates was determined using Raman Spectroscopy and Scanning Electron Microscopy. Results in Chapter 3 indicated that polymorphs co-precipitate, with the ratio of aragonite to calcite increasing with increased Mg:Ca ratio and elevated temperature. The main difference between still and shaken conditions was that overall, more crystals of aragonite compared to calcite precipitate in shaking conditions. The crystal size is less influenced in aragonite, but calcite crystals were smaller. These results contradict current views on aragonite-calcite seas as spatially homogenous ocean states need to be re-examined to include the effect of temperature on the spatial distribution of CaCO3 polymorphs. Examining polymorph growth under these experimental constraints allows us to gain a better understanding of how temperature and Mg:Ca together control non-biogenic aragonite and calcite precipitation providing a more realistic environmental framework in which to evaluate the evolution of biomineralisation. To further this work, the same continuous addition technique was used with the presence of sulphate in the mother solution (Chapter 4). Sulphate being the 4th most common marine ion (Halvey et al., 2012) and known to have an influence on mineralogy (Kontrec et al., 2004). The presence of sulphate increase the aragonite to calcite proportion formed compared to sulphate-free conditions (Chapter 4). Elevated temperature with sulphate further increased the proportion of aragonite to calcite facilitated (Chapter 4). In the presence of sulphate the main difference between sulphate-free environments and those with sulphate environments was: in still conditions the presence of sulphate increased the crystal number more than the crystal size at 20°C; at 30°C or in shaken conditions the presence of sulphate increased the crystal size of aragonite to calcite much more than it had influence on the crystal number. Non-biogenically the influence of sulphate lowered the threshold of Mg:Ca ratio that the switch between calcite and aragonite would be facilitated at (Bots et al., 2011). This would have implications for marine calcification as pure calcite seas would become very rare and imply that organisms would be forming calcified hard parts out with the supported mineralogies. Biogenic application of these results is complex however as organisms often have the ability to select aragonite as their main polymorph for their own functional requirements (Weiner and Dove, 2003). The growth parameters of non-biogenic polymorph formations grown from artificial seawater can be used to understand how organism control can influence the polymorph formation under similar conditions (Kawano et al., 2009). Assessing the elemental composition of mussel shells grown under know conditions of temperature and pCO2 allowed the environmental influences on mineralogy be assessed under possible the projected changes in climate forecast to occur by 2100 by IPCC (2013). Prior to this research, no study had used Mytilus edulis shell elemental composition to test the influence of aragonite-calcite sea conditions on mineralogy. This research compiles a detailed source of information on the constraints from environmental sources such as temperature and pCO2, on the elemental concentrations within shell formation and what potential changes could occur in response to a changing marine environment (Chapter 5). Here elevated temperature significantly increased the concentration of magnesium in calcite, but did not influence the magnesium concentration of aragonite unless combined with elevated pCO2. The concentrations of sulphur in calcite were significantly decreased at elevated pCO2 or combined increased temperature and pCO2 as concentrations of sodium were found to be increased under these conditions. In aragonite the concentrations of both sulphur and sodium were significantly different under all scenarios. Strontium did not yield any significant results in this research in either calcite or aragonite. Results observed indicate that the shell elemental concentrations are influenced differently in aragonite or calcite, and further influenced by environmental conditions based on the original mineralogy. This suggests that physiological mechanisms under the constraints of increased temperature and pCO2 can override the seawater chemistry influences of aragonite-calcite seas impacting on mineralogy. / This research allows comparison of how non-biogenic and biogenic CaCO3 formation is influenced by seawater chemistry and environmental parameters to determine the dominant mineralogy. Increased temperature in both formations has shown to increase the impact of magnesium on calcite enabling the facilitation of aragonite. However, magnesium has influence on biogenic aragonite in extreme combined conditions of elevated temperature and pCO2. This work indicates that CaCO3 formation is complex and requires a multi-variable approach to understanding the mechanisms that facilitate the dominant mineralogy. By including variables such as temperature, this research suggests that aragonite-calcite seas conditions do not facilitate globally homogeneous switches in mineralogy, but the mineralogy is indeed influenced on latitudinal scales by other factors that influence the mechanisms involved.

The ability of a species to show plasticity throughout its range is suggested to be significant to the survival, maintenance, and expansion of populations. In the Southern Ocean, plastic traits may have enabled resilience since the onset of cooling, and given species the capacity to exploit empty niches after the retreat of ice in interglacial periods. Phenotypic plasticity has rarely been investigated in Southern Ocean invertebrates however, and the cold stenothermal environment, which prevails, has often been considered homogenous in its selection on fauna. Previous ecological studies have often pooled together material collected within predetermined biogeographic regions to overcome the limitations of sampling difficulties. Subtle differences between environments may however, be forcing ecological divergence in species, with possible implications for speciation processes. This thesis investigates the phenotypic plasticity and reproduction among populations of the small shallow-water brooding bivalve Lissarca miliaris over its Antarctic range, and of deep-sea protobranch bivalves Yoldiella ecaudata, Y. sabrina, and Y. valettei from contrasting benthic regions. The reproductive studies of L. miliaris revealed a previously unknown hermaphrodite trait, maximising the reproductive efficiency in a short-lived species where the female’s capacity to brood its young is limited. Reproduction is also described for the first time in deep-sea Antarctic protobranch bivalves and demonstrates lecithotrophic larval development. Additionally, Y. valettei shows evidence of simultaneous hermaphroditism, which may increase the likelihood of successful reproduction in low population densities. Phenotypic plasticity is observed among populations of bivalves, irrespective of geographical proximity, and with no latitudinal trends, but subtle differences in the environment. Significant differences in morphology and growth rates are identified among populations, and reproductive plasticity identified in L. miliaris and Y. sabrina. Increasing atmospheric temperature is also measured to show an effect on the ecophysiology of intertidal populations of L. miliaris at Signy Island over the past 40 years, with increasing growth rates at the cost of smaller offspring and pressure from endolithic algal decay.

No description available.