This study investigates the concentrations and characteristics of PCB congeners in aquaculture oysters (Crassostrea gigas) along the western coast of Taiwan. Oyster samples were collected from 5 aquacultural areas, Hsinchu, Changhua, Yunlin, Chiayi and Tainan, during May 2003 and March 2004. The results showed that the total PCB concentrations in the oysters were between 3.43 and 93.3 ng/g dry weight, and the median concentration was 20.3 ng/g dry weight. The highest concentrations were found in the oysters collected from Luermen (Tainan) (74.7~93.3 ng/g). Samples from other two stations of Tainan aquacultural area, Cigu and Anping, were also found relative high total PCB concentrations (46.5~72.0 ng/g) than the rest area. This indicates a local pollution source should be blamed on. Except the above areas, the total PCB concentrations were found evenly distributed throughout the coast (3.43~41.2 ng/g with a median concentration of 14.9 ng/g). The PCB concentrations were not significantly correlated with lipid contents and shell lengths. Therefore, the variation of PCB concentrations in all stations might be dependent on the presence of localized sources of contamination rather than on the lipid content and shell length variation of oysters. In some observed stations, the PCB concentrations of oysters in autumn are significantly higher than in summer. That is because the adoptive tide in winter will lead to the tendency to reduce PCB concentrations of oysters.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 5 uppsatser.

No description available.

A cachaça é uma bebida típica brasileira, majoritariamente consumida ao natural. Sua qualidade pode ser melhorada pelo envelhecimento. No Brasil, o envelhecimento é tradicionalmente feito pelo armazenamento do destilado em toneis de madeira de lei nacional. O uso de toneis demanda alto custo inicial e longo prazo de imobilização do produto e capital. Alternativas de armazenamento têm sido procuradas, porém sem solução para o envelhecimento. A possibilidade do uso de fragmentos de carvalho para a maturação da cachaça pode proporcionar um maior campo de tipicidades para a bebida. O objetivo deste trabalho foi estudar congêneres voláteis e de maturação em cachaça macerada com fragmentos de madeiras de carvalho proveniente de diferentes florestas francesas (Allier, Vosges e Nièvre) e com diferentes intensidades de tosta (fraca, média e forte). Os congêneres voláteis (acetaldeído, acetato de etila, metanol, 2-butanol, 1-propanol, isobutanol, 1- butanol, álcool isoamílico e ácido acético) foram detectados e quantificados por cromatografia gasosa com detector de ionização de chama (GC-FID) e os congêneres de maturação (ácido gálico, 5-hidroximetilfurfural, furfural, ácido vanílico, ácido siríngico, vanilina, siringaldeído, coniferaldeído e sinapaldeído) foram analisados por cromatografia líquida de alta eficiência (HPLC/CLAE). Testes sensoriais foram realizados para a verificação da aceitação das amostras pelos consumidores quanto aos parâmetros de cor, aroma, sabor e impressão global. A concentração de congêneres voláteis não foi influenciada pelos tratamentos. A presença de congêneres de maturação permitiu concluir que não há contestação na capacidade de ceder compostos entre as madeiras das diferentes florestas, porém a peculiaridade de cada uma delas é destacada quando se analisa a predominância dos compostos de interesse. Em virtude da ampla concentração de congêneres de maturação presente em madeiras de Vosges e de Allier com tosta forte, pudemos supor maior complexidade química na cachaça macerada nessas condições. Seria ainda possível a variação da cachaça macerada mediante uso de fragmentos de carvalho de origens distintas combinando com diferentes intensidades de tosta. Os testes sensoriais apontaram elevada aceitação quanto aos atributos analisados, porém não houve efeito perceptível entre as diferentes madeiras e tostas. O uso de lascas de madeira para a maceração de bebidas não é reconhecido como processo de envelhecimento, podendo ser confundido com ato fraudulento. O presente estudo representa um embasamento teórico-prático para a possível aplicação da metodologia, porém ressalta a importância do estudo comparativo entre o envelhecimento em toneis e por interação de lascas de madeira, visando identificar similaridades e diferenças entre as metodologias e verificar a viabilidade de sua aplicação. / Cachaça is a typical Brazilian spirit, consumed mostly natural. Its quality may be improved by aging. In Brazil the aging process is traditionally done by keeping the spirit in barrels made of national hardwood. The use of barrels demand high initial cost and long-term of immobilization of product and capital. Storage alternatives have been sought, but without solution for aging so far. The possibility of using oak fragments for cachaça maturation may provide a wider field of specificities to the spirit. The objective of this research was to study volatile and maturation congeners in cachaça macerated with fragments of oak wood from different French forests (Allier, Vosges and Nièvre) and with different intensities of toasting (low, medium and high). The volatile congeners (acetaldehyde, ethyl acetate, methanol, 2- butanol, 1-propanol, 1-butanol, isobutanol, isoamyl alcohol and acetic acid) were detected and quantified by gas chromatography with flame ionization detector (GCFID) and the maturation congeners (gallic acid, 5-hydroxymethylfurfural, furfural, vanillic acid, syringic acid, vanillin, syringaldehyde, coniferaldehyde and synapaldehyde) were measured by high performance liquid chromatography (HPLC). Sensory tests were performed to verify consumer´s acceptance concerning the parameters of color, aroma, flavor and global acceptation. The concentration of volatile congeners was not influenced by the treatments. The presence of maturation congeners indicated the ability of the different wood fragments in supplying compounds to the spirit. Nevertheless the peculiarity of each one is highlighted when the compounds predominance is investigated. Due to the high concentration of maturation congeners supplied by Allier and Vosges woods at high toast, we could assume more chemistry complexity for the cachaças macerated in these conditions. It could also be possible modeling cachaça based on maceration with oak fragments from different origins combined with different intensities of toasting. Sensory tests showed high acceptance on the attributes evaluated, but there was no considerable effect between the different woods and toastings. The use of wood fragments to cachaça maceration is not allowed by the Brazilian laws as an aging process, and might be considered a fraudulent act. This study represents a theoretical and practical basis for a possible application of the methodology. It stresses the importance of a further comparative study concerning aging in barrel and by interaction of wood fragments in order to identify similarities and differences between the methodologies and verify the feasibility of its implementation.

Climate change is a major threat to global biodiversity, and will alter species ranges, plant and animal phenology, and species interactions within ecosystems. Climate mediates plant-insect interactions, and consequently has the potential for positive or negative effects on biological control systems. Observational evidence suggests that a recent dramatic reduction in the density of diffuse knapweed, Centaurea diffusa Lamarck, in sites in British Columbia, Canada is attributed to the biological agent Larinus minutus Gyllenhal (Coleoptera: Curculionidae). This decline took place over several years of late spring and summer drought which suggested an association between dry conditions and successful biological control. To explore this, I conducted field experiments using rain shelters and watering treatments to assess the effectiveness of plant attack by L. minutus under moist and dry conditions. I found that L. minutus reduced seed production regardless of moisture conditions, with a trend towards greater seed reduction under dry conditions. Two or more species of insects in the same genera have been introduced in some weed biocontrol programs. If the species are ecological equivalents and compete the introduction of both species may be detrimental and reduce their impacts. If however the species vary in their distributions, the introduction of congeners may be advantageous. I review the following cases of species pair releases: the beetles Chrysolina quadrigemina (Suffrian) and Chrysolina hyperici (Forster) for St. John’s wort (Hypericum perforatum L.); the gallflies Urophora affinis Frfld. and Urophora quadrifasciata (Meig.) for Centaurea species; the weevils Neochetina bruchi Hustache and Neochetina eichhorniae Warner for water hyacinth (Eichhornia crassipes (Mart.) Solms.) and the beetles Galerucella pusilla Duftschmidt and Galerucella calmariensis L. for purple loosestrife (Lythrum salicaria L.). I found that congeneric agents can offer complementary control of target weeds in slightly different habitats. Given the increasing focus on possible non-target effects of biological control introductions, I recommend that greater care be taken to avoid mixed species introductions and that judicious use be made of controlled field experimentation to determine species impacts. Molecular studies of species before introduction could help prevent the accidental introduction of multiple species.

Climate change is a major threat to global biodiversity, and will alter species ranges, plant and animal phenology, and species interactions within ecosystems. Climate mediates plant-insect interactions, and consequently has the potential for positive or negative effects on biological control systems. Observational evidence suggests that a recent dramatic reduction in the density of diffuse knapweed, Centaurea diffusa Lamarck, in sites in British Columbia, Canada is attributed to the biological agent Larinus minutus Gyllenhal (Coleoptera: Curculionidae). This decline took place over several years of late spring and summer drought which suggested an association between dry conditions and successful biological control. To explore this, I conducted field experiments using rain shelters and watering treatments to assess the effectiveness of plant attack by L. minutus under moist and dry conditions. I found that L. minutus reduced seed production regardless of moisture conditions, with a trend towards greater seed reduction under dry conditions. Two or more species of insects in the same genera have been introduced in some weed biocontrol programs. If the species are ecological equivalents and compete the introduction of both species may be detrimental and reduce their impacts. If however the species vary in their distributions, the introduction of congeners may be advantageous. I review the following cases of species pair releases: the beetles Chrysolina quadrigemina (Suffrian) and Chrysolina hyperici (Forster) for St. John’s wort (Hypericum perforatum L.); the gallflies Urophora affinis Frfld. and Urophora quadrifasciata (Meig.) for Centaurea species; the weevils Neochetina bruchi Hustache and Neochetina eichhorniae Warner for water hyacinth (Eichhornia crassipes (Mart.) Solms.) and the beetles Galerucella pusilla Duftschmidt and Galerucella calmariensis L. for purple loosestrife (Lythrum salicaria L.). I found that congeneric agents can offer complementary control of target weeds in slightly different habitats. Given the increasing focus on possible non-target effects of biological control introductions, I recommend that greater care be taken to avoid mixed species introductions and that judicious use be made of controlled field experimentation to determine species impacts. Molecular studies of species before introduction could help prevent the accidental introduction of multiple species.

Hydramycin is an antitumor antibiotic isolated from Streptomyces violaceus. It is a pyranoanthraquinone-type antitumor agent that has shown broad-spectrum activity against a variety of human-derived cancer cell lines. Among tumors evaluated at the National Cancer Institute (lung, colon, melanoma, breast and prostate), GI50s were <10−10 M in the NCI's 60-cell-line panel. We embarked on the synthesis and evaluation of a simplified congener 2-(1-hydroxy-1-(oxiran-2-yl)ethyl)-4H-naphtho[2,3-h]chromene-4,7,12-trione(17), which would facilitate synthesis while retaining the potent activity. Hydramycin has two chiral centers, and our goal is to design and synthesize all the possible enantiomers (four in total) for the congener of hydramycin 17 in order to ascertain which of the enantiomers is responsible for the observed antitumor activity. The use of enantiospecific techniques such as the Sharpless epoxidation was initially tried to introduce the chiral centers at a later stage during the multi-step synthesis and obtain the required pure enantiomers. Due to some limitations observed with this technique and many other asymmetric epoxidation techniques which utilize very substrate-specific ligands, we then modified the synthetic scheme to use another procedure, the Sharpless asymmetric dihydroxylation in order to obtain two of the pure enantiomers of this congener of hydramycin. The other two enantiomers are selectively obtained using the Sharpless asymmetric dihydroxylation procedure via cyclic sulfate intermediates, followed by a modified irreversible Payne rearrangement procedure. These routes then allowed us to obtain separately all four stereoisomers, each having more than 90% ee as determined on chiral columns with HPLC. The four stereoisomers have been fully characterized and will then be tested separately to ascertain which of the isomers is responsible for the observed antitumor activity.

Climate change is a major threat to global biodiversity, and will alter species ranges, plant and animal phenology, and species interactions within ecosystems. Climate mediates plant-insect interactions, and consequently has the potential for positive or negative effects on biological control systems. Observational evidence suggests that a recent dramatic reduction in the density of diffuse knapweed, Centaurea diffusa Lamarck, in sites in British Columbia, Canada is attributed to the biological agent Larinus minutus Gyllenhal (Coleoptera: Curculionidae). This decline took place over several years of late spring and summer drought which suggested an association between dry conditions and successful biological control. To explore this, I conducted field experiments using rain shelters and watering treatments to assess the effectiveness of plant attack by L. minutus under moist and dry conditions. I found that L. minutus reduced seed production regardless of moisture conditions, with a trend towards greater seed reduction under dry conditions. Two or more species of insects in the same genera have been introduced in some weed biocontrol programs. If the species are ecological equivalents and compete the introduction of both species may be detrimental and reduce their impacts. If however the species vary in their distributions, the introduction of congeners may be advantageous. I review the following cases of species pair releases: the beetles Chrysolina quadrigemina (Suffrian) and Chrysolina hyperici (Forster) for St. John’s wort (Hypericum perforatum L.); the gallflies Urophora affinis Frfld. and Urophora quadrifasciata (Meig.) for Centaurea species; the weevils Neochetina bruchi Hustache and Neochetina eichhorniae Warner for water hyacinth (Eichhornia crassipes (Mart.) Solms.) and the beetles Galerucella pusilla Duftschmidt and Galerucella calmariensis L. for purple loosestrife (Lythrum salicaria L.). I found that congeneric agents can offer complementary control of target weeds in slightly different habitats. Given the increasing focus on possible non-target effects of biological control introductions, I recommend that greater care be taken to avoid mixed species introductions and that judicious use be made of controlled field experimentation to determine species impacts. Molecular studies of species before introduction could help prevent the accidental introduction of multiple species. / Science, Faculty of / Zoology, Department of / Graduate

A cachaça é uma bebida típica brasileira, majoritariamente consumida ao natural. Sua qualidade pode ser melhorada pelo envelhecimento. No Brasil, o envelhecimento é tradicionalmente feito pelo armazenamento do destilado em toneis de madeira de lei nacional. O uso de toneis demanda alto custo inicial e longo prazo de imobilização do produto e capital. Alternativas de armazenamento têm sido procuradas, porém sem solução para o envelhecimento. A possibilidade do uso de fragmentos de carvalho para a maturação da cachaça pode proporcionar um maior campo de tipicidades para a bebida. O objetivo deste trabalho foi estudar congêneres voláteis e de maturação em cachaça macerada com fragmentos de madeiras de carvalho proveniente de diferentes florestas francesas (Allier, Vosges e Nièvre) e com diferentes intensidades de tosta (fraca, média e forte). Os congêneres voláteis (acetaldeído, acetato de etila, metanol, 2-butanol, 1-propanol, isobutanol, 1- butanol, álcool isoamílico e ácido acético) foram detectados e quantificados por cromatografia gasosa com detector de ionização de chama (GC-FID) e os congêneres de maturação (ácido gálico, 5-hidroximetilfurfural, furfural, ácido vanílico, ácido siríngico, vanilina, siringaldeído, coniferaldeído e sinapaldeído) foram analisados por cromatografia líquida de alta eficiência (HPLC/CLAE). Testes sensoriais foram realizados para a verificação da aceitação das amostras pelos consumidores quanto aos parâmetros de cor, aroma, sabor e impressão global. A concentração de congêneres voláteis não foi influenciada pelos tratamentos. A presença de congêneres de maturação permitiu concluir que não há contestação na capacidade de ceder compostos entre as madeiras das diferentes florestas, porém a peculiaridade de cada uma delas é destacada quando se analisa a predominância dos compostos de interesse. Em virtude da ampla concentração de congêneres de maturação presente em madeiras de Vosges e de Allier com tosta forte, pudemos supor maior complexidade química na cachaça macerada nessas condições. Seria ainda possível a variação da cachaça macerada mediante uso de fragmentos de carvalho de origens distintas combinando com diferentes intensidades de tosta. Os testes sensoriais apontaram elevada aceitação quanto aos atributos analisados, porém não houve efeito perceptível entre as diferentes madeiras e tostas. O uso de lascas de madeira para a maceração de bebidas não é reconhecido como processo de envelhecimento, podendo ser confundido com ato fraudulento. O presente estudo representa um embasamento teórico-prático para a possível aplicação da metodologia, porém ressalta a importância do estudo comparativo entre o envelhecimento em toneis e por interação de lascas de madeira, visando identificar similaridades e diferenças entre as metodologias e verificar a viabilidade de sua aplicação. / Cachaça is a typical Brazilian spirit, consumed mostly natural. Its quality may be improved by aging. In Brazil the aging process is traditionally done by keeping the spirit in barrels made of national hardwood. The use of barrels demand high initial cost and long-term of immobilization of product and capital. Storage alternatives have been sought, but without solution for aging so far. The possibility of using oak fragments for cachaça maturation may provide a wider field of specificities to the spirit. The objective of this research was to study volatile and maturation congeners in cachaça macerated with fragments of oak wood from different French forests (Allier, Vosges and Nièvre) and with different intensities of toasting (low, medium and high). The volatile congeners (acetaldehyde, ethyl acetate, methanol, 2- butanol, 1-propanol, 1-butanol, isobutanol, isoamyl alcohol and acetic acid) were detected and quantified by gas chromatography with flame ionization detector (GCFID) and the maturation congeners (gallic acid, 5-hydroxymethylfurfural, furfural, vanillic acid, syringic acid, vanillin, syringaldehyde, coniferaldehyde and synapaldehyde) were measured by high performance liquid chromatography (HPLC). Sensory tests were performed to verify consumer´s acceptance concerning the parameters of color, aroma, flavor and global acceptation. The concentration of volatile congeners was not influenced by the treatments. The presence of maturation congeners indicated the ability of the different wood fragments in supplying compounds to the spirit. Nevertheless the peculiarity of each one is highlighted when the compounds predominance is investigated. Due to the high concentration of maturation congeners supplied by Allier and Vosges woods at high toast, we could assume more chemistry complexity for the cachaças macerated in these conditions. It could also be possible modeling cachaça based on maceration with oak fragments from different origins combined with different intensities of toasting. Sensory tests showed high acceptance on the attributes evaluated, but there was no considerable effect between the different woods and toastings. The use of wood fragments to cachaça maceration is not allowed by the Brazilian laws as an aging process, and might be considered a fraudulent act. This study represents a theoretical and practical basis for a possible application of the methodology. It stresses the importance of a further comparative study concerning aging in barrel and by interaction of wood fragments in order to identify similarities and differences between the methodologies and verify the feasibility of its implementation.

No description available.