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Fatores de risco para excesso de peso para filhos de m?es obesas operadas, e obesas n?o operadasPufal, Milene Amarante 10 December 2015 (has links)
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Previous issue date: 2015-12-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Background: Bariatric surgery patients are counseled to change their lifestyle behaviors. It is reasonable to presume that, by sharing the same environment, the child will be exposed to a healthier environment. Objective: To compare phenotypic and behavioral characteristics between children born to obese mothers before (BMS) or after (AMS) bariatric surgery. Methods: This retrospective cohort study made comparisons between these two groups regarding phenotyping and behavioral data. Results: The sample consisted of 101 participants aged 0 - 12 years, 67 BMS and 34 AMS. All were predominantly sedentary and reported eating an excess of total energy above estimated needs, with no difference between groups (BMS median = 569 kcal, IQR = 1,185; AMS median = 245 kcal, IQR = 1,055; P =.18). Consequently, there was a high prevalence of overweight (Percentile ? 85) in both groups (BMS N = 40, 59.7%; AMS N = 18, 52.9%, P = .52), as well as elevated abdominal and arm circumferences. Additionally, children in both groups reported a deficit in daily calcium intake. Conclusions: Despite mothers? guidance for lifestyle changes after bariatric surgery, the children in our sample reported multiple obesogenic environmental conditions, such as poor behavioral characteristics and, high prevalence of overweight. / Introdu??o: Os pacientes submetidos ? cirurgia bari?trica s?o aconselhados e recebem
orienta??es para mudar seus comportamentos de estilo de vida. ? razo?vel presumir que,
dividindo o mesmo ambiente, a crian?a vai estar exposta a um ambiente familiar mais
saud?vel. Objetivo: Comparar comportamentos das crian?as em rela??o a sua dieta e
atividade f?sica para avaliar desfechos fenot?picos entre crian?as que nasceram antes da
cirurgia materna (ACM) e depois da cirurgia materna (DCM) e verificar se o procedimento de
perda de peso da m?e mudou comportamento da crian?a. Metodologia: Este estudo de coorte
retrospectiva realizou compara??es entre os grupos ACM e DCM a respeito de dados
antropom?tricos, alimentares e de atividade f?sica. Resultados: A amostra consistiu em 101
participantes com idades entre 0 e 12 anos, N = 67 ACM e N = 34 DCM. Todos eram
predominantemente sedent?rios e reportaram ingerir um excesso de energia total acima das
necessidades nutricionais recomendadas para a idade e g?nero baseadas nas refer?ncias de
ingest?o diet?ticas (Dietary Reference Intakes, DRIs), sem diferen?a entre os grupos (ACM
mediana = 569 kcal, AIQ = 1.185; DCM mediana = 245 kcal, AIQ = 1.055, P = 0,18).
Consequentemente, observou-se uma alta preval?ncia de excesso de peso (Percentil ? 85) em
ambos os grupos (ACM N = 40, 59,7%; DCM N = 18, 52,9%, P = 0,52), bem como elevadas
circunfer?ncias abdominal e do bra?o. Conclus?o: Apesar das orienta??es ? m?e quanto as
mudan?as necess?rias de estilo de vida ap?s a cirurgia bari?trica, os dados de nossa amostra
relataram m?ltiplas condi??es obesog?nicas no ambiente familiar das crian?as, como pobres
caracter?sticas comportamentais e, consequentemente, alta preval?ncia de excesso de peso.
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An?lise da distribui??o espacial do melanismo na fam?lia felidae em fun??o de condicionantes ambientaisSilva, Lucas Gon?alves da 12 March 2014 (has links)
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Previous issue date: 2014-03-12 / Variation in animal coloration is a theme that has intrigued evolutionary biologists for a long time. Among the commonly observed pigmentation polymorphisms, melanism (darkening of the surface coloration) has been reported quite frequently in multiple groups of organisms. Several biological factors may be influenced by melanism, including thermoregulation, susceptibility or response to disease, camouflage, aposematism, sexual selection and reproductive success. Melanism is common in the Felidae, having been documented in 13 of its 38 species, in some cases reaching high frequencies in natural populations. Classical hypothesis have suggested that such coat color variants can present adaptive advantages under certain ecological conditions, but these ideas have never been rigorously tested for any wild cat species. In jaguars (Panthera onca), jaguarundis (Puma yagouaroundi) and leopards (Panthera pardus) melanism is caused by different mutations in the MC1R and ASIP genes, which present dominant, semi-dominant and recessive inheritance patterns, respectively. In this study we have focused on melanism in these three cat species, and considered two competing hypotheses: (I) melanism is a neutral polymorphism that is randomly distributed throughout the range of each of these species, bearing no association with particular habitats or environmental variables; and (II) melanism has a non-random distribution, and presents significantly different frequencies among distinct landscape conformations. We constructed databases of records obtained from scientific collections, camera trap studies, individual captures and fecal DNA samples that collectively covered most of the ranges of the focal species. We obtained 794 records of jaguars, 463 jaguarundis and 623 leopards, including individually ascertained information on coat color. We performed modeling and statistical analyses using the software packages Maxent (maximum entropy algorithm), ArcGis 9.3 and SPSS 17, based on environmental variables obtained from the Worldclim, Climond, SRTM and GlobCover databases. The results allowed for the first time the construction of maps depicting the geographic distribution of melanism in wild cat species, as well as estimates of its frequency in the three target species. The frequency of melanism was ca. 9% in jaguars, 80% in jaguarundis, and 10% in leopards, and all three species showed a non-random distribution pattern of this coloration variant. In jaguars, melanism was totally absent from ecoregions containing open and periodically flooded landscapes, such as the Pantanal (Brazil) and Llanos (Colombia/Venezuela), which was striking given the large number of samples surveyed in these regions; in contrast, forested areas displayed a melanism frequency that was similar to that expectation based on the species as a whole. In jaguarundis, the dark phenotype (which is evolutionarily derived) proved to be much more common in nature than the ancestral reddish form, with the former being distributed across all areas in which the species occurs, and the latter being highly associated with open and dry landscapes. In leopards, melanism was present in five of the nine currently recognized subspecies, and was strongly associated with tropical and subtropical moist forests, especially in Southeast Asia. Analyses of environmental parameters that seem to be most influential on the melanism occurrence in these three species suggest a relevant role for factors such as altitude, temperature, solar radiation and moisture in different landscape conformations. These observations support the hypothesis that melanism in felids is not a neutral polymorphism, and undergoes the influence of natural selection related to environmental variables and landscape conformations, leading to a non-random geographic distribution of this coloration phenotype. / A varia??o na colora??o animal ? um tema que intriga pesquisadores da ?rea de biologia evolutiva h? bastante tempo. Dentre as varia??es observadas, o melanismo ? um polimorfismo de colora??o comum em diversos grupos de organismos, definido pela predomin?ncia de uma cor escura na superf?cie do corpo. Diversos fatores biol?gicos, como termorregula??o, suscetibilidade ou resposta a doen?as, camuflagem, aposematismo, sele??o sexual e sucesso reprodutivo podem ser influenciados pelo melanismo, o que torna o seu estudo bastante relevante, inclusive como um sistema modelo para investiga??es evolutivas de polimorfismos fenot?picos em geral. Sua ocorr?ncia ? comum na fam?lia Felidae, tendo sido documentada em 13 das 38 esp?cies do grupo e, em alguns casos, podendo atingir altas frequ?ncias em certas popula??es. Hip?teses cl?ssicas sugerem que essas variantes de pelagem podem apresentar vantagens adaptativas em certas circunst?ncias ecol?gicas, o que at? o momento n?o foi testado de forma rigorosa para qualquer das esp?cies do grupo. O presente estudo teve como foco o melanismo em tr?s esp?cies de fel?deos: on?as-pintadas (Panthera onca), jaguarundis (Puma yagouaroundi) e leopardos (Panthera pardus), nas quais esta variante ? causada por diferentes muta??es nos genes MC1R e ASIP, de heran?a dominante, semi-dominante e recessiva, respectivamente. No presente estudo, para cada uma destas esp?cies, foram consideradas duas hip?teses concorrentes: (I) o melanismo constitui um polimorfismo neutro, presente em toda a ?rea de distribui??o e de forma aleat?ria entre ambientes distintos, com aus?ncia de associa??o com vari?veis ambientais; e (II) o melanismo est? distribu?do espacialmente de forma estruturada e n?o-rand?mica, e associada a par?metros ambientais e condicionantes biogeogr?ficos espec?ficos. A partir de registros provenientes de cole??es cient?ficas, armadilhas fotogr?ficas, capturas e DNA fecal cobrindo a maior parte da distribui??o geogr?fica das esp?cies focais, foram obtidas 794 amostras de on?as-pintadas, 463 de jaguarundis e 623 de leopardos, com aferi??o da colora??o em n?vel individual. As modelagens e an?lises estat?sticas foram realizadas com os programas Maxent (algoritmo de m?xima entropia), ArcGis 9.3 e SPSS 17, utilizando vari?veis ambientais obtidas a partir das bases de dados WorldClim, Climond, SRTM e GlobCover. Os resultados apresentam pela primeira vez um mapa de distribui??o geogr?fica do melanismo em felinos, bem como estimativas da frequ?ncia dessa caracter?stica nestas tr?s esp?cies. A frequ?ncia observada de melanismo foi de 9% em on?as-pintadas, 80% em jaguarundis e 10% em leopardos, sendo que em todas as esp?cies o padr?o de distribui??o geogr?fica foi significativamente n?o-aleat?rio. Nas on?as-pintadas, em ecoregi?es de paisagens abertas periodicamente inundadas como o Pantanal (Brasil) e os Llanos (Col?mbia/Venezuela), o melanismo foi totalmente ausente, apesar do grande n?mero de amostras provenientes destas regi?es, ao contr?rio de ?reas florestais, onde a frequ?ncia do melanismo se manteve semelhante ao esperado para a esp?cie como um todo. Em jaguarundis, o padr?o fenot?pico escuro (que ? evolutivamente derivado) mostrou-se muito mais comum na natureza do que a colora??o ancestral (avermelhada), estando o primeiro distribu?do em todas as ?reas de ocorr?ncia da esp?cie, e a segunda associada fortemente a paisagens mais secas e abertas. Em leopardos, o melanismo est? presente em cinco das nove subesp?cies atualmente reconhecidas, e fortemente associado a florestas tropicais e subtropicais ?midas, especialmente na regi?o do sudeste asi?tico. An?lises dos par?metros ambientais que parecem influenciar de forma mais relevante a ocorr?ncia do melanismo nestas tr?s esp?cies sugerem um papel importante de fatores como altitude, temperatura, radia??o solar e umidade em diferentes conforma??es de paisagem. Essas observa??es apoiam a hip?tese de que o melanismo em felinos n?o constitui um polimorfismo neutro, sofrendo a a??o de sele??o natural relacionada a vari?veis ambientais e conforma??es de paisagem, o que induz uma distribui??o geogr?fica n?o-aleat?ria deste fen?tipo de colora??o.
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Desenvolvimento de bebida energ?tica para atletas a partir de polpa de Jamel?o (Syzygium Cumini L. Skeels) e mistura de carboidratos: avalia??o sensorial e da capacidade antioxidante / Development of energy drink for athletes from Jamel?o pulp (L. Syzygium Cumini Skeels) and mixture of carbohydrate: antioxidant and sensory capacityNUNES, Camila Gomes 22 August 2016 (has links)
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Previous issue date: 2016-08-22 / Despite the nutritional and functional value the fruits of jamel?ozeiros (Syzygium Cumini L. Skeels) known as jamel?es are little consumed. In harvest seasons, production is abundant, however, there is no rational use of the fruit. The pulp of this fruit has a high content of anthocyanin, which gives it high antioxidant potential. The practice of physical exercise generates free radicals in the body, which has the antioxidant defense system; the effectiveness of this system is modulated by the intake of nutrients and other compounds with antioxidant potential, as presents in Jamel?o. The aim of the paper was develop energy drink, formulation for use with Jamel?o pulp and mix of carbohydrates, 100% natural, without colorings and flavorings. 11 formulations were produced according to the RDC / ANVISA n?18/2010, with variations in pulp content and mix of carbohydrates. The samples were subjected to sensory evaluation by the acceptance method with consumers and 4 samples with higher averages passed new sensory analysis by athletes, acceptance method and were also submitted to: physical analysis, chemical and physico-chemical, antioxidant activity by methods DPPH, anthocyanin content and content of phenolic compounds. The formulations 4,5,8 and 11 obtained the highest average with consumers and the sample 11 to greater acceptance by athletes. The sample 8 had higher anthocyanin content differing from the other. The sample 4 and 5 showed higher levels of phenolic and the sample 4 presented the highest antioxidant activity. In conclusion, the beverage had high and satisfactory levels of antioxidants and good acceptance by athletes. Therefore, the production of energy and functional drink for athletes and favors the development of new products using Jamel?o must be encouraged and exploited. / Apesar do valor nutricional e funcional, os frutos dos jamel?ozeiros (Syzygium Cumini L. Skeels) conhecidos como jamel?es, s?o pouco consumidos. Nas ?pocas de safra, a produ??o ? abundante, no entanto, n?o h? uso racional do fruto. A polpa desse fruto apresenta alto teor de antocianinas, que lhe confere alto potencial antioxidante. A pr?tica de exerc?cios f?sicos gera radicais livres no organismo que conta com o sistema de defesa antioxidante, a efic?cia desse sistema ? modulada pela ingest?o de nutrientes e outros compostos com potencial antioxidante, como os presentes no jamel?o. Desenvolver formula??o de bebida energ?tica pronta para consumo com polpa de jamel?o e mistura de carboidratos, 100% natural, sem corantes e aromatizantes. Foram produzidas 11 diferentes formula??es conforme a RDC/ANVISA n?18/2010, com varia??es no teor de polpa e do mix de carboidratos. As amostras foram submetidas a an?lise sensorial pelo m?todo de aceita??o com consumidores e as 4 amostras com maiores m?dias passaram por nova an?lise sensorial pelo m?todo de aceita??o com atletas e foram submetidas tamb?m a: An?lise f?sica, qu?mica e f?sico-qu?mica, atividade antioxidante pelos m?todos DPPH, teor de antocianinas e teor de compostos fen?licos totais. As formula??es 4,5,8 e 11 obtiveram as maiores m?dias com os consumidores sendo a amostra 11 a de maior aceita??o pelos atletas. A amostra 8 apresentou maior teor de antocianina diferindo das demais. As amostra 4 e 5 apresentaram maiores teores de compostos fen?licos sendo a amostra 4 a que apresentou maior atividade antioxidante. Em conclus?o, a bebida desenvolvida apresentou teores elevados e satisfat?rios de compostos antioxidantes e boa aceita??o entre os atletas. Logo, a produ??o de uma bebida energ?tica e funcional para atletas ? favor?vel e o desenvolvimento de novos produtos envolvendo o jamel?o como mat?ria-prima devem ser incentivados e explorados.
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Efeitos dos compostos quercetina, quercetina em nanoemuls?o, resveratrol e rutina sobre a hepatotoxicidade e neurotoxicidade induzidas por oxaliplatina em camundongosSchwingel, Tania Elaine 24 September 2013 (has links)
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Previous issue date: 2013-09-24 / Introduction : Oxaliplatin is an antineoplastic agent widely used in the treatment of some tumors. It is a third-generation platinum compound developed with the purpose of overcoming the limitations of toxicity, tumor resistance and poor oral bioavailability associated to cisplatin administration. Oxaliplatin-associated neurotoxicity represents the main dose limiting and there is not suitable treatment. Increasing doses of oxaliplatin can leed to the development of mechanical allodynia, cold sensitivity and peripheral sensory neuropathy, with increase of symptoms. Furthermore, despite its usefulness, chemotherapy with oxaliplatin increases the rate of developing hepatic damages together with inflammatory activity. This might be termed chemotherapy-associated steatohepatitis (CASH), a most severe form of non-alcoholic fatty liver disease. Therefore, in the presentstudy, we aimed to compare the effect of antioxidant compounds on simultaneous development of oxaliplatin-induced hepato and neurotoxicity in mice.
Methods : The Balb/c mice were treated with doses of oxaliplatin (OXA) for 6 weeks, 10 mg/kg, intraperitoneally (i.p), resulting in mechanical allodynia, and hepatic steatosis. We administered antioxidants compounds such as rutin (RUT) (20 mg/Kg/d), resveratrol (RVS) (100 mg/Kg/d), quercetin (QT) (20 mg/Kg/d) and nanoquerecetin (NQT) (20 mg/Kg/d) daily by gavageto Balb/c. N-acetyl-cysteine was used as control. Euthanasiaoccurred onday 43after treatment. We evaluated mechanical nociceptive threshold, ALT/AST, histopathological analysisand MPOactivity. Statistical analyses were made one way ANOVA, followed by Bonferroni post hoc test.
Results : The treatments with RSV, RUT or NQT were able to prevent mechanical allodynia when compared to OXA group. Regarding the effect on steatohepatitis, resveratrol, quercetin and quercetin nanoemulsion almost completely reversed the mean liver weight increase by OXA. In accordance with these previous data, histological evaluation depicted attenuation all features of hepatic steatosis evaluated in resveratrol, rutin, quercetin and quercetin nanoemulsion groups. On the other hand, only quercetin and quercetin nanoemulsion treatments were able to reduce neutrophils migration measured by MPO activity.
Conclusion : These results suggest that the use of compounds such as resveratrol, rutin, quercetin and quercetin nanoemulsion can beeffective to avoid oxaliplatin-inducing hepato and neurotoxicity in a rodent model. / Introdu??o : A oxaliplatina ? um agente antineopl?sico e tem sido amplamenteutilizado no tratamento de v?rios tumores. ? um composto derivado da platina de terceira gera??o desenvolvido com o prop?sito de ultrapassar as limita??es da toxicidade, a resist?ncia do tumor e a fraca biodisponibilidade oral associada ? administra??o decisplatina. Sintomas de neurotoxicidade est?o associados ao uso da oxaliplatina e n?o existe tratamento adequado. Doses crescentes de oxaliplatina podem levar ao desenvolvimento de sensibilidade a frio e neuropatia sensorial perif?rica, e a um aumento da intensidade dos sintomas. Al?m disso, apesar da sua utilidade, a quimioterapia aumenta a taxa de desenvolvimento de danos hep?ticos com atividade inflamat?ria. Esta manifesta??o pode ser chamada de esteato-hepatite associada ? quimioterapia (CASH), uma forma mais grave da doen?a hep?tica gordurosa n?o alco?lica. Deste modo, o presente estudo, objetivou comparar o efeito de alguns compostos antioxidantes no desenvolvimento simult?neo da hepato e neurotoxicidade induzida pela oxaliplatina em camundungos.
M?todos : Os camundongos Balb/c foram tratados intraperitonealmente (i.p.), com doses de 10 mg/kg de oxaliplatina durante 6 semanas, resultando em anodinia mec?nica, e indu??o de esteatose hep?tica. Os compostos rutina (RUT) (20 mg/Kg/d), resveratrol (RSV) (100 mg/Kg/dia), quercetina (QT) (20 mg/Kg/dia) e nanoquerecetina (NQT) (20 mg/Kg/dia), foram administrados diariamente por gavagem aos camundongos. N-acetilciste?na foi utilizada como controle. A eutan?sia ocorreu no 43? dia ap?s o tratamento. Foram analisadas a nocicep??o mec?nica, as aminotransferases ALT/AST, foi realizada avalia??o histopatol?gica e da atividade da mieloperoxidase. A an?lise estat?stica foi realizada por ANOVA de uma via seguida do teste de Bonferroni.
Resultados : Os tratamentos comresveratrol, rutinaouquercetina em nanoemuls?oforam capazes de impedira alodiniamec?nica, quandocomparados com o grupotratado com oxaliplatina. Em rela??o aoefeito sobre aesteato-hepatite, os tratamentos com resveratrol, quercetina e quercetina em nanoemuls?oreverteramsignificativamenteoaumento depeso m?dio do f?gadoinduzido pela oxaliplatina. Corroborando com estes dados, a avalia??ohistol?gicamostrou uma atenua??o em todas as caracter?sticas deesteatose hep?tica avaliados nos grupostratados com resveratrol, rutina, quercetina e quercetina em nanoemuls?o, apresentando caracter?sticas semelhantes ao controle positivo com N-acetilciste?na. Por outrolado,apenasos tratamentoscom quercetina e quercetina em nanoemuls?o foram capazes dereduzir a migra??ode neutr?filosmedidapela atividadede mieloperoxidase.
Conclus?o : Os resultados sugerem que o uso dos compostos resveratrol, rutina, quercetina e quercetina em nanoemuls?opodem se alternativas efetivas para o tratamento
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Hydrologic behaviour and hydraulic properties of a patterned fen in SaskatchewanHogan, Jaime Michele 30 January 2006
A patterned, partially-treed, fen in the mid-boreal region of central Saskatchewan was the site of renewed hydrological research from 2002 to 2004. Hydraulic conductivity, transmissivity, and storativity were determined through use of a surface loading test, pumping tests, and an enclosed field drainage test. None of these field tests have been previously described in the literature as having been used in peat environments. The combined results of field and laboratory drainage tests were used to obtain a general storativity with water table depth relationship in the upper peat layer. The hydraulic conductivity, measured with slug tests, the loading test, and pumping tests, is high near the surface, declining greatly with depth. These previously untested field methods have the advantage of representing volumes of peat from tenths of a meter to cubic meters. </p>Characterization of the hydrology of the peatland involved year round observations of water table, piezometric head, peat surface elevations, frost depth and peat temperatures. Fluctuations of the water table, and soil moisture changes produce changes in effective stress that lead to volume change in the highly compressible peat. This is particularly important for sites with thick peat deposits. Independent compressibility estimates were as high as 10-5 N/m2 in the upper peat. At three fen sites, changes in peat thickness were estimated from monthly estimates of effective stress change, using year round hydrological observations, and compared to measured annual peat thickness changes. Water table changes causing soil moisture changes, and freeze-thaw processes, explained the majority of peat surface movements.
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Restoration of a Rich Fen by Top Soil Removal : Temporal and Spatial Responses among Vascular Plants, Bryophytes and Land Snails during 15 yearsEvasdotter, Liselott January 2011 (has links)
Rich fens are calcareous and nutrient poor wetlands with a rich flora of orchids, sedges and mosses. As many as one hundred plant species are rich fen specialists. Many wetlands have been drained historically, and transformed to agricultural land or production forests. Today rich fens cover only 2-3% of the total mire area in Sweden. Rich fen is a rare and valuable habitat also from a European perspective and is protected in the Natura 2000-network. To increase and maintain the biodiversity and ecosystem services rich fens can offer, it is important to increase the rich fen area by restoration and management. Rich fen restoration can be carried out in different ways. In this report the restoration method of top soil removal is investigated. The method has never been tested before in Sweden and therefore it is important to evaluate the suitability of the method for further conservation work. Before restoration, the study area had been drained, used as arable land and pasture, and finally become abandoned and overgrown by tall eutrophic herbaceous vegetation. An excavator dug away the layer of nutrient rich top soil and then the site was left for spontaneous development. Adjacent to the restored area, there is a small remnant of rich fen. Monitoring of the restored area was performed during the first five years after the restoration. I repeated the monitoring after ten years, and analyzed the long-term succession of plants and snails, in comparison with the status in the reference fen. The vegetation in the restored parts is approaching the one in the reference fen. For example, the number of rich fen specialists has increased steadily. However, the colonization of bryophytes is slow. They cover at most 20 % in the restored parts, while 80 % in the reference fen, possibly because of dispersal limitation and the fact that the restored area is drier than the reference fen. More species of herbs can be found in the restored parts than in the reference fen. Another difference is the high cover of bare soil in the restored areas, compared to none in the reference fen. Some trees and bushes are growing in the area, primarily birch (Betula pubescens) and different species of Salix. The land snails have successfully colonized the restored areas. After two years the same number of species was found in the restored area, as in the reference fen. The total number of species found in the restored areas was 26, compared to 29 in the reference fen, among them three rare rich fen indicator species. The results show how the restored site has developed from bare mineral soil to a rich fen site, approaching the species composition of the reference fen. Several species of rich fen specialists among vascular plants, bryophytes and land snails have established in the restored areas. The small rich fen close to the restored area functions as a source from where plants and animals can spread. Overall the restoration shows very positive results, going from bare soil to rich fen vegetation in only ten years.
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Hydrologic behaviour and hydraulic properties of a patterned fen in SaskatchewanHogan, Jaime Michele 30 January 2006 (has links)
A patterned, partially-treed, fen in the mid-boreal region of central Saskatchewan was the site of renewed hydrological research from 2002 to 2004. Hydraulic conductivity, transmissivity, and storativity were determined through use of a surface loading test, pumping tests, and an enclosed field drainage test. None of these field tests have been previously described in the literature as having been used in peat environments. The combined results of field and laboratory drainage tests were used to obtain a general storativity with water table depth relationship in the upper peat layer. The hydraulic conductivity, measured with slug tests, the loading test, and pumping tests, is high near the surface, declining greatly with depth. These previously untested field methods have the advantage of representing volumes of peat from tenths of a meter to cubic meters. </p>Characterization of the hydrology of the peatland involved year round observations of water table, piezometric head, peat surface elevations, frost depth and peat temperatures. Fluctuations of the water table, and soil moisture changes produce changes in effective stress that lead to volume change in the highly compressible peat. This is particularly important for sites with thick peat deposits. Independent compressibility estimates were as high as 10-5 N/m2 in the upper peat. At three fen sites, changes in peat thickness were estimated from monthly estimates of effective stress change, using year round hydrological observations, and compared to measured annual peat thickness changes. Water table changes causing soil moisture changes, and freeze-thaw processes, explained the majority of peat surface movements.
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Förändring av våtmarkers areal och ekosystemtjänster i Byringe, Strängnäs kommun : En landskapsanalys på över 250 årRingborg, Evelina January 2014 (has links)
Wetlands have been considered throughout millenniums as valuable assets due to the ecosystem services they provide for humans. However, previous research has shown that the value of wetlands has declined over the last 150 years, in parallel to the growth of agriculture. Today, society has realized the value of ecosystem services, through increased knowledge and awareness.This study focuses on the area of Byringe, 20 km southwest of Strängnäs. The aim of this study was to identify changes of wetland areas, wetland classes and ecosystem services over time. This study compared four maps covering the area, between the years 1714 to 2013. The results show that the wetland areas have increased from their initial coverage of 6.5% up to 24.4% today. This 17.9% increase corresponds to 115.3 ha. A closer examination of this 300-year transformation showed variation among the wetland classes. Marshlands showed the largest increase of 44.3ha, followed by fen with 33.5ha and bog 7.6ha. In some areas fen had been converted to bog, which is a change in carbon storage and thus climate regulation. The lakes had developed into marshland, which has caused the disappearance of fish stocks, negatively affecting the generation of food supply. The increased marshland area has also resulted in increased carbon storage and provisioning services such as fiber material from plants and bioenergy production from trees. Furthermore, the recent transformation of agricultural land into fen has generated a loss in food production services such as crops. Instead, other services have appeared in terms of climate regulation, flood protection, increased protection against erosion, water purification and support of biodiversity.
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The long-term effects of drainage on carbon cycling in a boreal fenKotowska, Agnieszka 07 January 2013 (has links)
I investigated the effects of multi-decadal water table drawdown on carbon (C) exchange, as well as functional relationships between C fluxes and environmental controls, in a boreal rich fen. Drainage increased ecosystem respiration of CO2 and decreased CH4 fluxes, but did not affect understory primary productivity. Drainage altered plant responses to light availability, as well as the responses of ecosystem respiration and CH4 flux to water table position. In a laboratory experiment, I found that drainage reduced potential CO2 and CH4 fluxes suggestive of decreased peat substrate quality. Together, these results indicate that long-term drying increases C losses and that both environmental conditions and substrate quality influenced C fluxes post-drainage. My findings suggest that C losses from increased ecosystem respiration may not be mitigated by increases in plant productivity or decreases in substrate quality, and that long-term drainage reduced C storage capacity in this boreal fen. / The Natural Sciences and Engineering Research Council of Canada
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Eddy covariance measurements of methane flux in a subarctic fen with emphasis on spring-melt periodHanis, Krista L. 10 September 2010 (has links)
Reliable determinations of ecosystem scale fluxes of net carbon (C) and greenhouse gases for northern peatland ecosystems are of great value to determine the impact of soil warming and altered precipitation on emissions. Additionally, few studies have been performed which measure the C fluxes, particularly methane flux (FCH4), during the spring melt and fall freeze up periods, therefore making it difficult to provide adequate annual C estimates from northern peatland ecosystems. This study aimed to determine ecosystem scale FCH4 from a eutrophic Subarctic fen at Churchill, Manitoba (58°45'N 94°4'W), to understand (a) seasonal trends over two consecutive growing seasons,(b) if over-winter stored CH4 was released as a pulse during the spring-melt period, and (c) soil temperature - FCH4 relations for modelling FCH4 over the spring-melt period. An ecosystem scale methane (CH4) and carbon dioxide (CO2) flux measurement system using the eddy covariance (EC) technique was used from late-June to mid-October of 2008 and early-June to late-September of 2009, with focus on the spring-melt period of late-May to mid-July of 2009. The EC flux measurement system consisted of a closed-path RMT-200 Fast Methane Analyzer (Los Gatos Research Inc.) along with a LI-7500 open-path CO2/H2O gas analyzer (LI-COR Biosci.) and a CSAT3 3-dimensional sonic anemometer (Campbell Sci.). The system was powered by a combination of wind, solar, and gas electric generation. The EC flux measurement system provided seasonal FCH4 values of 0 – 90 nmol CH4 m-2 s-1, similar to previous studies in Subarctic and Arctic peatlands which incorporated the EC technique. A melt period CH4 emission burst was not observed, rather a gradual increase in emission over the spring period. Modelled FCH4 using a temperature-response curve relationship with soil temperature at 5 cm depth over the spring-melt period (May 30 – July 19, 2009) showed the fen to be a net source of CH4, of 1.4 mmol m-2 CO2 equivalent.
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