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Změny ve vegetaci přechodových rašelinišť v rybničních epilitorálech / Vegetation changes in transition bogs at fishpond epilitoralsSpilka, Josef January 2010 (has links)
This study concerns in a three peatland sites: the epilitorals of Pilská reservoir and Hořejší Padrťský fishpond in Příbram region and Kamenný fishpond in Pilsen. These peat-bobg were affected by negative conseqences of human activities. The aim of this study is to find out what kind these changes was and what extent they were. The changes in vegetation were observed from two points of view. The GIS analyses of aerial photographs represent the macroscale view. Repeating of old phytosociological relevées was the microscale view. To understand the cause of vegetation changes, the species-environment analyses were used. Four transects were made for this purpose and a water table level, pH and conductivity were mesured monthly along these transects. One-shot measurements of N and P water concentration and a peat depth were also carried out. Measured data from transects were uses in multivariate vegetation analyses and also in one- way analysis, aimed to an expansion plant species. All three sites of concern came through strong changes in past. In all of them the area of biotops of great conservation importance decreased and some endangered plant species have been lost there. The changes in Pilská reservoir epilitoral were mostly anthropogenic, whereas the mires of Hořejší Padrťský fishpond and Kamenný...
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Hydrogeologic Investigation of a Pumice Aquifer, Fremont/Winema National Forest, OregonWeatherford, Jonathan Michael 02 September 2015 (has links)
The middle Holocene cataclysmic eruption of Mount Mazama blanketed Walker Rim, in south central Oregon, with 270 cm to 300 cm of pumice, causing capture of surface water systems by groundwater, stream relocation, and the formation of biologically diverse fens and seasonal wetlands. The pumice aquifer at Round Meadow, an 8.6 km2 basin, hosts both a fen and seasonally ponded wetlands. The Round Meadow watershed lies within a closed basin between the upper Klamath and Deschutes river basins. As the highest meadow at Walker Rim, it is a relatively well-constrained system to study the effects of hydrological disruption.
A water budget was calculated for the basin, hydraulic conductivity was evaluated for the three main sediment layers in the meadow, recharge sources and evaporative trends were studied using stable isotope analysis, and aquifer residence times were estimated using CFC tracer water age dating. Water year 2014 was a drought year and observation of the system under stressed conditions allowed discrimination of four independently functioning components of the hydrogeologic system. These were the meadow, which is by far the largest component in terms of water storage, the fen where iron cementation and up to 1 m of peat holds water in a berm above the meadow, three springs which are sourced from deeper groundwater hosted in the bedrock which underlies the pumice deposit, and the outflow area. In all cases, the aquifer material is pumice, but the influence of the pre-eruption landscape and post-eruption modifications of the aquifer material have resulted in partial isolation of the components.
The water budget analysis indicated that the basin lost 44 cm of water storage during WY 2014. Hydraulic conductivity values of 1x10-6, 2x10-2, and 4x10-5 cm/s, were determined for the diatomaceous silt underlying the pumice, the Plinian pumice fall aquifer, and for the diatomaceous silt overlying the pumice, respectively. The pumice is characterized as a perched, weakly confined aquifer and residence times in the pumice are much longer (decades) than for water near the surface of the meadow. Water discharging at the springs is isotopically different (lighter) than either the surface water or groundwater in the pumice aquifer. The fen at Round Meadow appears dependent on seasonal precipitation to recharge water, and responds to fluctuations in annual precipitation. The wetland meadows are volumetrically the main water-storing features at Round Meadow, and these are not homogenous features, but a combination of discrete components.
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Permafrost Thaw Drives Changes in Plant Community Characteristics and NutrientStoichiometry, with Increases in the Magnitude of C-cycling in an Arctic PeatlandMcCabe, Samantha J. 02 October 2020 (has links)
No description available.
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ASSESSING THE ROLE OF GEOLOGIC SETTING ON THE HYDROLOGY AND GROUND WATER GEOCHEMISTRY OF FENS IN THE GLACIATED MIDWESTERN UNITED STATESGraves, Dustin 09 April 2007 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / ABSTRACT
Dustin Graves
ASSESSING THE ROLE OF GEOLOGIC SETTING ON THE HYDROLOGY AND GROUND WATER GEOCHEMISTRY OF FENS IN THE GLACIATED MIDWESTERN UNITED STATES
A water quality investigation of several fens located in the temperate glaciated Midwestern United States, near the southern limit of fen occurrence, was conducted to assess the role of geologic setting on the hydrogeochemical signature of fens and to compare hydrogeochemistry of fens located in different geographic and geologic settings. The five studied fens, located in the Central Till Plain physiographic region of Indiana, receive ground water sourced from glacial tills with very similar petrologic composition. These wetlands are hydrogeomorphically classified as slope wetlands with dominant ground water input. More specifically, these sites are inter-till / intra-till type fens (Type Ia and Ib) or outwash terrace type fens (Type II). Shallow ground water was collected just prior to surface interception (source water), and again after discharging into each fen (fen water) and measured for a suite of cations (Ca2+, Mg2+, K+, Na+) and anions (HCO3- SO42-, NO3-, NO2-, PO43-, and Cl-). Fen water hydroperiods showed similar dynamics, despite some variation in the hydrologic input of these systems (source water).
Central Indiana fens are recognized as Ca2+, Mg2+, and HCO3- dominated systems. Fen water showed substantial evolution from source water at each study site, evidently the result of carbonate and gypsum dissolution dynamics. However, when only fen water is analyzed, results suggest that ground water of the southern fens represents geochemical similarity, with the exception of anthropogenic influence. The greatest geochemical variation among central Indiana fens can be attributed to Na+ and Cl-, which has been linked to road salt contamination at two of the study sites.
This hydrogeochemical study also reveals that fens (slope wetlands) within this particular geologic setting of central Indiana show strong geochemical similarities to fens located throughout the temperate Northern Hemisphere. However, statistical analyses provide evidence that the parameters of Ca2+, HCO3-, and SO42- account for the greatest variation among these wetland communities, suggesting that calcium carbonate and gypsum dissolution dynamics are primarily fen specific while other parameters remain relatively homogenous across a wide geographical range.
Lenore P. Tedesco, Ph. D.
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Einfluss von Wiedervernässungsmaßnahmen auf den Stoffhaushalt degradierter NiedermooreVelty, Silke 08 April 2008 (has links)
Zur Einschätzung der Auswirkungen einer Wiedervernässungsmaßnahme auf den Stoffhaushalt eines degradierten Niedermoores wurde ein ehemals entwässertes und seit 1996 wieder vernässtes ca. 10 Hektar großes Areal im Randow-Welse-Bruch im nordöstlichen Brandenburg über mehrere Jahre untersucht. Stoffkreisläufe wurden vor allem in Abhängigkeit der sich durch die Wiedervernässung ändernden Redoxbedingungen modifiziert. Obwohl Phosphor, ein die Eutrophierung auslösendes Element, selbst direkt nicht durch einen Wechsel von aeroben zu anaeroben Bedingungen durch die Wiedervernässung beeinflusst wird, änderte sich dessen Mobilität auf Grund der Rücklösung seines Sorptionspartners. Infolge der anhaltend reduzierenden Bedingungen fand nach mehrjähriger Wiedervernässung der Prozess der Rücklösung amorpher Eisen(hydr)oxide statt, wobei der ehemals an diese Verbindungen fixierte Phosphor freigesetzt wurde. Bei Niedermooren, die infolge hoher Gehalte an Eisen(hydr)oxiden ein erhöhtes Phosphor-Freisetzungspotenzial besitzen, sollte eine Wiedervernässung mit gereinigtem kommunalen Abwasser nicht in Erwägung gezogen werden. Die Erfassung der gasförmigen Emissionen ermöglichte eine Berücksichtigung innerhalb der Stoffbilanzierung und eine Bewertung der Wiedervernässungsmaßnahme hinsichtlich ihrer Klimarelevanz. Auf Grund des anaeroben Milieus durch die Wiedervernässung wurde neben Lachgas auch molekularer Stickstoff als gasförmige Stickstoffverbindung gebildet. Gegenüber der entwässerten Lysimetervariante zeigte sich ein positiver Beitrag zur Reduzierung des Treibhauseffektes durch die Wiedervernässung. Jedoch ist die Qualität des Zusatzwassers, das zur Wiedervernässung der Torfprofile des Niedermoores Havelländisches Luch eingesetzt wurde, entscheidend. In eutrophen Niedermoorökosystemen sind nährstoffreiche Wasserzuflüsse aus kommunalen Abwasserbehandlungsanlagen als Wiedervernässungsmaßnahme geeignet, so dass gereinigtes Abwasser den Landschaftswasserhaushalt stützen könnte. / A formerly drained, and since 1996 rewetted, 10 ha fen site within the Randow-Welse-Bruch fen area in northeastern Brandenurg (Germany) has been investigated for several years to evaluate the impacts of rewetting on nutrient dynamics of the degraded fen. Modifications of nutrient cycles were attributed to changes in redox conditions after rewetting. Although phosphorus which causes eutrophication is not directly influenced by a change from aerobic to anaerobic conditions following rewetting its availability increased due to the dissolution of reactive iron (hydr)oxides where phosphorus was fixed before.With prolonged water-logging phosphorus was released from Fe(III) (hydr)oxides. A lysimeter study was carried out to promote the reuse of purified municipal wastewater as an alternative solution for water supply required during rewetting of fens. Fen soil lysimeters were irrigated with wastewater of the secondary treatment of a municipal wastewater treatment plant over the growing seasons. The objective of this study was to assess how restoration of a degraded fen by means of wastewater usage affects input/output nutrient mass balances. Furthermore, we assessed the effect on trace gas emissions and discussed potential changes in the greenhouse potential. No adverse impact of wastewater utilisation for rewetting the fen soil lysimeters on soil and water quality was found over the period of study with regard to the investigated nutrients and heavy metals. Gaseous fluxes during alternative rewetting were estimated for a consideration within nutrient balances and to evaluate the global warming and cooling, respectively. Besides nitrous oxide dinitrogen was formed and released under anaerobic conditions following rewetting. A potential increase of the nitrate concentration in wastewater would be harmless because a high denitrification of the fen soil would cause a major share of dinitrogen emissions of the total gaseous nitrogen loss.
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Zwischen Niedermoor und Boden / pedogenetische Untersuchungen und Klassifikation von mitteleuropäischen MuddenChmieleski, Jana 25 April 2007 (has links)
Böden aus Mudde entstehen in ehemaligen Seen, meist unter Luftzutritt infolge von künstlicher Entwässerung. Entwässerung und Nutzung führen zu einer sekundären Pedogenese, einhergehend mit der Veränderung der chemischen und physikalischen Bodeneigenschaften. Die nachhaltige Nutzung dieser meist jungen Böden ist von besonderer Bedeutung, da es sich überwiegend um Niedermoorflächen mit großer Bedeutung der Filter- und Speicher- sowie der Lebensraumfunktion handelt. Dabei ist, um negative Konsequenzen ihrer Entwicklung zu verhindern, folgende Wirkungskette zu untersuchen: Entstehung des subhydrischen Sedimentes -> Entwässerung -> landwirtschaftliche Nutzung und Bodenentwicklung -> Degradation. In Nordeuropa sind Böden aus Mudde vor allem in Norddeutschland und Polen sowie Finnland und Schweden zu finden. Es wurden 60 Bodenprofile auf 13 Untersuchungsflächen in Deutschland und Polen detailliert beschrieben und untersucht. Dabei erfolgte für jeden Horizont die Entnahme von ungestörten Proben mittels Stechzylindern für die Analyse der bodenphysikalischen Parameter (pF-Kurven, Trockenrohdichte) und von gestörten Beutelproben für die chemische Analytik (Glühverlust, Kalkgehalt, Elementgehalte mittels RFA und ICP). Bisher noch nicht beschriebene Horizonte wurden vorzugsweise anhand des Bodengefüges identifiziert. Mudden unterscheiden sich in ihrer mineralischen Zusammensetzung erheblich von allen anderen Ablagerungen. Der Anteil an organischer Substanz und Kalziumkarbonat beträgt zwischen 5 und 95 %. Wegen ihres hohen Anteils an kleinen Partikeln weisen sie ein sehr großes Porenvolumen bis zu 90 % auf, wobei die Mittel- und Feinporen mehr als 50 % ausmachen. Das Porenvolumen steigt mit dem Anteil an organischer Bodensubstanz. Als Folge der Bodenentwicklung verringert sich das Porenvolumen bei gleichzeitiger Zunahme des Anteils der Feinporen auf Kosten der Mittelporen. / The formation of gyttja soils takes place in former lakes, predominantly under aeration. This phenomenon of now terrestrial, but formerly subhydric soils (so called gyttja soils) is mainly due to artificial drainage. Their cultivation led to a secondary pedogenesis, which had an effect on their chemical and physical properties. Thus, the sustainable use of this special type of very young land (subhydric soils) is of special importance. Hence, special emphasis has to be directed towards evaluating sequential changes: formation of sediment under water -> drainage/drying -> agricultural use/pedogenesis -> degradation/devastation in order to prevent negative consequences for the environment. In Northern Europe, gyttja deposits can be found in Northern Germany, Finland, Sweden, and mainly in Poland. 13 sites in Germany and Poland with gyttja soils have been investigated. A total of 60 profiles are described in detail. For each horizon, undisturbed samples for physical (tension curves for pF 1.5, 1.8, 2.0, 2.5 and 4.2, dry bulk density) and disturbed samples for chemical analysis have been taken (loss on ignition, CaCO3 content, X-ray fluorescence spectroscopy). Previously not described horizons could be visually distinguished mainly by their structure. Subhydric soils have a very specific composition, which differs greatly from other soils. The amount of organic matter and CaCO3 ranges from 5 to 95 %. Almost all sediments contain a high amount of very small particles and, as a consequence, a high pore space volume of up to 90 %. The amount of the medium and micro-pores is more than 50 %. The porosity increases with the content of organic matter. As a result of pedogenesis, the porosity decreases while the volume of micro-pores increases and the volume of medium pores decreases.
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Dynamique spatio-temporelle des communautés virales et microbiennes des tourbières à Sphagnum / Spatio-temporal dynamic of viral and microbial communities in Sphagnum-dominated peatlandsBallaud, Flore 17 December 2015 (has links)
Les tourbières couvrent 3 % des surfaces continentales et jouent un rôle important dans le cycle du carbone en stockant le tiers du carbone des sols. L'accumulation de tourbe est liée au déséquilibre production primaire/décomposition du à une activité microbienne limitée par les conditions environnementales. L'infection et la lyse virale ont un impact sur la diversité et l'activité des communautés microbiennes, et influent sur le cycle du carbone. Cependant, le fonctionnement de ce compartiment viral n'avait jamais été pris en compte dans les études de fonctionnement des tourbières. Le but de ce travail de thèse était d'analyser et comprendre la dynamique spatiale et temporelle de l'abondance et de la diversité virale des tourbières à Sphagnum. L'analyse de l'abondance virale et procaryote et de 12 metaviromes en lien avec la physico-chimie d'une tourbière tempérée en France montre une forte variation saisonnière des communautés virales. Cette variation semble très liée aux conditions environnementales générées par la fluctuation de la nappe d'eau. Dans cette même tourbière, l'analyse de la diversité taxonomique et fonctionnelle des communautés de microorganismes présents (métagénomes) et métaboliquement actifs (métatranscriptomes) indique que la structure taxonomique est différente entre les des deux principaux stades, le fen et le bog, mais que ces communautés présentent une diversité fonctionnelle similaire, dont l'expression est liée aux changements des conditions environnementales avec la profondeur. L'abondance des particules virales étudiées dans 5 tourbières à Sphagnum réparties en Finlande, au Canada, en France, et sur l'île subantarctique d'Amsterdam varie fortement avec les sites. L'analyse de la diversité virale de la matrice et de l'eau de tourbe du Canada et de Finlande montre que la diversité virale est structurée par le site, puis le stade dynamique, puis la profondeur, avec un rôle important de la saturation en eau au niveau du site. Ces résultats valident le fonctionnement proposé du compartiment viral et de la communauté d'hôtes procaryotes. Ces connaissances ont été utilisées pour analyser le fonctionnement du compartiment microbien de tourbières à Sphagnum soumises à des perturbations d'origine anthropique. Les 31 métaviromes produits pour cette thèse constituent l'une des plus grandes bases de données sur la diversité virale des écosystèmes alors que la diversité virale des sols n'avait presque jamais été étudiée auparavant. / Peatlands cover 3 % of the continental surfaces but represent up to a third of the soil carbon stock. Peat accumulation results from the imbalance between primary production and decomposition due to the limitation of the prokaryote activity caused by the environmental conditions. Viral infection and lysis impact the diversity and the activity of the microbial communities and influence the carbon cycle. However, the functioning of the viral compartment had never been taken into account in peatlands. The aim of this thesis was to gain knowledge about the spatio-temporal dynamic of viral abundance and diversity in Sphagnum-dominated peatlands. Spatio-temporal analysis of viral and prokaryote abundance and of 12 metaviromes (viral diversity) in relation to the physico-chemical features in a temperate Sphagnum-dominated peatland in France revealed the high seasonal variability of the viral communities. This dynamic appeared mainly related to the environmental conditions shaped by the fluctuation of the water-table level. In the same peatland the taxonomic diversity of the present microorganisms (metagenomes) differed between the fen and the bog, but these communities present a similar functional diversity, which expression in selected in the same way in the two dynamic stages, in relation to depth-related environmental conditions. Viral abundance analyzed in 5 Sphagnum-dominated peatlands from Finland, Canada, France and subantarctic Amsterdam Isle presented a high geographical variability. Investigation of the diversity of the viral communities from the peat matrix and the pore-water in Finland and Canada emphasized the structuration of the viral communities by the site, then the dynamic stage, and finally depth. These results confirm the first hypotheses about the functioning of the viral compartment depending on environmental conditions and prokaryote activity. Effects of human-derived disturbances on viral ecology in peatlands were investigated based on this knowledge. While soil viral diversity was poorly documented at the start of this thesis, the collection of 31 metaviromes from Sphagnum-dominated peatlands produced for this project represents the second largest dataset representing the viral diversity from environmental samples.
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Endokrine Wirkungen (anti)androgener Substanzen bei der Ploetze (Rutilus rutilus)Ballegooy, Christoph van 28 March 2008 (has links)
Substanzen, die durch ihr hormonell wirksames Potenzial mit dem Hormonsystem interagieren und adverse Effekte auf die Reproduktion von Invertebraten und Vertebraten ausueben koennen, erlangten in den letzten Jahrzehnten große Aufmerksamkeit. Viele dieser Substanzen reduzieren die Fertilitaet oder die Fekunditaet, fuehren zu Abnormalitaeten in der Ontogenese oder im Verhalten der Tiere und haben Einfluss auf die Geschlechterverhaeltnisse. In der vorliegenden Arbeit wurden verschiedene Aspekte dieses Themengebietes bearbeitet. Das in Europa endemisch vorkommende Rotauge (Rutilus rutilus), ein Sueßwasserfisch, wurde als Modelltier fuer den Nachweis von (anti)androgenen Effekten auf aquatisch lebende Organismen etabliert. Zum Nachweis der (anti)androgenen Wirkmechanismen wurden die Tiere mit Modellsubstanzen aus drei verschiedenen Gruppen exponiert. Aus der Gruppe der Substanzen mit potenziell androgener Wirkung wurden Triphenylzinn (TPT) und Methyltestosteron (MT) verwendet, aus der Gruppe der Antiandrogene Vinclozolin (VIN) und Cyproteronazetat (CYP) und aus der Gruppe der Aromatasehemmer, und somit potenziell androgener Wirkung, Letrozol (LET) und Fenarimol (FEN). Feedbackmechanismen auf die Hypothalamus-Hypophysen-Gonaden-Achse (mRNA-Expression des Luteinisierenden Hormons, des Follikel stimulierenden Hormons und der Aromatase), mRNA-Expression potentieller Biomarker in der Leber (Androgen-Rezeptor-mRNA, Oestrogen-Rezeptor-mRNA), Sexsteroidspiegel im Blutplasma (17beta-Oestradiol und 11-keto-Testosteron), Enzymaktivitaeten im Gehirn (Aromatase), Histologie der Gonaden, Totallaenge, Gewicht und Geschlechterverteilung wurden als Endpunkte analysiert, um adverse Effekte auf die Reproduktionsbiologie von R. rutilus zu zeigen. Die untersuchten Endpunkte eigneten sich sehr gut zum Nachweis verschiedener Wirkmechanismen. / Substances that are able to interact with the endocrine system and cause adverse effects on the reproduction of invertebrates and vertebrates have gained much attention over the last few decades. Many of these substances reduce fertility or fecundity, lead to developmental abnormalities or abnormalities in the behaviour of animals and have an impact on sex ratios. The present study examines various aspects of these topics. The roach (Rutilus rutilus), a freshwater fish endemic in Europe, was established as a model animal for the detection of (anti)androgenic effects on aquatic organisms. For examination of the (anti)androgenic action, the animals were exposed to model compounds from three different groups: triphenyltin (TPT) and methyltestosterone (MT) from the group of substances with potentially androgenic effect, vinclozolin (VIN) and cyproteronacetate (CYP) from the group of antiandrogens, and letrozol (LET) and fenarimol (FEN) from the group of aromatase inhibitors, which thus have a potentially androgenic effect. Feedback mechanisms on the hypothalamus-pituitary-gonad-axis (mRNA expression of luteinising hormone, follicle stimulating hormone and aromatase), mRNA expression of potential biomarkers in the liver (androgen receptor mRNA, oestrogen receptor mRNA), steroid levels in the blood plasma (17beta-oestradiol and 11-ketotestosterone), enzyme activity in the brain (aromatase), histology of the gonads, total length, weight and sex ratios were analysed as endpoints to show adverse effects on the reproductive biology of R. rutilus. The studied endpoints are suitable for the detection of different modes of action. The histological examination of the gonads proved to be especially sensitive with the exposure to AACs to resulting in fundamental adverse damages to the gonads. It was ascertained that - in the early stages of ontogeny - androgens play as crucial of a role in the development of the gonads as previously attributed primarily to oestrogens.
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O modelo religioso e a experi?ncia religiosa da comunidade mateana: uma an?lise ? luz de Max Scheler. / The religious model and the religious experience of the Matthean community: an analysis based on Max Scheler.Miguel, Maiara R?bia 12 September 2016 (has links)
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Previous issue date: 2016-09-12 / Pontif?cia Universidade Cat?lica de Campinas ? PUC Campinas / This study aims to analyze the influences that a religious model has on a religious community, stablishing a correlation between Max Scheler?s conception of religious model, ethical progress and religious experience with the bible text Sermon on Mount, specially, the Antitheses (Mt 5, 17-48) and the Lord?s Prayer ritual orientation. With this purpose, in this study is made a research to identify the religious model from Matthew?s community to understand the powerful influence to the construction of the meanings in the social world of this community. This study was possible approaching Max Scheler?s phenomenological works to contextualize the religious model, religious experience and ethical progress concepts. As well as, it was necessary to go deep in historical, social and exegetical aspects from Matthew?s bible text. It was necessary to enable the correlation method associated to the Matthew?s bible text phenomenological analyses to apply Scheler?s horizon to the bible reality, to answer what is the relation between a religious model and religious experience in the community from the Matthew?s bible text. / O presente trabalho tem o prop?sito de analisar as for?as de influ?ncia que o modelo religioso exerce em uma comunidade religiosa. Isso se fundamenta a partir da correla??o estabelecida entre a conceitua??o de modelo religioso, progresso ?tico e experi?ncia religiosa ao mundo social apreendido do texto b?blico o Serm?o da Montanha. A an?lise ter? como objeto a releitura do texto o Serm?o da Montanha, localizado no Evangelho de Mateus, em espec?fico, as Ant?teses (Mt 5.17-48) e a orienta??o ritual?stica do Pai-Nosso (Mt 6.5-15), ? luz do pensamento de Max Scheler. Partindo desse prop?sito, busca-se identificar o modelo religioso da comunidade mateana e compreender a for?a de influ?ncia desse modelo nos significados do mundo social dessa comunidade. O arcabou?o conceitual foi constru?do tendo como base obras do per?odo fenomenol?gico de Max Scheler para contextualiza??o dos conceitos de modelo religioso, progresso ?tico e experi?ncia religiosa. Foi necess?ria a constru??o de uma abordagem cr?tica dos aspectos hist?ricos, sociais e exeg?ticos da per?cope mateana. Por isso, foi poss?vel, a partir do m?todo da correla??o associado ? an?lise fenomenol?gica do Evangelho de Mateus, aplicar o horizonte conceitual scheleriano ? realidade dos vers?culos b?blicos, a fim de responder qual a rela??o entre modelo religioso e experi?ncia religiosa da comunidade mateana.
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Determina??o do conte?do de subst?ncias fen?licas e avalia??o da capacidade antioxidante em m?is de Apis mellifera comercializados no estado do Rio de Janeiro / Determination of total phenolic compounds and the evaluation of the antioxidant capacity of Apis mellifera honeys commercialized in the state of Rio de JaneiroSANT?ANA, Luiza D?Oliveira 05 July 2010 (has links)
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Previous issue date: 2010-07-05 / This work aimed at the evaluation of the total phenolic and flavonoid contents of sixty Apis mellifera honey samples, commercialized in different regions of the state of Rio de Janeiro (Metropolis, Southern, Central, Northwestern and Seaside). For each sample, the total phenolic and the total flavonoid contents were analyzed by the Folin-Denis and aluminum chloride (AlCl3) methods, respectively. Also, the antioxidant activity (%AA and EC50) for all the honey samples was evaluated, as well as for some phenolic acids and flavonoids, used as standards. The determination of the antioxidant capacity was carried out by the method of trapping the 2,2-diphenyl-1-picryl-hydrazyl organic radical (DPPH) by antioxidant compounds, resulting in an absorbance decrease at 520 nm.
The analyzed honeys were classified as monofloral or heterofloral. For the monofloral samples, it was observed that Anadenanthera honeys showed the highest average value for total phenolics (112,60 mgEAG/100g) and also for the antioxidant capacity (59,93 (AA)mgEQC/500g or 18,92 mg/mL if expressed as EC50), while the Eucalyptus honeys showed the highest mean for total flavonoids (9,17 mgEQC/100g).
With these results, a comparative study was carried out with diverse honey samples of different regions, in terms of total phenolic and flavonoid content, antioxidant capacity and some physico-chemistry parameters (HMF, acidity, pH, humidity, water activity and color intensity). Comparison of these results allowed to observe that darker honeys showed both higher antioxidant activity and the highest values for total phenolic and flavonoid contents, as well as for all the other physico-chemical parameters. / O objetivo deste trabalho foi avaliar os teores de fen?licos e flavon?ides totais de sessenta amostras de mel de Apis mellifera comercializadas em diferentes mesorregi?es do estado do Rio do Janeiro (Metropolitana, Sul, Centro, Noroeste Fluminense e Baixada Litor?nea). Para cada amostra foram analisados os totais de fen?licos e flavon?ides, atrav?s dos m?todos de Folin-Denis e cloreto de alum?nio (AlCl3), respectivamente. Foi determinado, tamb?m, o potencial da atividade antioxidante (%AA e CE50) para todas as amostras de mel, bem como para alguns padr?es de ?cidos fen?licos e flavon?ides. O m?todo utilizado para determinar a capacidade antioxidante foi o de captura do radical org?nico 2,2-difenil-1-picril-hidrazil (DPPH) por antioxidantes, produzindo um decr?scimo da absorb?ncia a 520 nm.
Os m?is avaliados foram classificados de monoflorais e heteroflorais. Para os monoflorais foi observado que os m?is de Anadenanthera apresentaram a maior m?dia em totais de fen?licos (112,60 mgEAG/100g), e tamb?m a maior atividade antioxidante (59,93 (AA)mgEQC/500g ou 18,92 mg/mL em termos de CE50), enquanto os m?is de Eucalyptus apresentaram, em m?dia, o maior conte?do de flavon?ides totais (9,17 mgEEC/100g).
A partir dos resultados obtidos foi feito um estudo comparativo entre as v?rias amostras de m?is de diferentes regi?es quanto ao teor de fen?licos e flavon?ides totais, a atividade antioxidante e algumas propriedades f?sico-qu?micas (HMF, acidez, pH, umidade, atividade de ?gua e intensidade de colora??o). Ao comparar esses resultados, foi poss?vel observar que os m?is mais escuros apresentaram uma maior atividade antioxidante e uma maior quantidade de fen?licos e flavon?ides totais, bem como valores mais altos para todos os outros par?metros f?sico-qu?micos comparados.
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