944 resultados para White River Group
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group coursework to create a resource or artefact and document the process via a poster. Individual component of the assessment is also specified.
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Presentation motivating the activities around group work /teamwork and personal managment
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Much research in understanding plant diseases has been undertaken, but there has been insufficient attention given to dealing with coordinated approaches to preventing and managing diseases. A global management approach is essential to the long-term sustainability of banana production. This approach would involve coordinated surveys, capacity building in developing countries, development of disease outbreak contingency plans and coordinated quarantine awareness, including on-line training in impact risk assessment and web-based diagnostic software. Free movement of banana plants and products between some banana-producing countries is causing significant pressure on the ability to manage diseases in banana. The rapid spread of Fusarium oxysporum f. sp. cubense 'tropical race 4' in Asia, bacterial wilts in Africa and Asia and black leaf streak [Mycosphaerella fijiensis] in Brazil and elsewhere are cases in point. The impact of these diseases is devastating, severely cutting family incomes and jeopardising food security around the globe. Agreements urgently need to be reached between governments to halt the movement of banana plants and products between banana-producing countries before it is too late and global food security is irreparably harmed. Black leaf streak, arguably the most serious banana disease, has become extremely difficult to control in commercial plantations in various parts of the world. Sometimes in excess of 50 fungicide sprays have to be applied each year. Disease eradication and effective disease control is not possible because there is no control of disease inoculum in non-commercial plantings in these locations. Additionally, there have been enormous sums of money invested in international banana breeding programmes over many years only to see the value of hybrid products lost too soon. 'Goldfinger' (AAAB, syn. 'FHIA-01'), for example, has recently been observed severely affected by black leaf streak in Samoa. Resistant cultivars alone cannot be relied upon in the fight against this disease. Real progress in control may only come when the local communities are engaged and become actively involved in regional programmes. Global recommendations are long overdue and urgently needed to help ensure the long-term sustainable utilisation of the products of the breeding programmes.
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The population genetic structure of fish parasitic nematode, Camallanus cotti, collected from the Yangtze River, Pearl River and Minjiang River in China was investigated. From these parasites, the similar to 730 bp of the first internal transcribed spacer of ribosomal DNA (ITS1 rDNA) and the 428 bp of mitochondrial cytochrome c oxidase subunit I (COI) gene were sequenced. For the ITS1 rDNA data set, highly significant Fst values and low rates of migration were detected between the Pearl River group and both the Yangtze River (Fst = 0.70, P < 0.00001; Nm = 0.21) and Minjiang River (Fst = 0.73, P < 0.00001; Nm = 0.18) groups, while low Fst value (Fst = 0.018, P > 0.05) and high rate of migration (Nm = 28.42) were found between the Minjiang and the Yangtze rivers. When different host/locality populations (subpopulations) within each river were considered, subpopulations between the Yangtze River and Minjiang River had low Fst values (<= 0.12) and high Nm values (>3.72), while Pearl River subpopulations were significantly different from the Yangtze River and Minjiang River subpopulations (Fst >= 0.59; Nm < 1). The COI gene data set revealed a similar genetic structure. Both phylogenetic analyses and a statistical parsimony network grouped the Pearl River haplotypes into one phylogroup, while the Yangtze River and Minjiang River haplotypes formed a second group. These results suggested that the Yangtze River and Minjiang River subpopulations constituted a single reproductive pool that was distinct from the Pearl River subpopulations. In addition, the present study did not find host-related genetic differentiation occurring in the same drainage. (C) 2009 Published by Elsevier B.V.
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Far-travelled volcanic ashes (tephras) from Holocene eruptions in Alaska and the Pacific northwest have been traced to the easternmost extent of North America, providing the basis for a new high-precision geochronological framework throughout the continent through tephrochronology (the dating and correlation of tephra isochrons in sedimentary records). The reported isochrons are geochemically distinct, with seven correlated to documented sources in Alaska and the Cascades, including the Mazama ash from Oregon (w7600 years old) and the eastern lobe of the White River Ash from Alaska (~1150 years old). These findings mark the beginning of a tephrochronological framework of enhanced precision across North America, with applications in palaeoclimate, surface process and archaeological studies. The particle travel distances involved (up tow7000 km) also demonstrate the potential for continent-wide or trans-Atlantic socio-economic disruption from similar future eruptions.
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Cryptotephras (tephra not visible to the naked eye) form the foundation of the tephrostratigraphic frameworks used in Europe to date and correlate widely distributed geologic, paleoenvironmental and archaeological records. Pyne-O'Donnell et al. (2012) established the potential for developing a similar crypto-tephrostratigraphy across eastern North America by identifying multiple tephra, including the White River Ash (east; WRAe), St. Helens We and East Lake, in a peat core located in Newfoundland. Following on from this work, several ongoing projects have examined additional peat cores from Michigan, New York State, Maine, Nova Scotia and Newfoundland to build a tephrostratigraphic framework for this region. Using the precedent set by recent research by Jensen et al.(in press) that correlated the Alaskan WRAe to the European cryptotephra AD860B, unknown tephras identified in this work were not necessarily assumed to be from "expected" source areas (e.g. the Cascades). Here we present several examples of the preservation of tephra layers with an intercontinental distribution (i.e. WRAe and Ksudach 1), from relatively small magnitude events (i.e. St. Helens layer T, Mono Crater), and the first example of a Mexican ash in the NE (Volcan Ceboruco, Jala pumice). There are several implications of the identification of these units. These far-travelled ashes: (1) highlight the need to consider "ultra" distal source volcanoes for unknown cryptotephra deposits,. (2) present an opportunity for physical volcanologists to examine why some eruptions have an exceptional distribution of ash that is not necessarily controlled by the magnitude of the event. (3) complicate the idea of using tephrostratigraphic frameworks to understand the frequency of eruptions towards aiding hazard planning and prediction (e.g. Swindles et al., 2011). (4) show that there is a real potential to link tropical and mid to high-latitude paleoenvironmental records. Jensen et al. (in press) Transatlantic correlation of the Alaskan White River Ash. Geology. Pyne-O'Donnell et al. (2012). High-precision ultra-distal Holocene tephrochronology in North America. Quaternary Science Reviews, 52, 6-11. Swindles et al. (2011). A 7000 yr perspective on volcanic ash clouds affecting northern Europe. Geology, 39, 887-890.
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Holocene cryptotephras of Alaskan and Pacific Northwestern origin have recently been detected ca. 7000 km away on the east coast of North America. This study extends the emerging North American tephrochronological framework by geochemically characterising seventeen cryptotephra layers from four newly explored peatlands. All detected tephras were deposited during the late Holocene, with no horizons present in the peat between ca. 3000–5000 years ago. The prevalence of the Alaskan White River Ash eastern lobe (AD 847 ± 1) is confirmed across the eastern seaboard from Newfoundland to Maine and a regional depositional pattern from Mount St Helens Set W (AD 1479–1482) is presented. The first occurrences of four additional cryptotephras in eastern North America are described, three of which may originate from source regions in Mexico, Kamchatka (Russia) and Hokkaido (Japan). The possibility of such tephras reaching eastern North America presents the opportunity to link palaeo-archives from the tropics and eastern Asia with those from the western Atlantic seaboard, aiding inter-regional comparisons of proxy-climatic records.
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Objetivos: avaliar a correlação entre os aspectos laparoscópicos e os achados histológicos estromais incluindo, a profundidade da lesão endometriótica peritoneal, e na relação com a teoria evolutiva da endometriose. Métodos: foram selecionadas para o estudo 67 pacientes submetidas à laparoscopia por algia pélvica, infertilidade, tumor anexial e outras indicações. A avaliação laparoscópica baseou-se no aspecto visual do implante suspeito de endometriose peritoneal, o qual foi biopsiado. de acordo com o aspecto laparoscópico, as lesões foram agrupadas em: grupo V - lesões vermelhas, grupo N - lesões negras e grupo B - lesões brancas. Os parâmetros histológicos estudados foram: profundidade da lesão, presença de hemossiderina no estroma, vascularização estromal e presença de fibrose no estroma. Resultados: a profundidade da lesão mostrou diferenças estatisticamente significantes entre os grupos de estudo. As lesões vermelhas mostraram-se superficiais em 100% dos casos. As lesões negras apresentaram-se superficiais em 55,6%, intermediárias em 38,9% e profundas em 5,5%. As lesões brancas mostraram-se superficiais em 28%, intermediárias em 68% e profundas em 4%. A presença de hemossiderina no estroma se mostrou equivalente nos 3 grupos. A presença de vasos no estroma da lesão endometriótica, que foi classificada de I a III de acordo com a quantidade, demonstrou diferenças significantes entre os 3 grupos, sendo que a vascularização exuberante (grau III) esteve presente em 60% das lesões vermelhas e em 10% das lesões brancas. A presença de tecido fibrótico na lesão endometriótica apresentou diferenças estatisticamente significantes nos 3 grupos de estudo, sendo mais freqüente no grupo B (lesões brancas), com 70,6%. Conclusão: as variáveis analisadas nos diferentes grupos de estudo demostraram diferença significantes entre os grupos, reforçando a teoria evolutiva da endometriose peritoneal.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Water contaminants have a high potential risk for the health of populations and for this reason their toxic effects urgently should be established. The present study was carried out to determine whether an environmentally realistic intake of water contaminants can induce tissue lesions, and to clarify the contribution of superoxide radical (O-2(.-)) formation to this effect. Male Wistar rats were given drinking water from the Tiett River (group A) and from the Capivara River (group B). The increased creatinine, glucose, alanine transaminase and amylase levels in serum reflected the toxic effects of river-water contaminants to renal, pancreatic and hepatic tissues of rats. As changes in lipoperoxide were observed in rats after river-water intake while superoxide dismutase activities decreased in these animals, it is assumed that the superoxide anion elicits lipoperoxide formation and induces tissue damage. There is evidence that oxygen tension reflects water pollution, since river-water with a-low oxygen tension induced more elevated toxicity in rat tissues. (C) 1999 Elsevier B.V. Ltd. All rights reserved.
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The effects of extracts from Azadirachta indica A. Juss and streptozotocin, in extreme high dilutions in dinamized systems, on hepatocyte morphometry of rats with diabetes mellitus induced by streptozotocin were evaluated. Some parameters presented significant differences among the experimental groups, but the effect of treatments to make better or worse the consequences of diabetes mellitus on liver was not detected using only the hepatocyte morphometry. The morphometric analysis evidenced that the white control group presented the highest mean values for nucleus and cytoplasm parameters, with the exception of the nuclear shape factor. However, this situation did not imply the diabetes mellitus was the cause of drastic reduction in these values, since the literature describes lower measurements for rats from the control group (non-diabetic rats).
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People increasingly desire tooth whitening. Considering the wide range of whitening products on the market, this study evaluated the efficacy of whitening toothpastes and mouth rinses compared with the 10% carbamide peroxide (CP) whitening gel. We obtained 120 cylindrical specimens from bovine teeth, which were darkened for 24 hours in a coffee solution. The color measurement was performed by a spectrophotometer using the CIE L*a*b* system, and specimens were divided into six groups according to the use of the following agents: group 1, conventional fluoridated toothpaste; group 2, Close Up White Now; group 3, Listerine Whitening; group 4, Colgate Plax Whitening; group 5, experimental mouth rinse with Plasdone; and group 6, 10% CP Whiteness Perfect. After the simulation of 12 weeks of treatment for groups 1 to 5 and 14 days of treatment for group 6, the specimens were subjected to a new color reading. Data were subjected to one-way analysis of variance (α=0.05), which showed significant differences among groups after 12 weeks for ΔE (p=0.001). Results of the Tukey test revealed that groups 3, 4, and 6 presented significantly higher color alteration than groups 1, 2, and 5. The whitening toothpaste Close Up White Now and the experimental mouth rinse with Plasdone showed similar color alteration as conventional toothpaste after a 12-week treatment simulation. These groups presented significantly lower color alteration compared with whitening mouth rinses Listerine and Colgate Plax Whitening, which showed similar results to those observed after 14 days of bleaching with 10% CP treatment.
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Pós-graduação em Reabilitação Oral - FOAR
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Pós-graduação em Ciências Odontológicas - FOAR