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Merlin, Bailey. "Sentinel." Digital Commons @ Butler University, 2017. https://digitalcommons.butler.edu/grtheses/496.
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Devastated by the mysterious death of her guardians, Elizabeth Davenport finds herself thrust into a new world that proves to be scintillating and dangerous. Can she trust those who claim to be her friends? Or will her trust lead her into trouble? When a mysterious letter presents itself and proves that her guardians might have been more than they ever let on, Elizabeth must gather her courage and pursue the truth, whatever the cost.
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Halliday, J. E. B. "Animal sentinel surveillance : evaluating domestic dogs as sentinels for zoonotic pathogen surveillance." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/4794.
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The capacity of zoonotic pathogens to infect multiple hosts creates surveillance challenges but also provides opportunities to gather data from animal species that can be used to understand risks to human health. This thesis presents a conceptual and practical assessment of the utility of domestic dog serosurveillance for the detection and surveillance of two pathogens, influenza A and Leptospira spp. The first chapter gives a theoretical framework that can be used to explore the attributes of animal sentinels and assess their utility in different contexts. In subsequent chapters, this framework is applied in a practical assessment of the utility of a domestic dog serosurveillance approach for the detection and surveillance influenza A and Leptospira spp. at two sites in Africa. Two cross-sectional surveys of the avian and mammal populations at a site in Northern Cameroon were conducted in early 2006 to determine if H5N1 influenza A viruses had circulated in this area and in which species that presence could be detected. Serological and molecular evidence of extensive H5 virus circulation in the domestic duck population was identified. 47% of domestic ducks at the Maga site were cELISA positive for anti-influenza A antibodies and 20% were HI test positive against an H5N1 antigen. There was also evidence of exposure to H5 subtype viruses in the local dog and pig populations. At the Kibera site in Nairobi, a cohort study was established to carry out surveillance of influenza A and Leptospira spp. in the domestic dog population and cross-sectional surveys of the domestic poultry and rodent populations were completed. There was no indication of influenza A circulation in any of the animal species surveyed, indicating low risk of zoonotic influenza A infection in the human population of Kibera. In contrast, there was extensive molecular and serological evidence of the presence of Leptospira spp. in both the rodent and dog populations. 18% of 236 trapped rodents were PCR positive for kidney carriage of pathogenic leptospires and the estimated seroprevalence of anti- Leptospira antibodies in the dog population ranged from 5-36% during the course of the study, indicating high potential risk of leptospirosis infection in the human population. The results indicate that dog serosurveillance can be used as useful tool for the determination of broad-scale patterns of pathogen presence and relative levels of population exposure. However, there are limitations of the data that can be gathered from animal sentinels and the complexities introduced particularly by incomplete understanding of diagnostic test performance must be recognized. Animal sentinel surveillance may be of most use for addressing fundamental questions of what pathogens are present where. In the developing world particularly where disease burden data are still lacking, dog sentinel serosurveillance can provide essential baseline data that can be used to target future research and resource allocation.
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Peres, Gabriel. "Biópsia de linfonodo sentinela na recidiva locorregional do melanoma maligno revisão sistemática /." Botucatu, 2020. http://hdl.handle.net/11449/191662.
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Orientador: Antônio José Maria CataneoResumo: Introdução: No melanoma primário, a aplicabilidade da biópsia de linfonodo sentinela (BLS), seguida ou não de esvazimento linfonodal (EL) é conhecida. Na recidiva locorregional (RL) de melanoma, alguns serviços tendem a indicá-la, buscando estadiamento mais acurado para embasar condutas individualizadas aos pacientes, ainda que as evidências sejam insuficientes. Objetivo: Avaliar o sucesso da BLS no encontro do linfonodo sentinela (LNS) e sua positividade na RL. Comparar a sobrevida entre os pacientes com LNS positivo e negativo. Verificar diferença na sobrevida pós EL. Métodos: Revisão sistemática, através das bases MEDLINE via PUBMED, LILACS, SCOPUS, EMBASE e CENTRAL, buscando estudos experimentais e observacionais sobre BLS na RL de melanoma. Desfechos avaliados: sucesso na BLS pelo encontro do LNS, positividade para melanoma no LNS; sobrevida no subgrupo LNS positivo comparado com o negativo; sobrevida livre de doença no subgrupo LNS positivo comparada com o negativo; sobrevida dos pacientes submetidos ao EL. Para metanálises, utilizaram-se RevMan 5.3 e StatsDirect 3.0.121. Resultados: Foram identificados 1872 estudos, destes, seis estudos observacionais foram incluídos, totalizando 449 pacientes. O LNS foi encontrado em 98% das BLS (IC 95-100%, I2=53,7% - seis estudos). LNS com 32% de positividade para melanoma (IC 19-47%, I2= 84,6% - seis estudos). A chance de sobrevida global em cinco anos foi 2,49 vezes maior no subgrupo com LNS negativo (IC 95% 1,41-4,38, I2=0% - qua... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Background: In primary melanoma, the applicability of sentinel lymph node biopsy (SLB), followed or not by complete lymph node dissection (CLND) is known. In locoregional recurrence (LR) of melanoma, some groups may indicate it for more accurate staging to support individualized management, even with scarce evidence. Objective: To evaluate success in SLB and its positivity in LR. Compare survival between patients with positive and negative sentinel lymph node (SLN). Check for survival modification after CLND. Methods: Systematic review through databases such as MEDLINE via PUBMED, LILACS, SCOPUS, EMBASE and CENTRAL, searching for experimental and observational studies on SLB in melanoma LR. Outcomes assessed: success in SLB by finding the SLN, positivity for melanoma in the SLN; survival in the positive SLN subgroup compared to the negative one; disease-free survival in the positive versus negative SLN subgroup; survival of patients undergoing CLND. For meta-analyzes, RevMan 5.3 and StatsDirect 3.0.121 were used. Results: The total number of patients in six observational studies was 449, over 1872 studies indentified. The SNL was found in 98% of SLB (95-100% CI, I2 = 53.7%, 6 studies). SLB detected 32% positivity for melanoma on SNL (CI 19-47%, I2 = 84.6%, 6 studies). The chance of five year overall survival was 2,49 higher in the negative SNL subgroup (95% CI 1.41-4.38, I2 = 0%, 4 studies). Meta-analyzes were not performed due to lack of objective data for disease-free survi... (Complete abstract click electronic access below)
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Karlsson, Mona. "Sentinel node based immunotherapy of cancer /." Stockholm, 2007. http://diss.kib.ki.se/2007/978-91-7357-203-3/.
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Rogers, Clare Elizabeth. "Sentinel node biopsy in breast cancer." Thesis, University of Hull, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403680.
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Anninga, Bauke. "Magnetic identification of sentinel lymph nodes." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/magnetic-identification-of-sentinel-lymph-nodes(48d202b4-345a-4386-91d3-dac9686e73ef).html.
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Sentinel lymph node biopsy (SLNB) is currently performed using radioisotope and blue dye injections. Drawbacks to using radioisotopes include exposure to radiation, limited global availability and a short half-life. A newly developed magnetic technique for identification of sentinel lymph nodes (SLNs) can overcome these problems. The magnetic technique is nonradioactive as it uses iron oxide particles as a magnetic tracer. The tracer causes a brown colour change in the SLN, which is visualised at surgery and it can be localised intraoperatively using a handheld magnetometer. The aims of this thesis were to evaluate multiple parameters of the magnetic technique using an animal model and to test the feasibility of this technique to identify the SLN(s) in melanoma. In addition, the imaging characteristics of magnetic tracers were investigated, including pre-operative lymphatic staging and postoperative effects of the injection of the magnetic tracer on MRI. A porcine animal model was used to test the magnetic technique and a total of 92 magnetic SLNB procedures were performed in 46 mini-pigs. A range of injected volumes, from 0.06 mL to 2.0 mL, was tested. Histological assessment, magnetic counts, iron content, concentration and time elapse since injections were evaluated. The technique was successfully applied to the porcine model, as evidenced by a 100% identification of the SLN(s) (92/92). The magnetic technique was successful using volumes of as low as 0.06 mL and magnetic tracer was taken up in the SLN(s) within minutes. The MELAMAG trial of the magnetic technique in melanoma, reported in this thesis, evaluated SLN identification rate per patient, with the radioisotope/blue dye and magnetic techniques. The magnetic technique was found to be feasible for SLNB in melanoma with a high SLN identification rate. The magnetic iron oxide tracer can be used as contrast agent for MRI with high sensitivity and specificity for lymphatic staging. This thesis includes a meta-analysis of contrast enhanced MRI for axillary staging in early breast cancer. Is also includes and investigation of the susceptibility artefact of magnetic tracer in the breast following SLN identification using the magnetic technique and it reports its potential impact on subsequent MRI scans.
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Henzel, Maja [Verfasser], and Tanja [Akademischer Betreuer] Fehm. "Prädiktion von Non-Sentinel-Lymphknotenmetastasen bei Mammakarzinompatientinnen mit positivem Sentinel-Lymphknoten durch Nomogramme / Maja Henzel ; Betreuer: Tanja Fehm." Tübingen : Universitätsbibliothek Tübingen, 2017. http://d-nb.info/1199468711/34.
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Kuehn, Aida. "Sentinel-Lymphknotenbiopsie nach neoadjuvanter Chemotherapie beim Mammakarzinom." Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-143829.
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Lundberg, Ludvig. "Damage Assessment of Mozambique Flooding Using Sentinel." Thesis, KTH, Geoinformatik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-272396.
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In the past 40 years, floods have become a bane of Mozambique’s inhabitants and economy. The latest of them, caused by the cyclone Idai, has devastated the area resulting in loss of life and property. It was estimated that around 715 000 hectares of farmland was destroyed as a result of the cyclone. The main goal of this thesis was to assess the extent of the flooding and to determine the types of land cover that were affected. This was done in Google Earth Engine, using SAR change detection on Sentinel 1 data to create a mask for the flooded areas, followed by a supervised image classification on Sentinel 2 data to identify the types of land cover that were flooded. Two classifications were done, using imagery from early periods of the country’s plant growing season and later periods of the same season, respectively. The results of both classifications were below standard, with the main problems stemming from difficulties with differentiating between agriculture and roads along with agriculture and vegetation. Multiple ways to improve the results and avoid the errors in future similar projects were discussed, including using multi temporal data and utilizing a road map for the area to create a large amount of training points for the classification. In conclusion, while the results were not as good as was envisioned, the thesis provided ample opportunity to analyze errors and to theorize methods for improving future work.
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Cavonius, Johansson Hanna, and Jens Henriksson. "Skattning av skogliga variabler genom satellitbilder från Sentinel 2 : Estimation of forest variables using satellite images from Sentinel 2." Thesis, Linnéuniversitetet, Institutionen för skog och träteknik (SOT), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-94004.
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Stora arealer skog behöver övervakas. Att göra detta på ett kostnadseffektivt sätt är något som skogssektorn efterfrågar. Syftet med studien var att undersöka möjligheten att skatta skogliga variabler med satellitbilder från Sentinel 2. Korrelationen mellan granskogens uppmätta reflektans i satellitbilder från Sentinel 2 och uppmätta variablerna i fält har beräknats och analyserats. Resultatet visar att styrkan i korrelation skiljer sig mellan olika rumsliga upplösningar, vilken tid på året satellitbilderna är tagna, vilka spektrala band och vegetationsindex som används samt vilka skogliga variabler som avses uppskattas. Att använda enskilda satellitbilders värden från Sentinel 2 ger inte tillräckligt tillförlitliga data för att uppskatta skogliga variabler.
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Gottardi, Beatrice. "Automatic methods for crop classification by merging satellite radar (sentinel 1) and optical (sentinel 2) . data and artificial intelligence analysis." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20635/.
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Land use and land cover maps can support our understanding of coupled human- environment systems and provide important information for environmental modelling and water resource management. Satellite data are a valuable source for land use and land cover mapping. However, cloud-free or weather independent data are necessary to map cloud-prone regions. Merging radar with optical images would increase the accuracy of the study.
Agricultural land cover is characterized by strong variations within relatively short time intervals. These dynamics are challenging for land cover classifications on the one hand, but deliver crucial information that can be used to improve the machine learning classifier’s performance on the other hand.
A parcel-based map of the main crop classes of the Netherlands was produced implementing a script on GEE and using Copernicus data. The machine-learning model used is a Random Forest Classifier. This was done by combining time series of radar and multispectral images from Sentinel 1 and Sentinel 2 satellites, respectively. The results show the potential of providing useful information delivered by entirely open source data and uses a cloud computing-based approach. The algorithm combines the two satellites data of one year in a multibands image to feed in the classifier. Standard deviation and several vegetation indexes were added in order to have more variables for each 15-day-median image composite. The process paid particular attention to time variability of mean values of each field. This will provide useful information both for understanding differences among crops and variability over the phenology of the plant. The accuracy assessment demonstrates that several crop types (i.e. corn, tulip) can be better classified with both radar and optical images while others (i.e. sugar beet, barley) have an increased accuracy with only radar. The overall accuracy of RFC with optical and radar is 76% while it is 74% if only radar is used.
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Bader, Claudia. "Verlaufsstudie bei Melanompatienten nach Entfernung tumorbefallener Sentinel-Lymphknoten." Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-141161.
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Richardson, Keith. "Sentinel lymph node biopsy for papillary thyroid cancer." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114194.
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Objective: To prospectively evaluate the role of sentinel lymph node (SLN) biopsy in the management of well differentiated thyroid carcinoma (WDTC)Methods: I designed and implemented a SLN biopsy protocol and subsequently performed it on consecutive patients undergoing thyroid surgery. Thyroid nodules were injected with methylene blue dye. A central compartment neck dissection (CCND) was performed. Frozen section analysis of the SLNs was performed.Results: 157 patients are included in this study. 94 patients had WDTC. Sevently three percent (69/94) of WDTC patients were found to have detectable SLNs. Twenty percent (14/69) of patients with SLNs were found to have central compartment metastases. The sensitivity, specificity, positive predictive value and negative predictive value of our SLN biopsy technique to remove all disease from the central compartment was 92.9%, 100%, 100% and 98.8% respectively (p < 0.0001). Conclusion: This data series suggests that if a patient has SLNs deemed as negative for malignancy on frozen section, the rest of the central compartment is unlikely to have lymph node metastasis.Contexte: Notre objectif est d'évaluer prospectivement le rôle du biopsy ganglion sentinelle dans la gestion du cancer de la thyroïde bien différencié Méthodes: Nous avons conçu et mis en place un protocole de biopsie du ganglion sentinelle et par la suite effectuées notre protocol sur des patients consécutifs subissant une thyroïdectomie. Les nodules ont été injectés avec du bleu de méthylène. Un dissection du cou central a été effectuée. Examen intra-operatoire des ganglion a été réalisée.Résultats: 157 patients sont inclus dans cette étude. 94 patients avaient un dissection central du cou. 73% (69/94) des patients ont été trouvés à avoir ganglion détectable. 20% (14/69) des patients atteints de ganglion ont été trouvés à avoir des métastases compartiment central. La sensibilité, spécificité, valeur prédictive positive et valeur prédictive négative de notre technique de biopsie du ganglion sentinelle pour enlever toutes les maladies à partir du compartiment central était de 92,9%, 100%, 100% et 98,8% respectivement (p <0,0001).Conclusion: Cette série de données volumineux suggère que si un patient a jugé comme négatif intra-operatoire de malignité sur la section gelée, un dissection central peut être preventire.
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Pilla, Rachel M. "Lake Temperatures as Sentinel Responses to Climate Change." Miami University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=miami1443090263.
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Karavalaki, Maria. "Die Sentinel-Node-Biopsie beim Mammakarzinom $hMaria Karavalaki." [S.l. : s.n.], 2006.
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Núñez, Eutimio Gustavo Fernández. "Desenvolvimento de conjugados de dextran manose radiomarcados para detecção de linfonodo sentinela." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-29062011-164358/.
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O diagnóstico precoce de tumores e metástase constitui atualmente o elemento de maior impacto dentro das políticas de saúde públicas contra o câncer. No câncer de mama e melanoma, a técnica de biópsia de linfonodo sentinela, para o diagnostico de metástase, tem sido muito utilizada evitando a dissecção total dos nodos da região anatômica afetada, e permitindo definir com precisão o procedimento terapêutico a utilizar. O objetivo principal deste trabalho centrou-se no desenvolvimento de conjugados radiomarcados de dextran-manose para diagnóstico, utilizando o núcleo de tecnécio altamente estável, [99mTc(CO)3]+. A cisteína, ligante tridentado, foi incorporada na estrutura dos conjugados, como agente quelante do Tecnécio-99m. As condições de marcação definidas para os produtos avaliados garantiram altos valores de pureza radioquímica (>90%) e atividade específica (>59,9 MBq/nmol) assim como uma alta estabilidade in vitro. Os conjugados de dextran-cisteína-manose demonstraram uma captação superior (4 vezes maior) nos nodos linfáticos em relação aos homólogos que não possuíam manose na estrutura. O conjugado de dextran-cisteína-manose de 30 kDa radiomarcado (99mTc-DCM2) foi o traçador com melhor desempenho biológico entre os avaliados à diferentes atividades injetadas. Demonstrou-se que concentrações superiores a 1 M favorecem a retenção do produto nos nodos linfáticos. As comparações com radiofármacos já utilizados no Brasil (Dextran-500 e Fitato) para detecção de linfonodo sentinela evidenciaram a superioridade do 99mTc-DCM2.Early diagnosis of tumors and metastasis is the current cornerstone in public health policies directed towards the fights against cancer. In breast cancer and melanoma, the sentinel lymph node biopsy has been widely used for diagnoses of metastasis. The minor impact in patient of this technique compared with total nodes dissection and the accurate definition of therapeutic strategies have powered its spreading. The aim of this work was the development of radiolabeled dextran-mannose conjugates for diagnosis using the stable technetium core [99mTc(CO)3]+. Cysteine, a trident ligand, was attached to the conjugates backbone, as a chelate for 99mTc labeling. Radiolabeling conditions established for all products considered in this study showed high radiochemical purities (> 90%) and specific activities (>59,9 MBq/nmol) as well and high stability obtained through in vitro tests. The lymphatic node uptake increased significantly (4-folds) when mannose units were added to the conjugates compared with those without this monosaccharide. The radiolabeled cysteine-mannose-dextran conjugate with 30 kDa (99mTc-DCM2) showed the best performance at different injected activities among the studied tracers. Concentrations of this radiocomplex higher than 1 M demonstrated an improvement of lymph node uptakes. Comparisons of 99mTc-DCM2 performance with commercial radiopharmaceuticals in Brazil market for lymph node detection showed its upper profile.
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Dias, Ivo Miguel Lourenço. "Caracterização de parâmetros da qualidade do solo através da análise de satélite de observação da terra." Master's thesis, Universidade de Évora, 2021. http://hdl.handle.net/10174/29812.
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A realização de mapas da condutividade elétrica aparente do solo, associados ao tipo textural do mesmo é usual, contudo, este é um procedimento que requer equipamento especializado e mão-de-obra para realizar a operação, aspetos que o tornam dispendioso.
O uso de imagens de satélite das missões Sentinel 1 e 2, para observação da superfície terrestre, podem contornar essa situação, disponibilizando continuamente informação. Face ao exposto, este estudo tem como objetivo principal avaliar a capacidade dos satélites de observação da Terra para descrever as propriedades do solo. Com amostras texturais de solo e medições in loco obtém-se um método de comparação, acompanhando a evolução temporal. As medições foram realizadas por sonda TDR. Além dos dados retirados no local foram recolhidos os dados pluviométricos, para compreender o respetivo regime hidrológico.
O método que mostrou melhores resultados foi a sonda TDR, contudo, as imagens de satélite do Sentinel-1 na polarização VV assemelharam-se aos sensores próximos, tanto na distinção textural do solo como, no teor de água. Também as imagens do Sentinel-2 mostraram uma correlação com o solo através do índice Clay Ratio, esta de menor expressão que os métodos anteriores. A polarização VH não apresentou nenhuma relação. Cada método apresentou distintas épocas de melhor eficácia; Characterization of soil through the analysis of Earth observation satellite images
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The making of maps with apparent electrical conductivity of the soil, associated with its textural type is usual, but, this is a procedure that requires skilled equipment to perform the operation, aspects that make it expensive.
The use of satellite images from the Sentinel 1 and 2 missions, to observe the Earth's surface, can work around this situation, making information available continuously. So, this study aims to evaluate the ability of Earth observation satellites to describe soil properties. With the soil textures and chosen in loco, a comparison method is obtained, following the temporal evolution. Those were performed by a TDR probe. In addition to the data collected at the site, rainfall data were collected to understand the respective hydrological regime.
The method that showed the best results was the TDR probe, however, the satellite images of the Sentinel-1 in the VV polarization resembled the nearby sensors, both in the textural distinction of the soil and in the water content. Also, the images of Sentinel-2 showed a correlation with the soil through the Clay Ratio index, this one of lesser expression than the previous methods. The VH polarization had no relationship. Each method has different times of best effectiveness.
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Hunger, Sebastian, Pierre Karrasch, and Christine Wessollek. "Evaluating the potential of image fusion of multispectral and radar remote sensing data for the assessment of water body structure." SPIE, 2016. https://tud.qucosa.de/id/qucosa%3A34859.
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The European Water Framework Directive (Directive 2000/60/EC) is a mandatory agreement that guides the member states of the European Union in the field of water policy to fulfil the requirements for reaching the aim of the good ecological status of water bodies. In the last years several work ows and methods were developed to determine and evaluate the haracteristics and the status of the water bodies. Due to their area measurements remote sensing methods are a promising approach to constitute a substantial additional value. With increasing availability of optical and radar remote sensing data the development of new methods to extract information from both types of remote sensing data is still in progress. Since most limitations of these data sets do not agree the fusion of both data sets to gain data with higher spectral resolution features the potential to obtain additional information in contrast to the separate processing of the data. Based thereupon this study shall research the potential of multispectral and radar remote sensing data and the potential of their fusion for the assessment of the parameters of water body structure. Due to the medium spatial resolution of the freely available multispectral Sentinel-2 data sets especially the surroundings of the water bodies and their land use are part of this study. SAR data is provided by the Sentinel-1 satellite. Different image fusion methods are tested and the combined products of both data sets are evaluated afterwards. The evaluation of the single data sets and the fused data sets is performed by means of a maximum-likelihood classification and several statistical measurements. The results indicate that the combined use of different remote sensing data sets can have an added value.
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Gerrells, Nathan S. "Fusion of Sentinel-1B and Sentinel-2B Data for Forest Disturbance Mapping| Detection of Bark Beetle Mortality in the Southern Sierra Nevada." Thesis, California State University, Long Beach, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10840103.
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Since 2010 approximately 129 million trees in California have been killed by bark beetle attacks. The detection and mapping of bark beetle infestations is an important component for monitoring overall forest health and sustainability. Using remote sensing techniques and European Space Agency (ESA) Sentinel-1 and Sentinel-2 imagery, bark beetle infestation in the southern Sierra Nevada range were mapped. Sentinel-1 Synthetic Aperture Radar imagery was co-registered with Sentinel-2 multispectral imagery and the machine learning algorithms Random Forest and Support Vector Machines were utilized in a supervised classification scheme on two user generated training and validation data samples. The observed accuracy for this analysis ranged from 79.1% to 88.7%. As climate change intensifies, it can be expected that the extent and severity of epidemic bark beetle mortality will continue to spread in western North America. The investigation of bark beetle outbreaks and subsequent impacts is an important component to monitoring overall forest health and sustainability.
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Wahed, Shajahan. "Minimally invasive sentinel lymph node biopsy in oesophageal adenocarcinoma." Thesis, University of Newcastle upon Tyne, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.720011.
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Introduction and Aims Sentinel lymph nodes are the first nodes draining a primary tumour and the most likely sites of early metastases. A minimally invasive technique of identifying sentinel nodes in oesophageal adenocarcinoma could revolutionise management by determining whether patients with submucosal disease can be treated solely by endoscopic resection and whether other patients are suitable for a less radical lymphadenectomy. We evaluated a laparoscopic technique of identifying abdominal sentinel lymph nodes in patients with oesophageal adenocarcinoma and assessed whether these nodes could predict overall lymph node status. Methods This trial recruited patients with lower-third oesophageal adenocarcinoma planned for two-stage oesophagectomy with two-field lymphadenectomy. Sentinel node identification occurred immediately before resection, following endoscopic submucosal injection of 99mTechnetium-nanocol!oid. A laparoscopic gamma probe measured radioactivity from all nodal stations at laparoscopy, from the open abdomen, from the mediastinum following thoracotomy and ex vivo following removal of the specimen. Sentinel nodes had in vivo radioactivity greater than twice and ex vivo greater than 10 times background. Specimens were examined using haematoxylin and eosin and immunohistochemistry. Results A total of 1297 lymph nodes were examined from 40 patients (median 31 nodes). The median age and BMI were 65.5years and 26.5kg/m2 re s pectively. The overall sentinel node detection rate was 85% and sensitivity 88%. The laparoscopic abdominal sentinel node detection rate was 58% (23/40). Lymph node metastases were identified in 13 of these 23 patients, in whom laparoscopic abdominal sentinel nodes were positive in 10 but negative in three (sensitivity 77%). Two of these negative patients had mediastinal sentinel node micrometastases. Eleven patients had only mediastinal sentinel nodes. Five patients had no sentinel nodes. Adhesions prevented laparoscopy in one patient. Conclusions Laparoscopic identification of abdominal sentinel lymph using 99mTechnetium in patients with oesophageal adenocarcinoma was safe and technically feasible but not sensitive enough to predict overall nodal status.
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Doting, Meintje Hylkje Edwina. "Sentinel lymph node biopsy in breast cancer and melanoma." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2007. http://irs.ub.rug.nl/ppn/300326254.
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Jansen, Liesbeth. "Sentinel node biopsy evolving from melanoma to breast cancer /." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2000. http://dare.uva.nl/document/57077.
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Tanis, Pieter Job. "Methodology and implications of lymphatic mapping and sentinel lymphadenectonomy." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2002. http://dare.uva.nl/document/64162.
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Fischer, Julian [Verfasser]. "Lymphszintigraphische Darstellung des Sentinel-Lymphknotens beim Mammakarzinom / Julian Fischer." Bonn : Universitäts- und Landesbibliothek Bonn, 2013. http://d-nb.info/1047185202/34.
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Strunz, Günter, and Sassen Stella von. "Das Copernicus-Satellitenprogramm Sentinel – Neue Anwendungsmöglichkeiten für die Erdbeobachtung." Leibniz-Institut für ökologische Raumentwicklung, 2015. https://slub.qucosa.de/id/qucosa%3A7559.
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Im Rahmen des europäischen Erdbeobachtungsprogramms Copernicus wird eine leistungsfähige Infrastruktur zur Erzeugung von hochwertiger Geoinformation aufgebaut. Copernicus umfasst sowohl ein umfangreiches Satellitenprogramm – die sog. Sentinel-Satelliten – als auch die Copernicus-Dienste. Diese Dienste stellen Informationen von der lokalen bis zur globalen Ebene bereit und nutzen dazu satellitengestützte und terrestrische Messungen. Als erste operationelle Dienste wurden die Copernicus-Dienste für das „Katastrophen- und Krisenmanagement“ und die „Landüberwachung“ in Betrieb genommen. Der vorliegende Beitrag gibt einen Überblick zum aktuellen Stand der Sentinel-Missionen, den Copernicus-Diensten und den Copernicus-Maßnahmen in Deutschland.
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MANFREDI, MARTINA. "IMAGING THE SENTINEL LYMPH NODE IN SMALL ANIMAL ONCOLOGY." Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/829131.
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Sentinel lymph node (SLN) biopsy has become the cornerstone for tumor staging in patients affected by different solid tumors. To identify the first lymph node draining the tumor site, several mapping modalities have been investigated in human medicine and applied in veterinary oncology, either as experimental models or in clinical setting. In this dissertation, after an extensive literature review, we investigate the principal SLN imaging techniques, such as lymphoscintigraphy, which is considered the gold standard in human oncology, the use of blue dye and computed tomography (CT)-indirect lymphography for SLN mapping in canine patients with spontaneous malignant tumors. The feasibility of Single Proton Emission Computed Tomography (SPECT)/CT images fusion is described for the first time in clinical veterinary oncology. The results of these studies reinforce the paramount importance of SLN mapping incorporation in veterinary practice, supporting the use of combined techniques to increase the SLN detection rate.
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Ertelt, Ulrich Willi [Verfasser], and Matthias [Akademischer Betreuer] Kalder. "Vergleichende Wertung von Mikro- und Makrometastasen in axillären Sentinel- und non-Sentinel Lymphknoten bei Frauen mit Mammakarzinom / Ulrich Willi Ertelt. Betreuer: Matthias Kalder." Marburg : Philipps-Universität Marburg, 2016. http://d-nb.info/1113183675/34.
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Andersson, Yvette. "Sentinel Node in Clinical Practice : Implications for Breast Cancer Treatment and Prognosis." Doctoral thesis, Uppsala universitet, Institutionen för kirurgiska vetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-171078.
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The introduction of sentinel lymph node biopsy (SLNB) has conveyed several new issues, such as the risk of false negativity, long-term consequences, the prognostic significance of micrometastases and whether ALND can be omitted in sentinel lymph node- (SLN) positive patients. Archived SLN specimens from 50 false negative patients and 107 true negative controls were serially sectioned and stained with immunohistochemistry. The detection rate of previously unknown metastases did not differ between the false and the true negative patients. The risk of false negativity was higher in patients with multifocal or hormone receptor-negative tumours, or if only one SLN was found. In a Swedish multicentre cohort, 2216 SLN-negative patients in whom ALND was omitted were followed up for a median of 65 months. The isolated axillary recurrence rate was only 1.0%, and the overall survival was high (93%). The survival of 3369 breast cancer patients (2383 node-negative (pN0), 107 isolated tumour cells (pN0(i+), 123 micrometastases (pN1mi) and 756 macrometastases (pN1)) was analysed. The 5-year cause-specific and event-free survival was worse for pN1mi and pN1 patients than for pN0 patients. There was no difference in survival between pN0(i+) and pN0 patients. Tumour and SLN characteristics in 869 SLN-positive patients were compared between those with and without non-SLN metastases, and the Tenon score was calculated. The risk of non-SLN metastases was higher in case of SLN macrometastases (compared with micrometastases), a high positive/total SLN ratio and Elston grade 3 tumours, and increased with increasing tumour size. The area under the curve (AUC) for the Tenon score was 0.65, and the test thus performed inadequately in this population. In conclusion, despite the risk of false negativity, SLNB with omission of ALND in SLN-negative patients appears to be safe even in the long term. The presence of micrometastases is of prognostic importance and should entail adjuvant treatment. The need for ALND in patients with SLN micro- and even macrometastases has been questioned, but the occurrence of non-SLN metastases is hard to predict, and strong evidence for the safe omission of ALND is lacking.
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de, Boniface Jana. "Sentinel Node Biopsy in Breast Cancer : Clinical and Immunological Aspects." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7890.
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Hung, Wai-ka, and 熊維嘉. "Application of the sentinel node concept in breast cancer surgery." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B48128648.
Full textAbstract:
This thesis consisted a series of sentinel node biopsy (SNB) studies in Chinese
patients to evaluate its impact on the management of breast cancer.
Pilot studies
The first SNB pilot study was performed in 30 patients using the blue dye
technique. Accuracy was verified by axillary lymph node dissection (ALND). The
success rate was 83% and the false-negative rate was 25%. The second pilot study
was performed in 50 patients using combined mapping with isotope and dye. The
success rate was 94% with no false-negative. SNB is shown to be feasible and
accurate in Chinese.
The optimal mapping method
Combined mapping was superior to the blue dye technique. This could be due to
the mapping technique or improved experience. One hundred and twenty-three
women were randomly assigned to either the blue dye or combined mapping.
Combined mapping had a higher success rate than the blue dye technique (100%
versus 86%). False-negative rates were similar (0% versus 4.5%). Combined
mapping is the preferred method.
Accuracy of frozen section (FS)
FS was used intra-operatively to guide the need of ALND. In 260 SNB, FS was
compared to serial section and immuno-histochemical staining. FS detected 53 of
86 patients with SN metastases with a false-negative rate of 38.4%. The
false-negative rates for macro-, micro-metastases and isolated tumour cells (ITC)
were 2.4%, 57.7% and 94.4%. FS was accurate to diagnose macro-metastases but
not micro-metastases and ITC.
Can we skip ALND in SN metastases?
139 patients with SNB and ALND were studied to identify predictive factors for
non-SN metastases. 55 had metastatic SN but 38 (69%) had no residual
metastases in non-SN. Tumours <3 cm, a single metastatic SN, micro-metastases
and absence of extra-capsular spread were significant factors to predict no
residual nodal disease. Non-SN metastases were found in 42%, 19% and 0% when
SN contained macro-, micro-metastases and ITC. Based on risk of non-SN
involvement, ALND is indicated for macro- and micro-metastases but not for
ITC.
Extended indication for ductal carcinoma in situ (DCIS)
SNB may be useful for staging of patients with a pre-operative diagnosis of DCIS
because invasive cancer is not infrequently found on pathological examination of
resected specimens after surgical excision. One hundred and seven patients with
DCIS on core biopsy underwent SNB. Thirty-two patients (29.9%) were upstaged
to invasive cancer and 9 (28.1%) had SN metastases. Performing SNB reduced the
re-operation rate from 29.9% to 1.9%. Palpable mass and radiological mass lesion
were associated with upstage.
Extended indication: Sentinel Node Occult Lesion Localisation (SNOLL)
Radioisotope is used to localise non-palpable breast cancer and SN. Seventy-four
patients with non-palpable breast cancers underwent SNOLL. Radioisotope was
injected into cancer and gamma probe guided breast cancer and SN resection.
Primary cancer was removed in 73 patients (99%) after the first-round excision
and 82% had complete excision. Gamma probe identified SN in 82% and
supplementary blue dye increased SN detection to 97%.
SNB modified the practice of breast cancer surgery. It has a major impact on the
diagnosis, staging and treatment of breast cancer.published_or_final_version
Surgery
Master
Master of Surgery
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Sahbai, Samine [Verfasser]. "Scintigraphic detection of sentinel nodes in endometrial cancer / Samine Sahbai." Tübingen : Universitätsbibliothek Tübingen, 2019. http://d-nb.info/1227963939/34.
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LeitÃo, Bruno Tigre de Arruda. "Identification of sentinel lymph of inguinal region in dogs Model." Universidade Federal do CearÃ, 2010. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=9042.
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CoordenaÃÃo de AperfeiÃoamento de NÃvel SuperiorCancer of the penis is a rare neoplasm in developed countries, but troubling in the countries of Latin America, Asia and Africa. In Brazil represents about 2% of male malignancies. Considering this incidence is estimated for 2010 some 160 new cases in CearÃ. Because there is a scarcity of publications on this disease, there are still numerous issues in their management. The penis has peculiar features of lymphatic drainage. In its treatment are carried out bilateral inguinal lymphadenectomy, which have high morbidity (infection and swelling of limbs). Cabanas first described the anatomical concept of sentinel lymph node which unfortunately did not win the reliability expected. Perhaps the disbelief in this procedure refers to the fact that few series deserve credibility, which hinders their diffusion as well as high rates of false negatives. Following the same line of sentinel lymph node in canine models for breast and stomach, this work aims to define an experimental model of sentinel lymph node in dog penis, using patent blue and technetium 99m phytate This model can serve both for training of professionals in the sentinel lymph node biopsy for penile cancer, how to evaluate other feasible research methods that can be brought into clinical practice. Procedures were used in 19 dogs, healthy adult, mixed breed, weighing between 10 and 20kg. Infiltrated 0.2 ml of saline containing Technetium 5μCi the leading edge of the glans penis (shaft 12h), after 10 minutes injected with 0.5 mL of patent blue in one place. Waiting over 10 minutes was searched with the probe transcutaneously hot spots in the inguinal and iliac chains. In this place an incision was made and evaluated with the probe sentinel lymph node in-vivo and ex vivo, writing down the values. Registered lymph nodes stained and not stained with blue dye was performed statistical analysis and intercession of the two methods. It is observed in this study, the identification of 94.76% of the SLN. There was no statistical difference between right and left sides (P> 0.05) and there was good correlation between the methods of patent blue staining and labeling with technetium (kappa: 0.642) on the right and perfect correlation between the methods the left ( kappa: 1) indicating a good consistency in the procedures. Based on these results, we can conclude that research in the penis linfondo sentry dog is feasible
O cÃncer de pÃnis à uma neoplasia rara nos paÃses desenvolvidos, porÃm preocupante nos paÃses da America Latina, Ãsia e Ãfrica. No Brasil representa cerca de 2% dos tumores malignos masculinos. Considerando essa incidÃncia estima-se para 2010 cerca de 160 casos novos no CearÃ. Como hà uma escassez de publicaÃÃes sobre esta doenÃa, ainda hà inÃmeras questÃes no seu manejo. O pÃnis tem caracterÃsticas de drenagem linfÃtica peculiares. No seu tratamento sÃo realizadas linfadenectomia inguinal bilateral que tÃm elevada morbidade (edema e infecÃÃo de membros inferiores). Cabanas descreveu pela primeira vez o conceito anatÃmico de linfonodo sentinela que infelizmente nÃo ganhou a confiabilidade esperada. Talvez a descrenÃa neste procedimento se refere ao fato de que poucas sÃries merecem credibilidade, o que dificulta a sua difusÃo, bem como as altas taxas de falso-negativos. Seguindo a mesma linha de pesquisa de linfonodo sentinela em modelos caninos para mama e estÃmago, este trabalho tem como objetivo definir um modelo experimental de pesquisa do linfonodo sentinela em pÃnis de cÃes, utilizando-se azul patente e o fitato TecnÃcio 99mTc . Este modelo pode servir tanto para treinamento de profissionais da Ãrea na pesquisa do linfonodo sentinela para o cÃncer de pÃnis, quanto para avaliar outros mÃtodos de pesquisa factÃveis que possam ser levados para prÃtica clÃnica. Foram utilizados nos procedimentos 19 cÃes, adultos, sadios, sem raÃa definida, com peso variando entre 10 e 20kg. Infiltrou-se 0,2 ml de soluÃÃo fisiolÃgica contendo 5μCi de TecnÃcio na borda anterior da glande peniana (eixo de 12h); apÃs 10 minutos injetou-se 0,5mL de azul patente no mesmo local. Esperado mais 10 minutos pesquisou-se transcutaneamente com o probe pontos âquentesâ na regiÃo inguinal e cadeias ilÃacas. Neste local realizou-se incisÃo e avaliou-se com o probe o linfonodo sentinela in-vivo e ex-vivo, anotando-se os valores. Registrados os linfonodos corados e nÃo corados com azul patente foi feito a anÃlise estatÃstica e intercessÃo dos dois mÃtodos. Nesse estudo observa-se em 94.76% dos casos a identificaÃÃo do linfonodo sentinela atravÃs do uso do azul patente e do tecnÃcio. NÃo houve diferenÃa estatÃstica na sua identificaÃÃo entreos lados direito e esquerdo (P>0,05) e houve boa correlaÃÃo entre os mÃtodos de coloraÃÃo pelo azul patente e de marcaÃÃo com tecnÃcio (kappa:0,642) à direita e correlaÃÃo perfeita entre os mÃtodos a esquerda ( kappa:1) indicando uma boa constÃncia nos procedimentos. Diante dos resultados obtidos, pode-se concluir que apesquisa no linfondo sentinela no pÃnis do cÃo à exeqÃÃvel.
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Portela, De Araujo Bernacke Samir. "principi di funzionamento del tropospheric monitoring instrument – sentinel-5p tropomi." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23034/.
Full textAbstract:
In questo elaborato vengono descritti brevemente i mezzi utilizzati per costruire Sentinel-5P e per il suo corretto posizionamento in orbita, le tecnologie impiegate per il mantenimento delle telecomunicazioni fra la sonda e le basi a terra e, infine, viene fatta una descrizione più accurata dello strumento principale di bordo: TROPOMI, che si occupa della scansione dei gas terrestri, sfruttando diverse bande dello spettro elettromagnetico.
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Beetz, Sabine, and Hillevi Ericsson. "Identifiering av granbarkborreskador med hjälp av satellitdata från Sentinel-2." Thesis, Linnéuniversitetet, Institutionen för skog och träteknik (SOT), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-101732.
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Korowlay, Nisaar Ahmed. "The use of lymphoscintigraphy to localise the sentinel lymph node." Master's thesis, University of Cape Town, 2005. http://hdl.handle.net/11427/2802.
Full textAbstract:
Includes bibliographical references (leaves 72-90).Sentinel lymph node (SLN) biopsy is being used increasingly for staging early breast carcinoma in place of complete axillary lymph node dissection. The optimal method to identify the SLN and has not been clearly elucidated in the literature. A number of techniques have been proposed for identifying SLN/s. The main debate centres on whether to use a blue dye or radiopharmaceutical method either singly or in combination.
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Dayan, Davut [Verfasser]. "Die Bedeutung der extranodalen Infiltration des Sentinel-Nodes als Prädiktor für non-Sentinel-Metastasen und der Einfluss auf die Überlebensparameter beim primären Mammakarzinom / Davut Dayan." Ulm : Universität Ulm, 2018. http://d-nb.info/1152324519/34.
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Marques, Francisco José Mendonça. "Utilidade agronómica dos índices NDVI e NDWI obtidos por imagem dos satélites Sentinel - 2: estudos de caso nas culturas de trigo, brócolo e arroz." Master's thesis, Universidade de Évora, 2018. http://hdl.handle.net/10174/24272.
Full textAbstract:
Este estudo analisa a potencial utilidade agronómica dos satélites Sentinel-2 nas culturas
do Trigo, Brócolo e Arroz, através de técnicas de detecção remota, recorrendo aos
índices NDVI (Índice de Vegetação por Diferença Normalizada) e NDWI (Índice de
Diferença Normalizada da Água). Para as culturas do Trigo e do Brócolo, instaladas na
zona de Évora, recorreu-se a imagens de satélite (NDVI e NDWI), em tempo real, para
auxiliar na identificação de áreas com maior e menor desenvolvimento vegetativo.
Efectuaram-se ainda medições no campo, ao nível da fisiologia das plantas, bem como
da sua capacidade produtiva. A cultura do arroz, instalada na zona de Coruche, foi
estudada através do histórico de imagens NDVI e NDWI. Os resultados permitiram
relacionar nos casos das culturas cerealíferas, diferentes padrões de clorofila com
condições edáficas distintas, explicando os distintos níveis de produtividade. No caso do
brócolo foi possível associar padrões de desenvolvimento a factores edafo-climáticos e
culturais; Agronomic utility of NDVI and NDWI indices obtained through Sentinel-
2 satellite images: study cases in Wheat, Broccoli and Rice Crops
ABSTRACT:
This study analyzes the potential agronomic utility of Sentinel-2 satellites in Wheat,
Broccoli and Rice crops through remote sensing techniques using NDVI (Normalized
Difference Vegetation Index) and NDWI (Normalized Difference Water Index) indices.
Wheat and Broccoli crops (Évora area), satellite images (NDVI and NDWI) were used in
real time to help identify areas with higher and lower vegetative development. In these
crops, measurements were also made in the field, at physiology plant level, as well as
productive capacity level. Rice crop (Coruche area) was studied through NDVI and
NDWI images historical. The results allowed to associate different chlorophyll patterns
with distinct soil conditions in Rice and Wheat crops, explaining the different yield
levels. In Broccoli, the use of Sentinel-2 helped in establishing a relation between crop
development, climatic and soil-related factors and farming procedures.
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Trick, Daniela Carmen. "Prognostisch bedeutsame histomorphometrische Parameter in Sentinel-node-Metastasen beim malignen Melanom." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=969593511.
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Lamb, Peter. "Sentinel node biopsy to evaluate the metastatic dissemination of oesophageal adenocarcinoma." Thesis, University of Newcastle upon Tyne, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397345.
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Nelson, Marc. "Evaluating Multitemporal Sentinel-2 data for Forest Mapping using Random Forest." Thesis, Stockholms universitet, Institutionen för naturgeografi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-146657.
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The mapping of land cover using remotely sensed data is most effective when a robust classification method is employed. Random forest is a modern machine learning algorithm that has recently gained interest in the field of remote sensing due to its non-parametric nature, which may be better suited to handle complex, high-dimensional data than conventional techniques. In this study, the random forest method is applied to remote sensing data from the European Space Agency’s new Sentinel-2 satellite program, which was launched in 2015 yet remains relatively untested in scientific literature using non-simulated data. In a study site of boreo-nemoral forest in Ekerö mulicipality, Sweden, a classification is performed for six forest classes based on CadasterENV Sweden, a multi-purpose land covermapping and change monitoring program. The performance of Sentinel-2’s Multi-SpectralImager is investigated in the context of time series to capture phenological conditions, optimal band combinations, as well as the influence of sample size and ancillary inputs.Using two images from spring and summer of 2016, an overall map accuracy of 86.0% was achieved. The red edge, short wave infrared, and visible red bands were confirmed to be of high value. Important factors contributing to the result include the timing of image acquisition, use of a feature reduction approach to decrease the correlation between spectral channels, and the addition of ancillary data that combines topographic and edaphic information. The results suggest that random forest is an effective classification technique that is particularly well suited to high-dimensional remote sensing data.
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Cazals, Cécile. "Apport des données Sentinel-1 pour la cartographie des milieux humides." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1226/document.
Full textAbstract:
Les milieux humides sont menacés par le changement climatique et l'anthropisation des milieux naturels. La télédétection est un moyen efficace de suivre des variables environnementales sur de grands espaces. Cependant, lorsqu’il s’agit de l’étude de la dynamique hydrologique, une résolution temporelle importante est indispensable. Or celle-ci est difficilement accessible par l'imagerie optique satellitaire du fait de l’important couvert nuageux qui masque le sol. Les capteurs radars, travaillant dans le domaine des micro-ondes, sont tout particulièrement adaptés à la caractérisation des dynamiques hydrologiques grâce à la sensibilité de leurs mesures en présence d’eau et ce quelque soit la végétation en place. Il en découle que toutes les acquisitions Radar à Synthèse d’Ouverture (RSO) sont exploitables, acquises de jour comme de nuit, quel que soit le couvert nuageux.Récemment la télédétection radar satellitaire a vécu une véritable révolution grâce au lancement du satellite Sentinel-1A en 2014 suivi de son jumeaux Sentinel-1B deux ans plus tard par l'Agence Spatiale Européenne dans le cadre du programme Copernicus. Ces capteurs acquièrent des données en bande C (λ = 5,6 cm) sur toute l'Europe chaque 12 jours par satellite et leur diffusion est libre et gratuite pour tous. Le présent travail de thèse vise à évaluer le potentiel de ces données à haute résolution temporelle pour le suivi des surfaces d'eau et des milieux humides.Dans une première partie consacrée à la cartographie des surfaces d'eau, nous avons identifié une confusion la réponse radar en bande C des surfaces d'eau et celle de certains sols nus. Nous avons alors montré que la période hivernale est celle qui présente le moins d’ambiguïté et que la polarisation VH est la plus adaptée à la cartographie des surfaces en eau. Quatre méthodes de détection des zones en eau ont été comparées, il résulte que l’utilisation de méthodes non-supervisées sans données a priori n'est pas envisageable et que les méthodes prenant en compte le voisinage spatial donnent de meilleurs résultats. Un filtrage temporel a été mis au point et a permis d'améliorer la détection et de s'affranchir des confusions entre sols nus et surfaces d'eau permanentes. Les surfaces d'eau de plus de 0,5 ha ont plus de 80 % de chances d'être détectées.Un second volet de cette thèse est consacré au suivi d'une zone humide prairiale par télédétection radar. L'utilisation d'images pleinement polarimétriques a montré que la configuration de polarimétrie partielle VV/VH disponible sur le capteur de Sentinel-1 permet de caractériser l'inondation prairiale avec ou sans végétation. Une méthode prenant en compte l'information de voisinage temporel a permis de traiter une série de 14 images Sentinel-1 pour obtenir 14 cartes d'inondation pour l’année 2015. Une estimation de la précision à l'échelle intra-parcellaire a été mise au point, il apparaît que si la précision est relativement bonne (80 %), le rappel est assez bas (40 %). Cette méthode permet d'établir des bilans d'évolution intra- et inter-annuels.Cette thèse a montré le potentiel de l'utilisation d'images radar à haute résolution temporelle tant pour la cartographie des surfaces en eau que pour le suivi d'une zone humide prairialeWetlands are threatened by climate change and the anthropization of natural environments. Satellite remote sensing is useful for environmental monitoring at large areas. However, when it comes to the study of hydrological dynamics, a significant temporal resolution is essential. The latter is difficult to reach with optical satellite imagery because of the cloud cover that masks the ground. Radar sensors are well suited to the characterization of hydrological dynamics thanks to the sensitivity of their measurements in the presence of water, whatever the vegetation in place. As a result, all Synthetic Aperture Radar (SAR) acquisitions are available, both day and night, regardless of cloud cover.Satellite radar remote sensing has gone through a revolution with the launch of the Sentinel-1A satellite, followed by its twins Sentinel-1B by the European Space Agency as part of the Copernicus program in 2014. These sensors acquire C-band data (λ = 5.6 cm) on a regular basis on Europe and their distribution is free for all users. Their temporal frequency initially of 12 days has decreased to 6 days from the end of 2016. This work aims at evaluating the potential of these data with high temporal resolution for the monitoring of water bodies and wetlands.The first part of this thesis focuses on water bodies mapping. We found confusion in the C-band radar response between water surfaces and that of some bare soils. We showed that the winter period is the least ambiguous and that the VH polarization is the most suitable for the mapping of water surfaces. Four methods of water detection have been compared. It appears that the use of unsupervised methods without a priori data is not conceivable and that the methods taking into account the spatial neighborhood give better results. Temporal filtering has been developed and has improved detection and avoided confusion between bare soil and permanent water surfaces. Water surfaces of more than 0.5 ha are more than 80% likely to be detected.A second part of this thesis is devoted to the monitoring of wet grasslands by radar remote sensing. The use of fully polarimetric data has shown that the VV/VH partial polarimetry configuration available on the Sentinel-1 sensor is able to characterize the prairial floods with or without vegetation. A method taking into account the temporal neighborhood allowed to process a series of 14 Sentinel-1 images to obtain 14 flood maps. The accuracy of floods maps at the intra-parcel scale has been estimated, it appears that if the precision is relatively good (80%), but the recall is rather low (40%). This method allow to establish intra- and inter-annual monitoring.This thesis has shown the potential of high temporal resolution radar images for the mapping of the water surfaces and for the monitoring of a wetland meadow
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Masannat, Yazan Adnan. "The biological effects of the dyes used in sentinel node biopsy." Thesis, University of Leeds, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.503284.
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Mitra, Angana. "Predictors of sentinel node biopsy positivity and outcome in cutaneous melanoma." Thesis, University of Leeds, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.545705.
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Schilling, Clare. "Novel techniques for sentinel node biopsy in head and neck cancer." Thesis, King's College London (University of London), 2018. https://kclpure.kcl.ac.uk/portal/en/theses/novel-techniques-for-sentinel-node-biopsy-in-head-and-neck-cancer(29d9343f-9b2a-4d34-9d9e-3770f835c06f).html.
Full textAbstract:
The most important prognostic indicator in early cancer is whether the disease has metastasised to regional lymph nodes. Pre-operative imaging is not sensitive enough to detect micrometastatic deposits therefore most patients judged to have more than 20% risk of disease spread will have elective surgical removal of the draining lymph node basins in order to reduce the risk of leaving tumour behind. Such operations can be lengthy and associated morbidity can reduce the patient’s quality of life. In the majority of these elective nodal clearances histopathological analysis is clear of disease in the majority suggesting that the surgery could be omitted without affecting the patient’s disease free survival. Sentinel node biopsy (SNB) is a surgical stating test in which the tumour draining lymph nodes can be thoroughly investigated for metastasis. If free of disease there is no indication to subject the patient to further surgery. SNB has been validated in oral cancer, but there is a false negative rate of up to 14%. Recent developments may improve the accuracy of the SNB test. This work evaluated new sentinel node technologies (navigation surgery, fluorescence imaging, and improved tracer formulations) in oral cancer, and opened up new applications for the test in other head and neck cancers (salivary, thyroid and larynx). These refinements in sentinel node process may allow many patients suffering with early cancer to benefit from personalised staging and treatment.
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Sumner, Rebecca. "Environmental impact on male reproductive function : focusing on a canine sentinel." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/41120/.
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Over the last three decades, there has been increasing concern over environmental effects on human male reproductive health. Both temporal and regional trends in semen quality, testicular cancer and malformations at birth have been associated with changes or differences in exposure to chemicals present within the environment. These abnormalities are typically classified under one entity, Testicular Dysgenesis Syndrome [TDS]. Since temporal trends in sperm quality have also been reported in the dog, it was proposed that this may reflect a common cross-species environmental aetiology and that the dog is a sentinel for human exposure to ECs. The overarching hypothesis of this thesis is that the dog may exhibit regional differences symptomatic of TDS and may respond to environmental influences in a similar manner to the human. Experimental studies designed to test this hypothesis focused on (1) the sensitivity of sperm to environmental influences, (2) canine sentinel testicular chemical profiles and pathological features of testes from specific geographical regions and (3) possible environmental influences impacting on cryptorchidism in dogs. Humans and animals are not directly exposed to single chemicals but to a mixture of environmental toxicants present within the environment. Chapter 3 initiated investigations into mixture effects of ECs by utilising a novel full factorial chemical model of two chemicals known to be present in reproductive tissues. Concentrations of di (2-ethylhexyl) phthalate [DEHP] and polychlorinated biphenyl congener 153 [PCB-153] at environmentally relevant levels, as determined by testicular chemical profiling of dog testes, and their effects upon parameters of sperm quality, were tested in vitro. While subtle differences in motility were observed between species, DNA fragmentation was increased similarly in both the human and dog following EC exposure. Although this applied to individual and mixed chemicals, the effects of one chemical impacted on the activity of the other dependent on the concentration ratio. Interestingly, for DNA fragmentation, data presented suggests that PCB-153 is the driver behind increased sperm DNA damage in both species. Since the data alluded to above support the concept of utilising the domestic dog as a sentinel for human exposure to ECs, the dog was used to investigate regional variation upon testicular developmental, morphological and histopathological features. The regions selected for in this component of the thesis display different degrees of industrialisation and thus variation in exposure to environmental contaminants. Data presented demonstrate significant regional variation in chemical profiles, testicular developmental markers and histopathological features indicative of TDS. Specifically, testicular DEHP and PCB-153 with known geographical variation, were found to be positively associated with markers of proliferation and spermatogenesis. Interestingly, a further chemical present in dog testis, poly-brominated diphenyl ether congener 47 [PBDE-47], was negatively correlated with these markers. Furthermore, a novel system developed to assess and score histopathological abnormalities in testes, revealed a higher range of atypical features in testes from the UK compared to those collected from Scandinavia. A further novel element of this thesis was the development of a survey to assess environmental influences on cryptorchidism across several breeds of dog. Uniquely, a higher prevalence of cryptorchidism was observed in deerhounds originating from the East Midlands. Of the range of environmental influences investigated, a key observation was that some bitches of cryptorchid pups were fed a specific brand of feed previously reported to contain ECs. Assessment of further environmental factors covered by the survey such as exposure to pesticides, cigarette smoke and air fresheners provided preliminary information pending the further repeat release of the survey to the same breeders in future years. These data provide preliminary evidence into possible environmental factors that could influence canine and human reproductive health. In conclusion, the results presented in this thesis are significant since they add considerable weight to the paradigm that environmental factors impact directly on male reproductive function. Unique data presented within this thesis emphasises that specific chemical types perturb sperm function and these chemicals vary by region. Furthermore, the work presented here consolidate the suitability of the domestic dog as a sentinel for human exposure to contaminants thus providing the added benefit of enabling access to reproductive tissues from different regions as an index of human reproductive health.
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Jungnickl, Christian, and Ralf Bill. "Abschätzung des Versiegelungsgrades mit Sentinel-2-Daten durch Anwendung von Bebauungsindizes." Rhombos-Verlag, 2017. https://slub.qucosa.de/id/qucosa%3A21264.
Full textAbstract:
Die Ableitung von Informationen über die Flächennutzung aus Fernerkundungsdaten ist eine wichtige Komponente des Umwelt- und Städtemonitorings. Die Sentinel-Missionen des europäischen Erdbeobachtungsprogramms Copernicus stellen in dieser Hinsicht aktuell eine vielversprechende Datenquelle mit enormen Potenzial dar. Ein wichtiger
Indikator, der mittels Satellitendaten erhoben werden kann, ist die Flächenversiegelung. Diese lässt Rückschlüsse auf den anthropogenen Einfluss, den Landschaftszustand oder die Siedlungsentwicklung zu. In dieser Arbeit werden verschiedene Bebauungsindizes für den Stadt-Umland-Raum Rostock berechnet. Als Datengrundlage dienen Multispektraldaten des Sentinel-2A-Sensors. Eine Vielzahl von Indizes wird berechnet und deren Fähigkeit bezüglich der Abschätzung des Versiegelungsgrades anhand von manuell kartierten Referenzdaten bewertet. Die Untersuchungsergebnisse deuten darauf hin, dass der Built-up Index (BUI) und der Combinational Built-up Index (CBI) Vorteile bei der Abschätzung des Versiegelungsgrades besitzen. Während der BUI die konstantesten Ergebnisse im Jahresverlauf liefert, erreicht der CBI mit einer Overall Accuracy (Gesamtgenauigkeit) von 87 % die höchste Übereinstimmung mit den Referenzdaten.
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Gustafsson, Nora, and Andreas Klasson. "Förändringsanalys för detektering av stormfälld skog i satellitbilder från Sentinel 2." Thesis, Högskolan i Gävle, Samhällsbyggnad, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-33274.
Full textAbstract:
En av Sveriges största industrier är skogsindustrin. Att sköta stora skogsinnehav medför vissa svårigheter, t.ex. så kan i händelse av en storm kan delar av skogen bli vindfälld. Det är då viktigt att upptäcka och ta bort de fallna träden eftersom det annars kan leda till granbarkborrangrepp. En metod för att upptäcka den vindfällda skogen är att ta flygbilder över området, vilket kan bli både dyrt och tidsödande. Därför testas i denna studie detektering av stormfälld skog i Sentinel 2 bilder. Sentinel 2 har valts ut eftersom den har både en hög spatial- och temporal upplösning samt att bilderna är tillgängliga gratis. Tidigare studier på området har använt satellitbilder med en lägre spatial upplösning eller data från andra typer av fjärranalys. De flesta av dessa metoder är ganska komplexa eller väldigt specifika för ett särskilt fall. Metoden som tas fram i denna studie ska vara enkel att implementera även för personer utan någon djupare kunskap inom fjärranalys. Bilddifferens med olika index såsom NDVI, NDMI och GreenNDVI testas. Även oövervakad klassificering testas. Noggrannheten har utvärderats med två-stegs metoden med en noggrannhet på 85 % men även en konfusionsmatris tillämpas för att utvärdera noggrannheten av områden där ingen förändring inträffat. Bilddifferens med NDVI och GreenNDVI klarar två-stegs testet när ett statistiskt bestämt tröskelvärde används, NDVI får högst användarnoggrannhet. Felmatrisen visar dock att det finns många stormfällen i ytorna som blivit klassade som ingen förändring, den oövervakade klassificeringen får inte det problemet i samma utsträckning. Bilddifferens i NDVI med statistiskt bestämt tröskelvärde bedöms vara den mest effektiva metoden för att detektera stormfälld skog.
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Uren, Roger. "Lymphatic mapping of the skin and breast: locating the sentinel node." Thesis, University of Sydney, 1999. https://hdl.handle.net/2123/27546.
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Lymphoscintigraphy has been used for many years to study the physiology of the lymphatic drainage of the skin. Following the intradermal injection of 99mTc antimony sulphide colloid images can be obtained using a gamma camera which display the pattern of lymphatic drainage from the injection site. When we first started performing the lymphatic mapping studies for patients of the Sydney Melanoma Unit we were using the study to clarify flow patterns in patients who had melanomas in skin sites which were considered on clinical grounds to have ambiguous lymphatic drainage. These were sites close to the midline of the trunk where drainage could occur to either axilla or sites close to a line drawn around the waist at the level of the umbilicus when drainage might occur to the axilla or groin. Sites on the head and neck were also included as drainage could occur to several different node fields. These clinical judgements were made based on the teachings of Sappey, a French physicians who had produced an elaborate atlas of the lymphatic drainage of the skin late in the 19th century. The imaging in each patient involved standard protocols which has been determined many years previously. In appropriate patients when lymphoscintigraphy had designed the pattern of lymphatic drainage an elective dissection of the node field was performed as part of the treatment of the patients melanoma. Our practice changed dramatically following the description of the sentinel node concept by Morton and colleagues.
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Bioresita, Filsa. "Exploitation de séries temporelles d'images multi-sources pour la cartographie des surfaces en eau." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAH004/document.
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Les eaux de surface sont des ressources importantes pour la biosphère et l'anthroposphère. Elles favorisent la préservation des habitats, le développement de la biodiversité et le maintien des services écosystémiques en contrôlant le cycle des nutriments et le carbone à l’échelle mondiale. Elles sont essentielles à la vie quotidienne de l’homme, notamment pour l'irrigation, la consommation d’eau potable, la production hydro-électrique, etc. Par ailleurs, lors des inondations, elles peuvent présenter des dangers pour l'homme, les habitations et les infrastructures. La surveillance des changements dynamiques des eaux de surface a donc un rôle primordial pour guider les choix des gestionnaires dans le processus d’aide à la décision. L’imagerie satellitaire constitue une source de données adaptée permettant de fournir des informations sur les eaux de surface. De nos jours, la télédétection satellitaire a connu une révolution avec le lancement des satellites Sentinel-1 (Radar) et Sentinel-2 (Optique) qui disposent d’une haute fréquence de revisite et d’une résolution spatiale moyenne à élevée. Ces données peuvent fournir des séries temporelles essentielles pour apporter davantage d'informations afin d'améliorer la capacité d'observation des eaux de surface. L’exploitation de telles données massives et multi-sources pose des défis en termes d’extraction de connaissances et de processus de traitement d’images car les chaines de traitement doivent être le plus automatiques possibles. Dans ce contexte, l'objectif de ce travail de thèse est de proposer de nouvelles approches permettant de cartographier l’extension spatiales des eaux de surface et des inondations, en explorant l'utilisation unique et combinée des données Sentinel-1 et Sentinel-2Surface waters are important resources for the biosphere and the anthroposphere. Surface waters preserve diverse habitat, support biodiversity and provide ecosystem service by controlling nutrient cycles and global carbon. Surface waters are essential for human's everyday life, such as for irrigation, drinking-water and/or the production of energy (power plants, hydro-electricity). Further, surface waters through flooding can pose hazards to human, settlements and infrastructures. Monitoring the dynamic changes of surface waters is crucial for decision making process and policy. Remote sensing data can provide information on surface waters. Nowadays, satellite remote sensing has gone through a revolution with the launch of the Sentinel-1 SAR data and Sentinel-2 optical data with high revisit time at medium to high spatial resolution. Those data can provide time series and multi-source data which are essential in providing more information to upgrade ability in observing surface water. Analyzing such massive datasets is challenging in terms of knowledge extraction and processing as nearly fully automated processing chains are needed to enable systematic detection of water surfaces.In this context, the objectives of the work are to propose new (e.g. fully automated) approaches for surface water detection and flood extents detection by exploring the single and combined used of Sentinel-1 and Sentinel-2 data
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Castro, alvarado Enzo. "Exploiting multi-year high-resolution Sentinel-2 image time series for mapping fallow practice in West Africa." Electronic Thesis or Diss., Paris, AgroParisTech, 2023. http://www.theses.fr/2023AGPT0015.
Full textAbstract:
En Afrique de l'Ouest, la cartographie des jachères est essentielle pour caractériser les systèmes agricoles et évaluer avec précision la durabilité agroécologique des pratiques actuelles et leur contribution à la sécurité alimentaire. Cependant, les méthodes actuellement disponibles pour la cartographie des surfaces cultivées ne sont pas adaptées aux conditions environnementales et culturales rencontrées en contexte d'agriculture familiale en Afrique sub-saharienne. Dans cette thèse de Doctorat, plusieurs stratégies de cartographie des jachères basées sur des approches de classification supervisée ont été explorées. Pour ce faire, des séries temporelles d'images Sentinel-2 ainsi que des données pluviométriques ont été confrontées à une importante base de données collectées sur le terrain entre 2016 et 2021 sur le site de Koumbia, localisé en zone soudanienne au Burkina Faso. Les résultats de ce travail de thèse ont montré que les méthodes d'apprentissage automatique, dites "traditionnelles", ne permettent pas de détecter les surfaces en jachère pour les conditions pédoclimatiques de la zone d'étude. En effet, les précisions obtenues sont très faibles, avec des F1-scores inférieurs à 0.20. Les résultats les plus prometteurs ont été obtenus à partir d'une approche basée sur l'analyse des trajectoires. Une série d'adaptations méthodologiques a alors dû être effectuée afin de pouvoir exploiter l'orientation pluri-annuelle de données annuelles. Pour ce dernier cas, cette thèse s'est concentrée sur la classe "terres agricoles non actives" (NAAL en anglais) pour laquelle des valeurs de F1-scores entre 0.75 et 0.92 ont été obtenus, en considérant un jeu de données de référence complet. Par ailleurs, nos résultats ont mis en évidence que les stratégies de cartographie intégrant des informations spectrales pluri-annuelles dans le processus d'apprentissage constituent une approche viable, permettant de décrire les surfaces en jachère non pas par leur état actuel (c'est-à-dire par l'occupation du sol), mais par les changements à l'œuvre au cours de la période qui jouxte la mise au repos des cultures. Cependant, nos résultats ont également montré que le domaine de validité spatiale de l'approche pouvait être limité, en raison de l'augmentation de l'incertitude du modèle dans les zones où aucune donnée de terrain n'est disponible. Cela souligne l'importance d'incorporer des approches non supervisées au processus de classification afin de permettre plus de fiabilité dans le processus d'extrapolation spatiale. Des stratégies pluri-annuelles plus explicites, où le processus d'analyse temporelle est délégué aux algorithmes de classification ont également été testées et ont montré des résultats légèrement améliorés par rapport aux stratégies de cartographie annuelles directes. Toutefois les performances obtenues restent modérées avec un F1-score moyen de 0.44. Des développements méthodologiques sont encore nécessaires pour (a) exploiter de manière plus efficiente et directe les données pluri-annuelles, et (b) mettre en place des approches non-supervisées plus efficaces pouvant être testées dans les environnements pauvres en données de terrainFallow mapping in West Africa is essential to accurately assess agricultural systems and its contribution to food security and agro-ecological sustainability of current practices, and yet the available mapping methodologies are not adapted to the environmental and cropping conditions encountered when addressing tropical smallholder agriculture. In this doctoral thesis, we explore different mapping strategies based on supervised classification techniques and making use of Sentinel-2 imagery and rainfall data as input, as well as multiple years of in-situ data to map fallow land at local scale in a Soudanian site in Burkina Faso (Koumbia) between the years 2016 and 2021. Results show that "traditional" machine learning based mapping approaches are not sufficient for detecting fallow land under the given pedoclimatic conditions, resulting in very low accuracy figures (e.g., F1-scores below the 0.2 mark). Most promising results were obtained when following a trajectory analysis approach, where a series of methodological adaptations had to be done to exploit annual data in a multi-year oriented manner. In this last case we reformulate the mapping problem to target non-active agricultural land (NAAL) as whole, obtaining F1-score ranging from 0.75 to 0.92 values when validating against complete (no data gaps) reference data set.Our results show that strategies that incorporate multiple years of spectral data in their learning process as a potential viable approach, where fallow land is not described by current status of land surface (i.e. land cover) but rather by the changes of it along the period that encircles the moment in which crop inactivity begins. However, results also indicate that the spatial application scope might be limited, with an augmentation of model uncertainty in areas where no ground truth data is available, highlighting the need to incorporate unsupervised approaches for enhanced extrapolation. On the other hand more explicit multi-year strategies, where temporal analysis is delegated to model classifiers yielded marginally better results than annual direct mapping strategies, yet performances obtained do not reach satisfying results, with top average F1-score reaching the 0.44 mark. Methodological development is still required for both (a) exploiting more efficiently and direct manner multi-year data, and (b) building more cost-efficient unsupervised solutions that could be tested in areas with a reduce amount of ground truth data