7 research outputs found

    Можливості оптимізації терапії апендикулярних інфільтратів

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    Актуальність. Гострий апендицит – інфекційно-запальне захворювання хробакоподібного відростка, якє має найбільшу питому вагу в ургентній хірургії. Актуальність проблеми лікування хворих з гострим апендицитом зумовлена значною частотою ускладнень, яка сягає 9,9–21%. Одним із поширених і загрозливих поміж них залишається апендикулярний інфільтрат. Частота останнього за даними різних авторів знаходиться у межах 0,2–5,8 %. З огляду на те що кількість хворих на гострий апендицит на теренах України протягом року залишається відносно стабільною і складає 12–15 тис. чоловік, актуальність проблеми є очевидною. Оперативне лікування таких хворих у більшості випадках не застосовується, а консервативне, основу якого складає антибіотикотерапія, буває тривалим і не завжди ефективним, проте завжди дороговартісним, що обґрунтовує потребу пошуків нових і більш ефективних методів. Мета. Вивчити можливості антибіотикотерапії шляхом лімфотропних технологій

    The Forest Observation System, building a global reference dataset for remote sensing of forest biomass

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    International audienceForest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (aGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. aGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. all plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS-based biomass products while developing new synergies between the RS and ground-based ecosystem research communities

    Taxonomic assessment of O. furcillata (Oxalidaceae)

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    Thesis (MSc (Botany and Zoology))--University of Stellenbosch, 2005.The family Oxalidaceae has a worldwide distribution, but is most common in tropical and subtropical regions. Oxalis L. is the largest genus of the family comprising ca. 800 of the 900 species. Oxalis species are annual or perennial herbs or rarely subshrubs or trees. The current study assesses on the taxonomic placement of O. furcillata Salter. Currently this species, comprising two varieties, O. furcillata var. furcillata and O. furcillata var. caulescens Salter, is placed in section Foveolatae. Members of this section have endospermous seeds and fleshy leaflets. However, both in terms of leaf morphological and seed characters the two varieties of this species appear to be misplaced within this section. In addition O. furcillata var. caulescens has a unique pollen type, different from both the typical variety and the rest of the section. Both lines of evidence thus suggest that O. furcillata var. caulescens may be misplaced within this section. The present study thus sets out to assess the placement of O. furcillata in general, and the placement of O. furcillata var. caulescens in particular. A multi-disciplinary approach was followed, which included analyses of macro-morphological (including LM and SEM analyses), biogeographical and palynological characters. The variability of quantitative characters was assessed using the STATISTICA 6.0 software package. Leaf dimensions, plant height, bulb length, petiole length and palynology showed sufficient differences between the two taxa to confirm the separate identity of these two varieties as separate species. O. furcillata var. caulescens was thus raised to specific status as O. caulescens (Salter) Bissiengou. The results suggest two different options in terms of the taxonomic placement of the species O. furcillata and O. caulescens. They can either remain in section Foveolatae, best placed near O. senecta and O. densa or may moved to the highly variable section Latifoliolatae. But retaining them within the section Foveolatae appeared to be the better alternative. The correct position will be established both through further morphological analyses and correlation to the trnL-F and ITS sequence-based phylogeny of the southern African members of Oxalis

    A map of African humid tropical forest aboveground biomass derived from management inventories

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    International audienceForest biomass is key in Earth carbon cycle and climate system, and thus under intense scrutiny in the context of international climate change mitigation initiatives (e.g. REDD+). In tropical forests, the spatial distribution of aboveground biomass (AGB) remains, however, highly uncertain. There is increasing recognition that progress is strongly limited by the lack of field observations over large and remote areas. Here, we introduce the Congo basin Forests AGB (CoFor-AGB) dataset that contains AGB estimations and associated uncertainty for 59,857 1-km pixels aggregated from nearly 100,000 ha of in situ forest management inventories for the 2000 – early 2010s period in five central African countries. A comprehensive error propagation scheme suggests that the uncertainty on AGB estimations derived from c. 0.5-ha inventory plots (8.6–15.0%) is only moderately higher than the error obtained from scientific sampling plots (8.3%). CoFor-AGB provides the first large scale view of forest AGB spatial variation from field data in central Africa, the second largest continuous tropical forest domain of the world

    In Situ Reference Datasets From the TropiSAR and AfriSAR Campaigns in Support of Upcoming Spaceborne Biomass Missions

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    International audienceTropical forests are a key component of the global carbon cycle. Yet, there are still high uncertainties in forest carbon stock and flux estimates, notably because of their spatial and temporal variability across the tropics. Several upcoming spaceborne missions have been designed to address this gap. High-quality ground data are essential for accurate calibration/validation so that spaceborne biomass missions can reach their full potential in reducing uncertainties regarding forest carbon stocks and fluxes. The BIOMASS mission, a P-band SAR satellite from the European Space Agency (ESA), aims at improving carbon stock mapping and reducing uncertainty in the carbon fluxes from deforestation, forest degradation, and regrowth. In situ activities in support of the BIOMASS mission were carried out in French Guiana and Gabon during the TropiSAR and AfriSAR campaigns. During these campaigns, airborne P-band SAR, forest inventory, and lidar data were collected over six study sites. This paper describes the methods used for forest inventory and lidar data collection and analysis, and presents resulting plot estimates and aboveground biomass maps. These reference datasets along with intermediate products (e.g., canopy height models) can be accessed through ESA's Forest Observation System and the Dryad data repository and will be useful for BIOMASS but also to other spaceborne biomass missions such as GEDI, NISAR, and Tandem-L for calibration/validation purposes. During data quality control and analysis, prospects for reducing uncertainties have been identified, and this paper finishes with a series of recommendations for future tropical forest field campaigns to better serve the remote sensing community

    LiDAR-based reference aboveground biomass maps for tropical forests of South Asia and Central Africa

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    International audienceAccurate mapping and monitoring of tropical forests aboveground biomass (AGB) is crucial to design effective carbon emission reduction strategies and improving our understanding of Earth’s carbon cycle. However, existing large-scale maps of tropical forest AGB generated through combinations of Earth Observation (EO) and forest inventory data show markedly divergent estimates, even after accounting for reported uncertainties. To address this, a network of high-quality reference data is needed to calibrate and validate mapping algorithms. This study aims to generate reference AGB datasets using field inventory plots and airborne LiDAR data for eight sites in Central Africa and five sites in South Asia, two regions largely underrepresented in global reference AGB datasets. The study provides access to these reference AGB maps, including uncertainty maps, at 100 m and 40 m spatial resolutions covering a total LiDAR footprint of 1,11,650 ha [ranging from 150 to 40,000 ha at site level]. These maps serve as calibration/validation datasets to improve the accuracy and reliability of AGB mapping for current and upcoming EO missions (viz., GEDI, BIOMASS, and NISAR)

    The Forest Observation System, building a global reference dataset for remote sensing of forest biomass

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    Forest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (AGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. AGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. All plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS- based biomass products while developing new synergies between the RS and ground-based ecosystem research communities.</p
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