294 research outputs found

    Machine learning for cloud detection of globally distributed sentinel-2 images

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    In recent years, a number of different procedures have been proposed for segmentation of remote sensing images, basing on spectral information. Model-based and machine learning strategies have been investigated in several studies. This work presents a comprehensive overview and an unbiased comparison of the most adopted segmentation strategies: Support Vector Machines (SVM), Random Forests, Neural networks, Sen2Cor, FMask and MAJA. We used a training set for learning and two different independent sets for testing. The comparison accounted for 135 images acquired from 54 different worldwide sites. We observed that machine learning segmentations are extremely reliable when the training and test are homogeneous. SVM performed slightly better than other methods. In particular, when using heterogeneous test data, SVM remained the most accurate segmentation method while state-of-the-art model-based methods such as MAJA and FMask obtained better sensitivity and precision, respectively. Therefore, even if each method has its specific advantages and drawbacks, SVM resulted in a competitive option for remote sensing applications

    Development and distribution of the non-indigenous Pacific oyster (Crassostrea gigas) in the Dutch Wadden Sea

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    Pacific oysters (Crassostrea gigas) were first observed in the Dutch Wadden Sea near Texel in 1983. The population increased slowly in the beginning but grew exponentially from the mid-1990s onwards, although now some stabilisation seems to be occurring. They occur on a variety of substrates such as mussel beds (Mytilus edulis), shell banks, dikes and poles. After initial settlement spat may fall on older individuals and congregate to dense clumps and subsequently form reefs. Individual Pacific oysters grow 3–4 cm long in their first year and 2–3 cm in their second year. Many mussel beds (Mytilus edulis) are slowly taken over by Pacific oysters, but there are also several reports of mussel spat settling on Pacific oyster reefs. This might in the end result in combined reefs. Successful Pacific oyster spat fall seems to be related to high summer temperatures, but also after mild summers much spat can be found on old (Pacific oyster) shells. Predation is of limited importance. Mortality factors are unknown, but every now and then unexplained mass mortality occurs. The gradual spread of the Pacific oyster in the Dutch Wadden Sea is documented in the first instance based on historical and anecdotal information. At the start of the more in-depth investigation in 2002, Pacific oysters of all size classes were already present near Texel. Near Ameland the development could be followed from the first observed settlement. On dense reefs each square metre may contain more than 500 adult Pacific oysters, weighing more than 100 kg per m² fresh weigh

    First synthesis of a fully active spin-labeled peptide hormone

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    For the first time in the electron spin resonance (ESR) and peptide synthesis fields, a fully active spin-labeled peptide hormone was reported. the ESR spectra of this alpha-melanocyte stimulating hormone (alpha-MSH) analogue (acetyl-Toac(0)-alpha-MSH) where Toac is the paramagnetic amino acid probe 2,2,6,6-tetramethylpiperidine-1-oxyl-4-amino-4-carboxylic acid, suggested a pH-independent conformation and a more restricted movement comparatively to the free Toac, Owing to its equivalent biological potency in a skin pigmentation assay as compared to the native alpha-MSH and its unique characteristic (paramagnetic, naturally fluorescent and fully active), this analogue is of great potential for investigation of relevant physiological roles reported for a-MSH, (C) 1999 Federation of European Biochemical Societies.Universidade Federal de São Paulo, Dept Biofis, BR-04044020 São Paulo, BrazilUniv São Paulo, Inst Fis, BR-01498 São Paulo, BrazilUniv São Paulo, Inst Biociencias, Dept Fisiol, BR-01498 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04044020 São Paulo, BrazilWeb of Scienc

    On the trail of medieval wolves: ancient DNA, CT-based analyses and palaeopathology of a 1000-year-old wolf cranium from the Po Valley (northern Italy)

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    The Middle Ages represented a crucial period for the evolutionary history of wolves (Canis lupus), marked by both significant ecosystem changes, especially through the degradation of wooded landscapes and heavy persecution, that drove this species to a dramatic demographic decline. In Europe, informative and well-documented wolf remains from the Medieval Ages are exceptionally rare and are mostly represented by teeth and postcranial elements. In this study, we describe a well-preserved wolf cranium dated to ca. 967–1157 AD from the Po Valley (northern Italy). The specimen was analysed through a multidisciplinary approach including CT-based, ancient DNA, and palaeopathological analyses. Morphological and genetic data supported the assignment of this sample to Canis lupus species. CT-based analyses indicated a typical wolf-like morphology falling into the extant variability of the medium-sized subspecies C. lupus italicus, whereas palaeopathological analyses indicated a severe periodontitis. Phylogenetic analyses showed that the Po valley wolf had a unique and never described mtDNA control region haplotype, testifying variability in the ancient Italian wolf, which has now been lost. This study provides the first comprehensive description of a wolf from the Middle Ages, adding useful information for a deeper knowledge about population dynamics, variability, and diseases of this species

    ProNGF Is a Cell-Type-Specific Mitogen for Adult Hippocampal and for Induced Neural Stem Cells

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    The role of proNGF, the precursor of Nerve Growth Factor (NGF), on the biology of adult neural stem cells (aNSCs) is still unclear. Here I analyzed adult hippo-campal neurogenesis in AD11 transgenic mice, in which the constitutive expression of anti-NGF antibody leads to an imbalance of proNGF over mature NGF. I found in-creased proliferation of progenitors but a reduced neurogenesis in the AD11 DG- hippocampus (HP-DG). Also in vitro, AD11 hippocampal neural stem cells (NSCs) pro-liferated more but were unable to differentiate into morphologically mature neu-rons. By treating wild-type (WT) hippocampal progenitors with the uncleavable form of proNGF (proNGF-KR) I demonstrated that proNGF acts as mitogen on aNSCs at low concentration. The mitogenic effect of proNGF was specifically addressed to the radial glia-like (RGL) neural stem cells through the induction of cyclin D1 expression. These cells express high level of p75NTR, as demonstrated by immunofluorescence analyses performed ex vivo on RGL cells isolated from freshly-dissociated HP-DG or selected in vitro from NSCs by LIF (leukemia inhibitory factor). Clonogenic assay per-formed in the absence of mitogens showed that RGLs respond to proNGF-KR by re-activating their proliferation and thus leading to neurospheres formation. The mito-genic effect of proNGF was further exploited in the expansion of mouse induced Neural Stem Cells (iNSCs). Chronic exposure of iNSCs to proNGF-KR increased their proliferation. Altogether, I demonstrated that proNGF acts as mitogen on hippo-campal and induced neural stem cells.The role of proNGF, the precursor of nerve growth factor (NGF), in the biology of adult neural stem cells (aNSCs) is still unclear. Here, we analyzed adult hippocampal neurogenesis in AD11 transgenic mice, in which the constitutive expression of anti-NGF antibody leads to an imbalance of proNGF over mature NGF. We found increased proliferation of progenitors but a reduced neurogenesis in the AD11 dentate gyrus (DG)-hippocampus (HP). Also in vitro, AD11 hippocampal neural stem cells (NSCs) proliferated more, but were unable to differentiate into morphologically mature neurons. By treating wild-type hippocampal progenitors with the uncleavable form of proNGF (proNGF-KR), we demonstrated that proNGF acts as mitogen on aNSCs at low concentration. The mitogenic effect of proNGF was specifically addressed to the radial glia-like (RGL) stem cells through the induction of cyclin D1 expression. These cells express high levels of p75NTR, as demonstrated by immunofluorescence analyses performed ex vivo on RGL cells isolated from freshly dissociated HP-DG or selected in vitro from NSCs by leukemia inhibitory factor. Clonogenic assay performed in the absence of mitogens showed that RGLs respond to proNGF-KR by reactivating their proliferation and thus leading to neurospheres formation. The mitogenic effect of proNGF was further exploited in the expansion of mouse-induced neural stem cells (iNSCs). Chronic exposure of iNSCs to proNGF-KR increased their proliferation. Altogether, we demonstrated that proNGF acts as mitogen on hippocampal and iNSCs. Stem Cells 2019;37:1223–1237

    Irrigation Scheduling in Crop Management System

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    Center pivor systems are widely used to suppress the irrigation needs of agricultural fields. In this article, we propose an autonomous to improve the low efficiency of this method of irrigation, developing a system based on the water requirement of the plantation, through field data (local temperature, local wind, soil moisture and precipitation forecast) and soil evapotranspiration calculation. The stored information will allow to calculatem the real evapotranspiration, not being necessary to restrict to lysometric measures. Accordingly, it is possible to schedule the irrigation for the period in which it has the lowest cost, considering the energy produced locally and the price of energy bought in the main market. Irrigation must be carried out within the time interval in which the plantation does not reach the wilding point, so it will be carried out at the time of the lowest cost.The present work was done and funded in the scope of the following project: Eco Rural IoT project funded by TETRAMAX-VALUECHAIN-TTX-1, and UID/EEA/00760/2019 funded by FEDER Funds through COMPETE program and by National Funds through FCT.info:eu-repo/semantics/publishedVersio

    The State of the ReCLes. pt CLIL training project

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    Content and Language Integrated Learning (CLIL), an area that has only recently been more thoroughly explored for appropriate use at higher levels of education, has been one of the research areas identified by the Association of Language Centers in Higher Education in Portugal (ReCLes.pt). ReCLes.pt members – administration and research professors are striving to make a difference in the paucity of scientific publications in this area with the creation of their national program for training content teachers in Portuguese higher education. To best learn from each other in a collaborative network and apply well-informed teaching and learning methodology to English-taught classrooms, the underlying concepts range from classroom management and scaffolding to learner autonomy and from Web 2.0 tools to terminology-based learning. As an update of the current state of the art as interpreted in this project, the outreach and reception will be described in full with attention to some detailed examples of the more successful aspects as well as others where we have found room for improvement. Recommendations will be made for other networks and individual schools aiming to effectively prepare their students for the market by using an integrated approach to content and language learning. This paper reports on the current state of the ongoing ReCLes.pt CLIL Training Project, financed in part by the FCT (the Portuguese Foundation for Science and Technology), with project members from a number of universities and polytechnics across Portugal.info:eu-repo/semantics/publishedVersio

    Lumbar spine bone mineral density and trabecular bone score-adjusted FRAX, but not FRAX without bone mineral density, identify subclinical carotid atherosclerosis

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    Purpose: Osteoporosis and atherosclerosis share common risk factors. Aim of this study was to test if FRAX (which is an algorithm that can identify subjects at risk of fracture), without or with BMD values, also adjusted for trabecular bone score (TBS) was able to identify subclinical atherosclerosis, evaluated by measurement of carotid intima media thickness (cIMT ≥ 0.9 mm) as compared to DXA values. Methods: Ninety postmenopausal women underwent DXA measurement and cIMT evaluation. For each patient, the FRAX algorithm for major osteoporotic fracture (M) and for hip fracture (H) without BMD was computed, together with FRAX with BMD and TBS-adjusted FRAX. Serum levels of osteoprotegerin, sRANKL, and interleukin-6 were also measured. Results: There were no differences in anthropometric parameters and cardiovascular risk factors between subjects with cIMT ≥ 0.9 mm (35% of subjects, group A) compared to those with cIMT < 0.9 mm (group B). The prevalence of osteoporosis and FRAX BMD, TBS-adjusted FRAX both for M and H were higher in group A compared to group B. The best ROC curves to identify subjects with a cIMT ≥ 0.9 mm were: lumbar spine T-score, with a threshold of − 2.5 SD (area under the curve, AUC 0.64; p = 0.02) with a sensibility of 50% and a specificity of 76%; TBS-adjusted FRAX H with a sensibility of 50% and a specificity of 72% (AUC 0.64; p = 0.01 with a threshold of 3%). Interleukin-6 positively correlated with FRAX BMD H and M. Conclusions: FRAX without BMD does not identify subclinical carotid atherosclerosis, while lumbar spine T-score and TBS-adjusted FRAX H similarly detected it with higher specificity for T-score

    Desenvolvimento de modelo de simulação da metodologia DDMRP

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    O Planeamento de Necessidades de Materiais Orientado pela Procura (DDMRP) foi introduzido em 2011 para melhorar o desempenho do planeamento da cadeia de abastecimento, é um método que promete ser revolucionário na área do planeamento e gestão de materiais. De acordo com relatórios do Demand Driven Institute (DDI), o DDMRP reduz os níveis de inventário em cerca de 31% enquanto melhora os níveis de serviço em cerca de 13% e permite a redução dos prazos de entrega dos pedidos dos clientes. Esses resultados podem ter um impacto significativo no desempenho financeiro de uma empresa e fornecer vantagem competitiva. Esta monografia tem como objetivo contribuir para a melhor compreensão do método DDMRP, bem como demonstrar e facilitar a sua implementação através do desenvolvimento de um simulador que permite criar, analisar e otimizar diferentes configurações da cadeia de abastecimento.The Demand-Driven Material Requirements Planning (DDMRP) was introduced in 2011 to improve the performance of supply chain planning, it is method that promises to be revolutionary in the scope of materials planning and management. According to reports by the Demand Driven Institute (DDI), the DDMRP reduces inventory levels around 31% while improve service levels around 13% and it allows the reduction of delivery times for customer orders. Such results can have a significant impact on a company's financial performance and provide a competitive advantage. This monograph intends contribute to a better understanding of the DDMRP method, as well, to explain and facilitate the implementation through the development of a simulator that allows to create, analyze and optimize the different configurations of the supply chain

    Psi clustering for the assessment of underground infrastructure deterioration

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    Remote sensing images find application in several different domains, such as land cover or land usage observation, environmental monitoring, and urbanization. This latter field has recently witnessed an interesting development with the use of remote sensing for infrastructural monitoring. In this work, we present an analysis of Sentinel-1 images, which were used to monitor the Italian provinces of Bologna and Modena located at the Emilia Region Apennines foothill. The goal of this study was the development of a machine learning-based detection system to monitor the deterioration of public aqueduct infrastructures based on Persistent Scatterer Interferometry (PSI). We evaluated the land deformation over a temporal range of five years; these series feed a k-means clustering algorithm to separate the pixels of the region according to different deformation patterns. Furthermore, we defined the critical areas as those areas where different patterns collided or overlapped. The proposed approach provides an informative tool for the structural health monitoring of underground infrastructures
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