23 research outputs found

    Reviews and syntheses: Remotely sensed optical time series for monitoring vegetation productivity

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    Vegetation productivity is a critical indicator of global ecosystem health and is impacted by human activities and climate change. A wide range of optical sensing platforms, from ground-based to airborne and satellite, provide spatially continuous information on terrestrial vegetation status and functioning. As optical Earth observation (EO) data are usually routinely acquired, vegetation can be monitored repeatedly over time, reflecting seasonal vegetation patterns and trends in vegetation productivity metrics. Such metrics include gross primary productivity, net primary productivity, biomass, or yield. To summarize current knowledge, in this paper we systematically reviewed time series (TS) literature for assessing state-of-the-art vegetation productivity monitoring approaches for different ecosystems based on optical remote sensing (RS) data. As the integration of solar-induced fluorescence (SIF) data in vegetation productivity processing chains has emerged as a promising source, we also include this relatively recent sensor modality. We define three methodological categories to derive productivity metrics from remotely sensed TS of vegetation indices or quantitative traits: (i) trend analysis and anomaly detection, (ii) land surface phenology, and (iii) integration and assimilation of TS-derived metrics into statistical and process-based dynamic vegetation models (DVMs). Although the majority of used TS data streams originate from data acquired from satellite platforms, TS data from aircraft and unoccupied aerial vehicles have found their way into productivity monitoring studies. To facilitate processing, we provide a list of common toolboxes for inferring productivity metrics and information from TS data. We further discuss validation strategies of the RS data derived productivity metrics: (1) using in situ measured data, such as yield; (2) sensor networks of distinct sensors, including spectroradiometers, flux towers, or phenological cameras; and (3) inter-comparison of different productivity metrics. Finally, we address current challenges and propose a conceptual framework for productivity metrics derivation, including fully integrated DVMs and radiative transfer models here labelled as “Digital Twin”. This novel framework meets the requirements of multiple ecosystems and enables both an improved understanding of vegetation temporal dynamics in response to climate and environmental drivers and enhances the accuracy of vegetation productivity monitoring

    Reviews and syntheses:Remotely sensed optical time series for monitoring vegetation productivity

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    International audienceAbstract. Vegetation productivity is a critical indicator of global ecosystem health and is impacted by human activities and climate change. A wide range of optical sensing platforms, from ground-based to airborne and satellite, provide spatially continuous information on terrestrial vegetation status and functioning. As optical Earth observation (EO) data are usually routinely acquired, vegetation can be monitored repeatedly over time; reflecting seasonal vegetation patterns and trends in vegetation productivity metrics. Such metrics include e.g., gross primary productivity, net primary productivity, biomass or yield. To summarize current knowledge, in this paper, we systematically reviewed time series (TS) literature for assessing state-of-the-art vegetation productivity monitoring approaches for different ecosystems based on optical remote sensing (RS) data. As the integration of solar-induced fluorescence (SIF) data in vegetation productivity processing chains has emerged as a promising source, we also include this relatively recent sensor modality. We define three methodological categories to derive productivity metrics from remotely sensed TS of vegetation indices or quantitative traits: (i) trend analysis and anomaly detection, (ii) land surface phenology, and (iii) integration and assimilation of TS-derived metrics into statistical and process-based dynamic vegetation models (DVM). Although the majority of used TS data streams originate from data acquired from satellite platforms, TS data from aircraft and unoccupied aerial vehicles have found their way into productivity monitoring studies. To facilitate processing, we provide a list of common toolboxes for inferring productivity metrics and information from TS data. We further discuss validation strategies of the RS-data derived productivity metrics: (1) using in situ measured data, such as yield, (2) sensor networks of distinct sensors, including spectroradiometers, flux towers, or phenological cameras, and (3) inter-comparison of different productivity products or modelled estimates. Finally, we address current challenges and propose a conceptual framework for productivity metrics derivation, including fully-integrated DVMs and radiative transfer models here labelled as "Digital Twin". This novel framework meets the requirements of multiple ecosystems and enables both an improved understanding of vegetation temporal dynamics in response to climate and environmental drivers and also enhances the accuracy of vegetation productivity monitoring

    Testing the normality of the residuals of surface temperature data at VLBI/GPS co-located sites by goodness of fit tests

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    Evaluating the distribution patterns of surface temperature data at Very Long Baseline Interferometry (VLBI)/Global Positioning System (GPS) co-located sites w.r.t. normality is one of the most important issues in modeling surface temperature data over long periods. Such evaluation can generate algorithms for filling in missing data at measurement sites. Some algorithms in the literature, such as those in the study of Cho et al. J Coast Res 65. doi: 10. 2112/SI65-321. 1, (2013), require trend, harmonic, and residual components to fill in the missing data. Trend and harmonic components estimate an optimal model that can be used to assist such algorithms when filling in missing data. The present study is based on the investigation of the normal distribution of the residuals of a surface temperature time series at VLBI/GPS co-located sites, after removing the trend and seasonal effects through harmonic components (inter-daily variations). This study uses surface temperature data collected from the VLBI/GPS co-located sites of two different regions in Europe: Matera (Italy) and Wettzell (Germany). The data collected from these sites form a time series, and time series analyses and conventional k-sigma outlier detection are implemented on these data sets before subjecting them to goodness of fit tests for normality. The residual components of the time series are acquired through a decomposing trend and signal effect from the original time series, assuming that the residuals of the time series are normally distributed. In testing the hypothesis that an observed frequency distribution fits the normal distribution, the following tests are used: Pearson chi (2), Kolmogorov-Smirnov, Anderson-Darling, Shapiro-Wilk or Shapiro-Francia, D'Agostino, Jarque-Bera, skewness, and kurtosis tests. Some graphical methods are also applied to support the results of the goodness of fit tests for normality. Some proposals on the application of the goodness of fit tests are put forward, such as the evaluation of the estimation model for trend and harmonic components by considering the properties of the implemented goodness of fit tests. The results of this study can be used to determine the optimal model for estimating trend and harmonic components. The output of the present study is expected to have an important role in modeling surface temperature distributions at co-located VLBI/GPS sites for filling in missing data. Above all, meteorological data, such as temperature, pressure, and humidity, are of specific interest for modeling tropospheric delay, the main error factor in positioning in space geodesy, which in turn makes investigations on the distribution of meteorological data more attractive in geoscience

    Analysis of ionospheric TEC anomalies for global earthquakes during 2000-2019 with respect to earthquake magnitude (Mw >= 6.0)

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    ULUKAVAK, Mustafa/0000-0003-2092-3075WOS: 000528012200005In this work, a relationship between ionospheric TEC anomalies and different earthquake magnitude groups before the main shocks was investigated. For this purpose, 2942 global earthquakes with Mw >= 6 from 2000 to 2019 and possible ionospheric TEC anomalies that occurred before earthquakes were examined by considering 13 different index values of space weather conditions (geomagnetic storm indices and solar activity indices). Anomalies of ionospheric TEC changes were defined for 15-days before and 4-days after the earthquakes by using 15-days moving median method with the length of 15 days. Earthquakes were first grouped according to their magnitudes, and then negative and positive TEC anomalies in quiet days before the earthquakes were detected. These anomalies were observed as similar to 5-13, similar to 5-10, similar to 5-15, similar to 3-13, similar to 7-15, similar to 1 and similar to 5-8 days ago for the earthquakes of 6.0 = 6) in the short-term earthquake prediction for main shocks.TUBITAK (The Scientific and Technological Research Council of Turkey), Environment, Atmosphere, Earth and Marine Science Research Support Group (CAYDAG)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [116Y109]The authors would like to thank, the CDDIS (Crustal Dynamics Data and Information System) data and products archive, for providing the IONEX files, and also, we acknowledge the use of NASA/GSFC's Space Physics Data Facility's OMNIWeb (or CDAWeb or FTP) service, and OMNI data. We would like to express our special thanks to TUBITAK (The Scientific and Technological Research Council of Turkey), Environment, Atmosphere, Earth and Marine Science Research Support Group (CAYDAG) that supporting our project with grant no. 116Y109

    Pediatric Neutropenic Patients Care In Turkey

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    Objective: Infection is a common complication in children with malignancies. There is no consistent guidance for environmental infection control and isolation precautions for neutropenic patients (NP). There are differences between centers. The aim of this questionnaire study was to determine these differences in Turkey. Material and Methods: A multicenter-descriptive questionnaire was conducted on 36 centers from different geografical locations of Turkey. Bone marrow transplantation units were excluded. Each center was contacted at least three-times. Questionnaire was answered by two different doctors from each center. Results: Thirty-six centers including 20 (55.5%) University Hospitals, 12 (%33.3) Research Hospitals, three (8.3%) State Hospital and one Private University Hospital participated in this survey. 94.3% of the centers had a bed capacity of 50 beds and over. Twenty-one (58.3%) centers had pediatric infection ward that followed febrile NP. All centers had an infection control committee. 25% (9/36) of the centers always followed pediatric neutropenic fever patients in a single room. 66.6% (24/36) of the centers had toilet in all patients' room. The door features of patients' room included mostly (94.1%, 32/34) manually opened door. Ten (27.7%) centers had hepa filter system, five of them had positive-negative pressure room. Thirteen (38.2%, 13/34) centers prefered hickmann catheter for accessing a patient's central line. Training was given for catheteter care in all centers. Sixteen (44.4%) centers had determined policies about keeping toys in patient rooms. Visitor restrictions were performed in all centers. None of the centers allowed plants or flowers in hospital rooms. There was a neutropenic diet specific for pediatric NP provided in twenty-seven centers (75%). Conclusion: The prevention and control of infection contributes to the improvement of the prognosis of patients with hematological malignancies. Physicians must be aware of the infection risks and take precautions for infectious complications through the neutropenic period and standard protocols should be established and implemented for patients with hematological malignancies.WoSScopu

    Türkiye’ de Pediatrik Nötropenik Hasta İzlemi

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    Objective: Infection is a common complication in children with malignancies. There is no consistent guidance for environmental infection control and isolation precautions for neutropenic patients (NP). There are differences between centers. the aim of this questionnaire study was to determine these differences in Turkey. Material and Methods: A multicenter-descriptive questionnaire was conducted on 36 centers from different geografical locations of Turkey. Bone marrow transplantation units were excluded. Each center was contacted at least three-times. Questionnaire was answered by two different doctors from each center. Results: Thirty-six centers including 20 (55.5%) University Hospitals, 12 (%33.3) Research Hospitals, three (8.3%) State Hospital and one Private University Hospital participated in this survey. 94.3% of the centers had a bed capacity of 50 beds and over. Twenty-one (58.3%) centers had pediatric infection ward that followed febrile NP. All centers had an infection control committee. 25% (9/36) of the centers always followed pediatric neutropenic fever patients in a single room. 66.6% (24/36) of the centers had toilet in all patients’ room. the door features of patients’ room included mostly (94.1%, 32/34) manually opened door. Ten (27.7%) centers had hepa filter system, five of them had positive-negative pressure room. Thirteen (38.2%, 13/34) centers prefered hickmann catheter for accessing a patient’s central line. Training was given for catheteter care in all centers. Sixteen (44.4%) centers had determined policies about keeping toys in patient rooms. Visitor restrictions were performed in all centers. None of the centers allowed plants or flowers in hospital rooms. There was a neutropenic diet specific for pediatric NP provided in twenty-seven centers (75%). Conclusion: the prevention and control of infection contributes to the improvement of the prognosis of patients with hematological malignancies. Physicians must be aware of the infection risks and take precautions for infectious complications through the neutropenic period and standard protocols should be established and implemented for patients with hematological malignancies.Giriş: Maligniteli hastaların tedavi sürecindeki en önemli komplikasyonlardan biri enfeksiyonlardır. Nötropenik hastalarda enfeksiyon kontrolü ve izolasyon önlemleri için merkezden merkeze değişen farklı uygulamalar mevcuttur. Anket çalışmasının amacı Türkiye’deki bu farklılıkları ve ihtiyaçları belirlemektir. Gereç ve Yöntemler: Çok merkezli tanımlayıcı çalışmaya Türkiye’nin farklı coğrafik bölgelerinden pediatrik nötropenik hasta takip eden 36 merkez dahil edildi. Kemik iliği transplantasyon üniteleri çalışmaya alınmadı. Her merkezle en az üç kez iletişime geçildi. Anketi her merkezden iki doktor yanıtladı. Anket kişisel, genel hasta bakımı ve nötropenik hasta bakımını içeren 64 sorudan oluşmaktaydı. Bulgular: Çalışmaya katılan merkezlerin 20 (%55.5)’si üniversite hastanesi, 12 (%33.3)’si eğitim araştırma hastanesi, 3 (%8.3)’ ü devlet hastanesi ve bir tanesi de özel üniversite hastanesi idi. Merkezlerin %94.3’ünün yatak kapasitesi 50 yatak ve üzerinde idi. Yirmi bir (%58) merkezin çocuk enfeksiyon hastalıkları servisi mevcuttu. Tüm merkezlerin enfeksiyon kontrol komitesi vardı. Merkezlerin %25 (n= 9)‘inde nötropenik ateş (NPA) tanısı alan çocuk hastalar tek kişilik odalarda izleniyordu. Tüm odalarda tuvalet bulunan merkez sayısı 24 (%66.6) idi. Hasta odalarının büyük çoğunluğunda elle açılıp kapanır kapı (%94.1) ve musluk (%97.1) mevcuttu. on (%27.7) merkezin oda havalandırması için hepa-filtreli sistemi vardı. Beşinde negatif basınçlı oda mevcuttu. on üç merkezde kateter olarak hickman kateter tercih edilmişti. Tüm merkezlerde kateter bakımı için eğitim verilmekte idi. Hiçbir merkezde hasta ziyaretine ve hastane odasında bitki veya çiçek bulundurmaya izin verilmemekteydi. Merkezlerin %45.7’sinde hastanede oyuncak bulundurma ile ilgili hastane politikası vardı. Sonuç: Sonuç olarak, nötropenik hastaları enfeksiyondan korumak için hastanelerde çeşitli yaklaşımlar uygulanmaktadır. Rehberler belirlenip bu rehberler ışığında hastane koşulları düzenlenmeli ve nötropenik hasta izlemi yapılmalıdır

    Multicenter Hospital-Based Prospective Surveillance Study of Bacterial Agents Causing Meningitis and Seroprevalence of Different Serogroups of Neisseria meningitidis, Haemophilus influenzae Type b, and Streptococcus pneumoniae during 2015 to 2018 in Turkey

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    The etiology of bacterial meningitis in Turkey changed after the implementation of conjugated vaccines against Streptococcus pneumoniae and Haemophilus influenzae type b (Hib) in the Turkish National Immunization Program (NIP). Administration of Hib vaccine and PCV-7 (7-valent pneumococcal conjugate vaccine) was implemented in NIP in 2006 and 2009, respectively. In 2011, PCV-7 was replaced with PCV-13. Meningococcal vaccines have not yet been included in Turkish NIP. This prospective study comprised 27 hospitals located in seven regions of Turkey and represented 45% of the population. Children aged between 1 month and 18 years who were hospitalized with suspected meningitis were included. Cerebrospinal fluid (CSF) samples were collected, and bacterial identification was made according to the multiplex PCR assay results. During the study period, 994 children were hospitalized for suspected meningitis, and Hib (n = 3, 2.4%), S. pneumoniae (n = 33, 26.4%), and Neisseria meningitidis (n = 89, 71%) were detected in 125 samples. The most common meningococcal serogroup was MenB. Serogroup W comprised 13.9% (n = 5) and 7.5% (n = 4) of the meningococci in 2015 to 2016 and 2017 to 2018, respectively. Serogroup C was not detected. There were four deaths in the study; one was a pneumococcus case, and the others were serogroup B meningococcus cases. The epidemiology of meningococcal diseases has varied over time in Turkey. Differing from the previous surveillance periods, MenB was the most common serogroup in the 2015-to-2018 period. Meningococcal epidemiology is so dynamic that, for vaccination policies, close monitoring is crucial
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