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1.
Sensors (Basel) ; 19(14)2019 Jul 21.
Article in English | MEDLINE | ID: mdl-31330897

ABSTRACT

The main purpose of this study is to investigate the performance of two radar backscattering models; the calibrated integral equation model (CIEM) and the modified Dubois model (MDB) over an agricultural area in Karaj, Iran. In the first part, the performance of the models is evaluated based on the field measurement and the mentioned backscattering models, CIEM and MDB performed with root mean square error (RMSE) of 0.78 dB and 1.45 dB, respectively. In the second step, based on the neural networks (NNS), soil surface moisture is estimated using the two backscattering models, based on neural networks (NNs), from single polarization Sentinel-1 images over bare soils. The inversion results show the efficiency of the single polarized data for retrieving soil surface moisture, especially for VV polarization.

2.
Sensors (Basel) ; 19(4)2019 Feb 16.
Article in English | MEDLINE | ID: mdl-30781451

ABSTRACT

The objective of this paper is to present an analysis of Sentinel-1 derived surface soil moisture maps (S1-SSM) produced with high spatial resolution (at plot scale) and a revisit time of six days for the Occitanie region located in the South of France as a function of precipitation data, in order to investigate the potential of S1-SSM maps for detecting heavy rainfalls. First, the correlation between S1-SSM maps and rainfall maps provided by the Global Precipitation Mission (GPM) was investigated. Then, we analyzed the effect of the S1-SSM temporal resolution on detecting heavy rainfall events and the impact of these events on S1-SSM values as a function of the number of days that separated the heavy rainfall and the S1 acquisition date (cumulative rainfall more than 60 mm in 24 hours or 80 mm in 48 hours). The results showed that the six-day temporal resolution of the S1-SSM map doesn't always permit the detection of an extreme rainfall event, because confusion will appear between high S1-SSM values due to extreme rainfall events occurring six days before the acquisition of S1-SSM, and high S1-SSM values due to light rain a few hours before the acquisition of Sentinel-1 images. Moreover, the monitoring of extreme rain events using only soil moisture maps remains difficult, since many environmental parameters could affect the value of SSM, and synthetic aperture radar (SAR) doesn't allow the estimation of very high soil moistures (higher than 35 vol.%).

3.
Methods Mol Biol ; 1829: 325-339, 2018.
Article in English | MEDLINE | ID: mdl-29987732

ABSTRACT

Plastid transformation is an attractive alternative to nuclear transformation enabling manipulation of native plastid genes and the insertion of foreign genes into plastids for applications in agriculture and industrial biotechnology. Transformation is achieved using dominant positive selection markers that confer resistance to antibiotics. The very high copy number of plastid DNA means that a prolonged selection step is required to obtain a uniform population of transgenic plastid genomes. Repair of mutant plastid genes with the corresponding functional allele allows selection based on restoration of the wild type phenotype. The use of deletion rather than point mutants avoids spontaneous reversion back to wild type. Combining antibiotic resistance markers with native plastid genes speeds up the attainment of homoplasmy and allows early transfer of transplastomic lines to soil where antibiotic selection is replaced by selection for photoautotrophic growth. Here we describe our method using the wild type rbcL gene as a plastid transformation marker to restore pigmentation and photosynthesis to a pale green heterotrophic rbcL mutant.


Subject(s)
Biolistics/methods , Mutation , Nicotiana/genetics , Plants/genetics , Plastids/genetics , Drug Resistance, Microbial/genetics , Genetic Markers , Photosynthesis/genetics , Pigmentation/genetics , Plant Leaves/genetics , Plants, Genetically Modified , Ribulose-Bisphosphate Carboxylase/genetics , Sequence Deletion , Nicotiana/drug effects , Nicotiana/growth & development
4.
Sensors (Basel) ; 17(11)2017 Nov 14.
Article in English | MEDLINE | ID: mdl-29135929

ABSTRACT

The main objective of this study is to analyze the potential use of Sentinel-1 (S1) radar data for the estimation of soil characteristics (roughness and water content) and cereal vegetation parameters (leaf area index (LAI), and vegetation height (H)) in agricultural areas. Simultaneously to several radar acquisitions made between 2015 and 2017, using S1 sensors over the Kairouan Plain (Tunisia, North Africa), ground measurements of soil roughness, soil water content, LAI and H were recorded. The NDVI (normalized difference vegetation index) index computed from Landsat optical images revealed a strong correlation with in situ measurements of LAI. The sensitivity of the S1 measurements to variations in soil moisture, which has been reported in several scientific publications, is confirmed in this study. This sensitivity decreases with increasing vegetation cover growth (NDVI), and is stronger in the VV (vertical) polarization than in the VH cross-polarization. The results also reveal a similar increase in the dynamic range of radar signals observed in the VV and VH polarizations as a function of soil roughness. The sensitivity of S1 measurements to vegetation parameters (LAI and H) in the VV polarization is also determined, showing that the radar signal strength decreases when the vegetation parameters increase. No vegetation parameter sensitivity is observed in the VH polarization, probably as a consequence of volume scattering effects.

5.
Health Informatics J ; 23(2): 146-156, 2017 06.
Article in English | MEDLINE | ID: mdl-26951569

ABSTRACT

Clinical practice guidelines are valuable sources of clinical knowledge for healthcare professionals. However, the passive dissemination of clinical practice guidelines like publishing in medical journals is ineffective in changing clinical practice behaviour. In this work, we proposed a framework to help adopting an active clinical practice guideline dissemination approach by automatically extracting clinical knowledge from clinical practice guidelines into a clinical decision support system-friendly format. The proposed framework is intended to help human modellers by automating some of the manual formalization activities in order to minimize their manual effort. We evaluated our framework using all recommendations from two clinical practice guidelines produced by the Scottish Intercollegiate Guidelines Network: the 'Management of lung cancer' clinical practice guideline and the 'Management of chronic pain' clinical practice guideline. We conclude that the proposed framework can be effectively used to formalize drug and procedure recommendation in clinical contexts.


Subject(s)
Automation/instrumentation , Decision Support Techniques , Guidelines as Topic , Software Design , Artificial Intelligence/trends , Automation/methods , Humans , Programming Languages
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