Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Data Brief ; 52: 109850, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38146302

RESUMO

In this paper, three datasets are described. The first dataset is a complete set of GNSS-R (GNSS-R: Global Navigation Satellite System - Reflectometry) airborne data. This dataset has been generated with the data acquired with the GLObal Navigation Satellite System Reflectometry Instrument (GLORI) developed at Centre d'Etudes Spatiales de la Biosphère (CESBIO), during the Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment (LIAISE) campaign in north-eastern Spain during the summer of 2021. It is the first time to our knowledge that a complete dataset of GNSS-R observables (reflectivity, incoherent component relative to the total scattering signal to noise ratio (SNR) for copolarized (right-right) and cross-polarized (right-left) measurements has been made available. The two other datasets are ground truth sets of measurements which have been acquired simultaneously with the flights. The in-situ measurements dataset consists in soil measurements (surface soil moisture, surface roughness, Leaf Area Index (LAI)) over 24 reference fields). The land use dataset provides a land use map (along with 385 ground truth plots) over the studied site for GLORI data evaluation. The combined datasets are particularly relevant for soil moisture and vegetation retrievals from GNSS-R observables, as well as studies for calibration and validation of bistatic empirical or physical models simulating coherent or incoherent components on agriculture sites, in the context of the preparation of future GNSS-R space missions, such as HydroGNSS, a European Space Agency mission, launch foreseen in 2024. The entire database is archived in the AERIS LIAISE database. One DOI is available for each of the 3 datasets (airborne GLORI dataset, in situ measurements dataset and land use dataset).

2.
Virus Evol ; 9(2): vead054, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37719779

RESUMO

Our knowledge of the diversity of eukaryotic viruses has recently undergone a massive expansion. This diversity could influence host physiology through yet unknown phenomena of potential interest to the fields of health and food production. However, the assembly processes of this diversity remain elusive in the eukaryotic viromes of terrestrial animals. This situation hinders hypothesis-driven tests of virome influence on host physiology. Here, we compare taxonomic diversity between different spatial scales in the eukaryotic virome of the mosquito Culex pipiens. This mosquito is a vector of human pathogens worldwide. The experimental design involved sampling in five countries in Africa and Europe around the Mediterranean Sea and large mosquito numbers to ensure a thorough exploration of virus diversity. A group of viruses was found in all countries. This core group represented a relatively large and diverse fraction of the virome. However, certain core viruses were not shared by all host individuals in a given country, and their infection rates fluctuated between countries and years. Moreover, the distribution of coinfections in individual mosquitoes suggested random co-occurrence of those core viruses. Our results also suggested differences in viromes depending on geography, with viromes tending to cluster depending on the continent. Thus, our results unveil that the overlap in taxonomic diversity can decrease with spatial scale in the eukaryotic virome of C. pipiens. Furthermore, our results show that integrating contrasted spatial scales allows us to identify assembly patterns in the mosquito virome. Such patterns can guide future studies of virome influence on mosquito physiology.

3.
Bioengineering (Basel) ; 10(6)2023 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-37370587

RESUMO

Microencapsulation of extra virgin olive oil has been taken into consideration. Initially, emulsions were prepared using extra virgin olive oil and aqueous solutions of different proportions of maltodextrin (MD) having dextrose equivalent (DE) 19 and whey protein isolates (WPI), such as 100% MD, 100% WPI, 25% MD + 75% WPI, 50% MD + 50% WPI and 75% MD + 25% WPI. Subsequently, emulsions were used for dehydration by either spray-drying (SD) or freeze-drying (FD) to produce olive oil microcapsules. Emulsion stability, viscosity and droplet size influenced the characteristics of the microcapsules. The highest encapsulation efficiency was achieved using 50% MD + 50% WPI in the emulsions with subsequent SD. The moisture content of the microcapsules increased with increasing proportions of MD. The size of the microcapsules increased with increasing proportions of WPI. The bulk density and tapped density were reduced with higher proportions of MD in the microcapsules. Furthermore, microcapsules with a higher proportion of MD exhibited poor flowability and high cohesiveness. Microcapsules from the higher proportion MD emulsions, followed by SD were spherical with a smooth surface; however, microcapsules with dent structures were produced from 100% WPI in the emulsions with subsequent SD. Microcapsules, produced from emulsions with a higher proportion of WPI, followed by FD were flat flakes and had irregular surfaces.

4.
Sensors (Basel) ; 22(2)2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-35062540

RESUMO

The objective of this paper was to estimate soil moisture in pepper crops with drip irrigation in a semi-arid area in the center of Tunisia using synthetic aperture radar (SAR) data. Within this context, the sensitivity of L-band (ALOS-2) in horizontal-horizontal (HH) and horizontal-vertical (HV) polarizations and C-band (Sentinel-1) data in vertical-vertical (VV) and vertical-horizontal (VH) polarizations is examined as a function of soil moisture and vegetation properties using statistical correlations. SAR signals scattered by pepper-covered fields are simulated with a modified version of the water cloud model using L-HH and C-VV data. In spatially heterogeneous soil moisture cases, the total backscattering is the sum of the bare soil contribution weighted by the proportion of bare soil (one-cover fraction) and the vegetation fraction cover contribution. The vegetation fraction contribution is calculated as the volume scattering contribution of the vegetation and underlying soil components attenuated by the vegetation cover. The underlying soil is divided into irrigated and non-irrigated parts owing to the presence of drip irrigation, thus generating different levels of moisture underneath vegetation. Based on signal sensitivity results, the potential of L-HH data to retrieve soil moisture is demonstrated. L-HV data exhibit a higher potential to retrieve vegetation properties regarding a lower potential for soil moisture estimation. After calibration and validation of the proposed model, various simulations are performed to assess the model behavior patterns under different conditions of soil moisture and pepper biophysical properties. The results highlight the potential of the proposed model to simulate a radar signal over heterogeneous soil moisture fields using L-HH and C-VV data.


Assuntos
Radar , Solo , Monitoramento Ambiental , Água
5.
Artigo em Inglês | MEDLINE | ID: mdl-19162648

RESUMO

A new approach for ECG data compression is proposed in this paper. Using a nonlinear least squares optimization procedure, the approach employs an algorithm based on template model fitting. Only 12 parameters are required to fully represent the ECG signal without diagnostic information loss. The effectiveness of our ECG compression technique is described in terms of high compression ratios, relatively low distortion values of less than 9%, and a low computational cost, thus demonstrating the beneficial use of our technique for ECG data storage and online transmission. Comparisons with other recent compression methods in the literature have shown that our method performs better.


Assuntos
Algoritmos , Compressão de Dados/métodos , Diagnóstico por Computador/métodos , Eletrocardiografia/métodos , Processamento de Sinais Assistido por Computador , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...