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1.
Sci Data ; 9(1): 402, 2022 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-35831313

RESUMO

Synthetic Aperture Radar (SAR) data handling, processing, and interpretation are barriers preventing a rapid uptake of SAR data by application specialists and non-expert domain users in the field of agricultural monitoring. To improve the accessibility of Sentinel-1 data, we have generated a reduced-volume, multi-year Sentinel-1 SAR database. It includes mean and standard deviation of VV, VH and VH/VV backscatter, pixel counts, geometry, crop type, local incidence angle and azimuth angle at parcel-level. The database uses around 3100 Sentinel-1 images (5 TB) to produce a 12 GB time series database for approximately 770,000 crop parcels over the Netherlands for a period of three years. The database can be queried by Sentinel-1 system parameters (e.g. relative orbit) or user application-specific parameters (e.g. crop type, spatial extent, time period) for parcel level assessment. The database can be used to accelerate the development of new tools, applications and methodologies for agricultural and water related applications, such as parcel-level crop bio-geophysical parameter estimation, inter-annual variability analysis, drought monitoring, grassland monitoring and agricultural management decision-support.

2.
Glob Chang Biol ; 27(23): 6005-6024, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34478589

RESUMO

Droughts in a warming climate have become more common and more extreme, making understanding forest responses to water stress increasingly pressing. Analysis of water stress in trees has long focused on water potential in xylem and leaves, which influences stomatal closure and water flow through the soil-plant-atmosphere continuum. At the same time, changes of vegetation water content (VWC) are linked to a range of tree responses, including fluxes of water and carbon, mortality, flammability, and more. Unlike water potential, which requires demanding in situ measurements, VWC can be retrieved from remote sensing measurements, particularly at microwave frequencies using radar and radiometry. Here, we highlight key frontiers through which VWC has the potential to significantly increase our understanding of forest responses to water stress. To validate remote sensing observations of VWC at landscape scale and to better relate them to data assimilation model parameters, we introduce an ecosystem-scale analog of the pressure-volume curve, the non-linear relationship between average leaf or branch water potential and water content commonly used in plant hydraulics. The sources of variability in these ecosystem-scale pressure-volume curves and their relationship to forest response to water stress are discussed. We further show to what extent diel, seasonal, and decadal dynamics of VWC reflect variations in different processes relating the tree response to water stress. VWC can also be used for inferring belowground conditions-which are difficult to impossible to observe directly. Lastly, we discuss how a dedicated geostationary spaceborne observational system for VWC, when combined with existing datasets, can capture diel and seasonal water dynamics to advance the science and applications of global forest vulnerability to future droughts.


Assuntos
Secas , Ecossistema , Florestas , Folhas de Planta , Árvores , Xilema
3.
Cytotherapy ; 23(9): 852-860, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33941482

RESUMO

BACKGROUND AIMS: Next-generation immune cell therapy products will require complex modifications using engineering technologies that can maintain high levels of cell functionality. Non-viral engineering methods have the potential to address limitations associated with viral vectors. However, while electroporation is the most widely used non-viral modality, concerns about its effects on cell functionality have led to the exploration of alternative approaches. Here the authors have examined the suitability of the Solupore non-viral delivery system for engineering primary human T cells for cell therapy applications. METHODS: The Solupore system was used to deliver messenger RNA (mRNA) and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) guide RNA ribonucleoprotein (RNP) cargos to T cells, and efficiency was measured by flow cytometry. Cell perturbation was assessed by immune gene expression profiling, including an electroporation comparator. In vitro and in vivo cytotoxicity of chimeric antigen receptor (CAR) T cells generated using the Solupore system was evaluated using a real-time cellular impedance assay and a Raji-luciferase mouse tumor model, respectively. RESULTS: Efficient transfection was demonstrated through delivery of mRNA and CRISPR CAS9 RNP cargos individually, simultaneously and sequentially using the Solupore system while consistently maintaining high levels of cell viability. Gene expression profiling revealed minimal alteration in immune gene expression, demonstrating the low level of perturbation experienced by the cells during this transfection process. By contrast, electroporation resulted in substantial changes in immune gene expression in T cells. CAR T cells generated using the Solupore system exhibited efficient cytotoxicity against target cancer cells in vitro and in vivo. CONCLUSIONS: The Solupore system is a non-viral means of simply, rapidly and efficiently delivering cargos to primary human immune cells with retention of high cell viability and functionality.


Assuntos
Vetores Genéticos , Linfócitos T , Animais , Terapia Baseada em Transplante de Células e Tecidos , Eletroporação , Humanos , Camundongos , Transfecção
4.
New Phytol ; 223(3): 1166-1172, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30919449

RESUMO

Although primarily valued for their suitability for oceanographic applications and soil moisture estimation, microwave remote sensing observations are also sensitive to plant water content (Mw ). Since Mw depends on both plant water status and biomass, these observations have the potential to be useful for a range of plant drought response studies. In this paper, we introduce the principles behind microwave remote sensing observations to illustrate how they are sensitive to plant water content and discuss the relationship between landscape-scale Mw and common stand-scale metrics, including plant-scale relative water content, live fuel moisture content and leaf water potential. Lastly, we discuss how various sensor types can be leveraged for specific applications depending on the spatio-temporal resolution needed.


Assuntos
Fenômenos Ecológicos e Ambientais , Micro-Ondas , Plantas/química , Tecnologia de Sensoriamento Remoto , Água/química , Modelos Biológicos
5.
J Immunol ; 201(7): 2070-2081, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30143585

RESUMO

IL-27 is a cytokine exerting pleiotropic immunomodulatory effects on a broad spectrum of immune cells. Optimal IL-27 production downstream of TLR3/4 ligand stimulation relies on autocrine type I IFN signaling, defining a first and second phase in IL-27 production. This work shows that IL-1 receptor-associated kinase 1 (IRAK1) limits TLR3/4- and IFNAR-induced IL-27 production. At the mechanistic level, we identified IRAK1 as a novel regulator of STAT1, IRF1, and IRF9. We found hyperactivation of STAT1 together with increased nuclear levels of IRF1 and IRF9 in IRAK1-deficient murine macrophages compared with control cells following stimulation with LPS and poly(I:C). IRAK1-deficient human microglial cells showed higher basal levels of STAT1 and STAT2 compared with control cells. Blocking the kinase activity of TBK1/IKKε in IRAK1 knockdown human microglial cells reduced the high basal levels of STAT1/2, uncovering a TBK1/IKKε kinase-dependent mechanism controlling basal levels of STAT1/2. Stimulating IRAK1 knockdown human microglial cells with IFN-ß led to increased IL-27p28 expression compared with control cells. In IRAK1-deficient murine macrophages, increased IL-27 levels were detected by ELISA following IFN-ß stimulation compared with control macrophages together with increased nuclear levels of p-STAT1, IRF1, and IRF9. Treatment of wild-type and IRAK1-deficient murine macrophages with fludarabine similarly reduced TLR3/4-induced IL-27 cytokine levels. To our knowledge, this work represents the first report placing IRAK1 in the IFNAR pathway and identifies IRAK1 as an important regulator of STAT1, controlling IL-27 production downstream of TLR3/4 and IFNAR signaling pathways.


Assuntos
Quinases Associadas a Receptores de Interleucina-1/metabolismo , Interleucina-27/metabolismo , Macrófagos/metabolismo , Microglia/metabolismo , Receptor de Interferon alfa e beta/metabolismo , Animais , Células HEK293 , Humanos , Fator Gênico 3 Estimulado por Interferon/metabolismo , Quinases Associadas a Receptores de Interleucina-1/genética , Camundongos , Fosforilação , Receptor de Interferon alfa e beta/genética , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais , Receptor 3 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo
6.
Sensors (Basel) ; 17(9)2017 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-28902141

RESUMO

Several recent studies have highlighted the potential of Actively Heated Fiber Optics (AHFO) for high resolution soil moisture mapping. In AHFO, the soil moisture can be calculated from the cumulative temperature ( T cum ), the maximum temperature ( T max ), or the soil thermal conductivity determined from the cooling phase after heating ( λ ). This study investigates the performance of the T cum , T max and λ methods for different heating strategies, i.e., differences in the duration and input power of the applied heat pulse. The aim is to compare the three approaches and to determine which is best suited to field applications where the power supply is limited. Results show that increasing the input power of the heat pulses makes it easier to differentiate between dry and wet soil conditions, which leads to an improved accuracy. Results suggest that if the power supply is limited, the heating strength is insufficient for the λ method to yield accurate estimates. Generally, the T cum and T max methods have similar accuracy. If the input power is limited, increasing the heat pulse duration can improve the accuracy of the AHFO method for both of these techniques. In particular, extending the heating duration can significantly increase the sensitivity of T cum to soil moisture. Hence, the T cum method is recommended when the input power is limited. Finally, results also show that up to 50% of the cable temperature change during the heat pulse can be attributed to soil background temperature, i.e., soil temperature changed by the net solar radiation. A method is proposed to correct this background temperature change. Without correction, soil moisture information can be completely masked by the background temperature error.

7.
Sensors (Basel) ; 17(5)2017 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-28492477

RESUMO

Trees play a crucial role in the water, carbon and nitrogen cycle on local, regional and global scales. Understanding the exchange of momentum, heat, water, and CO 2 between trees and the atmosphere is important to assess the impact of drought, deforestation and climate change. Unfortunately, ground measurements of tree properties such as mass and canopy interception of precipitation are often expensive or difficult due to challenging environments. This paper aims to demonstrate the concept of using robust and affordable accelerometers to measure tree properties and responses. Tree sway is dependent on mass, canopy structure, drag coefficient, and wind forcing. By measuring tree acceleration, we can relate the tree motion to external forcing (e.g., wind, precipitation and related canopy interception) and tree physical properties (e.g., mass, elasticity). Using five months of acceleration data of 19 trees in the Brazilian Amazon, we show that the frequency spectrum of tree sway is related to mass, canopy interception of precipitation, and canopy-atmosphere turbulent exchange.


Assuntos
Árvores , Acelerometria , Brasil , Mudança Climática , Folhas de Planta
8.
J Immunol ; 190(6): 2844-56, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23396947

RESUMO

IRAK1 is involved in the regulation of type I IFN production downstream of TLR3. Previous work indicated that IRAK1 negatively regulates TRIF-mediated activation of IRF3 and IRF7. We report that IRAK1 limits the activation of the TLR3-NF-κB pathway. Following TLR3 stimulation, IRAK1-deficient macrophages produced increased levels of IL-6 and IFN-ß compared with wild type macrophages. Pharmacological inhibition of TAK1 reduced this increase in IFN-ß, together with the heightened activation of IRF3 and p65 found in TLR3-ligand stimulated IRAK1-deficient macrophages. Recently, IKKε and TANK-binding kinase 1 (TBK1) were reported to limit activation of the NF-κB pathway downstream of IL-1R, TNFR1, and TLRs. We show that TBK1 has a positive role in the TLR3-NF-κB pathway, because we detected reduced levels of IL-6 and reduced activation of p65 in TBK1-deficient macrophages. In contrast, we show that IKKε limits the activation of the TLR3-NF-κB pathway. Furthermore, we show that IRAK1 is required for the activation of IKKε downstream of TLR3. We report impaired activation of ERK1/2 in IRAK1- and IKKε-deficient macrophages, a novel finding for both kinases. Importantly, this work provides novel mechanistic insight into the regulation of the TLR3-signaling pathway, providing strong evidence that an IRAK1-IKKε-signaling axis acts to limit the production of both type I IFNs and proinflammatory cytokines by regulating TAK1 activity.


Assuntos
Proteínas de Transporte/metabolismo , Regulação para Baixo/imunologia , Quinase I-kappa B/fisiologia , Quinases Associadas a Receptores de Interleucina-1/fisiologia , MAP Quinase Quinase Quinases/metabolismo , Sistema de Sinalização das MAP Quinases/imunologia , Receptor 3 Toll-Like/metabolismo , Animais , Proteínas de Transporte/antagonistas & inibidores , Linhagem Celular , Regulação para Baixo/genética , Células HEK293 , Humanos , Quinase I-kappa B/genética , Inflamação/enzimologia , Inflamação/genética , Inflamação/imunologia , Quinases Associadas a Receptores de Interleucina-1/genética , Peptídeos e Proteínas de Sinalização Intracelular , MAP Quinase Quinase Quinases/antagonistas & inibidores , MAP Quinase Quinase Quinases/genética , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Microglia/enzimologia , Microglia/imunologia , Microglia/patologia , Mapeamento de Interação de Proteínas , Receptor 3 Toll-Like/genética , Fatores de Elongação da Transcrição
9.
Sensors (Basel) ; 12(5): 5471-85, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22778596

RESUMO

Over the past five years, Distributed Temperature Sensing (DTS) along fiber optic cables using Raman backscattering has become an important tool in the environmental sciences. Many environmental applications of DTS demand very accurate temperature measurements, with typical RMSE < 0.1 K. The aim of this paper is to describe and clarify the advantages and disadvantages of double-ended calibration to achieve such accuracy under field conditions. By measuring backscatter from both ends of the fiber optic cable, one can redress the effects of differential attenuation, as caused by bends, splices, and connectors. The methodological principles behind the double-ended calibration are presented, together with a set of practical considerations for field deployment. The results from a field experiment are presented, which show that with double-ended calibration good accuracies can be attained in the field.

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