The objective of this study is to evaluate the relationship between the response (
σ°) of airborne P-band Synthetic Aperture Radar (SAR) polarimetric data versus biomass values of primary forest and ...secondary succession. To ensure that different landscapes of “Terra firme” tropical forest of the Brazilian Amazon were represented, a test-site was selected in the lower Tapajós river region (Pará State). The microwave signals from the P-band polarimetric images were related to the aboveground biomass data by statistical regression models (logarithmic and polynomial functions). In the field survey, physiognomic and structural aspects of primary forest and regrowth were collected and afterwards the biomass was estimated using allometric equations based on dendrometric parameters. As an example of the potential use of P-band polarimetric images, they were classified by a contextual classifier (ICM), whose thematic stratification of land use/land cover was associated with biomass class intervals for mapping purposes. The main objective of this P-band experiment is to improve this tool for regional mapping of Amazon landscape changes, due to the growing rate of land use occupation.
We present nighttime worldwide distributions of key features of Blue LUminous Events (BLUEs) detected by the Modular Multispectral Imaging Array of the Atmosphere‐Space Interaction Monitor. Around ...10% of all detected BLUEs exhibit an impulsive single pulse shape. The rest of BLUEs are unclear (impulsive or not) single, multiple or with ambiguous pulse shapes. BLUEs exhibit two distinct populations with peak power density <25 µWm−2 (common) and ≥25 µWm−2 (rare) with different rise times and durations. The altitude (and depth below cloud tops) zonal distribution of impulsive single pulse BLUEs indicate that they are commonly present between cloud tops and a depth of ≤4 km in the tropics and ≤1 km in mid and higher latitudes. Impulsive single pulse BLUEs in the tropics are the longest (up to ∼4 km height) and have the largest number of streamers (up to ∼3 × 109). Additionally, the analysis of BLUEs has turned out to be particularly complex due to the abundance of radiation belt particles (at high latitudes and in the South Atlantic Anomaly SAA) and cosmic rays all over the planet. True BLUEs can not be fully distinguished from radiation belt particles and cosmic rays unless other ground‐based measurements associated with the optically detected BLUEs are available. Thus, the search algorithm of BLUEs presented in Soler et al. (2021), https://doi.org/10.1029/2021gl094657 is now completed with a new additional step that, if used, can considerably smooth the SAA shadow but can also underestimate the number of BLUEs worldwide.
Plain Language Summary
The presence of corona electrical discharges in thunderclouds has been suspected for a long time. These thunderstorm coronas can be observed as Blue LUminous Events (BLUEs) formed by a large number of streamers characterized by their distinct 337 nm light flashes with absent (or negligible) 777.4 nm component (typical of lightning leaders). The Modular Multispectral Imaging Array of the Atmosphere‐Space Interaction Monitor has successfully allowed us to map and characterize BLUEs. The results presented here include a global analysis of key properties of BLUEs such as their characteristic rise times and duration, their depth with respect to cloud tops, vertical length and number of streamers. This study also includes two different global annual average climatologies of BLUEs depending on considerations about the rise time and total duration of BLUEs worldwide.
Key Points
BLUEs are found between ∼1 and ∼4 km below cloud tops in the tropics and ≤1 km in mid and higher latitudes
Two distinct populations of BLUEs with peak power density <25 μWm−2 (common) and ≥25 μWm−2 (rare) are observed
Fast rise time (<0.05 ms) BLUEs occur very superficially (<1 km) near cloud tops with high power density ≥100 μWm−2
The disease caused by Tomato leaf curl New Delhi virus (ToLCNDV), which is naturally transmitted by the whitefly Bemisia tabaci, causes important economic losses in cucurbit crops. The availability ...of simple and efficient inoculation protocols and detection methods is necessary for screening varieties and germplasm collections as well as for breeding populations. We evaluated the infectivity of ToLCNDV inocula prepared using three different buffers for mechanical sap inoculation in a susceptible variety of zucchini. We found that inoculum prepared with buffer III, which contains polyvinylpyrrolidone, is highly efficient for mechanical inoculation, with 100% of plants displaying severe symptoms 21 days post‐inoculation. Using this buffer, we mechanically inoculated 19 commercial varieties of cucurbit crops (six of cucumber, six of melon and seven of zucchini), evaluated the evolution of symptoms and diagnosed infection using nine different ToLCNDV detection methods (four based on serology, four based on molecular hybridization and one based on PCR detection). The results revealed that all varieties are susceptible, although cucumber varieties display less severe symptoms than those of melon or zucchini. All detection methods were highly efficient (more than 85% of plants testing positive) in melon and zucchini, but in cucumber, the percentage of positive plants detected with serology and molecular hybridization methods ranged from 20.4% with Squash leaf curl virus (SLCV) antiserum, to 78.5% with DNA extract hybridization. Overall, the best detection results were obtained with PCR, with 92.6%, 92.4% and 98.4% cucumber, melon and zucchini plants, respectively, testing positive. When considering the overall results in the three crops, the best serology and molecular hybridization methods were those using Watermelon chlorotic stunt virus (WmCSV) antiserum and DNA extract, respectively. The inoculation methodology developed and the information on detection methods are of great relevance for the selection and breeding of varieties of cucurbit crops that are tolerant or resistant to ToLCNDV.
Agricultural census data and fieldwork observations are used to analyze changes in land cover/use intensity across Rondônia and Mato Grosso states along the agricultural frontier in the Brazilian ...Amazon. Results show that the development of land use is strongly related to land distribution structure. While large farms have increased their share of annual and perennial crops, small and medium size farms have strongly contributed to the development of beef and milk market chains in both Rondônia and Mato Grosso. Land use intensification has occurred in the form of increased use of machinery, labor in agriculture and stocking rates of cattle herds. Regional and national demands have improved infrastructure and productivity. The data presented show that the distinct pathways of land use development are related to accessibility to markets and processing industry as well as to the agricultural colonization history of the region. The data analyzed do not provide any indication of frontier stagnation, i.e., the slowdown of agricultural expansion, in the Brazilian Amazon. Instead of frontier stagnation, the data analyzed indicate that intensification processes in consolidated areas as well as recent agricultural expansion into forest areas are able to explain the cycle of expansion and retraction of the agricultural frontier into the Amazon region. The evolution of land use is useful for scenario analysis of both land cover change and land use intensification and provides insights into the role of market development and policies on land use.
Spondylitis is the most common osseous manifestation of Mycobacterium tuberculosis infection. Although treatable, it continues to cause significant mortality and morbidity. Early diagnosis through ...familiarity with its imaging characteristics is essential to permit rapid treatment and prevent potential life-limiting consequences. In this review, we demonstrate the key magnetic resonance imaging features of this disease.
Dietary guidelines urge Brazilians to increase their consumption of raw vegetables. Yet key issues must be tackled by the government and civil society, not only to foster consumers’ appetite for ...healthier food, but more importantly to diminish the gaps between local demand and production, determined by food and land accessibility. We examine whether vegetable production in Brazil meets the demand to provide Brazilians the daily amount of fresh food recommended by the World Health Organization (WHO). We developed demand scenarios in Brazil for 2008 and 2030, based on demand density maps built at the district level using production census surveys, household acquisition data, and population growth estimates. Results reveal an inherent inequality in vegetable consumption between the southern and central northern regions of Brazil that follows food insecurity regional indicators. Even in more urbanized regions and metropolitan areas, where the best balance between vegetable production and acquisition is found, simulated demand is far from WHO recommendations. A complementary discussion regarding land distribution and fresh food production supports our outlook on the weaknesses of existing rural policies for land reform and sustainable local fresh food production that directly affect demand and nutritional security. This work was the foundation to the Delivering Food Security on Limited Land (DEVIL) project in Brazil supported by Belmont Forum consortium.
► Development of real time RT-PCR for
Tomato spotted wilt virus (TSWV). ► Estimation of the number of RNA copies of TSWV genomic segment M. ► Quantitation of TSWV in different host plants and the ...thrips vector. ► Quantitation of different TSWV genotypes in mixed infections.
A quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR) procedure using a general primer set and three TaqMan
®MGB probes was developed for general and genotype-specific detection and quantitation of the genomic M segment of
Tomato spotted wilt virus (TSWV). Standard curves using RNA transcripts homologous to the three probes allowed reproducible quantitative assays with a wide dynamic range (10
3–10
10 TSWV M segment RNA copies/ng of total RNA) and high sensitivity. This protocol was assayed with a battery of TSWV isolates, covering the range of the present known genetic variation, in single and/or mix infections in three plant hosts, as well as in the thrips vector
Frankliniella occidentalis. This quantitative detection assay will be a valuable tool for molecular biology and epidemiology studies, diagnosis and disease control.
Resistance to
Tomato yellow leaf curl virus
(TYLCV) and
Tomato spotted wilt virus
(TSWV), among other diseases, has been reported in
Solanum peruvianum
PI 126944. Introgression lines (ILs) from
S. ...peruvianum
PI 126944 into the genetic background of cultivated tomato (
S. lycopersicum
) are being developed. Several generations were derived from three interspecific hybrids previously obtained. A lot of crosses and embryo rescue were required until the third backcross, due to the high degree of incompatibility existing between tomato and PI 126944. Crosses between F
1
plants were made to obtain a pseudo-F
2
generation. The same procedure was followed up to the pseudo-F
6
generation. Additional crosses between plants of different generations were made in order to increase progeny. Of 263 molecular markers tested, 105 were polymorphic between tomato and PI 126944. This set of polymorphic markers consisted of 90 simple sequence repeats (SSR) and 15 cleaved amplified polymorphic sequences (CAPS). The amount of the
S. peruvianum
genome was reduced in advancing generations and this was coupled in some cases with a reduction of incompatibility. However, the
S
.
peruvianum
genome was almost completely represented among the different plants of the most advanced generations. ILs will be basically developed from them. Some of the generations developed were resistant to TYLCV and TSWV.
Tomato spotted wilt virus (TSWV) causes serious diseases of many economically important crops. Disease control has been achieved by breeding tomato and pepper cultivars with the resistance genes Sw‐5 ...and Tsw, respectively. However, TSWV isolates overcoming these genetic resistances have appeared in several countries. To evaluate the risk of spread of these resistance‐breaking isolates, we tested their ability of transmission by the main vector of TSWV, the thrips Frankliniella occidentalis. We compared the transmission rate by thrips of six TSWV isolates of different biotype (able or unable to overcome this resistance in pepper and tomato), and with divergent genotype (A and B). Our results indicate that the transmission rate was related to the amount of virus accumulated in thrips but not to virus accumulation in the source plants on which thrips acquired the virus. No correlation was found between transmission efficiency by thrips and the genotype or between transmission efficiency and the ability of overcoming both resistances. This result suggests that resistance‐breaking isolates have the same potential to be transmitted as the isolates unable to infect resistant tomato and pepper cultivars.
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