SUMMARY Introduction High-flow nasal cannula therapy (HFNC) has been shown to be more effective than continuous positive airway pressure (CPAP) in reducing intubations and ventilator days. HFNC likely provides mechanisms to support respiratory efficiency beyond application of distending pressure. We reason that HFNC washout of nasopharyngeal dead space impacts CO2 removal along with oxygenation. The aim of this study was to demonstrate the flow dependence of CO2 reduction and improved oxygenation during HFNC and the dependence on leak around the nasal prongs. Materials and Methods Neonatal piglets (n=13; 2-6kg) were injured with IV oleic acid and supported with HFNC at 2 through 8 L/minute. High and low leak around the nasal prongs was accomplished by using single and double prong cannulae, respectively. Measurement of hemodynamic, respiratory and blood gas parameters were made at each setting following 10 minutes for physiologic equilibration. Tracheal pressures were recorded by transmural catheters. Results With HFNC, CO2 trended downward in a flow dependent manner independent of leak. Oxygenation and tracheal pressures increased in a flow dependent manner with the greatest effect during double prong. At 8L/minute, tracheal pressures did not exceed 6±1 cmH2O. Conclusions HFNC improves gas exchange in a flow dependent manner; double prong had greater impact on O2; single prong had greater impact on CO2 elimination.

High-Throughput Biomass Estimation in Rice Crops Using UAV Multispectral Imagery The International Center for Tropical Agriculture (CIAT) believes that open access contributes to its mission of reducing hunger and poverty, and improving human nutrition in the tropics through research aimed at increasing the eco-efficiency of agriculture. CIAT is committed to creating and sharing knowledge and information openly and globally. We do this through collaborative research as well as through the open sharing of our data, tools, and publications.

Fusarium oxysporum f. sp. cubense Tropical Race 4 (Foc TR4), the causal agent of Fusarium wilt of banana (FWB), is currently the major threat to the banana industry worldwide (Dita et al. 2018). Restricted to South Asia for more than 20 years, Foc TR4 has spread in the last years to the Middle East, Mozambique, and Colombia (García-Bastidas et al. 2019; https://pestdisplace.org/embed/news/map/disease/11). The incursion of Foc TR4 in Colombia increased awareness and prevention efforts across Latin American and the Caribbean (LAC). However, new Foc TR4 outbreaks in LAC countries were considered a matter of time. In April 2021, banana (Musa spp., Cavendish, AAA) plants (30% of incidence) showing typical symptoms of FWB, such as leave yellowing, wilting and vascular discoloration were observed in one farm (about 1 ha) located in Querecotillo, Peru (4°43’54.84”S 80°33’45.00”W). Mycological analyses of samples (pseudostem strands) collected from 10 symptomatic plants were performed as described by Dita et al. (2010). These analyses revealed a continuous presence of fungal colonies identified as Fusarium oxysporum species complex. Molecular diagnostics targeting two different genome regions (Dita et al 2010; Li et al. 2013) identified nine of these isolates as Foc TR4. These results were further confirmed by qPCR analyses using the commercial Clear Detections TR4 kit. The genome of four single-spore isolates (PerS1, PerS2, PerS3 and PerS4) was sequenced using the Illumina platform (MiSeq Kit, 2x151 bp Paired-End). The strain PerS4 was also sequenced using Oxford Nanopore (FLOW-MIN111; R10.3 chemistry) as described by Lopez-Alvarez et al., (2020). The generated draft assembly yielded 533 contigs for a size of 47 Mbp (BioProject: PRJNA755905), which is comparable with sizes of previously reported Foc TR4 strains (Asai et al. 2019; García-Bastidas et al. 2019; Maymon et al. 2020; Warmington et al. 2019; Zheng et al. 2018). The sequence assembly showed high contiguity (94.9%) and high similarity (95.48%) with the high-quality genome sequence of the Foc TR4 isolate ‘UK0001’ (Warmington et al. 2019). Further analyses to identify the presence/absence of full sequences for the putative effector genes (Secreted In Xylem - SIX) and their allelic copies, also revealed that the SIX genes profile of the strains isolated from Querecotillo matched with previously reported Foc TR4 isolates (Czislowski et al. 2017). Pathogenicity tests with three isolates and water controls were performed as described by Dita et al. (2010), using five Cavendish plantlets per treatment. Four weeks after the inoculation typical external and internal symptoms of FWB were observed only in the inoculated plants. Fungal isolates recovered from inoculated plants tested positive for Foc TR4 when analyzed with PCR diagnostics as mentioned above. No fungal isolates were recovered from water-control plants which did not show any symptoms. Altogether, our results confirm the first incursion of Foc TR4 in Peru. Currently, Foc TR4 has the phytosanitary status of a present pest with restricted distribution in Peru and it is under official control of the National Plant Protection Organization – SENASA. Reinforced prevention and quarantine measures, disease monitoring and capacity building to detect, contain and manage eventual new outbreaks of Foc TR4 are strongly encouraged across LAC banana producing countries, especially for those bordering Peru with larger banana plantations, such as Ecuador and Brazil.

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