Performance of Deterministic and Probabilistic Hydrological Forecasts for the Short-Term Optimization of a Tropical Hydropower Reservoir

Hydropower is the most important source of electricity in Brazil. It is subject to the natural variability of water yield. One building block of the proper management of hydropower assets is the short-term forecast of reservoir inflows as input for an online, event-based optimization of its release strategy. While deterministic forecasts and optimization schemes are the established techniques for short-term reservoir management, the use of probabilistic ensemble forecasts and multi-stage stochastic optimization techniques is receiving growing attention. The present work introduces a novel, mass conservative scenario tree reduction in combination with a detailed hindcasting and closed-loop control experiments for a multi-purpose hydropower reservoir in a tropical region in Brazil. The case study is the hydropower project Três Marias, which is operated with two main objectives: (i) hydroelectricity generation and (ii) flood control downstream. In the experiments, precipitation forecasts based on observed data, deterministic and probabilistic forecasts are used to generate streamflow forecasts in a hydrological model over a period of 2 years. Results for a perfect forecast show the potential benefit of the online optimization and indicate a desired forecast lead time of 30 days. In comparison, the use of actual forecasts of up to 15 days shows the practical benefit of operational forecasts, where stochastic optimization (15 days lead time) outperforms the deterministic version (10 days lead time) significantly. The range of the energy production rate between the different approaches is relatively small, between 78% and 80%, suggesting that the use of stochastic optimization combined with ensemble forecasts leads to a significantly higher level of flood protection without compromising the energy production

Long-term monitoring for the surveillance of the conservation status of Tursiops truncatus in an EU Natura2000 site in the Mediterranean Sea. A pilot study in the Tuscan Archipelago

A pilot study, using the dataset from the research network ‘FLT Med Net’, which regularly monitors transborder regions in the Mediterranean Sea using ferries as platform for systematic surveys, was undertaken to assess common bottlenose dolphin range and population trends within the Natura 2000 EU marine site “Tutela del Tursiops truncatus”. The site was recently designated by the Tuscany Region (Italy) within the requirement of the EU Habitats Directive. In order to evaluate the conservation status of bottlenose dolphin according to the surveillance scheme of the Directive, two six-year periods (2007-2012; 2013-2018) were compared to assess trends in distribution-occurrence (range); Sightings Per Unit of Effort and Density (population). In total, 18146 NM were surveyed along two fixed transects, recording 90 sightings of Tursiops truncatus and a total of 268 specimens. Between the two periods, slight but not statistically significant differences were assessed, with decreasing trend in range and population  of the species; no variation was detected in mean group sizes. Travelling was the most common behaviour, and juveniles were present in 20% of the sightings, concentrated during spring and summer. The consistent FLT Med Net dataset was found to be appropriate to evaluate important parameters for the assessment of trends in the conservation status of Tursiops truncatus at the Natura2000 site scale.

3D vs. 2D MRI radiomics in skeletal Ewing sarcoma: Feature reproducibility and preliminary machine learning analysis on neoadjuvant chemotherapy response prediction

ObjectiveThe extent of response to neoadjuvant chemotherapy predicts survival in Ewing sarcoma. This study focuses on MRI radiomics of skeletal Ewing sarcoma and aims to investigate feature reproducibility and machine learning prediction of response to neoadjuvant chemotherapy. Materials and methodsThis retrospective study included thirty patients with biopsy-proven skeletal Ewing sarcoma, who were treated with neoadjuvant chemotherapy before surgery at two tertiary sarcoma centres. 7 patients were poor responders and 23 were good responders based on pathological assessment of the surgical specimen. On pre-treatment T1-weighted and T2-weighted MRI, 2D and 3D tumour segmentations were manually performed. Features were extracted from original and wavelet-transformed images. Feature reproducibility was assessed through small geometrical transformations of the regions of interest mimicking multiple manual delineations, and intraclass correlation coefficient >0.75 defined feature reproducibility. Feature selection also consisted of collinearity and significance analysis. After class balancing in the training cohort, three machine learning classifiers were trained and tested on unseen data using hold-out cross-validation. Results1303 (77%) 3D and 620 (65%) 2D radiomic features were reproducible. 4 3D and 4 2D features passed feature selection. Logistic regression built upon 3D features achieved the best performance with 85% accuracy (AUC=0.9) in predicting response to neoadjuvant chemotherapy. ConclusionCompared to 2D approach, 3D MRI radiomics of Ewing sarcoma had superior reproducibility and higher accuracy in predicting response to neoadjuvant chemotherapy, particularly when using logistic regression classifier

Estimation of the light field inside photosynthetic microorganism cultures through Mittag-Leffler functions at depleted light conditions

[EN] Light attenuation within suspensions of photosynthetic microorganisms has been widely described by the Lambert-Beer equation. However, at depths where most of the light has been absorbed by the cells, light decay deviates from the exponential behaviour and shows a lower attenuation than the corresponding from the purely exponential fall. This discrepancy can be modelled through the Mittag-Leffler function, extending Lambert-Beer law via a tuning parameter ¿ that takes into account the attenuation process. In this work, we describe a fractional Lambert-Beer law to estimate light attenuation within cultures of model organism Synechocystis sp. PCC 6803. Indeed, we benchmark the measured light field inside cultures of two different Synechocystis strains, namely the wild-type and the antenna mutant strain called Olive at five different cell densities, with our in silico results. The Mittag-Leffler hyper-parameter ¿ that best fits the data is 0.995, close to the exponential case. One of the most striking results to emerge from this work is that unlike prior literature on the subject, this one provides experimental evidence on the validity of fractional calculus for determining the light field. We show that by applying the fractional Lambert-Beer law for describing light attenuation, we are able to properly model light decay in photosynthetic microorganisms suspensions.This project has received funding from the European Unions Seventh Programme for Research, technological development and demonstration under grant agreement No 308518 CyanoFactory. David Fuente is supported by grant Contratos Predoctorales FPI 2013 of the Universitat Politecnica de Valencia. Carlos Lizama is supported by Programa de Apoyo a la Investigation y Desarrollo (PAID-02-15) de la Universitat Politecnica de Valencia and CONICYT - PIA - Anillo ACT1416Fuente, D.; Lizama, C.; Urchueguía Schölzel, JF.; Conejero, JA. (2018). Estimation of the light field inside photosynthetic microorganism cultures through Mittag-Leffler functions at depleted light conditions. Journal of Quantitative Spectroscopy and Radiative Transfer. 204:23-26. https://doi.org/10.1016/j.jqsrt.2017.08.012S232620

Determinação do estádio de dessecação em soja de hábito de crescimento indeterminado no Mato Grosso

For cultivars with indeterminate habit, there are no reports of the most appropriate period to conducted burndown in pre-harvest. The study aimed to evaluate the influence of burndown on three different times over physiological and sanitary quality of seeds and agronomic characteristics of SYN-9074 RR cultivar with indeterminate habit, in three areas simultaneously. It was used a randomized complete block design with four replications, and joint analysis were conducted for the three distinct areas. Treatments refer to the application period of diquat (0.3 kg ha-1), or better, in soybean plants at maturation stages R6.5 (fully formed seeds, pods 50% yellow and 50% green), R7 (pods 70% yellow, with a fully mature pod on the main stem) and R7.5 (90% yellow pods) and a check without herbicide. Germination test, dry mass of dossel and little root part, shoot length and little root, sanitary condition and mass of 1000 seeds and yield were evaluated. The period more adequate to accomplish burndown in pre harvest of SYN-9074 RR cultivar with indeterminate habit was with plants showing 90% of yellow pods, or maturation period R7.5, that provided higher yield and lower incidence índex of Phoma sp., Colletotrichum dematium var. truncata and Fusarium sp. fungi.Para as cultivares de hábito indeterminado, não há relatos do momento mais adequado para realizar a aplicação da dessecação em pré-colheita. O trabalho teve como objetivo avaliar a influência da dessecação realizada em três épocas sobre a qualidade fisiológica e sanitária das sementes e características agronômicas da cultivar de hábito indeterminado SYN-9074 RR, cultivada em três áreas simultaneamente. O delineamento experimental utilizado foi o de blocos casualizados, com quatro tratamentos e quatro repetições, sendo realizada análise conjunta para três áreas distintas. Os tratamentos referem-se a diferentes épocas de aplicação de diquat (0,3 kg ha-1), ou seja, em plantas de soja nos estádios de maturação R6.5 (sementes totalmente formadas, vagens 50% amareladas e 50% verdes), R7 (vagens 70% amareladas, com uma vagem totalmente madura na haste principal), R7.5 (vagens 90% amareladas) e testemunha sem aplicação. Realizaram-se testes de germinação, massa seca da parte aérea e radícula, comprimento da parte aérea e radícula, sanidade e massa de 1000 sementes e produtividade de grãos. O estádio mais adequado para realizar a dessecação em pré-colheita da cultivar de soja de hábito indeterminado SYN-9074 RR foi com plantas apresentando 90% de amarelecimento das vagens, ou estádio de maturação R7.5, o qual proporcionou maior produtividade e o menor índice de incidência de fungos Phoma sp., Colletotrichum dematium var. truncata e Fusarium sp

High Risk of Secondary Infections Following Thrombotic Complications in Patients With COVID-19

Background. This study’s primary aim was to evaluate the impact of thrombotic complications on the development of secondary infections. The secondary aim was to compare the etiology of secondary infections in patients with and without thrombotic complications. Methods. This was a cohort study (NCT04318366) of coronavirus disease 2019 (COVID-19) patients hospitalized at IRCCS San Raffaele Hospital between February 25 and June 30, 2020. Incidence rates (IRs) were calculated by univariable Poisson regression as the number of cases per 1000 person-days of follow-up (PDFU) with 95% confidence intervals. The cumulative incidence functions of secondary infections according to thrombotic complications were compared with Gray’s method accounting for competing risk of death. A multivariable Fine-Gray model was applied to assess factors associated with risk of secondary infections. Results. Overall, 109/904 patients had 176 secondary infections (IR, 10.0; 95% CI, 8.8–11.5; per 1000-PDFU). The IRs of secondary infections among patients with or without thrombotic complications were 15.0 (95% CI, 10.7–21.0) and 9.3 (95% CI, 7.9–11.0) per 1000-PDFU, respectively (P = .017). At multivariable analysis, thrombotic complications were associated with the development of secondary infections (subdistribution hazard ratio, 1.788; 95% CI, 1.018–3.140; P = .043). The etiology of secondary infections was similar in patients with and without thrombotic complications. Conclusions. In patients with COVID-19, thrombotic complications were associated with a high risk of secondary infections