Transient stability analysis using potential energy indices for determining critical generator sets

In this paper, we propose the enhancement of existing power system stability analysis techniques through the use of a proposed set of potential energy indices, applied for observing the separation of generators into critical sets during transient events. This proposed potential-energy-based description of system transient stability behavior permits the formation of a critical generator cutset, which is then used in a quantitative single machine equivalent (SIME) energy-function analysis of system stability. The derivation of the method will show that the proposed potential energy indices do not rely on a detailed representation of the network model, making the indices suitable for use in a variety of applications. This method enhances the current capabilities of SIME analysis for pre-fault offline stability studies, but may also be useful for near-real-time stability analysis, owing to the lack of dependence of the proposed potential energy indices on the network parameters. The ability to utilize the proposed indices without the need for network parameters or fault location information, typically obtained from updated SCADA data, potentially allows the proposed method to be applied for real-time stability analysis utilizing only PMU input data

Serious Games Application for Memory Training Using Egocentric Images

Mild cognitive impairment is the early stage of several neurodegenerative diseases, such as Alzheimer's. In this work, we address the use of lifelogging as a tool to obtain pictures from a patient's daily life from an egocentric point of view. We propose to use them in combination with serious games as a way to provide a non-pharmacological treatment to improve their quality of life. To do so, we introduce a novel computer vision technique that classifies rich and non rich egocentric images and uses them in serious games. We present results over a dataset composed by 10,997 images, recorded by 7 different users, achieving 79% of F1-score. Our model presents the first method used for automatic egocentric images selection applicable to serious games.Comment: 11 page

Economic evaluation of mechanical harvesting of lemons

[EN] Several hypotheses regarding hand and mechanical harvesting have been analysed, in order to estimate the economic possibilities for the mechanical harvesting of lemons taking into account the current availability of technology. We considered several detachment options under experimental conditions; only yellow detachment has been considered for mechanical harvesting, because the sensitivity to the impacts is lower and mechanical detachment was high (80%). Price changes throughout the season were also considered. Total harvest cost is an average of the cost of mechanical harvesting (80%) and the cost of manually harvesting remaining fruit (20%), plus the cost of handling the mechanical harvested fraction. This cost ranges between 0.031 and 0.058 € kg-1 for outputs between 20 and 60 t ha-1, respectively, which is always lower than harvesting by hand (0.065 € kg-1). A Monte Carlo approach was used to study the sensitivity of the results, and Value at Risk (VaR) calculated. The analysis showed that the mechanical harvesting margin is c0.020 € kg-1 higher than the hand harvesting margin, and the output dispersion is higher in March. The VaR analysis showed that at 10% there was no risk that the hand margin is higher than the mechanical margin; at 5% the risk is very low and only for March harvesting. Mechanical harvesting represents a good economic option compared to hand harvesting, since it can increase farmer income by between 400 and 1200 € ha-1.This work was funded by Consejería de Agricultura y Agua de la Región de Murcia and by INIA and FEDER funds (project no. RTA2014-00025-C05-02).Brotons-Martínez, JM.; Martín-Górriz, B.; Torregrosa, A.; Porras, I. (2018). Economic evaluation of mechanical harvesting of lemons. Outlook on Agriculture. 47(1):44-50. https://doi.org/10.1177/0030727018762657S4450471Bordas, M., Torrents, J., Arenas, F. J., & Hervalejo, A. (2012). HIGH DENSITY PLANTATION SYSTEM OF THE SPANISH CITRUS INDUSTRY. Acta Horticulturae, (965), 123-130. doi:10.17660/actahortic.2012.965.15Burns, J. K., Roka, F. M., Li, K.-T., Pozo, L., & Buker, R. S. (2006). Late-season `Valencia’ Orange Mechanical Harvesting with an Abscission Agent and Low-frequency Harvesting. HortScience, 41(3), 660-663. doi:10.21273/hortsci.41.3.660Grafiadellis, I., Mattas, K., Maloupa, E., Tzouramani, I., & Galanopoulos, K. (2000). An Economic Analysis of Soilless Culture in Gerbera Production. HortScience, 35(2), 300-303. doi:10.21273/hortsci.35.2.300Manera, F. J., Brotons, J. M., Conesa, A., & Porras, I. (2012). Influence of temperature on the beginning of degreening in lemon peel. Scientia Horticulturae, 145, 34-38. doi:10.1016/j.scienta.2012.07.021Moreno, R., Torregrosa, A., Moltó, E., & Chueca, P. (2015). Effect of harvesting with a trunk shaker and an abscission chemical on fruit detachment and defoliation of citrus grown under Mediterranean conditions. Spanish Journal of Agricultural Research, 13(1), e0206. doi:10.5424/sjar/2015131-6590Roka, F. M., & Hyman, B. R. (2012). MECHANICAL HARVESTING OF SWEET ORANGES FOR JUICE PROCESSING. Acta Horticulturae, (965), 241-243. doi:10.17660/actahortic.2012.965.32Sanders, K. F. (2005). Orange Harvesting Systems Review. Biosystems Engineering, 90(2), 115-125. doi:10.1016/j.biosystemseng.2004.10.006A. Torregrosa, I. Porras, & B. Martín. (2010). Mechanical Harvesting of Lemons (cv. Fino) in Spain Using Abscission Agents. Transactions of the ASABE, 53(3), 703-708. doi:10.13031/2013.30062Wagner, H. M. (1995). Global Sensitivity Analysis. Operations Research, 43(6), 948-969. doi:10.1287/opre.43.6.948J. D. Whitney. (1999). FIELD TEST RESULTS WITH MECHANICAL HARVESTING EQUIPMENT IN FLORIDA ORANGES. Applied Engineering in Agriculture, 15(3), 205-210. doi:10.13031/2013.576

No Evidence That Gratitude Enhances Neural Performance Monitoring or Conflict-Driven Control

It has recently been suggested that gratitude can benefit self-regulation by reducing impulsivity during economic decision making. We tested if comparable benefits of gratitude are observed for neural performance monitoring and conflict-driven self-control. In a pre-post design, 61 participants were randomly assigned to either a gratitude or happiness condition, and then performed a pre-induction flanker task. Subsequently, participants recalled an autobiographical event where they had felt grateful or happy, followed by a post-induction flanker task. Despite closely following existing protocols, participants in the gratitude condition did not report elevated gratefulness compared to the happy group. In regard to self-control, we found no association between gratitude--operationalized by experimental condition or as a continuous predictor--and any control metric, including flanker interference, post-error adjustments, or neural monitoring (the error-related negativity, ERN). Thus, while gratitude might increase economic patience, such benefits may not generalize to conflict-driven control processes

Block length-dependent protein fouling on Poly(2-oxazoline)-based polymersomes: influence on macrophage association and circulation behavior

Polymersomes are vesicular structures self-assembled from amphiphilic block copolymers and are considered an alternative to liposomes for applications in drug delivery, immunotherapy, biosensing, and as nanoreactors and artificial organelles. However, the limited availability of systematic stability, protein fouling (protein corona formation), and blood circulation studies hampers their clinical translation. Poly(2-oxazoline)s (POx) are valuable antifouling hydrophilic polymers that can replace the current gold-standard, poly(ethylene glycol) (PEG), yet investigations of POx functionality on nanoparticles are relatively sparse. Herein, a systematic study is reported of the structural, dynamic and antifouling properties of polymersomes made of poly(2-methyl-2-oxazoline)-block-poly(dimethylsiloxane)-block-poly(2-methyl-2-oxazoline) (PMOXA-b-PDMS-b-PMOXA). The study relates in vitro antifouling performance of the polymersomes to atomistic molecular dynamics simulations of polymersome membrane hydration behavior. These observations support the experimentally demonstrated benefit of maximizing the length of PMOXA (degree of polymerization (DP) > 6) while keeping PDMS at a minimal length that still provides sufficient membrane stability (DP > 19). In vitro macrophage association and in vivo blood circulation evaluation of polymersomes in zebrafish embryos corroborate these findings. They further suggest that single copolymer presentation on polymersomes is outperformed by blends of varied copolymer lengths. This study helps to rationalize design rules for stable and low-fouling polymersomes for future medical applications

Heterologous expression screens in Nicotiana benthamiana identify a candidate effector of the wheat Yellow Rust Pathogen that associates with processing bodies

Rust fungal pathogens of wheat (Triticum spp.) affect crop yields worldwide. The molecular mechanisms underlying the virulence of these pathogens remain elusive, due to the limited availability of suitable molecular genetic research tools. Notably, the inability to perform high-throughput analyses of candidate virulence proteins (also known as effectors) impairs progress. We previously established a pipeline for the fast-forward screens of rust fungal candidate effectors in the model plant Nicotiana benthamiana. This pipeline involves selecting candidate effectors in silico and performing cell biology and protein-protein interaction assays in planta to gain insight into the putative functions of candidate effectors. In this study, we used this pipeline to identify and characterize sixteen candidate effectors from the wheat yellow rust fungal pathogen Puccinia striiformis f sp tritici. Nine candidate effectors targeted a specific plant subcellular compartment or protein complex, providing valuable information on their putative functions in plant cells. One candidate effector, PST02549, accumulated in processing bodies (P-bodies), protein complexes involved in mRNA decapping, degradation, and storage. PST02549 also associates with the P-body-resident ENHANCER OF mRNA DECAPPING PROTEIN 4 (EDC4) from N. benthamiana and wheat. We propose that P-bodies are a novel plant cell compartment targeted by pathogen effectors

Schmallenberg virus pathogenesis, tropism and interaction with the innate immune system of the host

Schmallenberg virus (SBV) is an emerging orthobunyavirus of ruminants associated with outbreaks of congenital malformations in aborted and stillborn animals. Since its discovery in November 2011, SBV has spread very rapidly to many European countries. Here, we developed molecular and serological tools, and an experimental in vivo model as a platform to study SBV pathogenesis, tropism and virus-host cell interactions. Using a synthetic biology approach, we developed a reverse genetics system for the rapid rescue and genetic manipulation of SBV. We showed that SBV has a wide tropism in cell culture and “synthetic” SBV replicates in vitro as efficiently as wild type virus. We developed an experimental mouse model to study SBV infection and showed that this virus replicates abundantly in neurons where it causes cerebral malacia and vacuolation of the cerebral cortex. These virus-induced acute lesions are useful in understanding the progression from vacuolation to porencephaly and extensive tissue destruction, often observed in aborted lambs and calves in naturally occurring Schmallenberg cases. Indeed, we detected high levels of SBV antigens in the neurons of the gray matter of brain and spinal cord of naturally affected lambs and calves, suggesting that muscular hypoplasia observed in SBV-infected lambs is mostly secondary to central nervous system damage. Finally, we investigated the molecular determinants of SBV virulence. Interestingly, we found a biological SBV clone that after passage in cell culture displays increased virulence in mice. We also found that a SBV deletion mutant of the non-structural NSs protein (SBVΔNSs) is less virulent in mice than wild type SBV. Attenuation of SBV virulence depends on the inability of SBVΔNSs to block IFN synthesis in virus infected cells. In conclusion, this work provides a useful experimental framework to study the biology and pathogenesis of SBV

Prediction of photoperiodic regulators from quantitative gene circuit models

Photoperiod sensors allow physiological adaptation to the changing seasons. The external coincidence hypothesis postulates that a light-responsive regulator is modulated by a circadian rhythm. Sufficient data are available to test this quantitatively in plants, though not yet in animals. In Arabidopsis, the clock-regulated genes CONSTANS (CO) and FLAVIN, KELCH, F-BOX (FKF1) and their lightsensitive proteins are thought to form an external coincidence sensor. We use 40 timeseries of molecular data to model the integration of light and timing information by CO, its target gene FLOWERING LOCUS T (FT), and the circadian clock. Among other predictions, the models show that FKF1 activates FT. We demonstrate experimentally that this effect is independent of the known activation of CO by FKF1, thus we locate a major, novel controller of photoperiodism. External coincidence is part of a complex photoperiod sensor: modelling makes this complexity explicit and may thus contribute to crop improvement