Design of a linear time-varying Model Predictive Control energy regulator for grid-tied VSCs

This paper presents an energy regulator based on a Model Predictive Control (MPC) algorithm for a Voltage Source Converter (VSC). The MPC is formulated to optimise the converter performance according to the weights defined in an objective function that trades off additional features, such as current harmonic distortion, reactive power tracking and DC bus voltage oscillation. Differently from most approaches found in the research literature, the MPC proposed here considers the coupling dynamics between the AC and DC sides of the VSC. This study is focused on the example case of a single-phase VSC, which presents a nonlinear relationship between its AC and DC sides and a sustained double-line frequency power disturbance in its DC bus. To reduce the burden of the MPC, the controller is formulated to benefit from the slow energy dynamics of the system. Thus, the cascaded structure typically used in the control of VSCs is kept and the MPC is set as an energy regulator at a reduced sampling frequency while the current control relies on a fast inner controller. The computational burden of the algorithm is further reduced by using a linear time-varying approximation. The controller is presented in detail and experimental validation showing the performance of the algorithm is provided

Effectiveness of individualized inhaler technique training on low adherence (LowAd) in ambulatory patients with COPD and asthma

© 2022. This document is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/ This document is the published version of a published work that appeared in final form in npj primary care respiratory medicineTo analyze whether there is improvement in adherence to inhaled treatment in patients with COPD and asthma after an educational intervention based on the teach-to-goal method. This is a prospective, non-randomized, single-group study, with intervention and before-after evaluation. The study population included 120 patients (67 females and 53 males) diagnosed with asthma (70.8%) and COPD (29.1%). The level of adherence (low and optimal) and the noncompliance behavior pattern (erratic, deliberate and unwitting) were determined by the Test of the adherence to Inhalers (TAI). This questionnaire allows you to determine the level of adherence and the types of noncompliance. Low Adherence (LowAd) was defined as a score less than 49 points. All patients received individualized educational inhaler technique intervention (IEITI). Before the IEITI, 67.5% of the patients had LowAd. Following IEITI, on week 24, LowAd was 55% (p = 0.024). Each patient can present one or more types of noncompliance. The most frequent type was forgetting to use the inhaler (erratic), 65.8%. The other types were deliberate: 43.3%, and unwitting: 57.5%. All of them had decreased on the final visit: 51.7% (p = 0.009), 25.8% (p = 0.002), 39.2% (p = 0.002). There were no significant differences in adherence between asthma and COPD patients at the start of the study. The only predicting factor of LowAd was the female gender. An individualized educational intervention, in ambulatory patients with COPD and asthma, in real-world clinical practice conditions, improves adherence to the inhaled treatment

Thermal behaviour of the different parts of almond shells as waste biomass

The main aim of this study is to investigate the thermal behaviour of the different parts of almond shells produced in an almond industry as a waste biomass. For this purpose, several experiments have been conducted under laboratory conditions. After removing the mature almonds, the waste raw materials subject of this study were treated with distilled water (10 min) and separated in several parts. Taking into account their physical characteristics, they were: (a) complete shells: exocarp, mesocarp and endocarp without grinding (Sample C); (b) ground samples of complete shells, sieved under 0.2 mm (Sample M); (c) hard layers of the endocarp (Sample E); (d) internal layers of the endocarp (Sample I); and (e) mature drupes (Sample P) or skin, being constituted by the flexible part of green colour (fresh form) or yellow (after drying). The thermal behaviour of all these sample materials has been investigated using a laboratory furnace, with determination of ash contents and mass loss by progressive heating (120 min of holding time). Elemental and DTA-TG/DTG analyses of selected sample materials have been carried out. Although a complete study can be very complex, a first approach has been performed in this investigation. Results on thermal decomposition of this biomass waste have been presented to emphasize the main differences between sample materials of almond shells. These results have demonstrated the influence of several parameters, such as the particle size, and previous treatments in the thermal behaviour of the different parts of the almond shells, as showed in this investigation. Structural analysis of almond shells allowed to determine lignin, cellulose and hemicellulose. From the lignin content, it has been predicted the higher heating value (18.24 MJkg(-1)) of this waste as by-product of industrial interest. Other linear correlations to calculate this parameter have been applied with similar results in all these samples

Strong mucosal immune responses in SIV infected macaques contribute to viral control and preserved CD4+ T-cell levels in blood and mucosal tissues

<p>Abstract</p> <p>Background</p> <p>Since there is still no protective HIV vaccine available, better insights into immune mechanism of persons effectively controlling HIV replication in the absence of any therapy should contribute to improve further vaccine designs. However, little is known about the mucosal immune response of this small unique group of patients. Using the SIV-macaque-model for AIDS, we had the rare opportunity to analyze 14 SIV-infected rhesus macaques durably controlling viral replication (controllers). We investigated the virological and immunological profile of blood and three different mucosal tissues and compared their data to those of uninfected and animals progressing to AIDS-like disease (progressors).</p> <p>Results</p> <p>Lymphocytes from blood, bronchoalveolar lavage (BAL), and duodenal and colonic biopsies were phenotypically characterized by polychromatic flow cytometry. In controllers, we observed higher levels of CD4+, CD4+CCR5+ and Gag-specific CD8+ T-cells as well as lower immune activation in blood and all mucosal sites compared to progressors. However, we could also demonstrate that immunological changes are distinct between these three mucosal sites.</p> <p>Intracellular cytokine staining demonstrated a significantly higher systemic and mucosal CD8+ Gag-specific cellular immune response in controllers than in progressors. Most remarkable was the polyfunctional cytokine profile of CD8+ lymphocytes in BAL of controllers, which significantly dominated over their blood response. The overall suppression of viral replication in the controllers was confirmed by almost no detectable viral RNA in blood and all mucosal tissues investigated.</p> <p>Conclusion</p> <p>A strong and complex virus-specific CD8+ T-cell response in blood and especially in mucosal tissue of SIV-infected macaques was associated with low immune activation and an efficient suppression of viral replication. This likely afforded a repopulation of CD4+ T-cells in different mucosal compartments to almost normal levels. We conclude, that a robust SIV-specific mucosal immune response seems to be essential for establishing and maintaining the controller status and consequently for long-term survival.</p

Improving statistical inference on pathogen densities estimated by quantitative molecular methods: malaria gametocytaemia as a case study

BACKGROUND: Quantitative molecular methods (QMMs) such as quantitative real-time polymerase chain reaction (q-PCR), reverse-transcriptase PCR (qRT-PCR) and quantitative nucleic acid sequence-based amplification (QT-NASBA) are increasingly used to estimate pathogen density in a variety of clinical and epidemiological contexts. These methods are often classified as semi-quantitative, yet estimates of reliability or sensitivity are seldom reported. Here, a statistical framework is developed for assessing the reliability (uncertainty) of pathogen densities estimated using QMMs and the associated diagnostic sensitivity. The method is illustrated with quantification of Plasmodium falciparum gametocytaemia by QT-NASBA. RESULTS: The reliability of pathogen (e.g. gametocyte) densities, and the accompanying diagnostic sensitivity, estimated by two contrasting statistical calibration techniques, are compared; a traditional method and a mixed model Bayesian approach. The latter accounts for statistical dependence of QMM assays run under identical laboratory protocols and permits structural modelling of experimental measurements, allowing precision to vary with pathogen density. Traditional calibration cannot account for inter-assay variability arising from imperfect QMMs and generates estimates of pathogen density that have poor reliability, are variable among assays and inaccurately reflect diagnostic sensitivity. The Bayesian mixed model approach assimilates information from replica QMM assays, improving reliability and inter-assay homogeneity, providing an accurate appraisal of quantitative and diagnostic performance. CONCLUSIONS: Bayesian mixed model statistical calibration supersedes traditional techniques in the context of QMM-derived estimates of pathogen density, offering the potential to improve substantially the depth and quality of clinical and epidemiological inference for a wide variety of pathogens

Amplification by PCR Artificially Reduces the Proportion of the Rare Biosphere in Microbial Communities

The microbial world has been shown to hold an unimaginable diversity. The use of rRNA genes and PCR amplification to assess microbial community structure and diversity present biases that need to be analyzed in order to understand the risks involved in those estimates. Herein, we show that PCR amplification of specific sequence targets within a community depends on the fractions that those sequences represent to the total DNA template. Using quantitative, real-time, multiplex PCR and specific Taqman probes, the amplification of 16S rRNA genes from four bacterial species within a laboratory community were monitored. Results indicate that the relative amplification efficiency for each bacterial species is a nonlinear function of the fraction that each of those taxa represent within a community or multispecies DNA template. Consequently, the low-proportion taxa in a community are under-represented during PCR-based surveys and a large number of sequences might need to be processed to detect some of the bacterial taxa within the ‘rare biosphere’. The structure of microbial communities from PCR-based surveys is clearly biased against low abundant taxa which are required to decipher the complete extent of microbial diversity in nature

Cognitive impairment induced by delta9-tetrahydrocannabinol occurs through heteromers between cannabinoid CB1 and serotonin 5-HT2A receptors

Delta-9-tetrahydrocannabinol (THC), the main psychoactive compound of marijuana, induces numerous undesirable effects, including memory impairments, anxiety, and dependence. Conversely, THC also has potentially therapeutic effects, including analgesia, muscle relaxation, and neuroprotection. However, the mechanisms that dissociate these responses are still not known. Using mice lacking the serotonin receptor 5-HT2A, we revealed that the analgesic and amnesic effects of THC are independent of each other: while amnesia induced by THC disappears in the mutant mice, THC can still promote analgesia in these animals. In subsequent molecular studies, we showed that in specific brain regions involved in memory formation, the receptors for THC and the 5-HT2A receptors work together by physically interacting with each other. Experimentally interfering with this interaction prevented the memory deficits induced by THC, but not its analgesic properties. Our results highlight a novel mechanism by which the beneficial analgesic properties of THC can be dissociated from its cognitive side effects

Embodied perspective-taking indicated by selective disruption from aberrant self motion

Spatial perspective-taking that involves imagined changes in one’s spatial orientation is facilitated by vestibular stimulation inducing a congruent sensation of self-motion. We examined further the role of vestibular resources in perspective-taking by evaluating whether aberrant and conflicting vestibular stimulation impaired perspective-taking performance. Participants (N = 39) undertook either an “own body transformation” (OBT)task, requiring speeded spatial judgments made from the perspective of a schematic figure, or a control task requiring reconfiguration of spatial mappings from one’s own visuo-spatial perspective. These tasks were performed both without and with vestibular stimulation by whole-body Coriolis motion, according to a repeated measures design, balanced for order. Vestibular stimulation was found to impair performance during the first minute post stimulus relative to the stationary condition. This disruption was task-specific, affecting only the OBT task and not the control task, and dissipated by the second minute post-stimulus. Our experiment thus demonstrates selective temporary impairment of perspective-taking from aberrant vestibular stimulation, implying that uncompromised vestibular resources are necessary for efficient perspective-taking. This finding provides evidence for an embodied mechanism for perspective-taking whereby vestibular input contributes to multisensory processing underlying bodily and social cognition. Ultimately, this knowledge may contribute to the design of interventions that help patients suffering sudden vertigo adapt to the cognitive difficulties caused by aberrant vestibular stimulation

The Level of DING Proteins Is Increased in HIV-Infected Patients: In Vitro and In Vivo Studies

DING proteins constitute an interesting family, owing to their intriguing and important activities. However, after a decade of research, little is known about these proteins. In humans, at least five different DING proteins have been identified, which were implicated in important biological processes and diseases, including HIV. Indeed, recent data from different research groups have highlighted the anti-HIV activity of some DING representatives. These proteins share the ability to inhibit the transcriptional step of HIV-1, a key step of the viral cycle that is not yet targeted by the current therapies. Since such proteins have been isolated from humans, we undertook a comprehensive study that focuses on the relationship between these proteins and HIV-infection in an infectious context. Hence, we developed a home-made ELISA for the quantification of the concentration of DING proteins in human serum. Using this method, we were able to determine the concentration of DING proteins in healthy and HIV-infected patients. Interestingly, we observed a significant increase of the concentration of DING proteins in non treated and treated HIV-infected patients compared to controls. In addition, cell cultures infected with HIV also show an increased expression of DING proteins, ruling out the possible role of antiretroviral treatment in the increase of the expression of DING proteins. In conclusion, results from this study show that the organism reacts to HIV-infection by an overexpression of DING proteins

HIV Infection and Gut Mucosal Immune Function: Updates on Pathogenesis with Implications for Management and Intervention

HIV is primarily a sexually transmitted infection. However, given that the gastrointestinal tract (GIT) houses most of the body’s lymphocytes, including activated memory CD4+ T cells that are preferential targets for HIV, recent research has focused on the role of the GIT in transmission and pathogenesis. In health, the GIT maintains a balance between immune tolerance and rapid responsiveness. A complex network of innate and adaptive responses maintains this balance, which is severely perturbed in HIV infection. Recent studies have focused on mechanisms of GIT CD4+ T-cell depletion and epithelial disruption in HIV infection, the role of inflammation in accelerating viral dissemination, the kinetics of the adaptive response following transmission, and the extent of T-cell reconstitution following antiretroviral therapy. This review summarizes the results of recent investigations that may have important implications for the development of vaccines, microbicides, and therapeutic interventions for HIV and other mucosal pathogens