1,081 research outputs found
Application of quadratically-constrained model predictive control in power systems
Simulations for the quadratically-constrained model
predictive control (qc-MPC) with power system linear models are
studied in this work. In qc-MPC, the optimization is imposed
with two additional constraints to achieve the closed-loop system
stability and the recursive-feasibility simultaneously. Instead of
engaging the traditional terminal constraint for MPC, both
constraints in qc-MPC are imposed on the first control vector
of the MPC control sequence. As a result, qc-MPC has the
potential for further extension to the control of network centric
power systems. The algorithm of qc-MPC has been developed
in a previous paper. Here, simulation studies with small-signal
linear models of three typical power systems are presented
to demonstrate its efficacy. We also develop a computational
strategy for the decentralized static state-feedback control using
the same quadratic dissipativity constraint as of the qc-MPC.
Only state constraints are considered in the state feedback design.
A comparison is then provided in the simulation study of qc-MPC
relatively to the constrained-state feedback control.This publication is made possible by the Singapore National Research
Foundation under its Campus for Research Excellence And Technological
Enterprise (CREATE) programmeThis is the author accepted manuscript. The final version is available from IEEE via http://dx.doi.org/10.1109/ICARCV.2014.706430
Moving from evidence-based medicine to evidence-based health.
While evidence-based medicine (EBM) has advanced medical practice, the health care system has been inconsistent in translating EBM into improvements in health. Disparities in health and health care play out through patients' limited ability to incorporate the advances of EBM into their daily lives. Assisting patients to self-manage their chronic conditions and paying attention to unhealthy community factors could be added to EBM to create a broader paradigm of evidence-based health. A perspective of evidence-based health may encourage physicians to consider their role in upstream efforts to combat socially patterned chronic disease
RNA-DNA differences are rarer in proto-oncogenes than in tumor suppressor genes
It has long been assumed that DNA sequences and corresponding RNA transcripts are almost identical; a recent discovery, however, revealed widespread RNA-DNA differences (RDDs), which represent a largely unexplored aspect of human genome variation. It has been speculated that RDDs can affect disease susceptibility and manifestations; however, almost nothing is known about how RDDs are related to disease. Here, we show that RDDs are rarer in proto-oncogenes than in tumor suppressor genes; the number of RDDs in coding exons, but not in 3′UTR and 5′UTR, is significantly lower in the former than the latter, and this trend is especially pronounced in non-synonymous RDDs, i.e., those cause amino acid changes. A potential mechanism is that, unlike proto-oncogenes, the requirement of tumor suppressor genes to have both alleles affected to cause tumor ‘buffers' these genes to tolerate more RDDs
First results from the Solar Orbiter Heavy Ion Sensor
Context.
Aims. Solar Orbiter launched in February 2020 with the goal of revealing the connections between the Sun’s interior, atmosphere, and
the heliosphere. The Solar Orbiter Heavy Ion Sensor (HIS) is a time-of-flight ion mass spectrometer dedicated to measuring heavy
ions in the solar wind.
Methods. We present an overview of the first measurements of heavy ion composition from HIS, reviewing the methods used to
transform the spectra obtained on board into scientific data products and examining two solar wind case studies as well as the
statistical properties of the heavy ion composition observed by HIS. We also carried out a comparison with prior measurements of
heavy ions at L1.
Results. The HIS data set provides the first mass- and charge-resolved heavy ion measurements in the inner heliosphere.
Conclusions. These high temporal resolution data have the potential to transform our understanding of the connections between the
solar wind and its origin at the Sun, as well as the interaction between the solar wind and the environment around planets, comets,
and in the interstellar medium
First report of generalized face processing difficulties in möbius sequence.
Reverse simulation models of facial expression recognition suggest that we recognize the emotions of others by running implicit motor programmes responsible for the production of that expression. Previous work has tested this theory by examining facial expression recognition in participants with Möbius sequence, a condition characterized by congenital bilateral facial paralysis. However, a mixed pattern of findings has emerged, and it has not yet been tested whether these individuals can imagine facial expressions, a process also hypothesized to be underpinned by proprioceptive feedback from the face. We investigated this issue by examining expression recognition and imagery in six participants with Möbius sequence, and also carried out tests assessing facial identity and object recognition, as well as basic visual processing. While five of the six participants presented with expression recognition impairments, only one was impaired at the imagery of facial expressions. Further, five participants presented with other difficulties in the recognition of facial identity or objects, or in lower-level visual processing. We discuss the implications of our findings for the reverse simulation model, and suggest that facial identity recognition impairments may be more severe in the condition than has previously been noted
The effects of Gilles de la Tourette syndrome and other chronic tic disorders on quality of life across the lifespan:a systematic review
Gilles de la Tourette syndrome (GTS) and other chronic tic disorders are neurodevelopmental conditions characterized by the presence of tics and associated behavioral problems. Whilst converging evidence indicates that these conditions can affect patients' quality of life (QoL), the extent of this impairment across the lifespan is not well understood. We conducted a systematic literature review of published QoL studies in GTS and other chronic tic disorders to comprehensively assess the effects of these conditions on QoL in different age groups. We found that QoL can be perceived differently by child and adult patients, especially with regard to the reciprocal contributions of tics and behavioral problems to the different domains of QoL. Specifically, QoL profiles in children often reflect the impact of co-morbid attention-deficit and hyperactivity symptoms, which tend to improve with age, whereas adults' perception of QoL seems to be more strongly affected by the presence of depression and anxiety. Management strategies should take into account differences in age-related QoL needs between children and adults with GTS or other chronic tic disorders
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
Potential conservation of circadian clock proteins in the phylum Nematoda as revealed by bioinformatic searches
Although several circadian rhythms have been described in C. elegans, its molecular clock remains elusive. In this work we employed a novel bioinformatic approach, applying probabilistic methodologies, to search for circadian clock proteins of several of the best studied circadian model organisms of different taxa (Mus musculus, Drosophila melanogaster, Neurospora crassa, Arabidopsis thaliana and Synechoccocus elongatus) in the proteomes of C. elegans and other members of the phylum Nematoda. With this approach we found that the Nematoda contain proteins most related to the core and accessory proteins of the insect and mammalian clocks, which provide new insights into the nematode clock and the evolution of the circadian system.Fil: Romanowski, Andrés. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones BioquÃmicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones BioquÃmicas de Buenos Aires; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologÃa. Laboratorio de CronobiologÃa; ArgentinaFil: Garavaglia, MatÃas Javier. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologÃa. Laboratorio de Ing.genética y Biolog.molecular y Celular. Area Virus de Insectos; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Goya, MarÃa Eugenia. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologÃa. Laboratorio de CronobiologÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Ghiringhelli, Pablo Daniel. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologÃa. Laboratorio de Ing.genética y Biolog.molecular y Celular. Area Virus de Insectos; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Golombek, Diego Andres. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologÃa. Laboratorio de CronobiologÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
Outcomes research in the development and evaluation of practice guidelines
BACKGROUND: Practice guidelines have been developed in response to the observation that variations exist in clinical medicine that are not related to variations in the clinical presentation and severity of the disease. Despite their widespread use, however, practice guideline evaluation lacks a rigorous scientific methodology to support its development and application. DISCUSSION: Firstly, we review the major epidemiological foundations of practice guideline development. Secondly, we propose a chronic disease epidemiological model in which practice patterns are viewed as the exposure and outcomes of interest such as quality or cost are viewed as the disease. Sources of selection, information, confounding and temporal trend bias are identified and discussed. SUMMARY: The proposed methodological framework for outcomes research to evaluate practice guidelines reflects the selection, information and confounding biases inherent in its observational nature which must be accounted for in both the design and the analysis phases of any outcomes research study
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