2,832 research outputs found

    Short-Term Price Forecasting Models Based on Artificial Neural Networks for Intraday Sessions in the Iberian Electricity Market

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    This paper presents novel intraday session models for price forecasts (ISMPF models) for hourly price forecasting in the six intraday sessions of the Iberian electricity market (MIBEL) and the analysis of mean absolute percentage errors (MAPEs) obtained with suitable combinations of their input variables in order to find the best ISMPF models. Comparisons of errors from different ISMPF models identified the most important variables for forecasting purposes. Similar analyses were applied to determine the best daily session models for price forecasts (DSMPF models) for the day-ahead price forecasting in the daily session of the MIBEL, considering as input variables extensive hourly time series records of recent prices, power demands and power generations in the previous day, forecasts of demand, wind power generation and weather for the day-ahead, and chronological variables. ISMPF models include the input variables of DSMPF models as well as the daily session prices and prices of preceding intraday sessions. The best ISMPF models achieved lower MAPEs for most of the intraday sessions compared to the error of the best DSMPF model; furthermore, such DSMPF error was very close to the lowest limit error for the daily session. The best ISMPF models can be useful for MIBEL agents of the electricity intraday market and the electric energy industry

    Prevention of Bone Loss in a Model of Postmenopausal Osteoporosis through Adrenomedullin Inhibition

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    Despite recent advances in the understanding and treatment options for osteoporosis, this condition remains a serious public health issue. Adrenomedullin (AM) is a regulatory peptide with reported activity on bone remodeling. To better understand this relationship we built an inducible knockout for AM. An outstanding feature of knockout mice is their heavier weight due, in part, to the presence of denser bones. The femur of knockout animals was denser, had more trabeculae, and a thicker growth plate than wild type littermates. The endocrine influence of AM on bone seems to be elicited through an indirect mechanism involving, at least, the regulation of insulin, glucose, ghrelin, and calcitonin gene-related peptide (CGRP). To confirm the data we performed a pharmacological approach using the AM inhibitor 16311 in a mouse model of osteoporosis. Ovariectomized females showed significant bone mass loss, whereas ovariectomized females treated with 16311 had similar bone density to sham operated females. In conclusion, we propose the use of AM inhibitors for the treatment of osteoporosis and other conditions leading to the loss of bone mass

    Simultaneous aberration and aperture control using a single spatial light modulator

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    ©. This manuscript version is made available under the CC-BY-NC 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This document is the, Published, version of a Published Work that appeared in final form in Optics Express. To access the final edited and published work see: https://doi.org/10.1364/OE.27.012399A method to simultaneously control aberrations and the aperture of an optical system using a single phase-only spatial light modulator was investigated. The experiment was performed using a liquid-crystal-on-silicon spatial light modulator (LCoS-SLM) within an adaptive optics system used for visual testing, although the method has broader applications in adaptive optics field. The performance of the technique was characterized through the estimation of the system’s modulation transfer functions (MTFs) by using a random chart method. MTFs obtained from the phase modulation-based approach were compared with those from using a real aperture (diaphragm). The areas under the MTFs for the two conditions were similar up to 98%, confirming that the low-pass filter effect associated to the size of the entrance pupil was similar for the phase-modulated pupil and the physical pupil. As an example of application, both aberrations and pupil were controlled by a single phase-only modulator to study the through-focus visual performance in real subjects. Limitations and possible enhancements of the presented method were also discussed. The presented technique reduces complexity and cost of adaptive optics systems. It opens the door to new experiments by allowing dynamic modulation of aberrations and apertures of any shape

    Immunotherapeutic synergy between anti-CD137 mAb and intratumoral administration of a cytopathic Semliki Forest virus encoding IL-12

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    Intratumoral injection of Semliki Forest virus encoding interleukin-12 (SFV-IL-12) combines acute expression of IL-12 and stressful apoptosis of infected malignant cells. Agonist antibodies directed to costimulatory receptor CD137 (4-1BB) strongly amplify pre-existing cellular immune responses toward weak tumor antigens. In this study, we provide evidence for powerful synergistic effects of a combined strategy consisting of intratumoral injection of SFV-IL-12 and systemic delivery of agonist anti-CD137 monoclonal antibodies (mAbs), which was substantiated against poorly immunogenic B16 melanomas (B16-OVA and B16.F10) and TC-1 lung carcinomas. Effector CD8(β)(+) T cells were sufficient to mediate complete tumor eradications. Accordingly, there was an intensely synergistic in vivo enhancement of cytotoxic T lymphocytes (CTL)-mediated immunity against the tumor antigens OVA and tyrosine-related protein-2 (TRP-2). This train of phenomena led to long-lasting tumor-specific immunity against rechallenge, attained transient control of the progression of concomitant tumor lesions that were not directly treated with SFV-IL-12 and caused autoimmune vitiligo. Importantly, we found that SFV-IL-12 intratumoral injection induces bright expression of CD137 on most tumor-infiltrating CD8(+) T lymphocytes, thereby providing more abundant targets for the action of the agonist antibody. This efficacious combinatorial immunotherapy strategy offers feasibility for clinical translation since anti-CD137 mAbs are already undergoing clinical trials and development of clinical-grade SFV-IL-12 vectors is in progress

    Entrenamiento de las señales corticales a través de un sistema BMI-EEG, evolución e intervención. A propósito de un caso = Training cortical signals by means of a BMI-EEG system, its evolution and intervention. A case report

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    INTRODUCTION: In the last years, new technologies such as the brain-machine interfaces (BMI) have been incorporated in the rehabilitation process of subjects with stroke. These systems are able to detect motion intention, analyzing the cortical signals using different techniques such as the electroencephalography (EEG). This information could guide different interfaces such as robotic devices, electrical stimulation or virtual reality. CASE REPORT: A 40 years-old man with stroke with two months from the injury participated in this study. We used a BMI based on EEG. The subject's motion intention was analyzed calculating the event-related desynchronization. The upper limb motor function was evaluated with the Fugl-Meyer Assessment and the participant's satisfaction was evaluated using the QUEST 2.0. The intervention using a physical therapist as an interface was carried out without difficulty. CONCLUSIONS: The BMI systems detect cortical changes in a subacute stroke subject. These changes are coherent with the evolution observed using the Fugl-Meyer Assessment

    Altitude as a risk factor for the development of hypospadias. Geographical cluster distribution analysis in South America

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    Q2307.e1-307.e5Objective Hypospadias is the most common congenital anomaly affecting the genitals. It has been established as a multifactorial disease with increasing prevalence. Many risk factors have been identified such as prematurity, birth weight, mother's age, and exposure to endocrine disruptors. In recent decades multiple authors using surveillance systems have described an increase in prevalence of hypospadias, but most of the published literature comes from developed countries in Europe and North America and few of the published studies have involved cluster analysis. Few large-scale studies have been performed addressing the effect of altitude and other geographical aspects on the development of hypospadias. Acknowledging this limitation, we present novel results of a multinational spatial scan statistical analysis over a 30-year period in South America and an altitude analysis of hypospadias distribution on a continent level. Method A retrospective review was performed of the Latin American collaborative study of congenital malformations (ECLAMC). A total of 4,020,384 newborns was surveyed between 1982 and December 2011 in all participating centers. We selected all patients with hypospadias. All degrees of clinical severity were included in the analysis. Each participating center was geographically identified with its coordinates and altitude above sea level. A spatial scan statistical analysis was performed using Kulldorf's methodology and a prevalence trend analysis over time in centers below and above 2000 m. Results During the study period we found 159 hospitals in six different countries (Colombia, Bolivia, Brazil, Argentina, Chile, and Uruguay) with 4,537 cases of hypospadias and a global prevalence rate of 11.3/10,000 newborns. Trend analysis showed that centers below 2000 m had an increasing trend with an average of 10/10,000 newborns as opposed to those centers above 2000 m that showed a reducing trend with an average prevalence of 7.8 (p = 0.1246). We identified clusters with significant increases of prevalence in five centers along the coast at an average altitude of 219.8 m above sea level (p > 0.0000). Reduction in prevalence was found in clusters located in two centers on the Andes mountains. Altitude of 2,000 m was associated with hypospadias (Figure), with an OR 0.59 (0.5–0.69). There are ethnic arguments to support our results supported by protective polymorphism distribution in high lands. Conclusion Altitude above 2,000 m is suggested to have a protective effect for hypospadias. Specific clusters have been identified with increased risk for hypospadias. Environmental risk factors in these areas need to be further studied given the association seen between altitude and the distribution of more severe cases

    Immunological identity of brucella native hapten, polysaccharide B, and yersinia enterocolitica serotype 9 native hapten

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    Yersinia enterocolitica serotype 9 contained an antigenic component giving a reaction of total identity with Brucella native hapten and polysaccharide B. This component was present in a phenol-water extract (fraction 5; M. Redfearn, Ph.D. Thesis, University of Wisconsin, Madison, 1960) along with the smooth lipopolysaccharide. The native hapten could be purified free of lipopolysaccharide and proteins by gel filtration

    Comparative analysis of zebrafish bone morphogenetic proteins 2, 4 and 16: molecular and evolutionary perspectives

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    BMP2, BMP4 and BMP16 form a subfamily of bone morphogenetic proteins acting as pleiotropic growth factors during development and as bone inducers during osteogenesis. BMP16 is the most recent member of this subfamily and basic data regarding protein structure and function, and spatio-temporal gene expression is still scarce. In this work, insights on BMP16 were provided through the comparative analysis of structural and functional data for zebrafish BMP2a, BMP2b, BMP4 and BMP16 genes and proteins, determined from three-dimensional models, patterns of gene expression during development and in adult tissues, regulation by retinoic acid and capacity to activate BMP-signaling pathway. Structures of Bmp2a, Bmp2b, Bmp4 and Bmp16 were found to be remarkably similar; with residues involved in receptor binding being highly conserved. All proteins could activate the BMP-signaling pathway, suggesting that they share a common function. On the contrary, stage-and tissue-specific expression of bmp2, bmp4 and bmp16 suggested the genes might be differentially regulated (e.g. different transcription factors, enhancers and/or regulatory modules) but also that they are involved in distinct physiological processes, although with the same function. Retinoic acid, a morphogen known to interact with BMP-signaling during bone formation, was shown to downregulate the expression of bmp2, bmp4 and bmp16, although to different extents. Taxonomic and phylogenetic analyses indicated that bmp16 diverged before bmp2 and bmp4, is not restricted to teleost fish lineage as previously reported, and that it probably arose from a whole genomic duplication event that occurred early in vertebrate evolution and disappeared in various tetrapod lineages through independent events

    Room-temperature Operation of Low-voltage, Non-volatile, Compound-semiconductor Memory Cells

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    Whilst the different forms of conventional (charge-based) memories are well suited to their individual roles in computers and other electronic devices, flaws in their properties mean that intensive research into alternative, or emerging, memories continues. In particular, the goal of simultaneously achieving the contradictory requirements of non-volatility and fast, low-voltage (low-energy) switching has proved challenging. Here, we report an oxide-free, floating-gate memory cell based on III-V semiconductor heterostructures with a junctionless channel and non-destructive read of the stored data. Non-volatile data retention of at least 104 s in combination with switching at ≤2.6 V is achieved by use of the extraordinary 2.1 eV conduction band offsets of InAs/AlSb and a triple-barrier resonant tunnelling structure. The combination of low-voltage operation and small capacitance implies intrinsic switching energy per unit area that is 100 and 1000 times smaller than dynamic random access memory and Flash respectively. The device may thus be considered as a new emerging memory with considerable potential
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