959 research outputs found

    Impact of the use of different blends of wood chips from diverse botanical species on quality parameters of white wine from Encruzado variety. A study on the effects of a different kind of wood on a white wine with no contact with lees

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    Mestrado Vinifera Euromaster - Viticulture and Enology - Instituto Superior de AgronomiaThe aim of this study was to assess the influence of blends of wood from different botanical species in a white wine from Encruzado variety; the botanical species used in this study were French oak (Quercus peatraea), American oak (Quercus alba) and Cherry (Prunus avium) during a 60 days maceration period, with sampling done after 15, 30 and 60 days. The blends were obtained by combining 2 woods species in a ratio of 1:1, obtaining 3 blends; that is, Cherry and American oak (Ch+Am), French and American oak (Fr+Am), and Cherry and American oak (Ch+Am). In addition to these treatments 3 Control treatments were created by adding single wood of Cherry (CCh), American oak (CAm) and French oak (CFr), moreover a treatment without wood was kept (C). The amount of wood used was the same for all the treatments, that is 0,5 g/l. on the different sampling days were run both sensory analysis, by a panel of judges, evaluating aroma and taste parameters, and chemical analysis, that is, total phenols, non flavonoids and flavonoids phenols, color evolution, maderization test and tanning power. At the end of the experiment statistical analysis showed relevant data in almost all the analysis, for the chemical analysis cherry showed the highest level of total phenols and flavonoids, which is reflected also in the blends with other woods, while the French oak and its blends showed significant levels of non flavonoids phenols. The browning potential showed an decrease in wines in contact with wood except for CCh, while tanning power showed an increase in all the wines in contact with wood with the blend of cherry and American being the highest tannicity. In the sensory analysis we can observe how the global appreciation of the wines decrease with increasing maceration period with the wood both for the taste and aroma parameters, with C being the most appreciated wine at the last sampling, while the sampling of 15 and 30 days shows the wine with cherry and with American oak showing the highest valuesN/

    Evolutionary modes in protein observable space: the case of Thioredoxins

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    In this article, we investigated the structural and dynamical evolutionary behaviour of a set of ten thioredoxin proteins as formed by three extant forms and seven resurrected ones in laboratory. Starting from the crystallographic structures, we performed all-atom molecular dynamics simulations and compare the trajectories in terms of structural and dynamical properties. Interestingly, the structural properties related to the protein density (i.e. the number of residues divided by the excluded molecular volume) well describe the protein evolutionary behaviour. Our results also suggest that the changes in sequence as occurred during the evolution have affected the protein essential motions, allowing us to discriminate between ancient and extant proteins in terms of their dynamical behaviour. Such results are yet more evident when the bacterial, archaeal and eukaryotic thioredoxins are separately analysed

    Deterministic Cramer-Rao bound for strictly non-circular sources and analytical analysis of the achievable gains

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    Recently, several high-resolution parameter estimation algorithms have been developed to exploit the structure of strictly second-order (SO) non-circular (NC) signals. They achieve a higher estimation accuracy and can resolve up to twice as many signal sources compared to the traditional methods for arbitrary signals. In this paper, as a benchmark for these NC methods, we derive the closed-form deterministic R-D NC Cramer-Rao bound (NC CRB) for the multi-dimensional parameter estimation of strictly non-circular (rectilinear) signal sources. Assuming a separable centro-symmetric R-D array, we show that in some special cases, the deterministic R-D NC CRB reduces to the existing deterministic R-D CRB for arbitrary signals. This suggests that no gain from strictly non-circular sources (NC gain) can be achieved in these cases. For more general scenarios, finding an analytical expression of the NC gain for an arbitrary number of sources is very challenging. Thus, in this paper, we simplify the derived NC CRB and the existing CRB for the special case of two closely-spaced strictly non-circular sources captured by a uniform linear array (ULA). Subsequently, we use these simplified CRB expressions to analytically compute the maximum achievable asymptotic NC gain for the considered two source case. The resulting expression only depends on the various physical parameters and we find the conditions that provide the largest NC gain for two sources. Our analysis is supported by extensive simulation results.Comment: submitted to IEEE Transactions on Signal Processing, 13 pages, 4 figure

    R-dimensional ESPRIT-type algorithms for strictly second-order non-circular sources and their performance analysis

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    High-resolution parameter estimation algorithms designed to exploit the prior knowledge about incident signals from strictly second-order (SO) non-circular (NC) sources allow for a lower estimation error and can resolve twice as many sources. In this paper, we derive the R-D NC Standard ESPRIT and the R-D NC Unitary ESPRIT algorithms that provide a significantly better performance compared to their original versions for arbitrary source signals. They are applicable to shift-invariant R-D antenna arrays and do not require a centrosymmetric array structure. Moreover, we present a first-order asymptotic performance analysis of the proposed algorithms, which is based on the error in the signal subspace estimate arising from the noise perturbation. The derived expressions for the resulting parameter estimation error are explicit in the noise realizations and asymptotic in the effective signal-to-noise ratio (SNR), i.e., the results become exact for either high SNRs or a large sample size. We also provide mean squared error (MSE) expressions, where only the assumptions of a zero mean and finite SO moments of the noise are required, but no assumptions about its statistics are necessary. As a main result, we analytically prove that the asymptotic performance of both R-D NC ESPRIT-type algorithms is identical in the high effective SNR regime. Finally, a case study shows that no improvement from strictly non-circular sources can be achieved in the special case of a single source.Comment: accepted at IEEE Transactions on Signal Processing, 15 pages, 6 figure

    On the SNR Variability in Noisy Compressed Sensing

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    Compressed sensing (CS) is a sampling paradigm that allows to simultaneously measure and compress signals that are sparse or compressible in some domain. The choice of a sensing matrix that carries out the measurement has a defining impact on the system performance and it is often advocated to draw its elements randomly. It has been noted that in the presence of input (signal) noise, the application of the sensing matrix causes SNR degradation due to the noise folding effect. In fact, it might also result in the variations of the output SNR in compressive measurements over the support of the input signal, potentially resulting in unexpected non-uniform system performance. In this work, we study the impact of a distribution from which the elements of a sensing matrix are drawn on the spread of the output SNR. We derive analytic expressions for several common types of sensing matrices and show that the SNR spread grows with the decrease of the number of measurements. This makes its negative effect especially pronounced for high compression rates that are often of interest in CS.Comment: 4 pages + reference

    Assessment of tissue fibrosis in skin biopsies from patients with systemic sclerosis employing confocal laser scanning microscopy: an objective outcome measure for clinical trials?

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    OBJECTIVES: To obtain an objective, unbiased assessment of skin fibrosis in patients with SSc for use in clinical trials of SSc disease-modifying therapeutics. METHODS: Skin biopsies from the dorsal forearm of six patients with diffuse SSc and six healthy controls, and skin biopsies from the forearm of one patient with diffuse SSc before and following 1 year treatment with mycophenolate mofetil were analysed by confocal laser scanning microscopy (CLSM) with specific antibodies against collagen types I and III or fibronectin. The integrated density of fluorescence (IDF) was calculated employing National Institutes of Health-ImageJ software in at least four different fields per biopsy spanning the full dermal thickness. RESULTS: The intensities of collagen types I and III and fibronectin IDF were 174, 147 and 139% higher in SSc skin than in normal skin, respectively. All differences were statistically significant. The sum of the IDF values obtained for the three proteins yielded a comprehensive fibrosis score. The average fibrosis score for the six SSc samples was 28.3 x 10(6) compared with 18.6 x 10(6) for the six normal skin samples (P \u3c 0.0001). Comparison of skin biopsies obtained from the same SSc patient before treatment and after 12 months of treatment with mycophenolate mofetil showed a reduction of 39% in total fibrosis score after treatment. CONCLUSIONS: CLSM followed by quantitative image analysis provides an objective and unbiased assessment of skin fibrosis in SSc and could be a useful end-point for clinical trials with disease-modifying agents to monitor the response or progression of the disease

    The ONIOM/PMM Model for Effective Yet Accurate Simulation of Optical and Chiroptical Spectra in Solution: Camphorquinone in Methanol as a Case Study

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    This paper deals with the development and first validation of a composite approach for the simulation of chiroptical spectra in solution aimed to strongly reduce the number of full QM computations without any significant accuracy loss. The approach starts from the quantum mechanical computation of reference spectra including vibrational averaging effects and taking average solvent effects into account by means of the polarizable continuum model. Next, the snapshots of classical molecular dynamics computations are clusterized and one reference configuration from each cluster is used to compute a reference spectrum. Local fluctuation effects within each cluster are then taken into account by means of the perturbed matrix model. The performance of the proposed approach is tested on the challenging case of the optical and chiroptical spectra of camphorquinone in methanol solution. Although further validations are surely needed, the results of this first study are quite promising also taking into account that agreement with experimental data is reached by just a couple of full quantum mechanical geometry optimizations and frequency computations

    5G new radio physical downlink control channel reliability enhancements for multiple transmission-reception-point communications

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    Non-coherent transmission from multiple transmission-reception-points (TRPs), i.e., base stations, or base station panels to a user equipment (UE) is exploited in 5G New Radio (NR) to improve downlink reliability and cell-edge throughput. Ultra reliable low-latency communications (URLLC) and enhanced Mobile BroadBand (eMBB) are prominent target use-cases for multi-TRP or multi-panel transmissions. In Third-Generation Partnership Project (3GPP) Release 17 specifications, multi-TRP-based transmissions were specified for the physical downlink control channel (PDCCH) specifically to enhance its reliability and robustness. In this work, a comprehensive account of various multi-TRP reliability enhancement schemes applicable for the 5G NR PDCCH, including the ones supported by the 3GPP Release 17 specifications, is provided. The impact of the specifications for each scheme, UE and network complexity and their utility in various use-cases is studied. Their error performances are evaluated via link-level simulations using the evaluation criteria agreed in the 3GPP proceedings. The 3GPP-supported multi-TRP PDCCH repetition schemes, and the additionally proposed PDCCH repetition and diversity schemes are shown to be effective in improving 5G NR PDCCH reliability and combating link blockage in mmWave scenarios. The link-level simulations also provide insights for the implementation of the decoding schemes for the PDCCH enhancements under different channel conditions. Analysis of the performance, complexity and implementation constraints of the proposed PDCCH transmission schemes indicate their suitability to UEs with reduced-capability or stricter memory constraints and flexible network scheduling

    CPL Spectra of Camphor Derivatives in Solution by an Integrated QM/MD Approach

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    We extend a recently proposed computational strategy for the simulation of absorption spectra of semi-rigid molecular systems in condensed phases to the emission spectra of flexible chromophores. As a case study, we have chosen the CPL spectrum of camphor in methanol solution, which shows a well-defined bisignate shape. The first step of our approach is the quantum mechanical computation of reference spectra including vibrational averaging effects and taking bulk solvent effects into account by means of the polarizable continuum model. In the present case, the large amplitude inversion mode is explicitly treated by a numerical approach, whereas the other small-amplitude vibrational modes are taken into account within the harmonic approximation. Next, the snapshots of classical molecular dynamics computations are clusterized and one representative configuration from each cluster is used to compute a reference spectrum. In the present case, different clusters correspond to the two stable conformers of camphor in the S1 excited electronic state and, for each of them, to different numbers of strong solute-solvent hydrogen bonds. Finally, local fluctuation effects within each cluster are taken into account by means of the perturbed matrix model. The overall procedure leads to good agreement with experiment for absorption and emission spectra together with their chiral counterparts, thus allowing to analyze the role of different effects (stereo-electronic, vibrational, environmental) in tuning the overall experimental spectra

    The role of allograft inflammatory factor 1 in systemic sclerosis

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    Purpose of review: The aim of this article is to review studies which support the hypothesis that allograft inflammatory factor-1, a protein initially identified in chronically rejected cardiac allografts, may be involved in the pathogenesis of the progressive fibroproliferative vasculopathy which is a hallmark of systemic sclerosis. Recent findings: Recent findings demonstrated elevated allograft inflammatory factor-1 expression both in systemic sclerosis affected tissues and peripheral blood mononuclear cells. A detailed immunohistopathologic study examined the tissue and cellular localization of the protein in affected systemic sclerosis tissues and demonstrated its expression in the endothelium of dermal and pulmonary vessels, in the pulmonary parenchyma, and in relevant inflammatory cells including T cells and macrophages. Furthermore, functional studies showed specific allograft inflammatory factor-1 isoform expression stimulation by transforming growth factor-[beta]. Summary: This review summarizes recent findings suggesting that allograft inflammatory factor-1 may play an important role in systemic sclerosis vasculopathy and provides supporting evidence to consider the molecule as a novel therapeutic target
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