1,828 research outputs found

    Cosmic ray secular variations in terrestrial records and aurorae

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    The rediscovery that the Sun and the solar wind can undergo important changes on historical time scales has brought into question the stability of the cyclic behavior of past time series of solar and solar-terrestrial origin. It was found by Vector Fourier analysis that the solar 11 year cycle is present in the series of 10Be, delta 180, in ice cores and of thermoluminescence (TL) in sea sediments during the last Millennia with a frequency modulation, related to the Sun behavior, as tested by comparison with the Sunspot number R sub z series. It was shown that the cyclogram of the series of yearly Aurorae from 1721 to 1979 linear-regression-corrected-for-R sub z is straight for the periodicity zeta=11,1y, which indicates that such periodicity is constant in time corresponding to the only line present in the 11y band. The maxima of this component appear at the same time together with the high speed solar wind streams taking place in coronal holes situated in high heliolatitudes. It is evidenced that the 11 year cycle has undergone frequency oscillations on a time scale of two centuries, although it is very difficult to determine the periodicities with high accuracy

    Cosmic rays 10Be biennal data and their relationship to aurorae and sunspots

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    The galactic cosmic ray (C.R.) variations which should give information on three dimensional aspects of the heliospheric magnetic fields and on the solar wind, which modulate their influx into the Solar System were studied. In order to decode the information from the C.R. series it is necessary to know the mechanisms through which the modulation is produced. It it clear that a balance of effects with sources at different heliospheric latitudes results in the modulated C.R. intensity. It is found that the modulation of 10Be in polar ice may be due to at least two main contributions: (1) negative and in phase with the Solar flare activity modulating the cosmic ray flux in Forbush-type decreases, and (2) positive in phase with the appearance of large wind streams situated at both polar coronal holes. It is found that the high heliolatitude activity is related to a stable periodicity of 11.1y whereas the low heliolatitude activity contributes to the wondering of the solar cycles

    Estimating local records for Northern and Central Italy from a sparse secular temperature network and from 1961–1990 climatologies

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    The paper presents monthly 30-arc-second-resolution Northern and Central Italy temperature climatologies and discusses the procedure we adopt to superimpose the information of temperature secular records onto these climatologies. The climatologies are obtained by means of a step-wise linear regression method which aims at determining the temperature dependence on geographical and morphological variables. Such a method is applied to a database of about 800 monthly 1961–1990 temperature normals. In the first regression (temperature vs. elevation) the recorded data are considered; the further regressions concern the residuals obtained after taking into account the effect of each variable, in order of importance. An estimated secular anomaly record can be obtained for each point of the climatology grid by means of a distance-weighted average of the temperature anomaly records of the stations surrounding the grid point

    The incorporation of alpha-tocopherol and functional doses of phytosterol esters during cheesemaking does not affect DNA or mRNA dynamics of Streptococcus thermophilus and Lactococcus lactis throughout and after the end of ripening

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    Tocopherols and phytosterols are lipid-soluble molecules which have been widely used in the food industry. Nevertheless, the influence of these compounds on the performance of starter lactic acid bacteria (SLAB) in fermented foods has received little attention. Here, we assessed the behavior of Streptococcus thermophilus and Lactococcus lactis during the ripening of a functional Port Salut light cheese elaborated with these SLAB and with alpha-tocopherol and phytosterol esters as bioactive molecules. Functional and control cheeses were manufactured at an industrial plant and sampled at 7, 21, 40, 60 and 90 days after elaboration for real-time quantitative PCR (qPCR) or reverse transcription-qPCR (RT-qPCR) experiments. Target DNA and mRNA from both SLAB were detected after 90 days of elaboration in both functional and control cheeses, supporting their potential role in generating flavor metabolites. Furthermore, here we showed for the first time that the addition of alpha-tocopherol and functional doses of phytosterols did not affect DNA or mRNA dynamics of these SLAB during cheesemaking, throughout and after the end of ripening. Therefore, our results support the use of cheese manufactured with both S. thermophilus and L. lactis as an optimal delivery system for these beneficial bioactive compounds.Fil: Pega, Juan Franco. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Pérez, Carolina Daiana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Rizzo, Sergio Anibal. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; ArgentinaFil: Rossetti, Luciana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; ArgentinaFil: Diaz, G.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; ArgentinaFil: Ruzal, Sandra Mónica. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nanni, M.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; ArgentinaFil: Descalzo, Adriana Maria. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Centre de Coopération Internationale en Recherche Agronomique pour le Développerment; Francia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Superficial heating evaluation by thermographic imaging before and after tecar therapy in six dogs submitted to a rehabilitation protocol: A pilot study

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    Thermography is a non-invasive diagnostic method commonly used to monitor changes of the body surface temperature potentially induced by different conditions such as fever, inflammation, trauma, or changes of tissue perfusion. Capacitive-resistive diathermy therapy (such as energy transfer capacitive and resistive\u2014Tecar) is commonly used in rehabilitation due to its diathemic effect secondary to blood circulation increase that could accelerate the healing process. The aim of this study was to monitor by thermal camera the diathermic effects induced by Tecar on the surface of the region of application. The investigation was conducted on six dogs referred for Tecar therapy to treat muscle contractures (three dogs) or osteoarthritis (three dogs). Eleven anatomical treated regions were recorded. Thermographic images and relative measurements were obtained by each region immediately before (T0), at conclusion (T1), and sixty seconds after the Tecar application (T2). Data were recorded and statistically analyzed. A comparison of temperature differences (maximum, minimum and mean values) between T0 and T1, T0 and T2, and T1 and T2 was performed by ANOVA test with Bonferroni post hoc (p 64 0.05). Statistically significant differences were detected for mean temperature between T0 (32.42 \ub1 1.57\u25e6C) and T1 (33.36 \ub1 1.17\u25e6C) (p = 0.040) and between T1 and T2 (32.83 \ub1 1.31\u25e6C) (p = 0.031). Furthermore, there was no significant difference between the mean temperature at T0 and T2, demonstrating that superficial diathermic effect exhausted within 60 s

    Recent results and new hardware developments for protein crystal growth in microactivity

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    Protein crystal growth experiments have been performed on 16 space shuttle missions since April, 1985. The initial experiments utilized vapor diffusion crystallization techniques similar to those used in laboratories for earth-based experiments. More recent experiments have utilized temperature induced crystallization as an alternative method for growing high quality protein crystals in microgravity. Results from both vapor diffusion and temperature induced crystallization experiments indicate that proteins grown in microgravity may be larger, display more uniform morphologies, and yield diffraction data to significantly higher resolutions than the best crystals of these proteins grown on earth

    The 500 ks Chandra observation of the z = 6.31 QSO SDSS J1030+0524

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    We present the results from a ∼500\sim500 ks Chandra observation of the z=6.31z=6.31 QSO SDSS J1030+0524. This is the deepest X-ray observation to date of a z∼6z\sim6 QSO. The QSO is detected with a total of 125 net counts in the full (0.5−70.5-7 keV) band and its spectrum can be modeled by a single power-law model with photon index of Γ=1.81±0.18\Gamma = 1.81 \pm 0.18 and full band flux of f=3.95×10−15f=3.95\times 10^{-15} erg s−1^{-1} cm−2^{-2}. When compared with the data obtained by XMM-Newton in 2003, our Chandra observation in 2017 shows a harder (ΔΓ≈−0.6\Delta \Gamma \approx -0.6) spectrum and a 2.5 times fainter flux. Such a variation, in a timespan of ∼2\sim2 yrs rest-frame, is unexpected for such a luminous QSO powered by a >109 M⊙> 10^9 \: M_{\odot} black hole. The observed source hardening and weakening could be related to an intrinsic variation in the accretion rate. However, the limited photon statistics does not allow us to discriminate between an intrinsic luminosity and spectral change, and an absorption event produced by an intervening gas cloud along the line of sight. We also report the discovery of diffuse X-ray emission that extends for 30"x20" southward the QSO with a signal-to-noise ratio of ∼\sim6, hardness ratio of HR=0.03−0.25+0.20HR=0.03_{-0.25}^{+0.20}, and soft band flux of f0.5−2 keV=1.1−0.3+0.3×10−15f_{0.5-2 \: keV}= 1.1_{-0.3}^{+0.3} \times 10^{-15} erg s−1^{-1} cm−2^{-2}, that is not associated to a group or cluster of galaxies. We discuss two possible explanations for the extended emission, which may be either associated with the radio lobe of a nearby, foreground radio galaxy (at z≈1−2z \approx 1-2), or ascribed to the feedback from the QSO itself acting on its surrounding environment, as proposed by simulations of early black hole formation.Comment: 13 pages, 9 figures, A&A accepte
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