143 research outputs found

    Compound-specific stable carbon isotope values of fatty acids in modern aquatic and terrestrial animals from the Baltic Sea and Finland as an aid to interpretations of the origins of organic residues preserved in archaeological pottery

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    The compound-specific stable carbon isotope (δ13C) analysis of organic residues is commonly used in the identification of lipid residues preserved in archaeological cooking vessels. This paper reports on the δ13C values for saturated fatty acids from modern freshwater and brackish fish, wild mammals, domesticated animal muscle tissues, and their milk, collected from Finland and the Baltic Sea. Differences are shown to exist in the δ13C values of carcass fatty acids of reindeer (Rangifer tarandus), wild forest reindeer (Rangifer tarandus fennicus), and other ruminant animals. Thus, the results reported in this paper show the importance of using modern reference fat data from similar ecological conditions to those of the studied archaeological site. This is especially vital at sites where wild fauna are known to have contributed significantly to human diet. In addition, discussion on problems related to representativeness of modern reference animal tissues for the interpretation of ancient fats is also carried out.</p

    Characterization of the Pore Structure of Functionalized Calcium Carbonate Tablets by Terahertz Time-Domain Spectroscopy and X-Ray Computed Microtomography

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    Novel excipients are entering the market to enhance the bioavailability of drug particles by having a high porosity and, thus, providing a rapid liquid uptake and disintegration to accelerate subsequent drug dissolution. One example of such a novel excipient is functionalized calcium carbonate, which enables the manufacture of compacts with a bimodal pore size distribution consisting of larger interparticle and fine intraparticle pores. Five sets of functionalized calcium carbonate tablets with a target porosity of 45%-65% were prepared in 5% steps and characterized using terahertz time-domain spectroscopy and X-ray computed microtomography. Terahertz time-domain spectroscopy was used to derive the porosity using effective medium approximations, that is, the traditional and an anisotropic Bruggeman model. The anisotropic Bruggeman model yields the better correlation with the nominal porosity (R2^{2} = 0.995) and it provided additional information about the shape and orientation of the pores within the powder compact. The spheroidal (ellipsoids of revolution) shaped pores have a preferred orientation perpendicular to the compaction direction causing an anisotropic behavior of the dielectric porous medium. The results from X-ray computed microtomography confirmed the nonspherical shape and the orientation of the pores, and it further revealed that the anisotropic behavior is mainly caused by the interparticle pores. The information from both techniques provides a detailed insight into the pore structure of pharmaceutical tablets. This is of great interest to study the impact of tablet microstructure on the disintegration and dissolution performance.Drs Markl and Zeitler would like to acknowledge the U.K. Engineering and Physical Sciences Research Council for funding (EP/L019922/1)

    Radio-to-UV monitoring of AO 0235+164 by the WEBT and Swift during the 2006--2007 outburst

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    The blazar AO 0235+164 was claimed to show a quasi-periodic behaviour in the radio and optical bands. Moreover, an extra emission component contributing to the UV and soft X-ray flux was detected, whose nature is not yet clear. A predicted optical outburst was observed in late 2006/early 2007. We here present the radio-to-optical WEBT light curves during the outburst, together with UV data acquired by Swift in the same period. We found the optical outburst to be as strong as the big outbursts of the past: starting from late September 2006, a brightness increase of 5 mag led to the outburst peak in February 19-21, 2007. We also observed an outburst at mm and then at cm wavelengths, with an increasing time delay going toward lower frequencies during the rising phase. Cross-correlation analysis indicates that the 1 mm and 37 GHz flux variations lagged behind the R-band ones by about 3 weeks and 2 months, respectively. These short time delays suggest that the corresponding jet emitting regions are only slightly separated and/or misaligned. In contrast, during the outburst decreasing phase the flux faded contemporaneously at all cm wavelengths. This abrupt change in the emission behaviour may suggest the presence of some shutdown mechanism of intrinsic or geometric nature. The behaviour of the UV flux closely follows the optical and near-IR one. By separating the synchrotron and extra component contributions to the UV flux, we found that they correlate, which suggests that the two emissions have a common origin.Comment: 9 pages, 7 figures, in press for Astronomy and Astrophysic

    Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution

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    The larger number of models of asteroid shapes and their rotational states derived by the lightcurve inversion give us better insight into both the nature of individual objects and the whole asteroid population. With a larger statistical sample we can study the physical properties of asteroid populations, such as main-belt asteroids or individual asteroid families, in more detail. Shape models can also be used in combination with other types of observational data (IR, adaptive optics images, stellar occultations), e.g., to determine sizes and thermal properties. We use all available photometric data of asteroids to derive their physical models by the lightcurve inversion method and compare the observed pole latitude distributions of all asteroids with known convex shape models with the simulated pole latitude distributions. We used classical dense photometric lightcurves from several sources and sparse-in-time photometry from the U.S. Naval Observatory in Flagstaff, Catalina Sky Survey, and La Palma surveys (IAU codes 689, 703, 950) in the lightcurve inversion method to determine asteroid convex models and their rotational states. We also extended a simple dynamical model for the spin evolution of asteroids used in our previous paper. We present 119 new asteroid models derived from combined dense and sparse-in-time photometry. We discuss the reliability of asteroid shape models derived only from Catalina Sky Survey data (IAU code 703) and present 20 such models. By using different values for a scaling parameter cYORP (corresponds to the magnitude of the YORP momentum) in the dynamical model for the spin evolution and by comparing synthetics and observed pole-latitude distributions, we were able to constrain the typical values of the cYORP parameter as between 0.05 and 0.6.Comment: Accepted for publication in A&A, January 15, 201

    Sähköisten terveyspalveluiden opetus lääketieteessä

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    Digitalisaation myötä terveydenhuollon toiminnot muuttuvat nopeasti, ja sähköiset työkalut sekä palvelut ovat jo arkipäivää. Vaikutukset näkyvät koulutustarpeena, koska terveydenhuollon ammattilaisten digiosaaminen tulee turvata. Lääkärien peruskoulutuksen tulisi sisältää etälääketiedettä ja sähköisen terveydenhuollon palveluja (e-health) koskevaa opetusta. Kansallisessa MEDigi-hankkeessa määriteltiin suomalaisen e-health-opetuksen aihealueet ja tehtiin niille ydinainesanalyysi. Työryhmän työn perusteella määräytyi kaksitoista e-health-opetukseen soveltuvaa aihealuetta lääketieteen ja hammaslääketieteen peruskoulutuksessa. Niiden sisältämien opetusaiheiden keskeisyys määriteltiin kolmiportaisesti. Tuloksia sovellettiin pilottina Oulun yliopistossa lääketieteen viidennen vuosikurssin opiskelijoille toteutettuun teemapäivään, jonka opetussisältö muokattiin vastaamaan ydinainesanalyysin tuloksia. Opetus toteutettiin koronapandemian takia kokonaan etäopetuksena. Jatkossa tavoitteena on kansallisesti integroida ydinainesanalyysiin perustuva e-health-opetus suomalaiseen lääkärikoulutukseen

    The Recently-Discovered Dwarf Nova System ASAS J002511+1217.2: A New WZ Sagittae Star

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    The cataclysmic variable ASAS J002511+1217.2 was discovered in outburst by the All-Sky Automated Survey in September 2004, and intensively monitored by AAVSO observers through the following two months. Both photometry and spectroscopy indicate that this is a very short-period system. Clearly defined superhumps with a period of 0.05687 +/- 0.00001 days (1-sigma) are present during the superoutburst, 5 to 18 days following the ASAS detection. We observe a change in superhump profile similar to the transition to ``late superhumps'' observed in other short-period systems; the superhump period appears to increase slightly for a time before returning to the original value, with the resulting superhump phase offset by approximately half a period. We detect variations with a period of 0.05666 +/- 0.00003 days (1-sigma) during the four-day quiescent phase between the end of the main outburst and the single echo outburst. Weak variations having the original superhump period reappear during the echo and its rapid decline. Time-resolved spectroscopy conducted nearly 30 days after detection and well into the decline yields an orbital period measurement of 82 +/- 5 minutes. Both narrow and broad components are present in the emission line spectra, indicating the presence of multiple emission regions. The weight of the observational evidence suggests that ASAS J002511+1217.2 is a WZ Sge-type dwarf nova, and we discuss how this system fits into the WZ classification scheme.Comment: 24 pages, 11 figures, accepted to PASP; minor revision to add two authors and adjust text to match that of the published version. No adjustments to results or conclusion

    WEBT and XMM-Newton observations of 3C 454.3 during the post-outburst phase. Detection of the little and big blue bumps

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    The blazar 3C 454.3 underwent an unprecedented optical outburst in spring 2005. This was first followed by a mm and then by a cm radio outburst, which peaked in February 2006. We report on follow-up observations by the WEBT to study the multiwavelength emission in the post-outburst phase. XMM-Newton observations on July and December 2006 added information on the X-ray and UV fluxes. The source was in a faint state. The radio flux at the higher frequencies showed a fast decreasing trend, which represents the tail of the big radio outburst. It was followed by a quiescent state, common at all radio frequencies. In contrast, moderate activity characterized the NIR and optical light curves, with a progressive increase of the variability amplitude with increasing wavelength. We ascribe this redder-when-brighter behaviour to the presence of a "little blue bump" due to line emission from the broad line region, which is clearly visible in the source SED during faint states. Moreover, the data from the XMM-Newton OM reveal a rise of the SED in the UV, suggesting the existence of a "big blue bump" due to thermal emission from the accretion disc. The X-ray spectra are well fitted with a power-law model with photoelectric absorption, possibly larger than the Galactic one. However, the comparison with previous X-ray observations would imply that the amount of absorbing matter is variable. Alternatively, the intrinsic X-ray spectrum presents a curvature, which may depend on the X-ray brightness. In this case, two scenarios are possible.Comment: 9 pages, 7 figures, accepted for publication in A&
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