145 research outputs found

    Tyrnipuristeen sisältämät rasvaliukoiset uuteaineet

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    Tiivistelmä. Mehun tuotannossa marjoja puristetaan, ja niistä jää jäljelle kiinteä osa. Kiinteää osaa kutsutaan puristeeksi, ja sitä syntyy tyrnimehun puristuksessa lähes saman verran kuin itse mehua. Tyrnipuriste on merkittävä mehun tuotannon sivuvirta, jonka hyödyntäminen parantaa mehun tuotannon kannattavuutta ja ympäristöystävällisyyttä. Tutkielmassa tarkastellaan puristeen sisältämiä yhdisteitä ja puristeen käyttökohteita, keskittyen erityisesti öljyn uuttamiseen puristeesta. Eri uuttomenetelmiä verrataan, käydään läpi parhaat uuttoparametrit, sekä vertaillaan menetelmien tehoa tokoferolien, sterolien ja karotenoidien uuttoon. Tutkielmassa tarkastellaan myös valitun uuttomenetelmän vaikutusta ympäristöön ja terveyteen. Aineistoina käytettiin tutkimusdataa tyrniöljyn uutosta, puristeen sekä koko marjan sisällöstä ja muuta tyrniöljyn sekä puristeen käyttökohteisiin ja kiinteä-nesteuuttoon liittyvää tietoa. Tyrniöljyn uutossa puristeesta käytetään poolittomia liuottimia, esimerkiksi heksaania. Heksaani on fossiilisiin raaka-aineisiin pohjautuva liuotin, ja uusia vihreitä uuttomenetelmiä on kehitetty sen syrjäyttämiseksi. Näistä tutkielmassa tarkastellaan ylikriittistä hiilidioksidiuuttoa, ylikriittistä uuttoa kanssaliuottimella, paineistettua nesteuuttoa, ultraääniavusteista uuttoa, mikroaaltoavusteista uuttoa, entsyymiavusteista uuttoa ja emulsiopohjaista uuttoa. Tyrnin puristeöljy sisältää paljon rasvahappoja, tokoferoleja, steroleja ja karotenoideja. Rasvahapoista suurin osa on monityydyttymättömiä. Ylikriittinen hiilidioksidi ja monet muut vihreät liuottimet ja uuttomenetelmät ovat toimiva tapa uuttaa tyrnin puristeöljyä. Esimerkiksi ylikriittisellä hiilidioksidilla päästään samansuuruisiin tuloksiin kaikkien tässä tutkielmassa käsitellyiden yhdisteiden uutossa

    Mass calibration of the CODEX cluster sample using SPIDERS spectroscopy - II. The X-ray luminosity-mass relation

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    We perform the calibration of the X-ray luminosity-mass scaling relation on a sample of 344 CODEX clusters with z <0.66 using the dynamics of their member galaxies. Spectroscopic follow-up measurements have been obtained from the SPIDERS survey, leading to a sample of 6658 red member galaxies. We use the Jeans equation to calculate halo masses, assuming an NFW mass profile and analysing a broad range of anisotropy profiles. With a scaling relation of the form L-X proportional to A(X)M(200c)(BX) E(z)(2)(1 + z)(gamma x), we find best-fitting parameters A(X) = 0.62(-0.06)(+0.05) (+/- 0.06) x 10(44) erg s(-)(1), B-X = 2.35(-0.18)(+0.21)(+/- 0.09), gamma(X) = -2.77(-1.05)(+1.06)(+/- 0.79), where we include systematic uncertainties in parentheses and for a pivot mass and redshift of 3 x 10(14) M-circle dot and 0.16, respectively. We compare our constraints with previous results, and we combine our sample with the SPT SZE-selected cluster subsample observed with XMM-Newton extending the validity of our results to a wider range of redshifts and cluster masses.Peer reviewe

    A large-scale study of microplastic abundance in sediment cores from the UK continental shelf and slope

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    To inform risk assessments, reliable, time efficient and affordable quantification methods are required for creating a microplastic (MP) pollution baseline in the world's oceans. To facilitate this, MP abundance was investigated in sediments of three contrasting areas of the UK continental shelf: North West of Jones Bank, the Canyons in the Celtic Sea and Dogger Bank in the North Sea, utilising the Nile Red tagging method to assess its time efficiency and cost. Average MP abundance in the top 10 cm was 1050–2700 MP kg−1. MP abundance decreased with increasing sediment depth and increased with increasing water depth. The findings emphasise the extent of MP pollution and illustrate the value of Nile Red for large scale mapping at relatively low cost

    SPIDERS : overview of the X-ray galaxy cluster follow-up and the final spectroscopic data release

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    SPIDERS (The SPectroscopic IDentification of eROSITA Sources) is a large spectroscopic programme for X-ray selected galaxy clusters as part of the Sloan Digital Sky Survey-IV (SDSS-IV). We describe the final data set in the context of SDSS Data Release 16 (DR16): the survey overall characteristics, final targeting strategies, achieved completeness, and spectral quality, with special emphasis on its use as a galaxy cluster sample for cosmology applications. SPIDERS now consists of about 27 000 new optical spectra of galaxies selected within 4000 photometric red sequences, each associated with an X-ray source. The excellent spectrograph efficiency and a robust analysis pipeline yield a spectroscopic redshift measurement success rate exceeding 98 per cent, with a median velocity accuracy of 20 kms(-1) (at z = 0.2). Using the catalogue of 2740 X-ray galaxy clusters confirmed with DR16 spectroscopy, we reveal the 3D map of the galaxy cluster distribution in the observable Universe up to z similar to 0.6. We highlight the homogeneity of the member galaxy spectra among distinct regions of the galaxy cluster phase space. Aided by accurate spectroscopic redshifts and by a model of the sample selection effects, we compute the galaxy cluster X-ray luminosity function and we present its lack of evolution up to z = 0.6. Finally we discuss the prospects of forthcoming large multiplexed spectroscopic programmes dedicated to follow up the next generation of all-sky X-ray source catalogues.Peer reviewe

    Testing of the assisting software for radiologists analysing head CT images: lessons learned

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    Background: Assessing a plan for user testing and evaluation of the assisting software developed for radiologists.Methods: Test plan was assessed in experimental testing, where users performed reporting on head computed tomography studies with the aid of the software developed. The user testing included usability tests, questionnaires, and interviews. In addition, search relevance was assessed on the basis of user opinions.Results: The testing demonstrated weaknesses in the initial plan and enabled improvements. Results showed that the software has acceptable usability level but some minor fixes are needed before larger-scale pilot testing. The research also proved that it is possible even for radiologists with under a year's experience to perform reporting of non-obvious cases when assisted by the software developed. Due to the small number of test users, it was impossible to assess effects on diagnosis quality.Conclusions: The results of the tests performed showed that the test plan designed is useful, and answers to the key research questions should be forthcoming after testing with more radiologists. The preliminary testing revealed opportunities to improve test plan and flow, thereby illustrating that arranging preliminary test sessions prior to any complex scenarios is beneficial

    Mass calibration of the CODEX cluster sample using SPIDERS spectroscopy - I. The richness-mass relation

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    This article has an erratum: DOI 10.1093/mnras/stz1826We use galaxy dynamical information to calibrate the richness-mass scaling relation of a sample of 428 galaxy clusters that are members of the CODEX sample with redshifts up to z similar to 0.7. These clusters were X-ray selected using the ROSAT All-Sky Survey (RASS) and then cross-matched to associated systems in the redMaPPer (the red sequence Matched-filter Probabilistic Percolation) catalogue from the Sloan Digital Sky Survey. The spectroscopic sample we analyse was obtained in the SPIDERS program and contains similar to 7800 red member galaxies. Adopting NFW mass and galaxy density profiles and a broad range of orbital anisotropy profiles, we use the Jeans equation to calculate halo masses. Modelling the scaling relation as lambda proportional to A(lambda) M-200c(B lambda) (1 + z)()lambda), we find the parameter constraints A(lambda) = 38.6(-4.1)(+3.1) +/- 3.9, B-lambda = 0.99(-0.07)(+0.06) +/- 0.04, and gamma(lambda) = -1.13(-0.34)(+0.32) +/- 0.49, where we present systematic uncertainties as a second component. We find good agreement with previously published mass trends with the exception of those from stacked weak lensing analyses. We note that although the lensing analyses failed to account for the Eddington bias, this is not enough to explain the differences. We suggest that differences in the levels of contamination between pure redMaPPer and RASS + redMaPPer samples could well contribute to these differences. The redshift trend we measure is more negative than but statistically consistent with previous results. We suggest that our measured redshift trend reflects a change in the cluster galaxy red sequence (RS) fraction with redshift, noting that the trend we measure is consistent with but somewhat stronger than an independently measured redshift trend in the RS fraction. We also examine the impact of a plausible model of correlated scatter in X-ray luminosity and optical richness, showing it has negligible impact on our results.Peer reviewe

    Stellar mass-halo mass relation for the brightest central galaxies of X-ray clusters since z similar to 0.65

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    We present the brightest cluster galaxies (BCGs) catalog for SPectroscoic IDentification of eROSITA Sources (SPIDERS) DR14 cluster program value-added catalog. We list the 416 BCGs identified as part of this process, along with their stellar mass, star formation rates (SFRs), and morphological properties. We identified the BCGs based on the available spectroscopic data from SPIDERS and photometric data from SDSS. We computed stellar masses and SFRs of the BCGs on the basis of SDSS, WISE, and GALEX photometry using spectral energy distribution fitting. Morphological properties for all BCGs were derived by Sersic profile fitting using the software package SIGMA in different optical bands (g,r,i). We combined this catalog with the BCGs of galaxy groups and clusters extracted from the deeper AEGIS, CDFS, COSMOS, XMM-CFHTLS, and XMM-XXL surveys to study the stellar mass-halo mass relation using the largest sample of X-ray groups and clusters known to date. This result suggests that the mass growth of the central galaxy is controlled by the hierarchical mass growth of the host halo. We find a strong correlation between the stellar mass of BCGs and the mass of their host halos. This relation shows no evolution since z similar to 0.65. We measure a mean scatter of 0.21 and 0.25 for the stellar mass of BCGs in a given halo mass at low (0.1 <z <0.3) and high (0.3 <z <0.65) redshifts, respectively. We further demonstrate that the BCG mass is covariant with the richness of the host halos in the very X-ray luminous systems. We also find evidence that part of the scatter between X-ray luminosity and richness can be reduced by considering stellar mass as an additional variable.Peer reviewe

    Gathering at the top? Environmental controls of microplastic uptake and biomagnification in freshwater food webs

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    Microplastics are ubiquitous in the environment, with high concentrations being detected now also in river corridors and sediments globally. Whilst there has been increasing field evidence of microplastics accumulation in the guts and tissues of freshwater and marine aquatic species, the uptake mechanisms of microplastics into freshwater food webs, and the physical and geological controls on pathway-specific exposures to microplastics, are not well understood. This knowledge gap is hampering the assessment of exposure risks, and potential ecotoxicological and public health impacts from microplastics. This review provides a comprehensive synthesis of key research challenges in analysing the environmental fate and transport of microplastics in freshwater ecosystems, including the identification of hydrological, sedimentological and particle property controls on microplastic accumulation in aquatic ecosystems. This mechanistic analysis outlines the dominant pathways for exposure to microplastics in freshwater ecosystems and identifies potentially critical uptake mechanisms and entry pathways for microplastics and associated contaminants into aquatic food webs as well as their risk to accumulate and biomagnify. We identify seven key research challenges that, if overcome, will permit the advancement beyond current conceptual limitations and provide the mechanistic process understanding required to assess microplastic exposure, uptake, hazard, and overall risk to aquatic systems and humans, and provide key insights into the priority impact pathways in freshwater ecosystems to support environmental management decision making

    Attachment and Entry of Chlamydia Have Distinct Requirements for Host Protein Disulfide Isomerase

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    Chlamydia is an obligate intracellular pathogen that causes a wide range of diseases in humans. Attachment and entry are key processes in infectivity and subsequent pathogenesis of Chlamydia, yet the mechanisms governing these interactions are unknown. It was recently shown that a cell line, CHO6, that is resistant to attachment, and thus infectivity, of multiple Chlamydia species has a defect in protein disulfide isomerase (PDI) N–terminal signal sequence processing. Ectopic expression of PDI in CHO6 cells led to restoration of Chlamydia attachment and infectivity; however, the mechanism leading to this recovery was not ascertained. To advance our understanding of the role of PDI in Chlamydia infection, we used RNA interference to establish that cellular PDI is essential for bacterial attachment to cells, making PDI the only host protein identified as necessary for attachment of multiple species of Chlamydia. Genetic complementation and PDI-specific inhibitors were used to determine that cell surface PDI enzymatic activity is required for bacterial entry into cells, but enzymatic function was not required for bacterial attachment. We further determined that it is a PDI-mediated reduction at the cell surface that triggers bacterial uptake. While PDI is necessary for Chlamydia attachment to cells, the bacteria do not appear to utilize plasma membrane–associated PDI as a receptor, suggesting that Chlamydia binds a cell surface protein that requires structural association with PDI. Our findings demonstrate that PDI has two essential and independent roles in the process of chlamydial infectivity: it is structurally required for chlamydial attachment, and the thiol-mediated oxido-reductive function of PDI is necessary for entry

    Stellar mass -- halo mass relation for the brightest central galaxies of X-ray clusters since z~0.65

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    We present the brightest cluster galaxies (BCGs) catalog for SPectroscoic IDentification of eROSITA Sources (SPIDERS) DR14 cluster program value-added catalog. We list the 416 BCGs identified as part of this process, along with their stellar mass, star formation rates, and morphological properties. We identified the BCGs based on the available spectroscopic data from SPIDERS and photometric data from SDSS. We computed stellar masses and SFRs of the BCGs on the basis of SDSS, WISE, and GALEX photometry using spectral energy distribution fitting. Morphological properties for all BCGs were derived by Sersic profile fitting using the software package SIGMA in different optical bands (g,r,i). We combined this catalog with the BCGs of galaxy groups and clusters extracted from the deeper AEGIS, CDFS, COSMOS, XMM-CFHTLS, and XMM-XXL surveys to study the stellar mass - halo mass relation using the largest sample of X-ray groups and clusters known to date. This result suggests that the mass growth of the central galaxy is controlled by the hierarchical mass growth of the host halo. We find a strong correlation between the stellar mass of BCGs and the mass of their host halos. This relation shows no evolution since z \sim 0.65. We measure a mean scatter of 0.21 and 0.25 for the stellar mass of BCGs in a given halo mass at low (0.1<z<0.30.1<z < 0.3) and high (0.3<z<0.650.3<z<0.65) redshifts, respectively. We further demonstrate that the BCG mass is covariant with the richness of the host halos in the very X-ray luminous systems. We also find evidence that part of the scatter between X-ray luminosity and richness can be reduced by considering stellar mass as an additional variable
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