821 research outputs found

    The Effect of Colcemid on the Heat Survival of Mitotic V79 Chinese Hamster Cells

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    V79 Chinese hamster cells were collected by colcemid addition to study the effect of heat on mitosis. When they were heated at 42°C and 45°C in the presence of 0.06 μg/mL colcemid, cell survival increased over the control samples, which were heated in ordinary medium. Scanning electron microscopy showed that cells heated to 45°C in the presence or absence of colcemid had fewer microvilli on the surface, but they did not have increased bleb formation. Transmission electron microscopy showed that the chromatin was diffuse in the heated cells and the kinetochores were indistinct. The mitochondria in the heated cells were also swollen and contained visible particles

    ArCo: the Italian Cultural Heritage Knowledge Graph

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    ArCo is the Italian Cultural Heritage knowledge graph, consisting of a network of seven vocabularies and 169 million triples about 820 thousand cultural entities. It is distributed jointly with a SPARQL endpoint, a software for converting catalogue records to RDF, and a rich suite of documentation material (testing, evaluation, how-to, examples, etc.). ArCo is based on the official General Catalogue of the Italian Ministry of Cultural Heritage and Activities (MiBAC) - and its associated encoding regulations - which collects and validates the catalogue records of (ideally) all Italian Cultural Heritage properties (excluding libraries and archives), contributed by CH administrators from all over Italy. We present its structure, design methods and tools, its growing community, and delineate its importance, quality, and impact

    Activity of 50 Long-Period Comets Beyond 5.2 AU

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    Remote investigations of the ancient solar system matter has been traditionally carried out through the observations of long-period (LP) comets that are less affected by solar irradiation than the short-period counterparts orbiting much closer to the Sun. Here we summarize the results of our decade-long survey of the distant activity of LP comets. We found that the most important separation in the dataset is based on the dynamical nature of the objects. Dynamically new comets are characterized by a higher level of activity on average: the most active new comets in our sample can be characterized by afrho values >3--4 higher than that of our most active returning comets. New comets develop more symmetric comae, suggesting a generally isotropic outflow. Contrary to this, the coma of recurrent comets can be less symmetrical, ocassionally exhibiting negative slope parameters, suggesting sudden variations in matter production. The morphological appearance of the observed comets is rather diverse. A surprisingly large fraction of the comets have long, teniouos tails, but the presence of impressive tails does not show a clear correlation with the brightness of the comets.Comment: 21 pages, 4 figures, accepted for publication in A

    The Szemeredi-Trotter Theorem in the Complex Plane

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    It is shown that nn points and ee lines in the complex Euclidean plane C2{\mathbb C}^2 determine O(n2/3e2/3+n+e)O(n^{2/3}e^{2/3}+n+e) point-line incidences. This bound is the best possible, and it generalizes the celebrated theorem by Szemer\'edi and Trotter about point-line incidences in the real Euclidean plane R2{\mathbb R}^2.Comment: 24 pages, 5 figures, to appear in Combinatoric

    Leiomyosarcoma of the breast in a patient with a 10-year-history of cyclophosphamide exposure: a case report

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    A 50 year old woman with a 10-year history of systemic lupus erythematosus (SLE) and intermittent low-dose cyclophosphamide therapy developed a palpable mass at the periphery of her left breast. Ultrasound guided core biopsy revealed a spindle cell neoplasm characterized on final pathology as a low grade leiomyosarcoma

    SN 2016coi/ASASSN-16fp: An example of residual helium in a type Ic supernova?

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    The optical observations of Ic-4 supernova (SN) 2016coi/ASASSN-16fp, from 2\sim 2 to 450\sim450 days after explosion, are presented along with analysis of its physical properties. The SN shows the broad lines associated with SNe Ic-3/4 but with a key difference. The early spectra display a strong absorption feature at 5400\sim 5400 \AA\ which is not seen in other SNe~Ic-3/4 at this epoch. This feature has been attributed to He I in the literature. Spectral modelling of the SN in the early photospheric phase suggests the presence of residual He in a C/O dominated shell. However, the behaviour of the He I lines are unusual when compared with He-rich SNe, showing relatively low velocities and weakening rather than strengthening over time. The SN is found to rise to peak 16\sim 16 d after core-collapse reaching a bolometric luminosity of Lp 3×1042\sim 3\times10^{42} \ergs. Spectral models, including the nebular epoch, show that the SN ejected 2.542.5-4 \msun\ of material, with 1.5\sim 1.5 \msun\ below 5000 \kms, and with a kinetic energy of (4.57)×1051(4.5-7)\times10^{51} erg. The explosion synthesised 0.14\sim 0.14 \msun\ of 56Ni. There are significant uncertainties in E(B-V)host and the distance however, which will affect Lp and MNi. SN 2016coi exploded in a host similar to the Large Magellanic Cloud (LMC) and away from star-forming regions. The properties of the SN and the host-galaxy suggest that the progenitor had MZAMSM_\mathrm{ZAMS} of 232823-28 \msun\ and was stripped almost entirely down to its C/O core at explosion.Comment: Accepted for publication in MNRAS. Updated to reflect the published version, minor typographical changes onl

    Y-chromosomal connection between Hungarians and geographically distant populations of the Ural Mountain region and West Siberia

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    Hungarians who live in Central Europe today are one of the westernmost Uralic speakers. Despite of the proposed Volga-Ural/West Siberian roots of the Hungarian language, the present-day Hungarian gene pool is highly similar to that of the surrounding Indo-European speaking populations. However, a limited portion of specific Y-chromosomal lineages from haplogroup N, sometimes associated with the spread of Uralic languages, link modern Hungarians with populations living close to the Ural Mountain range on the border of Europe and Asia. Here we investigate the paternal genetic connection between these spatially separated populations. We reconstruct the phylogeny of N3a4-Z1936 clade by using 33 high-coverage Y-chromosomal sequences and estimate the coalescent times of its sub-clades. We genotype close to 5000 samples from 46 Eurasian populations to show the presence of N3a4-B539 lineages among Hungarians and in the populations from Ural Mountain region, including Ob-Ugric-speakers from West Siberia who are geographically distant but linguistically closest to Hungarians. This sub-clade splits from its sister-branch N3a4-B535, frequent today among Northeast European Uralic speakers, 4000–5000 ya, which is in the time-frame of the proposed divergence of Ugric languages

    Анализ результатов биопсий предстательной железы, выполненных с 10-летним интервалом

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    Introduction and objective: the authors compared the results of biopsies performed in 1994 and 2004, respectively.The analysis of the results of prostate biopsy obtained in 1994 and 2004 was carried out. Prostate cancer is the most common malignant tumor in males; its diagnostic algorithm and therapy were analyzed. The aim of the study was to compare data from the prostate biopsies performed in 1994 with those of 2004. During this decade, 4.5 fold increase of the number of prostate biopsies has been observed. In 1994, 36.2%, while in 2004, 47.5% of the biopsies proved to be a cancer. The mean age of the patients undergoing biopsy decreased from 69.7 to 62.3 years; however, the mean age of patients who were suffering from prostate cancer remained constant (70.8 vs. 71.3 years).Conclusions: Whereas in 1994 only the total level of PSA was estimated, in 2004 the diagnostic algorithm included additional measurements of free-PSA and PSA-density. Prostate biopsy was performed by a trans-rectal ultrasound guided technique unlike the blind or trans-perineal methods which were only available previously. Although the effectiveness of the prostate biopsy is improved, the diagnosis and identification of prostate cancer at a younger age remains to be a challenge. The Gleason score marking the aggressiveness of the prostate cancers was lower; therefore, more patients were found suitable for curative surgery. However, the increased mean value of PSA level indicated that patients were still rather of a more advanced stage in majority, which could only be treated by palliative therapy.

    Absolute Distances to Nearby Type Ia Supernovae via Light Curve Fitting Methods

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    We present a comparative study of absolute distances to a sample of very nearby, bright Type Ia supernovae (SNe) derived from high cadence, high signal-to-noise, multi-band photometric data. Our sample consists of four SNe: 2012cg, 2012ht, 2013dy and 2014J. We present new homogeneous, high-cadence photometric data in Johnson-Cousins BVRI and Sloan g' r' i' z' bands taken from two sites (Piszkesteto and Baja, Hungary), and the light curves are analyzed with publicly available light curve fitters (MLCS2k2, SNooPy2 and SALT2.4). When comparing the best-fit parameters provided by the different codes, it is found that the distance moduli of moderately reddened SNe Ia agree within less than or similar to 0.2 mag, and the agreement is even better (less than or similar to 0.1 mag) for the highest signal-to-noise BVRI data. For the highly reddened SN 2014J the dispersion of the inferred distance moduli is slightly higher. These SN-based distances are in good agreement with the Cepheid distances to their host galaxies. We conclude that the current state-of-the-art light curve fitters for Type Ia SNe can provide consistent absolute distance moduli having less than similar to 0.1-0.2 mag uncertainty for nearby SNe. Still, there is room for future improvements to reach the desired similar to 0.05 mag accuracy in the absolute distance modulus
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