1,335 research outputs found

    Open-closed Gromov-Witten invariants of 3-dimensional Calabi-Yau smooth toric DM stacks

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    We study open-closed orbifold Gromov-Witten invariants of 3-dimensional Calabi-Yau smooth toric Deligne-Mumford (DM) stacks (with possibly non-trivial generic stabilizers and semi-projective coarse moduli spaces) relative to Lagrangian branes of Aganagic-Vafa type. We present foundational materials of enumerative geometry of stable holomorphic maps from bordered orbifold Riemann surfaces to a 3-dimensional Calabi-Yau smooth toric DM stack with boundaries mapped into a Aganagic-Vafa brane. All genus open-closed Gromov-Witten invariants are defined by torus localization and depend on the choice of a framing which is an integer. We also provide another definition of all genus open-closed Gromov-Witten invariants based on algebraic relative orbifold Gromov-Witten theory; this generalizes the definition in Li-Liu-Liu-Zhou [arXiv:math/0408426] for smooth toric Calabi-Yau 3-folds. When the toric DM stack a toric Calabi-Yau 3-orbifold (i.e. when the generic stabilizer is trivial), we define generating functions of open-closed Gromov-Witten invariants or arbitrary genus gg and number hh of boundary circles; it takes values in the Chen-Ruan orbifold cohomology of the classifying space of a finite cyclic group of order mm. We prove an open mirror theorem which relates the generating function of orbifold disk invariants to Abel-Jacobi maps of the mirror curve of the toric Calabi-Yau 3-orbifold. This generalizes a conjecture by Aganagic-Vafa [arXiv:hep-th/0012041] and Aganagic-Klemm-Vafa [arXiv:hep-th/0105045] (proved in full generality by the first and the second authors in [arXiv:1103.0693]) on the disk potential of a smooth semi-projective toric Calabi-Yau 3-fold.Comment: 42 pages, 7 figure

    SUPRASPECIFIC TAXA OF THE BIVALVIA FIRST NAMED, DESCRIBED, AND PUBLISHED IN CHINA (1927–2007)

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    A total of 209 bivalve generic (subgeneric) and 19 familial (subfamilial) names first proposed by Chinese palaeontologists and published in China are treated herein as an annotated database. The present paper is designed especially for the Treatise on Invertebrate Paleontology Bivalvia revision project, because access to bivalve taxa published by Chinese authors in China has been difficult for non-Chinese researchers. The original diagnoses of these taxa, including the original descriptions and explanation of figures of all the type species, have been translated from Chinese into English, so that non-Chinese colleagues can more easily have access to them

    Aged Biochar for the Remediation of Heavy Metal Contaminated Soil: Analysis through an Experimental Case the Physicochemical Property Changes of Field Aging Biochar and Its Effects on the Immobilization Mechanism for Heavy Metal

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    Heavy metal inducing contamination soil has become a serious concern. Contaminated soil can cause physiochemical and biochemical changes into soil and the plants. Thus, the plant growth and the yield were affected. In additionally, that ultimately leads to the problem of food security and human health. In recent years, many kinds of ways were used for the remediation of heavy metal contaminated soil, such as isolation, phytoremediation, immobilization, extraction, and soil washing. As a new carbon-rich material, biochar has been applied to the remediation of heavy metal pollution in soil. As biochar is rich with porous structure, high cation exchange capacity, pH value, and surface function, it has become an adsorbent for soil heavy metal remediation. While, with time, the capacity of biochar to immobilize the heavy metals may be modified as the sorption sites may get occupied with native soil organic matter or competing contaminant, etc. And that the physicochemical properties of biochar changed significantly during field aging. Thus, to clarify the mechanism of field-aged biochar for the remediation of heavy metal contaminated soil, we analysis, through an experimental case, the physicochemical property changes of field-aged biochar and its effects on the immobilization mechanism for heavy metal

    Plant diversity is closely related to the density of zokor mounds in three alpine rangelands on the Tibetan Plateau

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    Background Plateau zokor (Myospalax baileyi) is a subterranean rodent endemic to the Tibetan Plateau. This species has been generally viewed as a pest in China due to the competition for food with livestock and also causing soil erosion. As a result, plateau zokor has been the target of widespread poisoning or trapping campaigns designed to control or eliminate it since 1970s. But there is little research on the effect of plateau zokor on plant diversity in alpine rangelands. Therefore, objectively evaluating the positive effects of the plateau zokors disturbance on their living environment and plant communities is of great significance to understand the function of plateau zokor in alpine ecosystem. Methods Here, we selected three rangelands (alpine meadow, alpine steppe and alpine shrub meadow) in which plateau zokors are typically distributed on the Tibetan Plateau, and five zokor mound density gradients were selected in each rangeland type to study the effects of the mounds on soil moisture and temperature related to plant species diversity. Results The results showed that, with the mound density increasing, the soil temperature decreased significantly in all three rangeland types, and the soil moisture significantly increased in all three rangeland types. In the alpine meadow, both the plant diversity and cumulative species richness increased significantly with increasing mound density. The increase in broad-leaved forbs is the main reason for the increase of plant diversity in the alpine meadow disturbed by zokor mounds. In the alpine steppe, the plant diversity decreased significantly with increasing mound density, while the cumulative species richness initially decreased and then increased. In the alpine shrub meadow, the plant diversity first increased and then decreased with increasing mound density as did the cumulative species richness. In conclusion, plateau zokor mounds dominated the distribution of soil moisture and temperature and significantly affected plant diversity in these three rangelands on Tibetan Plateau; the results further deepen our understanding toward a co-evolved process

    The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda and Triangulum Galaxies -- II. Results from the Commissioning Observations and the Pilot Surveys

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    We present new quasars discovered in the vicinity of the Andromeda and Triangulum galaxies with the LAMOST during the 2010 and 2011 observational seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m telescope, XSTPS optical, and WISE near infrared photometric data. We present 509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new quasars discovered in an area of ~100 sq. deg that covers the central region and the southeastern halo of M31 in the 2010 commissioning datasets. These 526 new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to 3.2. They represent a significant increase of the number of identified quasars in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0 respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars provide an invaluable collection with which to probe the kinematics and chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars are now known with locations within 2.5 deg of M31, of which 73 are newly discovered. Tens of quasars are now known to be located behind the Giant Stellar Stream, and hundreds behind the extended halo and its associated substructures of M31. The much enlarged sample of known quasars in the vicinity of M31 and M33 can potentially be utilized to construct a perfect astrometric reference frame to measure the minute PMs of M31 and M33, along with the PMs of substructures associated with the Local Group of galaxies. Those PMs are some of the most fundamental properties of the Local Group.Comment: 26 pages, 6 figures, AJ accepte

    Tumor-Associated Macrophage-Induced Invasion and Angiogenesis of Human Basal Cell Carcinoma Cells by Cyclooxygenase-2 Induction

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    Tumor-associated macrophages (TAMs) and cyclooxygenase-2 (COX-2) are associated with invasion, angiogenesis, and poor prognosis in many human cancers. However, the role of TAMs in human basal cell carcinoma (BCC) remains elusive. We found that the number of TAMs infiltrating the tumor is correlated with the depth of invasion, microvessel density, and COX-2 expression in human BCC cells. TAMs also aggregate near COX-2 expressing BCC tumor nests. We hypothesize that TAMs might activate COX-2 in BCC cells and subsequently increase their invasion and angiogenesis. TAMs are a kind of M2 macrophage derived from macrophages exposed to Th2 cytokines. M2-polarized macrophages derived from peripheral blood monocytes were cocultured with BCC cells without direct contact. Coculture with the M2 macrophages induced COX-2-dependent invasion and angiogenesis of BCC cells. Human THP-1 cell line cells, after treated with phorbol myristate acetate (PMA), differentiated to macrophages with M2 functional profiles. Coculture with PMA-treated THP-1 macrophages induced COX-2-dependent release of matrix metalloproteinase-9 and subsequent increased invasion of BCC cells. Macrophages also induced COX-2-dependent secretion of basic fibroblast growth factor and vascular endothelial growth factor-A, and increased angiogenesis in BCC cells

    Polycythemia vera as a presentation of renal angiomyolipoma: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Angiomyolipoma is a common benign renal tumor composed of thick-walled blood vessels, smooth muscle, and adipose tissue. It may be found incidentally during workup for suspected renal disease. Although angiomyolipoma may present as a palpable, tender renal mass with flank pain and gross or microscopic hematuria, many patients are asymptomatic. Erythrocytosis is an unusual presentation, and malignant transformation may be suspected. This report describes a rare case of a woman diagnosed with renal angiomyolipoma and polycythemia vera. The report discusses the differential diagnosis using erythropoietin, erythropoietin-receptor and Janus kinase 2.</p> <p>Case presentation</p> <p>A 79-year-old Chinese woman was diagnosed with erythrocytosis according to World Health Organization criteria. An upper left renal pole angiomyolipoma was successfully ablated after multiple phlebotomy treatments. Red cell count immediately returned to normal, but gradually increased after 4 months. Polycythemia vera was finally diagnosed by positive mutation of Janus kinase 2 and negative erythropoietin protein expression. Her clinical symptoms improved with regular phlebotomy and hydroxyurea treatment.</p> <p>Conclusion</p> <p>Concurrent occurence of angiomyolipoma and polycythemia vera is rare. Polycythemia vera can be easily missed. Polycythemia vera can be confirmed with high specificity and sensitivity by the acquired somatic mutation. Surgical intervention for this renal tumor should be avoided unless malignancy or renal cell carcinoma is suspected or to prevent spontaneous rupture of larger tumors.</p
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