1,336 research outputs found
Period, Central Charge and Effective Action on Ricci-Flat Manifolds with Special Holonomy
Motivated by the Gamma conjecture, we introduce a notion of numerical vectors, such as Chern character and Mukai vector, and a notion of numerical t-stabilities and numerical slope functions on triangulated categories. The study of the derived categories of Calabi-Yau manifolds leads us to a conjecture which gives a relation between numerical t-stability and Bridgelands stability on smooth varieties. And when there exists generalized twisted Mukai vectors, we also obtain the results regarding the cohomological Fourier-Mukai (FM) transforms associated to the FM ones on the level of derived categories. In some cases, these cohomological FM transforms agree with the ones on the derived categories of twisted sheaves. In the second part, we discuss geometric and topological properties of G_2 manifolds due to the Kovalev's twisted connected sum constrction. In the Kovalev limit the Ricci-flat metrics on X_{L/R} approximate the Ricci-flat G_2-metrics and we identify the universal modulus, called the Kovalevton, that parametrizes this limit. Moreover, the low energy effective theory exhibits gauge theory sectors with extended supersymmetry in this limit. The universal (semi-classical) Kähler potential of the effective N=1 supergravity action is a function of the Kovalevton and the volume modulus of the G_2-manifold. We describe geometric degenerations in X_{L/R}, which lead to non-Abelian gauge symmetries enhancements with various matter content. Studying the resulting gauge theory branches, we argue that they lead to transitions compatible with the gluing construction and provide many new explicit examples of G_2-manifolds
High expression FUT1 and B3GALT5 is an independent predictor of postoperative recurrence and survival in hepatocellular carcinoma.
Cancer may arise from dedifferentiation of mature cells or maturation-arrested stem cells. Previously we reported that definitive endoderm from which liver was derived, expressed Globo H, SSEA-3 and SSEA-4. In this study, we examined the expression of their biosynthetic enzymes, FUT1, FUT2, B3GALT5 and ST3GAL2, in 135 hepatocellular carcinoma (HCC) tissues by qRT-PCR. High expression of either FUT1 or B3GALT5 was significantly associated with advanced stages and poor outcome. Kaplan Meier survival analysis showed significantly shorter relapse-free survival (RFS) for those with high expression of either FUT1 or B3GALT5 (P = 0.024 and 0.001, respectively) and shorter overall survival (OS) for those with high expression of B3GALT5 (P = 0.017). Combination of FUT1 and B3GALT5 revealed that high expression of both genes had poorer RFS and OS than the others (P < 0.001). Moreover, multivariable Cox regression analysis identified the combination of B3GALT5 and FUT1 as an independent predictor for RFS (HR: 2.370, 95% CI: 1.505-3.731, P < 0.001) and OS (HR: 2.153, 95% CI: 1.188-3.902, P = 0.012) in HCC. In addition, the presence of Globo H, SSEA-3 and SSEA-4 in some HCC tissues and their absence in normal liver was established by immunohistochemistry staining and mass spectrometric analysis
An efficient surrogate model for emulation and physics extraction of large eddy simulations
In the quest for advanced propulsion and power-generation systems,
high-fidelity simulations are too computationally expensive to survey the
desired design space, and a new design methodology is needed that combines
engineering physics, computer simulations and statistical modeling. In this
paper, we propose a new surrogate model that provides efficient prediction and
uncertainty quantification of turbulent flows in swirl injectors with varying
geometries, devices commonly used in many engineering applications. The novelty
of the proposed method lies in the incorporation of known physical properties
of the fluid flow as {simplifying assumptions} for the statistical model. In
view of the massive simulation data at hand, which is on the order of hundreds
of gigabytes, these assumptions allow for accurate flow predictions in around
an hour of computation time. To contrast, existing flow emulators which forgo
such simplications may require more computation time for training and
prediction than is needed for conducting the simulation itself. Moreover, by
accounting for coupling mechanisms between flow variables, the proposed model
can jointly reduce prediction uncertainty and extract useful flow physics,
which can then be used to guide further investigations.Comment: Submitted to JASA A&C
Electrocoagulation in Wastewater Treatment
A review of the literature published in from 2008 to 2010 on topics related to electrochemical treatment within wastewater was presented. The review included several sections such as optimization, modeling, various wastewater treatment techniques, analytical and instrumentation, and comparison with other treatment methods
Malignant phyllodes tumors display mesenchymal stem cell features and aldehyde dehydrogenase/disialoganglioside identify their tumor stem cells.
IntroductionAlthough breast phyllodes tumors are rare, there is no effective therapy other than surgery. Little is known about their tumor biology. A malignant phyllodes tumor contains heterologous stromal elements, and can transform into rhabdomyosarcoma, liposarcoma and osteosarcoma. These versatile properties prompted us to explore their possible relationship to mesenchymal stem cells (MSCs) and to search for the presence of cancer stem cells (CSCs) in phyllodes tumors.MethodsParaffin sections of malignant phyllodes tumors were examined for various markers by immunohistochemical staining. Xenografts of human primary phyllodes tumors were established by injecting freshly isolated tumor cells into the mammary fat pad of non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice. To search for CSCs, xenografted tumor cells were sorted into various subpopulations by flow cytometry and examined for their in vitro mammosphere forming capacity, in vivo tumorigenicity in NOD-SCID mice and their ability to undergo differentiation.ResultsImmunohistochemical analysis revealed the expression of the following 10 markers: CD44, CD29, CD106, CD166, CD105, CD90, disialoganglioside (GD2), CD117, Aldehyde dehydrogenase 1 (ALDH), and Oct-4, and 7 clinically relevant markers (CD10, CD34, p53, p63, Ki-67, Bcl-2, vimentin, and Globo H) in all 51 malignant phyllodes tumors examined, albeit to different extents. Four xenografts were successfully established from human primary phyllodes tumors. In vitro, ALDH+ cells sorted from xenografts displayed approximately 10-fold greater mammosphere-forming capacity than ALDH- cells. GD2+ cells showed a 3.9-fold greater capacity than GD2- cells. ALDH+/GD2+cells displayed 12.8-fold greater mammosphere forming ability than ALDH-/GD2- cells. In vivo, the tumor-initiating frequency of ALDH+/GD2+ cells were up to 33-fold higher than that of ALDH+ cells, with as few as 50 ALDH+/GD2+ cells being sufficient for engraftment. Moreover, we provided the first evidence for the induction of ALDH+/GD2+ cells to differentiate into neural cells of various lineages, along with the observation of neural differentiation in clinical specimens and xenografts of malignant phyllodes tumors. ALDH+ or ALDH+/GD2+ cells could also be induced to differentiate into adipocytes, osteocytes or chondrocytes.ConclusionsOur findings revealed that malignant phyllodes tumors possessed many characteristics of MSC, and their CSCs were enriched in ALDH+ and ALDH+/GD2+ subpopulations
SEISMIC ANALYSIS OF WATER SUPPLY SYSTEMS BY EARTHQUAKE SCENARIO SIMULATION
In the past decade, scenario simulation has played a more and more important role in urban earthquake hazard mitigation and emergency response. Both public and private sectors can be enhanced in terms of their seismic preparedness and operation if adequate implementation of seismic scenario simulation can be employed. Regarding water utilities, system-wide retrofit and emergency planning can be conducted to reduce the likely damage and losses prior to the occurrence of a devastating earthquake. Post-earthquake repair personnel and material dispatching, temporary water supply for affected people, emergency water supply for hospitals and fire fighting, strategies for restoration and recovery can all benefit from scenario-based analyses. In this research work, efforts were made to study and integrate pivotal technologies essential to the earthquake damage and serviceability analysis of water systems, such as seismic hazard analysis, empirical formulae for pipe repair rates, hydraulic analysis of water network system in terms of pressurized pipe flow simulation, hydraulic models for various types of pipe damages, and Monte Carlo method for the performance analysis of large and complicated systems. The water system in Yi-lan County, Taiwan was selected as a test bed for the demonstration of its seismic serviceability analysis under an M7.1 earthquake scenario
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