7,253 research outputs found
D-Brane Gauge Theories from Toric Singularities and Toric Duality
Via partial resolution of Abelian orbifolds we present an algorithm for
extracting a consistent set of gauge theory data for an arbitrary toric variety
whose singularity a D-brane probes. As illustrative examples, we tabulate the
matter content and superpotential for a D-brane living on the toric del Pezzo
surfaces as well as the zeroth Hirzebruch surface. Moreover, we discuss the
non-uniqueness of the general problem and present examples of vastly different
theories whose moduli spaces are described by the same toric data. Our methods
provide new tools for calculating gauge theories which flow to the same
universality class in the IR. We shall call it ``Toric Duality.''Comment: 38 pages, 6 figures, 2 references added and 1 equation correcte
On correspondences between toric singularities and (p,q) webs
We study four-dimensional N=1 gauge theories which arise from D3-brane probes of toric Calabi-Yau threefolds. There are some standing paradoxes in the literature regarding relations among (p,q)-webs, toric diagrams and various phases of the gauge theories, we resolve them by proposing and carefully distinguishing between two kinds of (p,q)-webs: toric and quiver (p,q)-webs. The former has a one to one correspondence with the toric diagram while the latter can correspond to multiple gauge theories. The key reason for this ambiguity is that a given quiver (p,q)-web can not capture non-chiral matter fields in the gauge theory. To support our claim we analyse families of theories emerging from partial resolution of Abelian orbifolds using the Inverse Algorithm of hep-th/0003085 as well as (p,q)-web techniques. We present complex inter-relations among these theories by Higgsing, blowups and brane splittings. We also point out subtleties involved in the ordering of legs in the (p,q) diagram
Penalized survival models for the analysis of alternating recurrent event data
Recurrent event data are widely encountered in clinical and observational studies. Most methods for recurrent events treat the outcome as a point process and, as such, neglect any associated event duration. This generally leads to a less informative and potentially biased analysis. We propose a joint model for the recurrent event rate (of incidence) and duration. The two processes are linked through a bivariate normal frailty. For example, when the event is hospitalization, we can treat the time to admission and lengthâofâstay as two alternating recurrent events. In our method, the regression parameters are estimated through a penalized partial likelihood, and the varianceâcovariance matrix of the frailty is estimated through a recursive estimating formula. Moreover, we develop a likelihood ratio test to assess the dependence between the incidence and duration processes. Simulation results demonstrate that our method provides accurate parameter estimation, with a relatively fast computation time. We illustrate the methods through an analysis of hospitalizations among endâstage renal disease patients.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155997/1/biom13153_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155997/2/biom13153-sup-0003-supmat.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155997/3/biom13153-sup-0001-Supplement_Lili_accepted_paper_1_10SEP2019.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155997/4/biom13153.pd
Evaluating centerâspecific longâterm outcomes through differences in mean survival time: Analysis of national kidney transplant data
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149342/1/sim8076.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149342/2/sim8076_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149342/3/SIM_8076-Supp-0002-Web_Supple.pd
The origin of noncommutativity?
Consistent boundary Poisson structures for open string theory coupled to
background -field are considered using the new approach proposed in
hep-th/0111005. It is found that there are infinitely many consistent Poisson
structures, each leads to a consistent canonical quantization of open string in
the presence of background -field. Consequently, whether the -branes to
which the open string end points are attached is noncommutative or not depends
on the choice of a particular Poisson structure.Comment: Revtex4, published versio
Using Curcumin Nano-Lipid Particles in a Therapeutic Approach
Curcumin (Curcuma longa) is a plant-based polyphenol known to have several medicinal properties. Although several promising effects of using curcumin in clinical trials have been observed, its overall medicinal qualities are still limited due to low bioavailability. In order to increase the bioavailability, we are embedding curcumin within Nano-Lipid Particles (both curcumin telodendrimer discs and curcumin tNLPs). Telodendrimer nanolipoprotein particles (tNLPs) are discoidal self-assemblies containing lipids and apolipoproteins which can be used as a vehicle to carry proteins and other small molecules to the cell. Telodendrimer NLPs have been used to increase the bioavailability of drugs, and provide an ideal platform to increase curcumin bioavailability. The generation of tNLPs can be accomplished using several methods; such as cellfree assembly and in-vitro assembly. Curcumin telodendrimer discs (curcumin telo-discs) are a nano-lipid mixture of lipids, curcumin, and telodendrimer that acts as the basis for the curcumin tNLP reaction. Using the curcumin telo-disc as the starting additive, we demonstrate that we can purify properly formed curcumin tNLPs via affinity columns and size-exclusion chromatography (SEC). Here, we show that with two separate methods: a cell-free expressed method and in-vitro assembly, we can demonstrate that curcumin
Pulmonary tumor embolism: A retrospective study over a 30-year period
BACKGROUND: Pulmonary tumor embolism (PTE) is difficult to detect before death, and it is unclear whether the discrepancy between antemortem clinical and postmortem diagnosis improves with the advance of the diagnostic technologies. In this study we determined the incidence of PTE and analyzed the discrepancy between antemortem clinical and postmortem diagnosis.
METHODS: We performed a retrospective autopsy study on patients with the history of malignant solid tumors from 1990 to 2020 and reviewed all the slides of the patients with PTE. We also analyzed the discrepancies between antemortem clinical and postmortem diagnosis in 1999, 2009 and 2019 by using the Goldman criteria. Goldman category major 1 refers to cases in which an autopsy diagnosis was the direct cause of death and was not recognized clinically, but if it had been recognized, it may have changed treatment or prolonged survival.
RESULTS: We found 20 (3%) cases with PTE out of the 658 autopsy cases with solid malignancies. Out of these 20 cases, urothelial carcinoma (30%, 6/20) and invasive ductal carcinoma of the breast (4/20, 20%) were the most common primary malignancies. Seven patients with shortness of breath died within 3-17 days (average 8.4+/-2.2 days) after onset of the symptoms. Pulmonary embolism was clinically suspected in seven out of twenty (35%, 7/20) patients before death, but only two patients (10, 2/20) were diagnosed by imaging studies before death. The rate of Goldman category major 1 was 13.2% (10/76) in 1999, 7.3% (4/55) in 2009 and 6.9% (8/116) in 2019. Although the rate of Goldman category major 1 appeared decreasing, the difference was not statistically significant. The autopsy rate was significantly higher in 2019 (8.4%, 116/1386) than in 2009 (4.4%, 55/1240).
CONCLUSIONS: The incidence of PTE is uncommon. Despite the advances of the radiological techniques, radiological imaging studies did not detect the majority of PTEs. The discrepancy between the antemortem clinical and the postmortem diagnosis has not improved significantly over the past 30 years, emphasizing the value of autopsy
Boundary Rings and N=2 Coset Models
We investigate boundary states of N=2 coset models based on Grassmannians
Gr(n,n+k), and find that the underlying intersection geometry is given by the
fusion ring of U(n). This is isomorphic to the quantum cohomology ring of
Gr(n,n+k+1), and thus can be encoded in a ``boundary'' superpotential whose
critical points correspond to the boundary states. In this way the intersection
properties can be represented in terms of a soliton graph that forms a
generalized, Z_{n+k+1} symmetric McKay quiver. We investigate the spectrum of
bound states and find that the rational boundary CFT produces only a small
subset of the possible quiver representations.Comment: 40p, 5 figs, refs added, typos and minor errors correcte
Noncommutative quantum mechanics and the Aharonov-Casher effect
In this work a new method is developed to investigate the Aharonov-Casher
effect in a noncommutative space. It is shown that the holonomy receives
non-trivial kinematical corrections.Comment: 8 pages, Plain Tex, to appear in Eur. Phys. J.
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