100 research outputs found
Orbifold Gromov-Witten Theory
In this article, we introduce the notion of good map and use it to establish
Gromov-Witten theory for orbifolds.Comment: Late
Orbifold Quantum Cohomology
This is a research announcement of the theory of orbifold quantum cohomology.Comment: Revised version, adding more reference
Minimum Initial Marking Estimation in Labeled Petri Nets With Unobservable Transitions
In the literature, researchers have been studying the minimum initial marking (MIM) estimation problem in the labeled Petri nets with observable transitions. This paper extends the results to labeled Petri nets with unobservable transitions (with certain special structure) and proposes algorithms for the MIM estimation (MIM-UT). In particular, we assume that the Petri net structure is given and the unobservable transitions in the net are contact-free. Based on the observation of a sequence of labels, our objective is to find the set of MIM(s) that is(are) able to produce this sequence and has(have) the smallest total number of tokens. An algorithm is developed to find the set of MIM(s) with polynomial complexity in the length of the observed label sequence. Two heuristic algorithms are also proposed to reduce the computational complexity. An illustrative example is also provided to demonstrate the proposed algorithms and compare their performance
A New Cohomology Theory for Orbifold
Motivated by orbifold string theory, we introduce orbifold cohomology group
for any almost complex orbifold and orbifold Dolbeault cohomology for any
complex orbifold. Then, we show that our new cohomology group satisfies
Poincare duality and has a natural ring structure. Some examples of orbifold
cohomology ring are computed.Comment: Correct some minor mistake
Characterization of Human Coronavirus Etiology in Chinese Adults with Acute Upper Respiratory Tract Infection by Real-Time RT-PCR Assays
BACKGROUND: In addition to SARS associated coronaviruses, 4 non-SARS related human coronaviruses (HCoVs) are recognized as common respiratory pathogens. The etiology and clinical impact of HCoVs in Chinese adults with acute upper respiratory tract infection (URTI) needs to be characterized systematically by molecular detection with excellent sensitivity. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we detected 4 non-SARS related HCoV species by real-time RT-PCR in 981 nasopharyngeal swabs collected from March 2009 to February 2011. All specimens were also tested for the presence of other common respiratory viruses and newly identified viruses, human metapneumovirus (hMPV) and human bocavirus (HBoV). 157 of the 981 (16.0%) nasopharyngeal swabs were positive for HCoVs. The species detected were 229E (96 cases, 9.8%), OC43 (42 cases, 4.3%), HKU1 (16 cases, 1.6%) and NL63 (11 cases, 1.1%). HCoV-229E was circulated in 21 of the 24 months of surveillance. The detection rates for both OC43 and NL63 were showed significantly year-to-year variation between 2009/10 and 2010/11, respectively (P<0.001 and P = 0.003), and there was a higher detection frequency of HKU1 in patients aged over 60 years (P = 0.03). 48 of 157(30.57%) HCoV positive patients were co-infected. Undifferentiated human rhinoviruses and influenza (Flu) A were the most common viruses detected (more than 35%) in HCoV co-infections. Respiratory syncytial virus (RSV), human parainfluenza virus (PIV) and HBoV were detected in very low rate (less than 1%) among adult patients with URTI. CONCLUSIONS/SIGNIFICANCE: All 4 non-SARS-associated HCoVs were more frequently detected by real-time RT-PCR assay in adults with URTI in Beijing and HCoV-229E led to the most prevalent infection. Our study also suggested that all non-SARS-associated HCoVs contribute significantly to URTI in adult patients in China
Comparative proteomic analysis reveals alterations in development and photosynthesis-related proteins in diploid and triploid rice
Six pairs of primers were designed for gene-specific transcript amplification. (DOC 25 kb
Comparative proteomic analysis reveals alterations in development and photosynthesis-related proteins in diploid and triploid rice
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