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关键词： Associative rings and modules   Torsion and divisible modules   Comodules and contramodules   Harrison-Matlis category equivalences   Triangulated recollement   Kronecker quiver  

摘要： Under mild assumptions, we construct the two Maths additive category equivalences for an associative ring epimorphism u: R -> U. Assuming that the ring epimorphism is homological of flat/projective dimension 1, we discuss the abelian categories of u-comodules and u-contramodules and construct the recollement of unbounded derived categories of R-modules, U-modules, and complexes of R-modules with u-co/contramodule cohomology. Further assumptions allow to describe the third category in the recollement as the unbounded derived category of the abelian categories of u-comodules and u-contramodules. For commutative rings, we also prove that any homological epimorphism of projective dimension 1 is flat. Injectivity of the map u is not required. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Category captaincy   Category management   Strategic enablement   Enabling strategies  

摘要： Many retailers seek growth by strategically enabling a category captain to manage a category on their behalf. Past research assesses the efficacy of category captaincy from a retailer perspective, with results showing effective categorycaptain arrangements depend on the respective abilities of actors to effectively operate in such a network structure. Less is known about what and how manufacturers become successful captains or how challenger manufacturers unseat an incumbent captain. With this research, we contribute to the growing but still small literature on category captaincy in two main ways. First, we re-orient the focus from the retailer to the manufacturer (both captain and non-captains) to uncover the enabling strategies and underlying capabilities captains and non-captains require when operating in category captaincy networks. Second, we contextualize the captaincy lifecycle in terms of three stages;consideration, captaincy, and renewal. Drawing on interviews with retailers, category captains, and non-captains from six sectors we develop propositions whereby capabilities are contingent on actor goals across the captaincy lifecycle. In so doing, we extend existing research by identifying the capabilities necessary for different actors to gain benefits from category captaincy arrangements.

关键词： Retinal images   Artery/vein classification   Deep learning   Graph model  

摘要： Background and Objective: Automatic artery/vein (A/V) classification in retinal images is of great importance in detecting vascular abnormalities, which may provide biomarkers for early diagnosis of many systemic diseases. It is intuitive to apply popular deep semantic segmentation network for A/V classification. However, the model is required to provide powerful representation ability since vessel is much more complex than general objects. Moreover, deep network may lead to inconsistent classification results for the same vessel due to the lack of structured optimization objective. Methods: In this paper, we propose a novel segmentation network named AVNet, which effectively enhances the classification ability of the model by integrating category-attention weighted fusion (CWF) module, significantly improving the pixel-level A/V classification results. Then, a graph based vascular structure reconstruction (VSR) algorithm is employed to reduce the segment-wise inconsistency, verifying the effect of the graph model on noisy vessel segmentation results. Results: The proposed method has been verified on three datasets, i.e. DRIVE, LES-AV and WIDE. AVNet achieves pixel-level accuracies of 90.62%, 90.34%, and 93.16%, respectively, and VSR further improves the performance by 0.19%, 1.85% and 0.64%, achieving the state-of-the-art results on these three datasets. Conclusion: The proposed method achieves competitive performance in A/V classification task. (C) 2020 Elsevier B.V. All rights reserved.

关键词： electron complexes   protein function prediction   representation learning   transfer learning   word embeddings   motif frequencies  

摘要： We herein proposed a novel approach based on the language representation learning method to categorize electron complex proteins into 5 types. The idea is stemmed from the the shared characteristics of human language and protein sequence language, thus advanced natural language processing techniques were used for extracting useful features. Specifically, we employed transfer learning and word embedding techniques to analyze electron complex sequences and create efficient feature sets before using a support vector machine algorithm to classify them. During the 5-fold cross-validation processes, seven types of sequence-based features were analyzed to find the optimal features. On an average, our final classification models achieved the accuracy, specificity, sensitivity, and MCC of 96 %, 96.1 %, 95.3 %, and 0.86, respectively on cross-validation data. For the independent test data, those corresponding performance scores are 95.3 %, 92.6 %, 94 %, and 0.87. We concluded that using feature extracted using these representation learning methods, the prediction performance of simple machine learning algorithm is on par with existing deep neural network method on the task of categorizing electron complexes while enjoying a much faster way for feature generation. Furthermore, the results also showed that the combination of features learned from the representation learning methods and sequence motif counts helps yield better performance.

关键词： acute myeloid leukaemia   molecular analysis   stem cell transplantation   leukaemia  

摘要： In the European LeukemiaNet favourable risk category, allogeneic haematopoietic stem cell transplantation (alloSCT) is not indicated in first complete remission for patients with acute myeloid leukaemia (AML) with NPM1 mutations (ELNfav NPM1 AML), although a proportion of these patients will relapse. Given the prognostic importance of measurable residual disease (MRD), CETLAM-12 considered a pre-emptive intervention in patients with molecular failure (MF). We analyzed 110 ELNfav NPM1 AML patients achieving complete remission (CR) after induction chemotherapy. Two-year cumulative incidence of relapse (CIR), overall survival (OS) and leukaemia-free survival (LFS) were 17%, 81 center dot 5% and 82%, respectively. Forty-six patients required additional therapy for MF (n = 33) or haematological relapse (HemR;n = 13), resulting in a molecular LFS (molLFS) and a cumulative incidence of MF at two years of 61% and 38% respectively. Two-year OS for these 46 patients was 66%, with a different outcome between patients with MF (86%) and HemR (42%) (P = 0 center dot 002). Quantitative NPM1 detection at different timepoints was predictive of molLFS;an MRD ratio (NPM1mut/ABL1 x 100) cut-off of 0 center dot 05 after first consolidation identified two cohorts with a two-year molLFS of 77% and 40% for patients below and above 0 center dot 05, respectively. In conclusion, MRD-based pre-emptive intervention resulted in a favourable outcome for ELNfav NPM1 AML patients.

摘要： Let coh X be the category of coherent sheaves over a weighted projective line X and let D-b (coh X) be its bounded derived category. The present paper focuses on the study of the right and left mutation functors arising in D-b (coh X) attached to certain line bundles. As applications, we first show that these mutation functors give rise to simple reflections for the Weyl group of the star-shaped quiver Q associated with X. By further dealing with the Ringel-Hall algebra of X, we show that these functors provide a realization for Tits' automorphisms of the Kac-Moody algebra g(Q) associated with Q, as well as for Lusztig's symmetries of the quantum enveloping algebra of g(Q).

关键词： Soliton fiber lasers   Mode-locked fiber lasers   Group velocity dispersion   Dissipative solitons  

摘要： Optical solitons generated from fiber lasers have been extensively investigated for their good stability, narrow pulse width and high peak power, which play an indispensable role in many fields such as mechanical micromachining, optical microscope, imaging technology, optical soliton communication and so on. In this review, we summarize the development of soliton fiber laser, and the current application of soliton pulses. There are many different kinds of mode-locking technologies to generate solitons, such as actively mode-locked fiber lasers, passively mode-locked fiber lasers and hybrid mode-locked fiber lasers. During the long-term research of solitons, various types of solitons have been gradually realized under different group velocity dispersion (GVD) conditions in passively mode-locked fiber lasers, such as conventional solitons (CSs) (GVD < 0), dispersion-managed solitons (DMSs) (GVD approximate to 0), self-similar solitons (GVD >= 0), dissipative solitons (DSs) (GVD > 0). And in order to apply solitons to more fields, soliton amplification and compression technologies are widely used to improve the performance of solitons, such as chirped pulse amplification (CPA) technology, self-similar soliton amplification technology, large-mode area (LMA) fiber, etc. Finally, the development prospect of soliton in the future is prospected.

关键词： Biomonitoring   Bioassessment   Tolerance value   Biological water quality classification   Invertebrate  

摘要： Biotic index (BI) based on macroinvertebrate tolerance value (TV) is widely used for water quality bioassessment and environmental management. Most regional used BI versions were adapted from the original Hilsenhoff BI and Hilsenhoff TVs. Here, we aim to build a BI classification of water quality for streams in the Yangtze River Delta using statistical methods to set quality class boundary. We determined reference sites using a combination of priori objective screening criteria of total nitrogen (TN, <= 1.409 mg/L), total phosphorus (TP, <= 0.035 mg/L), and electrical conductivity (EC, <= 249 mu s/cm) and the most-disturbed sites with all TN, TP, and EC values higher than 75th percentile across the 233 sites sampled during 2004 to 2011 in Yangtze River Delta. We applied the 75th percentile of BI values across 19 reference sites as the benchmark of high class and then equally divided the range between the benchmark and the expected highest BI values into four categories. We then proposed five biological classes of water quality: high (BI < 3.91), good (3.91-5.43), moderate (5.44-6.95), poor (6.96-8.47) and bad (BI > 8.47) with a bias of 0.22 for each class. The BI performed well for the discrimination of the most-disturbed sites with accuracies of 88.24% and test sites with accuracies of 81.22%. BIs showed the highest remarkable linear relationship with a surrogate of comprehensive gradient of seven measured environmental variables. In addition, BI was significantly related with community taxa richness, Simpson and Shannon diversity indices. A total of 69.53% investigated sites had a quality above the good class, indicating that most streams were in good condition in Yangtze River Delta. Our study highlighted that the BI is a useful index for water quality biomonitoring and assessment in the Yangtze River Delta. We suggest that local government agencies apply the BI to their regular water quality assessments and even use it in their annual water quality reports to ad

关键词： 18E30   16E40   18G50   18G60  

摘要： In this paper we relate triangulated category structures to the cohomology of small categories and define initial obstructions to the existence of an algebraic or topological enhancement. We show that these obstructions do not vanish in an example of triangulated category without models. We also obtain cohomological characterizations of pre-triangulated DG, A-infinity, and spectral categories.

关键词： Exact category   Resolving subcategory   Localization   Abelian category  

摘要： The paper exhibits three constitutive exact subcategories of Adelman's free abelian category Ab(A) over a Quillen exact category A, which provide an intrinsic description of Ab(A) and encapsulate the mechanism of (finite or infinite) tilting. In general, two of these subcategories are left and right abelian, respectively, and a tilting adjunction takes place between them if they are abelian. The third category Im(A) contains the acyclic closure T(A) of d as an exact subcategory of those objects which arise as images of the morphisms in an exact complex over d. If the exact structure of A is trivial, T(A) consists of the Gorenstein projectives over A, a category that does not depend on an embedding of A into some ambient abelian category. The construction of Ab(A) and its intrinsic description sheds some light upon old and new concepts and results concerning Gruson-Jensen duality, resolving subcategories, representations of Cohen-Macaulay orders, Gorenstein projectivity, non-commutative resolutions, and representation dimension. Applications to infinite tilting and existence of derived equivalences will be given in a forthcoming publication. (C) 2020 Elsevier B.V. All rights reserved.