Modelling efficient and anti-efficient frontiers in DEA without explicit inputs

Data envelopment analysis (DEA) is one of the most widely used tools in efficiency analysis of many business and non-profit organisations. Recently, more and more researchers investigated DEA models without explicit input (DEA-WEI). DEA-WEI models can divide DMUs into two categories: efficient DMUs and inefficient DMUs. Usually there is a set of DMUs, which are ‘efficient’ so that conventional DEA models could not rank them. In this paper, we first develop a performance index based on efficient and anti-efficient frontiers in DEA-WEI models. Further, the corresponding performance index in DEA-WEI models with quadratic utility terms (quadratic DEA-WEI) is proposed also. Finally, we present two case studies on performance assessment of basketball players and the evaluation of research institutes in Chinese Academy of Sciences (CAS) to show the applicability and usefulness of the performance indices developed in this paper

Stable functors and cohomology theory in Grothendieck categories

In this paper, we introduce and study a relative complete cohomology theory in Grothendieck categories. Some properties of this cohomology including vanishing and balancedness are given. As an application of our approach, we prove a new balanced result for Tate cohomology in Grothendieck categories.Comment: 25 page

Research on basis of reverse genetics system of a Sindbis-like virus XJ-160

As a Sindbis-like virus (SINLV), XJ-160 virus was isolated from a pooled sample of Anopheles mosquitoes collected in Xinjiang, China, in 1990. Recombinant plasmid pBR-XJ160 is an infectious full-length cDNA clone of XJ-160 virus, from which rescued virus BR-XJ160 can be obtained by transcription in vitro and transfection. The BR-XJ160 virus raised in BHK-21 cells was indistinguishable from the XJ-160 virus in its biological properties, including its plaque morphology, growth kinetics and suckling mouse neurovirulence. On basis of pBR-XJ160, the effects of substitutions within nonstructural protein 1 (nsP1) or nsP2 on the infectivity and pathogenesis of Sindbis virus (SINV) have been investigated. We have also confirmed the essential role of E2 glycoprotein, especially the domain of 145-150 (amino acid) aa, in SINV infection through the interaction with cellular heparan sulfate (HS). In addition, we have developed XJ-160 virus-based vector system, including replicon vector, defective helper (DH) plasmids and the packaging cell lines (PCLs). Here we provide an update of main development in the field concerned with XJ-160 virus