7,486 research outputs found
The effects of KSEA interaction on the ground-state properties of spin chains in a transverse field
The effects of symmetric helical interaction which is called the Kaplan,
Shekhtman, Entin-Wohlman, and Aharony (KSEA) interaction on the ground-state
properties of three kinds of spin chains in a transverse field have been
studied by means of correlation functions and chiral order parameter. We find
that the anisotropic transition of chain in a transverse field (TF)
disappears because of the KSEA interaction. For the other two chains, we find
that the regions of gapless chiral phases in the parameter space induced by the
DM or type of three-site interaction are decreased gradually with
increase of the strength of KSEA interaction. When it is larger than the
coefficient of DM or type of three-site interaction, the gapless
chiral phases also disappear.Comment: 7 pages, 3 figure
Some university students are more equal than others: Efficiency evidence from England
This paper estimates the efficiency of students in English universities using Data Envelopment Analysis (DEA) and a new dataset which is able to capture the behaviour of university students. Two output variables are specified: the classification of a university degree, and student satisfaction. Three input variables are specified: teaching hours, private study and entry qualifications. The results reveal that university students differ in terms of the efficiency with which they use inputs in generating good degrees and satisfaction. Students in some post-92 universities may be more efficient than students in some pre-92 universities.Data Envelopment Analysis; Efficiency; Education Economics; Universities.
Crossing by a single scalar field coupling with matter and the observational constraints
Motivated by Yang-Mills dark energy model, we propose a new model by
introducing a logarithmic correction. we find that this model can avoid the
coincidence problem naturally and gives an equation of state smoothly
crossing -1 if an interaction between dark energy and dark matter exists. It
has a stable tracker solution as well. To confront with observations based on
the combined data of SNIa, BAO, CMB and Hubble parameter, we obtain the best
fit values of the parameters with errors for the
noncoupled model: ,
, and for the coupled model with a decaying
rate : ,
. In particular, it is found that the
non-coupled model has a dynamic evolution almost undistinguishable to
CDM at the late-time Universe.Comment: 12 pages, 3 figures, the published versio
Galectin-12 in Cellular Differentiation, Apoptosis and Polarization.
Galectin-12 is a member of a family of mammalian lectins characterized by their affinity for ÎČ-galactosides and consensus amino acid sequences. The protein structure consists of a single polypeptide chain containing two carbohydrate-recognition domains joined by a linker region. Galectin-12 is predominantly expressed in adipose tissue, but is also detected in macrophages and other leukocytes. Downregulation of galectin-12 in mouse 3T3-L1 cells impairs their differentiation into adipocytes. Conversely, overexpression of galectin-12 in vitro induces cell cycle arrest in G1 and apoptosis. Upregulation of galectin-12 and initiation of G1 cell cycle arrest are associated with driving pre-adipocytes toward terminal differentiation. Galectin-12 deficiency increases insulin sensitivity and glucose tolerance in obese animals. Galectin-12 inhibits macrophage polarization to the M2 population, enhancing inflammation and decreasing insulin sensitivity in adipocytes. Galectin-12 also affects myeloid differentiation, which is associated with chemotherapy resistance. In addition to highlighting the above-mentioned aspects, this review also discusses the potential clinical applications of modulating the function of galectin-12
An exploration of ex post contract adjustment under public private partnership with special investigation of the transportation industry
This research focuses on ex post Contract Adjustment (CA) under Public Private Partnership (PPP) program. It includes theoretical exploration and empirical investigation. The former has one model while the latter finishes two sets of regression with a simple simulation. The research question is âwhat are the reason for and consequence of ex post Contract Adjustment (expressed by CA only in following) under PPP?â.PPP has been applied increasingly in developing and developed countries. However, the potential problems surrounding CA under PPP is explored or investigated inadequately by scholars. For one thing, most of literatures in PPP focus on ex ante contract design instead of ex post problems. For another, ex post CA, this topic that should be in New Institutional Economics (NIE) is unfortunately overlooked by NIE. Even some works relate to CA with the focus on some similar topic, e.g. contract renegotiation; CA is treated as a condition instead of process.Considering the inherent incentive of government to rescue firm under ex post risk to keep PPP program going, our model figure out the specific situation when takeover policy of government has be adopted. The basic conclusion of modelling is that holdup problem or uncontrollable ex post CA(s) could force government to terminate PPP in the end.For investigating the compensation effect under ex post CA, author creates data after thirty-two PPP case study. It could be found that ex ante contract and the way of ex post adjustment is meaningful as predicted while ex post risk is not as expected for ex post CA. Based on regression, policy suggestions are given for ex post CA under PPP. Moreover, data are also used for simulation, the corresponding conclusion coincides the conclusion of modelling
Mott-Hubbard transition in infinite dimensions
We analyze the unanalytical structure of metal-insulator transition (MIT) in
infinite dimensions. By introducing a simple transformation into the dynamical
mean-field equation of Hubbard model, a multiple-valued structure in Green's
function and other thermodynamical quantities with respect to the interaction
strength are found at low temperatures. A unified description of stable,
metastable and unstable phases is obtained in the regime
, and the Maxwell construction is performed to evaluate
the MIT line . We show how the first-order MIT at
for evolves into second-order one at for . The phase
diagram near MIT is presented.Comment: 5 pages with 3 figures, text and figures revise
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