Facial structures for various notions of positivity and applications to the theory of entanglement

In this expository note, we explain facial structures for the convex cones consisting of positive linear maps, completely positive linear maps, decomposable positive linear maps between matrix algebras, respectively. These will be applied to study the notions of entangled edge states with positive partial transposes and optimality of entanglement witnesses.Comment: An expository note. Section 7 and Section 8 have been enlarge

Preparation of Mgo-ceo2 Mixed Oxide with Ionic Liquid as Catalyst for Dimethyl Carbonate Synthesis Via Transesterification

The synthesis and application of dimethyl carbonate (DMC) are achieving increasing importance due to its low toxicity and versatile reactivity. The phosgenation-route has been losing attraction recently due to the use of virulent phosgene. In transesterification process, DMC is co-generated with ethylene glycol (EG). In this study, various ionic liquids were used as template in coprecipitation methods to prepare mesoporous MgO-CeO2 mixed oxides particles. Among the ionic liquids, [Bmim][BF6] displayed the best performance in terms of activity, while [Omim][PF6] obtained the best selectivity for this reaction. The addition of IL's in the coprecipitation method increased the surface areaand pore volume of the catalysts. Meanwhile, the crystallite size of the catalysts was reduced many times. However, there is no effect of the surface areaand particle size as well on the catalytic activity of the catalyst in this reaction. The activity and selectivity of the catalyst depend on the base strength distribution. The moderate basic site is responsible for the catalytic activity, while the selectivity is more dependableon the strong basic site

Topical rosiglitazone is an effective anti-scarring agent in the cornea

Corneal scarring remains a major cause of blindness world-wide, with limited treatment options, all of which have side-effects. Here, we tested the hypothesis that topical application of Rosiglitazone, a Thiazolidinedione and ligand of peroxisome proliferator activated receptor gamma (PPARγ), can effectively block scar formation in a cat model of corneal damage. Adult cats underwent bilateral epithelial debridement followed by excimer laser ablation of the central corneal stroma to a depth of ~160 µm as a means of experimentally inducing a reproducible wound. Eyes were then left untreated, or received 50 µl of either 10 µM Rosiglitazone in DMSO/Celluvisc, DMSO/Celluvisc vehicle or Celluvisc vehicle twice daily for 2 weeks. Cellular aspects of corneal wound healing were evaluated with in vivo confocal imaging and post-mortem immunohistochemistry for alpha smooth muscle actin (αSMA). Impacts of the wound and treatments on optical quality were assessed using wavefront sensing and optical coherence tomography at 2, 4, 8 and 12 weeks post-operatively. In parallel, cat corneal fibroblasts were cultured to assess the effects of Rosiglitazone on TGFβ-induced αSMA expression. Topical application of Rosiglitazone to cat eyes after injury decreased αSMA expression and haze, as well as the induction of lower-order and residual, higher-order wavefront aberrations compared to vehicle-treated eyes. Rosiglitazone also inhibited TGFβ-induced αSMA expression in cultured corneal fibroblasts. In conclusion, Rosiglitazone effectively controlled corneal fibrosis in vivo and in vitro, while restoring corneal thickness and optics. Its topical application may represent an effective, new avenue for the prevention of corneal scarring with distinct advantages for pathologically thin corneas

Separability problem for multipartite states of rank at most four

One of the most important problems in quantum information is the separability problem, which asks whether a given quantum state is separable. We investigate multipartite states of rank at most four which are PPT (i.e., all their partial transposes are positive semidefinite). We show that any PPT state of rank two or three is separable and has length at most four. For separable states of rank four, we show that they have length at most six. It is six only for some qubit-qutrit or multiqubit states. It turns out that any PPT entangled state of rank four is necessarily supported on a 3x3 or a 2x2x2 subsystem. We obtain a very simple criterion for the separability problem of the PPT states of rank at most four: such a state is entangled if and only if its range contains no product vectors. This criterion can be easily applied since a four-dimensional subspace in the 3x3 or 2x2x2 system contains a product vector if and only if its Pluecker coordinates satisfy a homogeneous polynomial equation (the Chow form of the corresponding Segre variety). We have computed an explicit determinantal expression for the Chow form in the former case, while such expression was already known in the latter case.Comment: 19 page

The Normal State Resistivity of Grain Boundaries in YBa2Cu3O7-delta

Using an optimized bridge geometry we have been able to make accurate measurements of the properties of YBa2Cu3O7-delta grain boundaries above Tc. The results show a strong dependence of the change of resistance with temperature on grain boundary angle. Analysis of our results in the context of band-bending allows us to estimate the height of the potential barrier present at the grain boundary interface.Comment: 11 pages, 3 figure

Partnership Process Guidelines: Social Work Perspectives on Creating and Sustaining Real-World University-Community Partnerships

The authors, representing community practitioners, faculty, students, and administration, collaborated to produce guidelines for university-community partnerships that reflect social work’s commitment to social justice in practice, education, and research. The respective experiences and voices of the authors contribute to a wider perspective on the explicit social justice implications of partnership formation for community-based participatory research, which is a vision shared by many disciplines. These guidelines introduce a communication outline that may augment the creation and maintenance of thriving university-community partnerships across multiple disciplines that promote social justice

The Dynamical Behaviors in (2+1)-Dimensional Gross-Neveu Model with a Thirring Interaction

We analyze (2+1)-dimensional Gross-Neveu model with a Thirring interaction, where a vector-vector type four-fermi interaction is on equal terms with a scalar-scalar type one. The Dyson-Schwinger equation for fermion self-energy function is constructed up to next-to-leading order in 1/N expansion. We determine the critical surface which is the boundary between a broken phase and an unbroken one in ($\alpha_c,~ \beta_c,~ N_c$) space. It is observed that the critical behavior is mainly controlled by Gross-Neveu coupling $\alpha_c$ and the region of the broken phase is separated into two parts by the line $\alpha_c=\alpha_c^*(=\frac{8}{\pi^2})$. The mass function is strongly dependent upon the flavor number N for $\alpha > \alpha_c^*$, while weakly for $\alpha \alpha_c^*$, the critical flavor number $N_c$ increases as Thirring coupling $\beta$ decreases. By driving the CJT effective potential, we show that the broken phase is energetically preferred to the symmetric one. We discuss the gauge dependence of the mass function and the ultra-violet property of the composite operators.Comment: 19 pages, LaTex, 6 ps figure files(uuencoded in seperate file

Community College Student Engagement Patterns: A Typology Revealed Through Exploratory Cluster Analysis

This study employs survey data from the Center for Community College Student Engagement to examine the similarities and differences that exist across student-level domains in terms of student engagement in community colleges. In total, the sample used in the analysis pools data from 663 community colleges and includes more than 320,000 students. Using data-mining techniques to discover a parsimonious number of natural clusters and, in turn, a k-means cluster analysis as a means of revealing a naturally occurring typology of engagement patterns, our findings reveal that support service utilization is the most distinguishing feature of the similarities and dissimilarities across student groups, suggesting areas for further theory development and testing

Community College Student Engagement Patterns: A Typology Revealed Through Exploratory Cluster Analysis

This study employs survey data from the Center for Community College Student Engagement to examine the similarities and differences that exist across student-level domains in terms of student engagement in community colleges. In total, the sample used in the analysis pools data from 663 community colleges and includes more than 320,000 students. Using data-mining techniques to discover a parsimonious number of natural clusters and, in turn, a k-means cluster analysis as a means of revealing a naturally occurring typology of engagement patterns, our findings reveal that support service utilization is the most distinguishing feature of the similarities and dissimilarities across student groups, suggesting areas for further theory development and testing