Geometric transitions, Chern-Simons gauge theory and Veneziano type amplitudes

We consider the geometric transition and compute the all-genus topological string amplitudes expressed in terms of Hopf link invariants and topological vertices of Chern-Simons gauge theory. We introduce an operator technique of 2-dimensional CFT which greatly simplifies the computations. We in particular show that in the case of local Calabi-Yau manifolds described by toric geometry basic amplitudes are written as vacuum expectation values of a product vertex operators and thus appear quite similar to the Veneziano amplitudes of the old dual resonance models. Topological string amplitudes can be easily evaluated using vertex operator algebra.Comment: 16 pages, 2 figures, (v2,3) minor changes, to appear in Phys. Lett.

Pyramidal neurons in the superficial layers of rat retrosplenial cortex exhibit a late-spiking firing property

The rodent granular retrosplenial cortex (GRS) is reciprocally connected with the hippocampus. It is part of several networks implicated in spatial learning and memory, and is known to contain head-direction cells. There are, however, few specifics concerning the mechanisms and microcircuitry underlying its involvement in spatial and mnemonic functions. In this report, we set out to characterize intrinsic properties of a distinctive population of small pyramidal neurons in layer 2 of rat GRS. These neurons, as well as those in adjoining layer 3, were found to exhibit a late-spiking (LS) firing property. We established by multiple criteria that the LS property is a consequence of delayed rectifier and A-type potassium channels. These were identified as Kv1.1, Kv1.4 and Kv4.3 by Genechip analysis, in situ hybridization, single-cell reverse transcriptase-polymerase chain reaction, and pharmacological blockade. The LS property might facilitate comparison or integration of synaptic inputs during an interval delay, consistent with the proposed role of the GRS in memory-related processes.RIKEN Brain Science Institut

CFT Description of String Theory Compactified on Non-compact Manifolds with G_2 Holonomy

We construct modular invariant partition functions for strings propagating on non-compact manifolds of G_2 holonomy. Our amplitudes involve a pair of N=1 minimal models M_m, M_{m+2} (m=3,4,...) and are identified as describing strings on manifolds of G_2 holonomy associated with A_{m-2} type singularity. It turns out that due to theta function identities our amplitudes may be cast into a form which contain tricritical Ising model for any m. This is in accord with the results of Shatashvili and Vafa. We also construct a candidate partition function for string compactified on a non-compact Spin(7) manifold.Comment: It is found that tricritical Ising model is contained in our amplitues in agreement with the results of Shatashvili and Vafa. Manuscript is revised accordingly. A new reference is also adde

E-portfolios in an educational and ocupational context

AbstractePortfolios (or e-portfolios) are also known as “electronic” or ‘digital’ portfolios, “webfolios” and even “on-line personal development plans” or “Digital notebook”.There are also many definitions of ePortfolios, but it is important to remember that an ePortfolio is best defined by its purpose.However, the ePortfolios allows learners to trace the development of their thinking and learning over time and to show those competencies to the university and to employers.More than that, ePortfolios can provide digital resources relevant to their own study (personalised information) and links to other learners (for collaboration and feedback).When working with e-portfolios in an educational context, it is important to not only introduce the method, but to also implement ePortfolios as an overall concept. Successful implementation of the ePortfolios approach demands a different approach to teaching and learning. When working with ePportfolios, the focus lies in the combination of storing both the products and the process of learning. The documentation of learning processes is achieved by recording reflections on the learning progress of individuals.In this presentation we will analyze the ePortfolios from the main actors’ perspective:Studentsthe main challenge is to acquire the necessary skills to build a professional ePortfolio and, more fundamentally, to develop the ability to reflect on and accept greater responsibility for their own professional development. Using ePortfolios, students learned to think more about their own learning, to organize their work better, to plan how to improve their skills and competences etc.Teachersthe use of new tools, resources and approaches can definitely contribute to the new vision of professional development that is being called in favor to support teachers’ efforts and to adjust their teaching to the actual learning needs of their students.ePortfolios can serve these purposes, allowing and contributing for the reflection on the teachers’ goals, assessing their practice strengths and areas which need improvement documenting at the same time their professional growth thus generating ideas for future teaching development. Additionally, teachers need strategies to support learners in creating and maintaining their ePortfolios, and in evaluating the outcomes.Employersthey are interested to find on the labor market highly qualified graduates, according with their expectations and without a great effort or time consumingIn this respect, during this paper we will present how and in which way the educational actors can benefit if they implement ePortfolios in the educational and occupational context

Neurotrophin-3 Is Involved in the Formation of Apical Dendritic Bundles in Cortical Layer 2 of the Rat

Apical dendritic bundles from pyramidal neurons are a prominent feature of cortical neuropil but with significant area specializations. Here, we investigate mechanisms of bundle formation, focusing on layer (L) 2 bundles in rat granular retrosplenial cortex (GRS), a limbic area implicated in spatial memory. By using microarrays, we first searched for genes highly and specifically expressed in GRS L2 at postnatal day (P) 3 versus GRS L2 at P12 (respectively, before and after bundle formation), versus GRS L5 (at P3), and versus L2 in barrel field cortex (BF) (at P3). Several genes, including neurotrophin-3 (NT-3), were identified as transiently and specifically expressed in GRS L2. Three of these were cloned and confirmed by in situ hybridization. To test that NT-3–mediated events are causally involved in bundle formation, we used in utero electroporation to overexpress NT-3 in other cortical areas. This produced prominent bundles of dendrites originating from L2 neurons in BF, where L2 bundles are normally absent. Intracellular biocytin fills, after physiological recording in vitro, revealed increased dendritic branching in L1 of BF. The controlled ectopic induction of dendritic bundles identifies a new role for NT-3 and a new in vivo model for investigating dendritic bundles and their formation

Non-HDL-C and CVD

Aims: We aimed to investigate the association between non-high-density lipoprotein cholesterol (non-HDL-C) levels and the risk of cardiovascular disease (CVD) and its subtypes. Methods: In this contemporary cohort study, we analyzed the data of 63,814 Japanese employees aged ≥ 30 years, without known CVD in 2012 and who were followed up for up to 8 years. The non-HDL-C level was divided into 5 groups: ＜110, 110-129, 130-149, 150-169, and ≥ 170 mg/dL. The Cox proportional hazards model was used to calculate the hazard ratios (HRs) and the corresponding 95% confidence intervals (CIs) for CVD and its subtypes associated with each non-HDL-C group, considering 130-149 mg/dL as the reference group. Results: During the study period, 271 participants developed CVD, including 78 myocardial infarctions and 193 strokes (102 ischemic strokes, 89 hemorrhagic strokes, and 2 unknowns). A U-shaped association between non-HDL-C and stroke was observed. In the analysis of stroke subtypes, the multivariable-adjusted HR (95% CI) for hemorrhagic stroke was 2.61 (1.19–5.72), 2.02 (0.95–4.29), 2.10 (1.01–4.36), and 1.98 (0.96-4.08), while that for ischemic stroke was 1.54 (0.77-3.07), 0.91 (0.46-1.80), 0.73 (0.38-1.41), and 1.50 (0.87-2.56) in the ＜110, 110-129, 150-169, and ≥ 170 mg/dL groups, respectively. Individuals with elevated non-HDL-C levels had a higher risk of myocardial infarction. Conclusions: High non-HDL-C levels were associated with an increased risk of myocardial infarction. Moreover, high and low non-HDL-C levels were associated with a high risk of stroke and its subtypes among Japanese workers