Dynamical virial masses of Lyman-break galaxy haloes at z=3

We improve on our earlier dynamical estimate of the virial masses of the haloes of Lyman-break galaxies (LBGs) at redshift z=3 by accounting for the effects of seeing, slit width, and observational uncertainties. From an analysis of the small number of available rotation curves for LBGs we determine a relation Vc7=(1.9+/-0.2)sigma between circular velocity at a radius of 7kpc, and central line velocity width. We use this relation to transform the measured velocity widths of 32 LBGs to the distribution of circular velocities, for the population of LBGs brighter than R=25.5. We compare this distribution against the predicted distribution for the 'massive-halo' model in which LBGs pinpoint all of the highest mass dark matter haloes at that epoch. The observed LBG circular velocities are smaller than the predicted circular velocities by a factor >1.4+/-0.15. This is a lower limit as we have ignored any increase of circular velocity caused by baryonic dissipation. The massive-halo model predicts a median halo virial mass of 10^12.3 Msol, and a small spread of circular velocities. Our median estimated dynamical mass is <10^(11.6+/-0.3) Msol, which is significantly smaller; furthermore, the spread of our circular velocities is much larger than the massive-halo prediction. These results are consistent with a picture which leaves some of the most-massive haloes available for occupation by other populations which do not meet the LBG selection criteria. The median halo mass recently estimated by Adelberger et al. from the measured clustering of LBGs is 10^(11.86+/-0.3) Msol. Our dynamical analysis appears to favour lower masses and to be more in line with the median mass predicted by the collisional starburst model of Somerville et al., of 10^11.3 Msol. [abridged]Comment: 6 pages, 5 figures, MNRAS Letters, Accepte

Rules for the Cortical Map of Ocular Dominance and Orientation Columns

Three computational rules are sufficient to generate model cortical maps that simulate the interrelated structure of cortical ocular dominance and orientation columns: a noise input, a spatial band pass filter, and competitive normalization across all feature dimensions. The data of Blasdel from optical imaging experiments reveal cortical map fractures, singularities, and linear zones that are fit by the model. In particular, singularities in orientation preference tend to occur in the centers of ocular dominance columns, and orientation contours tend to intersect ocular dominance columns at right angles. The model embodies a universal computational substrate that all models of cortical map development and adult function need to realize in some form.Air Force Office of Scientific Research (F49620-92-J- 0499, F49620-92-J-0334); Office of Naval Research (N00014-92-J-4015, N00014-91-J-4100); National Science Foundation (IRI-90-24877); British Petroleum (BP 89A-1204

Sectarianism and state funded schooling in Scotland. A critical response to the final report of the Advisory Group on Tackling Sectarianism in Scotland

The Scottish Government has recently invested considerable energy and resource into tackling sectarianism in Scotland. They have commissioned reviews of existing research, commissioned new research and funded community based projects. They also appointed an independent Advisory Group in 2012 to investigate the scope of sectarianism and provide some recommendations on how to address sectarianism. This article is focused on the Final Report of the Advisory Group on Tackling Sectarianism in Scotland - April 2015 (Scottish Government, 2015a) and the key statements in this Final Report that refer to state funded school education. The article argues that there is much to commend in the Final Report and provides a critical examination of the discussion of the relationship between school education and sectarianism and the contribution of school education to anti-sectarian activities and education

Comprehensive Creativity When We Need It, review of The Cambridge Handbook of Creativity, edited by James C. Kaufman and Robert J. Sternberg

Reviews the book, The Cambridge handbook of creativity edited by James C. Kaufman and Robert J. Sternberg (see record 2010-21837-000). The title suggests that The Cambridge handbook of creativity is an encyclopedic collection of all the major chunks of knowledge connected to creative behavior. Although it does not disappoint in that regard, the contributing authors do a superb job of capturing the coherence and the theoretical and thematic developments of their respective areas. Overall the reviewer would recommend The Cambridge handbook of creativity to serious researchers in creativity and anyone who wants to be seriously creative. Psychologists and educators are advised to keep a copy close by. (PsycINFO Database Record (c) 2011 APA, all rights reserved

(WP 2016-06) The Effectiveness of Central Bank Forward Guidance under Inflation and Price-Level Targeting

This paper examines the effectiveness of central bank forward guidance under inflation and price-level targeting monetary policies. The results show that the attenuation of the effects of forward guidance can be solved if a central bank switches from inflation targeting to price-level targeting. Output and inflation respond more favorably to forward guidance with price-level targeting than inflation targeting. A monetary policy rule that aggressively reacts to inflation and includes interest rate inertia narrows the performance gap between the two policy regimes. However, forward guidance with price-level targeting is still preferred to forward guidance with inflation targeting after performing multiple robustness checks

Homological finiteness conditions for groups, monoids and algebras

Recently Alonso and Hermiller introduced a homological finiteness condition\break $bi{-}FP_n$ (here called {\it weak} $bi{-}FP_n$) for monoid rings, and Kobayashi and Otto introduced a different property, also called $bi{-}FP_n$ (we adhere to their terminology). From these and other papers we know that: $bi{-}FP_n \Rightarrow$ left and right $FP_n \Rightarrow$ weak $bi{-}FP_n$; the first implication is not reversible in general; the second implication is reversible for group rings. We show that the second implication is reversible in general, even for arbitrary associative algebras (Theorem 1'), and we show that the first implication {\it is} reversible for group rings (Theorem 2). We also show that the all four properties are equivalent for connected graded algebras (Theorem 4). A result on retractions (Theorem 3') is proved, and some questions are raised.Comment: 10 page