Fast or slow melting of the Marinoan snowball Earth? The cap dolostone record

The end of the Neoproterozoic era is punctuated by two global glacial events marked by the presence of glacial deposits overlaid by cap carbonates. Duration of glacial intervals is now consistently constrained to 3-12 million years but the duration of the post-glacial transition is more controversial due to the uncertainty in cap dolostone sedimentation rates. Indeed, the presence of several stratabound magnetic reversals in Brazilian cap dolostones recently questioned the short sedimentation duration (a few thousand years at most) that was initially suggested for these rocks. Here, we present new detailed magnetostratigraphic data of the Mirassol d`Oeste cap dolostones (Mato Grosso, Brazil) and ""bomb-spike"" calibrated AMS (14)C data of microbial mats from the Lagoa Vermelha (Rio de Janeiro, Brazil). We also compile sedimentary, isotopic and microbiological data from post-Marinoan outcrops and/or recent depositional analogues in order to discuss the deposition rate of Marinoan cap dolostones and to infer an estimation of the deglaciation duration in the snowball Earth aftermath. Taken together, the various data point to a sedimentation duration in the range of a few 10(5) years. (C) 2010 Elsevier B.V. All rights reserved.

Operations research/management science tools for integrating people with disabilities into employment. A study on Valencia`s Sheltered Work Centres for Disabled

People with disabilities have a right to a full life in every sense and one of those fundamental rights is the possibility to work. In this paper, the importance of social employment integration of disabled people is highlighted as one of the stakeholders to be satisfied by companies in the new framework that corporate social responsibility is constructing. The objective of the paper is to revise the benefits of some well-known operations research/management science tools that, if applied correctly, have a double positive impact on work accessibility and improved productivity. The responses collected from managers of Valencia`s ShelteredWork Centres for Disabled by means of a structured questionnaire are used to analyse the level of implementation of these tools and their impact depending on the type of centre, the kind of disability and other structural variables.