11,583 research outputs found
Degree growth of monomial maps and McMullen's polytope algebra
We compute all dynamical degrees of monomial maps by interpreting them as
mixed volumes of polytopes. By exploiting further the isomorphism between the
polytope algebra of P. McMullen and the universal cohomology of complete toric
varieties, we construct invariant positive cohomology classes when the
dynamical degrees have no resonance.Comment: 26 pages. Minor modification
Effect of a direct-fed microbial (Eubios 1090) in the presence of antibiotics (Carbadox or CTC-Denagard) on post-weaning pig growth performance and immune response
A study was conducted to determine the effects of a probiotic (Eubios 1090), in the presence of two different antibiotics, on performance in nursery pigs. A total of 216 pigs were weaned at an average of 21 d, blocked by initial body weight (BW = 6.79 kg), and distributed into 32 pens of 6 to 7 pigs per pen in an offsite nursery facility. Pens were randomly assigned to 1 of 4 dietary treatments (8 pens per treatment) that were fed throughout post-weaning phase 1 (day (D) 0 to 10), phase 2 (D 10 to 20), and phase 3 (D 20 to 34). Dietary treatments were: 1) Carbadox without Eubios 1090; 2) Chlortetracycline + Tiamulin (CTC-Denagard) without Eubios 1090; 3) Carbadox + Eubios 1090; and 4) CTC-Denagard + Eubios 1090. There was no interaction observed between the two antibiotics and addition of the probiotic. There was a tendency for greater gain to feed ratio (G:F) in phase 2 when nursery pigs received Carbadox compared to CTC-Denagard (P = 0.08), and a tendency for greater average daily feed intake (ADFI) in the overall nursery period when pigs were fed CTCDenagard compared to Carbadox (P = 0.10). Pigs that received the non-Eubios 1090 diets had greater average daily gain (ADG), G:F, and body weight (BW) during phase 2 compared to pigs that received diets containing Eubios 1090 (P = 0.05). In phase 3, pigs receiving the Eubios 1090 diet had increased ADG and G:F (P = 0.05). Between the Carbadox diet and the CTC-Denagard diet, the diet containing CTC-Denagard increased ADFI throughout the 3 phases. In summary, probiotic supplementation demonstrated negative effects in phase 2 and positive effects to growth performance in nursery pigs during the latter part of early post-weaning (phase 3)
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People, place, enterprise: proceedings of the first annual conference on Olympic Legacy 8 and 9 May 2008
The Olympic Legacy: People, Place, Enterprise conference took place at the University of Greenwich in May 2008. The first in a series of annual conferences, it brought together leading academics, policy makers and practitioners to debate the lasting legacy of the games.
The conference had four themes: social and cultural regeneration; Olympic tourism; enterprise, including social enterprise and skills development, and education, providing a multi-dimensional perspective on the likely impacts of the forthcoming London Olympics
Embedded Clusters in Molecular Clouds
Stellar clusters are born embedded within giant molecular clouds (GMCs) and
during their formation and early evolution are often only visible at infrared
wavelengths, being heavily obscured by dust. Over the last 15 years advances in
infrared detection capabilities have enabled the first systematic studies of
embedded clusters in galactic molecular clouds. In this article we review the
current state of empirical knowledge concerning these extremely young
protocluster systems. From a survey of the literature we compile the first
extensive catalog of galactic embedded cluster properties. We use the catalog
to construct the mass function and estimate the birthrate for embedded clusters
within roughly 2 Kpc of the Sun. We find that the embedded cluster birthrate
exceeds that of visible open clusters by an order of magnitude or more
indicating a high infant mortality rate for protocluster systems. Less than
4-7% of embedded clusters survive emergence from molecular clouds to become
bound clusters of Pleiades age. The vast majority (90%) of stars that form in
embedded clusters form in rich clusters of 100 or more members with masses in
excess of 50 solar masses. We review the role of embedded clusters in
investigating the nature of the IMF which, in one nearby example, has been
measured over the entire range of stellar and substellar mass, from OB stars to
subsellar objects near the deuterium burning limit. We also review the role
embedded clusters play in the investigation of circumstellar disk evolution and
the important constraints they provide for understanding the origin of
planetary systems. Finally, we discuss current ideas concerning the origin and
dynamical evolution of embedded clusters and the implications for the formation
of bound open clusters.Comment: To appear in Annual Reviews of Astronomy and Astrophysics v41.
Manuscript consists of 73 pages with 14 figures. Due to space limitations 5
figures are included as separate low quality jpeg figures. A complete
manuscript with full resolution figures can be downloaded from
http://cfa-www.harvard.edu/~clada/preprints.htm
Building Citywide Systems for Quality: A Guide and Case Studies for Afterschool Leaders
This guide is intended to help cities strengthen and sustain quality afterschool programs by using an emerging practice known as a quality improvement system (QIS). The guide explains how to start building a QIS or how to further develop existing efforts and features case studies of six communities' QIS
Community supported agriculture as a model for an ethical agri-food system in north east England
PhD ThesisCommunity Supported Agriculture (CSA) has not spread rapidly in the UK, and in the north east of England its growth has been particularly slow. The purpose of this study was to develop an action research programme into CSA in this location to discover if it could be animated using a community-based participatory action research approach and to find out what benefits would accrue to participants of such a scheme. Participatory action research (PAR) with local collaborators took place between 2006 and 2009. Some data collection relating to the global CSA movement continued through to 2011.
The thesis documents how two research groups adapted to restraints and opportunities to achieve their aims through the iterative cycle of planning, acting, observing and reflecting. The benefits to participants are understood and analysed in terms of community development and care theory. The thesis also includes an in-depth examination of action research and a comprehensive account of the history and development of CSA.
The distinctive contribution to knowledge is in two regards. First, the use of PAR in facilitating stakeholder collaboration to develop CSA schemes enables an analysis of the role of PAR in animating rural development initiatives. Second, the specific socio-economic characteristics of Weardale mean that this research provides a highly original and distinctive contribution by examining how PAR might animate local food initiatives in a deprived area.
The analysis demonstrates how the structure, form and practice of CSA reflect an ethic of care. PAR also stems from motivations of care and concern and is a search for knowledge and action that can contribute towards addressing situations that are deemed to be socially, economically or environmentally unsatisfactory. It is claimed that, although individual CSAs may focus their attention on achieving their immediate goals and tasks, nevertheless, CSA contains within it the potential to effect wider transformational change.collaborative studentship sponsored by the Economic and Social Research Council and the Regional Development Agency, One North East
The Equitable Classroom: A Critical Comparison of the Austrian and American Educational Systems
Would Higher Salaries Keep Teachers in High-Poverty Schools? Evidence from a Policy Intervention in North Carolina
For a three-year time period beginning in 2001, North Carolina awarded an annual bonus of $1,800 to certified math, science and special education teachers working in high poverty or academically failing public secondary schools. Using longitudinal data on teachers, we estimate hazard models that identify the impact of this differential pay by comparing turnover patterns before and after the program%u2019s implementation, across eligible and ineligible categories of teachers, and across eligible and barely-ineligible schools. Results suggest that this bonus payment was sufficient to reduce mean turnover rates of the targeted teachers by 12%. Experienced teachers exhibited the strongest response to the program. Finally, the effect of the program may have been at least partly undermined by the state%u2019s failure to fully educate teachers regarding the eligibility criteria. Our estimates most likely underpredict the potential outcome of a program of permanent salary differentials operating under complete information.
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