7,275 research outputs found
Building from strength: asset-based community development
Before embarking on a community development effort, consider making a list of local strengths instead of just problems. A new assessment technique encourages all residents to participate in mapping community assets and helps generate the can-do attitude needed to move mountains.Community development
Higher-Dimensional Algebra VII: Groupoidification
Groupoidification is a form of categorification in which vector spaces are
replaced by groupoids, and linear operators are replaced by spans of groupoids.
We introduce this idea with a detailed exposition of "degroupoidification": a
systematic process that turns groupoids and spans into vector spaces and linear
operators. Then we present three applications of groupoidification. The first
is to Feynman diagrams. The Hilbert space for the quantum harmonic oscillator
arises naturally from degroupoidifying the groupoid of finite sets and
bijections. This allows for a purely combinatorial interpretation of creation
and annihilation operators, their commutation relations, field operators, their
normal-ordered powers, and finally Feynman diagrams. The second application is
to Hecke algebras. We explain how to groupoidify the Hecke algebra associated
to a Dynkin diagram whenever the deformation parameter q is a prime power. We
illustrate this with the simplest nontrivial example, coming from the A2 Dynkin
diagram. In this example we show that the solution of the Yang-Baxter equation
built into the A2 Hecke algebra arises naturally from the axioms of projective
geometry applied to the projective plane over the finite field with q elements.
The third application is to Hall algebras. We explain how the standard
construction of the Hall algebra from the category of representations of a
simply-laced quiver can be seen as an example of degroupoidification. This in
turn provides a new way to categorify - or more precisely, groupoidify - the
positive part of the quantum group associated to the quiver.Comment: 67 pages, 14 eps figures; uses undertilde.sty. This is an expanded
version of arXiv:0812.486
Phytochrome A mediates blue-light enhancement of second-positive phototropism in Arabidopsis
Hypocotyl phototropism of etiolated Arabidopsis seedlings is primarily mediated by the blue-light receptor kinase phototropin 1 (phot1). Phot1-mediated curvature to continuous unilateral blue light irradiation (0.5 µmol m-2 s-1) is enhanced by overhead pre-treatment with red light (20 µmol m-2 s-1 for 15 min) through the action of phytochrome (phyA). Here, we show that pre-treatment with blue light is equally as effective in eliciting phototropic enhancement and is dependent on phyA. Although blue pre-treatment was sufficient to activate early phot1 signalling events, phot1 autophosphorylation in vivo was not found to be saturated, as assessed by subsequently measuring phot1 kinase activity in vitro. However, enhancement effects to red and blue pre-treatment were not observed at higher intensities of phototropic stimulation (10 µmol m-2 s-1). Phototropic enhancement to red and blue pre-treatments to 0.5 µmol m-2 s-1 unilateral blue light irradiation was also lacking in transgenic Arabidopsis where PHOT1 expression was restricted to the epidermis. Together, these findings indicate that phyA-mediated effects on phot1 signalling are restricted to low intensities of phototropic stimulation and originate from tissues other than the epidermis
Early Outcomes for Programs and Families in Children's Futures
Assesses the programmatic achievements and outcomes for families in the first five years of a community change initiative providing an array of social services. Discusses lessons learned and issues of cost, partnership development, and sustainability
Community Assessment Scales: The State of the Art
Community development activities are founded on the assumption that citizens have some concept of a good community toward which they want to move. Attention needs to be given to how community developers can determine citizen values and attitudes about the type of community that they want. Community assessment scales (CAS\u27s) have been used as one means of measuring community attitudes and desires.
This paper explores the state of the art of the development and use of CAS\u27s. The conclusions are that there has been only minimal use of CAS\u27s and that there are many conceptual and methodological problems with the existing scales.
It is suggested that CAS\u27s, if properly designed, could be useful and practical tools for community development
Discovery and Presentation of Evidence in Adversary and Nonadversary Proceedings
In order to evaluate fully the advantage claimed for the adversary model we sought to add a third element that would test the hypothesis under a variety of conditions. The degree to which the evidence discovered in a case favors one party at the expense of another appeared to meet this criterion. This fact-distribution element is a pervasive condition of legal conflict resolution that, intuition suggests, may significantly influence information search and transmission. Further, this variable could be easily and accurately controlled by regulating the flow of favorable information acquired by the subjects during the experiment.
The remainder of this article reports a laboratory experiment intended to cast light on both the specific claim made on behalf of the adversary system and the nature of information processing in legal systems generally
- …