This article presents a community learning model formulated by Engineers Without Borders Colombia with the aim of providing communities with tools to create sustainable productive solutions which have relevancy for members and for potential customers. The goal of this formulation is to promote learning processes that are guided by decisions made by community members to propose sustainable and replicable initiatives. The model applicability is evidenced through a case study devoted to strengthening community-led green businesses in the Guavio Province, Colombia by collecting lessons and conclusions. Ultimately, this collection will prove useful in replicating the learning model in other similar rural communities.
Summary The solubilizing effect of Triton X-100 on beef heart submitochondrial particles (ETPH) has been studied under various physiological conditions. Coupled, uncoupled and azide-inhibited ETPH particles have been studied. Quantitative and qualitative differences are found in the proteins solubilized by the detergent from ETPH particles under the various conditions tested.Acknowledgments: This work was supported in part by a grant from a Spanish Comisión Asesora para la Investigación Cientifica y Técnica. M.C. Barbero was recipient of a scholarship from the Basque Government. 相似文献
Summary High-affinity, Na+-independent binding of -alanine to a synaptosomal fraction of rat brain was potently inhibited by glycine and by some other -amino acids, but not by taurine or GABA. This binding mechanism, which was also sensitive to both bicuculline and strychnine, might involve synaptic receptors for both -alanine and glycine.This study was supported in part by Centro Ramón y Cajal and Fundacion Juan March. 相似文献
Direct observations over the past four centuries show that the number of sunspots observed on the Sun's surface varies periodically, going through successive maxima and minima. Following sunspot cycle 23, the Sun went into a prolonged minimum characterized by a very weak polar magnetic field and an unusually large number of days without sunspots. Sunspots are strongly magnetized regions generated by a dynamo mechanism that recreates the solar polar field mediated through plasma flows. Here we report results from kinematic dynamo simulations which demonstrate that a fast meridional flow in the first half of a cycle, followed by a slower flow in the second half, reproduces both characteristics of the minimum of sunspot cycle 23. Our model predicts that, in general, very deep minima are associated with weak polar fields. Sunspots govern the solar radiative energy and radio flux, and, in conjunction with the polar field, modulate the solar wind, the heliospheric open flux and, consequently, the cosmic ray flux at Earth. 相似文献
Autism spectrum disorders (ASDs) comprise a range of disorders that share a core of neurobehavioural deficits characterized by widespread abnormalities in social interactions, deficits in communication as well as restricted interests and repetitive behaviours. The neurological basis and circuitry mechanisms underlying these abnormal behaviours are poorly understood. SHANK3 is a postsynaptic protein, whose disruption at the genetic level is thought to be responsible for the development of 22q13 deletion syndrome (Phelan-McDermid syndrome) and other non-syndromic ASDs. Here we show that mice with Shank3 gene deletions exhibit self-injurious repetitive grooming and deficits in social interaction. Cellular, electrophysiological and biochemical analyses uncovered defects at striatal synapses and cortico-striatal circuits in Shank3 mutant mice. Our findings demonstrate a critical role for SHANK3 in the normal development of neuronal connectivity and establish causality between a disruption in the Shank3 gene and the genesis of autistic-like behaviours in mice. 相似文献
The dwarf planet Eris is a trans-Neptunian object with an orbital eccentricity of 0.44, an inclination of 44 degrees and a surface composition very similar to that of Pluto. It resides at present at 95.7 astronomical units (1?AU is the Earth-Sun distance) from Earth, near its aphelion and more than three times farther than Pluto. Owing to this great distance, measuring its size or detecting a putative atmosphere is difficult. Here we report the observation of a multi-chord stellar occultation by Eris on 6 November 2010 UT. The event is consistent with a spherical shape for Eris, with radius 1,163?±?6?kilometres, density 2.52?±?0.05 grams per cm(3) and a high visible geometric albedo, Pv = 0.96(+0.09)(-0.04). No nitrogen, argon or methane atmospheres are detected with surface pressure larger than ~1?nanobar, about 10,000 times more tenuous than Pluto's present atmosphere. As Pluto's radius is estimated to be between 1,150 and 1,200 kilometres, Eris appears as a Pluto twin, with a bright surface possibly caused by a collapsed atmosphere, owing to its cold environment. We anticipate that this atmosphere may periodically sublimate as Eris approaches its perihelion, at 37.8 astronomical units from the Sun. 相似文献
It has been proposed that neuroinflammation, among other factors, may trigger an aberrant neuronal cell cycle re-entry leading
to neuronal death. Cell cycle disturbances are also detectable in peripheral cells from Alzheimer’s disease (AD) patients.
We previously reported that the anti-inflammatory 15- deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) increased the cellular content of the cyclin-dependent kinase inhibitor p27, in lymphoblasts from AD patients. This work
aimed at elucidating the mechanisms of 15d-PGJ2-induced p27 accumulation. Phosphorylation, half-life, and the nucleo-cytoplasmic traffic of p27 protein were altered by 15d-PGJ2
by mechanisms dependent on PI3K/Akt activity. 15d-PGJ2 prevents the calmodulin-dependent Akt overactivation in AD lymphoblasts by blocking its binding to the 85-kDa regulatory
subunit of PI3K. These effects of 15d-PGJ2 were not mimicked by 9,10-dihydro-15-deoxy-Δ12,14- prostaglandin J2, suggesting that 15d-PGJ2 acts independently of peroxisome proliferator-activated receptor γ activation and that the α,β-unsaturated carbonyl group
in the cyclopentenone ring of 15d-PGJ2 is a requisite for the observed effects.
Received 14 July 2008; received after revision 2 September 2008; accepted 12 September 2008 相似文献