Cure of epoxy resins determined by simple tests

Rapid visual and simple quantitative tests indicate the degree of cure of particular epoxy resin binders in prepreg stock. It is possible that these tests may be extended to a number of different epoxy formulations

Human central nervous system (CNS) ApoE isoforms are increased by age, differentially altered by amyloidosis, and relative amounts reversed in the CNS compared with plasma

The risk of Alzheimer's disease (AD) is highly dependent on apolipoprotein-E (apoE) genotype. The reasons for apoE isoform-selective risk are uncertain; however, both the amounts and structure of human apoE isoforms have been hypothesized to lead to amyloidosis increasing the risk for AD. To address the hypothesis that amounts of apoE isoforms are different in the human CNS, we developed a novel isoform-specific method to accurately quantify apoE isoforms in clinically relevant samples. The method utilizes an antibody-free enrichment step and isotope-labeled physiologically relevant lipoprotein particle standards produced by immortalized astrocytes. We applied this method to a cohort of well characterized clinical samples and observed the following findings. The apoE isoform amounts are not different in cerebrospinal fluid (CSF) from young normal controls, suggesting that the amount of apoE isoforms is not the reason for risk of amyloidosis prior to the onset of advanced age. We did, however, observe an age-related increase in both apoE isoforms. In contrast to normal aging, the presence of amyloid increased apoE3, whereas apoE4 was unchanged or decreased. Importantly, for heterozygotes, the apoE4/apoE3 isoform ratio was increased in the CNS, although the reverse was true in the periphery. Finally, CSF apoE levels, but not plasma apoE levels, correlated with CSF β-amyloid levels. Collectively, these findings support the hypothesis that CNS and peripheral apoE are separate pools and differentially regulated. Furthermore, these results suggest that apoE mechanisms for the risk of amyloidosis and AD are related to an interaction between apoE, aging, and the amount of amyloid burden

Scaling out agroecology from the school garden and the importance of recognizing culture, food, and place

We explore potential and limitations for agroecological scaling through formal educational structures, using the LabVida school gardens program in Chiapas, Mexico as a case study. Through LabVida training, educators gained an appreciation of agroecology and were able to apply agroecological practices in their school gardens, although their understanding of agroecological principles and scientific process remained limited. The greatest program impact was on educators’ eating habits, and their perception of the value of local knowledge and its relevance to schoolwork. The case study demonstrates the potential of school gardens work for catalyzing communities of practice that contribute to agroecological scaling.En este texto se explora el potencial y las limitaciones del escalamiento de la agroecología a través de las estructuras educativas formales; para ello se utiliza como estudio de caso el programa de huertos escolares LabVida en Chiapas, México. Mediante un ejercicio de formación de docentes en LabVida, ellos adquirieron una apreciación de la agroecología y fueron capaces de aplicarla en sus huertos escolares, aunque su comprensión de los principios agroecológicos y del proceso científico siguió siendo limitada. Una conclusión fue observar que el mayor impacto del programa se produjo en los hábitos alimentarios de los educadores y en su percepción del valor del conocimiento local y su relevancia para el trabajo escolar. Esta investigación demuestra el potencial del trabajo en los huertos escolares para catalizar comunidades de práctica que contribuyan al escalamiento de la agroecología

The Influence of Recent Climate Change on Tree Height Growth Differs with Species and Spatial Environment

Tree growth has been reported to increase in response to recent global climate change in controlled and semi-controlled experiments, but few studies have reported response of tree growth to increased temperature and atmospheric carbon dioxide (CO2) concentration in natural environments. This study addresses how recent global climate change has affected height growth of trembling aspen (Populus tremuloides Michx) and black spruce (Picea mariana Mill B.S.) in their natural environments. We sampled 145 stands dominated by aspen and 82 dominated by spruce over the entire range of their distributions in British Columbia, Canada. These stands were established naturally after fire between the 19th and 20th centuries. Height growth was quantified as total heights of sampled dominant and co-dominant trees at breast-height age of 50 years. We assessed the relationships between 50-year height growth and environmental factors at both spatial and temporal scales. We also tested whether the tree growth associated with global climate change differed with spatial environment (latitude, longitude and elevation). As expected, height growth of both species was positively related to temperature variables at the regional scale and with soil moisture and nutrient availability at the local scale. While height growth of trembling aspen was not significantly related to any of the temporal variables we examined, that of black spruce increased significantly with stand establishment date, the anomaly of the average maximum summer temperature between May-August, and atmospheric CO2 concentration, but not with the Palmer Drought Severity Index. Furthermore, the increase of spruce height growth associated with recent climate change was higher in the western than in eastern part of British Columbia. This study demonstrates that the response of height growth to recent climate change, i.e., increasing temperature and atmospheric CO2 concentration, did not only differ with tree species, but also their growing spatial environment

La soberanía alimentaria: Cultivando nuevas alianzas entre campo, bosque y ciudad

In June, 2008, we convoked a forum and workshop in Chiapas, Mexico to strengthen alliances among farmers’ organizations, conservationists and academics. Speakers outlined the evolution of the relations among production systems, forests and biodiversity from the prehispanic era through the current crisis in the neoliberal economic model and industrial agriculture. They also framed a new conservation paradigm that prioritizes the role of farmers. We formed working groups that elaborated proposals for collaboration among the participating sectors. Cooperative networks emerged as appropriate structures for coordinating action and facilitating the exchange of information and support at various geographic scales. Solidarity-based markets are a venue where diverse interests converge, favoring the formation of such networks. We also identified some specific issues for collaboration, including: agrofuels and energy sovereignty, environmental services and rural education. Biodiversity and food sovereignty are the two axes of this agenda for cooperation that forms part of an international struggle to reconstruct our food systems.En junio de 2008 convocamos un foro-taller en Chiapas, México para potencializar alianzas entre organizaciones campesinas, conservacionistas y académicos. Los ponentes trazaron la evolución de las relaciones entre sistemas productivos, bosques y biodiversidad desde la época prehispánica hasta la actual crisis de la economía neoliberal y la agricultura industrial. También delinearon un nuevo paradigma para la conservación en donde los campesinos son protagonistas. En grupos de trabajo, elaboramos propuestas para cimentar una agenda común entre los distintos sectores representados. Las redes de cooperación emergieron como estructuras para coordinar acción y facilitar el intercambio de información y apoyo a distintas escalas geográficas. Los mercados solidarios son la confluencia de diversos intereses en dónde se pueden constituir dichas redes. También identificamos algunos temas específicos de trabajo, entre ellos: los agrocombustibles y la soberanía energética, los servicios ambientales y la educación para el campo. La biodiversidad y la soberanía alimentaria y territorial son los ejes de esta agenda de cooperación, que forma parte de una lucha internacional para reconstruir nuestros sistemas alimenticios

Bioprospecting the African Renaissance: The new value of muthi in South Africa

This article gives an overview of anthropological research on bioprospecting in general and of available literature related to bioprospecting particularly in South Africa. It points out how new insights on value regimes concerning plant-based medicines may be gained through further research and is meant to contribute to a critical discussion about the ethics of Access and Benefit Sharing (ABS). In South Africa, traditional healers, plant gatherers, petty traders, researchers and private investors are assembled around the issues of standardization and commercialization of knowledge about plants. This coincides with a nation-building project which promotes the revitalization of local knowledge within the so called African Renaissance. A social science analysis of the transformation of so called Traditional Medicine (TM) may shed light onto this renaissance by tracing social arenas in which different regimes of value are brought into conflict. When medicinal plants turn into assets in a national and global economy, they seem to be manipulated and transformed in relation to their capacity to promote health, their market value, and their potential to construct new ethics of development. In this context, the translation of socially and culturally situated local knowledge about muthi into global pharmaceuticals creates new forms of agency as well as new power differentials between the different actors involved