Reachability for dynamic parametric processes

In a dynamic parametric process every subprocess may spawn arbitrarily many, identical child processes, that may communicate either over global variables, or over local variables that are shared with their parent. We show that reachability for dynamic parametric processes is decidable under mild assumptions. These assumptions are e.g. met if individual processes are realized by pushdown systems, or even higher-order pushdown systems. We also provide algorithms for subclasses of pushdown dynamic parametric processes, with complexity ranging between NP and DEXPTIME.Comment: 31 page

Innovating with rural stakeholders in the developing world: Action research in partnership

‘Action research in partnership’ (ARP) is an approach that combines knowledge generation, transformation of social realities and building up skills, both individual and collective. Drawing on a range of experiences in agriculture and rural development in developing countries, this book helps the reader understand the background to this approach and how to put it into practice. Intended for researchers and professionals working in the field rural development, the publication prepares practitioners to better address complex situations requiring interactions with a diversity of stakeholders

Innover avec les acteurs du monde rural: la recherche-action en partenariat

Cet ouvrage destiné aux chercheurs et aux spécialistes du développement rural s'appuie sur un large éventail d'expériences de recherche-action en agriculture pour envisager les aspects théoriques et pratiques de la démarche. Le lecteur y trouvera une description des fondements de la recherche-action en partenariat et divers exemples illustrant les moyens mis en œuvre par des praticiens pour relever les défis d'une recherche-action collaborative

Observación de dinámicas colectivas de transición agroecológica en Francia

En el marco del proyecto de Observatorios de Dinámicas Territoriales (LABINTEX) se participa en 4 dispositivos de investigación participativa sobre diferentes situaciones territoriales con el objetivo de analizar la capacidad de dichos dispositivos de crear redes socio-técnicas con capacidad de agencia. Dos de estos dispositivos (CapVert y ObsTAE) están vinculados a situaciones de grupos de productores implicados en procesos de transición agroecológica. En ambos se realiza una caracterización de diferentes situaciones grupales y se hacen seguimientos de grupos seleccionados. En esta ponencia nos proponemos caracterizar estos dispositivos y mostrar algunos avances de los seguimientos realizados. Dos hipótesis principales guían esta presentación: 1) la pertenencia a un grupo facilita el proceso de transición agroecológica 2) Existe una correlación entre el avance en prácticas agroecológicas y la emergencia de nuevas formas de cooperación entre los productores y actores del territorio. Los primeros trabajos de terreno nos alientan a validar ambas hipótesis.In the framework of the project “Observatories of Territorial Dynamics” (LABINTEX) we participate in 4 devices of participatory research on different territorial situations in order to test the ability of these devices to create socio-technical networks with agency capability. Two of these devices (Capvert and ObsTAE) are linked to situations of farmers groups involved in processes of agroecological transition. In both cases the different group situations are characterized and monitoring of selected groups is made. In this paper we propose to characterize these devices and show some progress in the performed follow-ups. Two main hypotheses guide this presentation: 1) membership to a group facilitates the process of agroecological transition 2) There is a correlation between moving forward to agro-ecological practices and the emergence of new forms of cooperation between producers and actors of the territory. The first field works encourage us to validate both hypotheses.Eje A6: Desarrollo Rural, Movimientos Sociales, Estado y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Estado del arte de la quinua en el mundo en 2013

Alimento de base de las poblaciones andinas desde hace milenios, la quinua se ha convertido hoy en un producto apreciado en el mercado internacional de alimentos dietéticos, orgánicos y equitativos. Este cambio lo iniciaron los mismos productores del Altiplano Sur de Bolivia hace aproximadamente unos 40 años. En medio de un desierto de altura, ellos lograron desarrollar una floreciente producción agrícola de exportación. Aunque cuentan con lucrativos nichos de mercado, los productores de quinua no son agricultores especializados, ni residen de forma permanente en la zona de producción. Estas son algunas de las paradojas que caracterizan la producción de quinua en el Altiplano Sur de Bolivia. Después de describir el origen, la diversidad y los rasgos biológicos del ecotipo Quinua Real en el cual se basa la producción de esta zona, se plantea la importancia de la quinua en los agrosistemas locales y, más allá, en los sistemas de actividades agrícolas y no agrícolas manejados por las familias del Altiplano Sur. Movilidad geográfica y pluriactividad forman parte del modo de vida ancestral de estas poblaciones y determinan hasta hoy en día las condiciones de uso de los recursos territoriales y la organización de los productores en el contexto del auge comercial de la quinua. La producción actual de quinua en la región presenta rasgos de vulnerabilidad agroecológica y social, así como capacidades adaptativas para enfrentarlos. Se resaltan como puntos clave para la sostenibilidad de los agrosistemas locales : i) la concertación de reglas comunales e individuales para el acceso y uso de la tierra en agrosistemas socialmente equitativos y equilibrados entre cultivo y ganadería, ii) las normas internacionales para el reconocimiento de la Quinua Real en los mercados de exportación, iii) una actualización continua de las reglas y normas para mantener la adaptabilidad de los agrosistemas locales a los cambios imprevisibles del contexto socio-ecológico a varias escalas de espacio y de tiempo

Stromal cell-derived factor 1 (SDF-1) and antenatal human B cell lymphopoiesis: Expression of SDF-1 by mesothelial cells and biliary ductal plate epithelial cells

The chemokine stromal cell-derived factor 1 (SDF-1) stimulates the growth of pre-B cells in vitro, and mice with a disrupted SDF-1 gene have abnormal fetal liver B cell lymphopoiesis. The origin of SDF-1 production has not been determined yet. Using an anti-SDF-1 mAb, we performed immunohistochemical studies in four human embryos and five fetuses to define which cells express the SDF-1 protein at sites of antenatal B cell lymphopoiesis. All mesothelial cells contained SDF-1 at all stages of development, including in the intraembryonic splanchnopleuric mesoderm early into gestation. In fetal lungs and kidneys, SDF-1 was expressed by epithelial cells, and a few B lymphoid precursors, expressing V pre-B chains, were also detected. In the fetal liver, in addition to mesothelial cells, biliary epithelial cells were the only cells to contain SDF-1. Pre-B cells expressing V chains were abundant and exclusively located around the edge of portal spaces, in close contact with biliary ductal plate epithelial cells. They did not colocalize with biliary collecting ducts. Biliary ductal plate epithelial cells and liver B cell lymphopoiesis display a parallel development and disappearance during fetal life. These results indicate that early B cell lymphopoiesis in the splanchnopleura may be triggered by mesothelial cells producing SDF-1. Later into gestation, biliary ductal plate epithelial cells may support B cell lymphopoiesis, thus playing a role similar to that of epithelial cells in the avian bursa of Fabricius, and of thymic epithelial cells for T cell lymphopoiesis

QTLs for oil yield components in an elite oil palm (Elaeis guineensis) cross

Increased modern farming of superior types of the oil palm, Elaeis guineensis Jacq., which has naturally efficient oil biosynthesis, has made it the world’s foremost edible oil crop. Breeding improvement is, however, circumscribed by time and costs associated with the tree’s long reproductive cycle, large size and 10–15 years of field testing. Marker-assisted breeding has considerable potential for improving this crop. Towards this, quantitative trait loci (QTL) linked to oil yield component traits were mapped in a high-yield population. In total, 164 QTLs associated with 21 oil yield component traits were discovered, with cumulative QTL effects increasing in tandem with the number of QTL markers and matching the QT+ alleles for each trait. The QTLs confirmed all traits to be polygenic, with many genes of individual small effects on independent loci, but epistatic interactions are not ruled out. Furthermore, several QTLs maybe pleiotropic as suggested by QTL clustering of inter-related traits on almost all linkage groups. Certain regions of the chromosomes seem richer in the genes affecting a particular yield component trait and likely encompass pleiotropic, epistatic and heterotic effects. A large proportion of the identified additive effects from QTLs may actually arise from genic interactions between loci. Comparisons with previous mapping studies show that most of the QTLs were for similar traits and shared similar marker intervals on the same linkage groups. Practical applications for such QTLs in marker-assisted breeding will require seeking them out in different genetic backgrounds and environments

A multi-scale analysis of bull sperm methylome revealed both species peculiarities and conserved tissue-specific

peer-reviewedBackground: Spermatozoa have a remarkable epigenome in line with their degree of specialization, their unique nature and different requirements for successful fertilization. Accordingly, perturbations in the establishment of DNA methylation patterns during male germ cell differentiation have been associated with infertility in several species.Background: Spermatozoa have a remarkable epigenResults: The quantification of DNA methylation at CCGG sites using luminometric methylation assay (LUMA) highlighted the undermethylation of bull sperm compared to the sperm of rams, stallions, mice, goats and men. Total blood cells displayed a similarly high level of methylation in bulls and rams, suggesting that undermethylation of the bovine genome was specific to sperm. Annotation of CCGG sites in different species revealed no striking bias in the distribution of genome features targeted by LUMA that could explain undermethylation of bull sperm. To map DNA methylation at a genome-wide scale, bull sperm was compared with bovine liver, fibroblasts and monocytes using reduced representation bisulfite sequencing (RRBS) and immunoprecipitation of methylated DNA followed by microarray hybridization (MeDIP-chip). These two methods exhibited differences in terms of genome coverage, and consistently, two independent sets of sequences differentially methylated in sperm and somatic cells were identified for RRBS and MeDIP-chip. Remarkably, in the two sets most of the differentially methylated sequences were hypomethylated in sperm. In agreement with previous studies in other species, the sequences that were specifically hypomethylated in bull sperm targeted processes relevant to the germline differentiation program (piRNA metabolism, meiosis, spermatogenesis) and sperm functions (cell adhesion, fertilization), as well as satellites and rDNA repeats. Conclusions: These results highlight the undermethylation of bull spermatozoa when compared with both bovine somatic cells and the sperm of other mammals, and raise questions regarding the dynamics of DNA methylation in bovine male germline. Whether sperm undermethylation has potential interactions with structural variation in the cattle genome may deserve further attention. While bull semen is widely used in artificial insemination, the literature describing DNA methylation in bull spermatozoa is still scarce. The purpose of this study was therefore to characterize the bull sperm methylome relative to both bovine somatic cells and the sperm of other mammals through a multiscale analysis