1,211 research outputs found
Wheat-Faba bean intercrops improve plant nutrition, yield, and availability of nitrogen (N) and phosphorus (P) in soil
Received: June 27th, 2022 ; Accepted: July 27th, 2022 ; Published: August 1st, 2022 ; Correspondance: [email protected] order to promote agroecological practices, this study compares two cropping
systems, i.e., intercropping versus sole cropping of a cereal - durum wheat (Triticum durum
Desf. ) and a nitrogen-fixing legume - faba bean (Vicia faba L.) on plant growth, Efficiency in
the use of rhizobial symbiosis (EURS), grain yield and phosphorus (P) and nitrogen (N)
accumulation in soil and plant. This study conducted during two cropping seasons in a field trial
in the region of Tizi Ouzou, Algeria, shows that shoot dry weight (SDW), nitrogen nutrition index
(NNI), phosphorus use efficiency (PUE), land use efficiency (LER), and grain yield were
significantly higher for intercropped than for the sole cropped wheat. Furthermore, there was a
considerable increase in soil P and N content across the two years of intercropping and sole
cropping compared to the unseeded weeded fallow. Intercropping, it is claimed, improves wheat
N nutrition by increasing the availability of soil-N for wheat. This increase might be due to
reduced interspecific competition between legumes and wheat plants than intraspecific
competition between wheat plants due to the legume’s ability to compensate by atmospheric
nitrogen fixation
Towards the integration of functions, relations and types in an AI programming language
This paper describes the design and implementation of the programming language PC-Life. This language integrates the functional and the Logic-oriented programming style and feature types supporting inheritance. This combination yields a language particularly suited to knowledge representation, especially for application in computational linguistics
Simulation de l'écoulement des pâtes cimentaires par un modèle diphasique
La modélisation de l'écoulement des pâtes cimentaires est un problème difficile car le matériau a non seulement un comportement rhéologique complexe mais il peut également présenter des hétérogénéités induites par l'écoulement. L'apparition de ces hétérogénéités résulte de la filtration de phases fluides au travers de phases solides et peut conduire au blocage de l'écoulement. Pour modéliser l'écoulement d'un tel matériau il est nécessaire de prendre en compte la présence d'au moins deux phases. Dans notre modélisation nous considérons que les deux phases sont continues et admettent un comportement rhéologique en loi de puissance. Le couplage entre les deux phases est pris en compte au moyen d'une loi de Darcy généralisée à un fluide en loi de puissance. Le modèle est résolu par la méthode des éléments finis et validé dans le cas d'un test d'écrasement. Nous montrons que ces simulations permettent d'établir des diagrammes d'ouvrabilité des pâtes cimentaires
TWAM: A Certifying Abstract Machine for Logic Programs
Type-preserving (or typed) compilation uses typing derivations to certify
correctness properties of compilation. We have designed and implemented a
type-preserving compiler for a simply-typed dialect of Prolog we call T-Prolog.
The crux of our approach is a new certifying abstract machine which we call the
Typed Warren Abstract Machine (TWAM). The TWAM has a dependent type system
strong enough to specify the semantics of a logic program in the logical
framework LF. We present a soundness metatheorem which constitutes a partial
correctness guarantee: well-typed programs implement the logic program
specified by their type. This metatheorem justifies our design and
implementation of a certifying compiler from T-Prolog to TWAM.Comment: 41 pages, under submission to ACM Transactions on Computational Logi
Intercropping Promotes the Ability of Legume and Cereal to Facilitate Phosphorus and Nitrogen Acquisition through Root- Induced Processes
Intercropping of cereal and legume can improve the use of resources for crop growth compared to cropping system. An increase in soil phosphorus (P) and nitrogen (N) acquisition by root-induced biochemical changes of intercropped species has been reported as key processes of facilitation and complementarily between both intercropping legumes and cereals. Indeed, the functional facilitation prevails over interspecific competition under nutrients limiting for crop growth. Results showed that P availability significantly increased in the rhizosphere of both species, especially in intercropping under the P-deficient soil conditions. This increase was associated with high efficiency efficiency in use of rhizobial, plant growth and resource use efficiency as indicated by higher land equivalent ratio (LER) and N nutrition index. In addition, the rhizosphere P availability and nodule biomass were positively correlated (r2 = 0.71**, and r2 = 0.62**) in the intercropped common bean grown at P-deficient soil. The increased P availability presumably improved biomass and yield in intercropping, although it mainly enhanced intercropped maize grain yield. Exploiting belowground parameters in a legume-cereal intercropping is likely necessary to maximize rhizosphere-interspecific interactions as a strategy to improve the symbiotic rhizobial efficiency and microbial activities, as a result of root-induced pH and N availability changes under low P soils
Cell Migration in the Immune System: the Evolving Inter-Related Roles of Adhesion Molecules and Proteinases
Leukocyte extravasation into perivascular tissue during inflammation and lymphocyte homing
to lymphoid organs involve transient adhesion to the vessel endothelium, followed by transmigration
through the endothelial cell (EC) layer and establishment of residency at the tissue site
for a period of time. In these processes, leukocytes undergo multiple attachments to, and detachments
from, the vessel-lining endothelial cells, prior to transendothelial cell migration. Transmigrating
leukocytes must traverse a subendothelial basement membrane en route to perivascular
tissues and utilize enzymes known as matrix metalloproteinases to make selective clips in the
extracellular matrix components of the basement membrane. This review will focus on the evidence
for a link between adhesion of leukocytes to endothelial cells, the induction of matrix
metalloproteinases mediated by engagement of adhesion receptors on leukocytes, and the ability
to utilize these matrix metalloproteinases to facilitate leukocyte invasion of tissues. Leukocytes
with invasive phenotypes express high levels of MMPs, and expression of MMPs
enhances the migratory and invasive properties of these cells. Furthermore, MMPs may be used
by lymphocytes to proteolytically cleave molecules such as adhesion receptors and membrane
bound cytokines, increasing their efficiency in the immune response. Engagement of leukocyte
adhesion receptors may modulate adhesive (modulation of integrin affinities and expression),
synthetic (proteinase induction and activation), and surface organization (clustering of proteolyric
complexes) behaviors of invasive leukocytes. Elucidation of these pathways will lead to
better understanding of controlling mechanisms in order to develop rational therapeutic
approaches in the areas of inflammation and autoimmunity
Improving the compilation of prolog to C using moded types and determinism information
We describe the current status of and provide performance
results for a prototype compiler of Prolog to C, ciaocc. ciaocc is novel in that it is designed to accept different kinds of high-level information, typically obtained via an automatic analysis of the initial Prolog program and expressed in a standardized language of assertions. This information is used to optimize the resulting C code, which is then processed by an off-the-shelf C compiler. The basic translation process essentially mimics the unfolding of a bytecode emulator with respect to the particular bytecode corresponding to the Prolog program. This is facilitated by a flexible design of the instructions and their lower-level components. This approach allows reusing a sizable amount of the machinery of the bytecode emulator: predicates already written in C, data definitions, memory management routines and áreas, etc., as well as mixing emulated bytecode with native code in a relatively straightforward way. We report on the performance of programs compiled by the current versión of the system, both with and without analysis information
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