221 research outputs found
SOIL ORGANIC MATTER IN AFFORESTED POST-AGRICULTURAL SOILS
The studies were carried out in central Poland. Total organic carbon (Corg), total nitrogen (Nt) andCof humus fractions in uppermost soil horizons were analyzed in afforested meadow soils in first and fifth year of afforestation (2 profiles) and compared to about 70-year-old continuous forest soils. Soil was collected from 0-5, 5-10, 10-15 and 15-20 cm layers depth. The results showed that the soil Corganic (Corg) and Ntotal (Nt) decreased with depth in both studied periods. The Corg amounts were higher in the second period (5 years after afforestation) in almost every layer of the humus horizons in comparison to the first year of afforestation. The Nt content rather decreased in particular layers during five years, but mean values of 0-20 cm depth were lower or higher in dependence on soil type. The content of both elements in the studied layers was lower in the 5-year afforested soils than in the continuous forest soils. The results indicated changes in organic matter properties too, but the distribution of the different soil organic matter fractions in humus layers in time was dependent on soil properties
ROLE OF APORRECTODEA CALIGINOSA IN THE PROCESSES OF SOIL ORGANIC MATTER TRANSFORMATION UNDER THE CONDITION OF MONOCULTURE AND MULTISPECIES PLANT COMMUNITY
The study has been carried out in the experimental field of the Centre for Ecological Research of the Polish Academy of Sciences, PAN, located in Dziekanów Leoeny (north of Warsaw). Six hundred lysimeters were installed covering the experimental area. The surface of the experimental plots (both lysimeters and their vicinity) was sown with either one grass (Festuca rubra) on half of the area, or with a mixture of 8 grass species on the other half of the area. In the next year, geophagous earthworms A. caliginosa were introduced to half of the lysimeters. The content of C-org, N-total, and the fractional composition of soil humus, were first determined at the beginning; at the end of the experiment also pH and the capacity of sorption complex were identified. The empirical results were subject to statistical analyses. After two years of the study, in comparison to red fescue sodding, the grass mixture sodding caused an increase in the content of organic carbon, total nitrogen and carbon of the humus fraction. The differences between the mean values of both soddings were not statistically significant. In soils under grass mixture, A. caliginosa caused an increase in the contents of organic carbon and fulvic acids carbon in relation to the initial soil; the CHA/CFA ratio significantly decreased. A slight increase in the degree of organic matter humification was observed in both soddings in combination with earthworms
A practical approach to project management in a very small company
This article shows how a very small company has tailored Scrum according to its own needs. The main additions made were the “sprint design” phase and the “sprint test” phase. Before the sprint 0, the requirements elicitation and the functional specification were made in order to meet deadlines and costs agreed with clients. Besides, the introduction of an agile project management tool has supported all the process and it is considered the main success factor for the institutionalization of the Scrum process
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ELAV links paused Pol II to alternative polyadenylation in the Drosophila nervious system
Alternative polyadenylation (APA) has been implicated in a variety of developmental and disease processes. A particularly dramatic form of APA occurs in the developing nervous system of flies and mammals, whereby various developmental genes undergo coordinate 3' UTR extension. In Drosophila, the RNA-binding protein ELAV inhibits RNA processing at proximal polyadenylation sites, thereby fostering the formation of exceptionally long 3' UTRs. Here, we present evidence that paused Pol II promotes recruitment of ELAV to extended genes. Replacing promoters of extended genes with heterologous promoters blocks normal 3' extension in the nervous system, while extension-associated promoters can induce 3' extension in ectopic tissues expressing ELAV. Computational analyses suggest that promoter regions of extended genes tend to contain paused Pol II and associated cis-regulatory elements such as GAGA. ChIP-seq assays identify ELAV in the promoter regions of extended genes. Our study provides evidence for a regulatory link between promoter-proximal pausing and APA
Towards a Formalization of a Framework to Express and Reason about Software Engineering Methods
Software Engineering is considered a knowledge-intensive discipline, in which knowledge creation, collection and sharing is an uninterrupted process. However, a large part of this knowledge exists in a tacit form and depends on practitioners. Therefore defining a mechanism to transform tacit knowledge into explicit one is of upmost importance. This paper presents a formalization approach to represent Software Engineering practitioners' tacit knowledge, which is related to their ways of working, as a set of explicit statements. The formalization is based on KUALI-BEH, which is a normative kernel extension of ESSENCE formal specification, and consists of three parts: an ontology to share a common representation of knowledge as a set of concepts; a Situational Method Engineering based algebra that represents well-defined method properties and operations; and a knowledge representation of the ontology and algebra using Description Logics. The main objectives of this initial formalization are to improve communication among humans and machines, computational inference and reuse of knowledge
Dynamic Regulation by Polycomb Group Protein Complexes Controls Pattern Formation and the Cell Cycle in Drosophila
SummaryPolycomb group (PcG) proteins form conserved regulatory complexes that modify chromatin to repress transcription. Here, we report genome-wide binding profiles of PhoRC, the Drosophila PcG protein complex containing the DNA-binding factor Pho/dYY1 and dSfmbt. PhoRC constitutively occupies short Polycomb response elements (PREs) of a large set of developmental regulator genes in both embryos and larvae. The majority of these PREs are co-occupied by the PcG complexes PRC1 and PRC2. Analysis of PcG mutants shows that the PcG system represses genes required for anteroposterior, dorsoventral, and proximodistal patterning of imaginal discs and that it also represses cell cycle regulator genes. Many of these genes are regulated in a dynamic manner, and our results suggest that the PcG system restricts signaling-mediated activation of target genes to appropriate cells. Analysis of cell cycle regulators indicates that the PcG system also dynamically modulates the expression levels of certain genes, providing a possible explanation for the tumor phenotype of PcG mutants
Blending process assessment and employees competencies assessment in very small entities
The ISO/IEC 29110 series aims to provide Very Small Entities (VSEs) with a set of standards based on subsets of existing standards. Process capability determination does not seem suitable for a VSE in terms of return on investment. Our approach proposes to move the viewpoint away from process and to the human resources. We propose a blended assessment model using the ISO/IEC 15504 for the level 1, but based on competency assessment for higher capability levels
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