Search results for "Topic"
showing 10 items of 2844 documents
Theoretical evaluation of 15N isotopic methods for measuring symbiotic nitrogen fixation in the fied
2008
International audience; Isotopic methods for the measurement of symbiotic N2 fixation by leguminous plants in the field rely on the use of differences in 15N enrichment between the N sources potentially available for leguminous crops, soil mineral N and atmospheric N2 . This methodology has been fully documented, especially concerning limitations due to non uniform and non constant distribution of 15N and to the use of a reference plant to measure it. Although all authors recognise the necessity of isotopic methods for giving yield independent and time-integrated estimates of symbiotic fixation, they also agree that these methods intrinsically remain imperfect. Our aim in this chapter is (i…
Delineating Aspects of Understanding Eigentheory through Assessment Development
2018
International audience; In this report, we share insights we have gained from developing an assessment for documenting students' understanding of eigentheory. We explain the literature and theory that influenced the assessment's development and share question examples. We frame our results in terms of three eigentheory settings (Ax = λx, (A - λI)x = 0, and eigenspaces) and four interpretations (numeric, algebraic, geometric, and verbal). Results from our analysis include students' reasoning being influenced by setting, insights into students' struggle with understanding eigenspaces, and the importance of making connections between and across various interpretations.
TOPICS
2018
Our problematic concerns the links between logic and topoï, semantics and topoï and finally between logic and semantics. The work therefore consists in highlighting the durability of the notion of topos, its evolution and its integration in logic, in semantics and even in computer science. From then on, topoi, logic and semantics are the three facets of this problematic. The purpose of this thesis is to present the history of topoi, to identify their linguistic properties. It also shows that this notion is present in all linguistic approaches and that semantics is the unifying axis of all linguistic research.It is not our intention to give a new definition, but we have tried to su…
Adipokines as Biomarkers of Atopic Dermatitis in Adults
2020
Atopic dermatitis (AD) is characterized by chronic, relapsing, pruritic skin inflammation and does not have a well-understood pathogenesis. In this study, we addressed the contribution of adipokines to AD eczema based on the assessment of blood levels of adiponectin, resistin, leptin, lipocalin-2, and vaspin in adult non-obese patients suffering from chronic extrinsic childhood-onset AD. We investigated 49 AD patients with a median age of 37 years. The control group consisted of 30 age-matched healthy subjects. Adipokines were assessed in the serum by ELISA assays and the severity of AD with the SCORing Atopic Dermatitis (SCORAD) index. We found that adiponectin and resistin decreased and l…
Bone marrow-derived progenitors are greatly reduced in patients with severe COPD and low-BMI.
2009
Chronic obstructive pulmonary disease (COPD) patients have reduced circulating hemopoietic progenitors. We hypothesized that severity of COPD parallels the decrease in progenitors and that the reduction in body mass index (BMI) could be associated with more severe bone marrow dysfunction. We studied 39 patients with moderate to very severe COPD (18 with low-BMI and 21 with normal-BMI) and 12 controls. Disease severity was associated to a greater reduction in circulating progenitors. Proangiogenetic and inflammatory markers correlated with disease severity parameters. Compared to normal-BMI patients, low-BMI patients showed: greater reduction in circulating progenitors; higher VEGF-A, VEGF-C…
The effect of allergen immunotherapy in the onset of new sensitizations: a meta-analysis.
2017
Background Although the preventive efficacy of allergen immunotherapy (AIT) in the onset of new allergen sensitizations has been asserted by many reviews, position papers, and consensus conferences, the evidence available is from only 3 studies. The objective of this work was a systematic review to evaluate the preventive efficacy of AIT in the onset of new allergen sensitizations. The end-point was the risk difference (RD) in the onset of new allergen sensitizations between patients treated with AIT and pharmacotherapy. Methods Computerized bibliographic searches of MEDLINE, EMBASE, and the Cochrane Library (until November 30th, 2016) were done. Random-effects and fixed-effects model meta-…
Cloning and Targeted Deletion of the Mouse Fetuin Gene
1998
We proposed that the alpha2-Heremans Schmid glycoprotein/fetuin family of serum proteins inhibits unwanted mineralization. To test this hypothesis in animals, we cloned the mouse fetuin gene and generated mice lacking fetuin. The gene consists of seven exons and six introns. The cystatin-like domains D1 and D2 of mouse fetuin are encoded by three exons each, whereas a single terminal exon encodes the carboxyl-terminal domain D3. The promoter structure is well conserved between rat and mouse fetuin genes within the regions shown to bind transcription factors in the rat system. Expression studies demonstrated that mice homozygous for the gene deletion lacked fetuin protein and that mice heter…
Learning complex analysis in different branches – Project Spotlight-Y for future teachers
2018
International audience; At the University of Bremen in teaching complex analysis, we split the last part of the lecture into two branches according to profession: While future mathematicians deepen their understanding in a branch for them, future teachers take a branch of the lecture where they prepare a task with dynamical geometry software for pupils which is based on phenomena of complex analysis. Here, we describe the design of the course, some general aims and first results obtained from the branch for future teachers.
Spatially restricted expression of PlOtp, a Paracentrotus lividus Orthopedia-related homeobox gene, is correlated with oral ectodermal patterning and…
1999
ABSTRACT Several homeobox genes are expressed in the sea urchin embryo but their roles in development have yet to be elucidated. Of particular interest are homologues of homeobox genes that in mouse and Drosophila are involved in patterning the developing central nervous system (CNS). Here, we report the cloning of an orthopedia (Otp)-related gene from Paracentrotus lividus, PlOtp. Otp is a single copy zygotic gene that presents a unique and highly restricted expression pattern. Transcripts were first detected at the mid-gastrula stage in two pairs of oral ectoderm cells located in a ventrolateral position, overlying primary mesenchyme cell (PMC) clusters. Increases in both transcript abund…
Quantitative determination of casein genetic variants in goat milk: Application in Girgentana dairy goat breed
2016
The study was conducted to develop a high-performance liquid chromatographic (HPLC) method to quantify casein genetic variants (αs2-, β-, and κ-casein) in milk of homozygous individuals of Girgentana goat breed. For calibration experiments, pure genetic variants were extracted from individual milk samples of animals with known genotypes. The described HPLC approach was precise, accurate and highly suitable for quantification of goat casein genetic variants of homozygous individuals. The amount of each casein per allele was: αs2-casein A = 2.9 ± 0.8 g/L and F = 1.8 ± 0.4 g/L; β-casein C = 3.0 ± 0.8 g/L and C1 = 2.0 ± 0.7 g/L and κ-casein A = 1.6 ± 0.3 g/L and B = 1.1 ± 0.2 g/L. A good correl…