Soil CO2 efflux at timberline on Mt. Fuji

Soil CO2 effluxes were investigated at timberline on Mt. Fuji. Three study plots along a sequence of vegetation zones (dwarf, tall Japanese larch, and Veitch\u27s silver fir proceeding downward) in the vicinity of timberline were selected for the measurement of soil CO2 efflux. The results showed differences in the temperature dependence of the soil CO2 efflux among the three study plots. The highest value (Q10 = 4.4) was derived at the upper plot where the vegetation and soil formation were underdeveloped. Environmental data also showed differences among the three plots in soil temperature and soil water content. The upper study plot was exposed to higher soil temperature and lower soil moisture than the other two plots because of poor vegetation cover and underdeveloped soil formation. The total soil CO2 efflux during the snow free period from June to October was estimated for the upper, middle, and lower plots as 3.3, 3.0, and 3.7 Mg C ha-1 5 months-1. The results suggest that the amount of soil CO2 efflux does not always correspond to vegetation and soil development

Subunit modification and association in VR1 ion channels

BACKGROUND: The capsaicin (vanilloid) receptor, VR1, is an agonist-activated ion channel expressed by sensory neurons that serves as a detector of chemical and thermal noxious stimuli. RESULTS: In the present study we investigated the properties of VR1 ion channels expressed in Xenopus oocytes. A VR1 subunit with a FLAG epitope tag at the C-terminus was constructed. When examined for size on an SDS gel, VR1-expressing oocytes produced a doublet corresponding to the size of the monomer and a band at about twice the molecular weight of the monomer. A consensus site for N-linked glycosylation was identified in the primary sequence at position 604. In channels in which the putative glycosylation site was mutated from asparagine to serine (N604S), the larger of the two monomer bands could no longer be detected on the gel. Electrophysiological experiments showed these unglycosylated channels to be functional. The high molecular weight band observed on the gel could represent either a dimer or a monomer conjugated to an unknown factor. To distinguish between these possibilities, we coexpressed a truncated VR1 subunit with full-length VR1. A band of intermediate molecular weight (composed of one full-length and one truncated subunit) was observed. This dimer persisted under strongly reducing conditions, was not affected by capsaicin or calcium, and was refractory to treatment with transglutaminase inhibitors. CONCLUSIONS: The persistence of this dimer even under harsh denaturing and reducing conditions indicates a strong interaction among pairs of subunits. This biochemical dimerization is particularly intriguing given that functional channels are almost certainly tetramers

Fragment Size And Density Effects On The Growth And Survival Of Montipora Capitata

OCN 499 - Undergraduate Thesi

Functional interleukin-7 receptors (IL-7Rs) are expressed by marrow stromal cells: binding of IL-7 increases levels of IL-6 mRNA and secreted protein.

DNA spotted microarrays were used to compare gene expression profiles from 2 functionally distinct human marrow stromal cell lines: HS-27a, which supports cobblestone area formation by early hematopoietic progenitors, and HS-5, which secretes multiple cytokines that support the proliferation of committed progenitors. One unexpected result was the high level of interleukin-7 receptor (IL-7R) gene expression in HS-27a stromal cells. Northern blot analysis confirmed the IL-7R RNA expression, and Western blots for the IL-7R protein detected both a full-length (90-kd) IL-7R and a smaller 30-kd fragment in both HS-27a cells and primary stromal cell cultures, whereas only the 90-kd receptor protein was detected in peripheral blood mononuclear cells. Biotinylated IL-7 was shown to bind to HS-27a cells under physiologic conditions, and this binding was inhibited by blocking anti-IL-7 antibodies. Tyrosine phosphorylation of several proteins (55 kd, 30 kd, and 24 kd) in HS-27a cells was rapidly increased after incubation with recombinant IL-7. One of the phosphorylated proteins proved to be the 30-kd IL-7R fragment. Exposure of HS-27a cells to IL-7 resulted in a 10-fold increase in secretion of IL-6 into culture supernatants but no increase in the cytokines stromal cell-derived factor 1, macrophage inflammatory protein 1 alpha, or IL-1 beta. The up-regulation of IL-6 secretion is associated with a rapid but transient increase in detectable levels of IL-6 messenger RNA. These data suggest that IL-7 may function to regulate the milieu of the microenvironment by modulating IL-6 secretion by the IL-7R-expressing stromal elements

Formation of superconducting yttrium barium copper oxide using sulphur-containing templates

The formation of yttrium barium copper oxide (YBCO) via biotemplated routes is often plagued by unwanted stable intermediates, some of which arise from the template itself. Here we describe a method which allows sulphur-containing templates, such as proteins, to form superconducting YBCO which would have hitherto resulted in non-superconducting sulphated phases

Difficultés d’Enseignement/Apprentissage de l’Expression Ecrite En Classe de CM1 dans la Circonscription Scolaire de Bacongo (République du Congo)

Abstract The purpose of the study that we conducted was based on analyzing the difficulties encountered by teachers and learners during the teaching /learning process of written expression. This study took place in the school district of Bacongo which is the second district of Brazzaville in the Republic of Congo. The non-experimental method underpinned by two approaches were used in particular: the quantitative approach and the qualitative approach. The instruments that we used to carry out the survey were the questionnaire and the documentary analysis. The questionnaire was sent to teachers, education supervisors and students. The documentary analysis focused on primary school curricula, text books used by teachers and analysis of copies. The results from the questionnaire were sometime contradictory between the teachers and their supervisors.  Some have said that they are not followed when they teach written expression, while others oppose them. However, they unanimous regarding the absence of continuing education and educational documents. Indeed, teachers suffer from the absence or insufficiency of both initial and continuous training relating to written expression, which results from the documentary analysis corroborate those of the questionnaire. To this lack of training is added the difficulty of the language used at school, which is a foreign language: French. To this end, the multiplication training sessions relating to this teaching and the linguistic both are essential.Keywords: difficulties-teaching/learning-written expression-initial training-continual training Résumé :L’étude que nous avons menée s’est focalisé sur l’analyse des difficultés que rencontrent les enseignants et les apprenants lors du processus enseignement/ apprentissage de l’expression écrite. Cette étude s’est passée dans la circonscription scolaire de Bacongo qui est le deuxième arrondissement de Brazzaville en République du Congo. La méthode non expérimentale sous tendue par deux approches a été utilisée notamment : l’approche quantitative et l’approche qualitative. Les instruments qui ont servi pour réaliser l’enquête ont été le questionnaire et l’analyse documentaire. Le questionnaire a été adressé aux enseignants, aux encadreurs pédagogiques et aux élèves. L’analyse documentaire s’est focalisée sur les programmes scolaires du primaire, les manuels utilisés par les enseignants et l’analyse des copies. Les résultats issus du questionnaire ont été parfois contradictoires entre les enseignants et leurs encadreurs. Les uns ont affirmé qu’ils ne sont pas suivis lorsqu’ils déroulent l’enseignement de l’expression écrite par contre les autres les contrarient. Cependant, ils ont été unanimes en ce qui concerne l’absence de la formation continue et des documents pédagogiques. En effet, les enseignants souffrent de l’absence ou de l’insuffisance de la formation tant initiale que continue relative à l’expression écrite, ce qui a pour conséquence la mauvaise production écrite des apprenants. Les résultats issus de l’analyse documentaire corroborent ceux du questionnaire. A ce manque de formation s’ajoute la difficulté de la langue utilisée à l’école qui est une langue étrangère : le français. A cet effet, la multiplication des sessions de formation relative à cet enseignement et le bain linguistique s’avèrent indispensable.Mots clés : difficultés- enseignement/apprentissage- expression écrite -formation initiale -formation continue