Contribution à l'étude de l'acide chondroïtine-sulfurique

Summary It is found that chondroitinsulfuric acid is composed of unbranched chain-molecules containing rests of glucuronic acid and N-acetyl-galactosamine-6-sulfate combined in one of the following manners (a) or (b):      

Does Paramecium primaurelia use a different genetic code in its macronucleus?

It has long been known that messenger RNAs (mRNAs) of ciliates and in particular of Paramecium are not translated well in heterologous in vitro translation systems. Recently, we have demonstrated for Paramecium primaurelia that this phenomenon results from the presence of well-defined blocking sites in the coding sequences of almost all mRNAs, and that these sites are an intrinsic feature of the primary as opposed to the secondary structure of the mRNAs. Here we show that both the gene and the mRNA for the G surface antigen of P. primaurelia contain numerous TAA and TAG codons scattered throughout their coding sequences. We propose that these codons do not represent termination codons in P. primaurelia but instead code for glutamic acid or glutamine and that the in vitro translation of Paramecium mRNAs is blocked by their presence.     

Break the Ties for NEH Heuristic in Solving the Permutation Flow Shop Problems

This study deals with the Permutation Flow Shop Scheduling Problem （PFSP） based on the maximum completion time （makespan）. NEH （ the algorithm of Nawaz, Eascore and Ham） is the concluded most efficient constructive method in solving this NP-hard problem. The principal features of its strengths are the initial arrangement of jobs and the job insertion phase. In some instances, ties will occur in both the initial permutation and the partial sequences. The problem of ties breaking may have a significant impact on the NEH performance, but evaluate all the ties will be non-polynomial in the worst case. Several kinds of methods are presented in the paper to break the ties in a quick time. Together with the basic one, all 22 methods are tested on the famous Taillard＇s benchmarks and the most suitable ties breaking policy is recommended.     

环境科学和化学中的偏序

偏序原本是一个数学问题。许多数学教科书中解释了什么是偏序，需要有一定数学基础的人才能领会。这些数学教科书主要是关于离散数学和理论信息领域的教科书。量子力学中也谈到偏序，但是应用实例很少。近年来，各种学科杂志中发表了大量的有关偏序在化学和环境科学中应用的论文。     

Minibiotus acadianus (Eutardigrada: Macrobiotidae), a new species of Tardigrada from southern Louisiana, U.S.A.

Over 200 species of freshwater and terrestrial water bears (phylum Tardigrada) are known to occur in North America. Of these, 16 species have been collected in Louisiana. Foliose and fruticose lichens collected on 18 April 2010 in Acadia Parish, Louisiana, were stored in paper envelopes and later soaked in tap water overnight. Tardigrade specimens and eggs were extracted and mounted in polyvinyl lactophenol. The samples contained a new species of tardigrade. Minibiotus acadianus sp. n. has a buccal tube with single anterior curvature, 2 macroplacoids and 1 microplacoid. Small gibbosities are present on the fourth pair of legs, in 3 caudal rows, and in a single row at the level of the third pair of legs. Minibiotus acadianus sp. n. differs from the most similar tardigrade species, Minibiotus fallax (found in Australia and Florida), in having a shorter and wider buccal tube, a different pattern of gibbosities, and short, peg-shaped processes in addition to long, filamentous processes on the eggs. Reexamination of specimens identified as M. fallax in an earlier paper on the Tardigrada of Louisiana indicates that they are, in fact, M. acadianus sp. n., suggesting that the new species is widely distributed in Louisiana. Se conocen más de 200 especies de osos de agua (phylum Tardigrada) terrestres y de agua dulce que ocurren en Norteamérica. De éstas, 16 se han colectado en Louisiana. Se colectaron líquenes foliosos y fruticosos en la parroquia de Acadia, Louisiana, el 18 de abril de 2010, los cuales fueron guardados en sobres de papel y después remojados en agua de la llave durante toda la noche. Se extrajeron especímenes y huevos de tardígrados y se fijaron en polivinilo lactofenol. Las muestras contenían una nueva especie de tardígrado. Minibiotus acadianus sp. n. tiene un tubo bucal con una única curvatura anterior, dos macroplacoides y un microplacoide. Pequeñas gibosidades están presentes en el cuarto par de patas, en tres hileras caudales y en una sola hilera al nivel del tercer par de patas. Minibiotus acadianus sp. n. difiere de la especie más próxima, Minibiotus fallax, una especie que se encontró en Australia y Florida, porque tiene un tubo bucal más corto y ancho, un patrón distinto de gibosidades y apófisis cortas en forma de estaquilla en los huevos, además de apófisis largas y filamentosas. Una reexaminación de los especímenes identificados como M. fallax en una publicación previa sobre los tardígrados de Louisiana indica que son más bien M. acadianus sp. n., lo cual sugiere que esta nueva especie tiene una distribución extensa en Louisiana.     

Analysis of <Emphasis Type="Italic">Dictyostelium</Emphasis> TACC reveals differential interactions with CP224 and unusual dynamics of <Emphasis Type="Italic">Dictyostelium</Emphasis> microtubules

We have localized TACC to the microtubule-nucleating centrosomal corona and to microtubule plus ends. Using RNAi we proved that Dictyostelium TACC promotes microtubule growth during interphase and mitosis. For the first time we show in vivo that both TACC and XMAP215 family proteins can be differentially localized to microtubule plus ends during interphase and mitosis and that TACC is mainly required for recruitment of an XMAP215-family protein to interphase microtubule plus ends but not for recruitment to centrosomes and kinetochores. Moreover, we have now a marker to study dynamics and behavior of microtubule plus ends in living Dictyostelium cells. In a combination of live cell imaging of microtubule plus ends and fluorescence recovery after photobleaching (FRAP) experiments of GFP-α-tubulin cells we show that Dictyostelium microtubules are dynamic only in the cell periphery, while they remain stable at the centrosome, which also appears to harbor a dynamic pool of tubulin dimers.     

Some observations on the Rohon-Beard cell perikaryon.

During the hatching period, the Rohon-Beard cells of Salmo gairdneri showed definite structural maturity of their perikarya, which is in contrast to the amphibian species investigated, where neuronal maturation of the Rohon-Beard cells is finished only in later -- posthatching -- developmental stages.     

Mutations in the desmosomal protein plakophilin-2 are common in arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with fibrofatty replacement of cardiac myocytes, ventricular tachyarrhythmias and sudden cardiac death. In 32 of 120 unrelated individuals with ARVC, we identified heterozygous mutations in PKP2, which encodes plakophilin-2, an essential armadillo-repeat protein of the cardiac desmosome. In two kindreds with ARVC, disease was incompletely penetrant in most carriers of PKP2 mutations.