RNA deep sequencing reveals differential MicroRNA expression during development of sea urchin and sea star

microRNAs (miRNAs) are small (20-23 nt), non-coding single stranded RNA molecules that act as post-transcriptional regulators of mRNA gene expression. They have been implicated in regulation of developmental processes in diverse organisms. The echinoderms, Strongylocentrotus purpuratus (sea urchin) and Patiria miniata (sea star) are excellent model organisms for studying development with well-characterized transcriptional networks. However, to date, nothing is known about the role of miRNAs during development in these organisms, except that the genes that are involved in the miRNA biogenesis pathway are expressed during their developmental stages. In this paper, we used Illumina Genome Analyzer (Illumina, Inc.) to sequence small RNA libraries in mixed stage population of embryos from one to three days after fertilization of sea urchin and sea star (total of 22,670,000 reads). Analysis of these data revealed the miRNA populations in these two species. We found that 47 and 38 known miRNAs are expressed in sea urchin and sea star, respectively, during early development (32 in common). We also found 13 potentially novel miRNAs in the sea urchin embryonic library. miRNA expression is generally conserved between the two species during development, but 7 miRNAs are highly expressed in only one species. We expect that our two datasets will be a valuable resource for everyone working in the field of developmental biology and the regulatory networks that affect it. The computational pipeline to analyze Illumina reads is available at http://www.benoslab.pitt.edu/services.html. © 2011 Kadri et al

CD40 signaling predicts response to preoperative trastuzumab and concomitant paclitaxel followed by 5-fluorouracil, epirubicin, and cyclophosphamide in HER-2-overexpressing breast cancer

Introduction We performed gene expression analysis to identify molecular predictors of resistance to preoperative concomitant trastuzumab and paclitaxel followed by 5-fluorouracil, epirubicin, and cyclophosphamide (T/FEC). Methods Pretreatment fine-needle aspiration specimens from 45 patients with HER-2-overexpressing stage II to IIIA breast cancer were subjected to transcriptional profiling and examined for differential expression of various genes and gene sets. The primary endpoint for tumor response was pathologic complete response (pCR). Correlations between pCR and gene expression were sought. Results The overall pCR rate was 64%. Age, nuclear grade, tumor size, nodal status, quantitative expression of estrogen and HER-2 receptor mRNA, and HER-2 gene copy number showed no correlation with pCR. Results of gene set enrichment analysis suggested that the lower expression of genes involved with CD40 signaling is associated with a greater risk of residual cancer after the preoperative chemotherapy that includes trastuzumab. Conclusion CD40 signaling may play a role in determining response to trastuzumab-plus-T/FEC therapy in patients with HER-2-overexpressing breast cancer.PubMedWoSScopu

Combined effect of chemical nature of fineness of mineral powders on Portland cement hydration

This paper focuses on the influence of the chemical nature and the fineness of the fillers on the hydration process and on the compressive strength development. Four different types of fillers are considered in combination with Portland cement: quartzite filler, alumina filler, limestone filler, and silica fume. The study deals with blended mortars having a 0.45 water to powder (cement and filler) ratio with a 10% substitution of cement by filler. Quartzite fillers do not seem to accelerate the hydration process in a significant way. No positive effect is noticed on the strength development either. The presence of a fine inert alumina powder increases the rate of early hydration of Portland cement. The greater the fineness, the faster the rate of hydration heat development. This reactivity leads to an increase in the compressive strength at early age for mortar containing the finest alumina powders. In case of coarse alumina powder, no acceleration effect is obtained. Finely ground limestone (calcite) fillers promote heterogeneous nucleation of hydrates which significantly accelerates hydration. At early age, this also results in an increased mortar compressive strength in comparison with the control mortar. From the obtained results, it is clear that both chemical natures as well as fineness are important with regard to the accelerating effect of the hydration process. With increasing fineness, the accelerating effect increases. For powders with comparable fineness, it is clear that limestone powder has a more significant accelerating effect than silica fume and alumina filler. Quartzite filler seems to have no significant effect

Influence of aggregate skeleton on shrinkage properties: validation of the model developed by Le Roy for the case of self-compacting concrete

Shrinkage behavior of self-compacting concrete (SCC) can be different from that of traditional vibrated concrete, because of different paste and aggregate volumes. For traditional concrete, shrinkage can be estimated based on shrinkage results obtained on paste level. Based on homogenization techniques, Le Roy developed a model relating the shrinkage of concrete to the shrinkage of the representative cement paste, considering a granular coefficient taking into account the elastic properties and the concentration of the aggregates. By means of an extended experimental program, the applicability of this model to the case of SCC has been verified. Furthermore, some known results on the influence of water/cement ratio and filler/cement ratio have been confirmed and can be explained by porosity results

Validation of the model developed by Le Roy for the shrinkage of self-compacting concrete

By means of concrete equivalent mortar (CEM) principle, concrete properties can be experimentally studied at mortar level. Based on this principle, this paper studies the influence of mix design parameters on autogenous and drying shrinkage of self-compacting concrete by means of experiments at mortar level. Mix design parameters of this study are W/C (water/cement) ratio and A/C (limestone filler/cement) ratio. The results show that autogenous shrinkage increases with decreasing W/C and A/C contrary to drying shrinkage which increases with higher ratios. Furthermore, based on mortar and paste results, it is shown that the model developed by Le Roy to predict the shrinkage of CEM and possibly of SCC, from shrinkage measured on cementing paste, is also valid for shrinkage of limestone filler based self-compacting cementious materials. Furthermore, some known results on the influence of water/cement ratio and filler/cement ratio have been confirmed and can be explained by porosity results

Centrifugal effects on coaxial cylinders concrete tribometer

Concrete pumping has become a widely placing technique. However, the pumping pressure estimation which is based on the rheological and tribological properties of concretes has not been well optimized. Due to its rheological properties, the traditional concrete flows in a pipe only by sliding on the pipe wall. This movement is governed by the local velocities developed in the slip layer wich is situated at the conrete-wall interface. As a result, the slip layer thickness and rheological properties become the determining factors on the flow of the traditional concrete in the pipe. In order to study the behavior of the slip layer, a coaxial cylinders tribometer has been developed. This paper shows the influences of the eccentricity effects on the overestimation of the slip layer thickness. This overestimation results an incorrect prediction of the flow profile and the pumping pressure calculation. A modification on the working principle of the tribometer is suggested and validated by experimentations

Velocity profile of self compacting concrete and traditional concrete flowing in a half open pipe

ABSTRACT: The behavior of concrete flowing in a pipe is a key factor for mastering the concrete pumping technique. Due to the non-homogeneity of concrete, the concentration of particles (aggregate, sand, cement…) is not the same everywhere in the pipe. Particularly in the highly sheared zone near the wall, the concentration of coarse particles is much lower than that in the bulk. As a result, the rheological properties across the cross section vary with the distance from the wall. This phenomenon affects directly the velocity profile across the section. However, the velocity profile of concrete flowing in a pipe has never been quantitatively measured. This paper shows an experimental method to accurately measure the velocity profile. On the other hand, the influence of the variation of the rheological properties on the velocity profile across the pipe is also studied. Finally, a comparison between experimental analyses and numerical simulations shows reasonable correlation. This paper concentrates on the difference between the flow of a self-compacting concrete and that of a traditional concrete based on their different rheological properties