151 research outputs found
Integrating R and Hadoop for Big Data Analysis
Analyzing and working with big data could be very diffi cult using classical
means like relational database management systems or desktop software packages
for statistics and visualization. Instead, big data requires large clusters
with hundreds or even thousands of computing nodes. Offi cial statistics is
increasingly considering big data for deriving new statistics because big data
sources could produce more relevant and timely statistics than traditional
sources. One of the software tools successfully and wide spread used for
storage and processing of big data sets on clusters of commodity hardware is
Hadoop. Hadoop framework contains libraries, a distributed fi le-system (HDFS),
a resource-management platform and implements a version of the MapReduce
programming model for large scale data processing. In this paper we investigate
the possibilities of integrating Hadoop with R which is a popular software used
for statistical computing and data visualization. We present three ways of
integrating them: R with Streaming, Rhipe and RHadoop and we emphasize the
advantages and disadvantages of each solution.Comment: Romanian Statistical Review no. 2 / 201
An overview of higher education at the European level
Higher education has a key role in the new knowledge society. In Europe there are over 4,000 higher education institutions of which 3300 are in EU27 countries and over 20 million students. EU countries' governments and higher education institutions are in a continuous process of finding ways to create better conditions for studies considering the very important role that higher education plays in the economic development of a country. This article presents an overview of the main statistical indicators which monitors achievements in higher education in EU27 countries during 2011 and 2012, revealing large differences still exist between the EU27
Thyroid lymphoepithelial nodule
Thyroid benign lymphoepithelial lesions are rare in adults, reported as associated with thyroiditis or adjacent to tumours. Here we report a unique case of a thyroid solid nodule with benign lymphoepithelial morphology. A 56-year-old woman presented with a thyroid nodule increasing in size. Thyroid function was normal. On the surgical resection specimen, in addition to a 2-cm follicular adenoma, there was, at distance, a 0.5-cm solid nodule with lymphoepithelial morphology, without Hassal’s corpuscles or calcifications. On immunohistochemistry, the epithelial component was cytokeratin 5/6 positive and very focally cytokeratin 7 positive, the immunophenotype of the lymphoid tissue confirming the benign nature. The diagnosis of thyroid benign lymphoepithelial nodule was proposed. In conclusion, recognition of thyroid solid benign lymphoepithelial nodules is important since they can be misdiagnosed with other thyroid micronodule types including carcinoma, primary or metastatic
miR-9 Acts as an OncomiR in Prostate Cancer through Multiple Pathways That Drive Tumour Progression and Metastasis
Identification of dysregulated microRNAs (miRNAs) in prostate cancer is critical not only for diagnosis, but also differentiation between the aggressive and indolent forms of the disease. miR-9 was identified as an oncomiR through both miRNA panel RT-qPCR as well as high-throughput sequencing analysis of the human P69 prostate cell line as compared to its highly tumorigenic and metastatic subline M12, and found to be consistently upregulated in other prostate cell lines including DU-145 and PC3. While miR-9 has been characterized as dysregulated either as an oncomiR or tumour suppressor in a variety of other cancers including breast, ovarian, and nasopharyngeal carcinomas, it has not been previously evaluated and proven as an oncomiR in prostate cancer. miR-9 was confirmed an oncomiR when found to be overexpressed in tumour tissue as compared to adjacent benign glandular epithelium through laser-capture microdissection of radical prostatectomy biopsies. Inhibition of miR-9 resulted in reduced migratory and invasive potential of the M12 cell line, and reduced tumour growth and metastases in male athymic nude mice. Analysis showed that miR-9 targets e-cadherin and suppressor of cytokine signalling 5 (SOCS5), but not NF-ĸB mRNA. Expression of these proteins was shown to be affected by modulation in expression of miR-9
Glass Foam Made with Silicon Nitride and Manganese Oxide by Microwave Irradiation
A high mechanical strength (6.1 MPa) glass foam was produced by sintering/foaming at 830 ºC in an experimental 0.8 kW-microwave oven. The basic raw material was a colorless flat glass waste and the foaming agent was Si3N4 powder (2 wt.%). As an oxygen supplying agent, a MnO2 powder (3.1 wt.%) was used. The main physical, mechanical, thermal and morphological characteristics of the optimal sample were: apparent density of 0.47 g/cm3, porosity of 77.6%, thermal conductivity of 0.105 W/m·K, compressive strength of 6.1 MPa and pore size between 0.15-0.40 mm. The optimal glass foam sample has the required characteristics of a thermal insulation material usable under mechanical stress conditions in civil engineering. The originality of the paper is the application of the unconventional microwave heating technique, faster and more economical, unlike the other papers in the same area published in the literature, followers of the traditional conventional heating technique
Manufacturing Ceramic Foams at Very High Temperature by the Unconventional Process of Direct Microwave Heating
Abstract
SiC ceramic foams were manufactured by direct microwave heating up to 1520 ºC. Silicon carbide (42-68 wt.%), quartz sand as a silica supplier (20-38 wt.%), coal fly ash (12-20 wt.%) and a constant water addition of 15 wt.% were used as starting materials. The ceramic foam samples had semi-open microstructures in which neighboring cells are partially connected to each other and partially closed. Due to the very dense cellular walls and the very low cells size (below 21 μm), the compressive strength had very high values (41.3-56.5MPa), the porosity was within an average value range (52.4-57.6%) and the thermal conductivity and the apparent density had relatively high values. In energy terms, the technique of direct microwave heating was very advantageous, the specific energy consumption being very low (1.04-1.21 kWh/kg) compared to the consumptions achieved by conventional methods. The application field of SiC ceramic foams obtained by the bonding method and using silica as a bonding agent includes hot gas or molten metal filters, porous burners, catalytic supports and others. From the four tested experimental variants, it could be concluded that the optimal sample was that achieved at 1520 ºC with 68% silicon carbide, 20% quartz sand, 12% coal fly ash and 15% water addition, having the porosity of 57.6%, thermal conductivity of 0.174 W/m·K, compressive strength of 56.5 MPa and the equivalent pore size between 9-21 μm
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