Multipliers on Dirichlet type spaces

In this article we examine Dirichlet type spaces in the unit polydisc, and multipliers between these spaces. These results extend the corresponding work of G. D. Taylor in the unit disc. In addition, we consider functions on the polydisc whose restrictions to lower dimensional polydiscs lie in the corresponding Dirichet type spaces. We see that such functions need not be in the Dirichlet type space of the whole polydisc. Similar observations are made regarding multipliers.Comment: 21 page

STARNET 2: a web-based tool for accelerating discovery of gene regulatory networks using microarray co-expression data

<p>Abstract</p> <p>Background</p> <p>Although expression microarrays have become a standard tool used by biologists, analysis of data produced by microarray experiments may still present challenges. Comparison of data from different platforms, organisms, and labs may involve complicated data processing, and inferring relationships between genes remains difficult.</p> <p>Results</p> <p><b>S<smcaps>TAR</smcaps>N<smcaps>ET</smcaps> 2 </b>is a new web-based tool that allows post hoc visual analysis of correlations that are derived from expression microarray data. <b>S<smcaps>TAR</smcaps>N<smcaps>ET</smcaps> 2 </b>facilitates user discovery of putative gene regulatory networks in a variety of species (human, rat, mouse, chicken, zebrafish, <it>Drosophila</it>, <it>C. elegans</it>, <it>S. cerevisiae</it>, <it>Arabidopsis </it>and rice) by graphing networks of genes that are closely co-expressed across a large heterogeneous set of preselected microarray experiments. For each of the represented organisms, raw microarray data were retrieved from NCBI's Gene Expression Omnibus for a selected Affymetrix platform. All pairwise Pearson correlation coefficients were computed for expression profiles measured on each platform, respectively. These precompiled results were stored in a MySQL database, and supplemented by additional data retrieved from NCBI. A web-based tool allows user-specified queries of the database, centered at a gene of interest. The result of a query includes graphs of correlation networks, graphs of known interactions involving genes and gene products that are present in the correlation networks, and initial statistical analyses. Two analyses may be performed in parallel to compare networks, which is facilitated by the new <b>H<smcaps>EAT</smcaps>S<smcaps>EEKER </smcaps></b>module.</p> <p>Conclusion</p> <p><b>S<smcaps>TAR</smcaps>N<smcaps>ET</smcaps> 2 </b>is a useful tool for developing new hypotheses about regulatory relationships between genes and gene products, and has coverage for 10 species. Interpretation of the correlation networks is supported with a database of previously documented interactions, a test for enrichment of Gene Ontology terms, and heat maps of correlation distances that may be used to compare two networks. The list of genes in a <b>S<smcaps>TAR</smcaps>N<smcaps>ET </smcaps></b>network may be useful in developing a list of candidate genes to use for the inference of causal networks. The tool is freely available at <url>http://vanburenlab.medicine.tamhsc.edu/starnet2.html</url>, and does not require user registration.</p

Classification of Genes and Putative Biomarker Identification Using Distribution Metrics on Expression Profiles

BACKGROUND: Identification of genes with switch-like properties will facilitate discovery of regulatory mechanisms that underlie these properties, and will provide knowledge for the appropriate application of Boolean networks in gene regulatory models. As switch-like behavior is likely associated with tissue-specific expression, these gene products are expected to be plausible candidates as tissue-specific biomarkers. METHODOLOGY/PRINCIPAL FINDINGS: In a systematic classification of genes and search for biomarkers, gene expression profiles (GEPs) of more than 16,000 genes from 2,145 mouse array samples were analyzed. Four distribution metrics (mean, standard deviation, kurtosis and skewness) were used to classify GEPs into four categories: predominantly-off, predominantly-on, graded (rheostatic), and switch-like genes. The arrays under study were also grouped and examined by tissue type. For example, arrays were categorized as 'brain group' and 'non-brain group'; the Kolmogorov-Smirnov distance and Pearson correlation coefficient were then used to compare GEPs between brain and non-brain for each gene. We were thus able to identify tissue-specific biomarker candidate genes. CONCLUSIONS/SIGNIFICANCE: The methodology employed here may be used to facilitate disease-specific biomarker discovery

Improving cereal productivity and farmers’ income using a strategic application of fertilizers in West Africa

In the past two years, ICRISAT, in collaboration with other International Agricultural Research Centres, National Agricultural Research and Extension Systems, has been evaluating and promoting point or hill application of fertilizer along with “Warrantage” in three West African countries, namely, Burkina Faso, Mali and Niger. The hill application of fertilizers consists of applying small doses of fertilizer in the planting hills of millet and sorghum. The combination of strategic hill application of fertilizer with complementary institutional and market linkages, through an inventory credit system (known as “Warrantage”) offers a good opportunity to improve crop productivity and farmers’ incomes. Results from the two year on-farm trials showed that, on average, in all the three countries, grain yields of millet and sorghum were greater by 44 to 120% while incomes of farmers increased by 52 to 134% when using hill application of fertilizer than with the earlier recommended fertilizer broadcasting methods and farmers’ practice. Substantial net profits were obtained by farmers using “Warrantage”. Farmers’ access to credit and inputs was improved substantially through the “Warrantage” system. The technology has reached up to 12650 farm households in the three countries and efforts are in progress to further scale-up and out the technology to wider geographical area

Utility of Surgeon-Performed Ultrasound Assessment of the Lateral Neck for Metastatic Papillary Thyroid Cancer

Ultrasound is the recommended staging modality for papillary thyroid cancer. Surgeons proficient in US assessment of the neck and experienced in the management of papillary thyroid cancer (PTC) appear uniquely qualified to assess the lateral cervical lymph nodes for metastatic disease. Of 310 patients treated for PTC between 2000 and 2008, 109 underwent surgeon-performed ultrasound (SUS) of the lateral neck preoperatively. Fine needle aspiration was performed on suspicious lateral lymph nodes. SUS findings were compared with FNA cytology and results of postoperative imaging studies. The sensitivity and negative predictive value of SUS were 88% and 97%, respectively. Four patients were found to have missed metastatic disease within 6 months. No patient underwent a nontherapeutic neck dissection. SUS combined with US-guided FNA of suspicious lymph nodes can accurately stage PTC to reliably direct surgical management

Clinical Study Utility of Surgeon-Performed Ultrasound Assessment of the Lateral Neck for Metastatic Papillary Thyroid Cancer

Ultrasound is the recommended staging modality for papillary thyroid cancer. Surgeons proficient in US assessment of the neck and experienced in the management of papillary thyroid cancer (PTC) appear uniquely qualified to assess the lateral cervical lymph nodes for metastatic disease. Of 310 patients treated for PTC between 2000 and 2008, 109 underwent surgeon-performed ultrasound (SUS) of the lateral neck preoperatively. Fine needle aspiration was performed on suspicious lateral lymph nodes. SUS findings were compared with FNA cytology and results of postoperative imaging studies. The sensitivity and negative predictive value of SUS were 88% and 97%, respectively. Four patients were found to have missed metastatic disease within 6 months. No patient underwent a nontherapeutic neck dissection. SUS combined with US-guided FNA of suspicious lymph nodes can accurately stage PTC to reliably direct surgical management