MULTI-K: accurate classification of microarray subtypes using ensemble k-means clustering

<p>Abstract</p> <p>Background</p> <p>Uncovering subtypes of disease from microarray samples has important clinical implications such as survival time and sensitivity of individual patients to specific therapies. Unsupervised clustering methods have been used to classify this type of data. However, most existing methods focus on clusters with compact shapes and do not reflect the geometric complexity of the high dimensional microarray clusters, which limits their performance.</p> <p>Results</p> <p>We present a cluster-number-based ensemble clustering algorithm, called <it>MULTI-K</it>, for microarray sample classification, which demonstrates remarkable accuracy. The method amalgamates multiple <it>k</it>-means runs by varying the number of clusters and identifies clusters that manifest the most robust co-memberships of elements. In addition to the original algorithm, we newly devised the <it>entropy-plot </it>to control the separation of singletons or small clusters. MULTI-K, unlike the simple <it>k</it>-means or other widely used methods, was able to capture clusters with complex and high-dimensional structures accurately. MULTI-K outperformed other methods including a recently developed ensemble clustering algorithm in tests with five simulated and eight real gene-expression data sets.</p> <p>Conclusion</p> <p>The geometric complexity of clusters should be taken into account for accurate classification of microarray data, and ensemble clustering applied to the number of clusters tackles the problem very well. The C++ code and the data sets tested are available from the authors.</p

Work-related Attitudes of Non-regular and Regular Workers in Korea: Exploring Distributive Justice as a Mediator

Raising the timely issue of the non-regular workforce in South Korea, this article examined the degree and intensity of commitment of non-regular workers (contingent and part-time workers) to their job and organization. The results showed that both contingent and parttime workers were less committed to the organization and job than regular workers. This article showed that work status affected the individual, by influencing subjective stratum and his or her perception of distributive justice, which in turn had an impact on organizational commitment and job involvement. Finally, the article stressed that nonregular workers did not constitute a homogeneous group and that, consequently, part-time workers should be treated as distinct from other types of non-regular workers. The sociological implications of the non-regular workforce were discussed

Comparison of maternal health services and indicators in three districts of the Volta Region, Ghana

Background: Ghana’s maternal mortality ratio continues to decline, but is not expected to meet the Millennium Development Goal (MDG) 5 target. The Ghana Health Service and Ministry of Health have displayed a high commitment to the improvement of maternal health in the country. One of the most recent partnerships directed at this is with the Korea International Cooperation Agency.Methods: This study was conducted among women between ages 15 and 49 resident in Keta Municipal, Ketu North and Ketu South districts in the Volta Region of Ghana who were pregnant or who had children aged less than five. Ethical approval was obtained from the Ghana Health Service Ethical Review Committee. Data were collected using questionnaires, entered into Stata version 12 and analyzed using frequency distribution and assessment of means. Comparisons among districts were conducted using chi square test and one way analysis of variance (ANOVA).Results: The study covered 630 women whose mean age was 28.4 years. Almost all participants (99.1%) from Ketu North knew where to obtain family planning services. Use of modern contraception was highest in Ketu North with 31% of respondents using a modern method. Delivery in a health facility was highest in Keta Municipal (62.3%) with overall institutional delivery being 57.6%. Delivery by a skilled birth attendant (SBA) was also highest in Keta Municipal.Conclusion: Indicators used to assess maternal health services show a coverage of over 50% but we need to improve institutional delivery, use of modern contraception and education about danger signs in pregnancy. Funding: This work was supported by the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2013S1A5B8A01055336) and the Korea International Cooperation Agency(2013).Keywords: Maternal Health, Ghana, Volta Region, Family Planning, Skilled Birth Attendan

Association of Polymorphisms in Browzine Journal Cover Fshr, inha, Esr1, and Bmp15 With Recurrent Implantation Failure

Recurrent implantation failure (RIF) refers to two or more unsuccessful in vitro fertilization embryo transfers in the same individual. Embryonic characteristics, immunological factors, and coagulation factors are known to be the causes of RIF. Genetic factors have also been reported to be involved in the occurrence of RIF, and some single nucleotide polymorphisms (SNPs) may contribute to RIF. We examined SNPs i

Unleashing the full potential of Hsp90 inhibitors as cancer therapeutics through simultaneous inactivation of Hsp90, Grp94, and TRAP1

Cancer therapeutics: Extending a drug&apos;s reach A new drug that blocks heat shock proteins (HSPs), helper proteins that are co-opted by cancer cells to promote tumor growth, shows promise for cancer treatment. Several drugs have targeted HSPs, since cancer cells are known to hijack these helper proteins to shield themselves from destruction by the body. However, the drugs have had limited success. Hye-Kyung Park and Byoung Heon Kang at Ulsan National Institutes of Science and Technology in South Korea and coworkers noticed that the drugs were not absorbed into mitochondria, a key cellular compartment, and HSPs in this compartment were therefore not being blocked. They identified a new HSP inhibitor that can reach every cellular compartment and inhibit all HSPs. Testing in mice showed that this inhibitor effectively triggered death of tumor cells, and therefore shows promise for anti-cancer therapy. The Hsp90 family proteins Hsp90, Grp94, and TRAP1 are present in the cell cytoplasm, endoplasmic reticulum, and mitochondria, respectively; all play important roles in tumorigenesis by regulating protein homeostasis in response to stress. Thus, simultaneous inhibition of all Hsp90 paralogs is a reasonable strategy for cancer therapy. However, since the existing pan-Hsp90 inhibitor does not accumulate in mitochondria, the potential anticancer activity of pan-Hsp90 inhibition has not yet been fully examined in vivo. Analysis of The Cancer Genome Atlas database revealed that all Hsp90 paralogs were upregulated in prostate cancer. Inactivation of all Hsp90 paralogs induced mitochondrial dysfunction, increased cytosolic calcium, and activated calcineurin. Active calcineurin blocked prosurvival heat shock responses upon Hsp90 inhibition by preventing nuclear translocation of HSF1. The purine scaffold derivative DN401 inhibited all Hsp90 paralogs simultaneously and showed stronger anticancer activity than other Hsp90 inhibitors. Pan-Hsp90 inhibition increased cytotoxicity and suppressed mechanisms that protect cancer cells, suggesting that it is a feasible strategy for the development of potent anticancer drugs. The mitochondria-permeable drug DN401 is a newly identified in vivo pan-Hsp90 inhibitor with potent anticancer activity

In-situ fabrication of cobalt-doped SrFe2As2 thin films by using pulsed laser deposition with excimer laser

The remarkably high superconducting transition temperature and upper critical field of iron(Fe)-based layered superconductors, despite ferromagnetic material base, open the prospect for superconducting electronics. However, success in superconducting electronics has been limited because of difficulties in fabricating high-quality thin films. We report the growth of high-quality c-axis-oriented cobalt(Co)-doped SrFe2As2 thin films with bulk superconductivity by using an in-situ pulsed laser deposition technique with a 248-nm-wavelength KrF excimer laser and an arsenic(As)-rich phase target. The temperature and field dependences of the magnetization showing strong diamagnetism and transport critical current density with superior Jc-H performance are reported. These results provide necessary information for practical applications of Fe-based superconductors.Comment: 8 pages, 3figures. to be published at Appl. Phys. Let