ST7-mediated suppression of tumorigenicity of prostate cancer cells is characterized by remodeling of the extracellular matrix

Multiple lines of evidence have provided compelling evidence for the existence of a tumor suppressor gene (TSG) on chromosome 7q31.1. ST7 may be the target of this genetic instability but its designation as a TSG is controversial. In this study, we show that, functionally, ST7 behaves as a tumor suppressor in human cancer. ST7 suppressed growth of PC-3 prostate cancer cells inoculated subcutaneously into severe combined immunodeficient mice, and increased the latency of tumor detection from 13 days in control tumors to 23 days. Re-expression of ST7 was also associated with suppression of colony formation under anchorage-independent conditions in MDA-MB-231 breast cancer cells and ST7 mRNA expression was downregulated in 44% of primary breast cancers. Expression profiling of PC-3 cells revealed that ST7 predominantly induces changes in genes involved in re-modeling the extracellular matrix such as SPARC, IGFBP5 and several matrix metalloproteinases. These data indicate that ST7 may mediate tumor suppression through modification of the tumor microenvironment.

The role of core protest group members in sustaining protest against controversial construction and engineering projects

Community-based protests against major construction and engineering projects are becoming increasingly common as concerns over issues such as corporate social accountability, climate change and corruption become more prominent in the public's mind. Public perceptions of risk associated with these projects can have a contagious effect, which mismanaged can escalate into long-term and sometimes acrimonious protest stand-offs that have negative implications for the community, firms involved and the construction industry as a whole. This paper investigates the role of core group members in sustaining community-based protest against construction and engineering projects. Using a thematic story telling approach which draws on ethnographic method and social contagion theories, it presents an in-depth analysis of a single case study - one of Australia's longest standing community protests against a construction project. It concludes that core group members play a critical role, within anarchic structures which provide a high degree of spontaneity and improvisation, in sustaining movement continuity by building collective identity, mobilising resources and a moving interface which developers find hard to communicate with.

An examination of microfinance self-help groups and the poorest of the poor women in Tamil Nadu, India

This study examined the formation and operation of women's microfinance self-help groups in southern India and investigated whether or not the poorest of the poor women were accepted as members of those groups. The study found that caste was used as a selection criterion. Many eligible women excluded themselves from joining the self-help group due to their own lack of education, age, poor health, poverty and lack of trust in the system. The research revealed that self-help groups enhanced women's income and education, improved village infrastructure, and reduced household conflict. Factors that might prevent inclusion of the poorest of the poor in future microfinance programs were identified.

Modelling airport passenger group dynamics using an agent-based method

This thesis investigates the influence of passenger group dynamics on passengers' behaviour in an international airport. A simulation model is built to analyse passengers' behaviour during airport departure processes and during an emergency event. Results from the model showed that passengers' group dynamics have significant influences on the performance and utilisation of airport services. The agent-based model also provides a convenient way to investigate the effectiveness of space design and service allocations, which may contribute to the enhancement of passenger airport experiences.

Enhancement of RAD51 recombinase activity by the tumor suppressor PALB2

Homologous recombination mediated by RAD51 recombinase helps eliminate chromosomal lesions, such as DNA double-strand breaks induced by radiation or arising from injured DNA replication forks. The tumor suppressors BRCA2 and PALB2 act together to deliver RAD51 to chromosomal lesions to initiate repair. Here we document a new function of PALB2: to enhance RAD51's ability to form the D loop. We show that PALB2 binds DNA and physically interacts with RAD51. Notably, although PALB2 alone stimulates D-loop formation, it has a cooperative effect with RAD51AP1, an enhancer of RAD51. This stimulation stems from the ability of PALB2 to function with RAD51 and RAD51AP1 to assemble the synaptic complex. Our results demonstrate the multifaceted role of PALB2 in chromosome damage repair. Because PALB2 mutations can cause cancer or Fanconi anemia, our findings shed light on the mechanism of tumor suppression in humans.

MicroRNAs targeting mutant K-ras by electrotransfer inhibit human colorectal adenocarcinoma cell growth in vitro and in vivo

Mutations of K-ras have been found in 30-60% of colorectal carcinomas and are believed to be associated with tumor initiation, tumor progression and metastasis formation. Therefore, silencing of mutant K-ras expression has become an attractive therapeutic strategy for colorectal cancer treatment. The aim of our study was to investigate the effect of microRNA (miRNA) molecules directed against K-ras (miRNA-K-ras) on K-ras expression level and the growth of colorectal carcinoma cell line LoVo in vitro and in vivo. In addition, we evaluated electroporation as a gene delivery method for transfection of LoVo cells and tumors with plasmid DNA encoding miRNA-K-ras (pmiRNA-K-ras). Results of our study indicated that miRNAs targeting K-ras efficiently reduced K-ras expression and cell survival after in vitro electrotransfection of LoVo cells with pmiRNA-K-ras. In vivo, electroporation has proven to be a simple and efficient delivery method for local administration of pmiRNA-K-ras molecules into LoVo tumors. This therapy shows pronounced antitumor effectiveness and has no side effects. The obtained results demonstrate that electrogene therapy with miRNA-K-ras molecules can be potential therapeutic strategy for treatment of colorectal cancers harboring K-ras mutations. © 2010 Nature Publishing Group All rights reserved.

The renormalization group: A perturbation method for the graduate curriculum

In this paper the renormalization group (RG) method of Chen, Goldenfeld, and Oono [Phys. Rev. Lett., 73 (1994), pp.1311-1315; Phys. Rev. E, 54 (1996), pp.376-394] is presented in a pedagogical way to increase its visibility in applied mathematics and to argue favorably for its incorporation into the corresponding graduate curriculum.The method is illustrated by some linear and nonlinear singular perturbation problems. Key word. © 2012 Society for Industrial and Applied Mathematics.

A Combined Renormalization Group-Multiple Scale Method for Singularly Perturbed Problems

This paper introduces a straightforward method to asymptotically solve a variety of initial and boundary value problems for singularly perturbed ordinary differential equations whose solution structure can be anticipated. The approach is simpler than conventional methods, including those based on asymptotic matching or on eliminating secular terms. © 2010 by the Massachusetts Institute of Technology.

Reduction of amplitude equations by the renormalization group approach

This article elucidates and analyzes the fundamental underlying structure of the renormalization group (RG) approach as it applies to the solution of any differential equation involving multiple scales. The amplitude equation derived through the elimination of secular terms arising from a naive perturbation expansion of the solution to these equations by the RG approach is reduced to an algebraic equation which is expressed in terms of the Thiele semi-invariants or cumulants of the eliminant sequence { Zi } i=1 . Its use is illustrated through the solution of both linear and nonlinear perturbation problems and certain results from the literature are recovered as special cases. The fundamental structure that emerges from the application of the RG approach is not the amplitude equation but the aforementioned algebraic equation. © 2008 The American Physical Society.

The renormalization group and the implicit function theorem for amplitude equations

This article lays down the foundations of the renormalization group (RG) approach for differential equations characterized by multiple scales. The renormalization of constants through an elimination process and the subsequent derivation of the amplitude equation [Chen, Phys. Rev. E 54, 376 (1996)] are given a rigorous but not abstract mathematical form whose justification is based on the implicit function theorem. Developing the theoretical framework that underlies the RG approach leads to a systematization of the renormalization process and to the derivation of explicit closed-form expressions for the amplitude equations that can be carried out with symbolic computation for both linear and nonlinear scalar differential equations and first order systems but independently of their particular forms. Certain nonlinear singular perturbation problems are considered that illustrate the formalism and recover well-known results from the literature as special cases. © 2008 American Institute of Physics.

Secular series and renormalization group for amplitude equations

We have developed a technique that circumvents the process of elimination of secular terms and reproduces the uniformly valid approximations, amplitude equations, and first integrals. The technique is based on a rearrangement of secular terms and their grouping into the secular series that multiplies the constants of the asymptotic expansion. We illustrate the technique by deriving amplitude equations for standard nonlinear oscillator and boundary-layer problems. © 2008 The American Physical Society.