6,794 research outputs found

    Transcription Factor AP-2 Regulatory Signatures in Breast Cancer

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    PhDAP-2 transcription factors are highly conserved basic helix-span-helix proteins whose members ((x, ß, y, S and c) are crucial regulators of bryonic development. They also play an important role in human neoplasia. uohis ochemical studies have detected high levels of AP-2y expression in primary tumo of breast cancer patients. This high expression has been correlated with reduced survival in all patients and reduced survival in an ERa positive subset treated with hormone therapy. In breast cancer cell lines, AP- 2 factors have been implicated in the regulation of the ERBB2 proto-oncogene and ERa. In an effort to further understand the role of AP-2y in breast carcinoma, this study has sought to identify additional AP-2 activated cellular pathways and ultimately novel transcriptional targets for AP-2 through the use of gene expression profiling. RNAi using three independent AP-2y targeting sequences, has been used to deplete AP- 2y levels in the ERa positive MCF-7 breast carcinoma cell line, chosen as it exclusively expresses the AP-2y family member. Microarrays were then utilised to create an AP-2y dependent transcription profile. Statistical comparisons between non-silencing control siRNA and AP-2y targeting siRNA groups identified a total of 162 gene expression changes (p<0.01). These changes implicate AP-2y in the control of cell cycle progression and developmental signalling. Indeed a role for AP-2y in the control of cell cycle, in particular at the GUS transition, has been verified using flow cytometry. Several of these gene expression changes, including IGFBP3, Transgelin and KIAA1324, have been confirmed using qPCR and immunoblotting. Finally, elevated levels of p21 mRNA and protein have been observed following AP-2y silencing in MCF-7 cells. Additionally, the activity of a p21 promoter reporter is repressed following transfection with an AP-2y expression construct in HepG2 cells. These results coupled with ChIP experiments showing AP-2y occupancy at the proximal promoter region of p21 in cycling MCF-7 cells, implicate AP-2y in the repression of p21 transcription and suggest a role for AP2y in- the, control of cell cycle in breast carcinoma in part through the transcriptional repression of p21

    Female prison guards often behind sex misconduct

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    HELENA, Mont. (AP) — Inmate Michael Murphy sought out female guards and prison workers that he knew would be easy to charm

    The Treatment of Ties in AP Correlation

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    The Kendall tau and AP correlation coefficients are very commonly use to compare two rankings over the same set of items. Even though Kendall tau was originally defined assuming that there are no ties in the rankings, two alternative versions were soon developed to account for ties in two different scenarios: measure the accuracy of an observer with respect to a true and objective ranking, and measure the agreement between two observers in the absence of a true ranking. These two variants prove useful in cases where ties are possible in either ranking, and may indeed result in very different scores. AP correlation was devised to incorporate a top-heaviness component into Kendall tau, penalizing more heavily if differences occur between items at the top of the rankings, making it a very compelling coefficient in Information Retrieval settings. However, the treatment of ties in AP correlation remains an open problem. In this paper we fill this gap, providing closed analytical formulations of AP correlation under the two scenarios of ties contemplated in Kendall tau. In addition,we developed an R package that implements these coefficients.Best Short Paper Accepted author manuscriptMultimedia ComputingWeb Information System

    Further Evidence Against the AP/HP Scales

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    Data across 3 studies, all providing evidence that the AP/HP scales are not valid measures for assessing the theoretical constructs of authentic/hubristic pride, as defined by Tracy and Robins (2007). The AP scale appears to be a generic pride scale, or a more broadly interpreted measure relating to positive feelings about success and self-esteem. Additionally, the HP scale does not appear to measure any singular psychological construct, and should not be used in future research

    Delamination Analysis of A Class of AP-PLY Composite Laminates

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    A recently developed fiber placement architecture, AP-PLY, has been shown to give significantly improved damage tolerance characteristics of composite structures. The behavior of delaminations resulting from low speed impact damage is of particular concern. Major attention has been paid to expand current knowledge on the delamination response of simple AP-PLY composite structure and move towards in-depth understanding of the failure mechanisms behind the damage tolerance. This thesis presents the approaches to predict delamination onset and analyze delamination growth, in support of the search of the optimum woven pattern for AP-PLY composite laminates. The recovered interlaminar stress between layers combined with the maximum stress criterion determined the delamination onset of simple AP-PLY composite laminate under out-of-plane loads. 2D finite element models with cohesive elements inserted in the interfaces of woven layers have been built to evaluate the delamination initiation and propagation in the different woven patterns of simple AP-PLY composite beams. The parameters of the woven pattern, such as the woven angle, the number of woven plies, the number of straight filled plies, and the location of the woven patterns in through the thickness direction, were investigated and shown to have a significant effect on delamination creation and growth. An energy method based on beam theory was proposed to analyze the strain energy release rate (SERR) of an existing crack in an AP-PLY beam structure. The developed analytical method was implemented in isotropic materials and the obtained SERR of a crack was validated by reference results and finite element solutions. The general behavior of crack growth on the left or right crack tip was evaluated and basic trends leading to crack propagation on one side of the crack were established. A correction factor was introduced to improve the accuracy of the SERR of a small crack through the numerical calculation. The singularity of crack tip caused by dissimilar materials was investigated and was found that the inclusion of the singularity effect could increase the accuracy for small cracks. It has been shown that the neutral axis needs to be relocated to decouple the bending and membrane behavior of unsymmetrical composite laminates, thus to meet the requirement of minimizing the strain energy of the delaminated beam to calculate the SERR of a delaminated composite beam. The calculated SERR of a crack in a composite beam has been verified by comparing with a finite element model. The woven plies in AP-PLY composite laminate altered the layup and two conventional laminates with different stacking sequences were identified in an AP-PLY composite laminate based on the assumption that the resin areas were ignored. A step by step approach was developed to obtain the SERR of a crack that goes across different materials. The analytical SERR determined when two materials are used in sequence, sets the stage for optimization of AP-PLY composite laminates without taking account of the effect of the resin area. The procedure of optimization of simple AP-PLY pattern was proposed and industry may benefit for many applications. An equivalent stiffness approach was used to model regions containing resin pockets and straight or inclined composite layers. A series of three point bending tests was carried out where the failure process and loading capacity were evaluated. The methodology, procedure of optimization, philosophy outlined in this thesis might also be applied to the more complicated fully woven AP-PLY composite laminates. The work in this thesis contributes to the understanding of the behavior of AP-PLY composite laminates with delaminations

    Further Evidence Against the AP/HP Scales

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    Data across 3 studies, all providing evidence that the AP/HP scales are not valid measures for assessing the theoretical constructs of authentic/hubristic pride, as defined by Tracy and Robins (2007). The AP scale appears to be a generic pride scale, or a more broadly interpreted measure relating to positive feelings about success and self-esteem. Additionally, the HP scale does not appear to measure any singular psychological construct, and should not be used in future research. Much of this data is now included in a paper in press with Frontiers

    Early growth response genes -2 and -3 are essential for optimal immune responses

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    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Early Growth Response Genes (EGR) is a family of four transcription factors containing a unique zinc finger domain. EGR-2 and EGR-3 are important for hindbrain development and myelination. These transcription factors are also necessary for lymphocyte function however, the mechanisms are still unclear. Previous findings have shown that EGR-2cKO mice develop lupus-like autoimmune disease with high levels of pro-inflammatory cytokines despite showing normal T and B cell proliferation after mitogenic stimulation. Therefore we established the CD2-EGR-2-/-EGR-3-/- mouse model to explore the phenotype, susceptibility to autoimmune disease and relevant lymphocyte function. We discovered that CD2-EGR-2-/-EGR-3-/- mice developed severe systemic autoimmune disease and expressed high levels of inflammatory cytokines. More importantly we discovered a novel finding that CD2-EGR-2-/-EGR-3-/- T and B cells had impaired cell proliferation after mitogenic stimulation. Further investigations revealed that the molecular mechanism defected in the T cell receptor signalling pathway is due to a dysfunction in Activator Protein-1 (AP-1). AP-1 is a heterodimeric protein composed of AP-1 family members including Jun, Atf and Fos. Our data shows that EGR-2 and EGR-3 directly bind with the Atf family member Batf, which prevents Batf’s inhibitory function on AP-1 activation. This research demonstrates that EGR-2 and EGR-3 intrinsically regulate chronic inflammation and also positively regulate antigen receptor activation. In conclusion EGR-2 and EGR-3 are essential for providing optimal immune responses, whilst limiting inflammatory immunopathology. We propose that this new model could be used for studying autoimmune disease

    Structure function analysis of blazars AP Librae and 3c279

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    Highest Honors in AstronomyBlazars AP Librae and 3c279 are analyzed for microvariability using a technique known as structure function analysis. AP Librae was observed in April of 2005 and 3c279 was observed in April of 2007. The data for AP Librae was previously reduced by Andrew Collazzi and the author reduced the data for 3c279. Both sets of data were reduced using Robert Knop's data reduction program. The author ran structure function analysis on both sets of data. Structure function analysis is a statistical analysis run on data that is suppose to nd timescales of variability, periodicity, and the noise type of data. Previous analysis of AP Librae confirmed mircrovariability, which also shows up in the structure function of AP Librae. Blazar 3c279 was much quieter than AP Librae and showed no microvariability durning any of the nights.College of Arts and ScienceDepartment of Physics and Astronom

    Microarray analysis of tamoxifen resistance in breast cancer.

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    PhDTamoxifen remains a widely used hormone therapy for pre and postmenopausal women with hormone receptor positive breast cancer in both adjuvant and metastatic disease settings. Resistance to this well tolerated and cost-effective drug limits its use. Only an improved understanding of the mechanisms of tamoxifen resistance will provide the basis for overcoming this phenomenon. Expression profiles from tamoxifen-resistant and sensitive MCF7 derived breast cancer cell lines were prepared, using Affymetrix HG_U133A cDNA microarrays. The data generated was analysed to identify novel pathways and genes associated with tamoxifen resistance or sensitivity. Selected genes, whose expression correlates with response to tamoxifen, were validated using RT-PCR in cell lines and following this, in situ hybridisation and immunohistochemistry on cell lines. Functional analyses of these genes were carried out: genes that were down-regulated in tamoxifen resistant MCF7 cells (HRASLS3, CTSD, CAXII) were selectively knocked down using RNA interference. Cell lines stably over-expressing genes upregulated in the tamoxifen resistant MCF7s (ATP1B1, SOCS2, NR4A2) were selected. These manipulated cells were subsequently tested for their response to anti-oestrogen treatment. Another major marker in breast cancer is the ERBB2 proto-oncogene; overexpressed in 20% of breast carcinomas, it is associated with poor prognosis and hormone resistance. The transcriptional deregulation of ERBB2 in breast cancer may in part be mediated by the transcription factors AP-2 and . Previous studies have shown that ERBB2 expression is repressed by oestrogen activated oestrogen receptor and that AP-2 binding sites within the ERBB2 promoter and the intronic enhancer are required for this oestrogenic repression. Using RNA interference, AP-2 and were successfully knocked down in breast cancer cell lines MCF7, T47D and ZR75-1. These have been used to investigate the effect of AP-2 loss on ERBB2 expression in hormonally manipulated cells

    AP-based wireless intrusion detection systems

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    This thesis was scanned from the print manuscript for digital preservation and is copyright the author. Researchers can access this thesis by asking their local university, institution or public library to make a request on their behalf. Monash staff and postgraduate students can use the link in the References field
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