151,261 research outputs found

    Extended field-of-view in a lensless endoscope using an aperiodic multicore fiber

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    We investigate lensless endoscopy using coherent beam combining and aperiodic multicore fibers (MCF). We show that diffracted orders, inherent to MCF with periodically arranged cores, dramatically reduce the field of view (FoV) and that randomness in MCF core positions can increase the FoV up to the diffraction limit set by a single fiber core, while maintaining MCF experimental feasibility. We demonstrate experimentally pixelation-free lensless endoscopy imaging over a 120 micron FoV with an aperiodic MCF designed with widely spaced cores. We show that this system is suitable to perform beam scanning imaging by simply applying a tilt to the proximal wavefront.Comment: Submitted to Optics Letter

    Differential disease restriction of Moloney and Friend murine leukemia viruses by the mouse Rmcf gene is governed by the viral long terminal repeat.

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    Neonatal CxD2 (Rmcfr) and Balb/c (Rmcfs) mice inoculated with Moloney murine leukemia virus (M-MuLV) exhibited approximately equivalent time course and pathology for disease. CxD2 mice showed only slightly reduced presence of Moloney mink cell focus-forming virus (M-MCF) provirus as seen by Southern blot analysis compared to Balb/c mice. This lack of restriction for disease and spread of MCF was in sharp contrast to that seen for CxD2 mice inoculated with Friend murine leukemia virus (F-MuLV), where incidence of disease and propagation of MCFs were severely restricted, as previously reported. Inoculation of CxD2 mice with FM-MuLV, a recombinant F-MuLV virus containing M-MuLV LTR sequences (U3 and R), resulted in T cell disease of time course equal to that seen in Balb/c mice; there also was little restriction for propagation of MCFs. This indicated that presence of the M-MuLV long terminal repeat (LTR) was sufficient for propagation of MCFs in CxD2 mice. Differing restriction for F-MuLV vs. M-MuLV in CxD2 mice was explained on the basis of different "MCF propagator cells" for the two viruses. It was suggested that cells propagating F-MCF (e.g., erythroid progenitors) are blocked by endogenous MCF-like gp70env protein, whereas cells propagating M-MCF (e.g., lymphoid) do not express this protein on their surface. F-MuLV disease in CxD2 mice was greatly accelerated when neonates were inoculated with a F-MuLV/F-MCF pseudotypic mixture. However, F-MCF provirus was not detectable or only barely detectable in F-MuLV/F-MCF-induced tumors, suggesting that F-MCF acted indirectly in induction of these tumors

    Neckpinch dynamics for asymmetric surfaces evolving by mean curvature flow

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    We study surfaces evolving by mean curvature flow (MCF). For an open set of initial data that are C3C^3-close to round, but without assuming rotational symmetry or positive mean curvature, we show that MCF solutions become singular in finite time by forming neckpinches, and we obtain detailed asymptotics of that singularity formation. Our results show in a precise way that MCF solutions become asymptotically rotationally symmetric near a neckpinch singularity.Comment: This revision corrects minor but potentially confusing misprints in Section

    The Marginal Cost of Public Funds is One

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    This paper develops a Mirrlees (1971) framework with heterogeneous agents to analyze optimal redistributive taxes, optimal provision of public goods and the marginal cost of public funds (MCF). Standard MCF measures are shown to suffer from three defects: i) The MCF for the (non-individualized) lump-sum tax is generally not equal to one. ii) The MCF for distortionary taxes is not directly related to the marginal excess burden. iii) MCF measures for both lump-sum and distortionary taxes are highly sensitive to the choice of the untaxed numéraire good. These problems are caused by using the private rather than the social marginal value of private income to calculate the MCF, and disappear by using the social marginal value of private income. Moreover, by allowing for redistributional concerns, the marginal excess burden of distortionary taxes equals the marginal distributional gain at the optimal tax system. MCF therefore equals one, both for lump-sum and distortionary taxes, and the modified Samuelson rule should not be corrected for the marginal cost of public funds.marginal cost of funds; marginal excess burden; optimal taxation; optimal redistribution; optimal provision of public goods; Samuelson rule

    2010 Outlook Report

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    To assess the outlook for grantmaking in Minnesota in 2010, the Minnesota Council on Foundations (MCF) conducted its 2010 Outlook Report survey in October and November of 2009. The survey asked MCF members and other large grantmakers in the state to predict how their 2010 giving will compare to 2009. In all, 125 organizations responded, representing about 70 percent of annual grantmaking in the state

    The small heat shock protein B8 (HSPB8) modulates proliferation and migration of breast cancer cells

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    open12noBreast cancer (BC) is one of the major causes of cancer death in women and is closely related to hormonal dysregulation. Estrogen receptor (ER)-positive BCs are generally treated with anti hormone therapy using antiestrogens or aromatase inhibitors. However, BC cells may become resistant to endocrine therapy, a process facilitated by autophagy, which may either promote or suppress tumor expansion. The autophagy facilitator HSPB8 has been found overexpressed in some BC. Here we found that HSPB8 is highly expressed and differentially modulated by natural or synthetic selective ER modulators (SERMs), in the triple-positive hormone-sensitive BC (MCF-7) cells, but not in triple-negative MDA-MB-231 BC cells. Specific SERMs induced MCF-7 cells proliferation in a HSPB8 dependent manner whereas, did not modify MDA-MB-231 cell growth. ER expression was unaffected in HSPB8-depleted MCF-7 cells. HSPB8 over-expression did not alter the distribution of MCF-7 cells in the various phases of the cell cycle. Conversely and intriguingly, HSPB8 downregulation resulted in an increased number of cells resting in the G0/G1 phase, thus possibly reducing the ability of the cells to pass through the restriction point. In addition, HSPB8 downregulation reduced the migratory ability of MCF-7 cells. None of these modifications were observed, when another small HSP (HSPB1), also expressed in MCF-7 cells, was downregulated. In conclusion, our data suggest that HSPB8 is involved in the mechanisms that regulate cell cycle and cell migration in MCF-7 cells.openPiccolella, Margherita; Crippa, Valeria; Cristofani, Riccardo; Rusmini, Paola; Galbiati, Mariarita; Elena Cicardi, Maria; Meroni, Marco; Ferri, Nicola; Morelli, Federica F; Carra, Serena; Messi, Elio; Poletti, AngeloPiccolella, Margherita; Crippa, Valeria; Cristofani, Riccardo; Rusmini, Paola; Galbiati, Mariarita; Elena Cicardi, Maria; Meroni, Marco; Ferri, Nicola; Morelli, Federica F; Carra, Serena; Messi, Elio; Poletti, Angel

    Insect bioactive capabilities of Epichloë festucae var lolii AR48 infected Lolium perenne : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Biochemistry at Massey University, Manawatū, New Zealand

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    Figures printed with permission from respective publishers.As the modern world expands and develops, new innovative methodologies for more efficient and environmentally friendly agricultural practices are required. Loss of crops through abiotic (e.g. drought) and biotic (e.g. herbivory) stresses has a major effect on the success of an agricultural industry. For animal production pasture crops are a key aspect of animal husbandry and directly affects yield and health. Symbiotic fungi belonging to the genus Epichloë form associations with cool season forage grasses and have been exploited as a new innovative method for insect pest management. Ryegrass infected with the asexual E. festucae var lolii strain AR48 has insect bioactivity against both the stem boring fly (SBF-Ceradontha australis) and cutworm moth caterpillar (CC -Agrotis ipsilion). The bioactive/s targeting both insects is currently unknown. The aim of this thesis was to identify the gene/s and/or bioactive/s present in AR48 infected ryegrass that have bioactivity against the SBF and/or CC. Two approaches were taken; the known insect bioactive secondary metabolite pathways in Epichloë were investigated in AR48 through bioinformatics and mass spectrometry, and the gene ‘makes caterpillars floppy’ (mcf), encoding an insect toxin like protein, was investigated through reverse genetics and insect bioactivity trials. A new indole diterpene compound (IDT) was identified in AR48 infected plant material and this compound was absent in other Epichloë strains that do not have SBF and CC bioactivity. The same mcf gene allele as that present in the E. typhina mcf model, previously identified as having CC bioactivity, is present and predicted to be functional in AR48. The other Epichloë strains also have mcf genes predicted to be functional, however the mcf allele is different to the bioactive E. typhina mcf model. Overall, this project was able to identify a new IDT compound with potential insect bioactivity as well as identify two Epichloë mcf gene alleles that potentially have differing insect bioactivities

    Overexpression of microRNA-16 declines cellular growth, proliferation and induces apoptosis in human breast cancer cells

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    MicroRNAs (miRNA) are a large family of small single-stranded RNA molecules found in all multicellular organisms. Early studies have been shown that miRNA are involved in cancer development and progression, and this role can be done by working as an oncogenes and tumor suppressor genes, so manipulation of this molecules can be a promising approach in cancer therapy, and experimental results represented that the modification in breast cancer phenotype is possible by miRNA expression alteration. miR-16, which is located in 13q14 chromosome, plays critical roles as a tumor suppressor by targeting several oncogenes which regulate cell cycle and apoptosis. Hence, in the present study, we investigated whether miR-16 could decline growth and survival of MCF-7 cell line as model of human breast cancer. MCF-7 cell line was infected with lentiviruses containing miR-16 precursor sequence. The effects of ectopic expression of miR-16 on breast cancer phenotype were examined by cell cycle analysis and apoptosis assays. miR-16 cytotoxicity effect was measured by the MTT assay. We showed that the miR-16 overexpression reduces Cyclin D1 and BCL2 at messenger RNA (mRNA) and protein levels in MCF-7 cell line. In addition, this is found that enforced expression of miR-16 decreases cell growth and proliferation and induces apoptosis in MCF-7 cells. In conclusion, our results revealed that upregulation of miR-16 would be a potential approach for breast cancer therapy. © 2015, The Society for In Vitro Biology
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