47 research outputs found

    Development Discourse and Practice: Alternatives and New Directions from Postcolonial Perspectives

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    Development and aid programs, such as those aimed at promoting economic growth and prosperity in ‘Third World’ nations and transition economies, often arise out of Western and neo-liberal policy ideologies and practices. These programs may, in some cases, provide useful guidelines for restructuring institutional structures and governance mechanisms in nations that have long struggled with poverty, economic instability, health crises, and social and political turmoil. However, a growing number of critical voices are raising concerns over the guiding assumptions and inclusiveness of these policies and programs in their aims to promote economic development and social well-being in non-Western nations. We join these critical perspectives by way of postcolonial frameworks to highlight some of the problematic assumptions and oversights of development programs, while offering new alternatives and directions. By doing so, we contribute to organizational theorizing in a global context, as postcolonial insights provide much needed engagement with international aid policies and programs, as well as development organizations and institutions. To accomplish this, we offer a historical perspective on development, present a critique of the policies and practices guiding many aid programs, and conclude with suggestions emanating from postcoloniality

    MicroRNA-34a Modulates c-Myc Transcriptional Complexes to Suppress Malignancy in Human Prostate Cancer Cells

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    MicroRNA-34a (miR-34a), a potent mediator of tumor suppressor p53, has been reported to function as a tumor suppressor and miR-34a was found to be downregulated in prostate cancer tissues. We studied the functional effects of miR-34a on c-Myc transcriptional complexes in PC-3 prostate cancer cells. Transfection of miR-34a into PC-3 cells strongly inhibited in vitro cell proliferation, cell invasion and promoted apoptosis. Transfection of miR-34a into PC-3 cells also significantly inhibited in vivo xenograft tumor growth in nude mice. miR-34a downregulated expression of c-Myc oncogene by targeting its 3â€Č UTR as shown by luciferase reporter assays. miR-34a was found to repress RhoA, a regulator of cell migration and invasion, by suppressing c-Myc–Skp2–Miz1 transcriptional complex that activates RhoA. Overexpression of c-Myc reversed miR-34a suppression of RhoA expression, suggesting that miR-34a inhibits invasion by suppressing RhoA through c-Myc. miR-34a was also found to repress c-Myc-pTEFB transcription elongation complex, indicating one of the mechanisms by which miR-34a has profound effects on cellular function. This is the first report to document that miR-34a suppresses assembly and function of the c-Myc–Skp2–Miz1 complex that activates RhoA and the c-Myc-pTEFB complex that elongates transcription of various genes, suggesting a novel role of miR-34a in the regulation of transcription by c-Myc complex

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Nitrogen acquisition by roots: physiological and developmental mechanisms ensuring plant adaptation to a fluctuating resource

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    Variable resistance to Quambalaria pitereka in spotted gum reveal opportunities for disease screening

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    Quambalaria shoot blight, caused by the fungus Quambalaria pitereka, is a serious disease affecting the development of spotted gum (Corymbia citriodora subsp. citriodora, C. citriodora subsp. variegata, C. henryi and C. maculata) plantations in subtropical and tropical Australia. Incorporation of screening for resistance to Q. pitereka into current breeding programs is essential for the future development of plantations using spotted gum and Corymbia hybrids. The aim of this study was to determine whether there is variability in resistance among and within different species provenances and families of spotted gum to infection by Q. pitereka. A secondary aim was to consider whether the origin of seed source is a significant indicator of resistance to Q. pitereka. Assessments were conducted in trials consisting of spotted gum provenances, families and clones, all at the same site with high levels of disease pressure and with optimum climatic conditions for disease development. While all species and provenances of spotted gum could be infected by Q. pitereka, results showed that there are high levels of variability in resistance between and within species, provenances and families, indicating the potential to select for disease resistance. Provenance was shown to be an unreliable indicator of resistance to Q. pitereka

    Cord Blood-Derived Macrophage-Lineage Cells Rapidly Stimulate Osteoblastic Maturation in Mesenchymal Stem Cells in a Glycoprotein-130 Dependent Manner

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    In bone, depletion of osteoclasts reduces bone formation in vivo, as does osteal macrophage depletion. How osteoclasts and macrophages promote the action of bone forming osteoblasts is, however, unclear. Since recruitment and differentiation of multi-potential stromal cells/mesenchymal stem cells (MSC) generates new active osteoblasts, we investigated whether human osteoclasts and macrophages (generated from cord blood-derived hematopoietic progenitors) induce osteoblastic maturation in adipose tissue-derived MSC. When treated with an osteogenic stimulus (ascorbate, dexamethasone and ÎČ-glycerophosphate) these MSC form matrix-mineralising, alkaline phosphatase-expressing osteoblastic cells. Cord blood-derived progenitors were treated with macrophage colony stimulating factor (M-CSF) to form immature proliferating macrophages, or with M-CSF plus receptor activator of NFÎșB ligand (RANKL) to form osteoclasts; culture medium was conditioned for 3 days by these cells to study their production of osteoblastic factors. Both osteoclast- and macrophage-conditioned medium (CM) greatly enhanced MSC osteoblastic differentiation in both the presence and absence of osteogenic medium, evident by increased alkaline phosphatase levels within 4 days and increased mineralisation within 14 days. These CM effects were completely ablated by antibodies blocking gp130 or oncostatin M (OSM), and OSM was detectable in both CM. Recombinant OSM very potently stimulated osteoblastic maturation of these MSC and enhanced bone morphogenetic protein-2 (BMP-2) actions on MSC. To determine the influence of macrophage activation on this OSM-dependent activity, CM was collected from macrophage populations treated with M-CSF plus IL-4 (to induce alternative activation) or with GM-CSF, IFNÎł and LPS to cause classical activation. CM from IL-4 treated macrophages stimulated osteoblastic maturation in MSC, while CM from classically-activated macrophages did not. Thus, macrophage-lineage cells, including osteoclasts but not classically activated macrophages, can strongly drive MSC-osteoblastic commitment in OSM-dependent manner. This supports the notion that eliciting gp130-dependent signals in human MSC would be a useful approach to increase bone formation
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