311 research outputs found

    4 Technological Advancement and Long-Term Economic Growth in Asia

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    We are living in an age of remarkable technological change that is forcing us to think very hard about the linkages between technology and economic development. The harder we think about it,the more we realize that technological innovation i

    Institutions and Geography: Comment on Acemoglu, Johnson and Robinson (2000)

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    This paper responds to findings by Acemoglu, Johnson and Robinson (2000) that suggest weak institutions, but not physical geography and correlates like disease burden, explain current variation in levels of economic development across former colonies. Using similar data and expanding the sample of countries analyzed, our regression analysis shows that both institutions and geographically-related variables such as malaria incidence or life expectancy at birth are strongly linked to gross national product per capita. We argue that the evidence presented in Acemoglu, Johnson and Robinson is likely limited by the inherently small sample of ex-colonies and the limited geographic dispersion of those countries.

    Waveguide grating mirror in a fully suspended 10 meter Fabry-Perot cavity

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    We report on the first demonstration of a fully suspended 10m Fabry-Perot cavity incorporating a waveguide grating as the coupling mirror. The cavity was kept on resonance by reading out the length fluctuations via the Pound-Drever-Hall method and employing feedback to the laser frequency. From the achieved finesse of 790 the grating reflectivity was determined to exceed 99.2% at the laser wavelength of 1064\,nm, which is in good agreement with rigorous simulations. Our waveguide grating design was based on tantala and fused silica and included a ~20nm thin etch stop layer made of Al2O3 that allowed us to define the grating depth accurately during the fabrication process. Demonstrating stable operation of a waveguide grating featuring high reflectivity in a suspended low-noise cavity, our work paves the way for the potential application of waveguide gratings as mirrors in high-precision interferometry, for instance in future gravitational wave observatories

    Distance Scale Zero Points from Galactic RR Lyrae Star Parallaxes

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    We present new absolute trigonometric parallaxes and proper motions for seven Population II variable stars—five RR Lyr variables: RZ Cep, XZ Cyg, SU Dra, RR Lyr, and UV Oct; and two type 2 Cepheids: VY Pyx and κ Pav. We obtained these results with astrometric data from Fine Guidance Sensors, white-light interferometers on Hubble Space Telescope. We find absolute parallaxes in milliseconds of arc: RZ Cep, 2.12 ± 0.16 mas; XZ Cyg, 1.67 ± 0.17 mas; SU Dra, 1.42 ± 0.16 mas; RR Lyr, 3.77 ± 0.13 mas; UV Oct, 1.71 ± 0.10 mas; VY Pyx, 6.44 ± 0.23 mas; and κ Pav, 5.57 ± 0.28 mas; an average σπ/π = 5.4%. With these parallaxes, we compute absolute magnitudes in V and K bandpasses corrected for interstellar extinction and Lutz-Kelker-Hanson bias. Using these RR Lyrae variable star absolute magnitudes, we then derive zero points for MV -[Fe/H] and MK -[Fe/H]-log P relations. The technique of reduced parallaxes corroborates these results. We employ our new results to determine distances and ages of several Galactic globular clusters and the distance of the Large Magellanic Cloud. The latter is close to that previously derived from Classical Cepheids uncorrected for any metallicity effect, indicating that any such effect is small. We also discuss the somewhat puzzling results obtained for our two type 2 Cepheids

    Distinct Clinical and Pathological Features Are Associated with the BRAFT1799A(V600E) Mutation in Primary Melanoma

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    The BRAFT1799A mutation encodes BRAFV600E that leads to activation of the mitogen-activated protein kinase pathway. This study aimed to assess the clinico-pathological features of primary invasive melanomas containing the BRAFT1799A mutation. Patients (n=251) with invasive primary melanomas from Australia were interviewed and examined with respect to their melanoma characteristics and risk factors. Independent review of pathology, allele-specific PCR for the BRAFT1799A mutation, immunohistochemical staining with Ki67, and phospho-histone-H3 (PH3) were performed. The BRAFT1799A mutation was found in 112 (45%) of the primary melanomas. Associations with the BRAFT1799A mutation (P<0.05) were as follows: low tumor thickness (odds ratio (OR)=3.3); low mitotic rate (OR=2.0); low Ki67 score (OR=5.0); low PH3 score (OR=3.3); superficial spreading melanoma (OR=10.0); pigmented melanoma (OR=3.7); a lack of history of solar keratoses (OR=2.7); a location on the trunk (OR=3.4) or extremity (OR=2.0); a high level of self-reported childhood sun exposure (OR=2.0); ≤50 years of age (OR=2.5); and fewer freckles (OR=2.5). We conclude that the BRAFT1799A mutation has associations with host phenotype, tumor location, and pigmentation. Although implicated in the control of the cell cycle, the BRAFT1799A mutation is associated with a lower rate of tumor proliferation
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