U.S. and them : the geography of academic research

Using a database of 76,046 empirical economics papers published between 1985 and 2004 in the top 202 economics journals, the authors report two associations. First, per-capita research output on a given country increases with the country's per capita gross domestic product (GDP). Regressions controlling for data availability and quality in the country, indicators of governance and the use of English yield an estimated research-GDP elasticity of 0.37; surprisingly, the United States (US) is not an outlier in the production of empirical research. Second, papers written about the US are far more likely to be published in the top five economics journals, even after the quality of research has been partially controlled for through fixed-effects for the authors'institutional affiliations; the estimates suggest that papers on the US are 2.6 percentage points more likely to be published in the top-five journals. This is a large effect because only 1.5 percent of all papers written about countries other than the US are published in the top-five journals. The authors speculate about the interpretations of these facts, and invite further analysis and additions to the public release of the database that accompanies this paper.Information Security&Privacy,Economic Theory&Research,Tertiary Education,Labor Policies,Agricultural Knowledge&Information Systems

Automatic Indian Sign Language Recognition for Continuous Video Sequence

Sign Language Recognition has become the active area of research nowadays. This paper describes a novel approach towards a system to recognize the different alphabets of Indian Sign Language in video sequence automatically. The proposed system comprises of four major modules: Data Acquisition, Pre-processing, Feature Extraction and Classification. Pre-processing stage involves Skin Filtering and histogram matching after which Eigen vector based Feature Extraction and Eigen value weighted Euclidean distance based Classification Technique was used. 24 different alphabets were considered in this paper where 96% recognition rate was obtained.Keywords: Eigen value, Eigen vector, Euclidean Distance (ED),Human Computer Interaction, Indian Sign Language (ISL), Skin Filtering.Cite as:Joyeeta Singh, Karen Das "Automatic Indian Sign Language Recognition for Continuous Video Sequence", ADBU J.Engg.Tech., 2(1)(2015) 0021105(5pp

Spatial reactions to crime: fortressing or emancipation of public urban space? Potchefstroom as a case study

In both historical, as well as contemporary cities, it was and still is believed that the built environment can play an essential role in the protection of its inhabitants. Today, one of the major challenges facing urban planners, specially in South Africa, is to offer possible spacial solutions to prevent crime in cities. While the traditional city were enclosed by thick walls and incorporate the public spaces, the contemporary city is following a new kind of fortress mentality where various smaller urban spaces (in most cases residential areas), scattered throughout the city, are enclosed by physical barriers with the result of internal spaces, once public spaces, now being privatised. This concept of fortressing - known as 'gated communities' - is multiplying drastically in both metropolitan as well as small and medium sized South African cities. Apart from the responsibilty to address crime, urban planners are simultaneously faced here with other responsibilities (in the way they design the physical environment): efforts in reviving a dying public realm in cities and addressing the segregation of urban space, created by the previous political dogm, are some of the major challenges. In this regard the notion of 'gated communities' could spell doom to a possible safe and vibrant urban future. This paper questions the long term consequences of a fortress mentality on the well-being of the public realm of our cities and explore, by means of an analysis of 'gated communities' in Potchefstroom, possible compromises to be made

Antarctic surface melting dynamics : enhanced perspectives from radar scatterometer data

Author Posting. © American Geophysical Union, 2012. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 117 (2012): F02023, doi:10.1029/2011JF002126.Antarctic ice sheet surface melting can regionally influence ice shelf stability, mass balance, and glacier dynamics, in addition to modulating near-surface physical and chemical properties over wide areas. Here, we investigate variability in surface melting from 1999 to 2009 using radar backscatter time series from the SeaWinds scatterometer aboard the QuikSCAT satellite. These daily, continent-wide observations are explored in concert with in situ meteorological records to validate a threshold-based melt detection method. Radar backscatter decreases during melting are significantly correlated with in situ positive degree-days as well as meltwater production determined from energy balance modeling at Neumayer Station, East Antarctica. These results support the use of scatterometer data as a diagnostic indicator of melt intensity (i.e., the relative liquid water production during melting). Greater spatial and temporal melting detected relative to previous passive microwave-based studies is attributed to a higher sensitivity of the scatterometer instrument. Continental melt intensity variability can be explained in part by the dynamics of the Southern Annular Mode and the Southern Oscillation Index, and extreme melting events across the Ross Ice Shelf region may be associated with El Niño conditions. Furthermore, we find that the Antarctic Peninsula accounts for only 20% of Antarctic melt extent but greater than 50% of the total Antarctic melt intensity. Over most areas, annual melt duration and intensity are proportional. However, regional and localized distinctions exist where the melt intensity metric provides greater insight into melting dynamics than previously obtainable with other remote sensing techniques.Support for this research was provided by NASA grant NNX10AP09G and NSF grant ANT-063203.2012-11-1

Interleukin-33 contributes to both M1 and M2 chemokine marker expression in human macrophages

Abstract Background Interleukin-33 is a member of the IL-1 cytokine family whose functions are mediated and modulated by the ST2 receptor. IL-33-ST2 expression and interactions have been explored in mouse macrophages but little is known about the effect of IL-33 on human macrophages. The expression of ST2 transcript and protein levels, and IL-33-mediated effects on M1 (i.e. classical activation) and M2 (i.e. alternative activation) chemokine marker expression in human bone marrow-derived macrophages were examined. Results Human macrophages constitutively expressed the membrane-associated (i.e. ST2L) and the soluble (i.e. sST2) ST2 receptors. M2 (IL-4 + IL-13) skewing stimuli markedly increased the expression of ST2L, but neither polarizing cytokine treatment promoted the release of sST2 from these cells. When added to naïve macrophages alone, IL-33 directly enhanced the expression of CCL3. In combination with LPS, IL-33 blocked the expression of the M2 chemokine marker CCL18, but did not alter CCL3 expression in these naive cells. The addition of IL-33 to M1 macrophages markedly increased the expression of CCL18 above that detected in untreated M1 macrophages. Similarly, alternatively activated human macrophages treated with IL-33 exhibited enhanced expression of CCL18 and the M2 marker mannose receptor above that detected in M2 macrophages alone. Conclusions Together, these data suggest that primary responses to IL-33 in bone marrow derived human macrophages favors M1 chemokine generation while its addition to polarized human macrophages promotes or amplifies M2 chemokine expression.http://deepblue.lib.umich.edu/bitstream/2027.42/78250/1/1471-2172-11-52.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78250/2/1471-2172-11-52.pdfPeer Reviewe