Labor Market Density and Increasing Returns to Scale: How Strong is the Evidence?

Models of economic geography posit that the density of economic activity has two e¤ects that oppose each other in equilibrium: decreasing returns to productive activities due to congestion e¤ects and increasing returns that result from information spillovers and local demand externalities. In an in�uential paper, Ciccone and Hall (1996) looked at the effect of county level labor market concentration on per-worker Gross State Product in a cross section of US States, and observed that on net, the increasing returns/agglomeration effect dominates. We extend their analysis and re-examine the relationship between density and productivity across industries and over both states and time. Through careful identi�cation of the source and nature of productivity shocks, we show that the evidence for agglomeration effects is indeed quite robust, even within industries, providing evidence for the presence of Marshallian externalities. As for the balance of agglomeration and congestion e¤ects found in previous literature, what we call �net increasing returns to scale", the evidence is much weaker.

The Changing Relation Between the Canadian and U.S. Yield Curves

The term structures of Canada and of the United States, two countries with historically close economic ties, have been closely linked. We investigate the link between Canadian and U.S. yield curves and show previously strong correlations between yield curve components dissipate after Canadian monetary policy reforms in the early 1990s. First, the effect is particularly evident in the diminished cross-country correlations of the short term bond yields. Secondly, cross-country yields are cointegrated before the reforms, but not afterwards. Lastly, the results on the term structure are shown using a vector autoregression with an endogenously determined break date for Canadian and U.S. estimates of the three-factor Nelson-Siegel (1987) yield curve model.

Complement abnormalities in membranoproliferative glomerulonephritis and C3 glomerulopathy

PhD ThesisMembranoproliferative glomerulonephritis (MPGN) and C3 glomerulopathy (C3G) are rare diseases that associate with dysregulation of the alternative pathway (AP). The earliest abnormalities associated with these diseases were C3 nephritic factor and also rare genetic variants in the gene CFH that caused factor H (FH) deficiency. Since then, other acquired and genetic abnormalities in AP have been reported in MPGN and C3G. The aim of this project was to screen cohorts of MPGN and C3G for such abnormalities. Screening for rare sequence variants in genes encoding proteins involved in AP activity in two cohorts revealed a low prevalence of genetic abnormalities. Compared to the prevalence of C3 nephritic factor and autoantibodies to complement proteins, it was clear that the predominant abnormalities in these cohorts were acquired. Though few, rare genetic variants identified in CFH were studied in functional studies. The first was identified in a case of familial MPGN in the N-terminal domain of CFH. Functional studies included surface plasmon resonance and haemolytic assays to study a mutant protein in the setting of a short fragment comprising the N-terminal domain of FH. This initial study confirmed loss of function in a familial variant and formed the basis for further studies. In studies of eight other variants identified in MPGN and C3G and two other diseases that share complement risk factors, only two variants were likely to be functionally significant as demonstrated by complete loss of function. This highlights the need for such studies to correctly identify important variants. The significant functional effects initially identified in studies using short fragments were then confirmed in studies using full length protein. The significance of rare genetic variants in CFH needs to be considered even though MPGN and C3G are largely an autoimmune phenomenon.Medical Research Council and Northern Counties Kidney Research Fun

Symmetry selective third harmonic generation from plasmonic metacrystals

Nonlinear processes are often governed by selection rules imposed by the symmetries of the molecular configurations. The most well-known examples include the role of mirror symmetry breaking for the generation of even harmonics, and the selection rule related to the rotation symmetry in harmonic generation for fundamental beams with circular polarizations. While the role of mirror symmetry breaking in second harmonic generation has been extensively studied in plasmonic systems, the investigation on selection rules pertaining to circular polarization states of harmonic generation has been limited to crystals, i.e. symmetries at the atomic level. Here we demonstrate the rotational symmetry dependent third harmonic generation from nonlinear plasmonic metacrystals. We show that the selection rule can be imposed by the rotational symmetry of meta-crystals embedded into an isotropic organic nonlinear thin film. The results presented here may open new avenues for designing symmetry-dependent nonlinear optical responses with tailored plasmonic nanostructures.Comment: 13 pages, 3 figure

The Effectiveness of a Pro-Abstinence Sex Education Curriculum in Singapore

In this study, we investigate the impact of the pro-abstinence Sex Education curriculum on youths in Singapore, by examining if there is a relationship between pro-abstinence Sex Education and the rates of Sexually Transmitted diseases (STD)/Sexually Transmitted Infections (STI). As the rates of STD/STI transmission have been on the rise, it is crucial that the system be re-evaluated to include a curriculum that educates on protection and contraception. To study this relationship, we compiled secondary data over a course of 20 to 30 years from the Ministry of Health (MOH), as well as past studies of the impact of pro-abstinence Sex Education on youths aged between 16 to 25. Despite no research about the effectiveness of Singapore’s sex education curriculum which was introduced in 2000, with multiple resources and research studies that were conducted in the United States, a comparison between the sex education curriculum in Singapore and reevaluated curriculums overseas can be made to draw a conclusion. Through regression analysis done on two different sets of data, we concluded that there was little to no difference in having a pro-abstinence Sex Education in decreasing the rate of both STI and STD

Crystallization and preliminary crystallographic analysis of the central domain of Drosophila Dribble, a protein that is essential for ribosome biogenesis. Addendum

An addition to the paper by Cheng et al. [(2010), Acta Cryst. F66, 546–548]

Integration of Use Case Formal Template Using Mapping Rules

The integration of use case and formal specification plays an essential role in addressing the issue of gaining the rigor and reliable software model such as formal model via easy and economic model such as object model. Although extensive research has been carried out on this Integration, however there is a huge challenge on bridging the gaps between natural language used In use case scenario and the mathematics model used in formal model. This Is mainly because of the differences In syntax and semantic of these two models. Natural language requirement is well documented that it is being inconsistent, inherently ambiguous, and incomplete even though natural language Is universal, widespread, and flexible. As a consequence, It may lead to misunderstanding and produce an incorrect and inaccurate analysis and design model. Therefore, this paper aims to propose a use case formal template and define a new set of mapping rules that Is used for formalizing UML use case by transforming use case scenarios which are written In natural language Into VDM++ formal specification. The formal verification for the generated VDM++ formal specification can be further conducted by adopting the existing support tool of VDM++ (i. e. VDM++ ToolBox) to verify the correctness of the specification

Estimation of acute and chronic Q fever incidence in children during a three-year outbreak in the Netherlands and a comparison with international literature

Background:  In the Dutch 2007-2009 Q fever outbreak Coxiella burnetii was transmitted aerogenically from dairy goat farms to those living in the surrounding areas. Relatively few children were reported. The true number of pediatric infections is unknown. In this study, we estimate the expected number of acute and chronic childhood infections. Methods:  As Coxiella was transmitted aerogenic to those living near infected dairy goat farms, we could use adult seroprevalence data to estimate infection risk for inhabitants, children and adults alike. Using Statistics Netherlands data we estimated the number of children at (high) risk for developing chronic Q fever. Literature was reviewed for childhood (0-15 years) Q fever reports and disease rates. We compared this with Dutch reported and our estimated data for 2007-2009. Results:  In The Netherlands epidemic, 44 children were reported (1.2 % of total notifications). The childhood incidence was 0.15 compared to 2.6 per 10,000 inhabitants for adults. No complications were reported. Based on the expected similarity in childhood and adult exposure we assume that 9.8 % of children in the high-risk area had Q fever infection, resulting in 1562 acute infections during the Q fever epidemic interval. Based on the prevalence of congenital heart disease, at least 13 children are at high risk for developing chronic Q fever. In medical literature, 42 case reports described 140 childhood Q fever cases with a serious outcome (four deaths). In chronic Q fever, cardiac infections were predominant. Four outbreaks were reported involving children, describing 11 childhood cases. 36 National and/or regional studies reported seroprevalences varying between 0 and 70 %. Conclusion:  In the 3-year Dutch epidemic, few childhood cases were reported, with pulmonary symptoms leading, and none with a serious presentation. With an estimated 13 high-risk children for chronic infection in the high exposure area, and probably forty in the whole country, we may expect several chronic Q fever complications in the coming years in paediatric practice