Estimation of the vertical wavelength of atmospheric gravity waves from airglow imagery

Abstract In the summer of 2010, two imagers were installed in New Mexico with the objective of making stereoscopic observations of atmospheric gravity waves (AGWs). As AGWs propagate vertically, they spatially perturb the airglow emission layers in all three dimensions. Estimates of the vertical wavelength, horizontal wavelength, and the intrinsic frequency are needed to characterize an AGW and quantify its effects on upper atmospheric dynamics. The dispersion relation describes the relationship between vertical and horizontal wavelengths as a function of the intrinsic frequency. Thus, any two of the three aforementioned parameters can be used to determine the third. Mesospheric winds are hard to measure and consequently the intrinsic frequency is difficult to estimate. However, the horizontal wavelength can be directly measured from airglow imagery once the three-dimensional imager field of view is projected onto the two-dimensional image plane. This thesis presents a method to estimate the vertical wavelength using an airglow perturbation model proposed by Anderson et al. (2009). The model is subsequently validated using the observations from ground-based imagers installed in New Mexico. Abstract The perturbed airglow is modeled as a quasi-monochromatic wave and thus, it can be characterized using only a few parameters, one of which is the vertical wavelength. Because the vertical wavelength is embedded in both the phase and the magnitude of this model, two values of the vertical wavelength are estimated by applying two different parameter estimation techniques on the phase and magnitude. The estimation of the vertical wavelength from the phase of the model entails solving an overdetermined system of linear equations by minimizing the sum of the squared residuals. This estimate is then compared to that obtained by iteratively finding the best approximation to the roots of a function, representing the magnitude of the perturbation model. These two techniques are applied on three nights in 2010, and the estimates for the vertical wavelength match to within a few kilometers. Thus, the perturbation model is validated using real data

Relative Profitability, Supply Shifters and Dynamic Output Response:The Indian Foodgrains

The realisation that the wage-goods constraint, if binding, could stall the growth process of a developing country, prompted policy makers to encourage agriculture by various means. The success of public policy depends, however, on how strongly farmers respond to the incentives provided. Using a large panel dataset pertaining to Indian agriculture - spanning the period 1967-68/1999-00, and covering the 6 important food crops cultivated across 16 major states - we provide estimates of area, yield and output elasticities w.r.t price and nonprice factors. We find consistent evidence, that the supply response of food crops is influenced by rainfall, input availability (specifically irrigation, fertilizer and improved seeds), and relative profits, in that order of importance. Our results prompt us to conclude, that all things considered, the preferred policy should be to encourage irrigation, fertilizer use and the use of modern seeds, rather than raise output support/procurement prices period after period.wage-goods, price incentives, supply shifters

Price Incentives, Nonprice factors, and Crop Supply Response:The Indian Cash Crops

Agriculture as a source of growth was sorely neglected in the early development strategies of the currently developing countries. Realisation of this shortcoming prompted public policy in these countries to encourage agriculture by various means. The success of these policies depends, however, on how farmers respond to the incentives provided. Using panel data pertaining to Indian agriculture for the period 1967-68/1999-00, covering 7 major 'annual' cash crops cultivated across 16 major states, we provide estimates of area, yield and output elasticities w.r.t price and nonprice variables. Our results suggest that the preferred policy ought to be to enhance irrigation and encourage the use of fertiliser and HYVs, if long-run agricultural growth is to be achieved.Incentives, supply response, deprivation

Innovation and Intellectual Property Rights

Very little empirical evidence exists on the relationship between intellectual property rights and innovation. Existing studies tend to be indirect and do not consider the influence of IPRs on innovation per se; nor do they adequately allow for the endogeneity of IPRs. Correcting for these omissions, we show that the strength of intellectual property protection has a strong positive influence on innovation.Innovation, IPRs, Endogeneity.

Intellectual Property Protection and the Licensing of Technology to Developing Countries

In this paper we study the influence of stronger intellectual property protection on technology transfer into developing countries via licensing. Using panel data for the post-TRIPs period 1995-2005, we find that stronger protection is associated with increased royalty and license fee payments by developing countries, implying greater technology transfer into these countries. This result is robust to the inclusion of country fixed effects, as well as alternative specifications of the model estimated. The strong overall statistical significance of the protection variable is found to be driven by the sub-index of coverage, which makes eminent sense in view of the substantial increase in the coverage of patentable subject matter by developing countries post- TRIPs. Other factors of importance are scale variables such as per capita income and population, as well as human capital and trade openness of the technology-importing countries. The economic significance of the protection variable also appears to be substantial, with changes in this variable accounting for technology inflows of about US $3.4 billion to US$5.5 billion (base year 2000) in the post-TRIPs sample period. These magnitudes comprise 3.5% to 5.7% of the total value of royalty and license fees over 1995-2005 (at 2000 prices). Overall, our results are noteworthy.intellectual property protection, licensing technology

Does Intellectual Property Lead to Intellectual Property Protection?

Researchers studying the differential commitment of countries to intellectual property rights, often appear to run into the claim that countries with a relatively higher and significantly changing technological base (the developed countries) opt for relatively stronger protection, whereas those with a relatively low and essentially unchanging technological base (the developing countries) opt for weaker protection. While the reasons for such strategic choice may vary between the two sets of countries, it appears to be a short step from the above assertion to the claim that such behaviour on the part of the developing countries results in huge trade losses for the developed countries. Using cross-country panel data for the period 1981-1995, this paper finds that the generation of intellectual property or technological change (proxied by private R&D investment) does not have any significant positive influence on the strength of intellectual property protection that nations provide.Intellectual Property, Protection, Technolgical Change

Do Money Or Oil And Crop Productivity Shocks Lead To Inflation: The Case Of Pakistan

The worst economic outcomes have been argued as a result of the mismanagement in money supply especially in 1929’s Great Depression, 1970’s Stagflation and 2008’s Economic depression in the global economy. However, economic recessions tend to appear after oil price phenomenon. In particular, the global inflationary pressures of 2008 became severe with the spikes up in oil prices as well as crop productivity shocks in the world economy including Pakistan. The object of the present paper is to discuss inflation in the framework of Monetary and external Oil Price Shocks, Crop Productivity Propositions, Inflation Inertia, and real GDP growth. The empirical studies broadly uphold the monetary explanation of inflation in the Pakistan’s economy. This paper offers the policy implication that the combination of monetary as well as productivity management is required to arrest inflationary pressures in the economy. In addition, we find the comprehensive evidence that food inflation is also a monetary phenomenon in the Pakistan’s economy. On the other hand, the continuous persistence in inflation inertia does not hold as a result of the absence of autocorrelation in money supply in AR (2) or higher process in the data. Oil prices in terms of domestic currency highlight the fact that the transmission channel of world shocks via exchange rate fluctuations leaves significant impacts upon domestic inflation in the economy.Money; Inflation; Oil; Productivity

Does Intellectual Property Protection Spur Technological Change

Of the diverse factors motivating technological change, one factor that has received increasing attention in the recent past has been the protection of intellectual property rights. Given fairly recent changes in the international policy ethos where a regime of stronger intellectual property protection has become a fait accompli for most developing countries, it is of some significance to ask whether more stringent protection of intellectual property does indeed encourage innovation. And this is the question which this paper examines, utilising cross-country panel data on R&D investment, patent protection and other country-specific characteristics spanning the period 1981-1990. The evidence unambiguously indicates the significance of intellectual property rights as incentives for spurring innovation.Intellectual Property Rights, Technological Change, Economic Growth

Phase Unwrapping and One-Dimensional Sign Problems

Sign problems in path integrals arise when different field configurations contribute with different signs or phases. Phase unwrapping describes a family of signal processing techniques in which phase differences between elements of a time series are integrated to construct non-compact unwrapped phase differences. By combining phase unwrapping with a cumulant expansion, path integrals with sign problems arising from phase fluctuations can be systematically approximated as linear combinations of path integrals without sign problems. This work explores phase unwrapping in zero-plus-one-dimensional complex scalar field theory. Results with improved signal-to-noise ratios for the spectrum of scalar field theory can be obtained from unwrapped phases, but the size of cumulant expansion truncation errors is found to be undesirably sensitive to the parameters of the phase unwrapping algorithm employed. It is argued that this numerical sensitivity arises from discretization artifacts that become large when phases fluctuate close to singularities of a complex logarithm in the definition of the unwrapped phase.Comment: 42 pages, 16 figures. Journal versio

Genes Encoding Recognition of the Cladosporium fulvum Effector Protein Ecp5 Are Encoded at Several Loci in the Tomato Genome

The molecular interactions between tomato and Cladosporium fulvum have been an important model for molecular plant pathology. Complex genetic loci on tomato chromosomes 1 and 6 harbor genes for resistance to Cladosporium fulvum, encoding receptor like-proteins that perceive distinct Cladosporium fulvum effectors and trigger plant defenses. Here, we report classical mapping strategies for loci in tomato accessions that respond to Cladosporium fulvum effector Ecp5, which is very sequence-monomorphic. We screened 139 wild tomato accessions for an Ecp5-induced hypersensitive response, and in five accessions, the Ecp5-induced hypersensitive response segregated as a monogenic trait, mapping to distinct loci in the tomato genome. We identified at least three loci on chromosomes 1, 7 and 12 that harbor distinct Cf-Ecp5 genes in four different accessions. Our mapping showed that the Cf-Ecp5 in Solanum pimpinellifolium G1.1161 is located at the Milky Way locus. The Cf-Ecp5 in Solanum pimpinellifolium LA0722 was mapped to the bottom arm of chromosome 7, while the Cf-Ecp5 genes in Solanum lycopersicum Ontario 7522 and Solanum pimpinellifolium LA2852 were mapped to the same locus on the top arm of chromosome 12. Bi-parental crosses between accessions carrying distinct Cf-Ecp5 genes revealed putative genetically unlinked suppressors of the Ecp5-induced hypersensitive response. Our mapping also showed that Cf-11 is located on chromosome 11, close to the Cf-3 locus. The Ecp5-induced hypersensitive response is widely distributed within tomato species and is variable in strength. This novel example of convergent evolution could be used for choosing different functional Cf-Ecp5 genes according to individual plant breeding needs