Observations of the Vertical Structure of Tidal Currents in Two Inlets

Observations of the vertical structure of broad band tidal currents were obtained at two energetic inlets. Each experiment took place over a 4 week period, the first at Hampton Inlet in southeastern New Hampshire, USA, in the Fall of 2011, and the second at New River Inlet in southern North Carolina, USA, in the spring of 2012. The temporal variation and vertical structure of the currents were observed at each site with 600 kHz and 1200 kHz RDI Acoustic Doppler Current Profilers (ADCP) deployed on low-profile bottom tripods in 7.5 and 12.5 m water depths near the entrance to Hampton Inlet, and in 8 and 9 m water depth within and outside New River Inlet, respectively. In addition, a Nortek Aquapro ADCP was mounted on a jetted pipe in about 2.5 m water depth on the flank of the each inlet channel. Flows within the Hampton/Seabrook Inlet were dominated by semi-diurnal tides ranging 2.5 - 4 m in elevation, with velocities exceeding 2.5 m/s. Flows within New River inlet were also semi-diurnal with tides ranging about 1 – 1.5 m in elevation and with velocities exceeding 1.5 m/s. Vertical variation in the flow structure at the dominant tidal frequency are examined as a function of location within and near the inlet. Outside the inlet, velocities vary strongly over the vertical, with a nearly linear decay from the surface to near the bottom. The coherence between the upper most velocity bin and the successively vertically separated bins drops off quickly with depth, with as much as 50% coherence decay over the water column. The phase relative to the uppermost velocity bin shifts over depth, with as much as 40 deg phase lag over the vertical, with bottom velocities leading the surface. Offshore, rotary coefficients indicate a stable ellipse orientation with rotational directions consistent over the vertical. At Hampton, the shallower ADCP, but still outside the inlet, shows a rotational structure that changes sign in the vertical indicating a sense of rotation at the bottom that is opposite to that at the surface. Within the inlet, the flow is more aligned with the channel, the decay in amplitude over the vertical is diminished, the coherence and phase structure is nearly uniform, and the rotary coefficients indicate no sense of rotation in the flow. The observations are qualitatively consistent with behavior described by Prandle (1982) for shallow water tidal flows

The prospect of \u27Chindia\u27 as a world power

A significant global development in the first decade of the 21st Century has been the rise of several nationshitherto not considered key players in the international scene. The following up and coming nations have recentlybeen grouped respectively as BRIC and BASIC: Brazil, Russia, India, and China (BRIC); and Brazil, South Africa,India, and China (BASIC) (Wilson & Purushothaman, 2003). Noticeably, the two nations featured in both thesegroupings are China and India. China’s and India’s meteoric rise to the global arena, and the sheer magnitude oftheir populations, has led some scholars to assert that there is an ‘irresistible’ shift of global power toward Asia,dubbing this as the ‘Asian Century’ (Mahbubani, 2008, p. 43). And some scholars have gone so far as to coin theportmanteau ‘Chindia’ to signify the ascendency of these two Asian giants (Ramesh, 2005; Sheth, 2008). In thisarticle, I begin by examining Ramesh’s (2005) and Sheth’s (2008) definitions of the term Chindia. I then proceedto situate Chindia according to classical international relations theory of how global peace and prosperity havebeen historically attributed to a few strong nations in the world. I then undertake an historical overview of China-India relations, followed by a brief summary of the commonalities and differences between the two nations.Finally, I make an assessment whether Chindia is a dream or a possibility

The Formation of a Bubble from a Submerged Orifice

The formation of a single bubble from an orifice in a solid surface, submerged in an in- compressible, viscous Newtonian liquid, is simulated. The finite element method is used to capture the multiscale physics associated with the problem and to track the evolution of the free surface explicitly. The results are compared to a recent experimental analysis and then used to obtain the global characteristics of the process, the formation time and volume of the bubble, for a range of orifice radii; Ohnesorge numbers, which combine the material parameters of the liquid; and volumetric gas flow rates. These benchmark calculations, for the parameter space of interest, are then utilised to validate a selection of scaling laws found in the literature for two regimes of bubble formation, the regimes of low and high gas flow rates.Comment: Accepted for publication in the European Journal of Mechanics B/Fluid

Spherical collapse model in agegraphic dark energy cosmologies

Under the commonly used spherical collapse model, we study how dark energy affects the growth of large scale structures of the Universe in the context of agegraphic dark energy models. The dynamics of the spherical collapse of dark matter halos in nonlinear regimes is determined by the properties of the dark energy model. We show that the main parameters of the spherical collapse model are directly affected by the evolution of dark energy in the agegraphic dark energy models. We compute the spherical collapse quantities for different values of agegraphic model parameter $\alpha$ in two different scenarios: first, when dark energy does not exhibit fluctuations on cluster scales, and second, when dark energy inside the overdense region collapses similar to dark matter. Using the Sheth-Tormen and Reed mass functions, we investigate the abundance of dark matter halos in the framework of agegraphic dark energy cosmologies. The model parameter $\alpha$ is a crucial parameter in order to count the abundance of dark matter halos. Specifically, the present analysis suggests that the agegraphic dark energy model with bigger (smaller) value of $\alpha$ predicts less (more) virialized halos with respect to that of $\Lambda$CDM cosmology. We also show that in agegraphic dark energy models, the number of halos strongly depends on clustered or uniformed distributions of dark energy.Comment: 14 pages, 7 figures. Accepted in Physical Review

MCMC-ODPR : primer design optimization using Markov Chain Monte Carlo sampling

Background Next generation sequencing technologies often require numerous primer designs that require good target coverage that can be financially costly. We aimed to develop a system that would implement primer reuse to design degenerate primers that could be designed around SNPs, thus find the fewest necessary primers and the lowest cost whilst maintaining an acceptable coverage and provide a cost effective solution. We have implemented Metropolis-Hastings Markov Chain Monte Carlo for optimizing primer reuse. We call it the Markov Chain Monte Carlo Optimized Degenerate Primer Reuse (MCMC-ODPR) algorithm. Results After repeating the program 1020 times to assess the variance, an average of 17.14% fewer primers were found to be necessary using MCMC-ODPR for an equivalent coverage without implementing primer reuse. The algorithm was able to reuse primers up to five times. We compared MCMC-ODPR with single sequence primer design programs Primer3 and Primer-BLAST and achieved a lower primer cost per amplicon base covered of 0.21 and 0.19 and 0.18 primer nucleotides on three separate gene sequences, respectively. With multiple sequences, MCMC-ODPR achieved a lower cost per base covered of 0.19 than programs BatchPrimer3 and PAMPS, which achieved 0.25 and 0.64 primer nucleotides, respectively. Conclusions MCMC-ODPR is a useful tool for designing primers at various melting temperatures at good target coverage. By combining degeneracy with optimal primer reuse the user may increase coverage of sequences amplified by the designed primers at significantly lower costs. Our analyses showed that overall MCMC-ODPR outperformed the other primer-design programs in our study in terms of cost per covered base

Violence in Illicit Markets: Unintended Consequences and the Search for Paradoxical Effects of Enforcement

The textbook competitive model of drug markets predicts that greater law enforcement leads to higher black market prices, but also to the unintended consequences of greater revenue and violence. These predictions are not in accord with the paradoxical outcomes evinced by recent history in some drug markets, where enforcement rose even as prices fell. We show that predictions of the textbook model are not unequivocal, and that when bandwagon effects among scofflaws are introduced, the simple predictions are more likely to be reversed. We next show that even simple models of noncompetitive black markets can elicit paradoxical outcomes. Therefore, we argue that instead of searching for assumptions that lead to paradoxical outcomes, which is the direction the literature has taken, it is better for policy analysis to choose appropriate assumptions for the textbook model. We finish with performing such an analysis for the case of banning menthol cigarettes. Under the most plausible assumptions enforcement will indeed spur violence, although the legal availability of electronic cigarettes may mitigate or reverse this conclusion

Cigarette Taxes and Illicit Trade in Europe Online Appendix

Cigarettes are highly taxed in Europe to discourage tobacco use and to fund public-health measures to mitigate the harms from tobacco consumption. At higher prices some consumers substitute more toward illicit cigarettes. We find that raising prices in any one country would lead to substantial increases in the expected illicit market share and volume in that country. This appendix contains more complete information about the data and additional regressions to which the article published in Economic Inquiry (and also available in earlier form as School of Public Policy Working Paper 60) refers