Velocity-dependent inverse cubic force and solar system gravity tests

Higher mass dimension terms in an effective field theory framework for tests of spacetime symmetries are studied. Using a post-Newtonian expansion method, we derive the spacetime metric and the equations of motion for a binary system. This reveals an inverse cubic force correction to General Relativity that depends on the velocity of the bodies in the system. The results are studied in the context of laboratory and space-based tests including the effects on solar-system ephemeris, laser ranging observations, and gravimeter tests. This work reveals the coefficient combinations for mass dimension 5 operators controlling CPT violation for gravity that can be measured using analysis from these tests. Other tests including light propagation can be used to probe these coefficients. Sensitivity estimates are provided and the results are contrasted with the minimal mass dimension 4 terms in the gravity sector.Comment: 10 pages, matches published versio

Innovation and export portfolios

This paper examines the link between sectoral concentration and overall performance in the search for on-the-frontier innovations, inside-the-frontier innovations, and export booms. It extends the literature by increasing country coverage and the types of search processes considered, and by focusing on the links with overall performance in these search processes. After controlling for the necessary relationships as well as fixed effects at the country/commodity group level, the paper finds a clear negative relationship between the concentration of innovation portfolios and performance: countries that are the most successful in these search processes have their successes spread across a broader range of industries than those with poorer performance. Furthermore, the search for export booms exhibits the least amount of sectoral concentration and path-dependence. These findings suggest that public support for these processes need not be focused in a narrow range of sectors, and modeling of these processes in theoretical work, particularly in the search for export booms, should be of a stochastic flavor.Education for Development (superceded),Economic Theory&Research,Innovation,Achieving Shared Growth,Technology Industry

Diversification, innovation, and imitation inside the Global Technological Frontier

Recent research highlights the relationship between economic development and productive diversification, which may be hindered by market failures. After identifying stages of diversification in disaggregated export data, the authors develop a metric for the flows of export"discoveries,"or inside-the-frontier innovations in developing countries. They then explore the empirical relationship between economic development and (1) inside-the-frontier-innovation as reflected by the introduction of new export products, (2) export diversification measured by an index of export-revenue concentration, and (3) on-the-frontier innovation as reflected in patents. The data suggest, unsurprisingly, that inside-the-frontier innovation is more common among poor countries than among industrial economies. Overall export diversification increases at low levels of development but declines with development after a high-income point, whereas patenting activity rises exponentially with development. The data also suggest that the relationship between the frequency of export discoveries and economic development is not due to changes in the industrial composition of exports. The authors use a simple model of innovation and imitation to test the hypothesis that the threat of imitation inhibits the discovery of new exports. Econometric evidence suggests that the frequency of export discoveries across countries rises with the returns of export activities (proxied by exogenous export growth during the sample period), but the magnitude of this effect increases with barriers to entry. The count-data estimations deal with unobserved international heterogeneity, and the results are robust to various changes in the specification of the empirical model. This finding supports the hypothesisthat market failures inhibit inside-the-frontier innovation.Economic Theory&Research,Markets and Market Access,Water Resources Assessment,Achieving Shared Growth,Airports and Air Services

Discovery and development : an empricial exploration of"new"products

The authors use disaggregated export data to explore the relationship between economic discovery and economic development. They find that discoveries, or episodes, when countries begin exporting a new product are not limited to so-called"dynamic"industries. Rather, they also occur in traditional sectors such as agriculture. In addition, the data suggest discovery is a component of the stages of productive diversification that occur with development, following a consistent pattern-discovery activity peaks at the lower-middle income level and then declines. Based on this pattern, the authors show that discovery in the 1990s occurred with a higher than expected frequency in Eastern Europe and Central Asia, and lower than expected frequency in Sub-Saharan Africa. Discovery is not found to be a product of structural transformation based on changing factor endowments across income levels. Beyond export growth, population, and development, there are no significant and positive relationships between the expected drivers of entrepreneurship and the frequency of discovery. Combined with the finding that higher absorptive capacity and lower barriers to entry are associated with a reduction in discovery, this suggests that market failures arising from imitation and free-riding may be inhibiting the emergence of new export products in developing countries.Environmental Economics&Policies,Economic Theory&Research,Information Technology,Judicial System Reform,Labor Policies,Economic Theory&Research,Environmental Economics&Policies,Information Technology,Achieving Shared Growth,Airports and Air Services

Characterization of the PCMBS-dependent modification of KCa3.1 channel gating.

Intermediate conductance, calcium-activated potassium channels are gated by the binding of intracellular Ca(2+) to calmodulin, a Ca(2+)-binding protein that is constitutively associated with the C terminus of the channel. Although previous studies indicated that the pore-lining residues along the C-terminal portion of S6 contribute to the activation mechanism, little is known about whether the nonluminal face of S6 contributes to this process. Here we demonstrate that the sulfhydral reagent, parachloromercuribenze sulfonate (PCMBS), modifies an endogenous cysteine residue predicted to have a nonluminal orientation (Cys(276)) along the sixth transmembrane segment (S6). Modification of Cys(276) manipulates the steady-state and kinetic behavior of the channel by shifting the gating equilibrium toward the open state, resulting in a left shift in apparent Ca(2+) affinity and a slowing in the deactivation process. Using a six-state gating scheme, our analysis shows that PCMBS slows the transition between the open state back to the third closed state. Interpreting this result in the context of the steady-state and kinetic data suggests that PCMBS functions to shift the gating equilibrium toward the open state by disrupting channel closing. In an attempt to understand whether the nonluminal face of S6 participates in the activation mechanism, we conducted a partial tryptophan scan of this region. Substituting a tryptophan for Leu(281) recapitulated the effect on the steady-state and kinetic behavior observed with PCMBS. Considering the predicted nonluminal orientation of Cys(276) and Leu(281), a simple physical interpretation of these results is that the nonluminal face of S6 forms a critical interaction surface mediating the transition into the closed conformation, suggesting the nonluminal C-terminal portion of S6 is allosterically coupled to the activation gate

Land Grant Application- Bailey, Daniel (Woolwich)

Land grant application submitted to the Maine Land Office on behalf of Daniel Bailey for service in the Revolutionary War, by their widow Susanna.https://digitalmaine.com/revolutionary_war_me_land_office/1049/thumbnail.jp

We must defend public libraries from the threat of a market-based ideological framework

Since the global financial crash, public libraries in the UK have come under threat in the face of local government budget cuts. It is the logic of market values and profitability, rather than by a concern for inequalities, community and inclusive access to information and literature, which is the criteria upon which this area of public spending is being judged. Daniel Bailey argues that we should not apply the market logic to public libraries, but instead see them as an essential public good