Radiation reaction at 3.5 post-Newtonian order in effective field theory

We derive the radiation reaction forces on a compact binary inspiral through 3.5 order in the post-Newtonian expansion using the effective field theory approach. We utilize a recent formulation of Hamilton’s variational principle that rigorously extends the usual Lagrangian and Hamiltonian formalisms to dissipative systems, including the inspiral of a compact binary from the emission of gravitational waves. We find agreement with previous results, which thus provides a non-trivial confirmation of the extended variational principle. The results from this work nearly complete the equations of motion for the generic inspiral of a compact binary with spinning constituents through 3.5 post-Newtonian order, as derived entirely with effective field theory, with only the spin-orbit corrections to the potential at 3.5 post-Newtonian remaining

Reply to "Comment on 'Finite size corrections to the radiation reaction force in classical electrodynamics'"

We reply to P. Forg\'acs, T. Herpay, and P. Kov\'acs (arXiv: 1202.6289).Comment: 1 page. To be published in Physical Review Letter

Probing a Secluded U(1) at B-factories

A secluded U(1) gauge field, kinetically mixed with Standard Model hypercharge, provides a `portal' mediating interactions with a hidden sector at the renormalizable level, as recently exploited in the context of WIMP dark matter. The secluded U(1) symmetry-breaking scale may naturally be suppressed relative to the weak scale, and so this sector is efficiently probed by medium energy electron-positron colliders. We study the collider signatures of the minimal secluded U(1) model, focusing on the reach of B-factory experiments such as BaBar and BELLE. In particular, we show that Higgs-strahlung in the secluded sector can lead to multi-lepton signatures which probe the natural range for the kinetic mixing angle of 10^(-2)-10^(-3) over a large portion of the kinematically accessible parameter space.Comment: 14 pages, 3 figure

Proposed Keystone XL Pipeline: Legal Issues

[Excerpt] In 2008, TransCanada Corp. applied for a presidential permit from the State Department to construct and operate an oil pipeline across the U.S.-Canada border in a project known as Keystone XL. The Keystone XL pipeline would transport oil produced from oil sands in Alberta,Canada, to Gulf Coast refineries. The permit application was subjected to review by the State Department pursuant to executive branch authority over cross-border pipeline facilities as articulated in Executive Order 13337. After several phases of review, on November 10, 2011, the State Department announced that it would seek additional information about alternative pipeline routes before it could move forward with a national interest determination. In response, several pieces of legislation were introduced, including Title V of the Temporary Payroll Tax Cut Continuation Act of 2011. Title V dictated that President must grant the Keystone XL pipeline permit within 60 days of the law’s enactment, unless the President determined that the pipeline is not in the national interest. If the President did not make a national interest determination and took no action to grant the permit, then the law provided that the permit “shall be in effect by operation of law.” The Temporary Payroll Tax Cut Continuation Act of 2011 (P.L. 112-78), including Title V addressing the Keystone XL permit, was enacted on December 23, 2011. Pursuant to the requirements of Title V, on January 18, 2012, the State Department recommended that “the presidential permit for the proposed Keystone XL pipeline be denied and, that at this time, the TransCanada Keystone XL Pipeline be determined not to serve the national interest. ”The same day, the President stated his determination that the Keystone XL pipeline project“ would not serve the national interest. ”New legislative activity with respect to the permitting of border-crossing facilities, a subject previously handled exclusively by the executive branch, has triggered inquiries as to whether this raises constitutional issues related to the jurisdiction of the two branches over such facilities. Additionally, as states have begun to contemplate taking action with respect to the pipeline siting, some have questioned whether state siting of a pipeline is preempted by federal law. Others argue that states dictating the route of the pipeline violates the dormant Commerce Clause of the Constitution which, among other things, prohibits one state from acting to protect its own interests to the detriment of other states. This report reviews those legal issues. First, it suggests that legislation related to cross-border facility permitting is unlikely to raise significant constitutional questions, despite the fact that such permits have traditionally been handled by the executive branch alone pursuant to its constitutional “foreign affairs” authority. Next, it observes generally that state oversight of pipeline siting decisions does not appear to violate existing federal law or the Constitution. Finally, the report suggests that State Department’s implementation of the existing authority to issue presidential permits appears to allow for judicial review of its National Environmental Policy Act determinations

Studies on the distribution and excretion of mercury, gold, and lead under the influence of dithiols

l. Studies have been made of the distribution and excretion of mercury, gold and lead, in rabbits, without and with treatment with dithiols The method involves the use of radio- active isotopes of these elements.2. MERCURY. After the intravenous injection of 5μM. /kg. of mercuric chloride, the highest concentrations of mercury were found in the kidneys. Of the other tissues, only the liver contained more than one microgramme of mercury per gramme consistently. The excretion of mercury was slow and accounted for only two-thirds of the dose after two weeks, occurring mainly in the urine.After treatment with dimercaprol, much smaller amounts of mercury were found in the kidneys. The excretion of mercury in the urine was greatly enhanced, but the faecal excretion was unaffected. These changes were found even when treatment was delayed until nine days after poisoning.Similar changes occurred after the administration of dimercaprol glucoside, except that the concentrations of mercury in the plasma, and the biliary excretion, increased. The urinary excretion of mercury was less than that obtained after treatment with dimercaprol.3. GOLD. After the intravenous injection of 0.01mó./ kg. of gold chloride, high concentrations of gold were found in the spleen, kidneys, plasma, bone marrow, liver and bile. Excretion occurred very slowly, about one -fifth of the dose being eliminated in the urine and faeces in five days.After treatment with dimercaprol, the concentrations of gold in the blood were reduced and the urinary and biliary excretion increased. No substantial change occurred in the amounts of gold found in other tissues, or in the faecal excretion.4. LEAD. High concentrations of lead were found in the liver, spleen, bone marrow, epiphyses, and kidneys, twenty -four hours after the intravenous injection of 0.01mM./kg. of lead acetate. Only 1-4 per cent of the dose was excreted in the urine in this period.After the administration of dimercaprol glucoside, the quantities of lead in the liver and blood cells decreased. This was accompanied by increased urinary and biliary excretion of lead.5. Both dimercaprol and dimercaprol glucoside increased the urinary excretion of lead after the injection of O.1mM./kg. of lead acetate, and were approximately equally effective.6. After the intravenous injection of 0.01mM./kg. of lead acetate, treatment with 1:4-dithioerythritol slightly, and with 1:3- dimercaptopropanol greatly, increased the urinary excretion of lead.7. Twenty -one days after the intravenous injection of 0.01mM./kg. of lead acetate, about 50 per cent of the dose had been excreted, predominantly in the faeces, and the bones contained about 25 per cent of the dose. The bone marrow and the liver were the only other tissues which consistently contained more than 1 per cent.Treatment with dimercaprol or parathyroid extract or both, caused no substantial change in - the distribution or the excretion of lead, apart from a transient increase in the urinary excretion after dimercaprol.8. The method and the significance of these results are discussed

The tail effect in gravitational radiation-reaction: time non-locality and renormalization group evolution

We use the effective field theory (EFT) framework to calculate the tail effect in gravitational radiation reaction, which enters at 4PN order in the dynamics of a binary system. The computation entails a subtle interplay between the near (or potential) and far (or radiation) zones. In particular, we find that the tail contribution to the effective action is non-local in time, and features both a dissipative and a `conservative' term. The latter includes a logarithmic ultraviolet (UV) divergence, which we show cancels against an infrared (IR) singularity found in the (conservative) near zone. The origin of this behavior in the long-distance EFT is due to the point-particle limit -shrinking the binary to a point- which transforms a would-be infrared singularity into an ultraviolet divergence. This is a common occurrence in an EFT approach, which furthermore allows us to use renormalization group (RG) techniques to resum the resulting logarithmic contributions. We then derive the RG evolution for the binding potential and total mass/energy, and find agreement with the results obtained imposing the conservation of the (pseudo) stress-energy tensor in the radiation theory. While the calculation of the leading tail contribution to the effective action involves only one diagram, five are needed for the one-point function. This suggests logarithmic corrections may be easier to incorporate in this fashion. We conclude with a few remarks on the nature of these IR/UV singularities, the (lack of) ambiguities recently discussed in the literature, and the completeness of the analytic Post-Newtonian framework.Comment: 24 pages. 3 figures. v2: Extended discussion on the nature of IR/UV singularities. Published versio

Diagnostic and therapeutic considerations in idiopathic hypereosinophilia with warm autoimmune hemolytic anemia.

Hypereosinophilic syndrome (HES) encompasses numerous diverse conditions resulting in peripheral hypereosinophilia that cannot be explained by hypersensitivity, infection, or atopy and that is not associated with known systemic diseases with specific organ involvement. HES is often attributed to neoplastic or reactive causes, such as chronic eosinophilic leukemia, although a majority of cases remains unexplained and are considered idiopathic. Here, we review the current diagnosis and management of HES and present a unique case of profound hypereosinophilia associated with warm autoimmune hemolytic anemia requiring intensive management. This case clearly illustrates the limitations of current knowledge with respect to hypereosinophilia syndrome as well as the challenges associated with its classification and management

The C-terminal portion of the cleaved HT motif is necessary and sufficient to mediate export of proteins from the malaria parasite into its host cell

The malaria parasite exports proteins across its plasma membrane and a surrounding parasitophorous vacuole membrane, into its host erythrocyte. Most exported proteins contain a Host Targeting motif (HT motif) that targets them for export. In the parasite secretory pathway, the HT motif is cleaved by the protease plasmepsin V, but the role of the newly generated N-terminal sequence in protein export is unclear. Using a model protein that is cleaved by an exogenous viral protease, we show that the new N-terminal sequence, normally generated by plasmepsin V cleavage, is sufficient to target a protein for export, and that cleavage by plasmepsin V is not coupled directly to the transfer of a protein to the next component in the export pathway. Mutation of the fourth and fifth positions of the HT motif, as well as amino acids further downstream, block or affect the efficiency of protein export indicating that this region is necessary for efficient export. We also show that the fifth position of the HT motif is important for plasmepsin V cleavage. Our results indicate that plasmepsin V cleavage is required to generate a new N-terminal sequence that is necessary and sufficient to mediate protein export by the malaria parasite