Classical-Quantum Mixing in the Random 2-Satisfiability Problem

Classical satisfiability (SAT) and quantum satisfiability (QSAT) are complete problems for the complexity classes NP and QMA which are believed to be intractable for classical and quantum computers, respectively. Statistical ensembles of instances of these problems have been studied previously in an attempt to elucidate their typical, as opposed to worst case, behavior. In this paper we introduce a new statistical ensemble that interpolates between classical and quantum. For the simplest 2-SAT/2-QSAT ensemble we find the exact boundary that separates SAT and UNSAT instances. We do so by establishing coincident lower and upper bounds, in the limit of large instances, on the extent of the UNSAT and SAT regions, respectively.Comment: Updated reference

Improved determination of hadron matrix elements using the variational method

The extraction of hadron form factors in lattice QCD using the standard two- and three-point correlator functions has its limitations. One of the most commonly studied sources of systematic error is excited state contamination, which occurs when correlators are contaminated with results from higher energy excitations. We apply the variational method to calculate the axial vector current gA and compare the results to the more commonly used summation and two-exponential fit methods. The results demonstrate that the variational approach offers a more efficient and robust method for the determination of nucleon matrix elements.Comment: 7 pages, 6 figures, talk presented at Lattice 2015, PoS (LATTICE2015

Specializations of Iterated Galois Groups of PCF Rational Functions

We obtain a criterion for when the specialization of the iterated Galois group for a post-critically finite (PCF) rational map is as large as possible, i.e., it equals the generic iterated Galois group for the given map

New oral anticoagulants and their reversal agents

Atrial fibrillation is a commonly encountered pathology in medical practice, and its prevalence has shown a continuous rise over the past years. Atrial fibrillation has a significant impact on patients\u27 quality of life, not only due to the standard anticoagulant treatment with vitamin K antagonists that require close monitoring and dose adjustment, but also due to the fragile equilibrium between hemorrhagic and thrombotic risks. The introduction of new oral anticoagulants (NOACs) in the treatment guidelines for atrial fibrillation has improved the quality of life, as NOACs do not require close monitoring or dose adjustments. However, even if the safety profile of the NOACs regarding the hemorrhagic risk is superior to vitamin K antagonists, the problem raised by an unexpected hemorrhage (e.g. severe hemorrhage after an accident) and the need for efficient hemostasis in a chronic anticoagulated patient has remained unsolved. To find a solution for this problem, reversal agents for NOACs have been developed and tested, and two of them, idarucizumab and andexanet-alpha, have already been approved by the FDA, thus making NOACs increasingly appealing as a choice of anticoagulation treatment

Provenance and Paleogeography of the 25-17 Ma Rainbow Gardens Formation: Evidence for Tectonic Activity at Ca. 19 Ma and Internal Drainage rather than Throughgoing Paleorivers on the Southwestern Colorado Plateau

The paleogeographic evolution of the Lake Mead region of southern Nevada and northwest Arizona is crucial to understanding the geologic history of the U.S. Southwest, including the evolution of the Colorado Plateau and formation of the Grand Canyon. The ca. 25–17 Ma Rainbow Gardens Formation in the Lake Mead region, the informally named, roughly coeval Jean Conglomerate, and the ca. 24–19 Ma Buck and Doe Conglomerate southeast of Lake Mead hold the only stratigraphic evidence for the Cenozoic pre-extensional geology and paleogeography of this area. Building on prior work, we present new sedimentologic and stratigraphic data, including sandstone provenance and detrital zircon data, to create a more detailed paleogeographic picture of the Lake Mead, Grand Wash Trough, and Hualapai Plateau region from 25 to 18 Ma. These data confirm that sediment was sourced primarily from Paleozoic strata exposed in surrounding Sevier and Laramide uplifts and active volcanic fields to the north. In addition, a distinctive signal of coarse sediment derived from Proterozoic crystalline basement first appeared in the southwestern corner of the basin ca. 25 Ma at the beginning of Rainbow Gardens Formation deposition and then prograded north and east ca. 19 Ma across the southern half of the basin. Regional thermochronologic data suggest that Cretaceous deposits likely blanketed the Lake Mead region by the end of Sevier thrusting. Post-Laramide northward cliff retreat off the Kingman/Mogollon uplifts left a stepped erosion surface with progressively younger strata preserved northward, on which Rainbow Gardens Formation strata were deposited. Deposition of the Rainbow Gardens Formation in general and the 19 Ma progradational pulse in particular may reflect tectonic uplift events just prior to onset of rapid extension at 17 Ma, as supported by both thermochronology and sedimentary data. Data presented here negate the California and Arizona River hypotheses for an “old” Grand Canyon and also negate models wherein the Rainbow Gardens Formation was the depocenter for a 25–18 Ma Little Colorado paleoriver flowing west through East Kaibab paleocanyons. Instead, provenance and paleocurrent data suggest local to regional sources for deposition of the Rainbow Gardens Formation atop a stripped low-relief western Colorado Plateau surface and preclude any significant input from a regional throughgoing paleoriver entering the basin from the east or northeast

Universal behaviour of ideal and interacting quantum gases in two dimensions

I discuss ideal and interacting quantum gases obeying general fractional exclusion statistics. For systems with constant density of single-particle states, described in the mean field approximation, the entropy depends neither on the microscopic exclusion statistics, nor on the interaction. Such systems are called {\em thermodynamically equivalent} and I show that the microscopic reason for this equivalence is a one-to-one correspondence between the excited states of these systems. This provides a method, different from the bosonisation technique, to transform between systems of different exclusion statistics. In the last section the macroscopic aspects of this method are discussed. In Appendix A I calculate the fluctuation of the ground state population of a condensed Bose gas in grandcanonical ensemble and mean field approximation, while in Appendix B I show a situation where although the system exhibits fractional exclusion properties on microscopic energy intervals, a rigorous calculation of the population of single particle states reveals a condensation phenomenon. This also implies a malfunction of the usual and simplified calculation technique of the most probable statistical distributions.Comment: About 14 journal pages, with 1 figure. Changes: Body of paper: same content, with slight rephrasing. Apendices are new. In the original submission I just mentioned the condensation, which is now detailed in Appendix B. They were intended for a separate paper. Reason for changes: rejection from Phys. Rev. Lett., resubmission to J. Phys. A: Math. Ge

Connectivity Among Populations of the Top Shell Gibbula divaricata in the Adriatic Sea

Genetic connectivity studies are essential to understand species diversity and genetic structure and to assess the role of potential factors affecting connectivity, thus enabling sound management and conservation strategies. Here, we analyzed the patterns of genetic variability in the marine snail Gibbula divaricata from five coastal locations in the central-south Adriatic Sea (central Mediterranean) and one in the adjacent northern Ionian Sea, using 21 described polymorphic microsatellite loci. Observed and expected heterozygosity varied from 0.582 to 0.635 and 0.684 to 0.780, respectively. AMOVA analyses showed that 97% of genetic variation was observed within populations. Nevertheless, significant, although small, genetic differentiation was found among nearly all of the pairwise FST comparisons. Over a general pattern of panmixia, three groups of populations were identified: eastern Adriatic populations, western Adriatic populations, and a third group represented by the single northern Ionian Sea population. Nonetheless, migration and gene flow were significant between these groups. Gibbula divaricata is thought to have a limited dispersal capacity related to its lecithotrophic trochophore larval stage. Our results indicated high levels of self-recruitment and gene flow that is mainly driven through coastline dispersion, with populations separated by the lack of suitable habitats or deep waters. This stepping-stone mode of dispersion together with the high levels of self-recruitment could lead to higher levels of population structuring and differentiation along the Adriatic Sea. Large effective population sizes and episodic events of long-distance dispersal might be responsible for the weak differentiation observed in the analyzed populations. In summary, the circulation system operating in this region creates natural barriers for dispersion that, together with life-history traits and habitat requirements, certainly affect connectivity in G. divaricata. However, this scenario of potential differentiation seems to be overridden by sporadic events of long-distance dispersal across barriers and large effective population sizes

Age and growth rate dynamics of an old African baobab determined by radiocarbon dating

Author Posting. © Arizona Board of Regents on behalf of the University of Arizona, 2010. This article is posted here by permission of Dept. of Geosciences, University of Arizona for personal use, not for redistribution. The definitive version was published in Radiocarbon 52 (2010): 727-734.In 2008, a large African baobab (Adansonia digitata L.) from Makulu Makete, South Africa, split vertically into 2 sections, revealing a large enclosed cavity. Several wood samples collected from the cavity were processed and radiocarbon dated by accelerator mass spectrometry (AMS) for determining the age and growth rate dynamics of the tree. The 14C date of the oldest sample was found to be of 1016 ± 22 BP, which corresponds to a calibrated age of 1000 ± 15 yr. Thus, the Makulu Makete tree, which eventually collapsed to the ground and died, becomes the second oldest African baobab dated accurately to at least 1000 yr. The conventional growth rate of the trunk, estimated by the radial increase, declined gradually over its life cycle. However, the growth rate expressed more adequately by the cross-sectional area increase and by the volume increase accelerated up to the age of 650 yr and remained almost constant over the past 450 yr.This material is based on work supported by a grant from the Romanian National University Research Council (PN II - IDEI 2354 Nr. 1092) and by US National Science Foundation under Cooperative Agreement OCE-022828996