Reducing the federal deficit: approaches in some other countries

The United States is not the first advanced modern economy to face a serious federal budget challenge. A number of countries have seen their debt rise to unacceptable levels in recent decades, and they have taken steps to rein it in. We explore the approaches that Canada and the United Kingdom have used. Though there are important differences in approaches and countries, we draw five useful lessons for the reforms that may be proposed in the U.S. as it addresses its fiscal challenges.Debts, Public - Canada ; Deficit financing ; Debt - United States ; Debts, Public - United Kingdom

Elliptic Rydberg states as direction indicators

The orientation in space of a Cartesian coordinate system can be indicated by the two vectorial constants of motion of a classical Keplerian orbit: the angular momentum and the Laplace-Runge-Lenz vector. In quantum mechanics, the states of a hydrogen atom that mimic classical elliptic orbits are the coherent states of the SO(4) rotation group.It is known how to produce these states experimentally. They have minimal dispersions of the two conserved vectors and can be used as direction indicators. We compare the fidelity of this transmission method with that of the idealized optimal method

Dark matter and U(1)' symmetry for the right-handed neutrinos

We consider a U(1)' gauge symmetry acting on three generations of right-handed neutrinos. The U(1)' symmetry is broken at the TeV scale and its remnant discrete symmetry makes one of the right-handed neutrinos stable. As a natural consequence of the anomaly cancellation, the neutrino mass matrix consists of a combination of Type I (TeV scale) seesaw and radiative correction. The stable right-handed neutrino communicates with the Standard Model via s-channel exchange of the Higgs field and the U(1)' gauge boson, so that the observed relic density for dark matter is obtained in a wide range of the parameter space. The experimental signatures in collider and other experiments are briefly discussed.Comment: 16 pages, 4 figure

On the spectrum of operator families on discrete groups over minimal dynamical systems

It is well known that, given an equivariant and continuous (in a suitable sense) family of selfadjoint operators in a Hilbert space over a minimal dynamical system, the spectrum of all operators from that family coincides. As shown recently similar results also hold for suitable families of non-selfadjoint operators in \ell^p (\ZM). Here, we generalize this to a large class of bounded linear operator families on Banach-space valued $\ell^p$-spaces over countable discrete groups. We also provide equality of the pseudospectra for operators in such a family. A main tool for our analysis are techniques from limit operator theory.Comment: minor revisio

Identifikation geschlechterspezifischer Mobilitätsbarrieren anhand drittvariablengestützter Mobilitätsverhaltensanalyse

Eine wesentliche Qualitätsanforderung an Smart Cities stellt die sozial nachhaltige Entwicklung der städtischen Infrastruktur dar. Insbesondere die Bereitstellung von Verkehrsinfrastrukturen und Mobilitätsangeboten ist auf bestehende Nutzerbedürfnisse auszurichten und unterliegt dadurch Anforderungen hoher Diversität. Schlüssel zu einer sozial nachhaltigen Mobilität ist die Sicherstellung einer hinreichenden Erreichbarkeit relevanter Ziele, wie Arbeitsplätzen, Bildungs- und Versorgungseinrichtungen oder Freizeitangeboten für alle Personengruppen. Personengruppen können in der Ausübung ihrer Mobilität jedoch durch gruppenspezifische Barrieren eingeschränkt werden. Für Menschen im Rollstuhl können beispielsweise Hochborde, Treppen oder nicht-barrierefreie ÖPNV-Zugangspunkte Barrieren bilden. Menschen mit Migrationshintergrund und begrenzten Deutschkenntnissen können hingegen durch deutschsprachige Fahrgastinformationen in Ihrer Mobilität beschränkt sein. Analog ist davon auszugehen, dass spezifische Barrieren bei der Realisierung geschlechterspezifischer Mobilitätsbedürfnisse vorliegen. Um Männer und Frauen gleichwertige Mobilitätschancen zu ermöglichen, müssen ihre jeweiligen Zugangsvoraussetzungen und Mobilitätsbedürfnisse erkannt und ihre spezifischen Barrieren identifiziert werden. Daher wurde am Institut für Stadtbauwesen und Stadtverkehr anhand der Mobilitätserhebung „Mobilität in Deutschland 2008“ eine umfassende Analyse des geschlechtsspezifischen Mobilitätsverhaltens durchgeführt. Die Analyse erfolgte in zwei aufeinander aufbauenden Stufen. In einer ersten Stufe wurde eine statistisch-deskriptive Analyse der Daten vorgenommen, in der unterschiedliche Mobilitätskennwerte untersucht wurden. Anschließend wurden die gewonnenen Ergebnisse in einer zweiten Stufe durch eine Drittvariablenkontrolle validiert. Anhand der Ergebnisse wurden Personengruppen identifiziert, für die geschlechtsspezifische Unterschiede im Mobilitätsverhalten deutlich stärker auftreten, als in der Gesamtstichprobe. Dabei handelte es sich um Personen, die in einem Haushalt mit Kindern bis 14 Jahren leben, Personen ohne Hochschulabschluss, Rentner und Pensionäre, sowie Personen mit moblitätseinschränkender Behinderung

The Scalability-Efficiency/Maintainability-Portability Trade-off in Simulation Software Engineering: Examples and a Preliminary Systematic Literature Review

Large-scale simulations play a central role in science and the industry. Several challenges occur when building simulation software, because simulations require complex software developed in a dynamic construction process. That is why simulation software engineering (SSE) is emerging lately as a research focus. The dichotomous trade-off between scalability and efficiency (SE) on the one hand and maintainability and portability (MP) on the other hand is one of the core challenges. We report on the SE/MP trade-off in the context of an ongoing systematic literature review (SLR). After characterizing the issue of the SE/MP trade-off using two examples from our own research, we (1) review the 33 identified articles that assess the trade-off, (2) summarize the proposed solutions for the trade-off, and (3) discuss the findings for SSE and future work. Overall, we see evidence for the SE/MP trade-off and first solution approaches. However, a strong empirical foundation has yet to be established; general quantitative metrics and methods supporting software developers in addressing the trade-off have to be developed. We foresee considerable future work in SSE across scientific communities.Comment: 9 pages, 2 figures. Accepted for presentation at the Fourth International Workshop on Software Engineering for High Performance Computing in Computational Science and Engineering (SEHPCCSE 2016

Vortex Dynamics and Hall Conductivity of Hard Core Bosons

Magneto-transport of hard core bosons (HCB) is studied using an XXZ quantum spin model representation, appropriately gauged on the torus to allow for an external magnetic field. We find strong lattice effects near half filling. An effective quantum mechanical description of the vortex degrees of freedom is derived. Using semiclassical and numerical analysis we compute the vortex hopping energy, which at half filling is close to magnitude of the boson hopping energy. The critical quantum melting density of the vortex lattice is estimated at 6.5x10-5 vortices per unit cell. The Hall conductance is computed from the Chern numbers of the low energy eigenstates. At zero temperature, it reverses sign abruptly at half filling. At precisely half filling, all eigenstates are doubly degenerate for any odd number of flux quanta. We prove the exact degeneracies on the torus by constructing an SU(2) algebra of point-group symmetries, associated with the center of vorticity. This result is interpreted as if each vortex carries an internal spin-half degree of freedom ('vspin'), which can manifest itself as a charge density modulation in its core. Our findings suggest interesting experimental implications for vortex motion of cold atoms in optical lattices, and magnet-transport of short coherence length superconductors.Comment: 15 pages, 15 figure

Transcriptomic-metabolomic reprogramming in EGFR-mutant NSCLC early adaptive drug escape linking TGFβ2-bioenergetics-mitochondrial priming.

The impact of EGFR-mutant NSCLC precision therapy is limited by acquired resistance despite initial excellent response. Classic studies of EGFR-mutant clinical resistance to precision therapy were based on tumor rebiopsies late during clinical tumor progression on therapy. Here, we characterized a novel non-mutational early adaptive drug-escape in EGFR-mutant lung tumor cells only days after therapy initiation, that is MET-independent. The drug-escape cell states were analyzed by integrated transcriptomic and metabolomics profiling uncovering a central role for autocrine TGFβ2 in mediating cellular plasticity through profound cellular adaptive Omics reprogramming, with common mechanistic link to prosurvival mitochondrial priming. Cells undergoing early adaptive drug escape are in proliferative-metabolic quiescent, with enhanced EMT-ness and stem cell signaling, exhibiting global bioenergetics suppression including reverse Warburg, and are susceptible to glutamine deprivation and TGFβ2 inhibition. Our study further supports a preemptive therapeutic targeting of bioenergetics and mitochondrial priming to impact early drug-escape emergence using EGFR precision inhibitor combined with broad BH3-mimetic to interrupt BCL-2/BCL-xL together, but not BCL-2 alone

Highly sensitive quantitative PCR for the detection and differentiation of Pseudogymnoascus destructans and other Pseudogymnoascus species

White-nose syndrome is a fungal disease that has decimated bat populations across eastern North America. Identification of the etiologic agent, Pseudogymnoascus destructans (formerly Geomyces destructans), in environmental samples is essential to proposed management plans. A major challenge is the presence of closely related species, which are ubiquitous in many soils and cave sediments and often present in high abundance. We present a dual-probe real-time quantitative PCR assay capable of detecting and differentiating P. destructans from closely related fungi in environmental samples from North America. The assay, based on a single nucleotide polymorphism (SNP) specific to P. destructans, is capable of rapid low-level detection from various sampling media, including sediment, fecal samples, wing biopsy specimens, and skin swabs. This method is a highly sensitive, high-throughput method for identifying P. destructans, other Pseudogymnoascus spp., and Geomyces spp. in the environment, providing a fundamental component of research and risk assessment for addressing this disease, as well as other ecological and mycological work on related fungi

On ionisation effects and abundance ratios in damped Lyman-alpha systems

The similarity between observed velocity structures of Al III and singly ionised species in damped Lyman-alpha systems (DLAs) suggests the presence of ionised gas in the regions where most metal absorption lines are formed. To explore the possible implications of ionisation effects we construct a simplified two-region model for DLAs consisting of an ionisation bounded region with an internal radiation field and a neutral region with a lower metal content. Within this framework we find that ionisation effects are important. If taken into account, the element abundance ratios in DLAs are quite consistent with those observed in Milky Way stars and in metal-poor H II regions in blue compact dwarf galaxies. In particular we cannot exclude the same primary N origin in both DLAs and metal-poor galaxies. From our models no dust depletion of heavy elements needs to be invoked; little depletion is however not excluded.Comment: to appear in "Evolution of Galaxies. I. Observational clues", Eds. J.M. Vilchez, G. Stasinska, Astrophysics and Space Science, in press. 5 pages, including 3 figure