B_K in Staggered Chiral Perturbation Theory

We calculate the kaon B-parameter, B_K, to next-to-leading order in staggered chiral perturbation theory. We find expressions for partially quenched QCD with three sea quarks, quenched QCD, and full QCD with m_u = m_d but not equal to m_s. We extend the usual power counting to include the effects of using perturbative (rather than non-perturbative) matching factors. Taste breaking enters through the O(a^2) terms in the effective action, through O(a^2) terms from the discretization of operators, and through the truncation of matching factors. These effects cause mixing with several additional operators, complicating the chiral and continuum extrapolations. In addition to the staggered expressions, we present B_K at next-to-leading order in continuum partially quenched chiral perturbation theory for N_f=3 sea quarks with m_u = m_d but not equal to m_s.Comment: 56 pages, 3 figures (v3: Corrected normalization error in Eq.(4) and subsequent equations; physics results unchanged. Version accepted to Phys. Rev. D.

SHELL-BASED EXPERT SYSTEMS IN BUSINESS: A RETURN ON INVESTMENT PERSPECTIVE

This paper examines an important issue emerging in information systems management--the decision to proceed with an expert system application in a business setting. The focus is knowledge based systems at the lower end of the complexity spectrum--small, very focused systems that can be implemented by the use of shell-based development environments. This group represents the majority of expert systems that are currently being implemented and has some characteristics quite different from the larger systems. A classification scheme is suggested to differentiate three levels of ES development, from multi-million dollar life cycle cost ES environments to those that are in the low five figure range. The Low End segment of the range, the focus of this paper, is characterized by lower unit costs, powerful development tools and a large number of small, successful applications. The important role of Low End systems is discussed, with particular emphasis on their relatively high yield in standalone applications. Such systems do not meet the AI demands of moderately or very complex problems but there is a surprising breadth in their use. A group of key success factors for Low End systems is proposed, based on a synthesis of the applications literature. To operationalize these factors, three actual cases using Low End technology--from marketing, government and agribusiness-- are briefly described. Low End systems are not all gain. Their low unit costs can often mask the risks of proceeding headlong into an application without careful examination of the variables that can predict successful results. An agenda for action is offered for specific management policies for the planning of knowledge-based applications

Stereochemical studies on protonated bridgehead amines. ^1H NMR determination of cis and trans B-C ring-fused structures for salts of hexahydropyrrolo [2,1-a] isoquinolines and related C ring homologs. Capture of unstable ring-fused structures in the solid state

Acid-addition salts of tricyclic isoquinolines 2a/b, 3a/b, 4a-4c, 5, 6a/b, 7, 8a/b, 9a/b, and 17a/b were studied by high-field ^1H NMR in CDCl_3 solution. Cis (e.g., 14 and 15 in Figure 1) and trans (e.g., 13)B-C ring-fused structures were identified by using the vicinal ^3J(CH-NH) coupling constants, which demonstrate a Karplus-like behavior. In some cases, we initially observed a trans form, which converted to a cis A form by N H proton exchange. For 4c.HBr, the exchange process was slowed by addition of trifluoroacetic acid. In many cases, cis A and cis B structures were preferred in solution. The pendant phenyl group exerted a strong influence on the preferred solution structure. Observation of the initial, unstable trans-fused structures was related to their capture in the solid state and release intact on dissolution. X-ray diffraction was performed on the HBr salts of 2a (B-C cis), 2b (B-C cis), and 4c (B-C trans). The result for 4c.HBr confirmed the connection between the initial trans form in solution and the solid state. For 17b.HCI two conformers, associated with hindered rotation about the bond connecting the 2,6-disubstituted phenyl group to the tricyclic array, were detected at ambient probe temperature; however, rotamers were not observed for either of the two forms (trans and cis A) of 17a.HBr. Two conformers were also found for 16b.HBr. Temperature-dependent behavior was recorded in the ^1H NMR spectra of 17b.HBr and 16b.HBr; the activation free energy for interconversion of conformers was estimated to be in the vicinity of 17 kcal/mol for the former and 14-15 kcal/mol for the latter. The ^1H NMR spectrum of butaclamol hydrochloride (20.HC1), a potent neuroleptic agent, in Me_2SO-d_6 revealed two species in a ratio of 81:19, which were assigned as trans and cis A forms, respectively. ^1H NMR data for various free bases are also presented and discussed. Empirical force field calculations on three model hydrocarbons are discussed from a perspective of finding an explanation for the configurational/conformational behavior of the bridgehead ammonium salts. Diverse literature examples of structures for protonated bridgehead amines are also discussed. A tentative rationale is suggested for the preference of cis A forms in some protonated tetrahydroisoquinoline derivatives

Staggered Chiral Perturbation Theory at Next-to-Leading Order

We study taste and Euclidean rotational symmetry violation for staggered fermions at nonzero lattice spacing using staggered chiral perturbation theory. We extend the staggered chiral Lagrangian to O(a^2 p^2), O(a^4) and O(a^2 m), the orders necessary for a full next-to-leading order calculation of pseudo-Goldstone boson masses and decay constants including analytic terms. We then calculate a number of SO(4) taste-breaking quantities, which involve only a small subset of these NLO operators. We predict relationships between SO(4) taste-breaking splittings in masses, pseudoscalar decay constants, and dispersion relations. We also find predictions for a few quantities that are not SO(4) breaking. All these results hold also for theories in which the fourth-root of the fermionic determinant is taken to reduce the number of quark tastes; testing them will therefore provide evidence for or against the validity of this trick.Comment: 39 pages, 6 figures (v3: corrected technical error in enumeration of a subset of NLO operators; final conclusions unchanged

Bankfull Hydraulic Geometry Relationships for the Inner and Outer Bluegrass Regions of Kentucky

Bankfull hydraulic geometry relationships relate bankfull stream dimensions, such as cross-sectional area, width, mean depth, mean velocity, width to depth ratio, and slope to bankfull discharge. These relationships can assist in determining a design discharge for stream restoration and management projects. This study assessed 27 stable streams located in the Inner Bluegrass and Outer Bluegrass regions of Kentucky. Reaches were selected based on the presence of a U.S. Geological Survey gage, as well as other conditions such as presence of readily identifiable bankfull indicators, stability indices, and site accessibility. Bankfull channel dimensions and discharges were determined, and hydraulic geometry relationships were developed for both the Inner Bluegrass and Outer Bluegrass regions. These scaling relationships for karst-influenced streams were similar to others reported in the literature for non-karst areas. Significant differences between the regions were found only for bankfull width and width-to-depth ratio. Streams in the Inner Bluegrass tended to be more narrow and deep at bankfull discharges less than 10 m3s−1 and wider and shallower at bankfull discharges greater than 20 m3s−1 as compared to stream in the Outer Bluegrass. It is suspected that physiographic conditions related to local geology and/or riparian vegetation at three sites in the Outer Bluegrass accounted for these differences. Results of this study indicate that in instances of geologic variation within a physiographic region, hydraulic geometry relationships may require evaluation at the watershed scale

Lineage A betacoronavirus NS2 proteins and the homologous torovirus Berne pp1a carboxy-terminal domain are phosphodiesterases that antagonize activation of RNase L

Viruses in the family Coronaviridae, within the order Nidovirales, are etiologic agents of a range of human and animal diseases, including both mild and severe respiratory diseases in humans. These viruses encode conserved replicase and structural proteins as well as more diverse accessory proteins, encoded in the 3′ ends of their genomes, that often act as host cell antagonists. We previously showed that 2′,5′-phosphodiesterases (2′,5′-PDEs) encoded by the prototypical Betacoronavirus, mouse hepatitis virus (MHV), and by Middle East respiratory syndrome-associated coronavirus antagonize the oligoadenylate-RNase L (OAS-RNase L) pathway. Here we report that additional coronavirus superfamily members, including lineage A betacoronaviruses and toroviruses infecting both humans and animals, encode 2′,5′-PDEs capable of antagonizing RNase L. We used a chimeric MHV system (MHV(Mut)) in which exogenous PDEs were expressed from an MHV backbone lacking the gene for a functional NS2 protein, the endogenous RNase L antagonist. With this system, we found that 2′,5′-PDEs encoded by the human coronavirus HCoV-OC43 (OC43; an agent of the common cold), human enteric coronavirus (HECoV), equine coronavirus (ECoV), and equine torovirus Berne (BEV) are enzymatically active, rescue replication of MHV(Mut) in bone marrow-derived macrophages, and inhibit RNase L-mediated rRNA degradation in these cells. Additionally, PDEs encoded by OC43 and BEV rescue MHV(Mut) replication and restore pathogenesis in wild-type (WT) B6 mice. This finding expands the range of viruses known to encode antagonists of the potent OAS-RNase L antiviral pathway, highlighting its importance in a range of species as well as the selective pressures exerted on viruses to antagonize it. IMPORTANCE Viruses in the family Coronaviridae include important human and animal pathogens, including the recently emerged viruses severe acute respiratory syndrome-associated coronavirus (SARS-CoV) and Middle East respiratory syndrome-associated coronavirus (MERS-CoV). We showed previously that two viruses within the genus Betacoronavirus, mouse hepatitis virus (MHV) and MERS-CoV, encode 2′,5′-phosphodiesterases (2′,5′-PDEs) that antagonize the OAS-RNase L pathway, and we report here that these proteins are furthermore conserved among additional coronavirus superfamily members, including lineage A betacoronaviruses and toroviruses, suggesting that they may play critical roles in pathogenesis. As there are no licensed vaccines or effective antivirals against human coronaviruses and few against those infecting animals, identifying viral proteins contributing to virulence can inform therapeutic development. Thus, this work demonstrates that a potent antagonist of host antiviral defenses is encoded by multiple and diverse viruses within the family Coronaviridae, presenting a possible broad-spectrum therapeutic target

Opportunities for lattice QCD in quark and lepton flavor physics

This document is one of a series of whitepapers from the USQCD collaboration. Here, we discuss opportunities for lattice QCD in quark and lepton flavor physics. New data generated at Belle II, LHCb, BES III, NA62, KOTO, and Fermilab E989, combined with precise calculations of the relevant hadronic physics, may reveal what lies beyond the Standard Model. We outline a path toward improvements of the precision of existing lattice-QCD calculations and discuss groundbreaking new methods that allow lattice QCD to access new observables.Comment: USQCD whitepape

Mammographic breast density refines Tyrer-Cuzick estimates of breast cancer risk in high-risk women: findings from the placebo arm of the International Breast Cancer Intervention Study I

Introduction: Mammographic density is well-established as a risk factor for breast cancer, however, adjustment for age and body mass index (BMI) is vital to its clinical interpretation when assessing individual risk. In this paper we develop a model to adjust mammographic density for age and BMI and show how this adjusted mammographic density measure might be used with existing risk prediction models to identify high-risk women more precisely. Methods: We explored the association between age, BMI, visually assessed percent dense area and breast cancer risk in a nested case-control study of women from the placebo arm of the International Breast Cancer Intervention Study I (72 cases, 486 controls). Linear regression was used to adjust mammographic density for age and BMI. This adjusted measure was evaluated in a multivariable logistic regression model that included the Tyrer-Cuzick (TC) risk score, which is based on classical breast cancer risk factors. Results: Percent dense area adjusted for age and BMI (the density residual) was a stronger measure of breast cancer risk than unadjusted percent dense area (odds ratio per standard deviation 1.55 versus 1.38; area under the curve (AUC) 0.62 versus 0.59). Furthermore, in this population at increased risk of breast cancer, the density residual added information beyond that obtained from the TC model alone, with the AUC for the model containing both TC risk and density residual being 0.62 compared to 0.51 for the model containing TC risk alone (P =0.002). Approximately 16% of controls and 19% of cases moved into the highest risk group (8% or more absolute risk of developing breast cancer within 10 years) when the density residual was taken into account. The net reclassification index was +15.7%. Conclusions: In women at high risk of breast cancer, adjusting percent mammographic density for age and BMI provides additional predictive information to the TC risk score, which already incorporates BMI, age, family history and other classic breast cancer risk factors. Furthermore, simple selection criteria can be developed using mammographic density, age and BMI to identify women at increased risk in a clinical setting