Exploring CP Violation and η\eta-η′\eta' Mixing with the Bs,d0→J/ψη(′)B^0_{s,d} \to J/\psi \eta^{(\prime)} Systems

The $B^0_{s,d} \to J/\psi \eta^{(\prime)}$ decays provide new terrain for exploring CP violation. After briefly discussing $\eta$-$\eta'$ mixing, we analyse the effective lifetimes and CP-violating observables of the $B_s$ channels, which allow us to probe New-Physics effects in $B^0_s$-$\bar B^0_s$ mixing. We have a critical look at these observables and show how hadronic corrections can be controlled by means of the $B_d$ decays. Using measurements of the $B^0_{s,d}\to J/\psi \eta^{(\prime)}$ branching ratios by the Belle collaboration, we discuss tests of the $SU(3)_F$ flavour symmetry of strong interactions, obtain the first constraints on the hadronic parameters entering the $B^0_{s,d} \to J/\psi \eta$ system, and predict the $B^0_d\to J/\psi \eta'$ branching ratio at the $5\times10^{-6}$ level. Furthermore, we present strategies for the determination of the $\eta$-$\eta'$ mixing parameters from the $B^0_{s,d} \to J/\psi \eta^{(\prime)}$ observables. We also observe that the $B^0_{s,d} \to J/\psi \eta$ and $B^0_{s,d} \to J/\psi \eta'$ decays are - from a formal point of view - analogous to the quark-antiquark and tetraquark descriptions of the $f_0(980)$ in the $B^0_{s,d} \to J/\psi f_0(980)$ channels, respectively.Comment: 17 pages, 3 figure

Anatomy of Bs,d0→J/ψf0(980)B^0_{s,d} \to J/\psi f_0(980)

The $B^0_s\to J/\psi f_0(980)$ decay offers an interesting experimental alternative to the well-known $B^0_s\to J/\psi \phi$ channel for the search of CP-violating New-Physics contributions to $B^0_s$--$\bar B^0_s$ mixing. As the hadronic structure of the $f_0(980)$ has not yet been settled, we take a critical look at the implications for the relevant observables and address recent experimental data. It turns out that the effective lifetime of $B^0_s\to J/\psi f_0(980)$ and its mixing-induced CP asymmetry $S$ are quite robust with respect to hadronic effects and thereby allow us to search for a large CP-violating $B^0_s$--$\bar B^0_s$ mixing phase $\phi_s$, which is tiny in the Standard Model. However, should small CP violation, i.e. in the range -0.1\lsim S\lsim 0, be found in $B^0_s\to J/\psi f_0(980)$, it will be crucial to constrain hadronic corrections in order to distinguish possible New-Physics effects from the Standard Model. We point out that $B^0_d\to J/\psi f_0(980)$, which has not yet been measured, is a key channel in this respect and discuss the physics potential of this decay.Comment: 32 pages, 7 figure

The 41-kDa Protein of Human Herpesvirus 6 Specifically Binds to Viral DNA Polymerase and Greatly Increases DNA Synthesis

AbstractWe previously isolated a 41-kDa early antigen of human herpesvirus 6 (HHV-6), which exhibited nuclear localization and DNA-binding activity (Agulnicket al.,1993). In this study, we observed that a 110-kDa protein was coimmunoprecipitated with p41 from HHV-6-infected cells by an anti-p41 antibody. This 110-kDa protein was identified as the HHV-6 DNA polymerase (Pol-6) by an antibody raised against the N terminus of Pol-6. Reciprocal immunoprecipitation and Western blot analyses confirmed that p41 complexes with Pol-6 in HHV-6-infected cells. In addition, both p41 and Pol-6 were expressedin vitroand shown to form a specific complex. Anin vitroDNA synthesis assay using primed M13 single-stranded DNA template demonstrated that p41 not only increased the DNA synthesis activity of Pol-6 but also allowed Pol-6 to synthesize DNA products corresponding to full-length M13 template (7249 nucleotides). By contrast, Pol-6 alone could only synthesize DNA of <100 nucleotides. The functional interaction between Pol-6 and p41 appears to be specific because they could not be physically or functionally substitutedin vitroby their herpes simplex virus 1 homologues. Moreover, as revealed by mutational analysis, both the N and C termini of Pol-6 contribute to its binding to p41. In the case of p41, the N terminus is required for increasing DNA synthesis but not binding to Pol-6, whereas the C terminus is totally dispensable

Identification of Polymerase and Processivity Inhibitors of Vaccinia DNA Synthesis Using a Stepwise Screening Approach

Nearly all DNA polymerases require processivity factors to ensure continuous incorporation of nucleotides. Processivity factors are specific for their cognate DNA polymerases. For this reason, the vaccinia DNA polymerase (E9) and the proteins associated with processivity (A20 and D4) are excellent therapeutic targets. In this study, we show the utility of stepwise rapid plate assays that i) screen for compounds that block vaccinia DNA synthesis, ii) eliminate trivial inhibitors, e.g. DNA intercalators, and iii) distinguish whether inhibitors are specific for blocking DNA polymerase activity or processivity. The sequential plate screening of 2,222 compounds from the NCI Diversity Set library yielded a DNA polymerase inhibitor (NSC 55636) and a processivity inhibitor (NSC 123526) that were capable of reducing vaccinia viral plaques with minimal cellular cytotoxicity. These compounds are predicted to block cellular infection by the smallpox virus, variola, based on the very high sequence identity between A20, D4 and E9 of vaccinia and the corresponding proteins of variola

Predictors of Clostridium Difficile Colitis Infections in Hospitals.

Hospital-level predictors of high rates of \u27Clostridium difficile-associated disease\u27 (CDAD) were evaluated in over 2300 hospitals across California, Arizona, and Minnesota. American Hospital Association data were used to determine hospital characteristics associated with high rates of CDAD. Significant correlations were found between hospital rates of CDAD, common infections and other identified pathogens. Hospitals in urban areas had higher average rates of CDAD; yet, irrespective of geographic location, hospital rates of CDAD were associated with other infections. In addition, hospitals with \u27high CDAD\u27 rates had slower turnover of beds and were more likely to offer transplant services. These results reveal large differences in rates of CDAD across regions. Hospitals with high rates of CDAD have high rates of other common infections, suggesting a need for broad infection control policies

Impact of a novel surgical wound protection device on observed versus expected surgical site infection rates after colectomy using the National Surgical Quality Improvement Program Risk Calculator

Surgical site infection (SSI) remains a persistent and morbid problem in colorectal surgery. A novel surgical device that combines barrier surgical wound protection and continuous surgical wound irrigation was evaluated in a cohort of elective colorectal surgery patients. A retrospective analysis was performed comparing rates of SSI observed in a prospective cohort study with the predicted rate of SSI using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) Risk Calculator.A prospective multi-center study of colectomy patients was conducted using a study device for surgical site retraction and protection, as well as irrigation of the incision. Patients were followed for 30 days after the surgical procedure to assess for SSI. After completion of the study, patients' characteristics were inserted into the ACS-NSQIP Risk Calculator to determine the predicted rate of SSI for the given patient population and compared with the observed rate in the study.A total of 108 subjects were enrolled in the study. The observed rate of SSI in the prospective study using the novel device was 3.7% (4/108). The predicted rate of SSI in the same patient population utilizing the ACS-NSQIP Risk Calculator was estimated to be 9.5%. This demonstrated a 61% difference (3.7% vs. 9.5%, p = 0.04) in SSI from the NSQIP predicted rate with the use of the irrigating surgical wound protection and retraction device.These data suggest the use of a novel surgical wound protection device seems to reduce the rate of SSIs in colorectal surgery

Ecological and genetic effects of introduced species on their native competitors

Species introductions to new habitats can cause a decline in the population size of competing native species and consequently also in their genetic diversity. We are interested in why these adverse effects are weak in some cases whereas in others the native species declines to the point of extinction. While the introduction rate and the growth rate of the introduced species in the new environment clearly have a positive relationship with invasion success and impact, the influence of competition is poorly understood. Here, we investigate how the intensity of interspecific competition influences the persistence time of a native species in the face of repeated and ongoing introductions of the nonnative species. We analyze two stochastic models: a model for the population dynamics of both species and a model that additionally includes the population genetics of the native species at a locus involved in its adaptation to a changing environment. Counterintuitively, both models predict that the persistence time of the native species is lowest for an intermediate intensity of competition. This phenomenon results from the opposing effects of competition at different stages of the invasion process: With increasing competition intensity more introduction events are needed until a new species can establish, but increasing competition also speeds up the exclusion of the native species by an established nonnative competitor. By comparing the ecological and the eco-genetic model, we detect and quantify a synergistic feedback between ecological and genetic effects.Comment: version accepted at Theoretical Population Biolog

Fatty acids and stable isotopes (13C, 15N) in southern right whale Eubalaena australis calves in relation toage and mortality at Peninsula Valdes, Argentina

Baleen whales accumulate fat reserves during the summer to sustain reproduction while fasting in the winter. The southern right whale Eubalaena australis population that calves off Península Valdés, Argentina, experienced high calf mortality events from 2003 to 2013 and poor nutritional states of mothers could be a contributing cause. Previous studies found that the population’s reproductive success is influenced by prey availability. Mothers unable to build sufficient fat reserves or feeding on prey with different nutritional value may fail to meet the demands of lactation. Milk is the only source of nutrients and energy for calves at Valdés, so their fatty acids (FAs) and stable isotopes should reflect their mother’s diet and feeding-ground locations. Here, we compared FA profiles and C and N stable isotopes of dead calves with those of living calves to evaluate the potential impact of maternal nutrition on calf survival. We found no differences in the FA composition of blubber in dead and living calves, indicating similar maternal diets. Likewise, the isotopic values of living and dead calves imply that their mothers had similar foraging ranges. However, FA composition was greatly affected by calf length, indicating effects of calf age and duration of nursing. These findings suggest that mothers of dead calves did not feed on different diets or feeding grounds compared to mothers of living calves. Future research should further assess the overall health and body condition of the Valdés southern right whale calves.Fil: Marón, Carina Flavia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Conservación de Ballenas; ArgentinaFil: Budge, Suzanne M.. Dalhousie University Halifax; CanadáFil: Ward, Robert E.. Utah State University; Estados UnidosFil: Valenzuela, Luciano Oscar. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Sociales. Departamento de Arqueología. Laboratorio de Ecología Evolutiva Humana (Sede Quequén); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil; ArgentinaFil: Di Martino, Matías. Programa de Monitoreo Sanitario Ballena Franca Austral; ArgentinaFil: Ricciardi, Marcos. Instituto de Conservación de Ballenas; ArgentinaFil: Sironi, Mariano. Instituto de Conservación de Ballenas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica; Argentina. Programa de Monitoreo Sanitario Ballena Franca Austral; ArgentinaFil: Uhart, Marcela. Programa de Monitoreo Sanitario Ballena Franca Austral; Argentina. University of California; Estados UnidosFil: Seger, Jon. University Of Utah. Department Of Biology; Estados UnidosFil: Rowntree, Victoria J.. University Of Utah. Department Of Biology; Estados Unidos. Instituto de Conservación de Ballenas; Argentina. Programa de Monitoreo Sanitario Ballena Franca Austral; Argentina. Whale Conservation Institute/Ocean Alliance; Estados Unido