Search

An element a in a ring R has a gs-Drazin inverse if there exists p 2 = p ∈ comm 2 (a) such that a − p ∈ R qnil . In this paper, we extend Cline's formula and Jacobson's Lemma for gs-Drazin inverses. Various additive properties of gs-Drazin inverses are thereby obtained. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a new notion which lies properly between strong π -regularity and pseudopolarity. A ring R is feckly polar if for any a ∈ R there exists e ∈ comm 2 (a) such that a − e ∈ U (R) , e − e 2 ∈ J (R)  and  (a e) n ∈ J (R)  for some  n ∈ ℕ. Many structure theorems are proved. Further, we investigate feck polarity for triangular matrix and matrix rings. The relations among strongly π -regular rings, pseudopolar rings and feckly polar rings are also obtained. [ABSTRACT FROM AUTHOR]

In this paper we introduce a class of quasipolar rings which is a generalization of J -quasipolar rings. Let R be a ring with identity. An element a ϵ 2 R is called 1-quasipolar if there exists p2 = p ϵ comm2(a) such that a + p is contained in δ(R), and the ring R is called δ-quasipolar if every element of R is δ-quasipolar. We use 1-quasipolar rings to extend some results of J-quasipolar rings. Then some of the main results of J-quasipolar rings are special cases of our results for this general setting. We give many characterizations and investigate general properties of 1-quasipolar rings. [ABSTRACT FROM AUTHOR]

Human noroviruses are the leading cause of non-bacterial shellfish associated gastroenteritis. Here we report on the detection and characterization of norovirus (NoV) in shellfish associated outbreaks. Requests were received from state and federal officials for technical assistance in the analysis of shellfish for NoV and male specific coliphage (MSC; an enteric virus surrogate) during the years 2009 thru 2014. In outbreaks where NoV was detected, genogroup II (GII) levels ranged from 2.4 to 82.0 RT-qPCR U/g of digestive diverticula (DD) while NoV genogroup I (GI) levels ranged from 1.5 to 29.8 RT-qPCR U/g of DD. Murine norovirus extraction efficiencies ranged between 50 and 85%. MSC levels ranged from <6 to 80 PFU/100 g. Phylogenetic analysis of the outbreak sequences revealed strains clustering with GI.8, GI.4, GII.3, GII.4, GII.7, and GII.21. There was 100% homology between the shellfish and clinical strains occurring in 2 of 8 outbreaks. Known shellfish consumption data demonstrated probable infectious particles ingested as low as 12. These investigations demonstrate effective detection, quantification, and characterization of NoV in shellfish associated with illness. [ABSTRACT FROM AUTHOR]

In this paper, we introduce a kind of quasipolarity notion for rings, namely, an element a of a ring R is called central quasipolar if there exists p2 = p 2 R such that a+p is central in R, and the ring R is called central quasipolar if every element of R is central quasipolar. We give many characterizations and investigate general properties of central quasipolar rings. We determine the conditions that some subrings of upper triangular matrix rings are central quasipolar. A diagonal matrix over a local ring is characterized in terms of being central quasipolar. We prove that the class of central quasipolar rings lies between the classes of commutative rings and Dedekind INFnite rings, and a ring R is central quasipolar if and only if it is central clean. Further we showthat several results of quasipolar rings can be extended to central quasipolar rings in this general setting. [ABSTRACT FROM AUTHOR]

We discuss the building blocks for a consistent inclusion of chiral three-nucleon (3N) interactions into ab initio nuclear structure calculations beyond the lower p shell. We highlight important technical developments, such as the similarity renormalization group (SRG) evolution in the 3N sector, a JT-coupled storage scheme for 3N matrix elements with efficient on-the-fly decoupling, and the importance-truncated no-core shell model with 3N interactions. Together, these developments make converged ab initio calculations with explicit 3N interactions possible also beyond the lower p shell. We analyze in detail the impact of various truncations of the SRG-evolved Hamiltonian, in particular the truncation of the harmonic-oscillator model space used for solving the SRG flow equations and the omission of the induced beyond-3N contributions of the evolved Hamiltonian. Both truncations lead to sizable effects in the upper p shell and beyond and we present options to remedy these truncation effects. The analysis of the different truncations is a first step towards a systematic uncertainty quantification of all stages of the calculation. [ABSTRACT FROM AUTHOR]

The article explores the inclusion of evolved chiral nucleon-nucleon + three-nucleon (NN + 3N) Hamiltonians for ab initio nuclear structure calculations beyond the lower p shell of the nuclear structure. Topics discussed include the importance-truncated no-core shell model (IT-NCSM) with 3N interactions, the similarity renormalization group (SRG) evolution in the 3 N interactions and the truncation of the harmonic-oscillator model space.

The article offers information about the evolution of chiral two-nucleon (NN) and three-nucleon (3N) Hamiltonians for ab initio nuclear structure calculations. Topics discussed include important technical developments including the similarity renormalization group (SRG) evolution in the 3N sector, the 3N interactions included in ab initio nuclear structure calculations, and the transformation of the 3N matrix elements to a J T-coupled storage scheme.

The article focuses on a study related to the ab initio nuclear structure calculations for chiral three-nucleon interaction (3N). Topics discussed include properties of similarity renormalization group evolved Hamiltonians, ground-state energies obtained with standard Hamiltonian and frequency conversion.

The article presents a study that discusses the developments for a consistent inclusion of chiral three-nucleon (3 N) interactions into ab initio nuclear structure calculations beyond the lower p shell. Topics include the similarity renormalization group (SRG) evolution in the 3N sector, the importance-truncated no-core shell model with 3N interactions, and the impact of various truncations of the SRG-evolved Hamiltonian.

The article presents brief information on evolved chiral NN + 3N Hamiltonians for calculations of ab initio nuclear structure. It highlights the building blocks for a consistent inclusion of chiral three-nucleon (3 N) interactions into ab initio nuclear structure calculations. Information on impact of several truncations of Hamiltonian, mainly the truncation of the harmonic-oscillator model space, is offered.

We summarize recent advances in ab initio nuclear structure theory, aiming to connect few- and many-body systems in a coherent theoretical framework. Starting from chiral effective field theory to construct the nuclear Hamiltonian and the similarity renormalization group to soften it, we address several many-body approaches that have seen major developments over the past few years. We show that the domain of ab initio nuclear structure theory has been pushed well beyond the p-shell and that quantitative predictions connected to QCD via chiral effective field theory are becoming possible all the way from the proton to the neutron drip line up into the medium-mass regime. [ABSTRACT FROM AUTHOR]

Previous results demonstrated that hepatitis A virus (HAV) could be inactivated by high hydrostatic pressure (HHP) (D. H. Kingsley, D. Hoover, E. Papafragkou, and G. P. Richards, J. Food Prot. 65:1605-1609, 2002); however, direct evaluation of HAY inactivation within contaminated oysters was not performed. In this study, we report confirmation that HAV within contaminated shellfish is inactivated by HHP. Shellfish were initially contaminated with HAV by using a flowthrough system. PFU reductions of >1, >2, and >3 log10 were observed for 1-min treatments at 350, 375, and 400 megapascals, respectively, within a temperature range of 8.7 to 10.3°C. Bioconcentration of nearly 6 log10 PFU of HAV per oyster was achieved under simulated natural conditions. These results suggest that HHP treatment of raw shellfish will be a viable strategy for the reduction of infectious HAV. [ABSTRACT FROM AUTHOR]

Identifies factors that contribute to the temporal occurrence of enteric viruses in oysters from the Gulf Coast. Investigation of the seasonal bioaccumulation of the traditional and alternative sanitary indicator microorganisms from estuarine water by oysters; Trials that could provide insight into the seasonal occurrence of gastrointestinal illnesses.

Focuses on the development of rapid oyster-processing procedures that can be used for sensitive polymerase chain reaction detection of pathogenic viruses from oysters implicated in gastroenteritis outbreaks. Use of a poliovirus type 3 Sabin strain; Use of acid adsorption-elution; RNA extraction; Detection sensitivity of the method.

Background: The optimal prophylactic dose of heparin in patients with coronavirus-associated disease 2019 (COVID-19) in the emergency department (ED) is debated. This study aimed to analyze different thromboprophylaxis approaches in unvaccinated COVID-19 patients admitted to ED without initial venous thromboembolism.Methods: Retrospectively, the effect of intermediate/high versus low dose heparin treatment was evaluated from December 2020 to July 2021 in a tertiary Academic Hospital in northeast Italy. The primary outcome comprised arterial or venous thromboembolism or all-cause death within 30 days. Secondary outcomes comprised each single primary outcome component or major hemorrhagic event. Cox regression was used to determine predictors of the primary outcome and propensity score weights to balance the effect of heparin treatment on all outcomes.Results: Data of 144 consecutive patients (age 70 ± 13, 33% females) were included in the study. High-dose prophylactic heparin was used in 69%, intermediate in 15%, and low in 17% of patients. The primary outcome occurred in 48 patients. Independent predictors of the primary outcome were COVID-19 severity (hazards ratio (HR) 1.96, 95% confidence interval (CI) 1.05-3.65, p = 0.035) and D-dimer levels (HR each log ng/dl 1.38, 95% CI 1.04-1.84, p = 0.026). Intermediate/high dose heparin did not affect the risk of the primary outcome compared with the low dose (weighted HR 1.39, 95% CI 0.75-2.56, p = 0.292). Intermediate/high heparin increased the risk of major hemorrhagic events (weighted HR 5.92, 95% CI 1.09-32, p = 0.039).Conclusions: In unvaccinated COVID-19 patients admitted to ED, prophylaxis with heparin at the intermediate/high dose did not reduce primary outcome compared with the low dose but increased the risk of major hemorrhagic events. [ABSTRACT FROM AUTHOR]

Presents information on a study which determined the occurrence of male-specific bacteriophage (MSB) densities in animal and human fecal wastes to assess their potential impact on aquatic environments. Application of MSB as an indicator of viral contamination from human sources; Methodology of the study; Discussion of results.

We employ a variety of ab initio methods, including Faddeev-Yakubovsky equations, no-core configuration interaction approach, coupled-cluster theory, and in-medium similarity renormalization group, to perform a comprehensive analysis of the nucleon-deuteron elastic and breakup reactions and selected properties of light and medium-mass nuclei up to 48Ca using the recently constructed semilocal coordinate-space regularized chiral nucleon-nucleon potentials. We compare the results with those based on selected phenomenological and chiral EFT two-nucleon potentials, discuss the convergence pattern of the chiral expansion, and estimate the achievable theoretical accuracy at various chiral orders using an approach to quantify truncation errors of the chiral expansion without relying on cutoff variation. We also address the robustness of this method and explore alternative ways to estimate the theoretical uncertainty from the truncation of the chiral expansion. [ABSTRACT FROM AUTHOR]

Background: The exotic 9He nucleus, which presents one of the most extreme neutron-to-proton ratios, belongs to the N=7 isotonic chain famous for the phenomenon of ground-state parity inversion with decreasing number of protons. Consequently, it would be expected to have an unnatural (positive) parity ground state similar to 11Be and 10Li. Despite many experimental and theoretical investigations, its structure remains uncertain. Apart from the fact that it is unbound, other properties including the spin and parity of its ground state, and the very existence of additional low-lying resonances are still a matter of debate. Purpose: In this work, we study the properties of 9He by analyzing the n+8He continuum in the context of the ab initio no-core shell model with continuum (NCSMC) formalism with chiral nucleon-nucleon interactions as the only input. Methods: The NCSMC is a state-of-the-art approach for the ab initio description of light nuclei. With its capability to predict properties of bound states, resonances, and scattering states in a unified framework, the method is particularly well suited for the study of unbound nuclei such as 9He. Results: Our analysis produces an unbound 9He nucleus. Two resonant states are found at the energies of ~1 and ~3.5 MeV, respectively, above the n+8He breakup threshold. The first state has a spin-parity assignment of Jp=1/2- and can be associated with the ground state of 9He, while the second, broader state has a spin parity of 3/2-. No resonance is found in the 1/2+ channel, only a very weak attraction. Conclusions: We find that the 9He ground-state resonance has a negative parity and thus breaks the parity-inversion mechanism found in the 11Be and 10Li nuclei of the same N=7 isotonic chain. [ABSTRACT FROM AUTHOR]

We present a nucleus-dependent valence-space approach for calculating ground and excited states of nuclei, which generalizes the shell-model in-medium similarity renormalization group to an ensemble reference with fractionally filled orbitals. Because the ensemble is used only as a reference, and not to represent physical states, no symmetry restoration is required. This allows us to capture three-nucleon (3N) forces among valence nucleons with a valence-space Hamiltonian specifically targeted to each nucleus of interest. Predicted ground-state energies from carbon through nickel agree with results of other large-space ab initio methods, generally to the 1% level. In addition, we show that this new approach is required in order to obtain convergence for nuclei in the upper p and sd shells. Finally, we address the 1+/3+ inversion problem in 22Na and 46V. This approach extends the reach of ab initio nuclear structure calculations to essentially all light-and medium-mass nuclei. [ABSTRACT FROM AUTHOR]

The weakly bound exotic 11Be nucleus, famous for its ground-state parity inversion and distinct n+10Be halo structure, is investigated from first principles using chiral two- and three-nucleon forces. An explicit treatment of continuum effects is found to be indispensable. We study the sensitivity of the 11Be spectrum to the details of the three-nucleon force and demonstrate that only certain chiral interactions are capable of reproducing the parity inversion. With such interactions, the extremely large E1 transition between the bound states is reproduced. We compare our photodisintegration calculations to conflicting experimental data and predict a distinct dip around the 3/2-1 resonance energy. Finally, we predict low-lying 3/2+ and 9/2+ resonances that are not or not sufficiently measured in experiments. [ABSTRACT FROM AUTHOR]

Starting from a set of different two- and three-nucleon interactions from chiral effective field theory, we use the importance-truncated no-core shell model for ab initio calculations of excitation energies as well as electric quadrupole (E2) and magnetic dipole (M1) moments and transition strengths for selected p-shell nuclei. We explore the sensitivity of the excitation energies to the chiral interactions as a first step towards and systematic uncertainty propagation from chiral inputs to nuclear structure observables. The uncertainty band spanned by the different chiral interactions is typically in agreement with experimental excitation energies, but we also identify observables with notable discrepancies beyond the theoretical uncertainty that reveal insufficiencies in the chiral interactions. For electromagnetic observables we identify correlations among pairs of E2 or M1 observables based on the ab initio calculations for the different interactions. We find extremely robust correlations for E2 observables and illustrate how these correlations can be used to predict one observable based on an experimental datum for the second observable. In this way we circumvent convergence issues and arrive at far more accurate results than any direct ab initio calculation. A prime example for this approach is the quadrupole moment of the first 2+ state in C12, which is predicted with an drastically improved accuracy. [ABSTRACT FROM AUTHOR]

We apply improved nucleon-nucleon potentials up to fifth order in chiral effective field theory, along with a new analysis of the theoretical truncation errors to study nucleon-deuteron (Nd) scattering and selected low-energy observables in ³H,4He, and 6Li. Calculations beyond second order differ from experiment well outside the range of quantified uncertainties, providing truly unambiguous evidence for missing three-nucleon forces within the employed framework. The sizes of the required three-nucleon-force contributions agree well with expectations based on Weinberg's power counting. We identify the energy range in elastic Nd scattering best suited to study three-nucleon-force effects and estimate the achievable accuracy of theoretical predictions for various observables. [ABSTRACT FROM AUTHOR]

We discuss the approximate inclusion of three-nucleon (3N) interactions into ab initio nuclear structure calculations using a multireference formulation of normal ordering and Wick's theorem. Following the successful application of single-reference normal ordering for the study of ground states of closed-shell nuclei, e.g., in coupled-cluster theory, multireference normal ordering opens a path to open-shell nuclei and excited states. Based on different multideterminantal reference states we benchmark the truncation of the normal-ordered Hamiltonian at the two-body level in no-core shell-model calculations for p-shell nuclei, including 6Li,12C, and 10B. We find that this multireference normal-ordered two-body approximation is able to capture the effects of the 3N interaction with sufficient accuracy, both for ground-state and excitation energies, at the computational cost of a two-body Hamiltonian. It is robust with respect to the choice of reference states and has a multitude of applications in ab initio nuclear structure calculations of open-shell nuclei and their excitations as well as in nuclear reaction studies. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine countermovement vertical jump performance among female athletes who rely heavily on vertical jump performance within their given sport. Forty-five female athletes representing 3 teams (basketball, volleyball, and beach volleyball) competing at the NCAA Division I level completed 2 maximal effort countermovement jumps (CMJ) using a portable force platform. A 1-way analysis of variance was used to compare groups across each variable. Statistically significant differences were found between the groups regarding propulsive duration and time to takeoff with basketball showing the shortest time and beach volleyball having the longest times (p, 0.05). In addition, differences were seen in countermovement depth and mean propulsive force between the groups with basketball displaying the smallest countermovement and highest force (p, 0.05). No differences were seen in jump height and reactive strength index modified. Greater force and shorter durations in basketball athletes versus the low force and long durations in the beach volleyball athletes suggest that sporting backgrounds play a large role in how the CMJ is performed. This information can aid strength and conditioning practitioners in the design of training programs that are sport specific to the strategies used by the athlete. [ABSTRACT FROM AUTHOR]

This study examined the inactivation of human norovirus (HuNoV) GI.1 and GII.4 by chlorine under conditions mimicking sewage treatment. Using a porcine gastric mucin-magnetic bead (PGM-MB) assay, no statistically significant loss in HuNoV binding (inactivation) was observed for secondary effluent treatments of ≤25 ppm total chlorine; for both strains, 50 and 100 ppm treatments resulted in ≤0.8-log10 unit and ≥3.9-log10 unit reductions, respectively. Treatments of 10, 25, 50, and 100 ppm chlorine inactivated 0.31, 1.35, >5, and >5 log10 units, respectively, of the norovirus indicator MS2 bacteriophage. Evaluation of treatment time indicated that the vast majority of MS2 and HuNoV inactivation occurred in the first 5 min for 0.2-mfiltered, prechlorinated secondary effluent. Free chlorine measurements of secondary effluent seeded with MS2 and HuNoV demonstrated substantial oxidative burdens. With 25, 50, and 100 ppm treatments, free chlorine levels after 5 min of exposure ranged from 0.21 to 0.58 ppm, from 0.28 to 16.7 ppm, and from 11.6 to 53 ppm, respectively. At chlorine treatment levels of >50 ppm, statistically significant differences were observed between reductions for PGM-MB-bound HuNoV (potentially infectious) particles and those for unbound (noninfectious) HuNoV particles or total norovirus particles. While results suggested that MS2 and HuNoV (measured as PGM-MB binding) behave similarly, although not identically, both have limited susceptibility to chlorine treatments of ≤25 ppm total chlorine. Since sewage treatment is performed at ≤25 ppm total chlorine, targeting free chlorine levels of 0.5 to 1.0 ppm, these results suggest that traditional chlorine-based sewage treatment does not inactivate HuNoV efficiently. [ABSTRACT FROM AUTHOR]

Effects of land use on hydrology, organic matter sources, and processing may be proportionately greater in tidal creeks than large estuaries, yet tidal creek systems have been undervalued in assessments of emerging effects of anthropogenic land use. Through sampling of dated sediment cores, we identified indicators of historical land use change (past 150 yr) in a microtidal northern Gulf of Mexico tidal creek system in the early stages of urbanization. We found that tidal creeks differed from open water sites, and urbanized sites differed from less altered sites, primarily due to changes in carbon sources indicated by differences in sediment stable carbon isotope ( δ13C) values, and concentrations of fecal indicator bacterium Clostridium perfringens. Total organic carbon (%TOC) and carbon : nitrogen (C : N) increased twofold in tidal creeks during upstream urbanization in the early 20th century, which led to elevated mid-century sediment TOC accumulation rates (5-10 mg C cm−2 yr−1), followed by decreases in TOC accumulation in tidal creeks and open waters since the 1960s (0.4-1.8 mg C cm−2 yr−1). C. perfringens and nitrogen stable isotope values ( δ15N) were, respectively, 1.8 and 1.5 times higher at wastewater-influenced sites than at other sites, increasing through time or remaining high at wastewater-influenced sites from approximately the 1950s-present, when human populations quadrupled. Hence, urbanization altered estuarine inputs from upland C sources and increased inputs from human-derived N and microbes. These findings suggest that tidal creeks are more sensitive archives of land-use change than open water systems due to their proximity and greater connectivity to the watershed. [ABSTRACT FROM AUTHOR]

We present the first ab initio calculations of nuclear ground states up into the domain of heavy nuclei, spanning the range from 16 O to 132 Sn, based on two- plus three-nucleon interactions derived within chiral effective field theory. We employ the similarity renormalization group for preparing the Hamiltonian and use coupled-cluster theory to solve the many-body problem for nuclei with closed sub-shells. Through an analysis of theoretical uncertainties resulting from various truncations in this framework, we identify and eliminate the technical hurdles that previously inhibited the step beyond medium-mass nuclei, allowing for reliable validations of nuclear Hamiltonians in the heavy regime. Following this path we show that chiral Hamiltonians qualitatively reproduce the systematics of nuclear ground-state energies up to the neutron-rich Sn isotopes. [ABSTRACT FROM AUTHOR]

We investigate selected static and transition properties of 12C using ab initio no-core shell model (NCSM) methods with chiral two- and three-nucleon interactions. We adopt the similarity renormalization group (SRG) to assist convergence including up to three-nucleon (3 AO contributions. We examine the dependencies of the l2C observables on the SRG evolution scale and on the model-space parameters. We obtain nearly converged low-lying excitation spectra. We compare results of the full NCSM with the importance truncated NCSM in large model spaces for benchmarking purposes. We highlight the effects of the chiral 3N interaction on several spectroscopic observables. The agreement of some observables with experiment is improved significantly by the inclusion of 3N interactions, e.g., the B(M1) from the first Jπ T = 1+1 state to the ground state. However, in some cases the agreement deteriorates, e.g., for the excitation energy of the first l + 0 state, leaving room for improved next-generation chiral Hamiltonians. [ABSTRACT FROM AUTHOR]

We generalize the coupled-cluster (CC) approach with singles, doubles, and the noniterative treatment of triples termed ACCSD(T) to Hamiltonians containing three-body interactions. The resulting method and the underlying CC approach with singles and doubles only (CCSD) are applied to the medium-mass closed-shell nuclei 16O,24O, and 40Ca. By comparing the results of CCSD and ACCSD(T) calculations with explicit treatment of three-nucleon interactions to those obtained using an approximate treatment in which they are included effectively via the zero-, one-, and two-body components of the Hamiltonian in normal-ordered form, we quantify the contributions of the residual three-body interactions neglected in the approximate treatment. We find these residual normal-ordered three-body contributions negligible for the ACCSD(T) method, although they can become significant in the lower-level CCSD approach, particularly when the nucleon-nucleon interactions are soft. [ABSTRACT FROM AUTHOR]

We formulate the in-medium similarity renormalization group (IM-SRG) for open-shell nuclei using a multireference formalism based on a generalized Wick theorem introduced in quantum chemistry. The resulting multireference IM-SRG (MR-IM-SRG) is used to perform the first ab initio study of all even oxygen isotopes with chiral nucleon-nucleon and three-nucleon interactions, from the proton to the neutron drip lines. We obtain an excellent reproduction of experimental ground-state energies with quantified uncertainties, which is validated by results from the importance-truncated no-core shell model and the coupled cluster method. The agreement between conceptually different many-body approaches and experiment highlights the predictive power of current chiral two- and three-nucleon interactions, and establishes the MR-IM-SRG as a promising new tool for ab initio calculations of medium-mass nuclei far from shell closures. [ABSTRACT FROM AUTHOR]

We present the first ab initio coupled-cluster calculations of medium-mass nuclei with explicit chiral three-nucleon (3N) interactions. Using a spherical formulation of coupled cluster with singles and doubles excitations including explicit 3N contributions, we study ground states of 16,24O, 40,48Ca, and 56Ni. We employ chiral nucleon-nucleon (NN) plus 3N interactions softened through a similarity renormalization group (SRG) transformation at the three-body level. We investigate the impact of all truncations and quantify the resulting uncertainties--this includes the contributions from triple excitations, the truncation of the set of three-body matrix elements, and the omission of SRG-induced four-body interactions. Furthermore, we assess the quality of a normal-ordering approximation of the 3N interaction beyond light nuclei. Our study points towards the predictive power of chiral Hamiltonians in the medium-mass regime. [ABSTRACT FROM AUTHOR]

Abstract: A real-time, reverse transcription-PCR (RT-qPCR) assay was developed to differentiate the four genogroups of male-specific ssRNA coliphages (FRNA) (family Leviviridae). As FRNA display a trend of source-specificity (human sewage or animal waste) at the genogroup level, this assay provides a tool to help identify the origin of fecal contamination. Primers and probes were designed using complete genomic sequences from 29 FRNA phages. The final selection of primer/probe sets were based on (i) ability to amplify a single, specific product, (ii) genogroup specificity, (iii) lack of cross-reactivity, and (iv) experimental reproducibility and sensitivity over a range of target concentrations. Assay time was reduced by using heat-released viral RNA rather than purified RNA. For quality assurance, a custom RNA molecule was employed as an internal, non-competitive control. The usefulness of this method to identify sources of fecal contamination was tested on a total of 49 FRNA phages isolated from various warm-blooded animals, sewage and combined sewage overflow. FRNA phages from animal wastes were genotyped as 86% I, 4% III Q-like and 9% IV. Two sewage isolates typed to genogroup I and combined sewage overflow isolates genotyped as 40% II and 52% III. Primer specificity designed from this comprehensive sequence database may better discriminate FRNA from different sources. [Copyright &y& Elsevier]

Purpose: To present the patients' view on the monitoring of their wet Age‐related Macular Degeneration (wet AMD) during Coronavirus disease 2019 (COVID‐19), and the impact that telemedicine could have on it. Methods: Wet AMD patients of Swiss Visio Montchoisi and RétinElysée (Lausanne, Switzerland), who had intravitreal anti‐Vascular Endothelial Growth Factor (anti‐VEGF) injections before and after the first period of the Swiss confinement due to COVID‐19, completed two questionnaires. The first evaluated their view on their adherence to their scheduled injections during the confinement, and on the future use of telemedicine. The second, adapted from National Eye Institute Visual Function Questionnaire‐25, evaluated their opinion on their visual function during the confinement. Results: From a total of 130 patients, 8.5% responded they did not respect their assigned injection interval during the confinement (group 1), while 91.5% responded they did (group 2). The majority of group 1 (37.5%) responded they did not attend their scheduled visit to avoid using public transportation. The majority of group 2 (78.7%) considered the continuation of their treatment more important than the risk of contracting COVID‐19. Before the lockdown, patients of group 2 had more need for help from others than the patients of group 1 (p = 0.02). In a future lockdown, 36.3% of group 1 and 8.7% of group 2 would prefer remote monitoring of their wet AMD via telemedicine (p = 0.02), 54.5% and 86.9% would prefer to visit the clinic (p = 0.02), while 9% and 4.3% would avoid the visit, respectively. 70% of group 1 and 33.6% of group 2 would rather use the telemedicine application in their home than visit a telemedicine center (p = 0.04). Conclusions: Despite our availability to provide continuous intravitreal anti‐VEGF injections during the COVID‐19 confinement, many wet AMD patients did not receive their scheduled treatment. In similar future circumstances, most patients would prefer to visit the clinic. The patients of group 1 would prefer remote monitoring of their AMD via telemedicine at a higher rate than the patients of group 2. Bibliography: Visual Function Questionnaire 25. https://www.nei.nih.gov/learn‐about‐eye‐health/resources‐for‐health‐educators/outreach‐materials/visual‐function‐questionnaire‐25 [ABSTRACT FROM AUTHOR]

Murine norovirus (strain MNV-1), a propagable norovirus, was evaluated for susceptibility to high-pressure processing. Experiments with virus stocks in Dulbecco's modified Eagle medium demonstrated that at room temperature (20°C) the virus was inactivated over a pressure range of 350 to 450 MPa, with a 5-min, 450-MPa treatment being sufficient to inactivate 6.85 log10 PFU of MNV-1. The inactivation of MNV.1 was enhanced when pressure was applied at an initial temperature of 5°C; a 5-min pressure treatment of 350 MPa at 30°C inactivated 1.15 log10 PFU of virus, while the same treatment at 5°C resulted in a reduction of 5.56 log10 PFU. Evaluation of virus inactivation as a function of treatment times ranging from 0 to 150 s and 0 to 900 s at 5°C and 20°C, respectively, indicated that a decreasing rate of inactivation with time was consistent with Weibull or log-logistic inactivation kinetics. The inactivation of MNV-1 directly within oyster tissues was demonstrated; a 5-min, 400-MPa treatment at 5°C was sufficient to inactivate 4.05 log10 PFU. This work is the first demonstration that norovirus can be inactivated by high pressure and suggests good prospects for inactivation of nonpropagable human norovirus strains in foods. [ABSTRACT FROM AUTHOR]

Abstract: Pressure inactivation of four types of coliphages, ϕX 174 (ssDNA virus), MS2 (ssRNA virus), λ imm434 (dsDNA virus) and T4 (dsDNA virus), was studied to evaluate their potential as human enteric viral surrogates for use in validation of commercial pressure processing treatments. Phage ϕX 174 demonstrated an unexpected high resistance to pressure with no more than 1-log10 reduction observed following exposures to 350–600MPa. There was no greater than 1-log10 reduction below 500MPa for MS2 in modified phosphate-buffered saline, but a 3.3-log10 reduction was observed for MS2 pressurized at 600MPa. Coliphages λ imm434 and T4 were relatively sensitive to pressure in demonstrating inactivation at 350MPa. At 21°C, λ imm434 was inactivated in modified phosphate-buffered saline or Dulbecco''s Modified Eagle''s Medium plus 5% fetal bovine sera by at least 7.5-log10 when exposed to 400MPa for 5min. Treatment at 450MPa for 5min was necessary to obtain a log10 reduction of 6–7 for T4. [Copyright &y& Elsevier]

Introduction: Candidemia causes high mortality and is occuring at increasing rate in intensive care units (ICUs). (1,3)- β-D-glucan (BDG) testing is recommended in neutropenic patients. However the usefulness of BDG in ICUs is unclear. Methodology: This study was conducted to compare the diagnostic value of Candida score (CS), colonization index (CI), serum BDG detection, and routine laboratory parameters in ICU patients. Characteristics and laboratory data of 83 patients (15 patients with candidemia and 68 patients without candidemia) were evaluated. Results: Median serum BDG was significantly higher in the candidemia group (129 pg/mL vs. 36 pg/mL, p < 0.001). BDG assay with standard cut-off value ≥ of 80 pg/mL had 93.33% sensitivity and 64.18% specificity (Areas under the ROC curve (AUC): 0.788). This study concluded that the optimal cut-off value for BDG assay was 112 pg/mL with sensitivity of 86.67% and specificity of 82.09% (AUC: 0.844). C-reactive protein (CRP) with optimal cut-off value ≥ 85 mg/L and BDG ≥ 80 pg/mL had the highest AUC (0.862, 95% CI: 0.768 - 0.928) with sensitivity 93.33% and specificity 79.1%. Conclusions: Predicting candidemia is essential in critically ill patients who are at high risk and have high mortality rates. The results of this study suggest that BDG testing is useful for predicting candidemia in ICU. However, BDG combined with CRP may be a stronger predictor for candidemia. [ABSTRACT FROM AUTHOR]

Background: The nuclear optical potential is a successful tool for the study of nucleon-nucleus elastic scattering and its use has been further extended to inelastic scattering and other nuclear reactions. The nuclear density of the target nucleus is a fundamental ingredient in the construction of the optical potential and thus plays an important role in the description of the scattering process. Purpose: In this paper we derive a microscopic optical potential for intermediate energies using ab initio translationally invariant nonlocal one-body nuclear densities computed within the no-core shell model (NCSM) approach utilizing two- and three-nucleon chiral interactions as the only input. Methods: The optical potential is derived at first order within the spectator expansion of the nonrelativistic multiple scattering theory by adopting the impulse approximation. Nonlocal nuclear densities are derived from the NCSM one-body densities calculated in the second quantization. The translational invariance is generated by exactly removing the spurious center-of-mass (COM) component from the NCSM eigenstates. Results: The ground-state local and nonlocal densities of 4,6,8He, 12C, and 16O are calculated and applied to optical potential construction. The differential cross sections and the analyzing powers for the elastic proton scattering off these nuclei are then calculated for different values of the incident proton energy. The impact of nonlocality and the COM removal is discussed. Conclusions: The use of nonlocal densities has a substantial impact on the differential cross sections and improves agreement with experiment in comparison to results generated with the local densities especially for light nuclei. For the halo nuclei 6He and 8He, the results for the differential cross section are in a reasonable agreement with the data although a more sophisticated model for the optical potential is required to properly describe the analyzing powers. [ABSTRACT FROM AUTHOR]

Human norovirus (NoV) is the leading cause of foodborne illness in the United States and Canada. Wastewater treatment plant (WWTP) effluents impacting bivalve mollusk-growing areas are potential sources of NoV contamination. We have developed a meta-analysis that evaluates WWTP influent concentrations and log10 reductions of NoV genotype I (NoV GI; in numbers of genome copies per liter [gc/liter]), NoV genotype II (NoV GII; in gc/liter), and male-specific coliphage (MSC; in number of PFU per liter), a proposed viral surrogate for NoV. The meta-analysis included relevant data (2,943 measurements) reported in the scientific literature through September 2013 and previously unpublished surveillance data from the United States and Canada. Model results indicated that the mean WWTP influent concentration of NoV GII (3.9 log10 gc/liter; 95% credible interval [CI], 3.5, 4.3 log10 gc/liter) is larger than the value for NoV GI (1.5 log10 gc/liter; 95% CI, 0.4, 2.4log10 gc/liter), with large variations occurring from one WWTP to another. For WWTPs with mechanical systems and chlorine disinfection, mean log10 reductions were-2.4 log10 gc/liter (95% CI,-3.9,-1.1 log10 gc/liter) for NoV GI,-2.7 log10 gc/liter (95% CI,-3.6,-1.9 log10 gc/liter) for NoV GII, and-2.9 log10 PFU per liter (95% CI,-3.4,-2.4 log10 PFU per liter) for MSCs. Comparable values for WWTPs with lagoon systems and chlorine disinfection were-1.4 log10 gc/liter (95% CI,-3.3, 0.5 log10 gc/liter) for NoV GI,-1.7 log10 gc/liter (95% CI,-3.1,-0.3 log10 gc/liter) for NoV GII, and-3.6 log10 PFU per liter (95% CI,-4.8,-2.4 PFU per liter) for MSCs. Within WWTPs, correlations exist between mean NoV GI and NoV GII influent concentrations and between the mean log10 reduction in NoV GII and the mean log10 reduction in MSCs. [ABSTRACT FROM AUTHOR]

We extend the recently proposed ab initio no-core shell model with continuum to include three-nucleon (3N) interactions beyond the few-body domain. The extended approach allows for the assessment of effects of continuum degrees of freedom as well as of the 3N force in ab initio calculations of structure and reaction observables of p- and lower-sd-shell nuclei. As a first application we concentrate on energy levels of the 9Be system for which all excited states lie above the n-Be8 threshold. For all energy levels, the inclusion of the continuum significantly improves the agreement with experiment, which was an issue in standard no-core shell model calculations. Furthermore, we find the proper treatment of the continuum indispensable for reliable statements about the quality of the adopted 3N interaction from chiral effective field theory. In particular, we find the ½+ resonance energy, which is of astrophysical interest, in good agreement with experiment. [ABSTRACT FROM AUTHOR]

We report ab initio calculations for neutron drops in a 10 MeV external harmonic-oscillator trap using chiral nucleon–nucleon plus three-nucleon interactions. We present total binding energies, internal energies, radii and odd–even energy differences for neutron numbers N = 2 – 18 using the no-core shell model with and without importance truncation. Furthermore, we present total binding energies for N = 8 , 16 , 20 , 28 , 40 , 50 obtained in a coupled-cluster approach. Comparisons with quantum Monte Carlo results, where available, using Argonne v 8 ′ with three-nucleon interactions reveal important dependences on the chosen Hamiltonian. [ABSTRACT FROM AUTHOR]

We present the first ab initio calculations for p-shell single-A hypemuclei. For the solution of the manybaryon problem, we develop two variants of the no-core shell model with explicit A and Σ+,Σ0,Σ- hyperons including A-Σ conversion, optionally supplemented by a similarity renormalization group transformation to accelerate model-space convergence. In addition to state-of-the-art chiral two- and three-nucleon interactions, we use leading-order chiral hyperon-nucleon interactions and a recent mesonexchange hyperon-nucleon interaction. We validate the approach for 5-shell hypemuclei and apply it to p-shell hypemuclei, in particular to 7ΛLi, 9ΛBe, and 13ΛC. We show that the chiral hyperon-nucleon interactions provide ground-state and excitation energies that generally agree with experiment within the cutoff dependence. At the same time we demonstrate that hypemuclear spectroscopy provides tight constraints on the hyperon-nucleon interactions. [ABSTRACT FROM AUTHOR]

We use the newly developed multireference in-medium similarity renormalization group to study all even isotopes of the calcium and nickel isotopic chains, based on two- plus three-nucleon interactions derived from chiral effective field theory. We present results for ground-state and two-neutron separation energies and quantify their theoretical uncertainties. At shell closures, we find excellent agreement with coupled-cluster results obtained with the same Hamiltonians. Our results confirm the importance of chiral 3N interactions to obtain a correct reproduction of experimental energy trends, and their subtle impact in neutron-rich Ca and Ni isotopes. At the same time, we uncover and discuss deficiencies of the input Hamiltonians which need to be addressed by the next generation of chiral interactions. [ABSTRACT FROM AUTHOR]

We present the first ab initio construction of valence-space Hamiltonians for medium-mass nuclei based on chiral two- and three-nucleon interactions using the in-medium similarity renormalization group. When applied to the oxygen isotopes, we find experimental ground-state energies are well reproduced, including the flat trend beyond the drip line at 24O. Similarly, natural-parity spectra in 21,22,23,24O are jn agreement with experiment, and we present predictions for excited states in 25,26O. The results exhibit a weak dependence on the harmonic-oscillator basis parameter and reproduce spectroscopy within the standard sd valence space. [ABSTRACT FROM AUTHOR]

The description of structural and dynamical properties of nuclei starting from the fundamental interaction between nucleons has been a long-standing goal in nuclear physics. The ab initio No-Core Shell Model combined with the Resonating-Group Method (NCSM/RGM) is capable of addressing both structural and reaction properties of light-nuclei. While promising results have already been achieved starting from a two-body Hamiltonian, a truly realistic prediction of nuclear observables requires the treatment of the three-nucleon interaction. Using similarity-renormalization-group evolved two- and three-nucleon interactions, we will present recent applications to n-He scattering process when accounting for the chiral two- plus three-nucleon interaction versus the chiral two-nucleon interaction. We compare our results to phase shifts obtained from R-matrix analysis of data up to 16 MeV neutron energy, below the d-H threshold. [ABSTRACT FROM AUTHOR]

We extend the ab initio no-core shell model/resonating-group method to include three-nucleon (3N) interactions for the description of nucleon-nucleus collisions. We outline the formalism, give algebraic expressions for the 3N-force integration kernels, and discuss computational aspects of two alternative implementations. The extended theoretical framework is then applied to nucleon-4He elastic scattering using similarity-renormalization-group (SRG)-evolved nucleon-nucleon plus 3N potentials derived from chiral effective field theory. We analyze the convergence properties of the calculated phase shifts and explore their dependence upon the SRG evolution parameter. We include up to six excited states of the 4He target and find significant effects from the inclusion of the chiral 3N force, e.g., it enhances the spin-orbit splitting between the 3/2-and 1/2- resonances and leads to an improved agreement with the phase shifts obtained from an accurate R-matrix analysis of the five-nucleon experimental data. We find remarkably good agreement with measured differential cross sections at various energies below the d-3H threshold, while analyzing powers manifest larger deviations from experiment for certain energies and angles. [ABSTRACT FROM AUTHOR]