Five-Loop Running of the QCD Coupling Constant.

We analytically compute the five-loop term in the beta function which governs the running of α_{s}-the quark-gluon coupling constant in QCD. The new term leads to a reduction of the theory uncertainty in α_{s} taken at the Z-boson scale as extracted from the τ-lepton decays as well as to new, improved by one more order of perturbation theory, predictions for the effective coupling constants of the standard model Higgs boson to gluons and for its total decay rate to the quark-antiquark pairs.

Standard finishing categories for high-throughput sequencing of viral genomes.

Viral genome sequencing has become the cornerstone of almost all aspects of virology. In particular, high-throughput, next-generation viral genome sequencing has become an integral part of molecular epidemiological investigations into outbreaks of viral disease, such as the recent outbreaks of Middle Eastern respiratory syndrome, Ebola virus disease and Zika virus infection. Multiple institutes have acquired the expertise and necessary infrastructure to perform such investigations, as evidenced by the accumulation of thousands of novel viral sequences over progressively shorter time periods. The authors recently proposed a nomenclature comprised of five high-throughput sequencing standard categories to describe the quality of determined viral genome sequences. These five categories (standard draft, high quality, coding complete, complete and finished) cover all levels of viral genome finishing and can be applied to sequences determined by any technology platform or assembly technique.

Le séquençage des génomes viraux est devenu la pierre angulaire de pratiquement toutes les facettes de la virologie. En particulier, le séquençage à haut débit de nouvelle génération est désormais une partie intégrante des enquêtes d'épidémiologie moléculaire relatives aux foyers de maladies virales, par exemple les récentes épidémies du syndrome respiratoire du Moyen-Orient, la maladie due au virus Ebola ou l'infection par le virus Zika. Nombre d'institutions ont acquis les compétences techniques et les infrastructures nécessaires pour réaliser ce type d'enquêtes, comme en témoigne l'accumulation de milliers de séquences virales nouvelles obtenues en un laps de temps de plus en plus court. Les auteurs ont récemment élaboré une nomenclature constituée de cinq catégories de référence décrivant la qualité des séquences d'un génome viral obtenues par séquençage à haut débit. Ces cinq catégories (ébauche de référence, séquence de haute qualité, séquence codante complète, séquence complète et séquence finie) couvrent toutes les étapes de la finition du génome viral et s'appliquent quelle que soit la plateforme technologique ou la technique d'assemblage utilisée pour déterminer la séquence.

La secuenciación del genoma vírico se ha erigido a día de hoy en la piedra angular de casi todos los aspectos de la virología. La secuenciación de alto rendimiento de próxima generación, en particular, es ahora un componente integral de las investigaciones de epidemiología molecular sobre brotes de enfermedades víricas como los registrados últimamente de síndrome respiratorio de Oriente Medio, enfermedad por el virus del Ebola o infección por el virus Zika. Numerosas instituciones se han dotado de las competencias técnicas y la infraestructura necesaria para llevar a cabo tales investigaciones, como deja patente la acumulación de miles de nuevas secuencias víricas en periodos de tiempo cada vez más cortos. En fechas recientes los autores han propuesto una nomenclatura compuesta de cinco categorías de referencia que sirven para describir la calidad de las secuencias de genoma vírico determinadas por secuenciación de alto rendimiento. Estas cinco categorías (borrador normal, gran calidad, codificación completa, completa y acabada) cubren toda la gradación de acabados en la secuenciación de genoma vírico y pueden ser aplicadas a las secuencias obtenidas por cualquier dispositivo técnico o cualquier técnica de ensamblaje.

PCR-based assay to detect sheeppox virus in ocular, nasal, and rectal swabs from infected Moroccan sheep.

Sheeppox is now enzootic in Morocco. The development of a reliable method for rapid diagnosis of the disease is a central part of any control strategy. The aim of this study is to determine the diagnostic value of a variety of clinical samples such as ovine nasal, ocular or rectal swabs for the detection of sheeppox virus (SPPV) by qualitative conventional polymerase chain reaction (PCR), using a single pair of primers targeting the inverted terminal repeats of the SPPV InS-1 strain, a virulent field isolate. Swab and blood samples were collected from forty animals naturally infected with SPPV who had clinical signs of sheeppox. All animals tested PCR-positive for SPPV. Positive results were obtained infrequently with blood samples, whereas swab samples from at least two sites (nasal, ocular, rectal) were positive per evaluated animal. These results indicate that swab samples are suitable for quantitative molecular SPPV diagnosis. PCR product sequences obtained from all types of sheep samples proved to be identical to the corresponding regions of sheeppox virus strain Romania 65.

Complete O(αs4) QCD corrections to hadronic Z decays.

Corrections of order α(s)(4) for the axial singlet contributions for the decay rate of the Z boson into hadrons are evaluated in the limit of the heavy top quark mass. Combined with recently finished O(α(s)(4)) calculations of the nonsinglet corrections, the new results directly lead us to the first complete O(α(s)(4)) prediction for the total hadronic decay rate of the Z boson. The new O(α(s)(4)) term in Z-decay rate leads to a significant stabilization of the perturbative series, to a reduction of the theory uncertainty in the strong coupling constant α(s), as extracted from these measurements, and to a small shift of the central value.

Adler function, Bjorken sum rule, and the Crewther relation to order alpha(s)(4) in a general gauge theory.

We compute, for the first time, the order alpha(s)(4) contributions to the Bjorken sum rule for polarized electron-nucleon scattering and to the (nonsinglet) Adler function for the case of a generic color gauge group. We confirm at the same order a (generalized) Crewther relation which provides a strong test of the correctness of our previously obtained results: the QCD Adler function and the five-loop beta function in quenched QED. In particular, the appearance of an irrational contribution proportional to zeta(3) in the latter quantity is confirmed. We obtain the commensurate scale equation relating the effective strong coupling constants as inferred from the Bjorken sum rule and from the Adler function at order alpha(s)(4).

Order alphas4 QCD corrections to Z and tau decays.

Using recently developed methods for the evaluation of five-loop amplitudes in perturbative QCD, corrections of order alphas4 for the nonsinglet part of the cross section for electron-positron annihilation into hadrons and for the decay rates of the Z boson and the tau lepton into hadrons are evaluated. The new terms lead to a significant stabilization of the perturbative series, to a reduction of the theory uncertainly in the strong coupling constant alphas, as extracted from these measurements, and to a small shift of the central value, moving the two central values closer together. The agreement between two values of alphas measured at vastly different energies constitutes a striking test of asymptotic freedom. Combining the results from Z and tau decays we find alphas(MZ)=0.1198+/-0.0015 as one of the most precise and presently only result for the strong coupling constant in order alphas4.

Four-loop QCD corrections to the electroweak rho parameter.

The four-loop QCD corrections to the electroweak rho parameter arising from top and bottom quark loops are computed. Specifically we evaluate the missing "nonsinglet" piece. Using algebraic methods the amplitude is reduced to a set of around 50 new master integrals which are calculated with various analytical and numerical methods. The inclusion of the newly completed term halves the final value of the four-loop correction for the minimally renormalized top-quark mass. The predictions for the shift of the weak mixing angle and the W-boson mass are thus stabilized.

Scalar correlator at [symbol: see text](alpha(s)4), Higgs boson decay into bottom quarks, and bounds on the light-quark masses.

We compute, for the first time, the absorptive part of the massless correlator of two quark scalar currents in five loops. As physical applications, we consider the [symbol: see text](alpha(s)4) corrections to the decay rate of the standard model Higgs boson into quarks, as well as the constraints on the strange quark mass following from QCD sum rules.

Strange-quark mass from tau-lepton decays with O(alpha3s) accuracy.

The first complete calculation of the quadratic quark mass correction to the correlator of the two currents relevant for the strangeness-changing semihadronic tau-decay rate is presented including its real part at the four-loop level. This allows us to perform the extraction of the strange-quark mass m(s) from the decay width of the tau-lepton with full O(alpha3s) accuracy. In agreement with previous estimates, the newly computed alpha3s term proves to be rather large. This justifies inclusion of the similarly estimated alpha4s term in phenomenological analysis. Combined with an updated value of V us and an "improved" version of the renormalization group improvement of the perturbative series, this leads to an increase of the central value of m(s) by about 20% and a partial reduction of the theoretical uncertainty by about 50%.

Angiotensin-converting enzyme 2: a functional receptor for SARS coronavirus.

Cellular entry of enveloped viruses is often dependent on attachment proteins expressed on the host cell surface. Viral envelope proteins bind these receptors, and, in an incompletely understood process, facilitate fusion of the cellular and viral membranes so as to introduce the viral core into the cytoplasm. Only a small fraction of viral receptors have been identified so far. Recently, a novel coronavirus was identified as the etiological agent of severe acute respiratory syndrome (SARS). The fusion protein gene of SARS coronavirus (SARS-CoV) was cloned and characterized, and shortly thereafter, angiotensin-converting enzyme 2 (ACE2) was shown to be its functional receptor. Identification of ACE2 as a receptor for SARS-CoV will likely contribute to the development of antivirals and vaccines. It may also contribute to the development of additional animal models for studying SARS pathogenesis, and could help identify the animal reservoir of SARS-CoV.

Genetic analysis of the M RNA segment of Crimean-Congo hemorrhagic fever virus strains involved in the recent outbreaks in Russia.

Crimean-Congo hemorrhagic fever (CCHF) is a severe zoonosis with a high fatality rate. In Russia, local CCHF outbreaks have occurred in the Stavropol Territory, and the Volgograd and Astrakhan Regions during 2000 and 2001. Seven strains of CCHF virus (CCHFV) were isolated from infected patients and collected ticks. Two fragments of the CCHF virus M genome segment were PCR amplified and their nucleotide sequences were determined. All these virus strains appear to be closely related (up to 5.8% nucleotide sequence differences) and form a distinct clade on the CCHFV phylogenetic tree. Within this clade, CCHFV strains from Stavropol and Astrakhan cluster together, whereas those from Volgograd form a separate subgroup.

Cross section of e(+)e(-) annihilation into hadrons of order alpha(4)(s)n(2)(f) in perturbative QCD.

We present the first genuine QCD five-loop calculation of the vacuum polarization functions: analytical terms of order alpha(4)(s)n(2)(f) to the absorptive parts of vector and scalar correlators. These corrections form an important gauge-invariant subset of the full omicron(alpha(4)(s)) correction to e(+)e(-) annihilation into hadrons and the Higgs decay rate into hadrons, respectively. They discriminate between different widely used estimates of the full result.