47,849 research outputs found
Real-time reverse transcription polymerase chain reaction development for rapid detection of Tomato brown rugose fruit virus and comparison with other techniques
Background: Tomato brown rugose fruit virus (ToBRFV) is a highly infectious tobamovirus that causes severe disease in tomato (Solanum lycopersicum L.) crops. In Italy, the first ToBRFV outbreak occurred in 2018 in several provinces of the Sicily region. ToBRFV outbreak represents a serious threat for tomato crops in Italy and the Mediterranean Basin. Methods: Molecular and biological characterisation of the Sicilian ToBRFV ToB-SIC01/19 isolate was performed, and a sensitive and specific Real-time RT-PCR TaqMan minor groove binder probe method was developed to detect ToBRFV in infected plants and seeds. Moreover, four different sample preparation procedures (immunocapture, total RNA extraction, direct crude extract and leaf-disk crude extract) were evaluated. Results: The Sicilian isolate ToB-SIC01/19 (6,391 nt) showed a strong sequence identity with the isolates TBRFV-P12-3H and TBRFV-P12-3G from Germany, Tom1-Jo from Jordan and TBRFV-IL from Israel. The ToB-SIC01/19 isolate was successfully transmitted by mechanical inoculations in S. lycopersicum L. and Capsicum annuum L., but no transmission occurred in S. melongena L. The developed real-time RT-PCR, based on the use of a primer set designed on conserved sequences in the open reading frames3, enabled a reliable quantitative detection. This method allowed clear discrimination of ToBRFV from other viruses belonging to the genus Tobamovirus, minimising false-negative results. Using immunocapture and total RNA extraction procedures, the real-time RT-PCR and end-point RT-PCR gave the same comparable results. Using direct crude extracts and leaf-disk crude extracts, the end-point RT-PCR was unable to provide a reliable result. This developed highly specific and sensitive real-time RT-PCR assay will be a particularly valuable tool for early ToBRFV diagnosis, optimising procedures in terms of costs and time
Stationary configurations of two extreme black holes obtainable from the Kinnersley-Chitre solution
Stationary axisymmetric systems of two extreme Kerr sources separated by a
massless strut, which arise as subfamilies of the well-known Kinnersley-Chitre
solution, are studied. We present explicit analytical formulas for the
individual masses and angular momenta of the constituents and establish the
range of the parameters for which such systems can be regarded as describing
black holes. The mass-angular momentum relations and the interaction force in
the black-hole configurations are also analyzed. Furthermore, we construct a
charging generalization of the Kinnersley-Chitre metric and, as applications of
the general formulas obtained, discuss two special cases describing a pair of
identical co- and counterrotating extreme Kerr-Newman black holes kept apart by
a conical singularity. From our analysis it follows in particular that the
equality relating the mass, angular momentum per unit mass and
electric charge of a single Kerr-Newman extreme black hole is no longer
verified by the analogous extreme black-hole constituents in binary
configurations.Comment: final version revised according to referee's suggestion
Noncommutative spacetime symmetries: Twist versus covariance
We prove that the Moyal product is covariant under linear affine spacetime
transformations. From the covariance law, by introducing an -space
where the spacetime coordinates and the noncommutativity matrix components are
on the same footing, we obtain a noncommutative representation of the affine
algebra, its generators being differential operators in -space. As
a particular case, the Weyl Lie algebra is studied and known results for Weyl
invariant noncommutative field theories are rederived in a nutshell. We also
show that this covariance cannot be extended to spacetime transformations
generated by differential operators whose coefficients are polynomials of order
larger than one. We compare our approach with the twist-deformed enveloping
algebra description of spacetime transformations.Comment: 19 pages in revtex, references adde
Instability of Amorphous Ru-Si-O Thin Films under Thermal Oxidation
Ternary films about 200 nm thick of composition Ru20Si15O65 have been synthesized by reactive rf magnetron sputtering of a Ru1Si1 target in an argon-oxygen gas. As-deposited, the films are X-ray-amorphous. Their atomic density is 8.9 × 10^22/cm^3 (5.1 g/cm^3), and their electrical resistivity is in the range of 2 mOmega cm. After annealing in dry oxygen at 600°C for 30 min, micron-sized grains of RuO2 grow out of the film and volatile RuO4 escapes. The significance of these results is discussed
Rosenblatt distribution subordinated to gaussian random fields with long-range dependence
The Karhunen-Lo\`eve expansion and the Fredholm determinant formula are used
to derive an asymptotic Rosenblatt-type distribution of a sequence of integrals
of quadratic functions of Gaussian stationary random fields on R^d displaying
long-range dependence. This distribution reduces to the usual Rosenblatt
distribution when d=1. Several properties of this new distribution are
obtained. Specifically, its series representation in terms of independent
chi-squared random variables is given, the asymptotic behavior of the
eigenvalues, its L\`evy-Khintchine representation, as well as its membership to
the Thorin subclass of self-decomposable distributions. The existence and
boundedness of its probability density is then a direct consequence.Comment: This paper has 40 pages and it has already been submitte
Characterization of the Turbulent Magnetic Integral Length in the Solar Wind: From 0.3 to 5 Astronomical Units
The solar wind is a structured and complex system, in which the fields vary
strongly over a wide range of spatial and temporal scales. As an example, the
turbulent activity in the wind affects the evolution in the heliosphere of the
integral turbulent scale or correlation length [{\lambda}], usually associated
with the breakpoint in the turbulent-energy spectrum that separates the
inertial range from the injection range. This large variability of the fields
demands a statistical description of the solar wind. In this work, we study the
probability distribution function (PDF) of the magnetic autocorrelation lengths
observed in the solar wind at different distances from the Sun. We use
observations from Helios, ACE, and Ulysses spacecraft. We distinguish between
the usual solar wind and one of its transient components (Interplanetary
Coronal Mass Ejections, ICMEs), and study also solar wind samples with low and
high proton beta [\beta_p ]. We find that in the last 3 regimes the PDF of
{\lambda} is a log-normal function, consistent with the multiplicative and
non-linear processes that take place in the solar wind, the initial {\lambda}
(before the Alfv\'enic point) being larger in ICMEs
Sterile neutrino decay and the LSND experiment
We propose a new explanation of the intriguing LSND evidence for electron
antineutrino appearance in terms of heavy (mostly sterile) neutrino decay via a
coupling with a light scalar and light (mostly active) neutrinos. We perform a
fit to the LSND data, as well as all relevant null-result experiments, taking
into account the distortion of the spectrum due to decay. By requiring a
coupling g ~ 10^{-5}, a heavy neutrino mass m_4 ~ 100 keV and a mixing with
muon neutrinos |U_{mu 4}|^2 ~ 10^{-2}, we show that this model explains all
existing data evading constraints that disfavor standard (3+1) neutrino models.Comment: 3pp. Talk given at 9th International Conference on Astroparticle and
Underground Physics (TAUP 2005), Zaragoza, Spain, 10-14 Sep 200
Comparison of Employment Disability Discrimination Claims with Other Statutes Across U.S. Equal Opportunity Commission and Fair Employment Practice Agencies Nationally
Although 15 years have passed since the employment provisions of the Americans with Disabilities Act of 1990 (ADA) became effective, significant employment disparities for persons with disabilities persist. It is important to assess how employer policies and practices may contribute to this disparity. Analyses of employment-related discrimination claims and subsequent legal outcomes are an important source of information about where and how disability employment discrimination is perceived to be happening. Examining the disability employment discrimination charges filed with the U.S. Equal Employment Opportunity Commission (EEOC) and Fair Employment Practice Agencies (FEPAs) within states can inform an understanding of where specific issues continue. This research uses the EEOC\u27s Charge Data System (CDS) (later called the Integrated Mission System, IMS) to explore difference between the filing of discrimination claims at EEOC offices and state FEPA offices. To date, most analyses of these charges have occurred on the EEOC charge data only. Yet of the 328,001 disability employment discrimination charges filed across both agencies during 1993 – 2003, almost half (46 percent) of these charges have been filed in FEPA offices. Analyzing both sets of data provides a fuller picture of disability employment discrimination claims nationally and subsequently further informs our understanding of where problems may be occurring in the implementation of the ADA Title I provisions.
For more information, Contact Susanne Bruyère: [email protected]
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