393 research outputs found
Field Application of a Monoclonal Antibody Panel to Differentiate Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) Isolates
Porcine reproductive and respiratory syndrome (PRRS) is recognized as the most economically devastating disease of swine throughout the world. Nucleotide sequencing and serological studies have deomnstrated sustantial antigenic variation amoung PRRS virus (PRRSV) isolates (Murtaugh, et al., 1995; Nelson, et al., 1993, 1996). Recently, European-like PRRSV isolates have been identified in the US (Rossow, et al. 2000) and other new, highly virulent PRRSV isolates have appeared and affect sows at all stages of gestation causing mortality of adult pigs as well as young pigs (Epperson et al., 1997). Therefore, it is even more important to control the spread of these new strains. Clinical signs vary between herds, indicating that viruses may differ in pathogenicity. Furthermore, effective use of vaccines and management approaches to control PRRS has not always been successful
RZ Comae - A W-Type Overcontact Eclipsing Binary}
RZ Com (GSC 1990-2841) is a short period (P = 0.3385 d) W UMa-type
binary system, type-W, which has had, over the years, two spectroscopic and
numerous light curve studies. The various mass determinations show a large
scatter. Here we present the results of new light curve and radial velocity
observations, and a fresh analysis by the Wilson-Devinney 2003 code. We
have been able to obtain a unified model for photometric five datasets,
each used one or more filters. The main model parameters such as mass ratio,
temperature, potential, and inclination were in close agreement, as
were derived quantities such as mass, stellar radius, etc. Only the spot
parameters differed, as one might expect. Further, we determined a distance
estimate, r = 204 +- 5 pc, in good agreement with the Gaia value of
r = 203.1 +- 3.7 pc. We also presented four new eclipse timings, performed
a renewed period analysis attaining a LiTE fit. With that we
determined a rate of intrinsic period change dP/dt = 3.86(2) x 10^-8
days/year, and - assuming conservative processes - a rate of mass exchange
dm_1/ dt = -4.1(3) x 10^-8 Msun/year which means that the less massive
star is losing mass to its companion
Period Analysis, Roche Modeling and Absolute Parameters for AU Ser, an Overcontact Binary System
CCD photometric data collected at UnderOak Observatory (UO) and Desert Bloom Observatory (DBO) in three bandpasses (B, V and I_C) produced 10 new times of minimum for AU Ser which were used to revise the linear ephemeris. These results captured in 2011 and 2018 reinforced a longstanding observation that the shape of the light curve from this W UMa binary system (P=0.386497 d) is highly variable. Significantly skewed peaks and differences at maximum light were detected during quadrature which could only be simulated during Roche modeling by positioning a hot spot on the secondary star close to the neck between both constituents. Historically this system has been variously classified as an F8, G5 and K0 system; however, this study supports more recent reports that AU Ser is best described as spectral type K1V-K2V. A fresh assessment of eclipse time residuals over the past 80 years has provided additional insight regarding cyclical changes in orbital period experienced by this interesting variable star
ORFanID: A Web-Based Search Engine for the Discovery and Identification of Orphan and Taxonomically Restricted Genes
With the multiplicity of genomes sequenced today, it has been shown that significant percentages of genes in any given taxon do not possess orthologous sequences in other taxa. These sequences are typically designated as orphans/ORFans when found as singletons in one species only or taxonomically restricted genes (TRGs) when found at higher taxonomic ranks. Quantitative and collective studies of these genes are necessary for understanding their biological origins. Currently, orphan gene identifying software is limited, and those previously available are either not functional, are limited in their database search range, or are very complex algorithmically. Thus, an interested researcher studying orphan genes must harvest their data from many disparate sources. ORFanID is a graphical web-based search engine that efficiently finds both orphan genes and TRGs at all taxonomic levels, from DNA or amino acid sequences in the entire NCBI database cluster and other large bioinformatics repositories. This algorithm allows the easy identification of both orphan genes and TRGs using both nucleotide and protein sequences in any species of interest. ORFanID identifies genes unique to any taxonomic rank, from species to a domain, using standard NCBI systematic classifiers. The software allows for user control of the NCBI database search parameters. The results of the search are provided in a spreadsheet as well as a graphical display. All the tables in the software are sortable by column, and results can be easily filtered with fuzzy search functionality. In addition, the visual presentation is expandable and collapsible by taxonomy
Enhancement of pair correlation in a one-dimensional hybridization model
We propose an integrable model of one-dimensional (1D) interacting electrons
coupled with the local orbitals arrayed periodically in the chain. Since the
local orbitals are introduced in a way that double occupation is forbidden, the
model keeps the main feature of the periodic Anderson model with an interacting
host. For the attractive interaction, it is found that the local orbitals
enhance the effective mass of the Cooper-pair-like singlets and also the pair
correlation in the ground state. However, the persistent current is depressed
in this case. For the repulsive interaction case, the Hamiltonian is
non-Hermitian but allows Cooper pair solutions with small momenta, which are
induced by the hybridization between the extended state and the local orbitals.Comment: 11 page revtex, no figur
Current Status of Simulations
As the title suggests, the purpose of this chapter is to review the current
status of numerical simulations of black hole accretion disks. This chapter
focuses exclusively on global simulations of the accretion process within a few
tens of gravitational radii of the black hole. Most of the simulations
discussed are performed using general relativistic magnetohydrodynamic (MHD)
schemes, although some mention is made of Newtonian radiation MHD simulations
and smoothed particle hydrodynamics. The goal is to convey some of the exciting
work that has been going on in the past few years and provide some speculation
on future directions.Comment: 15 pages, 14 figures, to appear in the proceedings of the ISSI-Bern
workshop on "The Physics of Accretion onto Black Holes" (8-12 October 2012
An exploratory study into the role and interplay of intrinsic and extrinsic cues in Australian consumers’ evaluations of fish.
This study explores the role and interplay of intrinsic and extrinsic cues when evaluating fish quality and in shaping consumers' attitudes toward fish consumption. A sensory analysis of nine different fish including five variants of barramundi was conducted to determine how consumers evaluated the fish on intrinsic cues. Focus groups were then conducted to explore the impact of extrinsic cues on attitudes and purchase intentions. While the sensory analysis revealed distinct differences between barramundi variants on intrinsic cues (notably taste), the focus groups revealed that, as a brand, barramundi is perceived much more favourably and consistently. Consumers used extrinsic cues, particularly country of origin, as surrogate indicators of quality. Aquaculture producers need to ensure intrinsic product quality and consistency, as while consumers use the extrinsic cue of "Australian grown" as a surrogate indicator of quality, as their familiarity and confidence with seafood grows, this overreliance on extrinsic cues may diminish
Description of the third instar larva of Megadytes latus (Fabricius) (Coleoptera, Dytiscidae), with an identification key for described larvae of the genus
Ultrafaint [C II] emission in a redshift = 2 gravitationally lensed metal-poor dwarf galaxy
Galaxie
Mathematical model of plant-virus interactions mediated by RNA interference
Cross-protection, which refers to a process whereby artificially inoculating a plant with a mild strain provides protection against a more aggressive isolate of the virus, is known to be an effective tool of disease control in plants. In this paper we derive and analyse a new mathematical model of the interactions between two competing viruses with particular account for RNA interference. Our results show that co-infection of the host can either increase or decrease the potency of individual infections depending on the levels of cross-protection or cross-enhancement between different viruses. Analytical and numerical bifurcation analyses are employed to investigate the stability of all steady states of the model in order to identify parameter regions where the system exhibits synergistic or antagonistic behaviour between viral strains, as well as different types of host recovery. We show that not only viral attributes but also the propagating component of RNA-interference in plants can play an important role in determining the dynamics
- …