266,394 research outputs found
Reproductive biology, spawning season, and growth of female rex sole (Glyptocephalus zachirus) in the Gulf of Alaska
Rex sole (Glyptocephalus zachirus) have a wide distribution throughout the North Pacific, ranging from central Baja California to the western Bering Sea. Although rex sole are an important species in the commercial trawl fisheries off the U.S. West Coast, knowledge of their reproductive biology is limited to one study off the Oregon coast where ovaries were analyzed with gross anatomical methods. This study was initiated to determine reproductive and growth parameters specific to rex sole in the Gulf of Alaska (GOA) stock. Female rex sole (n=594) ranging in total length from 166 to 552 mm were collected opportunistically around Kodiak Island, Alaska, from February 2000 to October 2001. All ovaries were analyzed by using standard histological criteria to determine the maturity stage. Year-round sampling of rex sole ovaries confirmed that rex sole are batch spawners and have a protracted spawning season in the GOA that lasts at least eight months, from October to May; the duration of the spawning season and the months of spawning activity are different from those previously estimated. Female rex sole in the GOA had an estimated length at 50% maturity (ML50) of 352 mm, which is greater than the previously estimated ML50 at southern latitudes. The maximum age of collected female rex sole was 29 years, and the estimated age at 50% maturity (MA50) in the GOA was 5.1 years. The von Bertalanffy growth model for rex sole in the GOA was significantly different from the previously estimated model for rex sole off the Oregon coast. This study indicated that there are higher growth rates for rex sole in the GOA than off the Oregon coast and that there are differences in length at maturity and similarity in age at maturity between the two regions
Expression of alternatively spliced human T-cell leukemia virus type 1 mRNAs is influenced by mitosis and by a novel cis-acting regulatory sequence
Human T-cell leukemia virus type 1 (HTLV-1) expression depends on the concerted action of Tax, which drives transcription of the viral genome, and Rex, which favors expression of incompletely spliced mRNAs and determines a 2-phase temporal pattern of viral expression. In the present study, we investigated the Rex dependence of the complete set of alternatively spliced HTLV-1 mRNAs. Analyses of cells transfected with Rex-wild-type and Rex-knockout HTLV-1 molecular clones using splice site-specific quantitative reverse transcription (qRT)-PCR revealed that mRNAs encoding the p30Tof, p13, and p12/8 proteins were Rex dependent, while the p21rex mRNA was Rex independent. These findings provide a rational explanation for the intermediate-late temporal pattern of expression of the p30tof, p13, and p12/8 mRNAs described in previous studies. All the Rex-dependent mRNAs contained a 75-nucleotide intronic region that increased the nuclear retention and degradation of a reporter mRNA in the absence of other viral sequences. Selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) analysis revealed that this sequence formed a stable hairpin structure. Cell cycle synchronization experiments indicated that mitosis partially bypasses the requirement for Rex to export Rex-dependent HTLV-1 transcripts. These findings indicate a link between the cycling properties of the host cell and the temporal pattern of viral expression/latency that might influence the ability of the virus to spread and evade the immune system
First analysis of inclined air showers detected by Tunka-Rex
The Tunka Radio Extension (Tunka-Rex) is a digital antenna array for the
detection of radio emission from cosmic-ray air showers in the frequency band
of 30 to 80 MHz and for primary energies above 100 PeV. The standard analysis
of Tunka-Rex includes events with zenith angle of up to 50. This cut is
determined by the efficiency of the external trigger. However, due to the
air-shower footprint increasing with zenith angle and due to the more efficient
generation of radio emission (the magnetic field in the Tunka valley is almost
vertical), there are a number of ultra-high-energy inclined events detected by
Tunka-Rex. In this work we present a first analysis of a subset of inclined
events detected by Tunka-Rex. We estimate the energies of the selected events
and test the efficiency of Tunka-Rex antennas for detection of inclined air
showers.Comment: ARENA2018 proceeding
Latest results of the Tunka Radio Extension (ISVHECRI2016)
The Tunka Radio Extension (Tunka-Rex) is an antenna array consisting of 63
antennas at the location of the TAIGA facility (Tunka Advanced Instrument for
cosmic ray physics and Gamma Astronomy) in Eastern Siberia, nearby Lake Baikal.
Tunka-Rex is triggered by the air-Cherenkov array Tunka-133 during clear and
moonless winter nights and by the scintillator array Tunka-Grande during the
remaining time. Tunka-Rex measures the radio emission from the same air-showers
as Tunka-133 and Tunka-Grande, but with a higher threshold of about 100 PeV.
During the first stages of its operation, Tunka-Rex has proven, that sparse
radio arrays can measure air-showers with an energy resolution of better than
15\% and the depth of the shower maximum with a resolution of better than 40
g/cm\textsuperscript{2}. To improve and interpret our measurements as well as
to study systematic uncertainties due to interaction models, we perform radio
simulations with CORSIKA and CoREAS. In this overview we present the setup of
Tunka-Rex, discuss the achieved results and the prospects of mass-composition
studies with radio arrays.Comment: proceedings of ISVHECRI2016 conferenc
A splice variant in KRT71 is associated with curly coat phenotype of Selkirk Rex cats.
One of the salient features of the domestic cat is the aesthetics of its fur. The Selkirk Rex breed is defined by an autosomal dominant woolly rexoid hair (ADWH) abnormality that is characterized by tightly curled hair shafts. A genome-wide case - control association study was conducted using 9 curly coated Selkirk Rex and 29 controls, including straight-coated Selkirk Rex, British Shorthair and Persian, to localize the Selkirk autosomal dominant rexoid locus (SADRE). Although the control cats were from different breed lineages, they share recent breeding histories and were validated as controls by Bayesian clustering, multi-dimensional scaling and genomic inflation. A significant association was found on cat chromosome B4 (Praw = 2.87 × 10(-11)), and a unique haplotype spanning ~600 Kb was found in all the curly coated cats. Direct sequencing of four candidate genes revealed a splice site variant within the KRT71 gene associated with the hair abnormality in Selkirk Rex
The Specification in Z of the REX Protocol
REX is a protocol supporting a client/server style of interaction between a number of entities in a distributed system. Within this interaction paradigm, client entities may request services supplied by server entities, by interacting with intermediate protocol entities. This paper presents a Z specification of part of the REX protocol
Emission Line AGNs from the REX survey: Results from optical spectroscopy
We present 71 Emission Line objects selected from the REX survey. Except for
3 of them, for which the presence of an active nucleus is dubious, all these
sources are Active Galactic Nuclei (QSOs, Seyfert galaxies, emission line
radiogalaxies). In addition, we present the spectra of other 19 AGNs included
in a preliminary version of the REX catalog but not in the final one. The
majority (80) of the 90 sources presented in this paper is newly discovered.
Finally, we present the general properties in the radio and in the X-ray band
of all the AGNs discovered so far in the REX survey.Comment: 27 pages. To be published in Astronomy and Astrophysics, Supplement
Series. Better quality figures can be asked to the autho
Radio measurements of the energy and the depth of the shower maximum of cosmic-ray air showers by Tunka-Rex
We reconstructed the energy and the position of the shower maximum of air
showers with energies PeV applying a method using radio
measurements performed with Tunka-Rex. An event-to-event comparison to
air-Cherenkov measurements of the same air showers with the Tunka-133
photomultiplier array confirms that the radio reconstruction works reliably.
The Tunka-Rex reconstruction methods and absolute scales have been tuned on
CoREAS simulations and yield energy and values consistent
with the Tunka-133 measurements. The results of two independent measurement
seasons agree within statistical uncertainties, which gives additional
confidence in the radio reconstruction. The energy precision of Tunka-Rex is
comparable to the Tunka-133 precision of , and exhibits a
uncertainty on the absolute scale dominated by the amplitude calibration of the
antennas. For , this is the first direct experimental
correlation of radio measurements with a different, established method. At the
moment, the resolution of Tunka-Rex is approximately g/cm. This resolution can probably be improved by deploying additional
antennas and by further development of the reconstruction methods, since the
present analysis does not yet reveal any principle limitations.Comment: accepted for publication by JCA
Tunka-Rex: the Cost-Effective Radio Extension of the Tunka Air-Shower Observatory
Tunka-Rex is the radio extension of the Tunka cosmic-ray observatory in
Siberia close to Lake Baikal. Since October 2012 Tunka-Rex measures the radio
signal of air-showers in coincidence with the non-imaging air-Cherenkov array
Tunka-133. Furthermore, this year additional antennas will go into operation
triggered by the new scintillator array Tunka-Grande measuring the secondary
electrons and muons of air showers. Tunka-Rex is a demonstrator for how
economic an antenna array can be without losing significant performance: we
have decided for simple and robust SALLA antennas, and we share the existing
DAQ running in slave mode with the PMT detectors and the scintillators,
respectively. This means that Tunka-Rex is triggered externally, and does not
need its own infrastructure and DAQ for hybrid measurements. By this, the
performance and the added value of the supplementary radio measurements can be
studied, in particular, the precision for the reconstructed energy and the
shower maximum in the energy range of approximately eV. Here
we show first results on the energy reconstruction indicating that radio
measurements can compete with air-Cherenkov measurements in precision.
Moreover, we discuss future plans for Tunka-Rex.Comment: Proceeding of UHECR 2014, Springdale, Utah, USA, accepted by JPS
Conference Proceeding
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