753 research outputs found
Belgian Register of Marine Species, compiled and validated by the VLIZ Belgian Marine Species Consortium
Forbidden oxygen lines at various nucleocentric distances in comets
To study the formation of the [OI] lines - i.e., 5577 A (the green line),
6300 A and 6364 A (the two red lines) - in the coma of comets and to determine
the parent species of the oxygen atoms using the green to red-doublet emission
intensity ratio (G/R ratio) and the lines velocity widths. We acquired at the
ESO VLT high-resolution spectroscopic observations of comets C/2002 T7
(LINEAR), 73P-C/Schwassmann-Wachmann 3, 8P/Tuttle, and, 103P/Hartley 2 when
they were close to the Earth (< 0.6 au). Using the observed spectra, we
determined the intensities and the widths of the three [OI] lines. We have
spatially extracted the spectra in order to achieve the best possible
resolution of about 1-2", i.e., nucleocentric projected distances of 100 to 400
km depending on the geocentric distance of the comet. We have decontaminated
the [OI] green line from C2 lines blends. It is found that the observed G/R
ratio on all four comets varies as a function of nucleocentric projected
distance. This is mainly due to the collisional quenching of O(1S) and O(1D) by
water molecules in the inner coma. The observed green emission line width is
about 2.5 km/s and decreases as the distance from the nucleus increases which
can be explained by the varying contribution of CO2 to the O(1S) production in
the innermost coma. The photodissociation of CO2 molecules seems to produce
O(1S) closer to the nucleus while the water molecule forms all the O(1S) and
O(1D) atoms beyond 1000 km. Thus we conclude that the main parent species
producing O(1S) and O(1D) in the inner coma is not always the same. The
observations have been interpreted in the framework of the
coupled-chemistry-emission model of Bhardwaj & Raghuram (2012) and the upper
limits of CO2 relative abundances are derived from the observed G/R ratios.
Measuring the [OI] lines could indeed provide a new way to determine the CO2
relative abundance in comets.Comment: accepted for publication in A&A, the abstract is shortene
Pleiotropic functions of the tumor- and metastasis-suppressing Matrix Metalloproteinase-8 in mammary cancer in MMTV-PyMT transgenic mice
Matrix metalloproteinase-8 (MMP-8; neutrophil collagenase) is an important regulator of innate immunity which has onco-suppressive actions in numerous tumor types
Aphia for a World Register of Marine Species (WoRMS)
An authoritative and global register of all marine species is urgently needed to facilitate biological data management and exchange, the integration of ecological and biodiversity data with non-biological ocean data, and to assist taxonomists in describing new species, revisions and correcting past nomenclatural confusion. The exercise of producing this list has added benefits in fostering collaboration between experts at a global scale and maintaining taxonomic expertise. Easy access to the register will allow local ecologists and biologists to use correct taxonomic names, and will encourage addition of overlooked species to the list. This will in turn stimulate a.o. biodiversity Species’(WoRMS) is the logical next step for ocean biodiversity informatics (OBI) to become an everyday and essential supporting infrastructure for the marine sciences, monitoring and environmental management. WoRMS is a standards based, quality controlled, expert validated, open-access infrastructure for research, education, and data and resource management. It builds on experience in developing the European Register of Marine Species and the Ocean Biogeographic Information System, and will collaborate with and contribute to the GBIF’s ECAT and planned Global Names Architecture, Species 2000, the Catalogue of Life, the Ocean Biogeographic Information System, the Encyclopaedia of Life, SeaLifeBase, IOC’s International Oceanographic Data and Information Exchange, and related initiatives. The Aphia database, developed and maintained by the Flanders Marine Institute (VLIZ), serves as the IT platform for WoRMS. Currently, well over 100 world leading taxonomists are contributing towards this World Register WoRMS webportal and all its functionalities, such as the web-based services and the online edit tool for the taxonomic experts. For further details see http://www.marinespecies.org
An Evaluation of Technical Analysis as a Marketing Tool for Farmers
The increased price volatility of the past decade has increased the importance of producer marketing strategies. With wide price ranges, producers now have more monetary incentive to attempt to store when prices are low, and incentive to attempt to sell when prices are high, than when price ranges were relatively narrow. Many farmers are seeking professional marketing advice, in attempts to improve their marketing information. A recent survey indicated that over 57 percent of farmers with sales over $100,000 subscribed to at least one market advisory service. This professional advice often includes technical analysis. However, from the producers\u27 perspective, the benefits and gains, and the problems and drawbacks of charting, have not been adequately studied. Few studies have considered the implications of producers dealing with both the futures market and the cash market. This study deals with this important distinction. Despite a lack of evidence, farmers are paying to receive technical analysis. from experts. One farmer oriented, professional charting service implies that using their charts will improve one\u27s trading proficiency by 10%-20%. Left unanswered is what benefit this is to a grain farmer who sells only two or three times per year. Other charting services make unsupported claims, too. One advertisement stated, Oats are very nice to trade technically. This commodity always goes where it is projected to go--even if only for one trade. The purpose of the study was to evaluate the usefulness of technical analysis for farmers, not futures market speculators. A major objective of this study was to examine the cash market prices that would have been paid or received if cash transactions had been made when futures market price charts signaled to buy or sell. The short-run forecasting accuracy of price chart formations was also analyzed. A second major objective was to analyze the results of three producer marketing strategies which use technical analysis. The first strategy compared hedging for short periods, to selling in the cash market. The goal of this test was to find the effective annual interest rate that a producer could obtain by hedging under certain conditions. The second strategy tested was graphing of the basis with moving averages. As the basis changed, the moving averages changed, causing buy and sell signals. The objective of this test was to evaluate the prices paid and received from this strategy\u27s signals, compared to the overall average price. The third strategy tested the usefulness of selective hedging. The objective was to evaluate the benefits and risks of selective hedging for producers
Cystatin C and lactoferrin concentrations in biological fluids as possible prognostic factors in eye tumor development
Objectives. To investigate the possible role of cystatin C in eye biological fluids locally and in serum and lactoferrin revealing anti-tumor activity in eye tumor development. Background. The increased number of eye tumors was registered recently not only in the countries with high insolation, but also in the northern countries including Russia (11 cases per million of population). Search for new biological markers is important for diagnosis and prognosis in eye tumors. Cystatin C, an endogenous inhibitor of cysteine proteases, plays an important protective role in several tumors. Lactoferrin was shown to express anti-tumor and antiviral activities. It was hypothesized that cystatin C and lactoferrin could serve as possible biomarkers in the diagnosis of malignant and benign eye tumors. Study design. A total of 54 patients with choroidal melanoma and benign eye tumors were examined (part of them undergoing surgical treatment). Serum, tear fluid and intraocular fluid samples obtained from the anterior chamber of eyes in patients with choroidal melanoma were studied. Methods. Cystatin C concentration in serum and eye biological fluids was measured by commercial ELISA kits for human (BioVendor, Czechia); lactoferrin concentration – by Lactoferrin-strip D 4106 ELISA test systems (Vector-BEST, Novosibirsk Region, Russia). Results. Cystatin C concentration in serum of healthy persons was significantly higher as compared to tear and intraocular fluids. In patients with choroidal melanoma, increased cystatin C concentration was similar in tear fluid of both the eyes. Lactoferrin level in tear fluid of healthy persons was significantly higher than its serum level. Significantly increased lactoferrin concentration in tear fluid was noted in patients with benign and malignant eye tumors. Conclusion. Increased level of cystatin C in tear fluid seems to be a possible diagnostic factor in the eye tumors studied. However, it does not allow us to differentiate between malignant and benign eye tumors. Similar changes were noted for lactoferrin in tear fluid
Detection of variable VHE gamma-ray emission from the extra-galactic gamma-ray binary LMC P3
Context. Recently, the high-energy (HE, 0.1-100 GeV) -ray emission
from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered
to be modulated with a 10.3-day period, making it the first extra-galactic
-ray binary.
Aims. This work aims at the detection of very-high-energy (VHE, >100 GeV)
-ray emission and the search for modulation of the VHE signal with the
orbital period of the binary system.
Methods. LMC P3 has been observed with the High Energy Stereoscopic System
(H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has
been folded with the known orbital period of the system in order to test for
variability of the emission. Energy spectra are obtained for the orbit-averaged
data set, and for the orbital phase bin around the VHE maximum.
Results. VHE -ray emission is detected with a statistical
significance of 6.4 . The data clearly show variability which is
phase-locked to the orbital period of the system. Periodicity cannot be deduced
from the H.E.S.S. data set alone. The orbit-averaged luminosity in the
TeV energy range is erg/s. A luminosity of erg/s is reached during 20% of the orbit. HE and VHE
-ray emissions are anti-correlated. LMC P3 is the most luminous
-ray binary known so far.Comment: 5 pages, 3 figures, 1 table, accepted for publication in A&
Characterizing the gamma-ray long-term variability of PKS 2155-304 with H.E.S.S. and Fermi-LAT
Studying the temporal variability of BL Lac objects at the highest energies
provides unique insights into the extreme physical processes occurring in
relativistic jets and in the vicinity of super-massive black holes. To this
end, the long-term variability of the BL Lac object PKS 2155-304 is analyzed in
the high (HE, 100 MeV 200 GeV)
gamma-ray domain. Over the course of ~9 yr of H.E.S.S observations the VHE
light curve in the quiescent state is consistent with a log-normal behavior.
The VHE variability in this state is well described by flicker noise
(power-spectral-density index {\ss}_VHE = 1.10 +0.10 -0.13) on time scales
larger than one day. An analysis of 5.5 yr of HE Fermi LAT data gives
consistent results ({\ss}_HE = 1.20 +0.21 -0.23, on time scales larger than 10
days) compatible with the VHE findings. The HE and VHE power spectral densities
show a scale invariance across the probed time ranges. A direct linear
correlation between the VHE and HE fluxes could neither be excluded nor firmly
established. These long-term-variability properties are discussed and compared
to the red noise behavior ({\ss} ~ 2) seen on shorter time scales during
VHE-flaring states. The difference in power spectral noise behavior at VHE
energies during quiescent and flaring states provides evidence that these
states are influenced by different physical processes, while the compatibility
of the HE and VHE long-term results is suggestive of a common physical link as
it might be introduced by an underlying jet-disk connection.Comment: 11 pages, 16 figure
How Accurate Is the Antiprimer Quenching-Based Real-Time PCR for Detection of Her2/neu in Clinical Cancer Samples?
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