3,846 research outputs found
Whistle source levels of free-ranging beluga whales in Saguenay-St. Lawrence marine park
International audienceWild beluga whistle source levels (SLs) are estimated from 52 three-dimensional (3D) localized calls using a 4-hydrophone array. The probability distribution functions of the root-mean-square (rms) SL in the time domain, and the peak, the strongest 3-dB, and 10-dB SLs from the spectrogram, were non-Gaussian. The average rms SL was 143.8 +- 6.7 dB re 1microPa at 1m. SL spectral metrics were, respectively, 145.8 +- 8 dB, 143.2 +-7.1 dB, and 138.5 +-6.9 dB re 1 microPa. 1microPa / Hz at 1m
The Galaxy Populations of X-Ray Detected, Poor Groups
(Abridged) We determine the quantitative morphology and star formation
properties of galaxies in six nearby X-ray detected, poor groups using
multi-object spectroscopy and wide-field R imaging. We measure structural
parameters for each galaxy by fitting a PSF-convolved, two component model to
their surface brightness profiles. To compare directly the samples, we fade,
smooth, and rebin each galaxy image so that we effectively observe each galaxy
at the same redshift (9000 km/s) and physical resolution (0.87h^(-1) kpc). We
compare results for the groups to a sample of field galaxies. We find that: 1)
Galaxies spanning a wide range in morphological type and luminosity are
well-fit by a de Vaucouleurs bulge with exponential disk profile. 2)
Morphologically classifying these nearby group galaxies by their bulge fraction
(B/T) is fairly robust on average, even when their redshift has increased by up
to a factor of four and the effective resolution of the images is degraded by
up to a factor of five. 3) The fraction of bulge-dominated systems in these
groups is higher than in the field (~50% vs. ~20%). 4) The fraction of
bulge-dominated systems in groups decreases with increasing radius, similar to
the morphology-radius (~density) relation observed in galaxy clusters. 5)
Current star formation in group galaxies is correlated with significant
morphological asymmetry for disk-dominated systems (B/T<0.4). 6) The group
galaxies that are most disk-dominated (B/T<0.2) are less star forming and
asymmetric on average than their counterparts in the field.Comment: Accepted for publication in the Astrophysical Journal (26 pages + 12
figures); Figs 1 & 2 also available at
http://www.ucolick.org/~vy/astronomy/groups_figs.tar.g
Density and Richness of Benthic Invertebrate Populations in the North Sydenham River of Southwestern Ontario (1996-2000) Compared with Those of the St. Clair River (1990-1995)
Richness (the number of invertebrate families/sample site) and density (the number of invertebrates/sq m) of benthic populations in the North Sydenham River were measured and compared with similar estimates for the St. Clair River. Seventeen sample sites were examined from May to October over five consecutive years. At each sample site, particle size distribution of the sediment, sediment temperature, total phosphorous, total nitrogen, total carbon, and water flow rate were measured. Physical and chemical characteristics of the North Sydenham system over the 100 km run examined were less variable than those of the St. Clair. Statistically significant but weak multiple linear correlations were found for richness and density with several of the measured variables. Invertebrate populations in the North Sydenham River were less rich and less dense than those in the downstream reach of the St. Clair and exhibited a different distribution of abundance among the orders of organisms. As in the St. Clair River, some evidence of long term cycling of abundance in several families of invertebrates was found in the North Sydenham
COMPLEXO: identifying the missing heritability of breast cancer via next generation collaboration
published_or_final_versio
Aromatic L-Amino Acid Decarboxylase Deficiency Is a Cause of Long-Fasting Hypoglycemia
Objective/Context:
Long-fasting hypoglycemia in children may be induced by neurotransmitter disorders.
Case Report:
A 5-year-old girl with a medical history of chronic diarrhea presented three episodes of severe hypoglycemia (20 mg/dL) between ages 3 and 5 years. She became pale and sweaty with hypothermia (33.5°C), bradycardia (45 bpm), and acidosis and presented a generalized seizure. During the 17-hour fast test performed to determine the etiology of her hypoglycemia, insulin and C-peptide were appropriately low, and human GH, IGF-I, cortisol, amino acids, and acylcarnitines were in the usual range for fasting duration. However, the presence of vanillactic and vanilpyruvic acids in urine led us to investigate the metabolism of dopamine and serotonin in the cerebrospinal fluid. Indeed, these results indicated an aromatic L-amino acid decarboxylase deficiency that impairs the synthesis of serotonin, dopamine, and catecholamines. The diagnosis was confirmed by the low aromatic L-amino acid decarboxylase (AADC) enzyme activity in plasma (5 pmol/min/mL; reference value, 20â130) and the presence of two heterozygous mutations, c.97G>C (p.V33L, inherited from her father) and c.1385G>C (p.R462P, inherited from her mother) in the DCC gene. She was supplemented with pyridoxine and raw cornstarch (1 g/kg) at evening dinner to reduce the night fast. The episodes of hypoglycemia and the chronic diarrhea were suppressed.
Conclusion:
Here is the first case report of long-fasting hypoglycemia due to a nontypical AADC deficiency. Hypoglycemia was severe, but the other neurological clinical hallmarks present in AADC-deficient patients were mild to moderate. Thus, neurotransmitter disorders should be considered in any patients presenting hypoglycemia with urine excretion of vanillactic acid
Searches for neutrinoless double beta decay
Neutrinoless double beta decay is a lepton number violating process whose
observation would also establish that neutrinos are their own anti-particles.
There are many experimental efforts with a variety of techniques. Some (EXO,
Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has
reported the first measurement of the half life for the double beta decay with
two neutrinos of Xe. The sensitivities of the different proposals are
reviewed.Comment: 8 pages, prepared for TAUP 201
Searches for neutrinoless double beta decay
Neutrinoless double beta decay is a lepton number violating process whose
observation would also establish that neutrinos are their own anti-particles.
There are many experimental efforts with a variety of techniques. Some (EXO,
Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has
reported the first measurement of the half life for the double beta decay with
two neutrinos of Xe. The sensitivities of the different proposals are
reviewed.Comment: 8 pages, prepared for TAUP 201
Searches for neutrinoless double beta decay
Neutrinoless double beta decay is a lepton number violating process whose
observation would also establish that neutrinos are their own anti-particles.
There are many experimental efforts with a variety of techniques. Some (EXO,
Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has
reported the first measurement of the half life for the double beta decay with
two neutrinos of Xe. The sensitivities of the different proposals are
reviewed.Comment: 8 pages, prepared for TAUP 201
Kinematic modelling of disk galaxies I. A new method to fit tilted rings to data cubes
This is the first of a series of papers in which the kinematics of disk
galaxies over a range of scales is scrutinised employing spectroscopy. A
fundamental aspect of these studies is presented here: the new publicly
available software tool TiRiFiC
(http://www.astro.uni-bonn.de/~gjozsa/tirific.html) enables a direct fit of a
``tilted-ring model'' to spectroscopic data cubes. The algorithm generates
model data cubes from the tilted-ring parametrisation of a rotating disk, which
are automatically adjusted to reach an optimum fit via a chi-squared
minimisation method to an observed data cube. The structure of the new
software, the shortcomings of the previously available programs to produce a
tilted-ring model, and the performance of TiRiFiC are discussed. Our method is
less affected by the well-known problem of beam smearing that occurs when
fitting to the velocity field. Since with our method we fit many data points in
a data cube simultaneously, TiRiFiC is sensitive to very faint structures and
can hence be used to derive tilted-ring models significantly extending in
radius beyond those derived from a velocity field. The software is able to
parametrise HI disks of galaxies that are intersected by the line-of-sight
twice or more, i.e. if the disks are heavily warped, and/or with a significant
shift of the projected centre of rotation, and/or if seen edge-on. Furthermore,
our method delivers the surface-brightness profile of the examined galaxy in
addition to the orientational parameters and the rotation curve. In order to
derive kinematic and morphological models of disk galaxies, especially reliable
rotation curves, a direct-fit method as implemented in our code should be the
tool of choice.Comment: 37 pages, 24 figures. Accepted for publication in Astronomy and
Astrophysic
H-alpha kinematics of a z ~ 1 disc galaxy from near-IR integral field spectroscopy
In this letter we present the first 3D spectroscopic study of H-alpha
emission in a z ~ 1 field galaxy with an integral field unit. Using the CIRPASS
spectrograph on Gemini-South we map the spatial and velocity distribution of
H-alpha emission in the z=0.819 galaxy CFRS 22.1313. We detect two H-alpha
emitting regions with a velocity separation of 220+/-10 km/s. Combining the 2D
map of H-alpha emission with HST F814W imaging, we determine a lower limit of
180+/-20 km/s for the rotation velocity of this M_B(rest) ~ -21 galaxy. We note
that our value is significantly higher than the rotation velocity of
120+/-10km/s reported by Barden et al. (2003) for their long-slit spectroscopic
study of this galaxy. Our lower limit on the rotation velocity is entirely
consistent with no evolution of the rest B-band Tully-Fisher relation. The
position of this galaxy relative to the mean rest B-band Tully-Fisher relation
of Tully & Pierce (2000) is consistent with brightening of no more than ~ 1mag
at z=0.8. A larger integral field unit sample, without the uncertainties
inherent to long-slit samples, is needed to accurately determine the evolution
of the Tully-Fisher relation out to z ~ 1.Comment: Accepted for publication in MNRAS (Letters). 5 page
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