4,297 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
COMPLEXO: identifying the missing heritability of breast cancer via next generation collaboration
published_or_final_versio
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
Technical design and performance of the NEMO3 detector
The development of the NEMO3 detector, which is now running in the Frejus
Underground Laboratory (L.S.M. Laboratoire Souterrain de Modane), was begun
more than ten years ago. The NEMO3 detector uses a tracking-calorimeter
technique in order to investigate double beta decay processes for several
isotopes. The technical description of the detector is followed by the
presentation of its performance.Comment: Preprint submitted to Nucl. Instrum. Methods A Corresponding author:
Corinne Augier ([email protected]
Epiparasitic plants specialized on arbuscular mycorrhizal fungi
Over 400 non-photosynthetic species from 10 families of vascular plants obtain their carbon from fungi and are thus defined as myco-heterotrophs. Many of these plants are epiparasitic on green plants from which they obtain carbon by 'cheating' shared mycorrhizal fungi. Epiparasitic plants examined to date depend on ectomycorrhizal fungi for carbon transfer and exhibit exceptional specificity for these fungi, but for most myco-heterotrophs neither the identity of the fungi nor the sources of their carbon are known. Because many myco-heterotrophs grow in forests dominated by plants associated with arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota), we proposed that epiparasitism would occur also between plants linked by AMF. On a global scale AMF form the most widespread mycorrhizae, thus the ability of plants to cheat this symbiosis would be highly significant. We analysed mycorrhizae from three populations of Arachnitis uniflora (Corsiaceae, Monocotyledonae), five Voyria species and one Voyriella species (Gentianaceae, Dicotyledonae), and neighbouring green plants. Here we show that non-photosynthetic plants associate with AMF and can display the characteristic specificity of epiparasites. This suggests that AMF mediate significant inter-plant carbon transfer in nature
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, 20–130) 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
Study of 2b-decay of Mo-100 and Se-82 using the NEMO3 detector
After analysis of 5797 h of data from the detector NEMO3, new limits on
neutrinoless double beta decay of Mo-100 (T_{1/2} > 3.1 10^{23} y, 90% CL) and
Se-82 (T_{1/2} > 1.4 10^{23} y, 90% CL) have been obtained. The corresponding
limits on the effective majorana neutrino mass are: m < (0.8-1.2) eV and m <
(1.5-3.1) eV, respectively. Also the limits on double-beta decay with Majoron
emission are: T_{1/2} > 1.4 10^{22} y (90% CL) for Mo-100 and T_{1/2}> 1.2
10^{22} y (90%CL) for Se-82. Corresponding bounds on the Majoron-neutrino
coupling constant are g < (0.5-0.9) 10^{-4} and < (0.7-1.6) 10^{-4}.
Two-neutrino 2b-decay half-lives have been measured with a high accuracy,
T_{1/2} Mo-100 = [7.68 +- 0.02(stat) +- 0.54(syst) ] 10^{18} y and T_{1/2}
Se-82 = [10.3 +- 0.3(stat) +- 0.7(syst) ] 10^{19} y.Comment: 5 pages, 4 figure
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