71 research outputs found
In-Air Evoked Potential Audiometry of Grey Seals (Halichoerus grypus) from the North and Baltic Seas
In-air anthropogenic sound has the potential to affect grey seal (Halichoerus grypus) behaviour and interfere with acoustic communication. In this study, a new method was used to deliver acoustic signals to grey seals as part of an in-air hearing assessment. Using in-ear headphones with adapted ear inserts allowed for the measurement of auditory brainstem responses (ABR) on sedated grey seals exposed to 5-cycle (2-1-2) tone pips. Thresholds were measured at 10 frequencies between 1–20 kHz. Measurements were made using subcutaneous electrodes on wild seals from the Baltic and North Seas. Thresholds were determined by both visual and statistical approaches (single point F-test) and good agreement was obtained between the results using both methods. The mean auditory thresholds were ≤40 dB re 20 µPa peak equivalent sound pressure level (peSPL) between 4–20 kHz and showed similar patterns to in-air behavioural hearing tests of other phocid seals between 3 and 20 kHz. Below 3 kHz, a steep reduction in hearing sensitivity was observed, which differed from the rate of decline in sensitivity obtained in behavioural studies on other phocids. Differences in the rate of decline may reflect influence of the ear inserts on the ability to reliably transmit lower frequencies or interference from the structure of the distal end of the ear canal
Leveraging SN Ia spectroscopic similarity to improve the measurement of
Recent studies suggest spectroscopic differences explain a fraction of the
variation in Type Ia supernova (SN Ia) luminosities after light-curve/color
standardization. In this work, (i) we empirically characterize the variations
of standardized SN Ia luminosities, and (ii) we use a spectroscopically
inferred parameter, SIP, to improve the precision of SNe Ia along the distance
ladder and the determination of the Hubble constant (). First, we show
that the \texttt{Pantheon+} covariance model modestly overestimates the
uncertainty of standardized magnitudes by %, in the parameter space
used by the Team to measure ; accounting for this alone
yields km s Mpc. Furthermore, accounting
for spectroscopic similarity between SNe~Ia on the distance ladder reduces
their relative scatter to mag per object (compared to
mag previously). Combining these two findings in the model of SN covariance, we
find an overall 14% reduction (to km s Mpc) of the
uncertainty in the Hubble constant and a modest increase in its value.
Including a budget for systematic uncertainties itemized by Riess et al.
(2022a), we report an updated local Hubble constant with %
uncertainty, km s Mpc. We conclude that
spectroscopic differences among photometrically standardized SNe Ia do not
explain the ``Hubble tension." Rather, accounting for such differences
increases its significance, as the discrepancy against CDM calibrated
by the 2018 measurement rises to 5.7.Comment: 28 pages, 15 figures, accepted to JCA
The prevalence of substance use disorders and psychiatric disorders as a function of psychotic symptoms
Psychotic symptoms represent one of the most severe and functionally impairing components of several psychological disorders. One group with particularly high rates of psychotic symptoms is chronic substance users. However, the literature on psychotic symptoms and substance use is quite narrow and has focused almost exclusively on drug-induced psychosis, neglecting the population of substance users with psychotic symptoms occurring independently of acute drug effects
Microwave Spectroscopy of Thermally Excited Quasiparticles in YBa_2Cu_3O_{6.99}
We present here the microwave surface impedance of a high purity crystal of
measured at 5 frequencies between 1 and 75 GHz. This data
set reveals the main features of the conductivity spectrum of the thermally
excited quasiparticles in the superconducting state. Below 20 K there is a
regime of extremely long quasiparticle lifetimes, due to both the collapse of
inelastic scattering below and the very weak impurity scattering in the
high purity -grown crystal used in this study. Above 20 K, the
scattering increases dramatically, initially at least as fast as .Comment: 13 pages with 10 figures. submitted to Phys Rev
Risk-taking, delay discounting, and time perspective in adolescent gamblers: an experimental study
Previous research has demonstrated that adult pathological gamblers (compared to controls) show risk-proneness, foreshortened time horizon, and preference for immediate rewards. No study has ever examined the interplay of these factors in adolescent gambling. A total of 104 adolescents took part in the research. Two equal-number groups of adolescent non-problem and problem gamblers, defined using the South Oaks Gambling Screen-Revised for Adolescents (SOGS-RA), were administered the Balloon Analogue Risk Task (BART), the Consideration of Future Consequences (CFC-14) Scale, and the Monetary Choice Questionnaire (MCQ). Adolescent problem gamblers were found to be more risk-prone, more oriented to the present, and to discount delay rewards more steeply than adolescent non-problem gamblers. Results of logistic regression analysis revealed that BART, MCQ, and CFC scores predicted gambling severity. These novel finding provides the first evidence of an association among problematic gambling, high risk-taking proneness, steep delay discounting, and foreshortened time horizon among adolescents. It may be that excessive gambling induces shortsighted behaviors that, in turn, facilitate gambling involvement
Malformações arteriovenosas do lobo parietal: revisão clÃnico-cirúrgica de 17 casos
The incidence, clinical occurences, diagnosis and surgical procedures registered in 17 cases of arteriovenous malformations of the parietal lobe are reported. The authors conclude: The arteriovenous anomalies located in the parietal lobe were mostly (65%) nourished by more than one arterial group. The venous cortical drainage in these malformations was more frequent (59%) than the deep one (12%). The deep vein drainage makes the prognostic worse. There was a large number of failures with the patients bearing intracerebral hematoma. Angiography during operation proved to be very usefull and must be inclused in the routine of the surgical treatment of arteriovenous malformations
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