No abstract

The photoelectron-collection efficiency from photocathodes in noble gases and methane is experimentally investigated. The ratio between the number of transmitted photoelectrons in the gas media and in vacuum is determined as a function of the applied reduced electric field E/p, where p is the gas pressure. Results are presented for He, Ne, Ar, Xe, Kr and CH 4 .

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficits in social interaction, impaired communication, and repetitive behaviors. ASD presents a 3:1 ratio of diagnosed boys and girls, raising the question regarding sexual dimorphic mechanisms underlying ASD symptoms, and their molecular basis. Here, we performed in vivo proton magnetic resonance spectroscopy in juvenile male and female Tsc2+/− mice (an established genetic animal model of ASD). Moreover, behavior and ultrasonic vocalizations during social and repetitive tasks were analyzed. We found significant sexual dimorphisms in the levels of metabolites in the hippocampus and prefrontal cortex. Further, we observed that female mutant animals had a differential social behavior and presented an increase in repetitive behavior. Importantly, while mutant females displayed a more simplified communication during social tasks, mutant males exhibited a similar less complex vocal repertoire but during repetitive tasks. These results hint toward sex-dependent alterations in molecular and metabolic pathways, which can lead to the sexual dimorphic behaviors and communication observed in social and repetitive environments.

The response of a YAP, NaI(Tl) and BaF 2 scintillators to X-rays with energies around the Y, I, and Ba K-absorption edges, respectively, was investigated. For all the scintillators, the amplitude response follows different linear trends for X-ray energies below and above the respective K-edges, presenting a discontinuity at these energies. An abrupt decrease of about 3%, 5% and 2% were observed in the detector amplitude at the K-edges, for the YAP, the NaI(Tl) and the BaF 2 scintillator, respectively, corresponding to a decrease of 0.570.1, 1.770.3 and 0.870.2 keV in the energy calibration line. These discontinuities result in a region within 0.570.1, 1.670.3 and 0.970.2 keV where the X-ray energy cannot be obtained unambiguously. The scintillation yields for X-rays present abrupt decreases of about 3%, 4% and 2%, respectively, at the K-edges. The measured non-linearity effects are significantly larger than those obtained for gaseous and semiconductor detectors. The higher amplitude non-linearity observed in NaI(Tl) is attributed to the larger light yield non-linearity in the electron response of this crystal.

A major mode of rodent communication occurs through ultrasonic vocalizations (USVs), which are influenced by environmental factors, mouse strain or genetic background and, importantly, by developmental stage. However, few studies have looked into the age-dependent evolution of spectral features of mouse USVs. Here, we report the existence of a novel vocalization, previously unreported, which we named “Fleeting” consisting of two acoustic elements produced with a narrow silent temporal interval between them. Strikingly, this vocalization pattern was extinguished after the second postnatal week, and this temporal pattern was associated with increased emission of Complex vocalizations, by gradual loss of the inter-element interval, suggesting a maturation process occurring at this time point. Importantly, the Fleeting vocalization was analyzed in a mouse model (Tsc2+/-) of Autism Spectrum Disorder (ASD), and showed an abnormal persistence, in particular in females which presented delayed conversion of Fleeting into Complex vocalizations compared with males. The identification of this novel vocalization represents an important insight into the maturation of mouse vocal repertoire and may be used as a developmental milestone in studies on neurodevelopmental disorders with communication impairments.