Superluminal Propagation of Pulse as another Ultra-Fast Phenomenon, And its Application

Another kind of ultra-fast phenomenon, superluminal transmission of light pulse，was proposed, its velocity can faster than the infinite that was proved in theory and experiment. Based on two kinds of epistemology and world, both deeply effects on Science and technology and open new application of Laser discussed briefly. We also suggested add the content of two kinds of epistemology and worlds in Physics to clear the relationship between the Relativity and general Physics

SiPM dynamic range for CEPC scintillator-based electromagnetic calorimeter

A high-granularity scintillator calorimeter readout with silicon photomultipliers (SiPMs) is an electromagnetic calorimeter (ECAL) candidate for experiments at the Circular Electron Positron Collider (CEPC). A critical design parameter of this ECAL candidate is the dynamic range of the SiPMs. This study investigates the SiPM dynamic range required for the CEPC scintillator ECAL. A model is developed on the basis of the operation principles of SiPMs to describe the response of an SiPM to light pulses within one recovery period by considering the cross-talk effect, photon detection efficiency, and number of pixels. The response curve of a 10000-pixel SiPM predicted by the model is consistent with the measured curve within 2% for an incident light pulse of up to 12000 photons. The intrinsic fluctuations of the SiPM response naturally exist in this model, and the correction of the saturation effect in the SiPM response is investigated. Monte Carlo (MC) simulation shows that the algorithm can restore the response linearity of an SiPM for an incident light pulse in which the number of photons is up to around six times the number of SiPM pixels. The model and correction program are implemented for full simulation of the ZH production Z → νν, H → γγ channel to evaluate the impact of the SiPM dynamic range of the CEPC scintillator ECAL on the reconstructed Higgs boson mass and the sensitivity to the Higgs signal in this channel. The results show that the CEPC scintillator ECAL equipped with no less than 4000 SiPM pixels and operated with a light yield of 20 photon-electrons per channel for a single minimum ionizing particle can meet the requirements for Higgs boson precision measurement in the di-photon channel at the CEPC.

RNA-sequencing and Mathematical Modeling Identify Suite of Light-sensitive Circadian Genes in an Orb-web Weaving Spider

BackgroundMost organisms rely on a molecular circadian clock to orchestrate a wide range of physiological processes to match the 24-hour day. These molecular clocks are typically based on a negative feedback loop among a small set of proteins that govern the circadian output. Light or other environmental conditions can reset the circadian clock, but true circadian behaviors continue to cycle even in constant darkness, with an intrinsic period called the free-running period (FRP). Spiders have unusual FRPs, with some species having extremely short FRP (e.g. 18 hours for trashline orb weaver), and many having highly variable FRPs (intraspecific variation of up to 10 hours). In the absence of any genetic model of circadian rhythms in spiders, we developed a mathematical model to optimize experimental conditions for identifying circadian genes that also respond to light cues. ResultsOur mathematical model involved a single gene that encodes a protein that inhibits its own transcription. In our model, light degrades the circadian transcript, which allows a broad range of FRPs to be entrained to a 24-hour day. Our model predicted that exposing spiders to a pulse of light in the middle of the night would cause a pattern of expression between two later time points that was opposite the pattern exhibited by spiders who did not receive a pulse of light. RNA-sequencing of four groups of adult female orb weaving spiders, Metazygia wittfeldae, under these experimental conditions resulted in 528 significantly differentially expressed (DE) transcripts between the two collection times or between the light pulse and no light pulse. Consistent with our model, we found a cluster of transcripts with the flipped pattern of expression between the two collection times, dependent on the application of light.ConclusionsOur DE transcripts represent the first genetic evidence for circadian output in spiders. Furthermore, those transcripts with a flipped pattern of expression represent prime candidates for light-sensitive circadian genes, which may be involved in entraining the circadian clock to light. Functions of these genes varied from growth and development to reproduction to gene regulation, consistent with other circadian systems.

Spatiotemporal observation of light propagation in a three-dimensional scattering medium

Spatiotemporal information about light pulse propagation obtained with femtosecond temporal resolution plays an important role in understanding transient phenomena and light–matter interactions. Although ultrafast optical imaging techniques have been developed, it is still difficult to capture light pulse propagation spatiotemporally. Furthermore, imaging through a three-dimensional (3-D) scattering medium is a longstanding challenge due to the optical scattering caused by the interaction between light pulse and a 3-D scattering medium. Here, we propose a technique for ultrafast optical imaging of light pulses propagating inside a 3D scattering medium. We record an image of the light pulse propagation using the ultrashort light pulse even when the interaction between light pulse and a 3-D scattering medium causes the optical scattering. We demonstrated our proposed technique by recording converging, refracted, and diffracted propagating light for 59 ps with femtosecond temporal resolution.

In utero Exposure to Valproic-Acid Alters Circadian Organisation and Clock-Gene Expression: Implications for Autism Spectrum Disorders

Autism Spectrum Disorder (ASD) is a pervasive neurodevelopmental disorder characterised by restrictive patterns of behaviour and alterations in social interaction and communication. Up to 80% of children with ASD exhibit sleep-wake cycle disturbances, emphasising the pressing need for novel approaches in the treatment of ASD-associated comorbidities. While sleep disturbances have been identified in ASD individuals, little has been done to assess the contribution of the circadian system to these findings. The objective of this study is to characterise circadian behaviour and clock-gene expression in a valproic acid (VPA)-induced animal model of autism to highlight perturbations potentially contributing to these disturbances. Male and female VPA-exposed offspring underwent circadian challenges, including baseline light-dark cycles, constant dark/light and light pulse protocols. Baseline analysis showed that VPA-exposed males, but not females, had a greater distribution of wheel-running behaviour across light-dark phases and a later activity offset (p < 0.0001), while controls showed greater activity confinement to the dark phase (p = 0.0256). Constant light analysis indicated an attenuated masking response and an increase in the number of days to reach arrhythmicity (p < 0.0001). A 1-h light pulse (150 lux) at CT 15 after 6 days of constant dark showed that both sexes exposed to VPA exhibited a lesser phase-shift when compared to controls (p = 0.0043). Immunohistochemical and western-blot assays reveal no alterations in retinal organisation or function. However, immunohistochemical assay of the SCN revealed altered expression of BMAL1 expression in VPA-exposed males (p = 0.0016), and in females (p = 0.0053). These findings suggest alterations within the core clockwork of the SCN and reduced photic-entrainment capacity, independent of retinal dysfunction. The results of this study shed light on the nature of circadian dysregulation in VPA-exposed animals and highlights the urgent need for novel perspectives in the treatment of ASD-associated comorbidities.

The pupillary light reflex (PLR) as a marker for the ability to work or drive – a feasibility study

Background The PLR (pupillary light reflex) can be a marker for pathological medical conditions, such as neurodegenerative or mental health disorders and diseases as well as marker for physiological alterations, such as age, sex or iris color. PLR alterations have been described in people after alcohol consumption, as well. However, the effect of sleep deprivation on PLR parameters is still under debate. Methods The aim of this study was to investigate the feasibility of PLR measurements in sleep-deprived and alcohol-exposed participants. In addition, we wanted to identify PLR parameters that were altered by sleep deprivation and alcohol exposure. Results Altogether n = 50 participants have been included in this study. Differences in the PLR parameters initial diameter (dinit), latency (∆tlat), acceleration (∆ta), contraction velocity (ϑcon), quarter dilatation velocity (ϑ1/4dil), half dilatation time (∆t1/2), and the line integral (L(0.3500)) have been evaluated between baseline, sleep deprivation, as well as alcohol exposure. In a generalized linear mixed models design, we could observe statistically significant associations between the type of exposure and the PLR parameters half dilatation time and half dilatation time after the first light pulse (all p < 0.05). The participants’ latency showed a significant association in dependence of the type of exposure after the second light pulse (p < 0.05). Conclusion Our study delivers first promising results to further develop devices that may identify conditions that impair the ability to work or drive.