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Karlynn E Neu, Qingming Tang, Patrick C Wilson, Aly A Khan
Single-cell genomics offers powerful tools for studying immune cells, which make it possible to observe rare and intermediate cell states that cannot be resolved at the population level. Advances in computer science and single-cell sequencing technology have created a data-driven revolution in immunology. The challenge for immunologists is to harness computing and turn an avalanche of quantitative data into meaningful discovery of immunological principles, predictive models, and strategies for therapeutics...
January 13, 2017: Trends in Immunology
Jun Chen, Zhengyu Zhang, Min Zhu, Jintong Xu, Xiangyang Li
In this paper, we report a two-dimensional (2D) simulation for InGaAs/InAlAs separate absorption, grading, charge, and multiplication avalanche photodiodes (SAGCM APDs) and study the effect of the charge layer and multiplication layer on the operating voltage ranges of APD. We find that with the increase of the thicknesses as well as the doping concentrations of the charge layer and the multiplication layer, the punchthrough voltage increases; with the increase of the doping concentrations of two layers and the thickness of the charge layer, the breakdown voltage decreases; with the increase of the thickness of the multiplication layer, the breakdown voltage first rapidly declines and then slightly rises...
December 2017: Nanoscale Research Letters
Ville Raatikainen, Niko Huotari, Vesa Korhonen, Aleksi Rasila, Janne Kananen, Lauri Raitamaa, Tuija Keinänen, Jussi Kantola, Osmo Tervonen, Vesa Kiviniemi
This study investigated lag structure in the resting-state fMRI by applying a novel independent component (ICA) method to magnetic resonance encephalography (MREG) data. Briefly, the spatial ICA (sICA) was used for defining the frontal and back nodes of the default mode network (DMN), and the temporal ICA (tICA), which is enabled by the high temporal resolution of MREG (TR=100ms), was used to separate both neuronal and physiological components of these two spatial map regions. Subsequently, lag structure was investigated between the frontal (DMNvmpf) and posterior (DMNpcc) DMN nodes using both conventional method with all-time points and a sliding-window approach...
January 11, 2017: NeuroImage
Egor A Turovsky, Maria V Turovskaya, Sergei G Gaidin, Valery P Zinchenko
In the present work we compared the protective effect of anti-inflammatory cytokine IL-10 with the action of a PI3-kinase selective activator 740 Y-P, selective agonists of alpha-2 adrenoreceptor, guanfacine and UK-14,304, and compounds having antioxidant effect: recombinant human peroxiredoxin 6 and B27, in hippocampal cell culture during OGD (ischemia-like conditions). It has been shown that the response of cells to OGD in the control includes two phases. The first phase was accompanied by an increase in the frequency of spontaneous synchronous Ca(2+)-oscillations (SSCO) in neurons and Ca(2+)-pulse in astrocytes...
January 4, 2017: Archives of Biochemistry and Biophysics
Mohammed A Sheikh, Richard L Weaver, Karin A Dahmen
The star KIC8462852 (Tabby's star) has shown anomalous drops in light flux. We perform a statistical analysis of the more numerous smaller dimming events by using methods found useful for avalanches in ferromagnetism and plastic flow. Scaling exponents for avalanche statistics and temporal profiles of the flux during the dimming events are close to mean field predictions. Scaling collapses suggest that this star may be near a nonequilibrium critical point. The large events are interpreted as avalanches marked by modified dynamics, limited by the system size, and not within the scaling regime...
December 23, 2016: Physical Review Letters
Z Cheng, X Zheng, J Deen, H Peng, L Xing
PURPOSE: Silicon photomultiplier (SiPM) has recently emerged as a promising photodetector for biomedical imaging applications. Due to its high multiplication gain (comparable to PMT), fast timing, low cost and compactness, it is considered a good candidate for photon counting CT. Dark noise is a limiting factor which impacts both energy resolution and detection dynamic range. Our goal is to develop a comprehensive model for noise sources for SiPM sensors. METHODS: The physical parameters used in this work were based upon a test SPAD fabricated in 130nm CMOS process...
June 2016: Medical Physics
C McFadden, D Flint, D Sadetaporn, A Asaithamby, D Grosshans, G Sawakuchi
PURPOSE: To construct a custom and portable fluorescence confocal laser-scanning microscope (FCLSM) that can be placed in the path of therapeutic radiation beams to study real-time radiation-induced damage response in live cells. METHODS: We designed and constructed a portable FCLSM with three laser diodes for excitation (405, 488, and 635 nm). An objective lens focuses the excitation light and collects fluorescence from the sample. A pair of galvanometer mirrors scans/collects the laser beam/fluorescence along the focal plane (x/y-directions)...
June 2016: Medical Physics
J Scheuermann, A Howansky, A Goldan, S Leveille, O Tousignant, K Tanioka, W Zhao
PURPOSE: We present the first active matrix flat panel imager (AMFPI) capable of producing x-ray quantum noise limited images at low doses by overcoming the electronic noise through signal amplification by photoconductive avalanche gain (gav). The indirect detector fabricated uses an optical sensing layer of amorphous selenium (a-Se) known as High-Gain Avalanche Rushing Photoconductor (HARP). The detector design is called Scintillator HARP (SHARP)-AMFPI. This is the first image sensor to utilize solid-state HARP technology...
June 2016: Medical Physics
A Podgorsak, D Bednarek, S Rudin, C Ionita
PURPOSE: To successfully implement and operate a photon counting scheme on an electron multiplying charged-coupled device (EMCCD) based micro-CT system. METHODS: We built an EMCCD based micro-CT system and implemented a photon counting scheme. EMCCD detectors use avalanche transfer registries to multiply the input signal far above the readout noise floor. Due to intrinsic differences in the pixel array, using a global threshold for photon counting is not optimal...
June 2016: Medical Physics
D E Nichols, M W Johnson, C D Nichols
Scientific interest in serotonergic psychedelics (e.g., psilocybin and LSD; 5-HT2A receptor agonists) has dramatically increased within the last decade. Clinical studies administering psychedelics with psychotherapy have shown preliminary evidence of robust efficacy in treating anxiety and depression, as well as addiction to tobacco and alcohol. Moreover, recent research has suggested that these compounds have potential efficacy against inflammatory diseases through novel mechanisms, with potential advantages over existing antiinflammatory agents...
November 4, 2016: Clinical Pharmacology and Therapeutics
Klodian Dhoska, Helmuth Hofer, Beatrice Rodiek, Marco López, Toomas Kübarsepp, Stefan Kück
BACKGROUND: Silicon single-photon avalanche diodes (Si-SPADs) are the most used devices for measuring ultra-weak optical radiant fluxes in many quantum technology fields, such as quantum optics, quantum communication, quantum computing, etc. In all these fields, the detection efficiency is the main parameter, which has to be accurately known for achieving reliable measurements. In this paper we present the improvements performed on the setup described in López et al. (J Mod Opt 62:S21-S27, 2015) for determining the detection efficiency of Si-SPAD detectors with a low measurement uncertainty...
2016: SpringerPlus
Inam Mirza, Nadezhda M Bulgakova, Jan Tomáštík, Václav Michálek, Ondřej Haderka, Ladislav Fekete, Tomáš Mocek
In this paper, we establish connections between the thresholds and mechanisms of the damage and white-light generation upon femtosecond laser irradiation of wide-bandgap transparent materials. On the example of Corning Willow glass, evolution of ablation craters, their quality, and white-light emission were studied experimentally for 130-fs, 800-nm laser pulses. The experimental results indicate co-existence of several ablation mechanisms which can be separated in time. Suppression of the phase explosion mechanism of ablation was revealed at the middle of the irradiation spots...
December 19, 2016: Scientific Reports
Sanja Janićević, Lasse Laurson, Knut Jørgen Måløy, Stéphane Santucci, Mikko J Alava
Numerous systems ranging from deformation of materials to earthquakes exhibit bursty dynamics, which consist of a sequence of events with a broad event size distribution. Very often these events are observed to be temporally correlated or clustered, evidenced by power-law-distributed waiting times separating two consecutive activity bursts. We show how such interevent correlations arise simply because of a finite detection threshold, created by the limited sensitivity of the measurement apparatus, or used to subtract background activity or noise from the activity signal...
December 2, 2016: Physical Review Letters
Emna Amri, Gianluca Boso, Boris Korzh, Hugo Zbinden
Negative-feedback avalanche diodes (NFADs) provide a practical solution for different single-photon counting applications requiring free-running mode operation with low afterpulsing probability. Unfortunately, the timing jitter has never been as good as for gated InGaAs/InP single-photon avalanche diodes. Here we report on the timing jitter characterization of InGaAs/InP based NFADs with particular focus on the temperature dependence and the effect of carrier transport between the absorption and multiplication regions...
December 15, 2016: Optics Letters
Michael LeBlanc, Aya Nawano, Wendelin J Wright, Xiaojun Gu, J T Uhl, Karin A Dahmen
Extracting avalanche distributions from experimental microplasticity data can be hampered by limited time resolution. We compute the effects of low time resolution on avalanche size distributions and give quantitative criteria for diagnosing and circumventing problems associated with low time resolution. We show that traditional analysis of data obtained at low acquisition rates can lead to avalanche size distributions with incorrect power-law exponents or no power-law scaling at all. Furthermore, we demonstrate that it can lead to apparent data collapses with incorrect power-law and cutoff exponents...
November 2016: Physical Review. E
Andreas Klaus, Dietmar Plenz
During quiet resting behavior, involuntary movements are suppressed. Such movement control is attributed to cortico-basal ganglia loops, yet population dynamics within these loops during resting and their relation to involuntary movements are not well characterized. Here, we show by recording cortical and striatal ongoing population activity in awake rats during quiet resting that intrastriatal inhibition maintains a low-correlation striatal resting state in the presence of cortical neuronal avalanches. Involuntary movements arise from disturbed striatal resting activity through two different population dynamics...
December 2016: PLoS Biology
Charles R Schmidtlein, James N Turner, Michael O Thompson, Krishna C Mandal, Ida Häggström, Jiahan Zhang, John L Humm, David H Feiglin, Andrzej Krol
Using analytical and Monte Carlo modeling, we explored performance of a lightweight wearable helmet-shaped brain positron emission tomography (PET), or BET camera, based on thin-film digital Geiger avalanche photodiode arrays with Lutetium-yttrium oxyorthosilicate (LYSO) or [Formula: see text] scintillators for imaging in vivo human brain function of freely moving and acting subjects. We investigated a spherical cap BET and cylindrical brain PET (CYL) geometries with 250-mm diameter. We also considered a clinical whole-body (WB) LYSO PET/CT scanner...
January 2017: Journal of Medical Imaging
Yuichiro Yada, Takeshi Mita, Akihiro Sanada, Ryuichi Yano, Ryohei Kanzaki, Douglas J Bakkum, Andreas Hierlemann, Hirokazu Takahashi
Self-organized criticality (SoC), a spontaneous dynamic state established and maintained in networks of moderate complexity, is a universal characteristic of neural systems. Such systems produce cascades of spontaneous activity that are typically characterized by power-law distributions and rich, stable spatiotemporal patterns (i.e., neuronal avalanches). Since the dynamics of the critical state confer advantages in information processing within neuronal networks, it is of great interest to determine how criticality emerges during development...
November 30, 2016: Neuroscience
Mathieu Pasquier, Olivier Hugli, Alexandre Kottmann, Frank Techel
: Pasquier, Mathieu, Olivier Hugli, Alexandre Kottmann, and Frank Techel. Avalanche accidents causing fatalities: are they any different in the summer? High Alt Med Biol. 16:000-000, 2016. AIMS: This retrospective study investigated the epidemiology of summer avalanche accidents that occurred in Switzerland and caused at least one fatality between 1984 and 2014. Summer avalanche accidents were defined as those that occurred between June 1st and October 31st. RESULTS: Summer avalanches caused 21 (4%) of the 482 avalanches with at least one fatality occurring during the study period, and 40 (6%) of the 655 fatalities...
December 2, 2016: High Altitude Medicine & Biology
R T Mumgaard, S D Scott, M Khoury
A multi-spectral line-polarization motional Stark effect (MSE-MSLP) diagnostic has been developed for the Alcator C-Mod tokamak wherein the Stokes vector is measured in multiple wavelength bands simultaneously on the same sightline to enable better polarized background subtraction. A ten-sightline, four wavelength MSE-MSLP detector system was designed, constructed, and qualified. This system consists of a high-throughput polychromator for each sightline designed to provide large étendue and precise spectral filtering in a cost-effective manner...
November 2016: Review of Scientific Instruments
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