On the vertex detector of the International Linear Collider, a large number of hits are generated by the charged particles coming from the beam background. These charged particles produce large ...angles of incidence and generate elongated clusters. The CMOS pixel sensor (CPS) which would contain on-chip artificial neural networks could tag and remove these clusters to reduce the data flow of the detector system. The clustering procedure is the first step of data preprocessing. The conventional clustering algorithm is not suitable for on-chip integration since it requires sequential and iterative processing. In this article, a 2-D real-time clustering algorithm is proposed. The clustering algorithm is tested by 4500 frames of pixel values (12 bit/pixel) from MIMOSA-18. The clustering algorithm is implemented using Very High-Speed Integrated Circuit Hardware Description Language (VHDL), synthesized for different windows, multiplexers, and analog-to-digital converter (ADC) resolution. Power consumption and the occupied surface of the clustering implementation are presented. This implementation provides a possibility to integrate the clustering procedure into a CPS.
Animal species differ considerably in their response to predation risks. Interspecific variability in prey behaviour and morphology can alter cascading effects of predators on ecosystem structure and ...functioning. We tested whether species‐specific morphological defenses may affect responses of leaf litter consuming invertebrate prey to sit‐and‐wait predators, the odonate Cordulegaster boltonii larvae, in aquatic food webs. Partly or completely blocking the predator mouthparts (mandibles and/or extensible labium), thus eliminating consumptive (i.e. lethal) predator effects, we created a gradient of predator‐prey interaction intensities (no predator < predator – no attack < predator – non‐lethal attacks < lethal predator). A field experiment was first used to assess both consumptive and non‐consumptive predator effects on leaf litter decomposition and prey abundances. Laboratory microcosms were then used to examine behavioural responses of armored and non‐armored prey to predation risk and their consequences on litter decomposition. Results show that armored and non‐armored prey responded to both acute (predator – non‐lethal attacks) and chronic (predator – no attack) predation risks. Acute predation risk had stronger effects on litter decomposition, prey feeding rate and prey habitat use than predator presence alone (chronic predation risk). Predator presence induced a reduction in feeding activity (i.e. resource consumption) of both prey types but a shift to predator‐free habitat patches in non‐armored detritivores only. Non‐consumptive predator effects on prey subsequently decreased litter decomposition rate. Species‐specific prey morphological defenses and behaviour should thus be considered when studying non‐consumptive predator effects on prey community structure and ecosystem functioning.
The phosphatase CDC25A is a key regulator of cell cycle progression by dephosphorylating and activating cyclin-CDK complexes. CDC25A is an unstable protein expressed from G1 until mitosis. CDC25A ...overexpression, which can be caused by stabilization of the protein, accelerates the G1/S and G2/M transitions, leading to genomic instability and promoting tumorigenesis. Thus, controlling CDC25A protein levels by regulating its stability is a critical mechanism for timing cell cycle progression and to maintain genomic integrity. Herein, we show that CDC25A is phosphorylated on Ser40 throughout the cell cycle and that this phosphorylation is established during the progression from G1 to S phase. We demonstrate that CyclinD-CDK4/CDK6 complexes mediate the phosphorylation of CDC25A on Ser40 during G1 and that these complexes directly phosphorylate this residue in vitro. Importantly, we also find that CyclinD1-CDK4 decreases CDC25A stability in a ßTrCP-dependent manner and that Ser40 and Ser88 phosphorylations contribute to this regulation. Thus our results identify cyclinD-CDK4/6 complexes as novel regulators of CDC25A stability during G1 phase, generating a negative feedback loop allowing control of the G1/S transition.
In a time of rapid environmental change, understanding how the challenges experienced by one generation can influence the fitness of future generations is critically needed. Using tolerance assays ...and transcriptomic and methylome approaches, we use zebrafish as a model to investigate cross-generational acclimation to hypoxia. We show that short-term paternal exposure to hypoxia endows offspring with greater tolerance to acute hypoxia. We detected two hemoglobin genes that are significantly upregulated by more than 6-fold in the offspring of hypoxia exposed males. Moreover, the offspring which maintained equilibrium the longest showed greatest upregulation in hemoglobin expression. We did not detect differential methylation at any of the differentially expressed genes, suggesting that other epigenetic mechanisms are responsible for alterations in gene expression. Overall, our findings suggest that an epigenetic memory of past hypoxia exposure is maintained and that this environmentally induced information is transferred to subsequent generations, pre-acclimating progeny to cope with hypoxic conditions.
Suitable habitat for translocated animals should meet the candidate species' total abiotic and biotic needs through space and time and for all life stages. An important aspect of habitat assessment ...for reptile translocations is the thermal suitability of the release site. Here we provide a strategic framework for evaluating the thermal suitability of a release site for egg‐laying reptiles with temperature‐dependent sex determination (TSD). We apply the framework to a case study of tuatara Sphenodon punctatus reintroduced to the south‐eastern South Island of New Zealand. Our approach allows the assessment of the thermal suitability of future translocation sites for tuatara, and can be readily modified for any translocation of a reptile species with TSD.
Contamination of soft X-rays beamline optics due to carbon cracking and deposition under X- ray irradiation is especially critical for spectromicroscopy operations near the carbon K-absorption edge ...from organic materials, polymers and nanoparticles. In this paper we present the strategy and procedure followed on the HERMES beamline (Synchrotron SOLEIL) to minimize carbon contamination of the beamline optics. Measurements on a complex organic test sample are reported to demonstrate the performance of the beamline at the carbon K-edge in imaging, spectroscopy and spectromicroscopy modes.
The initial decoupling of the (6√3×6√3)R30° buffer layer also called zero layer graphene (ZLG) on 6H-SiC(0001) by Si intercalation has been investigated by means of high resolution photoemission ...spectroscopy (HRPES) and microscopy imaging techniques. A combination of complementary techniques has shown that the annealing above 700°C of amorphous Si deposited on ZLG leads to the diffusion of the silicon over the surface. Two competing processes are then observed. Part of the silicon contributes to a progressive decoupling of the ZLG from the substrate (partial decoupling) while the rest agglomerates at the surface to form oriented silicon clusters. After sequences of Si deposition, followed by annealing at 750°C, complete decoupling is observed into quasi-free standing monolayer (ML) graphene. Investigation of the evolution of the C1s and Si2p core levels during the intermediate states shows that the appearance of the graphene contribution coincides with the creation of an extra SiC bulk component, indicating their electronic decoupling. At partial decoupling of the ZLG, we have the coexistence of structurally linked metal-semiconducting materials presenting mutual electronic interactions and composed of nanometric metal-semiconducting heterojunctions.
The ultra-thin and highly granular CMOS Monolithic Active Pixel Sensors (MAPS) are typically optimized for high rate high precision tracking, which implies the use of a very thin active medium and ...digital readout. Both features hamper using the devices for identifying low momentum particles by means of dE/dx. Still, MAPS feature charge sharing and typically clusters of more than one fired pixel per impinging particles are formed. It was previously shown that the number of fired pixels per cluster scales with the dE/dx, which allowed identifying highly ionizing nuclear fragments 1. Assuming a sufficiently strong response to different dE/dx, this approach could also be considered for distinguishing minimum ionizing particles (MIP) from light fragments like alpha particles in tracking detectors. In this work, we study this response with particle beams with a dE/dx of up to four times the ones of MIPs, for non-irradiated and irradiated chips, with different sensing nodes as implemented in the MIMOSIS-1 prototype used for the vertex detector of the CBM experiment.
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