Lag and residual contrast have been quantified in an amorphous selenium (a-Se) active-matrix flat-panel imager (AMFPI) as a function of frame time, kilovoltage (kV) and megavoltage (MV) x-ray photon energies and amount of radiation incident on the detector. The AMFPI contains a 200 microm thick a-Se layer deposited on a thin film transistor (TFT) array of size 8.7 cm x 8.7 cm with an 85-microm pixel pitch. For all energies, the lag (signal normalized to the signal due to exposure) for the first (n = 1) and second (n = 2) frame after exposure ranges from 0.45% to 0.91% and from 0.29% to 0.51%, respectively. The amount of lag was determined to be a function of the time after the x-ray exposure irrespective of frame time or the magnitude of exposure. The lag for MV photon energies was slightly less than that for kV photon energies. The residual contrast for all energies studied ranges from 0.41% to 0.75% and from 0.219% to 0.41% for the n = 1 and n = 2 frames, respectively. These results show that lag and residual contrast in kV and MV radiographic applications are always less than 1% for the detection system used and only depend on the time after x-ray exposure.

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Small size, low power consumption and the capability to produce sharp images without need of an objective make MEMS scanning laser based pico-projectors an attractive solution for embedded cell-phone projection displays. To fulfil the high image resolution demands the MEMS scanning mirror has to show large scan angles, a large mirror aperture size and a high scan frequency. An additional important requirement in pico-projector applications is to minimize power consumption of the MEMS scanner to enable a long video projection time. Typically high losses in power are caused by gas damping. For that reason Fraunhofer ISIT has established a fabrication process for 2D-MEMS mirrors that includes vacuum encapsulation on 8-inch wafers. Quality factors as high as 145,000 require dedicated closed loop phase control electronics to enable stable image projection even at rapidly changing laser intensities. A capacitive feedback signal is the basis for controlling the 2D MEMS oscilla tion and for synchronising the laser sources. This paper reports on fabrication of two-axis wafer level vacuum packaged scanning micromirrors and its use in a compact laser projection display. The paper presents different approaches of overcoming the well-known reflex problem of packaged MEMS scanning mirrors

Background: Nonhuman primate models (NHP) are commonly used to advance our understanding of brain function and organization. However, to date, they have offered few insights into individual differences among NHPs. In large part, this is due to the logistical challenges of NHP research, which limit most studies to five subjects or fewer. Methods:We leveraged the availability of a large-scale open NHP imaging resource to provide an initial examination of individual differences in the functional organization of the nonhuman primate brain. Specifically, we selected one awake fMRI dataset (Newcastle: n = 10) and two anesthetized fMRI data sets (Oxford: n = 19; UC-Davis: n = 19) to examine individual differences in functional connectivity characteristics across the cortex, as well as potential state dependencies. Results:We noted significant individual variations of functional connectivity across the macaque cortex. Similar to the findings in human, during the awake state, the primary sensory and motor cortices showed lower variability than the high-order association regions. This variability pattern was significantly correlated with T1w/T2w map, the degree of long-distance connectivity, but not short-distance connectivity. However, the inter-individual variability under anesthesia exhibited a very distinct pattern, with lower variability in medial frontal cortex, precuneus and somatomotor regions and higher variability in the lateral ventral frontal and insular cortices. Conclusions:This work has implications for our understanding of the evolutionary origins of individual variation in the human brain, as well as methodological implications that must be considered in any pursuit to study individual variation in NHP models.