BACKGROUND Feeder cells are frequently used for the early-stage of derivation and culture of human embryonic stem cell (hESC) lines. METHODS We established a conditionally immortalized human foreskin ...fibroblast line that secreted basic fibroblast growth factor (bFGF). These cells were used as feeder cells for hESC culture and induced pluripotent stem (iPS) cell derivation and expansion. This conditional immortalization was performed using lentiviral vector (LV) mediated transduction of Bmi-1 and human telomerase reverse transcriptase genes and the resulting cell line was further modified by LV-mediated transduction of a secreted form of bFGF gene product. Three different laboratories have tested whether this feeder cell line could support the maintenance of four different hESC lines. RESULTS Immortalized fibroblasts secreting stable amounts of bFGF supported the growth of all hESC lines, which remained pluripotent and had a normal karyotype for at least 10 passages. Even at high passage (p56), these modified cells, when used as feeders, could support iPS derivation and propagation. Derived iPS cells expressed pluripotency markers, had hESC morphology and produced tissue components of the three germ layers when differentiated in vitro. CONCLUSION These modified fibroblasts are useful as a genetically-defined feeder cell line for reproducible and cost-effective culture of both hESC and iPS cells.
Convolutional neural networks (CNNs) have produced unprecedented accuracy for many computer vision problems in the recent past. In power and compute-constrained embedded platforms, deploying modern ...CNNs can present many challenges. Most CNN architectures do not run in real-time due to the high number of computational operations involved during the inference phase. This emphasizes the role of CNN optimization techniques in early design space exploration. To estimate their efficacy in satisfying the target constraints, existing techniques are either hardware (HW) agnostic, pseudo-HW-aware by considering parameter and operation counts, or HW-aware through inflexible hardware-in-the-loop (HIL) setups. In this work, we introduce HW-Flow, a framework for optimizing and exploring CNN models based on three levels of hardware abstraction: Coarse, Mid and Fine. Through these levels, CNN design and optimization can be iteratively refined towards efficient execution on the target hardware platform. We present HW-Flow in the context of CNN pruning by augmenting a reinforcement learning agent with key metrics to understand the influence of its pruning actions on the inference hardware. With 2× reduction in energy and latency, we prune ResNet56, ResNet50, and DeepLabv3 with minimal accuracy degradation on the CIFAR-10, ImageNet, and CityScapes datasets, respectively.
In this work we investigate the behavior of MIS- and Schottky-gate AlGaN/GaN HEMTs under high-power pulse-stress. A special setup capable of applying pulses of constant power is used to evaluate the ...electro-thermal response in different operating points. For both types of devices, the time to failure was found to decrease with increasing drain-source voltage. Overall, the Schottky-gate device displays a higher pulse robustness. The pulse withstand time of the MIS-gate device is limited by the occurrence of a thermal instability at approximately 240 °C while the Schottky-gate device displays a rapid increase of the gate leakage current prior to failure. The mechanism responsible for this gate current is further investigated by static and transient temperature measurements and yielded activation energies of 0.6 eV and 0.84 eV.
Closing the gap between the hardware requirements of state-of-the-art convolutional neural networks and the limited resources constraining embedded applications is the next big challenge in deep ...learning research. The computational complexity and memory footprint of such neural networks are typically daunting for deployment in resource constrained environments. Model compression techniques, such as pruning, are emphasized among other optimization methods for solving this problem. Most existing techniques require domain expertise or result in irregular sparse representations, which increase the burden of deploying deep learning applications on embedded hardware accelerators. In this paper, we propose the autoencoder-based low-rank filter-sharing technique (ALF). When applied to various networks, ALF is compared to state-of-the-art pruning methods, demonstrating its efficient compression capabilities on theoretical metrics as well as on an accurate, deterministic hardware-model. In our experiments, ALF showed a reduction of 70% in network parameters, 61% in operations and 41% in execution time, with minimal loss in accuracy.
This paper presents a measurement setup and an assembly technique suitable for characterization of power semiconductor devices under very high temperature conditions exceeding 500 °C. An important ...application of this is the experimental investigation of wide bandgap semiconductors. Measurement results are shown for a 1200V SiC MOSFET and a 650V depletion mode GaN HEMT.
Postpartum haemorrhage is a leading cause of maternal morbidity and mortality. Active management of the third stage of labour, including use of a uterotonic agent, has been shown to reduce blood ...loss. Misoprostol (a prostaglandin E1 analogue) has been suggested for this purpose because it has strong uterotonic effects, can be given orally, is inexpensive, and does not need refrigeration for storage. We did a multicentre, double-blind, randomised controlled trial to determine whether oral misoprostol is as effective as oxytocin during the third stage of labour.
In hospitals in Argentina, China, Egypt, Ireland, Nigeria, South Africa, Switzerland, Thailand, and Vietnam, we randomly assigned women about to deliver vaginally to receive 600 μg misoprostol orally or 10 IU oxytocin intravenously or intramuscularly, according to routine practice, plus corresponding identical placebos. The medications were administered immediately after delivery as part of the active management of the third stage of labour. The primary outcomes were measured postpartum blood loss of 1000 mL or more, and the use of additional uterotonics without an unacceptable level of side-effects. We chose an upper limit of a 35% increase in the risk of blood loss of 1000 mL or more as the margin of clinical equivalence, which was assessed by the confidence interval of the relative risk. Analysis was by intention to treat.
9264 women were assigned misoprostol and 9266 oxytocin. 37 women in the misoprostol group and 34 in the oxytocin group had emergency caesarean sections and were excluded. 366 (4%) of women on misoprostol had a measured blood loss of 1000 mL or more, compared with 263 (3%) of those on oxytocin (relative risk 1·39 95% CI 1·19–1·63, p<0·0001). 1398 (15%) women in the misoprostol group and 1002 (11%) in the oxytocin group required additional uterotonics (1·40 1·29–1·51, p<0·0001). Misoprostol use was also associated with a significantly higher incidence of shivering (3·48 3·15–3·84) and raised body temperature (7·17 5·67–9·07) in the first hour after delivery.
10 IU oxytocin (intravenous or intramuscular) is preferable to 600 μg oral misoprostol in the active management of the third stage of labour in hospital settings where active management is the norm.
After the first derivations of human embryonic stem cell (hESC) lines on fetal mouse feeder cell layers, the idea of using human cells instead of mouse cells as feeder cells soon arose. Mouse cells ...bear a risk of microbial contamination, and nonhuman immunogenic proteins are absorbed from the feeders to hESCs. Human skin fibroblasts can be effectively used as feeder cells for hESCs. The same primary cell line, which can be safely used for up to 15 passages after stock preparations, can be expanded and used for large numbers of hESC derivations and cultures. These cells are relatively easy to handle and maintain. No animal facilities or animal work is needed. Here, we describe the derivation, culture, and cryopreservation procedures for research-grade human skin fibroblast lines. We also describe how to make feeder layers for hESCs using these fibroblasts.
This paper presents a measurement setup and an assembly technique suitable for characterization of power semiconductor devices under very high temperature conditions exceeding 500 degree C. An ...important application of this is the experimental investigation of wide bandgap semiconductors. Measurement results are shown for a 1200V SiC MOSFET and a 650V depletion mode GaN HEMT.
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