315 research outputs found
Charge-noise-free Lateral Quantum Dot Devices with Undoped Si/SiGe Wafer
We develop quantum dots in a single layered MOS structure using an undoped
Si/SiGe wafer. By applying a positive bias on the surface gates, electrons are
accumulated in the Si channel. Clear Coulomb diamond and double dot charge
stability diagrams are measured. The temporal fluctuation of the current is
traced, to which we apply the Fourier transform analysis. The power spectrum of
the noise signal is inversely proportional to the frequency, and is different
from the inversely quadratic behavior known for quantum dots made in doped
wafers. Our results indicate that the source of charge noise for the doped
wafers is related to the 2DEG dopant.Comment: Proceedings of the 12th Asia Pacific Physics Conferenc
Emotions detection scheme using facial skin temperature and heart rate variability
Technology nowadays is aiming to provide a better life quality for people, schools and universities are working for the convenient of the students as well as ensuring a high quality of education is attained. Emotions detections system can be a solution for better education results and may also be used as a part of human-computer interaction applications such as robotics, games, and intelligent tutoring system, This study shows potentials method of detecting emotions using mobile computing to recognize and identify emotions (Relax, Fear, Sadness, and Joy) based on facial skin temperature, more specifically 5 spots on the face, Nose, Glabellar line (between the eyes and eyebrows) right\lift cheeks and the chin, in addition to the Heart Rate Variability (HRV). An experiment was conducted with 20 healthy subjects (10 females and 10 males, 20 to 31 years old), Both visual and auditory media were used to induce these emotions in the experiment. By the end of this paper, the output data will be anglicized by an Artificial neural network (ANN) The Multilayer Perceptron (MLP) was selected as a classifier with a result of 88.75 % accuracy. This mechanism proves that human`s emotions can easily identify without physical interaction with the subject and with high reliability with only 0.11 misprediction rat
Solutions to the ultradiscrete Toda molecule equation expressed as minimum weight flows of planar graphs
We define a function by means of the minimum weight flow on a planar graph
and prove that this function solves the ultradiscrete Toda molecule equation,
its B\"acklund transformation and the two dimensional Toda molecule equation.
The method we employ in the proof can be considered as fundamental to the
integrability of ultradiscrete soliton equations.Comment: 14 pages, 10 figures Added citations in v
Differential distribution of microtubules in immature osteocytes in vivo
Objectives: The transition from osteoblasts to osteocytes is associated with dramatic changes in the cytoskeleton. We previously showed that the formation of osteoblast cell processes in 3D culture is microtubule dependent. However, the distribution of microtubules during the transition from osteoblasts to osteocytes in vivo is unknown. In this study, we investigated the distribution of microtubules in osteocytes in vivo. Methods: We observed the microtubules in osteocytes in chick embryonic calvaria via fluorescence staining of microtubules and confocal laser scanning microscopy. Results: Microtubules were observed throughout the cytoplasm in all examined osteoblasts. In immature osteocytes, several cell processes contained microtubules, whereas in mature osteocytes, microtubules were localized only in the cell body. Conclusion: These results suggest that the early arrangement of microtubules may be correlated with the initial development of osteocyte processes. (C) 2018 Japanese Association for Oral Biology. Published by Elsevier B.V. All rights reserved.Peer reviewe
Intravital imaging of mouse urothelium reveals activation of extracellular signal-regulated kinase by stretch-induced intravesical release of ATP
To better understand the roles played by signaling molecules in the bladder, we established a protocol of intravital imaging of the bladder of mice expressing a Förster/fluorescence resonance energy transfer (FRET) biosensor for extracellular signal-regulated kinase (ERK), which plays critical roles not only in cell growth but also stress responses. With an upright two-photon excitation microscope and a vacuum-stabilized imaging window, cellular ERK activity was visualized in the whole bladder wall, from adventitia to urothelium. We found that bladder distention caused by elevated intravesical pressure (IVP) activated ERK in the urothelium, but not in the detrusor smooth muscle. When bladder distension was prevented, high IVP failed to activate ERK, suggesting that mechanical stretch, but not the high IVP, caused ERK activation. To delineate its molecular mechanism, the stretch-induced ERK activation was reproduced in an hTERT-immortalized human urothelial cell line (TRT-HU1) in vitro. We found that uniaxial stretch raised the ATP concentration in the culture medium and that inhibition of ATP signaling by apyrase or suramin suppressed the stretch-induced ERK activation in TRT-HU1 cells. In agreement with this in vitro observation, pretreatment with apyrase or suramin suppressed the high IVP-induced urothelial ERK activation in vivo. Thus, we propose that mechanical stretch induces intravesical secretion of ATP and thereby activates ERK in the urothelium. Our method of intravital imaging of the bladder of FRET biosensor-expressing mice should open a pathway for the future association of physiological stimuli with the activities of intracellular signaling networks
Vapors-liquid phase separator
The use of porous plugs, mostly with in the form of passive devices with constant area were considered as vapor-liquid phase separators for helium 2 storage vessels under reduced gravity. The incorporation of components with variable cross sectional area as a method of flow rate modification was also investigated. A particular device which uses a shutter-type system for area variation was designed and constructed. This system successfully permitted flor rate changes of up to plus or minus 60% from its mean value
Foetal neural progenitors contribute to postnatal circuits formation ex vivo: an electrophysiological investigation
Neuronal progenitor cells (NPC) play an essential role in homeostasis of the central nervous system (CNS). Considering their ability to differentiate into specific lineages, their manipulation and control could have a major therapeutic impact for those CNS injuries or degenerative diseases characterized by neuronal cell loss. In this work, we established an in vitro co-culture and tested the ability of foetal NPC (fNPC) to integrate among post-mitotic hippocampal neurons and contribute to the electrical activity of the resulting networks. We performed extracellular electrophysiological recordings of the activity of neuronal networks and compared the properties of spontaneous spiking in hippocampal control cultures (HCC), fNPC, and mixed circuitries ex vivo. We further employed patch-clamp intracellular recordings to examine single-cell excitability. We report of the capability of fNPC to mature when combined to hippocampal neurons, shaping the profile of network activity, a result suggestive of newly formed connectivity ex vivo
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