Intersubband electronic Raman scattering in narrow GaAs single quantum wells dominated by single-particle excitations

We measured resonant Raman scattering by intersubband electronic excitations in GaAs/AlAs single quantum wells (QWs) with well widths ranging from 8.5 to 18 nm. In narrow (less than 10 nm) QWs with sufficiently high electron concentrations, only single-particle excitations (SPEs) were observed in intersubband Raman scattering, which was confirmed by the well-width dependence of Raman spectra. We found characteristic variations in Raman shift and line shape for SPEs with incident photon energy in the narrow QWs.Comment: 5 pages including 4 figure

Intersubband absorption linewidth in GaAs quantum wells due to scattering by interface roughness, phonons, alloy disorder, and impurities

We calculate the intersubband absorption linewidth in quantum wells (QWs) due to scattering by interface roughness, LO phonons, LA phonons, alloy disorder, and ionized impurities, and compare it with the transport energy broadening that corresponds to the transport relaxation time related to electron mobility. Numerical calculations for GaAs QWs clarify the different contributions of each individual scattering mechanism to absorption linewidth and transport broadening. Interface roughness scattering contributes about an order of magnitude more to linewidth than to transport broadening, because the contribution from the intrasubband scattering in the first excited subband is much larger than that in the ground subband. On the other hand, LO phonon scattering (at room temperature) and ionized impurity scattering contribute much less to linewidth than to transport broadening. LA phonon scattering makes comparable contributions to linewidth and transport broadening, and so does alloy disorder scattering. The combination of these contributions with significantly different characteristics makes the absolute values of linewidth and transport broadening very different, and leads to the apparent lack of correlation between them when a parameter, such as temperature or alloy composition, is changed. Our numerical calculations can quantitatively explain the previously reported experimental results.Comment: 17 pages, including 15 figure

n-Si/SiGe quantum cascade structures for THz emission

In this work we report on modelling the electron transport in n-Si/SiGe structures. The electronic structure is calculated within the effective-mass complex-energy framework, separately for perpendicular (Xz) and in-plane (Xxy) valleys, the degeneracy of which is lifted by strain, and additionally by size quantization. The transport is described via scattering between quantized states, using the rate equations approach and tight-binding expansion, taking the coupling with two nearest-neighbour periods. The acoustic phonon, optical phonon, alloy and interface roughness scattering are taken in the model. The calculated U/I dependence and gain profiles are presented for a couple of QC structures

Anisotropic splitting of intersubband spin plasmons in quantum wells with bulk and structural inversion asymmetry

In semiconductor heterostructures, bulk and structural inversion asymmetry and spin-orbit coupling induce a k-dependent spin splitting of valence and conduction subbands, which can be viewed as being caused by momentum-dependent crystal magnetic fields. This paper studies the influence of these effective magnetic fields on the intersubband spin dynamics in an asymmetric n-type GaAs/AlGaAs quantum well. We calculate the dispersions of intersubband spin plasmons using linear response theory. The so-called D'yakonov-Perel' decoherence mechanism is inactive for collective intersubband excitations, i.e., crystal magnetic fields do not lead to decoherence of spin plasmons. Instead, we predict that the main signature of bulk and structural inversion asymmetry in intersubband spin dynamics is a three-fold, anisotropic splitting of the spin plasmon dispersion. The importance of many-body effects is pointed out, and conditions for experimental observation with inelastic light scattering are discussed.Comment: 8 pages, 6 figure

Statistical analyses on the morphology and environmental properties of warm-season quasi-stationary convective clusters in Japan

International Conference on Mesoscale Convective System and High-Impact Weather (ICMCS-XI), BEXCO, Busan, Korea, 25-28 April 201

Japanese eel (Anguilla japonica Temminck & Schlegel, 1846) propagation by using cryopreserved sperm samples

[EN] The aim of this study was to test the artificial seminal plasma (ASP) as the extender as well as methanol as the cryoprotectant for cryopreservation, and to collect information on the fertilizing capacity of cryopreserved sperm samples. Eggs from Japanese eel, Anguilla japonica, females were control-fertilized with native sperm diluted with ASP and cryopreserved sperm (ASP as extender [in 1:100 ratio] and 10% methanol in v/v final concentration). No statistical differences (p<.05) were among the measured parameters (hatching, survival after 10days post-hatch, malformation rates) between the two groups, thus this cryopreservation method can be used effectively for artificial propagation of the Japanese eel, Anguilla japonica.Tokyo University of Agriculture Strategic Research Program (TUA-SRP); Mohamed bin Zayed Species Conservation Fund, Grant/ Award Number: 162512761; Research Centre of Excellence, Grant/Award Number: 11476-3/ 2016/FEKUTMüller, T.; Matsubara, H.; Kubara, Y.; Horváth, Á.; Asturiano Nemesio, JF.; Urbányi, B. (2017). Japanese eel (Anguilla japonica Temminck & Schlegel, 1846) propagation by using cryopreserved sperm samples. Journal of Applied Ichthyology (Online). 33:550-552. https://doi.org/10.1111/jai.13316S55055233Abe, T., Ijiri, S., Adachi, S., & Yamauchi, K. (2010). Development of an in vitro culture system for producing eel larvae from immature ovarian follicles in Japanese eel Anguilla japonica. Fisheries Science, 76(2), 257-265. doi:10.1007/s12562-010-0216-8Asturiano, J., Sørensen, S., Pérez, L., Lauesen, P., & Tomkiewicz, J. (2016). First Production of Larvae Using Cryopreserved Sperm: Effects of Preservation Temperature and Cryopreservation on European Eel Sperm Fertilization Capacity. Reproduction in Domestic Animals, 51(4), 485-491. doi:10.1111/rda.12706Kurokawa, T., Okamoto, T., Gen, K., Uji, S., Murashita, K., Unuma, T., … Tanaka, H. (2008). Influence of Water Temperature on Morphological Deformities in Cultured Larvae of Japanese Eel,Anguilla japonica, at Completion of Yolk Resorption. Journal of the World Aquaculture Society, 39(6), 726-735. doi:10.1111/j.1749-7345.2008.00208.xMüller, T., Horváth, Á., Takahashi, E., Kolics, B., Bakos, K., Decsi, K., … Yamaha, E. (2012). Artificial hybridization of Japanese and European eel (Anguilla japonica×A. anguilla) by using cryopreserved sperm from freshwater reared males. Aquaculture, 350-353, 130-133. doi:10.1016/j.aquaculture.2012.04.007Ohta, H., Kagawa, H., Tanaka, H., Okuzawa, K., Iinuma, N., & Hirose, K. (1997). Fish Physiology and Biochemistry, 17(1/6), 163-169. doi:10.1023/a:1007720600588Okamoto, T., Kurokawa, T., Gen, K., Murashita, K., Nomura, K., Kim, S.-K., … Tanaka, H. (2009). Influence of salinity on morphological deformities in cultured larvae of Japanese eel, Anguilla japonica, at completion of yolk resorption. Aquaculture, 293(1-2), 113-118. doi:10.1016/j.aquaculture.2009.04.005Tanaka, S., Zhang, H., Horie, N., Yamada, Y., Okamura, A., Utoh, T., … Kurokura, H. (2002). Long-term cryopreservation of sperm of Japanese eel. Journal of Fish Biology, 60(1), 139-146. doi:10.1111/j.1095-8649.2002.tb02393.xUnuma, T., Kondo, S., Tanaka, H., Kagawa, H., Nomura, K., & Ohta, H. (2004). Determination of the rates of fertilization, hatching and larval survival in the Japanese eel, Anguilla japonica, using tissue culture microplates. Aquaculture, 241(1-4), 345-356. doi:10.1016/j.aquaculture.2004.08.00

Real Time Animation of Virtual Humans: A Trade-off Between Naturalness and Control

Virtual humans are employed in many interactive applications using 3D virtual environments, including (serious) games. The motion of such virtual humans should look realistic (or ‘natural’) and allow interaction with the surroundings and other (virtual) humans. Current animation techniques differ in the trade-off they offer between motion naturalness and the control that can be exerted over the motion. We show mechanisms to parametrize, combine (on different body parts) and concatenate motions generated by different animation techniques. We discuss several aspects of motion naturalness and show how it can be evaluated. We conclude by showing the promise of combinations of different animation paradigms to enhance both naturalness and control

Emerging roles of mitochondria and autophagy in liver injury during sepsis

Recent research indicates crucial roles of autophagy during sepsis. In animal models of sepsis induced by cecal ligation and puncture (CLP) or the systemic administration of lipopolysaccharides (LPS), autophagy is implicated in the activation and/or damage of various cells/organs, such as immune cells, heart, lung, kidney, and liver. Since sepsis is associated with an increased production of pro- as well as anti-inflammatory cytokines, it has long been considered that hypercytokinemia is a fetal immune response leading to multiple organ failure (MOF) and mortality of humans during sepsis. However, a recent paradigm illuminates the crucial roles of mitochondrial dysfunction as well as the perturbation of autophagy in the pathogenesis of sepsis. In the livers of animal models of sepsis, autophagy is involved in the elimination of damaged mitochondria to prevent the generation of mitochondrial ROS and the initiation of the mitochondrial apoptotic pathway. In addition, many reports now indicate that the role of autophagy is not restricted to the elimination of hazardous malfunctioning mitochondria within the cells; autophagy has been shown to be involved in the regulation of inflammasome activation and the release of cytokines as well as other inflammatory substances. In this review, we summarize recent literature describing the versatile role of autophagy and its possible implications in the pathogenesis of sepsis in the liver

A review on broodstock nutrition of marine pelagic spawners: the curious case of the freshwater eels (Anguilla spp.)

To sustain eel aquaculture, development of reproduction in captivity is vital. The aim of this review is to assess our current knowledge on the nutrition of broodstock eels in order to improve the quality of broodstock under farming conditions, drawing information from wild adult eels and other marine pelagic spawners. Freshwater eels spawn marine pelagic eggs with an oil droplet (type II), and with a large perivitelline space. Compared with other marine fish eggs, eel eggs are at the extreme end of the spectrum in terms of egg composition, even within this type II group. Eel eggs contain a large amount of total lipids, and a shortage of neutral lipids has been implied a cause for reduced survival of larvae. Eel eggs have higher ARA but lower EPA and DHA levels than in other fish. Too high levels of ARA negatively affected reproduction in the Japanese eel, although high levels of 18:2n-6 in the eggs of farmed eels were not detrimental. The total free amino acid amount and profile of eel eggs appears much different from other marine pelagic spawners. Nutritional intervention to influence egg composition seems feasible, but responsiveness of farmed eels to induced maturation might also require environmental manipulation. The challenge remains to succeed in raising European eel broodstock with formulated feeds and to enable the procurement of viable eggs and larvae, once adequate protocols for induced maturation have been developed

A study on the definition of Supported Decision-making based on the characteristics of Intentions : Introduction of the Concept of Shared decision making into Adult Guardianship

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