Showing papers by "Waseda University published in 2007"
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529 citations
TL;DR: Adipose tissue is a source of multipotent stem cells that can be easily isolated, selected, and induced into mature, transplantable hepatocytes, and the fact that they are easy to procure ex vivo in large numbers makes them an attractive tool for clinical studies in the context of establishing an alternative therapy for liver dysfunction.
520 citations
TL;DR: The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured electrons with 0.3 < p(T) < 9 GeV/c at midrapidity (y < 0.35) from heavy-flavor (charm and bottom) decays in Au + Au collisions at root s(NN) = 200 GeV as mentioned in this paper.
Abstract: The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured electrons with 0.3 < p(T) < 9 GeV/c at midrapidity (y < 0.35) from heavy-flavor (charm and bottom) decays in Au + Au collisions at root s(NN) = 200 GeV. The nuclear modification factor R-AA relative to p + p collisions shows a strong suppression in central Au + Au collisions, indicating substantial energy loss of heavy quarks in the medium produced at RHIC energies. A large azimuthal anisotropy v(2) with respect to the reaction plane is observed for 0.5 < p(T) < 5 GeV/c indicating substantial heavy-flavor elliptic flow. Both R-AA and v(2) show a p(T) dependence different from those of neutral pions. A comparison to transport models which simultaneously describe R-AA(p(T)) and v(2)(p(T)) suggests that the viscosity to entropy density ratio is close to the conjectured quantum lower bound, i.e., near a perfect fluid.
476 citations
TL;DR: The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured J/psi production for rapidities -2.2 < y < 2.2 in Au+Au collisions at root s(NN)=200 GeV as mentioned in this paper.
Abstract: The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured J/psi production for rapidities -2.2 < y < 2.2 in Au+Au collisions at root s(NN)=200 GeV. The J/psi invariant yield and nuclear modification factor R-AA as a function of centrality, transverse momentum, and rapidity are reported. A suppression of J/psi relative to binary collision scaling of proton-proton reaction yields is observed. Models which describe the lower energy J/psi data at the CERN Super Proton Synchrotron invoking only J/psi destruction based on the local medium density predict a significantly larger suppression at RHIC and more suppression at midrapidity than at forward rapidity. Both trends are contradicted by our data.
440 citations
TL;DR: In this article, the authors identify five different mutations in RAF1 in ten individuals with Noonan syndrome; those with any of four mutations causing changes in the CR2 domain of RAF1 had hypertrophic cardiomyopathy (HCM), whereas affected individuals with mutations leading to changes in CR3 domain did not.
Abstract: Noonan syndrome is characterized by short stature, facial dysmorphia and a wide spectrum of congenital heart defects1,2. Mutations of PTPN11, KRAS and SOS1 in the RAS-MAPK pathway cause ∼60% of cases of Noonan syndrome3,4,5,6,7,8,9. However, the gene(s) responsible for the remainder are unknown. We have identified five different mutations in RAF1 in ten individuals with Noonan syndrome; those with any of four mutations causing changes in the CR2 domain of RAF1 had hypertrophic cardiomyopathy (HCM), whereas affected individuals with mutations leading to changes in the CR3 domain did not. Cells transfected with constructs containing Noonan syndrome–associated RAF1 mutations showed increased in vitro kinase and ERK activation, and zebrafish embryos with morpholino knockdown of raf1 demonstrated the need for raf1 for the development of normal myocardial structure and function. Thus, our findings implicate RAF1 gain-of-function mutations as a causative agent of a human developmental disorder, representing a new genetic mechanism for the activation of the MAPK pathway.
418 citations
01 Oct 2007
TL;DR: It was demonstrated that magnetic properties of Fe(3)O(4) nanoparticles can be controlled by adjusting the molar ratio of ferrous to ferric ions as well as the particle diameter.
Abstract: Nanoparticles of Fe(3)O(4) were synthesized by hydrolysis in an aqueous solution containing ferrous and ferric salts at various ratios with 1,6-hexanediamine as a base. It was found that the ferrous to ferric ratio influences the reaction mechanism for the formation of Fe(3)O(4). When the ratio of ferrous to ferric ions was increased, the formation of large hydroxide particles as a precursor of Fe(3)O(4) was promoted, which resulted in an increase in the size of Fe(3)O(4) nanoparticles. As a result, the mean diameter of Fe(3)O(4) nanoparticles increased from approximately 9 to approximately 37 nm as the molar percentage of ferrous ions with respect to the total iron ions was increased from 33 to 100%. Furthermore, it was demonstrated that magnetic properties of Fe(3)O(4) nanoparticles can be controlled by adjusting the molar ratio of ferrous to ferric ions as well as the particle diameter.
397 citations
TL;DR: It is shown by high-speed imaging of rotation in single molecules of F(1) that phosphate release drives the last 40 degrees of the 120 degrees step, and that the 40 degrees rotation accompanies reduction of the affinity for phosphate.
375 citations
TL;DR: Results strongly suggest that types I and III IFN genes are regulated by a common mechanism, including a cluster of interferon regulatory factor-binding sites and a NF-κB-binding site essential for gene activation by the virus.
351 citations
TL;DR: In this paper, the scaling of elliptic flow (v(2) with eccentricity, system size, and transverse kinetic energy (KET) was shown to be compatible with hydrodynamic expansion of thermalized fluid.
Abstract: Differential measurements of elliptic flow (v(2)) for Au+Au and Cu+Cu collisions at root s(NN)=200 GeV are used to test and validate predictions from perfect fluid hydrodynamics for scaling of v(2) with eccentricity, system size, and transverse kinetic energy (KET). For KET equivalent to m(T)-m up to similar to 1 GeV the scaling is compatible with hydrodynamic expansion of a thermalized fluid. For large values of KET mesons and baryons scale separately. Quark number scaling reveals a universal scaling of v(2) for both mesons and baryons over the full KET range for Au+Au. For Au+Au and Cu+Cu the scaling is more pronounced in terms of KET, rather than transverse momentum.
333 citations
TL;DR: An extended algorithm, GNP with Reinforcement Learning (GNPRL) is proposed which combines evolution and reinforcement learning in order to create effective graph structures and obtain better results in dynamic environments.
Abstract: This paper proposes a graph-based evolutionary algorithm called Genetic Network Programming (GNP). Our goal is to develop GNP, which can deal with dynamic environments efficiently and effectively, based on the distinguished expression ability of the graph (network) structure. The characteristics of GNP are as follows. 1) GNP programs are composed of a number of nodes which execute simple judgment/processing, and these nodes are connected by directed links to each other. 2) The graph structure enables GNP to re-use nodes, thus the structure can be very compact. 3) The node transition of GNP is executed according to its node connections without any terminal nodes, thus the past history of the node transition affects the current node to be used and this characteristic works as an implicit memory function. These structural characteristics are useful for dealing with dynamic environments. Furthermore, we propose an extended algorithm, “GNP with Reinforcement Learning (GNPRL)” which combines evolution and reinforcement learning in order to create effective graph structures and obtain better results in dynamic environments. In this paper, we applied GNP to the problem of determining agents' behavior to evaluate its effectiveness. Tileworld was used as the simulation environment. The results show some advantages for GNP over conventional methods.
329 citations
TL;DR: Investigating the use of a prototype mobile-based intelligent vocabulary tutor system by learners in an advanced EFL class and the results are discussed in terms of learner usage patterns and learner perspectives regarding each platform.
Abstract: Mobile learning has long been identified as one of the natural directions in which CALL is expected to move, and as smaller portable technologies become less expensive, lighter and more powerful, they have the potential to become a more integral part of language learning courses as opposed to the more supplemental role often assigned to computer labs. Mobile phones have been the topic of a number of recent studies, including for learning pragmatic phrases via mobile email, and as electronic flash cards. With the development of mobile systems that can access the Internet, more sophisticated applications which allow the use of databases and interactive web content have been made possible. The current study describes one such application, investigating the use of a prototype mobile-based intelligent vocabulary tutor system by learners in an advanced EFL class. Learners used the tutor to complete vocabulary activities in a variety of task formats through either their mobile phone or through a computer, and th...
TL;DR: In September 2006, preliminary to the IWA biofilm conference, a second workshop about aerobic granular sludge was held in Delft, The Netherlands, of which a summary of the discussion outcomes is given in this paper.
TL;DR: The data suggest that unrelated cord blood could be as safe and effective a stem-cell source as related bone marrow or mobilized peripheral blood for adult patients when it is used as a primary unrelated stem- cell source.
TL;DR: A nitroxide radical functional polymer was photocrosslinked for the first time without significant side reactions, producing a cathode-active thin film, leading to an organic-based paper battery.
TL;DR: In this article, an alternative statistical empirical index of chemical weathering that is extracted by the principal component analysis (PCA) of a large dataset derived from unweathered igneous rocks and their weathering profiles is presented.
08 Oct 2007
TL;DR: An analytical method for estimating the location of the unknown tag by using the multilateration with the landmarks and a probabilistic RFID map-based technique with Kalman filtering to enhance the location estimation of the tag.
Abstract: Radio frequency identification (RFID) is a rapidly developing technology which uses wireless communication for automatic identification of objects. The localization of RFID tagged objects in their environment is becoming an important feature for the ubiquitous computing applications. In This paper we introduce a new positioning algorithm for RFID tags using two mobile RFID readers and landmarks which are passive or active tags with known location and distributed randomly. We present an analytical method for estimating the location of the unknown tag by using the multilateration with the landmarks and a probabilistic RFID map-based technique with Kalman filtering to enhance the location estimation of the tag. This algorithm is independent from the readers coordinates, and hence it can be more practical due to its mobility and its low cost to achieve a high deployment of this emerging technology. Results obtained after conducting extensive simulations demonstrate the validity and suitability of the proposed algorithm to provide high performance level in terms of accuracy and scalability.
TL;DR: A new genetic algorithm hybridized with an innovative local search procedure (bottleneck shifting) for the flexible job shop scheduling problem, which provides a closer approximation to real scheduling problems.
TL;DR: The use of technology in language teaching and learning has been the focus of a number of recent research review studies, including developments in technology and CALL research (Zhao, 2003, this article ), as an academic discipline (Debski, 2003), ICT effectiveness, and subject characteristics in Call research (Hubbard, 2005), to name a few.
Abstract: The use of technology in language teaching and learning has been the focus of a number of recent research review studies, including developments in technology and CALL research (Zhao, 2003), CALL as an academic discipline (Debski, 2003), ICT effectiveness (Felix, 2005), and subject characteristics in CALL research (Hubbard, 2005), to name a few. Such studies have contributed to clarifying how language learning technologies have been investigated, but questions remain regarding how these technologies have been used in achieving learning objectives. In other words, what technologies do CALL practitioners select for the teaching of a certain language skill or area such as listening, grammar or pronunciation? Are the decisions to use these technologies made on pedagogical grounds, or alternatively, are there other aspects that are more instrumental in influencing what is used in the language classroom? The purpose of this study is to review the literature to examine what technologies are used in the teaching of the language skills and areas. All empirical research articles appearing in four major English-language journals in the field of CALL (CALICO Journal, CALL, Language Learning & Technology, and ReCALL) from 2001 to 2005 were examined and the results collated to determine (1) what types of technologies are being used in the teaching of specific language skills and areas, (2) whether researchers had a clear idea in mind regarding their choice of technology or technologies in relation to their learning objectives, and (3) whether the researchers attempted to capitalise upon the features inherent in the technology or technologies as opposed to traditional, non-CALL means. The paper concludes with a discussion of the relationship between technology and pedagogical goals.
TL;DR: Constraints on spin, parity, and charge conjugation parity of the X(3872) particle are derived by comparing measured angular distributions of the decay products with predictions for different J(PC) hypotheses.
Abstract: The authors present an analysis of angular distributions and correlations of the X(3872) in the exclusive decay mode X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -} with J/{psi} {yields} {mu}{sup +}{mu}{sup -}. They use 780 pb{sup -1} of data from p{bar p} collisions at {radical}s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. They derive constraints on spin, parity, and charge conjugation parity of the X(3872) by comparing measured angular distributions of the decay products with predictions for different J{sup PC} hypotheses. The assignments J{sup PC} = 1{sup ++} and 2{sup -+} are the only ones consistent with the data.
TL;DR: In this article, the PHENIX experiment presented results from the Relativistic Heavy Ion Collider 2005 run with polarized proton collisions at 200 GeV, for inclusive {pi}{sup 0} production at midrapidity.
Abstract: The PHENIX experiment presents results from the Relativistic Heavy Ion Collider 2005 run with polarized proton collisions at sqrt(s)=200 GeV, for inclusive {pi}{sup 0} production at midrapidity. Unpolarized cross section results are given for transverse momenta p{sub T}=0.5 to 20 GeV/c, extending the range of published data to both lower and higher p{sub T}. The cross section is described well for p{sub T} 2 GeV/c, by perturbative QCD. Double helicity asymmetries ALL are presented based on a factor of 5 improvement in uncertainties as compared to previously published results, due to both an improved beam polarization of 50%, and to higher integrated luminosity. These measurements are sensitive to the gluon polarization in the proton. Using one representative model of gluon polarization it is demonstrated that the gluon spin contribution to the proton spin is significantly constrained.
TL;DR: The nitrogen removal performance of an anaerobic biological filtrated (ABF) reactor, filled with porous polyester nonwoven fabric carriers as a fixed bed for anammox bacteria, was tested at moderately low temperature and showed that an appropriate nitrite concentration in the influent and a shorter HRT resulted in high nitrogen conversion rates.
TL;DR: In this article, chemical analysis of biotite in representative granitic rocks in Japan shows that the total Al (TAl) content changes with the metal type of the accompanying hydrothermal ore deposits and increases in the following order: Pb-Zn and Mo deposits < Cu-Fe and Sn deposits < W deposits < non-mineralized granitic rock.
Abstract: Chemical analysis of biotite in representative granitic rocks in Japan shows that the total Al (TAl) content changes with the metal type of the accompanying hydrothermal ore deposits and increases in the following order: Pb-Zn and Mo deposits < Cu-Fe and Sn deposits < W deposits < non-mineralized granitic rocks. The TAl content of biotite in granitic rocks may be a useful indicator for distinguishing between mineralized and non-mineralized granitic rocks. A good positive correlation is seen between the TAl content of biotite and the solidification pressure of the granitic rocks estimated by sphalerite and hornblende geobarometers and the mineral assemblages of the surrounding rocks. These facts suggest that the TAl content of biotite can be used to estimate the solidification pressure (P) of the granitic rocks. The following empirical equation was obtained:
where TAl designates the total Al content in biotite on the basis O = 22. According to the obtained biotite geobarometer, it is estimated that Pb-Zn and Mo deposits were formed at pressures below 1 kb, Cu-Fe and Sn deposits at 1–2 kb, W deposits at 2–3 kb and non-mineralized granitic rocks were solidified at pressures above 3 kb.
TL;DR: In this paper, the neutrino signal from the gravitational collapse of a nonrotating massive star of 40 M is studied and the influence of realistic equations of state (EOSs) for dense matter is explored.
Abstract: We study black hole formation and the neutrino signal from the gravitational collapse of a nonrotating massive star of 40 M☉. Adopting two different sets of realistic equations of state (EOSs) for dense matter, we perform numerical simulations of general relativistic ν-radiation hydrodynamics under spherical symmetry. We make comparisons of core bounce, shock propagation, evolution of nascent proto-neutron stars, and the resulting recollapse to a black hole to reveal the influence of EOSs. We also explore the influence of EOSs on neutrino emission during the evolution toward black hole formation. We find that the speed of contraction of the nascent proto-neutron star, whose mass increases quickly due to the intense accretion, is different depending on the EOS and that the resulting profiles of density and temperature differ significantly. The black hole formation occurs at 0.6-1.3 s after bounce, when the proto-neutron star exceeds its maximum mass, which is crucially determined by the EOS. We find that the average energies of neutrinos increase after bounce because of rapid temperature increase, but at different speeds depending on the EOS. The duration of neutrino emission up to black hole formation is found to be different according to different recollapse timing. These characteristics of neutrino signatures are distinguishable from those for ordinary proto-neutron stars in successful core-collapse supernovae. We discuss the idea that a future detection of neutrinos from a black hole-forming collapse will contribute to revealing the black hole formation and to constraining the EOS at high density and temperature.
TL;DR: A variability-tolerant 6T-SRAM cell layout and new circuit techniques to improve both the read and the write operating margins in the presence of a large Vth variability are proposed.
Abstract: In the sub-100-nm CMOS generation, a large local Vth variability degrades the 6T-SRAM cell stability, so that we have to consider this local variability as well as the global variability to achieve high-yield SRAM products. Therefore, we need to employ some assist circuits to expand the SRAM operating margin. We propose a variability-tolerant 6T-SRAM cell layout and new circuit techniques to improve both the read and the write operating margins in the presence of a large Vth variability. By applying these circuit techniques to a 0.494-mum2 SRAM cell with a beta ratio of 1, which is an extremely small cell size, we can achieve a high-yield 8M-SRAM for a wide range of Vth values using a 65-nm low stand-by power (LSTP) CMOS technology
TL;DR: A general analytical model of materials flow analysis (MFA) incorporating physical waste input‐output is proposed that is fully consistent with the mass balance principle and applied to Japanese IO data for the flow of 11 base metals and their scrap.
Abstract: A general analytical model of materials flow analysis (MFA) incorporating physical waste input-output is proposed that is fully consistent with the mass balance principle. Exploiting the triangular nature of the matrix of input coefficients, which is obtained by rearranging the ordering of sectors according to degrees of fabrication, the material composition matrix is derived, which gives the material composition of products. A formal mathematical definition of materials (or the objects, the flow of which is to be accounted for by MFA) is also introduced, which excludes the occurrence of double accounting in economy-wide MFAs involving diverse inputs. By using the model, monetary input-output (IO) tables can easily be converted into a physical material flow account (or physical input-output tables [PIOT]) of an arbitrary number of materials, and the material composition of a product can be decomposed into its input origin. The first point represents substantial saving in the otherwise prohibitive cost that is associated with independent compilation of PIOT. The proposed methodology is applied to Japanese IO data for the flow of 11 base metals and their scrap (available as e-supplement on the JIE Web site).
TL;DR: Increased internal tibial rotation combined with greater quadriceps activity and a low HQR could be one reason female athletes have a higher incidence of noncontact ACL injuries.
Abstract: The likelihood of sustaining an ACL injury in a noncontact situation is two to eight times greater for females than for males. However, the mechanism and risk factors of ACL injury are still unknown. We compared knee kinematics as well as electromyographic activity during landing between male and female athletes. Eighteen male athletes and nineteen female athletes participated in the experiment. The angular displacements of flexion/extension, valgus/varus, and internal/external tibial rotation, as well as the translational displacements of anterior/posterior tibial translation during single limb drop landing were calculated. Simultaneous electromyographical activity of the rectus femoris (RF) and hamstrings (Ham) was taken. During landing, internal tibial rotation of the females was significantly larger than that of the males, while differences were not observed in flexion, varus, valgus, and anterior tibial translation. Hamstrings/quadriceps ratio (HQR) for the 50 ms time period before foot contact was greater in males than in females. The mechanism of noncontact ACL injury during a single limb drop landing would be internal tibial rotation combined with valgus rotation of the knee. Increased internal tibial rotation combined with greater quadriceps activity and a low HQR could be one reason female athletes have a higher incidence of noncontact ACL injuries.
TL;DR: It is found that the heat production in a single HeLa cell occurred with some time delay after the ionomycin-induced Ca(2+) influx from the extracellular space, and the increase in temperature was suppressed when Ca( 2+)-ATPases were blocked by thapsigargin.
TL;DR: In this paper, the authors presented a catalog of morphologically classified bright galaxies in the north equatorial stripe (230 deg2) derived from the Third Data Release of the Sloan Digital Sky Survey (SDSS).
Abstract: We present a catalog of morphologically classified bright galaxies in the north equatorial stripe (230 deg2) derived from the Third Data Release of the Sloan Digital Sky Survey (SDSS). Morphological classification is performed by visual inspection of images in the g band. The catalog contains 2253 galaxies complete to a magnitude limit of r = 16 after Galactic extinction correction, selected from 2658 objects that are judged to be extended in the photometric catalog in the same magnitude limit. A total of 1866 galaxies in our catalog have spectroscopic information. A brief statistical analysis is presented for the frequency of morphological types and mean colors in the catalog. A visual inspection of the images reveals that the rate of interacting galaxies in the local universe is approximately 1.5% in the r ≤ 16 sample. A verification is made for the photometric catalog generated by the SDSS, especially as to its bright-end completeness.
TL;DR: In this article, the effects of humidity on human comfort and productivity under transient conditions from hot and humid environment to thermally neutral condition were evaluated in two climate chambers adjoined each other.
TL;DR: This review focuses predominantly on the role of reactive oxygen and nitrogen species generated from muscle metabolism and muscle damage during exercise and on the modulatory effects of antioxidant supplements.
Abstract: Interest in the relationship between inflammation and oxidative stress has increased dramatically in recent years, not only within the clinical setting but also in the fields of exercise biochemistry and immunology. Inflammation and oxidative stress share a common role in the etiology of a variety of chronic diseases. During exercise, inflammation and oxidative stress are linked via muscle metabolism and muscle damage. Because oxidative stress and inflammation have traditionally been associated with fatigue and impaired recovery from exercise, research has focused on nutritional strategies aimed at reducing these effects. In this review, we have evaluated the findings of studies involving antioxidant supplementation on alterations in markers of inflammation (e.g., cytokines, C-reactive protein and cortisol). This review focuses predominantly on the role of reactive oxygen and nitrogen species generated from muscle metabolism and muscle damage during exercise and on the modulatory effects of antioxidant supplements. Furthermore, we have analyzed the influence of factors such as the dose, timing, supplementation period and bioavailability of antioxidant nutrients.