1,506 research outputs found
Towards dynamically consistent real-time gait pattern generation for full-size humanoid robots
We propose a two-stage gait pattern generation scheme for the full-scale humanoid robots, that considers the dynamics of the system throughout the process. The fist stage is responsible for generating semi-dynamically consistent step position and step time information, while the second stage incorporated with multi-body dynamics system is responsible for generation of gait pattern that is feasible and stable on the full-scale multi-degree-of-freedom humanoid robot. The approach allows for very rapid gait pattern regeneration during the swing phase of motion and includes information about present dynamic state when regenerating the new pattern. The paper contains description of a developed method, as well as experimental results proving its effectiveness
Sphingosine mediates FTY720-induced apoptosis in LLC-PK1 cells
FTY720, a synthetic sphingoid base analog, was examined as a new sphingosine kinase inhibitor, which converts endogenous sphingosine into its phosphate form. With 20 ??M of FTY720, sphingosine accumulated in the LLC-PK1 cells in a time- and dose-dependent manner. The FTY720 treated cells showed a high concentration of fragmented DNA, a high caspase-3 like activity and TUNEL staining cells. It was also found that the sphingosine and sphinganine level increased in a time- and dose-dependent manner within 12 h after the FTY720 treatment. The sphingosine kinase activity was reduced by FTY720 as much as other sphingosine kinase inhibitors, N, N-dimethylsphingosine (DMS), dl-threo-dihydrosphingosine (DHS). The fragmented DNA content as a result of the 20 ??M of FTY720 treatment and by 5 ??M of the exogenously added BSA-sphingosine complex indicated typical apoptosis. Under similar conditions, the accumulated sphingosine concentration in all the cells was almost identical even though the sphingosine distribution inside the cells was somewhat different. These results indicate that the FTY720 induced apoptosis is associated with the inhibition of the sphingosine kinase activity and is strongly associated with the successive accumulation of sphingosine.open172
Tractable Pathfinding for the Stochastic On-Time Arrival Problem
We present a new and more efficient technique for computing the route that
maximizes the probability of on-time arrival in stochastic networks, also known
as the path-based stochastic on-time arrival (SOTA) problem. Our primary
contribution is a pathfinding algorithm that uses the solution to the
policy-based SOTA problem---which is of pseudo-polynomial-time complexity in
the time budget of the journey---as a search heuristic for the optimal path. In
particular, we show that this heuristic can be exceptionally efficient in
practice, effectively making it possible to solve the path-based SOTA problem
as quickly as the policy-based SOTA problem. Our secondary contribution is the
extension of policy-based preprocessing to path-based preprocessing for the
SOTA problem. In the process, we also introduce Arc-Potentials, a more
efficient generalization of Stochastic Arc-Flags that can be used for both
policy- and path-based SOTA. After developing the pathfinding and preprocessing
algorithms, we evaluate their performance on two different real-world networks.
To the best of our knowledge, these techniques provide the most efficient
computation strategy for the path-based SOTA problem for general probability
distributions, both with and without preprocessing.Comment: Submission accepted by the International Symposium on Experimental
Algorithms 2016 and published by Springer in the Lecture Notes in Computer
Science series on June 1, 2016. Includes typographical corrections and
modifications to pre-processing made after the initial submission to SODA'15
(July 7, 2014
Agrobacterium-mediated genetic transformation of Miscanthus sinensis
Miscanthus species are tall perennial rhizomatous grasses with C4 photosynthesis originating from East Asia, and they are considered as important bioenergy crops for biomass production. In this study, Agrobacterium-mediated transformation system for M. sinensis was developed using embryogenic calli derived from mature seeds. In order to establish a stable system, optimum conditions to obtain highly regenerable and transformation-competent embryogenic calli were investigated, and embryogenic calli were efficiently induced with callus induction medium containing 3 mg L-1 2,4-dichlorophenoxyacetic acid and 25 mM l-proline, at pH 5.7 with an induction temperature of 28 A degrees C. In addition, the embryogenic callus induction and regeneration potentials were compared between seven M. sinensis germplasms collected from several sites in Korea, which revealed that the germplasm SNU-M-045 had superior embryogenic callus induction and regeneration potentials. With this germplasm, the genetic transformation of M. sinensis was performed using Agrobacterium tumefaciens EHA105 carrying pCAMBIA1300 with a green fluorescence protein gene as a reporter. After putative transgenic plants were obtained, the genomic integration of transgenes was confirmed by genomic PCR, transgene expression was validated by Northern blot analysis, and the number of transgene integration was confirmed by DNA gel blot analysis. Furthermore, the Agrobacterium-mediated transformation of M. sinensis was also performed with pCAMBIA3301 which contains an herbicide resistance gene (BAR), and we obtained transgenic M. sinensis plants whose herbicide resistance was confirmed by spraying with BASTA(A (R)). Therefore, we have established a stable Agrobacterium-mediated transformation system for M. sinensis, and also successfully produced herbicide-resistant Miscanthus plants by introducing BAR gene via the established method.X111210Ysciescopu
PPAR gamma-coactivator-1 alpha gene transfer reduces neuronal loss and amyloid-beta generation by reducing beta-secretase in an Alzheimer's disease model
Current therapies for Alzheimer’s disease (AD) are symptomatic and do not target the underlying Aβ pathology and other important hallmarks including neuronal loss. PPARγ-coactivator-1α (PGC-1α) is a cofactor for transcription factors including the peroxisome proliferator-activated receptor-γ (PPARγ), and it is involved in the regulation of metabolic genes, oxidative phosphorylation, and mitochondrial biogenesis. We previously reported that PGC-1α also regulates the transcription of β-APP cleaving enzyme (BACE1), the main enzyme involved in Aβ generation, and its expression is decreased in AD patients. We aimed to explore the potential therapeutic effect of PGC-1α by generating a lentiviral vector to express human PGC-1α and target it by stereotaxic delivery to hippocampus and cortex of APP23 transgenic mice at the preclinical stage of the disease. Four months after injection, APP23 mice treated with hPGC-1α showed improved spatial and recognition memory concomitant with a significant reduction in Aβ deposition, associated with a decrease in BACE1 expression. hPGC-1α overexpression attenuated the levels of proinflammatory cytokines and microglial activation. This effect was accompanied by a marked preservation of pyramidal neurons in the CA3 area and increased expression of neurotrophic factors. The neuroprotective effects were secondary to a reduction in Aβ pathology and neuroinflammation, because wild-type mice receiving the same treatment were unaffected. These results suggest that the selective induction of PGC-1α gene in specific areas of the brain is effective in targeting AD-related neurodegeneration and holds potential as therapeutic intervention for this disease
Application of Graphene within Optoelectronic Devices and Transistors
Scientists are always yearning for new and exciting ways to unlock graphene's
true potential. However, recent reports suggest this two-dimensional material
may harbor some unique properties, making it a viable candidate for use in
optoelectronic and semiconducting devices. Whereas on one hand, graphene is
highly transparent due to its atomic thickness, the material does exhibit a
strong interaction with photons. This has clear advantages over existing
materials used in photonic devices such as Indium-based compounds. Moreover,
the material can be used to 'trap' light and alter the incident wavelength,
forming the basis of the plasmonic devices. We also highlight upon graphene's
nonlinear optical response to an applied electric field, and the phenomenon of
saturable absorption. Within the context of logical devices, graphene has no
discernible band-gap. Therefore, generating one will be of utmost importance.
Amongst many others, some existing methods to open this band-gap include
chemical doping, deformation of the honeycomb structure, or the use of carbon
nanotubes (CNTs). We shall also discuss various designs of transistors,
including those which incorporate CNTs, and others which exploit the idea of
quantum tunneling. A key advantage of the CNT transistor is that ballistic
transport occurs throughout the CNT channel, with short channel effects being
minimized. We shall also discuss recent developments of the graphene tunneling
transistor, with emphasis being placed upon its operational mechanism. Finally,
we provide perspective for incorporating graphene within high frequency
devices, which do not require a pre-defined band-gap.Comment: Due to be published in "Current Topics in Applied Spectroscopy and
the Science of Nanomaterials" - Springer (Fall 2014). (17 pages, 19 figures
International Veterinary Epilepsy Task Force recommendations for a veterinary epilepsy-specific MRI protocol
Epilepsy is one of the most common chronic neurological diseases in veterinary practice. Magnetic resonance imaging (MRI) is regarded as an important diagnostic test to reach the diagnosis of idiopathic epilepsy. However, given that the diagnosis requires the exclusion of other differentials for seizures, the parameters for MRI examination should allow the detection of subtle lesions which may not be obvious with existing techniques. In addition, there are several differentials for idiopathic epilepsy in humans, for example some focal cortical dysplasias, which may only apparent with special sequences, imaging planes and/or particular techniques used in performing the MRI scan. As a result, there is a need to standardize MRI examination in veterinary patients with techniques that reliably diagnose subtle lesions, identify post-seizure changes, and which will allow for future identification of underlying causes of seizures not yet apparent in the veterinary literature.
There is a need for a standardized veterinary epilepsy-specific MRI protocol which will facilitate more detailed examination of areas susceptible to generating and perpetuating seizures, is cost efficient, simple to perform and can be adapted for both low and high field scanners. Standardisation of imaging will improve clinical communication and uniformity of case definition between research studies. A 6–7 sequence epilepsy-specific MRI protocol for veterinary patients is proposed and further advanced MR and functional imaging is reviewed
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
Stakeholder preference mapping : the case for built heritage of Georgetown, Malaysia
Purpose
While there is an established body of literature that discusses the importance of
stakeholder management, and also the need for involvement of all stakeholders so
that all values of a heritage site can be captured in a heritage management plan, the
concepts are not generally developed in ways that make them useful in practice. This
research seeks to bring greater clarity to the practice of stakeholder engagement in
built heritage, so that organisations can manage their stakeholders in ways that meet
their strategic goals. This study proposes a novel method to identify stakeholders, a
stakeholder preference mapping approach, which will depict their influence on
decisions based on a of power-interest scale.
Design/methodology/approach
This research posits a stakeholder preference mapping approach. Virtual Stakeholder
Groups (VSG) were identified and stakeholder’s significance impacts were measured
using the RIBA Plan of Work 2013 to determine in-depth consideration of each
stakeholder’s power and interest against differing stages of a heritage project.
Participants were convened through a 5-day workshop, consisting of twenty Malaysian
and nineteen international participants (80% academics and 20% Malaysian civil
servants). The Multi-Attribute Decision Analysis (MADA) technique was then used to
demonstrate how stakeholder identification and analysis can be used to help heritage
teams meet their mandates.
Findings
The research identified 8 virtual VSG (Extremist, Expert, Economic, Social,
Governance and Tourists) and their scale of power-interest influence at different
stages of the heritage management process. The findings reveal varying levels of
engagement from each of the different groups of stakeholders at each work stage –
with Stage 5 (Construction) being the least engaged.
Originality/value
It is anticipated that through stakeholder preference mapping, heritage teams can
increase the robustness of their strategies by identifying and effectively managing the
important concepts; heritage teams can effectively manage the interface between the
many (often competing) demands of differing stakeholders. Using Georgetown as a
case study, the research team were able to delineate the interaction and interplay
between the various stakeholders in the complex decision-making processes for a
UNESCO heritage site. Applying the RIBA 2013 Plan of Work as a framework to the
heritage management process enables a formalised mapping approach to the
process
Childhood predictors of deliberate self-harm behavior and suicide ideation in korean adolescents: a prospective population-based follow-up study.
The aim of this study was to investigate predictors of adolescence suicidality in a longitudinal study. Additionally, the prevalence of deliberate self-harm behavior and suicide ideation at age 7 and during middle school were examined. Initial assessment data was obtained from 1998 to 2000, and a follow-up assessment was performed in 2006 when the original subjects became middle school students. The addresses and names of 1,857 subjects were located from the original data; they were 910 boys and 947 girls. The subjects were evaluated with the Korean version of the Child Behavior Checklist (K-CBCL), which was administered by the parents of the children, and by various demographic and psychosocial factors. They were reassessed using self reports on the Korea Youth Self Report (K-YSR); in particular, replies to items related to self-harm behavior and suicide ideation were recorded. A logistic regression analysis showed that the factors of gender, economic status, the overall amount of behavior problems, the tendency to internalizing and externalizing problems, somatic problems, thought problems, delinquent behavior, and aggressive behavior were independent predictors of adolescent suicide ideation and self-harm behavior. The importance of total behavior problems suggested that adolescent difficulty is a consequence of an accumulation of various risk factors. Accordingly, clinicians must consider a range of internalizing and externalizing issues, especially overall adaptation, for suicide intervention
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