6,088 research outputs found
A Low-Cost Tele-Presence Wheelchair System
This paper presents the architecture and implementation of a tele-presence
wheelchair system based on tele-presence robot, intelligent wheelchair, and
touch screen technologies. The tele-presence wheelchair system consists of a
commercial electric wheelchair, an add-on tele-presence interaction module, and
a touchable live video image based user interface (called TIUI). The
tele-presence interaction module is used to provide video-chatting for an
elderly or disabled person with the family members or caregivers, and also
captures the live video of an environment for tele-operation and
semi-autonomous navigation. The user interface developed in our lab allows an
operator to access the system anywhere and directly touch the live video image
of the wheelchair to push it as if he/she did it in the presence. This paper
also discusses the evaluation of the user experience
Accretion Disc-Jet Couplings in X-ray Binaries
When the matter from a companion star is accreted towards the central compact
accretor, i.e. a black hole (BH) or a neutron star (NS), an accretion disc and
a jet outflow will form, providing bight X-ray and radio emission, which is
known as X-ray binaries (XRBs). In the low/hard state, there exist disc-jet
couplings in XRBs, but it remains uncertain whether the jet power comes from
the disc or the central accretor. Moreover, BHXRBs have different properties
compared with NSXRBs: quiescent BHXRBs are typically two to three orders of
magnitude less luminous than NSXRBs in X-ray, whereas BHXRBs are more radio
loud than NSXRBs. In observations, an empirical correlation has been
established between radio and X-ray luminosity, , where for BHXRBs and for non-pulsating NSXRBs.
However, there are some outliers of BHXRBs showing unusually steep correlation
as NSXRBs at higher luminosities. In this work, under the assumption that the
origin of jet power is related to the internal energy of the inner disc, we
apply our magnetized, radiatively efficient thin disc model and the well-known
radiatively inefficient accretion flow model to NSXRBs and BHXRBs. We find that
the observed radio/X-ray correlations in XRBs can be well understood by the
disc-jet couplings.Comment: 8 pages, 3 figures, accepted for publication in MNRA
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Taking your next vacation from home: Motivations and impacts of using live-streaming tourism
The research investigates a novel and alternative form of tourism, namely, live-streaming tourism (LST). Live-streaming tourism empowers individuals to experience new destinations at home without the risks associated with large-scale travel. Meanwhile, it boosts the economy by enabling destinations and micro-entrepreneurs to launch an alternative business model and create new employment opportunities. Specifically, the current study proposes and tests a conceptual model of viewers’ motivations and consequences of using live-streaming tourism based on the United Theory of Acceptance and Use of Technology 2.0 (UTAUT2). We explore how existing UTAUT2 antecedents, together with newly incorporated LST antecedents, affect viewers’ reuse and Word-of-Mouth intention of LST through the mediated effect of co-creation value. We adopt an online survey method to collect an estimated sample of 1000 viewers who have participated in live-streaming tourism in the past twelve months
Identifying targets of the Sox domain protein Dichaete in the Drosophila CNS via targeted expression of dominant negative proteins.
BACKGROUND: Group B Sox domain transcription factors play important roles in metazoan central nervous system development. They are, however, difficult to study as mutations often have pleiotropic effects and other Sox family members can mask phenotypes due to functional compensation. In Drosophila melanogaster, the Sox gene Dichaete is dynamically expressed in the embryonic CNS, where it is known to have functional roles in neuroblasts and the ventral midline. In this study, we use inducible dominant negative proteins in combination with ChIP, immunohistochemistry and genome-wide expression profiling to further dissect the role of Dichaete in these two tissues. RESULTS: We generated two dominant negative Dichaete constructs, one lacking a DNA binding domain and the other fused to the Engrailed transcriptional repressor domain. We expressed these tissue-specifically in the midline and in neuroblasts using the UAS/GAL4 system, validating their use at the phenotypic level and with known target genes. Using ChIP and immunohistochemistry, we identified two new likely direct Dichaete target genes, commisureless in the midline and asense in the neuroectoderm. We performed genome-wide expression profiling in stage 8-9 embryos, identifying almost a thousand potential tissue-specific Dichaete targets, with half of these genes showing evidence of Dichaete binding in vivo. These include a number of genes with known roles in CNS development, including several components of the Notch, Wnt and EGFR signalling pathways. CONCLUSIONS: As well as identifying commisureless as a target, our data indicate that Dichaete helps establish its expression during early midline development but has less effect on its established later expression, highlighting Dichaete action on tissue specific enhancers. An analysis of the broader range of candidate Dichaete targets indicates that Dichaete plays diverse roles in CNS development, with the 500 or so Dichaete-bound putative targets including a number of transcription factors, signalling pathway components and terminal differentiation genes. In the early neurectoderm we implicate Dichaete in the lateral inhibition pathway and show that Dichaete acts to repress the proneural gene asense. Our analysis also reveals that dominant negatives cause off-target effects, highlighting the need to use other experimental data for validating findings from dominant negative studies.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
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