2,606 research outputs found

    Subspace local quantum channels

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    A special class of quantum channels, named subspace local (SL), are defined and investigated. The proposed definition of subspace locality of quantum channels is an attempt to answer the question of what kind of restriction should be put on a channel, if it is to act `locally' with respect to two `locations', when these naturally correspond to a separation of the total Hilbert space in an orthogonal sum of subspaces, rather than a tensor product decomposition. It is shown that the set of SL channels decomposes into four disjoint families of channels. Explicit expressions to generate all channels in each family is presented. It is shown that one of these four families, the local subspace preserving (LSP) channels, is precisely the intersection between the set of subspace preserving channels and the SL channels. For a subclass of the LSP channels, a special type of unitary representation using ancilla systems is presented.Comment: References adde

    DIMP53-1:A novel small-molecule dual inhibitor of p53-MDM2/X interactions with multifunctional p53-dependent anticancer properties

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    The transcription factor p53 plays a crucial role in cancer development and dissemination, and thus, p53-targeted therapies are among the most encouraging anticancer strategies. In human cancers with wild-type (wt) p53, its inactivation by interaction with murine double minute (MDM)2 and MDMX is a common event. Simultaneous inhibition of the p53 interaction with both MDMs is crucial to restore the tumor suppressor activity of p53. Here, we describe the synthesis of the new tryptophanol-derived oxazoloisoindolinone DIMP53-1 and identify its activity as a dual inhibitor of the p53-MDM2/X interactions using a yeast-based assay. DIMP53-1 caused growth inhibition, mediated by p53 stabilization and upregulation of p53 transcriptional targets involved in cell cycle arrest and apoptosis, in wt p53-expressing tumor cells, including MDM2- or MDMX-overexpressing cells. Importantly, DIMP53-1 inhibits the p53-MDM2/X interactions by potentially binding to p53, in human colon adenocarcinoma HCT116 cells. DIMP53-1 also inhibited the migration and invasion of HCT116 cells, and the migration and tube formation of HMVEC-D endothelial cells. Notably, in human tumor xenograft mice models, DIMP53-1 showed a p53-dependent antitumor activity through induction of apoptosis and inhibition of proliferation and angiogenesis. Finally, no genotoxicity or undesirable toxic effects were observed with DIMP53-1. In conclusion, DIMP53-1 is a novel p53 activator, which potentially binds to p53 inhibiting its interaction with MDM2 and MDMX. Although target-directed, DIMP53-1 has a multifunctional activity, targeting major hallmarks of cancer through its antiproliferative, proapoptotic, antiangiogenic, anti-invasive, and antimigratory properties. DIMP53-1 is a promising anticancer drug candidate and an encouraging starting point to develop improved derivatives for clinical application

    TransNets: Learning to Transform for Recommendation

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    Recently, deep learning methods have been shown to improve the performance of recommender systems over traditional methods, especially when review text is available. For example, a recent model, DeepCoNN, uses neural nets to learn one latent representation for the text of all reviews written by a target user, and a second latent representation for the text of all reviews for a target item, and then combines these latent representations to obtain state-of-the-art performance on recommendation tasks. We show that (unsurprisingly) much of the predictive value of review text comes from reviews of the target user for the target item. We then introduce a way in which this information can be used in recommendation, even when the target user's review for the target item is not available. Our model, called TransNets, extends the DeepCoNN model by introducing an additional latent layer representing the target user-target item pair. We then regularize this layer, at training time, to be similar to another latent representation of the target user's review of the target item. We show that TransNets and extensions of it improve substantially over the previous state-of-the-art.Comment: Accepted for publication in the 11th ACM Conference on Recommender Systems (RecSys 2017

    The mass and energy budget of Cassiopeia A

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    Further analysis of X-ray spectroscopy results recently obtained from the MOS CCD cameras on-board XMM-Newton provides a detailed description of the hot and cool X-ray emitting plasma in Cas A. Measurement of the Doppler broadening of the X-ray lines is consistent with the expected ion velocities, ~1500 km/s along the line of sight, in the post shock plasma. Assuming a constant total pressure throughout the remnant we estimate the total remnant mass as 10 Msun and the total thermal energy as 7E43 J. We derive the differential mass distribution as a function of ionisation age for both X-ray emitting components. This distribution is consistent with a hot component dominated by swept up mass heated by the primary shock and a cool component which are ablated clumpy ejecta material which were and are still being heated by interaction with the preheated swept up material. We calculate a balanced mass and energy budget for the supernova explosion giving 1E44 J in ejected mass; approximately 0.4 Msun of the ejecta were diffuse with an initial rms velocity of 15000 km/s while the remaining ~1.8 Msun were clumpy with an initial rms velocity of ~2400 km/s. Using the Doppler velocity measurements of the X-ray spectral lines we can project the mass into spherical coordinates about the remnant. This provides quantitative evidence for mass and energy beaming in the supernova explosion. The mass and energy occupy less than 4.5 sr (<40 % of the available solid angle) around the remnant and 64 % of the mass occurs in two jets within 45 degrees of a jet axis. We calculate a swept up mass of 7.9 Msun in the emitting plasma and estimate that the total mass lost from the progenitor prior to the explosion could be as high as ~20 Msun.Comment: 8 pages, 7 figures, submitted to Astronomy & Astrophysic

    InGaAs/AlGaAsSb avalanche photodiode with high gain - bandwidth product

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    Increasing reliance on the Internet places greater and greater demands for high -speed optical communication systems. Increasing their data transfer rate allows more data to be transferred over existing links. With optical receivers being essential to all optical links, bandwidth performance of key components in receivers, such as avalanche photodiodes (APDs), must be improved. The APDs rely on In0.53Ga0.47As (grown lattice-matched to InP substrates) to efficiently absorb and detect the optical signals with 1310 or 1550 nm wavelength, the optimal wavelengths of operation for these optical links. Thus developing InP -compatible APDs with high gain-bandwidth product (GBP) is important to the overall effort of increasing optical links’ data transfer rate. Here we demonstrate a novel InGaAs/AlGaAsSb APD, grown on an InP substrate, with a GBP of 424 GHz, the highest value reported for InP -compatible APDs, which is clearly applicable to future optical communication systems at or above 10 Gb/s

    Search and orchestration of data and processes in a federated environment

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    This paper describes on-going research on streamlining the access and use of spatial data and processes in Australia. Spatial data in Australia is available on-line at many levels of government from local authorities, state and territories (jurisdictions), and nationally from the Commonwealth and other sources. Much of this data is available via Open Geospatial Consortium and World Wide Web Consortium standard web services. This abstract discusses three related research topics that have been identified by a wide range of stakeholders through a comprehensive consultation process. These are search and discovery, federation and orchestration of data and processes. The commonality across the three research topics is that they all require Semantic Web and Artificial Intelligence methods and embrace the various standards, and if needed, propose modifications to such standard

    Flipping the switches: CD40 and CD45 modulation of microglial activation states in HIV associated dementia (HAD)

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    Microglial dysfunction is associated with the pathogenesis and progression of a number of neurodegenerative disorders including HIV associated dementia (HAD). HIV promotion of an M1 antigen presenting cell (APC) - like microglial phenotype, through the promotion of CD40 activity, may impair endogenous mechanisms important for amyloid- beta (Aβ) protein clearance. Further, a chronic pro-inflammatory cycle is established in this manner. CD45 is a protein tyrosine phosphatase receptor which negatively regulates CD40L-CD40-induced microglial M1 activation; an effect leading to the promotion of an M2 phenotype better suited to phagocytose and clear Aβ. Moreover, this CD45 mediated activation state appears to dampen harmful cytokine production. As such, this property of microglial CD45 as a regulatory "off switch" for a CD40-promoted M1, APC-type microglia activation phenotype may represent a critical therapeutic target for the prevention and treatment of neurodegeneration, as well as microglial dysfunction, found in patients with HAD

    Benefits and challenges of electronic prescribing for general practitioners and pharmacists in regional Australia

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    Objective: To explore the benefits and challenges of electronic prescribing (e-prescribing) for general practitioners (GPs) and pharmacists in regional New South Wales (NSW). Methods: This qualitative study utilised semistructured interviews conducted virtually or in-person between July and September 2021. Setting and Participants: General practitioners and pharmacists practising in Bathurst NSW. Main Outcomes: Self-reported perceived and experienced benefits and challenges of e-prescribing. Results: Two GPs and four pharmacists participated in the study. Reported benefits of e-prescribing included improvement in the prescribing and dispensing process, patient adherence, and prescription safety and security. The increased convenience for the patients was appreciated particularly during the COVID-19 pandemic. Challenges discussed were how the system was perceived to be unsafe and insecure, costs of messaging and updating general practice software, utilisation of new systems and patient awareness. Pharmacists reported the need for education to patients and staff to minimise the impact of inexperience with the novel technology on workflow efficacy. Conclusion: This study provided first insight and information on the perspectives of GPs and pharmacists 12 months after the implementation of e-prescribing. Further nationwide studies are required to consolidate these findings; provide comparisons with the system's progress since conception; determine whether metropolitan and rural health care professionals share similar perspectives; and shed light on where additional government support may be required

    Developing a protocol and experimental setup for using a humanoid robot to assist children with autism to develop visual perspective taking skills

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    Visual Perspective Taking (VPT) is the ability to see the world from another person's perspective, taking into account what they see and how they see it, drawing upon both spatial and social information. Children with autism often find it difficult to understand that other people might have perspectives, viewpoints, beliefs and knowledge that are different from their own, which is a fundamental aspect of VPT. In this research we aimed to develop a methodology to assist children with autism develop their VPT skills using a humanoid robot and present results from our first long-term pilot study. The games we devised were implemented with the Kaspar robot and, to our knowledge, this is the first attempt to improve the VPT skills of children with autism through playing and interacting with a humanoid robot. We describe in detail the standard pre- and post- assessments that we performed with the children in order to measure their progress and also the inclusion criteria derived from the results for future studies in this field. Our findings suggest that some children may benefit from this approach of learning about VPT, which shows that this approach merits further investigation.Peer reviewe

    Genome-Wide Identification, Functional Analysis and Expression Profiling of the Aux/IAA Gene Family in Tomato

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    Auxin is a central hormone that exerts pleiotropic effects on plant growth including the development of roots, shoots, flowers and fruit. The perception and signaling of the plant hormone auxin rely on the cooperative action of several components,among which auxin/indole-3-acetic acid (Aux/IAA) proteins play a pivotal role. In this study, we identified and comprehensively analyzed the entire Aux/IAA gene family in tomato (Solanum lycopersicum), a reference species for Solanaceae plants, and the model plant for fleshy fruit development. Functional characterization using a dedicated single cell system revealed that tomato Aux/IAA proteins function as active repressors of auxin-dependent gene transcription, with, however, different Aux/IAA members displaying varying levels of repression. Phylogenetic analysis indicated that the Aux/IAA gene family is slightly contracted in tomato compared with Arabidopsis, with a lower representation of non-canonical proteins. Sl-IAA genes display distinctive expression pattern in different tomato organs and tissues, and some of them display differential responses to auxin and ethylene, suggesting that Aux/IAAs may play a role in linking both hormone signaling pathways. The data presented here shed more light on Sl-IAA genes and provides new leads towards the elucidation of their function during plant development and in mediating hormone cross-talk
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