764 research outputs found

    Towards Avatars with Artificial Minds: Role of Semantic Memory

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    he first step towards creating avatars with human-like artificial minds is to give them human-like memory structures with an access to general knowledge about the world. This type of knowledge is stored in semantic memory. Although many approaches to modeling of semantic memories have been proposed they are not very useful in real life applications because they lack knowledge comparable to the common sense that humans have, and they cannot be implemented in a computationally efficient way. The most drastic simplification of semantic memory leading to the simplest knowledge representation that is sufficient for many applications is based on the Concept Description Vectors (CDVs) that store, for each concept, an information whether a given property is applicable to this concept or not. Unfortunately even such simple information about real objects or concepts is not available. Experiments with automatic creation of concept description vectors from various sources, including ontologies, dictionaries, encyclopedias and unstructured text sources are described. Haptek-based talking head that has an access to this memory has been created as an example of a humanized interface (HIT) that can interact with web pages and exchange information in a natural way. A few examples of applications of an avatar with semantic memory are given, including the twenty questions game and automatic creation of word puzzles

    Is comprehensive medication review cost-effective for patients admitted to hospital?

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    Problematic polypharmacy is a major public health problem, linked to high morbidity, mortality and use of National Health Service (NHS) resources. Medicines optimisation supports management of polypharmacy, chronic conditions and comorbidities by ensuring appropriate use of medicines. A key component is comprehensive medication review (CMR) – evaluating patients’ medication to optimise use and reduce medication-related problems and waste. CMR is recommended for problematic polypharmacy but its cost-effectiveness in UK hospitals is unknown and uptake is low. This thesis investigates CMR cost-effectiveness in UK NHS hospitals. CMR is complex, with multiple interacting components, and economic evaluation should accommodate the context and complexity. Two de novo cost-effectiveness models were developed, which demonstrated that CMR compared to usual care is a cost-effective use of resources for the general population of elderly acutely hospitalised patients over a short timeframe and for elderly patients with heart failure over a long timeframe. Analysis of data from 3,043 patients in five London hospitals revealed the difference between the number of medicines on discharge and the number of medicines on admission was less with CMR than with usual care. CMR was associated with an increase in the number of medicines deprescribed, held and started. The saving from deprescribing medicines was -£2.78 per month per patient larger in the CMR group than in the usual care group. The results of the empirical study complement the findings from both cost-effectiveness models. Further review and analysis showed that targeting CMR at patients with significant morbidity and mortality, potentially inappropriate prescribing and high treatment costs may increase its health and economic impact. This was exemplified by the cost-effectiveness of CMR for patients with heart failure; the study could be replicated for other diseases. This thesis indicates that well-delivered CMR should be routine hospital care for older patients with co-morbidity and/or specific target conditions.Open Acces

    The C∗C^*-algebras of quantum lens and weighted projective spaces

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    It is shown that the algebra of continuous functions on the quantum 2n+1-dimensional lens space C(L2n+1q(N;m0,
,mn)) is a graph C*-algebra, for arbitrary positive weights m0,
,mn. The form of the corresponding graph is determined from the skew product of the graph which defines the algebra of continuous functions on the quantum sphere S2n+1q and the cyclic group â„€N, with the labelling induced by the weights. Based on this description, the K-groups of specific examples are computed. Furthermore, the K-groups of the algebras of continuous functions on quantum weighted projective spaces C(ℙnq(m0,
,mn)), interpreted as fixed points under the circle action on C(S2n+1q), are computed under a mild assumption on the weights

    A photometric and spectroscopic study of WW And - an Algol-type, long period binary system with an accretion disc

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    We have analyzed the available spectra of WW And and for the first time obtained a reasonably well defined radial velocity curve of the primary star. Combined with the available radial velocity curve of the secondary component, these data led to the first determination of the spectroscopic mass ratio of the system at q-spec = 0.16 +/- 0.03. We also determined the radius of the accretion disc from analysis of the double-peaked H-alpha emission lines. Our new, high-precision, Johnson VRI and the previously available Stromgren vby light curves were modelled with stellar and accretion disc models. A consistent model for WW And - a semidetached system harbouring an accretion disc which is optically thick in its inner region, but optically thin in the outer parts - agrees well with both spectroscopic and photometric data.Comment: Accepted by New Astronom

    Microvesicles released from ectopic endometrial foci as a potential biomarker of endometriosis

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    Objectives: Angiogenesis is engaged in endometriosis. It is regulated by regulatory factors and cytokines, transported in microvesicles. The purpose was to investigate the presence of MVs with vascular endothelial growth factor (VEGF) and metalloproteinase-9 (MMP-9) in peripheral blood and peritoneal fluid of women operated on for endometrioma or teratoma Material and methods: Microvesicles (MVs) were determined in blood samples and peritoneal fluid samples collected from women aged 20–60 years operated on for endometriosis (test group) and teratoma (control group). The final investigations were performed on 47 patients, who qualified for the study based on the meticulous inclusion criteria. MVs were analyzed by flow cytometry (FACS) using annexin V, antibodies for molecules characteristic of cells from endometriosis foci (keratin 18 (K18), CD105, CD146), and antibodies for intraepithelial vascular growth factor VEGF and metalloproteinase-9 (MMP-9). The sample was double “reading” using flow cytometry (FACSCantoII).  Results: Cytometry analysis confirmed MVs’ presence in plasma and peritoneal fluid collected from patients with both endometriosis and teratomas. A statistically significant higher level of AnnexinV (+) MVs were observed in plasma samples of endometriosis patients. In the control group, there was a higher percentage of double-positive VEGF (+)/MMP-9 (+) and single MMP-9 (+) positive MVs in the serum. In the peritoneal fluid higher frequency of double-positive VEGF (+)/MMP-9 (+) MVs were found in the control group. However, the amount of VEGF (+) / MMP-9 (+) MVs object did not enable to differentiate between the test and control groups. The study was the first, in which MVs were confirmed in plasma and peritoneal fluid in benign adnexa tumors.  Conclusions: Microvesicles are present in peripheral blood and peritoneal fluid samples collected from patients with endometriosis and teratomas. Microvesicles with proangiogenic factors (VEGF and MMP-9) are more abundant in blood and peritoneal fluid samples from patients with teratomas

    Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

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    Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a ZZ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 <pT<100< p_{\textrm{T}} < 100 GeV and in the pseudorapidity range 2.5<η<42.5 < \eta < 4. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb−1^{-1}. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

    Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

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    The decay B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} is studied in proton-proton collisions at a center-of-mass energy of s=13\sqrt{s}=13 TeV using data corresponding to an integrated luminosity of 5 fb−1\mathrm{fb}^{-1} collected by the LHCb experiment. In the Λc+K−\Lambda_{c}^+ K^{-} system, the Ξc(2930)0\Xi_{c}(2930)^{0} state observed at the BaBar and Belle experiments is resolved into two narrower states, Ξc(2923)0\Xi_{c}(2923)^{0} and Ξc(2939)0\Xi_{c}(2939)^{0}, whose masses and widths are measured to be m(Ξc(2923)0)=2924.5±0.4±1.1 MeV,m(Ξc(2939)0)=2938.5±0.9±2.3 MeV,Γ(Ξc(2923)0)=0004.8±0.9±1.5 MeV,Γ(Ξc(2939)0)=0011.0±1.9±7.5 MeV, m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV}, where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt Λc+K−\Lambda_{c}^{+} K^{-} sample. Evidence of a new Ξc(2880)0\Xi_{c}(2880)^{0} state is found with a local significance of 3.8 σ3.8\,\sigma, whose mass and width are measured to be 2881.8±3.1±8.5 MeV2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV} and 12.4±5.3±5.8 MeV12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}, respectively. In addition, evidence of a new decay mode Ξc(2790)0→Λc+K−\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-} is found with a significance of 3.7 σ3.7\,\sigma. The relative branching fraction of B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} with respect to the B−→D+D−K−B^{-} \to D^{+} D^{-} K^{-} decay is measured to be 2.36±0.11±0.22±0.252.36 \pm 0.11 \pm 0.22 \pm 0.25, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

    Measurement of the ratios of branching fractions R(D∗)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

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    The ratios of branching fractions R(D∗)≡B(Bˉ→D∗τ−Μˉτ)/B(Bˉ→D∗Ό−ΜˉΌ)\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu}) and R(D0)≡B(B−→D0τ−Μˉτ)/B(B−→D0Ό−ΜˉΌ)\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu}) are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb−1{ }^{-1} of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ−→Ό−ΜτΜˉΌ\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}. The measured values are R(D∗)=0.281±0.018±0.024\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024 and R(D0)=0.441±0.060±0.066\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is ρ=−0.43\rho=-0.43. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages
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