42 research outputs found
Distributed Ledger for Provenance Tracking of Artificial Intelligence Assets
High availability of data is responsible for the current trends in Artificial
Intelligence (AI) and Machine Learning (ML). However, high-grade datasets are
reluctantly shared between actors because of lacking trust and fear of losing
control. Provenance tracing systems are a possible measure to build trust by
improving transparency. Especially the tracing of AI assets along complete AI
value chains bears various challenges such as trust, privacy, confidentiality,
traceability, and fair remuneration. In this paper we design a graph-based
provenance model for AI assets and their relations within an AI value chain.
Moreover, we propose a protocol to exchange AI assets securely to selected
parties. The provenance model and exchange protocol are then combined and
implemented as a smart contract on a permission-less blockchain. We show how
the smart contract enables the tracing of AI assets in an existing industry use
case while solving all challenges. Consequently, our smart contract helps to
increase traceability and transparency, encourages trust between actors and
thus fosters collaboration between them
Anticancer efficacy of the hypoxia-activated prodrug evofosfamide (TH-302) in osteolytic breast cancer murine models
Tumor hypoxia is a major cause of treatment failure for a variety of malignancies. However, hypoxia offers treatment opportunities, exemplified by the development of compounds that target hypoxic regions within tumors. Evofosfamide (TH-302) is a prodrug created by the conjugation of 2-nitroimidazole to bromo-isophosphoramide mustard (Br-IPM). When evofosfamide is delivered to hypoxic regions, the DNA cross-linking effector, Br-IPM, is released. This study assessed the cytotoxic activity of evofosfamide in vitro and its antitumor activity against osteolytic breast cancer either alone or in combination with paclitaxel in vivo. A panel of human breast cancer cell lines were treated with evofosfamide under hypoxia and assessed for cell viability. Osteolytic MDA-MB-231-TXSA cells were transplanted into the mammary fat pad, or into tibiae of mice, allowed to establish and treated with evofosfamide, paclitaxel, or both. Tumor burden was monitored using bioluminescence, and cancer-induced bone destruction was measured using micro-CT. In vitro, evofosfamide was selectively cytotoxic under hypoxic conditions. In vivo evofosfamide was tumor suppressive as a single agent and cooperated with paclitaxel to reduce mammary tumor growth. Breast cancer cells transplanted into the tibiae of mice developed osteolytic lesions. In contrast, treatment with evofosfamide or paclitaxel resulted in a significant delay in tumor growth and an overall reduction in tumor burden in bone, whereas combined treatment resulted in a significantly greater reduction in tumor burden in the tibia of mice. Evofosfamide cooperates with paclitaxel and exhibits potent tumor suppressive activity against breast cancer growth in the mammary gland and in bone.Vasilios Liapis, Irene Zinonos, Agatha Labrinidis, Shelley Hay, Vladimir Ponomarev, Vasilios Panagopoulos, Aneta Zysk, Mark DeNichilo, Wendy Ingman, Gerald J. Atkins, David M. Findlay, Andrew C. W. Zannettino, Andreas Evdokio
Progressive resistance of BTK-143 osteosarcoma cells to Apo2L/TRAIL-induced apoptosis is mediated by acquisition of DcR2/TRAIL-R4 expression: resensitisation with chemotherapy
© 2003 Cancer Research UKApo2 ligand (Apo2L, also known as TRAIL) is a member of the tumour necrosis factor (TNF) family of cytokines that selectively induces the death of cancer cells, but not of normal cells. We observed that recombinant Apo2L/TRAIL was proapoptotic in early-passage BTK-143 osteogenic sarcoma cells, inducing 80% cell death during a 24 h treatment period. Apo2L/TRAIL-induced apoptosis was blocked by caspase inhibition. With increasing passage in culture, BTK-143 cells became progressively resistant to the apoptotic effects of Apo2L/TRAIL . RNA and flow cytometric analysis demonstrated that resistance to Apo2L/TRAIL was paralleled by progressive acquisition of the decoy receptor, DcR2. Blocking of DcR2 function with a specific anti-DcR2 antibody restored sensitivity to Apo2L/TRAIL in a dose-dependent manner. Importantly, treatment of resistant cells with the chemotherapeutic agents doxorubicin, cisplatin and etoposide reversed the resistance to Apo2L/TRAIL, which was associated with drug-induced upregulation of mRNA encoding the death receptors DR4 and DR5. BTK-143 cells thus represent a useful model system to investigate both the mechanisms of acquisition of resistance of tumour cells to Apo2L/TRAIL and the use of conventional drugs and novel agents to overcome resistance to Apo2L/TRAIL.S Bouralexis, D M Findlay, G J Atkins, A Labrinidis, S Hay & A Evdokio
Big data-driven fuzzy cognitive map for prioritising IT service procurement in the public sector
YesThe prevalence of big data is starting to spread across the public and private sectors however, an impediment to its widespread adoption orientates around a lack of appropriate big data analytics (BDA) and resulting skills to exploit the full potential of big data availability. In this paper, we propose a novel BDA to contribute towards this void, using a fuzzy cognitive map (FCM) approach that will enhance decision-making thus prioritising IT service procurement in the public sector. This is achieved through the development of decision models that capture the strengths of both data analytics and the established intuitive qualitative approach. By taking advantages of both data analytics and FCM, the proposed approach captures the strength of data-driven decision-making and intuitive model-driven decision modelling. This approach is then validated through a decision-making case regarding IT service procurement in public sector, which is the fundamental step of IT infrastructure supply for publics in a regional government in the Russia federation. The analysis result for the given decision-making problem is then evaluated by decision makers and e-government expertise to confirm the applicability of the proposed BDA. In doing so, demonstrating the value of this approach in contributing towards robust public decision-making regarding IT service procurement.EU FP7 project Policy Compass (Project No. 612133
Conformational analysis of C-disaccharides using molecular mechanics calculations
Relaxed-residue energy maps based on the MM3 force field were computed for the methyl glycosides of eight C-linked D-glucosyl disaccharides: the two-bond axial-equatorial linked disaccharides β-kojibioside [(1→2)α-], β-nigeroside [(1→3)α-] and β-maltose [(1→4)α-], the two-bond equatorial-equatorial linked disaccharides β-sophoroside [(1→2)β-], β-laminarabioside [(1→3)β-], β-cellobioside [(1→4)β-] and the three-bond-linked (1→6) disacharides C-isomaltoside and C-gentiobioside. Optimized structures were calculated on a 20° grid spacing of the torsional angles about the C-glycosidic bonds and the final isoenergy surfaces were based on 11664 conformations, for the two-bond-linked disaccharides and 69984 conformations for the three-bond-linked disaccharides. Boltzmann-weighted 3J coupling constants were calculated and compared to the experimental values. They are satisfactory except for maltose where hydrogen bonds cause an over-estimation of the energy differences between the conformers. The energy maps are similar to maps of the corresponding O-disaccharides, but there are differences in the locations and the relative energies of the minima. The preferred conformations of the C-glycosidic bonds are as if they were conforming to the exo-anomeric effect but are closer to staggered conformations than shown by the MM3 results for the O-linkages
Conformational Analysis of C-Trehaloses Using Molecular Mechanics Calculations
Relaxed-residue energy maps based on the MM3 force field were computed for the three C-linked (1-1) D-glucosyl disaccharides, C-trehaloses: the axial-axial linked α,α-trehalose, the axial-equatorial α,β-trehalose and the equatorial-equatorial linked β,β-trehalose. Optimized structures were calculated on a 20°-grid spacing of the torsional angles about the C-glycosidic bonds. Boltzman weighted 3J coupling constants were calculated and compared to the experimental values; they are satisfactory. The general shape of the energy maps indicates that α,α-trehalose is a quite rigid molecule adopting only one conformation around the C-glycosidic linkage, whereas the other two isomers are rather flexible. Compared to the corresponding O-disaccharides α,β-and β,β-trehaloses exhibit a larger number of low energy conformers and a larger area of the map energy < 8 kcal/mol. The preferred conformations of the axial C-glycosidic bond are in agreement with the exo-anomeric effect. Equatorial C- glycosidic bonds are rather flexible, influenced by the polarity of the milieu and the formation of interresidue hydrogen bonds
Conformational analysis of C-disaccharides using molecular mechanics calculations
International audienc
Conformational analysis of C-trehaloses using molecular mechanics calculations
International audienc