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Identification of compounds with cytotoxic activity from the leaf of the Nigerian medicinal plant, Anacardium occidentale L. (Anacardiaceae)Taiwo, Bamigboye J., Fatokun, Amos A., Olubiyi, O.O., Bamigboye-Taiwo, O.T., van Heerden, F.R., Wright, Colin W. 2017 February 1922 (has links)
Yes / Cancer is now the second-leading cause of mortality and morbidity, behind only heart disease,
necessitating urgent development of (chemo)therapeutic interventions to stem the growing
burden of cancer cases and cancer death. Plants represent a credible source of promising drug
leads in this regard, with a long history of proven use in the indigenous treatment of cancer. This
study therefore investigated Anacardium occidentale, one of the plants in a Nigerian Traditional
Medicine formulation commonly used to manage cancerous diseases, for cytotoxic activity.
Bioassay-guided fractionation, spectroscopy, Alamar blue fluorescence-based viability assay in
cultured HeLa cells and microscopy were used. Four compounds: zoapatanolide A (1),
agathisflavone (2), 1, 2-bis (2,6-dimethoxy-4-methoxybenzoyl) ethane (Anacardicin, 3) and
methyl gallate (4) were isolated, with the most potent being zoapatanolide A with an IC50 value
of 36.2 ± 9.8 μM in the viability assay. To gain an insight into the likely molecular basis of their observed cytotoxic effects, Autodock Vina binding free energies of each of the isolated
compounds with seven molecular targets implicated in cancer development (MAPK8, MAPK10,
MAP3K12, MAPK3, MAPK1, MAPK7 and VEGF), were calculated. Pearson correlation
coefficients were obtained with experimentally-determined IC50 in the Alamar blue viability
assay. While these compounds were not as potent as a standard anti-cancer compound,
doxorubicin, the results provide reasonable evidence that the plant species contains compounds
with cytotoxic activity. This study provides some evidence of why this plant is used ethnobotanically
in anti-cancer herbal formulations and justifies investigating Nigerian medicinal
plants highlighted in recent ethno-botanical surveys. / This work was supported by a British Council Researcher Links Travel Grant 2013 to TBJ, a South Africa’s National Research Foundation (NRF) Grant No 98345, 2016 to FRVH and an academic staff funding provided to AAF by the School of Pharmacy, University of Bradford, UK.
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Synthesis and biological evaluation of cyclobutane-based β3 integrin antagonists: A novel approach to targeting integrins for cancer therapySutherland, Mark, Gordon, Andrew, Al-Shammari, F.O.F.O., Throup, Adam E., La Corte, A.C., Philippou, H., Shnyder, Steven, Patterson, Laurence H., Sheldrake, Helen M. 14 August 2023 (has links)
Yes / The Arg-Gly-Asp (RGD)-binding family of integrin receptors, and notably the β3 subfamily, are key to multiple physiological processes involved in tissue development, cancer proliferation, and metastatic dissemination. While there is compelling preclinical evidence that both αvβ3 and αIIbβ3 are important anticancer targets, most integrin antagonists developed to target the β3 integrins are highly selective for αvβ3 or αIIbβ3. We report the design, synthesis, and biological evaluation of a new structural class of ligand-mimetic β3 integrin antagonist. These new antagonists combine a high activity against αvβ3 with a moderate affinity for αIIbβ3, providing the first evidence for a new approach to integrin targeting in cancer. / This work was supported by the EPSRC (RCUK Academic Fellowship and Grant EP/H002626/1 to H.M.S.) and Prostate Cancer UK (Pilot Grant PA10-01). F.O.F.O.A-S.. was funded by the Public Authority for Applied Education and Training, Kuwait (PhD studentship).
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Induction and Inhibition of a Neuronal Phenotype in Spodoptera Frugiperda (Sf21) Insect CellsJenson, Lacey Jo 15 April 2010 (has links)
Due to the increasing resistance demonstrated by insects to conventional insecticides, the need for compounds with novel modes of action is becoming more urgent. Also, the discovery and production of new insecticides is vital as regulations and restrictions on conventional insecticides become increasingly stringent (Casida and Quistad 1998). Research in this area requires screening of many candidate compounds which is costly and time-consuming. The goal of this research was to produce in vitro insect neurons from Sf21 insect ovarian cell lines, which could lead to new high throughput screening methods and a way to mass produce insect material for basic research. This study used a culture of Sf21 cells and a mixture of differentiation agents to produce viable neuron-like cells. In the presence of the molting hormone 20-hydroxyecdysone (20-HE), or insulin, in the growth medium, Sf21 cells began to express neuronal morphology, or the production of elongated, axon-like processes within 2-3 days. Maximal differentiation occurred when in the presence of 42 μM 20-HE or 10 μM insulin. Effects were maximal on day 2 for 20-E and day 3 for insulin. Insulin was more potent at day 2 for inducing differentiation (EC₅₀ = 247 nM) than 20-HE (EC₅₀ = 13 μM). In combination, 20-HE and insulin produced apparent synergistic effects on differentiation. Caffeine, a central nervous system (CNS) stimulant, inhibited induction of elongated processes by 20-HE and/or insulin. Caffeine was a potent inhibitor of 42 μM 20-HE, with an IC50 of 9 nM, and the inhibition was incomplete, resulting in about one quarter of the differentiated cells remaining, even at high concentrations (up to 1 mM). The ability to induce a neural phenotype simplifies studies with of insect cells, compared to either the use of primary nervous tissue or genetic engineering techniques. The presence of ion channels or receptors in the differentiated cells remains to be determined. If they are present, high throughput screening for new insecticides will be accelerated and made more economical by the utility of this method. / Master of Science
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An Extensible Information Dissemination Scheme over the Optimized Link State Routing Protocol for Mobile Ad Hoc NetworksMehrjoo, Kaveh 10 October 2007 (has links)
A mobile ad hoc network (MANET) is formed by a collection of self-organizing nodes. Such networks are being deployed in a variety of environments, for example to provide mission-critical services in times of crises. Nodes participating in a MANET tend to have limited energy and computing resources and depend on various network-based resources to operate as a cohesive system. The same features such as dynamic and adaptive network topologies that make MANETs powerful also make the discovery and operation of network services a challenge.
This thesis presents the design and implementation of an extensible information dissemination scheme that is integrated with the Optimized Link State Routing (OLSR) protocol to address the challenges of service discovery in mobile ad hoc networks. The thesis presents a detailed design of the information dissemination scheme based on the Naval Research Laboratory's (NRL) ProtoLib network protocol programming framework.
In the proposed scheme, a solution that separates the routing process from the NRL OLSR routing protocol was designed, thus making OLSR a topology discovery protocol. This can further facilitate the implementation of various routing algorithms based on other metrics, such as the signal-to-noise ratio (SNR) of wireless links or the nodes' level of cooperation, when forwarding messages in the network. Additionally, a reusable event-driven programming interface to the NRL OLSR routing protocol was designed and implemented in this research. Events are triggered based on changes in the network topology. This programming interface can be used by other management and monitoring clients on the network for receiving real-time updates about link and topology changes as seen by OLSR. A priority message delivery scheme was developed that provides different quality of service (QoS) levels for information dissemination in mobile ad hoc networks. To ensure a fair use of the transport media and support various message sizes, a message fragmentation solution was implemented.
The proposed information dissemination solution was then deployed in a real wireless ad-hoc environment for further validation and testing. Using experiments with six nodes and various test scenarios, this research verified the functionality and characterized the performance of the proposed system. It was observed that the link-state nature of information dissemination solution helped it to adapt to topology changes. It was also realized that service discovery latency after information convergence in the network was independent of the number of nodes between the service providers and clients. The experiments also confirmed that the immediate message delivery scheme provides superior quality of service to registered users in presence of radio interference and other delays caused by Multipoint Relay Nodes (MPR) message forwarding in OLSR. / Master of Science
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Improving RDF data with data miningAbedjan, Ziawasch January 2014 (has links)
Linked Open Data (LOD) comprises very many and often large public data sets and knowledge bases. Those datasets are mostly presented in the RDF triple structure of subject, predicate, and object, where each triple represents a statement or fact. Unfortunately, the heterogeneity of available open data requires significant integration steps before it can be used in applications. Meta information, such as ontological definitions and exact range definitions of predicates, are desirable and ideally provided by an ontology. However in the context of LOD, ontologies are often incomplete or simply not available. Thus, it is useful to automatically generate meta information, such as ontological dependencies, range definitions, and topical classifications.
Association rule mining, which was originally applied for sales analysis on transactional databases, is a promising and novel technique to explore such data. We designed an adaptation of this technique for min-ing Rdf data and introduce the concept of “mining configurations”, which allows us to mine RDF data sets in various ways. Different configurations enable us to identify schema and value dependencies that in combination result in interesting use cases. To this end, we present rule-based approaches for auto-completion, data enrichment, ontology improvement, and query relaxation. Auto-completion remedies the problem of inconsistent ontology usage, providing an editing user with a sorted list of commonly used predicates. A combination of different configurations step extends this approach to create completely new facts for a knowledge base. We present two approaches for fact generation, a user-based approach where a user selects the entity to be amended with new facts and a data-driven approach where an algorithm discovers entities that have to be amended with missing facts.
As knowledge bases constantly grow and evolve, another approach to improve the usage of RDF data is to improve existing ontologies. Here, we present an association rule based approach to reconcile ontology and data. Interlacing different mining configurations, we infer an algorithm to discover synonymously used predicates. Those predicates can be used to expand query results and to support users during query formulation.
We provide a wide range of experiments on real world datasets for each use case. The experiments and evaluations show the added value of association rule mining for the integration and usability of RDF data and confirm the appropriateness of our mining configuration methodology. / Linked Open Data (LOD) umfasst viele und oft sehr große öffentlichen Datensätze und Wissensbanken, die hauptsächlich in der RDF Triplestruktur bestehend aus Subjekt, Prädikat und Objekt vorkommen. Dabei repräsentiert jedes Triple einen Fakt. Unglücklicherweise erfordert die Heterogenität der verfügbaren öffentlichen Daten signifikante Integrationsschritte bevor die Daten in Anwendungen genutzt werden können. Meta-Daten wie ontologische Strukturen und Bereichsdefinitionen von Prädikaten sind zwar wünschenswert und idealerweise durch eine Wissensbank verfügbar. Jedoch sind Wissensbanken im Kontext von LOD oft unvollständig oder einfach nicht verfügbar. Deshalb ist es nützlich automatisch Meta-Informationen, wie ontologische Abhängigkeiten, Bereichs-und Domänendefinitionen und thematische Assoziationen von Ressourcen generieren zu können.
Eine neue und vielversprechende Technik um solche Daten zu untersuchen basiert auf das entdecken von Assoziationsregeln, welche ursprünglich für Verkaufsanalysen in transaktionalen Datenbanken angewendet wurde. Wir haben eine Adaptierung dieser Technik auf RDF Daten entworfen und stellen das Konzept der Mining Konfigurationen vor, welches uns befähigt in RDF Daten auf unterschiedlichen Weisen Muster zu erkennen. Verschiedene Konfigurationen erlauben uns Schema- und Wertbeziehungen zu erkennen, die für interessante Anwendungen genutzt werden können. In dem Sinne, stellen wir assoziationsbasierte Verfahren für eine Prädikatvorschlagsverfahren, Datenvervollständigung, Ontologieverbesserung und Anfrageerleichterung vor.
Das Vorschlagen von Prädikaten behandelt das Problem der inkonsistenten Verwendung von Ontologien, indem einem Benutzer, der einen neuen Fakt einem Rdf-Datensatz hinzufügen will, eine sortierte Liste von passenden Prädikaten vorgeschlagen wird. Eine Kombinierung von verschiedenen Konfigurationen erweitert dieses Verfahren sodass automatisch komplett neue Fakten für eine Wissensbank generiert werden. Hierbei stellen wir zwei Verfahren vor, einen nutzergesteuertenVerfahren, bei dem ein Nutzer die Entität aussucht die erweitert werden soll und einen datengesteuerten Ansatz, bei dem ein Algorithmus selbst die Entitäten aussucht, die mit fehlenden Fakten erweitert werden.
Da Wissensbanken stetig wachsen und sich verändern, ist ein anderer Ansatz um die Verwendung von RDF Daten zu erleichtern die Verbesserung von Ontologien. Hierbei präsentieren wir ein Assoziationsregeln-basiertes Verfahren, der Daten und zugrundeliegende Ontologien zusammenführt. Durch die Verflechtung von unterschiedlichen Konfigurationen leiten wir einen neuen Algorithmus her, der gleichbedeutende Prädikate entdeckt. Diese Prädikate können benutzt werden um Ergebnisse einer Anfrage zu erweitern oder einen Nutzer während einer Anfrage zu unterstützen.
Für jeden unserer vorgestellten Anwendungen präsentieren wir eine große Auswahl an Experimenten auf Realweltdatensätzen. Die Experimente und Evaluierungen zeigen den Mehrwert von Assoziationsregeln-Generierung für die Integration und Nutzbarkeit von RDF Daten und bestätigen die Angemessenheit unserer konfigurationsbasierten Methodologie um solche Regeln herzuleiten.
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Advanced Techniques for Improving the Efficacy of Digital Forensics InvestigationsMarziale, Lodovico 20 December 2009 (has links)
Digital forensics is the science concerned with discovering, preserving, and analyzing evidence on digital devices. The intent is to be able to determine what events have taken place, when they occurred, who performed them, and how they were performed. In order for an investigation to be effective, it must exhibit several characteristics. The results produced must be reliable, or else the theory of events based on the results will be flawed. The investigation must be comprehensive, meaning that it must analyze all targets which may contain evidence of forensic interest. Since any investigation must be performed within the constraints of available time, storage, manpower, and computation, investigative techniques must be efficient. Finally, an investigation must provide a coherent view of the events under question using the evidence gathered. Unfortunately the set of currently available tools and techniques used in digital forensic investigations does a poor job of supporting these characteristics. Many tools used contain bugs which generate inaccurate results; there are many types of devices and data for which no analysis techniques exist; most existing tools are woefully inefficient, failing to take advantage of modern hardware; and the task of aggregating data into a coherent picture of events is largely left to the investigator to perform manually. To remedy this situation, we developed a set of techniques to facilitate more effective investigations. To improve reliability, we developed the Forensic Discovery Auditing Module, a mechanism for auditing and enforcing controls on accesses to evidence. To improve comprehensiveness, we developed ramparser, a tool for deep parsing of Linux RAM images, which provides previously inaccessible data on the live state of a machine. To improve efficiency, we developed a set of performance optimizations, and applied them to the Scalpel file carver, creating order of magnitude improvements to processing speed and storage requirements. Last, to facilitate more coherent investigations, we developed the Forensic Automated Coherence Engine, which generates a high-level view of a system from the data generated by low-level forensics tools. Together, these techniques significantly improve the effectiveness of digital forensic investigations conducted using them.
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The Fool and the Flood: A JourneyHoover, Michelle R 18 May 2018 (has links)
This journey based narrative inspired by the traditional narrative of the Major Arcana cards in the tarot, centers on The Fool and his interactions with the rest of the Major Arcana. The Fool’s journey centers on memory, regaining personal power, admitting and accepting weakness, and creating a personal place in relation to a larger world. This evolution throughout the journey is explored through detailed repeating imagery and symbols drawn from a mixture of traditional tarot imagery and the author’s personal image set created for this narrative.
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An Integrative Approach To Structured Snp Prioritization And Representative Snp Selection For Genome-wide Association StudiesUstunkar, Gurkan 01 January 2011 (has links) (PDF)
Single Nucleotide Polymorphisms (SNPs) are the most frequent genomic variations and the main basis for genetic differences among individuals and many diseases. As genotyping millions of SNPs at once is now possible with the microarrays and advanced sequencing technologies, SNPs are becoming more popular as genomic biomarkers. Like other high-throughput research techniques, genome wide association studies (GWAS) of SNPs usually hit a bottleneck after statistical analysis of significantly associated SNPs, as there is no standardized approach to prioritize SNPs or to select representative SNPs that show association with the conditions under study. In this study, a java based integrated system that makes use of major public databases to prioritize SNPs according to their biological relevance and statistical significance has been constructed. The Analytic Hierarchy Process, has been utilized for objective prioritization of SNPs and a new emerging methodology for second-wave analysis of genes and pathways related to disease associated SNPs based on a combined p-value approach is applied into the prioritization scheme. Using the subset of SNPs that is most representative of all SNPs associated with the diseases reduces the required computational power for analysis and decreases cost of following association and biomarker discovery studies. In addition to the proposed prioritization system, we have developed a novel feature selection method based on Simulated Annealing (SA) for representative SNP selection. The validity and accuracy of developed model has been tested on real life case control data set and produced biologically meaningful results. The integrated desktop application developed in our study will facilitate reliable identification of SNPs that are involved in the etiology of complex diseases, ultimately supporting timely identification of genomic disease biomarkers, and development of personalized medicine approaches and targeted drug discoveries.
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Efficient and exact computation of inclusion dependencies for data integrationBauckmann, Jana, Leser, Ulf, Naumann, Felix January 2010 (has links)
Data obtained from foreign data sources often come with only superficial structural information, such as relation names and attribute names. Other types of metadata that are important for effective integration and meaningful querying of such data sets are missing. In particular, relationships among attributes, such as foreign keys, are crucial metadata for understanding the structure of an unknown database. The discovery of such relationships is difficult, because in principle for each pair of attributes in the database each pair of data values must be compared.
A precondition for a foreign key is an inclusion dependency (IND) between the key and the foreign key attributes. We present with Spider an algorithm that efficiently finds all INDs in a given relational database. It leverages the sorting facilities of DBMS but performs the actual comparisons outside of the database to save computation. Spider analyzes very large databases up to an order of magnitude faster than previous approaches. We also evaluate in detail the effectiveness of several heuristics to reduce the number of necessary comparisons. Furthermore, we generalize Spider to find composite INDs covering multiple attributes, and partial INDs, which are true INDs for all but a certain number of values. This last type is particularly relevant when integrating dirty data as is often the case in the life sciences domain - our driving motivation.
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Commuting costs in Hong Kong with reference to residents in Discovery BayWong, Sau-kuen, 黃秀娟 January 2003 (has links)
published_or_final_version / abstract / toc / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning
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