71 research outputs found

    A Privacy-Preserving Social P2P Infrastructure for People-Centric Sensing

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    The rapid miniaturization and integration of sensor technologies into mobile Internet devices combined with Online Social Networks allows for enhanced sensor information querying, subscription, and task placement within People-Centric Sensing networks. However, PCS systems which exploit knowledge about OSN user profiles and context information for enhanced service provision might cause an unsolicited application and dissemination of highly personal and sensitive data. In this paper, we propose a protocol extension to our OSN design Vegas which enables secure, privacy-preserving, and trustful P2P communication between PCS participants. By securing knowledge about social links with standard public key cryptography, we achieve a degree of anonymity at a trust level which is almost good as that provided by a centralized trusted third party

    Improving academic skills and attention/memory skills in self- contained learning disabled students through a package of cognitive training procedures

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    The purpose of this study was to determine if participation in a cognitive training program administered by teachers within their classrooms would significantly improve the academic achievement, attentional responding styles and auditory and visual attention and memory skills of elementary self-contained learning disabled students.;Subjects were thirty-six elementary age self-contained learning disabled students 8-0 to 11-11 years of age and with total I.Q. scores on the Wechsler intelligence Scale for Children-Revised of 80 or greater from the Virginia Beach City Public Schools in Virginia Beach, Virginia.;Three instruments were used to measure the dependent variables in this study: the reading, mathematics, and written language clusters of the Woodcock-Johnson Psycho-Educational Battery; the auditory and visual attention and memory subtests of the Detroit Tests of Learning Aptitude; and the Matching Familiar Figures Test to measure impulsive vs. reflective responding styles.;The research design was the Pretest-Posttest Control Groups Design. The data was analyzed using a 2 x 2 analysis of variance with the hypotheses being tested at the .05 level of confidence.;The findings indicated that participation in a program of cognitive training procedures administered by self-contained learning disabilities teachers in their classrooms did significantly improve the reading and math achievement test scores, the auditory memory and attention test scores and the reflective attending style test scores of the students involved in the training. No significant improvement was noted in the students written language test scores on the Woodcock or in the visual attention and memory test scores on the Detroit.;Future research is suggested with larger samples of both self-contained and resource learning disabled students

    Datenerfassung und Privatsphäre in partizipativen Sensornetzen

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    Partizipative Sensornetze (PSNs) stellen eine neue Art von Sensornetzen dar, die auf Basis von freiwillig zur Verfügung gestellten Mobiltelefonen etabliert werden. Sie ermöglichen eine großflächige Erfassung von Messdaten im direkten Umfeld von Menschen und können für zahlreiche Anwendungsszenarien verwendet werden. Neben ihren Vorzügen bringen PSNs aber auch Schwierigkeiten mit sich. Zwei zentrale Herausforderungen sind die ressourcenschonende Datenerfassung und der Schutz der Privatsphäre – beide resultieren aus der Instrumentalisierung privater Mobiltelefone zur Datenerfassung. Da der primäre Verwendungszweck der Geräte nicht die Aufzeichnung von Messdaten ist, darf diese deren Ressourcen nicht merklich belasten. Außerdem muss sichergestellt werden, dass durch die Erfassung von Messdaten die Privatsphäre der teilnehmenden Nutzer nicht verletzt wird. Der erste Teil der Arbeit beschäftigt sich mit dem Aspekt der ressourcenschonenden Datenerfassung. Zunächst werden PSNs betrachtet, bei denen punktuell Messungen durchgeführt werden. Bei diesen Netzen müssen die teilnehmenden Geräte über die durchzuführenden Messungen unterrichtet werden. Damit hierbei die Ressourcen der Endgeräte nicht unnötig belastet werden, wird ein Konzept vorgestellt, das einerseits eine robuste Verteilung der Messaufgaben sicherstellt, gleichzeitig jedoch versucht, die Energieressourcen der Mobiltelefone zu schonen. Bei PSNs mit großflächiger und kontinuierlicher Datenerfassung spielt die Verteilung der Messaufgaben keine so entscheidende Rolle. Hier muss vielmehr sichergestellt werden, dass die Energie- und die Übertragungskosten auf Seiten der Nutzer möglichst gering bleiben. Aus diesem Grund wird ein Ansatz zur lokalen Gruppierung von Messknoten beschrieben, der durch eine Aufteilung der anfallenden Aufgaben und eine intelligente Auswahl der Knoten zu einer ressourcenschonenden und weniger redundanten Datenerfassung führt. Der zweite Teil der Arbeit befasst sich mit dem Schutz der Privatsphäre der Teilnehmer und beinhaltet zwei Themenblöcke. Zum einen wird ein Ansatz zur automatisierten Erzeugung von Privatsphäre-Zonen vorgestellt, der ohne das Eingreifen der Nutzer die Zonen an das jeweilige Umfeld anpasst. Diese Zonen werden um die vom Nutzer häufig besuchten Orte erstellt und verhindern so mögliche, auf der Identifikation dieser Orte basierende Deanonymisierungsangriffe. Zum anderen wird ein Kalibrierungssystem für PSNs beschrieben, dessen Fokus sowohl auf der Verbesserung der Datenqualität als auch auf der Wahrung der Privatsphäre der Nutzer liegt. Hierfür ermöglicht dieses eine rückwirkende Anpassung bereits übertragener Daten, verhindert aber gleichzeitig durch eine Modifikation der Kalibrierungsparameter und der Upload-Zeitpunkte eine direkte Zuordnung zu einem Nutzer.Participatory Sensing Networks (PSNs) represent a new kind of sensor networks that are established on the basis of voluntarily provided mobile phones. They allow for large-scale data collection in the immediate environment of people and can be used for various application scenarios. However, alongside their advantages, PSNs entail several difficulties. Two key challenges are the resource-efficient data collection and the protection of privacy - both resulting from exploiting private mobile phones for data collection. As the recording of measurement data is not the devices’ primary purpose, it must not significantly burden their resources. In addition, it has to be ensured that the privacy of participating users is not violated by the acquisition of measurement data. The first part of this thesis addresses the issue of resource-efficient data collection. At first, PSNs are examined in which measurements are only conducted at selected places. In these networks, the participating devices have to be informed about the required measurements. To avoid an unnecessary burdening of device resources at this stage, a concept is presented that ensures a robust distribution of measurement tasks and, at the same time, tries to conserve the mobile phones’ energy resources. In PSNs with large and continuous data collection, the distribution of measurement tasks is less essential. It is rather necessary to ensure that energy and transmission costs on the user side remain as low as possible. For this reason, an approach for the local clustering of measurement nodes is described that allows for a resource-efficient and less redundant data collection by dividing and intelligently assigning occurring tasks. The second part of the thesis deals with the protection of the participants’ privacy and contains two thematic blocks. Firstly, an approach to automate the generation of privacy zones is presented. It adjusts the zones to the environment without the intervention of the user. These zones are created around the user’s frequently visited places and thereby prevent deanonymisation attacks based on the identification of these places. Secondly, a calibration system for PSNs is described that focuses both on improving data quality and on the protection of user privacy. It allows for a retroactive adjustment of already transferred data, but simultaneously prevents an unambiguous attribution to a user by modifying the calibration parameters and the time of their transmission

    Datenerfassung und Privatsphäre in partizipativen Sensornetzen

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    Partizipative Sensornetze (PSNs) stellen eine neue Art von Sensornetzen dar, die auf Basis von freiwillig zur Verfügung gestellten Mobiltelefonen etabliert werden. Sie ermöglichen eine großflächige Erfassung von Messdaten im direkten Umfeld von Menschen und können für zahlreiche Anwendungsszenarien verwendet werden. Neben ihren Vorzügen bringen PSNs aber auch Schwierigkeiten mit sich. Zwei zentrale Herausforderungen sind die ressourcenschonende Datenerfassung und der Schutz der Privatsphäre – beide resultieren aus der Instrumentalisierung privater Mobiltelefone zur Datenerfassung. Da der primäre Verwendungszweck der Geräte nicht die Aufzeichnung von Messdaten ist, darf diese deren Ressourcen nicht merklich belasten. Außerdem muss sichergestellt werden, dass durch die Erfassung von Messdaten die Privatsphäre der teilnehmenden Nutzer nicht verletzt wird. Der erste Teil der Arbeit beschäftigt sich mit dem Aspekt der ressourcenschonenden Datenerfassung. Zunächst werden PSNs betrachtet, bei denen punktuell Messungen durchgeführt werden. Bei diesen Netzen müssen die teilnehmenden Geräte über die durchzuführenden Messungen unterrichtet werden. Damit hierbei die Ressourcen der Endgeräte nicht unnötig belastet werden, wird ein Konzept vorgestellt, das einerseits eine robuste Verteilung der Messaufgaben sicherstellt, gleichzeitig jedoch versucht, die Energieressourcen der Mobiltelefone zu schonen. Bei PSNs mit großflächiger und kontinuierlicher Datenerfassung spielt die Verteilung der Messaufgaben keine so entscheidende Rolle. Hier muss vielmehr sichergestellt werden, dass die Energie- und die Übertragungskosten auf Seiten der Nutzer möglichst gering bleiben. Aus diesem Grund wird ein Ansatz zur lokalen Gruppierung von Messknoten beschrieben, der durch eine Aufteilung der anfallenden Aufgaben und eine intelligente Auswahl der Knoten zu einer ressourcenschonenden und weniger redundanten Datenerfassung führt. Der zweite Teil der Arbeit befasst sich mit dem Schutz der Privatsphäre der Teilnehmer und beinhaltet zwei Themenblöcke. Zum einen wird ein Ansatz zur automatisierten Erzeugung von Privatsphäre-Zonen vorgestellt, der ohne das Eingreifen der Nutzer die Zonen an das jeweilige Umfeld anpasst. Diese Zonen werden um die vom Nutzer häufig besuchten Orte erstellt und verhindern so mögliche, auf der Identifikation dieser Orte basierende Deanonymisierungsangriffe. Zum anderen wird ein Kalibrierungssystem für PSNs beschrieben, dessen Fokus sowohl auf der Verbesserung der Datenqualität als auch auf der Wahrung der Privatsphäre der Nutzer liegt. Hierfür ermöglicht dieses eine rückwirkende Anpassung bereits übertragener Daten, verhindert aber gleichzeitig durch eine Modifikation der Kalibrierungsparameter und der Upload-Zeitpunkte eine direkte Zuordnung zu einem Nutzer.Participatory Sensing Networks (PSNs) represent a new kind of sensor networks that are established on the basis of voluntarily provided mobile phones. They allow for large-scale data collection in the immediate environment of people and can be used for various application scenarios. However, alongside their advantages, PSNs entail several difficulties. Two key challenges are the resource-efficient data collection and the protection of privacy - both resulting from exploiting private mobile phones for data collection. As the recording of measurement data is not the devices’ primary purpose, it must not significantly burden their resources. In addition, it has to be ensured that the privacy of participating users is not violated by the acquisition of measurement data. The first part of this thesis addresses the issue of resource-efficient data collection. At first, PSNs are examined in which measurements are only conducted at selected places. In these networks, the participating devices have to be informed about the required measurements. To avoid an unnecessary burdening of device resources at this stage, a concept is presented that ensures a robust distribution of measurement tasks and, at the same time, tries to conserve the mobile phones’ energy resources. In PSNs with large and continuous data collection, the distribution of measurement tasks is less essential. It is rather necessary to ensure that energy and transmission costs on the user side remain as low as possible. For this reason, an approach for the local clustering of measurement nodes is described that allows for a resource-efficient and less redundant data collection by dividing and intelligently assigning occurring tasks. The second part of the thesis deals with the protection of the participants’ privacy and contains two thematic blocks. Firstly, an approach to automate the generation of privacy zones is presented. It adjusts the zones to the environment without the intervention of the user. These zones are created around the user’s frequently visited places and thereby prevent deanonymisation attacks based on the identification of these places. Secondly, a calibration system for PSNs is described that focuses both on improving data quality and on the protection of user privacy. It allows for a retroactive adjustment of already transferred data, but simultaneously prevents an unambiguous attribution to a user by modifying the calibration parameters and the time of their transmission

    Restrictions and constraints in mobile narratives for place-based community engagement

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    The usage of the mobile Internet increased tremendously within the last couple of years, and thereby the vision of accessing information anytime, anywhere became more realistic and a dominant design principle for providing content. However, this paper presents work-in-progress that challenges this paradigm of unlimited and unrestricted access, and explores and tests how constraints and restrictions may positively influence the motivation and enticement of mobile users to engage with location-specific content. Restrictions, such as a particular time or location that enables a user to access content, may be used to foster community participation and engagement, as well as to support locative media production and to enhance the user’s experience. In the end, we outline the timeline of our current work and further studies planned in order to verify our hypothesis

    Evaluacion de Impacto: Informe final, resultado y recomendaciones

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    A efectos de avanzar en la formulación de la iniciativa “Agricultura baja en emisiones y resiliente a la variabilidad y cambio climático en Colombia (LECRA)” se desarrolló una evaluación de impacto de los resultados del convenio de cooperación del 2013 y de las estrategias previstas para la iniciativa a futuro. En este documento, se presentan los principales resultados de dicha evaluación de impacto. El estudio fue llevado a cabo por la unión temporal entre la firma consultora INSUCO y la Universidad del Rosario, con el apoyo de la Alianza Bioversity – CIAT

    The Artemiside-Artemisox-Artemisone-M1 Tetrad: Efficacies against Blood Stage P. falciparum Parasites, DMPK Properties, and the Case for Artemiside

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    Because of the need to replace the current clinical artemisinins in artemisinin combination therapies, we are evaluating fitness of amino-artemisinins for this purpose. These include the thiomorpholine derivative artemiside obtained in one scalable synthetic step from dihydroartemisinin (DHA) and the derived sulfone artemisone. We have recently shown that artemiside undergoes facile metabolism via the sulfoxide artemisox into artemisone and thence into the unsaturated metabolite M1; DHA is not a metabolite. Artemisox and M1 are now found to be approximately equipotent with artemiside and artemisone in vitro against asexual P. falciparum (Pf) blood stage parasites (IC50 1.5–2.6 nM). Against Pf NF54 blood stage gametocytes, artemisox is potently active (IC50 18.9 nM early-stage, 2.7 nM late-stage), although against the late-stage gametocytes, activity is expressed, like other amino-artemisinins, at a prolonged incubation time of 72 h. Comparative drug metabolism and pharmacokinetic (DMPK) properties were assessed via po and iv administration of artemiside, artemisox, and artemisone in a murine model. Following oral administration, the composite Cmax value of artemiside plus its metabolites artemisox and artemisone formed in vivo is some 2.6-fold higher than that attained following administration of artemisone alone. Given that efficacy of short half-life rapidly-acting antimalarial drugs such as the artemisinins is associated with Cmax, it is apparent that artemiside will be more active than artemisone in vivo, due to additive effects of the metabolites. As is evident from earlier data, artemiside indeed possesses appreciably greater efficacy in vivo against murine malaria. Overall, the higher exposure levels of active drug following administration of artemiside coupled with its synthetic accessibility indicate it is much the preferred drug for incorporation into rational new artemisinin combination therapies

    The artemiside-artemisox-artemisone-m1 tetrad : efficacies against blood stage p. falciparum parasites, dmpk properties, and the case for artemiside

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    Because of the need to replace the current clinical artemisinins in artemisinin combination therapies, we are evaluating fitness of amino-artemisinins for this purpose. These include the thiomorpholine derivative artemiside obtained in one scalable synthetic step from dihydroartemisinin (DHA) and the derived sulfone artemisone. We have recently shown that artemiside undergoes facile metabolism via the sulfoxide artemisox into artemisone and thence into the unsaturated metabolite M1; DHA is not a metabolite. Artemisox and M1 are now found to be approximately equipotent with artemiside and artemisone in vitro against asexual P. falciparum (Pf ) blood stage parasites (IC50 1.5–2.6 nM). Against Pf NF54 blood stage gametocytes, artemisox is potently active (IC50 18.9 nM early-stage, 2.7 nM late-stage), although against the late-stage gametocytes, activity is expressed, like other amino-artemisinins, at a prolonged incubation time of 72 h. Comparative drug metabolism and pharmacokinetic (DMPK) properties were assessed via po and iv administration of artemiside, artemisox, and artemisone in a murine model. Following oral administration, the composite Cmax value of artemiside plus its metabolites artemisox and artemisone formed in vivo is some 2.6-fold higher than that attained following administration of artemisone alone. Given that efficacy of short half-life rapidly-acting antimalarial drugs such as the artemisinins is associated with Cmax, it is apparent that artemiside will be more active than artemisone in vivo, due to additive effects of the metabolites. As is evident from earlier data, artemiside indeed possesses appreciably greater efficacy in vivo against murine malaria. Overall, the higher exposure levels of active drug following administration of artemiside coupled with its synthetic accessibility indicate it is much the preferred drug for incorporation into rational new artemisinin combination therapies.Supplementary Material 1: S1 Efficacy of artemisox, dose response curves against asexual, and gametocyte blood stage parasites: Figure S1a–e; S2 Efficacy of M1, dose response curves against asexual, and gametocyte blood stage parasites: Figure S2a–d; S3 Pharmacokinetics and metabolism, circulating concentrations of artemiside, artemisox, and artemisone: Table S3a–f, LC-MS/MS chromatograms of M1 Figure S3a–c; S4 In vitro efficacy data— previously published data for artemiside, artemisone, M1: Table S4a–c; S5 In vivo efficacy data— previously published data for artemiside, artemisone: Table S5; S6 Neurotoxicity data–previously published neurotoxicity data for DHA, artesunate, artemiside, artemisone: Table S6.Supplementary Material 2: PDF copy of reference [37].The South African Medical Research Council (MRC) Flagship Project MALTB-Redox with funds from the National Treasury under its Economic Competitiveness and Support Package, a South African National Research Foundation (SA NRF) grant, and by a South African MRC Strategic Health Innovation Partnership (SHIP) grant, a South African MRC Collaborative Centre for Malaria Research grant and the Department of Science and Innovation and SA NRF South African Research Chairs Initiative (SARChI) Grant.https://www.mdpi.com/journal/pharmaceuticsam2022BiochemistryGeneticsMicrobiology and Plant PathologyUP Centre for Sustainable Malaria Control (UP CSMC

    Search for gravitational waves associated with the InterPlanetary Network short gamma ray bursts

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    We outline the scientific motivation behind a search for gravitational waves associated with short gamma ray bursts detected by the InterPlanetary Network (IPN) during LIGO's fifth science run and Virgo's first science run. The IPN localisation of short gamma ray bursts is limited to extended error boxes of different shapes and sizes and a search on these error boxes poses a series of challenges for data analysis. We will discuss these challenges and outline the methods to optimise the search over these error boxes.Comment: Methods paper; Proceedings for Eduardo Amaldi 9 Conference on Gravitational Waves, July 2011, Cardiff, U

    Pharmacokinetics of First-Line Drugs in Children With Tuberculosis, Using World Health Organization-Recommended Weight Band Doses and Formulations.

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    BACKGROUND: Dispersible pediatric fixed-dose combination (FDC) tablets delivering higher doses of first-line antituberculosis drugs in World Health Organization-recommended weight bands were introduced in 2015. We report the first pharmacokinetic data for these FDC tablets in Zambian and South African children in the treatment-shortening SHINE trial. METHODS: Children weighing 4.0-7.9, 8.0-11.9, 12.0-15.9, or 16.0-24.9 kg received 1, 2, 3, or 4 tablets daily, respectively (rifampicin/isoniazid/pyrazinamide [75/50/150 mg], with or without 100 mg ethambutol, or rifampicin/isoniazid [75/50 mg]). Children 25.0-36.9 kg received doses recommended for adults <37 kg (300, 150, 800, and 550 mg/d, respectively, for rifampicin, isoniazid, pyrazinamide, and ethambutol). Pharmacokinetics were evaluated after at least 2 weeks of treatment. RESULTS: In the 77 children evaluated, the median age (interquartile range) was 3.7 (1.4-6.6) years; 40 (52%) were male and 20 (26%) were human immunodeficiency virus positive. The median area under the concentration-time curve from 0 to 24 hours for rifampicin, isoniazid, pyrazinamide, and ethambutol was 32.5 (interquartile range, 20.1-45.1), 16.7 (9.2-25.9), 317 (263-399), and 9.5 (7.5-11.5) mg⋅h/L, respectively, and lower in children than in adults for rifampicin in the 4.0-7.9-, 8-11.9-, and ≥25-kg weight bands, isoniazid in the 4.0-7.9-kg and ≥25-kg weight bands, and ethambutol in all 5 weight bands. Pyrazinamide exposures were similar to those in adults. CONCLUSIONS: Recommended weight band-based FDC doses result in lower drug exposures in children in lower weight bands and in those ≥25 kg (receiving adult doses). Further adjustments to current doses are needed to match current target exposures in adults. The use of ethambutol at the current World Health Organization-recommended doses requires further evaluation
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