936 research outputs found

    Health and human rights: advocacy tools for structural HIV prevention among Russian drug users

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    Thesis (D.P.H.)--Boston UniversityInjection drug use fuels the HIV/AIDS epidemic in the Russian Federation (Russia). Evidence suggests that repressive drug law enforcement is part of the HIV risk environment and associated with risk behaviors that promote HIV transmission among people who inject drugs (PWID). However, no quantitative studies on police involvement and associated risk behaviors or health outcomes exist from Russia. We conducted a mixed-methods study in St. Petersburg, Moscow, and Vladikavkaz to characterize the impact of current policing practices on HIV-risk behaviors and overdose among PWID; and to explore attitudes of stakeholders about Russian drug policy and opportunities to change. Descriptive and multivariate regression analyses of quantitative cross-sectional data from 582 HIV prevention trial participants showed that reported policing practices such as arbitrary arrests, planting of false evidence, and extrajudicial syringe confiscations, are common in Russia and are associated with adverse risk behaviors and health outcomes such as receptive needle sharing and drug overdose, respectively. These policing practices often constitute human rights violations. We failed to demonstrate any deterrent effect of abusive policing practices on drug use. A qualitative exploration among 23 key stakeholders revealed that police violence in various forms is ubiquitous in the lives of Russian PWID. Police abuse is rooted in stigma and a power imbalance between police and PWID, and reinforced by police corruption and the dehumanization of PWID. This study suggests that police practices are part of the HIV risk environment of Russian PWID. The translation of empiric evidence into policy change in the Russian country context might be facilitated by police trainings emphasizing public health and harm reduction principles as well as the development of joint public safety/public health task forces. Using research evidence from other countries to influence policy in Russia has had limited effects. Therefore, more evidence from Russian studies is needed to advance the alignment of public health and public safety efforts to effectively address drug userelated harm and HIV prevention in Russia

    Recommendation in Enterprise 2.0 Social Media Streams

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    A social media stream allows users to share user-generated content as well as aggregate different external sources into one single stream. In Enterprise 2.0 such social media streams empower co-workers to share their information and to work efficiently and effectively together while replacing email communication. As more users share information it becomes impossible to read the complete stream leading to an information overload. Therefore, it is crucial to provide the users a personalized stream that suggests important and unread messages. The main characteristic of an Enterprise 2.0 social media stream is that co-workers work together on projects represented by topics: the stream is topic-centered and not user-centered as in public streams such as Facebook or Twitter. A lot of work has been done dealing with recommendation in a stream or for news recommendation. However, none of the current research approaches deal with the characteristics of an Enterprise 2.0 social media stream to recommend messages. The existing systems described in the research mainly deal with news recommendation for public streams and lack the applicability for Enterprise 2.0 social media streams. In this thesis a recommender concept is developed that allows the recommendation of messages in an Enterprise 2.0 social media stream. The basic idea is to extract features from a new message and use those features to compute a relevance score for a user. Additionally, those features are used to learn a user model and then use the user model for scoring new messages. This idea works without using explicit user feedback and assures a high user acceptance because no intense rating of messages is necessary. With this idea a content-based and collaborative-based approach is developed. To reflect the topic-centered streams a topic-specific user model is introduced which learns a user model independently for each topic. There are constantly new terms that occur in the stream of messages. For improving the quality of the recommendation (by finding more relevant messages) the recommender should be able to handle the new terms. Therefore, an approach is developed which adapts a user model if unknown terms occur by using terms of similar users or topics. Also, a short- and long-term approach is developed which tries to detect short-term interests of users. Only if the interest of a user occurs repeatedly over a certain time span are terms transferred to the long-term user model. The approaches are evaluated against a dataset obtained through an Enterprise 2.0 social media stream application. The evaluation shows the overall applicability of the concept. Specifically the evaluation shows that a topic-specific user model outperforms a global user model and also that adapting the user model according to similar users leads to an increase in the quality of the recommendation. Interestingly, the collaborative-based approach cannot reach the quality of the content-based approach

    Modelling and control of a high redundancy actuator

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    The high redundancy actuation concept is a completely new approach to fault tolerance, and it is important to appreciate that it provides a transformation of the characteristics of actuators so that the actuation performance (capability) degrades slowly rather than suddenly failing, even though individual elements themselves fail. This paper aims to demonstrate the viability of the concept by showing that a highly redundant actuator, comprising a relatively large number of actuation elements, can be controlled in such a way that faults in individual elements are inherently accommodated, although some degradation in overall performance will inevitably be found. The paper introduces the notion of fault-tolerant systems and the highly redundant actuator concept. Then a model for a two by two configuration with electro-mechanical actuation elements is derived. Two classical control approaches are then considered based on frequency domain techniques. Finally simulation results under a number of faults show the viability of the approach for fault accommodation without re-configuratio

    Experimental evaluation of two complementary decentralized event-based control methods

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    To appear in Control Engineering PracticeInternational audienceEvent-based control aims at the reduction of the feedback communication effort among the sensors, controllers and actuators in control loops. The feedback communication is invoked by some well-defined triggering condition. This paper presents a new method for the decentralized event-based control of physically interconnected systems and shows its experimental evaluation. The novel method is based on two complementary approaches, called the global and the local approach, which jointly ensure the ultimate boundedness of the closed-loop system. The global approach steers the state of each subsystem into a target region, whereas the local approach makes the state remain in this set in spite of exogenous disturbances and the effect of the interconnections to other subsystems. This event-based control method is applied to a continuous flow process to show its practical implementation and to evaluate the analytical results on the basis of experiments

    Recommending in an Enterprise Social Media Stream without Explicit User Feedback

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    Social Media Streams allow users to share user-generated content as well as aggregate different streams into one single stream. Additional Enterprise Social Media Streams organize the stream messages into projects with different usage patterns compared to public collaboration platforms such as Twitter. The aggregated stream helps the user to access the information in one single place but also leads to an information overload. Here, a recommendation engine can help to distinguish between relevant and irrelevant information for the users. In previous work we showed how features inferred from messages can predict relevant information and can be used to learn a user model. In this paper we show how this approach can be used in a productive enterprise social media stream application without using explicit user feedback. We develop a time binned evaluation measure which suits the scenario to steadily recommend messages of the stream. Finally, we evaluate our algorithm in different variations and show that it helps to identify relevant messages

    Update on ISFWM

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    Coping with drought : Strategies to improve genetic adaptation of common bean to drought-prone regions of Africa

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