Generalized Lineage-Aware Temporal Windows: Supporting Outer and Anti Joins in Temporal-Probabilistic Databases

The result of a temporal-probabilistic (TP) join with negation includes, at each time point, the probability with which a tuple of a positive relation ${\bf p}$ matches none of the tuples in a negative relation ${\bf n}$, for a given join condition $\theta$. TP outer and anti joins thus resemble the characteristics of relational outer and anti joins also in the case when there exist time points at which input tuples from ${\bf p}$ have non-zero probabilities to be $true$ and input tuples from ${\bf n}$ have non-zero probabilities to be $false$, respectively. For the computation of TP joins with negation, we introduce generalized lineage-aware temporal windows, a mechanism that binds an output interval to the lineages of all the matching valid tuples of each input relation. We group the windows of two TP relations into three disjoint sets based on the way attributes, lineage expressions and intervals are produced. We compute all windows in an incremental manner, and we show that pipelined computations allow for the direct integration of our approach into PostgreSQL. We thereby alleviate the prevalent redundancies in the interval computations of existing approaches, which is proven by an extensive experimental evaluation with real-world datasets

Dynamic in vivo imaging and cell tracking using a histone fluorescent protein fusion in mice

BACKGROUND: Advances in optical imaging modalities and the continued evolution of genetically-encoded fluorescent proteins are coming together to facilitate the study of cell behavior at high resolution in living organisms. As a result, imaging using autofluorescent protein reporters is gaining popularity in mouse transgenic and targeted mutagenesis applications. RESULTS: We have used embryonic stem cell-mediated transgenesis to label cells at sub-cellular resolution in vivo, and to evaluate fusion of a human histone protein to green fluorescent protein for ubiquitous fluorescent labeling of nucleosomes in mice. To this end we have generated embryonic stem cells and a corresponding strain of mice that is viable and fertile and exhibits widespread chromatin-localized reporter expression. High levels of transgene expression are maintained in a constitutive manner. Viability and fertility of homozygous transgenic animals demonstrates that this reporter is developmentally neutral and does not interfere with mitosis or meiosis. CONCLUSIONS: Using various optical imaging modalities including wide-field, spinning disc confocal, and laser scanning confocal and multiphoton excitation microscopy, we can identify cells in various stages of the cell cycle. We can identify cells in interphase, cells undergoing mitosis or cell death. We demonstrate that this histone fusion reporter allows the direct visualization of active chromatin in situ. Since this reporter segments three-dimensional space, it permits the visualization of individual cells within a population, and so facilitates tracking cell position over time. It is therefore attractive for use in multidimensional studies of in vivo cell behavior and cell fate

Lineage-Aware Temporal Windows: Supporting Set Operations in Temporal-Probabilistic Databases

In temporal-probabilistic (TP) databases, the combination of the temporal and the probabilistic dimension adds significant overhead to the computation of set operations. Although set queries are guaranteed to yield linearly sized output relations, existing solutions exhibit quadratic runtime complexity. They suffer from redundant interval comparisons and additional joins for the formation of lineage expressions. In this paper, we formally define the semantics of set operations in TP databases and study their properties. For their efficient computation, we introduce the lineage-aware temporal window, a mechanism that directly binds intervals with lineage expressions. We suggest the lineage-aware window advancer (LAWA) for producing the windows of two TP relations in linearithmic time, and we implement all TP set operations based on LAWA. By exploiting the flexibility of lineage-aware temporal windows, we perform direct filtering of irrelevant intervals and finalization of output lineage expressions and thus guarantee that no additional computational cost or buffer space is needed. A series of experiments over both synthetic and real-world datasets show that (a) our approach has predictable performance, depending only on the input size and not on the number of time intervals per fact or their overlap, and that (b) it outperforms state-of-the-art approaches in both temporal and probabilistic databases

Drama-in-education for critical historical thinkers: A case study in the Greek context

The case study presented in this article refers to the connection of drama-in-education and critical thinking in history, in order to highlight the importance of drama for the teaching of history in primary schools in Greece. The research plan adopted is quantitative and qualitative, and the research strategy applied is that of case study. For the purposes of this study, four scenarios based on drama-in-education techniques were designed and applied on a sample of forty-three primary students. The analysis of the findings show that the students’ understanding of historical contexts and objectives of historically active subjects was encouraged by drama-based instruction

An Exploration Of Parameters Affecting Employee Energy Conversation Behaviour At The Workplace, Towards IOT-Enabled Behavioural Interventions

Energy conservation is one of the widely recognised important means towards addressing CO2 emissions and the resulting global issue of climate change. Furthermore, public buildings have been recognised as contributing significantly to the consumption of energy worldwide. More importantly, occupant behaviour, a factor that needs to be studied further, can have a high impact on the energy consumed within public buildings. Through our study, we have conducted an exploratory study on the parameters affecting employee energy conservation behaviour in public buildings, towards constructing a behavioural model that can be employed in IoT-enabled personalised energy disaggregation initiatives. We propose an extension to an existing model of employee energy behaviour based on Values Beliefs Norms (VBN) theory, with the addition of five parameters – comfort levels, burnout, locus of control, personal disadvantages and energy awareness. In addition, we discriminate between two groups of inter-related energy conservation behaviours at work – popular and unpopular energy conservation behaviours – and explain our resulting behavioural models’ utility towards IoT-enabled energy conservation, within workplaces. We find that promoting employees’ energy awareness levels, as well as positively affecting their environmental worldviews and personal norms are important factors that should be considered in behavioural interventions toward energy conservation at the workplace

Gamification at Work: Employee Motivations to Participate and Preference for Energy Conservation

Energy wastage, especially in public buildings, is one of the widely acknowledged issues that have to be addressed towards protecting the environment. Furthermore, affecting the occupants’ behaviour has been identified in the literature as an under-investigated means of conserving energy. In this research paper we report on the results from an investigation we conducted in three different workplaces, situated in different EU countries. In a survey of N=119 employees, we explore Employee Motivations to Participate in Gamification at work (EMPG) and identify the needs for (i)Self- Actualisation, (ii)Self-Regulation, (iii)Rewards & Recognition and (iv)Affiliation as most prominent. Additionally we examine the employees’ profiles, specific needs and preferences in game elements, towards participating in gamification aimed at conserving energy at the workplace. Correlations of the four types of EMPG with basic game elements and energy-saving actions at work are consequently explored and discussed. Ultimately, taking into consideration employees’ motivations and preferences, we derive and propose design guidelines for gamified applications providing personalised feedback towards saving energy at work

Supporting Set Operations in Temporal-Probabilistic Databases

In temporal-probabilistic (TP) databases, the combination of the temporal and the probabilistic dimension adds significant overhead to the computation of set operations. Although set queries are guaranteed to yield linearly sized output relations, all of the existing solutions exhibit a quadratic runtime complexity. They suffer from redundant interval comparisons and additional joins for the formation of lineage expressions. In this paper, we formally define TP set operations and study their properties. For their efficient computation, we introduce the lineage-aware temporal window, a mechanism that binds intervals with lineage expressions. We suggest the lineage-aware window advancer (LAWA) for producing lineage-aware temporal windows, which enable direct filtering of irrelevant intervals and finalization of output lineage expressions. This way, we compute TP set operations in linearithmic time. A series of experiments over both synthetic and real-world datasets show that (a) our approach has predictable performance, which depends only on the size of the input relations and not on the number of time intervals per fact or the overlap of the time intervals, and that (b) it outperforms state-of-the-art approaches