Dialectica Categories for the Lambek Calculus

We revisit the old work of de Paiva on the models of the Lambek Calculus in dialectica models making sure that the syntactic details that were sketchy on the first version got completed and verified. We extend the Lambek Calculus with a \kappa modality, inspired by Yetter's work, which makes the calculus commutative. Then we add the of-course modality !, as Girard did, to re-introduce weakening and contraction for all formulas and get back the full power of intuitionistic and classical logic. We also present the categorical semantics, proved sound and complete. Finally we show the traditional properties of type systems, like subject reduction, the Church-Rosser theorem and normalization for the calculi of extended modalities, which we did not have before

Understanding the Situated Practices of School Technology Leaders in the Early Stages of Educational Technology Adoption

School-driven technological innovation has the potential to positively impact on classroom practice, yet it can also be disrupted by incompatibilities between the existing school ecology and new educational technologies. To help mitigate this disruption a particular staff member often takes on a facilitative leadership role to champion new technology initiatives. However little is known about how this technology leader role impacts on the adoption of new technologies in the classroom. Taking a situated lens, we embarked on a multiple case study of four schools who were aiming to adopt a new literacy game in the classroom. Through interviews with technology leaders and fieldnotes from our site observations, we systematically analysed their actions and concerns over two academic terms. This highlighted an overwhelming concern with managing the material dimension of the technology, teacher agency and division of labour and mechanisms for communication and monitoring. Our findings raise important considerations for HCI researchers seeking to embed their technologies into practice alongside recommendations for supporting leaders tasked with coordinating this process

Layer by layer - Combining Monads

We develop a method to incrementally construct programming languages. Our approach is categorical: each layer of the language is described as a monad. Our method either (i) concretely builds a distributive law between two monads, i.e. layers of the language, which then provides a monad structure to the composition of layers, or (ii) identifies precisely the algebraic obstacles to the existence of a distributive law and gives a best approximant language. The running example will involve three layers: a basic imperative language enriched first by adding non-determinism and then probabilistic choice. The first extension works seamlessly, but the second encounters an obstacle, which results in a best approximant language structurally very similar to the probabilistic network specification language ProbNetKAT

Relationship between susceptivity to triclosan sensitization by outer membrane permeabilization and cell surface hydrophobicity properties in opportunistically pathogenic Serratia species

BACKGROUND: The nosocomial opportunists Pseudomonas aeruginosa and Serratia marcescens are atypically resistant to the hydrophobic biocide triclosan due largely to outer membrane impermeability properties for hydrophobic substances. However, we have recently shown that the degree of cell envelope impermeability for triclosan differs dramatically among other opportunistically pathogenic Serratia species. Moreover, susceptivity to sensitization to triclosan by outer membrane premeabilization also differs among other intrinsically resistant species. The purpose of the present study was to determine if cell surface hydrophobicity (CSH) properties underlie susceptivity to triclosan sensitization by outer membrane premeabilization in selected species as we further characterize their cell surface properties in anticipation of investigating their propensities to form in vitro biofilms.METHODS: Three Serratia species (marcescens, fonticola, and odorifera) exhibiting disparate degrees of susceptivity to triclosan sensitization by outer membrane premeabilization were examined to determine their susceptibility levels to mechanistically-disparate hydrophobic molecules and their CSH properties. Intrinsic resistance to hydrophobic antibacterial agents was assessed using a standardized disk agar diffusion bioassay. CSH was determined using conventional crystal violet binding, hydrocarbon adherence, and 1-N-phenylnapthylamine uptake assays routinely employed in this laboratory.RESULTS: S. marcescens and S. fonticola were intrinsically resistant to all mechanistically-disparate hydrophobic antibacterial agents examined to include triclosan, while S. odorifera was susceptible. The CSH properties of all these differed only slightly, despite the disparate susceptivities of the two triclosan-resistant species to triclosan sensitization.CONCLUSION: These data suggest that phenotypic differences seen in three opportunistic Serratia species with regard to intrinsic resistance to hydrophobic antibacterial agents in general, and triclosan specifically are at least due in part to disparate abilities of their outer membranes to exclude hydrophobic substances. Moreover, susceptivity to triclosan sensitization by outer membrane premeabilization in the triclosan-resistant species S. marcescens and S. fonticola appears not to be influenced by differences in cell surface hydrophobicity properties

Embedding digital technologies in the school practice: Schools as agents of technology integration

Whilst digital education is becoming a reality for schools there is a role for CCI research to move beyond researcher-led school engagements to other types of research that support schools and their staff to lead on the appropriation of digital technologies. One way to advance our understanding of this issue is to examine and consolidate reflections from cases of school technology appropriation. This half-day workshop seeks to capture the enabling practices as well as those that posed barriers within the school. The work will be oriented to further identify necessary changes at different levels: e.g., the organizational level (school), the level of the practitioners (teachers) the level the school community. The mind-set of all the involved actors will also be explored aiming to identify the structures and mechanisms that can support a culture of participation and of collective responsibility by including also students and their families in the process of technology integration and appropriation. Note: This workshop is offered in conjunction with "For the Long Run: Promoting Sustainable Use of Learning Technologies in Schools"to form a full day workshop exploring both the technical characteristics and the contextual factors of sustainable integration of learning technologies in schools

Association Between Early Hyperoxia Exposure After Resuscitation From Cardiac Arrest and Neurological Disability: Prospective Multicenter Protocol-Directed Cohort Study

BACKGROUND: Studies examining the association between hyperoxia exposure after resuscitation from cardiac arrest and clinical outcomes have reported conflicting results. Our objective was to test the hypothesis that early postresuscitation hyperoxia is associated with poor neurological outcome. METHODS: This was a multicenter prospective cohort study. We included adult patients with cardiac arrest who were mechanically ventilated and received targeted temperature management after return of spontaneous circulation. We excluded patients with cardiac arrest caused by trauma or sepsis. Per protocol, partial pressure of arterial oxygen (Pao2) was measured at 1 and 6 hours after return of spontaneous circulation. Hyperoxia was defined as a Pao2 >300 mm Hg during the initial 6 hours after return of spontaneous circulation. The primary outcome was poor neurological function at hospital discharge, defined as a modified Rankin Scale score >3. Multivariable generalized linear regression with a log link was used to test the association between Pao2 and poor neurological outcome. To assess whether there was an association between other supranormal Pao2 levels and poor neurological outcome, we used other Pao2 cut points to define hyperoxia (ie, 100, 150, 200, 250, 350, 400 mm Hg). RESULTS: Of the 280 patients included, 105 (38%) had exposure to hyperoxia. Poor neurological function at hospital discharge occurred in 70% of patients in the entire cohort and in 77% versus 65% among patients with versus without exposure to hyperoxia respectively (absolute risk difference, 12%; 95% confidence interval, 1-23). Hyperoxia was independently associated with poor neurological function (relative risk, 1.23; 95% confidence interval, 1.11-1.35). On multivariable analysis, a 1-hour-longer duration of hyperoxia exposure was associated with a 3% increase in risk of poor neurological outcome (relative risk, 1.03; 95% confidence interval, 1.02-1.05). We found that the association with poor neurological outcome began at ≥300 mm Hg. CONCLUSIONS: Early hyperoxia exposure after resuscitation from cardiac arrest was independently associated with poor neurological function at hospital discharge

Developing a Pedagogical Framework for Designing a Multisensory Serious Gaming Environment

The importance of multisensory interaction for learning has increased with improved understanding of children’s sensory development, and a flourishing interest in embodied cognition. The potential to foster new forms of multisensory interaction through various sensor, mobile and haptic technologies is promising in providing new ways for young children to engage with key mathematical concepts. However, designing effective learning environments for real world classrooms is challenging, and requires a pedagogically, rather than technologically, driven approach to design. This paper describes initial work underpinning the development of a pedagogical framework, intended to inform the design of a multisensory serious gaming environment. It identifies the theoretical basis of the framework, illustrates how this informs teaching strategies, and outlines key technology research driven perspectives and considerations important for informing design. An initial table mapping mathematical concepts to design, a framework of considerations for design, and a process model of how the framework will continue to be developed across the design process are provided

Hilbert-Post completeness for the state and the exception effects

In this paper, we present a novel framework for studying the syntactic completeness of computational effects and we apply it to the exception effect. When applied to the states effect, our framework can be seen as a generalization of Pretnar's work on this subject. We first introduce a relative notion of Hilbert-Post completeness, well-suited to the composition of effects. Then we prove that the exception effect is relatively Hilbert-Post complete, as well as the "core" language which may be used for implementing it; these proofs have been formalized and checked with the proof assistant Coq.Comment: Siegfried Rump (Hamburg University of Technology), Chee Yap (Courant Institute, NYU). Sixth International Conference on Mathematical Aspects of Computer and Information Sciences , Nov 2015, Berlin, Germany. 2015, LNC

Information-theoretic significance of the Wigner distribution

A coarse grained Wigner distribution p_{W}(x,u) obeying positivity derives out of information-theoretic considerations. Let p(x,u) be the unknown joint PDF (probability density function) on position- and momentum fluctuations x,u for a pure state particle. Suppose that the phase part Psi(x,z) of its Fourier transform F.T.[p(x,u)]=|Z(x,z)|exp[iPsi(x,z)] is constructed as a hologram. (Such a hologram is often used in heterodyne interferometry.) Consider a particle randomly illuminating this phase hologram. Let its two position coordinates be measured. Require that the measurements contain an extreme amount of Fisher information about true position, through variation of the phase function Psi(x,z). The extremum solution gives an output PDF p(x,u) that is the convolution of the Wigner p_{W}(x,u) with an instrument function defining uncertainty in either position x or momentum u. The convolution arises naturally out of the approach, and is one-dimensional, in comparison with the two-dimensional convolutions usually proposed for coarse graining purposes. The output obeys positivity, as required of a PDF, if the one-dimensional instrument function is sufficiently wide. The result holds for a large class of systems: those whose amplitudes a(x) are the same at their boundaries (Examples: states a(x) with positive parity; with periodic boundary conditions; free particle trapped in a box).Comment: pdf version has 16 pages. No figures. Accepted for publ. in PR

On coalgebras with internal moves

In the first part of the paper we recall the coalgebraic approach to handling the so-called invisible transitions that appear in different state-based systems semantics. We claim that these transitions are always part of the unit of a certain monad. Hence, coalgebras with internal moves are exactly coalgebras over a monadic type. The rest of the paper is devoted to supporting our claim by studying two important behavioural equivalences for state-based systems with internal moves, namely: weak bisimulation and trace semantics. We continue our research on weak bisimulations for coalgebras over order enriched monads. The key notions used in this paper and proposed by us in our previous work are the notions of an order saturation monad and a saturator. A saturator operator can be intuitively understood as a reflexive, transitive closure operator. There are two approaches towards defining saturators for coalgebras with internal moves. Here, we give necessary conditions for them to yield the same notion of weak bisimulation. Finally, we propose a definition of trace semantics for coalgebras with silent moves via a uniform fixed point operator. We compare strong and weak bisimilation together with trace semantics for coalgebras with internal steps.Comment: Article: 23 pages, Appendix: 3 page