The Geometry of Interaction of Differential Interaction Nets

The Geometry of Interaction purpose is to give a semantic of proofs or programs accounting for their dynamics. The initial presentation, translated as an algebraic weighting of paths in proofnets, led to a better characterization of the lambda-calculus optimal reduction. Recently Ehrhard and Regnier have introduced an extension of the Multiplicative Exponential fragment of Linear Logic (MELL) that is able to express non-deterministic behaviour of programs and a proofnet-like calculus: Differential Interaction Nets. This paper constructs a proper Geometry of Interaction (GoI) for this extension. We consider it both as an algebraic theory and as a concrete reversible computation. We draw links between this GoI and the one of MELL. As a by-product we give for the first time an equational theory suitable for the GoI of the Multiplicative Additive fragment of Linear Logic.Comment: 20 pagee, to be published in the proceedings of LICS0

On Geometry of Interaction for Polarized Linear Logic

We present Geometry of Interaction (GoI) models for Multiplicative Polarized Linear Logic, MLLP, which is the multiplicative fragment of Olivier Laurent's Polarized Linear Logic. This is done by uniformly adding multipoints to various categorical models of GoI. Multipoints are shown to play an essential role in semantically characterizing the dynamics of proof networks in polarized proof theory. For example, they permit us to characterize the key feature of polarization, focusing, as well as being fundamental to our construction of concrete polarized GoI models. Our approach to polarized GoI involves two independent studies, based on different categorical perspectives of GoI. (i) Inspired by the work of Abramsky, Haghverdi, and Scott, a polarized GoI situation is defined in which multipoints are added to a traced monoidal category equipped with a reflexive object $U$. Using this framework, categorical versions of Girard's Execution formula are defined, as well as the GoI interpretation of MLLP, proofs. Running the Execution formula is shown to characterize the focusing property (and thus polarities) as well as the dynamics of cut-elimination. (ii) The Int construction of Joyal-Street-Verity is another fundamental categorical structure for modelling GoI. Here, we investigate it in a multipointed setting. Our presentation yields a compact version of Hamano-Scott's polarized categories, and thus denotational models of MLLP. These arise from a contravariant duality between monoidal categories of positive and negative objects, along with an appropriate bimodule structure (representing "non-focused proofs") between them. Finally, as a special case of (ii) above, a compact model of MLLP is also presented based on Rel (the category of sets and relations) equipped with multi-points.Comment: 54 page

Conditional U1 gene silencing in Toxoplasma gondii

The functional characterisation of essential genes in apicomplexan parasites, such as Toxoplasma gondii or Plasmodium falciparum, relies on conditional mutagenesis systems. Here we present a novel strategy based on U1 snRNP-mediated gene silencing. U1 snRNP is critical in pre-mRNA splicing by defining the exon-intron boundaries. When a U1 recognition site is placed into the 3’-terminal exon or adjacent to the termination codon, pre-mRNA is cleaved at the 3’-end and degraded, leading to an efficient knockdown of the gene of interest (GOI). Here we describe a simple method that combines endogenous tagging with DiCre-mediated positioning of U1 recognition sites adjacent to the termination codon of the GOI which leads to a conditional knockdown of the GOI upon rapamycin-induction. Specific knockdown mutants of the reporter gene GFP and several endogenous genes of T. gondii including the clathrin heavy chain gene 1 (chc1), the vacuolar protein sorting gene 26 (vps26), and the dynamin-related protein C gene (drpC) were silenced using this approach and demonstrate the potential of this technology. We also discuss advantages and disadvantages of this method in comparison to other technologies in more detail

Public Expenditure Accountability of the Indian Railways

The Indian Railways (IR) is one of the chief logistics agents of the Government of India (GOI). Considering the significant GOI funding into IR, public expenditure accountability (PEA) becomes an issue of importance. This paper looks into different aspects of the expenditure and financial management of IR. The paper is divided into three portions. The first portion looks at the railway-government interface. The main areas of focus here include a brief examination of The Indian Railways Act, the financial interface between the GOI and IR (consisting of budgetary support, market sourced financing and dividend payments), evaluating the need for a separate railway budget, political interference in the activities of IR and the interaction of IR with state governments. The second portion of the paper deals with the internal financial management of IR. In this section, there is an effort to evaluate the revenue generation by IR along with suggestions for enhancing its potential. This is followed by a look at the issue of subsidies to IR. Investment decisions of IR and the Special Railway Safety Fund (SRSF) along with the issue of excess manpower and cost reduction are other topics included in this section. The paper ends with a roadmap to corporatisation as a possible solution to the problems IR is faced with. The main areas dealt with are financial issues, pensions, the need for customer focus, the importance of focus on core competencies and a need to revamp IRs administrative structure and attitude.

Coalgebras and Higher-Order Computation: a GoI Approach

Girard\u27s geometry of interaction (GoI) can be seen---in one practical aspect of it---as a compositional compilation method from functional programs to sequential machines. There tokens move around and express interactions between (parts of) programs. Intrigued by the combination of abstract structures and concrete dynamics in GoI, our line of work has aimed at exploiting, in GoI, results from the theory of coalgebra---a categorical abstraction of state-based transition systems that has found its use principally in concurrency theory. Such reinforced connection between higher-order computation and state-based dynamics is made possible thanks to an elegant categorical axiomatization of GoI by Abramsky, Haghverdi and Scott, where traced monoidal categories are identified to be the essential structure behind. In the talk I shall lay out these basic ideas, together with some of our results on: GoI semantics for a quantum programming language; and our ``memoryful\u27\u27 extension of GoI with algebraic effects. The talk is based on my joint work with my colleague Naohiko Hoshino (RIMS, Kyoto Univer- sity) and my (former) students Koko Muroya (University of Birmingham) and Toshiki Kataoka (University of Tokyo), to whom I owe special thanks

A growing pain: an experimental approach to discover the most acceptable strategy for lifting fuel subsidy scheme in Indonesia

Fuel subsidy has been the biggest quandaries in Indonesian economy, as it has been creating a huge opportunity costs to the economy. The subsidy is implemented to a consumer good (i.e. fuels) as oppose to targeted recipients, creating distortion in the efficient resource allocation. It was estimated about 70% of the subsidy were received by 40% of top income households (World Bank, 2007). Although the budget plan for the subsidy in 2011 was Rp129.7 trillion or 10% of the GoI annual budget, the actual subsidy was Rp160.7 trillion (13.3% of the GoI annual budget). Indeed, no individual prefers to lose the subsidy that has been received for many years, however the Government of Indonesia (GoI) cannot maintain the subsidy policy on fuel price any longer without creating extra budgetary burden. This study use experimental approach to seek the most acceptable exit strategy of eliminating fuel subsidy scheme in Indonesia based on households’ perspective. 335 subjects participated in the experiment, ranging from those who do not own motor vehicle, those who have motor cycle(s) and those who have car(s). During the experiment, subjects were given several pair-wise choices and chose the most acceptable policy from each pair-wise policy choices. The results show that the combination of gradual elimination and earmarked reallocation scheme were the most desirable. Subject with very low and low-income background tend to be more receptive for sudden elimination of the subsidy in comparison to their counterpart from medium and high-income backgrounds.Fuel subsidy, experimental economics, analytical hierarchy process (AHP), preference relation, reallocation of resources

Le rôle des grandes organisations internationales dans l’adoption d’une sécurité sociale minimale et proactive dans les BRICS

Le propos de cette communication vise à indiquer les conséquences de la diffusion des normes sociales plébiscitées par les Grandes organisations internationales (GOI) (OCDE, OIT, AISS, Banque mondiale) sur les systèmes sociaux des BRICS (Brésil, Russie, Inde, Chine, Afrique du Sud). Pour ce faire, elle expose le fait que la mise en place de "socles" de sécurité sociale dans les BRICS fait écho à l’idée d’une couverture sociale minimale pour tous que plébiscitent les GOI. Puis elle montre que, parallèlement à cette sécurité sociale de base, l’institution d’une protection sociale active et dynamique préconisée par ces GOI exerce une influence sur la structuration des systèmes sociaux des BRICS

Le rôle des grandes organisations internationales dans l’adoption d’une sécurité sociale minimale et proactive dans les BRICS

Le propos de cette communication vise à indiquer les conséquences de la diffusion des normes sociales plébiscitées par les Grandes organisations internationales (GOI) (OCDE, OIT, AISS, Banque mondiale) sur les systèmes sociaux des BRICS (Brésil, Russie, Inde, Chine, Afrique du Sud). Pour ce faire, elle expose le fait que la mise en place de "socles" de sécurité sociale dans les BRICS fait écho à l’idée d’une couverture sociale minimale pour tous que plébiscitent les GOI. Puis elle montre que, parallèlement à cette sécurité sociale de base, l’institution d’une protection sociale active et dynamique préconisée par ces GOI exerce une influence sur la structuration des systèmes sociaux des BRICS

Quantum authentication with unitary coding sets

A general class of authentication schemes for arbitrary quantum messages is proposed. The class is based on the use of sets of unitary quantum operations in both transmission and reception, and on appending a quantum tag to the quantum message used in transmission. The previous secret between partners required for any authentication is a classical key. We obtain the minimal requirements on the unitary operations that lead to a probability of failure of the scheme less than one. This failure may be caused by someone performing a unitary operation on the message in the channel between the communicating partners, or by a potential forger impersonating the transmitter.Comment: RevTeX4, 10 page