Understanding Firms' Inflation Expectations Using the Bank of Canada's Business Outlook Survey

Inflation expectations are a key determinant of actual and future inflation and thus matter for the conduct of monetary policy. We study how firms form their inflation expectations using quarterly firm-level data from the Bank of Canada's Business Outlook Survey, spanning the 2001 to 2015 period. The data are aggregated to construct an inflation expectations index. Results based on the index suggest that expectations are not consistent with the rationality assumption but are, still, more complex than purely adaptive expectations. Firms' own unique experiences, such as the dynamics of the prices they expect to pay (wages/inputs), significantly influence aggregate expectations. Expectations are also found to be significantly and positively correlated with movements in oil prices. Most of the preceding results hold at the firm level. The estimation of structural shift specifications suggests that inflation expectations in Canada have drifted downward since the Great Recession. However, the data do not suggest that Canadian businesses' expectations have become unanchored

Ruin problems for risk processes with dependent phase-type claims

We consider continuous time risk processes in which the claim sizes are dependent and non-identically distributed phase-type distributions. The class of distributions we propose is easy to characterize and allows to incorporate the dependence between claims in a simple and intuitive way. It is also designed to facilitate the study of the risk processes by using a Markov-modulated fluid embedding technique. Using this technique, we obtain simple recursive procedures to determine the joint distribution of the time of ruin, the deficit at ruin and the number of claims before the ruin. We also obtain some bounds for the ultimate ruin probability. Finally, we provide a few examples of multivariate phase-type distributions and use them for numerical illustration

Understanding firms' inflation expectations using the Bank of Canada's Business Outlook Survey

Inflation expectations are a key determinant of actual and future inflation and thus matter for the conduct of monetary policy. We study how firms form their inflation expectations using quarterly firm-level data from the Bank of Canada's Business Outlook Survey, spanning the 2001 to 2015 period. The data are aggregated to construct an inflation expectations index. Results based on the index suggest that expectations are not consistent with the rationality assumption but are, still, more complex than purely adaptive expectations. Firms' own unique experiences, such as the dynamics of the prices they expect to pay (wages/inputs), significantly influence aggregate expectations. Expectations are also found to be significantly and positively correlated with movements in oil prices. Most of the preceding results hold at the firm level. The estimation of structural shift specifications suggests that inflation expectations in Canada have drifted downward since the Great Recession. However, the data do not suggest that Canadian businesses' expectations have become unanchored

Applying single-molecule localisation microscopy to achieve virtual optical sectioning and study T-cell activation

Single-molecule localisation microscopy (SMLM) allows imaging of fluorescently-tagged proteins in live cells with a precision well below that of the diffraction limit. As a single-molecule technique, it has also introduced a new quantitative approach to fluorescence microscopy. In the Part A of this thesis, the design and building of three SMLM instruments, the implementation of a custom-developed image analysis package and the characterisation of the photo-physical properties of the photo-activable fluorescent protein used in this thesis (mEos), are discussed. Then, a new post-processing method for SMLM analysis is characterised: axial optical sectioning of SMLM images is demonstrated by thresholding fitted localisations using their fitted width and amplitude to reject fluorophores that emit from above or below a virtual ‘light-sheet’, a thin volume centred on the focal plane of the microscope. This method provides qualitative and quantitative improvements to SMLM. In the Part B of this thesis, SMLM is applied to study T cell activation. Although the T cell receptor plays a key role in immunity, its stoichiometry in the membrane of resting T cells is still a matter of debate. Here, single-molecule counting methods are implemented to compare the stoichiometry of TCRs fused with mEos2 in resting T cells to monomeric and dimeric controls. However, because of the stochasticity of mEos2 photo-physics, results are inconclusive and new counting techniques based on structural imaging are discussed. In addition to TCR triggering, T cells require the co-stimulatory triggering of the CD28 transmembrane receptor to become fully activated. However, some immobilised anti-CD28 antibodies, referred to as super-agonists (SA), can directly activate T cells without triggering the TCR. In this thesis, single-molecule tracking techniques are used to investigate the molecular mechanism of CD28 super-agonism in live T cells. The results indicate that the diffusion of CD28 is slowed by SA binding. This effect is further discussed in light of the kinetic-segregation model proposed for TCR triggering. Quantitative SMLM as implemented and further developed in this work offers new tools to investigate the molecular mechanisms initiating T cell activation, ultimately facilitating the discovery of novel approaches to target these pathways for therapeutic purposes.This work was supported by the Wellcome Trust [studentship number 093756/B/10/Z]

Postural adjustments in catching: on the interplay between segment stabilization and equilibrium control

The purpose of this study was to investigate postural adjustments in one-handed ball catching. Specifically, the functional role of anticipatory postural adjustments (APA) during the initial arm raising and subsequent postural adjustments (SPA) for equilibrium control and ball-hand impact were scrutinized. Full-body kinematics and kinetics allowed an analysis of the mechanical consequences of raising up the arm and preparing for ball-hand impact. APA for catching were suggested to be for segment stabilization. SPA had a functional role for equilibrium control by an inverted pendulum mechanism but were also involved in preparing for the impact of the ball on the hand, which was illustrated by an increased postural response at the end of the movement. These results were compared with raising up the arm in a well-studied reaction-time task, for which an additional counter rotation equilibrium mechanism was observed. Together, our findings demonstrate that postural adjustments should be investigated in relation to their specific functional task constraints, rather than generalizing the functional role of these postural adjustments over different tasks

Allelic heterogeneity and trade-off shape natural variation for response to soil micronutrient

Peer reviewedPublisher PD

OA-SLAM: Leveraging Objects for Camera Relocalization in Visual SLAM

In this work, we explore the use of objects in Simultaneous Localization and Mapping in unseen worlds and propose an object-aided system (OA-SLAM). More precisely, we show that, compared to low-level points, the major benefit of objects lies in their higher-level semantic and discriminating power. Points, on the contrary, have a better spatial localization accuracy than the generic coarse models used to represent objects (cuboid or ellipsoid). We show that combining points and objects is of great interest to address the problem of camera pose recovery. Our main contributions are: (1) we improve the relocalization ability of a SLAM system using high-level object landmarks; (2) we build an automatic system, capable of identifying, tracking and reconstructing objects with 3D ellipsoids; (3) we show that object-based localization can be used to reinitialize or resume camera tracking. Our fully automatic system allows on-the-fly object mapping and enhanced pose tracking recovery, which we think, can significantly benefit to the AR community. Our experiments show that the camera can be relocalized from viewpoints where classical methods fail. We demonstrate that this localization allows a SLAM system to continue working despite a tracking loss, which can happen frequently with an uninitiated user. Our code and test data are released at gitlab.inria.fr/tangram/oa-slam.Comment: ISMAR 202

Performance Evaluation of Components Using a Granularity-based Interface Between Real-Time Calculus and Timed Automata

To analyze complex and heterogeneous real-time embedded systems, recent works have proposed interface techniques between real-time calculus (RTC) and timed automata (TA), in order to take advantage of the strengths of each technique for analyzing various components. But the time to analyze a state-based component modeled by TA may be prohibitively high, due to the state space explosion problem. In this paper, we propose a framework of granularity-based interfacing to speed up the analysis of a TA modeled component. First, we abstract fine models to work with event streams at coarse granularity. We perform analysis of the component at multiple coarse granularities and then based on RTC theory, we derive lower and upper bounds on arrival patterns of the fine output streams using the causality closure algorithm. Our framework can help to achieve tradeoffs between precision and analysis time.Comment: QAPL 201