Early identification of important patents through network centrality

One of the most challenging problems in technological forecasting is to identify as early as possible those technologies that have the potential to lead to radical changes in our society. In this paper, we use the US patent citation network (1926-2010) to test our ability to early identify a list of historically significant patents through citation network analysis. We show that in order to effectively uncover these patents shortly after they are issued, we need to go beyond raw citation counts and take into account both the citation network topology and temporal information. In particular, an age-normalized measure of patent centrality, called rescaled PageRank, allows us to identify the significant patents earlier than citation count and PageRank score. In addition, we find that while high-impact patents tend to rely on other high-impact patents in a similar way as scientific papers, the patents' citation dynamics is significantly slower than that of papers, which makes the early identification of significant patents more challenging than that of significant papers.Comment: 14 page

Wright meets Markowitz: How standard portfolio theory changes when assets are technologies following experience curves

We consider how to optimally allocate investments in a portfolio of competing technologies using the standard mean-variance framework of portfolio theory. We assume that technologies follow the empirically observed relationship known as Wright's law, also called a "learning curve" or "experience curve", which postulates that costs drop as cumulative production increases. This introduces a positive feedback between cost and investment that complicates the portfolio problem, leading to multiple local optima, and causing a trade-off between concentrating investments in one project to spur rapid progress vs. diversifying over many projects to hedge against failure. We study the two-technology case and characterize the optimal diversification in terms of progress rates, variability, initial costs, initial experience, risk aversion, discount rate and total demand. The efficient frontier framework is used to visualize technology portfolios and show how feedback results in nonlinear distortions of the feasible set. For the two-period case, in which learning and uncertainty interact with discounting, we compare different scenarios and find that the discount rate plays a critical role

Les témoins et la justice militaire pendant les Rébellions au Bas-Canada, 1837-1839

Ce mémoire analyse les Rébellions de 1837-1838 sous les angles sociopolitique et juridique. Nous nous intéressons plus particulièrement à la cour martiale de 1838. Cette institution a été créée dans le contexte du prolongement de la loi martiale utilisée pour réprimer la rébellion de 1838 et stabiliser la société bas-canadienne. Les procès de la cour martiale générale de Montréal rassemblent de nombreux civils venus témoigner pour ou contre les patriotes accusés de haute trahison envers la Couronne. Ces témoins constituent notre principal objet d'études. D'autres colonies britanniques telles que le Haut-Canada, l'Irlande et la Jamaïque ont vécu des rébellions civiles réprimées sous le couvert de la loi martiale et de ses procès envers les rebelles. Nous dressons d'abord un portrait de ces rébellions et leur répression afin de replacer l'exemple bas-canadien dans un contexte plus large. Nous effectuons ensuite une analyse prosopographique des témoins de la Couronne et de la défense afin de dresser leurs profils types. Enfin nous étudions les témoignages, les dépositions et les examens volontaires dans le but de dégager les principales stratégies judiciaires utilisées pour défendre ou incriminer un patriote accusé de haute trahison. Lors de la rébellion de 1837, les rebelles ont été jugés en cour criminelle ordinaire via divers procès pour meurtre, dont celui de l'informateur Joseph Armand dit Chartrand. Afin de mieux comprendre la transition de système judiciaire pour le traitement des témoins et des rebelles au Bas-Canada, nous comparons les données et les sources de ce procès avec deux procès de la cour martiale de 1838 : l'un des 4 procès des patriotes du camp de Napierville et celui des patriotes de Châteauguay.This thesis analyzes the Rebellions of 1837-1838 in the judiciary and sociopolitical angles. We especially focus on the 1838 court martial. This institution was created in the context of the extension of martial law which was used to repress the Rebellion of 1838 and stabilize lower-canadian society. The trials of the General Court Martial of Montreal call many civilians who came to testify for or against patriots accused of high treason against the Crown. These witnesses are our focus for this study. Other British colonies such as Upper Canada, Ireland and Jamaica had civil rebellions repressed in the cover of martial law and its trials against rebels. We first draw a picture of these rebellions and their repression to replace them in a larger context. We then perform a prosopographical analysis of the Crown and defense witnesses to draw their typical profile. Finally, we study the testimonies, depositions and voluntary reviews to identify the main strategies to defend or incriminate a patriot accused of high treason. During the Rebellion of 1837, rebels have been tried in criminal court during various murder trials such as the one for the murder of informant Joseph Armand dit Chartrand. To have a better understanding of the transition between judicial systems for the treatment of witnesses and rebels in Lower Canada, we compare the statistics and sources of this criminal trial with two trials of the 1838 court martial: one of the 4 trials of the Napierville camp patriots and the trial of the Châteauguay patriots

Rôles physiologiques des gènes Adamts1 et Adamts4 chez la souris

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Why is productivity slowing down?

The recent decline in aggregate labor productivity growth in leading economies has been widely described as a puzzle, even a paradox, leading to extensive research into possible explanations. Our review confirms the magnitude of the slowdown and finds that it is largely driven by a decline in total factor productivity and capital deepening. Disaggregation reveals that a significant part of the slowdown is due to sectors that experienced the large benefits from ICTs in the previous period, and that an increasing gap between frontier and laggard firms suggests slower technology diffusion and increasing misallocation of factors. We evaluate explanations that attempt to reconcile the paradox of slowing productivity growth and technological change, including mismeasurement, implementation lags for technologies, and creative destruction processes

Forecasting the propagation of pandemic shocks with a dynamic input-output model

We introduce a dynamic disequilibrium input-output model that was used to forecast the economics of the COVID-19 pandemic. This model was designed to understand the upstream and downstream propagation of the industry-specific demand and supply shocks caused by COVID-19, which were exceptional in their severity, suddenness and heterogeneity across industries. The model, which was inspired in part by previous work on the response to natural disasters, includes the introduction of a new functional form for production functions, which allowed us to create bespoke production functions for each industry based on a survey of industry analysts. We also introduced new elements for modeling inventories, consumption and labor. The resulting model made accurate real-time forecasts for the decline of sectoral and aggregate economic activity in the United Kingdom in the second quarter of 2020. We examine some of the theoretical implications of our model and find that the choice of production functions and inventory levels plays a key role in the propagation of pandemic shocks. Our work demonstrates that an out of equilibrium model calibrated against national accounting data can serve as a useful real time policy evaluation and forecasting tool

A prototyping method for the re-design of intensive perennial systems: the case of vineyards in France

The results of our re-design and experimentation of grapevine agrosystem, as well as on the other crops (Lançon et al., 2007 and Wery & Langeveld, 2010) show promising perspectives of the prototyping method to achieve high goals for performance and innovation. The complexity of the grapevine agrosystem (ie the number of technical interventions and their potential interactions) requires a strong systemic approach at the interface between the technical and biophysical dimensions of cropping systems (Rapidel et al., 2009). The approach must implement agro-ecological processes to greatly limit inputs. It also required a high innovation and significant changes in the grapevine agrosystem genetics, structure and management. Our results point out the need to re-design grapevine systems from the crop plantation with new varieties, new training systems and with intercrops aiming to improve ecosystem services and maintain a very high level of sustainability criteria

Npas4: Linking Neuronal Activity to Memory

Immediate-early genes (IEGs) are rapidly activated after sensory and behavioral experience and are believed to be crucial for converting experience into long-term memory. Neuronal PAS domain protein 4 (Npas4), a recently discovered IEG, has several characteristics that make it likely to be a particularly important molecular link between neuronal activity and memory: it is among the most rapidly induced IEGs, is expressed only in neurons, and is selectively induced by neuronal activity. By orchestrating distinct activity-dependent gene programs in different neuronal populations, Npas4 affects synaptic connections in excitatory and inhibitory neurons, neural circuit plasticity, and memory formation. It may also be involved in circuit homeostasis through negative feedback and psychiatric disorders. We summarize these findings and discuss their implications.National Institutes of Health (U.S.) (Grant MH091220-01