The dynamics of the volatility – trading volume relationship: New evidence from developed and emerging markets

This paper empirically investigates whether there is an evolution in the relation between stock market trading volume and volatility in 23 developed and 15 emerging markets. To answer this question, we develop a dynamic application of the TARCH (1, 1) model and first prove that the relationship is variable through time. Then, we focus our analysis on three major financial events, namely the Asian Crisis, the Dot Com bubble burst and the Subprime crisis. We find that the explanatory power of volume is greater during these periods. Finally, we show that the sign of the relationship cannot be clearly set for a specific country or sub group of developed or emerging markets.Mixture of distribution hypothesis, TARCH model, Conditional variance, Trading volume

Modelling adaptation strategies to climate change in Mediterranean small ruminant systems

Session 54. Life Green Sheep and Farm management to adapt goat and sheep farming toclimate change: solutions and experimentsInternational audienc

Farmer views of best climate change adaptation strategies for sheep farming in the Mediterranean

International audienceClimate Change (CC) impacts on agriculture will exacerbate in the next decades by a decrease of rainfall and increase of temperatures and extreme events. Pasture-based sheep farming systems in the Mediterranean basin are particularlyvulnerable as they depend on local feed resources, which are directly damaged by CC. Research has been on livestock adaptation strategies, usually follows top-down approaches not accounting for the experiential knowledge of farmers, limiting its applicability at farm level. This work aimed to analyse farmers views about CC impact and the effect of periodic events of food shortage (FS) and heat stress (HS) on animal and farm performance, to determine the usualpractices deployed to overcome these periodic events and the best herd and farm management strategies to adapt to CC. Data were collected through face-to-face surveys to 228 farmers in Egypt (n=47), France (34), Spain (45) andTunisia (101), covering representative sheep farming systems in 5 different Köppen climatic regions. CC scenarios were developed for each region based on the IPCC projections. All farmers recognize that CC is real, however, mostthink that it is a natural and human-induced process or even just a natural process (Egypt). Perceived risk is lower in the most extreme arid and semi-arid regions and in irrigated farms. Anyhow FS and HS are generally perceived asincreasingly important problems. Farms traditionally overcome periodic FS events mainly providing animals with food stuff produced on farm and kept for shortage periods, increasing purchased feed and/or modifying grazing schedules.90, 75 and 50% of French, Tunisian, Spanish farmers respectively reported recent farm changes to adapt to CC. Modification of grazing, lambing and sowing periods (France and Spain), breed substitutions (Tunisia), improvementsin farm buildings (all) were reported. Farmers identified three potential strategies named feed maximization, feed supplementation and herd downsizing, which feasibility varies across systems, countries and climatic regions

Exploring climate change adaptation strategies form the perspective of Mediterranean sheep farmers

Session 61 - Théâtre 10International audienceSheep production systems in the Mediterranean region are particularly vulnerable to the impact of climate change (CC) due to their relatively high use of local food resources. Most studies analysing farm adaptation strategies tend to follow top-down approaches without considering the feasibility of their implementation on farms. In this work, which is part of the PRIMA project Adapt-Herd, we investigated farmer perceived CC impact on-farm and their view about the best adaptation strategies to future CC scenarios in representative farming systems in Egypt, France, Spain, and Tunisia. Scenarios of CC were developed for each region based on IPCC projections. Two hundred-five farmers were surveyed face-to-face and asked to point out the actions they would take to adapt to the CC scenarios. Possible actions covered feed, grazing, reproduction and flock management, breeding, and machinery and facilities. Strategies were identified using K-modes cluster analysis. Discriminant analysis was used to determine their preferred strategies across countries, farming systems, farm features, and farmer profiles and perceptions. Five general strategies were identified: (1) farm machinery and facilities (high preference in Egypt, France. and Spain); (2) feed intensification (Egypt and Spain); (3) flock management and feed extensification (France); (4) feed optimization (Tunisia); and (5) general farm adaptation. Besides differences among countries, farmers with irrigation systems perceive the impact of feed shortage, and heat stress on farms to be lower than other farmers and tend to prefer strategies focus on machinery and facilities and feed intensification. Our results show that both farm profile and CC impact perception factors influence farmer’s views on adaptation strategies

Farmer views of best climate change adaptation strategies for sheep farming in the Mediterranean

International audienceClimate Change (CC) impacts on agriculture will exacerbate in the next decades by a decrease of rainfall and increase of temperatures and extreme events. Pasture-based sheep farming systems in the Mediterranean basin are particularlyvulnerable as they depend on local feed resources, which are directly damaged by CC. Research has been on livestock adaptation strategies, usually follows top-down approaches not accounting for the experiential knowledge of farmers, limiting its applicability at farm level. This work aimed to analyse farmers views about CC impact and the effect of periodic events of food shortage (FS) and heat stress (HS) on animal and farm performance, to determine the usualpractices deployed to overcome these periodic events and the best herd and farm management strategies to adapt to CC. Data were collected through face-to-face surveys to 228 farmers in Egypt (n=47), France (34), Spain (45) andTunisia (101), covering representative sheep farming systems in 5 different Köppen climatic regions. CC scenarios were developed for each region based on the IPCC projections. All farmers recognize that CC is real, however, mostthink that it is a natural and human-induced process or even just a natural process (Egypt). Perceived risk is lower in the most extreme arid and semi-arid regions and in irrigated farms. Anyhow FS and HS are generally perceived asincreasingly important problems. Farms traditionally overcome periodic FS events mainly providing animals with food stuff produced on farm and kept for shortage periods, increasing purchased feed and/or modifying grazing schedules.90, 75 and 50% of French, Tunisian, Spanish farmers respectively reported recent farm changes to adapt to CC. Modification of grazing, lambing and sowing periods (France and Spain), breed substitutions (Tunisia), improvementsin farm buildings (all) were reported. Farmers identified three potential strategies named feed maximization, feed supplementation and herd downsizing, which feasibility varies across systems, countries and climatic regions

Le Mans (Sarthe), Jardins de la cathédrale, histoire et archéologie des abords de la cathédrale Saint-Julien: Rapport de fouille 2021

International audienceLe projet d’aménagement des Jardins de la cathédrale au Mans a entraîné la mise en place de deux diagnostics archéologiques successifs réalisés début 2015 et à l’automne 2016, en amont des travaux sur les 2 800 m² d'emprise. Cette intervention fait suite à la fouille menée en 2014 au niveau de la place du Jet d'eau sur les parcelles attenantes à l'emprise. L'ensemble des opérations prescrites par le service régional de l'archéologie et réalisées par l'Inrap sont intrinsèquement liées ; elles permettent de renouveler grandement nos connaissances de la topographie historique de la ville. Le principal axe de recherche correspond à l'axe 9 de la programmation nationale de la recherche archéologique, en effet les travaux contribuent à mieux documenter le phénomène urbain

Nat Biotechnol

Most of the published quantitative models in biology are lost for the community because they are either not made available or they are insufficiently characterized to allow them to be reused. The lack of a standard description format, lack of stringent reviewing and authors' carelessness are the main causes for incomplete model descriptions. With today's increased interest in detailed biochemical models, it is necessary to define a minimum quality standard for the encoding of those models. We propose a set of rules for curating quantitative models of biological systems. These rules define procedures for encoding and annotating models represented in machine-readable form. We believe their application will enable users to (i) have confidence that curated models are an accurate reflection of their associated reference descriptions, (ii) search collections of curated models with precision, (iii) quickly identify the biological phenomena that a given curated model or model constituent represents and (iv) facilitate model reuse and composition into large subcellular models