On Jumps and Arch Effects in Natural Resource Prices. An Application to Stumpage Prices from Pacific Northwest National Forests

Models used for natural resources prices usually preclude the possibility of large changes (jumps) resulting from discrete, unexpected events. To test for the presence of jumps and ARCH effects, we propose to use bounds and bootstrap test techniques, thus solving the unidentified nuisance parameter problem. We apply this approach to stumpage price time series from the Pacific Northwest and find evidence of jumps and ARCH effects. Using real options, we then develop a stopping model to assess the impact of neglecting jumps on the decision to harvest old-growth timber. Our numerical results show the importance of modeling jumps explicitly.Jump processes, ARCH, Bootstrap, Stumpage prices, Real options

On Jumps and ARCH Effects in Natural Resource Prices. An Application to Stumpage Prices from Pacific Northwest National Forests

Models use for natural resources prices usually preclude the possibility of large changes (jumps) resulting from discrete, unexpected events. To test for the presence of jumps and ARCH effects, we propose to use bounds and bootstrap test techniques, thus solving the unidentified nuisance parameter problem. We apply this approach to stumpage price time series from the Pacific Northwest and find evidence of jumps and ARCH effects. Using real options, we then develop a stopping model to assess the impact of neglecting jumps on the decision to harvest old-growth timber. Our numerical results show the importance of modeling jumps explicitly.Jum Processes, ARCH, Bootstrap, Stumpage Prices, Real Options

Nouveaux mouvements sociaux et partis politiques au Québec : un défi organisationnel?

La présence de nouveaux mouvements sociaux (NMS) représente-t-elle un défi pour les partis politiques établis? Nous avons choisi de répondre à cette question en nous concentrant sur le défi organisationnel, considéré à la fois sous l’angle des motivations pour adhérer à un mouvement social ou à un parti politique, ce qui est à la base même de toute organisation, et sous l’angle de la conception que l’on a de sa propre organisation. Reposant sur des interviews menées auprès d’une quarantaine de militants et militantes, certains appartenant à des NMS (groupes environnementaux et groupes de femmes) et d’autres aux deux principaux partis politiques au Québec, cette recherche montre que deux visions s’opposent : l’une ciblée sur une seule cause dans les NMS, l’autre plus englobante dans les partis. Ces deux visions apparaissent irréconciliables, d’autant plus que chacun manifeste un certain scepticisme à l’égard des actions politiques de l’autre. De même, l’organisation hiérarchisée et centralisée des partis contraste fortement avec les structures souples et simples des NMS. Malgré tout, au lieu de parler de défi et d’opposition entre les deux, nous suggérons de parler plutôt de complémentarité.Does the presence of new social movements (NSM) represent a challenge for established political parties? We chose to answer this question by considering the organizational challenge from the standpoint of the motivations to adhere to a social movement or to a political party, that is at the root of every organization, and of the conception of the members' own organization. This study is based on interviews which were conducted with approximately forty male and female activists from twe NSM (environmental and women groups) along with both major political parties in Québec. This research shows that there are two diverging visions, one which is targeted on a unique cause in the NSM, the other more encompassing in the parties. These two visions appear irreconcilable, especially since each group displays a certain degree of skepticism toward the political actions of the other. Furthermore, the parties's hierarchical and centralized organization strongly contrasts with the flexible and simple structures which characterize the NSM. Nevertheless, rather than addressing the challenge and opposition between the two, we suggest to view them as complementary

Un instrument de mesure pour faciliter l’évaluation et l’intervention en protection de la jeunesse

L'objectif général de cette étude est de faciliter l'évaluation et l'intervention en contexte de protection de la jeunesse, grâce à l'information recueillie par l'Inventaire concernant le bien-être de l'enfant en relation avec l'exercice des responsabilités parentales (ICBE). Cette information permet notamment de préciser quels alinéas des articles 38 et 38.1 de la Loi sur la protection de la jeunesse peuvent être invoqués pour statuer sur la compromission. De plus, des seuils d'intervention, c'est-à-dire des scores qui permettent d'évaluer si une intervention est requise, sont établis

Le maintien du pouvoir chez la personne âgée hébergée souffrant de déficits cognitifs

Cet article théorique interpelle à la fois la recherche et l’intervention, à l’égard du mieux-être des personnes âgées hébergées présentant des troubles cognitifs associés à des démences dégénératives. Appuyé par la perspective de l’interactionnisme symbolique, il met l’accent sur les interactions entre le personnel soignant (infirmière, infirmière auxiliaire, préposée, ergothérapeute, personnel de réadaptation et des loisirs, travailleuse sociale, etc.) et les proches aidants, dans un objectif de maintien du pouvoir pour et par la personne âgée. Sous l’angle de l’approche centrée sur la personne, qui affirme l’importance de dépasser l’âgisme et l’impuissance quant à la démence, il aborde deux approches : l’approche prothétique élargie et l’approche biographique qui permettent de soutenir l’identité et l’affirmation de soi de la personne âgée hébergée souffrant de déficits cognitifs.This theoretical article presents some thoughts on research and intervention’s frameworks for the well-being of nursing homes’ residents with cognitive deficits associated with dementia. Based on a symbolic interactionism perspective, it examines the relations between the staff (nurses, social worker, rehabilitation worker, homecare employee) and family caregivers, to maintain identity for, by and behalf of the elderly. Adopting a critical perspective on the person-centered care approach for an clearer understanding of the person faced with dementia, the authors call for an integrating framework based on two approaches: a bibliographic approach and the holistic relational prothetic approach, allowing the recognition and support of a positive identity in elders with dementia for critical actions promoting their well-being in nursing homes

Students Motivations For Voluntary Remedial Learning In High School

Most high schools offer remedial learning sessions to their students; however, very little is known about the perception of these activities, especially with regards to the students motivations. In order to gain insights into both topics, an exploratory study was conducted within a sample of 1388 high school students in the Province of Quebec (Canada). Participants were selected on the basis of their voluntary participation or non-participation in remedial learning sessions held at school. School motivation was measured with a questionnaire based on Deci and Ryans SDT (Self Determination Theory); perceptions were gathered and measured with open-ended and multiple choice items. Quantitative results indicated that participants of remedial learning sessions were more strongly motivated towards school. No significant relationships were found between attendance and grades, with similar proportions of high, average and below average participating and non-participating students; however, among participants, girls outnumbered boys by 2:1. Two main categories emerged from qualitative analyses: remedial learning can be seen as: a) an instrumental support linked to the subject matter; or b) a relational support which fosters better learning

Abnormal insulin-like growth factor 1 signaling in human osteoarthritic subchondral bone osteoblasts

Insulin-like growth factor (IGF)-1 is a key factor in bone homeostasis and could be involved in bone tissue sclerosis as observed in osteoarthritis (OA). Here, we compare the key signaling pathways triggered in response to IGF-1 stimulation between normal and OA osteoblasts (Obs). Primary Obs were prepared from the subchondral bone of tibial plateaus of OA patients undergoing knee replacement or from normal individuals at autopsy. Phenotypic characterization of Obs was evaluated with alkaline phosphatase and osteocalcin release. The effect of IGF-1 on cell proliferation, alkaline phosphatase and collagen synthesis was evaluated in the presence or not of 50 ng/ml IGF-1, whereas signaling was studied with proteins separated by SDS-PAGE before western blot analysis. We also used immunoprecipitation followed by western blot analysis to detect interactions between key IGF-1 signaling elements. IGF-1 receptor (IGF-1R), Shc, Grb2, insulin receptor substrate (IRS)-1, and p42/44 mitogen-activated protein kinase (MAPK) levels were similar in normal and OA Obs in the presence or absence of IGF-1. After IGF-1 stimulation, the phosphorylation of IGF-1R in normal and OA Obs was similar; however, the phosphorylation of IRS-1 was reduced in OA Ob. In addition, the PI3K pathway was activated similarly in normal and OA Obs while that for p42/44 MAPK was higher in OA Obs compared to normal. p42/44 MAPK can be triggered via an IRS-1/Syp or Grb2/Shc interaction. Interestingly, Syp was poorly phosphorylated under basal conditions in normal Obs and was rapidly phosphorylated upon IGF-1 stimulation, yet Syp showed a poor interaction with IRS-1. In contrast, Syp was highly phosphorylated in OA Obs and its interaction with IRS-1 was very strong initially, yet rapidly dropped with IGF-1 treatments. The interaction of Grb2 with IRS-1 progressively increased in response to IGF-1 in OA Obs whereas this was absent in normal Ob. IGF-1 stimulation altered alkaline phosphatase in Ob, an effect reduced in the presence of PD98059, an inhibitor of p42/44 MAPK signaling, whereas neither IGF-1 nor PD98059 had any significant effect on collagen synthesis. In contrast, cell proliferation was higher in OA Obs compared to normal under basal conditions, and IGF-1 stimulated more cell proliferation in OA Obs than in normal Ob, an effect totally dependent on p42/44 MAPK activiy. The altered response of OA Obs to IGF-1 may be due to abnormal IGF-1 signaling in these cells. This is mostly linked with abnormal IRS-1/Syp and IRS-1/Grb2 interaction in these cells