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Terminal bud size, spring and summer temperatures regulate the timing of height-growth cessation of Smith fir on the southeastern Tibetan Plateau
No full textThe cessation of height growth, a key event of autumn phenology, plays a vital role for tree growth and forest productivity. Despite its importance, our knowledge of environmental and biotic factors affecting autumnal events in plants remains incomplete. In particular, questions remain whether thermal conditions and previous growth influence the cessation of height growth. Here, we assessed the effects of spring and summer temperatures and terminal bud size on the cessation in height growth of Smith fir (Abies georgei var. smithii) using phenological observations performed in 2013-2019 at four sites located along an altitudinal gradient between 3800 and 4400 m a.s.l. on the southeastern Tibetan Plateau. The cessation of height growth mainly occurred from late–July to early–August with a weak delay along altitude gradient (1.5 days 100 m−1). Structural equation modelling demonstrated that higher summer temperature (June–July) directly advanced the cessation of height growth, whereas warmer spring temperature (March–May) advanced the height-growth cessation mainly through inducing earlier bud swelling (i.e. the onset of height growth). Larger terminal buds delayed the cessation of height growth by increasing growth rates. However, bud swelling was more sensitive to the change in annual mean temperature than height-growth cessation, resulting in an extended duration of height growth under warmer conditions. The warmer conditions expected in a context of climate change would lengthen the period of tree growth and enhance forest productivity on the southeastern Tibetan Plateau
Reply to Weiss : tree-ring stable oxygen isotopes suggest an increase in Asian monsoon rainfall at 4.2 ka BP
Get PDFWeiss (1) raises interesting points on our article (2). Heobserves that the Delingha tree-ringδ18O record matchesKM-A speleothemδ18O record from the Mawmluh Cave in India, that defines the 4.2-ka event’s global-type stratum(3). This event is also manifested as a multicentennialdrought in the Iranian Gol-E-Zard speleothem record (4).Weiss further argues that the Delingha record is alsoconsistent with the 4.2-ka anomaly recorded in low-resolution proxy records from northern China despiteinherent limitations of these proxies
Xylem porosity, sapwood characteristics, and uncertainties in temperate and boreal forest water use
No full textSapwood characteristics, such as sapwood area as well as thermal and hydraulic conductivity, are linked to species-specific hydraulic function and resource allocation to water transport tissues (xylem). These characteristics are often unknown and thus a major source of uncertainty in sap flow data processing and transpiration estimates because bulk rather than species-specific values are usually applied. Here, we analyzed the sapwood characteristics of fifteen common tree species in eastern North America from different taxonomic (i.e., angiosperms and gymnosperms) and xylem porosity groups (i.e., tracheid-bearing, diffuse- or ring-porous species) and we assessed how uncertainties in sapwood characteristics involved in sap flow calculations are propagated in tree water use estimates. We quantified their sapwood area changes with stem diameter (allometric scaling) and thermal conductivity. We combined these measurements with species-specific values of wood density and hydraulic conductivity found in the literature and assessed the role of wood anatomy in orchestrating their covariation. Using an example sap flow dataset from tree species with different xylem porosity, we assessed the sensitivity of tree water use estimates to sapwood characteristics and their interactions. Angiosperms (ring- and diffuse-porous species), with specialized vessels for water transport, showed a steeper relationship (scaling) between tree stem diameter and sapwood area in comparison to gymnosperms (tracheid-bearing species). Gymnosperms (angiosperms) were characterized by lower (higher) wood density and higher (lower) sapwood moisture content, resulting in non-significant differences in sapwood thermal conductivity between taxonomic and xylem porosity groups. Clustering of species sapwood characteristics based on taxonomic or xylem porosity groups and constraining these parameters could facilitate more accurate sap flow calculations and tree water use estimates. When combined with an increasing number of sap flow observations, these findings should improve tree- and landscape-level transpiration estimates, leading to more robust partitioning of terrestrial water fluxes
Environmental impact of free-floating bike sharing: from life cycle perspective
Get PDFBike sharing is becoming increasingly popular around the world. However, there is little empirical evidence of the emerging free-floating bike sharing (FFBS) system, and even less from a product life cycle perspective. Based on actual urban transportation big data and related product life cycle data, this chapter takes Beijing FFBS system as a study case. By comparing the changes in the choice of transportation means of urban residents before and after the emergence of FFBS, and in combination with the evolution of the FFBS system, the real environmental impact of FFBS is dynamically observed and evaluated from a life cycle analysis (LCA) perspective. The results show that FFBS display desirable properties in reducing air waste in the form of greenhouse gas (GHG) emissions. This reduction effect is mainly achieved by connecting to the public transportation system, hence substituting for the use of private cars. Yet, in comparison to the period prior to the emergence of FFBS (i.e., 2016), the excessive supply of FFBS resulted in an average annual increase of 0.38% in air waste as GHG emissions by daily transportation of urban residents in 2017 and 2018, with a cumulative increase of 0.102 million tons CO2,e. Since then, under increased government control, the scale of the FFBS system has gradually become reasonable and the operating efficiency has gradually improved. In 2019, air waste as GHG emissions were reduced by 0.065 million tons compared with 2016. Especially, according to the development plan of Beijing FFBS system, it is expected that the emission reductions will reach 0.16 million tons, a reduction rate of about 1.13%
Compartment_Complex : subverting obsolescence – media archaeology and the materiality of analog video
Get PDFObsolescence devours media at an astonishing rate, especially electronic media. Although still useful, cutting-edge technology is rapidly obsoleted, creating mountains of junk to be shipped off to countries that can’t afford to refuse it. Avant-garde artists, such as Duchamp with his “Readymades”, have demonstrated that culture is clearly reflected in the things it throws out. This is doubly true for video media; from home movies to commercial programming, video media has proven itself a solid illustration of society – our hopes, our fears, and the lies we tell each other. Though unfortunately, analogue video is quickly being eclipsed by the ravenous tide of time and digitization, along with a portion of our media history. Here, I aim to answer: within the context of media archaeology, can an artist or researcher subvert analog video’s obsolescence by engendering new forms of mediated experience? Evidence suggests that theories and methodologies of media-archaeological figureheads, such as Jussi Parikka, Erkki Huhtamo, Michel Foucault and Friedrich Kittler offer promising avenues in exploring this question through artistic research-creation - the result being my multi-screen, interactive video installation : Compartement_Complex. This paper concludes with a self-analysis of my installation, and how it relates to media-archaeological methodologies. The analysis demonstrates an effective approach to subverting obsolescence through artistic practice.
Les processus d'obsolescence des technologies dévorent l'histoire médiatique, particulièrement l'histoire des médias électroniques, à un rythme incroyable. Les nombreux appareils électroniques de fine-pointe qui peuplent nos vies deviennent rapidement obsolètes, ce qui crée une pollution industrielle qui se retrouve dans des pays qui n’ont pas les moyens de les refuser. De nombreux artistes avant-gardistes, tels que Duchamp et ses « Ready Made », ont bien démontré que notre culture se révèle aussi dans les choses que nous jetons. Ceci est doublement vrai à la fois pour les dispositifs techniques que pour leurs produits ; grâce aux films de famille et aux émissions commerciales, les médias vidéo se sont montrés de solides aperçus de notre société. Ils illustrent nos espoirs, nos peurs et les mensonges que nous nous partageons. Dans ce contexte, en l'espace d'approximativement trente ans, la vidéo analogique s’est rapidement éclipsée due à la voracité du temps et de la numérisation, emportant avec elle Ici, je te n une partie de notre histoire médiatique. Ici je tenterai de répondre à la question suivante : comment peut-on subvertir l'obsolescence de la vidéo analogique et engendrer de nouvelles formes d'expériences médiatique, afin d'interroge r son occultation de l'histoire de l’art? Pour répondre à cette question, je me pencherai sur des noms importants dans le domaine de l'archéologie des médias, tels que Jussi Parikka, Michel Foucault, Friedrich Kittler et plus. Ceux-ci guideront la création et l'analyse de mon projet d'installation interactive ci guideront Compartment_Complex
Les outils des effets visuels au service du patrimoine immatériel de la danse Casino : archivage vidéo 360°, capture de mouvement et animation 3D
Get PDFLa recherche-création que j’ai entreprise est l’exploration des usages des technologies de l’animation 3D au service d’un objectif de médiation et de préservation culturelle de la pratique de la danse cubaine connue comme Casino (à Cuba, mais connue comme Salsa partout ailleurs). Le projet s’articule en plusieurs volets: capture de scènes de danse à plusieurs caméras dans des écoles de danse de la Havane, conversations avec les danseurs sur leur pratique, séances de capture de mouvement, visualisation-animation en 3D des mouvements capturés et diffusion dans un contexte de médiation culturelle. Dans un premier temps, je propose, en suivant une démarche semblable au chorégraphe-danseur William Forsyth et autres initiatives (Bleeker, 2016) d’entreprendre l’amorce d’un répertoire virtuel de mouvements de la danse Salsa via l’usage de technique de capture d’images d’une part ainsi que de capture de mouvement (MoCap). La mise en place d’une catégorisation des figures au sein d’une base de données, d’un « catalogue », constitue le premier volet de la recherche. En assemblant et en triant les éléments visuels (scènes de danse, conversations, scènes du quotidien de la Havane), il m’est apparu évident que la meilleure approche pour traiter cette information captée à plusieurs caméras était de construire des salles de danses virtuelles qu’on peut observer en mode immersif, soit en réalité virtuelle. Les scènes que j’ai ainsi créées m’ont confirmé que c’était là une approche valable et novatrice et tout à fait pertinente pour du film documentaire. La visualisation du mouvement de la danse à partir des données recueillies par la capture de mouvement serviront de point de départ à la création d’animations procédurales en 3D. Des traitements de particules seront alors appliqués afin de visualiser les mouvements, les déplacements et les interactions entre les danseurs. Cette scène d’animation montée en réalité virtuelle appellera le spectateur à explorer l’espace vu de l’intérieur de la danse. Finalement, ce projet constitue une oeuvre-frontière qui permet, en suivant une démarche de médiation culturelle, de recueillir des témoignages et des écrits de pratique des acteurs de la scène de la Casino de Cuba. Ils seront colligés et réinterprétés dans l’optique de dégager le sens et la valeur ethnographique de cette pratique de la danse
Precipitation Characteristics of HPVDC AlSi10Mg0.3Mn Alloy Under Different Temper Conditions
Get PDFThis work studied the precipitation characteristics of AlSi10Mg0.3Mn alloy produced by high-pressure vacuum die-casting in T5 and T6 conditions using transmission electron microscopy, differential scanning calorimetry and both electrical conductivity and microhardness measurements. Two different T6 tempers were used, involving partial solutionizing at 460 °C for 1 h and full solutionizing at 500 °C for 1 h, and were designated as T6P and T6F, respectively. The aging treatment was conducted at 185 °C for 4 h in all temper conditions. The results showed that conducting solution treatments resulted in the formation of α-Al(MnFe)Si dispersoids. In addition, Mg–Si rich precipitates formed and remained undissolved after partial solutionizing. The highest supersaturation of the α-Al was achieved in the as-fabricated (F) condition by the HPVDC process. The supersaturation degree decreased in both partial and full solutionizing conditions. TEM observations revealed different precipitation characteristics for T5, T6P and T6F tempers. β” precipitates just started to form in the T5 condition, whereas both β” and β’ precipitates completed their precipitation to different extents in the T6P and T6F conditions, resulting in different strengthening effects. The T6F temper yielded the highest microhardness followed by the T5 and T6P tempers
Identification de marqueurs protéomiques liés à la réponse positive induite par l'entraînement physique observée chez la population atteinte de dystrophie myotonique de type 1
Get PDFLa dystrophie myotonique de type 1 (DM1) est la myopathie la plus courante chez les adultes. Il s’agit d’une maladie multisystémique touchant donc plusieurs systèmes tels que les systèmes nerveux, cardiaque, digestif, endocrinien, et notamment le muscle squelettique, sur lequel les présents travaux se concentrent. En effet, dans le contexte de cette maladie le muscle squelettique est gravement affaibli : les personnes atteintes souffrent d’atrophie musculaire et subissent une perte progressive de la force musculaire maximale. Pour contrer ces déficiences, le renforcement musculaire est une stratégie thérapeutique prometteuse. L’exercice est sécuritaire et efficace pour augmenter la force musculaire en DM1, mais pour l’instant, les mécanismes biologiques sous-jacents demeurent inconnus. L’étude pilote des travaux présentés dans ce mémoire a montré des gains importants de la force musculaire et de la capacité fonctionnelle chez 11 hommes atteints de DM1 qui ont participé à un programme d’entraînement musculaire supervisé de 12 semaines. Dans le cadre de cette maitrise, afin d’identifier les mécanismes sous-jacents impliqués dans ces gains cliniques, des échantillons musculaires collectés chez les participants avant et après l’entraînement ont été étudiés. L’analyse protéomique a démontré que plusieurs fonctions moléculaires et processus biologiques ont été améliorés par le programme d’entraînement. Plus précisément, la modulation du protéome par l’exercice était liée au métabolisme énergétique, à la myogenèse, l’immunité, la contraction musculaire, la signalisation de l’insuline et l’apoptose. Ces résultats suggèrent que l’adaptation musculaire est possible en DM1 aux niveaux cliniques et biologiques.Finalement, l’identification de biomarqueurs musculaires par la protéomique pourrait permettre de jeter les bases de la médecine de précision afin d'améliorer les soins thérapeutiques à venir en DM1.
Myotonic dystrophy type 1 (DM1) is the most common myopathy in adults. It is a multisystemic disease affecting several systems such as the nervous, cardiac, digestive, endocrine systems, and in particular the skeletal muscle, on which my work focuses. Indeed, the skeletal muscle is severely weakened: affected individuals suffer from muscle atrophy and experience a progressive loss of maximum muscle strength. To counter these deficiencies, muscle strengthening is a promising therapeutic strategy. Exercise is safe and effective to increase muscle strength in DM1 but for now, the underlying biological mechanisms remain unknown. The pilot study of the works here presented showed significant gains in muscle strength and functional capacity of 11 men with DM1 who participated in a 12-week supervised strength training program. To identify the underlying mechanisms involved in these clinical gains, muscle samples collected from participants before and after training were studied. Proteomics analysis showed that several molecular functions and biological processes were improved by the training program. Specifically, the modulation of the proteome through exercise was related to energy metabolism, myogenesis, immunity, muscle contraction, insulin signaling, and apoptosis. These results suggest that muscle adaptation is possible in DM1 at the clinical and biological levels. Finally, the identification of muscle biomarkers by proteomics could lay the foundations of precision medicine to improve future therapeutic treatments in DM1
La bande dessinée comme outil de vulgarisation pour l’industrie des effets visuels
Get PDFJ’examinerai dans ce mémoire mes théories sur l’enseignement de l’industrie des effets visuels (VFX) aux jeunes étudiants (principalement de jeunes adultes). Le texte commencera par aborder mes expériences en tant qu’artiste d’effets visuels au cours des 30 dernières années ainsi que mes expériences d’enseignant, de conférencier et de spécialiste de la sensibilisation à l’industrie. Cela informera les lecteurs de ce que j’ai vécu et de la nécessité pour moi de faire des recherches et d’écrire sur les sujets traités ici. Le mémoire comportera des citations et des anecdotes provenant d’autres professionnels du domaine des effets visuels ainsi que de recherches que j’ai effectuées pendant toute ma carrière professionnelle. Le mémoire sera complété par une bande dessinée qui sera utilisée comme un outil pour présenter et enseigner aux étudiants l’industrie des effets visuels, et traitera également des motifs expliquant pourquoi l’utilisation d’une bande dessinée est le meilleur choix pour atteindre mes objectifs. Mon ambition est que le présent texte et la bande dessinée qui l’accompagne puissent être utilisés comme outil pédagogique et que d’autres supports comme celui-ci soient utilisés pour parler aux jeunes adultes de sujets et de domaines qui leur seraient autrement inconnus
Endocrine disruptors in cosmetics: a review
Get PDFThe body is regulated by the endocrine system; thus it is important that it is functional. However, we encounter more and more endocrine disruptors in our lives. As cosmetics represent daily exposure to many chemicals, concerns raise about the eventual presence of endocrine disruptors in cosmetics. Endocrine disrupting abilities of chemicals were widely investigated, as they can be found in food, materials, and environment. Considering the amount of data, one might find clear information with difficulty. The purpose of this review is to establish the state-of-the-art of endocrine disrupting properties of cosmetic ingredients. The method used was to read several articles related to skin penetration, nuclear receptor binding, epigenetic effects, adverse effects, and diseases. The toxic doses were not always found. The overall data was confronted to draw definite conclusion on the endocrine disruptor nature of each compound. If not enough information was found to bring out a sturdy conclusion, leads for further research were given. An overview of novel methods used to assess endocrine disruptors’ effects was also done. The major studied compounds were not clearly identified as endocrine disruptors when applied topically because of the skin barrier. Synergism and inhibition effects between several endocrine disruptors must be a subject of further investigation because it represents the reality of cosmetic formulations. Epidemiological studies should also be conducted to better assess risks of the ingredients. Overall, cosmetic ingredients applied via cosmetics do not have endocrine disrupting effects