Emission of monoterpenes from European beech (<i>Fagus</i><i> sylvatica</i> L.) as a function of light and temperature

International audienceUsing a dynamic branch enclosure technique European beech (Fagus sylvatica L.) was characterised as a strong emitter of monoterpenes, with sabinene being the predominant compound released. Since monoterpene emission was demonstrated to be a function of light and temperature, application of light and temperature dependent algorithms resulted in reasonable agreement with the measured data. Furthermore, during high temperature periods the depression of net CO2 exchange during midday (midday depression) was accompanied by a depression of monoterpene emission on one occasion. The species dependent standard emission factor and the light and temperature regulated release of monoterpenes is of crucial importance for European VOC emissions. All measurements were performed within the framework of the ECHO project (Emission and CHemical transformation of biogenic volatile Organic compounds) during two intensive field campaigns in the summers of 2002 and 2003

Isoprene and monoterpene fluxes from central amazonian rainforest inferred from tower-based and airborne measurements, and implications on the atmospheric chemistry and the local carbon budget

We estimated the isoprene and monoterpene source strengths of a pristine tropical forest north of Manaus in the central Amazon Basin using three different micrometeorological flux measurement approaches. During the early dry season campaign of the Cooperative LBA Airborne Regional Experiment (LBA-CLAIRE-2001), a tower-based surface layer gradient (SLG) technique was applied simultaneously with a relaxed eddy accumulation (REA) system. Airborne measurements of vertical profiles within and above the convective boundary layer (CBL) were used to estimate fluxes on a landscape scale by application of the mixed layer gradient (MLG) technique. The mean daytime fluxes of organic carbon measured by REA were 2.1 mg C m^−2 h^−1 for isoprene, 0.20 mg C m^−2 h^−1 for α-pinene, and 0.39 mg C m^−2 h^−1 for the sum of monoterpenes. These values are in reasonable agreement with fluxes determined with the SLG approach, which exhibited a higher scatter, as expected for the complex terrain investigated. The observed VOC fluxes are in good agreement with simulations using a single-column chemistry and climate model (SCM).\ud \ud In contrast, the model-derived mixing ratios of VOCs were by far higher than observed, indicating that chemical processes may not be adequately represented in the model. The observed vertical gradients of isoprene and its primary degradation products methyl vinyl ketone (MVK) and methacrolein (MACR) suggest that the oxidation capacity in the tropical CBL is much higher than previously assumed. A simple chemical kinetics model was used to infer OH radical concentrations from the vertical gradients of (MVK+MACR)/isoprene. The estimated range of OH concentrations during the daytime was 3–8×10^6 molecules cm^−3, i.e., an order of magnitude higher than is estimated for the tropical CBL by current state-of-the-art atmospheric chemistry and transport models. The remarkably high OH concentrations were also supported by results of a simple budget analysis, based on the flux-to-lifetime relationship of isoprene within the CBL. Furthermore, VOC fluxes determined with the airborne MLG approach were only in reasonable agreement with those of the tower-based REA and SLG approaches after correction for chemical decay by OH radicals, applying a best estimate OH concentration of 5.5×10^6 molecules cm^−3. The SCM model calculations support relatively high OH concentration estimates after specifically being constrained by the mixing ratios of chemical constituents observed during the campaign.\ud \ud The relevance of the VOC fluxes for the local carbon budget of the tropical rainforest site during the measurements campaign was assessed by comparison with the concurrent CO2 fluxes, estimated by three different methods (eddy correlation, Lagrangian dispersion, and mass budget approach). Depending on the CO2 flux estimate, 1–6% or more of the carbon gained by net ecosystem productivity appeared to be re-emitted through VOC emissions

Significant light and temperature dependent monoterpene emissions from European beech (fagus sylvatiga L.) and their potential impact on the European VOC budget

By using a dynamic branch enclosure system the emission of monoterpenes from European beech (Fagus sylvatica L.) was investigated during two consecutive summer vegetation periods in the years of 2002 and 2003 in Germany. All measurements were performed under field conditions within the framework of the ECHO project (Emission and Chemical Transformation of Biogenic Volatile Organic Compounds, AFO 2000). European beech was characterized as a substantial emitter of monoterpenes, with sabinene being the predominant compound released. The monoterpene emission from European beech was shown to be a function of light and temperature and agreed well to emission algorithms that consider a light and temperature dependent release of volatile organics. Standard emission factors that were measured from these sunlit leaves of European beech ranged up to 4–13 µg g-1 h-1 (normalized to 1000 µmol m-2 s-1, 30°C) in the years of 2003 and 2002, respectively. The nighttime emission of monoterpene compounds was negligible. Also the artificial darkening of the sunlit branch during daylight conditions led to an immediate cessation of monoterpene emission. European beech is the dominating deciduous tree species in Europe. To demonstrate the effect of an updated monoterpene emission factor for European beech in combination with the consideration of a light and temperature dependent monoterpene emission, we applied a species based model simulation on a European scale. With respect to conventional estimates of the European volatile organic compound budget, the latter simulation resulted in relative increases of 16% by taking solely this tree species into account. On local scales these increases exceeded even more than 100% depending on the respective vegetation area coverage of European beec

Fatigue as a key factor for testing knee stability with single leg drop landing for injury prevention and return to play tests

ObjectivesFatigue can decrease knee stability and increase the injury risk. However, fatigue is rarely being applied throughout movement analysis. The aim of this study was to investigate if the knee stability throughout SLDLs differ between cyclic and acyclic sports, before and after fatigue in general, and between the dominant and non-dominant leg of soccer players.MethodsA total of 43 active male (n = 34) and female (n = 9) athletes (age: 26.5 ± 7.2) participated in this study with a pre-post-design. Subjects performed a single leg drop landing (SLDL) from a plyobox. For each leg, the two-dimensional frontal plane projection angle (FPPA) was analyzed. After pretesting the shuttle run test was performed until exhaustion, before repeating the measurements.ResultsANOVA with repeated measures was applied and identified no significance difference for the FPPA between cyclic and acyclic sports (F = 0.98, p = 0.33), a significant difference before and after fatigue (F = 12.49, p = 0.002) and no significant difference between the dominant and non dominant leg of soccer players (F = 4.35, p = 0.26).DiscussionFatigue seems to be able to have a significant influence on knee stability in the frontal axis. Therefore, fatigue should be included in motion analysis for injury prevention and return to play tests because during this physical state most injuries happen

Tspan8 is expressed in breast cancer and regulates E-cadherin/catenin signalling and metastasis accompanied by increased circulating extracellular vesicles

Tspan8 exhibits a functional role in many cancer types including pancreatic, colorectal, oesophagus carcinoma, and melanoma. We present a first study on the expression and function of Tspan8 in breast cancer. Tspan8 protein was present in the majority of human primary breast cancer lesions and metastases in the brain, bone, lung, and liver. In a syngeneic rat breast cancer model, Tspan8$^{+}$ tumours formed multiple liver and spleen metastases, while Tspan8$^{-}$ tumours exhibited a significantly diminished ability to metastasise, indicating a role of Tspan8 in metastases. Addressing the underlying molecular mechanisms, we discovered that Tspan8 can mediate up‐regulation of E‐cadherin and down‐regulation of Twist, p120‐catenin, and β‐catenin target genes accompanied by the change of cell phenotype, resembling the mesenchymal–epithelial transition. Furthermore, Tspan8$^{+}$ cells exhibited enhanced cell–cell adhesion, diminished motility, and decreased sensitivity to irradiation. As a regulator of the content and function of extracellular vesicles (EVs), Tspan8 mediated a several‐fold increase in EV number in cell culture and the circulation of tumour‐bearing animals. We observed increased protein levels of E‐cadherin and p120‐catenin in these EVs; furthermore, Tspan8 and p120‐catenin were co‐immunoprecipitated, indicating that they may interact with each other. Altogether, our findings show the presence of Tspan8 in breast cancer primary lesion and metastases and indicate its role as a regulator of cell behaviour and EV release in breast cancer

Control of pneumatic servo-drive using fuzzy logic

Zastosowanie regulatora rozmytego (FLC) poprawiło dymanikę i dokładność pozycjonowania serwonapędu pneumatycznego oraz wyeliminowało zakłócenia w jego układzie regulacji. W procesie przetwarzania rozmytego zastosowano wyznaczanie poziomu zapłonu typu min, implikacji typu min oraz agregacji poszczególnych wyjść reguły typu max. W celu uzyskania ostrej wartości wyjścia zastosowano metodę środka obszaru COA. Analizowano przebiegi procesu regulacji rozmytej serwonapędu pneumatycznego z regulacją przestawną, regulacją nadążną oraz regulacją kontroli trajektorii ruchu. Badania wykazały, że logika rozmyta może być stosowana w regulacji serwopneumatycznych manipulatorów o różnej strukturze kinematycznej. Przedstawione badania sa podstawą do zastosowania logiki rozmytej w regulacji pneumatycznego manipulatora równoległego typu tripod.Application of fuzzy logic controller (FLC) improved dynamics and positioning accuracy of pneumatic servo-drive and eliminated disturbances in its control system. In fuzzyfication process conditionally firing rules of type min, implication operator of type min and aggregation of output rules of type max were employed. To obtain fuzzy output value the center of area function (COA) was used. Transpose control, follow-up control and trajectory motion control of pneumatic servo-drive with different input signals were carried out. The research proves applicability of fuzzy logic in control of servo-pneumatic manipulators with different kinematic chain structure. On the basis of the research the control of pneumatic tripod parallel manipulator using fuzzy logic can be established

Design and control development of a pneumatic parallel manipulator of tripod type

W pracy przedstawiono rozwój konstrukcji i sterowania pneumatycznego manipulatora równoległego typu tripod. Pneumatyczny manipulator równoległy składa się z podstawy, platformy roboczej i trzech pneumatycznymi napędów liniowych. Strukturę kinematyczną manipulatora tworzą trzy łańcuchy kinematyczne złożone z: uniwersalnego przegubu Kardana (U), przegubu pryzmatycznego (P) oraz przegubów obrotowych (R). Przegubami pryzmatycznymi są siłowniki pneumatyczne zastosowane jako osie napędowe. W pierwszej wersji manipulatora wykorzystano pneumatyczne siłowniki tłoczyskowe. Kolejna wersja manipulatora zbudowana została z pneumatycznych siłowników beztłoczyskowych. Ostateczna wersja pneumatycznego manipulatora równoległego o kinematyce 3-UPRR zbudowana została z trzech osi serwo-pneumatycznych złożonych z: siłowników beztłoczyskowych zintegrowanych z przetwornikami położenia i prędkości, serwozaworów, interfejsów osi, regulatora pozycjonowania i interfejsu Ethernet/CanBus.The paper deals with design and control development of pneumatic parallel manipulator of tripod type. Pneumatic paral- lel manipulator consists of fixed base, moving platform and three pneumatic linear motions. Kinematic structure of manipulator is composed of three kinematic chains containing universal joint (U), prismatic joint (P) and revolute joints (R). Prismatic joints are pneumatic cylinders used as axis drives. In the first version of manipulator rod pneumatic cylinder was applied. The next version contained rodless pneumatic cylinder. The final version of pneumatic parallel manipulator of 3-UPRR kinematic structure with servo-pneumatic axis consists of: rodless pneumatic cylinder with integral position and velocity transducer, servo-valves, axis interfaces, positioning axis sub-controller and Ethernet/Can Bus interface

Project of pneumatic parallel manipulator type delta with pneumatic muscle actuators

W referacie przedstawiono projekt elektropneumatycznego manipulatora równoległego o trzech stopniach swobody typu DELTA z pneumatycznymi aktuatorami mięśniowymi. Przedstawiono elementy składowe i konstrukcyjne, układ sterujący oraz wyniki prac projektowych.In the paper a design of electro-pneumatic parallel 3-DOF manipulator type of DELTA with pneumatic muscle actuator are presented.The solid model, construction, control system and design work are performed. Positioning control of pneumatic bi-muscular driving system was designed and constructed by means of xPC Target software of Matlab-Simulink package for rapid prototyping and hardware-in-the-loop simulation