42 research outputs found
Response of CO<sub>2</sub> and H<sub>2</sub>O fluxes in a mountainous tropical rainforest in equatorial Indonesia to El Niño events
The possible impact of El NiñoâSouthern Oscillation (ENSO) events on the
main components of CO<sub>2</sub> and H<sub>2</sub>O fluxes between the tropical rainforest
and the atmosphere is investigated. The fluxes were continuously measured in an
old-growth mountainous tropical rainforest in Central Sulawesi in
Indonesia using the eddy covariance method for the period from January 2004
to June 2008. During this period, two episodes of El Niño and one
episode of La Niña were observed. All these ENSO episodes had moderate
intensity and were of the central Pacific type. The temporal variability
analysis of the main meteorological parameters and components of CO<sub>2</sub>
and H<sub>2</sub>O exchange showed a high sensitivity of evapotranspiration (ET)
and gross primary production (GPP) of the tropical rainforest to
meteorological variations caused by both El Niño and La Niña
episodes. Incoming solar radiation is the main governing factor that is
responsible for ET and GPP variability. Ecosystem respiration (RE) dynamics
depend mainly on the air temperature changes and are almost insensitive to
ENSO. Changes in precipitation due to moderate ENSO events did not have any
notable effect on ET and GPP, mainly because of sufficient soil moisture
conditions even in periods of an anomalous reduction in precipitation in the
region
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1ÎČ, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1ÎČ innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
Radiation and Temperature Responses to a Small Clear-Cut in a Spruce Forest
Effects of a small clear-cutting on solar radiation, soil and air temperature regimes were investigated by continuous field measurements in a spruce forest in Solling, Central Germany, during vegetation period of 2005. Five meteorological stations, installed in central part of a small clear-cut area (2.5 ha) and close to edges of a surrounding forest, allowed to quantify the spatial variability of meteorological parameters within the clear-cut and to describe the impacts of the forest on clear-cut microclimate. The differences of microclimatic conditions between the clear-cut and the surrounding forest were derived using an additional station installed inside the forest about 150 m from the clear-cut. Results showed that clear-cutting leads to significant changes of spatial and temporal patterns of solar radiation and soil temperature. Solar radiation at the clear-cut was very heterogeneously distributed and about 5-11 times higher than inside the forest. It reached maximum at northeastern part and minimum at southwestern part of the clear-cut. The daily maximal soil temperature at 10 cm depth was measured at northern parts of the clear-cut and it was by up to 6°C higher than in the forest. Daily minimal soil temperature at the clear-cut was about 1-3°C higher than in the forest, too. The main factors influencing the soil temperature patterns were seasonally changed incoming solar radiation, ground vegetation and its phenology, as well as soil moisture. The mean daily maximal air temperature measured at the clear-cut was by up to 2.5°C higher and the mean daily minimal temperature by up to 0.5°C lower than in the surrounded forest
Impression de biomolécules par lithographie douce, applications pour les biopuces, de l échelle micrométrique à nanométrique
L objectif des travaux est de dĂ©montrer que la lithographie douce, quelquefois baptisĂ©e Micro-Contcat Printing ( CP) , constitue une mĂ©thode de dĂ©pĂŽt de biomolĂ©cules prĂ©sentant de nombreux avantages pour des applications de type Biopuces. Pour la fabrication de puces Ă ADN, nous dĂ©montrons que le CP est une technique compĂ©titive par rapport au dĂ©pĂŽt robotisĂ© de gouttes traditionnellement utilisĂ©. Le coĂ»t est infĂ©rieur, la densitĂ© des puces est augmentĂ©e et la qualitĂ© et la dĂ©finition des motifs biomolĂ©culaires sont supĂ©rieures. Une Ă©tude complĂšte des mĂ©canismes d encrage des timbres Ă©lastomĂšres d impression ainsi que des mĂ©canismes de transfert par contact des molĂ©cules vers le substrat est prĂ©sentĂ©e. Le rĂŽle prĂ©pondĂ©rant des fragments de polymĂšre non rĂ©ticulĂ©s prĂ©sents Ă la surface des timbres est mis en Ă©vidence. Dans un second volet nous Ă©tudions la possibilitĂ© de gĂ©nĂ©rer par la mĂȘme mĂ©thode des puces Ă biomolĂ©cules uniques. Nous montrons comment le CP peut ĂȘtre poussĂ© jusqu Ă une rĂ©solution sub-micromĂ©trique proche de 50 nm. Une voie technologique originale impliquant la lithographie douce est proposĂ©e : peigner individuellement en des sites organisĂ©s prĂ©cisĂ©ment sur la surface des longs brins d ADN pour des Ă©tudes de gĂ©nĂ©tiqueThe main purpose of this research work is the demonstration that soft-lithography, very often called Micro-Contact Printing ( CP) is an efficient patterning technique for arranging biomolecules on a surface in the perspective of biochip applications. For DNA Micro-arrays applications, we demonstrate that CP is a competitive method compared to the conventional spotting technology, commonly used today. The cost of the technology is much lower, the surface density of the chip is drastically increased and the quality and definition of the biopatterns are greatly improved. A systematic study of the inking mechanisms of the elastomeric stamps is provided together with the study and comprehension of transfer mechanisms of molecules from the surface of the stamp to the substrate. The crucial role played by the free fragments of polymers not cross-linked during the polymerisation of the stamp is highlighted. In a second section we investigate the possibility of using CP for generating single biomolecule biochips. We show how this printing technique can be optimized for reaching sub-micrometric scale down to 50 nanometers features. A technological process involving soft-lithography is proposed: combing long DNA molecules on spatially organized and registered positions for genetic applicationsINIST-CNRS (INIST), under shelf-number: RP 17272 / SudocSudocFranceF