36 research outputs found
Effectiveness of habitat management for improving grey partridge populations: a BACI experimental assessment
We assessed the impact of field division (4 m bare ground strips within wheat fields) and food supplementation (supplied through grain feeders) on grey partridge Perdix perdix L. populations using sixâyear âbeforeâafterâ/'controlâimpactâ (BACI) experiments. We did not detect any convincing positive effects of either of these two schemes on partridge pair density and reproductive success. Increases in pair densities were similar on managed and control areas, and contrasting results were found between some sites. No consistent pattern was observed between reproductive success and feeding intensity. Our studies highlight the need for field experiments at farmâscale to test the effectiveness of management measures. We conclude that, in the context in which they are applied, management techniques directed towards increasing partridge density do not systematically provide the desired outcome. We develop our point of view about management in the Discussion
Fingerprint of Climate Change on Southern Ocean Carbon Storage
The Southern Ocean plays a critical role in the uptake, transport, and storage of carbon by the global oceans. It is the ocean's largest sink of CO2, yet it is also among the regions with the lowest storage of anthropogenic carbon. This behavior results from a unique combination of high winds driving the upwelling of deep waters and the subduction and northward transport of surface carbon. Here we isolate the direct effect of increasing anthropogenic CO2 in the atmosphere from the indirect effect of climate variability and climate change on the reorganization of carbon in the Southern Ocean interior using a combination of modeling and observations. We show that the effect of climate variability and climate change on the storage of carbon in the Southern Ocean is nearly as large as the effect of anthropogenic CO2 during the period 1998â2018 compared with the climatology around the year 1995. We identify a distinct climate fingerprint in dissolved inorganic carbon (DIC), with elevated DIC concentration in the ocean at 300â600 m that reinforces the anthropogenic CO2 signal, and reduced DIC concentration in the ocean around 2,000 m that offsets the anthropogenic CO2 signal. The fingerprint is strongest at lower latitudes (30°â55°S). This fingerprint could serve to monitor the highly uncertain evolution of carbon within this critical ocean basin, and better identify its drivers
Global Carbon Budget 2022
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1Ï. For the year 2021, EFOS increased by 5.1â% relative to 2020, with fossil emissions at 10.1â±â0.5âGtCâyrâ1 (9.9â±â0.5âGtCâyrâ1 when the cement carbonation sink is included), and ELUC was 1.1â±â0.7âGtCâyrâ1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 10.9â±â0.8âGtCâyrâ1 (40.0â±â2.9âGtCO2). Also, for 2021, GATM was 5.2â±â0.2âGtCâyrâ1 (2.5â±â0.1âppmâyrâ1), SOCEAN was 2.9 â±â0.4âGtCâyrâ1, and SLAND was 3.5â±â0.9âGtCâyrâ1, with a BIM of â0.6âGtCâyrâ1 (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2 concentration averaged over 2021 reached 414.71â±â0.1âppm. Preliminary data for 2022 suggest an increase in EFOS relative to 2021 of +1.0â% (0.1â% to 1.9â%) globally and atmospheric CO2 concentration reaching 417.2âppm, more than 50â% above pre-industrial levels (around 278âppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959â2021, but discrepancies of up to 1âGtCâyrâ1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set
Global Carbon Budget 2022
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1Ï.
For the year 2021, EFOS increased by 5.1â% relative to 2020, with fossil emissions at 10.1â±â0.5âGtCâyrâ1 (9.9â±â0.5âGtCâyrâ1 when the cement carbonation sink is included), and ELUC was 1.1â±â0.7âGtCâyrâ1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 10.9â±â0.8âGtCâyrâ1 (40.0â±â2.9âGtCO2). Also, for 2021, GATM was 5.2â±â0.2âGtCâyrâ1 (2.5â±â0.1âppmâyrâ1), SOCEAN was 2.9 â±â0.4âGtCâyrâ1, and SLAND was 3.5â±â0.9âGtCâyrâ1, with a BIM of â0.6âGtCâyrâ1 (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2 concentration averaged over 2021 reached 414.71â±â0.1âppm. Preliminary data for 2022 suggest an increase in EFOS relative to 2021 of +1.0â% (0.1â% to 1.9â%) globally and atmospheric CO2 concentration reaching 417.2âppm, more than 50â% above pre-industrial levels (around 278âppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959â2021, but discrepancies of up to 1âGtCâyrâ1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set. The data presented in this work are available at https://doi.org/10.18160/GCP-2022 (Friedlingstein et al., 2022b)
Global Carbon Budget 2023
Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land-use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate
(GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based f CO2 products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. Additional lines of evidence on land and ocean sinks are provided by atmospheric inversions, atmospheric oxygen measurements, and Earth system models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and incomplete understanding
of the contemporary carbon cycle. All uncertainties are reported as ±1Ï. For the year 2022, EFOS increased by 0.9 % relative to 2021, with fossil emissions at 9.9 ± 0.5 Gt C yrâ1 (10.2 ± 0.5 Gt C yrâ1 when the cement carbonation sink is not included), and ELUC was 1.2 ± 0.7 Gt C yrâ1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 11.1 ± 0.8 Gt C yrâ1 (40.7±3.2 Gt CO2 yrâ1). Also, for 2022, GATM was 4.6±0.2 Gt C yrâ1 (2.18±0.1 ppm yrâ1; ppm denotes parts per million), SOCEAN was 2.8 ± 0.4 Gt C yrâ1, and SLAND was 3.8 ± 0.8 Gt C yrâ1, with a BIM of â0.1 Gt C yrâ1 (i.e. total estimated sources marginally too low or sinks marginally too high). The global atmospheric CO2 concentration averaged over 2022 reached 417.1 ± 0.1 ppm. Preliminary data for 2023 suggest an increase in EFOS relative to 2022 of +1.1 % (0.0 % to 2.1 %) globally and atmospheric CO2 concentration reaching 419.3 ppm, 51 % above the pre-industrial level (around 278 ppm in 1750). Overall, the mean of and trend in the components of the global carbon budget are consistently estimated over the period 1959â2022, with a near-zero overall budget imbalance, although discrepancies of up to around 1 Gt C yrâ1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows the following: (1) a persistent large uncertainty in the estimate of land-use changes emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living-data update documents changes in methods and data sets applied to this most recent global carbon budget as well as evolving community understanding of the global carbon cycle. The data presented in this work
are available at https://doi.org/10.18160/GCP-2023 (Friedlingstein et al., 2023)
Microfluidic platform for combinatorial synthesis in picolitre droplets
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Hydrography and biogeochemistry dedicated to the Mediterranean BGC-Argo network during a cruise with RV <i>Tethys 2</i> in May 2015
We report on data from an oceanographic cruise, covering western, central and
eastern parts of the Mediterranean Sea, on the French research vessel
Tethys 2 in May 2015. This cruise was fully dedicated to the
maintenance and the metrological verification of a biogeochemical observing
system based on a fleet of BGC-Argo floats. During the cruise, a
comprehensive data set of parameters sensed by the autonomous network was
collected. The measurements include ocean currents, seawater salinity and
temperature, and concentrations of inorganic nutrients, dissolved oxygen and
chlorophyll pigments. The analytical protocols and data processing methods
are detailed, together with a first assessment of the calibration state for
all the sensors deployed during the cruise. Data collected at stations are
available at https://doi.org/10.17882/51678 and data collected along the ship track are
available at https://doi.org/10.17882/51691
Impact d'une supplémentation orale en acide 13 cis rétinoique sur les fonctions leucocytaires : Etude chez des sujets sains jeunes et ùgés
National audienc
Efficient Alkylation Methods for the Synthesis of Hybrid Fluorocarbon - Hydrocarbon Tetrazoles as Potential Fluorinated Surfactants
High-resolution doseâresponse screening using droplet-based microfluidics
A critical early step in drug discovery is the screening of a chemical library. Typically, promising compounds are identified in a primary screen and then more fully characterized in a doseâresponse analysis with 7â10 data points per compound. Here, we describe a robust microfluidic approach that increases the number of data points to approximately 10,000 per compound. The system exploits TaylorâAris dispersion to create concentration gradients, which are then segmented into picoliter microreactors by droplet-based microfluidics. The large number of data points results in IC50 values that are highly precise (± 2.40% at 95% confidence) and highly reproducible (CV = 2.45%, n = 16). In addition, the high resolution of the data reveals complex doseâresponse relationships unambiguously. We used this system to screen a chemical library of 704 compounds against protein tyrosine phosphatase 1B, a diabetes, obesity, and cancer target. We identified a number of novel inhibitors, the most potent being sodium cefsulodine, which has an IC50 of 27 ± 0.83 ΌM