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Frederic Le A C Moigne - One of the best experts on this subject based on the ideXlab platform.
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Global database of ratios of particulate organic carbon to thorium 234 in the ocean improving estimates of the biological carbon pump
Earth System Science Data, 2020Co-Authors: Viena Puigcorbe, Pere Masque, Frederic Le A C MoigneAbstract:Abstract. The ocean's biological carbon pump (BCP) plays a major role in the Global carbon cycle. A fraction of the photosynthetically fixed organic carbon produced in surface waters is exported below the sunlit layer as settling particles (e.g., marine snow). Since the seminal works on the BCP, Global estimates of the Global Strength of the BCP have improved but large uncertainties remain (from 5 to 20 Gt C yr−1 exported below the euphotic zone or mixed-layer depth). The 234Th technique is widely used to measure the downward export of particulate organic carbon (POC). This technique has the advantage of allowing a downward flux to be determined by integrating the deficit of 234Th in the upper water column and coupling it to the POC∕234Th ratio in sinking particles. However, the factors controlling the regional, temporal, and depth variations of POC∕234Th ratios are poorly understood. We present a database of 9318 measurements of the POC∕234Th ratio in the ocean, from the surface down to >5500 m , sampled on three size fractions ( ∼ > 0.7 µm , ∼1 –50 µm , ∼ > 50 µm ), collected with in situ pumps and bottles, and also from bulk particles collected with sediment traps. The dataset is archived in the data repository PANGAEA® under https://doi.org/10.1594/PANGAEA.911424 (Puigcorbe, 2019). The samples presented in this dataset were collected between 1989 and 2018, and the data have been obtained from published papers and open datasets available online. Unpublished data have also been included. Multiple measurements can be found in most of the open ocean provinces. However, there is an uneven distribution of the data, with some areas highly sampled (e.g., China Sea, Bermuda Atlantic Time Series station) compared to some others that are not well represented, such as the southeastern Atlantic, the south Pacific, and the south Indian oceans. Some coastal areas, although in a much smaller number, are also included in this Global compilation. Globally, based on different depth horizons and climate zones, the median POC∕234Th ratios have a wide range, from 0.6 to 18 µmol dpm−1 .
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Global database of oceanic particulate organic carbon to 234 th ratios improving estimates of the biological carbon pump
Earth System Science Data Discussions, 2020Co-Authors: Viena Puigcorbe, Pere Masque, Frederic Le A C MoigneAbstract:Abstract. The ocean's biological carbon pump (BCP) plays a major role in the Global earth carbon cycle. A fraction of the photosynthetically fixed organic carbon produced in surface waters is exported below the sunlit layer in the form of settling particles (e.g. marine snow). Since the seminal works on the BCP, Global estimates of the Global Strength of the BCP have improved but large uncertainties remain (from 5 to 20 GtC yr−1 exported below the euphotic zone or mixed layer depth). The 234Th technique is widely used to measure the downward export of particulate organic carbon (POC). This technique has the advantage to allow a downward flux to be determined by integrating the deficit of 234Th in the upper water column and coupling it to an estimate of the POC/234Th ratio in sinking matter. However, the factors controlling the regional, temporal and depth variations of POC/234Th ratios are poorly understood. We present a database of 9110 measurements of the POC/234Th ratio in the ocean, from the surface down to > 5500 m, sampled on three size fractions (~ > 0.7 μm, ~ 1–50 μm, ~ > 50 μm), collected with in situ pumps and bottles, and also from bulk particles collected with sediment traps. The dataset is archived on the data repository PANGAEA® ( https://www.pangaea.de/ ) under https://doi.pangaea.de/10.1594/PANGAEA.902103 (Puigcorbe, 2019). The samples presented in this dataset were collected between 1989 and 2016 and the data have been obtained from published papers and open datasets available online. Unpublished data has also been included. Most of the open ocean provinces are represented by multiple measurements. However, there is an uneven distribution of the data, with some areas highly sampled (e.g, China Sea, Bermuda Atlantic Time Series station) compared to some others that are not well represented, such as the southeastern Atlantic, the south Pacific and the south Indian oceans. Some costal areas, although in a much smaller number, are also included in this Global compilation. Globally, based on different depths horizons and climate zones, the median POC/234Th ratios have a wide range, from 0.6 to 18 μmol dpm-1.
Pere Masque - One of the best experts on this subject based on the ideXlab platform.
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Global database of ratios of particulate organic carbon to thorium 234 in the ocean improving estimates of the biological carbon pump
Earth System Science Data, 2020Co-Authors: Viena Puigcorbe, Pere Masque, Frederic Le A C MoigneAbstract:Abstract. The ocean's biological carbon pump (BCP) plays a major role in the Global carbon cycle. A fraction of the photosynthetically fixed organic carbon produced in surface waters is exported below the sunlit layer as settling particles (e.g., marine snow). Since the seminal works on the BCP, Global estimates of the Global Strength of the BCP have improved but large uncertainties remain (from 5 to 20 Gt C yr−1 exported below the euphotic zone or mixed-layer depth). The 234Th technique is widely used to measure the downward export of particulate organic carbon (POC). This technique has the advantage of allowing a downward flux to be determined by integrating the deficit of 234Th in the upper water column and coupling it to the POC∕234Th ratio in sinking particles. However, the factors controlling the regional, temporal, and depth variations of POC∕234Th ratios are poorly understood. We present a database of 9318 measurements of the POC∕234Th ratio in the ocean, from the surface down to >5500 m , sampled on three size fractions ( ∼ > 0.7 µm , ∼1 –50 µm , ∼ > 50 µm ), collected with in situ pumps and bottles, and also from bulk particles collected with sediment traps. The dataset is archived in the data repository PANGAEA® under https://doi.org/10.1594/PANGAEA.911424 (Puigcorbe, 2019). The samples presented in this dataset were collected between 1989 and 2018, and the data have been obtained from published papers and open datasets available online. Unpublished data have also been included. Multiple measurements can be found in most of the open ocean provinces. However, there is an uneven distribution of the data, with some areas highly sampled (e.g., China Sea, Bermuda Atlantic Time Series station) compared to some others that are not well represented, such as the southeastern Atlantic, the south Pacific, and the south Indian oceans. Some coastal areas, although in a much smaller number, are also included in this Global compilation. Globally, based on different depth horizons and climate zones, the median POC∕234Th ratios have a wide range, from 0.6 to 18 µmol dpm−1 .
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Global database of oceanic particulate organic carbon to 234 th ratios improving estimates of the biological carbon pump
Earth System Science Data Discussions, 2020Co-Authors: Viena Puigcorbe, Pere Masque, Frederic Le A C MoigneAbstract:Abstract. The ocean's biological carbon pump (BCP) plays a major role in the Global earth carbon cycle. A fraction of the photosynthetically fixed organic carbon produced in surface waters is exported below the sunlit layer in the form of settling particles (e.g. marine snow). Since the seminal works on the BCP, Global estimates of the Global Strength of the BCP have improved but large uncertainties remain (from 5 to 20 GtC yr−1 exported below the euphotic zone or mixed layer depth). The 234Th technique is widely used to measure the downward export of particulate organic carbon (POC). This technique has the advantage to allow a downward flux to be determined by integrating the deficit of 234Th in the upper water column and coupling it to an estimate of the POC/234Th ratio in sinking matter. However, the factors controlling the regional, temporal and depth variations of POC/234Th ratios are poorly understood. We present a database of 9110 measurements of the POC/234Th ratio in the ocean, from the surface down to > 5500 m, sampled on three size fractions (~ > 0.7 μm, ~ 1–50 μm, ~ > 50 μm), collected with in situ pumps and bottles, and also from bulk particles collected with sediment traps. The dataset is archived on the data repository PANGAEA® ( https://www.pangaea.de/ ) under https://doi.pangaea.de/10.1594/PANGAEA.902103 (Puigcorbe, 2019). The samples presented in this dataset were collected between 1989 and 2016 and the data have been obtained from published papers and open datasets available online. Unpublished data has also been included. Most of the open ocean provinces are represented by multiple measurements. However, there is an uneven distribution of the data, with some areas highly sampled (e.g, China Sea, Bermuda Atlantic Time Series station) compared to some others that are not well represented, such as the southeastern Atlantic, the south Pacific and the south Indian oceans. Some costal areas, although in a much smaller number, are also included in this Global compilation. Globally, based on different depths horizons and climate zones, the median POC/234Th ratios have a wide range, from 0.6 to 18 μmol dpm-1.
S A P L Cloetingh - One of the best experts on this subject based on the ideXlab platform.
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Global model for the lithospheric Strength and effective elastic thickness
Tectonophysics, 2013Co-Authors: Magdala Tesauro, Mikhail K Kaban, S A P L CloetinghAbstract:Global distribution of the Strength and effective elastic thickness (Te) of the lithosphere are estimated using physical parameters from recent crustal and lithospheric models. For the Te estimation we apply a new approach, which provides a possibility to take into account variations of Young modulus (E) within the lithosphere. In view of the large uncertainties affecting Strength estimates, we evaluate Global Strength and Te distributions for possible end-member ‘hard’ (HRM) and a ‘soft’ (SRM) rheology models of the continental crust. Temperature within the lithosphere has been estimated using a recent tomography model of Ritsema et al. (2011), which has much higher horizontal resolution than previous Global models. Most of the Strength is localized in the crust for the HRM and in the mantle for the SRM. These results contribute to the long debates on applicability of the “creme brulee” or “jelly-sandwich” model for the lithosphere structure. Changing from the SRM to HRM turns most of the continental areas from the totally decoupled mode to the fully coupled mode of the lithospheric layers. However, in the areas characterized by a high thermal regime and thick crust, the layers remain decoupled even for the HRM. At the same time, for the inner part of the cratons the lithospheric layers are coupled in both models. Therefore, rheological variations lead to large changes in the integrated Strength and Te distribution in the regions characterized by intermediate thermal conditions. In these areas temperature uncertainties have a greater effect, since this parameter principally determines rheological behavior. Comparison of the Te estimates for both models with those determined from the flexural loading and spectral analysis shows that the ‘hard’ rheology is likely applicable for cratonic areas, whereas the ‘soft’ rheology is more representative for young orogens.
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Global Strength and elastic thickness of the lithosphere
Global and Planetary Change, 2012Co-Authors: Magdala Tesauro, Mikhail K Kaban, S A P L CloetinghAbstract:Abstract The Strength and effective elastic thickness (Te) of the lithosphere control its response to tectonic and surface processes. Here, we present the first Global Strength and effective elastic thickness maps, which are determined using physical properties from recent crustal and lithospheric models. Pronounced Strength contrasts exist between old cratons and areas affected by Tertiary volcanism, which mostly coincide with the boundaries of seimogenic zones. Lithospheric Strength is primarily controlled by the crust in young (Phanerozoic) geological provinces characterized by low Te (~ 25 km), high topography (> 1000 m) and active seismicity. In contrast, the old (Achaean and Proterozoic) cratons of the continental plates show Strength primarily in the lithospheric mantle, high Te (over 100 km), low topography (
Dusan Hadzipavlovic - One of the best experts on this subject based on the ideXlab platform.
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acute and chronic posttraumatic stress symptoms in the emergence of posttraumatic stress disorder a network analysis
JAMA Psychiatry, 2017Co-Authors: Richard A Bryant, Mark Creamer, Meaghan Odonnell, David Forbes, Alexander C Mcfarlane, Derrick Silove, Dusan HadzipavlovicAbstract:Importance Little is understood about how the symptoms of posttraumatic stress develop over time into the syndrome of posttraumatic stress disorder (PTSD). Objective To use a network analysis approach to identify the nature of the association between PTSD symptoms in the acute phase after trauma and the chronic phase. Design, Setting, and Participants A prospective cohort study enrolled 1138 patients recently admitted with traumatic injury to 1 of 4 major trauma hospitals across Australia from March 13, 2004, to February 26, 2006. Participants underwent assessment during hospital admission (n = 1388) and at 12 months after injury (n = 852). Networks of symptom associations were analyzed in the acute and chronic phases using partial correlations, relative importance estimates, and centrality measures of each symptom in terms of its association Strengths, closeness to other symptoms, and importance in connecting other symptoms to each other. Data were analyzed from March 3 to September 5, 2016. Main Outcomes and Measures Severity of PTSD was assessed at each assessment with the Clinician-Administered PTSD Scale. Results Of the 1138 patients undergoing assessment at admission (837 men [73.6%] and 301 women [26.4%]; mean [SD] age, 37.90 [13.62] years), strong connections were found in the acute phase. Reexperiencing symptoms were central to other symptoms in the acute phase, with intrusions and physiological reactivity among the most central symptoms in the networks in terms of the extent to which they occur between other symptoms (mean [SD], 1.2 [0.7] and 1.0 [0.9], respectively), closeness to other symptoms (mean [SD], 0.9 [0.3] and 1.1 [0.9], respectively), and Strength of the associations (mean [SD], 1.6 [0.3] and 1.5 [0.3] respectively) among flashbacks, intrusions, and avoidance of thoughts, with moderately strong connections between intrusions and nightmares, being upset by reminders, and physiological reactivity. Intrusions and physiological reactivity were central in the acute phase. Among the 852 patients (73.6%) who completed the 12-month assessment, overall network connectivity was significantly stronger at 12 months than in the acute phase (Global Strength values, 6.57 vs 7.60; paired difference, 1.03;P Conclusions and Relevance As time elapses after trauma, fear circuitry and dysphoric PTSD symptoms appear to emerge as connected networks. Intrusive memories and reactivity are centrally associated with other symptoms in the acute phase, potentially pointing to the utility of addressing these symptoms in early intervention strategies.
E Hage - One of the best experts on this subject based on the ideXlab platform.
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on the feasibility of friction spot joining in magnesium fiber reinforced polymer composite hybrid structures
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2011Co-Authors: S T Amanciofilho, Carlos Bueno, J Dos F Santos, N Huber, E HageAbstract:Abstract In the present study, the feasibility of the friction spot joining technique on magnesium AZ31–O/glass fiber and carbon fiber reinforced poly(phenylene sulfide) joints is addressed. The thermo-mechanical phenomena associated with the friction spot joining process promoted metallurgical and polymer physical–chemical transformations. These effects resulted in grain refinement by dynamic recrystallization and changes in local (microhardness) and Global Strength (lap shear). Friction spot lap joints with elevated mechanical performance (20–28 MPa) were produced without surface pre-treatment. This preliminary investigation has successfully shown that friction spot joining is an alternative technology for producing hybrid polymer–metal structures.