Biodiversity Productive Capacity in Mixed Farms of North-West France: A Multi-Output Primal System

Previous studies on the productive value of biodiversity emphasized that crop diversity increases crop yields. Here, we focus on the productivity of crop diversity and permanent grasslands for crops and milk. Using a GMM approach, we estimate detailed production functions using a sample of 3960 mixed farms from the FADN between 2002 and 2013. We highlight that permanent grasslands enhance crop production. We confirm that crop diversity increases crop and milk yields. Permanent grasslands and crop diversity are however substitute inputs. We also find that both of these biodiversity productive capacities influence variable input productivities. These results suggest the potential adaptations of farmers’ choices to environmental measures.La littérature sur la valeur productive de la biodiversité a souligné que la diversité des cultures augmentait les rendements des cultures. Nous examinons ici la productivité de la diversité des cultures et des prairies permanentes pour les céréales et le lait. A partir de la méthode des moments généralisés, nous estimons un système de fonctions de production détaillées sur un échantillon de 3960 fermes du RICA spécialisées en polyculture-élevage entre 2002 et 2013. Nous trouvons que les prairies permanentes augmentent les rendements des cultures. Nous confirmons que la diversité des cultures augmente les rendements des cultures mais aussi les rendements laitiers. Cependant, nous trouvons que la diversité des cultures et les prairies permanentes sont substituables. Elles interagissent par ailleurs avec les intrants variables. Ces résultats mettent en avant un potentiel d’adaptations de la production des agriculteurs à des mesures environnementales

Objectives’ alignment between members and agricultural cooperatives

Members’ commitment lessens when agricultural cooperatives grow larger. Their organization becomes more complex and their membership more heterogeneous, which threatens their sustainability and leads them to implement specific mechanisms for collective decisions. We explore how the alignment of objectives between a multi-purpose cooperative and its members influences member commitment. We estimate a multinomial probit model on a cross-section sample of 3,205 members from a large agricultural cooperative in France. We assess the determinants of member commitment through four factors: the offer of new agricultural practices, the availability of outlets and supplies to members, the farm distance to the cooperative headquarters and the farm governance. We show that the adoption of new agricultural practices has a small but significant effect. The availability of outlets and supplies has the strongest effect on the economic involvement of the farmers. Other determinants, such as farm governance or geographical distance to the cooperative headquarters, also reinforce member commitment.L'engagement des adhérents diminue lorsque la taille des coopératives agricoles augmente. En effet, à mesure que la taille des coopératives augmente, leur organisation devient plus complexe, leur sociétariat plus hétérogène, ce qui menace leur durabilité et les conduit à mettre en oeuvre de nouveaux mécanismes de décisions collectives. Nous explorons comment l'alignement des objectifs entre une coopérative polyvalente et ses adhérents influence leur engagement. Nous estimons un modèle probit multinomial sur un échantillon transversal de 3 205 adhérents d'une grande coopérative agricole française. Nous évaluons les déterminants de l'engagement des adhérents à partir de quatre critères: l'offre de nouvelles pratiques agricoles, la disponibilité des débouchés pour l’adhérent au sein de la coopérative, la distance entre le siège social de l’exploitation et celui de la coopérative et la gouvernance de l’exploitation. Nous montrons que l'adoption de nouvelles pratiques agricoles a un effet faible mais significatif sur l’engagement. La disponibilité des débouchés est le facteur qui a le plus d’impact sur l’engagement des adhérents. D'autres déterminants, tels que la gouvernance de l’exploitation ou la distance au siège social de la coopérative renforcent également l'engagement des adhérents

Studies on hemostasis in COVID-19 deserve careful reporting of the laboratory methods, their significance and their limitations

We read with much interest the recent observational study of Nougier et al., which aimed at studying thrombin generation (TG) and fibrinolysis profiles of COVID-19 patients admitted to an intensive care unit (ICU) or to an internal medicine ward and receiving various schemes of prophylactic heparin.[1] They reported that thrombin potential remained within normal range despite heparin and that fibrinolysis was decreased in relation with increased plasminogen activator inhibitor 1 (PAI-1) and thrombin-activatable fibrinolysis inhibitor (TAFI) antigen plasma levels. Using the rotational thromboelastometry (ROTEM) delta device with EXTEM reagents and the addition of 0.625µg/mL tPA (referred to as 'TEM-tPA'), they reported decreased clot lysis in COVID-19 patients, which was more pronounced in patients who presented a thrombotic event, compared to event-free patients

Prothrombotic Hemostasis Disturbances in Patients with Severe COVID-19:Individual daily data

This data article accompanies the manuscript entitled: "Prothrombotic Disturbances of hemostasis of Patients with Severe COVID-19: a Prospective Longitudinal Observational Cohort Study" submitted to by the same authors. We report temporal changes of plasma levels of an extended set of laboratory parameters during the ICU stay of the 21 COVID-19 patients included in the monocentre cohort: CRP, platelet count, prothrombin time; Clauss fibrinogen and clotting factors II, V and VIII levels, D-dimers, antithrombin activity, protein C, free protein S, total and free tissue factor pathway inhibitor, PAI-1 levels, von Willebrand factor antigen and activity, ADAMTS-13 (plasma levels); and of two integrative tests of coagulation (thrombin generation with ST Genesia) and fibrinolysis (global fibrinolytic capacity - GFC). Regarding hemostasis, we used double-centrifuged frozen citrated plasma prospectively collected after daily performance of usual coagulation tests. Demographic and clinical characteristics of patients and thrombotic and hemorrhagic complications were also collected from patient's electronic medical reports

Viscoelastometric Testing to Assess Hemostasis of COVID-19: A Systematic Review

Infection by SARS-CoV-2 is associated with a high risk of thrombosis. The laboratory documentation of hypercoagulability and impaired fibrinolysis remains a challenge. Our aim was to assess the potential usefulness of viscoelastometric testing (VET) to predict thrombotic events in COVID-19 patients according to the literature. We also (i) analyzed the impact of anticoagulation and the methods used to neutralize heparin, (ii) analyzed whether maximal clot mechanical strength brings more information than Clauss fibrinogen, and (iii) critically scrutinized the diagnosis of hypofibrinolysis. We performed a systematic search in PubMed and Scopus databases until 31st December 2020. VET methods and parameters, and patients' features and outcomes were extracted. VET was performed for 1063 patients (893 intensive care unit (ICU) and 170 non-ICU, 44 studies). There was extensive heterogeneity concerning study design, VET device used (ROTEM, TEG, Quantra and ClotPro) and reagents (with non-systematic use of heparin neutralization), timing of assay, and definition of hypercoagulable state. Notably, only 4 out of 25 studies using ROTEM reported data with heparinase (HEPTEM). The common findings were increased clot mechanical strength mainly due to excessive fibrinogen component and impaired to absent fibrinolysis, more conspicuous in the presence of an added plasminogen activator. Only 4 studies out of the 16 that addressed the point found an association of VETs with thrombotic events. So-called functional fibrinogen assessed by VETs showed a variable correlation with Clauss fibrinogen. Abnormal VET pattern, often evidenced despite standard prophylactic anticoagulation, tended to normalize after increased dosing. VET studies reported heterogeneity, and small sample sizes do not support an association between the poorly defined prothrombotic phenotype of COVID-19 and thrombotic events

Effect of silver and strontium incorporation route on hydroxyapatite coatings elaborated by rf-SPS

Hydroxyapatite coatings have been currently used on hip prostheses for their ability to promote faster osseointe- gration and bone growth. Nevertheless, post-operative infections remain a recurring problem. To overcome this issue, doping with antibacterial elements has become a new trend. In this work, hydroxyapatite coatings elab- orated by radio-frequency suspension plasma spraying (rf-SPS) were doped with silver and strontium. Several doping strategies were explored thanks to the versatility offered by SPS compared with conventional spraying. First way: calcium phosphate doped powders were synthesized by coprecipitation and then dispersed into water before plasma spraying; second way: undoped powder was dispersed into aqueous medium in which nitrates or nanoparticles of the dopant(s) were respectively dissolved/dispersed. XRD revealed a high level of crystallinity ratio (ISO 13 779) and hydroxyapatite proportion for most of the coatings, with the presence of Ag/Ag 2 O nanopar- ticles whatever the doping route. SEM-EDS and STEM have demonstrated a more homogeneous distribution of the strontium within the coating made from the doped powder. Adherence of the coatings was estimated via a 3-point bending test, while bacteriological tests with S. aureus and proliferation of mesenchymal stem cells (hMSC) were performed. The results indicated a preferential incorporation of strontium into the secondary phases, showed efficient bactericidal properties, excellent mechanical properties in comparison with an APS reference coating, and no evidence of cytotoxic effect. This opens the way of a new type of coatings with a finer structure and a higher homogeneity through a better control of physicochemical properties using a suspension as the precursor

Linking disease epidemiology and livestock productivity: the case of bovine respiratory disease in France

Concerns are growing over the impact of livestock farming on environment and public health. The livestock industry is faced with the double constraint of limiting its use of natural resources and antimicrobials while ensuring its economic sustainability. In this context, reliable methods are needed to evaluate the effect of the prevention of endemic animal diseases on the productivity of livestock production systems. In this study, an epidemiological and productivity model was used to link changes in Bovine Respiratory Disease (BRD) incidence with the productivity of the beef and dairy cattle sectors in France. Cattle production parameters significantly affected by BRD were selected through literature review. Previous field study results and national cattle performance estimates were used to infer growth performances, mortality rates and carcass quality in the cattle affected and not affected by BRD. A steady-state deterministic herd production model was used to predict the productivity of the dairy and beef sector and their defined compartments (breeding-fattening, feedlot young bulls, and feedlot veal) in case of BRD incidence reduction by 20%, 50% or 100%. Results suggested that BRD should be controlled at a priority in beef breeding farms as eradication of BRD in beef calves would increase the whole beef sector’s productivity by 4.7–5.5% while eradication in other production stages would result in lower productivity gain in their respective sectors. However, the analysis performed at compartment level showed that, in both the beef and dairy sector, young bull and veal feedlot enterprises derive more economic benefits from BRD eradication for their own compartment (increase in productivity of 8.7–12.8% for beef young bulls) than the breeding farms (increase in productivity of 5.1–6% for beef calves), which may limit the investments in BRD control

Agricultural management of ecosystem services: insights from production and environmental economics

The thesis aims to study both theoretically and empirically the management of ecosystem services by the farmers from the perspective of the economic theory. The concept of ecosystem services is an interdisciplinary concept that refers to "the services that nature offers to human for free". The economic literature has mainly investigated this concept in measuring the value of these services, with few attention to the behavior of agents modifying these services. The thesis is divided into two parts. In the first part, I study both the supply and the demand for the productive ecosystem services (for example, pollination or biological control) by analyzing the behavior of farmers, considered as potential agroecosystem managers. Inspired by the literature on landscape ecology, I introduce biodiversity indicators that are function of land-use into existing models from agricultural production economics literature. This reunion provides a unified theoretical model for analyzing farmers' choices regarding the management of productive ecosystem services. The empirical works consists in estimating all or parts of this theoretical model. My main contribution to the literature is to prove, based on the farmers' observed behavior, that farmers do manage productive ecosystem services. I bring other elements to the literature, notably by providing new insights on the agricultural technology when productive ecosystem services are considered, or by showing that collective management of productive ecosystem services can only rarely arise spontaneously in real landscapes where farmers are heterogeneous. In the second part, I study the demand for the jointly provided public goods by the farmers’ modification of ecosystem service flows, i.e. I study the specificities of the demand for environmental services provided by farmers (in the sense of Engel et al., 2008). In particular, I study the role of the geographic scale of the demand for the design of agri-environmental policy. Indeed, if local public goods influence the welfare of the agents within a defined geographical area (e.g., the improvement of water quality by maintaining a wetland upstream of a treatment plant), global public goods can influence the welfare of all agents (e.g., the carbon sequestration into the soil of a wetland). In this part, I apply the framework of several literatures developed in environmental economics (for example, the literature on environmental federalism or on the "distance-decay") to the specificities of the environmental services provided by farmers; in particular, I integrate that the environmental service provided by a farmer affects the supply of multiple public goods in most cases, the demand for these public goods arising at different geographical scales. I contribute to the literature by showing that, although most of the demand for environmental services provided by farmers is captured locally (at the municipal level), some of the demand is captured by larger and farer areas. This has implications for the governance and the design of agri-environmental policies, which I explore through two examples: the reduction of pesticide application and the maintenance of agricultural wetlands.La thèse étudie théoriquement et empiriquement la gestion des services écosystémiques par les agriculteurs sous l’angle de la théorie économique. Le concept de services écosystémiques est un concept interdisciplinaire désignant « les services qu’offrent gratuitement la nature à l’homme ». La littérature économique s’est principalement emparée de la question de la mesure de la valeur de ces services, en s’intéressant peu ou prou aux comportements des agents modifiant ces services. La thèse se divise en deux parties. Dans la première partie, je m’intéresse à l’offre et à la demande de service écosystémique productifs (par exemple, la pollinisation ou le contrôle biologique) en analysant le comportement des agriculteurs, considérés comme de potentiels gestionnaires des agroécosystèmes. Inspiré par la littérature en écologie du paysage, j’introduis des indicateurs de biodiversité dépendant des assolements dans des modèles existants issus de la littérature en économie de la production appliquée à l’agriculture. Ce rapprochement fournit un modèle théorique unifié où l’on peut analyser les choix des agriculteurs vis-à-vis des services écosystémiques productifs. Les travaux empiriques développés par la suite consistent à estimer toute ou partie de ce modèle théorique. Ma principale contribution à la littérature est de prouver, à partir de l’analyse des comportements observés des agriculteurs, que les agriculteurs gèrent consciemment les services écosystémiques productifs. J’apporte d’autres éléments à la littérature, en fournissant notamment des éléments importants sur la technologie agricole lorsque les services écosystémiques productifs sont considérés, ou en montrant que la gestion collective des services écosystémiques productifs ne peut que rarement émergée spontanément dans des paysages réels où les agriculteurs sont hétérogènes. Dans la deuxième partie, je m’intéresse à la demande pour les biens publics fournis conjointement par les agriculteurs via la modification des flux de services écosystémiques, i.e. je m’intéresse à la demande pour les services environnementaux fournis par les agriculteurs (au sens de Engel et al., 2008). En particulier, j’étudie le rôle de l’échelle géographique de la demande sur la conception de politique agro-environnementale. En effet, si les biens publics locaux vont influencer le bien-être des agents au sein d’une zone géographique délimitée (e.g. amélioration de la qualité de l’eau en maintenant une zone humide en amont d’une station de traitement), les biens publics globaux peuvent influencer le bien-être de l’ensemble des agents (e.g. séquestration du carbone dans une zone humide). Dans cette partie, j’applique les cadres d’analyse de plusieurs littératures développées en économie de l’environnement (par exemple, vi la littérature sur le fédéralisme environnemental ou sur le « distance-decay ») aux spécificités des services environnementaux fournis par l’agriculture ; en particulier, le service environnemental fourni par un agriculteur influe le plus souvent sur la fourniture de multiple biens publics, biens publics dont l’échelle de la demande diffèrent. Je contribue à la littérature en montrant que, bien que la plupart de la demande pour les services environnementaux fournis par les agriculteurs soit capturée localement (à l’échelle de la municipalité), une partie de la demande s’exprime à des échelles plus importantes. Cela a des implications pour la gouvernance et la conception des politiques agroenvironnementales, que j’explore à travers deux exemples : la réduction de l’application des pesticides et le maintien des zones humides agricoles

Gestion agricole des services écosystémiques : éclairages à partir de l’économie de la production et de l’économie de l’environnement

The thesis studies both theoretically and empirically the management of ecosystem services by farmers in two parts. In the first part, I study the supply and demand for productive ecosystem services by analyzing farmers’ behavior. I introduce biodiversity indicators that depend on acreage into existing models from production economics. My main contribution to the literature is to prove, from the analysis of farmers' observed behavior that farmers consciously manage productive ecosystem services. I bring other elements to the literature, such as new elements on the agricultural technology or showing that the collective management of ecosystem services rarely arises spontaneously in real landscapes.In the second part, I study the demand for non- productive ecosystem services. I apply several analytical frameworks developed in environmental economics to the specificities of agriculture, i.e. the environmental service influences the supply of multiple public goods with different spatial distribution of the demand. I contribute to the literature by showing that while most of the demand for environmental services provided by farmers is captured locally (at the municipal level), a part of the demand is expressed at larger scales. This has implications for agri-environmental policies, which I explore through two examples: the pesticide savings and the maintenance of agricultural wetlandsLa thèse étudie théoriquement et empiriquement la gestion des services écosystémiques par les agriculteurs sous le prisme économique. La thèse se divise en deux parties. Dans la première partie, je m'intéresse à l'offre et à la demande de services écosystémiques productifs en analysant le comportement des agriculteurs. J'introduis des indicateurs de biodiversité dépendants des assolements dans des modèles existants issus de l'économie de production. Ma principale contribution à la littérature est de prouver, à partir de l'analyse des comportements observés des agriculteurs, que les agriculteurs gèrent consciemment les services écosystémiques productifs. J'apporte d'autres éléments à la littérature, comme e.g. des nouveaux éléments sur la technologie agricole ou en montrant que la gestion collective des services écosystémiques productifs ne peut que rarement émergée spontanément dans des paysages réels.Dans la deuxième partie, j’étudie la demande de services écosystémiques non-productifs fournis par les agriculteurs. J’applique plusieurs cadres d’analyse développés en économie de l’environnement aux spécificités de l’agriculture, i.e. le service environnemental influe le plus souvent sur la fourniture de multiple biens publics, biens publics présentant des distributions spatiales de la demande différentes. Je contribue à la littérature en montrant que, bien que la plupart de la demande pour les services environnementaux fournis par les agriculteurs soit capturée localement (à l’échelle de la municipalité) ; une partie de la demande s’exprime à des échelles plus importante