Creation of helicopter dynamic systems digital twin using multibody simulations

International audienceThis paper presents a new approach to develop digital twins of helicopter dynamic systems. Helicopter industries attach growing attention to the development of digital twins to be more predictive of mechanical parts lifetime. The number of sensors available to measure loads during flights is limited. Complementary simulations are necessary to compute all the loads that the mechanical parts undergo. A new process is described to build these simulations fed with flights data records. Complexity of helicopters dynamics systems leads to create several local models of subsystems using a multibody dynamic formalism. A study focused on a swashplate rotor assembly is presented to illustrate this approach, including a new model of bearing and its validation based on bench tests

Primer registro de parasitismo del federal (Amblyramphus holosericeus) por parte del especialista Tordo pico corto (Molothrus rufoaxillaris)

Screaming Cowbird (Molothrus rufoaxillaris) is highly specialized parasitizing only three species, making records of new hosts very informative. During 2017 we studied nesting success on roadsides in Argentine Pampas. Fifty-seven nests (46%) belonged to the known host Brown-and-yellow Marshbirds (Pseudoleistes virescens). Four nests belonged to Scarlet-headed Blackbird (Amblyramphus holosericeus); one contained a Screaming Cowbird nestling that fledged with two of the host. We discuss similarities and differences among the Scarlet-headed Blackbird and old hosts. More studies are needed to confirm the regular parasitism of Scarlet-headed Blackbird by Screaming Cowbird, and to better understand their high specificity in host selection.El Tordo Pico Corto (Molothrus rufoaxillaris) es altamente especialista parasitando solo a tres especies de aves, lo que hace que registros de nuevos hospedadores sean muy informativos. Durante 2017 estudiamos el éxito de nidificación en bordes de camino en la región Pampeana de Argentina. Cincuenta y siete nidos (46%) pertenecieron al hospedador ya conocido Pecho Amarillo (Pseudoleistes virescens). Cuatro nidos pertenecieron al Federal (Amblyramphus holosericeus); uno contenía un pichón de Tordo Pico Corto que abandonó el nido como volantón junto con dos pichones del hospedador. Discutimos similitudes y diferencias entre el Federal y viejos hospedadores. Mayores estudios son necesarios para confirmar el parasitismo regular del Federal por parte del Tordo Pico Corto, y para comprender mejor su alta especificidad en la selección de hospedadores.Fil: Mermoz, Myriam Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Depalma, Daniela María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Charnelli, Emilio M.. Museo de Ciencias Naturales Tuyu Mapu; ArgentinaFil: Zilli, Carla Giannina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentin

Mapping co-benefits for carbon storage and biodiversity to inform conservation policy and action

International audienceIntegrated high-resolution maps of carbon stocks and biodiversity that identify areas of potential co-benefits for climate change mitigation and biodiversity conservation can help facilitate the implementation of global climate and biodiversity commitments at local levels. However, the multi-dimensional nature of biodiversity presents a major challenge for understanding, mapping and communicating where and how biodiversity benefits coincide with climate benefits. A new integrated approach to biodiversity is therefore needed. Here, we (a) present a new high-resolution map of global above- and below-ground carbon stored in biomass and soil, (b) quantify biodiversity values using two complementary indices (BIp and BIr) representing proactive and reactive approaches to conservation, and (c) examine patterns of carbon–biodiversity overlap by identifying 'hotspots' (20% highest values for both aspects). Our indices integrate local diversity and ecosystem intactness, as well as regional ecosystem intactness across the broader area supporting a similar natural assemblage of species to the location of interest. The western Amazon Basin, Central Africa and Southeast Asia capture the last strongholds of highest local biodiversity and ecosystem intactness worldwide, while the last refuges for unique biological communities whose habitats have been greatly reduced are mostly found in the tropical Andes and central Sundaland. There is 38 and 5% overlap in carbon and biodiversity hotspots, for proactive and reactive conservation, respectively. Alarmingly, only around 12 and 21% of these proactive and reactive hotspot areas, respectively, are formally protected. This highlights that a coupled approach is urgently needed to help achieve both climate and biodiversity global targets. This would involve (1) restoring and conserving unprotected, degraded ecosystems, particularly in the Neotropics and Indomalaya, and (2) retaining the remaining strongholds of intactnes

Plan de Gestión Parque Nacional Perito F. P. Moreno

Según la UICN, un área protegida (AP) es un espacio geográfico claramente definido, reconocido, dedicado y gestionado, mediante medios legales u otros tipos de medios eficaces, para conseguir la conservación a largo plazo de la naturaleza y de sus servicios ecosistémicos y sus valores culturales asociados (Dudley 2008). El Plan de Gestión (PG) es una herramienta importante para la adecuada gestión de las AP. Es el documento donde se definen los lineamientos técnicos y las normas generales de uso de un área de conservación. La planificación permite analizar, discutir y decidir el rumbo de las acciones para el correcto manejo o gestión del AP. Según Núñez Araya (2008), la planificación estratégica de un espacio protegido tiene como objetivo definir el futuro deseado y establecer la forma de alcanzar ese futuro, orientando la toma de decisiones para el mejor uso del espacio. Como dijo Carlos Matus (Amend et al. 2002), “o sabemos planificar o estamos obligados a la improvisación”. Por esta razón la APN ha incorporado la planificación de la gestión de las AP, recomendando lineamientos para su elaboración. En este marco se ha llevado a cabo este proceso que concluye en el presente documento.EEA Santa CruzFil: Blanco, Rocío. Administración De Parques Nacionales. Dirección Regional Patagonia Austral; Argentina.Fil: Malmierca, Laura. Administración De Parques Nacionales. Coordinación Patagonia Austral; Argentina.Fil: Mosti, Patricia. Administración De Parques Nacionales. Santa Cruz; Argentina.Fil: Valenzuela, Alejandro E.J. Administración De Parques Nacionales. Tierra del Fuego; Argentina.Fil: Aguirre, Emiliano. Parque Nacional Perito Francisco P. Moreno. Santa Cruz; ArgentinaFil: Del Castillo, Fabricio (Intendente). Parque Nacional Perito Francisco P. Moreno. Santa Cruz; Argentina.Fil: Spisso, Mariano. Parque Nacional Perito Francisco P. Moreno. Santa Cruz; Argentina.Fil: Chalukian, Silvia C. Administración de Parques Nacionales. Consultora externa; Argentina.Fil: Buria, Leonardo. Administración De Parques Nacionales. Delegación Regional Patagonia; Argentina.Fil: Caracotche, Soledad. Administración De Parques Nacionales. Delegación Regional Patagonia; Argentina.Fil: Lizárraga, Leonidas. Administración De Parques Nacionales. Dirección Regional Noroeste; Argentina.Fil: Martinez, Mariana G. Administración De Parques Nacionales. Delegación Regional Patagonia; Argentina.Fil: Mermoz, Mónica. Administración De Parques Nacionales. Delegación Regional Patagonia; Argentina.Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Ronda, Gonzalo M. Consejo Nacional De Investigaciones Científicas Y Técnicas. Instituto De Estudios Andinos "Don Pablo Groeber" (IDEAN); Argentina

Carbon losses from deforestation and widespread degradation offset by extensive growth in African woodlands

Degradation—the loss of carbon stored in intact woodland—is very difficult to measure over large areas. Here, the authors show that carbon emissions from degradation in African woodlands greatly exceed those from deforestation, but are happening alongside widespread increases in biomass in remote areas

Forest biomass retrieval approaches from earth observation in different biomes

The amount and spatial distribution of forest aboveground biomass (AGB) were estimated using a range of regionally developed methods using Earth Observation data for Poland, Sweden and regions in Indonesia (Kalimantan), Mexico (Central Mexico and Yucatan peninsula), and South Africa (Eastern provinces) for the year 2010. These regions are representative of numerous forest biomes and biomass levels globally, from South African woodlands and savannas to the humid tropical forest of Kalimantan. AGB retrieval in each region relied on different sources of reference data, including forest inventory plot data and airborne LiDAR observations, and used a range of retrieval algorithms. This is the widest inter-comparison of regional-to-national AGB maps to date in terms of area, forest types, input datasets, and retrieval methods. The accuracy assessment of all regional maps using independent field data or LiDAR AGB maps resulted in an overall root mean square error (RMSE) ranging from 10 t ha−1 to 55 t ha−1 (37% to 67% relative RMSE), and an overall bias ranging from −1 t ha−1 to +5 t ha−1 at pixel level. The regional maps showed better agreement with field data than previously developed and widely used pan-tropical or northern hemisphere datasets. The comparison of accuracy assessments showed commonalities in error structures despite the variety of methods, input data, and forest biomes. All regional retrievals resulted in overestimation (up to 63 t ha−1) in the lower AGB classes, and underestimation (up to 85 t ha−1) in the higher AGB classes. Parametric model-based algorithms present advantages due to their low demand on in situ data compared to non-parametric algorithms, but there is a need for datasets and retrieval methods that can overcome the biases at both ends of the AGB range. The outcomes of this study should be considered when developing algorithms to estimate forest biomass at continental to global scale level

Understanding ‘saturation’ of radar signals over forests

There is an urgent need to quantify anthropogenic influence on forest carbon stocks. Using satellite-based radar imagery for such purposes has been challenged by the apparent loss of signal sensitivity to changes in forest aboveground volume (AGV) above a certain ‘saturation’ point. The causes of saturation are debated and often inadequately addressed, posing a major limitation to mapping AGV with the latest radar satellites. Using ground- and lidar-measurements across La Rioja province (Spain) and Denmark, we investigate how various properties of forest structure (average stem height, size and number density; proportion of canopy and understory cover) simultaneously influence radar backscatter. It is found that increases in backscatter due to changes in some properties (e.g. increasing stem sizes) are often compensated by equal magnitude decreases caused by other properties (e.g. decreasing stem numbers and increasing heights), contributing to the apparent saturation of the AGV-backscatter trend. Thus, knowledge of the impact of management practices and disturbances on forest structure may allow the use of radar imagery for forest biomass estimates beyond commonly reported saturation points

Can the intake of antiparasitic secondary metabolites explain the low prevalence of hemoparasites among wild Psittaciformes?

Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significantly among taxa. Various factors might explain the differences in infection among taxa, including habitat, climate, host density, the presence of vectors, life history and immune defence. Feeding behaviour can also be relevant both through increased exposure to vectors and consumption of secondary metabolites with preventative or therapeutic effects that can reduce parasite load. However, the latter has been little investigated. Psittaciformes (parrots and cockatoos) are a good model to investigate these topics, as they are known to use biological control against ectoparasites and to feed on toxic food. We investigated the presence of avian malaria parasites (Plasmodium), intracellular haemosporidians (Haemoproteus, Leucocytozoon), unicellular flagellate protozoans (Trypanosoma) and microfilariae in 19 Psittaciformes species from a range of habitats in the Indo-Malayan, Australasian and Neotropical regions. We gathered additional data on hemoparasites in wild Psittaciformes from the literature. We considered factors that may control the presence of hemoparasites in the Psittaciformes, compiling information on diet, habitat, and climate. Furthermore, we investigated the role of diet in providing antiparasitic secondary metabolites that could be used as self-medication to reduce parasite load. Results: We found hemoparasites in only two of 19 species sampled. Among them, all species that consume at least one food item known for its secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, were free from hemoparasites. In contrast, the infected parrots do not consume food items with antimalarial or even general antiparasitic properties. We found that the two infected species in this study consumed omnivorous diets. When we combined our data with data from studies previously investigating blood parasites in wild parrots, the positive relationship between omnivorous diets and hemoparasite infestation was confirmed. Individuals from open habitats were less infected than those from forests. Conclusions: The consumption of food items known for their secondary metabolites with antimalarial, trypanocidal or general antiparasitic properties, as well as the higher proportion of infected species among omnivorous parrots, could explain the low prevalence of hemoparasites reported in many vertebrates