Comportamento de voo de aves em resposta ao uso de sinalizadores em linhas de transmissão de energia elétrica

Como consequência da ampliação do setor energético e da instalação de novas linhas de transmissão de energia (LTs), as aves estão expostas a um risco crescente de mortalidade direta em virtude da colisão com essas estruturas. Com o propósito de minimizar as colisões, sinalizadores de avifauna são instalados nos cabos para-raios das LTs. Buscamos testar a efi ciência dos sinalizadores por meio de observações da alteração no comportamento de voo de aves avaliado em nível de famílias taxonômicas. Consideramos duas variáveis de exposição ao risco de colisão - posição do voo de transposição da linha e distância perpendicular em relação aos cabos – observadas em vãos sinalizados e não sinalizados de uma LT localizada no litoral norte do Rio Grande do Sul – Brasil. Realizamos o teste Qui- Quadrado (α = 0,05) para as duas variáveis de risco e para cada família em separado. Das famílias analisadas (n = 13), somente uma (Hirundinidae) apresentou alteração do comportamento de voo na presença dos sinalizadores. Apesar da sinalização dos cabos ser indicada como a medida mais apropriada para a mitigação dessas fatalidades, nossos resultados não revelaram isso quando avaliados em nível de família. No entanto, antes de abandonar essa estratégia de mitigação, nós discutimos a necessidade da aplicação de meta-análises para verifi car a efetividade desses dispositivos nas LTs instaladas no Brasil, assim como a necessidade de aperfeiçoamento nos desenhos amostrais dos estudos de monitoramentos dessas infraestruturas.Bird fl ight behavior in response to marked wire use in power transmission lines. As a result of the expansion of the energy sector and the subsequent installation of new power transmission lines (LTs), birds are increasingly exposed to the risk of direct mortality due to collision with these structures. In order to minimize collisions, bird fl ight diverters are fi xed in the static wire. We tested, with an indirect measure, the eff ectiveness of this dispositive by means of observations of the alteration of the fl ight behavior in distinct bird families. We considered two risk variables - position of the line transposition fl ight and fl ight distance in relation to the cables - observed on mitigated and unmitigated spans of a LT located on the north coast of Rio Grande do Sul, Brazil. We used chi-square test (α = 0.05) for the two risk variables and for each family separately to test for diff erences in behavior responses to fl ight diverters. Out of 13 families, only Hirundinidae showed risk avoidance fl ight behavior on mitigated lines. Despite the wire marking be indicated as the most appropriate measure to mitigate these fatalities, our behavioral study do not supported this claim, at the family level. However, before their abandonment we discuss the need of a meta-analysis of their eff ectiveness on Brazilian TLs as well improvements needed in monitoring study designs

Semiconductor membranes for electrostatic exciton trapping in optically addressable quantum transport devices

Combining the capabilities of gate defined quantum transport devices in GaAs-based heterostructures and of optically addressed self-assembled quantum dots could open broad perspectives for new devices and functionalities. For example, interfacing stationary solid-state qubits with photonic quantum states would open a new pathway towards the realization of a quantum network with extended quantum processing capacity in each node. While gated devices allow very flexible confinement of electrons or holes, the confinement of excitons without some element of self-assembly is much harder. To address this limitation, we introduce a technique to realize exciton traps in quantum wells via local electric fields by thinning a heterostructure down to a 220 nm thick membrane. We show that mobilities over $1 \times 10^{6}$ cm$^{2}$V$^{-1}$s$^{-1}$ can be retained and that quantum point contacts and Coulomb oscillations can be observed on this structure, which implies that the thinning does not compromise the heterostructure quality. Furthermore, the local lowering of the exciton energy via the quantum-confined Stark effect is confirmed, thus forming exciton traps. These results lay the technological foundations for devices like single photon sources, spin photon interfaces and eventually quantum network nodes in GaAs quantum wells, realized entirely with a top-down fabrication process.Comment: v2: added missing acknowledgement. v3: fixed typos in acknolwedgemen

Power line electrocution as an overlooked threat to Lear's Macaw (Anodorhynchus leari)

Electrocution can pose a serious threat to large birds, particularly threatened species with low population sizes. However, few studies have focused on the impacts of electrocution on large parrots such as the Endangered Lear's Macaw Anodorhynchus leari, endemic to the Brazilian Caatinga. Here, we compile and describe 31 electrocution events, as reported by villagers, indicating that electrocution may be an important threat to Lear's Macaw. We suggest a research and monitoring agenda to better understand the spatial and temporal patterns of this impact and recommend some immediate mitigation measures for decreasing electrocutions.info:eu-repo/semantics/submittedVersio

Wild pigs and their widespread threat to biodiversity conservation in South America

Wild pigs, including wild boar (Sus scrofa) and feral domestic pig (Sus scrofa domestica), are associated with negative impacts in their native and introduced ranges. We compiled wild pig occurrence reports and utilized Maximum Entropy modelling to predict their potential distribution in ecoregions overlaying Argentina, Brazil, Bolivia, Chile, Uruguay and Paraguay. An analysis of their observed and potential distributions was carried out in relation to four biodiversity hotspots and 3766 protected areas to estimate the number of units and percent area currently and potentially invaded. Among biodiversity hotspots, Atlantic Forest, Cerrado, and Chilean Winter Rainfall-Valdivian Forests included 44.7% of wild pig records. The proportion of suitable area was 85% in Atlantic Forest, 61.3% in Cerrado, 37.5% in Chilean Winter Rainfall-Valdivian Forests, and 5.6% in Tropical Andes. The number of protected areas with known wild pig presence was led by Uruguay (100%), followed by Chile (20.3%), Argentina (15.8%), Paraguay (9.5%), Bolivia (6.5%), and Brazil (4.7%). The proportion of protected areas with predicted wild pig presence was highest in Uruguay (100%), followed by Paraguay (72.6%), Brazil (58.0%), Argentina (57.4%), Chile (42.2%), and Bolivia (35.9%). Our work represents the first assessment of wild pig potential distribution in South America and highlights the potentially devastating impacts of wild pigs on the regional biodiversity and national conservation targets, especially at mega-diverse areas. We present a dynamic web application that can be readily consulted by scientists, managers and decision makers to improve wild pig control and risk mitigation actions in the study region.Fil: la Sala, Luciano Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Burgos, Julian Mariano. Marine and Freshwater Research Institute; IslandiaFil: Caruso, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Bagnato, Camilo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones En Recursos Naturales, Agroecología y Desarrollo Rural. - Universidad Nacional de Rio Negro. Instituto de Investigaciones En Recursos Naturales, Agroecología y Desarrollo Rural; ArgentinaFil: Ballari, Sebastián A.. Administración de Parques Nacionales. Parque Nacional "Nahuel Huapi"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guadagnin, Demetrio L.. Universidade Federal do Rio Grande do Sul; BrasilFil: Kindel, Andreas. Universidade Federal do Rio Grande do Sul; BrasilFil: Etges, Matheus. Universidade Federal do Rio Grande do Sul; BrasilFil: Merino, Mariano Lisandro. Universidad Nacional del Noroeste de la Provincia de Buenos Aires; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Marcos, Andrea. Ministerio de Agricultura, Ganadería, Pesca y Alimento. Servicio Nacional de Sanidad y Calidad Agroalimentaria; ArgentinaFil: Skewes, Oscar. Universidad de Concepción; ChileFil: Schettino, Daniella. Instituto de Defesa Agropecuária de Mato Grosso; BrasilFil: Perez, Andres Maximiliano. University of Minnesota; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Condorí, Walter Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Tammone Santos, Agostina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Carpinetti, Bruno Nicolás. Universidad Nacional Arturo Jauretche. Instituto Ciencias Sociales y Administracion; ArgentinaFil: Zalba, Sergio Martín. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Grupo de Estudios en Conservación y Manejo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin