Avian mycoplasmosis update

Avian mycoplasmas occur in a variety of bird species. The most important mycoplasmas for chickens and turkeys are Mycoplasma gallisepticum (MG), M. synoviae (MS), and M. meleagridis. Besides, M. iowe (MI) is an emerging pathogen in turkeys, but of little concern for chickens. Mycoplasmas are bacteria that lack cell wall and belong to the class Mollicutes. Although they have been considered extracellular agents, scientists admit nowadays that some of them are obligatory intracellular microorganisms, whereas all other mycoplasmas are considered facultative intracellular organisms. Their pathogenic mechanism for disease include adherence to host target cells, mediation of apoptosis, innocent bystander damage to host cell due to intimate membrane contact, molecular (antigen) mimicry that may lead to tolerance, and mitotic effect for B and/or T lymphocytes, which could lead to suppressed T-cell function and/or production of cytotoxic T cell, besides mycoplasma by-products, such as hydrogen peroxide and superoxide radicals. Moreover, mycoplasma ability to stimulate macrophages, monocytes, T-helper cells and NK cells, results in the production of substances, such as tumor necrosing factor (TNF-alpha), interleukin (IL-1, 2, 6) and interferon (<FONT FACE=Symbol>a, b, g</FONT>). The major clinical signs seen in avian mycoplasmosis are coughing, sneezing, snicks, respiratory rales, ocular and nasal discharge, decreased feed intake and egg production, increased mortality, poor hatchability, and, primarily in turkeys, swelling of the infraorbital sinus(es). Nevertheless, chronic and unapparent infections are most common and more threatening. Mycoplasmas are transmitted horizontally, from bird to bird, and vertically, from dam to offspring through the eggs. Losses attributed to mycoplasmosis, mainly MG and MS infections, result from decreased egg production and egg quality, poor hatchability (high rate of embryonic mortality and culling of day-old birds), poor feed efficiency, increase in mortality and carcass condemnations, besides medication costs. Mycoplasmas are diagnosed by serologic tests, culture and PCR and are sensitive to antimicrobials whose action sites are other than the bacterial cell wall, such as tetracyclines, macrolides, quinolones and tiamulin. However, mycoplasma control is more efficiently achieved by acquisition of birds free of MG, MS, MM and/or MI, vaccination of layers, and monitoring of breeder flocks, followed by elimination of the infected flocks that are detected

More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia.

This is the author accepted manuscript. The final version is available from the American Association for the Advancement of Science via the DOI in this recordData and materials availability: Data from publicly available sources are cited in the supplementary materials. Other data and computer codes used in the analysis are publicly available at Zenodo repositoryIndigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.Coordination of Superior Level Staff Improvement under the Academic Excellence Program (CAPES/PROEX)Coordination of Superior Level Staff Improvement under the Academic Excellence Program (CAPES/PROEX)Coordination of Superior Level Staff Improvement under the Academic Excellence Program (CAPES/PROEX)National Council for Scientific and Technological Development (CNPQ)National Council for Scientific and Technological Development (CNPQ)National Council for Scientific and Technological Development (CNPQ)European Research CouncilSão Paulo Research Foundation (FAPESP)Amazon FundSão Paulo Research Foundation (FAPESP)PVEMEC/MCTI/CAPES/CNPq/FAPEuropean Union’s Horizon 2020European Union’s Horizon 2020CAPESANRMCT/CNPq/CT-INFRA/GEOMAMCT/CNPq/CT-INFRA/GEOMACAPES/PDSECAPES/FapespaCNPqFAPESPCNPq/CAPES/FAPS/BC-NewtonFAPEMATRoyal Society GCRF International Collaboration AwardNSF/DEBCNPQ/PQNatural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Natural Environment Research Council (NERC)Gordon and Betty Moore Foundatio