RESUMO
Migratory animals are declining worldwide and coordinated conservation efforts are needed to reverse current trends. We devised a novel genoscape-network model that combines genetic analyses with species distribution modeling and demographic data to overcome challenges with conceptualizing alternative risk factors in migratory species across their full annual cycle. We applied our method to the long distance, Neotropical migratory bird, Wilson's Warbler (Cardellina pusilla). Despite a lack of data from some wintering locations, we demonstrated how the results can be used to help prioritize conservation of breeding and wintering areas. For example, we showed that when genetic, demographic, and network modeling results were considered together it became clear that conservation recommendations will differ depending on whether the goal is to preserve unique genetic lineages or the largest number of birds per unit area. More specifically, if preservation of genetic lineages is the goal, then limited resources should be focused on preserving habitat in the California Sierra, Basin Rockies, or Coastal California, where the 3 most vulnerable genetic lineages breed, or in western Mexico, where 2 of the 3 most vulnerable lineages overwinter. Alternatively, if preservation of the largest number of individuals per unit area is the goal, then limited conservation dollars should be placed in the Pacific Northwest or Central America, where densities are estimated to be the highest. Overall, our results demonstrated the utility of adopting a genetically based network model for integrating multiple types of data across vast geographic scales and better inform conservation decision-making for migratory animals.
Un Modelo de Redes de Panorama Poblacional para la Priorización de la Conservación de un Ave Migratoria Resumen Los animales migratorios están pasando por una declinación mundial y se requieren esfuerzos coordinados de conservación para revertir las tendencias actuales. Diseñamos un modelo novedoso de redes de panorama poblacional que combina el análisis genético con el modelado de la distribución de especies y los datos demográficos para sobreponerse a los obstáculos con la conceptualización de los factores alternativos de riesgo en las especies migratorias durante su ciclo anual completo. Aplicamos nuestro método al chipe de corona negra (Cardellina pusilla), un ave migratoria neotropical que recorre largas distancias. A pesar de la falta de datos de algunas localidades de invernación, mostramos cómo pueden usarse los resultados para ayudar a priorizar la conservación de las áreas de reproducción y de invernación. Por ejemplo, mostramos que cuando se consideraron en conjunto los resultados del modelado genético, demográfico y de redes queda claro que las recomendaciones de conservación diferirán dependiendo de si el objetivo es preservar linajes genéticos únicos o el mayor número de aves por unidad de área. Más específicamente, si el objetivo es la conservación de los linajes genéticos, entonces los recursos limitados deberían enfocarse en preservar el hábitat en la Sierra de California, la Cuenca de las Rocallosas, la costa de California (lugares en donde se reproducen los tres linajes genéticos más vulnerables) o en el oeste de México (en donde dos de los tres linajes más vulnerables pasan el invierno). Alternativamente, si el objetivo es la conservación del mayor número de individuos por unidad de área, entonces el financiamiento limitado debería aplicarse en el noroeste del Pacífico o en América Central, en donde se estima que las densidades poblacionales son las más altas. En general, nuestros resultados demostraron la utilidad de adoptar un modelo de redes basadas en la genética para la integración de datos a lo largo de escalas geográficas amplias y para informar de mejor manera la toma de decisiones de conservación para los animales migratorios.
Assuntos
Migração Animal , Conservação dos Recursos Naturais , Animais , Aves/genética , América Central , México , Noroeste dos Estados Unidos , Estações do AnoRESUMO
Time series now have sufficient duration to determine harmful algal bloom (HAB) responses to changing climate conditions, including warming, stratification intensity, freshwater inputs and natural patterns of climate variability, such as the El Niño Southern Oscillation and Pacific Decadal Oscillation. Against the context of time series, such as those available from phytoplankton monitoring, dinoflagellate cyst records, the Continuous Plankton Recorder surveys, and shellfish toxin records, it is possible to identify extreme events that are significant departures from long-term means. Extreme weather events can mimic future climate conditions and provide a "dress rehearsal" for understanding future frequency, intensity and geographic extent of HABs. Three case studies of extreme HAB events are described in detail to explore the drivers and impacts of these oceanic outliers that may become more common in the future. One example is the chain-forming diatom of the genus Pseudo-nitzschia in the U.S. Pacific Northwest and its response to the 2014-16 northeast Pacific marine heat wave. The other two case studies are pelagic flagellates. Highly potent Alexandrium catenella group 1 dinoflagellate blooms (up to 150 mg/kg PST in mussels; 4 human poisonings) during 2012-17 created havoc for the seafood industry in Tasmania, south-eastern Australia, in a poorly monitored area where such problems were previously unknown. Early evidence suggests that changes in water column stratification during the cold winter-spring season are driving new blooms caused by a previously cryptic species. An expansion of Pseudochattonella cf. verruculosa to the south and A. catenella to the north over the past several years resulted in the convergence of both species to cause the most catastrophic event in the history of the Chilean aquaculture in the austral summer of 2016. Together, these two massive blooms were colloquially known as the "Godzilla-Red tide event", resulting in the largest fish farm mortality ever recorded worldwide, equivalent to an export loss of USD$800 million which when combined with shellfish toxicity, resulted in major social unrest and rioting. Both blooms were linked to the strong El Niño event and the positive phase of the Southern Annular Mode, the latter an indicator of anthropogenic climate change in the southeastern Pacific region. For each of these three examples, representing recent catastrophic events in geographically distinct regions, additional targeted monitoring was employed to improve the understanding of the climate drivers and mechanisms that gave rise to the event and to document the societal response. Scientists must be poised to study future extreme HAB events as these natural experiments provide unique opportunities to define and test multifactorial drivers of blooms.
Assuntos
Mudança Climática , Proliferação Nociva de Algas , Chile , Humanos , Noroeste dos Estados Unidos , Oceanos e MaresRESUMO
Forest dynamics are driven by top-down changes in climate and bottom-up positive (destabilizing) and negative (stabilizing) biophysical feedbacks involving disturbance and biotic interactions. When positive feedbacks prevail, the resulting self-propagating changes can potentially shift the system into a new state, even in the absence of climate change. Conversely, negative feedbacks help maintain a dynamic equilibrium that allows communities to recover their pre-disturbance characteristics. We examine palaeoenvironmental records from temperate forests to assess the nature of long-term stability and regime shifts under a broader range of environmental forcings than can be observed at present. Forest histories from northwestern USA, Patagonia, Tasmania and New Zealand show long-term trajectories that were governed by (i) the biophysical template, (ii) characteristics of climate and disturbance, (iii) historical legacies that condition the ecological capacity to respond to subsequent disturbances, and (iv) thresholds that act as irreversible barriers. Attention only to current forest conditions overlooks the significance of history in creating path dependency, the importance of individual extreme events, and the inherent feedbacks that force an ecosystem into reorganization. A long-time perspective on ecological resilience helps guide conservation strategies that focus on environmental preservation as well as identify vulnerable species and ecosystems to future climate change. This article is part of the theme issue 'Climate change and ecosystems: threats, opportunities and solutions'.
Assuntos
Biodiversidade , Mudança Climática , Conservação dos Recursos Naturais , Incêndios , Florestas , Árvores , Argentina , Nova Zelândia , Noroeste dos Estados Unidos , TasmâniaRESUMO
This article describes the conception, implementation, and evaluation of a wilderness medicine-based first aid class for the commercial fishing industry. Commercial fishing is a dangerous occupation in the United States. Currently, commercial fishermen often only have access to basic first aid classes. Because of its focus on austere environments, hazardous conditions, and distance from definitive medical care-hallmarks of commercial fisheries-wilderness medicine offers a more appropriate approach to decreasing morbidity and mortality in the industry. A 2-d, 16-h pilot wilderness medicine course for commercial fishermen, Fishermen First Aid and Safety Training (FFAST), conducted for Dungeness crab fishermen, was effective and well received, based on pre- and postcourse knowledge, skill, and attitude surveys. FFAST has been approved by the Coast Guard and is being made more widely available to commercial fishermen in the Pacific Northwest. The FFAST program offers an example of how wilderness medicine can improve safety and emergency medical response for a wide variety of austere environments not traditionally linked to the backcountry.
Assuntos
Serviços Médicos de Emergência/organização & administração , Pesqueiros , Medicina do Trabalho/organização & administração , Medicina Selvagem/organização & administração , Noroeste dos Estados Unidos , Estados UnidosRESUMO
Climate change-induced phenological variation in amphibians can disrupt time-sensitive processes such as breeding, hatching, and metamorphosis, and can consequently alter size-dependent interactions such as predation. Temperature can further alter size-dependent, predator-prey relationships through changes in species' behavior. We thus hypothesized that phenological shifts due to climate warming would alter the predator-prey dynamic in a larval amphibian community through changes in body size and behavior of both the predator and prey. We utilized an amphibian predator-prey system common to the montane wetlands of the U.S. Pacific Northwest: the long-toed salamander (Ambystoma macrodactylum) and its anuran prey, the Pacific chorus frog (Pseudacris regilla). We conducted predation trials to test if changes in predator phenology and environmental temperature influence predation success. We simulated predator phenological shifts using different size classes of the long-toed salamander representing an earlier onset of breeding while using spring temperatures corresponding to early and mid-season larval rearing conditions. Our results indicated that the predator-prey dynamic was highly dependent upon predator phenology and temperature, and both acted synergistically. Increased size asymmetry resulted in higher tadpole predation rates and tadpole tail damage. Both predators and prey altered activity and locomotor performance in warmer treatments. Consequently, behavioral modifications resulted in decreased survival rates of tadpoles in the presence of large salamander larvae. If predators shift to breed disproportionately earlier than prey due to climate warming, this has the potential to negatively impact tadpole populations in high-elevation amphibian assemblages through changes in predation rates mediated by behavior.
Assuntos
Comportamento Predatório , Urodelos , Ambystoma , Animais , Larva , Noroeste dos Estados UnidosRESUMO
The region encompassing the Pacific Northwest (PNW), Vancouver Island, Oregon, and Washington has been the location of an ongoing Cryptococcus gattii outbreak since the 1990s, and there is evidence that the outbreak is expanding along the West Coast into California. Here we report a clinical case of a 69-year-old, HIV-negative man from North Carolina who was diagnosed with a fungal brain mass by magnetic resonance imaging (MRI) and pathology. He had traveled to Seattle and Vancouver 3 years earlier and to Costa Rica 4 months prior to presentation. Phenotypic evidence showed that the fungal mass isolated from the patient's brain represented C. gattii In agreement with the phenotypic results, multilocus sequence typing (MLST) provided genotypic evidence that assigned the infecting organism within the C. gattii species complex and to the C. deuterogattii VGIIa clade. Whole-genome sequencing revealed >99.99% identity with the C. deuterogattii reference strain R265, indicating that the infecting strain is derived from the highly clonal outbreak strains in the PNW. We conclude that the patient acquired the C. gattii infection during his travel to the region 3 years prior and that the infection was dormant for an extended period of time before causing disease. The patient tested positive for anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) autoantibodies, supporting earlier reports that implicate these autoantibodies as a risk factor associated with C. gattii infection.IMPORTANCE Mortality rates associated with C. gattii infections are estimated to be between 13% and 33%, depending on an individual's predisposition, and C. gattii has caused at least 39 deaths in the PNW region. There have been four other international travel cases reported in patients from Europe and Asia with travel history to the PNW, but this report describes the first North American traveler who acquired C. deuterogattii infection presenting within the United States and the first case of a C. deuterogattii outbreak infection associated with anti-GM-CSF autoantibodies. Early and accurate diagnoses are important for disease prevention and treatment and for control of infectious diseases. Continual reporting of C. deuterogattii infections is necessary to raise awareness of the ongoing outbreak in the PNW and to alert travelers and physicians to the areas of endemicity with potential risks.
Assuntos
Autoanticorpos/sangue , Doenças Autoimunes/complicações , Cryptococcus/isolamento & purificação , Fator Estimulador de Colônias de Granulócitos e Macrófagos/antagonistas & inibidores , Meningite Criptocócica/diagnóstico , Meningite Criptocócica/patologia , Doença Relacionada a Viagens , Idoso , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Costa Rica , Cryptococcus/classificação , Cryptococcus/genética , Genótipo , Humanos , Hospedeiro Imunocomprometido , Imageamento por Ressonância Magnética , Masculino , Técnicas Microbiológicas , Tipagem de Sequências Multilocus , North Carolina , Noroeste dos Estados Unidos , Sequenciamento Completo do GenomaRESUMO
OBJECTIVES: Cryptococcus gattii from the North American Northwest (NW) have higher azole MICs than do non-NW C. gattii or Cryptococcus neoformans. Since mechanisms of azole resistance in C. gattii are not known, we identified C. gattii and C. neoformans plasma membrane azole efflux pumps and characterized their properties. METHODS: The C. gattii R265 genome was searched for orthologues of known fungal azole efflux genes, expression of candidate genes was assessed by RT-PCR and the expressed genes' cDNAs were cloned and expressed in Saccharomyces cerevisiae. Azole MICs and intracellular [(3)H]fluconazole were measured in C. gattii and C. neoformans and in S. cerevisiae expressing each cDNA of interest, as was [(3)H]fluconazole uptake by post-Golgi vesicles (PGVs) isolated from S. cerevisiae sec6-4 mutants expressing each cDNA of interest. RESULTS: Intracellular [(3)H]fluconazole concentrations were inversely correlated with fluconazole MICs only in 25 NW C. gattii strains. S. cerevisiae expressing three C. gattii cDNAs (encoded by orthologues of C. neoformans AFR1 and MDR1 and the previously unstudied gene AFR2) and their C. neoformans counterparts had higher azole MICs and lower intracellular [(3)H]fluconazole concentrations than did empty-vector controls. PGVs from S. cerevisiae expressing all six Cryptococcus cDNAs also accumulated more [(3)H]fluconazole than did controls, and [(3)H]fluconazole transport by all six transporters of interest was ATP dependent and was inhibited by excess unlabelled fluconazole, voriconazole, itraconazole and posaconazole. CONCLUSIONS: We conclude that C. gattii and C. neoformans AFR1, MDR1 and AFR2 encode ABC transporters that pump multiple azoles out of S. cerevisiae cells, thereby causing azole resistance.
Assuntos
Antifúngicos/metabolismo , Azóis/metabolismo , Cryptococcus gattii/enzimologia , Cryptococcus neoformans/enzimologia , Proteínas de Membrana Transportadoras/metabolismo , Transporte Biológico Ativo , Clonagem Molecular , Criptococose/microbiologia , Cryptococcus gattii/efeitos dos fármacos , Cryptococcus gattii/isolamento & purificação , Cryptococcus gattii/metabolismo , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/isolamento & purificação , Cryptococcus neoformans/metabolismo , Expressão Gênica , Perfilação da Expressão Gênica , Humanos , Marcação por Isótopo , Testes de Sensibilidade Microbiana , Noroeste dos Estados Unidos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Análise de Sequência de DNARESUMO
The emergence of distinct populations of Cryptococcus gattii in the temperate North American Pacific Northwest (PNW) was surprising, as this species was previously thought to be confined to tropical and semitropical regions. Beyond a new habitat niche, the dominant emergent population displayed increased virulence and caused primary pulmonary disease, as opposed to the predominantly neurologic disease seen previously elsewhere. Whole-genome sequencing was performed on 118 C. gattii isolates, including the PNW subtypes and the global diversity of molecular type VGII, to better ascertain the natural source and genomic adaptations leading to the emergence of infection in the PNW. Overall, the VGII population was highly diverse, demonstrating large numbers of mutational and recombinational events; however, the three dominant subtypes from the PNW were of low diversity and were completely clonal. Although strains of VGII were found on at least five continents, all genetic subpopulations were represented or were most closely related to strains from South America. The phylogenetic data are consistent with multiple dispersal events from South America to North America and elsewhere. Numerous gene content differences were identified between the emergent clones and other VGII lineages, including genes potentially related to habitat adaptation, virulence, and pathology. Evidence was also found for possible gene introgression from Cryptococcus neoformans var. grubii that is rarely seen in global C. gattii but that was present in all PNW populations. These findings provide greater understanding of C. gattii evolution in North America and support extensive evolution in, and dispersal from, South America. Importance: Cryptococcus gattii emerged in the temperate North American Pacific Northwest (PNW) in the late 1990s. Beyond a new environmental niche, these emergent populations displayed increased virulence and resulted in a different pattern of clinical disease. In particular, severe pulmonary infections predominated in contrast to presentation with neurologic disease as seen previously elsewhere. We employed population-level whole-genome sequencing and analysis to explore the genetic relationships and gene content of the PNW C. gattii populations. We provide evidence that the PNW strains originated from South America and identified numerous genes potentially related to habitat adaptation, virulence expression, and clinical presentation. Characterization of these genetic features may lead to improved diagnostics and therapies for such fungal infections. The data indicate that there were multiple recent introductions of C. gattii into the PNW. Public health vigilance is warranted for emergence in regions where C. gattii is not thought to be endemic.
Assuntos
Cryptococcus gattii/classificação , Cryptococcus gattii/genética , Genoma Fúngico/genética , Evolução Biológica , Noroeste dos Estados Unidos , América do SulRESUMO
Over the past two decades, several fungal outbreaks have occurred, including the high-profile 'Vancouver Island' and 'Pacific Northwest' outbreaks, caused by Cryptococcus gattii, which has affected hundreds of otherwise healthy humans and animals. Over the same time period, C. gattii was the cause of several additional case clusters at localities outside of the tropical and subtropical climate zones where the species normally occurs. In every case, the causative agent belongs to a previously rare genotype of C. gattii called AFLP6/VGII, but the origin of the outbreak clades remains enigmatic. Here we used phylogenetic and recombination analyses, based on AFLP and multiple MLST datasets, and coalescence gene genealogy to demonstrate that these outbreaks have arisen from a highly-recombining C. gattii population in the native rainforest of Northern Brazil. Thus the modern virulent C. gattii AFLP6/VGII outbreak lineages derived from mating events in South America and then dispersed to temperate regions where they cause serious infections in humans and animals.
Assuntos
Criptococose/microbiologia , Cryptococcus gattii/genética , Animais , Brasil , Colúmbia Britânica/epidemiologia , Células Cultivadas , Criptococose/epidemiologia , Cryptococcus gattii/classificação , Cryptococcus gattii/patogenicidade , Surtos de Doenças , Genes Fúngicos , Humanos , Funções Verossimilhança , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Técnicas de Tipagem Micológica , Noroeste dos Estados Unidos/epidemiologia , Filogenia , Polimorfismo de Fragmento de Restrição , Árvores , Clima Tropical , VirulênciaRESUMO
Under circumstances in which area for settlement is limited, the colonization of living substrata may become a highly valuable strategy for survival of marine invertebrates. This phenomenon, termed epibiosis, results in spatially close associations between two or more living organisms. Pelamis platurus, the yellow-bellied sea snake, is the only exclusively pelagic marine snake and its propensity for foraging along ocean slicks facilitates its colonization by pelagic epibionts. Herein, we report epibionts associated with P. platurus inhabiting the waters off the northwestern Pacific coast of Costa Rica. These associations include the first records of decapod epibionts from any marine snake. Decapod epibionts were found on 18.9% of P. platurus, and size of snake (total length) had a significant positive effect on the frequency and intensity of epibiosis. We discuss the spatial and ecological mechanisms that facilitate these interactions, as well as the suite of factors that either promote or deter epibiosis and ultimately dictate the frequency and intensity of these interactions. Finally, we provide a review of marine snake epibiosis. The intention of this review is to (1) provide contemporary researchers with a single, accessible reference to all known reports of epibionts associated with marine snakes and (2) discuss what is currently known with respect to diversity of epibionts from marine snakes.