Sarcomas are one of the rarest cancers, occurring in less than 1% of all adult malignancies. Spindle cell sarcomas are one subset of soft tissue sarcomas that are even less commonly reported in the literature due to the scarcity of cases, especially with the presence of brain metastases. We present a case of an adult male who presented with non-specific exertional dyspnea and chest pain, which was found to have spindle cell sarcoma with cerebellar metastasis.
View Article and Find Full Text PDFThe Scaled Antbird Drymophila squamata is a suboscine passerine endemic to the Atlantic Forest of eastern Brazil. Two subspecies, putatively diagnosed by the presence/absence of white spots on the crown, have traditionally been recognized: the nominate, ranging from Pernambuco to Bahia in northeastern Brazil, and D. squamata stictocorypha, from Minas Gerais to Santa Catarina in southeastern and southern Brazil.
View Article and Find Full Text PDFHeredity (Edinb)
February 2024
Investigating the impact of landscape features on patterns of genetic variation is crucial to understand spatially dependent evolutionary processes. Here, we assess the population genomic variation of two bird species (Conopophaga cearae and Sclerurus cearensis) through the Caatinga moist forest enclaves in northeastern Brazil. To infer the evolutionary dynamics of bird populations through the Late Quaternary, we used genome-wide polymorphism data obtained from double-digestion restriction-site-associated DNA sequencing (ddRADseq), and integrated population structure analyses, historical demography models, paleodistribution modeling, and landscape genetics analyses.
View Article and Find Full Text PDFIn this review, we aim to update readers about the most recent studies on common pharmaceuticals and their association with pancreatic cancer risk. The use of prophylactic aspirin, metformin, beta-blockers, and statins has been studied in the past but showed inconclusive results in the reduction of pancreatic cancer incidence. However, in recent studies, these medications along with combination therapy of aspirin and metformin were found to have a more significant association with decreasing risk.
View Article and Find Full Text PDFTropical mountains hold more biodiversity than their temperate counterparts, and this disparity is often associated with the latitudinal climatic gradient. However, distinguishing the impact of latitude versus the background effects of species history and traits is challenging due to the evolutionary distance between tropical and temperate assemblages. Here, we test whether microevolutionary processes are linked to environmental variation across a sharp latitudinal transition in 21 montane birds of the southern Atlantic Forest in Brazil.
View Article and Find Full Text PDFThe role of historical factors in establishing patterns of diversity in tropical mountains is of interest to understand the buildup of megadiverse biotas. In these regions, the historical processes of range fragmentation and contraction followed by dispersal are thought to be mediated by the interplay between rugged relief (complex topography) and climate fluctuations and likely explain most of the dynamics of diversification in plants and animals. Although empirical studies addressing the interaction between climate and topography have provided invaluable insights into population divergence and speciation patterns in tropical montane organisms, a more detailed and robust test of such processes in an explicit spatio-temporal framework is still lacking.
View Article and Find Full Text PDFIn March 2013 it was reported by the World Health Organization (WHO) the first cases of human infections with avian influenza virus A (H7N9). From 2013 to December 2019, 1568 cases have been reported with 616 deaths. H7N9 infection has been associated with high morbidity and mortality rates, and vaccination is currently the most effective way to prevent infections and consequently flu-related severe illness.
View Article and Find Full Text PDFA set of 16 microsatellite markers was characterized for Lear's macaw (Anodorhynchus leari) using DNA samples from captive individuals. Extending this molecular toolkit, including the use of samples from wild individuals, is expected to provide the required power of resolution for pedigree inference of both wild and captive individuals, and could support research on the genetic structure of wild populations. We characterize a set of 15 microsatellite markers optimized for the Lear's macaw, developed from a microsatellite-enriched library in a three-step procedure.
View Article and Find Full Text PDFComparative phylogeography is a powerful approach to investigate the role of historical and environmental processes in the evolution of biodiversity within a region. In this regard, comparative studies of species with similar habitat preferences are valuable to reduce the confounding influence of habitat association when interpreting phylogeographic patterns. In the Atlantic Forest of South America, phylogeographic studies of highland and lowland species have shown distinct population structure patterns so far, suggesting that such species have responded differently to Pleistocene glacial cycles.
View Article and Find Full Text PDFThe central Andean rainforests and the Atlantic Forest are two similar biomes that are fully isolated by xerophytic and open-vegetation regions (the Chaco and Cerrado, respectively). Even though there is evidence suggesting that these rainforests have been connected in the past, their dynamics of connection, the geographic areas that bridged these regions, and the biological processes that have promoted diversification between them remain to be studied. In this research, we used three passerine species (Poecilotriccus plumbeiceps, Phylloscartes ventralis and Cacicus chrysopterus) as models to address whether the Andean and the Atlantic forests have acted as a refugia system (macrorefugia), and to evaluate biogeographic hypotheses of diversification and connection between them.
View Article and Find Full Text PDFIn order to gain insights into the biogeographic processes underlying biotic diversification in the Atlantic Forest (AF), we used a multi-locus approach to examine the evolutionary history of the White-shouldered Fire-eye (Pyriglena leucoptera) and the Fringe-backed Fire-eye (Pyriglena atra), two parapatric sister species endemic to the AF. We sequenced one mitochondrial, three Z chromosome-linked and three anonymous markers of 556 individuals from 66 localities. We recovered four lineages throughout the AF: P.
View Article and Find Full Text PDFMontane organisms responded to Quaternary climate change by tracking suitable habitat along elevational gradients. However, it is unclear whether these past climatic dynamics generated predictable patterns of genetic diversity in co-occurring montane taxa. To test if the genetic variation is associated with historical changes in the elevational distribution of montane habitats, we integrated paleoclimatic data and a model selection approach for testing the demographic history of five co-distributed bird species occurring in the southern Atlantic Forest sky islands.
View Article and Find Full Text PDFMigratory animals move up to thousands of kilometers every year [1]. Losses of migration (i.e.
View Article and Find Full Text PDFThe role of climate as a speciation driver in the Amazon has long been discussed. Phylogeographic studies have failed to recover synchronous demographic responses across taxa, although recent evidence supports the interaction between rivers and climate in promoting speciation. Most studies, however, are biased toward upland forest organisms, while other habitats are poorly explored and could hold valuable information about major historical processes.
View Article and Find Full Text PDFDendrocincla woodcreepers are ant-following birds widespread throughout tropical America. Species in the genus are widely distributed and show little phenotypic variation. Notwithstanding, several subspecies have been described, but the validity of some of these taxa and the boundaries among them have been discussed for decades.
View Article and Find Full Text PDFCombining phylogeographic approaches and hybrid zone inference in a single framework is a robust way to depict respectively the biogeographic history of lineages and the evolutionary processes responsible for speciation. Here, we studied the spatiotemporal patterns of diversification and characterize the hybrid zone between two Atlantic Forest spinetails (Synallaxis ruficapilla and Synallaxis cinerea) using mitochondrial DNA and nuclear (autosomal and Z-linked) genes. We consistently recovered divergence between and within the two species during the late Pliocene and Pleistocene using an isolation with migration model.
View Article and Find Full Text PDFWe evaluated whether the Andean and the Atlantic forests acted as refugia during the Quaternary, and tested biogeographic hypotheses about the regions involved in the connectivity between those biomes (through the Chaco or the Cerrado). To achieve these goals we selected the Buff-browed Foliage-gleaner Syndactyla rufosuperciliata (Aves, Furnariidae) as a study system, a taxon distributed between the Andean and Atlantic forest. We first explored the historical connectivity between regions through niche modeling.
View Article and Find Full Text PDFParrots are one of the most distinct and intriguing groups of birds, with highly expanded brains [1], highly developed cognitive [2] and vocal communication [3] skills, and a long lifespan compared to other similar-sized birds [4]. Yet the genetic basis of these traits remains largely unidentified. To address this question, we have generated a high-coverage, annotated assembly of the genome of the blue-fronted Amazon (Amazona aestiva) and carried out extensive comparative analyses with 30 other avian species, including 4 additional parrots.
View Article and Find Full Text PDFAmazon parrots are long-lived birds with highly developed cognitive skills, including vocal learning. Several parrot mitogenomes have been sequenced, but important aspects of their organization and evolution are not fully understood or have limited experimental support. The main aim of the present study was to describe the mitogenome of the blue-fronted Amazon, Amazona aestiva, and compare it to other mitogenomes from the genus Amazona and the order Psittaciformes.
View Article and Find Full Text PDFThe central Andean rainforests and the Atlantic Forest are separated by the Chaco and the Cerrado domains. Despite this isolation, diverse evidence suggests that these rainforests have been connected in the past. However, little is known about the timing and geographic positions of these connections, as well as their effects on diversification of species.
View Article and Find Full Text PDFBefore populations become independent evolutionary lineages, the effects of micro evolutionary processes tend to generate complex scenarios of diversification that may affect phylogenetic reconstruction. Not accounting for gene flow in species tree estimates can directly impact topology, effective population sizes and branch lengths, and the resulting estimation errors are still poorly understood in wild populations. In this study, we used an integrative approach, including sequence capture of ultra-conserved elements (UCEs), mtDNA Sanger sequencing and morphological data to investigate species limits and phylogenetic relationships in face of gene flow in an Amazonian endemic species (Myrmoborus lugubris: Aves).
View Article and Find Full Text PDFThe Atlantic Forest is separated from the Andean tropical forest by dry and open vegetation biomes (Chaco and Cerrado). Despite this isolation, both rainforests share closely related lineages, which suggest a past connection. This connection could have been important for forest taxa evolution.
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