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Climate changes and associated glacial and interglacial cycles during the Quaternary strongly influenced the evolutionary history of countless number of species. Subtropical highland grasslands (SHG) in southern South America constitute a distinct vegetation type with high diversity and endemism rates. The most recent common ancestor of the genus Petunia (Solanaceae) originated in lowland grasslands, and some lineages secondarily migrated to SHG. Here, we describe the evolutionary history of an SHG species, P. altiplana, distributed throughout a wide area in a river-fragmented landscape. We used plastid and nuclear markers to evaluate the role of the Pelotas River and Quaternary climate cycles over the genetic structure and historical demography of this species based on a phylogeographical approach. We found moderate population expansions during the last 25 kyr, with a more recent (c. 1.6 kya) divergence between two groups of populations from opposite river margins, possibly caused by the expansion of the Araucaria Forest along the river valley, effectively isolating distinct grassland patches. [ABSTRACT FROM AUTHOR]

South America is a subcontinent with 393 million inhabitants with widely distinct countries and diverse ethnicities, cultures, political and societal organizations. The epidemiological transition that accompanied the technological and demographic evolution is happening in South America and leading to a rise in the incidence of neurodegenerative and cardiovascular diseases that now coexist with the still high burden of infectious diseases. South America is also quite heterogeneous regarding the existence of systems of care for the various neurological emergencies, with some countries having well-organized systems for some diseases, while others have no plan of action for the care of patients with acute neurological symptoms. In this article, we discuss the existing systems of care in different countries of South America for the treatment of neurological emergencies, mainly stroke, status epilepticus, and traumatic brain injury. We also will address existing gaps between the current systems and recommendations from the literature to improve the management of such emergencies, as well as strategies on how to solve these disparities. [ABSTRACT FROM AUTHOR]

Understanding the spatiotemporal distribution of genetic variation and the ways in which this distribution is connected to the ecological context of natural populations is fundamental for understanding the nature and mode of intraspecific and, ultimately, interspecific differentiation. The Petunia axillaris complex is endemic to the grasslands of southern South America and includes three subspecies: P. a. axillaris, P. a. parodii and P. a. subandina. These subspecies are traditionally delimited based on both geography and floral morphology, although the latter is highly variable. Here, we determined the patterns of genetic (nuclear and cp DNA), morphological and ecological (bioclimatic) variation of a large number of P. axillaris populations and found that they are mostly coincident with subspecies delimitation. The nuclear data suggest that the subspecies are likely independent evolutionary units, and their morphological differences may be associated with local adaptations to diverse climatic and/or edaphic conditions and population isolation. The demographic dynamics over time estimated by skyline plot analyses showed different patterns for each subspecies in the last 100 000 years, which is compatible with a divergence time between 35 000 and 107 000 years ago between P. a. axillaris and P. a. parodii, as estimated with the IMa program. Coalescent simulation tests using Approximate Bayesian Computation do not support previous suggestions of extensive gene flow between P. a. axillaris and P. a. parodii in their contact zone. [ABSTRACT FROM AUTHOR]