(Micro)evolutionary changes and the evolutionary potential of bird migration

Seasonal migration is the yearly long-distance movement of individuals between their breeding and wintering grounds. Individuals from nearly every animal group exhibit this behavior, but probably the most iconic migration is carried out by birds, from the classic V-shape formation of geese on migration to the amazing nonstop long-distance flights undertaken by Arctic Terns Sterna paradisaea. In this chapter, we discuss how seasonal migration has shaped the field of evolution. First, this behavior is known to turn on and off quite rapidly, but controversy remains concerning where this behavior first evolved geographically and whether the ancestral state was sedentary or migratory (Fig. 7.1d, e). We review recent work using new analytical techniques to provide insight into this topic. Second, it is widely accepted that there is a large genetic basis to this trait, especially in groups like songbirds that migrate alone and at night precluding any opportunity for learning. Key hypotheses on this topic include shared genetic variation used by different populations to migrate and only few genes being involved in its control. We summarize recent work using new techniques for both phenotype and genotype characterization to evaluate and challenge these hypotheses. Finally, one topic that has received less attention is the role these differences in migratory phenotype could play in the process of speciation. Specifically, many populations breed next to one another but take drastically different routes on migration (Fig. 7.2). This difference could play an important role in reducing gene flow between populations, but our inability to track most birds on migration has so far precluded evaluations of this hypothesis. The advent of new tracking techniques means we can track many more birds with increasing accuracy on migration, and this work has provided important insight into migration's role in speciation that we will review here

Thrombotic obstruction of the central venous catheter in patients undergoing hematopoietic stem cell transplantation Obstrucción trombótica del catéter venoso central en pacientes sometidos al trasplante de células-tronco hematopoyéticas Obstrução trombótica do cateter venoso central em pacientes submetidos ao transplante de células-tronco hematopoéticas

This is an integrative literature review with the aim of summarizing the prevention measures and treatment of thrombotic obstruction of long-term semi-implanted central venous catheters, in patients undergoing hematopoietic stem cell transplantation. The sample consisted of seven studies, being two randomized controlled clinical trials, three cohort studies and two case series. Regarding the prevention measures, one single study demonstrated effectiveness, which was a cohort study on the oral use of warfarin. In relation to the treatment measures, three studies evidenced effectiveness, one highlighted the efficacy of streptokinase or urokinase, one demonstrated the benefit of using low-molecular-weight heparin and the other treated the obstruction with heparin or urokinase. Catheter patency research shows a restricted evolution that does not follow the evolution of transplantations, mainly regarding nursing care.<br>Se trata de una revisión integradora de la literatura con objeto de sintetizar las medidas de prevención y tratamiento de obstrucción trombótica del catéter venosos central de larga permanencia y semi-implantado, en pacientes sometidos al trasplante de células-tronco hematopoyéticas. La muestra abarcó a siete estudios: dos ensayos clínicos controlados aleatorizados, tres estudios de cohorte y dos series de casos. Respecto a las medidas de prevención, fue identificado un único estudio efectivo, uno cohorte sobre el uso de la warfarina oral. Sobre las medidas de tratamiento, tres estudios evidenciaron efectividad, uno apuntó la eficacia de la estreptoquinasa o uroquinasa, otro mostró beneficio del uso de heparina de bajo peso molecular y otro trató la obstrucción con heparina o uroquinasa. Se observa que la evolución de la investigación sobre la permeabilidad del catéter fue limitada, no acompañando la evolución del trasplante, principalmente respecto a los cuidados de enfermería.<br>Trata-se de revisão integrativa da literatura, cujo objetivo foi sintetizar as medidas de prevenção e tratamento da obstrução trombótica no cateter venoso central de longa permanência e semi-implantado, em pacientes submetidos ao transplante de células-tronco hematopoéticas. A amostra foi constituída por sete estudos, sendo dois ensaios clínicos controlados randomizados, três estudos de coorte e duas séries de casos. Quanto às medidas de prevenção, um único estudo que se mostrou efetivo abordando pesquisa de coorte sobre o uso da varfarina oral. Em relação às medidas de tratamento, três estudos evidenciaram efetividade: um apontou a eficácia da estreptoquinase ou uroquinase, outro estudo mostrou benefício no uso de heparina de baixo peso molecular e outro tratou a obstrução com heparina ou uroquinase. Nota-se que a evolução da pesquisa referente à perviedade do cateter foi restrita, não acompanhando a evolução do transplante, principalmente no que tange aos cuidados de enfermagem