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Research into Heliconius butterflies has made a significant contribution to evolutionary biology. Here, we review our understanding of the diversification of these butterflies, covering recent advances and a vast foundation of earlier work. Whereas no single group of organisms can be sufficient for understanding life's diversity, after years of intensive study, research into Heliconius has addressed a wide variety of evolutionary questions. We first discuss evidence for widespread gene flow between Heliconius species and what this reveals about the nature of species. We then address the evolution and diversity of warning patterns, both as the target of selection and with respect to their underlying genetic basis. The identification of major genes involved in mimetic shifts, and homology at these loci between distantly related taxa, has revealed a surprising predictability in the genetic basis of evolution. In the final sections, we consider the evolution of warning patterns, and Heliconius diversity more generally, within a broader context of ecological and sexual selection. We consider how different traits and modes of selection can interact and influence the evolution of reproductive isolation.
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Adaptación Fisiológica , Evolución Biológica , Mariposas Diurnas/fisiología , Animales , Mariposas Diurnas/genética , Flujo Génico , Aislamiento Reproductivo , Selección Genética , Alas de AnimalesRESUMEN
We investigated TYRP1 as a candidate locus for the recessive, sex-linked roux (br(r)) phenotype in Japanese quail. A screen of the entire coding sequence of TYRP1 in roux and wild-type quail revealed a non-synonymous T-to-C substitution in exon 3, leading to a Phe282Ser mutation. This was perfectly associated with plumage phenotype: all roux birds were homozygous for Ser282. Co-segregation of the Phe282Ser mutation with the roux phenotype was confirmed in three br(r)/BR+ x br(r)/- backcrosses. We found no significant difference in TYRP1 expression between roux and wild-type birds, suggesting that this association is not due to linkage disequilibrium with an unknown regulatory mutation. In addition, the Phe282 amino acid appears to be of functional significance, as it is highly conserved across the vertebrates. This is the first demonstration that TYRP1 has a role in pigmentation in birds.
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Proteínas Aviares/genética , Coturnix/genética , Plumas/anatomía & histología , Oxidorreductasas/genética , Pigmentación/genética , Animales , Coturnix/anatomía & histología , Genes Recesivos , Masculino , Mutación Missense , Fenotipo , Análisis de Secuencia de ADNRESUMEN
We investigated melanocortin 1 receptor (MC1R) as a candidate locus for the Extended brown phenotype in quail, in which there is a general darkening throughout the plumage. An initial screen of variation in MC1R in Extended brown and in wild-type quails revealed two polymorphic non-synonymous sites. One of these sites, a G-to-A substitution leading to a Glu92Lys mutation, was perfectly associated with plumage phenotype; all Extended brown birds were homozygous for Lys92. Co-segregation of the Glu92Lys mutation with the Extended brown phenotype was confirmed in 24 progeny of an E/e(+) x E/e(+) cross. Glu92Lys is likely to be the causative mutation for the increased melanism in Extended brown, given that the same mutation is associated with melanic plumage in many breeds of domestic chicken, as well as in a wild passerine bird (the bananaquit, Coereba flaveola) and laboratory mice. Interestingly, the increase in melanization with the Glu92Lys mutation is less marked in quails than in most other birds and mammals. Phylogenetic results indicate that the Glu92Lys mutation has independently occurred in quail and chicken lineages.
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Proteínas Aviares/genética , Color , Coturnix/genética , Mutación Missense , Receptor de Melanocortina Tipo 1/genética , Alelos , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Proteínas Aviares/fisiología , Coturnix/anatomía & histología , Ácido Glutámico/genética , Lisina/genética , Fenotipo , Filogenia , Receptor de Melanocortina Tipo 1/fisiología , Alineación de Secuencia , Análisis de Secuencia de ProteínaRESUMEN
Clinical evaluative research are far too few. In this article, the authors describe a research process likely to favor its multiplication. They report on a case study of a process resembling a cooperative action-research led by a group of clinicians in pedopsychiatry. With the results and in the light of caracteristics of action-research, they explain why and how this group of clinicians has succeeded in establishing a research process. The lessons drawned from this experience are numerous. The authors conclude by proposing a cooperative action-research as a model that all clinicians could apply to a clinical study.
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UNLABELLED: To assess the role of postoperative analgesia on myocardial ischemia after aortic surgery, we compared intravenous patient-controlled analgesia (PCA) with thoracic epidural analgesia (TEA). One hundred twenty-four patients were prospectively randomized to the PCA or TEA group. In the TEA group, a T6-7 or T7-8 epidural catheter was inserted before the induction of general anesthesia. Within 1 h of the end of surgery, analgesia and 24-h two-channel Holter monitoring were begun. Myocardial ischemia was defined as ST segment depression > or = 1 mm, 0.06 s after the J point, and lasting for more than 1 min. In the PCA group, a bolus of morphine, 0.05 mg/kg, was given, followed by 0.02 mg/kg of morphine on demand every 10 min. Bupivacaine 0.125% and fentanyl 10 microg/mL was used in the TEA group. Analgesics were titrated to maintain a visual analog scale score < or = 3. The overall incidence of myocardial ischemia was 18.4%-18.2% for TEA and 18.6% for PCA (P = not significant). There were no differences between the groups in the total duration of ischemia per patient (22.2 +/- 119.8 min for TEA and 20.5 +/- 99 min for PCA) and the number of episodes per patient (0.69 +/- 2.1 for TEA and 1.2 +/- 4.9 for PCA). Twenty-three patients had an adverse cardiac outcome, although there were no differences between the groups. The postoperative pain control was superior with TEA. In these patients undergoing elective aortic surgery, the use of postoperative TEA did not result in a lower incidence of early myocardial ischemia compared with intravenous PCA with morphine, despite better analgesia with TEA. IMPLICATIONS: Postoperative myocardial ischemia is associated with adverse cardiac outcome. Using Holter monitoring after aortic surgery, this study shows that the use of thoracic epidural analgesia with bupivacaine and fentanyl did not result in a lower incidence of myocardial ischemia compared with intravenous patient-controlled analgesia with morphine.
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Analgesia Epidural , Analgesia Controlada por el Paciente , Aorta Abdominal/cirugía , Isquemia Miocárdica/etiología , Complicaciones Posoperatorias , Anciano , Analgésicos Opioides/administración & dosificación , Anestésicos Locales/administración & dosificación , Bupivacaína/administración & dosificación , Electrocardiografía Ambulatoria , Femenino , Fentanilo/administración & dosificación , Humanos , Masculino , Morfina/administración & dosificación , Isquemia Miocárdica/diagnóstico , Dimensión del Dolor , Dolor Postoperatorio/tratamiento farmacológico , Estudios ProspectivosRESUMEN
Changes in Ontario's political, social and economic environments have necessitated an unprecedented transformation in the health care system. The change in focus from the individual to the community now includes core units such as families, groups and communities. Visiting nurses, public health nurses and community health nurses have worked in Community Health Centres (CHCs) since 1970. However, the role of nurses working in these centres has not been clearly defined in the literature. Nor is there is a general consensus on their title. Nurse practitioners, primary care nurses or community health nurses are all used. As well, there is no existing educational program in Ontario that trains this type of nurse. This article discusses and gives examples of nurses working in community health, whose primary clinical expertise is in using community based and community development program strategies to plan health programs. These programs are specifically developed to address the health needs of the communities they serve--in this case, Toronto's francophone community. Also demonstrated are new approaches to nursing care within a community setting. From health promotion to disease prevention, from community development to research, the practice of community health nursing is complex and exciting.
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Enfermería en Salud Comunitaria , Innovación Organizacional , Enfermería en Salud Comunitaria/organización & administración , Humanos , Planificación de Atención al PacienteRESUMEN
The management of asymptomatic gallstones discovered during abdominal surgery is controversial. Should cholecystectomy be performed en passant? The authors report a 4-year survey of 109 patients with asymptomatic cholelithiasis who underwent surgery for other abdominal conditions: colorectal (31), gastric (24), vascular (20), gynecologic (21) and miscellaneous (13). Cholelithiasis was established preoperatively by ultrasonography in 52 of 55 examinations (95%). In the other 54, the gallstones were discovered at operation. Cholecystectomy was performed in 78 patients and in 31 the gallbladder was left in place. In the former group, 11 (14%) had complications, 2 being attributable to the cholecystectomy. Intraoperative cholangiograms were obtained in 43 and led to common-bile-duct explorations in 8. Common-bile-duct stones were found in seven. In the non-cholecystectomized group, three died postoperatively and three were lost to follow-up. Twelve of the remaining 25 are still asymptomatic and 13 have had symptoms: 7 underwent cholecystectomy (4 for acute cholecystitis) between 2 weeks and 11 months after the initial laparotomy. Because of the low morbidity and the relatively high number of cholecystectomies that were subsequently necessary, the authors recommend cholecystectomy en passant unless there is a specific contraindication. They also recommend ultrasonography before major gastrointestinal or vascular surgery in order to plan for cholecystectomy.