Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
2.
Heredity (Edinb) ; 96(2): 175-84, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16369575

RESUMEN

Hybridisation is a potent force in plant evolution, although there are few reported examples of stabilised species that have been created through homoploid hybridisation. We focus here on Quercus afares, an endemic North African species that combines morphological, physiological and ecological traits of both Q. suber and Q. canariensis, two phylogenetically distant species. These two species are sympatric with Q. afares over most of its distribution. We studied two Q. afares populations (one from Algeria and one from Tunisia), as well as several populations of both Q. suber and Q. canariensis sampled both within and outside areas where these species overlap with Q. afares. A genetic analysis was conducted using both nuclear (allozymes) and chloroplastic markers, which shows that Q. afares originates from a Q. suber x Q. canariensis hybridisation. At most loci, Q. afares predominantly possesses alleles from Q. suber, suggesting that the initial cross between Q. suber and Q. canariensis was followed by backcrossing with Q. suber. Other hypotheses that can account for this result, including genetic drift, gene silencing, gene conversion and selection, are discussed. A single Q. suber chlorotype was detected, and all Q. afares individuals displayed this chlorotype, indicating that Q. suber was the maternal parent. Q. afares is genetically, morphologically and ecologically differentiated from its parental species, and can therefore be considered as a stabilised hybrid species.


Asunto(s)
Marcadores Genéticos , Genética de Población , Hibridación Genética , Quercus/genética , África del Norte , Núcleo Celular/genética , Cloroplastos/genética , Citoplasma/genética , Enzimas/genética , Modelos Genéticos , Polimorfismo Genético , Polimorfismo de Longitud del Fragmento de Restricción
3.
Heredity (Edinb) ; 92(4): 343-51, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-14985782

RESUMEN

As a result of the early domestication and extensive cultivation of the olive tree throughout the Mediterranean Basin, the wild-looking forms of olive (oleasters) presently observed constitute a complex, potentially ranging from wild to feral forms. Allozyme variation was analysed at 10 loci in 31 large and 44 small oleaster populations distributed in various habitats of the Mediterranean Basin and in two populations of the wild subspecies Olea europaea subsp (ssp) guanchica, endemic to the Canary islands and closely related to oleasters. At eight polymorphic loci, 25 alleles were identified. Genetic evidence that nondomesticated oleasters still survive locally was provided by the occurrence of four and one alleles shared exclusively by the eight western and two eastern oleaster populations, respectively, which were collected in forests potentially containing genuinely wild forms according to environmental, historical and demographic criteria. As reported previously from cytoplasmic and RAPDs analysis, substantial genetic differentiation was observed between the eastern oleaster populations genetically close to most olive clones cultivated in the Mediterranean Basin, and the western populations that are related to the wild Canarian populations. In addition, the occurrence of significantly lower heterozygosity in cultivated olive than in oleasters, whatever their origin, suggests that intensive selection involving inbreeding has taken place under cultivation to obtain particular characteristics in the olive cultivars.


Asunto(s)
Variación Genética , Olea/genética , Enzimas/genética , Frecuencia de los Genes , Genética de Población , Genotipo , Región Mediterránea , Olea/enzimología
4.
Minerva Chir ; 46(12): 699-702, 1991 Jun 30.
Artículo en Italiano | MEDLINE | ID: mdl-1961595

RESUMEN

A case of blunt liver trauma with massive peritoneal hemorrhage due to a major intraparenchymal injury with active bleeding from a posterior tributary of the right hepatic vein is reported. The treatment consisted of resectional debridement of the VII and VI segment of Couinaud and hemostasis was possible in total vascular exclusion without an intracaval shunt.


Asunto(s)
Contusiones , Hígado/lesiones , Accidentes de Tránsito , Adulto , Hemoperitoneo/etiología , Humanos , Hígado/cirugía , Masculino
8.
Minerva Chir ; 44(21): 2255-8, 1989 Nov 15.
Artículo en Italiano | MEDLINE | ID: mdl-2533972

RESUMEN

The treatment of several cases of spontaneous haematomas of the abdominal wall triggers some remarks on clinical aspects of the condition.


Asunto(s)
Músculos Abdominales , Hematoma/etiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Musculares/etiología
20.
Minerva Chir ; 35(18): 1393-400, 1980 Sep 30.
Artículo en Italiano | MEDLINE | ID: mdl-7231727

RESUMEN

Five patients were admitted to the 1st and 2nd Division of General Surgery of Soronno Hospital between July '75 and September '78 suffering from fistulas complicating colon diverticulosis. A sixth patient, operated on for diverticulitis, developed a stercoraceous cutaneous fistula in the postoperative period. This was closed by conservative therapy. A woman patient suffering from colo-enteric fistula, was not operated because she refused. In all operated patients, broad resection of the sigmoid was carried out with end-to-end anastomosis. In three cases a caecostomy was formed to protect the anastomosis. All operated patients were treated preoperatively with laxatives, clysters and intestinal antibiotics, prevalently paromomycin and in one case neomycin plus base erythromycin. Surgery led to the cure of all patients treated.


Asunto(s)
Enfermedades del Colon/etiología , Divertículo del Colon/complicaciones , Fístula Intestinal/etiología , Fístula de la Vejiga Urinaria/etiología , Anciano , Diverticulitis del Colon/complicaciones , Femenino , Humanos , Fístula Intestinal/cirugía , Masculino , Persona de Mediana Edad , Fístula de la Vejiga Urinaria/cirugía
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA