Interacciones entre Geomorfología e intervención humana sobre la composición del matorral en la cuenca del río Guadalupejo (Extremadura)

19 páginas, 4 figuras, 2 tablas, 30 referencias.[EN]: The relationships between geomorphology and scrub composition and the effects of management practices on them bave been studied in Guadalupejo River bassin (W. Spain). The mediterranean climate has an annual precipitation of 803 mm and average temperature of 15ºC. Lithology is dominated by slates with surface deposits of conglomerates and clay. The area was subdivided on homogeneous units with geomorphic and management criteria in order to sample vegetation. Pressence/absence and abundance (as cover) of 30 scrub species was recorded on 56 10 x 10m. plots. Cluster analysis was used to classify vegetation types. Main type divisions are related primarily to human management and secondarily to geomorphic and physicochemical characters of substrate. Total plant cover, specific species contribution and pioneer/mature species ratio a1l are influenced by the predominant factors mentioned above. The relative weight of physical, biotic and human factors in determining vegetation composition is discussed. It is proposed that all processes involved may fall into three main categories: limitation, organisation and disruption.[ES]: Se han estudiado las relaciones entre geomorfología y composición del matorral mediterráneo y el efecto de la intervención humana sobre las mismas. Se escogió la parte baja de la cuenca del río Guadalupejo, afluente del Guadiana por su margen derecha. El clima es de tipo mediterráneo (803 mm; y 15°) y el sustrato está formado por pizarras, conglomerados y arcillas. Se sectorizó el área con criterios geomorfológicos y de tipos de intervención humana como base para el muestreo estratificado de la vegetación; se registró la presencia de las especies y se midió su cobertura en 36 parcelas de 10 x 10 m. La Matriz de datos cualitativos se analizó mediante técnicas de análisis de clasificación aglomerativa, para determinar tipos de matorral. Las principales diferencias entre los tipos de matorral se relacionan en primer lugar con la modalidad de intervención humana y en segundo con la geomorfología y composición fisicoquímica del sustrato. La cobertura total del matorral, importancia relativa de las distintas especies y relación entre coberturas especies pioneras/especies maduras también se relacionan con estos factores predominantes. Se discute la importancia de los procesos físicos, bióticos y humanos en la determinación de la composición de la vegetación, considerándolos agrupados en 3 grupos de procesos, limitativos, organizativos y desorganizativos.Peer reviewe

A new potential oncogenic mutation in the FERM domain of JAK2 in BCR-ABL1 negative and V617F negative chronic myeloproliferative neoplasms (CMPNs) revealed by a comprehensive screening of 17 tyrosine kinase coding genes

BCR/ABL1-negative chronic myeloproliferative neoplasms (CMPNs) are a heterogeneous group of clonal hematological malignancies. Over recent years, some genetic events in tyrosine kinase (TK) genes have been described as causal events of these diseases. To identify new genetic aberrations underlying these diseases, we used denaturing high performance liquid chromatography and fluorescence in situ hybridization (FISH) to analyze 17 genes from two receptor-TK families (III and IV) and from three cytoplasmic-TK families (Syk, Abl, and Jak) on samples from 44 BCR/ABL1-negative and JAK2(V617F)-negative CMPN patients with different clinical phenotypes. Although screening by FISH did not reveal novel chromosomal aberrations, several sequence changes were detected. None of them were frequent events, but we identified a new potential activating mutation in the FERM domain of JAK2(R340Q). None of the germline JAK2(V617F) single-nucleotide polymorphisms detected differed in distribution between patients and control subjects. In summary, data presented here show that these genes are not frequently mutated or rearranged in CMPNs, suggesting that molecular events causing these disorders must be located in other genes