RB1 gene mutation up-date, a meta-analysis based on 932 reported mutations available in a searchable database

BACKGROUND: Retinoblastoma, a prototype of hereditary cancer, is the most common intraocular tumour in children and potential cause of blindness from therapeutic eye ablation, second tumours in germ line carrier's survivors, and even death when left untreated. The molecular scanning of RB1 in search of germ line mutations lead to the publication of more than 900 mutations whose knowledge is important for genetic counselling and the characterization of phenotypic-genotypic relationships. RESULTS: A searchable database (RBGMdb) has been constructed with 932 published RB1 mutations. The spectrum of these mutations has been analyzed with the following results: 1) the retinoblastoma protein is frequently inactivated by deletions and nonsense mutations while missense mutations are the main inactivating event in most genetic diseases. 2) Near 40% of RB1 gene mutations are recurrent and gather in sixteen hot points, including twelve nonsense, two missense and three splicing mutations. The remainder mutations are scattered along RB1, being most frequent in exons 9, 10, 14, 17, 18, 20, and 23. 3) The analysis of RB1 mutations by country of origin of the patients identifies two groups in which the incidence of nonsense and splicing mutations show differences extremely significant, and suggest the involvement of predisposing ethnic backgrounds. 4) A significant association between late age at diagnosis and splicing mutations in bilateral retinoblastoma patients suggests the occurrence of a delayed-onset genotype. 5) Most of the reported mutations in low-penetrance families fall in three groups: a) Mutations in regulatory sequences at the promoter resulting in low expression of a normal Rb; b) Missense and in-frame deletions affecting non-essential sequence motifs which result in a partial inactivation of Rb functions; c) Splicing mutations leading to the reduction of normal mRNA splicing or to alternative splicing involving either true oncogenic or defective (weak) alleles. CONCLUSION: The analysis of RB1 gene mutations logged in the RBGMdb has shown relevant phenotype-genotype relationships and provided working hypothesis to ascertain mechanisms linking certain mutations to ethnicity, delayed onset of the disease and low-penetrance. Gene profiling of tumors will help to clarify the genetic background linked to ethnicity and variable expressivity or delayed onset phenotypes

Efficacy of Nanosilica Coatings in Calcium Looping Reactors

Nanosilica coatings are considered a simple physical treatment to alleviate the effect of cohesion on powder flowability. In limestone powders, these coatings buffer the rise in cohesion at high temperatures. Here, we investigate the role of particle size in the efficiency (and resilience) of these layers. To this end, this work examines a series of four limestone powders with very sharp particle size distributions: average particle size ranged from 15 to 60 μm. All the samples were treated with nanosilica at different concentrations from 0 to 0.82 wt %. Powders were subjected to short- and long-term storage conditions in calcium looping based systems: temperatures that vary from 25 to 500 °C and moderate consolidations (up to 2 kPa). Experiments monitored powder cohesion and its ability to flow by tracking the tensile strength of different samples while fluidized freely. Fluidization profiles were also used to infer variation in packings and the internal friction of the powder bed. Interestingly, for particle sizes below 50 μm, the nanosilica treatment mitigated cohesion significantly─the more nanosilica content, the better the flowability performance. However, at high temperatures, the efficiency of nanosilica coatings declined in 60 μm samples. Scanning electron microscopy images confirmed that only 60 μm samples presented surfaces barely coated after the experiments. In conclusion, nanosilica coatings on limestone are not stable beyond the 50 μm threshold. This is a critical finding for thermochemical systems based on the calcium looping process, since larger particles can still exhibit a significant degree of cohesion at high temperatures

Looking for Self-Organized Critical Behavior in Avalanches of Slightly Cohesive Powders

We report results from a statistical analysis of avalanches of cohesive powders in a slowly rotated drum. Interparticle adhesion, which diminishes the effect of inertia and whose magnitude strongly fluctuates in a local scale, makes avalanches in slightly cohesive powders eligible for displaying self-organized criticality. However, the results show that avalanche sizes, time interval between avalanches, and maximum stable angle do not follow a power-law distribution. Otherwise, these parameters scale with powder cohesiveness

Revista de Vertebrados de la Estación Biológica de Doñana

Ritmo diario de actividad social en (Gambusia affinis)Sobre la herpetofauna de la Sierra de Estrella (Portugal) con especial referencia a Coronella austriaca austriaca y Vipera latastiNuevos datos sobre la distribución geográfica de los anfibios y reptiles ibéricosBiogeografía en la evolución de un grupo de formas de Coluber en el Paleártico OccidentalDatos sobre la alimentación de ofidiosEstructura de las galerías de nidificación del Abejaruco (Merops apiaster) en DoñanaComportamiento de la Perdiz Moruna ( Alectoris barbara) en cautividadEl paso otoñal de Sylvia borin y Sylvia conmmunis en la Reserva de DoñanaSobre el lirón Gris (Glis glis pyrenaicus Cabrera, 1908) en España.Sobre alimentación y biología de la Gineta (Genetta genetta lo) en EspañaEliomys quercinus valverdei, un nuevo lirón careto del noroeste de la Península IbéricaPeer reviewe

IAA : Información y actualidad astronómica (49)

Sumario : El método Doppler y la estrella Próxima Centauri.-- Las estrellas ¡laten!.-- Dinámica de los sistemas planetarios.-- FRBs: fuentes transitorias sin un origen claro.-- DECONSTRUCCIÓN Y otros ENSAYOS. El proyecto CALIFA.-- CIENCIA EN HISTORIAS...Maria Assumpció Catalá i Poch.-- EL “MOBY DICK” DE... Emilio J. Alfaro (IAA).-- ACTUALIDAD.-- ENTRE BASTIDORES...Brexit, ¿ejemplo de incultura científica?.-- SALA LIMPIA.-- CIENCIA: PILARES E INCERTIDUMBRES. Puntos brillantes en la superficie del Sol.La página web de esta revista ha sido financiada por la Sociedad Española de Astronomía (SEA).N