Cockroaches are as of yet the only animal group with a fossil record complete enough to reveal the quantitative changes of individual intraspecific variability over a considerable interval of time (320 Ma). Ninety three individuals of the first known nocturnal and/or crepuscular carnivorous cockroach Divocina noci gen. et sp. nov. of the family Raphidiomimidae (Middle Jurassic Jiulongshan Formation; Daohugou, Inner Mongolia Province, China) now reveal the comparison of variability and symmetry of right and left wings separately. The sole significant difference is the more pronounced variability of the anterior part (involved in flight) of the leftforewings, which may be the consequence of the superposition of the left wing and its protective function associated with vein reorganizations. The overall variability coefficient of the number of veins in the distal forewing margin and total number of veins at the margin (CVtotal= 7.65; hindwing CVtotal= 7.54) was low when compared with the wing centre, which together with wing symmetry suggest comparatively good flight. The total number of veins is in perfect congruence with the variability of Fortiblatta cuspicolor Liang, Vrsansky and Ren, 2009- another raphidiomimidfrom the same locality (CVtotal = 7.70; hind wing CVtotal= 7.33). In spite of nearly identical overall variability, data for respective veins vary up to 30%. Different also is the mean asymmetry expressed as the difference in the number ofveins meeting at the margin between the respective sides (4.7% of Divocina vs 7.0% of Fortiblatta cuspicolor). Itfollows that the general variability is to a large extent independent of variability of respective characters as well as of symmetry values.

Las cucarachas son, hasta el momento, el único grupo animal con un registro fósil suficientemente completo para revelar los cambios cuantitativos de la variabilidad intraespecífica individual, a lo largo de un considerable intervalo de tiempo (320Ma). Noventa y tres individuos de la primera cucaracha nocturna carnívora y/o crepuscular, Divocina noci gen. et sp. nov. de la familia Raphidiomimidae (Formación Jiulongshan del Jurásico Medio; Daohugou, Provincia de Mongolia Interna, China), revelan ahora la comparación de la variabilidad y de las alas derecha e izquierda, por separado. La única diferencia significativa es la más pronunciada variabilidad de la porción anterior (involucrada en el vuelo) de las alas anteriores izquierdas, lo cual puede ser consecuencia de la superposición del ala izquierda y su función protectora, asociada a la reorganización de las venas. El coeficiente general de variabilidad del número de venas en el margen distal del ala anterior y el número total de venas en el margen (CVtotal= 7.65; ala posterior CVtotal= 7.54) fue bajo en comparación con el centro del ala lo que, aunado a la simetría del ala, sugiere, comparativamente, una adecuada capacidad de vuelo. El número total de venas es perfectamente congruente con la variabilidad de Fortiblatta cuspicolor Liang, Vrsansky y Ren, 2009- otro rafidiomímido de la misma localidad (CVtotal = 7.70; ala posterior CVtotal= 7.33). A pesar de la casi idéntica variabilidad general, los datos para las venas respectivas varían hasta en el 30%. También hay variación en la asimetría media, expresada como la diferencia en el número de venas que llegan al margen entre los lados respectivos (4.7% de Divocina vs 7.0% de Fortiblatta cuspicolor). Se concluye que la variabilidad general es en gran medida, independiente de la variabilidad de los caracteres respectivos, así como de los valores de simetría.

Many patients with hilar cholangiocarcinoma (HC) have a poor prognosis. Snail, a transcription factor and E-cadherin repressor, is a novel prognostic factor in many cancers. The aim of this study was to evaluate the relationship between snail and E-cadherin protein expression and the prognostic significance of snail expression in HC. We examined the protein expression of snail and E-cadherin in HC tissues from 47 patients (22 males and 25 females, mean age 61.2 years) using immunohistochemistry and RT-PCR. Proliferation rate was also evaluated in the same cases by the MIB1 index. High, low and negative snail protein expression was recorded in 18 (38%), 17 (36%), and 12 (26%) cases, respectively, and 40.4% (19/47) cases showed reduced E-cadherin protein expression in HC samples. No significant correlation was found between snail and E-cadherin protein expression levels (P = 0.056). No significant correlation was found between snail protein expression levels and gender, age, tumor grade, vascular or perineural invasion, nodal metastasis and invasion, or proliferative index. Cancer samples with positive snail protein expression were associated with poor survival compared with the negative expresser groups. Kaplan-Meier curves comparing different snail protein expression levels to survival showed highly significant separation (P < 0.0001, log-rank test). With multivariate analysis, only snail protein expression among all parameters was found to influence survival (P = 0.0003). We suggest that snail expression levels can predict poor survival regardless of pathological features and tumor proliferation. Immunohistochemical detection of snail protein expression levels in routine sections may provide the first biological prognostic marker.