Gymnorhadinorhynchus gen. n. is proposed to accommodate its type species, G. decapteri sp. n., a parasite of the marine fish Decapterus punctatus (Cuvier), caught from the coastal waters of Brazil. Gymnorhadinorhynchus decapteri sp. n. was morphologically most similar to species of two echinorhynchid families, the Rhadinorhynchidae and the Cavisomidae, particularly in the structure of the proboscis and the absence of somatic spines, respectively. This combination of morphological features made it difficult to assign our specimen to an extant family of the Acanthocephala. Therefore, in order to clarify the systematic placement of G. decapteri, a molecular phylogenetic analysis was performed based on the SSU and LSU rDNA and the mitochondrial cox1 gene sequences obtained for the new taxon and other 26 acanthocephalan species. The results of parsimony and maximum likelihood analyses, using individual, combined and concatenated sequence data, consistently indicate that the specimens do not belong to any known family of the Echinorhynchida. Rather, G. decapteri represents a distinct lineage that is closely related to the Transvenidae, but distantly related to both the Rhadinorhynchidae and the Cavisomidae. Gymnorhadinorhynchidae fam. n. is therefore erected. This newly described family can be distinguished from other families of Echinorhynchida by the combination of the following morphological characters: a proboscis cylindrical with 10 rows of 22-26 hooks, dorsoventral differences in proboscis hooks, basal hooks forming a ring and being abruptly larger than anterior hooks, absence of trunk spines and presence of four tubular cement glands. This combination, in addition to several molecular autapomorphies, justifies the erection of a new genus, Gymnorhadinorhynchus gen. n., in order to accommodate this new species.
We consider the Sturm-Liouville problem with symmetric boundary conditions and an integral condition. We estimate the first eigenvalue λ1 of this problem for different values of the parameters.
Changes in the activity of ribulose 1,5-bisphosphate carboxylase (RuBPC), soluble proteins and l‘*C02 fixation were studied in Vigna sinen.sis L. seedlings grovvn under nonnal and ultraviolet-B (UV-B) enhanced radiations at 10, 20, 30 and 40 ^C. The seedlings grown under nonnal radiation showed a progressive increase in enzyme activity, soluble protein and *‘*C02 fixation with an increase in temperature from 20 to 40 oC, while seedlings grown under UV-B enhanced radiation showed gradual decrease in these parameters with a maximum effect at 20-30 oC, At 40 oC, the inhibition was less. RuBPC activity, soluble protein content and '‘♦CO2 fixation showed parallel increases with increasing period of UV-B treatment at 10 oC, The polypeptide pattem of crude leaf extract showed progressive decrease in the level of 55 and 13 kDa polypeptides with the time of UV-B treatment at 20 and 30 °C. However, no such loss in these polypeptides was observed at 10 oC, and at 40 oC only a marginal loss in the level of 13 kDa polypeptide had occuned.