Organolanthanoids. XIII. Bis(pentadeuterocyclopentadienyl)ytterbium(II)

The complex (C₅D₅)₂Yb(dme) (dme = 1,2- dimethoxyethane) has been prepared by reaction of Tl(C₅D₅) with ytterbium metal in dme and is isostructural with (C₅H₅)₂Yb(dme). Thermal desolvation under vacuum yields (C₅D₅)₂Yb, for which essentially identical high resolution neutron powder diffraction data were obtained at 294 K and 77 K, but the structure could not be determined.     

Ichthyosporidium weissii n. sp. (Microsporidia) infecting the arrow goby (Clevelandia ios)

Gonadal infections by a novel microsporidium were discovered in 34% (13/38) of arrow gobies, Clevelandia ios, sampled over a 3‐yr period from Morro Bay Marina in Morro Bay, California. Gonadal tumors had been reported in arrow gobies from this geographic area. The infected gonads, found primarily in females, typically appeared grossly as large, white‐gray firm and lobulated masses. Histological examination revealed large, multilobate xenomas within the ovaries and no evidence of neoplasia. Typical of the genus Ichthyosporidium, the large xenomas were filled with developmental stages and pleomorphic spores. Wet mount preparations showed two general spore types: microspores with mean length of 6.2 (7.0–4.9, SD = 0.6, N = 20) μm and mean width of 4.3 (5.3–2.9, SD = 0.8) μm; and less numerous macrospores with mean length of 8.5 (10.1–7.1, SD = 1.0, N = 10) μm and mean width of 5.5 (6.2–4.8, SD = 0.5) μm. Transmission electron microscopy demonstrated stages consistent with the genus and 35–50 turns of the polar filament. Small subunit rDNA gene sequence analysis revealed that the parasite from arrow gobies was most closely related to, but distinct from Ichthyosporidium sp. based on sequences available in GenBank. We conclude that this microsporidium represents a new species of Ichthyosporidium, the first species of this genus described from a member of the family Gobiidae and from the Pacific Ocean.     

Nonea dumanii sp. nov. (Boraginaceae) from the Taurus mountains (south Turkey)

The new species Nonea dumanii, endemic to the mountains of the western Taurus in south Turkey (C4 Antalya), is described an illustrated based on original collections by the authors. Karyological observations and analysis of ITS1 DNA sequences showed that the species is probably hexaploid with 2n = 6x = 60 and has phylogenetic affinity to the diploid N. monticola from the Paphlagonian mountains as well as to the tetraploid N. anchusoides from northwest Iran and southeast Turkey. From these allopatric species it is morphologically distinct in characters of the indumentum, flower and fruit. Polyploidy is supported as a major driving force for speciation in Nonea, especially in the group of Anatolian mountain species with primary base number x = 10.     

Pliocene Ilyocyprididae (Ostracoda) from the Ebro Basin (N. Spain)

A revision of the Pliocene representatives of the Ilyocyprididae genera Ilyocypris Brady and Norman, 1889, and Qinghaicypris Huang, 1979, obtained from lacustrine sediments of the Villarroya section (La Rioja, N. Spain) is presented in this work. Based on carapace morphology and morphometrics, the occurrence in Europe of the genus Qinghaicypris is discussed. This genus is represented in this material by a new species, Qinghaicypris riojensis nov. sp., which is described herein. The occurrence of Ilyocypris and Qinghaicypris within the lacustrine series of Villarroya is analysed in relation to the hydrological evolution of the water bodies, which were very likely climatically driven. Palaeoecological as well as palaeobiogeographical interest of those genera is pointed out in the context of the aquatorium that spread over big areas of Europe during the Pliocene.     

Raphidascaris (Sprentascaris) lanfrediae sp. nov. (Nematoda: Anisakidae) from the fish Satanoperca jurupari (Osteichthyes: Cichlidae)

Raphidascaris (Sprentascaris) lanfrediae sp. nov. is described from the intestine of the freshwater fish Satanoperca jurupari (Heckel) (Cichlidae) from the Guamá River, state of Pará, Brazil. The prevalence in fish (n = 59) was 27% with intensity of one-124 (mean 16) nematodes per fish. The new species is characterized mainly by the markedly larger size of ventricular appendix in relation to the oesophagus, presence of short male caudal alae, 14-16 subventral pairs of preanal papillae and six pairs of postanal papillae.     

Molecular dynamics simulation of the DNA triplex d(TC)5.d(GA)5.d(C+T)5.

A molecular dynamics simulation of the DNA triple helix d(TC)5.d(GA)5.d(C+T)5 is described (C+ represents a protonated cytosine residue). The simulation has been performed using the program AMBER 3.1 and includes counterions and explicit solvent under periodic boundary conditions. Both the dynamic and time-averaged behaviour of the system has been analysed. Considerable deviations from the fibre-diffraction model for DNA triple helix structure are observed, including the repuckering of the purine strand sugars that has been identified in some nuclear magnetic resonance (n.m.r.) studies. The simulation suggests that this conformational change may be driven by the possibility of improved interactions between the phosphate groups of this strand and both the solvent and counterions. Several examples of a particular conformational transition are observed, involving correlated changes in the backbone angles alpha and gamma. These transitions provide a possible explanation for some unusual n.m.r. data that have been reported. The structure of the triple helix major groove also suggests an explanation for the observed stabilization of DNA triplexes by polyvalent cations, and their ability to interact with drugs that bind in the minor groove of DNA duplexes.     

Notes on the ontogeny and structure of the seed-coat of Sclerocarya birrea (Richard) Hochst. subsp. caffra (Sonder) Kokwaro (Anacardiaceae)

The pendulous, bitegmic, anatropous ovulr with dorsal raphe is suspended at the tip of a massive funicle. A group of nurellar cells with intensively staining cell walls, the hypostase sensu stricto , is present. The initially plate-like tanniniferous chalazal-nucellar tissue, with suberin and lignin impregnated cell walls represents a hypostase sensu lato . The mature seed-coat is formed by the raphe, extensive chalaza, adjacent, well-developed, cup-like hypostase sensu lato , remnants of the two integuments and a cuticular layer. The exalbuminous seed of Sclerocarya birrea suhsp. caffra (the Marula), is regarded to he a derived and phylogenetically advanced type. The undifferentiated seed-roat is very similar to that found in Lannea discolor which, like the marula, belongs to the tribe Spondieae. The similarities in the structure of the seed-coat and seed of the marula and L. discolor confirm their proposed close phylogenetir relationship.     

Lepidocoleus cf.ulrichi (Machaeridia) from the Trenton Group (Ordovician) of Ontario (Canada)

A specimen of the machaeridianLepidocoleus cf.ulrichi described herein focuses attention on taxonomical difficulties with extremely dorso-ventrally elongated sclerites found in some lepidocoleid taxa.Lepidocoleus ulrichi Withers, 1926 andLepidocoleus sigmoideus Withers, 1926 exhibit very similar appearances and prove indistinguishable based onWithers 1926 criteria. The key to separating taxa as similar as these may instead lie in the most juvenile stages of growth.     

Leucocytozoon muscicapa n. sp. (Leucocytozoidae: Apicomplexa) from the pied flycatcherFicedula hypoleuca (Pallas) (Passeriformes: Muscicapinae)

Leucocytozoon muscicapa n. sp. is described from the pied flycatcherFicedula hypoleuca (Pallas) (Passeriformes: Muscicapinae) from Finland and compared with other leucocytozoids of the family Muscicapidae.     

Procyonostrongylus muelleri gen. et sp. n. (Metastrongyloidea: Angiostrongylidae) from the raccoon (Procyon l. lotor)

Procyonostrongylus muelleri gen. et sp. n. from under the epithelium of the epiglottis of Procyon l. lotor is distinguished by 1) the absence of lips; 2) a highly developed reinforced bursa with a deep terminal incision; 3) highly developed toothlike dorsal rays; 1) greatly reduced externodorsal rays; and 5) the terminal or subterminal anus and vulva in the female.     

New Harpacticoida (Crustacea, Copepoda) from the North Atlantic Ocean. VIII. The description of Eurycletodes (Oligocletodes) quadrispinosa sp.n. and the male of E. (O.) monardi Smirnov (Cletodidae)

Eurycletodes (O.) quadrispinosa Sp.n. and the male of Eurycletodes (O.) monardi are described. E. quadrispinosa differs from the closely related species E. echinatus Lang, E. parasimilis Por and E. arcticus Lang in the setation of segment 1 and 2 Exp P2–P4, of segment 2 Exp p24 and of the Exp P5. Because of the same setation of the A2, Pl-P4 Exp and Exp as the female of E. monardi Smirnov the described male is regarded as that of E. monardi Smirnov. The species were collected at the Iceland Faroe Ridge from depths of 500. 1540 and 2500 m.     

Sarcocystis speeri N. sp. (Protozoa: Sarcocystidae) from the opossum (Didelphis virginiana)

The North American opossum (Didelphis virginiana) is host to at least 3 species of Sarcocystis: Sarcocystisfalcatula, Sarcocystis neurona, and a recently recognized Sarcocystis sp. A new name, Sarcocystis speeri, is proposed for the third unnamed Sarcocystis. Immunodeficient mice are an experimental intermediate host for S. speeri. Sarcocystis speeri sporocysts are 12-15 x 8-10 microm in size, and its schizonts are found in many organs of mice. Sarcocysts of S. speeri are found in skeletal muscles and they are up to 5 mm long and filiform. By light microscopy, the sarcocyst wall is thin (<1 microm thick); ultrastructurally, the cyst wall is up to 1.8 microm thick and has characteristic steeple-shaped villar protrusions surmounted by a spire. Sarcocystis speeri schizonts are morphologically and antigenically distinct from schizonts of S. neurona, and S. speeri sporocysts were not infective to budgerigars (Melopsittacus undulatus).     

Energetics of the B-H transition in supercoiled DNA carrying d(CT)x.d(AG)x and d(C)n.d(G)n inserts.

We have studied the B-H transition in the d(AG)x inserts of varying length under superhelical stress. The new data and previously published results for the d(G)31 insert are treated within a phenomenological model of the B-H transition, making it possible to obtain, for the first time, the energy parameters of the B-H transition in the d(AG)x and d(G)n sequences.