Electronic structures of collagen model polymers: (Gly-Pro)n, (Gly-Hyp)n, (Ala-Pro)n, (Ala-Hyp)n, (Gly-Pro-Gly)n, (Gly-Hyp-Gly)n, (Gly-Pro-Pro)n, and (Gly-Pro-Hyp)n

In order to investigate the relationship existing between the electronic structures of collagen and its biochemical functions in vivo, the semiempirical CNDO/2 SCF MO calculations were carried out on several model polymers of collagen, (Gly-Pro)_n, (Gly-Hyp)_n, (Ala-Pro)_n, (Ala-Hyp)_n, (Gly-Pro-Gly)_n, (Gly-Hyp-Gly)_n, (Gly-Pro-Pro)_n and (Gly-Pro-Hyp)_n. Geometries of the skeleton of these polymers were assumed to be the same as those of poly(l-proline) I (cis) and II (trans) and the calculations were performed only on infinite polymers in a single chain. The results show that the cis form is always more stable than the trans form for all the polymers treated. This energy difference between the cis and trans forms depends, for example, on the kind of amino acid residue, Gly or Ala, but this could not be seen in the Pro or Hyp residue. The flexibility or mobility of the collagen structure was explained using the energy difference between the cis and trans forms of the polymers, i.e. the cis-trans conversion of the collagen was discussed in connection with the energy difference. The reason why the collagen has the constitution of (Gly-Pro-Hyp)_n is briefly discussed.     

Linkage mapping of the ovine alpha-inhibin (INHA) beta(A)-inhibin/activin (INHBA) and beta(B)-inhibin/activin (INHBB) genes

A full-sib mapping population was typed for Taql Southern blot RFLPs at the ovine alpha-inhibin (INHA), beta(A)-inhibin/activin (INHBA), and beta(B)-inhibin/activin (INHBB) loci. The most likely positions were found by genetic linkage analysis. INHA was placed on ovine chromosome 2q, between microsatellite markers BM6444 and INRA135, while INHBB was located 39 cM proximal to INHA between markers BMS1126 and BMS2626. The INHBA gene, a comparative mapping anchor locus, mapped to chromosome 4, between microsatellites OARCP26 and BMS719. These data confirm and refine previous chromosomal assignments by in situ hybridization, provide comparative mapping information, and identify microsatellite markers suitable for QTL association studies with inhibin/activin genes in ruminants.     

Lanthanide ion catalysis of the trans-cis isomerization of trans-bis(oxalato)-diaquochromate(III) and trans-bis(malonato)diaquochromate(III) [1]

The lanthanide ion catalyzed trans-cis isomerizations of trans-bis(oxalato)diaquochromate(II) and trans-bis(malonato)diaquochromate(III) have been studied. A linear free energy relationship was found correlating the catalytic rate constants for the oxalate reaction with the corresponding formation constants of complexes formed between simple monocarboxylic acids and the light (LaGd) members of the lanthanide series. The results indicates that for this portion of the series, the reaction mechanism is related to the formation of monocarboxylate complex intermediates. When the ionic radius of the lanthanide ion decreases below a particular value (as in the latter half of the series), the metal ion remains coordinated to both carboxylates of the oxalate ion rather than simply binding to only one carboxylate. In either situation, isomerization to the cis product eventually occurs, and the lanthanide ion is released.The reaction rates associated with the trans-bis(malonato)diaquochromate(III) reaction were found to be significantly slower than those of the corresponding oxalate system. However, in the malonate system, no linear free energy relationship was found relating the catalytic rate constants with the corresponding formation constants of monocarboxylic acids. One does find a linear relationship between the catalytic rate constants for the malonate reaction and the log K₁ values for the corresponding lanthanide/malonate complexes. During the course of the trans-cis isomerization, the lanthanide ion chelates the dissociated malonate group of a pentavalent Cr(III) intermediate. In the mechanism the lanthanide ion does not aid in ring opening, and neither does it singly bond to the intermediate     

Kinetics of the cis-to-planar interconversion of cis-diaqua(1,4,7,11-tetraazacyclotetradecane)nickel(II) ion

In order to examine the effects of coordinated hydroxide ion and free hydroxide ion in configurational conversion of a tetraamine macrocyclic ligand complex, the kinetics of the cis-to-planar interconversion of cis-[Ni(isocyclam)(H₂O)₂]²⁺ (isocyclam, 1,4,7,11-tetraazacyclotetradecane) has been studied spectrophotometrically in basic aqueous solution. The interconversion requires the inversion of one sec-NH center of the folded cis-complex to have the planar species. Kinetic data are satisfactorily fitted by the rate law, R = k_OH[OH⁻][cis-[Ni(isocyclam)(H₂O)₂]²⁺], where k_OH = 3.84 × 10³ dm³ mol⁻¹ s⁻¹ at 25.0 ± 0.1 °C with I = 0.10 mol dm⁻³ (NaClO₄). The large ΔH^≠, 61.7 ± 3.2 kJ mol⁻¹, and the large positive ΔS^≠, 30.2 ± 10.8 J K⁻¹ mol⁻¹, strongly support a free-base-catalyzed mechanism for the reaction.     

Origin of the subgeneraCyclampterium, Paralampterium andSciadiopeplus fromLophocyrtis (Lophocyrtis) (Radiolaria, Theoperidae)

Work on the exceptionally well-preserved, rapidly accumulating Bath Cliff Section, Barbados and supplementary Deep Sea Drilling Project samples, has revealed the evolutionary origins of three stratigraphically useful species in theCryptoprora ornata Zone straddling the Eocene/Oligocene boundary and demonstrated the origin of the genusCyclampterium. Elucidation of the origin ofCyclampterium milowi necessitates a revision of the generaLophocyrtis andCyclampterium.Lophocyrtis (Lophocyrtis)jacchia is the ancestor ofL. (Cyclampterium)hadra, the earliest member in the subgenusCyclampterium which comprises the anagenetic lineage leading fromL. (C.)hadra toL. (C.)neatum. The monotypic subgenusSciadiopeplus branches off from an early member in theCyclampterium lineage. The new speciesL. (L.)exitelus andL. (S.)oberhaensliae terminate the subgeneraLophocyrtis andSciadiopeplus, respectively. During the investigation it also became clear that morphotypes resembling earlyL. (C.)milowi could be found in mid and high latitude assemblages in the late Early and late Middle Eocene. The origin of one these morphotypes was also traced toL. (Lophocyrtis)jacchia giving rise to the new subgenusParalampterium. This lineage includes the new speciesL. (Paralampterium)dumitricai and two species questionably assigned to it,L. (Paralampterium)?longiventer and the new speciesL. (Paralampterium) ?galenum. The relationship ofL. (P.)dumitricai toL. (P.) ?longiventer andL. (P.) ?galenum is unknown.     

Acaricidal activity of the essential oil from Tetradenia riparia (Lamiaceae) on the cattle tick Rhipicephalus (Boophilus) microplus (Acari; Ixodidae)

Tetradenia riparia (Lamiaceae) is a well-known herbal medicine with a variety of useful properties, including its acaricidal effect. This experiment was carried out to study the bioacaricidal activity of T. riparia essential oil (EO) against engorged females of Rhipicephalus (Boophilus) microplus (Acari; Ixodidae). For this purpose, nine serial concentrations (12.50%, 6.25%, 3.75%, 1.80%, 0.90%, 0.45%, 0.22%, 0.11%, and 0.056% w/v) of T. riparia were used for the adult immersion test (AIT). For the larval packet test (LPT), we used 14 serial concentrations (100.00%, 50.00%, 25.00%, 12.50%, 6.25%, 3.65%, 1.82%, 0.91%, 0.45%, 0.228%, 0.114%, 0.057%, 0.028%, and 0.014% w/v). The results for AIT showed 100.00% and 2.05% mortality, 19.00 and 90.20% for the total number of eggs, egg-laying inhibition of 0.00% and 90.20%, hatchability inhibition of 0.00% and 70.23%, and product effectiveness of 100.00% and 2.89%, respectively. The AIT indicated that the LC₅₀ and LC_99.9, calculated using the Probit test, were for mortality (%) 0.534 g/mL (0.436–0.632) and 1.552 g/mL (1.183–1.92); for total number of eggs were 0.449 g/mL (0.339–0.558) and 1.76 g/mL (1.27–2.248); and for hatchability inhibition were 0.114 g/mL (0.0–0.31) and 2.462 g/mL (1.501–3.422), respectively. Larvae between 14 and 21 days old were fasted and placed in each envelope. Bioassays were performed at 27° ± 1 °C, RH ? 80%. Larval mortality was observed 24 h after treatment and showed 10.60–100% mortality in the LPT bioassay. The LPT showed that the LC₅₀ and LC_99.9 were 1.222 g/mL (0.655–1.788) and 11.382 g/mL (7.84–14.91), respectively. A positive correlation between T. riparia EO concentration and tick control, was observed by the strong acaricidal effects against R. (B.) microplus, and the mortality rate of ticks was dose-dependent. Our results showed that T. riparia is a promising candidate as an acaricide against resistant strains of R. (B.) microplus.     

Neoechinorhynchus (Neoechinorhynchus) chimalapasensis n. sp. (Acanthocephala: Neoechinorhynchidae) from the freshwater fish Awaous banana (Valenciennes) (Gobiidae) in Mexico

Neoechinorhynchus (Neoechinorhynchus) chimalapasensis n. sp. (Eoacanthocephala: Neoechinorhynchidae) is described from the intestine of Awaous banana (Valenciennes) (Pisces: Gobiidae) collected in the Río Negro, a tributary in the upper Río Coatzacoalcos basin, Santa María Chimalapa, Oaxaca State, Mexico. It is the third species of Neoechinorhynchus Stiles & Hassall, 1905 described from Mexican freshwater fishes, although 36 other species are known from freshwater fishes in the Americas. Like four other species of Neoechinorhynchus from freshwater fishes in North America and Mexico, N. (N.) limi Muzzall & Buckner, 1982, (N.) rutili (Müller, 1780) Stiles & Hassall, 1905, N. (N.) salmonis Ching, 1984 and N. (N.) roseus Salgado-Maldonado, 1978, males and females of the new species are less than 20 mm in length, lack conspicuous sexual dimorphism in size, have a small proboscis of about 0.1 mm in length with the largest hooks being the anteriormost, about 30–90 μm in length and of equal size, and have subequal lemnisci, larger than the proboscis receptacle but still relatively short and, in males, generally restricted to a position considerably anterior to the testes. The new species is closest to N. (N.) roseus, but it is distinguished from it by having: (1) a slightly larger cylindrical proboscis with almost parallel sides versus a globular proboscis with a rounded tip which is shorter and somewhat wider in N. (N.) roseus; (2) smaller but robust anterior proboscis hooks that do not reach the equatorial level or extend beyond the hooks of the middle circle as in N. (N.) roseus; and (3) the female gonopore situated ventrally subterminal, as opposed to being a significant distance anteriorly to the posterior extremity in N. (N.) roseus.     

A review of the systematics of the sleeper shark genus Somniosus with redescriptions of Somniosus ( Somniosus) antarcticus and Somniosus ( Rhinoscymnus) longus (Squaliformes: Somniosidae)

Past treatments of the sleeper shark genus Somniosus generally recognize three species: S. microcephalus, S. pacificus, and S. rostratus. Based on morphometrics and meristics, we conclude that this genus includes two subgenera (Somniosus and Rhinoscymnus) and five species. Subgenus Somniosus differs from Rhinoscymnus by being much larger when adult and in having more numerous tooth rows in the lower jaw, hooklike rather than leaf-shaped dermal denticles, more numerous spiral valve and vertebral counts, and a poorly calcified vertebral column. Subgenus Somniosus includes S. (Somniosus) microcephalus and S. (S.) pacificus of the Northern Hemisphere and S. (S.) antarcticus of the Southern Hemisphere. Although Somniosus antarcticus has been synonymized with S. microcephalus and identified as S. pacificus in past literature, it differs from S. microcephalus in having a shorter interdorsal space, a more posterior first dorsal fin, lower dorsal fins, more numerous tooth rows in the lower jaw, more numerous spiral valve counts, and fewer precaudal vertebrae. Somniosus antarcticus also differs from S. pacificus by having a shorter prebranchial length, lower dorsal fins, more numerous spiral valve counts, and slightly more precaudal vertebrae. Subgenus Rhinoscymnus includes S. (Rhinoscymnus) rostratus from the eastern North Atlantic and Mediterranean Sea (senior synonym of S. bauchotae) and S. (R.) longus from the western Pacific Ocean. Somniosus longus has been synonymized with S. rostratus, but differs in having a relatively longer second dorsal fin, a slightly larger eye, more lower tooth rows, and slightly higher spiral valve counts. Both Somniosus (Somniosus) antarcticus and S. (Rhinoscymnus) longus from the Pacific Ocean were redescribed. A key to the species and the geographical distribution of all species are provided.     

Synthesis and study of Pt(II)-aromatic amines complexes of the types cis- and trans-Pt(amine)2(NO3)2 and cis-Pt(amine)2(R(COO)2)

Complexes of the types cis- and trans-Pt(amine)₂(NO₃)₂ with amines containing a phenyl group were synthesized and studied mainly by IR and multinuclear magnetic resonance spectroscopies. The cis complexes could be synthesized pure only with the amines of the type Ph-R-NH₂ (R = alkyl), while pure trans compounds were synthesized with all the studied amines. In ¹⁹⁵Pt NMR spectroscopy, the dinitrato complexes of the amines Ph-R-NH₂ were observed around −1700 ppm for the cis isomers and at about −1580 for the trans complexes. For the other amines, where a phenyl ring is directly attached to the amino group, the signals were observed at lower fields, −1528 ppm for cis-Pt(PhNH₂)(NO₃)₂ and around −1450 ppm for all the trans isomers. There is a linear relationship between the δ(Pt) of the Pt(amine)₂(NO₃)₂ complexes and the pK_a of the protonated amines. The coupling constants ²J(¹⁹⁵Pt-¹HN) are larger in the cis compounds (ave. 76 Hz) than in the trans isomers (ave. 63 Hz). The complexes cis-Pt(amine)₂(R(COO)₂) with bidentate dicarboxylato ligands were also synthesized and characterized mainly by IR spectroscopy. The compounds apparently decompose in DMF and are too insoluble in other solvents for solution studies.     

Comparative study of the structure of the reproductive system of dwarfish males of Glyphina betulae (Linnaeus, 1758) and Anoecia (Anoecia) corni (Fabricius, 1775) (Hemiptera, Aphididae)

The morphology and ultrastructure of the male reproductive system of dwarfish males of the monoecious aphid species Glyphina betulae (subfamily Thelaxinae) and the heteroecious species Anoecia (Anoecia) corni (subfamily Anoeciinae) are described. The testicular follicle of these species has the form of a single sac, the proximal parts of the vasa deferentia are slightly (G. betulae) or strongly (A. (A.) corni) expanded, the accessory glands are sack-shaped, and in G. betulae asymmetric and strongly elongated, whereas the ejaculatory duct is short.In both species only mature spermatozoa have been found within the testicular follicles, i.e. the consecutive stages of spermatogenesis have not been observed in adult males. Our studies also show that the testicular follicle, vasa deferentia, accessory glands and ejaculatory duct are histologically very simple. They are composed of more-or-less flattened epithelium of a secretory type, and thin muscle fibres. The epithelial cells are rich in rough endoplasmic reticulum, mitochondria and small vacuoles. The vasa deferentia, especially in G. betulae, are filled with an electron-dense secretion which, as was shown by histochemical staining, contains proteins and polysaccharides. We suggest that the maximum secretory activity of these epithelial cells occurs, as does spermatogenesis, during larval stages, so that the short living adult males are immediately ready for copulation as in other aphids with normal-sized males.     

Exploring the midgut proteome of partially fed female cattle tick (Rhipicephalus (Boophilus) microplus)

The continued development of effective anti-tick vaccines remains the most promising prospect for the control of the cattle tick, Rhipicephalus (Boophilus) microplus. A vaccine based on midgut proteins could interfere with successful tick feeding and additionally interfere with midgut developmental stages of Babesia parasites, providing opportunities for the control of both the tick and the pathogens it transmits. Midgut proteins from partially fed adult female cattle ticks were analysed using a combination of 2-DE and gel-free LC-MS/MS. Analysis of the urea-soluble protein fraction resulted in the confident identification of 105 gut proteins, while the PBS-soluble fraction yielded an additional 37 R. microplus proteins. The results show an abundance of proteins involved in mitochondrial ATP synthesis, electron transport chain, protein synthesis, chaperone, antioxidant and protein folding and transport activities in midgut tissues of adult female ticks. Among the novel products identified were clathrin-adaptor protein, which is involved in the assembly of clathrin-coated vesicles, and membrane-associated trafficking proteins such as syntaxin 6 and surfeit 4. The observations allow the formulation of hypotheses regarding midgut physiology and will serve as a basis for future vaccine development and tick-host interaction research.     

Taxonomic review of the subgenus Uroleucon (Uromelan) (Hemiptera: Aphididae) in the Korean peninsula

Until now, five species of the subgenus Uroleucon (Uromelan) have been recognized in Korea. This is the first report of Uroleucon (Uromelan) adenophorae (Matsumura, 1918) occurring on Adenophora triphylla (Campanulaceae) in Gangwon-do, South Korea. Host plants are reviewed and an identification key to species is presented for six Uroleucon (Uromelan) species from the Korean Peninsula.     

Lower Cambrian (Atdabanian/Botomian) Shallow-Marine carbonates of the Görlitz Synclinorium (Saxony/Germany)

Summary Geological, papaeontological and microfacies studies in the Lower Cambrian carbonate complex of the G?rlitz Synclinorium (eastern Germany/Saxony/Lusatian region) provide new data for the fossil content, depositional history and palaeogeography. The Lower Cambrian of the G?rlitz Synclinorium belongs to the facies zones 5, 7 and 8 ofWilson (1975)-platform rim with connections to the open ocean and to the restricted platform areas. An extraordinarily rich fauna was found with elements which are in some cases new for Europe (Rhombocorniculum cancellatum Cobbold,Fordilla sibirica Krasilova, Calodiscus lobatus Hall,Archaeooides granulatus Qian,Archiasterella pentactina Sdzuy,Allonia sp.,Obliquatheca aldanica Sysoiev,Conotheca circumflexa Missarzhevsky,Microcornus elongatus Missarzhevsky,Lenalituus sp.,Pelagiella cf.lorenzi Kobayashi,Beshtashella sp.,Comluella sp.,Cambroclavithidae gen. et sp. indet., Helcionellidae gen. et sp., indet. Eocrinoidea gen. et sp. indet.) This fauna indicates Lower Cambrian (higher Atdabanian/Botomian) age and reveals palaeobiogeographical connections to the Siberian Platform, to the Mediterranean area and to China. A somewhat new stratigraphical subdivision of the Lower Cambrian sequence (Zwetau Formation) is described. New units are established within the Ludwigsdorf Member (the carbonatic lower part of the sequence), the ‘Lower Ludwigsdorf Member’ (massive dolostone) and the ‘Upper Ludwigsdorf Member’ (bedeed limestones and their equivalents). The subsequentLusatiops Member is subdivided intoSerrodiscus Bed (claystones) andLusatiops Bed (siltstones).     

Characterization of the peptide-N4-(N-acetylglucosaminyl) asparagine amidase (PNGase Se) fromSilene alba cells

The peptide-N ⁴-(N-acetylglucosaminyl) asparagine amidase (PNGase Se) earlier described [Lhernould S., Karamanos Y., Bourgerie S., Strecker G., Julien R., Morvan H. (1992)Glycoconjugate J 9:191–97] was partially purified from culturedSilene alba cells using affinity chromatography. The enzyme is active between pH 3.0 and 6.5, and is stable in the presence of moderate concentrations of several other protein unfolding chemicals, but is readily inactivated by SDS. Although the enzyme cleaves the carbohydrate from a variety of animal and plant glycopeptides, it does not hydrolyse the carbohydrate from most of the corresponding unfolded glycoproteins in otherwise comparable conditions. The substrate specificity of this plant PNGase supports the hypothesis that this enzyme could be at the origin of the production of unconjugated N-glycans in a suspension medium of culturedSilene alba cells.Abbreviations GlcNAc N-acetylglucosamine - PNGase peptide-N ⁴-(N-acetylglucosaminyl) asparagine amidase - BSA bovine serum albumin - SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis - TLC thin layer chromatography - HPAEC-PAD High pH anion exchange chromatography-pulsed amperometric detection     

Electronic spectra of the chromium chalcocarbonyl complexes,Cr(CO)5(CX) and (η6-C6H6)Cr(CO)2(CX) (X= O,S,Se)

The room-temperature electronic spectra of the chromium chalcocarbonyl complexes, Cr(CO)₅(CX) and (η⁶-C₆H₆)Cr(CO)₂(CX) (X = O, S, Se), have been recorded in solution, and in some cases, in the gas phase. Assignments for the thiocarbonyl and selenocarbonyl spectra are proposed on the basis of the literature assignments for the parent all-CO derivatives. Overall, the data support the order of increasing electron withdrawing capacity of the chalcocarbonyl ligands as CO < CS < CSe.     

The distribution and abundance of Lernaeocera lusci (Copepoda) on hake (Merluccius merluccius) and bid (Trisopterus luscus) (Teleostei)

Distribution patterns, mean intensity and prevalence of Lernaeocera lusci (Copepoda, Pennellidae) in its 2 hosts Trisopterus luscus (Teleostei, Gadidae) and Merluccius merluccius (Teleostei, Merlucciidae) were examined, together with parasitic abundance and aggregation in relation to the size of the host. The mean parasite abundance and the variance to mean abundance ratio increased with host size, suggesting that the accumulation of this parasite had no noticeable impact on the structure of either host population. Merluccius merluccius being a newly colonized host in the Mediterranean, these results are discussed in relation to current ideas on the evolution of pathogenicity in heterospecific associations.     

Evolutionary divergence of the paralogs Methoprene tolerant (Met) and germ cell expressed (gce) within the genus Drosophila

Juvenile hormone (JH) signaling underpins both regulatory and developmental pathways in insects. However, the JH receptor is poorly understood. Methoprene tolerant (Met) and germ cell expressed (gce) have been implicated in JH signaling in Drosophila. We investigated the evolution of Met and gce across 12 Drosophila species and found that these paralogs are conserved across at least 63 million years of dipteran evolution. Distinct patterns of selection found using estimates of dN/dS ratios across Drosophila Met and gce coding sequences, along with their incongruent temporal expression profiles in embryonic Drosophila melanogaster, illustrate avenues through which these genes have diverged within the Diptera. Additionally, we demonstrate that the annotated gene CG15032 is the 5′ terminus of gce.In mosquitoes and beetles, a single Met-like homolog displays structural similarity to both Met and gce, and the intron locations are conserved with those of gce. We found that Tribolium and mosquito Met orthologs are assembled from Met- and gce-specific domains in a modular fashion. Our results suggest that Drosophila Met and gce experienced divergent evolutionary pressures following the duplication of an ancestral gce-like gene found in less derived holometabolous insects.     

Polyscias (Araliaceae) not Brucea (Simaroubaceae) is native to the Arabian Peninsula

It is shown that the single record of the genus Brucea J. F. Mill. (Simaroubaceae) from Yemen in the Arabian Peninsula (Wood 2886), identified as Brucea antidysenterica J. F. Mill., is based on a misidentification. The specimen is actually Polyscias fulva (Hiern) Harms in the Araliaceae, a genus and species not previously recorded from the Peninsula although a common pioneer tree of submontane forest in neighbouring continental Africa.     

Controlling the adhesion of the diatom Navicula perminuta using poly(N-isopropylacrylamide-co–N-(1-phenylethyl) acrylamide) films

Poly(N-isopropylacrylamide)-co–N-(1-phenylethyl) acrylamide [P(NIPAAm-co-PEAAm)] thermo-responsive thin films with a lower critical solution temperature (LCST) adjusted to fit marine applications were used to investigate the effect of changes in the wetting properties of a surface on the adhesion of the diatom Navicula perminuta, an organism which forms slime films on surfaces immersed in an aquatic environment. Although the strength of attachment of cells was affected by whether the film was collapsed or expanded, no significant decrease in adhesion strength occurred upon temperature decrease. The effects were attributed to possible strong interactions between the hydrophobic segments of the responsive film when collapsed with components in the adhesive complex.