A contribution towards resolving the nomenclature of Citharexylum (Verbenaceae): typification of names linked to South American taxa

During ongoing taxonomic studies in the genus Citharexylum (Verbenaceae), twenty names were found in need of typification or typification clarifications. Fourteen names (C. andinum, C. herrerae, C. ilicifolium, C. kunthianum, C. laetum, C. myrianthum var. acuminatum, C. myrianthum var. rigidum, C. pernambucense, C. poeppigii, C. quercifolium, C. solanaceum, C. solanaceum var. macrocalyx, C. surrectum and C. weberbaueri) are here lectotypified, and epitypes are selected for three names (C. herrerae, C. kunthianum and C. pernambucense). Neotypes are designated for the names C. berteroi, C. broadwayi and C. coriaceum. Furthermore, updates and supporting information for three names already typified by Harold Moldenke (C. macrochlamys, C. punctatum and C. subthyrsoideum) are provided.     

About the application of the Linnaean names Anthemis italica and A. tinctoria var. triumfettii (Asteraceae,Anthemidae)

The typification of the Linnaean names Anthemis italica and A. tinctoria var. triumfettii is discussed. Specimens from LINN (no. 1016.4) and SBT (no. 72) are designated as lectotypes. The name A. italica is proposed as a synonym of A. maritima, while A. tinctoria var. triumfettii is currently accepted under the genus Cota, as C. triumfettii.     

Morphological variation in populations of Bletia purpurea (Orchidaceae) and description of the new species B. riparia

Bletia purpurea is the most widespread species in its genus. Morphological variation has been recognized throughout the range of its distribution. In this paper, the morphological variation from 63 populations (583 individuals) ofBletia purpurea is assessed to determine whether more than one species were present. Forty-four quantitative and qualitative characters were examined by univariate analyses and exploratory multivariate analyses. Univariate analyses indicate that quantitative characters such as lateral sepal width, petal. width, lip length, and lip width are significantly different for populations from Acazónica, Mexico. Floral parts in the populations from Acazónica are the smallest among all populations. Qualitative characters such as petals covering the lip midlobe and horizontal lip position are found exclusively in the same populations. We concluded that these populations should be described as a new species,B. riparia. Multivariate analyses indicated that morphological variation among the other populations cannot be ascribed to geographic distribution or ecological factors.     

A synopsis of the genus Mandevilla (Apocynaceae) in Mexico and Central America

The 19 species of the genus Mandevilla in Mexico and Central America are treated synoptically. New synonymy is provided and a new species, Mandevilla rigidifolia, is described.     

A new species of Astyanax (Characiformes: Characidae) from Costa Rica and Panama,with a key to the lower Central American species of the genus

Astyanax anai, a new species of characid fish, is described from the Sixaola River basin, eastern Costa Rica–western Panama, Central America. The new species can be distinguished from all other congeners by the following combination of characters: premaxillary teeth 4–5 at the inner series and 4–6 at the outer series; maxillary teeth tricuspid, 2–4; predorsal scale series irregular and incomplete, with an unscaled space behind tip of supraoccipital process and 12–14 scales; lateral line scales 34–39; humeral region with a conspicuous black and rounded to horizontally ovate spot and two diffuse brown and vertically elongate bars (the first through the rounded to horizontally ovate spot, the second 2–4 scales behind the first); body depth 36·6–42·3% of standard length (L_S); midlateral stripe formed by a series of 10–14 anteriorly‐directed dermal herringbone, or chevron‐shaped, marks, most apparent in juveniles and in preserved specimens, extending above the lateral line from the black humeral spot or just behind it (from the second vertical bar) to the caudal peduncle; scale rows from lateral line to base of first dorsal‐fin ray 8–9; scale rows from lateral line to base of pelvic fin 7–8; pre‐anal distance 53·9–61·9% of L_S; total anal‐fin elements 29–33; caudal spot elongated, rhomboid or rectangular, with its anterior margin surpassing the middle of the caudal peduncle, usually reaching the anal‐fin insertion, posteriorly covering 4–7 principal caudal‐fin rays and not extending onto the ventral and dorsal margins of the caudal peduncle, covering 3–5 horizontal scale rows. In order to test the phylogenetic relationships of the new taxon in relation to the other North and Central American species of the genus, a new phylogenetic hypothesis based on a reanalysis of the morphological matrix by Schmitter‐Soto (2016) is proposed. A key to the lower Central American (southern Nicaragua to eastern Panama) species of Astyanax is also provided.     

Contributions towards the taxonomy of the African Naididae (Oligochaeta). IV. Zoogeographical and taxonomical considerations on African Naididae

A systematic revision of African Naididae confirmed the presence of 16 genera and 48 species. Allonais ranauana Boldt, 1932 is confirmed as a distinct species, Nais raviensis Stephenson, 1914 has very short gills and is a species of Dero, and Rhopalonais has equally obscure gills and is attributable to Dero. Pristina proboscidea Beddard, 1896 is synonymous with P. longiseta Ehrenberg, 1828.African naidids are primarily tropical, the most widespread genus is Pristina, followed by Aulophorus, Nais and Dero. Nais is dominant in South Africa, whereas the other genera predominate in the tropics along with Rhopalonais. The most widespread species are A. furcatus, N. variabilis, P. longiseta and P. menoni.Serrations on hair setae and intermediate teeth in bifid needles are universally present as seen under SEM, their reported absence under light microscopes is attributable to lack of resolution power. SEM is also useful in determining gills in Dero. Size of setae within and between individuals is more constant than the literature would suggest as the standard deviation is usually less than 10% of the mean. There is a constant relationship between setal length and size of worm, and between median ventral setae and needles in this material.Setal size is a diagnostic character in taxonomy. The standard deviation of the mean number of segments in front of the budding zone averages 9.9%, the highest value (25.7%) was for Stylaria fossularis. Differences of more than 10% may usually be considered diagnostic. The total number of segments is exceedingly variable and cannot be used as a taxonomical characteristic. The same applies to segment length or diameter.     

Comparative quantitative investigations on brains of wild cavies (Cavia aperea) and guinea pigs (Cavia aperea f. porcellus). A contribution to size changes of CNS structures due to domestication

Intraspecific allometric calculations of the brain to body size relation revealed distinct differences between 127 (67; 60) ancestral wild cavies and 82 (37; 45) guinea pigs, their domesticated relatives. The dependency of both measures from one another remained the same in both animal groups but the brains of guinea pigs were by 14.22% smaller at any net body weight. Consistent with results in other species the domestication of Cavia aperea is also characterized by a decrease of brain size. Fresh tissue sizes of the five brain parts medulla oblongata, cerebellum, mesencephalon, diencephalon and telencephalon were determined for 6 cavies and 6 guinea pigs by the serial section method. Additionally the sizes of 16 endbrain structures and those of the optic tract, the lateral geniculate body and the cochlear nucleus were measured. Different decrease values resulted for all these structures concomitant with domestication as was calculated from the amount of total brain size decrease and average relative structure values in the wild as well as the domesticated brain. The size decrease of the entire telencephalon (−13.7%) was within the range of the mean overall reduction as similarly was the case for the total neocortex (−10.7%) whereas the total allocortex (−20.9%) clearly was more strongly affected. The size decrease of the olfactory bulb (−41.9%) was extreme and clearly higher than found for the secondary olfactory structures (around −11%). The primary nuclei of other sensory systems (vision, audition) were decreased to less extent (lateral geniculate: −18.1%; cochlear nucleus: −12.6%). Mass decreases of pure white matter parts were nearly twice as high in contrast to associated grey matter parts (neocortex white versus grey matter; tractus opticus versus lateral geniculate body). The relatively great decrease values found for the limbic structures hippocampus (−26.9%) and schizocortex (−25.9%) are especially notable since they are in good conformity with domestication effects in other mammalian species. The findings of this study are discussed with regard to results of similar investigations on wild and domesticated gerbils (Meriones unguiculatus), the encephalization of the wild form, the special and species-specific mode and duration of domestication and in connection with certain behavioral changes as resulted from comparative investigations in ethology, socio-biology, endocrinology and general physiology.     

A new bacterial exopolysaccharide (YAS34). II. Influence of thermal treatments on the conformation and structure. Relation with gelation ability

This paper describes an original mechanism of evolution of a polysaccharide system occurring during thermal treatments. Under its native conformation, the YAS34 polymer presents a solution character in the dilute and semi-dilute regimes. However, the zero shear rate viscosity indicates existence of interchain interactions which disappear on the deacetylated polymer. Thermal treatments over the temperature of conformational change produce a progressive and irreversible evolution of the physical properties when the polymer is under its sodium salt form. This evolution was related to a modification of the arrangement of acetyl substituents. The heated polysaccharide gives thermoreversible gel which is very elastic. A gelation mechanism is proposed based on formation of helical segments connecting the network.     

The tardigrades of Emilia (Italy). II. Monte Rondinaio. A multihabitat study on a high altitude valley of the northern Apennines

We investigated a small valley of glacial origin in the northern Apennines (Italy). A multihabitat study was performed on the mosses and lichens on rocks, temporarily submersed mosses, beech litter, grass turf and sediments from pools, ponds and streams. A few species colonized more than one habitat. Several species were typical of high altitudes or latitudes, some were rare, and two, Hypsibius pradellii sp. nov. and Diphascon (Diphascon) secchii sp. nov. , were new to science.     

The functional morphology of the scolex of Diphyllobothrium Cobbold (Cestoda, Pseudophyllidea). A scanning electron and light microscopical study on scoleces of adult D. dendriticum (Nitzsch), D. latum (L). and D. ditremum (Creplin).

Scoleces of adult D. dendriticum, D. latum and D. ditremum were studied using scanning electron and light microscopy. In D. dendriticum and D. latum the transverse bar between the bothria at the scolex apex always possessed a frontal pit while in D. ditremum no such invagination was seen. The scoleces attach to the host intestine by taking a firm grip with each bothrium around one or two intestinal villi. In D. ditremum and D. latum a layer of secreted substance is present between the scolex apex and the host intestine and between the inner bothrium surface and the host intestinal villi. In D. dendriticum, however, such a secreted layer was only observed at the scolex apex. A general account of the musculature and nervous and excretory systems of a Diphyllobothrium scolex is given.     

Studies on trypsin inhibitors. Part IX. Synthesis and trypsin inhibitory activity of the duopentacontapeptide corresponding to the amino acid sequence of porcine pancreatic secretory trypsin inhibitor II (Kazal).

The synthesis of the protected duopentacontapeptide corresponding to the entire amino acid sequence I-52 of porcine pancreatic secretory trypsin inhibitor II (Kazal type) is described. The benzyloxycarbonyltetradecapeptide tert-butyloxycarbonylhydrazide (sequence 1-14) was selectively deblocked with trifluoroacetic acid and used to acylate, by the azide procedure, the peptide free base corresponding to the sequence 15-52. The isolated material was purified by ion exchange chromatography and the protecting groups were removed by successive treatments with anhydrous hydrogen fluoride, 1 M piperidine and mercuric acetate. F02M phosphate buffer, pH8. Determination of the inhibitory capacity indicated that the synthetic material is about 50% effective, at 30:1 inhibitor:trypsin molar ratio in inhibiting the tryptic hydrolysis of Nalpha-benzoyl-DL-arginine-4-nitroanilide. Full inhibition was achieved at a higher inhibitor:trypsin molar ratio. The stability constants and the standard free energy of binding of the complex between trypsin and the synthetic inhibitor have been determined.     

A revision of species of the genus Dicranotaenia (Cestoda: Hymenolepididae). II. New data on the type-specimens of Dicranotaenia sacciperium (Mayhew, 1925), D. macrostrobilodes (Mayhew, 1925) and D. introversa (Mayhew, 1925)

This second paper in a series on the revision of the type-specimens of older species of the genus Dicranotaenia Railliet, 1892 sensu Spassky & Spasskaya (1954) presents new information particularly on the measurements and configuration of cirrus and sacculus accessorius internus in D. sacciperium, D. macrostrobilodes and D. introversa. The type-material of the Dicranotaenia spp. studied, with the exception of D. sacciperium, has neither a protuberant cirrus nor a protuberant sacculus accessorius internus. The configuration of these organs, however, indicates that D. macrostrobilodes and D. introversa may be synonymous. To suggest their synonomy with D. coronula is, however, premature.     

Competitive cooperative bindings of a small ligand to a linear polymer. II. Investigations on the mechanisms of proflavine binding to poly (A) and DNA.

Experimental binding isotherms relative to the interactions between proflavine and poly(A) or DNA are analyzed by comparison with theoretical models dealing with competitive cooperative bindings. In the case of poly(A), there are apparently no specific binding sites for the positive co-operative binding (complex I) leading to dye aggregation along the polyanionic chain. The second complex (complex II) seems to involve specific base-dye interactions, but it cannot be said whether this binding displays negative cooperativity or noncooperativity. None of the two simpler theoretical models agree quantitatively with all experimental data. A plausible interpretation can be given if it is assumed that (i) the electrostatic binding of one isolated bound dye molecule (nucleus of complex I) involves a definite interaction between a phosphate group and the positive charge of the dye; (ii) the structure of complex II is such that a dye–phosphate ionic interaction is maintained. In the case of DNA, our model of monoexclusive interactions fits the data more closely than does the model of biexclusive interactions. This gives experimental support for structural models in which the intercalated molecule interacts preferentially with one strand of the double helix and blocks only one phosphate for electrostatic binding. In order to propose a mechanism consistent with equilibrium and relaxation kinetic data, a modified reaction scheme is considered which takes account of the cooperativity effects in external binding and extends previous models.     

An ab initio MO-LCAO investigation of the electronic structure of organic hydroperoxides and platinum(II) hydroperoxo complexes: A contribution to the knowledge of the mechanism of olefin epoxidation

A possible new process of activation of the OOH group in the mechanism of ethylene epoxidation catalysed by Pt(II) diphosphine complexes has been investigated by ab initio MO-LCAO calculations. The electronic and geometric features of YOOH species (Y = H, CH₃, t-But, CF₃, CH₃CO, (PH₃)₂Pt(CF₃), (PH₃)₃PtCl) have been evaluated and compared. Coordination of the OOH group to platinum induces an inversion of the polarity of the O-O bond when compared to any organic hydroperoxide; parallelly it favours the isomerisation of the OOH group from a hydroperoxo to an oxywater-like structure. This latter effect could be an important factor in favouring the reaction of the platinum coordinated OOH group with ethylene to form ethylene oxide. In fact, calculations on the energetics of the interaction between H₂O₂ and C₂H₄ have shown that isomerisation of HOOH to H₂OO oxywater structure is the rate determining step for the epoxidation process.     

Cytological and Reproductive Studies of Japanese Diplazium (Woodsiaceae; Pteridophyta). II. Polyploidy and Hybridity in the Species Group with Summer-Green Bi- to Tripinnate Leaves

Diplazium with summer-green bi- to tripinnate leaves. Diplazium mesosorum and D. sibiricum var. sibiricum are sexual diploids (2n=82; n=41ll); D. chinense and D. squamigerum are sexual tetraploids (2n=164; n=82ll); and D. sibiricum var. glabrum is a sterile triploid (2n=123; meiosis irregular). Diplazium nipponicum includes both sterile triploid and sexual tetraploid populations. The triploid is larger in relation to several morphological characteristics and occurs in more southern regions than the tetraploid. Allozyme analysis suggests that the triploid is a hybrid of recurrent origin between the tetraploid and an unknown diploid. Diplazium × bittyuense is a sterile tetraploid, and the mitotic chromosome number, meiotic chromosome behavior, and allozyme analysis confirm the working hypothesis that it is a hybrid between D. nipponicum and D. chinense. Apomicts are not found within Diplazium with summer-green bi- to tripinnate leaves, and the taxonomic complexity can be attributed to polyploidy and natural hybridization. Received 3 March 2000/ Accepted in revised form 19 April 2000     

The immune response of cattle to Babesia bovis (syn. B. argentina). Studies on the nature and specificity of protection.

Studies of the immune response to Babesia bovis (syn. B. argentina) in Bos taurus cattle, using the passive transfer of serum from immune animals, indicated that an effector mechanism was mediated by antibodies which reacted with the parasitized erythrocytes. During removal from the peripheral blood, the parasites did not show reduced viability on subinoculation into other non-infected animals, and thus were not dead or irreversibly damaged at this time. It was concluded that opsonization of infected erythrocytes was probably the basis of protection by the system. There was some evidence that minor variation of the protective antigen(s) occurred within strains of the parasite but this had little effect on the efficiency of the host's immune response. However, there was no cross-protection between the antibodies against different strains. These interstrain differences in antibody specificity were reconciled with earlier observations that cross-immunity commonly occurs between different strains in infected animals. It was concluded that the mechanism of cross-immunity relied on priming of the host's immune system by the protective antigen(s) of the strain so that a secondary response against the heterologous strain occurred soon after challenge.