Acid-base and copper (II) complexation equilibria of poly(inosinic)-poly(cytidylic)

The acid-base and copper (II) complexing properties of the heteropolynucleotide poly(inosinic)-poly(cytidylic) acid were studied by means of potentiometric, spectrophotometric, CD, and molecular fluorescence titrations in a working aqueous medium of 0.15 M ionic strength at 37°C. The study of the acid-base equilibria has proved the existence of four different species in the pH interval 2–11. Two new species are detected in the presence of copper(II) ion, at acidic and neutral pH values. Spectrophotometric, CD, melting, and fluorescence data were treated with a multivariate curve resolution procedure that allowed the determination of the number of species simultaneously present in each system [acid-base equilibria, copper(II) complexation equilibria], and the estimation of their concentration profiles and of the pure spectra for each species. From the concentration profiles an unambiguous assignment of which species are present at any pH conditions can be made. Furthermore, the knowledge of the pure uv-visible, fluorescence, and CD spectra recovered by the proposed resolution method for each species brings important structural information. When this mathematical approach was applied to the thermal denaturation data, the melting profile and the uv pure spectra for all the different species or conformations formed in the melting process, were calculated. © 1997 John Wiley & Sons, Inc. Biopoly 42: 271–283, 1997     

Distribution of native legumes (Leguminoseae) in frequently burned longleaf pine (Pinaceae)-wiregrass (Poaceae) ecosystems

Legume species distribution and abundance and selected environmental variables were quantified across a complex gradient (varying in both water-holding capacity and fertility) for frequently burned longleaf pine (Pinus palustris)–wiregrass (Aristida stricta) ecosystems. Legumes were present in all months; however, abundance peaked in June and was minimal after killing frosts in October. Legume species were prominent in the flora (43 species encountered) ubiquitous (94% of 2-m² subplots had at least one legume species), and abundant (nearly 120 000 stems/ha). Although most species were widely distributed throughout the gradient, Lespedeza angustifolia was distinctly associated with the more hydric end of the gradient, while both Petalostemon pinnatum and Galactia microphylla were located in the more xeric extreme. The percentage variation in species that could be accounted for by environmental variation was low (27%). Of the variation that could be accounted for, a number of environmental variables were important, including soil moisture, pine basal area (i.e., light), and bivalent base cations (e.g., Ca²⁺). Although gradients in resource availability among sites did not affect the distribution of species or abundance of legumes strongly, variation in resources are likely to regulate N₂-fixation rates of the various native legume species, and thereby affect ecological functions such as maintenance of N capital and productivity.     

A taxonomic review of Phlebotomus (Idiophlebotomus) (Psychodidae)

Five known species (asperulus Quate & Fairchild, erebicolus Quate, pholetor Quate & Fairchild, sejunctus Quate, and stellae Quate) of the caverni-colous subgenus Phlebotomus (Idiophlebotomus) are discussed in relation to newly recognized species from West Malaysia and India. P. frondifer n.sp. and P. tubifer n.sp. are described and a key to the adults of all seven species is given. General features of the subgenus are discussed, with particular reference to the functional relationships between the specialized morphology of the mouthparts and the probable bat hosts of these species.     

Australian species of Sinella (Sinella) Brook (Collembola: Entomobryidae)

Abstract  The Australian subgenus Sinella ( Sinella ) Brook is revised. Two species are recognised. A new species from New South Wales and South Australia, Sinella ( Sinella ) samueli , is described and the widely distributed species Sinella ( Sinella ) termitum Schött is redescribed based on examination of a specimen from the type series and fresh collections from a wide range of localities in south-eastern Australia. New patterns of chaetotaxy for the genus are described from these species.     

Simuliidae (Diptera) of Sabah (British North Borneo)

This paper is based on collections made in Sabah by John Smart and on an examination of named material (types) in the British Museum (Natural History), London.
Segregates discussed comprise:(1) six new species, (2) five named species from the area, described by the late F. W. Edwards (1933).     

The species of Geissorhiza (Iridaceae) of Thunberg's herbarium (Uppsala, Sweden)

The complex typification and nomenclature of the eight species of Geissorhiza based on Thunberg's Cape collections, is reviewed critically in preparation for a complete revision of the genus. These species, initially assigned to Ixia , were described by Thunberg and von Linné fil., founded on collections of twelve different species. Some well known species require changes to their nomenclature; G. rochensis sensu Ker becomes G. radians (Thunb.) Goldbl.; while Ixia scillaris Thunb. nom. illeg., based on three different species is lectotypified and shown to be G. scillaris Spreng., a species quite distinct from G. juncea , with which it has often been confused. Arguments for considering the name G. secunda illegitimate are reviewed. The species long known by this epithet must be called G. aspera Goldbl. Lectotypes have been designated for G. monanthos, G. radians, G. scillaris and G. setacea , none of which have been satisfactorily typified before.     

Embryology of Calenduleae (Compositae)

Microsporangial conditions, macrosporogenesis, embryo sac development and in some species endosperm formation have been studied in 5 species of Dimorphotheca Vaill. ex Mnch, 2 species of Castalis Cass., 16 species of Osteospermum L., 6 species of Calendula L., 1 species of Gibbaria Cass., and 1 species of Chrysanthemoides Tourn. ex Fabr.
The microsporangial wall consists of four different layers of cells. Miocrospore formation is simultaneous. The tetrads are mostly arranged in tetrahedrals. A tapetal periplasmodium develops.
The archespore of the macrosporangium is in most cases 1-celled, sometimes 2-or many-celled. The meiosis gives rise to a linear tetrad. Usually the chalazal macro-spore develops. The embryo sac development is monosporic of the Polygonum type. In a few cases in Dimorphotheca venusta T. Norl. a tetrasporic embryo sac development was observed besides the Polygonum type. Castalis tragus (Ait.) T. Norl. may have a bisporic embryo sac development in addition to the Polygonum type. All the Calendula species develop synergid haustoria. Antipode haustoria occur in Osteospermum sinuatum (DC.) T. Norl. and Chrysanthemoides monilifera (L.) T. Norl. Chalazally situated extra embryo sacs below the ordinary one in Dimorphotheca sinuata DC, D. venusta , and Castalis nudicaulis var. graminifolia (L.) T. Norl. are regarded to be aposporic. Six species have more than three antipodes per embryo sac. The antipodes occasionally become 2-or 4-nucleate.     

Experimental observations on the specificity of Apatemon (Australapatemon) minor (Yamaguti 1933) (Digenea: Strigeidae) toward leech (Hirudinea) second intermediate hosts

The infectivity of Apatemon (Australapatemon) minor cercariae to 7 species of freshwater leech was examined under laboratory conditions. The leech species exposed to infection were; Erpobdella octoculata, Helobdella stagnalis, Glossiphonia heteroclita, Glossiphonia complanata, Hemiclepsis marginata, Piscicola geometra, and Theromyzon tessulatum. Five species were capable of acting as second intermediate hosts. Despite this broad specificity only Erpobdella octoculata and Helobdella stagnalis could be considered to show a high degree of compatibility with the parasite. In these 2 leech species more than 38% of the cercariae successfully penetrated and established metacercarial cyst infections. The leeches Piscicola geometra and Theromyzon tessulatum did not become infected. Close parallels were found between the species order of host utilization determined experimentally and that revealed by a range of field surveys in Britain, Eastern Europe and Russia. This suggests that the order of second intermediate host utilization in the natural environment has, at least in part, a physiological basis. The degree to which different leeches are utilized as hosts may relate to the opportunity which they afford for transmission of A. minor to wildfowl definitive hosts.     

The separation of Pterodroma madeira (Zino's Petrel) from Pterodroma feae (Fea's Petrel) (Aves: Procellariidae)

The taxonomic status of petrels from the North East Atlantic has long been a matter of debate. Breeding colonies of petrels occurring on the islands of Madeira, Bugio and Cape Verde were originally thought to be outlying populations of the polytypic species Pterodroma mollis . Subsequent taxonomic treatments have varied considerably in their classification of birds from these islands. The petrel populations on Madeira and Bugio represent some of Europe's rarest breeding birds and their exact species designation, and hence relation to conservation mandates, is a question of considerable importance. In this study we use molecular techniques alongside more traditional taxonomic characters to confirm the existence of two species of the genus Pterodroma in the Archipelago of Madeira. We also discuss identification of these species in the field and the implications for their conservation management.     

Earthworm (Oligochaeta,Lumbricidae) Populations of the Karasu River Basin (Central Caucasus)

The species composition, population structure, and synecological characteristics of earthworms inhabiting forest and meadow formations of unique beech–hornbeam woodland of the Karasu River basin have been studied. Thirteen Lumbricidae species were found. The species composition and earthworm population structure depend on phytocenosis edificators. The greatest diversity, namely, species, chorological, and ecological, was recorded in soils of relict beech phytocenosis. It was shown that in the case of forest clearing its earthworm’s fauna remains intact. In the secondary meadows, the following was noted: the lowest species diversity of Lumbricidae, domination of soil species proper, and dramatically increasing diversity indices compared to forest associations.     

The ontogeny of appendages of Heterocypris salina (Brady, 1868) Ostracoda (Crustacea)

The post-embryonic development of the appendages of the Cyprididae ostracod Heterocypris salina (Brady, 1868) are described in detail and compared with those of other podocope species documented in previous studies. Generally, the appearence of limbs during onotgeny of H. salina is similar to that of other species, but small differences in limb morphologies were identified between H. salina and other Cyprididae species, including other Heterocypris species. Some features appear either earlier or later in the development of H. salina compared with other species, even species of the same genus. These features may be useful characters for phylogenetic analyses at the genus and family levels.     

Proton-NMR study of the interaction of trans-dichloro-diamine-platinum(II) with poly(I) and poly(I).poly(C)

The fixation of trans-(NH₃)₂Cl₂ Pt(II) to poly(I)·poly(C) at low r_b (< 0.05) leads to the formation of two complexed species. The major species (ca. 82% of bound platinum) involves coordination of platinum to a single hypoxanthine base, while the other species involves coordination of two hypoxanthine bases, which are either far apart on the same strand or on separate poly(I) strands, to the platinum. These same two species are found after reaction with poly(I), as are two other species throughout the entire r_b range studied (r_b = 0–0.30). The latter two species are assigned to trans-Pt bound to two bases on a poly(I) strand with (a) one or (b) two free bases between the two bound bases. These two species, (a) and (b), account for ca. 35% of the bound platinum, although the 1:1 species remains dominant (ca. 55%). These two additional species are observed at high r_b (>0.075) after reaction with poly(I)·poly(C) but as very minor species. They are formed by reaction with melted poly(I) loops. Also at high r_b, we have observed a shifted cytidine H⁵ resonance arising from interaction of trans-Pt with a melted loop of poly(C). Most probably, this arises from an intramolecular poly(I) to poly(C) crosslink. Results from the reaction of trans-Pt with poly(C) are presented for comparison.     

Polyphenism ofHalictus (Seladonia) tumulorum (L.) (Hymenoptera,Halictinae)

Summary A population ofHalictus (S.) tumulorum, a species whose biology is poorly known, was studied in eastern France. The polyphenism was evaluated by comparing a sample of foundresses (1991) with two samples of summer females (1991 and 1992).H. tumulorum is a primitively eusocial species with castes differing only slightly in size, but more in function, and producing numerous males in the first brood. The social level of the species appears rather low.     

Leaf anatomy of c(3)-c(4) species as related to evolution of c(4) photosynthesis

This study was undertaken to examine the degree of Kranz anatomy development in the species intermediate to C₃ and C₄ types (C₃-C₄) in Panicum, Neurachne, Flaveria, and Moricandia. In each genus, C₃ and/or C₄ species were used for comparison. Leaf transections from each species were examined by light and transmission electron microscopy. The percentages of leaf photosynthetic cell profiles partitioned to bundle sheaths were higher in C₄ than in C₃ species, while C₃-C₄ species tended to be in between. However, percentages for C₃-C₄ species in Moricandia and some C₃-C₄Flaveria species were not greater than C₃. When expressed on a cell profile area basis, C₃-C₄ species partitioned more photosynthetic tissue to bundle sheaths than C₃ species in Moricandia, but not in Flaveria. Neurachne minor S. T. Blake (C₃-C₄) partitioned a very small portion of cell profile area to the inner bundle sheaths (5%) compared to Neurachne munroi F. Muell (C₄) (21%). The percentage of organelles partitioned to bundle sheaths was much greater in C₃-C₄ than in C₃ species. The average C₃ percentages for mitochondria plus peroxisomes were 19, 8, and 19.5% for Neurachne, Flaveria, and Moricandia, respectively, compared to 41, 29, and 46.5% for the C₃-C₄ species. The CO₂ compensation concentration was negatively related to the partitioning of tissue to bundle sheaths and to the percentage of organelles in bundle sheaths. It is concluded that all of the C₃-C₄ species examined have developed some degree of Kranz anatomy and that this altered anatomy is involved in their reduced apparent photorespiration.     

New species of Haplometroides (Digenea: Plagiorchiidae) from Phalotris nasutus (Gomes, 1915) (Serpentes, Colubridae)

A new species of Haplometroides (Digenea, Plagiorchiidae) is described from a specimen of Phalotris nasutus (Gomes, 1915) (Serpentes, Colubridae). The host snake was obtained in the municipality of Corumbd, Mato Grosso do Sul State, Brazil. Trematodes were recovered from esophagus, stomach, and small intestine of the host. The main characteristic of the new species is the vitellaria, which is intercecal, cecal, and extracecal in the preacetabular region. A key for identification of the species in Haplometroides is proposed.     

Linkage of plasminogen (PLG) and apolipoprotein(a) (LPA) in baboons.

Four allelic forms of serum plasminogen (PLG) were detected in baboons (Papio hamadryas Linneaus 1758) by isoelectric focusing and were determined to be inherited as autosomal codominant traits. Linkage analysis of data from 179 progeny and their parents revealed that PLG is tightly linked (lod score = 30.20) to the gene encoding apolipoprotein(a) (LPA), as in humans. No recombinant individuals were identified. This is the first linkage detected between PLG and LPA in any species other than humans and is the first genetic linkage identified in a nonhuman primate species by family studies.     

Water-use efficiency and nitrogen-use efficiency of C(3) -C(4) intermediate species of Flaveria Juss. (Asteraceae)

Plants using the C(4) pathway of carbon metabolism are marked by greater photosynthetic water and nitrogen-use efficiencies (PWUE and PNUE, respectively) than C(3) species, but it is unclear to what extent this is the case in C(3) -C(4) intermediate species. In this study, we examined the PWUE and PNUE of 14 species of Flaveria Juss. (Asteraceae), including two C(3) , three C(4) and nine C(3) -C(4) species, the latter containing a gradient of C(4) -cycle activities (as determined by initial fixation of (14) C into C-4 acids). We found that PWUE, PNUE, leaf ribulose 1·5-bisphosphate carboxylase/oxygenase (Rubisco) content and intercellular CO(2) concentration in air (C(i) ) do not change gradually with C(4) -cycle activity. These traits were not significantly different between C(3) species and C(3) -C(4) species with less than 50% C(4) -cycle activity. C(4) -like intermediates with greater than 65% C(4) -cycle activity were not significantly different from plants with fully expressed C(4) photosynthesis. These results indicate that a gradual increase in C(4) -cycle activity has not resulted in a gradual change in PWUE, PNUE, intercellular CO(2) concentration and leaf Rubisco content towards C(4) levels in the intermediate species. Rather, these traits arose in a stepwise manner during the evolutionary transition to the C(4) -like intermediates, which are contained in two different clades within Flaveria.     

Morphometric discrimination of the sibling species Drosophila melanogaster (Meigen) and D. simulans (Sturtevant) (Diptera: Drosophilidae)

Abstract. The sibling species Drosophila melanogaster and D.simulans often co-occur. Males are easily distinguished using their genitalia while females of the two species are often deemed indistinguishable. A series of nine linear and two angular measurements were taken using the heads of both males and females of both species from the same locality. A simple comparison of cheek width and eye height accurately assigned all females to species. Multivariate techniques using linear head measures alone produced very good discrimination between both species and sexes. Drosophila simulans have significantly larger eyes and narrower eye margins than D.melanogaster. Unknown females collected from this locality could be easily and reliably assigned to species.