Studies of fossil hyaenas: affinities of Lycyaenops rhomboideae Kretzoi from Pestlorinc, Hungary

The holotype of the lower-middle Pliocene hyaenid Lycyaenops rhomboideae is redescribed and compared with contemporaneous hyaenids of the genera Lycyaena, Hyaenictis, Chasmaporthetes and Pliocmcuta. These comparisons show that the material represents a valid and distinct genus and species. The genus Lycyaenops is referred to the Chasmaporthetes lineage on the basis of its two-cusped m 1 talonid with reduced entoconid, reduced posterolingual cingulum cusp on p4 and premolar accessory cusps set in a straight line. It is distinguished from all other genera of that lineage by its smaller premolar accessory cusps, broad premolars and squared-off and very broad posterior premolar shelves. The species L. silberbergi, previously assigned to Chasmaporthetes, is also referred to Lycyaenops. It differs from L. rhomboideae in its greater development of the premolar accessory cusps and less developed posterior premolar shelves, but shares the broad, squared-off premolars. The interrelationships of Hyaenictis, Chasmaporthetes and Lycyaenops are at present best described by an unresolved trichotomy, with Lycyaena as its sister taxon.     

Studies of fossil hyaenids: the genus Adcrocuta Kretzoi and the interrelationships of some hyaenid taxa

Material of the Miocene hyaenid Adcrocuta eximia from China is analysed statistically. No heterogeneities were found within this material. Comparisons with material from Samos and Pikermi, Greece, show that no taxonomic differentiation between these three samples is warranted. Adcrocuta eximia latro from the Sivalik deposits is provisionally considered a valid subspecies. The species A. australis from Langebaanweg, South Africa is removed from Adcrocuta to the genus Chasmaporthetes . The phylogenetic position of Adcrocuta has been subject to dispute, and for this reason we present a study of the interrelationships of selected hyaenid taxa using numerical cladistic methods. Two equally parsimonious trees of length 47 and consistency index 0.766 were found. Adcrocuta is placed as a sister-group to the Recent Crocuta crocuta , and not as a separate clade as suggested by other workers. Recent hyaenids form a crown-group which does not extend deep into the cladogram. Hyaena hyaena and H. brunnea are not sister-groups, and we resurrect the genus Parahyaena for the latter species.     

The structure of the mandibular corpus and its relationship to feeding behaviours in extant carnivorans

Assuming some optimization of bone structure to applied mechanical loadings in vivo , different killing and feeding behaviours in carnivores should be reflected in observed differences in cross-sectional shape of their mandibular corpora. Section moduli are used to gauge the magnitudes of bending moments in the mandibular corpus and, when dentary length is controlled, the magnitudes of forces applied to the corpus. Comparisons are made of section moduli at the P₃P₄ and P₄M₁ interdental gaps among canids, felids and hyaenids; in canids only, the M₁M₂ interdental gap was also studied. Local variations in loadings are identified by comparing the section moduli at adjacent loci along the corpus within each family.
The findings of this study show that the precarnassial corpora of canids and hyaenids have greater strength in bending than the corpora of felids of similar body weight. This is taken to reflect relatively greater bending moments under loading in the corpora of canids and hyaenids due, in part, to their elongate dentaries (relative to body weight). Relative to dentary length , however, the precarnassial corpora of felids and hyaenids have much greater strength in bending than the corpora of canids. These scaling relationships appear to reflect the high customary forces (i.e. not moments) applied to the precarnassial corpora of felids and hyaenids with sustained canine killing bites and with bone ingestion using the premolars, respectively. An increase in bending strength of the corpus caudal to the camassial blade in canids is interpreted to be an adaptation for bone-crushing with the postcarnassial molars.     

A NEW SPECIES OF MOERITHERIUM (PROBOSCIDEA, MAMMALIA) FROM THE EOCENE OF ALGERIA: NEW PERSPECTIVES ON THE ANCESTRAL MORPHOTYPE OF THE GENUS

Abstract:  A new species of Moeritherium (Proboscidea, Mammalia), M. chehbeurameuri sp. nov., is described from remains discovered in the early late Eocene locality of Bir El Ater, Algeria. Although mainly represented by isolated teeth, it shows distinct synapomorphies which justify its attribution to the genus Moeritherium , together with exclusive features that led to the creation of the new species. The main characteristic of this new taxon is the almost complete lophodonty shown by its molars, while Moeritherium is commonly regarded as a bunolophodont to bunodont taxon. In addition to this lophodonty, this new taxon shows anatomical features as yet unknown for the genus, but often met within lophodont early proboscidean taxa such as Phosphatherium escuilliei and Numidotherium koholense . Although a revision of the whole genus Moeritherium is outside the scope of this paper, the main controversies and discussion about the definition of species within the genus Moeritherium are discussed. The surprising lophodonty of M. chehbeurameuri , together with its small size, its early late Eocene age and the weak molarization of its P₃ support the hypothesis of a lophodont hypothetical ancestor for moeritheres, and therefore strengthen the growing hypothesis of a lophodont dental ancestral morphotype for proboscideans.     

A NEW SPECIES OF THE GENUS HOMIDIA (COLLEM-BOLA: ENTOMOBRYIDAE) FROM CHINA

Abstract  A new species, Homidia latifolia is described from Mt. Tiantai, Zhejiang Province, East China. The species is characteristic in having leaflike setae on the mentum. The other characters, such as the color pattern, presence of labial seta M₂, chaetotaxy on abd. N and setae on ventral tube, also make it separable from all the known species in the genus.     

Revision of the genus Diplotaxis (Brassicaceae) in the Cape Verde Islands, W Africa

The genus Diplotaxis (Brassicaceae) in the Cape Verde Islands, W Africa, is revised. Nine taxa are accepted, of which five are described as new: D. antoniensis sp. nov., D. glauca, D. gorgadensis sp. nov., D. gorgadensis ssp. brochmannii ssp. nov., D. gracilis, D. hirta, D. sundingii sp. nov., D. varia sp. nov., and D. vogelii . All species are suffruticose, yellow-flowered perennials and belong to sect. Catocarpum . The species are endemic to the Cape Verde Islands, but show morphological and karyolog-ical affinity to the N African and Mediterranean D. harra s. lat. Analyses of morphological variation in 90 populations (400 plants) revealed a complex pattern, in particular in vegetative characters, most likely evolved by parallel ecogeographical differentiation in different islands. The chromosome number is 2n = 26 (n = 13) in the five taxa investigated. Self-pollination experiments indicate that the species are self-incompatible and outcrossing. Experimental F₁ hybrids with full seed set after open pollination were obtained in 30 interspecific combinations, and the taxa are considered fully interfertile. The taxa are thus isolated mainly by geographical and partly by ecological barriers and have evolved by vicariant evolution (most islands) and adaptive radiation (one island).     

PROTEIN COMPOSITION OF MYELIN OF THE PERIPHERAL NERVOUS SYSTEM

Abstract— Myelin was purified from the peripheral nervous system (PNS) of several species. The protein composition of these preparations was examined by discontinuous polyacrylamide gel electrophoresis in buffers containing sodium lauryl sulphate. Proteins characteristic of all samples include, in order of increasing mobility: a series of high molecular weight proteins, the major peripheral nerve protein (P₀), two uncharacterized proteins, and two basic proteins (P₁ and P₂). Quantitative results, obtained by densitometry of gels stained with Fast Green showed differences in protein distribution, both between species, and from different types of nerves obtained from the same animal. The relative amounts of P₁ and P₂ proteins were the most variable; e.g. myelin from guinea-pig sciatic nerve had little or no P₂ protein, whereas 15 per cent of the myelin protein of beef posterior intradural root was Pz protein. P₀, P₁ and P₂ proteins from rabbit sciatic nerve and P₀ and P₂ proteins from beef dorsal and ventral intradural roots were purified and their amino acid compositions were determined. Our results indicated that the P₁ protein is very similar in size and amino acid composition to the basic protein of central nervous system myelin, whereas the P₀ and P₂ proteins are unique to the PNS.     

The effect of variation of thermal processing on the microbial spoilage of chub-packed luncheon meat

Process pasteurization values for reference temperature 70°C (P₇₀) were calculated from the temperature profiles of 250 g luncheon meat chubs cooked under experimental conditions. A simple equation relating Process P₇₀-value and the time and temperature of cooking was derived. With minimal cooking (P₇₀= 40) the surviving microflora (10³/g) was dominated by species of Lactobacillus, Brochothrix and Micrococcus. These organisms were destroyed by more intensive cooking (P₇₀= 105), leaving a flora (10²/g) composed of Bacillus and Micrococcus species. The spoilage that developed after 14 d storage at 25°C reflected the severity of the heat treatment received by each chub: with P₇₀ between 40 and 90, a Streptococcus spoilage sequence occurred; with P₇₀ between 105 and 120, a Bacillus/Streptococcus spoilage sequence occurred; with P₇₀ of 135 and above, a Bacillus spoilage sequence occurred. Cooking to a P₇₀= 75 was adequate to reduce the surviving microflora to the 10²/g level associated with current good manufacturing practice.     

Identification of the Palmitoylation Site in Rat Myelin P0 Glycoprotein

Abstract: P₀ glycoprotein, the major protein of PNS myelin, contains approximately 1 mol of covalently bound long-chain fatty acids. To determine the chemical nature of the fatty acid-protein linkage, P₀ was labeled in rat sciatic nerve slices with [³H]palmitic acid and subsequently treated with various reagents. The protein-bound palmi-tate was released by incubation with the reducing agents dithiothreitol and 2-mercaptoethanol, and with 1 M hydrox-ylamine at pH 7.5. In addition, P₀ was deacylated by treatment with 10 m M NaBH₄ with the concomitant production of [³H]hexadecanol, indicating that the fatty acid is bound in a thioester linkage. This conclusion was supported further by the fact that deacylation with hydroxylamine generated free thiol groups, which were titrated with [¹⁴C]-iodoacetamide. To identify the cysteine residue involved in the thioester linkage, [¹⁴C]carboxyamidomethylated P₀was digested with trypsin and the resulting peptides analyzed by reversed-phase HPLC. Identification of the radioactive protein fragments by amino acid analysis and amino-terminal peptide sequencing revealed that Cys¹⁵³ in rat P₀ glycoprotein is the acylation site. The acylated cysteine is located at the junction of the putative transmem-brane and cytoplasmic domains. This residue is also present in the P₀ glycoprotein of other species, including human, bovine, mice, and chicken.     

Influence of P blood group phenotype on susceptibility to urinary tract infection

Abstract Bacterial attachment is an important event in the pathogenesis of urinary tract infection (UTI). Increased receptivity on the host cells has been suggested influence proneness to infection. The dual function of the globoseries of glycolipids both as receptors for attaching E. coli and as P blood group antigens lead us to examine the P blood group phenotype distribution in UTI prone patient populations. A correlation between the P₁ blood group phenotype and susceptibility to UTI was found. Patients with recurrent pyelonephritis had 74/79 (94%), P₁ compared to 75% in healthy controls. In contrast patients with asymptomatic bacteriuria (ABU) had a reduced frequency of P₁, 43/74 (58%). P₁ and P₂ individuals differ in amount and composition of the globoseries of glycolipids on their erythrocytes. A similar difference in other tissues, e.g. uroepithelial cells might explain the association of P₁ with UTI. There was, however, no significant difference in bacterial adherence to uroepithelial cells from P₁ and P₂ individuals. Other mechanisms explaining the increase in P₁ individuals in recurrent pyelonephritis are discussed.     

Basic proteins of rodent peripheral nerve myelin: immunochemical identification of the 21.5K, 18.5K, 17K, 14K, and P2 proteins

Abstract: Proteins in peripheral nervous system and central nervous system myelin and homogenates of sciatic nerve and brain from young and adult mice and rats were characterized with affinity-purified anti-P₂ and anti-myelin basic protein sera after electrophoretic transfer from sodium dodecyl sulfate-polyacrylamide gels to nitrocellulose sheets. Using this method we have identified a component of rodent peripheral nervous system myelin as P₂ protein. Peripheral nervous system myelin also showed the presence of four basic proteins in addition to P₂ protein. These were found to be analogous to the 14, 17, 18.5, and 21.5K species found in the central nervous system myelin. A number of high-molecular-weight proteins were also detected with anti-myelin basic protein serum in peripheral nervous system, as well as central nervous system myelin. In addition, we report the presence of a high-molecular-weight P₂ cross-reactive protein in rodent brain stem homogenates, but not in central nervous system myelin.     

Two new parrot species (Psittaciformes) from the early Pliocene of Langebaanweg,South Africa,and their palaeoecological implications

Two new parrot species (Psittaciformes) are described from the early Pliocene Varswater Formation at Langebaanweg, South Africa, an area where no parrots currently are found. A coracoid, humeri, ulnae, carpometacarpi, tibiotarsi and tarsometatarsi of at least four individuals are assigned to a new species of lovebird Agapornis. Additional tarsometatarsi of at least five individuals including a nestling are referred to a new genus and species of Psittacinae, a taxon endemic to Africa comprising the extant genera Poicephalus and Psittacus. Both species form the as yet earliest geological record of parrots in Africa and document the early diversification of the taxa Agapornis and Psittacinae. Evidence for parrots in general, and a putative graminivorous species of lovebird in particular, indicates that woodlands as well as grasslands were present at Langebaanweg during the early Pliocene, which is consistent with current hypotheses on the palaeoenvironment at and around this site.     

Depletion of Vipp1 in Synechocystis sp. PCC 6803 affects photosynthetic activity before the loss of thylakoid membranes

A vipp1 mutant of Synechocystis sp. PCC 6803 could not be completely segregated under either mixotrophic or heterotrophic conditions. A vipp1 gene with a copper-regulated promoter (P _petE -vipp1 ) was integrated into a neutral platform in the genome of the merodiploid mutant. The copper-induced expression of P _petE -vipp1 allowed a complete segregation of the vipp1 mutant and observation of the phenotype of Synechocystis 6803 with different levels of vesicle-inducing protein in plastids 1 (Vipp1). When P _petE -vipp1 was turned off by copper deprivation, Synechocystis lost Vipp1 and photosynthetic activity almost simultaneously, and at a later stage, thylakoid membranes and cell viability. The photosystem II (PSII)-mediated electron transfer was much more rapidly reduced than the PSI-mediated electron transfer. By testing a series of concentrations, we found that P _petE -vipp1 cells grown in medium with 0.025 μM Cu²⁺ showed no reduction of thylakoid membranes, but greatly reduced photosynthetic activity and viability. These results suggested that in contrast to a previous report, the loss of photosynthetic activity may not have been due to the loss of thylakoid membranes, but may have been caused more directly by the loss of Vipp1 in Synechocystis 6803.     

Changes in Orthophosphate, Pyrophosphate and Long-Chain Polyphosphate Levels in Leishmania major Promastigotes Incubated With and Without Glucose

The intracellular levels of orthophosphate (P₁), pyrophosphate (PP₁) and short- and long-chain polyphosphate (Poly P) were measured in Leishmania major promastigotes incubated in a phosphate-free medium. In the absence of exogenous substrate, the levels of both P₁ and PP₁ increased during a 1 h incubation. The increase in both P₁ and PP₁ was prevented when glucose was present, but glycerol prevented the rise in P₁ only. A rise in P₁ and PP₁ was also seen in cells incubated in the absence of exogenous substrate under anaerobic conditions. This was reversed upon addition of glucose plus oxygen. Polyphosphate, here shown to be present in L. major , was measured by means of a polyphosphate glucokinase assay. Short-chain Poly P content did not differ between cells incubated for 1 h in the absence of exogenous substrate or in the presence of glucose or glycerol. Long-chain Poly P content, however, was lower in cells incubated without glucose than in cells incubated with glucose and was also lower in cells incubated for 1 h with glycerol as compared with freshly washed cells. Up to 61% of the increase in P₁ and PP₁ that occurred in promastigotes incubated in the absence of exogenous substrate could have arisen from the concomitant decrease in long-chain Poly P.     

Formation of a Disulfide Bond in the Immunoglobulin Domain of the Myelin P0 Protein Is Essential for Its Adhesion

Abstract: It is widely accepted, although never demonstrated, that the formation of a disulfide bond in the majority of immunoglobulin (Ig)-like domains stabilizes their final conformation and thus is essential to their functioning as adhesion/recognition molecules. The myelin P₀ protein, which has been shown directly to behave as a homophilic adhesion molecule, contains a single Ig-like domain, stabilized by a putative Cys²¹-Cys⁹⁸ disulfide bond. To test if this bond is indeed necessary to the adhesive function of P₀, the nucleotides in the P₀ cDNA coding for Cys²¹ were altered to code for an alanine. The mutated P₀ cDNA was transfected into Chinese hamster ovary cells, expression of the mutated P₀ protein was characterized, and the adhesiveness of Cys²¹-mutated P₀-expressing cells and that of cells expressing equivalent surface amounts of the unmutated protein were compared. It was found, as we previously reported, that incubation of a single cell suspension of the unmutated P₀-expressing cells resulted in the rapid formation of large aggregates. In contrast, after a similar incubation the cells expressing the Cys²¹-mutated P₀ were still mostly single cells, a result indistinguishable from that observed with the control transfected cells. This suggests that the P₀ protein, when mutated at Cys²¹, does not behave as a homophilic adhesion molecule, which in turn implies that the formation of an Ig domain disulfide bond is essential to the functioning of this molecule.     

Strong and regulated promoters in the cyanobacterium Anabaena PCC 7120

Abstract The strengths of several promoters were assessed in the cyanobacterium Anabaena PCC 7120 by fusing them to luxAB , encoding bacterial luciferase. Two promoters, P _tac and P _psbA , with sequences nearly identical to consensus Escherichia coli σ ⁷⁰ promoters, gave as high or higher expression than the strong Anabaena promoter, P _rbc . P _npt , the natural promoter driving expression of the kanamycin-resistance determinant from Tn5, was poorly expressed in Anabaena . The Lac repressor partially repressed expression from P _tac , permitting regulated expression in Anabaena after induction with isopropyl thiogalactoside to a level 4–5-fold higher than without inducer.     

CAMELID MATERLAL OF THE GENUS PALAEOLAMA GERVAIS FROM THE TALARA TAR-SEEPS, PERU, WITH A DESCRIPTION OF A NEW SUBGENUS, ASTYLOLAMA

The remains of a large camelid from the Upper Pleistocene (Carolinian) tar-seep deposits near Talara, Peru, aro deseribed with measurements. Comparison with other described South American Pleistocene Camelidae indicates its conspecific identity with Pulaeolama aepuatorialis Hoffstetter, 1952. The absence of interlophar styles on both upper and lower molars is considered the main basis for tho recognition of a now subgenus, Astylolama subgen. nov. Palaenlamua is considered, therefore, to possess three subgenera, Palaeolama . ( Palaeolama ), P. (Protauchenia ) and P. (Astylolama .) A single large left phalanx II from the same deposit is assigned to Palaeolama sp., but may belong within Palaeolama crassa Hoffstetter, 1952 which is known only from a single metatarsal recovered from the Rio Chiche. An isolated right lower caniniform tooth resembling C₁ of P. weddellii and P₁ of Tanupolama stevensi is reported.     

Temporal and spatial distribution of planktic cyanobacteria in Lake Kastoria, Greece, a shallow, urban lake

The temporal and spatial distribution of planktic cyanobacteria and some environmental parameters were studied in the shallow, urban Lake Kastoria, Greece from June 1996 to June 1997. Water temperature varied from 6–27 °C, pH from 7.5–8.9 and dissolved O₂ concentration from 0.7–12 mg m^-3 10^-3. The mean annual Chl a concentration was 83 mg Chl a m^-3 indicative of the eutrophic-hypertrophic state of the lake. Cyanobacterial biomass ranged from 11–238 g FW m^-3, constituting about 90% of the total phytoplankton biomass throughout the year. Cyanobacterial biomass was non-uniformly distributed both vertically and horizontally from August to November 1996 and resulted mainly from the distribution of Microcystis. Seven cyanobacterial taxa were reported for the first time in Lake Kastoria. Six taxa were dominant: Microcystis aeruginosa, M. flos-aquae, M. novacekii. Limnothrix redekei, Anabaena sp. and Cylindrospermopsis raciborskii. The dominant cyanobacterial taxa can be grouped on the basis of their distribution patterns (1) Microcystis species: maximum biomass occurring at pH > 8, temperature 12–17 °C, depth < 0.2 m; (2) Anabaena sp. and Cylindrospermopsis raciborskii : maximum biomass at temperatures 23–26 °C; (3) Limnothrix redekei : maximum biomass at temperatures 6–27 °C. Usually, non-uniform, vertical distributions of cyanobacterial biomass were associated with the formation of temperature, pH and O₂ gradients. L. redekei was considered to be a key lake organism since it contributed up to 59% of the cyanobacterial biomass. Interestingly, three of the dominant cyanobacteria Microcystis aeruginosa, Anabaena sp. and Cylindrospermopsis raciborskii belong to genera that include toxin-producing species.     

Ultrastructural Localization of P2 Protein in Actively Myelinating Rat Schwann Cells

Abstract: The myelin specific protein, P₂, was localized immunocytochemically in electron micrographs of 4-day-old rat peripheral nerve by a preembedding technique. P₂ staining was restricted to Schwann cells that had established a one-to-one relationship with an axon. P₂ antiserum produced a diffuse staining throughout the entire cytosol of myelinating Schwann cells. In addition, the cytoplasmic side of Schwann cell plasma membranes and the membranes of cytoplasmic organelles that were exposed to cytosol were stained by P₂ antiserum. This cytoplasmic localization of P₂ protein is similar to that described for soluble or peripheral membrane proteins that are synthesized on free ribosomes. P₂ antiserum stained the cytoplasmic side of Schwann cell membranes that formed single or multiple loose myelin spirals around an axon. In the region of the outer mesaxon, P₂ antiserum stained the major dense line of compact myelin. These results demonstrate that P₂ protein is located on the cytoplasmic side of compact myelin membranes and are consistent with biochemical studies demonstrating P₂ to be a peripheral membrane protein.     

Changes of inositol phosphates during decapitation-induced lateral bud break of Malus domestica

An increase in phosphatidylcholine (PC), phosphatidyl-ethanolamine (PE), phosphatidylglycerol (PG), and phosphatidylinositol (PI) occurred during bud break induced by decapitation. Inositol-1-phosphate [Ins(l)P₁], inositol-1,4-bisphosphate [Ins(1,4)P₂], and inositol-1,4,5-triphosphate [Ins(1,4,5)P₃] were found in apple buds and increased progressively following decapitation. Ins(1)P₁ and Ins(1,4)P₂ peaked 48 h after decapitation and Ins(1,4,5)P₃ peaked 72 h after decapitation during the metabolic transition when buds emerged from dormancy. Ins(1,4)P₂ and Ins(1,4,5)P₃ levels declined there after. The lateral buds on shoots with intact terminals and decapitated shoots treated with indole-3-acetic acid (IAA) in the terminals tip remained dormant and there were no significant changes in phospholipid and inositol phosphate contents.