Species of Borrelia distinguished by restriction site polymorphisms in 16S rRNA genes

Abstract Three phyletic groups of Borrelia associated with Lyme disease, B. burgdorferi, B. garinii and group VS461 can be distinguished from each other and other species of Borrelia by Bfa I restriction site polymorphisms in PCR amplified 16S rRNA genes. One strain isolated from an Ixodes pacificus tick in California that was previously unclassifiable was distinguishable from B. burgdorferi by an Mnl I restriction site polymorphism.     

Spatial components of foraging behavior in an African Ponerine ant,Paltothyreus tarsatus

Colonies of the African stink ant Paltothyreus tarsatuslocated in the forest have nests with shorter horizontal galleries and a smaller total foraging surface than colonies located in open areas. Each solitary worker specializes on the same central or peripheral hunting zone but she does not specialize on a particular sector during group-retrieving. The search for prey is characterized by a wandering walk with spatial parameters varying in two ways. Capture of a termite releases a path characterized by sinuosity and a decrease in speed of movement. In contrast, a failure in the course of an attempted capture releases an increase in both sinuosity and speed of movement corresponding to a socalled reserve behavior. Each worker shortens her retrieving trip in comparison with her search trip and the straightness of the homing paths depends on the size and shape of the prey. Our data show that behavioral flexibility at the individual level in P. tarsatusis important in determining spatial foraging strategy at the colony level.     

Morphology of the Bony Labyrinth Supports the Affinities of Paradolichopithecus with the Papionina

International Journal of Primatology - Discoveries in recent decades indicate that the large papionin monkeys Paradolipopithecus and Procynocephalus are key members of the Late Pliocene –...     

Habitat selection and space use overlap between feral horses,pronghorn, and greater sage-grouse in cold arid steppe

Populations of feral horses (Equus ferus caballus) in the western United States have increased during the past decade, consequently affecting co-occurring wildlife habitat. Feral horses may influence 2 native wildlife species, greater sage-grouse (Centrocercus urophasianus; sage-grouse) and pronghorn (Antilocapra americana) through mechanisms of habitat alteration and competition. Wyoming, USA, contains the largest populations of pronghorn and sage-grouse of any state and also has the highest degree of range overlap between feral horses and these species. Consequently, the effects that horses may have on pronghorn and sage-grouse populations in Wyoming have implications at local, state, and population-wide levels. Managers need information concerning habitat selection and space use overlap among these species to develop appropriate management strategies; yet this information is absent for most feral horse management areas. To address this knowledge need, we attached global positioning system (GPS) transmitters to horses, pronghorn, and sage-grouse within the greater Bureau of Land Management–Adobe Town Herd Management Area in southern Wyoming and northern Colorado, USA, between 2017 and 2021 to evaluate habitat selection and space use of all species during 3 biologically relevant seasons: spring (Apr–Jun; sage-grouse breeding, nesting, and early-brood rearing; pronghorn late gestation and early parturition), summer (Jul–Oct; sage-grouse summer and late-brood rearing; pronghorn late parturition and breeding), and winter (Nov–Mar; non-breeding season). Feral horses selected flatter slopes and shorter mean shrub height across all seasons and were closer to water in spring and summer. Pronghorn habitat selection was similar to horses, but they also avoided oil and gas well pads year-round. During spring, sage-grouse selected greater herbaceous cover, flatter slopes, and areas farther from well pads. In summer, sage-grouse selected greater mean shrub height, flatter slopes, and were closer to water. In winter, sage-grouse selected flatter slopes and areas with greater vegetation production during the preceding summer. Our results indicate strong year-round overlap in space use between horses and pronghorn, whereas overlap between horses and sage-grouse is greatest during the summer in this region. Consequently, managers should recognize the potential for horses to influence habitat quality of pronghorn and sage-grouse in the region.     

Characterization of phosphoinositide kinases in normal and sickle anaemia red cells

PtdIns and PtdInsP kinases from normal erythrocyte (AA) membranes and sickle cell anaemia erythrocyte (SS) membranes have been characterized. PtdIns kinase was studied in native membranes under conditions in which PtdInsP kinase and PtdInsP phosphatase do not express any activity. Kinetic analysis of the AA and SS PtdIns kinases indicate similar K_m values for PtdIns and ATP but higher V_max values for SS PtdIns kinase. PtdInsP kinase was partially purified from erythrocyte ghosts by NaCl extraction. The kinetic parameters of PtdInsP kinase determined under these conditions were similar in AA and SS NaCl extracts. These data suggest the presence of some effector of PtdIns kinase in SS cell membranes, resulting in a greater activity of the enzyme. This leads consequently, to increase the PtdInsP pool and to activate PtdInsP kinase, in agreement with our previous observations of a greater [³²P]Pi incorporation in both polyphosphoinositides in SS cells relatively to AA cells.     

Bioguided Fractionation and Isolation of an Antiplasmodial Saponin from the Roots of Nauclea xanthoxylon (A.Chev.) Aubrév. (Rubiaceae)

The root extract of Nauclea xanthoxylon (A.Chev.) Aubrév. displayed significant 50 % inhibition concentration (IC₅₀s) of 0.57 and 1.26 μg/mL against chloroquine resistant and sensitive Plasmodium falciparum (Pf) Dd2 and 3D7 strains, respectively. Bio-guided fractionation led to an ethyl acetate fraction with IC₅₀s of 2.68 and 1.85 μg/mL and subsequently, to the new quinovic acid saponin named xanthoxyloside ( 1 ) with IC₅₀s of 0.33 and 1.30 μM, respectively against the tested strains. Further compounds obtained from ethyl acetate and hexane fractions were the known clethric acid ( 2 ), ursolic acid ( 3 ), quafrinoic acid ( 4 ), quinovic acid ( 5 ), quinovic acid 3-O-β-D-fucopyranoside ( 6 ), oleanolic acid ( 7 ), oleanolic acid 3-acetate ( 8 ), friedelin ( 9 ), β-sitosterol ( 10a ), stigmasterol ( 10b ) and stigmasterol 3-O-β-D-glucopyranoside ( 11 ). Their structures were characterised with the aid of comprehensive spectroscopic methods (1 and 2D NMR, Mass). Bio-assays were performed using nucleic acid gel stain (SYBR green I)-based fluorescence assay with chloroquine as reference. Extracts and compounds exhibited good selectivity indices (SIs) of >10. Significant antiplasmodial activities measured for the crude extract, the ethyl acetate fraction and xanthoxyloside ( 1 ) from that fraction can justify the use of the root of N. xanthoxylon in ethnomedicine to treat malaria.     

Persistent Intercolonial Trunkroute-marking in the African Weaver Ant Oecophylla longinoda Latreille (Hymenoptera,Formicidae): Tom Thumb's versus Ariadne's Orienting Strategies

The territorial African weaver ant Oecophylla longinoda forages in a 3-dimensional system when attending honeydew secreted by coccid colonies. The orienting strategy allowing workers to reach a static food resource was studied in laboratory conditions. Contrary to other studies devoted to territoriality in O. longinoda, our experiments show that, when moving off the nest, territorial faecal marking by the major workers is not randomly placed all over the home-range area. The chemical trail leading from the nest to a given food site is reinforced by faecal materials both on the horizontal and the vertical planes. In addition to visual cues and chemical trails laid by the major workers (Holldobler & Wilson 1978), foragers use the territorial marking both to localize the food site and to come back to the nest. Thus, anal-drop deposition in O. longinoda also has a clear dual-purpose function: territorial and orientationai marking. The ecological value of such a discrete Tom Thumb's orienting strategy enables workers to quickly reach a food location even after more than 5 months of inactivity on this given site. The persistent marked trail also has an intercolonial effect. This could allow the keeping of exploitation of a definite food site by alien colonies of the same species by reducing time costs for new exploring phases or for learning new spatial cues when foraging on an unknown environment.     

INORGANIC CARBON LIMITATION OF PHOTOSYNTHESIS IN ULVA ROTUNDATA (CHLOROPHYTA)1

A computerized oxygen electrode Astern was used to make rapid and accurate measurements of photosynthetic light and dissolved inorganic carbon (DIC) response cures with a macroalga. Ulva rotundata Blid. was grown in an outdoor, continuous flow system in seawater under sunlight or 9% of sunlight at Beaufort, North Carolina. The light compensation points in the shade- and sun-grown plants, measured in seawater, were at photon flux densities (PFDs) of 16 and 27 μmol. Photons·m^?2·s^?1, respectively but the quantum yield of O₂ evolution was not significantly different. Rates of photosynthesis in seawater per unit area of thallus under saturating light and rates of dark respiration were about 1.5-fold higher in sun- than in shade-grown plants. The concentration of DIC in seawater (approximately 2 mM) limited photosynthesis at absorbed PFDs above 60–70 μmol photons·m^?2·s^?1 Addition of 20 mM inorganic carbon had no effect on quantum yield but caused about a 1.5-fold increase in the light-saturated photosynthetic rate in both shade- and sun-grown Ulva. The effect of DIC supplementation was greatest in plants grown in October and least in plants grown in June. The light- and DIC-saturated rate of photosynthesis in seawater was similar to the maximum rate obtained by exposing Ulva to 10% CO₂, in the gas phase. The carbon isotope values (δ¹³C, reflecting the ¹³C/¹²C ratio compared to a standard) of Ulva grown in the same seawater supply were dependent on light and agitation. Samples from Beaufort Inlet were more negative (δ¹³C value, ?20.03‰) than those grown in bright light with agitation (δ¹³C value, ?17.78‰ outdoors; ?17.23‰ indoors), which may indicate DIC supply limited carbon uptake in seawater.