The angiotensin-converting enzyme (ACE) gene family of Anopheles gambiae

Background Members of the M2 family of peptidases, related to mammalian angiotensin converting enzyme (ACE), play important roles in regulating a number of physiological processes. As more invertebrate genomes are sequenced, there is increasing evidence of a variety of M2 peptidase genes, even within a single species. The function of these ACE-like proteins is largely unknown. Sequencing of the A. gambiae genome has revealed a number of ACE-like genes but probable errors in the Ensembl annotation have left the number of ACE-like genes, and their structure, unclear. Results TBLASTN and sequence analysis of cDNAs revealed that the A. gambiae genome contains nine genes (AnoACE genes) which code for proteins with similarity to mammalian ACE. Eight of these genes code for putative single domain enzymes similar to other insect ACEs described so far. AnoACE9, however, has several features in common with mammalian somatic ACE such as a two domain structure and a hydrophobic C terminus. Four of the AnoACE genes (2, 3, 7 and 9) were shown to be expressed at a variety of developmental stages. Expression of AnoACE3, AnoACE7 and AnoACE9 is induced by a blood meal, with AnoACE7 showing the largest (approximately 10-fold) induction. Conclusion Genes coding for two-domain ACEs have arisen several times during the course of evolution suggesting a common selective advantage to having an ACE with two active-sites in tandem in a single protein. AnoACE7 belongs to a sub-group of insect ACEs which are likely to be membrane-bound and which have an unusual, conserved gene structure

On the Treatment of Neutrino Oscillations Without Resort to Weak Eigenstates

We discuss neutrino oscillations in the framework of the quantum field theory without introducing the concept of neutrino weak eigenstates. The external particles are described by wave packets and the different mass eigenstate neutrinos propagate between the production and detection interactions, which are macroscopically localized in space-time. The time-averaged cross section, which is the measurable quantity in the usual experimental setting, is calculated. It is shown that only in the extremely relativistic limit the usual quantum mechanical oscillation probability can be factored out of the cross section.Comment: LaTeX-18pages, JHU-TIPAC-930011,DFTT 22/9

Movement of Four Satellite-Monitored Polar Bears in Lancaster Sound, Northwest Territories

Four female polar bears, fitted with satellite-monitored transmitters at Lancaster Sound, N.W.T. during May 1979, were tracked to determine seasonal distribution, movements relative to ice conditions, and home range. Most locations (68.7%, n = 46) of satellite-tracked bears were on landfast ice, 13.4% (n = 9) on old pack ice, 13.4% (n = 9) on land, 3.0% (n = 2) on bergy water, and 1.5% (n = 1) on young pack ice. These observations support the conclusions of mark-recapture studies in the area, that landfast ice is favored until breakup when bears move onto land. Data from the satellite-tracked bears indicate that they had home ranges.Key words: polar bear, telemetry, satelliteMots clés: ours blanc, télémesure, satellit

Effect of phosphorus form on short-term solubility and availability in soils

Non-Peer ReviewedA laboratory experiment was set up to compare solubility and “availability” of four phosphate fertilizer sources over a period of 32 d after application to soils with varying pH levels. Three soils, one acidic and two alkaline, one of which was non-calcareous and one calcareous, of similar texture and organic matter, were selected. A large number of samples treated with four phosphate products, namely, two ammonium orthophosphate (9-18-9 and 6-24-0), a polyphosphate (10-34-0), and an ammonium mono phosphate (11-52-0) at a rate of at 100 mg P kg-1 soil and an unfertilized control were incubated for a period of 32 d. Destructive sampling at 0, 1, 2, 4, 8, 16 and 32 d was used to assess water soluble and bicarbonate-extractable phosphorus (P). All treatments were replicated four times. Wide differences in soluble and bicarbonate extractable P levels from all four products in all three soils at the onset of incubation became insignificant after 2 to 4 d of incubation suggesting that when any of these products applied at seeding time would offer any advantage over the rest

Distribution, Movement and Abundance of Polar Bears in Lancaster Sound, Northwest Territories

Mark-recapture studies show that polar bears are distributed at varying densities throughout Lancaster Sound during winter and spring. Major concentrations occur along the north and south coasts and the transverse floe edge at the mouth of the sound. As the ice melts, some bears move west whereas others move to nearby land areas. There is some evidence that as the ice forms, polar bears return from their summer locations to eastern Lancaster Sound. Polar bears of Lancaster Sound are part of the larger population whose western range extends to Barrow Strait, Prince Regent Inlet, Wellington Channel and Jones Sound. The southern and eastern range limits are unknown although this population may extend at least to Clyde River on northeastern Baffin Island and probably to Greenland. Maternity denning appears to be widespread over the study area probably because of the abundance of suitable habitat. We estimated a population of 1031 ± 236 polar bears in Lancaster Sound during 1979: however, more estimates are needed to determine if this relatively high number is normal for the area.Key words: polar bear, distribution, movement, abundance, Baffin Bay, Lancaster Sound, summer retreat, dennin

Novel Synthesis and High Pressure Behavior of Na0.3CoO2 x 1.3 H2O and Related Phases

We have prepared powder samples of NaxCoO2 x yH2O using a new synthesis route. Superconductivity was observed in Na0.3CoO2 x 1.3H2O between 4 and 5K as indicated by the magnetic susceptibility. The bulk compressibilities of Na0.3CoO2 x 1.3H2O, Na0.3CoO2 x 0.6H2O and Na0.3CoO2 were determined using a diamond anvil cell and synchrotron powder diffraction. Chemical changes occurring under pressure when using different pressure transmitting media are discussed and further transport measurements are advocated.Comment: 7 pages, 4 figures, PRrapid submitte

Critical Point Field Mixing in an Asymmetric Lattice Gas Model

The field mixing that manifests broken particle-hole symmetry is studied for a 2-D asymmetric lattice gas model having tunable field mixing properties. Monte Carlo simulations within the grand canonical ensemble are used to obtain the critical density distribution for different degrees of particle-hole asymmetry. Except in the special case when this asymmetry vanishes, the density distributions exhibit an antisymmetric correction to the limiting scale-invariant form. The presence of this correction reflects the mixing of the critical energy density into the ordering operator. Its functional form is found to be in excellent agreement with that predicted by the mixed-field finite-size-scaling theory of Bruce and Wilding. A computational procedure for measuring the significant field mixing parameter is also described, and its accuracy gauged by comparing the results with exact values obtained analytically.Comment: 10 Pages, LaTeX + 8 figures available from author on request, To appear in Z. Phys.