Towards European climate risk surfaces: the extent and distribution of analogous and non-analogous climates 1931–2100

Aim Climate is an important determinant of species distributions. We assess different aspects of risk arising from future climate change by quantifying changes in the spatial distribution of future climatic conditions compared with the recent past. Location Europe. Methods A 10′ × 10′ resolution gridded data set of five climate variables was used to calculate expected changes to the area, distance and direction of 1931–60 climatic conditions under the HadCM3 climate model for four future climate scenarios based on different rates of greenhouse gas emissions (SRES scenarios). Three levels of tolerance ranges determined the thresholds for which future conditions are considered analogous to 1931–60 (pre‐warming) conditions. Results For many parts of Europe, areas with pre‐warming analogous climate conditions will be smaller and further away in the future than they are now. For any location in Europe, areas with pre‐warming analogous mean annual temperature conditions will, on average, be reduced between 23.7% (B1 scenario) and 49.7% (A1FI scenario) by 2100 when assuming a medium tolerance range. The mean distance to these areas will, on average, increase between 272 km (B1) and 645 km (A1FI). These changes are more pronounced for temperature than for water availability variables and also for narrow tolerance ranges compared to wide tolerance ranges. Using a combined measure of both temperature and precipitation variables, areas with prewarming analogous conditions are predicted to be in a more northeasterly direction in the future, but there are considerable regional differences within Europe. Main conclusions The results suggest that, for some parts of Europe, the loss of area with any suitable climatic conditions represents the greatest risk to biodiversity, but in other regions the distances that species may have to move to reach suitable climatic conditions may be a greater problem. Quantifying the distance and direction in analyses of change of climatically suitable areas can add additional information for climate change risk assessments.     

Specific Detection of Xanthomonas axonopodis pv. dieffenbachiae in Anthurium (Anthurium andreanum) Tissues by Nested PCR

Efficient control of Xanthomonas axonopodis pv. dieffenbachiae, the causal agent of anthurium bacterial blight, requires a sensitive and reliable diagnostic tool. A nested PCR test was developed from a sequence-characterized amplified region marker identified by randomly amplified polymorphic DNA PCR for the detection of X. axonopodis pv. dieffenbachiae. Serological and pathogenicity tests were performed concurrently with the nested PCR test with a large collection of X. axonopodis pv. dieffenbachiae strains that were isolated worldwide and are pathogenic to anthurium and/or other aroids. The internal primer pair directed amplification of the expected product (785 bp) for all 70 X. axonopodis pv. dieffenbachiae strains pathogenic to anthurium tested and for isolates originating from syngonium and not pathogenic to anthurium. This finding is consistent with previous studies which indicated that there is a high level of relatedness between strains from anthurium and strains from syngonium. Strains originating from the two host genera can be distinguished by restriction analysis of the amplification product. No amplification product was obtained with 98 strains of unrelated phytopathogenic bacteria or saprophytic bacteria from the anthurium phyllosphere, except for a weak signal obtained for one X. axonopodis pv. allii strain. Nevertheless, restriction enzyme analysis permitted the two pathovars to be distinguished. The detection threshold obtained with pure cultures or plant extracts (10³ CFU ml⁻¹) allowed detection of the pathogen from symptomless contaminated plants. This test could be a useful diagnostic tool for screening propagation stock plant material and for monitoring international movement of X. axonopodis pv. dieffenbachiae.     

What is a Suiforme (Artiodactyla)?: Contribution of Cranioskeletal and Mitochondrial DNA Data

Suiformes (Artiodactyla) traditionally includes three families: Suidae, Tayassuidae, and Hippopotamidae but the monophyly of this suborder has recently been questioned from molecular data. A maximum parsimony analysis of molecular, morphological, and combined data was performed on the same set of taxa including representatives of the three Artiodactyla suborders (Suiformes, Ruminantia, and Tylopoda) and Perissodactyla as outgroup. Mitochondrial (cytochromeband 12S rRNA) sequence comparisons support the monophyly of Suina (Suidae and Tayassuidae) and Ancodonta (Hippopotamidae) but not the monophyly of Suiformes. Inversely, our preliminary morphological analysis supports the monophyly of Suiformes whereas relationships among the three families are not resolved. The combined data set does not resolve the relationships between Suina, Ancodonta, and Ruminantia. These results are discussed in relation to morphological characters and paleontological data. Some improvements are suggested to clarify the morphological definition of Suiformes and relationships among them.     

Regulation of protein and prostaglandin secretion in polarized primary cultures of caprine uterine epithelial cells

Summary Caprine uterine epithelial (UE) cells were cultured on Matrigel-coated filters. Transmission electron microscopy revealed polarized UE cells characterized by basally located nuclei, apical microvilli, convoluted lateral membranes, and junctional complexes. Domain-specific secretion of prostaglandins and radiolabeled proteins provide further evidence of functional epithelial cell polarity. Two experiments were conducted to evaluate factors controlling prostaglandin E₂ (PGE) and prostaglandin F_2α (PGF) secretion. In experiment one, steroid-treated (estradiol, progesterone, or estradiol + progesterone) polarized UE cells were treated with interferon tau (IFNτ) and/or oxytocin (OT). Steroid treatment did not influence PGE or PGF secretion. However, analysis of variance revealed an IFNτ by OT interaction (P<.01) for both PGE and PGF. This interaction was caused by a reduction in PGE and PGF secretion by cultures receiving only IFNτ and the inability of IFNτ to block OT-induced release of PGE or PGF. In experiment 2, polarized UE cells were cultured in progesterone, with or without IFNτ, and sequentially challenged with estradiol and OT. Oxytocin stimulated the release of both PGE and PGF by polarized cUE cells (P<.01) and resulted in an increased accumulation of PGE (OT*domain; P<.01) in the basal compartment. Interferon tau did not influence PGE (P<.1) secretion. However, further analysis revealed that IFNτ reduced PGF secretion and was unable to block OT-induced PGF secretion (IFNτ*OT; P<.05) by polarized UE cells. Therefore, caprine UE cells form polarized monolayers and retain responsiveness to IFNτ and OT in vitro.     

Electron spin resonance detection of extracellular superoxide anion released by cultured endothelial cells

Objective and Methods Endothelium produces oxygen-derived free radicals which play a major role in vessel wall physiology and pathology. Whereas NO^· production from endothelium has been extensively characterized, little is known about endothelium-derived O^-·₂. In the present study, we determined the O^-·₂ production of bovine aortic endothelial cells (BAEC) using the spin trap 5,5-dimethyl-1 pyrroline-N-oxide (DMPO) and electron spin resonance (ESR) spectroscopy.

Results An ESR adduct DMPO-OH detected in the supernatant of BAEC after stimulation with the calcium ionophore A23187 originated from the trapping of extracellular O^-·₂, because coincubation with superoxide dismutase (30 U/ml) completely suppressed the ESR signal, whereas catalase (2000 U/ml) had no effect. A23187 stimulated extracellular O^-·₂ production in a time- and dose-dependent manner. The coenzymes NADH and NADPH both increased the ESR signal, whereas a flavin antagonist, diphenylene iodonium, abolished the ESR signal. Phorbol myristate acetate potentiated, whereas bisindolylmaleimide I inhibited the A23187-stimulated O^-·₂ production, suggesting the involvement of protein kinase C. These signals were not altered L-NAME, a NO-synthase inhibitor, suggesting that the endogenous production of NO^· did not alter O^-·₂ production. Finally, the amount of O^-·₂ generated by A23187-stimulated post-confluent BAEC was one order of magnitude higher than that evoked by rat aortic smooth muscle cells stimulated under the same conditions.     

Vessel-diameter distribution in roots of grapevines (Vitis vinifera L. cv. Shiraz)

The distribution frequency patterns of diameter of xylem vessels and percentage of total predicted axial conductances were studied in 190-day and 212-day-old main roots of grapevine (Vitis vinifera L. cv. Shiraz) grown under well-watered and stressed conditions. The protoxylem were the first to mature and were responsible for most of the theoretical conductance in root segments between the tip and 2.5 cm from the tip. Some large xylem vessels retained cross walls and protoplasm up to 22.5 cm from the tip. Statistical tests using the Kolmogorov-Smirnov two sample test showed that the pattern of distribution frequency of xylem vessels classified in different diameter classes varied with distance from the root tip. The distribution frequency of xylem vessels was similar in both well-watered and stressed plants from the tip up to 15 cm from the tip. At distances further from the tip the distribution frequency of xylem vessels of well-watered plants was significantly different from that of stressed plants, with the former having more larger vessels than the latter. The pattern of vessel distribution frequency was different from that of percent total axial conductance (K_h) predicted with fewer large vessels carrying most of the axial flow.     

Studies on conversion of labelled pregnenolone to progesterone by olive baboon placental cytotrophoblast cells in vitro

The experiments were designed to study the influence of a variety of substances, which have been reported to affect placental steroid metabolism, on pregnenolone metabolism by olive baboon placenta cells. Placentae were obtained from six baboons by caesarian section between 100 and 110 days of pregnancy. The cells were isolated by enzyme digestion and Ficoll gradient separation and incubated in Ham's F10 media with 5μ Ci [4,7, — 3H] pregnenolone in the presence or absence of indomethacin (0.1 mmol/1), dibutyryl cAMP (10 mmol/l), phorbol myristic acetate (10 nmol/l), 3-isobutyl-1-methylaxanthine (0.5 mmol/l), calcium ionophore A23187 (1 μmol/l), and nordihydroguaiaretic acid (40 μg/ml). Control experiments were done using leucocytes, inactivated placental cells and Ham's F10 media. Time course and dose response studies were also done. Placental cells converted pregnenolone to progesterone in a dose related manner. Addition of test compounds did not affect conversion rates. It is concluded that further studies are needed for elucidation of mechanisms that regulate progesterone synthesis in baboon placentae.