Breeding site selection by olfactory cues in the threatened northern spectacled salamander Salamandrina perspicillata (Savi, 1821)

• 1. The conservation of small aquatic habitats is fundamental to preserving diversity in Mediterranean freshwater ecosystems. Amphibians are particularly endangered, as their chemical world, represented by both abiotic and biotic scent trails, is highly susceptible to environmental changes.
• 2. Breeding site fidelity in the northern spectacled salamander, Salamandrina perspicillata, an Italian endemic vertebrate, was investigated with respect to the ability of this species to locate its own home water rather than that from other places. The choice of aquatic habitat for spawning was investigated in dark conditions by comparing different types of experimental water (home breeding water vs. breeding water of allopatric populations vs. mineral water vs. distilled water). Fifty‐eight reproductive females were collected at four breeding sites in the Lepini Mountains (Latium, central Italy). The number of eggs spawned by each specimen in the different types of experimental water was counted.
• 3. The very large majority of the eggs were found in the home breeding water. When the eggs counted in the other types of water were compared, no differences were found.
• 4. These findings revealed that in the northern spectacled salamander the choice of spawning site was affected by the scent trail of its own aquatic habitat. This new information has improved knowledge of the auto‐ecology of S. perspicillata, thus contributing to strategies for its conservation.

Copyright © 2007 John Wiley & Sons, Ltd.     

Chlorophyll a fluorescence analysis along a vertical gradient of the crown in a poplar (Oxford clone) subjected to ozone and water stress

An experiment in open-top chambers was carried out in summer 2008 at Curno (Northern Italy) in order to study the effects of ozone and mild water stress on poplar cuttings (Oxford clone). In this experiment direct fluorescence parameters (JIP-test) were measured in leaves from different sections of the crown (L: lower; M: medium; U: upper parts of the crown). The parameters considered were calculated at the different steps of the fluorescence transient, and include maximum quantum yield efficiency in the dark-adapted state (F(v)/F(M)); the L-band, at 100?∝?s, that expresses the stability of the tripartite system reaction centre-harvesting light complex-core antenna; the K-band, at 300?∝?s, that expresses the efficiency of the oxygen-evolving complex; the J-phase, at 2 ms, that expresses the efficiency with which a trapped exciton can move an electron into the electron transport chain from Q(A)(-) to the intersystem electron acceptors; the IP-phase, which expresses the efficiency of electron transport around the photosystem 1 (PSI) to reduce the final acceptors of the electron transport chain, i.e., ferredoxin and NADP; and finally the performance index total (PItot) for energy conservation from photons absorbed by PSII to the reduction flux of PSI end acceptors. The main results are: (i) different dynamics were observed between leaves in the lower section, whose PItot decreased over time, and those in the upper sections in which it increased, with a dynamic connected to the leaf age; (ii) ozone depressed all the considered fluorescence parameters in basal leaves of well-watered plants, while it had little or no damaging effect on medium-level or upper-section leaves; (iii) PItot and IP-phase increased in upper leaves of plants subjected to ozone stress, as well as the net photosynthesis; (iv) water stress increased PItot of leaves in all levels of the crown. The results suggest that ozone-damaged poplar plants compensate, at least partially, for the loss of photosynthesis with higher photosynthetic rates in young leaves (in the upper section of the crown), more efficient to fix carbon.     

Classification and class-modeling of "Riviera Ligure" extra-virgin olive oil using chemical-physical parameters

The Protected Designation of Origin (PDO) "Riviera Ligure" for extra-virgin olive oils from Liguria specifies three additional geographical mentions corresponding to three different geographical areas. To obtain a complete characterization of this typical Italian product, 217 samples of olive oils produced in this North Italian region during 1998/99 and 1999/2000 were analyzed. For each sample 31 variables were determined by chemical-physical analyses, and the data were subjected to a multivariate statistical analysis. For the 1998/99 crop, characterized by favorable climatic conditions, class-models of the three geographical areas were obtained with good predictive ability, also considering the influence of the month of olive harvesting. The oil samples from the 1999/2000 crop were similarly studied, but bad climatic conditions and a widespread Dacus oleae infestation leveled out the peculiar features of the oils produced in the three areas.     

Integration of biocontrol yeast and thiabendazole protects stored apples from fungicide sensitive and resistant isolates of Botrytis cinerea

Three selected biocontrol yeasts, known for their elevated antagonistic activity against several fungal pathogens, were tested in vitro for compatibility with common fungicides. The antagonists were resistant to several fungicides, but they were inhibited by triazoles and dithiocarbamates. The yeast isolate LS28 (Cryptococcus laurentii), which tolerated in vitro high rates of benzimidazoles, was tested, alone or in combination with a low dose (10% of the full label rate) of thiabendazole, against grey mould on stored apples. Wounded fruit were inoculated with thiabendazole resistant and sensitive isolates of Botrytis cinerea, applied separately or as a mixture. A more effective and prolonged control of fungal decay was always exerted by the biocontrol yeast applied together with thiabendazole at a low dose. This treatment provided synergistic effects and was markedly better than treatments applied separately, whereas the fungicide applied alone at the highest label dose was ineffective in the presence of the isolate of B. cinerea resistant to thiabendazole. The biocontrol yeast applied alone provided significant protection of apples stored for up to 12 days at 20 °C (from 39 to 81% less decay than untreated control), whereas the fungicide alone at low or high dose was always ineffective in the presence of the B. cinerea isolate resistant to benzimidazoles. The integrated treatment was highly effective and durable showing high reduction of decay (from 66 to 92%) even after 18 days of storage. This study suggests that the integration of a biocontrol agent with a low rate of fungicide may be a useful alternative strategy to manage both sensitive and resistant isolates of fungal pathogens efficiently and to reduce risks involved with extensive use of synthetic chemicals.     

LC/DAD/ESI/MS method for the determination of imidacloprid, thiacloprid, and spinosad in olives and olive oil after field treatment

The behavior in the field and the transfer from olives to olive oil during the technological process of imidacloprid, thiacloprid, and spinosad were studied. The extraction method used was effective in extracting the analytes of interest, and no interfering peaks were detected in the chromatogram. The residue levels found in olives after treatment were 0.14, 0.04, and 0.30 mg/kg for imidacloprid, thiacloprid, and spinosad, respectively, far below the maximum residue levels (MRLs) set for these insecticides in EU. At the preharvest interval (PHI), no residue was detected for imidacloprid and thiacloprid, while spinosad showed a residue level of 0.04 mg/kg. The study of the effect of the technological process on pesticide transfer in olive oil showed that these insecticides tend to remain in the olive cake. The LC/DAD/ESI/MS method showed good performance with adequate recoveries ranging from 80 to 119% and good method limits of quantitation (LOQs) and of determination (LODs). No matrix effect was detected.     

Effects of treatment with St. John's Wort on blood glucose levels and pain perceptions of streptozotocin-diabetic rats

This present study was undertaken to examine treating effects of St. John's Wort (SJW) extract on nociceptive perception of STZ-diabetic animals based on its potential antidiabetic and antinociceptive activities. One week administrations of SJW extract (125 and 250 mg/kg) induced significant decrease in high blood glucose levels of three weeks STZ-diabetic rats and improved their dysregulated metabolic parameters. In addition, SJW extract treatment caused restoration in the mechanical hyperalgesia of diabetic animals. These findings provide a rationale for the traditional use of SJW against diabetes and display the potential of this plant as a new drug candidate/source for the treatment of diabetic pain.     

Magmatic gas composition reveals the source depth of slug-driven strombolian explosive activity

Strombolian-type eruptive activity, common at many volcanoes, consists of regular explosions driven by the bursting of gas slugs that rise faster than surrounding magma. Explosion quakes associated with this activity are usually localized at shallow depth; however, where and how slugs actually form remain poorly constrained. We used spectroscopic measurements performed during both quiescent degassing and explosions on Stromboli volcano (Italy) to demonstrate that gas slugs originate from as deep as the volcano-crust interface (approximately 3 kilometers), where both structural discontinuities and differential bubble-rise speed can promote slug coalescence. The observed decoupling between deep slug genesis and shallow (approximately 250-meter) explosion quakes may be a common feature of strombolian activity, determined by the geometry of plumbing systems.     

Wood hydraulic and mechanical properties induced by low water availability on two ornamental species Photinia × fraseri var. Red Robin and Viburnum opulus L.

Deficit irrigation at the nursery stage induces drought acclimation through the establishment of avoiding mechanisms and hardening processes. In this experiment, we hypothesized that water deficit would affect wood hydraulic conductivity and mechanical properties with effects on the leaf water potentials of two ornamental species, Photinia × fraseri var. Red Robin and Viburnum opulus L.The experiment was conducted in a nursery (Pistoia, Italy) during summer 2011. Individuals were arranged in three plots under three watering regimes. The control plot (C) received an amount of water replacing that lost via evapotranspiration, while two plots were maintained under severe water deficit (SWD = 33% C) and moderate water deficit (MWD = 66% C).Water deficits reduced stem diameter in both species without changing wood density (D). Concerning mechanical properties, stiffness (E) and strength (YS) of Photinia resulted higher in Photinia than in Viburnum, which did not show differences between treatments in either E or YS, whereas in Photinia, E was lower in SWD (P < 0.05) than in C. Photinia was also characterized by higher k without significant differences between treatments while Viburnum showed a lower conductivity and a significant reduction of k_h under SWD (P < 0.05). Despite this, in field conditions the two species had similar behaviour concerning the leaf water status, showing a reduction of Ψ under SWD.A longer acclimation period would probably be necessary to induce major changes in wood mechanical properties, but the similarity of responses on leaf water status in MWD and C might indicate that a reduction to 66% of water need might be sufficient to maintain the level of turgor necessary for plant physiological functioning.