New insights into the photoreactivity of the organophosphorus pesticide fenthion: a sigma aryl cation as a key intermediate in the photodecomposition

The primary photodegradation processes of fenthion (FN), one of the most photosensitive pesticides used in agriculture, have been investigated by combining laser flash photolysis and steady-state measurements. The triplet state of FN is produced quite efficiently (Phi(isc) approximately 0.3). However, this excited state does not seem to trigger the primary photodecomposition pathways of the pesticide. It is demonstrated that FN undergoes photoheterolysis via the excited singlet state and gives the corresponding singlet "sigma aryl cation". Chemical evidence for the generation of this transient species is given by trapping with typical "sigma nucleophiles" such as chloride and methanol. This photodegradation mechanism is, in part, quite different with respect to what is known to date and may account for the formation of the O,O-dimethyl S-[3-methyl-4-(methylthio)phenyl] phosphorothioate discovered as a novel photodegradation product of FN.     

Antioxidant characterization of some Sicilian edible wild greens

Epidemiological studies have demonstrated that many antioxidants and the total antioxidant capacity (TAC) of the diet may protect against cancers and cardiovascular disease. Common fruits and vegetables are good sources of antioxidants, although in some Mediterranean areas traditional wild greens are responsible for a significant percentage of total dietary antioxidant intake. In the European Prospective Investigation into Cancer and Nutrition cohort of Ragusa (Sicily), a high number of subjects were found to frequently eat wild greens, including Sinapis incana and Sinapis nigra, Diplotaxis erucoides, Cichorium intybus, Asparagus acutifolius, and Borrago officinalis. On the basis of these observations, detailed characterization of single antioxidant components (i.e., polyphenols, carotenoids, chlorophylls, and ascorbic acid) and the TAC of these edible wild traditional plants was performed. The wild plants examined were found to be very rich in antioxidants, such as flavonoids and carotenoids, with high TAC values, suggesting that the importance of these vegetables, not only in the traditional but even in the contemporary diet, needs to be emphasized.     

Detection of Ramularia collo-cygni DMI- and SDHI-resistant field populations in Austria and the effect of fungicides on the population and genetic diversity

European Journal of Plant Pathology - Winter barley (Hordeum vulgare L.) is the third most cultivated crop after corn and wheat in Austria but one of the most challenging for disease control. The...     

Morphological and molecular data on the dermal microfilariae of a species of Cercopithifilaria from a dog in Sicily

Dermal microfilariae found in a dog from Sicily, Italy, were characterized morphologically and genetically and differentiated from those of all the other blood microfilariae commonly found in dogs. In particular, the microfilariae were short (mean length of 186.7 μm), presented a body flattened dorso-ventrally and a rounded head, bearing a tiny cephalic hook. The genetic identity of microfilariae herein studied was also assessed by molecular amplification, sequencing and analyzing of multiple ribosomal ITS-2 and mitochondrial (cox1 and 12S) target genes. Both morphologic and genetic characterization as well as the molecular phylogenetic history inferred using sequences of a barcoding dataset were concordant in supporting the identification of Cercopithifilaria at the genus level. Surprisingly, microfilariae here examined were well distinct from Cercopithifilaria grassii (Noè, 1907), from northern Italy, and resembled those of a species described in Brazil, Cercopithifilaria bainae Almeida & Vicente, 1984. This paper provides evidence for the existence of a Cercopithifilaria species infesting a dog from Sicily and also presents a PCR protocol on skin samples as a tool for further epidemiological studies, which could provide evidence on the aetiology and the natural history of this filarial species.     

Canine leishmaniasis surveillance in a northern Italy kennel

An epidemiological survey on canine leishmaniasis (CanL) was performed during a 3-year period (2007-2009) in a public kennel of the Bologna province. The presence of the disease was shown in the canine population for the first time in 2007 by indirect fluorescent antibody test (IFAT). The parasite circulation was confirmed also by direct diagnostic tools, as PCR, cytology and cultural method, performed on different bioptic materials. The parasite was isolated and identified as Leishmania infantum zymodeme MON 1. The serological monitoring was performed also in 2008 and 2009 on animals that previously showed negative or uncertain results. The incidence values calculated by significant seroconversions in IFAT titre ≥ 1/160, ranged between 4.9% and 6.6%, indicating a stable focus of leishmaniasis. The entomological survey, performed by sticky and CO(2)-baited traps in 2008, showed the presence of the vector Phlebotomus perfiliewi. This study allowed us to identify a stable focus of CanL in an area that was not considered eco-compatible with the presence of the vector and infection. Our results confirm the northward spread of CanL towards areas not previously affected by autochthonous foci.     

Responses of Rhynchophorus ferrugineus adults to selected synthetic palm esters: electroantennographic studies and trap catches in an urban environment

BACKGROUND: The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, accidentally introduced into the European countries facing the Mediterranean basin, is becoming the most serious pest for ornamental palms in the urban environment. In the present work, tests were conducted on the electroantennogram (EAG) and behavioural responses of RPW adults to five selected synthetic palm esters, ethyl propionate, ethyl butyrate, ethyl isobutyrate, ethyl lactate and ethyl acetate, to assess the application of a mass trapping technique in an urban environment. RESULTS: In the laboratory, EAG bioassays on RPW adults with the synthetic palm esters showed: (1) positive dose‐dependent responses; (2) differences among the treatments; (3) a greater response to ethyl propionate; (4) a higher sensitivity of female antennae compared with male antennae. In the urban environment, RPW behavioural responses, evaluated over six biweekly observations on pheromone‐ and molasses‐ baited traps, showed that more adults were caught by traps supplemented with ethyl propionate and ethyl acetate than by traps supplemented with only ethyl propionate. Similar catches were recorded in the traps supplemented with ethyl propionate or ethyl acetate. CONCLUSION: This study supports the application of the mass trapping implemented with synthetic palm esters as a potential tool for the management of RPW populations to protect ornamental palms in urban environments. Copyright © 2010 Society of Chemical Industry     

Improving the density of jammed disordered packings using ellipsoids

Packing problems, such as how densely objects can fill a volume, are among the most ancient and persistent problems in mathematics and science. For equal spheres, it has only recently been proved that the face-centered cubic lattice has the highest possible packing fraction phi=pi/18 approximately 0.74. It is also well known that certain random (amorphous) jammed packings have phi approximately 0.64. Here, we show experimentally and with a new simulation algorithm that ellipsoids can randomly pack more densely-up to phi= 0.68 to 0.71 for spheroids with an aspect ratio close to that of M&M's Candies-and even approach phi approximately 0.74 for ellipsoids with other aspect ratios. We suggest that the higher density is directly related to the higher number of degrees of freedom per particle and thus the larger number of particle contacts required to mechanically stabilize the packing. We measured the number of contacts per particle Z approximately 10 for our spheroids, as compared to Z approximately 6 for spheres. Our results have implications for a broad range of scientific disciplines, including the properties of granular media and ceramics, glass formation, and discrete geometry.     

Single-gene greenbeard effects in the social amoeba Dictyostelium discoideum

Selection can favor reproductive altruism if an altruism allele aids copies of itself by helping relatives. The alternative "greenbeard" mechanism, in which an allele directly recognizes and aids copies of itself in others, is generally thought to be too complex for a single gene to carry out. The csA gene in Dictyostelium discoideum acts as a single-gene greenbeard. When wild-type cells are mixed with csA-knockout cells, the wild type is more altruistic, but is also able preferentially to direct the benefits to other wild-type cells. Both properties derive directly from homophilic cell adhesion of the protein encoded by csA.     

Shape and intraporosity of topsoil aggregates under maquis and pasture in the Mediteranean region

The clearing of Mediterranean maquis along with the creation of new pasture land has been an important factor of soil and land degradation in the Mediterranean region. The present research compared soil aggregates and their intraporosity in paired pasture/maquis plots in central E Sardinia (Italy), to study the impact of land use change on soil structure. Undisturbed surface horizons were sampled for thin‐section analysis. Aggregate shape was compared and intraporosity was studied for representative aggregates at different depths. Furthermore, the interaction of root activity and grazing under pasture and maquis cover was discussed. The outcomes revealed a complex interplay of trampling and root activity effects. A decrease (–44%) in total voids (regular pores), along with higher aggregate regularity, was observed under pasture in the 0–2 cm layer, and an increase (+261%) in 50–100 μm planar (elongated) pores was determined in the 2–4 cm layer, suggesting a possible surface compaction due to trampling and an increased subsurface fine root activity by the grassland vegetation.