Cobalt hexafluoroacetylacetonate polyether adducts for thin films of cobalt oxides

The novel [Co(C₅F₆HO₂)₂ · 2H₂O · CH₃(OCH₂CH₂)₂OCH₃] and [Co(C₅F₆HO₂)₂ · 2H₂O · CH₃(OCH₂CH₂)₃OCH₃] low-melting adducts have been synthesized and characterized by elemental analysis, IR spectroscopy, mass spectra and TG-DTG thermal measurements. The former adduct is liquid at room temperature, whilst very mild heating of the latter results in a thermal stable liquid compound. Both adducts can easily be evaporated. Deposition experiments, in a low-pressure horizontal hot-wall reactor, on optical transparent SiO₂ substrates, using these precursors, result in CoO or Co₃O₄ films, depending on the deposition conditions. XRD measurements provide evidence that CoO and Co₃O₄ consist of cubic, highly oriented, (2 0 0) and (3 1 1) crystals, respectively. The mean crystallite sizes were evaluated from the XRD line broadening. Both optical spectra and resistivity measurements of Co₃O₄ films show that they are semi-conducting and their band-gap was determined from the optical induced transitions. The film cross section and the surface atomic composition were investigated by SEM and XPS analyses, respectively.     

Evaluation of the human transmission risk of an atypical bovine spongiform encephalopathy prion strain

Bovine spongiform encephalopathy (BSE), the prion disease in cattle, was widely believed to be caused by only one strain, BSE-C. BSE-C causes the fatal prion disease named new variant Creutzfeldt-Jacob disease in humans. Two atypical BSE strains, bovine amyloidotic spongiform encephalopathy (BASE, also named BSE-L) and BSE-H, have been discovered in several countries since 2004; their transmissibility and phenotypes in humans are unknown. We investigated the infectivity and human phenotype of BASE strains by inoculating transgenic (Tg) mice expressing the human prion protein with brain homogenates from two BASE strain-infected cattle. Sixty percent of the inoculated Tg mice became infected after 20 to 22 months of incubation, a transmission rate higher than those reported for BSE-C. A quarter of BASE strain-infected Tg mice, but none of the Tg mice infected with prions causing a sporadic human prion disease, showed the presence of pathogenic prion protein isoforms in the spleen, indicating that the BASE prion is intrinsically lymphotropic. The pathological prion protein isoforms in BASE strain-infected humanized Tg mouse brains are different from those from the original cattle BASE or sporadic human prion disease. Minimal brain spongiosis and long incubation times are observed for the BASE strain-infected Tg mice. These results suggest that in humans, the BASE strain is a more virulent BSE strain and likely lymphotropic.     

New experimental data on use of rotenone as an acaricide for control of Varroa destructor in honey bee colonies

Three slow release experimental rotenone formulations were tested to evaluate their effectiveness against Varroa destructor Anderson & Trueman in colonies with sealed brood and to determine whether they left residues in honey and bees wax: we evaluated cardboard strip containing 1 g rotenone and two types of polyvinyl chloride (PVC) strips containing 1 (high-dose) and 0.5 (low-dose) g of rotenone, respectively. In general, the efficacy of the treatments, expressed as percentage of mite mortality, was highly variable in all treatment groups (range, 0-96.8%). The highest effectiveness was obtained with the high-dose-PVC strips, which caused an average percentage of mortality ranging between 47 and 69% in the adult bees and sealed brood, respectively. At the end of the treatment, rotenone residues ranged between 0.03 and 0.06 and 1.5-144.0 mg/kg in honey and wax, respectively. Rotenone residues in wax were still detectable 4 mo after the treatment period, whereas no residues were found in honey. The higher residues content and persistence recorded in wax samples, was probably due to the lipophilic nature of rotenone. A reduction in the amount of adults was recorded for the group treated with high-dose-PVC strips compared with the untreated colonies. Toxicological risks connected with the use of rotenone and the low maximum level recently fixed by European legislation (0.01 mg/kg) suggest that rotenone is not a good candidate for reducing varroa populations in honey bee colonies.     

The origin of clonal diversity and structure of Populus alba in Sardinia: evidence from nuclear and plastid microsatellite markers

Background and Aims

Populus alba is a thermophilic forest tree present in the Mediterranean basin. Its habitat is highly fragmented and its distribution range has been subject to long-term human interference, resulting in debate surrounding whether certain populations are native or exotic in origin. In particular, populations from the islands of Corsica and Sardinia are of uncertain origin. While populations of P. alba mainly reproduce sexually, clonal reproduction is also common. The aims of this study were to locate and molecularly characterize the poorly studied island populations of P. alba and compare these with samples from various spatial scales, in order to provide information on the genetic structure and phylogeography of this species. This information will provide evidence on whether the species is native to Sardinia, which is important for the development of conservation strategies.

Methods

DNA extracts were obtained from the following P. alba trees: 159 from Sardinia, 47 from Ticino regional park (northern Italy), 15 acquired from an Italian Germoplasm Bank (IRC; Italian Reference Collection) and 28 from the Mediterranean basin (MB). Genetic polymorphisms were revealed at nuclear and chloroplast DNA (cpDNA) microsatellite loci, both at the island scale (Sardinia) and at broader scales, for comparative assessment of the genetic and genotypic diversity and phylogeography.

Key Results

Based on nuclear microsatellite loci, Sardinian white poplar consists of a small number of genets (26), each of which is represented by several ramets. Despite the uniqueness of the Sardinian haplotypes and the very low value of genetic diversity at the cpDNA level (v_K = 0·15), the H_T (0·60) and the A_R (3·61) values, estimated at the nuclear level for Sardinia, were comparable with those of the other populations and collections.

Conclusions

The uniqueness of the cpDNA haplotypes, the prevalence of clonality and the restricted number of genets recorded suggest that Sardinian white poplar could be a floristic relict of the native flora of the island, which has spread through available habitats on the island mainly by means of vegetative propagation and human activities.Key words: Populus alba, Sardinia, genets, ramets, phylogeography, native forest species     

Neuropeptide neurotensin stimulates intestinal wound healing following chronic intestinal inflammation

Because neurotensin (NT) and its high-affinity receptor (NTR1) modulate immune responses, chloride secretion, and epithelial cell proliferation, we sought to investigate their role in the repair process that follows the development of mucosal injuries during a persistent inflammation. Colonic NT and NTR1, mRNA, and protein significantly increased only after dextran sodium sulfate (DSS)-induced inflammatory damage developed. Colitis-induced body weight loss, colonic myeloperoxidase activity, and histological damage were significantly enhanced by SR-48642 administration, a nonpeptide NTR1 antagonist, whereas continuous NT infusion ameliorated colitis outcome. To evaluate the NT and NTR1 role in tissue healing, mucosal inflammatory injury was established administering 3% DSS for 5 days. After DSS discontinuation, mice rapidly gained weight, ulcers were healed, and colonic NT, NTR1, and cyclooxygenase (COX)-2 mRNA levels were upregulated, whereas SR-48642 treatment caused a further body weight loss, ulcer enlargement, and a blunted colonic COX-2 mRNA upregulation. In a wound-healing model in vitro, NT-induced cell migration in the denuded area was inhibited by indomethacin but not by an antitransforming growth factor-beta neutralizing antibody. Furthermore, NT significantly increased COX-2 mRNA levels by 2.4-fold and stimulated PGE(2) release in HT-29 cells. These findings suggest that NT and NTR1 are part of the network activated after mucosal injuries and that NT stimulates epithelial restitution at least, in part, through a COX-2 dependent pathway.     

LD50 and repellent effects of essential oils from Argentinian wild plant species on Varroa destructor

The repellent and acaricidal effects of some essential oils from the most typical wild plant species of northern Patagonia, Argentina, on Varroa destructor Anderson & Trueman were evaluated using a complete exposure test. Honey bees, Apis mellifera L., and mites (five specimens of each per dish) were introduced in petri dishes having different oil concentrations (from 0.1 to 25 micro per cage). Survival of bees and mites was registered after 24, 48, and 72 h. An attraction/repellence test was performed using a wax tube impregnated with essential oil and another tube containing wax only. The lowest LD50 values for mites were registered for Acantholippia seriphioides (A. Gray) Mold. (1.27 microl per cage) and Schinus molle L. (2.65 microl per cage) after 24 h, and for Wedelia glauca (Ortega) O. Hoffm. ex Hicken (0.59 microl per cage) and A. seriphioides (1.09 microl per cage) after 72 h of treatment. The oil with the highest selectivity ratio (A. mellifera LD50/V. destructor LD50) was the one extracted from S. molle (>16). Oils of Lippia junelliana (Mold.) Troncoso, Minthostachys mollis (HBK) Grieseb., and Lippia turbinata Grieseb. mixed with wax had repellent properties. None of the oils tested had attractive effects on Varroa mites.     

Recombination and migration of Cryphonectria hypovirus 1 as inferred from gene genealogies and the coalescent

Genealogy-based methods were used to estimate migration of the fungal virus Cryphonectria hypovirus 1 between vegetative compatibility types of the host fungus, Cryphonectria parasitica, as a means of estimating horizontal transmission within two host populations. Vegetative incompatibility is a self/non-self recognition system that inhibits virus transmission under laboratory conditions but its effect on transmission in nature has not been clearly demonstrated. Recombination within and among different loci in the virus genome restricted the genealogical analyses to haplotypes with common mutation and recombinational histories. The existence of recombination necessitated that we also use genealogical approaches that can take advantage of both the mutation and recombinational histories of the sample. Virus migration between populations was significantly restricted. In contrast, estimates of migration between vegetative compatibility types were relatively high within populations despite previous evidence that transmission in the laboratory was restricted. The discordance between laboratory estimates and migration estimates from natural populations highlights the challenges in estimating pathogen transmission rates. Genealogical analyses inferred migration patterns throughout the entire coalescent history of one viral region in natural populations and not just recent patterns of migration or laboratory transmission. This application of genealogical analyses provides markedly stronger inferences on overall transmission rates than laboratory estimates do.     

Bronchial hyperreactivity and spirometric impairment in polysensitized patients with allergic rhinitis

BACKGROUND: We previously demonstrated in a group of patients with perennial allergic rhinitis alone impairment of spirometric parameters and high percentage of subjects with bronchial hyperreactivity (BHR). The present study aimed at evaluating a group of polysensitized subjects suffering from allergic rhinitis alone to investigate the presence of spirometric impairment and BHR during the pollen season. METHODS: One hundred rhinitics sensitized both to pollen and perennial allergens were evaluated during the pollen season. Spirometry and methacholine bronchial challenge were performed. RESULTS: Six rhinitics showed impaired values of FEV1 without referred symptoms of asthma. FEF 25-75 values were impaired in 28 rhinitics. Sixty-six patients showed positive methacholine bronchial challenge. FEF 25-75 values were impaired only in BHR positive patients (p < 0.001). A significant difference was observed both for FEV1 (p < 0.05) and FEF 25-75 (p < 0.001) considering BHR severity. CONCLUSIONS: This study evidences that an impairment of spirometric parameters may be observed in polysensitized patients with allergic rhinitis alone during the pollen season. A high percentage of these patients had BHR. A close relationship between upper and lower airways is confirmed.     

The ecto-enzymes CD73 and adenosine deaminase modulate 5′-AMP-derived adenosine in myofibroblasts of the rat small intestine

Adenosine is a versatile signaling molecule recognized to physiologically influence gut motor functions. Both the duration and magnitude of adenosine signaling in enteric neuromuscular function depend on its availability, which is regulated by the ecto-enzymes ecto-5′-nucleotidase (CD73), alkaline phosphatase (AP), and ecto-adenosine deaminase (ADA) and by dipyridamole-sensitive equilibrative transporters (ENTs). Our purpose was to assess the involvement of CD73, APs, ecto-ADA in the formation of AMP-derived adenosine in primary cultures of ileal myofibroblasts (IMFs). IMFs were isolated from rat ileum longitudinal muscle segments by means of primary explant technique and identified by immunofluorescence staining for vimentin and α-smooth muscle actin. IMFs confluent monolayers were exposed to exogenous 5′-AMP in the presence or absence of CD73, APs, ecto-ADA, or ENTs inhibitors. The formation of adenosine and its metabolites in the IMFs medium was monitored by high-performance liquid chromatography. The distribution of CD73 and ADA in IMFs was detected by confocal immunocytochemistry and qRT-PCR. Exogenous 5′-AMP was rapidly cleared being almost undetectable after 60-min incubation, while adenosine levels significantly increased. Treatment of IMFs with CD73 inhibitors markedly reduced 5′-AMP clearance whereas ADA blockade or inhibition of both ADA and ENTs prevented adenosine catabolism. By contrast, inhibition of APs did not affect 5′-AMP metabolism. Immunofluorescence staining and qRT-PCR analysis confirmed the expression of CD73 and ADA in IMFs. Overall, our data show that in IMFs an extracellular AMP-adenosine pathway is functionally active and among the different enzymatic pathways regulating extracellular adenosine levels, CD73 and ecto-ADA represent the critical catabolic pathway.     

An environmental and economic analysis of the wood-pellet chain: two case studies in Southern Italy

Purpose

Wood pellet heating systems are considered as an essential component of European plans to reduce greenhouse gas (GHG) emissions. The goal of this analysis was to estimate and compare the environmental impacts and the costs of the production of packed wood pellets. Two pellet production systems, using roundwood logs (case 1) and mainly sawdust (case 2), have been analysed in 2015 in Basilicata region (Southern Italy).

Methods

A life cycle assessment (LCA) analysis was applied to calculate the environmental impact indicators of each system, whilst a life cycle cost (LCC) analysis was implemented to evaluate the pellets’ cost production. Hence, the functional unit chosen was 1 t of produced pellets. The system boundaries considered for the purpose of the current investigation were from the tree felling to the pellet packaging. In particular, the following activities were considered: motor-manual felling and delimbing with a chainsaw, timber yarding with a tractor along the forest track, loading and transportation of the logs to the collection point, transportation of timber to the factories for a distance of 35 km, pellet production and pellet packaging in low-density polyethylene bags with a total weight of 15 kg bag^?1.

Results and discussion

The production of 1 t of pellets emitted about 83 kg of CO₂eq in case 1 and 38 kg in case 2. In addition, 2.7 kg of SO₂eq and 0.005 kg of PO³ ₄-eq were produced in case 1 and 1.4 kg of SO₂eq and 0.002 kg of PO³ ₄-eq in case 2. Mineral extraction was equal to 0.9 MJ surplus energy in both cases. Case 1 led to higher environmental impacts (about 50% more), essentially for the operation of pelletisation, and in particular for the higher consumption of electricity that characterised it, whereas the production costs were 172 and 113 € t^?1 in case 1 and case 2, respectively. In both study cases, consumption costs (costs for raw material, electricity consumption, fuel usage) were the most important cost items.

Conclusions

Our studies highlight how, in both cases, the operations carried out in the forest produced the minor part of the environmental impact but, at the same time, were the most expensive operations. Further, our studies show how mixing lumbering by-products (sawdust) and forest management products (lumbers) can be an efficient solution to reduce both manufacturing costs and environmental impacts to produce wood pellets.