Definition and clinical evaluation of a recruiting airway pressure based on the specific lung elastance in anesthetized dogs

ObjectiveTo determine the specific lung elastance (SE_L) in anesthetized dogs and to evaluate the efficacy of a SE_L-based recruiting airway pressure (RP_aw) at improving global and regional lung aeration.Study designRetrospective and prospective clinical study.AnimalsA total of 28 adult dogs were included in the retrospective study and six adult dogs in the prospective study.MethodsRetrospective study: SE_L and SE_L-based RP_aw were determined using previously published data. In mechanically ventilated dogs undergoing thoracic computed tomography (CT), SE_L was calculated as ΔP_L/(V_T/EELV), where ΔP_L is the driving transpulmonary pressure, V_T is the tidal volume and EELV is the end-expiratory lung volume. The ratio of lung to respiratory system elastance (E_L/E_rs) was determined. SE_L and E_L/E_rs were used to calculate the SE_L-based RP_aw. Prospective study: dogs underwent thoracic CT at end-expiration and at end-inspiration using the SE_L-based RP_aw, and global and regional aeration was determined. For analysis of regional aeration, lungs were divided into cranial, intermediate and caudal regions. Regional compliance was also calculated. A p value <0.05 was considered significant.ResultsThe SE_L and E_L/E_rs were 12.7 ± 3.1 cmH₂O and 0.54 ± 0.07, respectively. The SE_L-based RP_aw was 29.1 ± 7.6 cmH₂O. In the prospective study, the RP_aw was 28.2 ± 1.3 cmH₂O. During RP_aw, hyperinflation increased (p = 0.0003) whereas poorly aerated (p < 0.0001) and nonaerated (p = 0.01) tissue decreased. Normally aerated tissue did not change (p = 0.265). Regional compliance was higher in the intermediate (p = 0.0003) and caudal (p = 0.034) regions compared with the cranial region. Aeration did not differ between regions (p > 0.05).Conclusions and clinical relevanceAn SE_L-based RP_aw reduces poorly and nonaerated lung tissue in anesthetized dogs. In nonsurgical anesthetized dogs, an RP_aw near 30 cmH₂O is effective at improving lung aeration.     

Bioaccessibility and antioxidant activity stability of phenolic compounds from extra-virgin olive oils during in vitro digestion

The impact of an in vitro procedure that mimics the physiochemical changes occurring in gastric and small intestinal digestion on the bioaccessibility and antioxidant activity of phenols from 10 extra-virgin olive oil samples was assessed. Extra-virgin olive oil phenols were totally extracted in the aqueous phase, which reproduces gastric fluids during the digestion procedure. A linear bioaccessibility model, based on tyrosol behavior in model oil samples, was used to estimate the bioaccessibility index (BI%) of extra-virgin olive oil phenols. The BI% varied amongst samples from a maximum of 90% to a minimum of 37%, thus indicating that only a fraction of phenols can be considered bioaccessible. The specific antioxidant activity of olive oil phenols proved to be negatively affected by the digestion procedure. By computing a principal component analysis, it was possible to show that differences in the potential bioactive effect of extra-virgin olive oil samples were related to different phenolic profiles.     

Higher-tier assessment of the potential for groundwater issues due to the use of 1,3-D soil fumigant; evaluation of the active ingredient, metabolites and potentially related chlorinated compounds

BACKGROUND: 1,3‐Dichloropropene (1,3‐D, CAS No. 542‐75‐6) is a broad‐spectrum soil fumigant used to control numerous species of soilborne plant‐parasitic nematodes. 1,3‐D consists of two isomers, (Z)‐ and (E)‐1,3‐D. There are a number of low‐level chlorinated compounds that could potentially be produced as a part of the 1,3‐D manufacturing process. 1,3‐D and its metabolites, as well as potentially related chlorinated compounds, represent potential groundwater contaminants. RESULTS: This study has investigated the hydrolytic stability, under biotic and abiotic conditions in the laboratory, of an extensive representative list of 1,3‐D and potentially related chlorinated compounds in order to predict their environmental fate. All of these compounds showed intrinsic hydrolytic instability under both abiotic and biotic test conditions. Furthermore, a monitoring programme was carried out. Twenty‐five wells were monitored in five Italian regions characterised by historical and existing use of 1,3‐D. The parent compound, its two major metabolites and potentially related chlorinated compounds were not detected in the well water at > 0.1 µg L^?1 at any sampling location. CONCLUSION: The soil fumigant (E,Z)‐1,3‐D, its metabolites and potentially related chlorinated compounds constitute a low risk to groundwater. Copyright © 2011 Society of Chemical Industry     

Genetic analysis and molecular characterisation of laboratory and field mutants of Botryotinia fuckeliana (Botrytis cinerea) resistant to QoI fungicides

BACKGROUND: QoI fungicides, inhibitors of mitochondrial respiration, are considered to be at high risk of resistance development. In several phytopathogenic fungi, resistance is caused by mutations (most frequently G143A) in the mitochondrial cytochrome b (cytb) gene. The genetic and molecular basis of QoI resistance were investigated in laboratory and field mutants of Botryotinia fuckeliana (de Bary) Whetz. exhibiting in vitro reduced sensitivity to trifloxystrobin. RESULTS: B. fuckeliana mutants highly resistant to trifloxystrobin were obtained in the laboratory by spontaneous mutations in wild‐type strains, or from naturally infected plants on a medium amended with 1–3 mg L^?1 trifloxystrobin and 2 mM salicylhydroxamic acid, an inhibitor of alternative oxidase. No point mutations were detected, either in the complete nucleotide sequences of the cytb gene or in those of the aox and Rieske protein genes of laboratory mutants, whereas all field mutants carried the G143A mutation in the mitochondrial cytb gene. QoI resistance was always maternally inherited in ascospore progeny of sexual crosses of field mutants with sensitive reference strains. CONCLUSIONS: The G143A mutation in cytb gene is confirmed to be responsible for field resistance to QoIs in B. fuckeliana. Maternal inheritance of resistance to QoIs in progeny of sexual crosses confirmed that it is caused by extranuclear genetic determinants. In laboratory mutants the heteroplasmic state of mutated mitochondria could likely hamper the G143A detection, otherwise other gene(s) underlying different mechanisms of resistance could be involved. Copyright © 2012 Society of Chemical Industry     

Nutritional and pathogenic fungi associated with the pine engraver beetle trigger comparable defenses in Scots pine

Conifer bark beetles are often associated with fungal complexes whose components have different ecological roles. Some associated species are nutritionally obligate fungi, serving as nourishment to the larvae, whereas others are pathogenic blue-stain fungi known to be involved in the interaction with host defenses. In this study we characterized the local and systemic defense responses of Scots pine (Pinus sylvestris L.) against Ophiostoma brunneo-ciliatum Math. (a blue-stain pathogen) and Hyalorhinocladiella macrospora (Franke-Grosm.) Harr. (a nutritional fungus). These fungi are the principal associates of the pine engraver beetle, Ips acuminatus (Gyll.). Host responses were studied following inoculation with the fungi, singly and as a fungal complex, and by identifying and quantifying terpenoids, phenolic compounds and lignin. Although the length of the necrotic lesions differed between control (wound) and fungal treatments, only two compounds (pinosylvin monomethyl ether and (+)-α-pinene) were significantly affected by the presence of the fungi, indicating that Scots pine has a generic, rather than specific, induced response. The fact that both nutritional and blue-stain fungi triggered comparable induced defense responses suggests that even a non-pathogenic fungus may participate in exhausting host plant defenses, indirectly assisting in the beetle establishment process. Our findings contribute to the further development of current theory on the role of associated fungal complexes in bark beetle ecology.     

Changes in the chemical composition of reduced cooked musts during the heating process

Cooked must is the starting raw material in Aceto Balsamico Tradizionale di Modena (ABTM) production, and the cooking process is a crucial step to ensure quality and safety standards. In particular, the furfural content has to be strictly monitored. In this study, we followed, directly at the production plant, nine cooking processes, differing for grape type and process conditions in order to monitor the actual variability in cooked must reduction. 5-Hydroxymethylfurfural (5-HMF) and furfural contents were determined by high performance liquid chromatography (HPLC) technique and glucose, fructose, and tartaric and malic acids by gas chromatography (GC) technique. Furthermore, some bulk properties, such as the water content, refractive index, density, and total acidity, were also measured. The obtained results show that the product undergoes, in the worse operating conditions, remarkable degradation, leading to extremely high levels of furfurals (5-HMF and furfural), corresponding to a water content lower than 40%. On the basis of these results, a first draft of an optimal heating protocol may be suggested in order to guarantee the safety and quality of the final product.     

Centimetre-scale digital representations of terrain and impacts on depression storage and runoff

The microscale topography of a 20 × 10 m hillslope in a burned portion of Kootenay National Park, British Columbia, Canada was determined through laser scanning at a sub-centimetre scale. Digital terrain models (DTM) were developed for this hillslope at the 0.75 cm, 10 cm, 25 cm, 50 cm, 75 cm and 1 m scales. Random Roughness, Tortuosity and Mean Upslope Depression were computed for bare and vegetated surfaces created at each resolution to determine mean depression storage as a function of resolution. Results for these various roughness parameters and associated depression storage values are not found to change appreciably between the vegetated and bare surface DTMs, and moreover do not change notably with increasing grid cell resolution. Depression storage was also computed using a GIS-based method, the values of which are considered to be, at the highest resolution of 0.75 cm, the most realistic for comparative purposes. Mean depression storage using this latter approach decreases significantly with an increase in grid cell size, in contrast to the values based on Random Roughness which remain stable with increasing grid cell size. The generation of Hortonian overland flow was modelled at different scales using the GIS-derived DTMs. The values of depression storage for the various scales of DTM are demonstrated to have significant influences on overland flow generation. The scale of the DTM affects the changes over time between the proportion of water going into depression storage and that contributing to overland flow, with more water being retained as depression storage at a particular value of rainfall excess after infiltration for the smaller DTM scalings. When overland flow develops from a rising groundwater table in a simulation exercise, water depths are initially lower than the primary roughness elements on the land surface and water is relatively disconnected. As water depths increase, more integrated connections form.     

Prediction of agrochemical residue data on fruit using an informatic system (PARDIS model)

A 'step-by-step' method was used to develop a simplified procedure for calculating pesticide residue levels on fruit at harvest by considering the application of the compound and the relevant routes of loss. The model is applicable to cases where the most important exposure route is by direct spray to the canopy of the crop and where uptake into the plant by the roots can be disregarded. The exposure dose is calculated by considering the proportion of total crop cover represented by the fruits. The loss processes considered are photodegradation, uptake, volatilization and washoff.The outputs of the model were compared with measured residues of pesticides on pear. Analysis of the model fit demonstrates that the model predicted the measured data with a good level of accuracy for four of seven investigated pesticides. The predicted/observed quotients are close to 1, as is the modelling efficiency, and there are no great differences between the predicted and observed values. Taking into account the extreme simplicity of the model and the complexity of the environmental processes considered, these results encourage further research into the modelling of residue behaviour in food commodities.The objectives of this work were to produce a tool to predict pesticide residues in products of plant origin, to complement monitoring of pesticide levels and to be useful in evaluating the effect of government policies on food safety. All predicted values were below the maximum levels fixed for pesticide residues in pear, as amended in Council Directives 86/362/EEC and 90/642/EEC. Copyright (c) 2008 Society of Chemical Industry.     

Annual survival probabilities of juvenile loggerhead sea turtles indicate high anthropogenic impact on Mediterranean populations

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