Prevalence, quantification and antimicrobial resistance of Campylobacter spp. on chicken neck-skins at points of slaughter in 5 major cities located on 4 continents

Quantitative data on Campylobacter contamination of food are lacking, notably in developing countries. We assessed Campylobacter contamination of chicken neck-skins at points of slaughter in 5 major cities in Africa (Dakar in Senegal, Yaounde in Cameroon), Oceania (Noumea in New Caledonia), the Indian Ocean (Antananarivo in Madagascar) and Asia (Ho Chi Minh City (HCMC) in Vietnam. One hundred and fifty slaughtered chickens were collected in each of the 5 major cities from semi-industrial abattoirs or markets (direct slaughter by the seller), and 65.5% (491/750) were found to be Campylobacter-positive. Two cities, Yaounde and Noumea, demonstrated high prevalence Campylobacter detection rates (92.7% and 96.7% respectively) in contrast with HCMC (15.3%). Four species were identified among 633 isolates, namely C. jejuni (48.3%), C. coli (37.3%), C. lari (11.7%) and C. upsaliensis (1%). HCMC was the only city with C. lari isolation as was Antananarivo for C. upsaliensis. C. coli was highly prevalent only in Yaounde (69.5%). Among the 491 samples positive in Campylobacter detection, 329 were also positive with the enumeration method. The number of Campylobacter colony-forming units (CFU) per gram of neck-skin in samples positive in enumeration was high (mean of the log(10): 3.2 log(10) CFU/g, arithmetic mean: 7900CFU/g). All the cities showed close enumeration means except HCMC with a 1.81 log(10) CFU/g mean for positive samples. Semi-industrial abattoir was linked to a significant lower count of Campylobacter contamination than direct slaughter by the seller (p=0.006). On 546 isolates (546/633, 86.3%) tested for antibiotic susceptibility, resistance to erythromycin, ampicillin and ciprofloxacin was observed for respectively 11%, 19% and 50%. HCMC was the city where antibiotic resistant rates were the highest (95%, p=0.014). Considering the 329 positive chickens in Campylobacter enumeration, the mean number of resistant isolates to at least 2 different antibiotic families (19.8%), may be estimated ca. 1500CFU/g; the corresponding mean of the log(10) would be 2.5 log(10)CFU/g. As chickens are sold at slaughter and brought directly at home to be cooked, these data suggest a high probability of cross-contamination. A substantial proportion of isolates are drug-resistant, which could lead to potential public health issues. Health authorities should consider measures to reduce Campylobacter contamination of chicken during farming and at slaughter, and to provide appropriate food hygiene education. Further studies are needed in particular to investigate food-handling practices in domestic kitchens.     

Antioxidant capacity and phenolics of <Emphasis Type="Italic">Pouteria macrophylla</Emphasis>, an under-utilized fruit from Brazilian Amazon

The potential of fruits occurring in the Amazon with regard to their antioxidant capacity is being addressed increasingly during the last years. In this paper, the antioxidant capacity of fruits from Pouteria macrophylla (cutite) and the compounds which are responsible for that functional property were studied. Diphenyl-picrylhydrazyl (DPPH) and total oxidant scavenging capacity (TOSC) assays were used for the evaluation of antioxidant capacity of fruit aqueous extracts. TOSC assay showed inhibitory effects against peroxyl (TOSC_50% = 560 mg/L) and peroxynitrite (TOSC_50% = 830 mg/L), two important reactive oxygen species, while DPPH showed that cutite (EC₅₀ = 300 ± 3.9 g/g DPPH) has significant antioxidant capacity, greater than many other known Amazon fruits. It was also seen that the cutite fruits are a good alimentary source of polyphenols (867 ± 8 mg GAE/100 g), analyzed by Folin-Ciocalteu assay. Using HPLC-DAD-ESI-MS ⁿ and HPLC-DAD, gallic acid (4.72 mg/g fresh fruit pulp) and digalloyl glucose were found as the main phenolic compounds in the cutite fruits. TOSC assays with HPLC fractions of fruit aqueous extracts show that both compounds are predominantly responsible for the antioxidant capacity observed in the cutite.     

Optimizing performances of photovoltaics in Reunion Island—tilt angle

As in Reunion Island, France, around 61% of electricity is produced by using coal and fuel oil with high greenhouse emissions, it is beneficial to the environment to produce electricity from solar energy. Therefore, there is a large push to generate electricity from solar energy by use of photovoltaic (PV) arrays. However, it is important to have high efficiency of electricity generation, that is, to locate PV arrays in an optimal direction. The investigated PV systems may take 1, 2, 4, and 12 tilts per year. For the PV arrays facing the north–south direction, this paper reports investigations of their optimum tilts and the maximum amounts of generated electricity. The investigated PV arrays are located in the towns of Saint‐Benoit, Les Avirons, Piton Saint‐Leu, and Petite‐France in Reunion Island. To obtain optimal tilt of the PV arrays for electricity production from solar energy, EnergyPlus software and GenOpt software are used with Hooke–Jeeves optimization routine. For the investigated PV arrays, the percentage gains in energy, exergy, avoided fossil energy, and the percentage decrease in CO₂ emission are around 5% when compared with that of the PV array that takes only one optimum tilt per year. Copyright © 2011 John Wiley & Sons, Ltd.     

Beyond PCBM: Understanding the Photovoltaic Performance of Blends of Indene‐C60 Multiadducts with Poly(3‐hexylthiophene)

The effect of functionalization of the C₆₀ cage with multiple indene groups in relation to the dynamics of photogenerated species in blends with poly(3‐hexylthiophene) (P3HT) and the performance of P3HT:indene‐C₆₀ photovoltaic devices is reported. Despite the systematic decrease of the electron affinity of the acceptor with the number of additions, exciton dissociation is efficient in blends of P3HT with all three indene‐C₆₀ derivatives. By replacing the prototypical acceptor [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PCBM) with mono‐indene‐C₆₀ (ICMA) or a sample of a mixture of bis‐indene‐C₆₀ regioisomers (ICBA) the power conversion efficiency is enhanced, predominantly due to an increase in the open‐circuit voltage that originates from the lower electron affinity of the indene‐C₆₀ acceptor. The use of an acceptor sample that represents a mixture of tris‐indene‐C₆₀ (ICTA) regioisomers results in a reduction of the short‐circuit current density, fill factor, and open‐circuit voltage of the photovoltaic device. The electron mobility in ICTA domains is ca. a factor 10 lower than in ICMA and ICBA. Density functional theory calculations of the LUMO energies in ICTA isomers demonstrate that energetic disorder caused by the presence of regioisomers is unlikely to be responsible for the low electron mobility in ICTA. The observed deterioration in device performance is attributed to the formation of small ICTA clusters “coated” in insulating indene units that reduce electronic coupling between the molecules and cause the low electron mobility in ICTA domains. These findings indicate that while multiple additions to a fullerene cage provide a facile methodology for controlling the energy levels, they may have limited success in improving OPV device performance.     

Maintenance of Arachidonic Acid and Evidence of Δ5 Desaturation in Cats Fed γ-Linolenic and Linoleic Acid Enriched Diets

Cats have limited Δ6 desaturase activity. However, γ-linolenate (GLA) feeding may by-pass the Δ6 desaturase step allowing arachidonate (ARA) accumulation via Δ5-desaturation. Alternatively, high dietary linoleate (LNA) may induce limited Δ6 desaturase also resulting in ARA accumulation. Fatty acid profiles were determined after feeding high LNA, high GLA, or adequate LNA diets. Adult female cats (n = 29) were assigned to one of three groups and fed for 8 weeks. Plasma samples were collected at weeks 0, 2, 4 and 8 for plasma triacylglycerol (TAG), total cholesterol (TC), lipoprotein (LP), and plasma and red blood cell membrane phospholipid fatty acid determinations. Time, but no diet, effects were observed for TAG, TC, and LP fractions at weeks 2 and 4 with significant increases likely due to increased dietary fat. However, all values were within feline normal limits. The GLA diet resulted in increased dihomo-γ-linolenic acid (DGLA) and ARA as early as week 2, supporting a ∆5 desaturase. Further evidence of Δ5 desaturase was found at high dietary LNA with the appearance of a novel fatty acid, 20:3 ∆7, 11, 14, apparently formed via ∆5 desaturation and chain elongation of LNA. However, Δ6 desaturase induction at high dietary LNA concentration was not observed. Cats are able to maintain plasma and red blood cell ARA when fed a practical diet containing GLA using what appears to be an active Δ5 desaturase enzyme.     

Toxicogenomic responses of nanotoxicity in Daphnia magna exposed to silver nitrate and coated silver nanoparticles

Applications for silver nanomaterials in consumer products are rapidly expanding, creating an urgent need for toxicological examination of the exposure potential and ecological effects of silver nanoparticles (AgNPs). The integration of genomic techniques into environmental toxicology has presented new avenues to develop exposure biomarkers and investigate the mode of toxicity of novel chemicals. In the present study we used a 15k oligonucleotide microarray for Daphnia magna, a freshwater crustacean and common indicator species for toxicity, to differentiate between particle specific and ionic silver toxicity and to develop exposure biomarkers for citrate-coated and PVP-coated AgNPs. Gene expression profiles revealed that AgNO(3) and AgNPs have distinct expression profiles suggesting different modes of toxicity. Major biological processes disrupted by the AgNPs include protein metabolism and signal transduction. In contrast, AgNO(3) caused a downregulation of developmental processes, particularly in sensory development. Metal responsive and DNA damage repair genes were induced by the PVP AgNPs, but not the other treatments. In addition, two specific biomarkers were developed for the environmental detection of PVP AgNPs; although further verification under different environmental conditions is needed.     

Terahertz Photometer to Observe Solar Flares in Continuum

Solar observations at sub-THz frequencies detected a new flare spectral component peaking in the THz range, simultaneously with the well known microwaves component, bringing challenging constraints for interpretation. Higher THz frequencies observations are needed to understand the nature of the mechanisms occurring in flares. A THz photometer system was developed to observe outside the terrestrial atmosphere on stratospheric balloons or satellites, or at exceptionally transparent ground stations. The telescope was designed to observe the whole solar disk detecting small relative changes in input temperature caused by flares at localized positions. A Golay cell detector is preceded by low-pass filters to suppress visible and near IR radiation, a band-pass filter, and a chopper. A prototype was assembled to demonstrate the new concept and the system performance. It can detect temperature variations smaller than 1 K for data sampled at a rate of 10/s, smoothed for intervals larger than 4 s. For a 76 mm aperture, this corresponds to small solar burst intensities at THz frequencies. A system with 3 and 7 THz photometers is being built for solar flare observations on board of stratospheric balloon missions.     

Control strategies against grey mould (Botrytis cinerea Pers.: Fr) and corresponding fungicide residues in grapes and wines

This study examines the most effective anti-Botrytis strategies leading to possible lower pesticides residues in wine. To provide wine growers with a number of high-quality solutions for protection against Botrytis for their vineyards while minimizing pesticide residues in the final product, various treatment approaches were tested. A total of 10 strategies with different specific fungicide treatments for controlling Botrytis cinerea were applied to grapes at different growing stages: flowering, bunch closure and colour change. The type of vine chosen was Gamay, as it is very sensitive to Botrytis cinerea. In each experimental plot, disease incidence and severity were assessed at harvest. In addition, pesticide residue analysis was carried out on grapes, musts and wines to monitor residue levels in each treatment and to follow changes at each stage of the wine-making process. A correlation was established between the efficiency of anti-Botrytis fungicide treatment and pesticide residues in wine. Several strategies using various fungicides showed good results in terms of treatment efficiency while minimizing pesticide residues in wine, thus providing interesting alternatives to limit the development of fungal resistance.     

In Vivo Genotoxicity Evaluation of an Artichoke (Cynara scolymus L.) Aqueous Extract

The Cynara scolymus (artichoke) is widely consumed as tea or food and shows important therapeutic properties. However, few studies have assessed the possible toxic effects of artichoke extracts. This study evaluates genotoxic and mutagenic activities of artichoke leaf aqueous extract in mice using the comet assay and the micronucleus test. Leaf extracts were given by gavage (500 mg/kg, 1000 mg/kg, and 2000 mg/kg) for 3 consecutive days. Extract composition was investigated using phytochemical screening and high‐performance liquid chromatography (HPLC). In addition, antioxidant capacity was analyzed through the diphenyl‐picrylhydrazyl (DPPH) and xanthine oxidase assay. Phytochemical screening detected the presence of phenolic compounds, flavonoids, and saponins. HPLC analyses indicated the presence of chlorogenic acid, caffeic acid, isoquercetrin, and rutin. Extracts showed a dose‐dependent free radical scavenging effect of DPPH and an inhibitory effect of xanthine oxidase. The genotoxic results showed that leaf extracts did not increase micronuclei in peripheral blood cells. Compared to the control group, a significant increase in comet assay values was observed only in bone marrow of group treated with 2000 mg/kg, the highest dose tested, indicating that artichoke tea should be consumed with moderation. Practical Application: This is the first report of in vivo mutagenic and genotoxic evaluation with C. scolymus. The present study revealed leaf aqueous extract from artichoke shows lack of mutagenicity in vivo, and low genotoxicity and antioxidant activity; indicating that artichoke tea should be consumed with moderation.     

Segmentation of scanning electron microscopy images from natural rubber samples with gold nanoparticles using starlet wavelets

Electronic microscopy has been used for morphology evaluation of different materials structures. However, microscopy results may be affected by several factors. Image processing methods can be used to correct and improve the quality of these results. In this article, we propose an algorithm based on starlets to perform the segmentation of scanning electron microscopy images. An application is presented in order to locate gold nanoparticles in natural rubber membranes. In this application, our method showed accuracy greater than 85% for all test images. Results given by this method will be used in future studies, to computationally estimate the density distribution of gold nanoparticles in natural rubber samples and to predict reduction kinetics of gold nanoparticles at different time periods. Microsc. Res. Tech. 77:71–78, 2014. © 2013 Wiley Periodicals, Inc.