Application of a low-cost RGB sensor to detect basil (Ocimum basilicum L.) nutritional status at pilot scale level

Precision Agriculture - In this work, basil plants were fertilized with 0, 2.5 mM and 10 mM nitrogen (with different NO3?/NH4+ ratios), and then monitored using a low-power...     

A Submarine Journey: The Pyrrole-Imidazole Alkaloids

In his most celebrated tale “The Picture of Dorian Gray”, Oscar Wilde stated that “those who go beneath the surface do so at their peril”. This sentence could be a prophetical warning for the practitioner who voluntarily challenges himself with trying to synthesize marine sponge-deriving pyrrole-imidazole alkaloids. This now nearly triple-digit membered community has been growing exponentially in the last 20 years, both in terms of new representatives and topological complexity – from simple, achiral oroidin to the breathtaking 12-ring stylissadines A and B, each possessing 16 stereocenters. While the biosynthesis and the role in the sponge economy of most of these alkaloids still lies in the realm of speculations, significant biological activities for some of them have clearly emerged. This review will account for the progress in achieving the total synthesis of the more biologically enticing members of this class of natural products.     

Column Elution Experiments on Volcanic Ash: Geochemical Implications for the Main Ethiopian Rift Waters

Column laboratory experiments were employed to assess the leaching behaviour of pyroclastic glassy ash deposits collected in the central Main Ethiopian Rift, where surface and groundwater resources are affected by fluoride (F^?) pollution, which is the cause of an endemic disease (fluorosis) in the local community. To elucidate the source of F^? and simulate the water–rock interaction processes, as well as quantify its distribution within different grain sizes, the pyroclastic ash was analysed by XRF, XRD and SEM and separated into coarse and fine fractions. Three columns were filled with raw (unsieved), coarse (63 μm–2 mm) and fine (<63 μm) fraction, respectively, and flushed with synthetic rain water in saturated conditions. Very fast F^? leaching was observed in the fine fraction column at the start of the experiment, while in the other two columns, F^? was slowly released; in addition, a strong accumulation of F^? was found in the fine fraction. The effect was more pronounced in the fine fraction column due to the available effective adsorbing surface area. Subsequent to elution experiments, the columns were characterised via moment analysis of tracer test. Finally, flow and transport modelling (MODFLOW-2000 and MT3DMS) was employed to compute the amount of F^? adsorbed onto the solid phase, comparing the calculated conservative transport of F^? and the observed concentrations. The results of this study suggest that fluoride is a fundamental constituent of the glass phase (about 0.3 wt.%) and that it is released during the incongruent dissolution of glassy particles. Dissolution of coatings on glass particles could provide an additional contribution to the geochemistry of the interacting fluids. These processes are more effective in the fine fraction due to a much higher reactive (specific) surface area.     

Prediction of milled maize fumonisin contamination by multispectral image analysis

Mycotoxin contamination is a major concern to the maize industry worldwide. Despite the several strategies that have been exploited in an attempt to reduce the severity of this problem, during conducive years, severely contaminated lots are still introduced in the maize processing chain affecting the general quality and safety of the product. As chemical analysis is laborious, time consuming and equipment dependent, more convenient methods are needed for the early identification of contaminated lots. Here a novel approach based on image analysis that provides fast response with minimal equipment and effort is presented. Maize samples were grounded and imaged under 10 different LED lights with emission centered at wavelengths ranging from 720 to 940 nm. The digital images were converted into matrices of data to compute comparative indexes. A three layers feed-forward neural network was trained to predict mycotoxin content from the calculated indexes. The results showed a significant correlation between predictions from image analysis and the concentration of the mycotoxin fumonisin as determined by chemical analysis. The technique developed produces reliable contamination estimates within few minutes and can be readily used to assist lot selection in various steps of the maize processing chain.     

Efficacy of a combination of imidacloprid 10%/permethrin 50% versus fipronil 10%/(S)-methoprene 12%, against ticks in naturally infected dogs

Preventing tick bites is a fundamental step towards reducing the impact of tick-borne protozoal, bacterial and viral diseases (TBDs) in humans and animals. The aim of this study was to evaluate the efficacy of a combination of imidacloprid 10%/permethrin 50% and of fipronil 10%/S-methoprene 12% against ticks in naturally infected dogs and to assess methodological parameters to calculate drug efficacy on tick immature stages.

From July to August 2004, 45 privately owned dogs of various sexes, ages, breeds, coat length and habits were enrolled in a trial carried out in an area (radius approximately 50 km) in Southern Italy. Three homogeneous groups (both for dog population and tick population) were formed: 15 dogs treated with imidacloprid 10% and permethrin 50% spot-on (group A), 15 dogs treated with fipronil 10% and methoprene 12% spot-on (group B) and 15 untreated dogs (group C). The dogs in each group were then sub-grouped according to their age and weight. Two different treatments were administered (time 0 and +28 days) to groups A and B, and the dogs were checked weekly for tick infestation until day +56 post-treatment (p.t.). Twenty-four areas distributed on the whole body surface were examined for ticks at each follow-up, while only at time 0 and at day +56 p.t., ticks were collected from the dogs and identified.

For the immature stages a semi-quantitative method was adopted and the load of immature stages was evaluated and grouped into four classes up to day +56 p.t. when the mean number of immature ticks (MIT) for each infection class was evaluated.

All the adult ticks collected were identified as brown dog ticks (Rhipicephalus sanguineus). Immature stages were first compared at day +28 p.t.. The efficacy of both products used in groups A and B on adult ticks was high and generally very similar. Conversely, the efficacy of imidacloprid 10% and permethrin 50% against immatures was higher than that of fipronil 10% and methoprene 12% throughout the observation period with statistically significant differences (p < 0.05) at day +28 p.t. (i.e. group A = 98.52%, group B = 72.40%).

On the whole, in analysing the efficacy of both products against adult plus immature ticks, it was found that the combination of imidacloprid 10% and permethrin 50% was more effective than fipronil 10% and methoprene 12%, with the differences being statistically significant at day +28 p.t. (group A = 98.43%, group B = 77.56%).     

A comparison of coprological, serological and molecular methods for the diagnosis of horse infection with Anoplocephala perfoliata (Cestoda, Cyclophyllidea)

Anoplocephala perfoliata (Cestoda, Cyclophyllidea), the commonest intestinal tapeworm of horses, can cause colic, intussusceptions, ileal impactions and intestinal perforations. Common diagnostic techniques for A. perfoliata infection, i.e. coprology and serology, show inherent limitations in terms of sensitivity and specificity and new approaches are thus required. Hence, the present study compared the reliability of coprological, serological (i.e. ELISA) and molecular (i.e. nested PCR) methods in detecting A. perfoliata infection in naturally infected horses and in horses treated with a combination of ivermectin and praziquantel. Of 42 horses subjected to coprological examination, 16 and 26 resulted negative and positive, respectively for the presence of A. perfoliata eggs at the coprological examination. The 26 coprologically positive animals were also positive by nested PCR. Fifteen out of the 16 horses coprologically negative were negative at the molecular assay, while one yielded a PCR product detectable on an agarose gel. Eighteen out of 26 positive horses were treated with a combination of ivermectin 18.7 mg/g and praziquantel 140.3mg/g and resulted subsequently negative by coprology and nested PCR performed 2 weeks after treatment. All infected and untreated animals had a high ELISA test optical density indicating high infection intensity and associated risk of colic. However, high optical density values were also obtained in four horses post-treatment and in three horses that were negative on molecular and coprological analysis. The results of the present work indicate that the nested PCR assay represents a valid method for the specific molecular detection of A. perfoliata in faecal samples collected from naturally infected horses and may have advantages over coprological and serological approaches for diagnosing A. perfoliata infection.     

Efficacy of a combination of 10% imidacloprid/50% permethrin for the prevention of leishmaniasis in kennelled dogs in an endemic area

The efficacy of imidacloprid 10%and permethrin 50% (Advantix; Bayer AG, Germany) in a spot-on formulation was evaluated in the field as a control measure to prevent canine leishmaniasis (CanL) in dogs in an endemic area of southern Italy. In February 2005, out of 845 dogs initially tested for CanL, 631 dogs which tested negative (315 from a kennel in Bari (KB) and 316 from a kennel in Ginosa (KG)) in a serological and a parasitological examination were allocated to one of three groups: Group A-treated with imidacloprid 10% and permethrin 50% once a month; Group B-treated every 2 weeks; and Group C-untreated control animals. All the dogs were examined serologically and parasitologically for CanL prior to the start of the study, in November 2005 (end of the sandfly season) and in March 2006 (end of the study). An initial CanL seroprevalence of 24.7% (209 dogs) was detected in KB and KG. In KB Leishmania infection, inferred by positivity in at least one of the three tests performed at the interim or final follow-up, was found in one animal from Group A and in nine from Group C. No positive animals were detected in Group B, thus giving a final protection efficacy of 88.9% in Group A and 100% in Group B. In KG Leishmania infection was identified in one animal from Groups A and B, respectively, and 11 from Group C (protection efficacy of 90.36% in Group A and 90.73% in Group B). The incidence density rates (IDRs) of infection in both Groups A and B at each kennel were statistically significantly lower than that registered in Group C (KB p<0.05 and KG p<0.01). The results clearly show that a combination of imidacloprid 10% and permethrin 50%, by virtue of its repellent activity against sandflies, is effective under both application regimes in preventing CanL in the field in endemic areas.     

Detection of genes encoding for virulence and adherence factors in Escherichia coli isolated in slaughtered Sarda breed sheep

In order to investigate the pathogenic profile of Escherichia coli hosted in “Sarda” sheep, autochthonous race present in Sardinia, thirty-seven E. coli strains collected from different sources (fleeces, carcass swabs and gut mucosa) of pre-chill slaughtered sheep (ewes and lambs) were serotyped using pheno- and genotypic methods. Furthermore, the presence of genes encoding for virulence factors and mediating for localized mucosal adherence factors was investigated, and pulsed-field gel electrophoresis (PFGE) characterization was performed.