Online Learning and Adaptation of Autonomous Mobile Robots for Sustainable Agriculture

In this paper we will introduce the application of our newly patented double hierarchical Fuzzy-Genetic system (British patent 99-10539.7) to produce an intelligent autonomous outdoor agricultural mobile robot capable of learning and calibrating its controller online in a short time interval and implementing a life long learning strategy. The online and life long learning strategy allow the outdoor robots to increase their experience and adapt their controllers in the face of the changing and dynamic unstructured outdoor agricultural environments. Such characteristics permit prolonged periods of operation within dynamic agricultural environments, which is an essential feature for the realization of a platform vehicle for use in sustainable agriculture and organic farming.     

A model for the release of sulfur from elemental S and superphosphate

A mathematical model was developed to predict the release of sulfate from elemental S (S⁰) and gypsum in single superphosphate. The release algorithm is based on the observation that release is linearly related to particle surface area. Release rates under various conditions could then be described by the change in radius for each time increment, which allows easier comparison of release rates between different particle sizes. A model based on spherical particles was found to be adequate in accounting for the range of particle shapes found in crushed agricultural S⁰. Release rates calculated from experimental data range from 0.07 to 0.45µm/d depending on environmental conditions.Equations for incorporating the effects of environmental variables and the release of S from S⁰ and from the gypsum component of single superphosphate (SSP) were developed from the literature, and were incorporated within a larger model of S cycling. The model predicted that after 72 days, 99% of the S in SSP would have been released, compared to a release after one year of 54% of the S in sulfur-fortified superphosphate, and 23% of that in crushed agricultural grade S⁰. The model provides a means of assessing the effect of the particle size of S⁰ on release rates and should allow the formulation of fertilizers that supply S at a rate closer to the rate of plant uptake.     

Effect of particle morphology on flow characteristics of a composite plasma spray powder

The effects of BaF₂-CaF₂ particle morphology on National Aeronautics and Space Administration (NASA) PS304 feedstock powder flowability were investigated, BaF₂-CaF₂ eutectic powders were fabricated by comminution (producing an angular morphology) and by gas atomization (producing a spherical morphology). The fluoride powders were added incrementally to the other powder constituents of the NASA PS304 feedstock, (Ni-Cr, Cr₂O₃, and Ag powders). A linear relationship between flow time and concentration of the BaF₂-CaF₂ powder was found. The flow of the powder blend with spherical BaF₂-CaF₂ was better than that with angular BaF₂-CaF₂. The flowability of the powder blend with angular fluorides decreased linearly with increasing fluoride concentration. However, the flow of the powder blend with spherical fluorides was independent of fluoride concentration. The results suggest that for this material blend, particle morphology plays a significant role in flow behavior, offering potential methods to improve powder flowability and enhance the commercial potential. These findings may be applicable to other difficult-to-flow powders such as cohesive ceramics.     

A gene for FG syndrome maps in the Xq12-q21.31 region

AIMS: An increased risk of adenocarcinoma of the oesophagus has been demonstrated in patients with long segments of Barrett's mucosa. The risk of cancer associated with short segments of metaplasia of the oesophagogastric junction is not known. METHODS AND RESULTS: We report a case of early adenocarcinoma of the oesophagus arising on short tongues of Barrett's mucosa associated with an oesophageal cyst. The patient was a 68-year-old man with no previous clinical history of gastro-oesophageal reflux disease. The fortuitous discovery of an oesophageal cyst lead to the diagnosis of short tongues of Barrett's mucosa with high-grade dysplasia. On pathological examination of the resected specimen, an early adenocarcinoma had developed in Barrett's mucosa, localized just above the oesophageal cyst. CONCLUSIONS: As oesophageal cysts can cause symptoms suggestive of reflux, we hypothesize that this association may not be fortuitous.     

Influence of Sulfur for Oxygen Substitution in the Solvolytic Reactions of Chloroformate Esters and Related Compounds

The replacement of oxygen within a chloroformate ester (ROCOCl) by sulfur can lead to a chlorothioformate (RSCOCl), a chlorothionoformate (ROCSCl), or a chlorodithioformate (RSCSCl). Phenyl chloroformate (PhOCOCl) reacts over the full range of solvents usually included in Grunwald-Winstein equation studies of solvolysis by an addition-elimination (A-E) pathway. At the other extreme, phenyl chlorodithioformate (PhSCSCl) reacts across the range by an ionization pathway. The phenyl chlorothioformate (PhSCOCl) and phenyl chlorothionoformate (PhOCSCl) react at remarkably similar rates in a given solvent and there is a dichotomy of behavior with the A-E pathway favored in solvents such as ethanol-water and the ionization mechanism favored in aqueous solvents rich in fluoroalcohol. Alkyl esters behave similarly but with increased tendency to ionization as the alkyl group goes from 1° to 2° to 3°. N,N-Disubstituted carbamoyl halides favor the ionization pathway as do also the considerably faster reacting thiocarbamoyl chlorides. The tendency towards ionization increases as, within the three contributing structures of the resonance hybrid for the formed cation, the atoms carrying positive charge (other than the central carbon) change from oxygen to sulfur to nitrogen, consistent with the relative stabilities of species with positive charge on these atoms.     

Amino‐polyvinyl Alcohol Coated Superparamagnetic Iron Oxide Nanoparticles are Suitable for Monitoring of Human Mesenchymal Stromal Cells In Vivo

Mesenchymal stromal cells (MSCs) are promising candidates in regenerative cell‐therapies. However, optimizing their number and route of delivery remains a critical issue, which can be addressed by monitoring the MSCs’ bio‐distribution in vivo using super‐paramagnetic iron‐oxide nanoparticles (SPIONs). In this study, amino‐polyvinyl alcohol coated (A‐PVA) SPIONs are introduced for cell‐labeling and visualization by magnetic resonance imaging (MRI) of human MSCs. Size and surface charge of A‐PVA‐SPIONs differ depending on their solvent. Under MSC‐labeling conditions, A‐PVA‐SPIONs have a hydrodynamic diameter of 42 ± 2 nm and a negative Zeta potential of 25 ± 5 mV, which enable efficient internalization by MSCs without the need to use transfection agents. Transmission X‐ray microscopy localizes A‐PVA‐SPIONs in intracellular vesicles and as cytosolic single particles. After identifying non‐interfering cell‐assays and determining the delivered and cellular dose, in addition to the administered dose, A‐PVA‐SPIONs are found to be non‐toxic to MSCs and non‐destructive towards their multi‐lineage differentiation potential. Surprisingly, MSC migration is increased. In MRI, A‐PVA‐SPION‐labeled MSCs are successfully visualized in vitro and in vivo. In conclusion, A‐PVA‐SPIONs have no unfavorable influences on MSCs, although it becomes evident how sensitive their functional behavior is towards SPION‐labeling. And A‐PVA‐SPIONs allow MSC‐monitoring in vivo.     

Effect of process variables on Mg-Si particles and extrudability of 6xxx series aluminum extrusions

The Mg-Si particles are one of the major constituents in the microstructure of 6xxx series aluminum alloys. The size, distribution, and morphology of the Mg-Si particle have significant impact on extrudability in terms of mechanical properties and surface quality of aluminum extrusions. The characteristics of the Mg-Si particles are influenced by various process parameters in the production of extrusions. This paper reviews the effects of the major process variables on the Mg-Si particle characteristics and extrudability of aluminum extrusions.     

Isolation of a second recombinant human respiratory syncytial virus monoclonal antibody fragment (Fab RSVF2-5) that exhibits therapeutic efficacy in vivo

A second human respiratory syncytial virus (RSV)-neutralizing monoclonal antibody was isolated and its binding site was identified. Fab F2-5 is a broadly reactive fusion (F) protein-specific recombinant Fab generated by antigen selection from a random combinatorial library displayed on the surface of filamentous phage. In an in vitro plaque-reduction test, the Fab RSVF2-5 neutralized the infectivity of a variety of field isolates representing viruses of both RSV subgroups A and B. The Fab recognized an antigenic determinant that differed from the only other human anti-F monoclonal antibody (RSV Fab 19) described thus far. A single dose of 4.0 mg of Fab RSVF2-5/kg of body weight administered by inhalation was sufficient to achieve a 2000-fold reduction in pulmonary virus titer in RSV-infected mice. The antigen-binding domain of Fab RSVF2-5 offers promise as part of a prophylactic regimen for RSV infection in humans.