Systematic experimental exploration of bifurcations with non-invasive control

We present a general method for systematically investigating the dynamics and bifurcations of a physical nonlinear experiment. In particular, we show how the odd-number limitation inherent in popular non-invasive control schemes, such as (Pyragas) time-delayed or washout-filtered feedback control, can be overcome for tracking equilibria or forced periodic orbits in experiments. To demonstrate the use of our non-invasive control, we trace out experimentally the resonance surface of a periodically forced mechanical nonlinear oscillator near the onset of instability, around two saddle-node bifurcations (folds) and a cusp bifurcation.Comment: revised and extended version (8 pages, 7 figures

Shear-invariant Sliding Contact Perception with a Soft Tactile Sensor

Manipulation tasks often require robots to be continuously in contact with an object. Therefore tactile perception systems need to handle continuous contact data. Shear deformation causes the tactile sensor to output path-dependent readings in contrast to discrete contact readings. As such, in some continuous-contact tasks, sliding can be regarded as a disturbance over the sensor signal. Here we present a shear-invariant perception method based on principal component analysis (PCA) which outputs the required information about the environment despite sliding motion. A compliant tactile sensor (the TacTip) is used to investigate continuous tactile contact. First, we evaluate the method offline using test data collected whilst the sensor slides over an edge. Then, the method is used within a contour-following task applied to 6 objects with varying curvatures; all contours are successfully traced. The method demonstrates generalisation capabilities and could underlie a more sophisticated controller for challenging manipulation or exploration tasks in unstructured environments. A video showing the work described in the paper can be found at https://youtu.be/wrTM61-pieUComment: Accepted in ICRA 201

Land O' Lakes

The case begins with an examination of Land O' Lakes' diversified portfolio of businesses. The business had undergone significant changes since 1998 - it dominated market share in butter and deli cheese, had become the largest crop protection, plant nutrient, and feed manufacturer in the US, and was the fourth largest US seed company. Land O'Lakes used mergers, joint ventures, acquisitions of public and private firms, and divestitures/closing of assets to restructure its portfolio to build its portfolio. The main issue was to evaluate its diversified portfolio of businesses and find ways to improve future performance.Dairy, Agribusiness, Portfolio, Cooperative, Agribusiness, Livestock Production/Industries,

Current Challenges in Financing Agricultural Cooperatives

Agricultural, Cooperatives, Finance, Agribusiness, L10, L23, L16, Q13,

An evaluation of a multi-site community pharmacy based chronic obstructive pulmonary disease support service

Background Chronic obstructive pulmonary disease (COPD) is a progressive chronic condition which can be effectively managed by smoking cessation, optimising prescribed therapy and providing treatment to prevent chest infections from causing hospitalisation. The government agenda in the UK is for community pharmacists to become involved in chronic disease management and COPD is one area where they are ideally located to provide a comprehensive service. Objective To evaluate the effect of a community pharmacy based COPD service on patient outcomes. Method Patients in one UK location were recruited over a 3 month period to receive a community pharmacy based COPD support service consisting of signposting to or provision of smoking cessation service, therapy optimisation, and recommendation to obtain a rescue pack containing steroid and antibiotic to prevent hospitalisation as a result of chest infection. Data was collected over a six month period for all recruited patients. Appropriate clinical outcomes, patient reported medication adherence, quality of life and NHS resource utilisation were measured. Key findings 306 patients accessed the service and full data to enable comparison before and after was available for 137. Significant improvements in patient reported adherence, utilisation of rescue packs, quality of life and a reduction in routine GP visits were identified. The intervention cost was estimated to be off-set by reductions in the use of other NHS services (GP and A&E visits and hospital admissions). Conclusion Results suggest that the service improved patient medicine taking behaviours and that it was cost-effective

Reductive and Oxidative DNA Damage by Photoactive Platinum(II) Intercalators

Several photoactive platinum R-diimine intercalators have been prepared to develop new probes of DNA oxidation and reduction chemistry. Five water-soluble bis(mes')Pt(II) complexes (mes') N,N,N,3,5-pentamethylaniline) with various aromatic α-diimine ligands (dppz= dipyridophenazine, np = naphtha[2,3-f][1,ω]phenanthroline, CN-np = naphtho[2,3-f][1,10]phenanthroline-9-carbonitrile, CN_2-np = naphtho[2,3-f][1,10]phenanthroline-9,14-dicarbonitrile, and bp = benzo-[f][1,10]phenanthroline) were synthesized. The complex [(np)Pt(mes')_2]Cl_2 was also characterized by X-ray crystallography, and the crystal structure shows that the ortho-methyl groups of the mes' ligands conveniently block substitution at the vacant sites of platinum without overlapping with the intercalating α-diimine ligand. The Pt(II) complexes were found to have excited-state oxidation and reduction potentials of -0.6 to -1.0 and 1.0 to 1.5 V versus NHE, respectively, making them potent photoreductants as well as photooxidants. Many of the complexes are found to promote the photooxidation of N^2-cyclopropyldeoxyguanosine (d^(Cp)G). Photoexcited [(dppz)Pt(mes')_2]^(2+) is found to be most efficient in this photooxidation, as well as in the photoreduction of N^4-cyclopropylcytidine (^(Cp)C); these modified nucleosides rapidly decompose in a ring-opening reaction upon oxidation or reduction. Photoexcited [(dppz)Pt(mes')_2]Cl_2, upon intercalation into the DNA π stack, is found, in addition, to promote reductive and oxidative damage within the DNA duplex, as is also probed using the kinetically fast electron and hole traps, ^(Cp)C and ^(Cp)G. These Pt complexes may therefore offer useful reactive tools to compare and contrast directly reductive and oxidative chemistry in double helical DNA

Bi-stability induced by motion limiting constraints on boring bar tuned mass dampers

This paper investigates the effect of displacement constraints on the attenuation performance of tuned mass dampers (TMDs) used in boring and turning applications. A simplified piecewise- smooth mechanical model is investigated through time domain simulations and hybrid periodic orbit continuation, first under harmonic excitation, then under regenerative cutting load. A quasi-frequency response function is derived for impacting TMDs through composition of different families of period-1 orbits, then an acceptability map for turning is formulated based on the appearance of cutting-edge contact-loss and fly-over events. The bi-stable domain boundaries are determined through two parameter continuation of contact-loss grazing events. It is shown that in both cases arising rigid body collisions can significantly hinder TMD damping performance and lead to resonance problems or machine tool chatter