Fruit thinning in organic apple growing with optimized timing and combination strategies including (new) natural spray products and mechanical rope-devices

The aim of our study was to find new thinning methods for organic apple production able to fulfil the standards of Bio-Suisse, the main label organisation of the organic food sector in Switzerland. The 14 trials reported were carried out during flowering period in 2003 and 2004 on the cultivars Pinova, Gala, Maigold, Elstar, Golden Delicious and Otava at different sites. The results confirm the good efficiency of mechanical thinning with the rope thinner and the thinning potential of vinasse, a by-product of molasses. Different vinasse products were tested (K-Vinasse, light-vinasse, N-Vinasse) and it was observed that those containing less nitrogen had a minor thinning effect. To avoid phytotoxicity on leaves, the concentration of N-Vinasse should not exceed 10 %. It seems that for Gala higher concentrations are needed, 7.5-10%, whereas with Maigold the efficacy of N-Vinasse was the same with the 2.5 % concentration as with 5 % and 10 %. On the other hand, partly good results were obtained when N-Vinasse was over-concentrated to 12 %, applied at warm weather and rinsed with clear water 4-6 hours later to avoid the phyto-toxic effect (“burn & rinse” method). Corn Oil, a commercial product from New Zealand, gave encouraging results. Lime sul-phur didn’t effectuate a significantly better thinning effect. The best method tested (fruit set reduction by 44 % and 26 % higher flower bud set next year) was achieved with a combination of rope thinner and N-Vinasse: rope thinner to thin the peripheral branches and to exert a physiological stress; and N-Vinasse to thin the inner parts of the canopy that the ropes can’t reach. Other tested products did not show satisfying effects. Trials also confirmed the importance of applying these thinning agents at least two times, at the appropriate phenological stage of flowering period (F,) F2 (full bloom) and G (= F2 of the one-year old shoots). Hitting also the flowers of the one-year old shoots is important to break bi-annual bearing. Pollen tube growth was assessed by fluorescence microscopy. Almost complete inhibition of pollen tube germina-tion was observed with Lime Sulphur and over-concentrated N-Vinasse (12 %) whereas with N-Vinasse at 5 % inhibition was 50 % less compared to untreated styles. Some contradictory results between different trials we ascribe to the air temperature during and after the treatments. It seems that treatments with N-Vinasse should be carried out at warm and sunny days above 16, better 18-20 deg. C. to maximize phytotoxicity on the styles; whereas we recommend to apply the rope thinner during periods of cold and clouded weather to maximize the thinning effect due to physiological stress and shortage of assimilates to the fruitlets. Concrete practical recommendations are given

Possible Implication of Red Blood Cells in the Prothrombotic Risk in Early Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease that can be considered as a prothrombotic state1. A great number of studies have investigated the possible role of reactive oxygen species (ROS) in the etiology and pathogenesis of this disease. The presence of large amounts of superoxide radicals and hydrogen peroxide produced by activated neutrophils has been reported in the synovial fluid of patients with RA. This may cause lipid peroxidation that yields a wide variety of end products, including malondialdehyde (MDA), a known marker of oxidative stress. These products are therefore transported from the synovial fluid to the blood circulation system2. Considering that elevated levels of MDA have been observed in the blood plasma of patients with RA2, the aim of this pilot study was to investigate whether the elevated levels of plasmatic MDA could be associated with a modification of the total antioxidant capacity (TAC) of blood plasma that is usually indicative of a “systemic” oxidative imbalance3. In addition, in view of their activity as redox effectors or scavengers4, as well as determinants of thrombus formation5, we evaluated red blood cell (RBC) features in terms of their redox state and lifespan marker molecules

A comparison between two pneumatic suspension architectures

The aim of this work is to assess and compare the mathematical models of two pneumatic suspension architectures and show how they can converge, after appropriate simplifications, to a general linear form. After making this model dimensionless, it will be used to study, with a transmissibility analysis, the behaviour of a mono-suspension (quarter-car model). Finally, an example of a design process will be shown to highlight the strengths and weaknesses of both architectures and to provide the reader with a practical design too

Evolution of Wheelchair.q, a Stair-climbing Wheelchair

This paper presents a solution for a stair-climbing wheelchair that can climb single steps or entire staircases. This device was designed in order to ensure greater autonomy for people with reduced mobility . The main component of the wheelchair structure is a three-wheel locomotion unit that allows obstacle climbing thanks to an epicycloidal transmission. The other characteristic element is an idle track that behaves like a second foothold giving static stability during stair-climbing. Another important feature concerned with this design is a reconfiguration mechanism that makes the wheelchair suitable both for stair-climbing and for moving on flat ground. This feature allows performances and overall dimensions comparable to traditional electric wheelchairs. The choice and design of the mechanisms for the reconfiguration phase are the main topics discussed in this article and represent the principal innovations of this wheelchair compared to earlier versions

Float-ram: a new human powered press for earth blocks

The Float-Ram is a novel kind of human-powered press for raw earth blocks. It is able to provide very high performance, while maintaining a limited cost, due to some technical characteristics like: •the adoption of a floating mould, which provides a bi-directional pressing action in simple way; •Optimized kinematic structure, based on a cam-roller transmission system; •General mechanical simplicity, since the node of all kinematic pairs is constituted by a single shaft. Therefore the Float-Ram can be considered as an important media for the diffusion of high-quality raw earth building in developing Countries

Virtual Networking Performance in OpenStack Platform for Network Function Virtualization

The emerging Network Function Virtualization (NFV) paradigm, coupled with the highly flexible and programmatic control of network devices offered by Software Defined Networking solutions, enables unprecedented levels of network virtualization that will definitely change the shape of future network architectures, where legacy telco central offices will be replaced by cloud data centers located at the edge. On the one hand, this software-centric evolution of telecommunications will allow network operators to take advantage of the increased flexibility and reduced deployment costs typical of cloud computing. On the other hand, it will pose a number of challenges in terms of virtual network performance and customer isolation. This paper intends to provide some insights on how an open-source cloud computing platform such as OpenStack implements multitenant network virtualization and how it can be used to deploy NFV, focusing in particular on packet forwarding performance issues. To this purpose, a set of experiments is presented that refer to a number of scenarios inspired by the cloud computing and NFV paradigms, considering both single tenant and multitenant scenarios. From the results of the evaluation it is possible to highlight potentials and limitations of running NFV on OpenStack

Mechanism and Machine Science Educational Workshop Based on Schröder-Reuleaux Ancient Models of Politecnico di Torino

Around the world, there are many collections of models of mechanisms and machine components of historical value. Among these, there is an important collection kept at the Politecnico di Torino, Department of Mechanical and Aerospace Engineering-DIMEAS. It consists of about 85 Reuleaux models manufactured by the Schröder company of Darmstadt in the second half of the 19th century. It includes linkages, gears, cam-follower systems, belt drives, couplings and clutches whose history is reconstructed. Some models are still used effectively today in teaching the science of mechanisms and machine. The paper presents both the important historical collection and the didactic methodology adopted in the course “Mechanics of Automatic Machines” in which students practice the developing of virtual models of some selected mechanisms