Some mechanical design aspects of the European Robotic Arm

The European Robotic Arm (ERA) is a contribution to the Russian Segment of the International Space Station Alpha. It will start operating on the Russian Segment during the assembly phase. ERA is designed and produced by a large industrial consortium spread over Europe with Fokker Space & Systems as prime contractor. In this paper, we will describe some of the overall design aspects and focus on the development of several mechanisms within ERA. The operation of ERA during the approach of its end effector towards the grapple interface and the grapple operation is discussed, with a focus on mechanisms. This includes the geometry of the end effector leading edge, which is carefully designed to provide the correct and complete tactile information to a torque-force sensor (TFS). The data from this TFS are used to steer the arm such that forces and moments are kept below 20 N and 20 N.m respectively during the grappling operation. Two hardware models of the end effector are built. The problems encountered are described as well as their solutions. The joints in the wrists and the elbow initially used a harmonic drive lubricated by MoS2. During development testing, this combination showed an insufficient lifetime in air to survive the acceptance test program. The switch-over to a system comprising planetary gearboxes with grease lubrication is described. From these development efforts, conclusions are drawn and recommendations are given for the design of complex space mechanisms

The economic development of small countries : problems, strategies and policies

The number of studies dealing with economic problems of small countries is growing. They have contributed to our general knowledge on the economics of these societies. Nevertheless, there is no clear evidence that a successful economic policy will be following from this knowledge. This, of course, is not unusual in matters of science. First of all, the exploration of an economic problem is one thing; the solution of problems is another thing altogether. And indeed, the economic problems of small countries, especially of the very small ones, seem so grave that one could seriously question any pretention of being able to solve these. We could emphasize the lack of development possibilities and point at the long list of impediments, at political and social structures which hamper development and which are quite difficult to change, if at all. All of these arguments could be substantiated. They have in fact been substantiated for a number of very small countries, where a virtual absence of resources or diseconomies of small scale seem to deprive their inhabitants of rather basic facilities (5, p.90]. But, for the sake of our argument, let us assume another reason why, so far, development successes in very small economies have not been realized, and let us point to the limited ability of science to propose effective measures to solve real world problems. Our argument is not a philosophical one. We, therefore, neglect the reasoning that solutions to problems almost always create new problems. Our argument is of a more theoretical nature. We simply feel that the ability of science to suggest policies is sometimes rather limited, precisely because of the limitations in our scientific way of dealing with reality. And, since some of these limitations, hampering our insights into the economic life of very small economies, seem to follow from the conception of science itself - since, so to speak, some of these limitations are self-imposed - we propose to look at the economic structures of very small economies in a different way. We have toyed with the idea to illustrate our largely theoretical exercise with a case study on Malta, but, our Institute being a very small economy itself, with limited resources, we had to confine ourselves to mere illustrations. For this and other reasons, our remarks should be seen as no more than a brief exploratory note on a large problem. Clearly, our approach does not pretend to render all other possible (scientific) approaches on formulating an economic policy obsolete or unjustified.peer-reviewe

Homozygous whole body Cbs knockout in adult mice features minimal pathology during ageing despite severe homocysteinemia

Deficiencies in Cystathionine-β-synthase (CBS) lead to hyperhomocysteinemia (HHCy), which is considered a risk factor for cardiovascular, bone and neurological disease. Moreover, CBS is important for the production of cysteine, hydrogen sulfide (H2 S) and glutathione. Studying the biological role of CBS in adult mice has been severely hampered by embryological disturbances and perinatal mortality. To overcome these issues and assess the effects of whole-body CBS deficiency in adult mice, we engineered and characterized a Cre-inducible Cbs knockout model during ageing. No perinatal mortality occurred before Cbs-/- induction at 10 weeks of age. Mice were followed until 90 weeks of age and ablation of Cbs was confirmed in liver and kidney but not in brain. Severe HHCy was observed in Cbs-/- (289 ± 58 µM) but not in Cbs+/- or control mice (<10 µM). Cbs-/- showed impaired growth, facial alopecia, endothelial dysfunction in absence of increased mortality, and signs of liver or kidney damage. CBS expression in skin localized to sebaceous glands and epidermis, suggesting local effects of Cbs-/- on alopecia. Cbs-/- showed increased markers of oxidative stress and senescence but expression of other H2 S producing enzymes (CSE and 3-MST) was not affected. CBS deficiency severely impaired H2 S production capacity in liver, but not in brain or kidney. In summary, Cbs-/- mice presented a mild phenotype without mortality despite severe HHCy. The findings demonstrate that HHCy is not directly linked to development of end organ damage

The Novel Compound Sul-121 Preserves Endothelial Function and Inhibits Progression of Kidney Damage in Type 2 Diabetes Mellitus in Mice

Diabetic nephropathy is still a common complication of type 2 diabetes mellitus (T2DM) and improvement of endothelial dysfunction (ED) and inhibition of reactive oxygen species (ROS) are considered important targets for new therapies. Recently, we developed a new class of compounds (Sul compounds) which inhibit mitochondrial ROS production. Here, we tested the therapeutic effects of Sul-121 on ED and kidney damage in experimental T2DM. Diabetic db/db and lean mice were implanted with osmotic pumps delivering Sul-121 (2.2 mg/kg/day) or vehicle from age 10 to 18 weeks. Albuminuria, blood pressure, endothelial mediated relaxation, renal histology, plasma creatinine, and H2O2 levels were assessed. Sul-121 prevented progression of albuminuria and attenuated kidney damage in db/db, as evidenced by lower glomerular fibronectin expression (~50%), decreased focal glomerular sclerosis score (~40%) and normalization of glomerular size and kidney weight. Further, Sul-121 restored endothelium mediated vasorelaxation through increased production of Nitric Oxide production and normalized plasma H2O2 levels. Sul-121 treatment in lean mice demonstrated no observable major side-effects, indicating that Sul-121 is well tolerated. Our data show that Sul-121 inhibits progression of diabetic kidney damage via a mechanism that involves restoration of endothelial function and attenuation of oxidative stress

An evolutionary approach to international political economy: the case of corporate tax avoidance

Corporate tax avoidance is both widespread and diverse in its practical mechanics. The scope of the phenomenon often leads economists to conclude that in the jungle of economic competition, tax planning (or optimisation) is among the necessary tools to ensure the survival of the fittest. This theory is increasingly associated with a Darwinian theory of economic evolution. In this paper, I develop a contrasting framework of the evolutionary political economy of corporate tax avoidance. Analysing core concepts of Old Institutionalist Economics (OIE), I examine the core drivers of corporate tax avoidance in a globalised system of states. The major contrast, I find, is between that of the corporate and legal personality and the institutional environment in which it operates. Historically, each corporate entity has been considered a separate legal person, yet a series of ‘mutations’ of incorporations laws created a widening gap between theory and reality, and these, in turn, give rise to tax arbitrage. Narrowing this gap, however, impinges on another venerable historical institution, the institution of sovereignty and sovereign inequality

Combating Environmental Irresponsibility of TNCs in Africa: An Empirical Analysis

Environmental irresponsibility is one of the most prominent issues confronting host communities of transnational corporations (TNCs) engaged in the production of economic goods and, sometimes, services. Drawing mainly on stakeholder theory, combined with legitimacy theory, this article addresses how host communities in Africa combat the challenge of environmental irresponsibility of TNCs. To illustrate the dimensions and dynamics of the challenge, this paper examines the experience of despoliation of Ogoniland by the oil giant Shell in Nigeria. The analysis draws attention to the significance of the role of individuals and civil society groups in securing accountability of one of the most formidable fronts of economic globalisation. The analysis is particularly relevant to the experience of environmental irresponsibility in the context of weak governance structures

Is the water footprint an appropriate tool for forestry and forest products: The Fennoscandian case

The water footprint by the Water Footprint Network (WF) is an ambitious tool for measuring human appropriation and promoting sustainable use of fresh water. Using recent case studies and examples from water-abundant Fennoscandia, we consider whether it is an appropriate tool for evaluating the water use of forestry and forest-based products. We show that aggregating catchment level water consumption over a product life cycle does not consider fresh water as a renewable resource and is inconsistent with the principles of the hydrologic cycle. Currently, the WF assumes that all evapotranspiration (ET) from forests is a human appropriation of water although ET from managed forests in Fennoscandia is indistinguishable from that of unmanaged forests. We suggest that ET should not be included in the water footprint of rain-fed forestry and forest-based products. Tools for sustainable water management should always contextualize water use and water impacts with local water availability and environmental sensitivity