The effect of advanced glycation endproduct accumulation on bone

Diabetes is associated with increased fracture risk, which leads to increased morbidity and eventual mortality with a substantial financial burden. Type 2 Diabetics also have increased fracture risk, despite having the same or higher BMD as non-diabetics with a low fracture risk. One hypothesis for this is increased modifications made to the extra-cellular matrix via non-enzymatic glycation (NEG) that can occur in a hyperglycemic environment, such as with diabetes. The accumulation of NEG products, known as advanced glycation endproducts (AGEs) can possibly lead to microdamage and eventual weakening of the bone itself. We developed a time-response model in order to induce a wide range of AGEs in a manner that would sustain the mineral integrity of the bone and could be applied to a variety of bone sample types. This was performed on 65 rat tibias, distributed amongst 8 groups (3,7,10, & 14 days) for both ribose and control. Secondly, the protocol was performed on human cortical beam samples cut from 10 donor tibias with 3,5 and 7 day time points for ribose and control groups. All samples were incubated in a 0.6 M ribose solution or 0.0 M ribose control solution. There was a 7, 4, and 5-fold increase in AGEs at the 7, 10, and 14 day time points respectively over controls in the rat tibia study. There was no significant variation in cortical porosity, however TTMD was significantly less dense in the 14-day ribose treated groups. There was a trend toward higher AGEs with time in the human cortical beam specimens, but no significant increase. The AGEs values in the human cortical beam specimens were much lower than expected based on previous trials and reports in the literature. We were able to establish a time-response model for AGE accumulation in bone. However, the effects of AGEs on bone material properties remains inconclusive

Kinetics of Topological Stone-Wales Defect Formation in Single Walled Carbon

Topological Stone-Wales defect in carbon nanotubes plays a central role in plastic deformation, chemical functionalization, and superstructure formation. Here, we systematically investigate the formation kinetics of such defects within density functional approach coupled with the transition state theory. We find that both the formation and activation energies depend critically on the nanotube chairality, diameter, and defect orientation. The microscopic origin of the observed dependence is explained with curvature induced rehybridization in nanotube. Surprisingly, the kinetic barrier follows an empirical Br{\o}nsted-Evans-Polanyi type correlation with the corresponding formation energy, and can be understood in terms of overlap between energy-coordinate parabolas representing the structures with and without the defect. Further, we propose a possible route to substantially decrease the kinetic activation barrier. Such accelerated rates of defect formation are desirable in many novel electronic, mechanical and chemical applications, and also facilitate the formation of three-dimensional nanotube superstructures.Comment: 10 pages, Supporting information, The Journal of Physical Chemistry C (2015

Setting up and management of public policies multifunctional purpose. The case of Developing Countries : Capitalisation of research results on the multifunctionality of agriculture and rural areas

The notion of multifuncionality appeared for the first time in 1992 in the proceedings of the International Conference of the United Nations on Environment and Development. But, the notion was and is mainly used by developed countries, particularly in Europe, with the purpose of preserving and reinforcing the involvement of agriculture in social and territorial fields. For many developing countries, multifunctionality is out of step since (i) a lot of them have severe social, political, institutional and budget constraints, (ii) the concept is not coherent with the liberalization patterns proposed and often imposed by international donors (withdrawal of the state, market and trade oriented policies), and (iii) multifunctionality is perceived as a tool used by the European countries in the context of trade negotiations to justify the subsidies to their agriculture, and consequently contrary to their own interests. However, changes seem to appear in some developing countries regarding the notion of multifuncionality considering the impacts of liberalization and the new rules for trade on their agriculture and rural areas. During the last two decades, most of the developing countries shifted their former integrated public policies (IP) - implemented before the debt crisis - to segmented (SP) or differential policies (DP) dedicated to targeted objectives. In that context many policies were implemented to create social safety nets or for the preservation of natural resources. In the agricultural sector, most of the policies are now residual (RP), but some countries, such as Brazil, are implementing differential policies targeted on territorial development or family agriculture. In most DCs market driven approaches to multifunctionality are not relevant because of a lack of national public funding, low institutional capacity, and narrow demand. Alternative modes of funding have to be designed, mixing public and private tools. In that perspective, some Asian countries have implemented innovative approaches encouraging a partnership between village communities and the state based on local know-how and public supports for marketing. Due to the very specific context of DC¿s, the main recommendations to the EU are: (i) to go deeper into the policy oriented research on the setting and management of multifunctionality, (ii) to take into account the consequences of the distortions due to its own public policy and to engage in a work about how to compensate market distortions or negative externalities for the DCs, (iii) to increase cooperation between EU and DCs on the processes of policy making related to agriculture and rural areas, (iv) to implement specific fundings to enhance the recognition of the different functions of agriculture and to fill the research gaps in the comprehension of the processes at stake necessary for the definition and implementation of a negotiated reform agenda based on the specificity of each national and local contexts. (Résumé d'auteur

Alternative research strategies in the exercise - mental health relationship

From the numerous investigations available, there is cautious support for the proposition that exercise is associated with enhanced emotion and mood in mental illness, but the strength of the conclusions derived from the empirical findings available will largely depend on the strength of the designs applied. In applied research, such as the investigation of the exercise - mental health relationship, this relationship depends on population, environmental and individual characteristics and a number of difficulties will certainly hinder progress in this area of inquiry. Randomised controlled trials are important but have the disadvantage of deemphasizing the importance of the individual. Single-case designs on the other hand have considerable potential to adequately unravel the mechanisms at work in the exercise - mental health relationship. From a clinical perspective however, research findings should be viewed based on the support of earlier epidemiological evidence, suggesting that mental illness indeed might be associated with low activity/fitness and that those who maintain activity are less likely to develop mental illness

Modelling the Network Effects of Road User Charging: Results from a SATURN Study.

The aim of this research has been to investigate the modelled effects of alternative road user charging systems upon an existing road network using the congested assignment models SATURN and CONTRAM applied to the city of Cambridge. Four road user charging systems which are being considered for practical application have been tested. These are toll cordons, time-based charging, a congestion charging system similar to that proposed in Cambridge and distance-based charging. Tests have been conducted using current morning peak travel demand patterns both with a fixed trip matrix, to isolate rerouteing issues and using the SATURN elastic assignment program, SATEASY, in order to address the effects of charging upon the frequency, timing and distribution of trips. Network impacts have been assessed using a series global indicators, in particular effects on vehicle-km, vehicle-hours and the resulting average network speeds. In addition, results have been obtained for total delay times, cordon crossing flows and revenues generated from charging. These results are presented and their implications discussed