A Socratic method for validation of measurement-based networking research

Nearly three decades of Internet measurement has resulted in large-scale global infrastructures used by an increasing number of researchers. They have examined various Internet properties in areas such as network infrastructure (routers, links), traffic (measurement at packet, flow, and session level) and applications (DNS, Web, P2P, Online Social Networks, etc.) and presented results in diverse venues. Key related topics like security and privacy have also been explored. There is however a lack of clearly articulated standards that reduce the probability of common mistakes made in studies involving measurements, their analysis and modeling. A community-wide effort is likely to foster fidelity in datasets obtained from measurements and reused in subsequent studies. We present a Socratic approach as steps towards a solution to this problem by enumerating a sequence of questions that can be answered relatively quickly by both measurers and reusers of datasets. To illustrate the applicability and appropriateness of the questions we answer them for a number of past and current measurement studies.     

Identifying and addressing barriers to renewable energy development in Pakistan

To ensure a sustainable energy future for Pakistan, it is necessary that the energy sector be accorded a high priority. Pakistan remains predominantly reliant on fossil fuels as its primary source of energy. Efforts to reduce reliance on fossil fuels through increasing the share of renewable energy in the energy supply systems have met with little success so far. The barriers to development of renewable energy can be broadly classified as policy and regulatory barriers, institutional barriers, fiscal and financial barriers, market-related barriers, technological barriers and information and social barriers. In this article, an effort has been made to identify the barriers that limit the use of renewable energy technologies in general and with specific reference to Pakistan, and outline the measures to address these barriers.     

Extending the solid-phase microextraction technique to high analyte concentrations: measurements and thermodynamic analysis

The solid-phase microextraction (SPME) technique has been used historically to quantify analytes present at the parts per million level. However, the nonintrusive nature of SPME lends itself to other applications involving analytes at higher concentration. In the current work, the possibility of using the SPME technique to measure concentrated gaseous samples was examined. Pentane concentrations between 0 and 100% saturation were studied, over a temperature range of 20-45 degrees C. The results showed that, up to a critical mole fraction in the solid phase, the concentrations of pentane in the polymeric extracting solid and vapor phases were related by a constant, equal to Henry's constant. The temperature dependence of Henry's constant was shown to follow the predicted trend with temperature, as determined from rigorous thermodynamic calculations. Above the pentane concentration in the polymeric phase, the response deviated from linearity. The nonideality was captured in an activity coefficient. An activity coefficient model developed to describe the nonideality was found to be a function of the swollen volume of the SPME polymer phase. The results indicate that the SPME technique can be applied to high analyte concentrations, although difficulties may be encountered when multiple analytes are absorbed.     

Knowledge Networking in Cross-Cultural Settings

Knowledge networking in the cross-cultural setting here focuses on promoting a culture of shared communication, values and knowledge, seeking cooperation through valorisation of diversity. The process is seen here in terms of creating new alliances of creators, users, mediators and facilitators of knowledge. At the global level, knowledge networking is seen as a symbiotic relationship between local and global knowledge resources. This focus is informed by the human-centred vision of the information society, which seeks a symbiotic relationship between technology and society. It explores the nature of the knowledge in transition, raising issues of technology and knowledge transfer in the local–global context. The notions of human–machine symbiosis and of diversity and coherence provide a handle to explore the role of technology for sustainable development. The centrality of knowledge in stimulating knowledge networking for cross-cultural collaboration is illustrated through an exemplar of an EU–India Cross-Cultural Innovation Network project, a collaboration between European and Indian universities and institutes.     

Feeding linseed to increase the n-3 PUFA of pork: fatty acid composition of muscle, adipose tissue, liver and sausages

Eighty pigs, male and female littermate pairs, were fed a control or a test diet from 25 to 95 kg live weight. The diets, as fed, contained 15.5 g/kg linoleic acid (18:2) and 1.9 g/kg α-linolenic acid (18:3) (control) or 10 g/kg linoleic acid and 4 g/kg α-linolenic acid (test). The test diet, with added linseed, was, therefore, high in the main n-3 polyunsaturated fatty acid (PUFA) 18:3 and low in the main n-6 PUFA 18:2. Making this relatively small change led to a 56% increase in the content of 18:3 in muscle and major increases in the contents of the beneficial longer chain PUFAs EPA (20:5n-3) (100% increase) and DHA (22:6n-3) (35% increase) which are synthesised from 18:3n-3. Levels of EPA and DHA in pigmeat adipose tissue were also increased by the test diet. In liver, the test diet resulted in an 18:3 level 4× higher than in muscle, with 10× more EPA and 20× more DHA. Sausages, analysed after 6 months frozen storage also had high n-3 PUFA levels, due to the contribution of these fatty acids from both muscle and adipose tissue. From a health perspective these results confirm the potential of pigmeat to supply valuable n-3 PUFA to the human diet. The test diet produced a PUFA:saturated FA ratio in muscle of 0.4, close to the minimum recommended value for the diet as a whole and an n-6:n-3 ratio of 5, a significant improvement on the current average for pigmeat (7). It is estimated that the test diet would provide 12 g of long chain n-3 PUFA to the human diet per annum at current pigmeat consumption levels in the UK, about a third of that from oily fish.     

Modelling of the disulphide-swapped isomer of human insulin-like growth factor-1: implications for receptor binding

Insulin-like growth factor-1 (IGF-1) is a serum protein whichunexpectedly folds to yield two stable tertiary structures withdifferent disulphide connectivities; native IGF-1 [18–61,6–48,47–52]and IGF-1 swap [18–61,6–47, 48–52]. Here we demonstratein detail the biological properties of recombinant human nativeIGF-1 and IGF-1 swap secreted from Saccharomyces cerevisiae.IGF-1 swap had a ~30 fold loss in affinity for the IGF-1 receptoroverexpressed on BHK cells compared with native IGF-1.The parallelincrease in dose required to induce negative cooperativity togetherwith the parallel loss in mitogenicity in NIH 3T3 cells impliesthat disruption of the IGF-1 receptor binding interaction ratherthan restriction of a post-binding conformational change isresponsible for the reduction in biological activity of IGF-1swap. Interestingly, the affinity of IGF-1 swap for the insulinreceptor was ~200 fold lower than that of native IGF-1 indicatingthat the binding surface complementary to the insulin receptor(or the ability to attain it) is disturbed to a greater extentthan that to the IGF-1 receptor. A 1.0 ns high-temperature moleculardynamics study of the local energy landscape of IGF-1 swap resultedin uncoiling of the first A-region -helix and a rearrangementin the relative orientation of the A- and B-regions. The modelof IGF-1 swap is structurally homologous to the NMR structureof insulin swap and CD spectra consistent with the model arepresented. However, in the model of IGF-1 swap the C-regionhas filled the space where the first A-region -helix has uncoiledand this may be hindering interaction of Val44 with the secondinsulin receptor binding pocket.     

The effect of copper oxide on sintering, microstructure, mechanical properties and hydrothermal ageing of coated 2.5Y-TZP ceramics

Copper oxide dopants in amounts up to 1 wt% were added to 2.5 mol% yttria-coated zirconia powders in studies of sintering, microstructure, mechanical properties and hydrothermal ageing behaviour. High densities (>6 Mgm^–3), high tetragonal phase content (>95%), and phenomenal fracture toughness values (>17 MPam^1/2), were obtained for lower dopant levels. Grain sizes of 0.13 to 0.25 m were measured for all samples sintered at 1300°C. Rounded pores in some doped samples indicated that a liquid phase was involved during sintering. Copper oxide additions aid low temperature sintering and offer potential for property enhancement with a particularly high toughness being measured as well as improving resistance to structural degradation in 180°C hydrothermal ageing.