Physiological flow in a model of arterial stenosis

No abstract available

Study on Input/Output Accounting Systems on EU agricultural holdings

Of 241 questionnaires sent out to 20 countries 55 completed forms were returned. No information could be obtained about systems in Portugal or the USA. The subject of nutrients was covered by 91% of systems, pesticides 38%, energy 29% and other subjects including wastes 44%. Nearly half of the systems covered more than one subject, the most common single subject system was nutrients. The arable sector was covered most often by the systems (76%), with dairy (62%) and pig (56%) the most prominent of the livestock sectors. The respondents judged that 65% of systems were at least moderately effective in improving the ratio of inputs to outputs. The highest levels of ratio reduction tended to occur with systems which included the livestock sectors or protected horticultural crops. Over half (56%) of farmers had a good opinion of the system, indifferent or bad opinions were more likely to be due to effect on income than the type of system or who managed it. High uptake was more likely in compensated systems. Farm incomes in the arable and dairy sectors were most likely to be improved by systems, negative effects were most likely in the horticultural sector. Government was the main driving force in 38% of the systems, but government was not necessarily the driving force behind the 15% compulsory systems and only one of these was compensated. Increasing concern about environmental issues was the driving force behind development of each of the systems studied. In most cases a major part of the funding to develop the system or run pilot projects came from government. Benefits in terms of increased awareness of problem areas were identified by several systems originators. Anecdotal evidence suggests that farmers are encouraged to make actual changes to their management on the basis of the systems, if they receive detailed help from an adviser associated with the system, or if the system results in a marketing advantage. It seems likely that input output accounting systems could be used to increase awareness and provide evidence of the impact of management changes, they may need to be linked to supporting systems of technical advice. More than 40 IOA systems representing very different approaches have been developed and applied on farms in European countries with the aim of improving environmental performance. Major differences regard especially two characteristics: The no topics covered (single or multiple) and the way indicators are presented. In many systems the indicators used are presented as calculations of input related to output and are derived from accounts based data. Other systems present indicators that are transformed to a standard scale and often these indicators are based on a combination of practise and account data compared with norms for Good Agricultural Practices. Moreover, the systems differ in their origin and driving force: Only a few systems have been developed for mandatory use or for labelling and formal auditioning. Most systems have been developed for the use by advisory services on a voluntary basis. A number of very different systems seem to have been successful. Effectiveness is defined here as the combination of a system with high (potential) impact on the participating farmers in combination with high uptake in terms of the no of farmers willing to use the system. Generally documentation of effects and uptake is poor and more investigations into this are needed. It seems that many systems have not passed the pilot phase, even though some of them did get a positive evaluation by the farmers. In several examples the effort of researchers to develop a scientifically valid concept was not matched by efforts to secure the uptake by advisors or other institutions afterwards. The right institutional setting and political context seems to be more important than the character of the indicators used for the question of farmer uptake. But that does not mean that the choice of indicators is not important from another point of view. In none of the reviewed systems were the use of confidence intervals or variation coefficients an established part of the procedure. Only few reports exist that analyse the variation between farms or between years on specific farms in order to decide to which degree differences are due to systematically different management practices

Multiple and plastic receptors mediate tonic GABAA receptor currents in the hippocampus

Persistent activation of GABAA receptors by extracellular GABA (tonic inhibition) plays a critical role in signal processing and network excitability in the brain. In hippocampal principal cells, tonic inhibition has been reported to be mediated by {alpha}5-subunit-containing GABAA receptors ({alpha}5GABAARs). Pharmacological or genetic disruption of these receptors improves cognitive performance, suggesting that tonic inhibition has an adverse effect on information processing. Here, we show that {alpha}5GABAARs contribute to tonic currents in pyramidal cells only when ambient GABA concentrations increase (as may occur during increased brain activity). At low ambient GABA concentrations, activation of {delta}-subunit-containing GABAA receptors predominates. In epileptic tissue, {alpha}5GABAARs are downregulated and no longer contribute to tonic currents under conditions of raised extracellular GABA concentrations. Under these conditions, however, the tonic current is greater in pyramidal cells from epileptic tissue than in pyramidal cells from nonepileptic tissue, implying substitution of {alpha}5GABAARs by other GABAA receptor subtypes. These results reveal multiple components of tonic GABAA receptor-mediated conductance that are activated by low GABA concentrations. The relative contribution of these components changes after the induction of epilepsy, implying an adaptive plasticity of the tonic current in the presence of spontaneous seizures

Coralline algae in a naturally acidified ecosystem persist by maintaining control of skeletal mineralogy and size

To understand the effects of ocean acidification (OA) on marine calcifiers, the trade-offs among different sublethal responses within individual species and the emergent effects of these trade-offs must be determined in an ecosystem setting. Crustose coralline algae (CCA) provide a model to test the ecological consequences of such sublethal effects as they are important in ecosystem functioning, service provision, carbon cycling and use dissolved inorganic carbon to calcify and photosynthesize. Settlement tiles were placed in ambient pH, low pH and extremely low pH conditions for 14 months at a natural CO2 vent. The size, magnesium (Mg) content and molecular-scale skeletal disorder of CCA patches were assessed at 3.5, 6.5 and 14 months from tile deployment. Despite reductions in their abundance in low pH, the largest CCA from ambient and low pH zones were of similar sizes and had similar Mg content and skeletal disorder. This suggests that the most resilient CCA in low pH did not trade-off skeletal structure to maintain growth. CCA that settled in the extremely low pH, however, were significantly smaller and exhibited altered skeletal mineralogy (high Mg calcite to gypsum (hydrated calcium sulfate)), although at present it is unclear if these mineralogical changes offered any fitness benefits in extreme low pH. This field assessment of biological effects of OA provides endpoint information needed to generate an ecosystem relevant understanding of calcifying system persistence

Measuring the indirect costs associated with the establishment of a wind farm: An application of the Contingent Valuation Method

Although a green energy source, the location of electrical generating windmills may cause a disamenity effect (negative externality). The establishment of a wind farm is known as a locally undesirable land use (LULU) and leads to the not-in-my-backyard syndrome (NIMBY). In an application of the contingent valuation method, a willingness-to-accept framework was used to estimate the aggregate annual compensation required to allow the construction of a wind farm near Jeffrey’s Bay, South Africa. This compensation amounted to R490 695. A binary choice logit analysis found that retirement status, concern about climate change, concern about view-shed impacts and the offer amount are important predictors of voting for or against the project.Contingent Valuation Method, indirect cost, wind farm

Macrophage autophagy in atherosclerosis

Macrophages play crucial roles in atherosclerotic immune responses. Recent investigation into macrophage autophagy (AP) in atherosclerosis has demonstrated a novel pathway through which these cells contribute to vascular inflammation. AP is a cellular catabolic process involving the delivery of cytoplasmic contents to the lysosomal machinery for ultimate degradation and recycling. Basal levels of macrophage AP play an essential role in atheroprotection during early atherosclerosis. However, AP becomes dysfunctional in the more advanced stages of the pathology and its deficiency promotes vascular inflammation, oxidative stress, and plaque necrosis. In this paper, we will discuss the role of macrophages and AP in atherosclerosis and the emerging evidence demonstrating the contribution of macrophage AP to vascular pathology. Finally, we will discuss how AP could be targeted for therapeutic utility

Percolation approach to quark gluon plasma in high energy pp collisions

We apply continuum percolation to proton-proton collisions and look for the possible threshold to phase transition from confined nuclear matter to quark gluon plasma. Making the assumption that J/Psi suppression is a good signal to the transition, we discuss this phenomenon for pp collisions, in the framework of a dual model with strings.Comment: 8 pages, 3 figure

A Curvature Principle for the interaction between universes

We propose a Curvature Principle to describe the dynamics of interacting universes in a multi-universe scenario and show, in the context of a simplified model, how interaction drives the cosmological constant of one of the universes toward a vanishingly small value. We also conjecture on how the proposed Curvature Principle suggests a solution for the entropy paradox of a universe where the cosmological constant vanishes.Comment: Essay selected for an honorable mention by the Gravity Research Foundation, 2007. Plain latex, 8 page

Consumer acceptance of novel fruits and fruit products

This report presents results of the consumer survey that was conducted in November, 2009, in four European countries – Poland, the Netherlands, Greece and Spain within WP 1.3 of ISAFRUIT Project. In the current deliverables (D1.3.5 and D1.3.8), the authors first focused on the influence of personal characteristics of the respondents, the evaluation of general fruit product characteristics, product evaluations of specific novel fresh fruits and fruit products and demographics on consumers' acceptance of fruit innovations. Furthermore, they identified cross cultural consumer segments, who each value different product characteristics. Moreover, these consumer segments differ in demographics, their willingness to accept fruit innovations and their personal characteristics. Policy recommendations for future product development of fresh fruits and fruit products and communication strategies were formulated, based on the results of the consumer survey and the identified cross cultural consumer segments