Reputation in perturbed repeated games

The paper analyzes reputation effects in perturbed repeated games with discounting. If there is some positive prior probability that one of the players is committed to play the same (pure) action in every period, then this provides a lower bound for her equilibrium playoff in all Nash equilibria. This bound is tight and independent of what other types have positive probability. It is generally lower than Fudenberg and Levine's bound for games with a long-run player facing a sequence of short-run opponents. The bound cannot be improved by considering types playing finitely complicated history-dependent commitment strategies

Influence of certain physical and chemical treatments on the germination and subsequent growth of coconut Cocos nucifera L.seedlings a preliminary study

The effect of certain physical and chemical treatments on the germination and asubsequent growth of coconut seedlings was tested. The treatments consisted of soaking the seed coconuts for 48hours in 0.01 and 0.02 molar potassium nitrate and sodium carbonate solutions, soaking in water for one week and two weeks durations and a physical treatment of chopping the husk from both ends of the nut. A control was also provided for comparison. The results indicated that all the treatements except the chopping of the ends significantly reduced the the germination period, gave a higher percentage germination and greater growth of seedlings when compared with the control. Amongst the treatments, simply soaking in water for 2 weeks is recommended as it ranked first in all characters and at the same time is simple and easy to follow by farmer

Is there a "heat or eat" trade-off in the UK?

In this research, funded by the Nuffield Foundation, we merge detailed household level expenditure data from older households with historical local weather information. We then test for a heat or eat trade off: do households cut back on food spending to finance the additional cost of keeping warm during cold shocks? We find evidence that the poorest of older households are unable to smooth spending over the worst temperature shocks. Statistically significant reductions in food spending are observed in response to temperatures two or more standard deviations colder than expected (which occur about one winter month in forty) and reductions in food expenditure are considerably larger in poorer households.

Is There a Heat or Eat Trade-off in the UK?

We merge detailed household level expenditure data from older households with historical local weather information. We then test for a heat or eat trade off: do households cut back on food spending to finance the additional cost of keeping warm during cold shocks? For households who cannot smooth consumption over time, cold weather shocks are equivalent to income shocks. We find evidence that the poorest of older households are unable to smooth spending over the worst temperature shocks. Statistically significant reductions in food spending are observed in response to winter temperatures two or more standard deviations colder than expected (which occur about one winter month in forty) and reductions in food expenditure are considerably larger in poorer households.

Cash by any other name? Evidence on labelling from the UK Winter Fuel Payment

Standard economic theory implies that the labelling of cash transfers or cash-equivalents (e.g. child benefits, food stamps) should have no effect on spending patterns. The empirical literature to date does not contradict this proposition. We study the UK Winter Fuel Payment (WFP), a cash transfer to older households. Exploiting sharp eligibility criteria in a regression discontinuity design, we find robust evidence of a behavioural effect of the labelling. On average households spend 41% of the WFP on fuel. If the payment was treated as cash, we would expect households to spend approximately 3% of the payment on fuel.

When to rebuild or when to adjust scorecards

Data-based scorecards, such as those used in credit scoring, age with time and need to be rebuilt or readjusted. Unlike the huge literature on modelling the replacement and maintenance of equipment there have been hardly any models that deal with this problem for scorecards. This paper identifies an effective way of describing the predictive ability of the scorecard and from this describes a simple model for how its predictive ability will develop. Using a dynamic programming approach one is then able to find when it is optimal to rebuild and when to readjust a scorecard. Failing to readjust or rebuild a scorecard when they aged was one of the defects in credit scoring identified in the investigations into the sub-prime mortgage crisis

Interspecific competition affects early growth of a Eucalyptus grandis x E. camaldulensis hybrid clone in Zululand, South Africa

To determine the effects of the onset and development of vegetation competition on tree performance, a Eucalyptus hybrid clone (GC304) was planted in a field trial in Zululand, South Africa. Nine vegetation management treatments, imposed from planting, included a weedy control treatment, a manually weeded treatment, a chemically weeded treatment (glyphosate), a 1.2m row and a 1.2m inter-row weeding, a 0.5m radius ring weeding, a complete weeding except for a 0.5m radius ring around the tree (no ring weeding), and the use of two legume cover-crops, Mucuna puriens (L.) DC. (velvet bean) and Vigna unguiculata (L.) Walp. (cowpea). The different treatments applied during establishment resulted in the differential growth of the trees as determined by measurements of tree height and crown diameter. This occurred from as early as 60 days after planting. The degree of competition could be directly related to the type of vegetation (cover-crops or naturally occurring weeds) and its proximity to the tree. The predominant vegetation on this site, yellow nutsedge (Cyperus esculentus L.), was able to colonise the site rapidly, causing severe and early competition. There were strong indications that this initial competition was mainly for moisture and possibly also for nutrients, rather than competition for light. Initially, trees in those treatments that had vegetation within their immediate vicinity were most affected (weedy control, inter-row weeding and no ring weeding). With time, tree performance was more closely related to an increase in the percentage of the area kept free of vegetation. At 180 days after planting the ranking of the top five treatments in relation to the area kept free of vegetation was: manually weeded treatment (100% of area free of vegetation) > chemically weeded treatment (100% of area free of vegetation) > no ring weeding (90% of area free of vegetation) > row weeding (40% of area free of vegetation) > ring weeding (10% of area free of vegetation). The planting of cover-crops, although beneficial in terms of the suppression of competing vegetation, also caused significant tree suppression. This occurred despite the fact that their initial biomass accumulation was slower than that of the natural weed population. Of the two covercrops, the use of a velvet bean cover-crop was not considered suitable due to its vigorous vining habit which adversely affected growth form

Observed changes in surface atmospheric energy over land

The temperature of the surface atmosphere over land has been rising during recent decades. But surface temperature, or, more accurately, enthalpy which can be calculated from temperature, is only one component of the energy content of the surface atmosphere. The other parts include kinetic energy and latent heat. It has been advocated in certain quarters that ignoring additional terms somehow calls into question global surface temperature analyses. Examination of all three of these components of atmospheric energetics reveals a significant increase in global surface atmospheric energy since the 1970s. Kinetic energy has decreased but by over two orders of magnitude less than the increases in both enthalpy and latent heat which provide approximately equal contributions to the global increases in heat content. Regionally, the enthalpy or the latent heat component can dominate the change in heat content. Although generally changes in latent heat and enthalpy act in concert, in some regions they can have the opposite signs

Sterol affinity for phospholipid bilayers is influenced by hydrophobic matching between lipids and transmembrane peptides

AbstractLipid self-organization is believed to be essential for shaping the lateral structure of membranes, but it is becoming increasingly clear that also membrane proteins can be involved in the maintenance of membrane architecture. Cholesterol is thought to be important for the lateral organization of eukaryotic cell membranes and has also been implicated to take part in the sorting of cellular transmembrane proteins. Hence, a good starting point for studying the influence of lipid–protein interactions on membrane trafficking is to find out how transmembrane proteins influence the lateral sorting of cholesterol in phospholipid bilayers. By measuring equilibrium partitioning of the fluorescent cholesterol analog cholestatrienol between large unilamellar vesicles and methyl-β-cyclodextrin the effect of hydrophobic matching on the affinity of sterols for phospholipid bilayers was determined. Sterol partitioning was measured in 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayers with and without WALP19, WALP23 or WALP27 peptides. The results showed that the affinity of the sterol for the bilayers was affected by hydrophobic matching. An increasing positive hydrophobic mismatch led to stronger sterol binding to the bilayers (except in extreme situations), and a large negative hydrophobic mismatch decreased the affinity of the sterol for the bilayer. In addition, peptide insertion into the phospholipid bilayers was observed to depend on hydrophobic matching. In conclusion, the results showed that hydrophobic matching can affect lipid–protein interactions in a way that may facilitate the formation of lateral domains in cell membranes. This could be of importance in membrane trafficking

Methane adsorption on shale under simulated geological temperature and pressure conditions

Shale gas is becoming an increasingly important energy resource. In this study, the adsorption of methane on a dry, organic-rich Alum shale sample was studied at pressures up to 14 MPa and temperatures in the range 300–473 K, which are relevant to gas storage under geological conditions. Maximum methane excess uptake was 0.176–0.042 mmol g–1 (125–30 scf t–1) for the temperature range of 300–473 K. The decrease in maximum methane surface excess with increasing temperature can be described with a linear model. An isosteric enthalpy of adsorption 19.2 ± 0.1 kJ mol–1 was determined at 0.025 mmol g–1 using the van’t Hoff equation. Supercritical adsorption was modeled using the modified Dubinin–Radushkevich and the Langmuir equations. The results are compared with absolute isotherms calculated from surface excess and the pore volumes obtained from subcritical gas adsorption (nitrogen (78 K), carbon dioxide (273 and 195 K), and CH4 (112 K)). The subcritical adsorption and the surface excess results allow an upper limit to be put on the amount of gas that can be retained by adsorption during gas generation from petroleum source rocks