Can successful forecasters help stabilize asset prices in a learning to forecast experiment?

We conduct a Learning to Forecast asset pricing experiment where the market impact of individual forecasts evolves endogenously based on the forecasters' past accuracy. We investigate how endogenous impacts affect price stability and mispricing relative to the fundamental price. Our results suggest that endogenous impacts can destabilize markets when impacts are quite sensitive to forecast accuracy: Price dispersion increases compared to the baseline treatment where impacts are constant and independent of forecast accuracy. On the other hand, mispricing can be reduced when markets are relatively stable and impacts are moderately sensitive to forecast accuracy

Contribution of oxygen extraction fraction to maximal oxygen uptake in healthy young men

We analysed the importance of systemic and peripheral arteriovenous O2 difference (a- v− O2 and a-vf O2 difference, respectively) and O2 extraction fraction for maximal oxygen uptake ( V˙ O2max ). Fick law of diffusion and the Piiper and Scheid model were applied to investigate whether diffusion vs perfusion limitations vary with V˙ O2max . Articles (n=17) publishing individual data (n=154) on V˙ O2max , maximal cardiac output ( Q˙ max ; indicator-dilution or Fick method), a- v− O2 difference (catheters or Fick equation) and systemic O2 extraction fraction were identified. For the peripheral responses, group-mean data (articles: n=27; subjects: n=234) on leg blood flow (LBF; thermodilution), a-vf O2 difference and O2 extraction fraction (arterial and femoral venous catheters) were obtained. Q˙ max and two-LBF increased linearly by 4.9-6.0 L·min-1 per 1 L·min-1 increase in V˙ O2max (R2 =0.73 and R2 =0.67, respectively; both P<0.001). The a- v− O2 difference increased from 118-168 mL·L-1 from a V˙ O2max of 2-4.5 L·min-1 followed by a reduction (second-order polynomial: R2 =0.27). After accounting for a hypoxemia-induced decrease in arterial O2 content with increasing V˙ O2max (R2 =0.17; P<0.001), systemic O2 extraction fraction increased up to ~90% ( V˙ O2max : 4.5 L·min-1 ) with no further change (exponential decay model: R2 =0.42). Likewise, leg O2 extraction fraction increased with V˙ O2max to approach a maximal value of ~90-95% (R2 =0.83). Muscle O2 diffusing capacity and the equilibration index Y increased linearly with V˙ O2max (R2 =0.77 and R2 =0.31, respectively; both P<0.01), reflecting decreasing O2 diffusional limitations and accentuating O2 delivery limitations. In conclusion, although O2 delivery is the main limiting factor to V˙ O2max , enhanced O2 extraction fraction (≥90%) contributes to the remarkably high V˙ O2max in endurance-trained individuals

On the Influence of Temperature upon the Photo-electric Effect

Photo-electric threshold frequency for metals.—Free electron theory. A discussion is given of the suggestion by Millikan that in the photo-electric effect the energy of the light is transferred to the free electrons of the metals as well as to the bound electrons, and the threshold frequency ν0 is interpreted by the equation hν0=ϕp-Ek where ϕp is the work necessary to remove a free electron from the metal. In cases where Ek is not small compared with ϕp the theory leads to a lack of sharpness in the definition of ν0. Neglecting variations of kinetic energy, the difference of stopping potentials comes out equal to the Peltier coefficient; hence the uniformity of stopping potentials for different metals observed by Millikan is due, according to the theory, to the smallness of the Peltier effect. The variation of the long wave-length limit with temperature comes out ∂λ0/∂T=(λ02/hc)eσ, σ being the Thomson coefficient. In most cases λ0 should be practically independent of temperature. In the case of aluminum, after prolonged heating, the photo-electric current due to λ2537 was found to remain constant within 1/2 per cent as the target was cooled from 400° to 100°C and this constancy is interpreted as evidence that the shift of the long wavelength limit with change of temperature is less than 1A. The limit was found to be at about 2700A. Similar observations with a nickel target and 2412A gave inconclusive results, as in spite of heating to 1300°C and reduction of the oxide on the surface by heating in hydrogen, reproducible results were not obtained. Photo-electric current from aluminum for λ2537.—(1) Effect of prolonged heating in vacuum by high frequency induction for many hours to near the melting point. The current remained strong. (2) Effect of cooling from 400° to 100°C. The current remained constant within 1/2 per cent

SELEX RICH Performance and Physics Results

SELEX took data in the 1996/7 Fixed Target Run at Fermilab. The excellent performance parameters of the SELEX RICH Detector had direct influence on the quality of the obtained physics results.Comment: Contributed talk at the Fourth Workshop on RICH Detectors, June 5-10, 2002, Pylos, Greece. Accepted for publication in NIM