Analysis of the Low-Energy Theorem for \gamma p \to p \pi^0

The derivation of the `classical' low-energy theorem (LET) for \gamma p \rightarrow p\pi^0 is re-examined and compared to chiral perturbation theory. Both results are correct and are not contradictory; they differ because different expansions of the same quantity are involved. Possible modifications of the extended partially conserved axial-vector current relation, one of the starting points in the derivation of the LET, are discussed. An alternate, more transparent form of the LET is presented.Comment: 5 pages, Revtex, no figures, no table

The Determination of the Effective Resistance of a Spindle Supporting a Model Airfoil

An attempt was made to determine the effect of spindle interference on the lift of the airfoil by measuring moments about the axis parallel to the direction of air flow. The values obtained are of the same degree as the experimental error, and for the present this effect will be neglected. The results obtained using a U.S.A. 15 wing (plotted here) show that the correction is nearly constant from 0 degrees to 10 degrees incidence and that at greater angles its value becomes erratic. At such angles, however, the wing drag is so high that the spindle correction and its attendant errors become relatively small and unimportant

Machine Learning and Irresponsible Inference: Morally Assessing the Training Data for Image Recognition Systems

Just as humans can draw conclusions responsibly or irresponsibly, so too can computers. Machine learning systems that have been trained on data sets that include irresponsible judgments are likely to yield irresponsible predictions as outputs. In this paper I focus on a particular kind of inference a computer system might make: identification of the intentions with which a person acted on the basis of photographic evidence. Such inferences are liable to be morally objectionable, because of a way in which they are presumptuous. After elaborating this moral concern, I explore the possibility that carefully procuring the training data for image recognition systems could ensure that the systems avoid the problem. The lesson of this paper extends beyond just the particular case of image recognition systems and the challenge of responsibly identifying a person’s intentions. Reflection on this particular case demonstrates the importance (as well as the difficulty) of evaluating machine learning systems and their training data from the standpoint of moral considerations that are not encompassed by ordinary assessments of predictive accuracy

Protein kinase C modulates the activity of a cloned gamma-aminobutyric acid transporter expressed in Xenopus oocytes via regulated subcellular redistribution of the transporter

We report that activators and inhibitors of protein kinase C (PKC) and protein phosphatases regulate the activity of a cloned rat brain gamma- aminobutyric acid (GABA) transporter (GAT1) expressed in Xenopus oocytes. Four compounds known to activate PKC increased GABA uptake 2- 3.5-fold over basal control levels. Inhibition of PKC by bisindolylmaleimide reduced basal GABA uptake 80% and blocked the phorbol 12-myristate 13-acetate (PMA)-induced stimulation of transport. Okadaic acid, a protein phosphatase inhibitor, stimulated transport 2.5- fold; a 4-fold increase in GABA uptake occurred when oocytes were treated with cyclosporin A, a specific inhibitor of protein phosphatase 2B. Modulation resulted in changes to Vmax but not to Km and was influenced by the functional expression level of the transporter protein; as expression level increased, the ability to up-regulate transporter activity decreased. Down-regulation of transporter activity was independent of expression level. Modulation did not occur through phosphorylation of the three consensus PKC sites predicted by the primary protein sequence since their removal had no effect on the susceptibility of the transporter to modulation by PMA or bisindolylmaleimide. Subcellular fractionation of oocyte membranes demonstrated that under basal level conditions, the majority of GAT1 was targeted to a cytoplasmic compartment corresponding to the trans- Golgi or low density vesicles. Stimulation of PKC with PMA resulted in a translocation of transporters from this compartment to the plasma membrane. At higher expression levels of GAT1 protein, a larger portion of GAT1 was found on the plasma membrane during basal level conditions and treatment with bisindolylmaleimide resulted in removal of these transporters from the plasma membrane. At expression levels demonstrated to be resistant to modulation by PMA, PMA-treatment still resulted in translocation of transporters from the cytoplasm to the plasma membrane. Thus, the inability of PMA to increase uptake at high expression of the GAT1 protein is due to saturation at a step subsequent to translocation. These findings 1) demonstrate the presence of a novel regulated secretory pathway in oocytes and 2) suggest a modulatory mechanism for neurotransmitter transporters that could have significant effects upon synaptic function

Reconsideration of Failure Initiating Mechanisms for Teton Dam

A review of failure mechanisms previously suggested for Teton Dam indicated that they were not fully supported by all the available data. The original mechanisms are reviewed and a failure initiation mechanism is then proposed which does satisfy all the available data, and laboratory tests supporting this mechanism are presented. Additional lessons to be learned from the failure are listed

Experimental manipulation of food bodies in Cecropia

Journal ArticleNeotropical Cecropia trees range from Mexico to Argentina and are typical of disturbed habitats. Cecropia plants provide food and housing for the ants in return for known or presumed protection from herbivores and vine cover. Glycogen-rich Mullerian bodies (MB's) are the predominant food source for ants and are produced at sites called trichilia. Working with Cecropia (prov.) "tessmannii", we continuously removed MB's from 10 of 20 plants in a common garden and left the remaining control plants unmanipulated. Control plants produced fewer MB's over the lifespan of a trichilia. Therefore, plants appear to regulate MB production so that energy is not wasted in biotic defense if appropriate ants are not present

Accomplishments of the NASA Johnson Space Center portion of the soil moisture project in fiscal year 1981

The NASA/JSC ground scatterometer system was used in a row structure and row direction effects experiment to understand these effects on radar remote sensing of soil moisture. Also, a modification of the scatterometer system was begun and is continuing, to allow cross-polarization experiments to be conducted in fiscal years 1982 and 1983. Preprocessing of the 1978 agricultural soil moisture experiment (ASME) data was completed. Preparations for analysis of the ASME data is fiscal year 1982 were completed. A radar image simulation procedure developed by the University of Kansas is being improved. Profile soil moisture model outputs were compared quantitatively for the same soil and climate conditions. A new model was developed and tested to predict the soil moisture characteristic (water tension versus volumetric soil moisture content) from particle-size distribution and bulk density data. Relationships between surface-zone soil moisture, surface flux, and subsurface moisture conditions are being studied as well as the ways in which measured soil moisture (as obtained from remote sensing) can be used for agricultural applications

Microscopic heat from the energetics of stochastic phenomena

The energetics of the stochastic process has shown the balance of energy on the mesoscopic level. The heat and the energy defined there are, however, generally different from their macroscopic counterpart. We show that this discrepancy can be removed by adding to these quantities the reversible heat associated with the mesoscopic free energy.Comment: 4 pages, 0 figur