When a bleached strain of Euglena is maintained in a medium containing very low con centrations of phosphate, the acid phosphatase activity increases. The increase in acid phosphatase activity is prevented by Actinomycin D and by p-fluorophenylalanine (PFA), indicating that the increased activity is due to de novo synthesis of acid phosphatase. When phosphate is replenished, the acid phosphatas...

BACKGROUND Platelet function testing may be warranted to assess response to aspirin and clopidogrel. HYPOTHESIS/OBJECTIVES To evaluate the effects of aspirin, clopidogrel, or combination therapy using 3 platelet function tests: Multiplate Analyzer (MP), Platelet Function Analyzer-200 (PFA), and Plateletworks (PW). ANIMALS Six healthy laboratory Beagles. METHODS Randomized double-blind pla...

Student modeling is a fundamental concept applicable to a variety of intelligent tutoring systems (ITS). However, there is not a lot of practical guidance on how to construct and train such models. This paper compares two approaches for student modeling, Knowledge Tracing (KT) and Performance Factors Analysis (PFA), by evaluating their predictive accuracy on individual student practice opportun...

The analysis of all Casimir force experiments using a sphere-plate geometry requires the use of the proximity-force approximation (PFA) to relate the Casimir force between a sphere and a flat plate to the Casimir energy between two parallel plates. Because it has been difficult to assess the PFA's range of applicability theoretically, we have conducted an experimental search for corrections to ...

Our aim is to construct a factor analysis method that can resist the effect of outliers. For this we start with a highly robust initial covariance estimator, after which the factors can be obtained from maximum likelihood or from principal factor analysis (PFA). We find that PFA based on the minimum covariance determinant scatter matrix works well. We also derive the influence function of the P...

We propose a new deep architecture for topic modeling, based on Poisson Factor Analysis (PFA) modules. The model is composed of a Poisson distribution to model observed vectors of counts, as well as a deep hierarchy of hidden binary units. Rather than using logistic functions to characterize the probability that a latent binary unit is on, we employ a Bernoulli-Poisson link, which allows PFA mo...

Investigations into the gait of persons with partial foot amputation (PFA) suggest that the effective foot length can be restored when the prosthesis incorporates a relatively stiff forefoot, restricts dorsiflexion, and includes a mechanism whereby forces caused by loading the toe lever can be comfortably distributed to the leg (e.g., an anterior tibial shell). The purpose of this investigation...

INTRODUCTION Hemostatic abnormalities in liver cirrhosis are complex and multifactorial and may predispose to prolonged hemorrhage following invasive procedures. Due to increased perioperative bleeding risks, patients with cirrhosis should undergo elective surgery after making medical preparations. It has been shown that 1-deamino-8-D-arginine vasopressin (DDAVP), desmopressin, can be used as a...

Building on the work of Schimmerling ([8]) and Steel ([14]), we show that the failure of square principle at a singular strong limit cardinal implies that there is a non-tame mouse. The proof presented is the first inductive step beyond L(R) of the core model induction that is aimed at getting a model of ADR + “Θ is regular” from the failure of square at a singular strong limit cardinal or PFA....

Morphological investigations of poly(tetrafluoroethylene-co-perfluorovinyl ether) (PFA)-g-polystyrene sulfonic acid membranes prepared by radiation-induced graft copolymerization of styrene onto PFA films followed by sulfonation were performed by X-ray photoelectron spectroscopy. The analyzed materials included grafted film and sulfonated membrane samples having various degrees of grafting. Ori...