PMN-PT single crystal, high-frequency ultrasonic needle transducers for pulsed-wave Doppler application

High-frequency needle ultrasound transducers with an aperture size of 0.4 mm were fabricated using lead magnesium niobate-lead titanate (PMN-33% PT) as the active piezoelectric material. The active element was bonded to a conductive silver particle matching layer and a conductive epoxy backing through direct contact curing. An outer matching layer of parylene was formed by vapor deposition. The active element was housed within a polyimide tube and a 20-gauge needle housing. The magnitude and phase of the electrical impedance of the transducer were 47 omega and -38 degrees, respectively. The measured center frequency and -6 dB fractional bandwidth of the PMN-PT needle transducer were 44 MHz and 45%, respectively. The two-way insertion loss was approximately 15 dB. In vivo high-frequency, pulsed-wave Doppler patterns of blood flow in the posterior portion and in vitro ultrasonic backscatter microscope (UBM) images of the rabbit eye were obtained with the 44-MHz needle transducer.     

Inducing Constructor Systems from Example-Terms by Detecting Syntactical Regularities

We present a technique for inducing functional programs from few, well chosen input/output-examples (I/O-examples). Potential applications for automatic program or algorithm induction are to enable end users to create their own simple programs, to assist professional programmers, or to automatically invent completely new and efficient algorithms. In our approach, functional programs are represented as constructor term rewriting systems (CSs) containing recursive rules. I/O-examples for a target function to be implemented are a set of pairs of terms (F(i_i),o_i) meaning that F(i_i)—denoting application of function F to input i_i—is rewritten to o_i by a CS implementing the function F. Induction is based on detecting syntactic regularities between example terms. In this paper we present theoretical results and describe an algorithm for inducing CSs over arbitrary signatures/data types which consist of one function defined by an arbitrary number of rules with an arbitrary number of non-nested recursive calls in each rule. Moreover, we present empirical results based on a prototypical implementation.     

From task parameters to motor synergies: A hierarchical framework for approximately optimal control of redundant manipulators

We present a hierarchical framework for approximately optimal control of redundant manipulators. The plant is augmented with a low‐level feedback controller, designed to yield input‐output behavior that captures the task‐relevant aspects of plant dynamics but has reduced dimensionality. This makes it possible to reformulate the optimal control problem in terms of the augmented dynamics, and optimize a high‐level feedback controller without running into the curse of dimensionality. The resulting control hierarchy compares favorably to existing methods in robotics. Furthermore, we demonstrate a number of similarities to (nonhierarchical) optimal feedback control. Besides its engineering applications, the new framework addresses a key unresolved problem in the neural control of movement. It has long been hypothesized that coordination involves selective control of task parameters via muscle synergies, but the link between these parameters and the synergies capable of controlling them has remained elusive. Our framework provides this missing link. © 2005 Wiley Periodicals, Inc.     

Juvenile chronic myelogenous leukemia

Juvenile chronic myelogenous leukemia (JCML) is an aggressive myeloproliferative disorder of childhood that differs both clinically and pathologically from adult type, Philadelphia chromosome positive chronic myelogenous leukemia, and from the other myeloproliferative disorders that are more common in adulthood. The disease can have widely varying clinical presentations and shares many features with the monosomy 7 syndrome and chronic myelomonocytic leukemia. With no specific marker chromosome, establishing the diagnosis can be difficult, and relies on a constellation of clinical, pathologic, and laboratory findings. This article discusses the differential diagnosis of JCML with an emphasis on the pathologic findings and laboratory data that are particularly important for confirming the diagnosis. The sensitivity, specificity, and clinical utility of cell culture colony assays are reviewed. Finally, current knowledge of the biology of JCML and some of the controversies regarding this disease are discussed.     

A Shallow Text Processing Core Engine

In this article we present SMES–SPPC, a high–performance system for intelligent extraction of structured data from free text documents. SMES–SPPC consists of a set of domain–adaptive shallow core components that are realized by means of cascaded weighted finite–state machines and generic dynamic tries. The system has been fully implemented for German; it includes morphological and on–line compound analysis, efficient POS–filtering, high–performance named–entity recognition and chunk parsing based on a novel divide–and–conquer strategy. The whole approach proved to be very useful for processing free word order languages such as German. SMES–SPPC has a good performance (more than 6000 words per second on standard PC environments) and achieves high linguistic coverage, especially for the divide–and–conquer parsing strategy, where we obtained an f –measure of 87.14% on unseen data.     

Positive effects of allosteric modulators on the binding properties and the function of muscarinic acetylcholine receptors

Data are reviewed indicating that allosteric modulators can enhance the affinities of muscarinic receptors for their antagonists and agonists, that the enhancement of the affinity for agonists is relevant functionally, and that the allosterically induced conformational change also affects the interaction between the receptors and the G proteins.     

Brain potentials as indices of orthographic and phonological interaction during word matching.

Studied the interaction between orthographic and phonological codes in a same–different judgment task by requiring 40 undergraduates to decide if 2 visually presented words either looked alike or rhymed. Word pairs were selected from 4 lists: words rhymed and looked alike, rhymed but did not look alike, looked alike but did not rhyme, or neither looked alike nor rhymed. The reaction time (RT) and percent error increased when there was a conflict between the orthography and phonology of the words. The N200 component of the event-related brain potential (ERP) indicated that Ss were capable of detecting phonological differences between words within 260 msec from the presentation of a word pair. The amplitude of the N200s also varied with the degree of mismatch between words. N200s were largest when both the orthography and phonology mismatched, of intermediate amplitude when either orthography or phonology mismatched, and smallest when both orthograpy and phonology matched. P300 latency was consistent with RT, increasing whenever there was a conflict between the 2 codes. Behavioral measures and the ERP data suggest that the extraction of the orthographic and phonological aspects of words occurs early in the information-processing sequence. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)