Probability effects on stimulus evaluation and response processes.

Investigated the effects of probability information on response preparation and stimulus evaluation. Eight Ss responded with 1 hand to the target letter H and with the other to the target letter S. The target letter was surrounded by noise letters that were either the same as or different from the target letter. In 2 conditions, the targets were preceded by a warning stimulus unrelated to the target letter. In 2 other conditions, a warning letter predicted that the same letter or the opposite letter would appear as the imperative stimulus with .80 probability. Correct reactions times (RTs) were faster and error rates were lower when imperative stimuli confirmed the predictions of the warning stimulus. Probability information affected (1) the preparation of motor responses during the foreperiod, (2) the development of expectancies for a particular target letter, and (3) a process sensitive to the identities of letter stimuli but not to their locations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditional stimulus probability and activity of hippocampal, cingulate cortical, and limbic thalamic neurons during avoidance conditioning in rabbits.

Multi-unit and field potential responses in the anterior (AC) and posterior cingulate cortices (PC), dentate gyrus (DG), and anterior ventral (AV) and medial dorsal (MD) thalamic nuclei of rabbits were recorded during acquisition and performance of a locomotor conditioned response (CR). The CR, stepping in an activity wheel in response to a tone (conditioned stimulus [CS+]), prevented the occurrence of a shock unconditioned stimulus (UCS) scheduled 5 sec after CS+ onset. Ss also learned to ignore a different tone (CS–), not predictive of the UCS. Training was given daily until behavioral discrimination reached criterion. After criterion, asymmetric probability (AP) sessions were given that were the same as the conditioning session except for probability manipulation. A significant discriminative response developed in all regions during behavioral acquisition. The unit response in the AP session was enhanced in all areas by rare presentation of the CS–, compared with the equal and frequent CS– conditions. Rare presentation of the CS+ enhanced the unit response in the AC, PC, and DG, but it suppressed the firing of AV and MD neurons. Rare CS+ presentations did not alter AV and PC neuronal activity in Ss with subicular lesions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.     

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)     

Passive shunt harmonic filters for low and medium voltage: a costcomparison study

This paper presents the cost of 480 V and 13.8 kV passive shunt harmonic filters tuned at 300, 420, 660 and 780 Hz. The cost is presented in function of the kVA of the load served by the filters, the 60 Hz reactive power produced by the filter end the total non60 Hz apparent power of the load. The main conclusion of this work is that for nonlinear loads in excess of 1 MVA it is more economical to use filter centers connected on the 13.8 kV side     

Interstitial pneumonitis in bone marrow transplant recipients is associated with local production of TH2-type cytokines and lack of T cell-mediated cytotoxicity

BACKGROUND: Interstitial pneumonitis, especially associated with cytomegalovirus (CMV) infection, is a serious complication after bone marrow transplantation (BMT), with a high fatality rate despite adequate antiviral treatment. The aim of this study was to elucidate the local immunopathogenesis of interstitial pneumonitis caused by CMV or other agents in BMT recipients. METHODS: Cryopreserved lung tissue obtained from 12 patients with interstitial pneumonitis following BMT was analyzed for cytokine production at the single-cell level using a cytokine-specific monoclonal antibody and immunohistochemical technique. Cytokine production in individual cells was analyzed using monoclonal antibodies to 23 different human cytokines: interleukin (IL)-1 to IL-13, tumor necrosis factor (TNF)-alpha, TNF-beta, interferon-gamma (IFNgamma), granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, and transforming growth factor (TGF)-beta1 to 3. RESULTS: Marrow transplant patients with interstitial pneumonia had increased numbers of infiltrating alveolar macrophages, CD3+, CD4+ T cells, and CD40+ B cells and significantly increased numbers of IL-4-, IL-10-, IL-1-, TGF-beta1-, TGF-beta2-, and TGF-beta3-producing cells than controls. IL-2-, IFN-gamma-, and TNF-beta-producing cells were undetectable in most patients with CMV pneumonitis (n=7). Neither perforin-positive CD8+ T lymphocytes nor up-regulation of the apoptotic pathway was detected in lung tissue from patients with interstitial pneumonia. In contrast, extensive local production of IgA, IgG, and IgM was demonstrated in all patients. Intracellular and extensive extracellular deposition of CD68, the L-1 antigen synthesized in CD14+ macrophages, was found. CONCLUSIONS: The cytokine profile suggested that Th1-type cytokine production was absent, whereas production of Th2-type cytokines was significantly up-regulated. Interstitial pneumonitis in BMT recipients with fatal outcome (11/12 patients) was associated with dysregulation in the local cytokine network notable for a predominant Th2 immune response with minimal or absent T cell-mediated cytotoxicity.