966 research outputs found

    The Specificity of the Search Template

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    When searching for a target object, observers use an internal representation of the target\u27s appearance as a search template. This study used naturalistic stimuli to examine the specificity of this template. Observers first learned several name-image pairs; they then participated in a search experiment in which the names served as cues and the images served as targets. To test whether the observers searched for the targets using an exact image template, we included targets that were transformations of the studied image and targets that belonged to the same subordinate-level category as the studied image. The same stimuli were also used in a search experiment involving image cues. The name cue and image cue experiments produced different patterns of results. Unlike image cues, name cues produced similar benefits for transformations of the studied images as for the studied images themselves. Also unlike image cues, names cues produced no benefit for members of the same subordinate-level category as the studied image. These results suggest that when observers are trained on an image, they develop a search template that is relatively specific for the image but still tolerant to changes in scale and orientation

    Natural antisense transcription from a comparative perspective

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    Natural antisense transcripts (NATs) can interfere with the expression of complementary sense transcripts with exquisite specificity. We have previously cloned NATs of Slc34a loci (encoding Na-phosphate transporters) from fish and mouse. Here we report the cloning of a human SLC34A1-related NAT that represents an alternatively spliced PFN3 transcript (Profilin3). The transcript is predominantly expressed in testis. Phylogenetic comparison suggests two distinct mechanisms producing Slc34a-related NATs: Alternative splicing of a transcript from a protein coding downstream gene (Pfn3, human/mouse) and transcription from the bi-directional promoter (Rbpja, zebrafish). Expression analysis suggested independent regulation of the complementary Slc34a mRNAs. Analysis of randomly selected bi-directionally transcribed human/mouse loci revealed limited phylogenetic conservation and independent regulation of NATs. They were reduced on X chromosomes and clustered in regions that escape inactivation. Locus structure and expression pattern suggest a NATs-associated regulatory mechanisms in testis unrelated to the physiological role of the sense transcript encoded protein

    Inappropriate sinus tachycardia: focus on ivabradine

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    Inappropriate sinus tachycardia (IST) is an incompletely understood condition characterised by an elevation in heart rate (HR) accompanied by wide ranging symptoms, in the absence of an underlying physiological stimulus. The condition often takes a chronic course with significant adverse effects on quality of life. Currently there is no effective treatment for IST. Beta-blockers, generally considered the cornerstone of treatment, are often ineffective and poorly tolerated. Ivabradine is a novel sinus node If "funny current" inhibitor which reduces the HR. It has been approved for the treatment of beta-blocker refractory chronic systolic heart failure and chronic stable angina, but more recently shown promise in the treatment of IST. This review provides an overview of IST prevalence and mechanisms, followed by an examination of the evidence for the role and efficacy of ivabradine in the treatment of IST

    Optimization of EDM process parameters for Al-SiC reinforced metal matrix composite

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    Volume 8 Issue 2 (February 201

    Toxoplasma gondii peroxiredoxin promotes altered macrophage function, caspase-1-dependent IL-1β secretion enhances parasite replication

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    Alternatively activated macrophages (AAM) are a key feature Th2 immunity and have been associated with a variety of roles during helminth infection. The role this cell subset plays in protzoan infection remain relatively unexplored, herein we describe the effects of a redox enzyme (rTgPrx) derived from Toxoplasma gondii on murine macrophage phenotype in vitro. RTgPrx has been previously associated with the maintainence of parasite oxidative balance. Here our experiments show that rTgPrx promotes AAM as indicated by high arginase-1 (arg-1), YM1 and FIZZ expression via both signal transducer and activator of transcription (STAT)6-dependent and -independent mechanisms. Additionally rTgPrx treatment reduced caspase-1 activity and IL-1β secretion, while simultaneously increasing IL-10 release. Furthermore the in vitro replication of T. gondii (RH strain) was enhanced when macrophages were treated with rTgPrx. This is in contrast with the previously described effects of a Plasmodium berghei ANKA 2-cys-peroxiredoxin that promotes pro-inflammatory cytokine production. These results highlight the role of T. gondii derived redox enzymes as important immune modulators and potentially indicate a role for AAM in modulating immunopathology and promoting parasite replication during T. gondii infection

    Entwicklung kreativen Denkens im kulturellen Kontext

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    Kann die 18F-FDG-PET/CT-Untersuchung die Panendoskopie zur Detektion von synchronen Zweitkarzinomen ersetzen?

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    Ziel der Arbeit war es, die Wertigkeit der 18F-FDG-PET/ CT-Untersuchung bezüglich synchroner Zweitkarzinome im Vergleich mit der Panendoskopie beim initialen Staging zu untersuchen. 311 Patienten wurden mit beiden Untersuchungsmethoden abgeklärt. Als Referenz galt die zytologische, histologische und/oder klinische oder radiologische Untersuchung. Die Prävalenz für synchrone Zweitkarzinome betrug mit der Panendoskopie 4,5%, während die Prävalenz mittels PET/ CT-Untersuchung 6,1% betrug. Die Sensitivität für die Panendoskopie betrug 74%, die Spezifität 99,7%, der positiv prädiktive Wert 93% und der negativ prädiktive Wert 98%. Die Sensitivität für die PET/CT-Untersuchung betrug 100%, die Spezifität 95,7% der positiv prädiktive Wert 59% und der negativ prädiktive Wert 100%. Die PET/CT-Untersuchung scheint der Panendoskopie überlegen zu sein. Bei bezüglich synchroner Zweitkarzinome unauffälligem PET/CT kann die Panendoskopie auf die Endoskopie und Beurteilung des Primärtumors beschränkt werden kann. Aufgrund der hohen Kosten und der grossen Anzahl falsch positiver Resultate, welche durch das PET/CT generiert werden, empfehlen wir die Durchführung dieser Untersuchung nur bei fortgeschrittenen Tumoren mit der Frage nach Fernmetastasen. Die Panendoskopie bleibt weiterhin der Goldstandar
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