David Schneider

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The Cyc project is predicated on the idea that effective machine learning depends on having a core of knowledge that provides a context for novel learned information – what is known informally as “common sense.” Over the last twenty years, a sufficient core of common sense knowledge has been entered into Cyc to allow it to begin effectively and flexibly(More)
Stimulation of the Drosophila immune response activates NF-kappaB and JNK signaling pathways. For example, infection by Gram-negative bacteria induces the Imd signaling pathway, leading to the activation of the NF-kappaB-like transcription factor Relish and the expression of a battery of genes encoding antimicrobial peptides. Bacterial infection also(More)
Drosophila has highly efficient defenses against infection. These include both cellular immune responses, such as the phagocytosis of invading microorganisms, and humoral immune responses, such as the secretion of antimicrobial peptides into the hemolymph [1] [2]. These defense systems are thought to interact, but the nature and extent of these interactions(More)
The electrophysiological and pharmacological properties of nicotinic acetylcholine receptors (nAChRs) were studied in guinea pig small intestinal myenteric neurons maintained in culture or in acutely isolated preparations. Acetylcholine and nicotine caused inward currents that desensitized in approximately 4 s. The current-voltage (I-V) relationship(More)
The expression and distribution of TTX-sensitive voltage-gated sodium channel (VGSC) alpha subunits in the enteric nervous system (ENS) has not been described. Using RT-PCR, expression of Na(v)1.2, Na(v)1.3, Na(v)1.6, and Na(v)1.7 mRNA was detected in small and large intestinal preparations from guinea pigs. Expression of Na(v)1.1 mRNA as well as(More)
Previous investigations into the mechanisms that control RNA Polymerase (Pol) I transcription have primarily focused on the process of transcription initiation, thus little is known regarding postinitiation steps in the transcription cycle. Spt4p and Spt5p are conserved throughout eukaryotes, and they affect elongation by Pol II. We have found that these(More)
The human homologue of yeast Rrn3 is an RNA polymerase I-associated transcription factor that is essential for ribosomal DNA (rDNA) transcription. The generally accepted model is that Rrn3 functions as a bridge between RNA polymerase I and the transcription factors bound to the committed template. In this model Rrn3 would mediate an interaction between the(More)
A cornerstone of preclinical cancer research has been the use of clonal cell lines. However, this resource has underperformed in its ability to effectively identify novel therapeutics and evaluate the heterogeneity in a patient's tumor. The patient-derived xenograft (PDX) model retains the heterogeneity of patient tumors, allowing a means to not only(More)
Chromosome condensation and the global repression of gene transcription are features of mitosis in most eukaryotes. The logic behind this phenomenon is that chromosome condensation prevents the activity of RNA polymerases. In budding yeast, however, transcription was proposed to be continuous during mitosis. Here we show that Cdc14, a protein phosphatase(More)
Nucleosomes and their histone components have generally been recognized to act negatively on transcription. However, purified upstream activating factor (UAF), a transcription initiation factor required for RNA polymerase (Pol) I transcription in Saccharomyces cerevisiae, contains histones H3 and H4 and four nonhistone protein subunits. Other studies have(More)