2,243 research outputs found
The Primex Proposal, Minimum Bid Price Requirements, And NASDAQ Market Woes
The objective of this case is to teach and initiate a class discussion about the Primex proposal and minimum bid price requirements at NASDAQ. The discussion is facilitated by a real world case example that focuses on current NASDAQ market woes. Issues central to the performance of NASDAQ as a market place are analyzed. In addition, this study considers the effect of the merger of Instinet and Island on NASDAQ and evaluates NASDAQ's IPO decision
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Holding On: Older Californians With Disabilities Rely on Public Services to Remain Independent
Presents findings from a study of low-income older Californians with disabilities receiving Medicare, Medi-Cal, and In-Home Supportive Services; their unmet physical, mental health, and social needs; and limited care options. Outlines policy implications
Effectively Identifying eQTLs from Multiple Tissues by Combining Mixed Model and Meta-analytic Approaches
Gene expression data, in conjunction with information on genetic variants, have enabled studies to identify expression quantitative trait loci (eQTLs) or polymorphic locations in the genome that are associated with expression levels. Moreover, recent technological developments and cost decreases have further enabled studies to collect expression data in multiple tissues. One advantage of multiple tissue datasets is that studies can combine results from different tissues to identify eQTLs more accurately than examining each tissue separately. The idea of aggregating results of multiple tissues is closely related to the idea of meta-analysis which aggregates results of multiple genome-wide association studies to improve the power to detect associations. In principle, meta-analysis methods can be used to combine results from multiple tissues. However, eQTLs may have effects in only a single tissue, in all tissues, or in a subset of tissues with possibly different effect sizes. This heterogeneity in terms of effects across multiple tissues presents a key challenge to detect eQTLs. In this paper, we develop a framework that leverages two popular meta-analysis methods that address effect size heterogeneity to detect eQTLs across multiple tissues. We show by using simulations and multiple tissue data from mouse that our approach detects many eQTLs undetected by traditional eQTL methods. Additionally, our method provides an interpretation framework that accurately predicts whether an eQTL has an effect in a particular tissue
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Phantom Acupuncture: Dissociating Somatosensory and Cognitive/Affective Components of Acupuncture Stimulation with a Novel Form of Placebo Acupuncture
In a clinical setting, acupuncture treatment consists of multiple components including somatosensory stimulation, treatment context, and attention to needle-based procedures. In order to dissociate somatosensory versus contextual and attentional aspects of acupuncture, we devised a novel form of placebo acupuncture, a visual manipulation dubbed phantom acupuncture, which reproduces the acupuncture needling ritual without somatosensory tactile stimulation. Subjects (N = 20) received both real (REAL) and phantom (PHNT) acupuncture. Subjects were retrospectively classified into two groups based on PHNT credibility (PHNTc, who found phantom acupuncture credible; and PHNTnc, who did not). Autonomic and psychophysical responses were monitored. We found that PHNT can be delivered in a credible manner. Acupuncture needling, a complex, ritualistic somatosensory intervention, induces sympathetic activation (phasic skin conductance [SC] response), which may be specific to the somatosensory component of acupuncture. In contrast, contextual effects, such as needling credibility, are instead associated with a shift toward relative cardiovagal activation (decreased heart rate) during needling and sympathetic inhibition (decreased SC) and parasympathetic activation (decreased pupil size) following acupuncture needling. Visual stimulation characterizing the needling ritual is an important factor for phasic autonomic responses to acupuncture and may undelie the needling orienting response. Our study suggests that phantom acupuncture can be a viable sham control for acupuncture as it completely excludes the somatosensory component of real needling while maintaining the credibility of the acupuncture treatment context in many subjects
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Parallel programming and designing in object oriented environment SS/1
Parallel software development requires the flexibility to describe algorithms regardless of hardware specification, the ability to accommodate existing applications. and maintainability throughout the software life cycle. We propose the following model to address these issues. Our model incorporates aspects of the object-oriented and large grain data flow programming paradigms, and introduces a concept called a "Server". "Servers" are objects as well as self-contained processes which communicate with each other by sending messages. The server paradigm considers all components of a program as servers. This concept helps in designing flexible and dynamically reconfigurable software. The major goals of the server model are reusability, maintainability, and productivity. These are realized through encapsulation, instantiation, and inheritance features of the server model, as well as a graphical design environment with the capability of tracing and debugging the user's design based on the data flow information
Genetic dissection of the pluripotent proteome through multi-omics data integration.
Genetic background drives phenotypic variability in pluripotent stem cells (PSCs). Most studies to date have used transcript abundance as the primary molecular readout of cell state in PSCs. We performed a comprehensive proteogenomics analysis of 190 genetically diverse mouse embryonic stem cell (mESC) lines. The quantitative proteome is highly variable across lines, and we identified pluripotency-associated pathways that were differentially activated in the proteomics data that were not evident in transcriptome data from the same lines. Integration of protein abundance to transcript levels and chromatin accessibility revealed broad co-variation across molecular layers as well as shared and unique drivers of quantitative variation in pluripotency-associated pathways. Quantitative trait locus (QTL) mapping localized the drivers of these multi-omic signatures to genomic hotspots. This study reveals post-transcriptional mechanisms and genetic interactions that underlie quantitative variability in the pluripotent proteome and provides a regulatory map for mESCs that can provide a basis for future mechanistic studies
Modulation of presynaptic plasticity and learning by the H-ras/extracellular signal-regulated kinase/synapsin I signaling pathway
Molecular and cellular studies of the mechanisms underlying mammalian learning and memory have focused almost exclusively on
postsynaptic function. We now reveal an experience-dependent presynaptic mechanism that modulates learning and synaptic plasticity
in mice. Consistent with a presynapticfunctionfor endogenous H-ras/extracellular signal-regulated kinase (ERK) signaling, we observed
that, under normal physiologic conditions in wild-type mice, hippocampus-dependent learning stimulated the ERK-dependent phosphorylation
of synapsin I, and MEK (MAP kinase kinase)/ERK inhibition selectively decreased the frequency of miniature EPSCs. By
generating transgenic mice expressing a constitutively active form of H-ras (H-rasG12V), which is abundantly localized in axon terminals,
we were able to increase the ERK-dependent phosphorylation of synapsin I. This resulted in several presynaptic changes, including a
higher density of docked neurotransmitter vesiclesin glutamatergicterminals, anincreasedfrequency of miniature EPSCs, andincreased
paired-pulse facilitation. In addition, we observed facilitated neurotransmitter release selectively during high-frequency activity with
consequent increases in long-term potentiation. Moreover, these mice showed dramatic enhancements in hippocampus-dependent
learning. Importantly, deletion of synapsin I, an exclusively presynaptic protein, blocked the enhancements of learning, presynaptic
plasticity, and long-term potentiation. Together with previous invertebrate studies, these results demonstrate that presynaptic plasticity
represents an important evolutionarily conserved mechanism for modulating learning and memory
Meta-analysis of neural systems underlying placebo analgesia from individual participant fMRI data
The brain systems underlying placebo analgesia are insufficiently understood. Here we performed a systematic, participant-level meta-analysis of experimental functional neuroimaging studies of evoked pain under stimulus-intensity-matched placebo and control conditions, encompassing 603 healthy participants from 20 (out of 28 eligible) studies. We find that placebo vs. control treatments induce small, widespread reductions in pain-related activity, particularly in regions belonging to ventral attention (including mid-insula) and somatomotor networks (including posterior insula). Behavioral placebo analgesia correlates with reduced pain-related activity in these networks and the thalamus, habenula, mid-cingulate, and supplementary motor area. Placebo-associated activity increases occur mainly in frontoparietal regions, with high between-study heterogeneity. We conclude that placebo treatments affect pain-related activity in multiple brain areas, which may reflect changes in nociception and/or other affective and decision-making processes surrounding pain. Between-study heterogeneity suggests that placebo analgesia is a multi-faceted phenomenon involving multiple cerebral mechanisms that differ across studies
Allosteric “beta-blocker” isolated from a DNA-encoded small molecule library
The present study reports the discovery of a small-molecule negative allosteric modulator for the β2-adrenergic receptor (β2AR) via in vitro affinity-based iterative selection of highly diverse DNA-encoded small-molecule libraries. Characterization of the compound demonstrates its selectivity for the β2AR and that it negatively modulates a wide range of receptor functions. More importantly, our findings establish a generally applicable, proof-of-concept strategy for screening DNA-encoded small-molecule libraries against purified G-protein–coupled receptors (GPCRs), which holds great potential for discovering therapeutic molecules
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