161 research outputs found

    Human Agency in AI Configurations Supporting Organizational Decision-making

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    The integration of human intelligence with Artificial Intelligence (AI) is becoming increasingly essential for leveraging benefits in organizational decision-making. This necessitates to understand human-AI collaboration configurations for managing collaborative intelligence. However, existing literature on Human-AI collaboration lacks structure and is fragmented regarding what exactly human intelligence (HI) contributes to AI collaboration and how AI systems can be configured in the decision-making process. This paper undertakes an organizing literature review to consolidate insights from existing literature. We identify six types of human agency as involved in collaborative intelligence and synthesize the findings into six Human-AI collaborative configurations explained by a matrix framework. By illuminating the complexities of Human-AI collaboration, the framework sheds light on the need for a nuanced understanding of the imbricating roles of HI and AI in decision-making, with important implications for the design and implementation of AI systems for organizational decision-making

    The Soft X-Ray Properties of a Complete Sample of Optically Selected Quasars II. Final Results

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    We present the final results of a ROSAT PSPC program to study the soft X-ray emission properties of a complete sample of low zz quasars. The main results are: 1. There is no evidence for significant soft excess emission or excess foreground absorption by cold gas in 22 of the 23 quasars. 2. The mean 0.2-2 keV continuum of quasars agrees remarkably well with an extrapolation of the mean 1050-350A continuum recently determined by Zheng et al. (1996), indicating that there is no steep soft component below 0.2 keV. 3. The occurrence of warm absorbers in quasars is rather rare, in sharp contrast to lower luminosity AGN. 4. The strongest correlation found is between the spectral slope, alpha_x, and the Hb FWHM. This remarkably strong correlation may result from a dependence of alpha_x on L/L_Edd, as seen in Galactic black hole candidates. 5. There appears to exist a distinct class of ``X-ray weak'' quasars. These may be quasars where the direct X-ray source is obscured, and only scattered X-rays are observed. 6. Thin accretion disk models cannot reproduce the observed optical to soft X-ray spectral shape. An as yet unknown physical mechanism maintains a strong correlation between the optical and soft X-ray emission. 7. The well known difference in alpha_x between radio-loud and radio-quiet quasars may be due only to their different Hb FWHM. 8. The agreement of the 21 cm and X-ray columns implies that He in the diffuse H II component of the Galactic ISM is ionized to He II or He III (shortened abstract).Comment: 19 pages of text only, uses aas2pp4.sty file, to appear in ApJ vol. 447, 3/1/97, complete postscript version of 34 pages including 5 tables and 8 figures available at http://physics.technion.ac.il/~laor/rosat/paper.p

    Reconstructing CNV genotypes using segregation analysis: combining pedigree information with CNV assay

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    <p>Abstract</p> <p>Background</p> <p>Repeated blocks of genome sequence have been shown to be associated with genetic diversity and disease risk in humans, and with phenotypic diversity in model organisms and domestic animals. Reliable tests are desirable to determine whether individuals are carriers of copy number variants associated with disease risk in humans and livestock, or associated with economically important traits in livestock. In some cases, copy number variants affect the phenotype through a dosage effect but in other cases, allele combinations have non-additive effects. In the latter cases, it has been difficult to develop tests because assays typically return an estimate of the sum of the copy number counts on the maternally and paternally inherited chromosome segments, and this sum does not uniquely determine the allele configuration. In this study, we show that there is an old solution to this new problem: segregation analysis, which has been used for many years to infer alleles in pedigreed populations.</p> <p>Methods</p> <p>Segregation analysis was used to estimate copy number alleles from assay data on simulated half-sib sheep populations. Copy number variation at the Agouti locus, known to be responsible for the recessive self-colour black phenotype, was used as a model for the simulation and an appropriate penetrance function was derived. The precision with which carriers and non-carriers of the undesirable single copy allele could be identified, was used to evaluate the method for various family sizes, assay strategies and assay accuracies.</p> <p>Results</p> <p>Using relationship data and segregation analysis, the probabilities of carrying the copy number alleles responsible for black or white fleece were estimated with much greater precision than by analyzing assay results for animals individually. The proportion of lambs correctly identified as non-carriers of the undesirable allele increased from 7% when the lambs were analysed alone to 80% when the lambs were analysed in half-sib families.</p> <p>Conclusions</p> <p>When a quantitative assay is used to estimate copy number alleles, segregation analysis of related individuals can greatly improve the precision of the estimates. Existing software for segregation analysis would require little if any change to accommodate the penetrance function for copy number assay data.</p

    Naloxone inhibits immune cell function by suppressing superoxide production through a direct interaction with gp91phox subunit of NADPH oxidase

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    <p>Abstract</p> <p>Background</p> <p>Both (-) and (+)-naloxone attenuate inflammation-mediated neurodegeneration by inhibition of microglial activation through superoxide reduction in an opioid receptor-independent manner. Multiple lines of evidence have documented a pivotal role of overactivated NADPH oxidase (NOX2) in inflammation-mediated neurodegeneration. We hypothesized that NOX2 might be a novel action site of naloxone to mediate its anti-inflammatory actions.</p> <p>Methods</p> <p>Inhibition of NOX-2-derived superoxide by (-) and (+)-naloxone was measured in lipopolysaccharide (LPS)-treated midbrain neuron-glia cultures and phorbol myristate acetate (PMA)-stimulated neutrophil membranes by measuring the superoxide dismutase (SOD)-inhibitable reduction of tetrazolium salt (WST-1) or ferricytochrome c. Further, various ligand (<sup>3</sup>H-naloxone) binding assays were performed in wild type and gp91<it><sup>phox-/- </sup></it>neutrophils and transfected COS-7 and HEK293 cells. The translocation of cytosolic subunit p47<it><sup>phox </sup></it>to plasma membrane was assessed by western blot.</p> <p>Results</p> <p>Both (-) and (+)-naloxone equally inhibited LPS- and PMA-induced superoxide production with an IC50 of 1.96 and 2.52 Ī¼M, respectively. Competitive binding of <sup>3</sup>H-naloxone with cold (-) and (+)-naloxone in microglia showed equal potency with an IC50 of 2.73 and 1.57 Ī¼M, respectively. <sup>3</sup>H-Naloxone binding was elevated in COS-7 and HEK293 cells transfected with gp91<sup><it>phox</it></sup>; in contrast, reduced <sup>3</sup>H-naloxone binding was found in neutrophils deficient in gp91<sup><it>phox </it></sup>or in the presence of a NOX2 inhibitor. The specificity and an increase in binding capacity of <sup>3</sup>H-naloxone were further demonstrated by 1) an immunoprecipitation study using gp91<sup><it>phox </it></sup>antibody, and 2) activation of NOX2 by PMA. Finally, western blot studies showed that naloxone suppressed translocation of the cytosolic subunit p47<sup><it>phox </it></sup>to the membrane, leading to NOX2 inactivation.</p> <p>Conclusions</p> <p>Strong evidence is provided indicating that NOX2 is a non-opioid novel binding site for naloxone, which is critical in mediating its inhibitory effect on microglia overactivation and superoxide production.</p

    NEDDylation is essential for Kaposi's sarcoma-associated herpesvirus latency and lytic reactivation and represents a novel anti-KSHV target.

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    Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL), which are aggressive malignancies associated with immunocompromised patients. For many non-viral malignancies, therapeutically targeting the ubiquitin proteasome system (UPS) has been successful. Likewise, laboratory studies have demonstrated that inhibition of the UPS might provide a promising avenue for the treatment of KSHV-associated diseases. The largest class of E3 ubiquitin ligases are the cullin-RING ligases (CRLs) that are activated by an additional ubiquitin-like protein, NEDD8. We show that pharmacological inhibition of NEDDylation (using the small molecule inhibitor MLN4924) is cytotoxic to PEL cells by inhibiting NF-ĪŗB. We also show that CRL4B is a novel regulator of latency as its inhibition reactivated lytic gene expression. Furthermore, we uncovered a requirement for NEDDylation during the reactivation of the KSHV lytic cycle. Intriguingly, inhibition prevented viral DNA replication but not lytic cycle-associated gene expression, highlighting a novel mechanism that uncouples these two features of KSHV biology. Mechanistically, we show that MLN4924 treatment precluded the recruitment of the viral pre-replication complex to the origin of lytic DNA replication (OriLyt). These new findings have revealed novel mechanisms that regulate KSHV latency and reactivation. Moreover, they demonstrate that inhibition of NEDDylation represents a novel approach for the treatment of KSHV-associated malignancies

    Deep Sequencing of the Nicastrin Gene in Pooled DNA, the Identification of Genetic Variants That Affect Risk of Alzheimer's Disease

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    Nicastrin is an obligatory component of the Ī³-secretase; the enzyme complex that leads to the production of AĪ² fragments critically central to the pathogenesis of Alzheimer's disease (AD). Analyses of the effects of common variation in this gene on risk for late onset AD have been inconclusive. We investigated the effect of rare variation in the coding regions of the Nicastrin gene in a cohort of AD patients and matched controls using an innovative pooling approach and next generation sequencing. Five SNPs were identified and validated by individual genotyping from 311 cases and 360 controls. Association analysis identified a non-synonymous rare SNP (N417Y) with a statistically higher frequency in cases compared to controls in the Greek population (OR 3.994, CI 1.105ā€“14.439, pā€Š=ā€Š0.035). This finding warrants further investigation in a larger cohort and adds weight to the hypothesis that rare variation explains some of genetic heritability still to be identified in Alzheimer's disease

    Identification and characterization of microRNAs expressed in the African malaria vector Anopheles funestus life stages using high throughput sequencing

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    Background: Over the past several years, thousands of microRNAs (miRNAs) have been identified in the genomes of various insects through cloning and sequencing or even by computational prediction. However, the number of miRNAs identified in anopheline species is low and little is known about their role. The mosquito Anopheles funestus is one of the dominant malaria vectors in Africa, which infects and kills millions of people every year. Therefore, small RNA molecules isolated from the four life stages (eggs, larvae, pupae and unfed adult females) of An. funestus were sequenced using next generation sequencing technology. Results: High throughput sequencing of four replicates in combination with computational analysis identified 107 mature miRNA sequences expressed in the An. funestus mosquito. These include 20 novel miRNAs without sequence identity in any organism and eight miRNAs not previously reported in the Anopheles genus but are known in non-anopheles mosquitoes. Finally, the changes in the expression of miRNAs during the mosquito development were determined and the analysis showed that many miRNAs have stage-specific expression, and are co-transcribed and co-regulated during development. Conclusions: This study presents the first direct experimental evidence of miRNAs in An. funestus and the first profiling study of miRNA associated with the maturation in this mosquito. Overall, the results indicate that miRNAs play important roles during the growth and development. Silencing such molecules in a specific life stage could decrease the vector population and therefore interrupt malaria transmission.IS

    Insights into the Genetic Architecture of Early Stage Age-Related Macular Degeneration: A Genome-Wide Association Study Meta-Analysis

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    10.1371/journal.pone.0053830PLoS ONE81

    The pathogenic mechanism of the Mycobacterium ulcerans virulence factor, mycolactone, depends on blockade of protein translocation into the ER.

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    Infection with Mycobacterium ulcerans is characterised by tissue necrosis and immunosuppression due to mycolactone, the necessary and sufficient virulence factor for Buruli ulcer disease pathology. Many of its effects are known to involve down-regulation of specific proteins implicated in important cellular processes, such as immune responses and cell adhesion. We have previously shown mycolactone completely blocks the production of LPS-dependent proinflammatory mediators post-transcriptionally. Using polysome profiling we now demonstrate conclusively that mycolactone does not prevent translation of TNF, IL-6 and Cox-2 mRNAs in macrophages. Instead, it inhibits the production of these, along with nearly all other (induced and constitutive) proteins that transit through the ER. This is due to a blockade of protein translocation and subsequent degradation of aberrantly located protein. Several lines of evidence support this transformative explanation of mycolactone function. First, cellular TNF and Cox-2 can be once more detected if the action of the 26S proteasome is inhibited concurrently. Second, restored protein is found in the cytosol, indicating an inability to translocate. Third, in vitro translation assays show mycolactone prevents the translocation of TNF and other proteins into the ER. This is specific as the insertion of tail-anchored proteins into the ER is unaffected showing that the ER remains structurally intact. Fourth, metabolic labelling reveals a near-complete loss of glycosylated and secreted proteins from treated cells, whereas cytosolic proteins are unaffected. Notably, the profound lack of glycosylated and secreted protein production is apparent in a range of different disease-relevant cell types. These studies provide a new mechanism underlying mycolactone's observed pathological activities both in vitro and in vivo. Mycolactone-dependent inhibition of protein translocation into the ER not only explains the deficit of innate cytokines, but also the loss of membrane receptors, adhesion molecules and T-cell cytokines that drive the aetiology of Buruli ulcer
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