24 research outputs found

    Beliefs about bad people are volatile

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    People form moral impressions rapidly, effortlessly and from a remarkably young age1,2,3,4,5. Putatively \u2018bad\u2019 agents command more attention and are identified more quickly and accurately than benign or friendly agents5,6,7,8,9,10,11,12. Such vigilance is adaptive, but can also be costly in environments where people sometimes make mistakes, because incorrectly attributing bad character to good people damages existing relationships and discourages forming new relationships13,14,15,16. The ability to accurately infer the moral character of others is critical for healthy social functioning, but the computational processes that support this ability are not well understood. Here, we show that moral inference is explained by an asymmetric Bayesian updating mechanism in which beliefs about the morality of bad agents are more uncertain (and therefore more volatile) than beliefs about the morality of good agents. This asymmetry seems to be a property of learning about immoral agents in general, as we also find greater uncertainty for beliefs about the non-moral traits of bad agents. Our model and data reveal a cognitive mechanism that permits flexible updating of beliefs about potentially threatening others, a mechanism that could facilitate forgiveness when initial bad impressions turn out to be inaccurate. Our findings suggest that negative moral impressions destabilize beliefs about others, promoting cognitive flexibility in the service of cooperative but cautious behaviour

    Sequence-Dependent Fluorescence of Cyanine Dyes on Microarrays

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    Cy3 and Cy5 are among the most commonly used oligonucleotide labeling molecules. Studies of nucleic acid structure and dynamics use these dyes, and they are ubiquitous in microarray experiments. They are sensitive to their environment and have higher quantum yield when bound to DNA. The fluorescent intensity of terminal cyanine dyes is also known to be significantly dependent on the base sequence of the oligonucleotide. We have developed a very precise and high-throughput method to evaluate the sequence dependence of oligonucleotide labeling dyes using microarrays and have applied the method to Cy3 and Cy5. We used light-directed in-situ synthesis of terminally-labeled microarrays to determine the fluorescence intensity of each dye on all 1024 possible 5′-labeled 5-mers. Their intensity is sensitive to all five bases. Their fluorescence is higher with 5′ guanines, and adenines in subsequent positions. Cytosine suppresses fluorescence. Intensity falls by half over the range of all 5-mers for Cy3, and two-thirds for Cy5. Labeling with 5′-biotin-streptavidin-Cy3/-Cy5 gives a completely different sequence dependence and greatly reduces fluorescence compared with direct terminal labeling

    Nucleic acid-based fluorescent probes and their analytical potential

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    It is well known that nucleic acids play an essential role in living organisms because they store and transmit genetic information and use that information to direct the synthesis of proteins. However, less is known about the ability of nucleic acids to bind specific ligands and the application of oligonucleotides as molecular probes or biosensors. Oligonucleotide probes are single-stranded nucleic acid fragments that can be tailored to have high specificity and affinity for different targets including nucleic acids, proteins, small molecules, and ions. One can divide oligonucleotide-based probes into two main categories: hybridization probes that are based on the formation of complementary base-pairs, and aptamer probes that exploit selective recognition of nonnucleic acid analytes and may be compared with immunosensors. Design and construction of hybridization and aptamer probes are similar. Typically, oligonucleotide (DNA, RNA) with predefined base sequence and length is modified by covalent attachment of reporter groups (one or more fluorophores in fluorescence-based probes). The fluorescent labels act as transducers that transform biorecognition (hybridization, ligand binding) into a fluorescence signal. Fluorescent labels have several advantages, for example high sensitivity and multiple transduction approaches (fluorescence quenching or enhancement, fluorescence anisotropy, fluorescence lifetime, fluorescence resonance energy transfer (FRET), and excimer-monomer light switching). These multiple signaling options combined with the design flexibility of the recognition element (DNA, RNA, PNA, LNA) and various labeling strategies contribute to development of numerous selective and sensitive bioassays. This review covers fundamentals of the design and engineering of oligonucleotide probes, describes typical construction approaches, and discusses examples of probes used both in hybridization studies and in aptamer-based assays

    An integrated electronic health record-based workflow to improve management of colonoscopy-generated pathology results

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    Spencer D Dorn, Holly O Cirri, Audrey O Chang, Seth D Crockett, Joseph A Galanko, John A Baron Division of Gastroenterology and Hepatology, University of North Carolina School of Medicine, Chapel Hill, NC, USA Purpose: Managing and communicating colonoscopy-generated pathology results and appropriate follow-up recommendations can be challenging. To improve this process, we developed and implemented a standardized electronic health record-based intervention with built-in decision support.Methods: Fourteen attending endoscopists performed enough colonoscopies to qualify for the study. For each, we randomly sampled and abstracted data from 35 colonoscopies that met prespecified inclusion criteria during both the pre-intervention and also post-intervention periods. Follow-up recommendations were compared to guidelines. We used the Wilcoxon Signed Rank Test to assess the change in the proportion of cases with guideline-concordant results, the proportion with a documented follow-up result letter, and the median time to letter completion. A brief survey assessed endoscopists’ satisfaction with the intervention.Results: In total, 1,947 colonoscopies were extracted, of which 968 met inclusion criteria. The proportion of follow-up recommendations that were guideline concordant increased from a median of 82.9% pre-intervention to 85.7% post-intervention (P=0.72). The proportion of observations with a documented follow-up result letter increased from a median of 88.9% pre-intervention to 97.1% post-intervention (P=0.07). The number of calendar days between the date of the colonoscopy and the date the letter was sent decreased from a median of 7.7 days pre-intervention to 6.8 days post-intervention (P=0.79). Eighty-six percentage of endoscopists were either “very satisfied” or “satisfied” with the overall process.Conclusion: The intervention was not associated with a statistically significant increase in guideline-concordant recommendations or efficiency measures, perhaps due to high baseline performance. The intervention was well received by endoscopists and captured data necessary for important downstream processes. Keywords: colonoscopy, pathology, quality, electronic health record, system

    Substance use and risky sexual behaviours among sexually experienced Ghanaian youth

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    <p>Abstract</p> <p>Background</p> <p>The association between risky sexual behaviours and substance uses among Ghanaian youth were investigated.</p> <p>Methods</p> <p>An in-school cross-sectional representative survey was conducted among 12-18-year- old youth in Ghana in 2008 (N = 1195, response rate =90%). Logistic regression analyses were employed to investigate the association between substance use (tobacco use, drunkenness, marijuana use and other drug uses) and risky sexual behaviours (sexual debut, condom use and number of sexual partners).</p> <p>Results</p> <p>Of all youth, 25% (28% boys and 23% girls) were sexually experienced. The mean age for first sexual intercourse was 14.8 years (14.4 years for boys and 15.1 years for girls). Among the sexually experienced, 31% had multiple sexual partners. Older age (OR = 3.4, 95% CI = 1.7-3.4) and rural residency (OR = 1.5, 95% CI = 1.1-2.1) were independently associated with sexual debut while only older age (OR = 2.4, 95% CI = 1.7-3.4) was associated with condom use. Additionally, smoking (OR = 3.7, 95% CI = 2.0-6.8), tawa use (OR = 2.4, 95% CI = 1.3-4.7), tobacco use (OR = 2.8, 95% CI = 1.7-4.7) drunkenness (OR = 1.7, 95% CI = 1.1-2.8) and marijuana use (OR = 3.3, 95% CI = 1.6-7.0) were independently associated with sexual debut. Furthermore, all substance uses studied were associated with having one or multiple sexual partners.</p> <p>Conclusion</p> <p>Substance use seems to be a gateway for risky sexual behaviours among Ghanaian youth. Public health interventions should take into account the likelihood of substance use among sexually experienced youth.</p
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