211 research outputs found

    Disturbances and noise: Defining furrow-form enamel hypoplasia

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    Objectives The investigation of the record of growth locked in dental enamel provides a unique opportunity to build a comprehensive picture of growth disruption episodes during childhood. This study presents a new methodological basis for the analysis of enamel growth disruptions (enamel hypoplasia) using incremental microstructures of enamel. Methods A three?dimensional technique based upon use of an Alicona 3D Infinite Focus imaging microscope and software is used to record developmental features in the enamel of human permanent mandibular lateral incisors of one individual from the Neolithic site of Çatalhöyük (Turkey). Using this new technique, perikymata are measured down the longitudinal axis of the crown from the incisal margin to the cervix and perikyma spacing profiles are constructed with this new technique. A mathematical basis for the detection of spacing anomalies, which serve as indicators of enamel hypoplasia is presented based upon these profiles. Results Three clearly delineated defects were identified visually, then matched and confirmed metrically using the enamel surface and perikyma spacing profiles. Discussion Human growth has often been used as an indicator of health in past societies because of developmental sensitivity to fluctuations in nutritional status and disease load. Hence, standardization of furrow?form defect identification is of crucial importance for reducing the amount of current subjectivity in the determination of a threshold for the identification of defects among individuals of past populations. The method presented here, which is based on microscopic images of the tooth crown as well as recorded measurements of incremental structures, represents a combined visual?metric approach using LOWESS residuals, and as such provides a substantial advancement to previous methods. It is therefore recommended that additional studies be carried out with this methodology to determine whether this method improves the reliability of enamel defect identification among individuals recovered from bioarchaeological contexts

    Synthetic Biology Open Language (SBOL) Version 1.1.0

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    In this BioBricks Foundation Request for Comments (BBF RFC), we specify the Synthetic Biology Open Language (SBOL) Version 1.1.0 to enable the electronic exchange of information describing DNA components used in synthetic biology. We define: 1. the vocabulary, a set of preferred terms and 2. the core data model, a common computational representation

    TAK1 expression is associated with increased PD-L1 and decreased cancer-specific survival in microsatellite-stable colorectal cancer

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    Background: Transforming growth factor β-activated protein kinase-1 (TAK1) plays an important role in MAPK and NFκB pathways and has been associated with colorectal cancer. The aim of this study was to determine how cytoplasmic and juxtanuclear punctate staining of TAK1 relates to immune checkpoint expression and cancer specific survival in colorectal cancer. Methods: Protein expression was assessed by immunohistochemistry on tissue microarrays from primary curative colorectal cancer resected specimens. Expression levels of cytoplasmic TAK1 by QuPath digital quantification and punctate TAK1 staining was scored using a manual point scoring technique and correlated with clinicopathological features, immune checkpoint expression and cancer-specific survival. Bulk RNA sequencing was performed in specimens to determine mutational profiles and differentially expressed genes. Results: A cohort of 875 patients who had undergone colorectal cancer resection were assessed for TAK1 expression. Higher levels of cytoplasmic TAK1 expression correlated with elevated PD1 and PD-L1 expression (p < 0.010). High punctate TAK1 expression was more commonly identified in poorly differentiated colorectal cancers (p = 0.036), had dysregulated mutational and transcriptional profiles with decreased insulin-like growth factor 2(IGF2) expression (p < 0.010), and independently predicted poor cancer-specific survival (HR 2.690, 95% CI 1.419–5.100, p = 0.002). The association of punctate TAK1 expression and recurrence remained after subgroup analysis for microsatellite-stable colorectal cancer (p = 0.028). Discussion: Punctate TAK1 expression is associated with worse cancer specific survival. TAK1 signalling may be an important pathway to investigate underlying mechanisms for recurrence in microsatellite-stable colorectal cancer

    The dental calculus metabolome in modern and historic samples.

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    INTRODUCTION: Dental calculus is a mineralized microbial dental plaque biofilm that forms throughout life by precipitation of salivary calcium salts. Successive cycles of dental plaque growth and calcification make it an unusually well-preserved, long-term record of host-microbial interaction in the archaeological record. Recent studies have confirmed the survival of authentic ancient DNA and proteins within historic and prehistoric dental calculus, making it a promising substrate for investigating oral microbiome evolution via direct measurement and comparison of modern and ancient specimens. OBJECTIVE: We present the first comprehensive characterization of the human dental calculus metabolome using a multi-platform approach. METHODS: Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) quantified 285 metabolites in modern and historic (200 years old) dental calculus, including metabolites of drug and dietary origin. A subset of historic samples was additionally analyzed by high-resolution gas chromatography-MS (GC-MS) and UPLC-MS/MS for further characterization of metabolites and lipids. Metabolite profiles of modern and historic calculus were compared to identify patterns of persistence and loss. RESULTS: Dipeptides, free amino acids, free nucleotides, and carbohydrates substantially decrease in abundance and ubiquity in archaeological samples, with some exceptions. Lipids generally persist, and saturated and mono-unsaturated medium and long chain fatty acids appear to be well-preserved, while metabolic derivatives related to oxidation and chemical degradation are found at higher levels in archaeological dental calculus than fresh samples. CONCLUSIONS: The results of this study indicate that certain metabolite classes have higher potential for recovery over long time scales and may serve as appropriate targets for oral microbiome evolutionary studies

    Principles of genetic circuit design

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    Cells navigate environments, communicate and build complex patterns by initiating gene expression in response to specific signals. Engineers seek to harness this capability to program cells to perform tasks or create chemicals and materials that match the complexity seen in nature. This Review describes new tools that aid the construction of genetic circuits. Circuit dynamics can be influenced by the choice of regulators and changed with expression 'tuning knobs'. We collate the failure modes encountered when assembling circuits, quantify their impact on performance and review mitigation efforts. Finally, we discuss the constraints that arise from circuits having to operate within a living cell. Collectively, better tools, well-characterized parts and a comprehensive understanding of how to compose circuits are leading to a breakthrough in the ability to program living cells for advanced applications, from living therapeutics to the atomic manufacturing of functional materials.National Institute of General Medical Sciences (U.S.) (Grant P50 GM098792)National Institute of General Medical Sciences (U.S.) (Grant R01 GM095765)National Science Foundation (U.S.). Synthetic Biology Engineering Research Center (EEC0540879)Life Technologies, Inc. (A114510)National Science Foundation (U.S.). Graduate Research FellowshipUnited States. Office of Naval Research. Multidisciplinary University Research Initiative (Grant 4500000552
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