790 research outputs found

    Bioinformatic and Proteomic Investigation of Chloroplast Transit Peptide Motifs and Genesis

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    The eukaryotic mitochondrion was formed by the endosymbiotic association of an - proteobacterium and a primordial phagocytic eukaryote. A second, and later, endosymbiosis between the eukaryote and a cyanobacterium gave rise to the chloroplast of plants. Following each of these events most of the organellar DNA was exported to the nucleus. A system evolved wherein proteins produced on cytosolic ribosomes are targeted to organelle protein translocators by N-terminal targeting sequences. Protein sorting between the chloroplast and the mitochondrion in the plant cell by the general import pathways shows remarkable fidelity despite a lack of sequence conservation among transit peptides and pre-sequences and despite very little sequence difference between these two targeting peptides. There is evidence for a hydrophobic recognition motif in mitochondrial presequences, and a similar motif has been proposed for the chloroplast transit peptide. We have developed novel motif-finding methods and applied them to our own chloroplast proteome data and to literature mitochondrial data. We fail to find a hydrophobic motif that discriminates the chloroplast and the mitochondrion. Another little understood phenomenon of organelle protein trafficking is how the targeting sequence is acquired after transfer of organelle DNA to the nucleus. It has been hypothesized that the transit peptide is acquired by exon shuffling. We find no correlation of transit peptide lengths with exon boundaries. Furthermore, using highly expressed cyanobacterial proteins conserved in plants, we find that the transit peptide appears as likely to be attached within the primordial sequence as without, indicating a more stochastic process for the origin of the transit peptide

    Perkin Reaction: Rapid and Efficient Process Optimization Through a Microwave/Design of Experiments Couple

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    Microwave chemistry and a Design of Experiments (DOE) protocol were employed together in order to rapidly and efficiently optimize a modified Perkin reaction. Microwave heating significantly reduced the reaction time, and the DOE provided a statistically significant understanding of underlying process relationships in a minimum number of experimental runs. In all, the reaction time was reduced from1hour to 2 minutes, factors important to yield were identified, an interesting cross-term interaction was discovered, and it was demonstrated that the more economical sodium acetate trihydrate catalyst was a viable alternative to the more costly anhydrous sodium acetate

    Metabolic Routing of Dietary Nutrients in Birds: Effects of Diet Quality and Macronutrient Composition Revealed Using Stable Isotopes

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    During fall migration many songbirds switch from consuming primarily insects to consuming mostly fruit. Fruits with more carbohydrates and less protein may be sufficient to rebuild expended fat stores, but such fruits may be inadequate to replace catabolized protein. We manipulated the concentrations and isotopic signatures of macronutrients in diets fed to birds to study the effects of diet quality on metabolic routing of dietary nutrients. We estimated that approximately 45% and 75%, respectively, of the carbon in proteinaceous tissue of birds switched to high‐ or low‐protein diets came from nonprotein dietary sources. In contrast, we estimated that approximately 100% and 20%–80%, respectively, of the nitrogen in proteinaceous tissues of birds switched to high‐ or low‐protein diets was attributable to dietary protein. Thus, the routing and assimilation of dietary carbon and nitrogen differed depending on diet composition. As a result, δ15N of tissues collected from wild animals that consume high‐quality diets may reliably indicate the dietary protein source, whereas δ13C of these same tissues is likely the product of metabolic routing of carbon from several macronutrients. These results have implications for how isotopic discrimination is best estimated and how we can study macronutrient routing in wild animals

    The Use of Neuroscience and Psychological Measurement in England's Court of Protection

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    The 2005 Mental Capacity Act of England and Wales provides a description in statute law of a test determining if a person lacks “mental capacity” to take a particular decision and describes how the “best interests” of such a person should be determined. The Act established a new Court of Protection (CoP) to hear cases related to the Act and to rule on disputes over mental capacity. The court gathers a range of evidence, including reports from clinicians and experts. Human rights organisations and others have raised concerns about the nature of assessments for incapacity, including the role of brain investigations and psychometric tests. Aim: Describe use and interpretation of structured measures of psychological and brain function in CoP cases, to facilitate standardisation and improvement of practices, both in the courtroom and in non-legal settings. Method: Quantitative review of case law using all CoP judgments published until 2019. The judgments (n = 408) were read to generate a subset referring to structured testing (n = 50). These were then examined in detail to extract the nature of the measurements, circumstances of their use and features of interpretation by the court. Results: The 408 judgments contained 146 references to structured measurement of psychological or brain function, spread over 50 cases. 120/146 (82.2%) referred to “impairment of mind or brain,” with this being part of assessment for incapacity in 58/146 (39.7%). Measurement referred on 25/146 (17.1%) occasions to “functional decision-making abilities.” Structured measures were used most commonly by psychiatrists and psychologists. Psychological measurements comprised 66.4% of measures. Neuroimaging and electrophysiology were presented for diagnostic purposes only. A small number of behavioural measures were used for people with disorders of consciousness. When assessing incapacity, IQ and the Mini-MentalState Examination were the commonest measures. A standardised measure of mental capacity itself was employed just once. Judges rarely integrated measurements in their capacity determinations. Conclusion: Structured testing of brain and psychological function is used in limited ways in the Court of Protection. Whilst there are challenges in creating measures of capacity, we highlight an opportunity for the neuroscience community to improve objectivity in assessment, inside and outside the courtroom

    Evolving American Investing Attitudes: The Hybrid Shift In Mutual Fund Distribution

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    This paper studies the dramatic evolution in the way American investors choose to invest in the mutual fund industry. The industry’s change from direct-to-shareholder model to a third-party distribution model is discussed, as well as the implications for future mutual fund investors. Ever since the first recorded asset and debt managers arose in the 14th and 15th centuries in Europe, investing has grown into a tug-and-pull type of system that the human mind seems drawn to. The way that Americans choose to invest their money is changing as we enter the 21st century and the new methods and procedures are having a greater impact than many of us realize. In the U.S., trillions of dollars each year are invested in mutual funds, but more and more investors are taking a less-involved route by allowing financial analysts to choose where their money is invested. In the following pages, we will take a closer look at the mutual fund market and its basic components, the ways that mutual funds have been viewed and traded in the past, and the revolutionary changes that are happening right under our noses that the average American may not even be aware of. With the help of many credible sources, such as the Investment Company Institute, Reflow Investments LLC, and the Financial Planning Journal, the change from direct-to-shareholder mutual fund distribution to third-party intermediary distribution will be explained and the effects these changes has on the average investor will be explored
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