147 research outputs found

    Acetyl Phosphate as a Primordial Energy Currency at the Origin of Life

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    Metabolism is primed through the formation of thioesters via acetyl CoA and the phosphorylation of substrates by ATP. Prebiotic equivalents such as methyl thioacetate and acetyl phosphate have been proposed to catalyse analogous reactions at the origin of life, but their propensity to hydrolyse challenges this view. Here we show that acetyl phosphate (AcP) can be synthesised in water within minutes from thioacetate (but not methyl thioacetate) under ambient conditions. AcP is stable over hours, depending on temperature, pH and cation content, giving it an ideal poise between stability and reactivity. We show that AcP can phosphorylate nucleotide precursors such as ribose to ribose-5-phosphate and adenosine to adenosine monophosphate, at modest (~2%) yield in water, and at a range of pH. AcP can also phosphorylate ADP to ATP in water over several hours at 50 °C. But AcP did not promote polymerization of either glycine or AMP. The amino group of glycine was preferentially acetylated by AcP, especially at alkaline pH, hindering the formation of polypeptides. AMP formed small stacks of up to 7 monomers, but these did not polymerise in the presence of AcP in aqueous solution. We conclude that AcP can phosphorylate biologically meaningful substrates in a manner analogous to ATP, promoting the origins of metabolism, but is unlikely to have driven polymerization of macromolecules such as polypeptides or RNA in free solution. This is consistent with the idea that a period of monomer (cofactor) catalysis preceded the emergence of polymeric enzymes or ribozymes at the origin of life

    An Origin-of-Life Reactor to Simulate Alkaline Hydrothermal Vents

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    Chemiosmotic coupling is universal: practically all cells harness electrochemical proton gradients across membranes to drive ATP synthesis, powering biochemistry. Autotrophic cells, including phototrophs and chemolithotrophs, also use proton gradients to power carbon fixation directly. The universality of chemiosmotic coupling suggests that it arose very early in evolution, but its origins are obscure. Alkaline hydrothermal systems sustain natural proton gradients across the thin inorganic barriers of interconnected micropores within deep-sea vents. In Hadean oceans, these inorganic barriers should have contained catalytic Fe(Ni)S minerals similar in structure to cofactors in modern metabolic enzymes, suggesting a possible abiotic origin of chemiosmotic coupling. The continuous supply of H2 and CO2 from vent fluids and early oceans, respectively, offers further parallels with the biochemistry of ancient autotrophic cells, notably the acetyl CoA pathway in archaea and bacteria. However, the precise mechanisms by which natural proton gradients, H2, CO2 and metal sulphides could have driven organic synthesis are uncertain, and theoretical ideas lack empirical support. We have built a simple electrochemical reactor to simulate conditions in alkaline hydrothermal vents, allowing investigation of the possibility that abiotic vent chemistry could prefigure the origins of biochemistry. We discuss the construction and testing of the reactor, describing the precipitation of thin-walled, inorganic structures containing nickel-doped mackinawite, a catalytic Fe(Ni)S mineral, under prebiotic ocean conditions. These simulated vent structures appear to generate low yields of simple organics. Synthetic microporous matrices can concentrate organics by thermophoresis over several orders of magnitude under continuous open-flow vent conditions

    Language matters. Addressing the use of language in the care of people with diabetes: position statement of the English Advisory Group

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    The language used by healthcare professionals can have a profound impact on how people living with diabetes, and those who care for them, experience their condition and feel about living with it day-to-day. At its best, good use of language, both verbal and written, can lower anxiety, build confidence, educate and help to improve self-care. Conversely, poor communication can be stigmatizing, hurtful and undermining of self-care and can have a detrimental effect on clinical outcomes. The language used in the care of those with diabetes has the power to reinforce negative stereotypes, but it also has the power to promote positive ones. The use of language is controversial and has many perspectives. The development of this position statement aimed to take account of these as well as the current evidence base. A working group, representing people with diabetes and key organizations with an interest in the care of people with diabetes, was established to review the use of language. The work of this group has culminated in this position statement for England. It follows the contribution of Australia and the USA to this important international debate. The group has set out practical examples of language that will encourage positive interactions with those living with diabetes and subsequently promote positive outcomes. These examples are based on a review of the evidence and are supported by a simple set of principles

    Concord Companions: Margaret Fuller, Friendship, and Desire

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    In this paper, we examine the rhetoric of friendship and desire in mid-nineteenth-century American writing. We begin by looking at Emerson's essay on friendship and Thoreau's poem "Sympathy" (1840) to provide a context for reading Margaret Fuller's fascinating texts on samesex bonds between women. Of particular interest to us is Fuller's translation of Elizabeth von Arnim's Die Gunderode (1840), a collection of letters between Arnim and the German Romantic poet Karoline von Gunderode which provides compelling insights into the early to mid-nineteenth-century continuum between female friendship and same-sex desire. We situate this translation alongside Fuller's own female friendships and expressions of love for women, more specifically her declarations of love to Anna Barker and, later, to George Sand. This latter relationship, we suggest, was a source of admiration and anxiety, for Sand's cross-dressing and fluid sense of gender identity was simultaneously celebrated and condemned in Fuller's Women in the Nineteenth Century (1843)

    The Rachel Carson Letters and the Making of Silent Spring

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    Environment, conservation, green, and kindred movements look back to Rachel Carson’s 1962 book Silent Spring as a milestone. The impact of the book, including on government, industry, and civil society, was immediate and substantial, and has been extensively described; however, the provenance of the book has been less thoroughly examined. Using Carson’s personal correspondence, this paper reveals that the primary source for Carson’s book was the extensive evidence and contacts compiled by two biodynamic farmers, Marjorie Spock and Mary T. Richards, of Long Island, New York. Their evidence was compiled for a suite of legal actions (1957-1960) against the U.S. Government and that contested the aerial spraying of dichlorodiphenyltrichloroethane (DDT). During Rudolf Steiner’s lifetime, Spock and Richards both studied at Steiner’s Goetheanum, the headquarters of Anthroposophy, located in Dornach, Switzerland. Spock and Richards were prominent U.S. anthroposophists, and established a biodynamic farm under the tutelage of the leading biodynamics exponent of the time, Dr. Ehrenfried Pfeiffer. When their property was under threat from a government program of DDT spraying, they brought their case, eventually lost it, in the process spent US$100,000, and compiled the evidence that they then shared with Carson, who used it, and their extensive contacts and the trial transcripts, as the primary input for Silent Spring. Carson attributed to Spock, Richards, and Pfeiffer, no credit whatsoever in her book. As a consequence, the organics movement has not received the recognition, that is its due, as the primary impulse for Silent Spring, and it is, itself, unaware of this provenance

    Evaluation of antiarthritic activity of Strychnos potatorum Linn seeds in Freund's adjuvant induced arthritic rat model

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    <p>Abstract</p> <p>Background</p> <p><it>Strychnos potatorum </it>Linn (Loganiaceae) is a moderate sized tree found in southern and central parts of India, Sri Lanka and Burma. In traditional system of medicine, <it>Strychnos potatorum </it>Linn seeds were used for various ailments including inflammation, diabetes etc. To investigate the folkloric use of the seeds the present study was carried out on Freund's adjuvant induced arthritic rats.</p> <p>Methods</p> <p>The present study states the effect of the aqueous extract (SPE) and the whole seed powder (SPP) of <it>Strychnos potatorum </it>Linn seeds on the Freund's complete adjuvant (FCA) induced arthritic rat paw edema, body weight changes and alterations in haematological and biochemical parameters in both developing and developed phases of arthritis. Histopathology of proximal interphalangeal joints and radiology of hind legs were studied.</p> <p>Results</p> <p>In FCA induced arthritic rats, there was significant increase in rat paw volume and decrease in body weight increment, whereas SPP and SPE treated groups, showed significant reduction in paw volume and normal gain in body weight. The altered haematological parameters (Hb, RBC, WBC and ESR) and biochemical parameters (blood urea, serum creatinine, total proteins and acute phase proteins) in the arthritic rats were significantly brought back to near normal by the SPP and SPE treatment at the dose of 200 mg/kg/p.o in both developing and developed phases of arthritis. Further the histopathological and radiological studies revealed the antiarthritic activity of SPP and SPE by indicating fewer abnormalities in these groups when compared to the arthritic control group.</p> <p>Conclusion</p> <p>In conclusion, both SPP and SPE at the specified dose level of 200 mg/kg, p.o. showed reduction in rat paw edema volume and it could significantly normalize the haematological and biochemical abnormalities in adjuvant induced arthritic rats in both developing and developed phases of FCA induced arthritis. Further the histopathological and radiological studies confirmed the antiarthritic activity of SPP and SPE.</p

    Co-design, evaluation and the Northern Ireland Innovation Lab

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    Around the world there are more than 100 policy labs—multi-disciplinary government teams developing public services and policies using innovation methods to engage citizens and stakeholders. These policy labs use a range of innovation methods and approaches, including co-production, co-creation, co-design, behavioural insights, systems thinking, ethnography, data science, nudge theory and lean processes. Although the methods may vary, one element is consistent: policy labs actively, creatively and collaboratively engage the public and a wide range of stakeholders in jointly developing solutions. The Northern Ireland Public Sector Innovation Lab (iLab) is part of a growing UK and international community of policy labs using co-design to engage with users for value co-creation, aiming to improve public governance by creating a safe space to generate ideas, test prototypes and refine concepts with beneficiaries. Drawing on iLab’s experience, this paper explores three questions: What are the main determinants of effective co-design? What are the unintended consequences of co-design? And what lessons can be learned from iLab and shared with other policy labs
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