Hydrogen peroxide thermochemical oscillator as driver for primordial RNA replication

This paper presents and tests a previously unrecognised mechanism for driving a replicating molecular system on the prebiotic earth. It is proposed that cell-free RNA replication in the primordial soup may have been driven by self-sustained oscillatory thermochemical reactions. To test this hypothesis a well-characterised hydrogen peroxide oscillator was chosen as the driver and complementary RNA strands with known association and melting kinetics were used as the substrate. An open flow system model for the self-consistent, coupled evolution of the temperature and concentrations in a simple autocatalytic scheme is solved numerically, and it is shown that thermochemical cycling drives replication of the RNA strands. For the (justifiably realistic) values of parameters chosen for the simulated example system, the mean amount of replicant produced at steady state is 6.56 times the input amount, given a constant supply of substrate species. The spontaneous onset of sustained thermochemical oscillations via slowly drifting parameters is demonstrated, and a scheme is given for prebiotic production of complementary RNA strands on rock surfaces.Comment: Submitted 14 Nov 2013 to J. Roy. Soc. Interface, accepted in final form 25 Feb 2014. An article on this paper appears on https://theconversation.com/au. A new recipe for primordial soup on the pre-biotic earth may help answer questions about the origin of life, and explain why new life does not emerge from non-living precursors on the modern eart

Thermodynamics of the deposition of complex waxes and asphaltenes in crude oil

Peer reviewedPublisher PD

Beliefs about brain injury in Britain

Primary objective: Surveys have revealed that a high proportion of the public in the US and Canada hold misconceptions pertaining to the sequelae of brain injury. This study examined whether similar misconceptions are endorsed by adults in Britain. Research design: Survey. Methods and procedures: Three hundred and twenty-two participants completed a 17-item questionnaire containing true or false statements about general knowledge of brain injury, coma and consciousness, memory impairments and recovery. Main outcomes and results: Regardless of age, sex, level of education and familiarity with brain injury, participants held mistaken beliefs about consciousness, were inclined to under-estimate the extent of memory deficits and were unaware that patients are more vulnerable and less resistant to further injury. A large proportion of respondents indicated that their knowledge of brain injury had been derived from the popular media. Conclusions: Similar misconceptions to those reported in previous studies exist in Britain. Notably in this study these misconceptions were endorsed by a greater percentage of respondents. Greater public awareness is needed for decisions concerning funding and patient care. It is therefore important for healthcare professionals and public health campaigns to dispel myths about brain injury

The life story of hydrogen peroxide II: a periodic pH and thermochemical drive for the RNA world

It is now accepted that primordial non-cellular RNA communities must have been subject to a periodic drive in order to replicate and prosper. We have pro- posed the oxidation of thiosulfate by hydrogen peroxide as this drive. This reaction system behaves as (i) a thermochemical and (ii) a pH oscillator, and in this work, we unify (i) and (ii) for the first time. We report thermally self- consistent, dynamical simulations in which the system transitions smoothly from nearly isothermal pH to fully developed thermo-pH oscillatory regimes. We use this oscillator to drive simulated replication of a 39-bp RNA species. Production of replicated duplex under thermo-pH drive was significantly enhanced compared with that under purely thermochemical drive, effectively allowing longer strands to replicate. Longer strands are fitter, with more poten- tial to evolve enzyme activity and resist degradation. We affirm that concern over the alleged toxicity of hydrogen peroxide to life is largely misplaced in the current context, we survey its occurrence in the solar system to motivate its inclusion as a biosignature in the search for life on other worlds and high- light that pH oscillations in a spatially extended, bounded system manifest as the fundamental driving force of life: a proton gradient.This work was funded by Australian Research Council Future Fellowship FT0991007 (R.B.)

Addendum

Possible amendments to Parts IV and V following review of the commentaries:As a result of a consideration of the commentaries on the Model Law we propose a number of possible amendments to Parts IV and V that take account of some of the points raised (see our response to the commentaries). We here reproduce the complete clauses as amended

Outline of The Model Law

Part I PrinciplesPart II General provisionsPart III Serious medical treatmentPart IV Informal patients needing care and treatmentPart V Compulsory provision of care and treatmentPart VI Forensic provisionsPart VII The Mental Capacity TribunalPart VIII Patient safeguard

A model law fusing incapacity and mental health legislation

An outline for a model law is presented here that would govern the non-consensual treatment of people who lack the capacity (or competence) to consent due to mental impairment, whether this is due to ‘mental disorder’ or ‘psychiatric disorder’ as conventionally conceived, or due to a ‘physical disorder’. Our aim in drafting this model law is to give coherent and practical expression to the case, previously made by two of the current authors, that separate legislation authorising the civil commitment of ‘mentally disordered’ persons is unnecessary, and discriminatory, and should be replaced by new, comprehensive legislation that would govern the non-consensual treatment of both ‘mental’ and ‘physical’ conditions. This new scheme – which we have described as the ‘fusion’ proposal – would be based squarely on incapacity principles: that is, on the impaired capacity of a person to make decisions about treatment, from whatever cause – whether this is due to schizophrenia, Alzheimer’s Disease, a learning disability, a confusional state due to infection, a cerebrovascular accident, a head injury, or any other mental impairment.A model statute of this kind, drafted largely by Rowena Daw, is presented here in skeleton form.  

Response to the Commentaries

We are immensely grateful to the commentators for their careful reading of the Model ‘Fusion’ Law (ML). The level of support for our proposal from most of the commentators is encouraging as is the news that Northern Ireland intends to introduce legislation along similar lines. The aim of the ML is to eliminate the unwarranted discrimination against people with mental disorder that is inherent in current mental health legislation in England and Wales and in many other jurisdictions. We remain convinced that the principles underlying the enterprise are right and that they can be translated into a practical form. At the same time, excellent points have been raised by the commentators that have stimulated us to think further and to propose a number of revisions.The editors have invited us to respond briefly to the commentaries. We should have liked to engage with each of the commentators on a number of specific issues, but in our response we must focus on the major themes that have emerged

Asklerogene pneumokonioze

Nous avons essayé dans le vaste tableau des pneumoconioses non. sclérogènes de mettre un peu d\u27ordre. Tout d\u27abord il y a lieu de faire rentrer dans le cadre de la silicose les diverses pneumoconioses où l\u27action de la silice est prédominante. Il s\u27agit de silicoses à poussières mixtes. Ensuite on peut ranger les pneumoconioses qui ne sont pas caractérisées par une fibrose diffuse progressive et qui n\u27entrainent des symptômes morbides que par leur accumulation dans le champ pulmonaire. Les rnétalloconioses donnent des images radiographiques particulières dues a la radioopacité des poussières inhalées. Elles n\u27entraient pas de sclérose sauf dans les cas de mélange avec la silice et elles entrent alors dans le cas des silicoses à poussières mixtes, sidère-silicose par exemple. Certaines poussières métalliques donnent lieu à. des accès hyperthermiques passagers, d\u27autres engendrent des pneumopathies aigües, d\u27 autres entrainent des formations granulomateuses, beaucoup laissent simplement une marque radio opaque. Les mycoconioses ou pneumomycoses sont plutôt des pneumopathies que des pneumoconioses. Elle3 sont à rechercher dans les professions où les sujets sont en contact avec les animaux ou les végétaux. Sous le nom d\u27allergoconioses nous rangeons les manifestations allergiques consécutives à l\u27inhalation de poussières végétales, en indiquant qu\u27elles peuvent elles aussi être associées à une pneumoconiose ou à une silicose. Notre classification est sujette à critiques, elle n\u27est que temporaire en attendant une meilleure mise en ordre.Autor predlaže novu klasifikaciju asklerogenih pneumokonioza. Po toj klasifikaciji treba među silikoze svrstati pneumokonioze uzrokovane miješanom prašinom, u kojoj je kvarc glavni sastavni dio. Prašine, koje izazivaju sliku bolesti samo zbog nakupljanja u plućima, uzrok su pneumokoniozama. Za metalokonioze je karakteristična rentgenska slika, koja nastaje zbog nepropusnosti prašine za rentgenske zrake. Te prašine, ukoliko nisu miješane s kvarcom, ne izazivaju silikozu nego druge simptome kao prolaznu hipertermiju, akutne pneumonije, granulomatozne formacije ili samo plućna zasjenjenja, već prema metalu, koji ih izaziva. Mikokonioze ili pneumomikoze su pneumopatije ljudi, koji su u kontaktu s biljem i životinjama. Medu alergokonioze pripadaju alergične manifestacije nakon udisanja biljne prašine, koje katkada dolaze u kombinaciji s pneumokoniozama i silikozom. Plućne promjene ne zavise samo od vrste prašine, nego i od broja i dimenzije čestica, trajanja ekspozicije i individualne osjetljivosti. Sve prašine zapravo oštećuju plućni epitel, a svaki je pojedinac manje ili više osjetljiv za bar jednu od navedenih vrsta prašine. Prema tome neškodljivih prašina nema, i zato se treba ozbiljno boriti za prevenciju svih vrsta pneumokonioza