289 research outputs found

    An Investigation of the Application of the Golden Ratio and Fibonacci Sequence Associated with the Chart of Nuclides

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    The aim of this investigation was to examine the relationship between the golden ratio and atomic structure. The chart of nuclides was evaluated for evidence of a true golden ratio. That is, the neutron number divided by the proton number needed to equal 1.618 and the atomic number (neutrons plus protons) divided by the neutron number needed to equal 1.618. Across the chart of nuclides, this ratio approximated the golden ratio to a varying degree of accuracy for some nuclides but rarely for both calculations. This relationship (golden ratio in the chart of nuclides) has not been previously reported. It was determined that specific nuclides exhibit the golden ratio between protons and neutrons, and that these produce a trend line on the chart of nuclides. The Fibonacci sequence is mathematically evident and this information can be used to postulate new nuclides or elements

    Pharmacokinetic Considerations for Digoxin in Older People

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    Objective: This review aims to arm readers with a deep understanding of pharmacokinetics of digoxin. Data Sources: Pharmacology and pharmacokinetic references texts, and peer reviewed medical journal manuscripts indexed on Medline included based on currency, accuracy and appropriateness. Results: Physiologic changes and disease associated with aging have an impact on pharmacokinetics and pharmacodynamics of medications. Altered drug response and increased adverse reactions are common amongst the elderly. The narrow therapeutic index of digoxin and pharmacokinetic changes associated with aging increases the risk of toxicity. In the aging population, a number of factors combine to increase the risk, severity and likelihood of hospitalisation or death due to adverse drug effects: • changes to absorption, distribution, metabolism and excretion, • increased susceptibility to drug sensitivity, • co-existing pathology, • polypharmacy. Conclusion: A thorough und erstanding of digoxin pharmacokinetics in the older person is essential for improved therapeutic outcomes, improved compliance, reduced morbidity and improved quality of life.6 page(s

    Come back Marshall, all is forgiven? : Complexity, evolution, mathematics and Marshallian exceptionalism

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    Marshall was the great synthesiser of neoclassical economics. Yet with his qualified assumption of self-interest, his emphasis on variation in economic evolution and his cautious attitude to the use of mathematics, Marshall differs fundamentally from other leading neoclassical contemporaries. Metaphors inspire more specific analogies and ontological assumptions, and Marshall used the guiding metaphor of Spencerian evolution. But unfortunately, the further development of a Marshallian evolutionary approach was undermined in part by theoretical problems within Spencer's theory. Yet some things can be salvaged from the Marshallian evolutionary vision. They may even be placed in a more viable Darwinian framework.Peer reviewedFinal Accepted Versio

    Retired A Stars and Their Companions. III. Comparing the Mass-Period Distributions of Planets Around A-Type Stars and Sun-Like Stars

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    We present an analysis of ~5 years of Lick Observatory radial velocity measurements targeting a uniform sample of 31 intermediate-mass subgiants (1.5 < M*/Msun < 2.0) with the goal of measuring the occurrence rate of Jovian planets around (evolved) A-type stars and comparing the distributions of their orbital and physical characteristics to those of planets around Sun-like stars. We provide updated orbital solutions incorporating new radial velocity measurements for five known planet-hosting stars in our sample; uncertainties in the fitted parameters are assessed using a Markov Chain Monte Carlo method. The frequency of Jovian planets interior to 3 AU is 26 (+9,-8)%, which is significantly higher than the ~5-10% frequency observed around solar-mass stars. The median detection threshold for our sample includes minimum masses down to {0.2, 0.3, 0.5, 0.6, 1.3} MJup within {0.1, 0.3, 0.6, 1.0, 3.0} AU. To compare the properties of planets around intermediate-mass stars to those around solar-mass stars we synthesize a population of planets based on the parametric relationship dN ~ M^{alpha}P^{beta} dlnM dlnP, the observed planet frequency, and the detection limits we derived. We find that the values of alpha and beta for planets around solar-type stars from Cumming et al. fail to reproduce the observed properties of planets in our sample at the 4 sigma level, even when accounting for the different planet occurrence rates. Thus, the properties of planets around A stars are markedly different than those around Sun-like stars, suggesting that only a small (~ 50%) increase in stellar mass has a large influence on the formation and orbital evolution of planets.Comment: Accepted by the Astrophysical Journal; 15 pages, 15 figure

    Travel plans for new developments: a global review

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    A travel plan is a mechanism for delivering a package of transport measures at a site to manage car use and encourage the use of more sustainable forms of transport. In recent years, travel plans have been required for new infill and greenfield developments through the land-use planning and approvals process, predominantly in the United Kingdom, the United States, continental Europe and Australia. This paper contributes to the literature by providing a global review of travel plans for new developments. The results show that while travel plans for new developments share a common set of elements with those for pre-existing sites, differences within each element are notable, particularly in the types of travel plan measures adopted, processes for managing the travel plan, and approaches to monitoring and review. Results of previous evaluations have varied considerably, although most have reported a reduction in car driver trips of 10–20 percentage points. Despite this, most evaluations lack rigour, with a paucity of robust evidence. Key success factors identified by the literature, such as the provision of an explicit policy supporting the role of travel plans, should be embedded within the travel planning process where possible to ensure best outcomes for new developments

    Biotransformation of lanthanum by Aspergillus niger

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    Lanthanum is an important rare earth element and has many applications in modern electronics and catalyst manufacturing. However, there exist several obstacles in the recovery and cycling of this element due to a low average grade in exploitable deposits and low recovery rates by energy-intensive extraction procedures. In this work, a novel method to transform and recover La has been proposed using the geoactive properties of Aspergillus niger. La-containing crystals were formed and collected after A. niger was grown on Czapek-Dox agar medium amended with LaCl 3. Energy-dispersive X-ray analysis (EDXA) showed the crystals contained C, O, and La; scanning electron microscopy revealed that the crystals were of a tabular structure with terraced surfaces. X-ray diffraction identified the mineral phase of the sample as La 2(C 2O 4) 3·10H 2O. Thermogravimetric analysis transformed the oxalate crystals into La 2O 3 with the kinetics of thermal decomposition corresponding well with theoretical calculations. Geochemical modelling further confirmed that the crystals were lanthanum decahydrate and identified optimal conditions for their precipitation. To quantify crystal production, biomass-free fungal culture supernatants were used to precipitate La. The results showed that the precipitated lanthanum decahydrate achieved optimal yields when the concentration of La was above 15 mM and that 100% La was removed from the system at 5 mM La. Our findings provide a new aspect in the biotransformation and biorecovery of rare earth elements from solution using biomass-free fungal culture systems. </p

    Physiological Correlates of Volunteering

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    We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation

    Act now against new NHS competition regulations: an open letter to the BMA and the Academy of Medical Royal Colleges calls on them to make a joint public statement of opposition to the amended section 75 regulations.

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    The TEXES Survey For H2 Emission From Protoplanetary Disks

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    We report the results of a search for pure rotational molecular hydrogen emission from the circumstellar environments of young stellar objects with disks using the Texas Echelon Cross Echelle Spectrograph (TEXES) on the NASA Infrared Telescope Facility and the Gemini North Observatory. We searched for mid-infrared H2 emission in the S(1), S(2), and S(4) transitions. Keck/NIRSPEC observations of the H2 S(9) transition were included for some sources as an additional constraint on the gas temperature. We detected H2 emission from 6 of 29 sources observed: AB Aur, DoAr 21, Elias 29, GSS 30 IRS 1, GV Tau N, and HL Tau. Four of the six targets with detected emission are class I sources that show evidence for surrounding material in an envelope in addition to a circumstellar disk. In these cases, we show that accretion shock heating is a plausible excitation mechanism. The detected emission lines are narrow (~10 km/s), centered at the stellar velocity, and spatially unresolved at scales of 0.4 arcsec, which is consistent with origin from a disk at radii 10-50 AU from the star. In cases where we detect multiple emission lines, we derive temperatures > 500 K from ~1 M_earth of gas. Our upper limits for the non-detections place upper limits on the amount of H2 gas with T > 500 K of less than a few Earth masses. Such warm gas temperatures are significantly higher than the equilibrium dust temperatures at these radii, suggesting that the gas is decoupled from the dust in the regions we are studying and that processes such as UV, X-ray, and accretion heating may be important.Comment: 24 pages, 16 figures, 5 tables, ApJ accepte
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