179 research outputs found

    Structure of 4-Cyclohexyl-3,4-dihydro-2-hydroxy-2-methyl-2\u3ci\u3eH\u3c/i\u3e,5\u3ci\u3eH\u3c/i\u3e-pyrano[ 3,2-\u3ci\u3ec\u3c/i\u3e][1]benzopyran-5-one

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    C19H22O4, monoclinic, P21/c, a = 2·515 (2), b = 17·472 (3), c = 7·489 (1) Å, β = 00·40 (1)°. The structure was solved by direct methods. The cyclohexyl group is pseudo-equatorial and trans to the axial hydroxyl; the dihydropyran ring is a half-chair distorted towards the d,e-diplanar conformation. Hydrogen bonding between the coumarin carbonyl and the hydroxyl groups at an O···O distance of 2·834 (4) Å is found. In CDC13 solution, this compound exists predominantly in the open-chain keto form

    Are there alternative adaptive strategies to human pro-sociality? The role of collaborative morality in the emergence of personality variation and autistic traits

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    Selection pressures to better understand other’s thoughts and feelings are seen as a primary driving force in human cognitive evolution. Yet might the evolution of social cognition be more complex than we assume, with more than one strategy towards social understanding and developing a positive pro-social reputation? Here we argue that social buffering of vulnerabilities through the emergence of collaborative morality will have opened new niches for adaptive cognitive strategies and widened personality variation. Such strategies include those that that do not depend on astute social perception or abilities to think recursively about other’s thoughts and feelings. We particularly consider how a perceptual style based on logic and detail, bringing certain enhanced technical and social abilities which compensate for deficits in complex social understanding could be advantageous at low levels in certain ecological and cultural contexts. ‘Traits of autism’ may have promoted innovation in archaeological material culture during the late Palaeolithic in the context of the mutual interdependence of different social strategies, which in turn contributed to the rise of innovation and large scale social networks

    α-L-Glutamylglycine

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    C7H12N 2O5, orthorhombic, P212121, a = 5·525(5), b = 12·565(4), c = 13·211(6) Å, Z = 4, Dc = l·48, Dm (flotation in chloroform/ methylene chloride) = 1·48(1) Mg m-3, R1 = 0·039, R2 = 0·040 for 1172 observations. The dipeptide crystallizes as a zwitterion with the main-chain carboxyl ionized and the amino terminus protonated. The conformation of the peptide group is trans; the glutamyl side chain is extended, but the carboxy terminus is held by hydrogen bonding in a non-extended conformation with a torsional angle ΦGly = -74.1°

    α-L-Aspartylglycine Monohydrate

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    C6H10N2O5, H2O, orthorhombic, P212121, a = 4·844 (5), b = 9·916 (3), c = 18·070(4) Å, V = 868·05 Å3, Z = 4, Dc = 1·59, Dm (flotation in chloroform/iodoform) = l·60 (1) Mg m-3; R1 = 0·040, R2 = 0·033 for 1088 observations. The dipeptide crystallizes as a zwitterion with the main-chain carboxyl ionized and the side-chain amino group protonated. The overall dipeptide conformation is highly extended and the molecule is extensively hydrogen bonded

    Synthesis and characterization of monomeric manganese(II) and cobalt(III) complexes of the hexadentate amine ligand N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine, C26H28N6 (tpen)

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    The syntheses and characterization of complexes of manganese(II) and cobalt(III) with the potentially hexadentate ligand N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine, C26H28N6 (tpen), are described. The monomeric manganese(II) complex [Mn(C26H28N6)(H2O)](ClO4)2 (1) crystallizes in the monoclinic space group C2/c with 4 formula units in a cell of dimensions a = 15.080(1) Å, b = 10.101(1) Å, c = 19.426(2) Å and b = 94.6l(l)°. The structure has been refined to a final value of the conventional R-factor of 0.0401 based on 2586 observed independent reflections. The geometry at the manganese center is seven-coordinate, and is best described as a capped trigonal pyramid with the water molecule forming the cap and the six nitrogen atoms of the tpen ligand occupying the pyramidal sites. The manganese atom and the water molecule lie on a crystallographic twofold axis. The related cobalt(III) complex, [Co(C26H28N6)] (C1O4)3 (4) crystallizes in the monoclinic space group P21/n with 4 formula units in a cell of dimensions a = 9.829(2) Å, b = 18.364(4) Å, c = 18.128(4) Å and b = 93.64(3)°. The structure has been refined to a final value of the conventional R-factor of 0.0526 based on 3574 observed independent reflections. The complex is approximately octahedral, the coordination being provided by the six nitrogen atoms of the tpen ligand. The EPR spectrum of 1 diluted into the corresponding Cd(II) host has been simulated with the parameters g = 2.00, A = 0.0080 cm-1, D = 0.116 cm-1, and E = 0.0013 cm-1. The small value of E/D is consistent with the observed symmetry of the complex. KEY WORDS: Monomeric manganese(II) complex, Monomeric cobalt(III) complex, Hexadentate ligand, N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine  Bull. Chem. Soc. Ethiop. 2004, 18(1), 17-28.

    A national survey of the availability of intensity-modulated radiation therapy and stereotactic radiosurgery in Canada

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    <p>Abstract</p> <p>Background</p> <p>The timely and appropriate adoption of new radiation therapy (RT) technologies is a challenge both in terms of providing of optimal patient care and managing health care resources. Relatively little is known regarding the rate at which new RT technologies are adopted in different jurisdictions, and the barriers to implementation of these technologies.</p> <p>Methods</p> <p>Surveys were sent to all radiation oncology department heads in Canada regarding the availability of RT equipment from 2006 to 2010. Data were collected concerning the availability and use of Intensity Modulated Radiation Therapy (IMRT) and stereotactic radiosurgery (SRS), and the obstacles to implementation of these technologies.</p> <p>Results</p> <p>IMRT was available in 37% of responding centers in 2006, increasing to 87% in 2010. In 2010, 72% of centers reported that IMRT was available for all patients who might benefit, and 37% indicated that they used IMRT for "virtually all" head and neck patients. SRS availability increased from 26% in 2006 to 42.5% in 2010. Eighty-two percent of centers reported that patients had access to SRS either directly or by referral. The main barriers for IMRT implementation included the need to train or hire treatment planning staff, whereas barriers to SRS implementation mostly included the need to purchase and/or upgrade existing planning software and equipment.</p> <p>Conclusions</p> <p>The survey showed a growing adoption of IMRT and SRS in Canada, although the latter was available in less than half of responding centers. Barriers to implementation differed for IMRT compared to SRS. Enhancing human resources is an important consideration in the implementation of new RT technologies, due to the multidisciplinary nature of the planning and treatment process.</p

    A glacial chronology for sub-Antarctic Marion Island from MIS 2 and MIS 3

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    It is increasingly apparent that local and regional factors, including geographic location, topography and climatic variability, strongly influence the timing and extent of glaciations across the Southern Hemisphere. Glacial chronologies of sub-Antarctic islands can provide valuable insights into the nature of regional climatic variability and the localised response(s) of glacial systems during periods of climatic change. With new cosmogenic 36Cl exposure ages from Marion Island in the southern Indian Ocean, we provide the oldest dated terrestrial moraine sequences for the sub-Antarctic islands. Results confirm that a local Last Glacial Maximum was reached prior to ∼56 ka when ice retreated with localised stand still events at ∼43 ka and between ∼38 and 33 ka. Evidence of ice re-advances throughout MIS 2 are limited and particularly absent for the cooling periods at ∼32 and ∼21 ka, and retreat continued until ∼17 ka ago. Any MIS 1 readvances on the island would be confined to altitudes above 900 m a.s.l. but the Holocene exposure ages remains to be documented. We compare Marion Island's glacial chronology with other sub-Antarctic islands (e.g., the Kerguelen archipelago, Auckland and Campbell islands and South Georgia) and review the evidence for a Southern Hemisphere glacial maximum in late MIS 3 (∼41 ka). At a regional scale we recognize sea surface temperatures, sea ice extent and the latitudinal position of the Southern Westerly Wind belt as key controls on equilibrium-line altitudes and ice accumulation due to their influence on air temperature and precipitation regimes. At an island scale, geomorphological mapping shows that deglaciation of individual glacier lobes was a-synchronous due to local physiographical and topographical factors controlling the island's micro-climate. We suggest that variability in deglaciation chronologies at smaller scales (particularly at the sub-Antarctic Islands) are important to consider when untangling climatic drivers across the Southern Ocean

    A glacial chronology for sub-Antarctic Marion Island from MIS 2 and MIS 3

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    It is increasingly apparent that local and regional factors, including geographic location, topography and climatic variability, strongly influence the timing and extent of glaciations across the Southern Hemisphere. Glacial chronologies of sub-Antarctic islands can provide valuable insights into the nature of regional climatic variability and the localised response(s) of glacial systems during periods of climatic change. With new cosmogenic 36Cl exposure ages from Marion Island in the southern Indian Ocean, we provide the oldest dated terrestrial moraine sequences for the sub-Antarctic islands. Results confirm that a local Last Glacial Maximum was reached prior to ∼56 ka when ice retreated with localised stand still events at ∼43 ka and between ∼38 and 33 ka. Evidence of ice re-advances throughout MIS 2 are limited and particularly absent for the cooling periods at ∼32 and ∼21 ka, and retreat continued until ∼17 ka ago. Any MIS 1 readvances on the island would be confined to altitudes above 900 m a.s.l. but the Holocene exposure ages remains to be documented. We compare Marion Island's glacial chronology with other sub-Antarctic islands (e.g., the Kerguelen archipelago, Auckland and Campbell islands and South Georgia) and review the evidence for a Southern Hemisphere glacial maximum in late MIS 3 (∼41 ka). At a regional scale we recognize sea surface temperatures, sea ice extent and the latitudinal position of the Southern Westerly Wind belt as key controls on equilibrium-line altitudes and ice accumulation due to their influence on air temperature and precipitation regimes. At an island scale, geomorphological mapping shows that deglaciation of individual glacier lobes was a-synchronous due to local physiographical and topographical factors controlling the island's micro-climate. We suggest that variability in deglaciation chronologies at smaller scales (particularly at the sub-Antarctic Islands) are important to consider when untangling climatic drivers across the Southern Ocean

    Identifying and prioritising unanswered research questions for people with hyperacusis: James Lind Alliance Hyperacusis Priority Setting Partnership

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    Objective To determine research priorities in hyperacusis that key stakeholders agree are the most important. Design/setting A priority setting partnership using two international surveys, and a UK prioritisation workshop, adhering to the six-staged methodology outlined by the James Lind Alliance. Participants People with lived experience of hyperacusis, parents/carers, family and friends, educational professionals and healthcare professionals who support and/or treat adults and children who experience hyperacusis, including but not limited to surgeons, audiologists, psychologists and hearing therapists. Methods The priority setting partnership was conducted from August 2017 to July 2018. An international identification survey asked respondents to submit any questions/uncertainties about hyperacusis. Uncertainties were categorised, refined and rephrased into representative indicative questions using thematic analysis techniques. These questions were verified as ‘unanswered’ through searches of current evidence. A second international survey asked respondents to vote for their top 10 priority questions. A shortlist of questions that represented votes from all stakeholder groups was prioritised into a top 10 at the final prioritisation workshop (UK). Results In the identification survey, 312 respondents submitted 2730 uncertainties. Of those uncertainties, 593 were removed as out of scope, and the remaining were refined into 85 indicative questions. None of the indicative questions had already been answered in research. The second survey collected votes from 327 respondents, which resulted in a shortlist of 28 representative questions for the final workshop. Consensus was reached on the top 10 priorities for future research, including identifying causes and underlying mechanisms, effective management and training for healthcare professionals. Conclusions These priorities were identified and shaped by people with lived experience, parents/carers and healthcare professionals, and as such are an essential resource for directing future research in hyperacusis. Researchers and funders should focus on addressing these priorities.Additional co-authors: Tracey Pollard, Helen Henshaw, Toto A Gronlund, Derek J Hoar
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