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Direct surface analysis coupled to high-resolution mass spectrometry reveals heterogeneous composition of the cuticle of Hibiscus trionum petals.
Plant cuticle, which is the outermost layer covering the aerial parts of all plants including petals and leaves, can present a wide range of patterns that, combined with cell shape, can generate unique physical, mechanical, or optical properties. For example, arrays of regularly spaced nanoridges have been found on the dark (anthocyanin-rich) portion at the base of the petals of Hibiscus trionum. Those ridges act as a diffraction grating, producing an iridescent effect. Because the surface of the distal white region of the petals is smooth and noniridescent, a selective chemical characterization of the surface of the petals on different portions (i.e., ridged vs smooth) is needed to understand whether distinct cuticular patterns correlate with distinct chemical compositions of the cuticle. In the present study, a rapid screening method has been developed for the direct surface analysis of Hibiscus trionum petals using liquid extraction surface analysis (LESA) coupled with high-resolution mass spectrometry. The optimized method was used to characterize a wide range of plant metabolites and cuticle monomers on the upper (adaxial) surface of the petals on both the white/smooth and anthocyanic/ridged regions, and on the lower (abaxial) surface, which is entirely smooth. The main components detected on the surface of the petals are low-molecular-weight organic acids, sugars, and flavonoids. The ridged portion on the upper surface of the petal is enriched in long-chain fatty acids, which are constituents of the wax fraction of the cuticle. These compounds were not detected on the white/smooth region of the upper petal surface or on the smooth lower surface.The authors acknowledge support by the ERC grant 279405.This is the author accepted manuscript. The final version is available at http://dx.doi.org/10.1021/acs.analchem.5b0249
Ichthyological Bulletin of the J.L.B. Smith Institute of Ichthyology; No. 50
The publication of a new phase of research on the fishes of the Okavango drainage starts with this account which gives the valid names and broad distribution patterns of all species known from the system. Eighty species and subspecies are recognised, of which at least two (Parakneria fortuita Penrith; Serranochromis gracilis Greenwood) are endemic. Notes on early collections, synonymy, taxonomic status and distribution are given. New synonyms are recognized under Aplocheilichthys hutereaui (A. schalleri), Aplocheilichthys johnstoni (Haplochilus carlislei) and Ctenopoma multispinis (Ctenopoma machadoi) respectively. Recently published taxonomic changes are incorporated including two genera (Mesobola and Afromastacembelus), a species Serranochromis (Sargochromis) gracilis and the re-allocated Amphilius uranoscopus. The Zambezian Hemichromis species is re-identified as H. elongatus. A number of unresolved taxonomic problems are pointed out and certain dubious records are excluded from the checklist. The Okavango has a diverse fish fauna with tropical affinities. Many fish species are poorly studied. Man-induced threats to the continued natural functioning of this complex and dynamic system, especially large-scale water abstraction, overgrazing, deforestation and biocide spraying to eliminate tsetse fly, make it imperative that studies on the nature and role of the fishes are continued.Rhodes University Libraries (Digitisation
Synthesis of a fullerene-based one-dimensional nanopolymer through topochemical transformation of the parent nanowire
Large-scale practical applications of fullerene (C60) in nanodevices could be
significantly facilitated if the commercially-available micrometer-scale raw
C60 powder were further processed into a one-dimensional (1D) nanowire-related
polymer displaying covalent bonding as molecular interlinks and resembling
traditional important conjugated polymers. However, there has been little study
thus far in this area despite the abundant literature on fullerene. Here we
report the synthesis and characterization of such a C60-based nanowire polymer,
(-C60TMB-)n, where TMB=1,2,4-trimethylbenzene, which displays a well-defined
crystalline structure, exceptionally large length-to-width ratio and excellent
thermal stability. The material is prepared by first growing the corresponding
nanowire through a solution phase of C60 followed by a topochemical
polymerization reaction in the solid state. Gas chromatography, mass
spectrometry and 13C nuclear magnetic resonance evidence is provided for the
nature of the covalent bonding mode adopted by the polymeric chains.
Theoretical analysis based on detailed calculations of the reaction energetics
and structural analysis provides an in-depth understanding of the
polymerization pathway. The nanopolymer promises important applications in
biological fields and in the development of optical, electrical, and magnetic
nanodevices.Comment: 30 pages, 12 figures, 2 table
Electronic excitations in molecular solids:bridging theory and experiment
As the spatial and temporal resolution accessible to experiment and theory converge, computational chemistry is an increasingly powerful tool for modelling and interpreting spectroscopic data. However, the study of molecular processes, in particular those related to electronic excitations (e.g. photochemistry), frequently pushes quantum-chemical techniques to their limit. The disparity in the level of theory accessible to periodic and molecular calculations presents a significant challenge when modelling molecular crystals, since accurate calculations require a high level of theory to describe the molecular species, but must also take into account the influence of the crystalline environment on their properties. In this article, we briefly review the different classes of quantum-chemical techniques, and present an overview of methods that account for environmental influences with varying levels of approximation. Using a combination of solid-state and molecular calculations, we quantitatively evaluate the performance of implicit-solvent models for the [Ni(Et4dien)(η2-O,ON)(η1-NO2)] linkage-isomer system as a test case. We focus particularly on the accurate reproduction of the energetics of the isomerisation, and on predicting spectroscopic properties to compare with experimental results. This work illustrates how the synergy between periodic and molecular calculations can be exploited for the study of molecular crystals, and forms a basis for the investigation of more challenging phenomena, such as excited-state dynamics, and for further methodological developments
Design programmes to maximise participant engagement: a predictive study of programme and participant characteristics associated with engagement in paediatric weight management.
BACKGROUND: Approximately 50% of paediatric weight management (WM) programme attendees do not complete their respective programmes. High attrition rates compromise both programme effectiveness and cost-efficiency. Past research has examined pre-intervention participant characteristics associated with programme (non-)completion, however study samples are often small and not representative of multiple demographics. Moreover, the association between programme characteristics and participant engagement is not well known. This study examined participant and programme characteristics associated with engagement in a large, government funded, paediatric WM programme. Engagement was defined as the family's level of participation in the WM programme. METHODS: Secondary data analysis of 2948 participants (Age: 10.44â±â2.80 years, BMI: 25.99â±â5.79 kg/m(2), Standardised BMI [BMI SDS]: 2.48â±â0.87 units, White Ethnicity: 70.52%) was undertaken. Participants attended a MoreLife programme (nationwide WM provider) between 2009 and 2014. Participants were classified into one of five engagement groups: Initiators, Late Dropouts, Low- or High- Sporadic Attenders, or Completers. Five binary multivariable logistic regression models were performed to identify participant (nâ=â11) and programmatic (nâ=â6) characteristics associated with an engagement group. Programme completion was classified as â„70% attendance. RESULTS: Programme characteristics were stronger predictors of programme engagement than participant characteristics; particularly small group size, winter/autumn delivery periods and earlier programme years (proxy for scalability). Conversely, participant characteristics were weak predictors of programme engagement. Predictors varied between engagement groups (e.g. Completers, Initiators, Sporadic Attenders). 47.1% of participants completed the MoreLife programme (mean attendance: 59.4â±â26.7%, mean BMI SDS change: -0.15â±â0.22 units), and 21% of those who signed onto the programme did not attend a session. CONCLUSIONS: As WM services scale up, the efficacy and fidelity of programmes may be reduced due to increased demand and lower financial resource. Further, limiting WM programme groups to no more than 20 participants could result in greater engagement. Baseline participant characteristics are poor and inconsistent predictors of programme engagement. Thus, future research should evaluate participant motives, expectations, and barriers to attending a WM programme to enhance our understanding of participant WM engagement. Finally, we suggest that session-by-session attendance is recorded as a minimum requirement to improve reporting transparency and enhance external validity of study findings
Sedentary time in older men and women: an international consensus statement and research priorities
Sedentary time is a modifiable determinant of poor health, and in older adults, reducing sedentary time may be an important first step in adopting and maintaining a more active lifestyle. The primary purpose of this consensus statement is to provide an integrated perspective on current knowledge and expert opinion pertaining to sedentary behaviour in older adults on the topics of measurement, associations with health outcomes, and interventions. A secondary yet equally important purpose is to suggest priorities for future research and knowledge translation based on gaps identified. A five-step Delphi consensus process was used. Experts in the area of sedentary behaviour and older adults (n=15) participated in three surveys, an in-person consensus meeting, and a validation process. The surveys specifically probed measurement, health outcomes, interventions, and research priorities. The meeting was informed by a literature review and conference symposium, and it was used to create statements on each of the areas addressed in this document. Knowledge users (n=3) also participated in the consensus meeting. Statements were then sent to the experts for validation. It was agreed that self-report tools need to be developed for understanding the context in which sedentary time is accumulated. For health outcomes, it was agreed that the focus of sedentary time research in older adults needs to include geriatric-relevant health outcomes, that there is insufficient evidence to quantify the dose-response relationship, that there is a lack of evidence on sedentary time from older adults in assisted facilities, and that evidence on the association between sedentary time and sleep is lacking. For interventions, research is needed to assess the impact that reducing sedentary time, or breaking up prolonged bouts of sedentary time has on geriatric-relevant health outcomes. Research priorities listed for each of these areas should be considered by researchers and funding agencies
The impact of the alkyne substitution pattern and metalation on the photo-isomerization of azobenzene-based platinum(II) diynes and polyynes
Trimethylsilyl-protected
dialkynes incorporating azobenzene linker groups, Me<sub>3</sub>SiCîŒCRCîŒCSiMe<sub>3</sub> (R = azobenzene-3,3âČ-diyl, azobenzene-4,4âČ-diyl,
2,5-dioctylazobenzene-4,4âČ-diyl), and the corresponding terminal
dialkynes, HCîŒCRCîŒCH, have been synthesized and characterized.
The CuI-catalyzed dehydrohalogenation reaction between <i>trans</i>-[PhÂ(Et<sub>3</sub>P)<sub>2</sub>PtCl] and the deprotected dialkynes
in a 2:1 ratio in <sup>i</sup>Pr<sub>2</sub>NH/CH<sub>2</sub>Cl<sub>2</sub> gives the platinumÂ(II) diynes <i>trans</i>-[PhÂ(Et<sub>3</sub>P)<sub>2</sub>PtCîŒCRCîŒCPtÂ(PEt<sub>3</sub>)<sub>2</sub>Ph], while the dehydrohalogenation polycondensation reaction
between <i>trans</i>-[(<sup>n</sup>Bu<sub>3</sub>P)<sub>2</sub>PtCl<sub>2</sub>] and the dialkynes in a 1:1 molar ratio under
similar reaction conditions affords the platinumÂ(II) polyynes, [âPtÂ(P<sup>n</sup>Bu<sub>3</sub>)<sub>2</sub>âCîŒCRCîŒCâ]<sub><i>n</i></sub>. The materials have been characterized spectroscopically,
with the diynes also studied using single-crystal X-ray diffraction.
The platinumÂ(II) diynes and polyynes are all soluble in common organic
solvents. Optical-absorption measurements show that the compounds
incorporating the <i>para</i>-alkynylazobenzene spacers
have a higher degree of electronic delocalisation than their <i>meta</i>-alkynylazobenzene counterparts. Reversible photoisomerization
in solution was observed spectroscopically for the alkynyl-functionalized
azobenzene ligands and, to a lesser extent, for the platinumÂ(II) complexes.
Complementary quantum-chemical modeling was also used to analyze the
optical properties and isomerization energetics
Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory
Data from the Pierre Auger Observatory are analyzed to search for
anisotropies near the direction of the Galactic Centre at EeV energies. The
exposure of the surface array in this part of the sky is already significantly
larger than that of the fore-runner experiments. Our results do not support
previous findings of localized excesses in the AGASA and SUGAR data. We set an
upper bound on a point-like flux of cosmic rays arriving from the Galactic
Centre which excludes several scenarios predicting sources of EeV neutrons from
Sagittarius . Also the events detected simultaneously by the surface and
fluorescence detectors (the `hybrid' data set), which have better pointing
accuracy but are less numerous than those of the surface array alone, do not
show any significant localized excess from this direction.Comment: Matches published versio
1960: Abilene Christian College Lectures - Full Text
Table of Contents:
Theme Speeches: Christian Faith in the Modern World
Basis of Faith - Leonard Mullens - 9
Authority in Christianity - John T. Smithson, Jr. - 27
Origin and Preservation of the Bible - Neil R. Lightfoot - 44
Alleged Discrepancies of the Bible - David H. Bobo - 62
The Unity of the Bible - Jack Meyer - 91
Faith and Reason - Joe Sanders - 115
The Reasonableness of Supernaturalism - Virgil Trout - 126
The Present Statue of the Doctrine of Organic Evolution - J.D. Thomas - 146
The Nature of Man - Roy F. Osborne, Jr. - 181
Modern Challenges to Christian Morals - Carl Spain - 199
The Christ, Whose Son is He? - Gordon Teel - 232
Special Speeches
Teaching the Word of God in Korea - L. Haskell Chessfire - 255
The Influence of Christian Education - Judge Jack Pope - 276
Mission Opportunities in the Far East - Harry Robert Fox - 288
Mission Work in Austria - Robert Skelton - 303
Report from Switzerland - Heinrich Blum - 313
The Work in Nigeria - Rees Byrant - 320
The Training of Evangelists in Foreign Fields - Reiner Kallus - 331
Christian Scholarships - Everett Ferguson - 340
Evangelizing the World - A.R. Holton - 349
Panel Discussions
The Significance of the Dead Sea Scrolls
The Scrolls and the Text of the Bible - Paul Rotenberry - 357
The Relation between the Religion of the Essenes and that of Early Christians - Jay Smith - 366
Biblical Interpretation
Expediency and Pattern Authority - J.W. Roberts - 381
Examples in Pattern Authority - Thomas B. Warren - 392
Mental Health and Sin
The Present State of Mental Health Knowledge - Donald R. Sime - 409
The Relationship of Mental Health Problems to Sin - Paul Easley - 421
The Teenager
The Problems of Youth - Mack Wayne Craig - 432
Influences for Good - Wyatt Sawyer - 443
The Benefits of Abilene Christian College
To the Church - Hulen Jackson - 451
To The Home - Robert S. Bell - 459
\u27To the Community - Louie Welch - 465
Expenses At Abilene Christian College - James C. Kerr - 469
The Graduate School at Abilene Christian College
What I Am Getting Now in the ACC Graduate Program - Harold Vanderpool - 475
How the ACC Graduate Program Has Stood Up - Everett Ferguson - 481
What the ACC Graduate Program Ought To Be - Frank Pack - 486
The Importance to the Church of the ACC Graduate Program A.R. Holton - 490
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Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
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