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Langner MC, Roy S, Huang SW, Koralek JD, Chuang YD, Dakovski GL, Turner JJ, Robinson JS, Coffee RN, Minitti MP, Seki S, Tokura Y, Schoenlein RW. Nonlinear Ultrafast Spin Scattering in the Skyrmion Phase of Cu_{2}OSeO_{3}. PHYSICAL REVIEW LETTERS 2017; 119:107204. [PMID: 28949160 DOI: 10.1103/physrevlett.119.107204] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Indexed: 05/26/2023]
Abstract
Ultrafast x-ray scattering studies of the topological Skyrmion phase in Cu_{2}OSeO_{3} show the dynamics to be strongly dependent on the excitation energy and fluence. At high photon energies, where the electron-spin scattering cross section is relatively high, the excitation of the topological Skyrmion phase shows a nonlinear dependence on the excitation fluence, in contrast to the excitation of the conical phase which is linearly dependent on the excitation fluence. The excitation of the Skyrmion order parameter is nonlinear in the magnetic excitation resulting from scattering during electron-hole recombination, indicating different dominant scattering processes in the conical and Skyrmion phases.
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Adam A, Robison J, Lu J, Jose R, Badran N, Vivas-Buitrago T, Rigamonti D, Sattar A, Omoush O, Hammad M, Dawood M, Maghaslah M, Belcher T, Carson K, Hoffberger J, Jusué Torres I, Foley S, Yasar S, Thai QA, Wemmer J, Klinge P, Al-Mutawa L, Al-Ghamdi H, Carson KA, Asgari M, de Zélicourt D, Kurtcuoglu V, Garnotel S, Salmon S, Balédent O, Lokossou A, Page G, Balardy L, Czosnyka Z, Payoux P, Schmidt EA, Zitoun M, Sevestre MA, Alperin N, Baudracco I, Craven C, Matloob S, Thompson S, Haylock Vize P, Thorne L, Watkins LD, Toma AK, Bechter K, Pong AC, Jugé L, Bilston LE, Cheng S, Bradley W, Hakim F, Ramón JF, Cárdenas MF, Davidson JS, García C, González D, Bermúdez S, Useche N, Mejía JA, Mayorga P, Cruz F, Martinez C, Matiz MC, Vallejo M, Ghotme K, Soto HA, Riveros D, Buitrago A, Mora M, Murcia L, Bermudez S, Cohen D, Dasgupta D, Curtis C, Domínguez L, Remolina AJ, Grijalba MA, Whitehouse KJ, Edwards RJ, Eleftheriou A, Lundin F, Fountas KN, Kapsalaki EZ, Smisson HF, Robinson JS, Fritsch MJ, Arouk W, Garzon M, Kang M, Sandhu K, Baghawatti D, Aquilina K, James G, Thompson D, Gehlen M, Schmid Daners M, Eklund A, Malm J, Gomez D, Guerra M, Jara M, Flores M, Vío K, Moreno I, Rodríguez S, Ortega E, Rodríguez EM, McAllister JP, Guerra MM, Morales DM, Sival D, Jimenez A, Limbrick DD, Ishikawa M, Yamada S, Yamamoto K, Junkkari A, Häyrinen A, Rauramaa T, Sintonen H, Nerg O, Koivisto AM, Roine RP, Viinamäki H, Soininen H, Luikku A, Jääskeläinen JE, Leinonen V, Kehler U, Lilja-Lund O, Kockum K, Larsson EM, Riklund K, Söderström L, Hellström P, Laurell K, Kojoukhova M, Sutela A, Vanninen R, Vanha KI, Timonen M, Rummukainen J, Korhonen V, Helisalmi S, Solje E, Remes AM, Huovinen J, Paananen J, Hiltunen M, Kurki M, Martin B, Loth F, Luciano M, Luikku AJ, Hall A, Herukka SK, Mattila J, Lötjönen J, Alafuzoff I, Jurjević I, Miyajima M, Nakajima M, Murai H, Shin T, Kawaguchi D, Akiba C, Ogino I, Karagiozov K, Arai H, Reis RC, Teixeira MJ, Valêncio CG, da Vigua D, Almeida-Lopes L, Mancini MW, Pinto FCG, Maykot RH, Calia G, Tornai J, Silvestre SSS, Mendes G, Sousa V, Bezerra B, Dutra P, Modesto P, Oliveira MF, Petitto CE, Pulhorn H, Chandran A, McMahon C, Rao AS, Jumaly M, Solomon D, Moghekar A, Relkin N, Hamilton M, Katzen H, Williams M, Bach T, Zuspan S, Holubkov R, Rigamonti A, Clemens G, Sharkey P, Sanyal A, Sankey E, Rigamonti K, Naqvi S, Hung A, Schmidt E, Ory-Magne F, Gantet P, Guenego A, Januel AC, Tall P, Fabre N, Mahieu L, Cognard C, Gray L, Buttner-Ennever JA, Takagi K, Onouchi K, Thompson SD, Thorne LD, Tully HM, Wenger TL, Kukull WA, Doherty D, Dobyns WB, Moran D, Vakili S, Patel MA, Elder B, Goodwin CR, Crawford JA, Pletnikov MV, Xu J, Blitz A, Herzka DA, Guerrero-Cazares H, Quiñones-Hinojosa A, Mori S, Saavedra P, Treviño H, Maitani K, Ziai WC, Eslami V, Nekoovaght-Tak S, Dlugash R, Yenokyan G, McBee N, Hanley DF. Abstracts from Hydrocephalus 2016. Fluids Barriers CNS 2017; 14:15. [PMID: 28929972 PMCID: PMC5471936 DOI: 10.1186/s12987-017-0054-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Dodd JM, Deussen AR, Mohamad I, Rifas-Shiman SL, Yelland LN, Louise J, McPhee AJ, Grivell RM, Owens JA, Gillman MW, Robinson JS. The effect of antenatal lifestyle advice for women who are overweight or obese on secondary measures of neonatal body composition: the LIMIT randomised trial. BJOG 2016; 123:244-53. [PMID: 26841217 DOI: 10.1111/1471-0528.13796] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2015] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To evaluate the effect of providing antenatal dietary and lifestyle advice on neonatal anthropometry, and to determine the inter-observer variability in obtaining anthropometric measurements. DESIGN Randomised controlled trial. SETTING Public maternity hospitals across metropolitan Adelaide, South Australia. POPULATION Pregnant women with a singleton gestation between 10(+0) and 20(+0) weeks, and body mass index (BMI) ≥25 kg/m(2). METHODS Women were randomised to either Lifestyle Advice (comprehensive dietary and lifestyle intervention over the course of pregnancy including dietary, exercise and behavioural strategies, delivered by a research dietician and research assistants) or continued Standard Care. Analyses were conducted using intention-to-treat principles. MAIN OUTCOME MEASURES Secondary outcome measures for the trial included assessment of infant body composition using body circumference and skinfold thickness measurements (SFTM), percentage body fat, and bio-impedance analysis of fat-free mass. RESULTS Anthropometric measurements were obtained from 970 neonates (488 Lifestyle Advice Group, and 482 Standard Care Group). In 394 of these neonates (215 Lifestyle Advice Group, and 179 Standard Care Group) bio-impedance analysis was also obtained. There were no statistically significant differences identified between those neonates born to women receiving Lifestyle Advice and those receiving Standard Care, in terms of body circumference measures, SFTM, percentage body fat, fat mass, or fat-free mass. The intra-class correlation coefficient for SFTM was moderate to excellent (0.55-0.88). CONCLUSIONS Among neonates born to women who are overweight or obese, anthropometric measures of body composition were not modified by an antenatal dietary and lifestyle intervention.
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Sanoufa M, Smisson W, Floyd H, Robinson JS. The effect of anaemia on hospital length of stay in lumbar decompression and fusion procedures. J Perioper Pract 2016; 25:267-71. [PMID: 26845789 DOI: 10.1177/175045891502501204] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Ways of reducing the length of hospital stay have received increased attention in recent years. Both preoperative and postoperative anaemia have been implicated as causative agents in increasing postoperative length of stay (LOS). In a retrospective study, 317 patients that underwent lumbar decompression and fusion surgery were assessed. Two separate block multivariate linear regression analyses were performed to evaluate the impact of preoperative anaemia, postoperative anaemia, and the degree of perioperative haemoglobin drop on LOS. Other anaemia related factors were also assessed. Preoperative anaemia, postoperative anaemia, and the amount of perioperative haemoglobin drop were all shown to prolong the length of hospitalisation and therefore to increase overall healthcare costs. Following strict anaemia corrective maneuvers could reasonably be expected to reduce expenditure.
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Minitti MP, Budarz JM, Kirrander A, Robinson JS, Ratner D, Lane TJ, Zhu D, Glownia JM, Kozina M, Lemke HT, Sikorski M, Feng Y, Nelson S, Saita K, Stankus B, Northey T, Hastings JB, Weber PM. Imaging Molecular Motion: Femtosecond X-Ray Scattering of an Electrocyclic Chemical Reaction. PHYSICAL REVIEW LETTERS 2015. [PMID: 26197134 DOI: 10.1103/physrevlett.114.255501] [Citation(s) in RCA: 181] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Structural rearrangements within single molecules occur on ultrafast time scales. Many aspects of molecular dynamics, such as the energy flow through excited states, have been studied using spectroscopic techniques, yet the goal to watch molecules evolve their geometrical structure in real time remains challenging. By mapping nuclear motions using femtosecond x-ray pulses, we have created real-space representations of the evolving dynamics during a well-known chemical reaction and show a series of time-sorted structural snapshots produced by ultrafast time-resolved hard x-ray scattering. A computational analysis optimally matches the series of scattering patterns produced by the x rays to a multitude of potential reaction paths. In so doing, we have made a critical step toward the goal of viewing chemical reactions on femtosecond time scales, opening a new direction in studies of ultrafast chemical reactions in the gas phase.
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Mankowsky R, Subedi A, Först M, Mariager SO, Chollet M, Lemke HT, Robinson JS, Glownia JM, Minitti MP, Frano A, Fechner M, Spaldin NA, Loew T, Keimer B, Georges A, Cavalleri A. Nonlinear lattice dynamics as a basis for enhanced superconductivity in YBa2Cu3O6.5. Nature 2015; 516:71-3. [PMID: 25471882 DOI: 10.1038/nature13875] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 09/19/2014] [Indexed: 11/09/2022]
Abstract
Terahertz-frequency optical pulses can resonantly drive selected vibrational modes in solids and deform their crystal structures. In complex oxides, this method has been used to melt electronic order, drive insulator-to-metal transitions and induce superconductivity. Strikingly, coherent interlayer transport strongly reminiscent of superconductivity can be transiently induced up to room temperature (300 kelvin) in YBa2Cu3O6+x (refs 9, 10). Here we report the crystal structure of this exotic non-equilibrium state, determined by femtosecond X-ray diffraction and ab initio density functional theory calculations. We find that nonlinear lattice excitation in normal-state YBa2Cu3O6+x at above the transition temperature of 52 kelvin causes a simultaneous increase and decrease in the Cu-O2 intra-bilayer and, respectively, inter-bilayer distances, accompanied by anisotropic changes in the in-plane O-Cu-O bond buckling. Density functional theory calculations indicate that these motions cause drastic changes in the electronic structure. Among these, the enhancement in the character of the in-plane electronic structure is likely to favour superconductivity.
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Cyna AM, Crowther CA, Robinson JS, Andrew MI, Antoniou G, Baghurst P. Hypnosis antenatal training for childbirth: a randomised controlled trial. BJOG 2013; 120:1248-59; discussion 1256-7. [PMID: 23834406 DOI: 10.1111/1471-0528.12320] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/19/2013] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine the use of pharmacologic analgesia during childbirth when antenatal hypnosis is added to standard care. DESIGN Randomised controlled clinical trial, conducted from December 2005 to December 2010. SETTING The largest tertiary referral centre for maternity care in South Australia. POPULATION A cohort of 448 women at >34 weeks of gestation, with a singleton pregnancy and cephalic presentation, planning a vaginal birth. Exclusions were: the need for an interpreter; pre-existing pain; psychiatric illness; younger than 18 years; and previous experience of hypnosis for childbirth. METHODS All participants received usual care. The group of women termed Hypnosis + CD (hypnotherapist guided) were offered three antenatal live hypnosis sessions plus each session's corresponding audio CD for further practise, as well as a final fourth CD to listen to during labour. The group of women termed CD only (nurse administered) were played the same antenatal hypnosis CDs as group 1, but did not receive live hypnosis training. The control group participants were given no additional intervention or CDs. MAIN OUTCOME MEASURE Use of pharmacological analgesia during labour and childbirth. RESULTS No difference in the use of pharmacological analgesia during labour and childbirth was found comparing hypnosis + CD with control (81.2 versus 76.2%; relative risk, RR 1.07; 95% confidence interval, 95% CI 0.95-1.20), or comparing CD only with control (76.9 versus 76.2%, RR 1.01, 95% CI 0.89-1.15). CONCLUSIONS Antenatal group hypnosis using the Hypnosis Antenatal Training for Childbirth (HATCh) intervention in late pregnancy does not reduce the use of pharmacological analgesia during labour and childbirth.
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Chuang YD, Lee WS, Kung YF, Sorini AP, Moritz B, Moore RG, Patthey L, Trigo M, Lu DH, Kirchmann PS, Yi M, Krupin O, Langner M, Zhu Y, Zhou SY, Reis DA, Huse N, Robinson JS, Kaindl RA, Schoenlein RW, Johnson SL, Först M, Doering D, Denes P, Schlotter WF, Turner JJ, Sasagawa T, Hussain Z, Shen ZX, Devereaux TP. Real-time manifestation of strongly coupled spin and charge order parameters in stripe-ordered La(1.75)Sr(0.25)NiO(4) nickelate crystals using time-resolved resonant x-ray diffraction. PHYSICAL REVIEW LETTERS 2013; 110:127404. [PMID: 25166848 DOI: 10.1103/physrevlett.110.127404] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Indexed: 05/19/2023]
Abstract
We investigate the order parameter dynamics of the stripe-ordered nickelate, La(1.75)Sr(0.25)NiO(4), using time-resolved resonant x-ray diffraction. In spite of distinct spin and charge energy scales, the two order parameters' amplitude dynamics are found to be linked together due to strong coupling. Additionally, the vector nature of the spin sector introduces a longer reorientation time scale which is absent in the charge sector. These findings demonstrate that the correlation linking the symmetry-broken states does not unbind during the nonequilibrium process, and the time scales are not necessarily associated with the characteristic energy scales of individual degrees of freedom.
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Hill CR, Robinson JS. Phosphorus flux from wetland ditch sediments. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 437:315-322. [PMID: 22954652 DOI: 10.1016/j.scitotenv.2012.06.109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/29/2012] [Accepted: 06/29/2012] [Indexed: 06/01/2023]
Abstract
The accumulation of phosphorus (P) in the bottom sediment of field drainage ditches poses a threat to the ecology both of the ditch water and downstream water courses. We investigated the amounts, forms and internal loading of sediment-bound P along two drainage ditches that regulate water levels in a basin fen (~200 ha) supporting a mixture of restored wetland and drained agricultural fields. Water levels in the Lady's Drove Rhyne are currently managed to enhance the biodiversity of the wetland (Catcott Lows Reserve - an area formerly cultivated for arable crop production); whereas, the East Ditch is managed to drain adjoining land that remains under arable and livestock production. Laboratory-based chemical fractionation schemes were used to characterise the forms and potential mobility of the sediment-bound P, whilst pore-water equilibrators were employed in situ to evaluate the diffusive flux of P through the sediment-water column, and to characterise the corresponding redox conditions. Along both ditches, sediment pore-water profiles indicated conditions ranging from weakly to very reducing conditions with increasing depth, and net fluxes of P from the sediment to overlying water. P flux values ranged from 0.33 to 1.30 mg m(-2) day(-1). Both the degree of P saturation (DPS) of the sediment and NaOH extractable (Fe/Al-bound) P correlated significantly (P<0.05) with P flux. Both in the wetland and agricultural ditches, by far the highest values for P flux were recorded at sites closest to points of drainage water entry from the corresponding, adjoining land. Although the P flux data were obtained from only a single sampling event, this study highlights the contribution of historical as well as ongoing agricultural land use on the sustained elevated P status of ditch sediments in lowland catchments.
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Frank F, Arrell C, Witting T, Okell WA, McKenna J, Robinson JS, Haworth CA, Austin D, Teng H, Walmsley IA, Marangos JP, Tisch JWG. Invited review article: technology for attosecond science. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:071101. [PMID: 22852664 DOI: 10.1063/1.4731658] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We describe a complete technological system at Imperial College London for Attosecond Science studies. The system comprises a few-cycle, carrier envelope phase stabilized laser source which delivers sub 4 fs pulses to a vibration-isolated attosecond vacuum beamline. The beamline is used for the generation of isolated attosecond pulses in the extreme ultraviolet (XUV) at kilohertz repetition rates through laser-driven high harmonic generation in gas targets. The beamline incorporates: interferometers for producing pulse sequences for pump-probe studies; the facility to spectrally and spatially filter the harmonic radiation; an in-line spatially resolving XUV spectrometer; and a photoelectron spectroscopy chamber in which attosecond streaking is used to characterize the attosecond pulses. We discuss the technology and techniques behind the development of our complete system and summarize its performance. This versatile apparatus has enabled a number of new experimental investigations which we briefly describe.
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Dodd JM, Crowther CA, Haslam RR, Robinson JS. Elective birth at 37 weeks of gestation versus standard care for women with an uncomplicated twin pregnancy at term: the Twins Timing of Birth Randomised Trial. BJOG 2012; 119:964-73. [PMID: 22691051 DOI: 10.1111/j.1471-0528.2012.03356.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
OBJECTIVE To evaluate whether for women with an uncomplicated twin pregnancy, elective birth at 37 weeks of gestation was associated with reduced risk of death or serious outcomes for babies, without increasing harm. DESIGN Randomised controlled trial. SETTING Maternity hospitals across Australia, New Zealand and Italy. POPULATION A total of 235 women with an uncomplicated twin pregnancy at 36(+6) weeks of gestation, with no contraindication to continuing their pregnancy. METHODS Using a computer-generated, central telephone randomisation service, 235 women were randomised to Elective Birth (birth at 37 weeks; n=116) or Standard Care (continued expectant management, with birth planned from 38 weeks; n=119). Outcome assessors were masked to treatment allocation. MAIN OUTCOME MEASURE A composite of serious adverse outcome for the infant. RESULTS For women with an uncomplicated twin pregnancy, elective birth at 37 weeks of gestation was associated with a significant reduction in risk of serious adverse outcome for the infant (Elective Birth 11/232 [4.7%] versus Standard Care 29/238 [12.2%]; risk ratio [RR] 0.39; 95% CI 0.20-0.75; P=0.005), reflecting a reduction in birthweight less than the third centile using singleton gestational age-specific charts (Elective Birth 7/232 [3.0%] versus Standard Care 24/238 [10.1%]; RR 0.30; 95% CI 0.13-0.67; P=0.004). In a post hoc analysis using twin gestational age-specific charts, there was evidence of a trend towards a reduction in the primary composite of serious adverse infant outcome (Elective Birth Group 4/232 [1.7%] versus Standard Care Group 12/238 [5.0%]; RR 0.34; 95% CI 0.11 to 1.05; P=0.06). CONCLUSION The findings of our study support recommendations for women with an uncomplicated twin pregnancy to birth at 37 weeks of gestation.
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Heidolph BB, Robinson JS. AACC International Food Safety Systems Task Force: Consumer Confidence Built with Collaboration, Not Competition. CEREAL FOOD WORLD 2012. [DOI: 10.1094/cfw-57-3-0125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Dodd JM, Robinson JS. Gestational weight loss in overweight and obese women is associated with an increased risk of small for gestational age infants. ACTA ACUST UNITED AC 2011; 16:125-6. [DOI: 10.1136/ebm1300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Dodd JM, Grivell RM, Crowther CA, Robinson JS. Antenatal interventions for overweight or obese pregnant women: a systematic review of randomised trials. BJOG 2010; 117:1316-26. [DOI: 10.1111/j.1471-0528.2010.02540.x] [Citation(s) in RCA: 207] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Gatford KL, Simmons RA, De Blasio MJ, Robinson JS, Owens JA. Review: Placental programming of postnatal diabetes and impaired insulin action after IUGR. Placenta 2010; 31 Suppl:S60-5. [PMID: 20096455 DOI: 10.1016/j.placenta.2009.12.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 12/12/2009] [Accepted: 12/14/2009] [Indexed: 01/23/2023]
Abstract
Being born small due to poor growth before birth increases the risk of developing metabolic disease, including type 2 diabetes, in later life. Inadequate insulin secretion and decreasing insulin sensitivity contribute to this increased diabetes risk. Impaired placental growth, development and function are major causes of impaired fetal growth and development and therefore of IUGR. Restricted placental growth (PR) and function in non-human animals induces similar changes in insulin secretion and sensitivity as in human IUGR, making these valuable tools to investigate the underlying mechanisms and to test interventions to prevent or ameliorate the risk of disease after IUGR. Epigenetic changes induced by an adverse fetal environment are strongly implicated as causes of later impaired insulin action. These have been well-characterised in the PR rat, where impaired insulin secretion is linked to epigenetic changes at the Pdx-1 promotor and reduced expression of this transcription factor. Present research is particularly focussed on developing intervention strategies to prevent or reverse epigenetic changes, and normalise gene expression and insulin action after PR, in order to translate this to treatments to improve outcomes in human IUGR.
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Walid MS, Osborne TJ, Robinson JS. Primary brain sarcoma or metastatic carcinoma? Indian J Cancer 2009; 46:174-5. [PMID: 19346656 DOI: 10.4103/0019-509x.49160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Chipperfield LE, Robinson JS, Tisch JWG, Marangos JP. Ideal waveform to generate the maximum possible electron recollision energy for any given oscillation period. PHYSICAL REVIEW LETTERS 2009; 102:063003. [PMID: 19257585 DOI: 10.1103/physrevlett.102.063003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Indexed: 05/27/2023]
Abstract
We present the perfect waveform which, during a strong field interaction, generates the maximum possible electron recollision energy for any given oscillation period, over 3 times as high as that for a pure sinusoidal wave. This ideal waveform has the form of a linear ramp with a dc offset. A genetic algorithm was employed to find an optimized practically achievable waveform composed of a longer wavelength field, to provide the offset, in addition to higher frequency components. This second waveform is found to be capable of generating electron recollision energies as high as those for the perfect waveform while retaining the high recollision amplitudes of a pure sinusoidal wave. Calculations of high harmonic generation demonstrate this enhancement, by increasing the cutoff energy by a factor of 2.5 while maintaining the harmonic yield, providing an enhanced tool for attosecond science.
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Chu WH, Harland L, Grant P, De Blasio M, Kong W, Moretta S, Robinson JS, Dziadek ME, Owens JA. 163. MATERNAL FOLIC ACID SUPPLEMENTATION INDUCED ALTERATIONS IN METABOLIC HEALTH OF PROGENY: ROLE OF microRNA REGULATORY NETWORKS. Reprod Fertil Dev 2009. [DOI: 10.1071/srb09abs163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background: Nutrition in early life can influence metabolic functionality in later life, in part via heritable epigenetic changes, which modify gene expression without altering DNA sequence. Folate supplies methyl groups for the methylation of DNA and histones, both major epigenetic marks that change dynamically in utero. We have recently shown that maternal folic acid supplementation (MFAS) in the pregnant rat increases insulin sensitivity in adult male progeny, while decreasing that of females. The molecular basis of this is unknown but microRNAs may play a role. MicroRNAs are epigenetically regulated non-coding RNAs that downregulate post-transcriptional expression of their targets. MFAS may modulate epigenetics and expression of microRNAs and their targets in adult progeny to alter insulin sensitivity. Aims/Hypotheses: The effect of MFAS before and throughout pregnancy on microRNA expression in liver and skeletal muscle of adult progeny was determined. Methods: Female Wistar rats were fed Control (n=11) or Folic Acid Supplemented (n=9) diets containing either 2 or 6 mg folic acid/kg respectively, from two weeks before mating and throughout pregnancy. One male and female progeny per litter were sacrificed on postnatal day 90 and microRNA expression was determined by Exiqon microRNA microarray v.8.1. Results: MFAS altered hepatic microRNA expression in adult male progeny, but did not alter that in females. Sixteen hepatic microRNAs were differentially expressed, with five predicted in silico (rno-miR: 23a, 23b, 212, 298 and 325-5p) to target several key insulin signalling molecules (p85α, p110β, Akt2, and Prkcz). miR-122a, which promotes cholesterol and lipid synthesis in vivo, was also downregulated. MFAS did not alter microRNA expression in skeletal muscle of adult male or female progeny. Conclusions: MFAS alters hepatic microRNA expression in adult male progeny. Changes in their expression together with their targets in insulin signalling pathway may initiate increased insulin sensitivity in adult male progeny.
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Pearce BL, Owens JA, Dziadek M, Grant PA, Wlodek M, Robinson JS, Pitcher JB. 162. THE EFFECT OF MATERNAL FOLIC ACID SUPPLEMENTATION THROUGHOUT PREGNANCY ON NEURODEVELOPMENT, MOTOR FUNCTION AND BEHAVIOUR OF PROGENY IN THE RAT. Reprod Fertil Dev 2009. [DOI: 10.1071/srb09abs162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background: Maternal folic acid supplementation (mFAS) during early pregnancy is recommended to reduce the incidence of neural tube defects and has recently been associated with improved neurodevelopment in children. However, the effect on neurodevelopment of mFAS from before conception and throughout pregnancy is unknown. We examined the effect of mFAS throughout the gestational period on postnatal growth, neurodevelopment and early adult motor function and behaviour in rat offspring. Methods: Female Wistar Rats were fed either a control (folic acid 2mg/kg, n=6) or moderate mFAS diet (folic acid 6mg/kg, n=6) from two weeks before mating with Lewis males, until birth of progeny. Male and female progeny (Control=36, mFAS=36) were weighed on postnatal day (PD) 3, 7, 14, 21, 40 and 90, and underwent various tests between PD4 and 14: righting reflex, palm-grasp reflex, negative geotaxis, forelimb hanging, ascent test and eye opening. Locomotor/ exploratory behaviour, motor coordination and anxiety were assessed using an open field test (PD52), rotarod (PD55) and elevated plus maze (PD58) (Control=24, mFAS=24). Results: mFAS did not alter maternal weight gain, litter-size at birth or progeny growth between PD3-90. mFAS tended to increase righting reflex time (p=0.057) and impair ascent ability (p=0.085). Negative geotaxis time was reduced at PD7 but not later (Diet x Age p=0.051). mFAS increased the proportion of progeny with eyes open at PD14 (p=0.008) and tended to increase forelimb hanging time(p=0.097). mFAS did not alter motor learning/function (rotarod), but increased ambulatory and exploratory behaviour (open field test; p=0.027). Conclusions: mFAS delays some early aspects of neurodevelopment including neonatal postural reflex maturation and proprioceptive/vestibular function, but accelerates others such as eye opening. However, the open field test indicated that mFAS improved the offspring's locomotion and exploratory behaviours in adulthood. Further studies will differentiate the neurodevelopmental effects of mFAS around conception from gestation-long mFAS.
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Baker S, Robinson JS, Lein M, Chirilă CC, Torres R, Bandulet HC, Comtois D, Kieffer JC, Villeneuve DM, Tisch JWG, Marangos JP. Dynamic two-center interference in high-order harmonic generation from molecules with attosecond nuclear motion. PHYSICAL REVIEW LETTERS 2008; 101:053901. [PMID: 18764392 DOI: 10.1103/physrevlett.101.053901] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2007] [Revised: 11/22/2007] [Indexed: 05/26/2023]
Abstract
We report a new dynamic two-center interference effect in high-harmonic generation from H2, in which the attosecond nuclear motion of H2+ initiated at ionization causes interference to be observed at lower harmonic orders than would be the case for static nuclei. To enable this measurement we utilize a recently developed technique for probing the attosecond nuclear dynamics of small molecules. The experimental results are reproduced by a theoretical analysis based upon the strong-field approximation which incorporates the temporally dependent two-center interference term.
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Silman RE, Street C, Holland D, Chard T, Falconer J, Robinson JS. The pars intermedia and the fetal pituitary-adrenal axis. CIBA FOUNDATION SYMPOSIUM 2008; 81:180-95. [PMID: 6268377 DOI: 10.1002/9780470720646.ch11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The increased production of cortisol by the fetal adrenal gland at term acts as the trigger for parturition in some species. The fetal pituitary controls fetal adrenal function. However, ACTH is only one of a family of closely related peptides which derive from a common precursor and we have shown that although ACTH is the dominant form in the adult pituitary, the expression of the "family trees' is altered in the fetus. In the sheep, it is large-molecular-weight precursors and, in the primate, the smaller peptides such as alpha-MSH, CLIP, beta-MSH and beta-endorphin that predominate in fetal life and which may be responsible for fetal adrenal function. It is still unclear what causes the developmental change in the ACTH "family tree'. Since it may result from a change in pituitary function - from the peptides of the pars intermedia, in the fetus, to those of pars anterior, in the adult - we have studied these two lobes separately in pituitaries taken from adult and fetal sheep and monkeys. Our preliminary results suggest that the change may occur in the neurointermediate lobe in the primate, but that in the sheep the developmental changes occur in the anterior lobe.
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Antoniadis V, Robinson JS, Alloway BJ. Effects of short-term pH fluctuations on cadmium, nickel, lead, and zinc availability to ryegrass in a sewage sludge-amended field. CHEMOSPHERE 2008; 71:759-764. [PMID: 18031788 DOI: 10.1016/j.chemosphere.2007.10.015] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Revised: 10/01/2007] [Accepted: 10/08/2007] [Indexed: 05/25/2023]
Abstract
In this field experiment, sewage sludge was applied at 0, 5, 10, and 50tha(-1), and the availability of Cd, Ni, Pb, and Zn was assessed both by ryegrass uptake and by DTPA extractions. The aim was to investigate the role of important soil parameters, particularly pH, on heavy metal availability. It was found that metal uptake and extractability increased significantly in the 50tha(-1) treatment. In the 16th week of the experiment there was a significant, although temporary, increase in DTPA-extractable Cd, Ni, and Zn concentrations. Metal concentrations in ryegrass were also significantly elevated in week 20 compared to the subsequent cuttings. These fluctuations in both DTPA and ryegrass uptake occurred only at 50tha(-1) and were probably induced by a sudden pH decrease measured in the same treatment in week 16. This suggests that soils which have received high applications of sewage sludge may be prone to fluctuations in metal availability.
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Moore AS, Gumbrell ET, Lazarus J, Hohenberger M, Robinson JS, Smith RA, Plant TJA, Symes DR, Dunne M. Full-trajectory diagnosis of laser-driven radiative blast waves in search of thermal plasma instabilities. PHYSICAL REVIEW LETTERS 2008; 100:055001. [PMID: 18352379 DOI: 10.1103/physrevlett.100.055001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Indexed: 05/26/2023]
Abstract
Experimental investigations into the dynamics of cylindrical, laser-driven, high-Mach-number shocks are used to study the thermal cooling instability predicted to occur in astrophysical radiative blast waves. A streaked Schlieren technique measures the full blast-wave trajectory on a single-shot basis, which is key for observing shock velocity oscillations. Electron density profiles and deceleration parameters associated with radiative blast waves were recorded, enabling the calculation of important blast-wave parameters including the fraction of radiated energy, epsilon, as a function of time for comparison with radiation-hydrodynamics simulations.
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Kapsalaki EZ, Lee GP, Robinson JS, Grigorian AA, Fountas KN. The role of intraoperative micro-Doppler ultrasound in verifying proper clip placement in intracranial aneurysm surgery. J Clin Neurosci 2007; 15:153-7. [PMID: 17981038 DOI: 10.1016/j.jocn.2006.11.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2006] [Revised: 11/06/2006] [Accepted: 11/08/2006] [Indexed: 11/29/2022]
Abstract
We present the results of a retrospective study employing intraoperative micro-Doppler ultrasonography (MDU) in verifying proper clip placement during cerebral aneurysmal surgery. One hundred and thirty-four patients surgically treated for 147 intracranial aneurysms were studied. Thirteen patients harboring 17 aneurysms were surgically treated on an elective basis, while 121 patients with 130 aneurysms, presented with subarachnoid hemorrhage (SAH). Blood flow velocities of the parent and adjacent vessels as well as the aneurysmal sac were measured using a Conforma Micro-Doppler (Cook Vascular Inc., Leechburg, PA, USA). Pre- and post-operative cerebral angiography was obtained in all our patients. In 23 aneurysms (15.6%) there was decreased or absent flow in the parent vessel or in one of the adjacent vessels after clipping. In another 19 aneurysms (12.9%), MDU demonstrated flow through the aneurysmal dome even though the aneurysmal neck appeared to be totally obliterated. Presence of SAH, anatomic location and size of the aneurysm were associated with improper clip placement in a statistically significant fashion. The false positive rate for MDU was 2% while there were no false negative findings in our study. MDU appears to be a non-invasive, reliable alternative methodology to intra-operative angiography. This inexpensive method may lend itself to routine usage in aneurysm surgery.
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Owens JA, Thavaneswaran P, De Blasio MJ, McMillen IC, Robinson JS, Gatford KL. Sex-specific effects of placental restriction on components of the metabolic syndrome in young adult sheep. Am J Physiol Endocrinol Metab 2007; 292:E1879-89. [PMID: 17327366 DOI: 10.1152/ajpendo.00706.2006] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Prenatal and early postnatal life experiences, reflected by size at birth and postnatal catch-up growth, contribute to the risk of developing the metabolic syndrome in adulthood, but their relative importance is unclear. Therefore, we determined the effects of restricted placental and fetal growth on components of the metabolic syndrome in young adult sheep and the relationships of the latter to size at birth and early postnatal growth. Fasting plasma metabolites, glucose tolerance (by intravenous glucose tolerance test, IVGTT), insulin secretion and sensitivity, and resting blood pressure were measured in 22 control and 20 placentally restricted (PR) 1-yr-old sheep. In male sheep, PR increased the initial rise in glucose during an IVGTT and reduced diastolic blood pressure, and small size at birth independently predicted reduced adult size, glucose tolerance, and fasting plasma insulin and insulin disposition of glucose metabolism but increased insulin disposition of circulating FFAs. Also in males, high fractional growth rates in early postnatal life independently predicted impaired early glucose clearance during an IVGTT. In female animals, PR increased insulin sensitivity of glucose metabolism and reduced fasting plasma FFAs, and thinness at birth predicted increased adult size, fasting blood glucose, and pulse pressure. In conclusion, PR and small size at birth are associated with more components of the metabolic syndrome in adult male than in adult female sheep, with few independent effects of early postnatal growth. These sex differences in the onset and extent of adverse metabolic consequences after prenatal restraint in the sheep are consistent with observations in humans.
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