ORCID Profile
0000-0002-2255-4296
Current Organisation
University of Sydney
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Publisher: Springer Science and Business Media LLC
Date: 12-2020
DOI: 10.1140/EPJC/S10052-020-08477-8
Abstract: The jet energy scale, jet energy resolution, and their systematic uncertainties are measured for jets reconstructed with the ATLAS detector in 2012 using proton–proton data produced at a centre-of-mass energy of 8 TeV with an integrated luminosity of $$20 \\, \\hbox {fb}^{-1}$$ 20 fb - 1 . Jets are reconstructed from clusters of energy depositions in the ATLAS calorimeters using the anti- $$k_t$$ k t algorithm. A jet calibration scheme is applied in multiple steps, each addressing specific effects including mitigation of contributions from additional proton–proton collisions, loss of energy in dead material, calorimeter non-compensation, angular biases and other global jet effects. The final calibration step uses several in situ techniques and corrects for residual effects not captured by the initial calibration. These analyses measure both the jet energy scale and resolution by exploiting the transverse momentum balance in $$\\gamma $$ γ + jet, Z + jet, dijet, and multijet events. A statistical combination of these measurements is performed. In the central detector region, the derived calibration has a precision better than 1% for jets with transverse momentum $$150 \\, \\hbox {GeV} p_{{\\mathrm {T}}} $$ 150 GeV p T 1500 GeV, and the relative energy resolution is $$(8.4\\pm 0.6)\\%$$ ( 8.4 ± 0.6 ) % for $$p_{{\\mathrm {T}}}= 100 \\, \\hbox {GeV}$$ p T = 100 GeV and $$(23\\pm 2)\\%$$ ( 23 ± 2 ) % for $$p_{{\\mathrm {T}}}= 20 \\, \\hbox {GeV}$$ p T = 20 GeV . The calibration scheme for jets with radius parameter $$R=1.0$$ R = 1.0 , for which jets receive a dedicated calibration of the jet mass, is also discussed.
Publisher: Bentham Science Publishers Ltd.
Date: 05-2010
Publisher: Wiley
Date: 07-12-2001
DOI: 10.1002/JCB.1269
Abstract: Mitochondria and crude nuclei containing fractions from human placenta have been shown to contain proteins which bind [alpha(32)P]-GTP. Prior to this study the number of GTP-binding proteins in placental nuclei and their nucleotide specificity was not known. Also unknown was the identity of any of the GTP-binding proteins in mitochondria of human placenta. Nuclei and mitochondria were purified from human placental extracts by sedimentation. Proteins were separated by electrophoresis and transferred to nitrocellulose membranes. Overlay blot with [alpha(32)P]-GTP identified two nuclei proteins with approximate molecular weights of 24 and 27 kDa. Binding of [alpha(32)P]-GTP to the 27 and 24 kDa proteins was significantly displaced by guanine nucleotides but not by adenine, thymine or cytosine nucleotides or deoxy (d) GTP. Western blot with a specific antibody to Ran identified a band at 27 kDa in nuclei and in mitochondrial fractions. These data indicate that both nuclei and mitochondria contain 24 and 27 kDa GTP-binding proteins. The GTP-binding proteins in nuclei display binding specificity for guanine nucleotides and the hydroxylated carbon 2 on the ribose ring of GTP appears essential for binding. It will be important in future studies to determine the functions of these small GTP-binding proteins in the development and physiology of the placenta.
Publisher: American Physical Society (APS)
Date: 26-03-2021
Publisher: Springer Science and Business Media LLC
Date: 03-2021
Abstract: This paper describes a measurement of light-by-light scattering based on Pb+Pb collision data recorded by the ATLAS experiment during Run 2 of the LHC. The study uses 2 . 2 nb − 1 of integrated luminosity collected in 2015 and 2018 at $$ \sqrt{s_{\mathrm{NN}}} $$ s NN = 5 . 02 TeV. Light-by-light scattering candidates are selected in events with two photons produced exclusively, each with transverse energy $$ {E}_{\mathrm{T}}^{\gamma } $$ E T γ 2 . 5 GeV, pseudorapidity |η γ | 2 . 37, diphoton invariant mass m γγ 5 GeV, and with small diphoton transverse momentum and diphoton acoplanarity. The integrated and differential fiducial cross sections are measured and compared with theoretical predictions. The diphoton invariant mass distribution is used to set limits on the production of axion-like particles. This result provides the most stringent limits to date on axion-like particle production for masses in the range 6–100 GeV. Cross sections above 2 to 70 nb are excluded at the 95% CL in that mass interval.
Publisher: Springer Science and Business Media LLC
Date: 1998
DOI: 10.1385/ENDO:9:3:221
Publisher: Springer Science and Business Media LLC
Date: 06-2021
Abstract: Fiducial and differential cross-section measurements of W + W − production in association with at least one hadronic jet are presented. These measurements are sensitive to the properties of electroweak-boson self-interactions and provide a test of perturbative quantum chromodynamics and the electroweak theory. The analysis is performed using proton-proton collision data collected at $$ \sqrt{s} $$ s = 13 TeV with the ATLAS experiment, corresponding to an integrated luminosity of 139 fb − 1 . Events are selected with exactly one oppositely charged electron-muon pair and at least one hadronic jet with a transverse momentum of p T 30 GeV and a pseudorapidity of | η | 4 . 5. After subtracting the background contributions and correcting for detector effects, the jet-inclusive W + W − + ≥ 1 jet fiducial cross-section and W + W − + jets differential cross-sections with respect to several kinematic variables are measured. These measurements include leptonic quantities, such as the lepton transverse momenta and the transverse mass of the W + W − system, as well as jet-related observables such as the leading jet transverse momentum and the jet multiplicity. Limits on anomalous triple-gauge-boson couplings are obtained in a phase space where interference between the Standard Model litude and the anomalous litude is enhanced.
Publisher: American Physical Society (APS)
Date: 24-03-2021
Publisher: Wiley
Date: 04-1990
DOI: 10.1111/J.1365-2826.1990.TB00848.X
Abstract: Abstract We have employed an in vitro system to study the time-course of beta-endorphin (beta-EP) immunoreactivity release from anterior pituitary cells stimulated with corticotropin-releasing factor (CRF) and whether exposure to CRF desensitizes the cells to subsequent stimulation. Ovine anterior pituitaries were enzymatically disrupted into single cells, mixed with Siegel P2 and superfused in mini-columns with carbogen-gassed medium at 37 degrees C. Superfusate fractions were collected at 5-min intervals and beta-EP immunoreactivity in the eluate was measured by radioimmunoassay. Peaks of beta-EP release that rose significantly above baseline noise were detected using the PULSAR algorithm. Unstimulated cell columns did not display any spontaneous peaks of beta-EP discharge detectable by PULSAR whereas peaks were identified in the output of columns exposed to 1 nM CRF for 100 min. beta-EP release increased after 10 min of stimulation and maximum stimulated output was achieved after 20 min of continuous CRF exposure. Between 20 and 60 min of CRF stimulation the rate of beta-EP release declined progressively but stabilized in the last 40 min of the exposure at a level significantly above controls for baseline secretion. Peak duration did not depend on the inclusion of calcium in the superfusion medium while peak litude and area were significantly reduced when cells were denied extracellular calcium. Following a 100-min exposure to 1 nM CRF, pituitary cell columns were given a 30-min rest period then restimulated with either 1 nM CRF or 50 mM KCI for 20 min. The columns given prior exposure to CRF did not mount a response (detectable by PULSAR) to a subsequent dose of 1 nM CRF whereas PULSAR detected a clear response in all members of a control group that had not received prior CRF challenge. Both CRF exposed and control columns responded to 50 mM KCI although the response was significantly attenuated in the cells that had received prior CRF treatment. These results indicate that unstimulated superfused isolated ovine anterior pituitary cells do not possess an inherent rhythmicity of beta-EP release that can be detected by the PULSAR algorithm while treatment of the cells with CRF results in detectable discharge. The rapid response of beta-EP discharge to CRF treatment suggests the presence of intracellular beta-EP stores available for rapid mobilization. Continuous exposure to 1 nM CRF can tonically lify corticotrope output for the duration of its presence in the environment of the corticotrope, but the maximum rate of release cannot be maintained. An inrush of extracellular calcium is not essential for the corticotrope to mount a detectable response to continuous CRF exposure but the release of a maximum amount of beta-EP relies on calcium entry. Long-term treatment with CRF prevents the corticotrope releasing a detectable peak of beta-EP on subsequent CRF stimulation and therefore CRF exposure leaves a lasting impression on the physiological machinery of the corticotrope. The attenuation of responsiveness to 50 mM KCI after long-term CRF treatment indicates that depletion of beta-EP stores may play a part in corticotrope desensitization although a reduction in CRF receptor number and an alteration in the intracellular mechanisms controlling beta-EP release may also be a factor.
Publisher: Springer Science and Business Media LLC
Date: 10-2020
DOI: 10.1140/EPJC/S10052-020-8227-9
Abstract: Higgs boson properties are studied in the four-lepton decay channel (where lepton = e , $$\\mu $$ μ ) using 139 $$\\hbox {fb}^{-1}$$ fb - 1 of proton–proton collision data recorded at $$\\sqrt{s}=$$ s = 13 TeV by the ATLAS experiment at the Large Hadron Collider. The inclusive cross-section times branching ratio for $$H\\rightarrow ZZ^*$$ H → Z Z ∗ decay is measured to be $$1.34 \\pm 0.12$$ 1.34 ± 0.12 pb for a Higgs boson with absolute rapidity below 2.5, in good agreement with the Standard Model prediction of $$1.33 \\pm 0.08$$ 1.33 ± 0.08 pb. Cross-sections times branching ratio are measured for the main Higgs boson production modes in several exclusive phase-space regions. The measurements are interpreted in terms of coupling modifiers and of the tensor structure of Higgs boson interactions using an effective field theory approach. Exclusion limits are set on the CP-even and CP-odd ‘beyond the Standard Model’ couplings of the Higgs boson to vector bosons, gluons and top quarks.
Publisher: Informa UK Limited
Date: 1988
DOI: 10.3109/09513598809023617
Abstract: Corticotropin-releasing hormone (CRH) immunoreactivity (IR) is present in the blood of women in the 3rd trimester of pregnancy and in placental extracts. We have used a placental fragment superfusion system to investigate the release of CRH from fresh placental tissue. Fragments of normal term placenta were mixed with Biogel P2, packed into minicolumns and superfused with carbogen-gassed Earles buffer at 37 degrees C. The rheology of the superfusion system was determined and the oxygen consumption of the superfused placental fragments indicated viability of the tissue preparation over a 5-hour time span. CRH IR in the eluate was measured by radioimmunoassay (RIA) using the 41 residue synthetic peptide human, rat CRH-41 (h, r CRH-41) as the standard, 125I labelled Tyr- h, r CRH as the tracer and rabbit anti-ovine CRH as the antibody. The sensitivity of the assay is 2 pM. Size exclusion chromatography on Sephadex G-50 of the placental column eluate displayed one major peak of CRH IR which co-eluted with that of h, r CRH. Placental fragment superfusate displayed potent CRH bioactivity as assessed by beta-endorphin secretion from ovine pituitary cells. Replacing the superfusing medium of the placental fragments with 45 mM KCl resulted in a prompt increase in the release of CRH IR. These results indicate that placental cells in vitro secrete a molecule of similar molecular weight, immunoreactivity and bioactivity to h, r CRH and that the rate of secretion may be regulated.
Publisher: Springer Science and Business Media LLC
Date: 19-04-2021
Abstract: A search for new phenomena with top quark pairs in final states with one isolated electron or muon, multiple jets, and large missing transverse momentum is performed. Signal regions are designed to search for two-, three-, and four-body decays of the directly pair-produced supersymmetric partner of the top quark (stop). Additional signal regions are designed specifically to search for spin-0 mediators that are produced in association with a pair of top quarks and decay into a pair of dark-matter particles. The search is performed using the Large Hadron Collider proton-proton collision dataset at a centre-of-mass energy of $$ \\sqrt{s} $$ s = 13 TeV recorded by the ATLAS detector from 2015 to 2018, corresponding to an integrated luminosity of 139 fb − 1 . No significant excess above the Standard Model background is observed, and limits at 95% confidence level are set in the stop-neutralino mass plane and as a function of the mediator mass or the dark-matter particle mass. Stops are excluded up to 1200 GeV (710 GeV) in the two-body (three-body) decay scenario. In the four-body scenario stops up to 640 GeV are excluded for a stop-neutralino mass difference of 60 GeV. Scalar and pseudoscalar dark-matter mediators are excluded up to 200 GeV when the coupling strengths of the mediator to Standard Model and dark-matter particles are both equal to one and when the mass of the dark-matter particle is 1 GeV.
Publisher: American Physical Society (APS)
Date: 21-09-2020
Publisher: Georg Thieme Verlag KG
Date: 1998
Abstract: Steroidogenic tissue can respond almost immediately to a stimulatory hormonal stimuli. Recent findings are shedding light on the molecular and cellular mechanisms that are used to synthesize and export steroid hormones in the acute phase of stimulation. In addition to utilising the cAMP intracellular messenger system to convey a stimulatory message, steroidogenic cells may employ the protein kinase C, arachidonic acid, tyrosine phosphate and nitrous oxide systems. It has been proposed that cholesterol laden vesicles travel along a network of intermediate filaments to reach the mitochondria. Cholesterol may then translocate from the outer mitochondrial membrane to the inner via sites of contact between the two membranes. These contact sites may be composed of protein bridges which include the constituents, porin, the benzodiazepine receptor and GTP binding proteins. Cholesterol is transported through the contact sites to the inner membrane and on reaching cytochrome P450 side chain cleavage (P450scc), cholesterol is converted to pregnenolone. Pregnenolone is in turn converted to a range of steroid hormones via enzyme casades. GTP binding proteins may regulate the contact site between the inner and outer membranes and thereby modulate cholesterol flux to P450scc. In the adrenal and gonads the rate that cholesterol traverses the contact point to reach the inner membrane is accelerated by the steroidogenic acute regulatory protein. Newly synthesized steroid hormones are transported to the cell periphery for export via a mechanism that may utilise an ion exchange protein.
Publisher: American Physical Society (APS)
Date: 19-02-2021
Publisher: Bentham Science Publishers Ltd.
Date: 11-2008
Publisher: Springer Science and Business Media LLC
Date: 02-2021
Abstract: A search for the supersymmetric partners of quarks and gluons (squarks and gluinos) in final states containing jets and missing transverse momentum, but no electrons or muons, is presented. The data used in this search were recorded by the ATLAS experiment in proton-proton collisions at a centre-of-mass energy of $$ \\sqrt{s} $$ s = 13 TeV during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb − 1 . The results are interpreted in the context of various R -parity-conserving models where squarks and gluinos are produced in pairs or in association and a neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 2.30 TeV for a simplified model containing only a gluino and the lightest neutralino, assuming the latter is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.85 TeV are excluded if the lightest neutralino is massless. These limits extend substantially beyond the region of supersymmetric parameter space excluded previously by similar searches with the ATLAS detector.
Publisher: American Physical Society (APS)
Date: 05-08-2020
Publisher: Springer Science and Business Media LLC
Date: 29-12-2012
DOI: 10.1007/S13105-012-0227-2
Abstract: In response to stress, the hypothalamus releases cortiticotropin releasing hormone (CRH) that travels to the anterior pituitary, where it stimulates the release of adrenocorticotropic hormone (ACTH). ACTH travels to the adrenal cortex, where it stimulates the release of cortisol and other steroids that liberate energy stores to cope with the stress. During pregnancy, the placenta synthesises CRH and releases it into the bloodstream at increasing levels to reach concentrations 1,000 to 10, 000 times of that found in the non-pregnant in idual. Urocortins, which are CRH analogues are also secreted by the placenta. Desensitisation of the maternal pituitary to CRH and resetting after birth may be a factor in post-partum depression. Recently, CRH has been found to modulate glucose transporter (GLUT) proteins in placental tissue, and therefore there may be a link between CRH levels and foetal growth. Evidence suggests CRH is involved in the timing of birth by modulating signalling systems that control the contractile properties of the myometrium. In the placenta, cortisol stimulates CRH synthesis via activation of nuclear factor kappa B (NF-κB), a component in a cellular messenger system that may also be triggered by stressors such as hypoxia and infection, indicating that intrauterine stress could bring forward childbirth and cause low birth weight infants. Such infants could suffer health issues into their adult life as a result of foetal programming. Future treatment of these problems with CRH antagonists is an exciting possibility.
Publisher: Elsevier BV
Date: 07-1998
DOI: 10.1016/S0305-0491(98)10043-3
Abstract: Protection of dietary lipids in a protein matrix prevents biohydrogenation in ruminants and increases the availability of polyunsaturated fatty acids. This alters the composition of the tissue lipids, including the membrane phospholipids, which are important substrates for signal transduction. This study investigates the effects of a diet containing protected fatty acids on the activities of key intracellular kinases in the skin. Two groups of six sheep were offered either a control diet or one containing protected cottonseed, a source of linoleic acid (C18:2), for 3 months. Skin was taken from August to October, and analysed for protein kinase C (PKC), protein kinase A (PKA), mitogen-activated protein kinase (MAPK), phosphotyrosine activity and epidermal growth factor (EGF) receptor content. Skin and wool s les were also taken to measure changes in the fibre characters and follicle function. At the end of the experiment, the mean linoleic acid content of skin phospholipids from sheep fed the protected diet was twice that of the controls. In both groups, PKC activity was significantly elevated in skin taken during September and October compared with August values. However, activities measured in the experimental sheep were higher than in controls. This coincided with a decline in wool production. PKA activity decreased significantly in both groups between August and October. MAPK activities did not alter during the experiment. Western analyses did not reveal differences in phosphotyrosine-positive or EGF receptor bands between the groups.
Publisher: Elsevier BV
Date: 03-1998
DOI: 10.1016/S0143-4004(98)90010-8
Abstract: In this study, an overlay blot method was used to identify GTP-binding proteins in fractions of human placenta. Human placenta were fractionated by centrifugation into preparations containing (1) mitochondria, (2) nucleoli and (3) microsomes, plasma membrane and cytosol. GTP-binding proteins were detected by overlay blot using alpha32P-GTP. Proteins of 23 and 25 kDa were identified in all fractions and GTP binding was higher in the presence of 1.0, 2.5, 5.0 and 10.0 mM MgCl2 as compared to equivalent concentrations of CaCl2. In mitochondrial preparations binding of alpha32P-GTP to 23 and 25 kDa was displaced significantly by GDP and GTP but not ADP or ATP. Fractions containing microsomes, plasma membrane and cytosol displayed two labelled bands of 14 and 18 kDa that were not present in other fractions. These data indicate that the placenta contains specific GTP-binding proteins of molecular weights that are consistent with the small monomeric GTP binding protein family (18-36 kDa). Two of these are located in the mitochondria and may regulate the function of these organelles in the placenta.
Publisher: Springer Science and Business Media LLC
Date: 11-2020
DOI: 10.1140/EPJC/S10052-020-08509-3
Abstract: A search is presented for four-top-quark production using an integrated luminosity of 139 fb $$^{-1}$$ - 1 of proton–proton collision data at a centre-of-mass energy of $$13~\\text {TeV}$$ 13 TeV collected by the ATLAS detector at the LHC. Events are selected if they contain a same-sign lepton pair or at least three leptons (electrons or muons). Jet multiplicity, jet flavour and event kinematics are used to separate signal from the background through a multivariate discriminant, and dedicated control regions are used to constrain the dominant backgrounds. The four-top-quark production cross section is measured to be $$24^{+7}_{-6}$$ 24 - 6 + 7 fb. This corresponds to an observed (expected) significance with respect to the background-only hypothesis of 4.3 (2.4) standard deviations and provides evidence for this process.
Publisher: Wiley
Date: 2002
Publisher: Springer Science and Business Media LLC
Date: 05-2021
Abstract: One correction is noted for the paper.
Publisher: Elsevier BV
Date: 1990
DOI: 10.1016/0041-0101(90)90004-Q
Abstract: Three new proteins with cardiac stimulatory and haemolytic activity, designated tenebrosins-A, -B and -C, have been purified from the Australian sea anemone Actinia tenebrosa. These proteins are basic (pI greater than or equal to 9.4), have mol. wt of about 20,000, and have very similar amino acid compositions and N-terminal amino acid sequences. None of the proteins contains cysteine or cystine residues. On isolated, spontaneously beating guinea pig atria they exhibit at 1-2 nM strong positive inotropic and slight to moderate chronotropic effects. In some cases a transient negative inotropic effect occurs prior to onset of the positive inotropic response. The proteins are also haemolytic, producing 50% haemolysis of guinea pig erythrocytes at concentrations similar to those showing positive inotropic effects.
Publisher: Springer Science and Business Media LLC
Date: 2021
Abstract: A measurement of event-shape variables in proton-proton collisions at large momentum transfer is presented using data collected at $$ \\sqrt{s} $$ s = 13 TeV with the ATLAS detector at the Large Hadron Collider. Six event-shape variables calculated using hadronic jets are studied in inclusive multijet events using data corresponding to an integrated luminosity of 139 fb − 1 . Measurements are performed in bins of jet multiplicity and in different ranges of the scalar sum of the transverse momenta of the two leading jets, reaching scales beyond 2 TeV. These measurements are compared with predictions from Monte Carlo event generators containing leading-order or next-to-leading order matrix elements matched to parton showers simulated to leading-logarithm accuracy. At low jet multiplicities, shape discrepancies between the measurements and the Monte Carlo predictions are observed. At high jet multiplicities, the shapes are better described but discrepancies in the normalisation are observed.
Publisher: Springer Science and Business Media LLC
Date: 2021
Abstract: One correction is noted for the paper. A wrong cross-section was used for the theory prediction in figure 6 due to not taking into account the VHH contamination properly in the rescaling formula for the signal s les.
Publisher: Elsevier BV
Date: 04-1995
DOI: 10.1016/0167-4838(94)00234-8
Abstract: We have identified two GTP-binding proteins in mitochondria from bovine adrenal cortex (fasciculata). Sub-mitochondrial particles were fractionated into inner membrane, contact point and outer membrane vesicles on sucrose density gradients. These sub-mitochondrial fractions were identified by the presence of enzyme markers and electron microscopy. Photoaffinity labelling with [gamma-32P]GTP identified a 45 kDa GTP-binding protein in outer mitochondrial membranes and a 19 kDa protein in the contact points. The molecular weight of 45 kDa and requirement for Mg2+ ions raise the possibility that this protein is an alpha subunit of a heterotrimeric GTP-binding protein or a novel GTP-binding protein. The specificity of nucleotide binding, the requirement for low concentrations of Mg2+ (0.1 mM) and molecular weight of 19 kDa suggest that this protein is a typical member of the so-called small GTP-binding protein family. The location of 45 kDa in the outer membrane and that of 19 kDa in the contact points suggest roles for these proteins in the interaction with the extramitochondrial environment and in the regulation of mitochondrial membranes, respectively.
Publisher: Wiley
Date: 08-2003
DOI: 10.1034/J.1600-0625.2003.00068.X
Abstract: Parathyroid hormone-related protein (PTHrP) is secreted by skin epithelial cells and is thought to play an important role in the development and function of the hair follicle. It was hypothesized that PTHrP binds to receptors in dermal papilla cells and modulates intracellular signaling systems in these cells. We tested the effects of PTHrP on protein synthesis, protein kinase A (PKA) and protein kinase C (PKC) activities as well as tyrosine phosphorylation in rat vibrissa dermal papilla and capsular fibroblast cells. Cells were cultured in the presence or absence of the N-terminal peptide PTHrP1-34 for 48 h and detergent extracts prepared. Proteins were separated by electrophoresis. Phosphotyrosine and the PTH/PTHrP receptor immunoreactivity was identified by Western blot analysis. PKC and PKA activities in the cells were measured using colorimetric enzyme assays. Extracts of both dermal papilla cells and capsular fibroblasts displayed immunoreactivity to the PTH/PTHrP receptor. Electrophoresis showed that PTHrP treatment reduced the density of a 50-kDa protein in dermal papilla cells but not in capsular fibroblasts. Media conditioned by the cells showed similar changes, indicating that the PTHrP-modulated 50-kDa protein was secreted. Furthermore, 2-D gel electrophoresis indicated that the protein had a number of phosphorylation sites. Western analysis with antiphosphotyrosine antibodies confirmed a significant decrease in the intensity of a phosphorylated 50-kDa protein in papilla cells and papilla cell-conditioned medium. PKC and PKA activities of papilla cells were unaffected by PTHrP. However, activities of PKC were increased and PKA reduced in capsular fibroblasts following peptide treatment. These cell-specific effects showed that endogenous PTHrP may activate different intracellular pathways in mesenchymal cells of skin and elicit changes in levels of locally secreted proteins that specifically modulate normal follicular function.
Publisher: Wiley
Date: 20-02-2003
DOI: 10.1002/BIES.10243
Abstract: The first and rate-limiting step of steroidogenesis is the transfer of cholesterol from the outer mitochondrial membrane to the inner membrane where it is converted to pregnenolone by cytochrome P450 side-chain cleavage (P450scc). This reaction is modulated in the gonads and adrenals by the steroidogenic acute regulatory protein (StAR), however, the mechanism used by StAR is not understood. The outer and inner mitochondrial membranes are joined at contact sites that are thought to be held in place by protein complexes that bridge the two membranes. While it is generally accepted that proteins are imported into the mitochondrion via contact sites, it is not clear whether cholesterol takes the same conduit to the inner membrane. Strategies to combat diseases caused by interrupted cholesterol transfer will rely on a full understanding of the steroidogenic mechanism. The challenge for the future is to determine whether StAR relies on the molecular architecture that spans the mitochondrial intermembrane space to deliver its cargo.
Publisher: Elsevier BV
Date: 07-2006
DOI: 10.1016/J.CBPB.2006.04.005
Abstract: Plastic changes occur in the morphology of the uterus at various stages of the reproductive cycle in both oviparous and viviparous lizards and these may be influenced by estrogen. Estrogen driven phosphorylation of effector proteins on tyrosine residues plays a major role in the plastic modulation of uterine anatomy and physiology in vertebrates. We used electrophoresis and Western blotting to characterize the phosphotyrosine protein profiles at various stages of the reproductive pathway in an oviparous lizard L ropholis guichenoti and a viviparous lizard Eul rus tympanum. L. guichenoti displayed major bands in the 200-35 kDa range and a triplet of bands of molecular masses 61 kDa, 52 kDa and 48 kDa in 50% of specimens and a 38 kDa band in all specimens. In contrast, E. tympanum s les all displayed a single major band at 40 kDa, which was significantly elevated at the early pregnancy stage. Somewhat paradoxically, the viviparous species, which has the more complex uterine epithelial changes during pregnancy, has the fewest phosphotyrosine bands, so how tyrosine phosphorylation is affected during the evolution of viviparity is not clear.
Publisher: Elsevier BV
Date: 06-1988
DOI: 10.1016/S0006-291X(88)81359-7
Abstract: The molecular forms of corticotrophin-releasing hormone (CRH) in human placentae and hypothalami were investigated by gel permeation chromatography of water extracts. Hypothalamic extracts produced one peak of immunoreactivity which coeluted with human CRH at Kd = 0.53. Placental extracts, however, had in addition to that peak, two other peaks eluting earlier at the void and at Kd = 0.35-0.38. Tryptic digestion of the middle peak produced immunoreactivity which coeluted with the standard. Larger forms were also found in plasma of women in the third trimester of pregnancy and during labour but not in eluates from superfused placental fragments which had only CRH41-sized material. These data indicate that tissue-specific post-translational processing occurs for CRH, and suggests that the link between synthesis and secretion is more immediate in the placenta than hypothalamus.
Publisher: Elsevier BV
Date: 02-2020
Publisher: Wiley
Date: 2002
DOI: 10.1002/CBF.974
Abstract: Recent studies have shown that GTP-binding proteins can modulate mitochondrial membrane fusion and fission. Furthermore, GTP-binding proteins can regulate the binding of ribosomes to the mitochondrial membrane and may facilitate the import of proteins through contact points between inner and outer mitochondrial membranes. Mitochondrial GTP-binding proteins therefore appear to have the potential to modulate physiological function of the organelle and may also be involved in cellular processes such as cellular transformation. A beginning has been made on the characterization of mitochondrial GTP-binding proteins and the DNA sequence of one protein has become newly available. Future studies are needed to determine whether GTP-binding proteins are interacting with cell signalling molecules such as protein kinases in the mitochondria.
Publisher: Springer Science and Business Media LLC
Date: 11-2020
Publisher: American Physical Society (APS)
Date: 10-06-2021
Publisher: Springer Science and Business Media LLC
Date: 02-2021
DOI: 10.1140/EPJC/S10052-020-08734-W
Abstract: Differential cross-section measurements are presented for the electroweak production of two jets in association with a Z boson. These measurements are sensitive to the vector-boson fusion production mechanism and provide a fundamental test of the gauge structure of the Standard Model. The analysis is performed using proton–proton collision data collected by ATLAS at $$\\sqrt{s}=13\\ \\hbox {TeV}$$ s = 13 TeV and with an integrated luminosity of $$139\\ \\hbox {fb}^{-1}$$ 139 fb - 1 . The differential cross-sections are measured in the $$Z\\rightarrow \\ell ^+\\ell ^-$$ Z → ℓ + ℓ - decay channel ( $$\\ell =e,\\mu $$ ℓ = e , μ ) as a function of four observables: the dijet invariant mass, the rapidity interval spanned by the two jets, the signed azimuthal angle between the two jets, and the transverse momentum of the dilepton pair. The data are corrected for the effects of detector inefficiency and resolution and are sufficiently precise to distinguish between different state-of-the-art theoretical predictions calculated using Powheg+Pythia8 , Herwig7+Vbfnlo and Sherpa 2.2. The differential cross-sections are used to search for anomalous weak-boson self-interactions using a dimension-six effective field theory. The measurement of the signed azimuthal angle between the two jets is found to be particularly sensitive to the interference between the Standard Model and dimension-six scattering litudes and provides a direct test of charge-conjugation and parity invariance in the weak-boson self-interactions.
Publisher: Springer Science and Business Media LLC
Date: 02-2002
DOI: 10.1007/S00018-002-8417-7
Abstract: The finding that mitochondria contain substrates for protein kinases lead to the discovery that protein kinases are located in the mitochondria of certain tissues and species. These include pyruvate dyhydrogenase kinase, branched-chain alpha-ketoacid dehydrogenase kinase, protein kinase A, protein kinase Cdelta, stress-activated kinase and A-Raf as well as unidentified kinases. Recent evidence suggests that mitochondrial protein kinases may be involved in physiological processes such as apoptosis and steroidogenesis. Additionally, the novel finding of low-molecular-weight GTP-binding proteins in mitochondria suggests the possibility that these may interact with mitochondrial protein kinases to regulate the activity of mitochondrial effector proteins. The fact that there are components of cellular regulatory systems in mitochondria indicates the exciting possibility of undiscovered systems regulating mitochondrial physiology.
Publisher: American Physical Society (APS)
Date: 07-06-2021
Publisher: Elsevier BV
Date: 05-2001
Publisher: Springer Science and Business Media LLC
Date: 08-2020
Abstract: The combination of measurements of the W boson polarization in top quark decays performed by the ATLAS and CMS collaborations is presented. The measurements are based on proton-proton collision data produced at the LHC at a centre-of-mass energy of 8 TeV, and corresponding to an integrated luminosity of about 20 fb − 1 for each experiment. The measurements used events containing one lepton and having different jet multiplicities in the final state. The results are quoted as fractions of W bosons with longitudinal ( F 0 ), left-handed ( F L ), or right-handed ( F R ) polarizations. The resulting combined measurements of the polarization fractions are F 0 = 0 . 693 ± 0 . 014 and F L = 0 . 315 ± 0 . 011. The fraction F R is calculated from the unitarity constraint to be F R = − 0 . 008 ± 0 . 007. These results are in agreement with the standard model predictions at next-to-next-to-leading order in perturbative quantum chromodynamics and represent an improvement in precision of 25 (29)% for F 0 ( F L ) with respect to the most precise single measurement. A limit on anomalous right-handed vector ( V R ), and left- and right-handed tensor ( g L , g R ) tWb couplings is set while fixing all others to their standard model values. The allowed regions are [ − 0 . 11 , 0 . 16] for V R , [ − 0 . 08 , 0 . 05] for g L , and [ − 0 . 04 , 0 . 02] for g R , at 95% confidence level. Limits on the corresponding Wilson coefficients are also derived.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Wiley
Date: 02-1990
DOI: 10.1111/J.1365-2826.1990.TB00399.X
Abstract: Abstract Human placental extracts fractionated with Sephadex G-50 produced three peaks of corticotrophin-releasing hormone immunoreactivity, a large molecular weight peak (M(r)30,000), an intermediate peak (4,758 < M(r) < 10,000) and a low molecular weight peak coeluting with the 41-residue hormone. All three peaks of immunoreactivity stimulated the release of beta-endorphin-like immunoreactivity from ovine pituitary cells superfused in vitro. No response was observed from unstimulated cells superfused in parallel. Gel chromatography indicated that intermediate and small molecular weight forms of human corticotrophin-releasing hormone immunoreactivity remained intact after contact with the ovine pituitary cells, whereas the large molecular weight material dissociated to produce 41-residue hormone immunoreactivity. The secreted beta-endorphin immunoreactivity was shown by gel chromatography to comprise both beta-lipotrophin-like and the 31-residue beta-endorphin-like immunoreactivity. The data show that the intermediate and low molecular weight forms of placental corticotrophin-releasing hormone immunoreactivity are bioactive and suggest that the intermediate form is a hormone precursor, possibly procorticotrophin-releasing hormone(125-196), and the small form is identical to the hypothalamic hormone. The results with the larger molecular weight material indicate that it is likely to be a complex of the mature 41-residue hormone and a binding protein.
Publisher: Springer Science and Business Media LLC
Date: 2021
Abstract: Differential cross-sections are measured for top-quark pair production in the all-hadronic decay mode, using proton-proton collision events collected by the ATLAS experiment in which all six decay jets are separately resolved. Absolute and normalised single- and double-differential cross-sections are measured at particle and parton level as a function of various kinematic variables. Emphasis is placed on well-measured observables in fully reconstructed final states, as well as on the study of correlations between the top-quark pair system and additional jet radiation identified in the event. The study is performed using data from proton-proton collisions at $$ \\sqrt{s} $$ s = 13 TeV collected by the ATLAS detector at CERN’s Large Hadron Collider in 2015 and 2016, corresponding to an integrated luminosity of 36.1 fb − 1 . The rapidities of the in idual top quarks and of the top-quark pair are well modelled by several independent event generators. Significant mismodelling is observed in the transverse momenta of the leading three jet emissions, while the leading top-quark transverse momentum and top-quark pair transverse momentum are both found to be incompatible with several theoretical predictions.
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 03-1990
DOI: 10.1016/0304-3940(90)90871-6
Abstract: It is not certain which protein kinase (A, C or both) is involved in the acute phase of beta-endorphin (beta-EP) release stimulated in the corticotrope by vasopressin (VP) and corticotropin-releasing factor (CRF). We have employed an isolated ovine anterior pituitary cell superfusion system to determine the dynamic effects of forskolin, a protein kinase A (PKA) stimulator, and phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator. Both secretagogues stimulated beta-EP release within 5 min and therefore both PKA and PKC are potential mediators of the acute phase of hormonal stimulation of the corticotrope. Pretreatment with PMA specifically desensitized the pituitary cell columns to subsequent PMA exposure while not significantly altering sensitivity to forskolin or 50 mM KCl.
Publisher: Elsevier BV
Date: 09-2005
DOI: 10.1016/J.CBPC.2005.07.001
Abstract: The gene HoxA10 and its protein product are essential for the formation of the extensions of the plasma membrane called uterodomes or pinopods in mammalian uterine epithelia. In mice, the presence of the HoxA10 protein and uterodomes is needed for uterine receptivity to blastocyst implantation. The viviparous lizard Eul rus tympanum displays uterodomes whereas the oviparous lizard L ropholis guichenoti does not. To explore the theory that HoxA10 is involved in the formation of uterodomes we investigated whether HoxA10 immunoreactive proteins were present in both species during their reproductive cycles. Oviduct proteins from vitellogenic, gravid or non-reproductive L. guichenoti (n=19) and E. tympanum (n=28) were separated by electrophoresis and analysed by Western blot and specific antibodies to HoxA10. E. tympanum displayed HoxA10 immunoreactive bands at 59 and 63 kDa in 20 out of the 28 s les. All of the L. guichenoti s les displayed HoxA10 immunoreactive bands, 18 had bands at 59 and 64 kDa and 1 animal had a single band at 59 kDa. There were no significant differences in the level of HoxA10 immunoreactivity between the different stages of reproductive cycle in either species. The different molecular mass of the larger band in L. guichenoti (64 kDa) compared to E. tympanum (63 kDa) indicates that the two lizards express different isoforms of the HoxA10-like proteins and it will be interesting in future studies to determine whether there are differences in the biological activity of the proteins that regulate different physiological functions in the uterus of viviparous and oviparous lizards.
Publisher: Wiley
Date: 09-11-2017
DOI: 10.1111/PHEN.12229
Publisher: Wiley
Date: 22-08-2016
DOI: 10.1111/IVB.12134
Publisher: Bentham Science Publishers Ltd.
Date: 11-04-2012
Publisher: Springer Science and Business Media LLC
Date: 03-2021
DOI: 10.1140/EPJC/S10052-021-08970-8
Abstract: A Correction to this paper has been published: 10.1140/epjc/s10052-020-08730-0
Publisher: Oxford University Press (OUP)
Date: 03-2018
DOI: 10.1530/EJE-18-0030
Publisher: Oxford University Press (OUP)
Date: 2009
DOI: 10.1651/08-3083.1
Publisher: Springer Science and Business Media LLC
Date: 02-2021
DOI: 10.1140/EPJC/S10052-020-08677-2
Abstract: Measurements of the Standard Model Higgs boson decaying into a $$b\\bar{b}$$ b b ¯ pair and produced in association with a W or Z boson decaying into leptons, using proton–proton collision data collected between 2015 and 2018 by the ATLAS detector, are presented. The measurements use collisions produced by the Large Hadron Collider at a centre-of-mass energy of $$\\sqrt{s} = 13\\,\\text {Te}\\text {V}$$ s = 13 Te , corresponding to an integrated luminosity of $$139\\,\\mathrm {fb}^{-1}$$ 139 fb - 1 . The production of a Higgs boson in association with a W or Z boson is established with observed (expected) significances of 4.0 (4.1) and 5.3 (5.1) standard deviations, respectively. Cross-sections of associated production of a Higgs boson decaying into bottom quark pairs with an electroweak gauge boson, W or Z , decaying into leptons are measured as a function of the gauge boson transverse momentum in kinematic fiducial volumes. The cross-section measurements are all consistent with the Standard Model expectations, and the total uncertainties vary from 30% in the high gauge boson transverse momentum regions to 85% in the low regions. Limits are subsequently set on the parameters of an effective Lagrangian sensitive to modifications of the WH and ZH processes as well as the Higgs boson decay into $$b\\bar{b}$$ b b ¯ .
Publisher: Wiley
Date: 12-08-2013
DOI: 10.1111/JMI.12075
Abstract: The cirolanid isopod Cirolana harfordi is described as a scavenger and a predator that lives in the intertidal region. In order to understand the microanatomy of the mouthparts and the setae that allow this animal to handle and eat its food, a scanning electron microscopy study was conducted. C. harfordi displays a variety in the types of setae distributed on its mouthparts in a site-specific fashion, including complex setae placed on the medial edge of the maxilliped and maxilla. Terminal pores in some setae were found to contain a cupule, which is a hemispherical structure, housed in the concave recess of the pore, which demonstrates that the pore is more than merely a thinning of the cuticle as has been proposed. Future studies on setal morphology are needed for comparative microanatomy of cirolanid isopods.
Publisher: Informa UK Limited
Date: 25-12-2019
Publisher: Elsevier BV
Date: 03-1991
DOI: 10.1016/S0950-351X(05)80102-8
Abstract: Plasma cortisol, adrenocorticotrophic hormone (ACTH), beta-endorphin and corticotrophin releasing hormone or factor (CRF) all rise progressively as pregnancy advances, and fall postnatally. The placenta produces large amounts of CRF in the third trimester and this is released into the maternal circulation. Present evidence suggests that it stimulates the maternal pituitary to produce ACTH while desensitizing the maternal pituitary to further stimulation with CRF. Maternal control of ACTH production is retained, allowing a persistent response to stress and a diurnal rhythm, perhaps through the secretion of vasopressin. The placenta also produces pro-opiomelanocortin peptides however, the nature of the fragments produced from the precursor differs from that formed in the anterior pituitary of the mother and the role of these fragments in the control of maternal adrenal function is unclear. These changes in the hypothalamo-pituitary-adrenal axis during pregnancy are associated with loss of the normal suppression of cortisol by dexamethasone and elevated basal levels of cortisol with preservation of a diurnal rhythm, features also found in some patients with endogenous depression. Several studies have suggested a relationship between alterations in maternal concentrations of cortisol and beta-endorphin and the development of postnatal mood disturbances.
Publisher: Elsevier BV
Date: 10-2020
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 03-1989
Publisher: Informa UK Limited
Date: 27-03-2014
Publisher: Springer Science and Business Media LLC
Date: 10-2020
Abstract: Figure 5b of the paper [1] contained a misinterpretation in the comparison between the reported new ATLAS measurement of the process pp → Xp and previously published CMS data [2]. The ATLAS measurement corresponds to cases where either proton dissociates.
Publisher: Springer Science and Business Media LLC
Date: 03-2021
DOI: 10.1140/EPJC/S10052-021-08929-9
Abstract: A search for the pair production of heavy leptons as predicted by the type-III seesaw mechanism is presented. The search uses proton–proton collision data at a centre-of-mass energy of 13 TeV, corresponding to $$ 139\\,{\\text {fb}}^{-1} $$ 139 fb - 1 of integrated luminosity recorded by the ATLAS detector during Run 2 of the Large Hadron Collider. The analysis focuses on the final state with two light leptons (electrons or muons) of different flavour and charge combinations, with at least two jets and large missing transverse momentum. No significant excess over the Standard Model expectation is observed. The results are translated into exclusion limits on heavy-lepton masses, and the observed lower limit on the mass of the type-III seesaw heavy leptons is 790 GeV at 95% confidence level.
Publisher: Elsevier BV
Date: 07-1998
DOI: 10.1016/S0167-4889(98)00069-X
Abstract: The discovery of GTP-binding proteins in mitochondria is a recent event. These regulatory proteins may be participating in membrane fusion and thereby playing important roles in the physiology of the mitochondrion. So far, it has been proposed that GTP-binding protein mediated membrane fusion may be involved in protein import, steroid hormone production and mitochondrial amalgamation during spermatogenesis.
Publisher: Brill
Date: 2010
Publisher: Springer Science and Business Media LLC
Date: 04-2021
Abstract: The Lagrangian in eq. (2.1) of JHEP 11 (2020) 005 has an erroneous factor of 1/2. The analysis code used for the results reported in the paper does not have this factor. The results remain unchanged.
Publisher: Elsevier BV
Date: 1994
DOI: 10.1016/0141-8130(94)90029-9
Abstract: Interactions between glycosaminoglycans (GAGs) and low density lipoprotein (LDL) are thought to influence the progression of atherogenesis. In an effort to gauge whether macrophages mediate GAG-LDL interaction by GAG modification, we have investigated the endocytosis, degradation and retro-endocytosis of the GAG heparan sulfate (HS) by mouse peritoneal macrophages. Radiolabelled HS was produced by derivatization with sulfosuccinimidyl-3-(4-hydroxyphenyl) propionate and radio-iodination by the chloramine T method. The amount of 125I-HS internalized by cultures of thioglycollate-elicited macrophages rose over a 24 h time period in proportion to the amount of tracer added to the wells (2-2500 ng ml-1). Analysis of GAG molecular weight was performed using gel filtration chromatography and polyacrylamide gel electrophoresis. After a 24 h pulse period, the 125I-HS in the intracellular fraction of the cultured cells was of smaller molecular weight than for control material. During a 24 h cold chase, fragments of 125I-HS were released into the medium. These fragments had lower affinity for Polybrene-Sepharose but did not appear significantly N-desulfated as determined by low pH nitrous acid treatment. The NADPH oxidase inhibitor diphenylene iodonium, although minimizing basal and phorbol ester-triggered radical output, did not inhibit 125I-HS depolymerization. These data indicate that elicited macrophages can interact with and reduce the polymer length of HS without extensively desulfating the molecule. They are consistent with a mechanism by which the macrophage internalizes and partially degrades HS by endoglucuronidase activity rather than NADPH oxidase-generated free radicals, followed by release of the products into the extracellular milieu.
No related grants have been discovered for Murray Thomson.