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  • Publication . Article . Preprint . 2020
    Open Access
    Authors: 
    Rubén J. Sánchez-García;
    Publisher: Springer Science and Business Media LLC
    Country: United Kingdom
    Project: UKRI | Isaac Newton Institute fo... (EP/K032208/1)

    Virtually all network analyses involve structural measures between pairs of vertices, or of the vertices themselves, and the large amount of symmetry present in real-world complex networks is inherited by such measures. This has practical consequences which have not yet been explored in full generality, nor systematically exploited by network practitioners. Here we study the effect of network symmetry on arbitrary network measures, and show how this can be exploited in practice in a number of ways, from redundancy compression, to computational reduction. We also uncover the spectral signatures of symmetry for an arbitrary network measure such as the graph Laplacian. Computing network symmetries is very efficient in practice, and we test real-world examples up to several million nodes. Since network models are ubiquitous in the Applied Sciences, and typically contain a large degree of structural redundancy, our results are not only significant, but widely applicable. Author name updated (accents added)

  • Open Access English
    Authors: 
    Muhammad Naveed; Mutez Ali Ahmed; Pascal Benard; Lawrie K. Brown; Timothy S. George; A. G. Bengough; Tiina Roose; Nicolai Koebernick; Paul D. Hallett;
    Publisher: Springer International Publishing
    Country: United Kingdom
    Project: UKRI | Rhizosphere by design: br... (BB/L026058/1), UKRI | Real-time in situ sensing... (BB/P004180/1), EC | DIMR (646809), UKRI | Truly Predicting Root Upt... (BB/J000868/1), UKRI | Rooting for sustainable p... (EP/M020355/1), UKRI | Rice germplasm for high g... (BB/J011460/1)

    Abstract\ud Aims Rhizodeposits collected from hydroponic solutions with roots of maize and barley, and seed mucilage washed from chia, were added to soil to measure their impact on water retention and hysteresis in a sandy loam soil at a range of concentrations. We test the hypothesis that the effect of plant exudates and mucilages on hydraulic properties of soils depend on their physicochemical characteristics and origin.\ud Methods Surface tension and viscosity of the exudate solutions were measured using the Du Noüy ring method and a cone-plate rheometer, respectively. The contact angle of water on exudate treated soil was measured with the sessile drop method. Water retention and hysteresis were measured by equilibrating soil samples, treated with exudates and mucilages at 0.46 and 4.6 mg g−1 concentration, on dialysis tubing filled with polyethylene glycol (PEG) solution of known osmotic potential.\ud Results Surface tension decreased and viscosity increased with increasing concentration of the exudates and mucilage in solutions. Change in surface tension and viscosity was greatest for chia seed exudate and least for barley root exudate. Contact angle increased with increasing maize root and chia seed exudate concentration in soil, but not barley root. Chia seed mucilage and maize root rhizodeposits enhanced soil water retention and increased hysteresis index, whereas barley root rhizodeposits decreased soil water retention and the hysteresis effect. The impact of exudates and mucilages on soil water retention almost ceased when approaching the wilting point at −1500 kPa matric potential.\ud Conclusions Barley rhizodeposits behaved as surfactants, drying the rhizosphere at smaller suctions. Chia seed mucilage and maize root rhizodeposits behaved as hydrogels that hold more water in the rhizosphere, but with slower rewetting and greater hysteresis.

  • Open Access English
    Authors: 
    Daniele Carrieri; Anneke Lucassen; Angus John Clarke; Sandi Dheensa; Shane Doheny; Peter D. Turnpenny; Susan E. Kelly;
    Publisher: Nature Publishing Group
    Country: United Kingdom
    Project: UKRI | Mainstreaming Genomics: R... (ES/L002868/1)

    Purpose: To ascertain whether and how recontacting occurs in the United Kingdom. Genet Med 18 9, 876–881. Method: A Web-based survey was administered online between October 2014 and July 2015. A link to the survey was circulated via an e-mail invitation to the clinical leads of the United Kingdom's 23 clinical genetics services, with follow-up with senior clinical genetics staff. Genet Med 18 9, 876–881. Results: The majority of UK services reported that they recontact patients and their family members. However, recontacting generally occurs in an ad hoc fashion when an unplanned event causes clinicians to review a file (a “trigger”). There are no standardized recontacting practices in the United Kingdom. More than half of the services were unsure whether formalized recontacting systems should be implemented. Some suggested greater patient involvement in the process of recontacting. Genet Med 18 9, 876–881. Conclusion: This research suggests that a thorough evaluation of the efficacy and sustainability of potential recontacting systems within the National Health Service would be necessary before deciding whether and how to implement such a service or to create guidelines on best-practice models. Genet Med 18 9, 876–881.

  • Publication . Article . Preprint . 2020 . Embargo End Date: 01 Jan 2019
    Open Access
    Authors: 
    Alexander Belyaev; Kazem Bitaghsir Fadafan; Nick Evans; Mansoureh Gholamzadeh;
    Publisher: arXiv
    Country: United Kingdom
    Project: UKRI | New Frontiers in Particle... (ST/P000711/1)

    We use a holographic description of technicolor dynamics to study gauge theories that only break chiral symmetry when aided by a strong four fermion interaction. These Nambu-Jona-Lasinio (NJL) assisted technicolor models provide examples of different dynamics from walking technicolor which can, by tuning, generate a light higgs like $\sigma$ meson. We compute the vector meson ($\rho$) and axial vector meson (A) spectrum for a variety of models with techni-quarks in the fundamental representation, enlarging the available parameter space over a previous analysis of walking theories. These predictions determine the parameter space of a low energy effective description where LHC constraints from dilepton channels have already been applied. Many of the models with low numbers of electroweak doublets still lie beyond current constraints and motivate exploration of new signatures beyond dilepton for LHC and a 100 TeV proton collider. Comment: 13 pages, 6 figures, 9 tables

  • Publication . Article . 2011
    Open Access English
    Authors: 
    Arjan van der Schaft; Paolo Rapisarda;
    Countries: Netherlands, United Kingdom
    Project: UKRI | Polynomial Algebraic Meth... (EP/I000909/1)

    We develop a new approach to the construction of state vectors for linear time-invariant systems described by higher-order differential equations. The basic observation is that the concatenation of two solutions of higher-order differential equations results in another (weak) solution once their remainder terms resulting from (repeated) integration by parts match. These remainder terms can be computed in a simple and efficient manner by making use of the calculus of bilinear differential forms and two-variable polynomial matrices. Factorization of the resulting two-variable polynomial matrix defines a state map, as well as a state map for the adjoint system. Minimality of these state maps is characterized. The theory is applied to three classes of systems with additional structure, namely self-adjoint Hamiltonian, conservative port-Hamiltonian, and time-reversible systems. For the first two classes it is shown how the factorization leading to a (minimal) state map is equivalent to the factorization of another two-variable polynomial matrix, which is immediately derived from the external system characterization, and defines a symplectic, respectively, symmetric, bilinear form on the minimal state space.

  • Open Access English
    Authors: 
    Chris Wilson; Chris W. Hughes; Jeffrey R. Blundell;
    Country: United Kingdom
    Project: UKRI | MESoscale Ocean eddies an... (NE/K005928/1)

    We use ensemble runs of a three-layer, quasigeostrophic idealized Southern Ocean model to explore the roles of forced and intrinsic variability in response to a linear increase of wind stress imposed over a 30-year period. We find no increase of eastward circumpolar volume transport in response to the increased wind stress. A large part of the resulting time series can be explained by a response in which the eddy kinetic energy is linearly proportional to the wind stress with a possible time lag, but no statistically significant lag is found. However, this simple relationship is not the whole story: several intrinsic timescales also influence the response. We find an e-folding timescale for growth of small perturbations of 1-2 weeks. The energy budget for intrinsic variability at periods shorter than a year is dominated by exchange between kinetic and potential energy. At longer timescales, we find an intrinsic mode with period in the region of 15 years, which is dominated by changes in potential energy and frictional dissipation in a manner consistent with that seen by Hogg and Blundell [2006]. A similar mode influences the response to changing wind stress. This influence, robust to perturbations, is different from the supposed linear relationship between wind stress and eddy kinetic energy, and persists for 5-10 years in this model, suggestive of a forced oscillatory mode with period of around 15 years. If present in the real ocean, such a mode would imply a degree of predictability of Southern Ocean dynamics on multi-year timescales.

  • Open Access
    Authors: 
    Matthias Feinaeugle; Daniel J. Heath; Benjamin Mills; James A. Grant-Jacob; Goran Z. Mashanovich; Robert W. Eason;
    Publisher: Springer Science and Business Media LLC
    Country: United Kingdom
    Project: UKRI | Integrated Photonic Mater... (EP/J008052/1), UKRI | Digital Multimirror Devic... (EP/L022230/1)

    Femtosecond laser-induced backward transfer of transparent photopolymers is demonstrated in the solid state, assisted by a digital micromirror spatial light modulator for producing shaped deposits. Through use of an absorbing silicon carrier substrate, we have been able to successfully transfer solid-phase material, with lateral dimensions as small as ~6 microns. In addition, a carrier of silicon incorporating a photonic waveguide relief structure enables the transfer of imprinted deposits that have been accomplished with surface features exactly complementing those present on the substrate, with an observed minimum feature size of 140 nm.

  • Publication . Article . Preprint . 2013 . Embargo End Date: 01 Jan 2013
    Open Access
    Authors: 
    Daniel Asmus; Sebastian F. Hönig; Poshak Gandhi; Alain Smette; Wolfgang J. Duschl;
    Publisher: arXiv
    Country: United Kingdom
    Project: UKRI | Black hole accretion and ... (ST/J003697/1)

    We present the first subarcsecond-resolution mid-infrared (MIR) atlas of local active galactic nuclei (AGN). Our atlas contains 253 AGN with a median redshift of z=0.016, and includes all publicly available MIR imaging performed to date with ground-based 8-m class telescopes, a total of 895 independent measurements. Of these, more than 60% are published here for the first time. We detect extended nuclear emission in at least 21% of the objects, while another 19% appear clearly point-like, and the remaining objects cannot be constrained. Where present, elongated nuclear emission aligns with the ionization cones in Seyferts. Subarcsecond resolution allows us to isolate the AGN emission on scales of a few tens of parsecs and to obtain nuclear photometry in multiple filters for the objects. Median spectral energy distributions (SEDs) for the different optical AGN types are constructed and individual MIR 12 and 18micron continuum luminosities are computed. These range over more than six orders of magnitude. In comparison to the arcsecond-scale MIR emission as probed by Spitzer, the continuum emission is much lower on subarcsecond scales in many cases. The silicate feature strength is similar on both scales and generally appears in emission (absorption) in type I (II) AGN. However, the polycyclic aromatic hydrocarbon emission appears weaker or absent on subarcsecond scales. The differences of the MIR SEDs on both scales are particularly large for AGN/starburst composites and close-by (and weak) AGN. The nucleus dominates over the total emission of the galaxy only at luminosities >=10^(44)erg/s. The AGN MIR atlas is well suited not only for detailed investigation of individual sources but also for statistical studies of AGN unification. Published in MNRAS. This version contains the individual object descriptions. Tables available at http://cdsarc.u-strasbg.fr/cgi-bin/VizieR?-source=J/MNRAS/439/1648. Fits images, tables & object descriptions accessible through the Virtual Observatory via GAVO (Topcat, Aladin etc.; ID: sasmirala). Original front-end: http://dc.g-vo.org/sasmirala

  • Open Access
    Authors: 
    Berridge, G; Menassa, D; Moloney, T; Waters, P; Welding, I; Thomsen, S; Zuberi, S; Fischer, R; Aricescu, A; Pike, M; +6 more
    Country: United Kingdom
    Project: UKRI | The structural biology of... (MR/L009609/1), WT | The immunobiology of auto... (104079), UKRI | The structural biology of... (MC_UP_1201/15), UKRI | Structural analysis of hu... (BB/M024709/1)

    Objective To identify neuronal surface antibodies in opsoclonus myoclonus ataxia syndrome (OMAS) using contemporary antigen discovery methodology. Methods OMAS patient serum immunoglobulin G immunohistochemistry using age-equivalent rat cerebellar tissue was followed by immunoprecipitation, gel electrophoresis, and mass spectrometry. Data are available via ProteomeXchange (identifier PXD009578). This generated a list of potential neuronal surface cerebellar autoantigens. Live cell-based assays were used to confirm membrane-surface antigens and adsorb antigen-specific immunoglobulin Gs. The serologic results were compared to the clinical data. Results Four of the 6 OMAS sera tested bound rat cerebellar sections. Two of these sera with similar immunoreactivities were used in immunoprecipitation experiments using cerebellum from postnatal rat pups (P18). Mass spectrometry identified 12 cell-surface proteins, of which glutamate receptor δ2 (GluD2), a predominately cerebellar-expressed protein, was found at a 3-fold-higher concentration than the other 11 proteins. Antibodies to GluD2 were identified in 14/16 (87%) OMAS samples, compared with 5/139 (5%) pediatric and 1/38 (2.6%) adult serum controls (p < 0.0001), and in 2/4 sera from patients with neuroblastoma without neurologic features. Adsorption of positive OMAS sera against GluD2-transfected cells substantially reduced but did not eliminate reactivity toward cerebellar sections. Conclusion Autoantibodies to GluD2 are common in patients with OMAS, bind to surface determinants, and are potentially pathogenic.

  • Open Access English
    Authors: 
    Mark D. Fletcher; Katrin Krumbholz; Jessica de Boer;
    Publisher: Springer
    Country: United Kingdom
    Project: UKRI | Non-invasive studies of a... (MC_U135097128)

    The active cochlear mechanism amplifies responses to low-intensity sounds, compresses the range of input sound intensities to a smaller output range, and increases cochlear frequency selectivity. The gain of the active mechanism can be modulated by the medial olivocochlear (MOC) efferent system, creating the possibility of top-down control at the earliest level of auditory processing. In humans, MOC function has mostly been measured by the suppression of optoacoustic emissions (OAEs), typically as a result of MOC activation by a contralateral elicitor sound. The exact relationship between OAE suppression and cochlear gain reduction, however, remains unclear. Here, we measured the effect of a contralateral MOC elicitor on perceptual estimates of cochlear gain and compression, obtained using the established temporal masking curve (TMC) method. The measurements were taken at a signal frequency of 2 kHz and compared with measurements of click-evoked OAE suppression. The elicitor was a broadband noise, set to a sound pressure level of 54 dB to avoid triggering the middle ear muscle reflex. Despite its low level, the elicitor had a significant effect on the TMCs, consistent with a reduction in cochlear gain. The amount of gain reduction was estimated as 4.4 dB on average, corresponding to around 18 % of the without-elicitor gain. As a result, the compression exponent increased from 0.18 to 0.27.

Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
1,995 Research products, page 1 of 200
  • Publication . Article . Preprint . 2020
    Open Access
    Authors: 
    Rubén J. Sánchez-García;
    Publisher: Springer Science and Business Media LLC
    Country: United Kingdom
    Project: UKRI | Isaac Newton Institute fo... (EP/K032208/1)

    Virtually all network analyses involve structural measures between pairs of vertices, or of the vertices themselves, and the large amount of symmetry present in real-world complex networks is inherited by such measures. This has practical consequences which have not yet been explored in full generality, nor systematically exploited by network practitioners. Here we study the effect of network symmetry on arbitrary network measures, and show how this can be exploited in practice in a number of ways, from redundancy compression, to computational reduction. We also uncover the spectral signatures of symmetry for an arbitrary network measure such as the graph Laplacian. Computing network symmetries is very efficient in practice, and we test real-world examples up to several million nodes. Since network models are ubiquitous in the Applied Sciences, and typically contain a large degree of structural redundancy, our results are not only significant, but widely applicable. Author name updated (accents added)

  • Open Access English
    Authors: 
    Muhammad Naveed; Mutez Ali Ahmed; Pascal Benard; Lawrie K. Brown; Timothy S. George; A. G. Bengough; Tiina Roose; Nicolai Koebernick; Paul D. Hallett;
    Publisher: Springer International Publishing
    Country: United Kingdom
    Project: UKRI | Rhizosphere by design: br... (BB/L026058/1), UKRI | Real-time in situ sensing... (BB/P004180/1), EC | DIMR (646809), UKRI | Truly Predicting Root Upt... (BB/J000868/1), UKRI | Rooting for sustainable p... (EP/M020355/1), UKRI | Rice germplasm for high g... (BB/J011460/1)

    Abstract\ud Aims Rhizodeposits collected from hydroponic solutions with roots of maize and barley, and seed mucilage washed from chia, were added to soil to measure their impact on water retention and hysteresis in a sandy loam soil at a range of concentrations. We test the hypothesis that the effect of plant exudates and mucilages on hydraulic properties of soils depend on their physicochemical characteristics and origin.\ud Methods Surface tension and viscosity of the exudate solutions were measured using the Du Noüy ring method and a cone-plate rheometer, respectively. The contact angle of water on exudate treated soil was measured with the sessile drop method. Water retention and hysteresis were measured by equilibrating soil samples, treated with exudates and mucilages at 0.46 and 4.6 mg g−1 concentration, on dialysis tubing filled with polyethylene glycol (PEG) solution of known osmotic potential.\ud Results Surface tension decreased and viscosity increased with increasing concentration of the exudates and mucilage in solutions. Change in surface tension and viscosity was greatest for chia seed exudate and least for barley root exudate. Contact angle increased with increasing maize root and chia seed exudate concentration in soil, but not barley root. Chia seed mucilage and maize root rhizodeposits enhanced soil water retention and increased hysteresis index, whereas barley root rhizodeposits decreased soil water retention and the hysteresis effect. The impact of exudates and mucilages on soil water retention almost ceased when approaching the wilting point at −1500 kPa matric potential.\ud Conclusions Barley rhizodeposits behaved as surfactants, drying the rhizosphere at smaller suctions. Chia seed mucilage and maize root rhizodeposits behaved as hydrogels that hold more water in the rhizosphere, but with slower rewetting and greater hysteresis.

  • Open Access English
    Authors: 
    Daniele Carrieri; Anneke Lucassen; Angus John Clarke; Sandi Dheensa; Shane Doheny; Peter D. Turnpenny; Susan E. Kelly;
    Publisher: Nature Publishing Group
    Country: United Kingdom
    Project: UKRI | Mainstreaming Genomics: R... (ES/L002868/1)

    Purpose: To ascertain whether and how recontacting occurs in the United Kingdom. Genet Med 18 9, 876–881. Method: A Web-based survey was administered online between October 2014 and July 2015. A link to the survey was circulated via an e-mail invitation to the clinical leads of the United Kingdom's 23 clinical genetics services, with follow-up with senior clinical genetics staff. Genet Med 18 9, 876–881. Results: The majority of UK services reported that they recontact patients and their family members. However, recontacting generally occurs in an ad hoc fashion when an unplanned event causes clinicians to review a file (a “trigger”). There are no standardized recontacting practices in the United Kingdom. More than half of the services were unsure whether formalized recontacting systems should be implemented. Some suggested greater patient involvement in the process of recontacting. Genet Med 18 9, 876–881. Conclusion: This research suggests that a thorough evaluation of the efficacy and sustainability of potential recontacting systems within the National Health Service would be necessary before deciding whether and how to implement such a service or to create guidelines on best-practice models. Genet Med 18 9, 876–881.

  • Publication . Article . Preprint . 2020 . Embargo End Date: 01 Jan 2019
    Open Access
    Authors: 
    Alexander Belyaev; Kazem Bitaghsir Fadafan; Nick Evans; Mansoureh Gholamzadeh;
    Publisher: arXiv
    Country: United Kingdom
    Project: UKRI | New Frontiers in Particle... (ST/P000711/1)

    We use a holographic description of technicolor dynamics to study gauge theories that only break chiral symmetry when aided by a strong four fermion interaction. These Nambu-Jona-Lasinio (NJL) assisted technicolor models provide examples of different dynamics from walking technicolor which can, by tuning, generate a light higgs like $\sigma$ meson. We compute the vector meson ($\rho$) and axial vector meson (A) spectrum for a variety of models with techni-quarks in the fundamental representation, enlarging the available parameter space over a previous analysis of walking theories. These predictions determine the parameter space of a low energy effective description where LHC constraints from dilepton channels have already been applied. Many of the models with low numbers of electroweak doublets still lie beyond current constraints and motivate exploration of new signatures beyond dilepton for LHC and a 100 TeV proton collider. Comment: 13 pages, 6 figures, 9 tables

  • Publication . Article . 2011
    Open Access English
    Authors: 
    Arjan van der Schaft; Paolo Rapisarda;
    Countries: Netherlands, United Kingdom
    Project: UKRI | Polynomial Algebraic Meth... (EP/I000909/1)

    We develop a new approach to the construction of state vectors for linear time-invariant systems described by higher-order differential equations. The basic observation is that the concatenation of two solutions of higher-order differential equations results in another (weak) solution once their remainder terms resulting from (repeated) integration by parts match. These remainder terms can be computed in a simple and efficient manner by making use of the calculus of bilinear differential forms and two-variable polynomial matrices. Factorization of the resulting two-variable polynomial matrix defines a state map, as well as a state map for the adjoint system. Minimality of these state maps is characterized. The theory is applied to three classes of systems with additional structure, namely self-adjoint Hamiltonian, conservative port-Hamiltonian, and time-reversible systems. For the first two classes it is shown how the factorization leading to a (minimal) state map is equivalent to the factorization of another two-variable polynomial matrix, which is immediately derived from the external system characterization, and defines a symplectic, respectively, symmetric, bilinear form on the minimal state space.

  • Open Access English
    Authors: 
    Chris Wilson; Chris W. Hughes; Jeffrey R. Blundell;
    Country: United Kingdom
    Project: UKRI | MESoscale Ocean eddies an... (NE/K005928/1)

    We use ensemble runs of a three-layer, quasigeostrophic idealized Southern Ocean model to explore the roles of forced and intrinsic variability in response to a linear increase of wind stress imposed over a 30-year period. We find no increase of eastward circumpolar volume transport in response to the increased wind stress. A large part of the resulting time series can be explained by a response in which the eddy kinetic energy is linearly proportional to the wind stress with a possible time lag, but no statistically significant lag is found. However, this simple relationship is not the whole story: several intrinsic timescales also influence the response. We find an e-folding timescale for growth of small perturbations of 1-2 weeks. The energy budget for intrinsic variability at periods shorter than a year is dominated by exchange between kinetic and potential energy. At longer timescales, we find an intrinsic mode with period in the region of 15 years, which is dominated by changes in potential energy and frictional dissipation in a manner consistent with that seen by Hogg and Blundell [2006]. A similar mode influences the response to changing wind stress. This influence, robust to perturbations, is different from the supposed linear relationship between wind stress and eddy kinetic energy, and persists for 5-10 years in this model, suggestive of a forced oscillatory mode with period of around 15 years. If present in the real ocean, such a mode would imply a degree of predictability of Southern Ocean dynamics on multi-year timescales.

  • Open Access
    Authors: 
    Matthias Feinaeugle; Daniel J. Heath; Benjamin Mills; James A. Grant-Jacob; Goran Z. Mashanovich; Robert W. Eason;
    Publisher: Springer Science and Business Media LLC
    Country: United Kingdom
    Project: UKRI | Integrated Photonic Mater... (EP/J008052/1), UKRI | Digital Multimirror Devic... (EP/L022230/1)

    Femtosecond laser-induced backward transfer of transparent photopolymers is demonstrated in the solid state, assisted by a digital micromirror spatial light modulator for producing shaped deposits. Through use of an absorbing silicon carrier substrate, we have been able to successfully transfer solid-phase material, with lateral dimensions as small as ~6 microns. In addition, a carrier of silicon incorporating a photonic waveguide relief structure enables the transfer of imprinted deposits that have been accomplished with surface features exactly complementing those present on the substrate, with an observed minimum feature size of 140 nm.

  • Publication . Article . Preprint . 2013 . Embargo End Date: 01 Jan 2013
    Open Access
    Authors: 
    Daniel Asmus; Sebastian F. Hönig; Poshak Gandhi; Alain Smette; Wolfgang J. Duschl;
    Publisher: arXiv
    Country: United Kingdom
    Project: UKRI | Black hole accretion and ... (ST/J003697/1)

    We present the first subarcsecond-resolution mid-infrared (MIR) atlas of local active galactic nuclei (AGN). Our atlas contains 253 AGN with a median redshift of z=0.016, and includes all publicly available MIR imaging performed to date with ground-based 8-m class telescopes, a total of 895 independent measurements. Of these, more than 60% are published here for the first time. We detect extended nuclear emission in at least 21% of the objects, while another 19% appear clearly point-like, and the remaining objects cannot be constrained. Where present, elongated nuclear emission aligns with the ionization cones in Seyferts. Subarcsecond resolution allows us to isolate the AGN emission on scales of a few tens of parsecs and to obtain nuclear photometry in multiple filters for the objects. Median spectral energy distributions (SEDs) for the different optical AGN types are constructed and individual MIR 12 and 18micron continuum luminosities are computed. These range over more than six orders of magnitude. In comparison to the arcsecond-scale MIR emission as probed by Spitzer, the continuum emission is much lower on subarcsecond scales in many cases. The silicate feature strength is similar on both scales and generally appears in emission (absorption) in type I (II) AGN. However, the polycyclic aromatic hydrocarbon emission appears weaker or absent on subarcsecond scales. The differences of the MIR SEDs on both scales are particularly large for AGN/starburst composites and close-by (and weak) AGN. The nucleus dominates over the total emission of the galaxy only at luminosities >=10^(44)erg/s. The AGN MIR atlas is well suited not only for detailed investigation of individual sources but also for statistical studies of AGN unification. Published in MNRAS. This version contains the individual object descriptions. Tables available at http://cdsarc.u-strasbg.fr/cgi-bin/VizieR?-source=J/MNRAS/439/1648. Fits images, tables & object descriptions accessible through the Virtual Observatory via GAVO (Topcat, Aladin etc.; ID: sasmirala). Original front-end: http://dc.g-vo.org/sasmirala

  • Open Access
    Authors: 
    Berridge, G; Menassa, D; Moloney, T; Waters, P; Welding, I; Thomsen, S; Zuberi, S; Fischer, R; Aricescu, A; Pike, M; +6 more
    Country: United Kingdom
    Project: UKRI | The structural biology of... (MR/L009609/1), WT | The immunobiology of auto... (104079), UKRI | The structural biology of... (MC_UP_1201/15), UKRI | Structural analysis of hu... (BB/M024709/1)

    Objective To identify neuronal surface antibodies in opsoclonus myoclonus ataxia syndrome (OMAS) using contemporary antigen discovery methodology. Methods OMAS patient serum immunoglobulin G immunohistochemistry using age-equivalent rat cerebellar tissue was followed by immunoprecipitation, gel electrophoresis, and mass spectrometry. Data are available via ProteomeXchange (identifier PXD009578). This generated a list of potential neuronal surface cerebellar autoantigens. Live cell-based assays were used to confirm membrane-surface antigens and adsorb antigen-specific immunoglobulin Gs. The serologic results were compared to the clinical data. Results Four of the 6 OMAS sera tested bound rat cerebellar sections. Two of these sera with similar immunoreactivities were used in immunoprecipitation experiments using cerebellum from postnatal rat pups (P18). Mass spectrometry identified 12 cell-surface proteins, of which glutamate receptor δ2 (GluD2), a predominately cerebellar-expressed protein, was found at a 3-fold-higher concentration than the other 11 proteins. Antibodies to GluD2 were identified in 14/16 (87%) OMAS samples, compared with 5/139 (5%) pediatric and 1/38 (2.6%) adult serum controls (p < 0.0001), and in 2/4 sera from patients with neuroblastoma without neurologic features. Adsorption of positive OMAS sera against GluD2-transfected cells substantially reduced but did not eliminate reactivity toward cerebellar sections. Conclusion Autoantibodies to GluD2 are common in patients with OMAS, bind to surface determinants, and are potentially pathogenic.

  • Open Access English
    Authors: 
    Mark D. Fletcher; Katrin Krumbholz; Jessica de Boer;
    Publisher: Springer
    Country: United Kingdom
    Project: UKRI | Non-invasive studies of a... (MC_U135097128)

    The active cochlear mechanism amplifies responses to low-intensity sounds, compresses the range of input sound intensities to a smaller output range, and increases cochlear frequency selectivity. The gain of the active mechanism can be modulated by the medial olivocochlear (MOC) efferent system, creating the possibility of top-down control at the earliest level of auditory processing. In humans, MOC function has mostly been measured by the suppression of optoacoustic emissions (OAEs), typically as a result of MOC activation by a contralateral elicitor sound. The exact relationship between OAE suppression and cochlear gain reduction, however, remains unclear. Here, we measured the effect of a contralateral MOC elicitor on perceptual estimates of cochlear gain and compression, obtained using the established temporal masking curve (TMC) method. The measurements were taken at a signal frequency of 2 kHz and compared with measurements of click-evoked OAE suppression. The elicitor was a broadband noise, set to a sound pressure level of 54 dB to avoid triggering the middle ear muscle reflex. Despite its low level, the elicitor had a significant effect on the TMCs, consistent with a reduction in cochlear gain. The amount of gain reduction was estimated as 4.4 dB on average, corresponding to around 18 % of the without-elicitor gain. As a result, the compression exponent increased from 0.18 to 0.27.

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