Recent Submissions

  • The Friedrichs extension for elliptic wedge operators of second order

    Krainer, T; Mendoza, GA (2018-03-01)
    Let M be a smooth compact manifold whose boundary is the total space of a fibration N → Y with compact fibers, let E → M be a vector bundle. Let be a second order elliptic semibounded wedge operator. Under certain mild natural conditions on the indicial and normal families of A, the trace bundle of A relative to ν splits as a direct sum I = IF ⊕ IaF and there is a natural map P: C∞(Y;IF) → C∞(M; E) such that CIF∞(M; E) = P(C∞(Y;IF)) + Ċ∞(M;E) ⊂ Dmax(A). It is shown that the closure of A when given the domain CIF∞(M;E) is the Friedrichs extension of (†) and that this extension is a Fredholm operator with compact resolvent. Also given are theorems pertaining the structure of the domain of the extension which completely characterize the regularity of its elements at the boundary.
  • Type II secretion-dependent aminopeptidase lapa and acyltransferase plac are redundant for nutrient acquisition during Legionella pneumophila intracellular infection of amoebas

    White, RC; Gunderson, FF; Tyson, JY; Richardson, KH; Portlock, TJ; Garnett, JA; Cianciotto, NP (2018-03-01)
    © 2018 White et al. Legionella pneumophila genes encoding LapA, LapB, and PlaC were identified as the most highly upregulated type II secretion (T2S) genes during infection of Acanthamoeba castellanii, although these genes had been considered dispensable on the basis of the behavior of mutants lacking either lapA and lapB or plaC. A plaC mutant showed even higher levels of lapA and lapB transcripts, and a lapA lapB mutant showed heightening of plaC mRNA levels, suggesting that the role of the LapA/B aminopeptidase is compensatory with respect to that of the PlaC acyltransferase. Hence, we made double mutants and found that lapA plaC mutants have an ~50-fold defect during infection of A. castellanii. These data revealed, for the first time, the importance of LapA in any sort of infection; thus, we purified LapA and defined its crystal structure, activation by another T2S-dependent protease (ProA), and broad substrate specificity. When the amoebal infection medium was supplemented with amino acids, the defect of the lapA plaC mutant was reversed, implying that LapA generates amino acids for nutrition. Since the LapA and PlaC data did not fully explain the role of T2S in infection, we identified, via proteomic analysis, a novel secreted protein (NttD) that promotes infection of A. castellanii. A lapA plaC nttD mutant displayed an even greater (100-fold) defect, demonstrating that the LapA, PlaC, and NttD data explain, to a significant degree, the importance of T2S. LapA-, PlaC-, and NttD-like proteins had distinct distribution patterns within and outside the Legionella genus. LapA was notable for having as its closest homologue an A. castellanii protein. IMPORTANCE Transmission of L. pneumophila to humans is facilitated by its ability to grow in Acanthamoeba species. We previously documented that type II secretion (T2S) promotes L. pneumophila infection of A. castellanii. Utilizing transcriptional analysis and proteomics, double and triple mutants, and crystal structures, we defined three secreted substrates/effectors that largely clarify the role of T2S during infection of A. castellanii. Particularly interesting are the unique functional overlap between an acyltransferase (PlaC) and aminopeptidase (LapA), the broad substrate specificity and eukaryotic-protein-like character of LapA, and the novelty of NttD. Linking LapA to amino acid acquisition, we defined, for the first time, the importance of secreted aminopeptidases in intracellular infection. Bioinformatic investigation, not previously applied to T2S, revealed that effectors originate from diverse sources and distribute within the Legionella genus in unique ways. The results of this study represent a major advance in understanding Legionella ecology and pathogenesis, bacterial secretion, and the evolution of intracellular parasitism.
  • Robust singlet fission in pentacene thin films with tuned charge transfer interactions

    Broch, K; Dieterle, J; Branchi, F; Hestand, NJ; Olivier, Y; Tamura, H; Cruz, C; Nichols, VM; Hinderhofer, A; Beljonne, D; Spano, FC; Cerullo, G; Bardeen, CJ; Schreiber, F (2018-12-01)
    © 2018 The Author(s). Singlet fission, the spin-allowed photophysical process converting an excited singlet state into two triplet states, has attracted significant attention for device applications. Research so far has focused mainly on the understanding of singlet fission in pure materials, yet blends offer the promise of a controlled tuning of intermolecular interactions, impacting singlet fission efficiencies. Here we report a study of singlet fission in mixtures of pentacene with weakly interacting spacer molecules. Comparison of experimentally determined stationary optical properties and theoretical calculations indicates a reduction of charge-transfer interactions between pentacene molecules with increasing spacer molecule fraction. Theory predicts that the reduced interactions slow down singlet fission in these blends, but surprisingly we find that singlet fission occurs on a timescale comparable to that in pure crystalline pentacene. We explain the observed robustness of singlet fission in such mixed films by a mechanism of exciton diffusion to hot spots with closer intermolecular spacings.
  • Hydroxide diffuses slower than hydronium in water because its solvated structure inhibits correlated proton transfer

    Chen, Mohan; Zheng, Lixin; Santra, Biswajit; Ko, Hsin-Yu; Jr, DiStasio Robert A; Klein, Michael L; Car, Roberto; Wu, Xifan; Santra, Biswajit|0000-0003-3609-2106 (2018-04)
    Proton transfer via hydronium and hydroxide ions in water is ubiquitous. It underlies acid-base chemistry, certain enzyme reactions, and even infection by the flu. Despite two-centuries of investigation, the mechanism underlying why hydronium diffuses faster than hydroxide in water is still not well understood. Herein, we employ state of the art Density Functional Theory based molecular dynamics, with corrections for nonlocal van der Waals interactions, and self-interaction in the electronic ground state, to model water and the hydrated water ions. At this level of theory, structural diffusion of hydronium preserves the previously recognized concerted behavior. However, by contrast, proton transfer via hydroxide is dominated by stepwise events, arising from a stabilized hyper-coordination solvation structure that discourages proton transfer. Specifically, the latter exhibits non-planar geometry, which agrees with neutron scattering results. Asymmetry in the temporal correlation of proton transfer enables hydronium to diffuse faster than hydroxide.
  • Design and performance of the spin asymmetries of the nucleon experiment

    Maxwell, JD; Armstrong, WR; Choi, S; Jones, MK; Kang, H; Liyanage, A; Meziani, ZE; Mulholland, J; Ndukum, L; Rondón, OA; Ahmidouch, A; Albayrak, I; Asaturyan, A; Ates, O; Baghdasaryan, H; Boeglin, W; Bosted, P; Brash, E; Brock, J; Butuceanu, C; Bychkov, M; Carlin, C; Carter, P; Chen, C; Chen, JP; Christy, ME; Covrig, S; Crabb, D; Danagoulian, S; Daniel, A; Davidenko, AM; Davis, B; Day, D; Deconinck, W; Deur, A; Dunne, J; Dutta, D; El Fassi, L; Elaasar, M; Ellis, C; Ent, R; Flay, D; Frlez, E; Gaskell, D; Geagla, O; German, J; Gilman, R; Gogami, T; Gomez, J; Goncharenko, YM; Hashimoto, O; Higinbotham, DW; Horn, T; Huber, GM; Jones, M; Kalantarians, N; Kang, HK; Kawama, D; Keith, C; Keppel, C; Khandaker, M; Kim, Y; King, PM; Kohl, M; Kovacs, K; Kubarovsky, V; Li, Y; Liyanage, N; Luo, W; Mamyan, V; Markowitz, P; Maruta, T; Meekins, D; Melnik, YM; Mkrtchyan, A; Mkrtchyan, H; Mochalov, VV; Monaghan, P; Narayan, A; Nakamura, SN; Nuruzzaman; Pentchev, L; Pocanic, D; Posik, M; Puckett, A; Qiu, X; Reinhold, J; Riordan, S; Roche, J; Sawatzky, B; Shabestari, M; Slifer, K; Smith, G; Soloviev, L; Solvignon, P; Tadevosyan, V; Tang, L; Vasiliev, AN; Veilleux, M; Walton, T (2018-03-21)
    © 2017 Elsevier B.V. The Spin Asymmetries of the Nucleon Experiment (SANE) performed inclusive, double-polarized electron scattering measurements of the proton at the Continuous Electron Beam Accelerator Facility at Jefferson Lab. A novel detector array observed scattered electrons of four-momentum transfer 2.5<Q2<6.5GeV2 and Bjorken scaling 0.3<x<0.8 from initial beam energies of 4.7 and 5.9 GeV. Employing a polarized proton target whose magnetic field direction could be rotated with respect to the incident electron beam, both parallel and near perpendicular spin asymmetries were measured, allowing model-independent access to transverse polarization observables A1, A2, g1, g2 and moment d2 of the proton. This document summarizes the operation and performance of the polarized target, polarized electron beam, and novel detector systems used during the course of the experiment, and describes analysis techniques utilized to access the physics observables of interest.
  • Stability in the feeding practices and styles of low-income mothers: Questionnaire and observational analyses

    Silva Garcia, K; Power, TG; Beck, AD; Fisher, JO; Goodell, LS; Johnson, SL; O'Connor, TM; Hughes, SO (2018-03-23)
    © 2018 The Author(s). Background: During the last two decades, researchers have devoted considerable attention to the role of maternal feeding behaviors, practices, and styles in the development of obesity in young children. Little is known, however, about the consistency of maternal feeding across settings and time. The purpose of this paper was to provide data on this issue by examining the consistency of observed maternal feeding behavior across multiple eating occasions, as well as examine the consistency of observed and self-reported maternal feeding behavior across 18 months. Methods: Videotapes from two studies of low-income mothers and their preschool children were coded for feeding practices, dimensions, and styles: a study of 137 low-income, African American and Latina mothers and their children observed during three meals in their homes over a two to three week period, and a study of 138 low-income, Latina mothers observed during a buffet meal in a laboratory setting on two separate occasions 18 months apart. Videotapes from both studies were coded for a wide range of maternal feeding behaviors and strategies. Mothers in the second study also completed three validated, self-report questionnaires on their feeding practices and styles. Results: Overall, both observed and self-reported feeding practices and styles showed only moderate levels of stability across meals and over time. Maternal attempts to regulate children's eating showed more stability across meals and over time than the content of general mealtime conversation. Also, greater stability was found in what mothers were trying to get their children to do during the meals than in the strategies they used to influence child behavior. Self-reports of feeding showed greater stability over time than observational measures. Across meals and across 18 months, the stability of general feeding styles was between 40% and 50%. Conclusions: The findings demonstrate that maternal feeding behavior was only moderately stable across meals and over time-that is, feeding behavior varied considerably across situations. The lack of high levels of consistency in feeding behavior suggests that situational factors may play a major role in influencing maternal behavior as well. Family-focused childhood obesity programs should focus not only on helping parents change their feeding practices and styles, but also focus on increasing parents' sensitivity to situational factors that affect their approach to feeding their children.
  • Computation of parton distributions from the quasi-PDF approach at the physical point

    Alexandrou, C; Bacchio, S; Cichy, K; Constantinou, M; Hadjiyiannakou, K; Jansen, K; Koutsou, G; Scapellato, A; Steffens, F (2018-03-26)
    © The Authors, published by EDP Sciences, 2018. We show the first results for parton distribution functions within the proton at the physical pion mass, employing the method of quasi-distributions. In particular, we present the matrix elements for the iso-vector combination of the unpolarized, helicity and transversity quasi-distributions, obtained with Nf = 2 twisted mass cloverimproved fermions and a proton boosted with momentum p→ = 0.83 GeV. The momentum smearing technique has been applied to improve the overlap with the proton boosted state. Moreover, we present the renormalized helicity matrix elements in the RI' scheme, following the non-perturbative renormalization prescription recently developed by our group.
  • Cosmogenic neutron production at Daya Bay

    An, FP; Balantekin, AB; Band, HR; Bishai, M; Blyth, S; Cao, D; Cao, GF; Cao, J; Chan, YL; Chang, JF; Chang, Y; Chen, HS; Chen, SM; Chen, Y; Chen, YX; Cheng, J; Cheng, ZK; Cherwinka, JJ; Chu, MC; Chukanov, A; Cummings, JP; Ding, YY; Diwan, MV; Dolgareva, M; Dove, J; Dwyer, DA; Edwards, WR; Gill, R; Gonchar, M; Gong, GH; Gong, H; Grassi, M; Gu, WQ; Guo, L; Guo, XH; Guo, YH; Guo, Z; Hackenburg, RW; Hans, S; He, M; Heeger, KM; Heng, YK; Higuera, A; Hsiung, YB; Hu, BZ; Hu, T; Huang, HX; Huang, XT; Huang, YB; Huber, P; Huo, W; Hussain, G; Jaffe, DE; Jen, KL; Ji, XL; Ji, XP; Jiao, JB; Johnson, RA; Jones, D; Kang, L; Kettell, SH; Khan, A; Koerner, LW; Kohn, S; Kramer, M; Kwok, MW; Langford, TJ; Lau, K; Lebanowski, L; Lee, J; Lee, JHC; Lei, RT; Leitner, R; Leung, JKC; Li, C; Li, DJ; Li, F; Li, GS; Li, QJ; Li, S; Li, SC; Li, WD; Li, XN; Li, XQ; Li, YF; Li, ZB; Liang, H; Lin, CJ; Lin, GL; Lin, S; Lin, SK; Lin, Y-C; Ling, JJ; Link, JM; Littenberg, L; Littlejohn, BR; Liu, JC; Liu, JL; Loh, CW; Lu, C; Lu, HQ; Lu, JS; Luk, KB; Ma, XB; Ma, XY; Ma, YQ; Malyshkin, Y; Caicedo, DA Martinez; McDonald, KT; McKeown, RD; Mitchell, I; Nakajima, Y; Napolitano, J; Naumov, D; Naumova, E; Ochoa-Ricoux, JP; Olshevskiy, A; Pan, H-R; Park, J; Patton, S; Pec, V; Peng, JC; Pinsky, L; Pun, CSJ; Qi, FZ; Qi, M; Qian, X; Qiu, RM; Raper, N; Ren, J; Rosero, R; Roskovec, B; Ruan, XC; Steiner, H; Sun, JL; Tang, W; Taychenachev, D; Treskov, K; Tsang, KV; Tse, W-H; Tull, CE; Viaux, N; Viren, B; Vorobel, V; Wang, CH; Wang, M; Wang, NY; Wang, RG; Wang, W; Wang, X; Wang, YF; Wang, Z; Wang, Z; Wang, ZM; Wei, HY; Wen, LJ; Whisnant, K; White, CG; Wise, T; Wong, HLH; Wong, SCF; Worcester, E; Wu, C-H; Wu, Q; Wu, WJ; Xia, DM; Xia, JK; Xing, ZZ; Xu, JL; Xu, Y; Xue, T; Yang, CG; Yang, H; Yang, L; Yang, MS; Yang, MT; Yang, YZ; Ye, M; Ye, Z; Yeh, M; Young, BL; Yu, ZY; Zeng, S; Zhan, L; Zhang, C; Zhang, CC; Zhang, HH; Zhang, JW; Zhang, QM; Zhang, R; Zhang, XT; Zhang, YM; Zhang, YM; Zhang, YX; Zhang, ZJ; Zhang, ZP; Zhang, ZY; Zhao, J; Zhou, L; Zhuang, HL; Zou, JH; Collaboration, Daya Bay (2018-03-26)
    Neutrons produced by cosmic ray muons are an important background for underground experiments studying neutrino oscillations, neutrinoless double beta decay, dark matter, and other rare-event signals. A measurement of the neutron yield in the three different experimental halls of the Daya Bay Reactor Neutrino Experiment at varying depth is reported. The neutron yield in Daya Bay's liquid scintillator is measured to be $Y_n=(10.26\pm 0.86)\times 10^{-5}$, $(10.22\pm 0.87)\times 10^{-5}$, and $(17.03\pm 1.22)\times 10^{-5}~\mu^{-1}~$g$^{-1}~$cm$^2$ at depths of 250, 265, and 860 meters-water-equivalent. These results are compared to other measurements and the simulated neutron yield in Fluka and Geant4. A global fit including the Daya Bay measurements yields a power law coefficient of $0.77 \pm 0.03$ for the dependence of the neutron yield on muon energy.
  • Perturbative Renormalization of Wilson line operators

    Constantinou, M; Panagopoulos, H (2018-03-26)
    © The Authors, published by EDP Sciences, 2018. We present results for the renormalization of gauge invariant nonlocal fermion operators which contain a Wilson line, to one loop level in lattice perturbation theory. Our calculations have been performed for Wilson/clover fermions and a wide class of Symanzik improved gluon actions. The extended nature of such 'long-link' operators results in a nontrivial renormalization, including contributions which diverge linearly as well as logarithmically with the lattice spacing, along with additional finite factors. We present nonperturbative prescriptions to extract the linearly divergent contributions.
  • Progress in computing parton distribution functions from the quasi-PDF approach

    Alexandrou, C; Cichy, K; Constantinou, M; Hadjiyiannakou, K; Jansen, K; Panagopoulos, H; Scapellato, A; Steffens, F (2018-03-26)
    © The Authors, published by EDP Sciences, 2018. We discuss the current developments by the European Twisted Mass Collaboration in extracting parton distribution functions from the quasi-PDF approach. We concentrate on the non-perturbative renormalization prescription recently developed by us, using the RI′ scheme. We show results for the renormalization functions of matrix elements needed for the computation of quasi-PDFs, including the conversion to the MS scheme, and for renormalized matrix elements. We discuss the systematic effects present in the Z-factors and the possible ways of addressing them in the future.
  • Dissipation of stop-and-go waves via control of autonomous vehicles: Field experiments

    Stern, RE; Cui, S; Delle Monache, ML; Bhadani, R; Bunting, M; Churchill, M; Hamilton, N; Haulcy, R; Pohlmann, H; Wu, F; Piccoli, B; Seibold, B; Sprinkle, J; Work, DB (2018-04-01)
    © 2018 Elsevier Ltd Traffic waves are phenomena that emerge when the vehicular density exceeds a critical threshold. Considering the presence of increasingly automated vehicles in the traffic stream, a number of research activities have focused on the influence of automated vehicles on the bulk traffic flow. In the present article, we demonstrate experimentally that intelligent control of an autonomous vehicle is able to dampen stop-and-go waves that can arise even in the absence of geometric or lane changing triggers. Precisely, our experiments on a circular track with more than 20 vehicles show that traffic waves emerge consistently, and that they can be dampened by controlling the velocity of a single vehicle in the flow. We compare metrics for velocity, braking events, and fuel economy across experiments. These experimental findings suggest a paradigm shift in traffic management: flow control will be possible via a few mobile actuators (less than 5%) long before a majority of vehicles have autonomous capabilities.
  • Elites are people, too: The effects of threat sensitivity on policymakers’ spending priorities

    Arceneaux, K; Dunaway, J; Soroka, S (2018-04-01)
    © 2018 Arceneaux et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Recent research suggests that psychological needs can influence the political attitudes of ordinary citizens, often outside of their conscious awareness. In this paper, we investigate whether psychological needs also shape the spending priorities of political elites in the US. Most models of policymaking assume that political elites respond to information in relatively homogeneous ways. We suggest otherwise, and explore one source of difference in information processing, namely, threat sensitivity, which previous research links to increased support for conservative policy attitudes. Drawing on a sample of state-level policymakers, we measure their spending priorities using a survey and their level of threat sensitivity using a standard psychophysiological measure (skin conductance). We find that, like ordinary citizens, threat sensitivity leads even state-level policymakers to prioritize spending on government polices that are designed to minimize threats.
  • K →π matrix elements of the chromomagnetic operator on the lattice

    Constantinou, M; Costa, M; Frezzotti, R; Lubicz, V; Martinelli, G; Meloni, D; Panagopoulos, H; Simula, S (2018-04-01)
    © 2018 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the »https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP 3 . We present the results of the first lattice QCD calculation of the K→π matrix elements of the chromomagnetic operator OCM=gsσμνGμνd, which appears in the effective Hamiltonian describing ΔS=1 transitions in and beyond the standard model. Having dimension five, the chromomagnetic operator is characterized by a rich pattern of mixing with operators of equal and lower dimensionality. The multiplicative renormalization factor as well as the mixing coefficients with the operators of equal dimension have been computed at one loop in perturbation theory. The power divergent coefficients controlling the mixing with operators of lower dimension have been determined nonperturbatively, by imposing suitable subtraction conditions. The numerical simulations have been carried out using the gauge field configurations produced by the European Twisted Mass Collaboration with Nf=2+1+1 dynamical quarks at three values of the lattice spacing. Our result for the B parameter of the chromomagnetic operator at the physical pion and kaon point is BCMOKπ=0.273(69), while in the SU(3) chiral limit we obtain BCMO=0.076(23). Our findings are significantly smaller than the model-dependent estimate BCMO∼1-4, currently used in phenomenological analyses, and improve the uncertainty on this important phenomenological quantity.
  • Topological susceptibility from twisted mass fermions using spectral projectors and the gradient flow

    Alexandrou, C; Athenodorou, A; Cichy, K; Constantinou, M; Horkel, DP; Jansen, K; Koutsou, G; Larkin, C (2018-04-01)
    © 2018 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the »https://creativecommons.org/licenses/by/4.0/» Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP 3 . We compare lattice QCD determinations of topological susceptibility using a gluonic definition from the gradient flow and a fermionic definition from the spectral-projector method. We use ensembles with dynamical light, strange and charm flavors of maximally twisted mass fermions. For both definitions of the susceptibility we employ ensembles at three values of the lattice spacing and several quark masses at each spacing. The data are fitted to chiral perturbation theory predictions with a discretization term to determine the continuum chiral condensate in the massless limit and estimate the overall discretization errors. We find that both approaches lead to compatible results in the continuum limit, but the gluonic ones are much more affected by cutoff effects. This finally yields a much smaller total error in the spectral-projector results. We show that there exists, in principle, a value of the spectral cutoff which would completely eliminate discretization effects in the topological susceptibility.
  • Validation of the Cancer Health Literacy Test-30 for Populations Without Cancer

    Dumenci, Levent; Matsuyama, Robin K; Riddle, Daniel L; Cartwright, Laura; Siminoff, Laura A; Siminoff, Laura|0000-0002-6775-665X (2018-04-01)
    Background: Cancer incidence continues to be common and highly consequential for future cancer patients, family members, and other untrained caregivers. Because low health literacy increases the likelihood of poor health outcomes, those with low health literacy would benefit from interventions to improve cancer health literacy. Objective: Our study was designed to address the need for measuring cancer health literacy in populations without cancer. Methods: The Cancer Health Literacy Test-30 (CHLT-30) was psychometrically tested on 512 people without a cancer diagnosis. Key Results: In this population without cancer, the CHLT-30 had strong psychometric properties including unidimensional measurement structure, high reliability, and invariant measurement between gender, race/ethnicity, and educational-attainment groups. Conclusion: These results support the use of the CHLT-30 to measure cancer health literacy in research studies of family members of people with cancer or the general public. The potential for using the CHLT-30 in clinical practice to assess the need for education for general patient and cancer patient populations is a future direction. [HLRP: Health Literacy Research and Practice. 2018;2(2):e58-e66.]. Plain Language Summary: Psychometric evidence suggests that the CHLT-30, originally developed for cancer patients, can be used to measure cancer health literacy of individuals with no history of cancer as well.
  • Altered neuromodulatory drive may contribute to exaggerated tonic vibration reflexes in chronic hemiparetic stroke

    McPherson, JG; McPherson, LM; Thompson, CK; Ellis, MD; Heckman, CJ; Dewald, JPA (2018-04-09)
    © 2018 McPherson, McPherson, Thompson, Ellis, Heckman and Dewald. Exaggerated stretch-sensitive reflexes are a common finding in elbow flexors of the contralesional arm in chronic hemiparetic stroke, particularly when muscles are not voluntarily activated prior to stretch. Previous investigations have suggested that this exaggeration could arise either from an abnormal tonic ionotropic drive to motoneuron pools innervating the paretic limbs, which could bring additional motor units near firing threshold, or from an increased influence of descending monoaminergic neuromodulatory pathways, which could depolarize motoneurons and amplify their responses to synaptic inputs. However, previous investigations have been unable to differentiate between these explanations, leaving the source(s) of this excitability increase unclear. Here, we used tonic vibration reflexes (TVRs) during voluntary muscle contractions of increasing magnitude to infer the sources of spinal motor excitability in individuals with chronic hemiparetic stroke. We show that when the paretic and non-paretic elbow flexors are preactivated to the same percentage of maximum prior to vibration, TVRs remain significantly elevated in the paretic arm. We also show that the rate of vibration-induced torque development increases as a function of increasing preactivation in the paretic limb, even though the amplitude of vibration-induced torque remains conspicuously unchanged as preactivation increases. It is highly unlikely that these findings could be explained by a source that is either purely ionotropic or purely neuromodulatory, because matching preactivation should control for the effects of a potential ionotropic drive (and lead to comparable tonic vibration reflex responses between limbs), while a purely monoaminergic mechanism would increase reflex magnitude as a function of preactivation. Thus, our results suggest that increased excitability of motor pools innervating the paretic limb post-stroke is likely to arise from both ionotropic and neuromodulatory mechanisms.
  • Daily Snacking Occasions and Weight Status Among US Children Aged 1 to 5 Years

    Kachurak, A; Davey, A; Bailey, RL; Fisher, JO (2018-06-01)
    © 2018 The Authors. Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS). Objective: To characterize associations of snacking frequency with weight status among US children aged 1 to 5 years. Methods: Participants were children (n = 4,669) aged 1 to 5 years in the 2005 to 2014 National Health and Nutrition Examination Survey (NHANES). Snacking was assessed by two 24-hour dietary recalls using definitions that considered “snack” occasions as well as other foods/beverages consumed between meals. Overweight/obesity (OW/OB) was defined using percentile cutoffs: ≥ 97.7th weight-for-length (< 2 years) cutoff and the ≥ 85th BMI-for-age (≥ 2 years) cutoff. Linear/logistic regressions evaluated snacking based on daily occasions and relative to current recommendations (two to three snacks per day). Results: During 2005 to 2014, US children aged 1 to 5 years consumed, on average, two to three snacks daily. Children with normal weight in both age groups tended to snack less frequently than children with OW/OB when considering all foods/beverages eaten between meals (P < 0.01-0.12). Across most snacking definitions, children < 2 years who snacked more frequently than recommended had greater odds of having OW/OB (P < 0.01-0.12) and consumed greater daily snack energy than those who snacked within recommendations (all P < 0.01). Recommendations did not clearly delineate weight status among children aged 2 to 5 years. Conclusions: Snacking frequency and weight are positively associated among US children 1 to 5 years old, with most consistent associations seen among children < 2 years old and when considering all foods/beverages consumed between meals.
  • Structure-Aware Bayesian Compressive Sensing for Frequency-Hopping Spectrum Estimation with Missing Observations

    Liu, S; Zhang, YD; Shan, T; Tao, R; Zhang, Yimin Daniel|0000-0002-4625-209X (2018-04-15)
    © 1991-2012 IEEE. In this paper, we address the problem of spectrum estimation of multiple frequency-hopping (FH) signals in the presence of random missing observations. The signals are analyzed within the bilinear time-frequency (TF) representation framework, where a TF kernel is designed by exploiting the inherent FH signal structures. The designed kernel permits effective suppression of cross-terms and artifacts due to missing observations while preserving the FH signal autoterms. The kerneled results are represented in the instantaneous autocorrelation function domain, which are then processed using a redesigned structure-aware Bayesian compressive sensing algorithm to accurately estimate the FH signal TF spectrum. The proposed method achieves high-resolution FH signal spectrum estimation even when a large portion of data observations is missing. Simulation results verify the effectiveness of the proposed method and its superiority over existing techniques.
  • Systemic inflammatory status predict the outcome of k-RAS WT metastatic colorectal cancer patients receiving the thymidylate synthase poly-epitope-peptide anticancer vaccine

    Correale, P; Botta, C; Staropoli, N; Nardone, V; Pastina, P; Ulivieri, C; Gandolfo, C; Baldari, TC; Lazzi, S; Ciliberto, D; Giannicola, R; Fioravanti, A; Giordano, A; Zappavigna, S; Caraglia, M; Tassone, P; Pirtoli, L; Cusi, MG; Tagliaferri, P; Giordano, Antonio|0000-0002-5959-016X (2018-04-17)
    © Correale et al. TSPP is an anticancer poly-epitope peptide vaccine to thymidylate synthase, recently investigated in the multi-arm phase Ib TSPP/VAC1 trial. TSPP vaccination induced immune-biological effects and showed antitumor activity in metastatic colorectal cancer (mCRC) patients and other malignancies. Progression-free and overall survival of 41 mCRC patients enrolled in the study correlated with baseline levels of CEA, immune-inflammatory markers (neutrophil/lymphocyte ratio, CRP, ESR, LDH, ENA), IL-4 and with post-treatment change in p-ANCA and CD56dimCD16brightNKs (p < 0.04). A subset of 19 patients with activating k-ras mutations showed a different immune-inflammatory response to TSPP as compared to patients with k-ras/wt and a worse outcome in term of PFS (p = 0.048). In patients with k-ras/mut, inflammatory markers lost their predictive value and their survival directly correlated with the baseline levels of IL17/A over the median value (p = 0.01). These results provide strong hints for the design of further clinical trials aimed to test TSPP vaccination in mCRC patients.
  • Baseline neutrophilia, derived neutrophil-to-lymphocyte ratio (dNLR), platelet-to-lymphocyte ratio (PLR), and outcome in non small cell lung cancer (NSCLC) treated with Nivolumab or Docetaxel

    Russo, A; Franchina, T; Ricciardi, GRR; Battaglia, A; Scimone, A; Berenato, R; Giordano, A; Adamo, V; Giordano, Antonio|0000-0002-5959-016X (2018-10-01)
    © 2018 The Authors. Journal of Cellular Physiology Published by WileyPeriodicals, Inc. Nivolumab is a novel therapeutic option in NSCLC, associated with a significant survival gain compared with Docetaxel. However, predictive biomarkers are lacking. The presence of systemic inflammation has been correlated with poor outcome in many cancer types. We aimed to evaluate whether there is a correlation between some indicators of inflammation and response to Nivolumab or Docetaxel in pre-treated NSCLCs. Data of 62 patients receiving Nivolumab or Docetaxel were analyzed. Baseline neutrophilia and thrombocytosis were not associated with response. High dNLR was associated with no response to Nivolumab, but not with Docetaxel, whereas high PLR correlated with low treatment response in both groups. Among refractory patients, a higher incidence of thrombocytosis, neutrophilia, high PLR, and high dNLR levels were observed compared with the overall population. This is one of the first reports in this field and suggests that indicators of inflammation might be included together with other predictive biomarkers in the baseline evaluation of patients candidate for immunotherapy.

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