873 research outputs found
Sex differences in the shared genetics of dimensions of self-reported depression and anxiety
No full textAbstract not available.Karen L.O. Burton, Leanne M. Williams, C. Richard Clark, Anthony Harris, Peter R. Schofield, Justine M. Gat
Modeling Phytoplankton Blooms and Inorganic Carbon Responses to Sea‐Ice Variability in the West Antarctic Peninsula
No full text© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Schultz, C., Doney, S. C., Hauck, J., Kavanaugh, M. T., & Schofield, O. Modeling phytoplankton blooms and inorganic carbon responses to sea-ice variability in the West Antarctic Peninsula. Journal of Geophysical Research: Biogeosciences, 126(4), (2021): e2020JG006227, https://doi.org/10.1029/2020JG006227.The ocean coastal-shelf-slope ecosystem west of the Antarctic Peninsula (WAP) is a biologically productive region that could potentially act as a large sink of atmospheric carbon dioxide. The duration of the sea-ice season in the WAP shows large interannual variability. However, quantifying the mechanisms by which sea ice impacts biological productivity and surface dissolved inorganic carbon (DIC) remains a challenge due to the lack of data early in the phytoplankton growth season. In this study, we implemented a circulation, sea-ice, and biogeochemistry model (MITgcm-REcoM2) to study the effect of sea ice on phytoplankton blooms and surface DIC. Results were compared with satellite sea-ice and ocean color, and research ship surveys from the Palmer Long-Term Ecological Research (LTER) program. The simulations suggest that the annual sea-ice cycle has an important role in the seasonal DIC drawdown. In years of early sea-ice retreat, there is a longer growth season leading to larger seasonally integrated net primary production (NPP). Part of the biological uptake of DIC by phytoplankton, however, is counteracted by increased oceanic uptake of atmospheric CO2. Despite lower seasonal NPP, years of late sea-ice retreat show larger DIC drawdown, attributed to lower air-sea CO2 fluxes and increased dilution by sea-ice melt. The role of dissolved iron and iron limitation on WAP phytoplankton also remains a challenge due to the lack of data. The model results suggest sediments and glacial meltwater are the main sources in the coastal and shelf regions, with sediments being more influential in the northern coast.C. Schultz, S. C. Doney, M. T. Kavanaugh, and O. Schofield acknowledge support by the US National Science Foundation (Grant no. PLR-1440435), and C. Schultz and S. C. Doney acknowledge support from the University of Virginia. This research has also received funding from the Helmholtz Young Investigator Group Marine Carbon and Ecosystem Feedbacks in the Earth System (MarESys), Grant number VH-NG-1301
Discontinuous molecular dynamics for semiflexible and rigid bodies
No full textA general framework for performing event-driven simulations of systems with semiflexible or rigid bodies interacting under impulsive forces is outlined. The method consists of specifying a means of computing the free evolution of constrained motion, evaluating the times at which interactions occur, and determining the consequences of interactions on subsequent motion. Algorithms for computing the times of interaction events and carrying out efficient event-driven simulations are discussed. The semiflexible case and the rigid case differ qualitatively in that the free motion of a rigid body can be computed analytically and need not be integrated numerically. (c) 2007 American Institute of Physics.PT: J; CR: ABRAMOWITZ M, 1965, HDB MATH FUNCTIONS F ALDER BJ, 1959, J CHEM PHYS, V31, P459 ALDER BJ, 1960, J CHEM PHYS, V33, P1439 ALLEN MP, 1987, COMPUTER SIMULATION ALLEN MP, 1989, COMPUT PHYS REP, V9, P301 ANDERSEN HC, 1983, J COMPUT PHYS, V52, P24 BARAFF D, 1989, COMPUT GRAPH, V23, P223 BARAFF D, 1992, THESIS CORNELL U BRENT RP, 1973, ALGORITHMS MINIMIZAT CARTER EA, 1989, CHEM PHYS LETT, V156, P472 CHAPELA GA, 1984, MOL PHYS, V53, P139 CHAPELA GA, 1989, CHEM PHYS, V129, P201 CICCOTTI G, 2004, J STAT PHYS, V115, P701 DELAPENA LH, UNPUB DELAPENA LH, 2005, J CHEM PHYS, V126 DEMICHELE C, 2006, J PHYS CHEM B, V110, P8064 DONEV A, 2005, J COMPUT PHYS, V202, P737 DONEV A, 2005, J COMPUT PHYS, V202, P765 ERPENBECK JJ, 1977, STAT MECH B FIXMAN M, 1974, P NATL ACAD SCI USA, V71, P3050 FRENKEL D, 2004, UNDERSTANDING MOL DY GALASSI M, 2005, GNU SCI LIB REFERENC GOLDSTEIN H, CLASSICAL MECH JACOBI CGJ, 1849, J CRELLE, V39, P293 KNOPP K, 1947, THEORY FUNCTIONS 2 LANDAU LD, 1976, MECHANICS LUBACHEVSKY BD, 1991, J COMPUT PHYS, V94, P255 MARIN M, 1993, J COMPUT PHYS, V109, P306 MARIN M, 1995, COMPUT PHYS COMMUN, V92, P214 MARSDEN JE, 2002, INTRO MECH SYMMETRY MASUTANI Y, 1994, P IEEE INT C ROB AUT, V2, P1066 MELCHIONNA S, 2000, PHYS REV E A, V61, P6165 MOSHIER SL, 1989, METHODS PROGRAMS MAT PRESS WH, 1992, NUMERICLA RECIPES FO RAMSHAW JD, 1986, PHYS LETT A, V116, P110 RAPAPORT DC, 1980, J COMPUT PHYS, V34, P184 RAPAPORT DC, 2004, ART MOL DYNAMICS SIM RUEB AS, 1834, THESIS UTRECHT NETHE RYCKAERT JP, 1977, J COMPUT PHYS, V23, P327 TUCKERMAN ME, 1999, EUROPHYS LETT, V45, P149 TUCKERMAN ME, 2001, J CHEM PHYS, V115, P1678 VANZON R, IN PRESS J COMPUT PH VANZON R, 2002, PHYS REV E 1, V65 WHITTAKER ET, 1937, TREATISE ANAL DYMANI; NR: 44; TC: 1; J9: J CHEM PHYS; PG: 13; GA: 138VLSource type: Electronic(1
Discontinuous molecular dynamics for rigid bodies: Applications
No full textEvent-driven molecular dynamics simulations are carried out on two rigid-body systems which differ in the symmetry of their molecular mass distributions. First, simulations of methane in which the molecules interact via discontinuous potentials are compared with simulations in which the molecules interact through standard continuous Lennard-Jones potentials. It is shown that under similar conditions of temperature and pressure, the rigid discontinuous molecular dynamics method reproduces the essential dynamical and structural features found in continuous-potential simulations at both gas and liquid densities. Moreover, the discontinuous molecular dynamics approach is demonstrated to be between 3 and 100 times more efficient than the standard molecular dynamics method depending on the specific conditions of the simulation. The rigid discontinuous molecular dynamics method is also applied to a discontinuous-potential model of a liquid composed of rigid benzene molecules, and equilibrium and dynamical properties are shown to be in qualitative agreement with more detailed continuous-potential models of benzene. The few qualitative differences in the angular dynamics of the two models are related to the relatively crude treatment of variations in the discontinuous repulsive interactions as one benzene molecule rotates by another. (c) 2007 American Institute of Physics.PT: J; CR: ALDER BJ, 1959, J CHEM PHYS, V31, P459 BELLEMANS A, 1980, MOL PHYS, V39, P781 CACELLI I, 2004, J AM CHEM SOC, V126, P14278 CHAPELA GA, 1984, MOL PHYS, V53, P139 CHAPELA GA, 1989, CHEM PHYS, V129, P201 DELAPENA LH, 2007, J CHEM PHYS, V126 DEMICHELE C, 2006, J PHYS CHEM B, V110, P8064 DING F, 2003, PROTEINS, V53, P220 DUANE S, 1987, PHYS LETT B, V195, P216 DULLWEBER A, 1997, J CHEM PHYS, V107, P5840 FALCONE DR, 1967, J PHYS CHEM-US, V71, P2754 MACKERELL AD, 1998, J PHYS CHEM B, V102, P3586 NGUYEN HD, 2006, J AM CHEM SOC, V128, P1890 PRESS WH, 1992, NUMERICLA RECIPES FO RAPAPORT DC, 1979, J CHEM PHYS, V71, P3299 RAPAPORT DC, 2004, ART MOL DYNAMICS SIM VANZON R, CONDMAT0612404 VANZON R, IN PRESS J COMPUT PH ZACHAROPOULOS N, 2005, J CHEM PHYS, V122 ZHOU YQ, 1999, J MOL BIOL, V293, P917; NR: 20; TC: 0; J9: J CHEM PHYS; PG: 12; GA: 138VLSource type: Electronic(1
c-axis transport in highly anisotropic metals: Role of small polarons
No full textWe show in a simple model of interlayer hopping of single electrons that transport along the weakly coupled c-axis of quasi-two-dimensional metals does not always probe only the in-plane electron properties. In our model where there is a strong coupling between electrons and a bosonic mode that propagates in the c direction only, we find a broad maximum in the c-axis resistivity at a temperature near the characteristic energy of the bosonic mode, while no corresponding feature appears in the ab plane transport. At temperatures far from this bosonic energy scale, the c-axis resistivity does track the in-plane electron scattering rate. We demonstrate a reasonable fit of our theory to the apparent metallic to nonmetallic crossover in the c-axis resistivity of the layered ruthenate Sr2RuO4
Modulation of the hypoxic response in cancer; inhibition of the HIF-1α/p300 protein-protein interaction
No full textHypoxia inducible factor (HIF)-1α is a heterodimerically-activated transcription factor central to the cellular response to hypoxic environments and is often upregulated in cancer. Binding of HIF-1α to the co-activator p300 is necessary for the hypoxia-induced transcription of many oncogenic proteins. The aim of this project was to develop novel small molecule inhibitors of the HIF-1α/p300 protein-protein interaction (PPI). Initial work focused on designing, validating and optimising two high-throughput competition binding assays to screen for inhibitors of the PPI (Chapter 2). Alongside these, zinc ejector assays for both p300 and KDM4A proteins were developed to probe the mechanism of action and selectivity. Analysis of hits from a natural product high-throughput screen (HTS) revealed two compound classes; benzoquinones and 2-substituted indandiones, which modulate the PPI. The potency of these series correlated with the reactivity of the core functional groups, which act as electrophiles to covalently modify reactive cysteines, ejecting structural zinc and disrupting the p300/KDM4A protein fold (Chapter 3). Conjugating electrophilic groups to putative HIF-1α/p300 inhibitors did not replicate the activity of the zinc ejecting HTS hits (Chapter 4). Further work focused on non-covalent inhibitors of the HIF-1α/p300 interaction, first with peptide truncates, and then rationally designed α-helix peptidomimetics. An 11mer truncate showed encouraging activity (IC50 ≈ 70 μM), and corresponded to a key α-helix in the HIF-1α C-terminal transactivation domain. Three distinct double-sided scaffolds were used to imitate up to five hot-spot ampiphilic residues on this α-helix (Chapter 6 and 7). Of the 35 compounds screened, only modest inhibition was observed (IC50 ≈ 200-500 μM). Future work will look to conjugate electrophilic functionality onto the 11mer peptide in an attempt to gain potency from zinc ejection, while maintaining selectivity for p300
Author Correction: Delineating COVID-19 subgroups using routine clinical data identifies distinct in-hospital outcomes
No full textCorrection to: Scientific Reports, published online 20 June 2023 The original version of this Article contained an error in the name of author, Andrew Scarsbrook which was incorrectly given as Prof Andrew Scarsbrook. He is a member of the NCCID Collaborative team. The original Article has been corrected
The impact of industrialization on adult mortality in Eastern Scotland, c. 1810-1861
No full textThis study investigates the links between economic and demographic variables by
examining the impact of industrialization on adult mortality in eastern Scotland, c. 1810-61.
Using the concept of the urban hierarchy, sixteen parishes in the counties of Angus and
Fife were selected to represent different degrees of industrialization. Patterns of adult
mortality in these parishes between 1810 and 1854 are then examined using data on burials
from the parish registers. The results are checked by comparing them with the results
obtained from an analysis of vital registration data on deaths for the period 1855-61. Thus
overall trends in adult mortality are identified and then disaggregated by age, sex, cause of
death and occupation.
The results show that adult mortality was generally higher in the most industrialized
areas. Furthermore, rates in these parishes generally increased over the period whilst in the
less industrialized areas they fell. Overall most people died from infectious diseases but
deaths from these causes (including tuberculosis) fell over the period. The increase in
mortality appears to be in part due to a rise in deaths from respiratory diseases (especially
amongst textile workers in the main industrial centres) and food- and water-borne illnesses.
This suggests that industrialization had a negative impact on adult mortality rates, causing a
short-term rise in mortality in the early to mid-nineteenth century. This was in part due to
the direct effect industrialization had, with the shift towards textile employment probably
leading to increased mortality from respiratory diseases especially amongst factory
workers. The impact of industrialization also appears to have operated indirectly via the
impetus it gave to urbanization and changes in the spatial distribution of the population that
resulted in worsening sanitary conditions and increased exposure to infection
Asymmetric transfer of the dynamic motion aftereffect between first- and second-order cues and among different second-order cues.
No full textRecent work on motion processing has suggested a distinction between first-order cues (such as luminance modulation [LM]) and second-order cues (such as local contrast modulation [CM]). We studied interactions between moving LM, CM, and orientation modulation (OM) first comparing their spatial- and temporal-frequency sensitivity. We then tested for the transfer of the dynamic motion aftereffect (dMAE) between the three cues, matched for visibility. Observers adapted to moving, 0.5-c/deg horizontal modulations for 2 min (with 10 s top-ups). Relatively strong dMAEs were found when the
adaptation and test patterns were defined by the same cue (i.e., both LM, both CM, or both OM); these effects were tuned for spatial frequency in the case of LM and CM. There was a partial transfer of the dMAE from LM to CM and OM; this transferred effect seemed to lose its tuning. The aftereffect transferred well from CM to OM and retained its tuning. There was little or no transfer from CM to LM or from OM to CM or LM. This asymmetric transfer of the dMAE between first- and second-order cues and between the second-order cues suggests some degree of separation between the mechanisms that process them
A European union and Canadian review of public health nursing preparation and practice.
No full textThis study explores the preparation and role of the public health nurse (PHN) across European Union (EU) countries (Finland, Sweden, and the United Kingdom) and Canadian provinces (Alberta, New Brunswick, and Prince Edward Island)
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