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Abstract
Tidal marshes store large amounts of organic carbon in their soils. Field data quantifying soil organic carbon (SOC) stocks provide an important resource for researchers, natural resource managers, and policy-makers working towards the protection, restoration, and valuation of these ecosystems. We collated a global dataset of tidal marsh soil organic carbon (MarSOC) from 99 studies that includes location, soil depth, site name, dry bulk density, SOC, and/or soil organic matter (SOM). The MarSOC dataset includes 17,454 data points from 2,329 unique locations, and 29 countries. We generated a general transfer function for the conversion of SOM to SOC. Using this data we estimated a median (± median absolute deviation) value of 79.2 ± 38.1 Mg SOC ha-1 in the top 30 cm and 231 ± 134 Mg SOC ha-1 in the top 1 m of tidal marsh soils globally. This data can serve as a basis for future work, and may contribute to incorporation of tidal marsh ecosystems into climate change mitigation and adaptation strategies and policies.
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Grants
- W912HZ2020070 United States Department of Defense | United States Army | US Army Corps of Engineers | Engineer Research and Development Center (U.S. Army Engineer Research and Development Center)
- 84375 NRF | South African Agency for Science and Technology Advancement (SAASTA)
- The Nature Conservancy through the Bezos Earth Fund and other donor support
- Nelson Mandela University
- State Research Agency of Spain (AEI; CGL2007-64915), the Mancomunidad de los Canales del Taibilla (MCT), and the Science and Technology Agency of the Murcia Region (Seneca Foundation; 00593/PI/04 & 08739/PI/08).
- Scottish Government and UK Natural Environment Research Council C-SIDE project (grant NE/R010846/1)
- COOLSTYLE/CARBOSTORE project
- New Zealand Ministry for Business, Innovation and Employment Contract #C01X2109
- Portuguese national funds from FCT - Foundation for Science and Technology through projects UIDB/04326/2020, UIDP/04326/2020, LA/P/0101/2020, and 2020.03825.CEECIND
- German Research Foundation (DFG project number: GI 171/25-1)
- State Research Agency of Spain (AEI; CGL2007-64915), the Mancomunidad de los Canales del Taibilla (MCT), the Science and Technology Agency of the Murcia Region (Seneca Foundation; 00593/PI/04 & 08739/PI/08), and a Ramón y Cajal contract from the Spanish Ministry of Science and Innovation (RYC2020-029322-I)
- Velux foundation (#28421, Blå Skove – Havets Skove som kulstofdræn)
- LIFE ADAPTA BLUES project Ref. LIFE18 CCA/ES/001160
- LIFE ADAPTA BLUES project Ref. LIFE18 CCA/ES/001160, support of national funds through Fundação para a Ciência e Tecnologia, I.P. (FCT), under the projects UIDB/04292/2020, UIDP/04292/2020, granted to MARE, and LA/P/0069/2020, granted to the Associate Laboratory ARNET
- Financial support provided by the Welsh Government and Higher Education Funding Council for Wales through the Sêr Cymru National Research Network for Low Carbon, Energy and Environment; as well as the Spanish Ministry of Science and Innovation (project PID2020-113745RB-I00) and FEDER
- South African Department of Science and Innovation (DSI)—National Research Foundation (NRF) Research Chair in Shallow Water Ecosystems (UID: 84375), and the Nelson Mandela University
- I+D+i projects RYC2019-027073-I and PIE HOLOCENO 20213AT014 funded by MCIN/AEI/10.13039/501100011033 and FEDER
- Funding support from the Scottish Government and UK Natural Environment Research Council C-SIDE project (grant NE/R010846/1)
- Xunta de Galicia (GRC project IN607A 2021-06)
- U.S. Army Engineering, Research and Development Center (ACTIONS project, W912HZ2020070)
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Dispersing artifacts in FT-STS: a comparison of set point effects across acquisition modes. NANOTECHNOLOGY 2016; 27:414004. [PMID: 27607539 DOI: 10.1088/0957-4484/27/41/414004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Fourier-transform scanning tunnelling spectroscopy (FT-STS), or quasiparticle interference, has become an influential tool for the study of a wide range of important materials in condensed matter physics. However, FT-STS in complex materials is often challenging to interpret, requiring significant theoretical input in many cases, making it crucial to understand potential artifacts of the measurement. Here, we compare the most common modes of acquiring FT-STS data and show through both experiment and simulations that artifact features can arise that depend on how the tip height is stabilized throughout the course of the measurement. The most dramatic effect occurs when a series of dI/dV maps at different energies are acquired with simultaneous constant current feedback; here a feature that disperses in energy appears that is not observed in other measurement modes. Such artifact features are similar to those arising from real physical processes in the sample and are susceptible to misinterpretation.
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3
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Acoustic buffeting by infrasound in a low vibration facility. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:093901. [PMID: 27782589 DOI: 10.1063/1.4962241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Measurement instruments and fabrication tools with spatial resolution on the atomic scale require facilities that mitigate the impact of vibration sources in the environment. One approach to protection from vibration in a building's foundation is to place the instrument on a massive inertia block, supported on pneumatic isolators. This opens the questions of whether or not a massive floating block is susceptible to acoustic forces, and how to mitigate the effects of any such acoustic buffeting. Here this is investigated with quantitative measurements of vibrations and sound pressure, together with finite element modeling. It is shown that a particular concern, even in a facility with multiple acoustic enclosures, is the excitation of the lowest fundamental acoustic modes of the room by infrasound in the low tens of Hz range, and the efficient coupling of the fundamental room modes to a large inertia block centered in the room.
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Pronounced polarization-induced energy level shifts at boundaries of organic semiconductor nanostructures. Nat Commun 2015; 6:8312. [PMID: 26440933 PMCID: PMC4600718 DOI: 10.1038/ncomms9312] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/11/2015] [Indexed: 11/09/2022] Open
Abstract
Organic semiconductor devices rely on the movement of charge at and near interfaces, making an understanding of energy level alignment at these boundaries an essential element of optimizing materials for electronic and optoelectronic applications. Here we employ low temperature scanning tunneling microscopy and spectroscopy to investigate a model system: two-dimensional nanostructures of the prototypical organic semiconductor, PTCDA (3,4,9,10-perylenetetracarboxylic dianhydride) adsorbed on NaCl (2 ML)/Ag(111). Pixel-by-pixel scanning tunneling spectroscopy allows mapping of occupied and unoccupied electronic states across these nanoislands with sub-molecular spatial resolution, revealing strong electronic differences between molecules at the edges and those in the centre, with energy level shifts of up to 400 meV. We attribute this to the change in electrostatic environment at the boundaries of clusters, namely via polarization of neighbouring molecules. The observation of these strong shifts illustrates a crucial issue: interfacial energy level alignment can differ substantially from the bulk electronic structure in organic materials. Interfaces are essential in organic semiconductor devices, yet the detailed connection between interface geometry and energy level alignment are not fully understood. Here, Cochrane et al. quantify energy level shifts with sub-molecular resolution within a nanoscale model organic semiconductor system.
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Abstract
Tuning the electronic properties of graphene by adatom deposition unavoidably introduces disorder into the system, which directly affects the single-particle excitations and electrodynamics. Using angle-resolved photoemission spectroscopy (ARPES) we trace the evolution of disorder in graphene by thallium adatom deposition and probe its effect on the electronic structure. We show that the signatures of quasiparticle scattering in the photoemission spectral function can be used to identify thallium adatoms, although charged, as efficient short-range scattering centers. Employing a self-energy model for short-range scattering, we are able to extract a δ-like scattering potential δ = -3.2 ± 1 eV. Therefore, isolated charged scattering centers do not necessarily act just as good long-range (Coulomb) scatterers but can also act as efficient short-range (δ-like) scatterers; in the case of thallium, this happens with almost equal contributions from both mechanisms.
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Quantifying many-body effects by high-resolution Fourier transform scanning tunneling spectroscopy. PHYSICAL REVIEW LETTERS 2013; 111:246804. [PMID: 24483688 DOI: 10.1103/physrevlett.111.246804] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Indexed: 06/03/2023]
Abstract
High-resolution Fourier transform scanning tunneling spectroscopy (FT-STS) is used to study many-body effects on the surface state of Ag(111). Our results reveal a kink in the otherwise parabolic band dispersion of the surface electrons and an increase in the quasiparticle lifetime near the Fermi energy Ef. The experimental data are accurately modeled with the T-matrix formalism for scattering from a single impurity, assuming that the surface electrons are dressed by the electron-electron and electron-phonon interactions. We confirm the latter as the interaction responsible for the deviations from bare dispersion. We further show how FT-STS can be used to simultaneously extract real and imaginary parts of the self-energy for both occupied and unoccupied states with a momentum and energy resolution competitive with angle-resolved photoemission spectroscopy. From our quantitative analysis of the data we extract a Debye energy of ℏΩD=14±1 meV and an electron-phonon coupling strength of λ=0.13±0.02, consistent with previous results. This proof-of-principle measurement advances FT-STS as a method for probing many body effects, which give rise to a rich array of material properties.
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Scanning tunneling spectroscopy of superconducting LiFeAs single crystals: evidence for two nodeless energy gaps and coupling to a bosonic mode. PHYSICAL REVIEW LETTERS 2012; 109:087002. [PMID: 23002767 DOI: 10.1103/physrevlett.109.087002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Indexed: 06/01/2023]
Abstract
The superconducting compound LiFeAs is studied by scanning tunneling microscopy and spectroscopy. A gap map of the unreconstructed surface indicates a high degree of homogeneity in this system. Spectra at 2 K show two nodeless superconducting gaps with Δ(1)=5.3±0.1 meV and Δ(2)=2.5±0.2 meV. The gaps close as the temperature is increased to the bulk T(c), indicating that the surface accurately represents the bulk. A dip-hump structure is observed below T(c) with an energy scale consistent with a magnetic resonance recently reported by inelastic neutron scattering.
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Detecting 2009 pandemic influenza A (H1N1) virus infection: availability of diagnostic testing led to rapid pandemic response. Clin Infect Dis 2011; 52 Suppl 1:S36-43. [PMID: 21342897 DOI: 10.1093/cid/ciq020] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Diagnostic tests for detecting emerging influenza virus strains with pandemic potential are critical for directing global influenza prevention and control activities. In 2008, the Centers for Disease Control and Prevention received US Food and Drug Administration approval for a highly sensitive influenza polymerase chain reaction (PCR) assay. Devices were deployed to public health laboratories in the United States and globally. Within 2 weeks of the first recognition of 2009 pandemic influenza H1N1, the Centers for Disease Control and Prevention developed and began distributing a new approved pandemic influenza H1N1 PCR assay, which used the previously deployed device platform to meet a >8-fold increase in specimen submissions. Rapid antigen tests were widely used by clinicians at the point of care; however, test sensitivity was low (40%-69%). Many clinical laboratories developed their own pandemic influenza H1N1 PCR assays to meet clinician demand. Future planning efforts should identify ways to improve availability of reliable testing to manage patient care and approaches for optimal use of molecular testing for detecting and controlling emerging influenza virus strains.
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Molecular dewetting on insulators. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:423101. [PMID: 21715835 DOI: 10.1088/0953-8984/21/42/423101] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Recent attention given to the growth and morphology of organic thin films with regard to organic electronics has led to the observation of dewetting (a transition from layer(s) to islands) of molecular deposits in many of these systems. Dewetting is a much studied phenomenon in the formation of polymer and liquid films, but its observation in thin films of the 'small' molecules typical of organic electronics requires additional consideration of the structure of the interface between the molecular film and the substrate. This review covers some key concepts related to dewetting and molecular film growth. In particular, the origins of different growth modes and the thickness dependent interactions which give rise to dewetting are discussed in terms of surface energies and the disjoining pressure. Characteristics of molecular systems which may lead to these conditions, including the formation of metastable interface structures and commensurate-incommensurate phase transitions, are also discussed. Brief descriptions of some experimental techniques which have been used to study molecular dewetting are given as well. Examples of molecule-on-insulator systems which undergo dewetting are described in some detail, specifically perylene derivatives on alkali halides, C(60) on alkali halides, and the technologically important system of pentacene on SiO(2). These examples point to some possible predicting factors for the occurrence of dewetting, most importantly the formation of an interface layer which differs from the bulk crystal structure.
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10
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Abstract
Non-contact atomic force microscopy is rapidly expanding from ultra-high vacuum to include the study of surfaces and biomolecules in liquids by high resolution imaging and force spectroscopy. This is despite the additional frequency shift noise due to the inherently low Q factor of the cantilever oscillating in a liquid. In this paper we present a tip based on an optical fiber which can operate in liquid with Q factors in excess of 100 using a 'diving bell' arrangement which allows only a small portion of the tip to be submerged. We demonstrate stable imaging and force spectroscopy using this set-up. The tips are based on scanning near-field optical microscopy tips and, when used with NC-AFM, provide a method of combining both high resolution mechanical and fluorescence studies of biomolecules and cells.
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Determination of the local contact potential difference of PTCDA on NaCl: a comparison of techniques. NANOTECHNOLOGY 2009; 20:264012. [PMID: 19509452 DOI: 10.1088/0957-4484/20/26/264012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
There has been increasing focus on the use of Kelvin probe force microscopy (KPFM) for the determination of local electronic structure in recent years, especially in systems where other methods, such as scanning tunnelling microscopy/spectroscopy, may be intractable. We have examined three methods for determining the local apparent contact potential difference (CPD): frequency modulation KPFM (FM-KPFM), amplitude modulation KPFM (AM-KPFM), and frequency shift-bias spectroscopy, on a test system of 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) on NaCl, an example of an organic semiconductor on a bulk insulating substrate. We will discuss the influence of the bias modulation on the apparent CPD measurement by FM-KPFM compared to the DC-bias spectroscopy method, and provide a comparison of AM-KPFM, AM-slope detection KPFM and FM-KPFM imaging resolution and accuracy. We will also discuss the distance dependence of the CPD as measured by FM-KPFM for both the PTCDA organic deposit and the NaCl substrate.
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12
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Comment on 'Temperature dependence of the energy dissipation in dynamic force microscopy'. NANOTECHNOLOGY 2008; 19:398001. [PMID: 21832607 DOI: 10.1088/0957-4484/19/39/398001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A recent article in this journal by Roll et al (2008 Nanotechnology 19 045703) presents experimental results of the temperature dependence of dissipation in dynamic force microscopy which they use to elucidate the mechanisms of such a dissipation signal in the PTCDA on KBr system. We argue here that dissipation results are often highly dependent upon the tip structure, and urge caution in the interpretation of single sets of experimental data.
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Strain induced dewetting of a molecular system: bimodal growth of PTCDA on NaCl. PHYSICAL REVIEW LETTERS 2008; 100:186104. [PMID: 18518395 DOI: 10.1103/physrevlett.100.186104] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2007] [Indexed: 05/10/2023]
Abstract
Submonolayer coverages of the molecule 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) deposited on NaCl(001) surfaces were imaged with high resolution noncontact-atomic force microscopy. Two island types were observed: monolayer islands with a p3x3 epitaxy at low coverage and a mixture of these and bulklike crystallites at higher coverage. The transition between the pure monolayer islands and mixed islands occurs at approximately 0.85 ML, corresponding to a complete p3x3 layer. Calculations show the p3x3 epitaxy to be incompatible with a multilayer crystal of PTCDA. Consequently, the growth of additional layers results in an adaptation of the interface structure forcing a dewetting transition.
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Abstract
Concordance with growth hormone (GH) therapy in 75 children was objectively assessed using data on GP prescriptions over 12 months. 23% missed >2 injections/week. Lower concordance was associated with longer duration on GH therapy (p<0.005), lack of choice of delivery device (p<0.005) and short prescription durations (p<0.005), and predicted lower height velocities (p<0.05).
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A role for the transcription factor RelB in IFN-alpha production and in IFN-alpha-stimulated cross-priming. Eur J Immunol 2006; 36:2085-93. [PMID: 16810633 DOI: 10.1002/eji.200535228] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Chimeric mice generated with bone marrow from RelB-deficient (-/-), RelB-heterozygous (+/-) and wild-type (+/+) mice were used to determine how total or partial absence of the transcription factor RelB in haematopoietic cells affects the immune response generated after lymphocytic choriomeningitis virus (LCMV) infection. In RelB(-/-) chimeras, early virus replication was enhanced and LCMV clearance was impaired. Although plasmacytoid dendritic cell numbers were similar, serum interferon (IFN)-alpha levels in RelB(-/-) and RelB(+/-) chimeras were markedly lower than in RelB(+/+) chimeras during early LCMV infection. Further, both RelB(-/-) and RelB(+/-) chimeras mounted a lower-magnitude LCMV-specific CD8(+) T cell response than their RelB(+/+) counterparts, although the LCMV-specific CD8(+) T cells present were differentiated into functional cytotoxic cells. In LCMV-infected RelB(-/-) mice, induction of cross-priming to an independently injected soluble protein, which depends on the IFN-alpha/beta made during the viral infection, was also impaired. Notably, provision of exogenous IFN-alpha did not restore the ability of RelB(-/-) mice to cross-prime. In summary, these results show that the RelB/NF-kappaB pathway is required for optimal IFN-alpha production after LCMV infection and suggest a crucial role for RelB in IFN-alpha-stimulated cross-priming of CD8(+) T cell responses.
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Nucleation and submonolayer growth of C60 on KBr. PHYSICAL REVIEW LETTERS 2005; 94:096102. [PMID: 15783979 DOI: 10.1103/physrevlett.94.096102] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2004] [Indexed: 05/05/2023]
Abstract
Noncontact atomic force microscopy has been applied to the prototypical molecule-insulator system C60 on KBr to study nucleation and submonolayer growth. Overview images reveal an island growth mode with unusual branching structures. Simultaneous molecular and atomic resolution on the C60 and KBr surfaces, respectively, was obtained revealing a coincident 8x3 superstructure. Also, a 21+/-3 pm apparent height difference was observed in atomic force microscopy topographies between some first layer molecules. One of the initial nucleation sites of the C60 islands was determined by observation of loosely bound molecules at kink sites in monatomic KBr steps, in conjunction with the observation that islands form preferentially at step edges.
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Detection of molecular diversity in Bacillus atrophaeus by amplified fragment length polymorphism analysis. Appl Environ Microbiol 2004; 70:2786-90. [PMID: 15128533 PMCID: PMC404429 DOI: 10.1128/aem.70.5.2786-2790.2004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phenotypically, Bacillus atrophaeus is indistinguishable from the type strain of Bacillus subtilis except by virtue of pigment production on certain media. Several pigmented variants of B. subtilis have been reclassified as B. atrophaeus, but several remain ambiguous in regard to their taxonomic placement. In this study, we examined strains within the American Type Culture Collection originally deposited as Bacillus globigii, B. subtilis var. niger, or Bacillus niger using 16S rRNA gene sequencing and amplified fragment length polymorphism (AFLP) analysis to determine the level of molecular diversity among these strains and their relationship with closely related taxa. The 16S rRNA gene sequences revealed little variation with one base substitution between the B. atrophaeus type strain ATCC 49337 and the other pigmented bacilli. AFLP analysis produced high-quality DNA fingerprints with sufficient polymorphism to reveal strain-level variation. Cluster analysis of Dice similarity coefficients revealed that three strains, ATCC 31028, ATCC 49760, and ATCC 49822, are much more closely related to B. atrophaeus than to B. subtilis and should be reclassified as B. atrophaeus. A very closely related cluster of B. atrophaeus strains was also observed; this cluster was genetically distinct from the type strain. The level of variation between the two groups was approximately the same as the level of variation observed between members of the two B. subtilis subspecies, subtilis and spizizenii. It is proposed that the cluster of strains typified by ATCC 9372 be designated a new subspecies, B. atrophaeus subsp. globigii.
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Routes of inoculation and the immune response to a resolving genital flavivirus infection in a novel murine model. Immunol Cell Biol 2004; 82:174-83. [PMID: 15061771 DOI: 10.1046/j.0818-9641.2004.01239.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The prolonged, abnormal immune response patterns produced by many sexually transmitted viruses have been intensively studied. Because normal antiviral immune responses in the vagina are less well-defined, we developed a resolving murine model using vaginal inoculation with the flavivirus, West Nile virus. Infection resulted in 12% mortality, with sterile protective immunity to vaginal or systemic re-challenge. B-cell numbers increased in the vaginal mucosa from day 1-7 after primary infection, while similar increases in B220(+), CD4(+) and CD8(+) lymphocytes in the draining lymph node were delayed by 48 h. By day 4 postinfection, a MHC-II(+) dendritic cell population became depleted from the stroma and formed aggregates below the basement membrane at points of demonstrable epithelial infection. In contrast, primary systemic or intradermal inoculation resulted in 80-90% mortality, but also conferred protective sterile immunity to vaginal West Nile virus re-challenge. Intravaginal and intradermal immunization elicited comparable, accelerated accumulation of larger B-cell numbers in the mucosa and draining lymph node upon intravaginal re-challenge than systemic immunization. However, accumulation of CD4(+) T cells in both sites in the intradermally immunized group was significantly greater than in intravaginally or systemically immunized mice. Accelerated accumulation of dendritic cells occurred at periodic sub-basement membrane sites in the absence of detectable virus 1 day after vaginal re-challenge, irrespective of the route of immunization. These data illustrate the diversity of possible effective immune responses to West Nile virus in the vaginal mucosa. They show primary vaginal inoculation produces effective immunity to flavivirus infection with lower mortality than other routes and suggest a local role for vaginal mucosal dendritic cells in both primary and secondary responses.
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Abstract
BACKGROUND Assessment of adjustment of patients in cancer treatment trials is becoming more common and increasingly regarded as a useful outcome measure. The widely used Mental Adjustment to Cancer (MAC) Scale was designed to measure Fighting Spirit (FS), Anxious Preoccupation (AP), Helpless-hopelessness (HH) and Fatalism. METHODS Questionnaire responses from 632 breast cancer patients were randomly divided into two groups, one for exploratory analyses and possible scale refinement, and the other for validation purposes. RESULTS Estimates of reliability (Cronbach's alpha) were satisfactory for two scales, FS (alpha = 0.85) and HH (alpha = 0.81), but lower for AP (alpha = 0.65) and Fatalism (alpha = 0.64). Exploratory factor analysis suggested that the MAC Scale might be measuring six independent constructs including two related to Fighting Spirit (Positive Orientation to the Illness, Minimizing the Illness), two related to Fatalism (Fatalism-revised, Loss of Control), a construct we have named Angst, and an unchanged HH construct. Scales developed to measure these constructs were satisfactorily replicated in confirmatory analyses but some reliabilities were lower than desirable. The general structure of the MAC Scale remained little changed despite the division of two scales and the suggested removal of six items. The refined scales correlated with the Hospital Anxiety and Depression scale and the Medical Coping Modes Questionnaire, indicating good concurrent validity. CONCLUSIONS While reasonable reliability of the original scales persists through analyses of the MAC Scale, the original factor structure could not be reproduced. Six refined constructs with strong construct validity were identified within the overall domain of mental adjustment to cancer.
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Clustered genes encoding the methyltransferases of methanogenesis from monomethylamine. J Bacteriol 1998; 180:3432-40. [PMID: 9642198 PMCID: PMC107300 DOI: 10.1128/jb.180.13.3432-3440.1998] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/1998] [Accepted: 04/06/1998] [Indexed: 02/07/2023] Open
Abstract
Coenzyme M (CoM) is methylated during methanogenesis from monomethyamine in a reaction catalyzed by three proteins. Using monomethylamine, a 52-kDa polypeptide termed monomethylamine methyltransferase (MMAMT) methylates the corrinoid cofactor bound to a second polypeptide, monomethylamine corrinoid protein (MMCP). Methylated MMCP then serves as a substrate for MT2-A, which methylates CoM. The genes for these proteins are clustered on 6.8 kb of DNA in Methanosarcina barkeri MS. The gene encoding MMCP (mtmC) is located directly upstream of the gene encoding MMAMT (mtmB). The gene encoding MT2-A (mtbA) was found 1.1 kb upstream of mtmC, but no obvious open reading frame was found in the intergenic region between mtbA and mtmC. A single monocistronic transcript was found for mtbA that initiated 76 bp from the translational start. Separate transcripts of 2.4 and 4.7 kb were detected, both of which carried mtmCB. The larger transcript also encoded mtmP, which is homologous to the APC family of cationic amine permeases and may therefore encode a methylamine permease. A single transcriptional start site was found 447 bp upstream of the translational start of mtmC. MtmC possesses the corrinoid binding motif found in corrinoid proteins involved in dimethylsulfide- and methanol-dependent methanogenesis, as well as in methionine synthase. The open reading frame of mtmB was interrupted by a single in-frame, midframe, UAG codon which was also found in mtmB from M. barkeri NIH. A mechanism that circumvents UAG-directed termination of translation must operate during expression of mtmB in this methanogen.
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Reconstitution of Monomethylamine:Coenzyme M methyl transfer with a corrinoid protein and two methyltransferases purified from Methanosarcina barkeri. J Biol Chem 1997; 272:16570-7. [PMID: 9195968 DOI: 10.1074/jbc.272.26.16570] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Methanogenesis from methylamines requires the intermediate methylation of 2-mercaptoethanesulfonate (CoM). In vitro reconstitution of CoM methylation with monomethylamine was achieved with three purified proteins: a monomethylamine corrinoid protein (MMCP), the "A" isozyme of methylcobamide:CoM methyltransferase (MT2-A), and a newly isolated protein termed monomethylamine methyltransferase (MMAMT).MMAMT is a 170-kDa protein with 52-kDa subunits. The MMAMT polypeptide was rate-limiting for methyl transfer until at a 2-fold molar excess over MMCP. MMAMT is a monomethylamine:MMCP methyltransferase, since methylation of MMCP required MMAMT but not MT2-A. MMCP and MMAMT formed a complex detectable by size exclusion high pressure liquid chromatography. Methyl group transfer from methyl-MMCP to CoM was mediated by MT2-A, since methyl iodide:CoM methyl transfer by MMCP and MT2-A did not require MMAMT. MT2-M, an isozyme of MT2-A, was inactive in MMCP-dependent methyl transfer. Immunodepletion of MMCP from the extract inhibited CoM methylation with monomethylamine but not dimethylamine. Purified MMCP reconstituted activity in immunodepleted extracts. These results show that MMCP is the major corrinoid protein for methanogenesis from monomethylamine detectable in extracts and that it interacts with two methyltransferases. MMAMT functions as a MMA:MMCP methyltransferase, while MT2-A functions as a methyl-MMCP:CoM methyltransferase.
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Involvement of the "A" isozyme of methyltransferase II and the 29-kilodalton corrinoid protein in methanogenesis from monomethylamine. J Bacteriol 1995; 177:4410-6. [PMID: 7635826 PMCID: PMC177191 DOI: 10.1128/jb.177.15.4410-4416.1995] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
An assay which allowed detection of proteins involved in the trimethylamine- or monomethylamine (MMA)-dependent methylation of coenzyme M (CoM) was developed. The two activities could be separated by anion-exchange chromatography. The unresolved activity responsible for MMA:CoM methyl transfer eluted from a gel permeation column in the molecular mass range of 32 kDa. The activity was purified to two monomeric proteins of 40 and 29 kDa. The preparation contained protein-bound corrinoid in a mixture of Co(II) and Co(III) states, as well as methyl-B12:CoM methyltransferase (MT2) activity. N-terminal sequence analysis demonstrated that the polypeptides were two previously identified proteins of undefined physiological function. The smaller polypeptide was the monomeric 29-kDa corrinoid protein. The larger polypeptide was the "A" isozyme of MT2. Individually purified preparations of both proteins increased the rate of MMA-dependent CoM methylation by approximately 1.7 mumol/min/mg of purified protein above background activity in the extract of methanol-grown cells. These results indicate that the 29-kDa corrinoid protein and the "A" isozyme of MT2 function in methanogenesis from MMA. A likely mechanism is that the 29-kDa corrinoid is methylated by MMA and the methyl group is then transferred by the "A" isozyme of MT2 to CoM.
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Return to work/work retention outcomes of a functional restoration program. A multi-center, prospective study with a comparison group. Spine (Phila Pa 1976) 1994; 19:1880-5; discussion 1886. [PMID: 7997919 DOI: 10.1097/00007632-199409000-00002] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN This was a study of a standardized functional restoration program that included 11 centers in seven states, involving 303 patients in the treatment group and 94 patients in the comparison group. OBJECTIVE To illustrate the positive effect a functional restoration program has on return to work rates and work retention regardless of previous surgical intervention. SUMMARY OF BACKGROUND DATA Data were obtained from the initial and discharge evaluations as well as at 6- and 12-month follow-up. METHODS Patients received a standardized work capacity assessment upon entrance and were recommended to the program if they adhered to specific entrance criteria. Treatment patients received the same evaluation at discharge. RESULTS Significant improvement in functional abilities, actual return to work, and work retention were noted in the treatment group regardless of treatment intervention. CONCLUSIONS This study demonstrated improved return to work rates and work retention with surgical and nonsurgical patients after their participation in a functional restoration program.
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Cyclic GMP levels and membrane current during onset, recovery, and light adaptation of the photoresponse of detached frog photoreceptors. J Biol Chem 1989; 264:15384-91. [PMID: 2549061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We have used a preparation of isolated, intact rod photoreceptors to correlate the effects of flash illumination on the intracellular cyclic GMP content and the membrane current. We find that the recovery of cyclic GMP levels after brief flash illumination requires approximately twice as much time as the recovery of the membrane current. In contrast, the subsecond kinetics of the cyclic GMP response to light are faster than the kinetics of membrane current suppression. Both cyclic GMP and the membrane current show graded responses to a wide range of flash intensities; however, in a low Ca2+-Ringer's solution, dim flashes can trigger a decrease in cyclic GMP concentration with no corresponding decrease in membrane current. These results suggest that either other factors can regulate the membrane current, or that measurements of total cellular cyclic GMP do not accurately reflect dynamic changes in cyclic GMP concentration in the vicinity of the light-regulated channel. Changes in cyclic GMP concentration in the presence of background illumination exhibit adaptational behavior similar to that observed in a light-adapted photoresponse: acceleration in the response kinetics and a decrease in response amplitude. That this result is observed in rods depleted of internal Ca2+ suggests a Ca2+-independent mechanism by which background illumination can accelerate the cyclic GMP response.
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Cyclic GMP levels and membrane current during onset, recovery, and light adaptation of the photoresponse of detached frog photoreceptors. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)84839-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Changes in cGMP concentration correlate with some, but not all, aspects of the light-regulated conductance of frog rod photoreceptors. J Biol Chem 1986; 261:12965-75. [PMID: 3020017 PMCID: PMC3376451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Cyclic GMP has been implicated in controlling the light-regulated conductance of rod photoreceptors of the vertebrate retina. However, there is little direct evidence correlating changes in cGMP concentration with the light-regulated permeability mechanism in living cells. A preparation of intact frog rod outer segments suspended in a Ringer's medium containing low Ca2+ has been used to demonstrate that initial changes in total cellular cGMP concentration parallel changes in the light-regulated membrane current over a wide range of light intensities. At light intensities bleaching from 160 to 5.6 X 10(6) rhodopsin molecules/rod/s, decreases in the response latency for the cGMP kinetics parallel decreases in the latent period of the electrical response. Further, changes in the rate of the cGMP decrease parallel the rate of membrane current suppression as the light intensity is varied. Up to 10(5) cGMP molecules are hydrolyzed per photolyzed rhodopsin, consistent with in vitro studies showing that each bleached rhodopsin can activate over 100 phosphodiesterase molecules. Addition of the Ca2+ ionophore, A23187, does not affect the initial kinetics of the cGMP decrease or of the electrical response, excluding a direct role for Ca2+ in the initial events of phototransduction. These results are consistent with cGMP being the intracellular messenger that links rhodopsin isomerization with changes in membrane permeability upon illumination. It is unlikely, however, that light-induced changes in total cGMP concentration are the sole regulators of membrane current. This is suggested by several observations: at bright light intensities, the subsecond light-induced cGMP decrease is essentially complete prior to complete suppression of membrane current; maximal light-induced decreases in cGMP concentration occur at all light intensities tested, whereas the extent of membrane current suppression varies over the same range of light intensities; changing the external Ca2+ concentration from 1 mM to 10 nM in the dark causes an increase in membrane current that is significantly more rapid than corresponding changes in cGMP concentration. Thus, light-induced changes in total cellular cGMP concentration correlate with some, but not all, aspects of the visual excitation process in vertebrate photoreceptors.
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