246 research outputs found

    Sovereignty in Antarctica

    Get PDF

    Marine Pollution and the Law of the Sea

    Get PDF
    This article reviews, Marine Pollution and the Law of the Sea, by John Warren Kindt, published by William S. Hem & Co., Inc. in 1986

    Influence of damping on the excitation of the double giant resonance

    Get PDF
    We study the effect of the spreading widths on the excitation probabilities of the double giant dipole resonance. We solve the coupled-channels equations for the excitation of the giant dipole resonance and the double giant dipole resonance. Taking Pb+Pb collisions as example, we study the resulting effect on the excitation amplitudes, and cross sections as a function of the width of the states and of the bombarding energy.Comment: 8 pages, 3 figures, corrected typo

    High rates of N-2 fixation in temperate, western North Atlantic coastal waters expand the realm of marine diazotrophy

    Get PDF
    © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Mulholland, M. R., Bernhardt, P. W., Widner, B. N., Selden, C. R., Chappell, P. D., Clayton, S., Mannino, A., & Hyde, K. High rates of N-2 fixation in temperate, western North Atlantic coastal waters expand the realm of marine diazotrophy. Global Biogeochemical Cycles, 33(7), (2019): 826-840, doi:10.1029/2018GB006130.Dinitrogen (N2) fixation can alleviate N limitation of primary productivity by introducing fixed nitrogen (N) to the world's oceans. Although measurements of pelagic marine N2 fixation are predominantly from oligotrophic oceanic regions, where N limitation is thought to favor growth of diazotrophic microbes, here we report high rates of N2 fixation from seven cruises spanning four seasons in temperate, western North Atlantic coastal waters along the North American continental shelf between Cape Hatteras and Nova Scotia, an area representing 6.4% of the North Atlantic continental shelf area. Integrating average areal rates of N2 fixation during each season and for each domain in the study area, the estimated N input from N2 fixation to this temperate shelf system is 0.02 Tmol N/year, an amount equivalent to that previously estimated for the entire North Atlantic continental shelf. Unicellular group A cyanobacteria (UCYN‐A) were most often the dominant diazotrophic group expressing nifH, a gene encoding the nitrogenase enzyme, throughout the study area during all seasons. This expands the domain of these diazotrophs to include coastal waters where dissolved N concentrations are not always depleted. Further, the high rates of N2 fixation and diazotroph diversity along the western North Atlantic continental shelf underscore the need to reexamine the biogeography and the activity of diazotrophs along continental margins. Accounting for this substantial but previously overlooked source of new N to marine systems necessitates revisions to global marine N budgets.Data presented in the body and supporting information of this manuscript have been deposited in the National Aeronautics and Space Administration (NASA) repository, SeaBASS and is publicly available at the following DOI address: 10.5067/SeaBASS/CLIVEC/DATA 001. This work was supported by a grant from NASA Grant Number: NNX09AE45G to M. R. M., A. M., and K. H.; a grant from NSF to P. D. C; and the Jacques S. Zaneveld and Neil and Susan Kelley Endowed Scholarships to C. S. We thank NOAA for ship time and the captain and crew of NOAA vessels Delaware II and Henry Bigelow for assistance during field sampling. Data have been submitted to SeaBASS (https://seabass.gsfc.nasa.gov/), NASA's preferred archival repository

    Angiographic correlations of patients with small vessel disease diagnosed by adenosine-stress cardiac magnetic resonance imaging

    Get PDF
    Cardiac magnetic resonance imaging (CMR) with adenosine-stress myocardial perfusion is gaining importance for the detection and quantification of coronary artery disease (CAD). However, there is little knowledge about patients with CMR-detected ischemia, but having no relevant stenosis as seen on coronary angiography (CA). The aims of our study were to characterize these patients by CMR and CA and evaluate correlations and potential reasons for the ischemic findings. 73 patients with an indication for CA were first scanned on a 1.5T whole-body CMR-scanner including adenosine-stress first-pass perfusion. The images were analyzed by two independent investigators for myocardial perfusion which was classified as subendocardial ischemia (n = 22), no perfusion deficit (n = 27, control 1), or more than subendocardial ischemia (n = 24, control 2). All patients underwent CA, and a highly significant correlation between the classification of CMR perfusion deficit and the degree of coronary luminal narrowing was found. For quantification of coronary blood flow, corrected Thrombolysis in Myocardial Infarction (TIMI) frame count (TFC) was evaluated for the left anterior descending (LAD), circumflex (LCX) and right coronary artery (RCA). The main result was that corrected TFC in all coronaries was significantly increased in study patients compared to both control 1 and to control 2 patients. Study patients had hypertension or diabetes more often than control 1 patients. In conclusion, patients with CMR detected subendocardial ischemia have prolonged coronary blood flow. In connection with normal resting flow values in CAD, this supports the hypothesis of underlying coronary microvascular impairment. CMR stress perfusion differentiates non-invasively between this entity and relevant CAD

    Synthesis, structural studies and photochemistry of cobalt(III) complexes of anthracenylcyclam macrocycles

    Get PDF
    This work reports the syntheses, structures and some photochemistry in DMF of the cobalt complexes trans-[CoIII( 2)Cl2]Cl·0.5CH3OH and trans-[CoIII( 3)Cl2]Cl·4H2O, where 2 is 6-(anthracen-9-ylmethyl)-1,4,8,11-tetraazacyclotetradecane-5,7-dione and 3 is 6-(anthracen-9-ylmethyl)-1,4,8,11-tetraazacyclotetradecane. In the preparation of the macrocyclic ligand, 3, the formation of a polycyclic bis(aminal) intermediate and its subsequent acid hydrolysis to 3 is a cleaner route than the traditional procedure in which the analogous dioxocyclam 2 is reduced with borane reagents. The crystal structure of trans-[CoIII( 3)Cl2]Cl·4H2O shows that the macrocycle adopts the trans-III conformation, in which the anthracene moiety is extended away from the cobalt ion and the anthracene to Co separation is 7.22 . For the related complex trans-[CoIII( 2)Cl2]Cl·0.5CH3OH, however, the anthracene is bent over the highly conjugated tetracycle and significant interactions between the anthracene and the complex occur. A novel new complex, trans-[Co( 12)Cl2](where 12 is 5,7-hydroxy-6-oxo-1,4,8,11-tetraazacyclotetradecane-4,7-diene) which is a degradation product of the complex trans-[CoIII( 2)Cl2]Cl is also reported

    A model for a large investor trading at market indifference prices. I: single-period case

    Get PDF
    We develop a single-period model for a large economic agent who trades with market makers at their utility indifference prices. A key role is played by a pair of conjugate saddle functions associated with the description of Pareto optimal allocations in terms of the utility function of a representative market maker.Comment: Shorten from 69 to 30 pages due to referees' requests; a part of the previous version has been moved to "The stochastic field of aggregate utilities and its saddle conjugate", arXiv:1310.728

    Naturopathic Care for Chronic Low Back Pain: A Randomized Trial

    Get PDF
    OBJECTIVE: Chronic low back pain represents a substantial cost to employers through benefits coverage and days missed due to incapacity. We sought to explore the effectiveness of Naturopathic care on chronic low back pain. METHODS: This study was a randomized clinical trial. We randomized 75 postal employees with low back pain of longer than six weeks duration to receive Naturopathic care (n = 39) or standardized physiotherapy (n = 36) over a period of 12 weeks. The study was conducted in clinics on-site in postal outlets. Participants in the Naturopathic care group received dietary counseling, deep breathing relaxation techniques and acupuncture. The control intervention received education and instruction on physiotherapy exercises using an approved education booklet. We measured low back pain using the Oswestry disability questionnaire as the primary outcome measure, and quality of life using the SF-36 in addition to low back range of motion, weight loss, and Body Mass Index as secondary outcomes. RESULTS: Sixty-nine participants (92%) completed eight weeks or greater of the trial. Participants in the Naturopathic care group reported significantly lower back pain (-6.89, 95% CI. -9.23 to -3.54, p = <0.0001) as measured by the Oswestry questionnaire. Quality of life was also significantly improved in the group receiving Naturopathic care in all domains except for vitality. Differences for the aggregate physical component of the SF-36 was 8.47 (95% CI, 5.05 to 11.87, p = <0.0001) and for the aggregate mental component was 7.0 (95% CI, 2.25 to 11.75, p = 0.0045). All secondary outcomes were also significantly improved in the group receiving Naturopathic care: spinal flexion (p<0.0001), weight-loss (p = 0.0052) and Body Mass Index (-0.52, 95% CI, -0.96 to -0.08, p = 0.01). CONCLUSIONS: Naturopathic care provided significantly greater improvement than physiotherapy advice for patients with chronic low back pain. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN41920953

    A Gene Regulatory Network for Root Epidermis Cell Differentiation in Arabidopsis

    Get PDF
    The root epidermis of Arabidopsis provides an exceptional model for studying the molecular basis of cell fate and differentiation. To obtain a systems-level view of root epidermal cell differentiation, we used a genome-wide transcriptome approach to define and organize a large set of genes into a transcriptional regulatory network. Using cell fate mutants that produce only one of the two epidermal cell types, together with fluorescence-activated cell-sorting to preferentially analyze the root epidermis transcriptome, we identified 1,582 genes differentially expressed in the root-hair or non-hair cell types, including a set of 208 “core” root epidermal genes. The organization of the core genes into a network was accomplished by using 17 distinct root epidermis mutants and 2 hormone treatments to perturb the system and assess the effects on each gene's transcript accumulation. In addition, temporal gene expression information from a developmental time series dataset and predicted gene associations derived from a Bayesian modeling approach were used to aid the positioning of genes within the network. Further, a detailed functional analysis of likely bHLH regulatory genes within the network, including MYC1, bHLH54, bHLH66, and bHLH82, showed that three distinct subfamilies of bHLH proteins participate in root epidermis development in a stage-specific manner. The integration of genetic, genomic, and computational analyses provides a new view of the composition, architecture, and logic of the root epidermal transcriptional network, and it demonstrates the utility of a comprehensive systems approach for dissecting a complex regulatory network
    corecore