19,821 research outputs found
Mesoscale variability of free tropospheric humidity near San Nicolas Island during FIRE
Humidity variability at the top of the marine boundary layer (MBL) and in the free troposphere was examined using a variety of measurements taken on and around San Nicolas Island (SNI) during the FIRE IFO in July, 1987. Doppler wind profiler reflectivity recorded at two minute time resolution has provided the most continuous record and detail of small scale humidity fluctuations. Rawinsonde data were available from both an island site and the research vessel Point Sur. The information extractable from these sources is somewhat limited due to the frequency of launches (3 to 4/day at SNI and 6/day on the Point Sur). Some additional data were available from instrumented aircraft although scheduling flights in the neighborhood of the island was difficult due to restrictions on the air space. Other relevant data were collected at SNI near the radar and rawinsonde launch sites. A continuous record of cloud base altitude was logged by a ceilometer. Doppler acoustic sounder (sodar) reflectivity data provided a good record of inversion height. The sodar also monitored turbulent temperature fluctuations in the MBL. A small ground station recorded hourly averages of solar irradiance and downward longwave irradiance. The analysis in progress of the various data sets for two adjacent two day periods from 11 July to 14 July is described. The earlier period was chosen because the marine inversion was unusually high and there was increased frequency of rawinsonde launches at SNI. The later period was chosen because of the significant descent with time of an elevated inversion indicated by the radar data. Throughout the four day period, but especially in the first half, the turbulent humidity structure calculated from Doppler radar reflectivity shows excellent agreement with humidity profiles evaluated from rawinsonde data
Solvation forces in Ising films with long-range boundary fields: density-matrix renormalization-group study
Using the quasi-exact density-matrix renormalization-group method we
calculate the solvation forces in two-dimensional Ising films of thickness L
subject to identical algebraically decaying boundary fields with various decay
exponents p. At the bulk critical point the solvation force acquires a
universal contribution which is long-ranged in L due to the critical
fluctuations, a phenomenon known as the critical Casimir effect. For p = 2, 3
and 50, we study the scaling behaviour of the solvation force along the
pseudo-phase coexistence and along the critical and sub-critical isotherms.Comment: 9 pages, 6 figures, accepted to Molecular Physic
Chronic pain assessments in children and adolescents : a systematic literature review of the selection, administration, interpretation, and reporting of unidimensional pain intensity scales
Background. Advances in pain assessment approaches now indicate which measures should be used to capture chronic pain experiences in children and adolescents. However, there is little guidance on how these tools should best be administered and reported, such as which time frames to use or how pain scores are categorised as mild, moderate, or severe. Objective. To synthesise current evidence on unidimensional, single-item pain intensity scale selection, administration, interpretation, and reporting. Methods. Databases were searched (inception: 18 January 2016) for studies in which unidimensional pain intensity assessments were used with children and adolescents with chronic pain. Ten quality criteria were developed by modifying existing recommendations to evaluate the quality of administration of pain scales most commonly used with children. Results. Forty-six studies met the inclusion criteria. The highest score achieved was 7 out of a possible 10 (median: 5; IQR: 4â6). Usage of scales varied markedly in administrator/completer, highest anchors, number of successive assessments, and time referent periods used. Conclusions. Findings suggest these scales are selected, administered, and interpreted inconsistently, even in studies of the same type. Furthermore, methods of administration are rarely reported or justified making it impossible to compare findings across studies. This article concludes by recommending criteria for the future reporting of paediatric chronic pain assessments in studies
Studies in the nitrogen heterocyclic series
PART I. SYNTHESES IN THE QUINOXALINE SERIES:
Several α-hydroxy nitrogen heterocyclic bases have been
treated with an equimolecular mixture of phosphorus oxychloride
and water.
Simple α-hydroxyquinoxalines, acridone, and phenanthridone
are converted to the corresponding chloro derivatives by this
mixture. The mixture is a less efficient chlorinating agent
than phosphorus oxychloride itself.
Derivatives of methin-(2'-(3'-keto) tetrahydroquinoxaline) I
are converted to the corresponding methin-(2'-dihydroquinoxaline)
bases II in good yield by this mixture.
Methin-(2- pyrazinyl)-(2'-dihydroquinoxaline) (II - R =
2-pyrazinyl) and a yellow base, CââHâNâ, for which the structure
10H- pyrazino (2',3':3,4)cyclopenta(b) quinoxaline III has been
suggested, are obtained when methin-(2-quinoxalinyl)-(2' -(3' -keto)
piperazine) IV is treated with the mixture.
Two bases are also obtained when methin-(2-pyrazinyl)-
(2' -(3'-keto)piperazine) is treated with the mixture. Structures
have been proposed for these bases.
Attempts to synthesise 1'-ketocyclopenta (4',5':2,3) quinoxaline,
the starting material for a proposed synthesis of 10H-pyrazino
(2', 3':3,4)cyclopenta(b)quinoxaline III, have been made.
PART II STUDIES ON CERTAIN QUINOXALINE DERIVATIVES.
This research has been directed toward the elucidation of the
structure of a red base, CâââHâNâ, obtained from the reaction of
2-acetyl-3-methylquinoxaline with 2-methylquinoxaline in dilute
acid. A structure, quinoxalo(2',3':8,9)benzo(2,3)-7-methyl-tropazine
V, had been proposed for this base.
An attempt to prepare quinoxalo (2',3':8,9)benzo(2,3)tropazine
by the cyclisation of α-(3-methylquinoxaliny1-2)-Ă-(quinoxalinyl-
2')-ethylene was unsuccessful.
Attempts to brominate the C-methyl group with bromine directly
and with N-bromosuccinimide failed.
Attempted oxidations of the C-methyl group with selenium
dioxide, and of the base with hydrogen peroxide, ozone and osmium
tetroxide failed to give identifiable products. Chromic acid
oxidation, however, gave a ketone, CââHâ or âNâ0, for which a
structure has been tentatively advanced.
Investigations into the method of formation of the base have
ruled out the previously proposed method of formation.
Doubt has been cast on the proposed structure of the base
and preliminary investigations of a similar bromo-substituted
red base have been made
Soluble Fermentable Dietary Fibre (Pectin) Decreases Caloric Intake, Adiposity and Lipidaemia in High-Fat Diet-Induced Obese Rats
Funding: This work was funded by the Scottish Government Rural and Environment Science and Analytical Services Division. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Influence of FK 506 (tacrolimus) on circulating CD4 <sup>+</sup> t cells expressing cd25 and cd45ra antigens in 19 patients with chronic progressive multiple sclerosis participating in an open label drug safety trial
We have taken the opportunity of a clinical trial of the potential efficacy and safety of FK 506 (tacrolimus) in chronic progressive multiple sclerosis (MS) to examine the influence of this potent new immunosuppressant on circulating T-lymphocytes in an otherwise healthy non-transplant population. Peripheral blood levels of subsets of CD4+ T lymphocytes expressing the activation molecule interleukin-2 receptor (p55 α chain; CD25) or the CD45RA isoform were determined sequentially in 19 patients that were treated continuously with oral FK 506 (starting dose 0.15 mg/kg/day) for 12 months. No significant change in the proportion of circulating CD25 + CD4+ cells was observed over the study period in which the mean trough plasma FK 506 level rose from 0.3 ±0.2 to 0.5 ±0.4 ng/ml. There was also no significant effect of FK 506 on the percentage of CD45RA + CD4 + cells in the peripheral blood at 12 months compared with pretreatment values. Analysis of a subgroup of 7 patients, who showed a sustained reduction in CD25 + CD4+ cells and a reciprocal increase in CD45RA* CD4 * cells for at least 6 months after start of treatment, did not reveal any difference in disability at one year compared with the treatment group as a whole. The side effects of FK 506 were mild and the overall degree of disability estimated by the mean Kurtzke expanded disability status scale (EDSS) score or the ambulation index did not deteriorate significantly in the 19 patients studied over the 12 months of FK 506 administration. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted
Knowledge of Objective 'Oughts': Monotonicity and the New Miners Puzzle
In the classic Miners case, an agent subjectively ought to do what they know is objectively wrong. This case shows that the subjective and objective âoughtsâ are somewhat independent. But there remains a powerful intuition that the guidance of objective âoughtsâ is more authoritativeâso long as we know what they tell us. We argue that this intuition must be given up in light of a monotonicity principle, which undercuts the rationale for saying that objective âoughtsâ are an authoritative guide for agents and advisors
Topological defect motifs in two-dimensional Coulomb clusters
The most energetically favourable arrangement of low-density electrons in an
infinite two-dimensional plane is the ordered triangular Wigner lattice.
However, in most instances of contemporary interest one deals instead with
finite clusters of strongly interacting particles localized in potential traps,
for example, in complex plasmas. In the current contribution we study
distribution of topological defects in two-dimensional Coulomb clusters with
parabolic lateral confinement. The minima hopping algorithm based on molecular
dynamics is used to efficiently locate the ground- and low-energy metastable
states, and their structure is analyzed by means of the Delaunay triangulation.
The size, structure and distribution of geometry-induced lattice imperfections
strongly depends on the system size and the energetic state. Besides isolated
disclinations and dislocations, classification of defect motifs includes defect
compounds --- grain boundaries, rosette defects, vacancies and interstitial
particles. Proliferation of defects in metastable configurations destroys the
orientational order of the Wigner lattice.Comment: 14 pages, 8 figures. This is an author-created, un-copyedited version
of an article accepted for publication in J. Phys.: Condens. Matter. IOP
Publishing Ltd is not responsible for any errors or omissions in this version
of the manuscript or any version derived from it. The definitive
publisher-authenticated version is available online at
10.1088/0953-8984/23/38/38530
- âŠ