930 research outputs found
Political prospects for an ocean regime
The subject area of this thesis is the proposed international sea regime. The regime in this context refers to the proposed international organization to control the resources of the sea-bed beyond the limits of national jurisdiction. Regime in the above context has a specific meaning and should not be confused with the more general meaning of a regime of the sea. In the more general sense a regime of the sea would encompass the entire law of the sea. Such a broad scope is not intended, therefore no treatment of fishing rights, limitation of nuclear arms, extensive oil deposits at centers are attempted except as they specifically relate to the proposed ocean regime and its jurisdiction
Referencing Sources of Molecular Spectroscopic Data in the Era of Data Science: Application to the HITRAN and AMBDAS Databases
The application described has been designed to create bibliographic entries
in large databases with diverse sources automatically, which reduces both the
frequency of mistakes and the workload for the administrators. This new system
uniquely identifies each reference from its digital object identifier (DOI) and
retrieves the corresponding bibliographic information from any of several
online services, including the SAO/NASA Astrophysics Data Systems (ADS) and
CrossRef APIs. Once parsed into a relational database, the software is able to
produce bibliographies in any of several formats, including HTML and BibTeX,
for use on websites or printed articles. The application is provided
free-of-charge for general use by any scientific database. The power of this
application is demonstrated when used to populate reference data for the HITRAN
and AMBDAS databases as test cases. HITRAN contains data that is provided by
researchers and collaborators throughout the spectroscopic community. These
contributors are accredited for their contributions through the bibliography
produced alongside the data returned by an online search in HITRAN. Prior to
the work presented here, HITRAN and AMBDAS created these bibliographies
manually, which is a tedious, time-consuming and error-prone process. The
complete code for the new referencing system can be found at
\url{https://github.com/hitranonline/refs}.Comment: 11 pages, 5 figures, already published online at
https://doi.org/10.3390/atoms802001
Developing 3D cell cultures for synthetic bone models
Bone is a difficult tissue type to investigate with much of the primary investigations performed in animals. While this can improve our understanding of the basic mechanisms of the tissue, the pace of research can be slow and have poor clinical translation from benchtop to clinic. Therefore, there is a need for an intermediate step, a synthetic tissue model that accurately recapitulates the biology of bone. This can be used as a substitute for animals in primary and investigatory research without the cost and ethical concerns associated with animal models. This thesis focused on the development of such models. A composite bioink formulation of alginate, collagen and hydroxyapatite was developed. A key feature of this bioink was fibrillar collagen formed within the alginate and in the presence of the hydroxyapatite mineral. To achieve the fibrillar collagen, low concentrations of alginate had to be used within the bioink that meant the printed constructs could not self-support. A suspended printing technique was incorporated and facilitated the 3D printing of the constructs, due to the low structural stability of the bioink, the constructs could not be removed from the bath. A novel in situ hybrid crosslinking 3D printing mechanism was developed to semi crosslink the constructs which allowed them to be retrieved. This mechanism was compatible with cell incorporation and fibril collagen formation
A crossover comparison of progression of chronic renal failure: Ketoacids versus amino acids
A crossover comparison of progression of chronic renal failure: Ketoacids versus amino acids. Rates of progression of chronic renal failure were compared in patients receiving alternately an amino acid supplement (AA) and a ketoacid supplement (KA) to a very low protein (0.3 g/kg), low phosphorus (7 to 9 mg/kg) diet. The first supplement was randomly chosen. Bias due to carryover effects was minimized by delaying the regression analysis until one month after starting or changing supplements. In order to minimize possible bias caused by initiating the two supplements at differing levels of severity, a multiple crossover design was used (ABA, BAB, ABAB, or BABA) with at least four GFR's in each treatment period (except for three GFR's in one instance). Sixteen patients completed the protocol; five dropped out. Average starting GFR's were nearly identical for the two supplements (15.4 and 15.9 ml/min). For each patient, mean progression on KA was compared with mean progression on AA. Thirteen out of 16 patients progressed more slowly on KA than AA. On the average, progression on KA was significantly slower (95% confidence limits = -0.36 to 0.09 ml/min/month) than on AA (-0.91 to -0.41 ml/min/month; P = 0.024). There was no significant difference in estimated protein intake, phosphate excretion, or mean arterial pressure between KA and AA periods. Serum triglyceride concentration was significantly lower on KA (P = 0.0026). 17-hydroxycorticosteroid excretion was also lower (P = 0.031). We conclude that KA slow progression, relative to AA, independently of protein or phosphorus intake, in patients on this regimen
Effects of diamagnetic levitation on bacterial growth in liquid
Diamagnetic levitation is a technique that uses a strong, spatially-varying magnetic field to levitate diamagnetic materials, such as water and biological cells. This technique has the potential to simulate aspects of weightlessness, on the Earth. In common with all ground-based techniques to simulate weightlessness, however, there are effects introduced by diamagnetic levitation that are not present in space. Since there have been few studies that systematically investigate these differences, diamagnetic levitation is not yet being fully exploited. For the first time, we critically assess the effect of diamagnetic levitation on a bacterial culture in liquid. We used a superconducting magnet to levitate growing bacterial cultures for up to 18 hours, in a series of experiments to determine the effect of diamagnetic levitation on all phases of the bacterial growth cycle. We find that diamagnetic levitation increases the rate of population growth in a liquid culture. The speed of sedimentation of the bacterial cells to the bottom of the container is considerably reduced. Further experiments and microarray gene analysis show that the growth enhancement is due to greater oxygen availability in the magnetically levitated sample. We demonstrate that the magnetic field that levitates the cells also induces convective stirring in the liquid, an effect not present in microgravity. We present a simple theoretical model, showing how the paramagnetic force on dissolved oxygen can cause the liquid to become unstable to convection when the consumption of oxygen by the bacteria generates an oxygen concentration gradient. We propose that this convection enhances oxygen availability by transporting oxygen around the sample. Since convection is absent in space, these results are of significant importance and timeliness to researchers considering using diamagnetic levitation to explore weightless effects on living organisms and a broad range of other topics in the physical and life sciences
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Addition to the HITRAN database of line-shape parameters due to the pressure of H2, He and CO2. Part 1: SO2, NH3, HF, HCL, OCS and C2H2
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