673 research outputs found
Remote sensing study of land use and sedimentation in the Ross Barnett Reservoir, Jackson, Mississippi area
This multi-year study is aimed at focusing on the recognition of sediment and other affluents in a selected area of the Ross Barnett Reservoir. The principle objectives are the determination of land use types, effect of land use on erosion, and the correlation of sediment with land use in the area. The I2S multi-band imagery was employed in conjunction with ground truth data for both water and land use studies. The selected test site contains approximately forty square miles including forest, open land, and water in addition to residential and recreational areas
Pleurocidin-family cationic antimicrobial peptides are cytolytic for breast carcinoma cells and prevent growth of tumor xenografts
Introduction: Cationic antimicrobial peptides (CAPs) defend against microbial pathogens; however, certain CAPs also exhibit anticancer activity. The purpose of this investigation was to determine the effect of the pleurocidin-family CAPs, NRC-03 and NRC-07, on breast cancer cells. Methods: MTT (3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) and acid phosphatase cell-viability assays were used to assess NRC-03- and NRC-07-mediated killing of breast carcinoma cells. Erythrocyte lysis was determined with hemolysis assay. NRC-03 and NRC-07 binding to breast cancer cells and normal fibroblasts was assessed with fluorescence microscopy by using biotinylated-NRC-03 and -NRC-07. Lactate dehydrogenase-release assays and scanning electron microscopy were used to evaluate the effect of NRC-03 and NRC-07 on the cell membrane. Flow-cytometric analysis of 3,3'-dihexyloxacarbocyanine iodide- and dihydroethidium-stained breast cancer cells was used to evaluate the effects of NRC-03 and NRC-07 on mitochondrial membrane integrity and reactive oxygen species (ROS) production, respectively. Tumoricidal activity of NRC-03 and NRC-07 was evaluated in NOD SCID mice bearing breast cancer xenografts. Results: NRC-03 and NRC-07 killed breast cancer cells, including drug-resistant variants, and human mammary epithelial cells but showed little or no lysis of human dermal fibroblasts, umbilical vein endothelial cells, or erythrocytes. Sublethal doses of NRC-03 and, to a lesser extent, NRC-07 significantly reduced the median effective concentration (EC 50) of cisplatin for breast cancer cells. NRC-03 and NRC-07 bound to breast cancer cells but not fibroblasts, suggesting that killing required peptide binding to target cells. NRC-03- and NRC-07-mediated killing of breast cancer cells correlated with expression of several different anionic cell-surface molecules, suggesting that NRC-03 and NRC-07 bind to a variety of negatively-charged cell-surface molecules. NRC-03 and NRC-07 also caused significant and irreversible cell-membrane damage in breast cancer cells but not in fibroblasts. NRC-03- and NRC-07-mediated cell death involved, but did not require, mitochondrial membrane damage and ROS production. Importantly, intratumoral administration of NRC-03 and NRC-07 killed breast cancer cells grown as xenografts in NOD SCID mice. Conclusions: These findings warrant the development of stable and targeted forms of NRC-03 and/or NRC-07 that might be used alone or in combination with conventional chemotherapeutic drugs for the treatment of breast cancer.Peer reviewed: YesNRC publication: Ye
The Fundamental Diagram of Pedestrian Movement Revisited
The empirical relation between density and velocity of pedestrian movement is
not completely analyzed, particularly with regard to the `microscopic' causes
which determine the relation at medium and high densities. The simplest system
for the investigation of this dependency is the normal movement of pedestrians
along a line (single-file movement). This article presents experimental results
for this system under laboratory conditions and discusses the following
observations: The data show a linear relation between the velocity and the
inverse of the density, which can be regarded as the required length of one
pedestrian to move. Furthermore we compare the results for the single-file
movement with literature data for the movement in a plane. This comparison
shows an unexpected conformance between the fundamental diagrams, indicating
that lateral interference has negligible influence on the velocity-density
relation at the density domain . In addition we test a
procedure for automatic recording of pedestrian flow characteristics. We
present preliminary results on measurement range and accuracy of this method.Comment: 13 pages, 9 figure
Radium contamination in the area around Dalgety Bay
In this report, the Committee on Medical Aspects of Radiation in the Environment (COMARE) presents a comprehensive review of the radium contamination in the area around Dalgety Bay. This report covers the history of the site, the type and extent of the contamination, the recent investigations and the cancer epidemiology for the area. The report also considers the implications for other similarly contaminated sites
Prehistory of Transit Searches
Nowadays the more powerful method to detect extrasolar planets is the transit
method. We review the planet transits which were anticipated, searched, and the
first ones which were observed all through history. Indeed transits of planets
in front of their star were first investigated and studied in the solar system.
The first observations of sunspots were sometimes mistaken for transits of
unknown planets. The first scientific observation and study of a transit in the
solar system was the observation of Mercury transit by Pierre Gassendi in 1631.
Because observations of Venus transits could give a way to determine the
distance Sun-Earth, transits of Venus were overwhelmingly observed. Some
objects which actually do not exist were searched by their hypothetical
transits on the Sun, as some examples a Venus satellite and an infra-mercurial
planet. We evoke the possibly first use of the hypothesis of an exoplanet
transit to explain some periodic variations of the luminosity of a star, namely
the star Algol, during the eighteen century. Then we review the predictions of
detection of exoplanets by their transits, those predictions being sometimes
ancient, and made by astronomers as well as popular science writers. However,
these very interesting predictions were never published in peer-reviewed
journals specialized in astronomical discoveries and results. A possible
transit of the planet beta Pic b was observed in 1981. Shall we see another
transit expected for the same planet during 2018? Today, some studies of
transits which are connected to hypothetical extraterrestrial civilisations are
published in astronomical refereed journals. Some studies which would be
classified not long ago as science fiction are now considered as scientific
ones.Comment: Submiited to Handbook of Exoplanets (Springer
Patient radiation dose issues resulting from the use of CT in the UK
In this report, COMARE presents a comprehensive review of the radiation dose issues associated with CT scans in the UK. The implications of the increase in the numbers of CT scans in the UK are considered in the report, with focus on the number of younger patients undergoing CT scans, who have greater sensitivity to x-rays. The report provides an update on the radiation protection aspects of justification (balancing risk and benefit) and optimisation (balancing the risk from the radiation dose with the quality of the image)
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