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Sankaran N.,The Green Office
Studies in History and Philosophy of Science Part C :Studies in History and Philosophy of Biological and Biomedical Sciences | Year: 2014

The discovery that cancer may be caused by viruses occurred in the early twentieth century, a time when the very concept of viruses as we understand it today was in a considerable state of flux. Although certain features were agreed upon, viruses, more commonly referred to as 'filterable viruses' were not considered much different from other microbes such as bacteria except for their extremely small size, which rendered them ultramicroscopic and filterable. For a long time, in fact, viruses were defined rather by what they were not and what they could not do, rather than any known properties that set them apart from other microbes. Consequently when Peyton Rous suggested in 1912 that the causative agent of a transmissible sarcoma tumor of chickens was a virus, the medical research community was reluctant to accept his assessment on the grounds that cancer was not infectious and was caused by a physiological change within the cells. This difference in the bacteriological and physiological styles of thinking appears to have been prevalent in the wider research community, for when in 1917 Felix d'Herelle suggested that a transmissible lysis in bacteria, which he called bacteriophagy, was caused by a virus, his ideas were also opposed on similar grounds. It was not until the 1950s when when André Lwoff explained the phenomenon of lysogeny through his prophage hypothesis that the viral identities of the sarcoma-inducing agent and the bacteriophages were accepted. This paper examines the trajectories of the curiously parallel histories of the cancer viruses and highlights the similarities and differences between the ways in which prevailing ideas about the nature of viruses, heredity and infection drove researchers from disparate disciplines and geographic locations to develop their ideas and achieve some consensus about the nature of cancer viruses and bacteriophages. © 2014 Elsevier Ltd. All rights reserved. Source

Park D.,Korea Railroad Research Institute | Oh M.,Korea Railroad Research Institute | Yoon Y.,The Green Office | Park E.,Korea Railroad Research Institute | And 2 more authors.
Atmospheric Environment | Year: 2012

Monitoring the air quality in subway passenger cabins is important because of the large number of passengers and potentially high levels of air pollution. This report characterized PM 10 levels in subway cabins in Seoul, Korea, and identified PM 10 sources using elemental analysis and receptor modeling. PM 10 levels in subway cabins were continuously measured using a light scattering monitor during rush and non-rush hours. A total of 41 measurements were taken during rush and non-rush hours, and the measurements were repeated in all four seasons. Filter samples were also collected for elemental composition analysis. Major PM 10 sources were identified using positive matrix factorization (PMF). The in-cabin PM 10 concentrations were the highest in the winter at 152.8μgm -3 during rush hours and 90.2μgm -3 during non-rush hours. While PM 10 levels were higher during rush hours than during non-rush hours in three seasons (excluding summer), these levels were not associated with number of passenger. Elemental analysis showed that the PM 10 was composed of 52.5% inorganic elements, 10.2% anions, and 37.3% other. Fe was the most abundant element and significantly correlated (p<0.01) with Mn (r=0.97), Ti (r=0.91), Cr (r=0.88), Ni (r=0.89), and Cu (r=0.88). Fe, Mn, Cr, and Cu are indicators of railroad-related PM 10 sources. The PM 10 sources characterized by PMF were soil and road dust sources (27.2%), railroad-related sources (47.6%), secondary nitrate sources (16.2%), and a chlorine factor mixed with a secondary sulfate source (9.1%). Overall, railroad-related sources contributed the most PM 10 to subway cabin air. © 2011 Elsevier Ltd. Source

Ohzuku T.,Osaka City University | Nagayama M.,Osaka City University | Nagayama M.,The Green Office | Tsuji K.,Osaka City University | Ariyoshi K.,Osaka City University
Journal of Materials Chemistry | Year: 2011

Lithium nickel manganese oxides Li[NixLi (1/3-2x/3)Mn(2/3-x/3)]O2 (x = 1/2, 2/7, and 1/5) are prepared and characterized by XRD and FT-IR, and the samples are examined in non-aqueous lithium cells at room temperature and 55 °C. Among these materials LiNi1/2Mn1/2O2 (x = 1/2) shows the highest operating voltage and the smallest polarization with a rechargeable capacity of ca. 230 mA h g-1 and Li[Li1/5Ni 1/5Mn3/5]O2 (x = 1/5) shows the lowest operating voltage and the largest polarization with a rechargeable capacity more than 300 mA h g-1. Extraordinarily large rechargeable capacity of Li[Li1/5Ni1/5Mn3/5]O2 together with an anomalously long voltage plateau at 4.5 V only observed at first charging process is examined by window-opening charge and discharge, continuous charge and discharge combined with differential chronopotentiometry at room temperature and at 55 °C, and possible mechanisms are discussed in terms of lithium insertion scheme. © 2010 The Royal Society of Chemistry. Source

Joe Y.H.,Yonsei University | Ju W.,Doosan Heavy Industries and Construction | Park J.H.,University of Iowa | Yoon Y.H.,The Green Office | Hwang J.,Yonsei University
Aerosol and Air Quality Research | Year: 2013

This study investigated the correlation between the antibacterial ability of silver nanoparticle air filters with the related dust loading. In addition, a decay equation with which the life cycle of the antibacterial air filters could be predicted was developed. Samples of a HEPA (High Efficiency Particulate Air) filter were coated with an antibacterial agent, silver nanoparticles, which were synthesized via an atmospheric spark discharge method and deposited onto the filters using forced convection flow. A specific amount of dust particles was then blown onto each filter sample. Two kinds of bacteria, Escherichia coli (E. coli), representing Gram-negative bacteria, and Staphylococcus epidermidis (S. epidermidis), representing Gram-positive bacteria, were used in order to examine the antibacterial abilities of the filter samples. The results of the disc diffusion method showed that the dust loading adversely affected the antibacterial efficacy. However, the silver nanoparticle mass density on a filter with a certain amount of dust does increase the antibacterial ability to a certain extent. Finally, decay equations for the decline rates of the antibacterial ability against E. coli and S. epidermidis were obtained with a dimensionless pressure drop across the antibacterial filter samples. © Taiwan Association for Aerosol Research. Source

Yang B.,University of Georgia | Madden M.,University of Georgia | Jordan T.R.,University of Georgia | Cordell H.K.,The Green Office
Ocean and Coastal Management | Year: 2012

Demarcation of upland and water/marsh boundary is a critical issue for management and protection of barrier island ecosystems. Most accurate, precise and confident approaches are required to resolve conflicts related to developable lands and conservation area. Barrier islands are especially prone to these conflicts because they are highly dynamic systems that are formed and reformed by rise and fall of tides and seal levels. In response, this research analyzes the demarcation of Jekyll Island State Park, Georgia, USA that is faced with management issues of balancing tourism and development with resource conservation. Questions addressed by this research include: (1) What are the standard sea levels used to demarcate barrier islands? (2) What are the best methods for most accurately estimating the total area of coastal barrier islands? (3) Do differences in tide elevations between back-barrier and ocean-front shorelines of barrier islands exist? Specifically, this research considers a number of environmental policies, regulations, and laws along with geospatial data such as aerial photography, Light Detection and Ranging (LiDAR) and GIS shapefiles. These data are used to define sea levels and outline of Jekyll Island State Park based on Mean High Water (MHW) levels with respect to 0.79-m, 0.85-m, 0.94-m, 1.00-m, and 1.49-m for the entire Jekyll Island State Park. The demarcations of different back-barrier marshland and ocean-front side of the island were also considered. Results indicate that the total area of Jekyll Island State Park may vary by as much as 3.31-km 2 or 7.2% depending on the jurisdictional sea level that is used to demarcate the island boundary. © 2011 Elsevier Ltd. Source

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