6,305 research outputs found
Differential Susceptibility of Human Cancer Cell Lines to Wild-Type Tanapoxvirus Infection
Tanapoxvirus (TPV) is a member of the genus Yatapoxvirus in the family Poxviridae and is endemic to equatorial Africa. This disease is restricted to human and non-human primates, producing a mild febrile illness characterized by a single or more rarely additional pock-like lesions on the extremities. While there are several studies elucidating the replication cycle and host range of TPV, there is currently no standardized investigation comparing the ability of TPV to successfully replicate in a variety of tumor cell lines. This study examined the cytopathic effect and calculated the efficiency of TPV replication in vitro using 14 different human cancer cell lines. TPV replicates efficiently in some human tumor cells, and is restricted in others when measured by viral titer at 7 days post infection. Results described here clearly demonstrate that TPV replication in one glioblastoma cell line (U-373), and one colorectal cancer cell line (HCT-116) is more productive than in owl monkey kidney cells (OMK). Replication in two renal cancer cell lines (ACHN and Caki-1) is also increased when compared to OMK. TPV infection produced the greatest change in cellular morphology in U-373 cells, and to a much lesser degree in the breast cancer cell lines T-47D and MCF-7, and in the ovarian cancer line SK-OV3. Negligible change was noted in glioblastoma line U-87, breast cancer line MDA-MB-435, osteosarcoma line HOS, melanoma line SK-MEL5, colorectal cancer line COLO205, and prostate cancer line PC3. The cell lines least permissive to TPV replication were the glioblastoma (U-87) and melanoma (SK-MEL5) cell lines
The K-alpha complex of He-like iron with dielectronic satellites
It is shown that the dielectronic satellites (DES) dominate X-ray spectral
formation in the 6.7 keV K-alpha complex of Fe XXV at temperatures below that
of maximum abundance in collisional ionization equilibrium T_m. Owing to their
extreme temperature sensitivity the DES are excellent spectral diagnostics for
T < T_m in photoionized, colllisional, or hybrid plasmas; whereas the
forbidden, intercombination, and resonance lines of Fe XXV are not. A
diagnostic line ratio GD(T) is defined including the DES and the lines, with
parameters from new relativistic atomic calculations. The DES absorption
resonance strengths may be obtained from differential oscillator strengths to
possibly yield the Fe XXIV/Fe XXV column densities. The DES contribution to
highly ionized Fe should be of interest for models of redward broadening of
K-alpha features, ionized accretion discs, accretion flows, and K-alpha
temporal-temperature variability in AGN.Comment: 5 pages, 4 Figs., submitted to MNRAS. High-resolution, full-size
figures are available from http://www.astronomy.ohio-state.edu/~pradha
A WORKFLOW MODEL TO SUPPORT LOCATION BASED PARTICIPATION TO POLICY MAKING PROCESSES
This paper aims to propose PMWF model, a new workflow model to automate ubiquitous policy making processes and facilitate citizen participation. While workflow technology has been widely adopted in public sector, the use of technology is mostly limited to supporting back-end administrative business processes. PMWF model targets front-end policy making processes that require active participation of large number of citizens. Automatic delivery of relevant policy issues into citizen’s life is expected to enhance their participation in policy formulation and implementation processes. PMWF model provides modelling constructs to link back-end admin tasks by policy makers to front-end opinion tasks whose main actors are citizens. The core constructs for linkage is opinion-tag which contains policy issues and is attached to geographical objects so that citizens can identify relevant policy issues in the middle of their every-day life patterns. The proposed model is applied to real world policy making processes in the UK and Turkey to show its generality
Application of PCM to shift and shave peak demand: Parametric studies
Space conditioning is a main contributor to energy usage in buildings. In Quebec, electric baseboard heaters are the predominant household space-heating systems, in the other words, electrical energy is the main source of energy used for space heating. Thus in such a cold climate like Quebec, residential peak heating demand is a significant contributor to high and critical electricity grid peak periods. Reducing peak heating demand by shifting a portion of peak heating demand to off-peak period is thus of high interest. On the supply side, this strategy requires less generated power, and on the demand side it helps downsize heating systems. One possible approach to shifting peak heating demand to off-peak time is to store thermal energy during off-peak periods and release the stored energy during peak periods. To adopt this approach, set-point temperature of heating systems can be lowered during the peak period, while a release of stored energy maintains the indoor temperature within the desired comfort zone. This capability could be implemented using the concept of latent heat, offered by phase-change-material (PCM)–impregnated building wallboard, such as PCM-gypsum wallboard. In this thesis, a PCM module within TRNSYS software is first validated with experimental data, available in literature, for a simple case of one cubicle. The code is then applied to a typical one-story residential building, also modeled in TRNSYS. Later, several parametric studies are carried out to investigate the influence of PCM’s thermal properties and convective heat transfer coefficient on the rate of PCM’s thermal discharge and its resulting improvement in indoor air condition. The simulation results reveal that it is possible to maintain a trade-off between shifting the peak heating demand and preserving thermal comfort by applying PCMs with proper characteristics. It was observed that improving thermal conductivity of PCM has a negligible impact on heat discharge during peak time. Simulations also show that the PCM melting temperature range should be chosen closest to the assigned set-point temperature. It has been shown that increasing the thickness of the PCM layer more than a certain value, 0.013 m, has no effect on thermal storage or, therefore, on PCM thermal discharge. Investigation of interior convective heat transfer on PCM discharge reveals that for a specific climate and PCM wallboard, there is a threshold for effective performance of PCM. For a building located in Montreal, it was shown that with a typical PCM-gypsum wallboard, the interior heat transfer coefficient has to be at least 6.6 W/m2K to sustain the desired thermal comfort. Finally, thermal behavior of the building integrated with PCM wallboards was assessed in three different climates and by applying two different PCM-gypsum wallboards. It was found that PCM wallboard selection and set-point temperature control strategy must be considered according to the outdoor weather conditions
Production and optimization of L-asparaginase by Bacillus sp. KK2S4 from corn cob
L-Asparaginase (L-asparagine amido hydrolase, E.C.3.5.1.1) is an important enzyme which has antitumor properties. This paper describes the production and optimization of L-asparaginase by Bacillus sp. KK2S4 utilization of ground corn cob waste as substrate to reduce and manage the waste in our environment. Thirty-nine (39) bacterial isolates were screened for their L-asparaginase productivity and protein content. Only Bacillus sp. KK2S4 was identified before and selected as the most potent isolate. Modified M9 (MM9) minimal complete medium (glucose free) was used as production media for enzyme production. The highest enzyme production was detected at pH 5.0 in presence of lactose and NaNO3 as the best carbon and nitrogen sources with high activity increasing percentage of 1058.9, 377.3 and 566.7%, respectively.Keywords: L-Asparaginase production, corn cob waste, enzyme optimization, anti-tumor agentAfrican Journal of Biotechnology Vol. 12(19), pp. 2654-265
Geological Effect on GPR System Due to Soil Properties in Malaysia
This paper present the measurement of dielectric properties of soil in Malaysia in three differences condition which are normal condition (ambience), heated (up to 50 OC) and wet condition (10 % water content). Eight (8) samples of soil have been collected in the local region and was measured in the frequency range from 0.5 GHz to 3.5 GHz for Ground Penetrating Radar (GPR) applications. The measurement of the dielectric properties has been conducted using Agilent high temperature probe (Model) integrated with Performance Network Analyzer (PNA E8362B). The uncertainties in measurement process, especially dealing with measurement data have been considered in order to eliminate the probability of error during the measurement. The measured result for permittivity and loss factor of the measured samples are tabulated in graphs and the analysis of the measured data are discussed in this paper
Production and characterization of enzyme-treated spray-dried soursop (Annona muricata L.) powder
Easily perishable soursop (Annona muricata L.) fruit was converted into powder for value‐addition. Soursop puree obtained from fruit pulp that had been treated with different concentrations (0–2% v/w) of Celluclast 1.5 L at fixed (1.5% v/w) concentration of Pectinase Ultra SP‐L were spray‐dried at various inlet temperatures (130–160 °C) after mixing the puree with maltodextrin (20–40% w/w). Multiple responses optimization from Response Surface Methodology (RSM) indicated puree that was pretreated with 1.3% (v/w) cellulase and incorporated with 37% w/w maltodextrin and spray‐dried at an inlet temperature of 156 °C could be transformed into powder that had the following physicochemical properties: moisture content, 2.03% (wb); Aw, 0.18; hygroscopicity, 29.02 g/100g; stickiness, 173.02 g and yield 70.56% of powder. The glass transition temperature (Tg) was found to range between 46.53 and 58.25 °C, indicating the spray‐dried powder was an amorphous material. Surface morphology of the powder particles, viewed using Scanning Electron Microscopy, showed they exhibited spherical in shape and possessed a continuous wall (crust) without surface cracks
Efficiency measurement of a Malaysian hotel chain using DEA
Efficiency evaluation has become an important improvement tool for hotels to sustain in today’s highly competitive environment. This study used DEA approach to evaluate the relative efficiency of a Malaysian hotel chain during the period of 2004 to 2008 in terms of Total Factor Productivity (TFP) change. TFP change is measured using DEA-Malmquist productivity index. DEA is a pragmatic tool which combines multiple inputs and outputs objectively onto an overall measure of organizational efficiency. The Malmquist TFP index measures are decomposed into technical efficiency change and technological change. The decomposition of technical efficiency change into two sub-components, pure technical efficiency change, and scale efficiency change is also discussed in this paper. The actual operating data of five inputs and five outputs were collected from 10 hotels under the chain. Empirical results revealed that the TFP of the hotel chain slightly increased by 0.7% over the time period. Six of the hotels in the chain experienced positive TFP change while the others experienced TFP decline. The quadrant of efficiency was proposed to give a two-dimensional view of the hotel efficiency. Meanwhile, technological change was found to be more important factor of TFP growth as compared to technical efficiency change. Therefore, hotels which faced negative growths of technological change are recommended to improve their efficiency through investment in new technology or by upgrading the necessary skills. Additionally, the paper has also identified the best performing hotel within the chain which can be benchmarked by others who are seeking for performance improvemen
The effective conductivity of arrays of squares: large random unit cells and extreme contrast ratios
An integral equation based scheme is presented for the fast and accurate
computation of effective conductivities of two-component checkerboard-like
composites with complicated unit cells at very high contrast ratios. The scheme
extends recent work on multi-component checkerboards at medium contrast ratios.
General improvement include the simplification of a long-range preconditioner,
the use of a banded solver, and a more efficient placement of quadrature
points. This, together with a reduction in the number of unknowns, allows for a
substantial increase in achievable accuracy as well as in tractable system
size. Results, accurate to at least nine digits, are obtained for random
checkerboards with over a million squares in the unit cell at contrast ratio
10^6. Furthermore, the scheme is flexible enough to handle complex valued
conductivities and, using a homotopy method, purely negative contrast ratios.
Examples of the accurate computation of resonant spectra are given.Comment: 28 pages, 11 figures, submitted to J. Comput. Phy
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