EDITORIAL: Too much Sitting: A Potential Health Hazard and a Global Call to Action
Pages 131-135
Sandeep Kumar Vashist

DOI: http://dx.doi.org/10.6000/1927-5129.2015.11.18

Published: 23 Feburary 2015

Editorial

On a Piece of Paper an a Pair of Scissors
Pages 115-117
François Dubeau

DOI: http://dx.doi.org/10.6000/1927-5129.2015.11.15

Published: 17 February 2015

Abstract: We discuss the problem of splitting a given geometrical plane figure in two regions of equal area by drawing a line through a given point in the plane. We also discuss the possibility of splitting the figure into regions in proportions p% and (1 − p)% of the area of the given figure.

Keywords: Lebesgue measure, continuity.

Cytotoxicity Induction in A549 Alveolar Epithelial Cells by Mycobacterium tuberculosis Isolates Cultured in the Presence and Absence of Oxygen
Pages 118-124
Olubisi T. Ashiru and A. Willem Sturm

DOI: http://dx.doi.org/10.6000/1927-5129.2015.11.16

Published: 17 February 2015

Abstract: Background: The emergence of drug resistant Mycobacterium tuberculosis and studies on clinical isolates of drug resistant M. tuberculosis highlight the need to obtain additional valuable information on this organism. In this study, we report on M. tuberculosis clinical isolates and laboratory strain induced cytotoxicity in A549 alveolar epithelial cells in vitro.

A549 cells were infected with 15 clinical isolates (members of the Beijing and F15/LAM4/KZN families, as well as isolates with unique DNA fingerprint), and two laboratory strains of M. tuberculosis grown in the presence of oxygen, and absence of oxygen. Lactate dehydrogenase released from A549 cells was quantified after infection to evaluate necrosis.

Results:The isolates grown in the absence of oxygen had a higher level of cytotoxicity than those grown in the presence of oxygen. Cytotoxicity levels induced by F15/LAM4/KZN and Beijing isolates grown in the absence of oxygen ranged from 18.4%-35.7% and 17.7%-27.5% respectively. The highest cytotoxicity level (35.7%) was produced by an extensively drug resistant isolate that belonged to the F15/LAM4/KZN family. Growth in the presence of oxygen resulted in lower levels of cytotoxicity, ranging from 14.3%-22.4% by the F15/LAM4/KZN isolates, and 13%-23.3% by the Beijing isolates. Isolates with unique DNA fingerprint induced cytotoxicity levels between 3.5%-8.5% (oxygen) and 5.3%-10.7% (no oxygen). The H37Rv and H37Ra bacilli induced cytotoxicity levels of 3.9% and 2.9% (oxygen) respectively and 5.7% and 3.3% (no oxygen) respectively.

Conclusion:These results correlate well with our previous findings on the adhesion and invasion rates of these isolates. The increased tissue destruction induced by the F15/LAM4/KZN isolate compared to the other isolates attest to its virulence and may partly explain the high mortality rates of patients infected with this strain in Kwa Zulu-Natal in 2005.

Keywords: Beijing, F15/LAM4/KZN, virulence, necrosis, drug-resistant, in-vitro.

Effect of Cyclone on the Composition of Rainfall at Karachi City
Pages 81-89
Sumayya Saied, Saiyada Shadiah Masood, Azhar Siddique, Haider Abbas Khwaja, Muhammad Kamran Khan and Mirza M. Hussain

DOI:http://dx.doi.org/10.6000/1927-5129.2015.11.11

Published: 06 February 2015

Abstract: A rapid urbanization results in increased levels of atmospheric pollutants and magnitude of this increase is much higher in the cities of developing world. Speciation of chemicals in rainwater is one way to assess the degree and nature of atmospheric contaminant accumulation and sources of these contaminants. In June 2010 an episode of heavy rain in the megacity of Karachi occurred due to the impact of Cyclone PHET, which was expected to hit Karachi city along the Arabian Sea. Cyclone impacted rainwater samples were collected from all over Karachi city and analyzed by chromatographic and spectroscopic techniques. A wide range of concentrations were observed among different sites i.e. pH (range 6.13 - 7.92, average 7.31), conductivity (range 9µS/cm - 154µS/cm), major anions F^- (0 - 9.22µeq/L), Cl^- (31.7 - 184.7µeq/L), NO₃^- (2.2 - 13.7µeq/L), SO₄^2- (9.3 - 614µeq/L) and cations Ca²⁺ (13.1 - 364.3µeq/L), Mg²⁺ (5.83 - 72.65µeq/L), Na⁺ (49.1 - 344.7µeq/L), NH₄⁺ (0.86 - 58.59µeq/L) and K⁺ (0 - 61.44µeq/L). This wide variation of distribution was attributed to the long range transportation and climatic conditions due to cyclone effect. Industrial area samples showed a dominating character of industrial influence whereas residential areas were influenced more with the coastal impact. Spatial interpolations were used to interpret the chemical data on geographical maps using ArcGIS®.

Effect of Wind Shear Coefficient for the Vertical Extrapolation of Wind Speed Data and its Impact on the Viability of Wind Energy Project
Pages 90-100
Saif ur Rehman, MuhammadShoaib, Imran Siddiqui, Firoz Ahmed, Muhammad Rashid Tanveer and Saif Uddin Jilani

DOI:http://dx.doi.org/10.6000/1927-5129.2015.11.12

Published: 06 February 2015

Abstract: The importance of characterizing the wind shear at a specified location for the utilization of wind turbine is of vital importance. Such study is considered necessary both for the turbine design and prediction of its power output. In situations where the wind speed at different heights is required if measured values are known at one height then, generally it is extrapolated to the hub height by using the one-seventh power law. The exponent in this case has a value of 1/7 but it is observed that, the value of exponent varies with the type of terrain therefore; the one-seventh power law is not suitable for wind speed extrapolation and energy estimation. It has been found that, the one-seventh power law has a tendency to miscalculate the actual long-term average wind speeds. Hence, for accurate estimation of wind speed at a height, both monthly or seasonal and diurnal values of wind shear coefficient (WSC) have to be used. In this paper, the power law exponent for three sites located over coastal sites in South of Pakistan, i.e., Katibandar, Jati and Gharo, is established using wind speeds measured at heights 10 m and 30 m above the ground (AGL). Wind data is obtained from Pakistan Meteorological Department (PMD). Mean values of WSC were found to be 0.318 at Jati, 0.321 at Gharo and 0.269 at KatiBander. In addition, yearly, monthly and diurnal variation for WSC is also analyzed. The research showed that, the wind shear coefficient significantly fluctuates by seasonal and diurnal changes. Comparisons has been made for discrepancies in energy estimation, payback period and cost of energy (Cents/Kwh) using wind speed values extrapolated from 10 m, for one-seventh power law and overall mean WSC as exponent. The study showed that, if wind speed is extrapolated with WSC of 0.143, the energy is underestimated by 16-33% at Gharo, 12-25% at Katibandar and 28-51% at Jati for all considered hub heights. Error in the Payback period is estimation as 19–34% at Gharo, 16–27% at Katibandar and 31–48% at Jati for all considered hub heights, for 10 m wind data extrapolated with WSC of 0.143. The percentage change in the COE estimation for the two wind shear factors and three sites under study show that, if 10 m wind data extrapolated with WSC 0.143, the COE overestimated is between 19-34% for Gharo, 16-27% for Katibandar and 31- 48% for Jati for all considered hub heights. It is evident from results that, the 1/7 power law, tends to produce misleading results for the feasibility study.