291 research outputs found

    Assessment of Marine Coastal Water Pollution from Karachi Harbour Pakistan

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    In Pakistan, marine pollution is a major problem that is caused by the waste from industrial, municipal, agronomy, and oil leak sources. The pollutant loads along with the coastline areas near Karachi is received from terrestrial contaminants including discharges from Karachi Harbour located on the estuary of the Lyari river. Karachi generates 472 Million Gallon per Day (MGD) of wastewater out of which only 55 MGD is treated and the rest is discharged in the sea. The prevailing sewage treatment plants are functioning at reduced capacity due to the insufficient transmission capacity of interceptors. Water sampling was carried out from the Lyari River and five different selected coastal point around Karachi harbour for physicochemical parameters and selected heavy metals. Results show that the Karachi Harbour area is noticeably polluted, whereas; the coastal environment in the vicinity of Karachi is also under the stress of pollution. High COD and BOD5 values were noticed at the Lyari river samples and the sampling locations close to the Lyari river outfall area. The Pb, Cd, Ni, and Hg heavy metals that pollute marine water are found. This situation is due to the discharge of mixed effluents of industrial and domestic wastes as well as dredging, cargo handling, dumping of ship waste and other coastal activities. The highest value of pollution observed at Karachi Harbour which is near Lyari river mouth, where the domestic and industrial effluents with organic and inorganic wastes have a greater influence on the water quality and the marine environment. At present, there is no effective controlling mechanism for industries to treat their waste, nor has any investigation to assess increasing marine pollution been carried out. As a result, there is an adverse impact on fish habitat and mangroves, corrosion of cargo ships, naval vessels and the residents living in the coastal area. Therefore, the government agencies and industrial sectors should work together to avert marine pollution and attain total environmental sustainability

    Assessment of Rice Husk Biomass Potential for Power Generation in Pakistan

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    Rice husk is one of the utmost obtainable feedstock for renewable energy production and can contribute to resolving energy scarcity and environmental problems. Appropriate knowledge of the rice husk's physiochemical properties is essential for the approach of thermochemical conversion systems. The present study delivers data on proximate and ultimate analysis and heating values of rice husk collected from different regions of Sindh, Pakistan. Moisture content was found low ranging between 12.76% to 13.50% (Mean 12.98%), higher volatile matter in the range of 55.77% to 62.88% (Mean 61.19%) and ash particles of 14.50% to 16.48% (Mean 15.20%). The lower concentrations of nitrogen, 0.37% to 1.31%, (Mean 0.70%) and sulfur, 0.02% to 0.19%, (Mean 0.11%) environmentally deal with more appropriate fuel properties. The heating value of rice husk ranges varied from 5,276.33 to 6,237.13 Btu/lb (Mean 5,859.87 Btu/lb). The significant values of the rice husk samples indicated that the locally available renewable resources can be transformed into an extensive amount of energy products at a small level from active conversion techniques. Therefore, rice husk can be deliberated as appropriate fuel for energy generation and can be considered as an environmentally friendly and economically feasible fuel that helps to decline harmful pollutions

    Ambient Air Quality Assessment in Karachi, Sindh Pakistan

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    Pakistan’s urban air pollution is amongst the utmost severity in the world that causes acute damage to the economy and human health. This study was designed for the assessment of ambient air quality in different areas of Karachi. The data were collected as pre-monsoon and post-monsoon season from main industrial zones of Karachi, S.I.T.E area, North Karachi industrial area, Korangi industrial area and Landhi industrial area in the year of 2017-2019. These zones are also a blend of industrial, residential, commercial and heavy traffic zones with dense populations. Ambient air data were collected for different pollutants like Nitrogen Oxides (NOx), Carbon Monoxide (CO), Sulfur Dioxide (SO2) and Particulate Matters (TSPM, PM10 and PM2.5). It is observed that in pre-monsoon, there is quite high intensity of particulate matter (TSPM, PM10 & PM2.5) present in the air, whereas CO and NO2 values found in all four zones are moderate in the air samples as prescribed by Sindh Environmental Protection Agency (SEPA) standards. It is observed specifically in Landhi, S.I.T.E Area and Korangi industrial area which are more prone to the exposure of these pollutants. In post-monsoon, the intensity of particulate matters (TSPM, PM10 & PM2.5), CO and NO2 values in all four zones are less to moderate than the values of pre-monsoon due to the seasonal effects. Study data shows that three major zones; Landhi, Korangi and S.I.T.E. industrial areas are at a high exposure to gases and other toxic elements. North Karachi is at the least risk because of having a small scale of industries present. The PM10 & PM2.5 levels average about 2 - 3-fold greater than the SEPA standards. High levels of ambient air pollutants cause severe health problems and chronic diseases on human health. Therefore the implementation of rules and regulations regarding ambient air pollutants should be more rigorous

    Spatial-Temporal Re-Analysis of Seasonal Air Quality Data in Karachi City for Future Prospects

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    Air quality in Karachi, Pakistan appears to be deteriorating in the world due to rapid increase in population, economic growth and subsequent increase in urbanization and energy demand. This study Re-is about the cumulative effects of anthropogenic activities on air chemistry of the study area atmosphere with ground base concentration measurements of gaseous air pollutants (SO2, NO2, CO, CO2 and O3), particulates (PM10 and TSP), Methane, Lead and Noise with temperature and seasonal influences on Karachi city. The primary goal of this study was to define spatial and temporal distribution of air pollutants with ArcGIS, seasonal behavior of airborne contaminants, convert the five major pollutants termed as criteria pollutants into Air Quality Index (AQI) and their temperature association for future prospects. The maximum average values of four seasons concentrations of air pollutants were found SO2=64.5 ug/m3 (GR), NO2=55.5 ug/m3 (FB), CO= 8.00 mg/m3 (CC), CO2=645 ug/m3 (NZ), O3=56.7 ug/m3 (ST), PM10=225 μg/m3 (CC), TSP=402 ug/m3 (CC), Methane=1.65 m/gm3 (CC), Lead=5.1 ug/m3 (ST), and Noise=85 dB (GR). The minimum four seasons average concentration values with monitoring location as {SO2=48.2 ug/m3 (FB), NO2=44.6 ug/m3 (NZ), CO=4.1 mg/m3 (BC), CO2=601 ug/m3 (JH), O3=42.4 ug/m3 (GR), PM10=150 ug/m3 (BC), TSP=226 ug/m3 (JH), Methane=0.68 mg/m3 (BC), Lead=32 ug/m3 (GZ), and Noise=81 dB (BC). The spatial-temporal analysis of air quality revealed that the pollutants in the summer are higher in industrial and high-density traffic junctions. In this study, temperature and air quality are significantly associated, while rainfall and relatively high humidity days are negatively correlated. High temperature months have highest air pollution values, whereas the washout impact of precipitation and relative humidity have the lowest levels. The analysis of air quality index parameters demonstrated a high coherence among NO2, CO and O3 with variation i

    Remediation of Polychlorinated Biphenyls (PCBs) through Bio and Phytoremediation in the Environment: A Review Study

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    One of the persistent organic pollutants (POPs) utilized globally between the 1930s and 1980s was polychlorinated biphenyls (PCBs). Even though their usage has been severely constrained, a lot of PCBs are still present in the environment, including soils and air. This local, national, international and governmental organizations regarding polychlorinated biphenyls and how can resolve and treat the problem sustainably. This can be achieved if seriously working on degrading persistent organic pollutants, especially polychlorinated biphenyls biologically via thorough research and sound implementation. The methods opted for remediation by the use of choosing suitable types of microorganisms and plants. These methods are practically active for the identification of the source, concentration level and effects on the ecosystem. It would help in developing appropriate strategy and data generation in formulating the inventories for the management of polychlorinated biphenyls in the future. It is also noted through numerous research that polychlorinated biphenyls are also found in human blood commonly analyzed by indicator congeners such as PCB 138,153, 180, and in air and soil markers of PCBs pollution include PCB congeners 28, 52,101,138,153 and 180 as well. The methods and mechanisms described for degrading the persistent pollutant in this research review the solutions for mitigating PCB pollution in an environment. The best option is to strictly ban it in Pakistan or weightage its usage with its multiple benefits and disadvantages. Promote biological treatment if the payback is healthy and environmentally sustainable

    Validation of Repeated Endothelial Function Measurements Using EndoPAT in Stroke

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    BackgroundDecreased endothelial function (EF) may be a prognostic marker for stroke. Measuring pharmacological effects on EF may be of interest in the development of personalized medicine for stroke prevention. In this study, we assessed the reliability of repeated EF measurements using a pulse amplitude tonometry technology in acute stroke patients. Similarly, reliability was tested in healthy subjects devoid of vascular disease to estimate reactivity and reliability in a younger non-stroke population.Materials and methodsEF was assessed using the EndoPAT2000 in 20 healthy volunteers (men 50%, mean age 35.85 ± 3.47 years) and 21 stroke patients (men 52%, mean age 66.38 ± 2.85 years, and mean NIHSS 4.09 ± 0.53) under standardized conditions. EF was measured as the reactive hyperemia index (RHI), logarithm of RHI (lnRHI), and Framingham RHI (fRHI). Measurements were separated by 1.5 and 24 h to assess same-day and day-to-day reliability, respectively.ResultsFair to moderate correlations of measurements [intraclass correlation coefficient (ICC)same-day 0.29 and ICCday-to-day 0.52] were detected in healthy subjects. In stroke patients, we found moderate to substantial correlation of both same-day and day-to-day repeated measurements (ICCsame-day 0.40 and ICCday-to-day 0.62). fRHI compared with RHI and lnRHI showed best reliability.ConclusionRepeated measurements of fRHI in stroke patients show moderate reliability on same-day and substantial on day-to-day measurements. Likewise, in healthy subjects there was substantial reliability on day-to-day measurement, but only moderate on same-day measurements. In general, day-to-day correlation of repeated EF measurements was far better than that of same-day measurements, which ranged from poor to moderate depending on the specific outcome measure of EF. A possible carryover effect should be considered if same-day repeated testing of drug effects is applied in future studies

    Two successive calcium-dependent transitions mediate membrane binding and oligomerization of daptomycin and the related antibiotic A54145

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    The final publication is available at Elsevier via http://doi.org/10.1016/j.bbamem.2016.05.020 © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Daptomycin and A54145 are homologous lipopeptide antibiotics that permeabilize the cell membranes of Gram-positive bacteria. Membrane permeabilization depends on the presence of both phosphatidylglycerol (PG) and calcium, and it involves the formation of oligomeric transmembrane pores that consist of approximately 6-8 subunits. We here show that each lipopeptide molecule binds two calcium ions in separable, successive steps. The first calcium ion causes the lipopeptide molecule to bind to the target membrane, and likely to form a loosely associated oligomer. Higher calcium concentrations induce binding of a second ion, which produces the more tightly associated and more deeply membrane-inserted final, functional form of the oligomer. Both calcium dependent steps are accompanied by fluorescence signals that indicate transition of specific amino acid residues into less polar environments, suggestive of insertion into the target membrane. Our findings agree with the earlier observation that two of the four acidic amino acid residues in the daptomycin molecule are essential for antibacterial activity. (C) 2016 Elsevier B.V. All rights reserved.This study was supported by operating grants by NSERC to Scott Taylor (155283-2012) and Michael Palmer (250265-2013)
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