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Abstract :The Impact of Sun Drying on the Occurrence of Aflatoxin in Red Chilies
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Abstract: A major challenge in post-harvest protection of chilies is its rapid drying to prevent quality deterioration as a result of fungal contamination. The speed and efficiency of drying is crucial as the improper and prolonged drying may eventually initiate the buildup of mycotoxins. This research demonstrated levels of aflatoxin in samples at different stages of drying with the objective to assess the efficiency of the common practice of on-farm sun drying in Pakistan. The results indicated that there was no significant pre-harvest contamination of aflatoxins in chilies grown at different locations under study. Sun drying of the harvested chilies over a post drying stage reduced average moisture content from 69.70% to 9.87%, but also led to a gradual increase in the level of aflatoxins. The correlation between the observed increase in aflatoxin levels and the length of the drying period was found to be statistically significant (P<0.05) at all the locations investigated. The implications of the findings are discussed in relation to optimizing the post-harvest drying process to minimize the levels of aflatoxin in chilies. Keywords: Red Chilies, Aflatoxin contamination, Post-harvest practices, Moisture content. Download Full Article |
Abstract: Preliminary Studies on the Occurrence and Abundance of Zooplankton Major Taxa in Keamari, Karachi- Backwaters
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Abstract: A preliminary study was conducted on the occurrence and abundance of zooplankton in the Karachi backwaters. Zooplankton sampling was conducted on monthly basis and the study was carried out on the basis of three seasons including pre-monsoon (January to May), monsoon (June to September) and post-monsoon (October to December) from a permanent station Napier Mole bridge (24o50’34’’.90 N, 66o59’17’’.55 E) during June 1996 to May 1998. The hydrographic parameters including air temperature (oC), water temperature (oC), salinity (ppt), dissolved oxygen (mg/L), pH, and transparency (cm) were recorded. Total 14 groups of zooplankton were recorded; hydromedusae, copepoda, mysids, amphipoda, acetes, lucifer, chaetognath, penaeid pl, caridean pl, zoea, megalopa, squilla larvae, fish larvae, fish eggs and others. Pre-monsoon season shows highest number of individuals and copepods were found to be the dominant group in all seasons. Zooplankton diversity, equitability and margalef index were measured seasonally. Highest shannon – wiener diversity index H' = (1.83), equitability E= (0.69) and margalef species richness Index d= (1.37) were measured in post-monsoon season. Statistical analysis (ANOVA) was performed in between seasons and zooplanktonic groups. No significant difference (at P>0.05, 0.148) was observed between zooplankton and seasons.
Keywords: Zooplankton, abundance, major taxa, Keamari Karachi-Backwaters. Download Full Article |
Abstract: Analysis of Socio-Economic Well-Being of Population in Khirthar National Park, Sindh: A Geographical Study
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Abstract: Pakistan’s two-third population lives in rural areas where the dependence on natural resources is foremost. National parks are protected areas where the natural environment is preserved for the future generations. The purpose of this study is to investigate the socio-economic aspects of the people living in such areas. For this a comparative study has been designed by selecting two areas of Kirthar National Park (KNP), Sindh, one within the boundary of park; Core and the other at the transition zone of the park. The data have been collected through extensive field survey and analyzed using correlation technique. The study can be helpful in assessing the interaction that exists between humans and dry natural environment. The results indicate a clear difference in the standard of living of the people living in these two selected areas. Such studies are very important from the point of view of rural development of local communities. Keywords: Kirthar National Park, natural environment, socio-economic conditions. Download Full Article |
Abstract: Wavelet Characterization of Seismicity and Geomagnetic Coupling at Coastal Regions of Pakistan
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Abstract: Earthquake recurrence is depicted on the basis of the time following subsequent seasons at the coastal regions of Pakistan. Recurrence time for intricate shock waves is simulated by using earth positions at equinoxes and perihelion-aphelion positions of the earth from the Sun. In connection to the spatial and temporal behavior of earth, the external geomagnetic variation is significant not only influenced by the distances between the Sun and earth and annual revolving period of earth around the Sun at heliocentric path but also affected by a lunar revolving period on an elliptical path around the earth. The Apparent path of the Sun during the year where earth is the center of the celestial sphere and relative to earth, the Sun appears on ecliptic sphere which intersects the celestial equator in two points known as the vernal equinox of 21st march and autumn equinox of 21st September. The perihelion position on earth is nearest to the Sun and aphelion is the furthest position of the earth from the Sun, these are empirically distributed on the basis of mutual interaction. The seasonal effects are recognized by the wavelet characterization on maximum amplitudes of shock waves with reference to vernal – autumn equinoxes of distributed perihelion-aphelion periods. The seasonal period of geomagnetic seismicity is a manifestation of the mean time between earthquakes within a specified region where many faults are activated. The cyclic nature of earthquakes and geomagnetic influences on seismic waves by stress-strain tectonic process and releasing energy for the relaxation mechanism are experienced in nature, therefore the issues relevant to their aphelion – perihelion periodicities, influential conditions of geomagnetic instability and their coupling for shock waves propagation are tackled by the wavelet applications. Keywords: Seismicity, Geomagnetism, Equinoxes, Perihelion-aphelion, Liquefaction. Download Full Article |
