Neurotoxicity of organophosphorus insecticides Leptophos and EPN.

Phosfolan, chlorpyrifos, and stirophos when applied to white mice at sublethal doses did not induce any delayed neurotoxic effect. On the other hand, Leptophos and EPN when administered orally at sublethal or lethal levels clearly produced a delayed neurotoxic ataxia in treated mice. The five tested organophosphorus insecticides were compared for their ability to inhibit cholinesterase, neurotoxic esterases and monoamine oxidase. I50 values were estimated for each case. The results revealed that all five compounds were inhibitors of cholinesterase, but only Leptophos and EPN were shown to be potent inhibitors for both neurotoxic esterase and monoamine oxidase in the mouse brain. Additional particular properties of both Leptophos and EPN were found in their ability to cause delayed neurotoxic ataxia in chickens and sheep fed once on sublethal doses of these compounds. It is believed that the phosphonate ester configuration of EPN and Leptophos has a specific mode of toxic action which is mainly located at the central nervous system. It is also postulated that these delayed neurotoxic agents might inhibit postganglionic sympathetic neurons, thus resulting in chronic paralytic effects.     

Thermodynamics of metal cation binding by a solid soil derived humic acid. 2. Binding of Mn(II), Co(NH3)6aq3+ and Hg(II)

Metal binding is an important function of humic acids (HAs) in soils, sediments and waters. At pH 2.0, Mn(II) and Co(NH3)6aq3+ bind tightly in one step labeled A to a solid humic acid NHA isolated from a New Hampshire soil. Two consecutive steps are observed for Hg(II) binding. All the binding isotherms fit the Langmuir model in the temperature range 10.0-50.0 degrees C. Stoichiometric site capacities indicate predominant binding by charge-neutralizing HA carboxylate groups for Mn(II) and the second step A of Hg(II) binding. The binding affinity order in step A is Co(NH3)(6)3+>Hg(II)>Mn(II). Metal binding enthalpy and entropy changes fit the linear correlation found previously for binding of other metal cations by solid HAs. Free energy buffering from cooperative enthalpy and entropy changes and lower enthalpies for metal-HA interactions in solution suggest that desolvation of the cations and HA binding sites as well as HA conformational changes to allow for inner-sphere complexation predominate metal binding by hydrated solid HAs.     

Mode choice model for vulnerable motorcyclists in Malaysia

OBJECTIVE: In developing countries, motorcycle use has grown in popularity in the past decades. Commensurate with this growth is the increase in death and casualties among motorcyclists in these countries. One of the strategic programs to minimize this problem is to reduce motorcyclists exposure by shifting them into safer modes of transport. This study aims to explore the differences in the characteristics of bus and motorcycle users. It identifies the factors contributing to their choice of transport mode and estimates the probability that motorcyclists might change their travel mode to a safer alternative; namely, bus travel. METHODS: In this article, a survey of 535 motorcycle and bus users was conducted in seven districts of Selangor state, Malaysia. A binary logit model was developed for the two alternative modes, bus and motorcycle. RESULTS: It was found that travel time, travel cost, gender, age, and income level are significant in influencing motorcyclists' mode choice behavior. The probability of motorcycle riders shifting to public transport was also examined based on a scenario of a reduction in bus travel time and travel cost. CONCLUSIONS: Reduction of total travel time for the bus mode emerges as the most important element in a program aimed at attracting motorcyclists towards public transport and away from the motorcycle mode.     

Smoldering combustion of dust layer on hot surface

The critical temperature as well as the critical flux for ignition of a dust layer of cornflour and a mixture of wheatflour and cornflour (80% wheatflour+20% cornflour) on a hot plate have been determined. The moulded sample was cylindrical in shape and of different heights and diameters. The particle size of dusts ranged between 63 μm to 150 μm. The temperature–time histories for self-heating without ignition and with ignition are offered, showing the critical boundaries between them. Also the times to ignition for each dust, showing the effect of sample size on their values, are determined. Certain experimental correlations which relate to times to ignition, as well as the critical temperature for ignition and thermal and geometrical dimensions of sample are presented.     

Water quality monitoring of Al-Habbaniyah Lake using remote sensing and in situ measurements

Environmental Monitoring and Assessment - A good quality drinking water is essential for human survival. However, a large percentage of the populations in most developing countries (Nigeria...     

Towards saving freshwater: halophytes as unconventional feedstuffs in livestock feed: a review

Water represents 71% of all earth area and about 97% of this water is salty water. So, only 3% of the overall world water quantity is freshwater. Human can benefit only from 1% of this water and the remaining 2% freeze at both poles of earth. Therefore, it is important to preserve the freshwater through increasing the plants consuming salty water. The future prosperity of feed resources in arid and semi-arid countries depends on economic use of alternative resources that have been marginalized for long periods of time, such as halophytic plants, which are one such potential future resource. Halophyte plants can grow in high salinity water and soil and to some extent during drought. The growth of these plants depends on the contact of the salted water with plant roots as in semi-desert saline water, mangrove swamps, marshes, and seashores. Halophyte plants need high levels of sodium chloride in the soil water for growth, and the soil water must also contain high levels of salts, as sodium hydroxide or magnesium sulfate. There are many uses for halophyte plants, including feed for animals, vegetables, drugs, sand dune stabilizers, wind shelter, soil cover, wetland cultivation, laundry detergents, and paper production. This paper will focus on the use of halophytes as a feed additive for animals. In spite of the good nutritional value of halophytes, some anti-nutritional factors as nitrates, nitrite complexes, tannins, glycosides, phenolic compounds, saponins, oxalates, and alkaloids may be present in some of them. The presence of such anti-nutritional agents makes halophytes unpalatable to animals, which tends to reduce feed intake and nutrient use. Therefore, the negative effects of these plants on animal performance are the only objection against using halophytes in animal feed diets. This review article highlights the beneficial impact of considering halophytes in animal feeding on saving freshwater and illustrates its nutritive value for livestock from different aspects.     

Nanocarrier-mediated co-delivery systems for lung cancer therapy: recent developments and prospects

Environmental Chemistry Letters - Research has recently focused on combinational therapy using nanocarriers to overcome the obstacles associated with conventional therapy of lung cancer. The...     

Impacts of and adaptation to climate change on the oil palm in Malaysia: a systematic review

Environmental Science and Pollution Research - The interaction and the interplay of climate change with oil palm production in the Southeast Asia region are of serious concern. This particularly...