Effect of ionic ordering in conductivity experiments of DNA aqueous solutions

The effects of ionic ordering in DNA water solutions are studied by conductivity experiments. The conductivity measurements are performed for the solutions of DNA with KCl salt in the temperature range from 28 to 70 C. Salt concentration vary from 0 to 2 M. The conductivity of solutions without DNA but with the same concentration of KCl salt are also performed. The results show that in case of salt free solution of DNA the melting process of the double helix is observed, while in case of DNA solution with added salt the macromolecule denaturation is not featured. For salt concentrations lower than some critical one (0.4 M) the conductivity of DNA solution is higher than the conductivity of KCl water solution without DNA. Starting from the critical concentration the conductivity of KCl solution is higher than the conductivity of DNA solution with added salt. For description of the experimental data phenomenological model is elaborated basing on electrolyte theory. In framework of the developed model a mechanism of counterion ordering is introduced. According to this mechanism under the low salt concentrations electrical conductivity of the system is caused by counterions of DNA ion-hydrate shell. Increasing the amount of salt to the critical concentration counterions condense on DNA polyanion. Further increase of salt concentration leads to the formation of DNA-salt complexes that decreases the conductivity of the system.Comment: 12 pages, 6figures. Ukr. J. Phys. (2014

Bioaccumulation Pattern of Cadmium and Lead in the Head Capsule and Body Muscle of Clarias gariepinus [Burchell, 1822] Exposed to Paint Emulsion Effluent

The toxicity of Sub-lethal concentrations of effluents from a paint emulsion industry were investigated on African catfish Clarias gariepinus in order to determine the bioaccumulation pattern of two heavy metals i.e., Lead and Cadmium in the Head capsule and Body muscle using a renewable static bioassay. The trend of bioconcentration of metals in the head capsule and muscle of the test organisms differs significantly (phead capsule. In the muscle, the highest bioaccumulation of lead was 0.4680 mg/L while the least was 0.0660 mg/L. Cadmium bioaccumulation in the head had the highest value to be 2.0424 mg/L while the lowest value was 0.0101 mg/L. In the head capsule on the other hand, the highest accumulation of lead was found to be 0.3918 mg/L while its lowest value was 0.1677 mg/L. The highest value for cadmium in the head capsule was 2.0249 mg/L while its lowest was 0.0058 mg/L. It was revealed in the study that fish can bioaccumulate heavy metals from a polluted environment, which often result in reduction or impairment of natural population size and could be a veritable source of these metals to man. Therefore corrective measures should be taken to avoid pollution of this sort in the environment

BIOCHEMICAL PROFILE OF CLARIAS GARIEPINUS EXPOSED TO SUB-LETHAL CONCENTRATIONS OF CHEMICAL ADDITIVES EFFLUENT.

Chemicals such as industrial effluents induces some level of alterations in the naturally occuring chemical composition of aquatic phase which in turn alters the behavioural, biochemistry, and general physiology of aquatic fauna among which is catfish, Clarias gariepinus. Chemical additives effluent was analysed to determine its physicochemical parameters. Part of the result conforms to the Federal Environmental Protection Agencies standard specification for effluent discharge into the aquatic environment while other parameters like TDS, TSS, and Alkalinity deviated from the standard. The fish, Clarias gariepinus was exposed to 0.25mg/L, 0.30mg/L, 0.35mg/L and 0.40mg/L concentrations of the effluent for 96 hours and the LC50 value for the acute toxicity was found to be 0.335223mg/L. The impact of long term exposure to the effluent was also evaluated through changes of selected biochemical parameters using the 20%, 10%, 5% and 2.5% of the 96-h LC50 value for 42 days.the parameters measured are glucose, total protein, cholesterol, albumin and globulin. All the parameters recorded a significant difference in their values as against the control except cholesterol. The alteration in all parameters was significantly concentration and time dependent and this could be attributed to stress behavioural response as a result of the toxicity of the effluent

Computational Predictive Framework towards the Control and Reduction of Malaria incidences in Africa

Malaria persists as a problematic disease in Africa. It is the main cause of morbidity and mortality of children and efforts are currently being pooled to increase the control measures within endemic countries. With this in mind, we developed and applied a malaria control strategy from a computational perspective, to analyze, predict and offer appropriate recommendations and control measures of malaria data obtained from WHO ten Sub Saharan countries malaria report of 2008 . The analytical tool used is based on the C# programming language embedded artificial neural network intelligence system. From the outcome obtained, the system demonstrated some level of intelligence and showed the effects and impacts of some controllable factors on future malaria occurrence. The system at 90% prediction intensity showed malaria infection course to decline sharply by 2014 in all the study countries, ranging from 15.71% in Madagascar, 35.46% in Malawi, 38.44% in Nigeria, 38.98% in Sudan , 39.05% in Ethiopia 39.09% in Zambia, 40,08% in Ghana, 42.61% in Kenya, 45.21% in Uganda and 46.63% Mozambique respectively. Therefore, more future prevention, control and management interventions are needed in Madagascar and Mozambique by 2014 as compared to the rest of the countries studied. In conclusion, the tool can be used to produce sensible and logical results which can be applied to achieve reduction of possible future malaria occurrences by governmental, NGOs and other relevant health agencies for proper public health planning

EVALUATION OF THE TEMPERATURE EFFECT OF A THERMOSYPHON SOLAR WATER HEATER

This study investigated the effect of system temperature on the performance of thermosyphon solar water heater. Solar collector was designed and developed with galvanized steel, wood and copper pipes for the experiment. While the copper pipes serves as the tube through which the cold water flows, the wood was employed for the frame and stand, and the galvanized steel for the collector material. Also employed were two hot and cold water tanks of 60 and 110 litre capacities respectively. The period of experiment were taken to be 3 days each for sunshine, sun-off and moderate sunshine days, with the average data employed for the analysis. The results showed that temperature has a domineering effect on the performance of the thermosyphon system. The maximum outlet temperature obtained for sunshine, moderate sunshine and sun-off days were 94.6, 73.5 and 51oC respectively. Also the system efficiency was found to be 61.04%, demonstrating good performance. However, considering the fact that the experiment was carried out in rainy season (between April and September), it was concluded that if it is repeated during the dry periods (October to March), the efficiency of performance will be more as these period is characterized by low cloud cover, high temperature and high radiation intensities. The outcome of the study was compared with published results and it clearly demonstrates that the designed system can suitably be employed for both domestic and industrial uses

The Switched Local Area Networks’ Delay Problem: Issues and a Deterministic Solution Approach

A large number of installed local area networks are sluggish in terms of speed of uploading and down- loading of information. Researchers have, therefore, proposed the need for such networks to be designed with specified maximum end-to-end delay. This is because, if the maximum packet delay between any two nodes of a network is not known, it is impossible to provide a deterministic guarantee of worst case response times of packets’ flows. Therefore, the need for analytic and formal basis for designing such networks becomes very imperative. In this regard, this chapter has discussed the switched local area networks’ delay problem and related issues. It compared the two principal approaches for determining the end-to-end response times of flows in communication networks – stochastic approach and determin- istic approach. The chapter goes on to demonstrate the superiority of the latter approach by using it to develop and validate the goodness of a general maximum delay packet switch model

Thermodynamics Characterization of Density models for an Effective Solar Water Heater Sizing

The problem faced in Sizing of an effective Solar Water Heater (SWH) by engineers to meet certain design requirement is highly enormous. Using the thermodynamic characterization relation and the knowledge of Solar Water Heater (SWH) density’s model; various design were evaluated. The result shows that density model actually predicts adequately and providing alternative means of estimating these design parameters. Also, the properties of the system, such as entropy and enthalpy (specific heat capacities), which cannot be determined directly from experimental axiom, were evaluated. These evaluations therefore, give room to express the thermodynamics properties of the system and consequently improve the design performance. Further comparisons with experimental results reveal a better outfit. Therefore through the knowledge of thermodynamic relation an efficient Solar Water Heater is operated and empirical data is expanded