Pollution in the aquatic ecosystem by pesticides, their metabolites and by-products is considered critical in the conservation of biodiversity and natural resources. Several studies have reported the toxicological issues and adverse effects of pesticides in aquatic biodiversity. After the development of the field ecotoxicology, researchers have expanded their studies towards the effects of pesticides in aquatic ecosystems. Pesticides containing chemicals such as Pyrethroids, cypermethrin, deltamethrin, cyphenothrin and other related compounds have been shown to cause adverse effects on the development, behaviour and mortality of different species of fish, birds, amphibians and aquatic mammals. This review article summarizes the adverse impact of the use of pesticides and related agrochemicals in populations of aquatic, amphibian and avian species.

Medicinal plants present a promising option in the treatment of infectious diseases. Although literature is replete of the traditional utilization of Jatropha curcas for healing various ailments, scientific studies validating its phytochemotherapeutic properties are limited. In this study, both aqueous and methanol extracts of Jatropha curcas were tested against thirteen clinical staphylococcal isolates including Methicillin Resistant Staphylococcus aureus (MRSA) using agar diffusion and microdilution techniques. Nineteen commonly used antibiotics were employed as control drugs and to determine the resistance profiles of the organisms. Bactericidal activity was evaluated by the time-kill assay. The susceptibility patterns of all the staphylococcal isolates tested were similar in aqueous and methanol extracts. The methanol extract (100mg/ml) demonstrated inhibitory activity against Staphylococcus haemolyticus, which was resistant to ciprofloxacin, tetracycline and erythromycin. The MIC and MBC of the methanol extract ranged between 0.5 and 8mg/ml and between 4 and 128mg/ml respectively while that of aqueous extract ranged between 1 and 8mg/ml and between 4 and 128mg/ml respectively. The MRSA strain was sensitive to the methanol extract but resistant to twelve of the 20 antibiotics studied. Within the first 2.5h and 5h of incubation with the methanol extract, the MRSA isolate declined by 1.7log10 and 2.3log10 respectively while incubation with ciprofloxacin declined the growth by 3log10 and 4log10 respectively. The methanol extract exhibited the highest killing rates of 13.88 x 105cell/h against S. haemolyticus. The lowest killing rate, 1.86 x 105 cell/h, was against MRSA. 1 x 106 of the resistant staphylococcal cells was completely inhibited within 8hrs and there was no growth after 7 days. The methanol stem extract of Jatropha curcas exhibited enhanced bactericidal activity against staphylococcal strains and could be indicated for the empiric treatment of staphylococcal infections. Toxicity studies may need to be carried out to authenticate its use.

Eight months (Feb-Sept. 2009) prospective study was carried out in Ebonyi State University teaching hospital (EBSUTH) Abakaliki to determine the distribution and antibiotic susceptibility pattern of uropathogenic Escherichia coli isolated from out-patients with community-acquired urinary tract infections (UTIs) in Abakaliki Ebonyi State, Nigeria. We consecutively collected one hundred and forty (140) non-duplicate isolates of E. coli from female out-patient with UTI. Urine samples were analyzed and organisms isolated using standard Microbiology technique, antibiotic susceptibility studies was carried out using Kirby and Bauer method of determining susceptibility. Bla TEM and SHV beta lactamases was determined in resistant isolates by specific PCR and clonal relatedness of strains was determined by randomly amplified polymorphic DNA (RAPD). Antibiotic susceptibility rates for E. coli were; aztreonam (86.1%), doxycycline (31%), ampicillin (5%), ceftazidime (99.1%), cefotaxime (95.6%), cefoxitin (91.9%, cefotaxime (96.5%), amoxicillin/clavulanic acid (82.9%), cefepime (89.1%), cefuroxime (89%), imipenem (99%), ciprofloxacin (65.4%), levofloxacin (69.1%), sulphamethoxazole/trimethoprim (6.4%), Nitrofurantoin (96.5%), gentamicin (72%), kanamycin (93.7%) and ticarcillin 39.1%. Bla TEM beta lactamase was polymerase chain reaction positive in all the strains while bla SHV was negative. RAPD analysis grouped our isolates into four clonal groups (A-D) with majority of the isolates belonging to clonal group A (85.7%). Our findings showed high rate of resistance of uropathogenic E. coli to ampicillin sulphamethoxazole/trimethoprim, tircarcillin and doxcycline. Uropathogenic E. coli resistance to ampicillin and sulphamethoxazole/trimethoprim which is the commonest oral drug of choice in treating UTIs, are worrisome and also the wide distribution of the majority of uropathogenic E. coli in one clonal group (A) may have a major public health implications.

Bifurcation and phyllotaxy are common and important processes in plants. Plantain leaf bifurcation occurs naturally in Lagos, Nigeria, especially for double-bunching plantains. Plantain leaf bifurcation studies are important because of the perceived special qualities impacted to the plantain pseudostem. Quasi-quantitative techniques were used for this study. As a result, both the physical presentation of the divided leaflets and bunches overhang characteristics were used to predict the most likely positioning of the plantain bunches overhang based on the work done by the plantain pseudostem itself. The results showed that the divergence angle of about 10° between the divided leaflets does not seem to agree with the tenets of the Fibonacci sequence of using the golden mean. The 90° bunches overhang can be used to predict at least two overhang positions. That is, in the same direction and also at 180° out of phase with each other. Similarly, the bifurcated leaflets presentation with four edges to the atmosphere seems to confer some compensatory adaptation to the environment. The thermodynamic implication of the four edges in the bifurcated leaflets ensure increased random mixing and transfer of greater amounts of carbon dioxide, water vapour and energy for improved photosynthate production. Consequently, plantain leaf bifurcation is an efficient self-organising method for coping with more food production under nutrients constraints.

Dry and rainy season leaf samples of Burkea africana were analyzed for proximate and mineral compositions, and antinutritional contents. Moisture contents of the dry season leaf samples of the plant were relatively low indicating good shelf life characteristics. High ash contents of dry and rainy season leaf samples of plant accounted for high mineral contents. High fibre and protein contents of leaf samples of plant indicate that the leaves could help treat constipation, improve general health and serve in growth and repair of tissues. The study revealed that leaves of the plant are rich in Ca, K, Na and Mg. Concentrations of trace metals in leaves of plant differ, with iron having the highest values of 481.03mg/Kg and 467.85mg/Kg in the rainy and dry season leaf samples respectively. Zinc concentrations range from 10.99mg/Kg in the rainy season leaf sample to 34.02mg/Kg in the dry season leaf sample of the plant. The high proximate and mineral compositions may be the factor to which elephants feed on the leaves of this plant. Also, results indicate that if leaves of Burkea africana are properly exploited and processed, they could be a high-quality and cheap source of feed for livestock especially ruminants.

In the present study, an evaluation of the total antioxidant capacity, nutrient composition, microbial load and percentage inhibitory activity of methanolic extract of unripe plantain flour on DPPH radical was carried out. The total antioxidant capacity of the extract as determined by the quantities of quercetin and peroxidase present was 0.532ug/ml and 52% ± 0.00 while the percentage inhibition on DPPH radical was 78.57%. Analysis of the proximate and phytochemical compositions of the flour using the AOAC methods showed that it contained 3.16 ± 0.04% protein, 0.21 ± 0.003% lipid, 5.2 ± 2.82% moisture, 5.5 ± 0.42% ash, 1.58 ± 0.04% tannin,1.82 ± 0.05% saponin, 1.37 ± 0.05% alkaloid and 0.98 ± 0.00% flavonoid. Further microbial analysis carried out revealed that the flour had good viable and fungal counts in addition as indicated by the low concentrations of S. Aureus and R. Stolonifer observed in the processed flour though the fungal counts was higher than the bacterial counts. These findings suggest that unripe plantain flour could serve as a natural source of antioxidants with free radical scavenging activity and its shelf life could be extended if packaged well and stored.

The in vitro anthelmintic activity of Caesalpinia bonduc leaves was evalauated. Four extracts viz. Petroleum ether, Dichloromethane (DCM), Ethyl acetate and Ethanol extracts of Caesalpinia Bonduc leaves were investigated for the anthelmintic activity against Earthworms (Eisenia foetida). Three concentrations (20, 40, 60mg/ml) of each extract were studied which included the determination of time of paralysis and time of death of earthworms. Piperazine citrate (10mg/ml) was used as standard drug and distilled water containing 2% Tween 80 was used as control. All the extracts exhibited dose dependent anthelmintic activity. The decreasing order of activity of extracts was ethyl acetate, ethanol, DCM and petroleum ether extracts. An Ethyl acetate extract of plant leaf exhibited in vitro anthelmintic activity in a concentration range of (20-60mg/ml). Conclusively, ethyl acetate extract of Caesalpinia bonduc leaves possesses vermicidal activity and found to be effective as an anthelmintic.

The antimicrobial activity of four plants’ extracts (Thyme leaves (Thymus vulgaris), Sage leaves (Salvia officinalis), Myrrh exudates (Boswelia carterii) and Oliban (Boswelia carterii)), used in traditional medicine in Saudi Arabia and other Middle East countries, were evaluated against the following seven bacterial species, Streptococcus sp., Staphylococcus aureus, Vibrio tubiashii, Micrococcus luteus ATCC 9341, Cellulosimicrobium cellulans, Bacillus cereus and Legionella pneumophila and two fungi species, Aspergillus flavus and Fusarium oxysporum f. sp. Lycopersicii. Our results showed that the highest antimicrobial activity was observed for the extracts of Thyme, Myrrah and Sage, and the Oliban extracts did not present any antimicrobial activity at any concentration. The minimum inhibitory concentration ranged from 2.0-4.0 % (v/v) for Thyme and Myrrh. The fungal species tested differed significantly in their susceptibility to plant extracts, with complete inhibition by Thyme to all tested microorganisms.

The intent of this paper is to introduce the notion of occasionally weakly compatible (owc) maps and prove common fixed point theorems for single and set valued maps without considering the completeness of the space and continuity of maps in fuzzy metric space. Our results extend, generalize and unify several results existing in the literature. AMS Mathematics subject classification. 2000. 47H10, 54H25.

Density functional theory (DFT) and ab- initio Quantum Mechanical calculations have been used to study the structures and properties of the Molecules Pyrimethamine and Sulfadoxine. Their molecular stabilities, structures, dipole moments, charges transfer, polarizability tensors, average polarizability anisotropy, energies, IR and Raman vibrational frequencies have been predicted. Tentative assignments for their intense IR active frequencies have been carried out and represented. We have used the Restricted Hartree-Fock (RHF) and density functional Becke3LYP (B3LYP) theories by employing 6- 311++G** basis set for inclusion of electron correlation. From our results we observe that the molecules are more stable at the RHF level of theory than at the B3LYP level of theory. The frequency calculations obtained at the B3LYP level are closer to some experimental values than those obtained at the RHF level due the effect of electron correlation. The magnitude of the dipole moment is higher in the RHF level and the polarizability tensor components, the average polarizability and the anisotropy are greater at the B3LYP level. This implies that the inclusion of electron correlation decreases the dipole moment and increases the polarizability tensors, the average polarizability and the anisotropy. The IR and Raman spectra of the molecules have also been presented and the IR spectrum of Pyrimethamine lies in the same range as that given by some experimental results.

In this paper we present significant study on the effect of temperature on the characteristics of a diode laser system subjected to external optical feedback. The presence of the feedback is seen to reduce the threshold current and slope efficiency which are important parameters for the solitary diode laser. In this sense the threshold reduction is a good indicator of the feedback level. At certain temperatures, the effect of optical feedback was actually seen to cause slight increase on the threshold current value. The results presented in this paper with regard to the temperature dependence and single optical feedback effect on the threshold and optical power output of diode laser systems will help in understanding the dynamical behavior of such systems.

The present paper aims to investigate the solidification behavior and the forgeability of Aluminum alloy (LM6)-SiCp composites at different section of three-stepped composite castings. LM6 metal matrix composites (MMCs) containing SiC particles (5 and 10 wt %) of 400mesh (average size) were prepared by using stir casting route. The temperature of the cast composites during solidification was measured by putting K-type thermocouples at the centre of the each step, from which the solidification curves were constructed. The forgeability of the as cast MMCs were also measured at different step of the casting. The results show that the forgeability of cast metal matrix composites at the middle section i.e. step-II of the casting is minimum compared to both end section of a three-step casting. The solidification curves of Aluminum alloy (LM6)-SiCp composites compared with the unreinforced alloy (LM6) and the results reveal that significant increase in solidification time with the addition of SiC particles. The curves also show that the rate cooling and the solidification time are different at different section of the castings. This practical research analysis and test results on solidification behavior and the forgeability of Al/SiCp-MMC will provide useful guidelines to the present day manufacturing engineers.

The world is undergoing significant changes both technologically and socially. Societies have witnessed growth unparallel in history over the past century. This growth world-over has been at the expense of ever increasing demand on energy; this demand is not showing any sign of abating. However the world’s energy resources are depleting at a very fast rate, particularly fossil fuels. Solar energy is a renewable energy source that can be used to generate energy using heat engines. In this work we outline an innovative approach to generate electricity using a combination of existing technologies such as the solar tower, Fresnel reflectors and Stirling engines. It is proposed to erect a domestic solar tower that has embedded Stirling engines for power production. The UAE has vast amount of solar irradiation which on yearly average is about 400 - 500 Watts/m2. Used intelligently, with carefully deployed Linear Fresnel reflectors, this technology can deliver electricity to far flung off-grid locations as well as feed into domestic electricity grid.

In this study statistical model of estimating global solar radiation over Enugu, Nigeria is presented. The study employed multiple regression analysis to estimate the monthly sunshine hours using four meteorological parameters for a period of eleven years (1997 to 2007). The parameters used included relative humility, temperature, rainfall and wind speed. The results showed the correlation coefficient of 0.849. Statistical test RMSE, MBE and MPE were employed to test accuracy the models used. The values of sunshine hours obtained were used to fit the Armstrong-Prescott equation to obtain the global solar radiation for Enugu.

In frameworks of Kane model we explored the effects of Coulomb electron-hole correlations and magnetic confinement for several cylindrical size combinations in a narrow-gap InSb cylindrical layer quantum dot for the heavy hole-electron and light hole-electron. The influence of excitonic effects on the behavior of the energetic spectrum of said system was discussed using a perturbation theory framework. Dependences of the electron-hole energetic spectrum versus the internal radius, external radius, and magnetic field are presented. It was shown that the exciton energy for both type of electrons strongly influenced by changing the geometrical parameters and the value of applied magnetic field. In addition to that it was found that the heavy hole-electron is less sensitive to those parameters comparing with the light holeelectron.

We modeled time dependent transport of oxygen in peripheral nerve by the simulation of steady-state oxygen tension, diffusion, chemical reactions and consumption of oxygen in capillaries using Krogh cylinder symmetry. These parameters were assumed to change rapidly to new. To characterize the approach of the oxygen tension to a new value, a monoexponential function is defined. Diffusion of oxygen is radial from capillary to a surrounding cylinder tissue and from arterial distance to veins, diffusion is axial. The time-dependent transport of oxygen is peripheral nerve with forward and backward reactions including first-order chemical kinetics has been considered, which makes this model different from the earlier studied models. We used Finite difference technique for the solution of this model.

One of the most active research areas in the field of robotics is robot manipulators control, because these systems are multi-input multi-output (MIMO), nonlinear, and uncertainty. At present, robot manipulators are used in unknown and unstructured situation and caused to provide complicated systems, consequently strong mathematical tools are used in new control methodologies to design nonlinear robust controller with satisfactory performance (e.g., minimum error, good trajectory, disturbance rejection). Robotic systems controlling is vital due to the wide range of application. Obviously stability and robustness are the most minimum requirements in control systems; even though the proof of stability and robustness is more important especially in the case of nonlinear systems. The strategies of robotic manipulators control are classified into two main groups: classical and non-classical methods, where the conventional control theory uses the classical method and the artificial intelligence theory (e.g., fuzzy logic, neural network, and neuro fuzzy) uses the non-classical methods. However both of classical and non-classical theories have applied successfully in many applications, but they also have some limitations. One of the best nonlinear robust controllers which can be used in uncertainty nonlinear systems is sliding mode controller (SMC). Sliding mode controller has two most important challenges: chattering phenomenon and nonlinear dynamic equivalent part. This paper is focused on the applied nonclassical method (e.g., Fuzzy Logic) in robust classical method (e.g., Sliding Mode Controller) in the presence of uncertainties and external disturbance to reduce the limitations. Applying the Mamdani’s error based fuzzy logic controller with 7 rules is the main goal that causes the elimination chattering phenomenon with regard to the variety of uncertainty and external disturbance; as a result this paper focuses on the sliding mode controller with artificial tuneable gain (SMCAT) to adjusting the sliding surface slope coefficient depends on applying fuzzy method.

The rise in global temperature is due to the increase in greenhouse gases, primarily in the form of carbon dioxide (CO2) - which has a rate of increase five times larger than before the pre-industrial era (Jansen et al., 2007). Historical atmospheric levels of CO2 obtained from glacial ice cores (Etheridge et al., 1998) can be combined with atmospheric CO2 levels collected on Mauna Loa in Hawaii (Keeling et. al., 2004; Pales and Keeling, 1965) to provide a record dating from the geologic past. Monthly readings at Mauna Loa since 1958, and now expanded to a network of worldwide sampling stations, provide essentially real-time monitoring of atmospheric CO2 levels.

Particles which undergo a change of state or phase transition to gaseous form by acquiring latent heat have shown a movement against the gravitational field. In this regard, upward mobility of iodine molecules under different conditions and geometries has been studied. No adequate explanation to this observation can be given with conventional laws in physics and hence a novel way of thinking is needed to explicate the behavior.

The paper is concerned with the applicability of the polynomial collocation method to a class of nonlinear singular integral equations with a Carleman shift preserving orientation on simple closed smooth Jordan curve in the generalized Holder space H (L) ? . The method is illustrated by considering some simple examples. 2000 AMS: Subject classification 45G05, 47H10, 47H30, 45L10, 65R20.