Bioactive molecule prediction using extreme gradient boosting

Following the explosive growth in chemical and biological data, the shift from traditional methods of drug discovery to computer-aided means has made data mining and machine learning methods integral parts of today's drug discovery process. In this paper, extreme gradient boosting (Xgboost), which is an ensemble of Classification and Regression Tree (CART) and a variant of the Gradient Boosting Machine, was investigated for the prediction of biological activity based on quantitative description of the compound's molecular structure. Seven datasets, well known in the literature were used in this paper and experimental results show that Xgboost can outperform machine learning algorithms like Random Forest (RF), Support Vector Machines (LSVM), Radial Basis Function Neural Network (RBFN) and Naïve Bayes (NB) for the prediction of biological activities. In addition to its ability to detect minority activity classes in highly imbalanced datasets, it showed remarkable performance on both high and low diversity datasets

New exact solutions of stokes' second problem for an MHD second grade fluid in a porous space

We investigate a problem describing the oscillating flow of an incompressible magnetohydrodynamic (MHD) second grade fluid in a porous half space. Exact solutions for sine and cosine oscillations are developed by applying the Laplace transform method. The total obtained solution is a sum of steady and transient solutions. Particular attention is given to the effects of magnetic and porous medium parameters on the velocity. It is shown that previous results for a non-porous medium and hydrodynamic fluid are the limiting cases of the present problem. The results for velocity are plotted and discussed carefully

Effect of Dynamic Voltage Restorer in Compensating for Voltage Sag and Controlling Harmonics in a Power Distribution System using Fumman Industry as a Case Study

Different power quality surveys done by researchers identify voltage sags as the most serious power quality problems for industrial customers. Voltage sag can cause serious problems to electric loads that cannot withstand variation in voltage such as adjustable speed drives, process control equipment and computers. This research work investigated the effect of Dynamic Voltage Restorer (DVR) in compensating for voltage sag and controlling harmonics in a power distribution system. A DVR is a power electronic converter base device that is used to regulate the voltage at the load terminals from various power quality problems like sag, swell unbalance etc in the supply voltage. The mathematical equations representing voltage sag and it compensation are presented. To implement the effect of DVR on industrial load network, Fumman Industry was considered as a case study. The DVR was modeled by building the subsystem of each major component. The components are injection transformer, fuzzy logic controller, battery and Pulse Width Modulation (PWM) inverter. Optimization technique was used to determine the appropriate battery size. Simulation was done without and with the DVR using Matlab/Simulink; under three and double phase line-to-ground faults.Simulation results showed that the modeled DVR can work very well against balanced and unbalanced voltage sag caused by fault in industrial distribution systemconsidering the harmonic limits

Preparation of Yeast (Saccharomyces cerevisiae) Biomass from Sugarcane Bagasse

In this study, the pretreatment by milling, dilute-acid hydrolysis of sugarcane bagasse, and subsequent fermentation of its glucose product was performed to investigate the effects of process conditions on the production of Saccharomyces cerevisiae. The hydrolysis was carried out using HCl at three substrate concentrations of 20, 25, and 30% (w/v) of bagasse to distilled water. Hydrolysis parameters (time, acid concentration, and temperature) were varied for each case of substrate concentration in full factorial experiments, and an optimum glucose yield of 1.907 g/L was obtained with the 20% (w/v) substrate concentration, at conditions of 10 min time, 0.5 M acid concentration, and 80°C temperature. Thereafter, fermentation experiment was performed with S. cerevisiae in the product of hydrolysis. An optimum ca. 207 yeast number of colonies (yield: 20, 700, 000 cfu/ml) was achieved in 40 h, and the growth of S. cerevisiae was governed by the kinetic equation, ln Xt = 8.4338 + 0.2943t

ABSORBED DOSE RATES ABOVE SOILS AND ROCK OUTCROPS IN SELECTED AREAS OF ABEOKUTA, NIGERIA

Outdoor absorbed dose rates were measured in selected areas of Abeokuta in Nigeria; some with rock outcrops and others with soil overburden. Measurements were carried out using a Geiger Muller Survey Meter and a Global Positioning System (GPS). Result shows absorbed dose rates ranged from 1.0 x 103 to 1.3 x 103 nGy/hr among the rock outcrop areas and from 0.6 x 103 to 0.8 x 103 nGy/hr among the soil -covered areas. The average absorbed dose rate was 1180 ±3 nGy/hr for the rock outcrop areas and 689 ±3 nGy/hr for the soil -covered areas and assuming 0.4 occupancy factor, the corresponding average annual effective dose rates were calculated to be 2.89 ± 0.01 mSv/yr for the rock outcrop areas and 1.69 ± 0.01 mSv/yr for the soil –covered areas based on occupancy factor of 0.4. The mean annual effective dose rates for both the rock outcrop and soil covered areas were  found to be higher than 1mSv/yr, the recommended dose limit for the public.     &nbsp

MEASUREMENT OF RADIATION DOSE IN SELECTED CEMENT STORES IN ABEOKUTA, OGUN STATE, USING GM SURVEY METER

Measurements were carried out using a Geiger Muller Survey Meter and a Global Positioning System (GPS) to find  the outdoor absorbed dose rates in selected cement stores in Abeokuta, Ogun State, Nigeria. The outdoor  absorbed dose rates  (control sites 10m away from cement depot) ranged from 400 nGy/hr) (Sapon) to 740 nGy/hr (Adatan) with the mean 554.7 ± 0.08 nGy/hr  and the indoor absorbed dose rate (store) ranged from 740 nGy/hr  (Lafenwa1&2) to 1240 nGy/hr (Isale-Ake) with the mean 909.3 ± 16 nGy/hr. The corresponding annual effective dose rates for the control sites ranged from 1.13 mSv/yr (sapon) to 2.09 mSv/yr (Adatan) with the mean 1.57 ± 0.32  mSv/yr, while it ranged from 2.45 mSv/yr (Lafenwa1&2) to 4.11 mSv/yr (Isale ake) for the cement depots  with the mean 3.01 ± 0.52 mSv/yr. It has been revealed from this study that cement may enhance exposure to radiation, since the value of the absorbed dose rates in the stores are higher than thoseof the control sites. The values for the annual effective dose calculated are higher than 1mSv/yr. &nbsp

COMPARISON OF ACTIVITY CONCENTRATIONS OF NATURAL RADIONUCLIDES IN SOILS COLLECTED AT DIFFERENT DEPTHS OF SELECTED HAND-DUG WELLS IN ABEOKUTA

This study was aimed at measuring and comparing the activity concentration of soil samples collected from some selected hand – dug wells with their corresponding depths of collection in Abeokuta metropolis. Total of twenty (20) soil samples were collected from hand-dug wells in five sites (Obada, Adigbe, Kuto, Olorunsogo, and Obantoko) within Abeokuta with four (4) soil samples from each hand-dug well at the surface, (0.0m) through to 2.25m depth. Gamma ray spectroscopy with High Purity Germanium (HPGe) detector was used for the measurements. The average activity concentrations obtained for the three natural radionuclides 226Ra, 232Th and 40K in Bq/Kg are 34.31 ± 2.01, 128.73 ± 4.41 and 152.31 ± 2.59 respectively at depth 0.00 m (surface), 23.00 ± 1.61, 68.39 ± 3.24 and 191.08 ± 3.11 respectively at depth 0.75 m, 31.52 ± 2.21, 145.37± 4.95 and 375.56 ± 5.50 respectively at 1.50 m and lastly 28.57±1.70, 95.61 ± 3.71 and 181.10 ± 3.94 respectively at 2.25 m depth. The world average activity concentrations for 226Ra, 232Th and 40K are given to be 35 Bqkg-1, 30 Bqkg-1 and 400 Bqkg-1 respectively (UNSCEAR 2000). 232Th showed  higher average values than the world’s average while averages of 226Ra and 40K were lower but most of the activity concentration values obtained in some of the locations are higher than the world’s average values, especially 226Raand 232Th in the soil samples.

IMPLEMENTATION OF THE ROOT BISECTION COMPUTATIONAL PHYSICS METHOD FOR THE DETERMINATION OF ROOTS OF NON-LINEAR EQUATIONS USING JAVA

Advancement in programming and language development has made possible improved efficiency and accuracy in solving numerical problems and hence the numerical computation of physical problems as used in Computational Physics. Hitherto, languages such as Basic, Fortran, C, among others, have commonly been employed in solving numerical problems. In this work, Java, a modern object oriented language was deployed in solving some physical problems, specifically, determination of roots of non-linear equations using the Root-Bisection Method. A comparison between results obtained showed faster convergence and greater accuracy using Java than as obtained using Fortran.     &nbsp

Cerebral Angiography Can Demonstrate Changes in Collateral Flow During Induced Hypertension

AbstractA 52-year-old woman with a large left-hemispheric stroke was transferred to our hospital for possible endovascular treatment. The patient underwent a cerebral angiogram at 7 hours after symptom onset with intent to treat and was found to have occlusion of the proximal M1-segment of the left middle cerebral artery (MCA). At that time it was felt that this was a high-risk patient for mechanical clot retrieval and it was decided to treat her with induced hypertension. The diagnostic catheter was left in place in the left internal carotid artery (ICA) and hypertension was induced in the angiography suite by means of an infusion of neosynephrine. Ten minutes after the goal blood pressure levels had been reached, a repeat left ICA injection was performed, which demonstrated more extensive collateralization of the MCA territory from anterior cerebral artery branches. Mean transit times (MTT) for the left ICA circulation improved from 9.5 seconds prior to induced hypertension to 6.0 seconds. The neosynephrine infusion was continued for a total of 24 hours and the patient showed neurological improvement. We suggest that induced hypertension led to the improved collateralization to the left MCA as evidenced by the improved MTT and augmentation of leptomeningeal collaterals, which in turn led to the patient's clinical improvement

Effect of Hibiscus sabdariffa Calyx (Zobo) on the Growth Performance of Broilers (Obamarshal) Chickens

Roselle (Hibiscus sabdariffa) is a leaf use to make a drink locally known as zobo. The seed is considered an excellent feed for chicken because of the presence of certain vitamins especially vitamin C which is known for its antioxidant property hence stimulating the immune system. Farmers are constantly seeking for cheaper and healthier means to improve the quality of meat and weight of broilers. Also cheap and readily available synthetic drugs including antibiotics that were used as growth promoters have been banned due to their side effect in both poultry and human health. Many attempts have been made locally by farmers to use natural plant as supplements for birds to replace synthetic antibiotics. There is also a significant lack of knowledge about the beneficial effect of Hibiscus sabdariffa in poultry. Although other supplements such as anise seed (pinpinell anisume )have been used to improve meat characteristics and carcass weight, there is a suggestion that calyxes of roselle (zobo) may be used as best alternative. The study aims to test the effect of feeding different level of “zobo” in drinking water on the growth performance of broilers.Fifty day old broilers were sourced and exposed to the same feeding, watering and other management conditions like vaccinations and treatment until they were 4 weeks old. They were then divided into groups of 10 and treated with different concentrations of roxelle calyx gotten from water and ethanol extraction. The groups were A1 (broiler chicks on 1g/4l water extract of roselle calyx), A2 (broiler chick on 1g/4L ethanol extract of roselle calyx), B1 (broiler chick on 2g/4L water extract of roselle calyx), B2 (broiler chick on 2g/4L ethanol extract of roselle calyx) and C which were the control (broilers on plain water). Rectal temperatures were taken every Mondays, Wednesdays and Fridays in the mornings and evenings. Live weight, carcass weight, dislocated carcass weight, internal organs and feed intake were the response criteria used when broilers were 8 weeks old. The birds (A2) on Hibiscus sabdariffa had the highest weight gain and consumed the largest quantity of feed as compared to control. This was statistically significant (P˂0.05). It can be concluded from this study that roselle calyx (zobo) tends to enhance weight gain, feed consumption and conversion in broilers. Keywords: Roselle calyx, zobo, water extract, ethanol extract, weight gain