Theoretical Analysis of Dynamic Processes for Interacting Molecular Motors

Biological transport is supported by collective dynamics of enzymatic molecules that are called motor proteins or molecular motors. Experiments suggest that motor proteins interact locally via short-range potentials. We investigate the fundamental role of these interactions by analyzing a new class of totally asymmetric exclusion processes where interactions are accounted for in a thermodynamically consistent fashion. Theoretical analysis that combines various mean-field cal- culations and computer simulations suggests that dynamic properties of molecular motors strongly depend on interactions, and correlations are stronger for interacting motor proteins. Surprisingly, it is found that there is an optimal strength of interactions (weak repulsion) that leads to a maxi- mal particle flux. It is also argued that molecular motors transport is more sensitive to attractive interactions. Applications of these results for kinesin motor proteins are discussed

From dependency to Interdependencies: The emergence of a socially rooted but commercial waste sector in Kampala City, Uganda

Urban waste has traditionally remained for municipal councils to manage in several sub-Saharan cities such as Kampala. However, due to noticeable inefficiencies at municipal level, there is a manifest of low-income groups that take the initiative to extract and add value to materials from the waste stream, although higher-income groups are engaged in similar activities. This signifies the gradual shift from dependency on municipal councils to neighborhood interdependencies in the management of urban waste. To gain an in-depth understanding of this shift, we conducted purposive observations and twelve (12) focused-group interviews amongst selected respondents, in the neighborhood of Kasubi-Kawaala, Makerere II and Bwaise III parishes, located in the north western part of Kampala. The key finding was that waste-user roles, preferences, and the preceding generation and extraction processes are socially rooted in neighborhood cultural-orientations, and the underlying social mobility and commercial drivers. From the study, three (3) types of low-income commercial waste vendors were identified including, regular waste vendors, wholesale waste dealers, and home to home waste dealers. Unfortunately, these low-income waste vendors still have the least opportunity to negotiate with municipal authorities on scaling-up their commercial activities for a greater social impact.Key words: Wastes, social rootedness, neighborhoods, commercial waste, Kampala City

Development of a diagnostic schedule for a defective LC-195V5 CNC Milling machine using PERT

Computer Numerical Control CNC machine tools usage are more and more extensive, its fault diagnosis research is becoming more essential. Failure forms accorded these machines are diversified, and fault reasons are very complicated. It should not be left unattended to, because this could lead to further deterioration. One of the parameters used in determining the efficiency of a technician (who repairs machine tools) is the time saved in locating faults, hence the development of a diagnostic schedule which shows the sequential means of troubleshooting within a possible shortest time. In this research two approaches were used to diagnose a defective LC-195V5 CNC milling machine. Forward Pass (FP), which involves the diagnosis from electrical parts through Computer (CNC) to mechanical component and Backward Pass (BP) which involves the diagnosis from computer component through electrical parts to mechanical parts. Three different trials were conducted for each of the mode of diagnosis and the time to diagnose each component part was recorded. Based on the interrelationship of the component parts, two separate PERT (Project Evaluation & Review Techniques) network diagrams were drawn and their Critical Paths were determined. The study reveals that Foward Pass method was able to save more time

Contrast Adaptation in Subthreshold and Spiking Responses of Mammalian Y-Type Retinal Ganglion Cells

Retinal ganglion cells adapt their responses to the amplitude of fluctuations around the mean light level, or the contrast. But, in mammalian retina, it is not known whether adaptation arises exclusively at the level of synaptic inputs or whether there is also adaptation in the process of ganglion cell spike generation. Here, we made intracellular recordings from guinea pig Y-type ganglion cells and quantified changes in contrast sensitivity (gain) using a linear-nonlinear analysis. This analysis allowed us to measure adaptation in the presence of nonlinearities, such as the spike threshold, and to compare adaptation in subthreshold and spiking responses. At high contrast (0.30), relative to low contrast (0.10), gain reduced to 0.82 ± 0.016 (mean ± SEM) for the subthreshold response and to 0.61 ± 0.011 for the spiking response. Thus, there was an apparent reduction in gain between the subthreshold and spiking response of 0.74 ± 0.013. Control experiments suggested that the above effects could not be explained by an artifact of the intracellular recording conditions: extracellular recordings showed a gain change of 0.58 ± 0.022. For intracellular recordings, negative current reduced the spike output but did not affect the gain change in the subthreshold response: 0.80 ± 0.051. Thus, adaptation in the subthreshold response did not require spike-dependent conductances. We conclude that the contrast-dependent gain change in the spiking response can be explained by both a synaptic mechanism, as reflected by responses in the subthreshold potential, and an intrinsic mechanism in the ganglion cell related to spike generation

THIAMINE – INDUCED FORMATION OF THE MONOPYRROLE MOIETY OF PRODIGIOSIN

Thiamine stimulates the production of a red pigment , which is chromatographically and spectrophotometrically identical to prodigiosin , by growing cultures of serratia marcescens mutant 9-3-3 . this mutant is blocked in the formation of 2- methyl -3- amyl pyrorol( MAP),the monopyrrole moiety of prodigiosin , but accumulates 4-methoxy-2, 2-bipyrrole -5- carboxaldehyde (MBC) and can couple this compound with( MAP) to form prodigiosin . Addition of thiamine caused production of( MAP) , and as little as 0.02 mg of thiamine / ml in peptone- glycerol medium stimulated production of measurable amounts of prodigiosin. Phosphate saltes and another type of peptone decreased the thiamine- induced formation of prodigiosin ,yeast extract and glycerol enhanced formation of this substance. Thiamine also enhanced production of prodigiosin by wiled – type Strain Nima of S. marcescens . The pyrimidine moiety of thiamine was also 10% as effective as the vitamin ; the thiazol moiety only 4% , and the two moieties together , 25% . Thiamine did not stimulate production of prodigiosin biosynthesis as strain 9-3-3 . This is not surprising since strain 9-3-3 originated as a result of two mutational events one event may involve thiamine directly , and the other may involve the biosynthesis of( MAP)

Performance Assessment of some Phishing predictive models based on Minimal Feature corpus

Phishing is currently one of the severest cybersecurity challenges facing the emerging online community. With damages running into millions of dollars in financial and brand losses, the sad tale of phishing activities continues unabated. This led to an arms race between the con artists and online security community which demand a constant investigation to win the cyberwar. In this paper, a new approach to phishing is investigated based on the concept of minimal feature set on some selected remarkable machine learning algorithms. The goal of this is to select and determine the most efficient machine learning methodology without undue high computational requirement usually occasioned by non-minimal feature corpus. Using the frequency analysis approach, a 13-dimensional feature set consisting of 85% URL-based feature category and 15% non-URL-based feature category was generated. This is because the URL-based features are observed to be more regularly exploited by phishers in most zero-day attacks. The proposed minimal feature set is then trained on a number of classifiers consisting of Random Tree, Decision Tree, Artificial Neural Network, Support Vector Machine and Naïve Bayes. Using 10 fold-cross validation, the approach was experimented and evaluated with a dataset consisting of 10000 phishing instances. The results indicate that Random Tree outperforms other classifiers with significant accuracy of 96.1% and a Receiver’s Operating Curve (ROC) value of 98.7%. Thus, the approach provides the performance metrics of various state of art machine learning approaches popular with phishing detection which can stimulate further deeper research work in the evaluation of other ML techniques with the minimal feature set approach

Comparative Quality And Performance Analysis Of Manual And Motorised Traditional Portable Rice Threshers

Traditional motorized and manual portable threshers are the two types of threshers common to average farmer in the African continent and about 70% food production is in the hands of these categories of farmers. This paper compares the suitability of these types of threshers for traditional African farmers. The production rates (quantity threshed) and quality (seed loss and mechanical damage) were analyzed for both manual and motorized rice threshers using actual research data.  The observed advantages and disadvantages based on production rate, quality, cost and farm sizes are outlined as a guide to farmers. The result of this analysis is also employed to improve the performance of motorized rice thresher. Key words: rice, threshers, farm machineries, portabilit

Drop out among Basic Technology Students in Nigerian Educational System: Causes, Effects and Remedies

The paper explained the causes of drop out among Basic technology students in Nigerian educational system.. It also discussed its effects and remedies. The reason for introducing Basic technology in Nigerian educational system was highlighted. Basic technology students’ enrolment by gender was mentioned in the paper. The paper disclosed that some of the causes of school dropout include parent socio- economic status, attitude of teachers to students in the class, the culture of people, distance of the school from the students and lack of school infrastructure. The effects of school dropout were discussed and this includes prostitution, spreading of diseases, increase in crime rate, and also turning the adolescent to a delinquent child. The remedies to school dropout include government providing incentives to students by giving them uniforms, exercise books, textbooks free and also provide conducive learning environment. Parents should monitor the progress of their children by going to the school during visiting period to check their performances. Communities can assist in minimizing school dropout rate by village heads advising parents about the importance of education and the effects of school dropout and also by introducing penalty for those that withdraw their children from school. Keywords: Basic technology, Causes, Drop out, Educational system, Effect, Remed

ADAPTING MODERN METHODS OF LECTURING IN NIGERIAN UNIVERSITIES: A CRITIQUE

Different disciplines have explored the concept of lecturing from different perspectives. However, adapting some modern methods of lecturing in Nigerian universities have not been systematically studied.   Therefore, this paper examines critically the modern   methods of lecturing in our modern days tertiary institutions in Nigeria.In agreement with other researches, this paper notes that there are many challenges facing the   methods of teaching in Nigerian Universities today. Triangulation method was used to gather information for this paper, and both primary and secondary   sources were used to obtain information for this article.  The findings of this paper show that the traditional lecture method will not lead to much educational achievements unless it is combined with interactive engagements with the students and prompt feedback from the tutorsThe paper recommends that if Government could live up to her   expectation by provision of basic amenities and   state-of-the-arts teaching facilities to the tertiary institutions, the phenomenon could be reduced. A concerted effort is therefore needed among all stake holders in the education sector for the task of promoting effective teaching in our tertiary institutions

Molecular pharmacological studies of CHFI-FXII interaction and FXII function

Corn Hageman factor inhibitor (CHFI) is a bifunctional serine protease / α-amylase inhibitor protein having 127 residues and a molecular weight of 13.6-kDa. CHFI is selective toward FXIIa without affecting the function of the other coagulation factors. Coagulation FXII is a serine protease recognized to cause kinin generation and blood coagulation, cleaving plasma kallikrein and FXI. Results from FXII-deficient animal models proposed that this protein contributes to stable thrombosis that can cause obstruction of the blood vessels and its subsequent complications such as ischemic stroke. In contrast to other blood coagulation factors, deficiency in FXII is not related with haemorrhage in patients or in animals. These findings propose that specific inhibition of FXII could be an attractive medicine and a new method of anticoagulation to treat or prevent pathological thrombosis that could have a lower risk for bleeding and a safer anticoagulation profile than the currently available anticoagulants. Therefore, the current PhD project aimed at pharmacological investigation into CHFI-FXII interaction and FXII function at molecular level through the following objectives: first, developing an efficient expression and purification system for generating soluble and functional recombinant native type CHFI and establishing an inhibitory activity assay against FXIIa to verify the proper function of the recombinant protein. The second objective was testing the different recombinant variants of CHFI with the desired point mutations guided by a proper prediction study of CHFI-FXII interaction. The third was to investigate into the hypothesis of the tight-binding property of CHFI via different approaches of enzyme inhibition mechanisms and kinetic data analysis. The last objective was to investigate into the function of FXII by examining theeffect of Cys466 and glycosylated peptide remnant from the proline-rich region on the function of the catalytic domain via characterizing the different recombinant variants of the catalytic domain of FXIIa, FXIIc, FXIIac, HISTF-β FXII, and MBP-β-FXIIa. In the current study, an efficient system for soluble expression, single step purification and proper storage of functional, wild type rHIS-GST-CHFI was, for the first time, identified. The fully functional recombinant protein was verified via developing an inhibition test against FXIIa. The established expression, purification and inhibition assays were used as a fundamental guide to both generating and characterizing mutant proteins of interest that were made on the basis of an appropriate docking model of CHFI-FXIIa interaction. For the first time, the current investigation into the question of specificity of CHFI against FXII revealed that the central Arg34 at the very top of the fully exposed region of CHFI inhibition loop play a central role in the inhibition function of CHFI toward FXIIa. In addition, this study identified Trp22 at the N-terminus and Arg43 at the C-terminus of the central inhibition loop as two key interaction residues with FXIIa. It was also observed that, in the preinhibition test, CHFI behaves as a noncompetitive inhibitor. In contrast, it acts as a competitive inhibitor in the acute inhibition test, proposing that CHFI is a competitive inhibitor with slow degree of reversibility due to tightness of binding. Reversibility assay showed that CHFI is an inhibitor with slow degree of dissociation. The tight-binding property of CHFI could be due to a non-active site interaction and or numerous hydrogen bonds between the III key interaction residues and their potential targets on FXIIa.With respect to the investigation into FXII function, It was observed that both Cys340-Cys466 and glycosylated peptide fragment of the proline-rich region have a functional role for the full catalytic activity of FXII protease domain. Cumulatively, the current study identified the key important residues on the exposed surface of CHFI and their potential target residues on the surface of FXIIa that would be highly informative and important factors helping to understand the mechanism of selective and tight binding interaction of CHFI with FXIIa. This project can be considered as an early, necessary approach to design novel, specific and safe anticoagulants for the treatment of thrombosis and its complications