An Evaluation of the Applications of Quantitative Techniques (QTs) to Production Planning and Control in Manufacturing Industries

This study examined the factors that affect applications of Quantitative Techniques (QTs) to production planning and control in selected Nigerian manufacturing industries. Data were collected using questionnaire administered on 160 staff of 20 companies randomly chosen from each of the 8 purposively selected Nigerian Small-Scale Industries. Analysis of data was done descriptively and quantitatively using cross tabulations, percentages and inferential statistical tools respectively. Specifically, student t test was used to test the significance of the number of companies that apply QTs, The results showed that the types of QTs commonly in use include: Graphical and Charting Techniques, Control Charts, Forecasting Techniques (Simple Regression and Time Series Analyses), Inventory Model, Range, Variance and Standard Deviation, Capacity Utilization Model, and Acceptance Sampling. Control Charts topped the list with 14 (35 %). Also, 40 companies (25 %) of the 160 surveyed actually apply QTs. This number was significant at 0.05 level with t= 8.819. Metal Works industry led others in the applications of QTs with 8 (40 %) of the 20 companies surveyed in each selected industry; it also recorded 8 (20 %) of the 40 companies from all the selected industries. The study concluded that certain QTs are being applied to production planning and control by a significant number of companies from the selected Nigerian small-scale industries. Lack of adequate financial resources was the most important of all the assessed factors. Keywords: Product planning and control, Operations research models, resources utilization decision makin

PSO Tuned Flatness Based Control of a Magnetic Levitation System

Investigation on the application of flatness-based feedback linearization to the magnetic levitation model of INTECOTm Maglev system is presented in this paper. The MAGLEV system dynamics studied consists of a set of third order nonlinear differential equations. Using computational techniques proposed by Levine, it is verified that the ball position is the flat output. The derived flat output is applied in the construction of a nonlinear control law used to control the levitation to a set point as well as tracking a sine function trajectory. The controller gains are obtained and optimized using particle swarm optimization. The simulation results compared very well with the default PID control. Real-time and non real-time simulation using the MATLAB/ SIMULINK real workshop environment is presented

Particle Swarm Optimization Tuned Flatness-Based Generator Excitation Controller

An optimal transient controller for a synchronous generator in a multi-machine power system is designed using the concept of flatness-based feedback linearization in this paper. The computation of the flat output and corresponding controller for reduced order model of the synchronous generator is presented. The required feedback gains used to close the linearization loop is optimized using particle swarm optimization for maximum damping. Typical results obtained for transient disturbances on a two-area, four-generator power system equipped with the proposed controller on one generator and conventional power system stabilizers on the remaining generators are presented. The effectiveness of the flatness-based controller for multi-machine power systems is discussed

Computed Tomography Dose for Adult Head Scan in Anambra State of Nigeria

Background: Computed tomography is associated with relatively high radiation doses and could cause serious health risks. Globally, it is reported that many physicians do not to have adequate knowledge about CT dose. Furthermore, although dose records are available from developed countries, there is a paucity of literature in Nigeria. Dose outputs in our locality are also scarce in the literature. Objective: To review adult head CT dose in the four largest centres in Anambra State. Methodology: A 6-month retrospective retrieval of dose summary from the control console. Digital folders of subjects ≥ 18 years were sampled purposively and sequentially, out of the 2015 population of CT examinations. The CTDIvol and DLP for each case were recorded in a pro forma. The mean dose in each centre as well as the combined mean for all centres were calculated. The results were compared with the recommendations of the European Commission and similar studies from Nigeria. Results: The digital folders of 200 subjects made up of 104 (52.0 %) males and 96 (48.0%) females with an age range of 18 – 93 years were involved in the study. Cranium (n = 164; 82 %) dominated the CT requests. The mean CTDIvol and DLP in the four centres was 58 mGy and 1112 mGy.cm. The mean CTDIvol (73 mGy) and DLP (1613 mGy-cm) in one of the centres was extreme. When excluded, the mean CTDIvol and DLP for the remaining three centres were 52 mGy and 945 mGy.cm, respectively. Conclusion: Dose output in Anambra State was comparable to the recommendation of the European Commission but varied significantly from other local studies. The establishment of diagnostic reference levels for CT procedure in the locality is imperative

Transcriptomic analysis of cutaneous squamous cell carcinoma reveals a multi-gene prognostic signature associated with metastasis.

BackgroundMetastasis of cutaneous squamous cell carcinoma (cSCC) is uncommon. Current staging methods are reported to have sub-optimal performances in metastasis prediction. Accurate identification of patients with tumours at high risk of metastasis would have a significant impact on management.ObjectiveTo develop a robust and validated gene expression profile (GEP) signature for predicting primary cSCC metastatic risk using an unbiased whole transcriptome discovery-driven approach.MethodsArchival formalin-fixed paraffin-embedded primary cSCC with perilesional normal tissue from 237 immunocompetent patients (151 non-metastasising and 86 metastasising) were collected retrospectively from four centres. TempO-seq was used to probe the whole transcriptome and machine learning algorithms were applied to derive predictive signatures, with a 3:1 split for training and testing datasets.ResultsA 20-gene prognostic model was developed and validated, with an accuracy of 86.0%, sensitivity of 85.7%, specificity of 86.1%, and positive predictive value of 78.3% in the testing set, providing more stable, accurate prediction than pathological staging systems. A linear predictor was also developed, significantly correlating with metastatic risk.LimitationsThis was a retrospective 4-centre study and larger prospective multicentre studies are now required.ConclusionThe 20-gene signature prediction is accurate, with the potential to be incorporated into clinical workflows for cSCC

Transcriptomic analysis of cutaneous squamous cell carcinoma reveals a multi-gene prognostic signature associated with metastasis.

BACKGROUND: Metastasis of cutaneous squamous cell carcinoma (cSCC) is uncommon. Current staging methods are reported to have sub-optimal performances in metastasis prediction. Accurate identification of patients with tumours at high risk of metastasis would have a significant impact on management. OBJECTIVE: To develop a robust and validated gene expression profile (GEP) signature for predicting primary cSCC metastatic risk using an unbiased whole transcriptome discovery-driven approach. METHODS: Archival formalin-fixed paraffin-embedded primary cSCC with perilesional normal tissue from 237 immunocompetent patients (151 non-metastasising and 86 metastasising) were collected retrospectively from four centres. TempO-seq was used to probe the whole transcriptome and machine learning algorithms were applied to derive predictive signatures, with a 3:1 split for training and testing datasets. RESULTS: A 20-gene prognostic model was developed and validated, with an accuracy of 86.0%, sensitivity of 85.7%, specificity of 86.1%, and positive predictive value of 78.3% in the testing set, providing more stable, accurate prediction than pathological staging systems. A linear predictor was also developed, significantly correlating with metastatic risk. LIMITATIONS: This was a retrospective 4-centre study and larger prospective multicentre studies are now required. CONCLUSION: The 20-gene signature prediction is accurate, with the potential to be incorporated into clinical workflows for cSCC

Impact of dietary patterns, individual and workplace characteristics on blood pressure status among civil servants in Bida and Wushishi communities of Niger State, Nigeria

The global burden estimate of hypertension is alarming and results in several million deaths annually. A high incidence of sudden deaths from cardiovascular diseases in the civil workforce in Nigeria is often reported. However, the associations between Dietary Patterns (DPs), individual, and workplace characteristics of hypertension among this workforce have not been fully explored. This study aimed to identify DP in the Bida and Wushishi Communities of Niger State and establish its relationship with hypertension along with other individual and workplace characteristics. Factor analysis was used to establish DP, Chi-square test to identify their relationships with hypertension, and logistic regression to determine the predictor risk factors. The prevalence of hypertension was 43.7%; mean weight, height, and body fat were: 72.8±15 kg, 166±8.9 mm and 30.4%, respectively. Three DPs: “Efficient Diet,” “Local diet,” and “Energy Boost Diet” were identified. The factor loading scores for these factors were divided into quintiles Q1–Q5; none of them had a significant effect on hypertension status. Conversely, increase in age, the Ministry, Department, and Agency (MDA) of employment, frequency of eating in restaurants, and obesity were identified as significant risk factors. After adjusting for confounders (age, body mass index, MDA, and eating habits), a high score (Q5) in “efficient diet pattern” was significantly related to a lower likelihood of hypertension than a low score (Q1). The prevalence of hypertension among the participants was relatively very high. An increase in age and working in educational sector were risk factors associated with hypertension. Therefore, it is recommended that civil servants engage in frequent exercise and undergo regular medical checkups, especially as they get older. These findings highlight the need for large-scale assessment of the impact of variables considered in this study on hypertension, among the civil workforce across Niger state and Nigeria

A calcineurin–Hoxb13 axis regulates growth mode of mammalian cardiomyocytes

10.1038/s41586-020-2228-6Nature5827811271-27

Structural and spectroscopic characterisation of a heme peroxidase from sorghum

A cationic class III peroxidase from Sorghum bicolor was purified to homogeneity. The enzyme contains a high-spin heme, as evidenced by UV-visible spectroscopy and EPR. Steady state oxidation of guaiacol was demonstrated and the enzyme was shown to have higher activity in the presence of calcium ions. A Fe(III)/Fe(II) reduction potential of -266 mV vs NHE was determined. Stopped-flow experiments with H2O2 showed formation of a typical peroxidase Compound I species, which converts to Compound II in the presence of calcium. A crystal structure of the enzyme is reported, the first for a sorghum peroxidase. The structure reveals an active site that is analogous to those for other class I heme peroxidase, and a substrate binding site (assigned as arising from binding of indole-3-acetic acid) at the γ-heme edge. Metal binding sites are observed in the structure on the distal (assigned as a Na(+) ion) and proximal (assigned as a Ca(2+)) sides of the heme, which is consistent with the Ca(2+)-dependence of the steady state and pre-steady state kinetics. It is probably the case that the structural integrity (and, thus, the catalytic activity) of the sorghum enzyme is dependent on metal ion incorporation at these positions