Vocal Acoustic Analysis

Vocal acoustic analysis is becoming a useful tool for the classification and recognition of laryngological pathologies. This technique enables a non-invasive and low-cost assessment of voice disorders, allowing a more efficient, fast, and objective diagnosis. In this work, ANN and SVM were experimented on to classify between dysphonic/control and vocal cord paralysis/control. A vector was made up of 4 jitter parameters, 4 shimmer parameters, and a harmonic to noise ratio (HNR), determined from 3 different vowels at 3 different tones, with a total of 81 features. Variable selection and dimension reduction techniques such as hierarchical clustering, multilinear regression analysis and principal component analysis (PCA) was applied. The classification between dysphonic and control was made with an accuracy of 100% for female and male groups with ANN and SVM. For the classification between vocal cords paralysis and control an accuracy of 78,9% was achieved for female group with SVM, and 81,8% for the male group with ANN.

Mechanistic modeling of cutting forces in high-speed microturning of titanium alloy with consideration of nose radius

Microturning is a micromechanical machining process used to produce microcylindrical or axially symmetrical parts. Microcylindrical parts are mainly used in microfluidic systems, intravenous micromotors, microsurgical applications, optical lens applications, and microinjection systems. The workpiece diameter is very small in microturning and therefore is greatly affected by the cutting forces. For this reason, it is important to predict the cutting forces when machining miniature parts. In this study, an analytical mechanistic model of microturning is used to predict the cutting forces considering the tool nose radius. In the semi-empirically developed mechanistic model, the tool radius was considered. A series of semi-orthogonal microturning cutting tests were carried out to determine the cutting and edge force coefficients. The mechanistic model was generalized depending on the cutting speed and depth of cut by performing multilinear regression analysis. In the study, the depth of cut (ap = 30–90 µm) and feed values (f = 0.5–20 µm/rev) were selected considering the nose radius and edge radius of the cutting tool. The experiments were carried out under high-cutting speeds (Vc = 150–500 m/min) and microcutting conditions. Ti6Al4V alloy was used as the workpiece material and the tests were carried out under dry cutting conditions. Validation tests for different cutting parameters were carried out to validate the accuracy of the developed mechanistic model. The results showed that the difference between the mechanistic model and the experimental data was a minimum of 3% and a maximum of 24%. The maximum difference between the experimental and the model usually occurs in forces in the tangential direction. It has been observed that the developed model gives accurate results even at a depth of cut smaller than the nose radius and at feed values smaller than the edge radius.

Is Coronary Artery Ectasia a Progressive Disease? A Self-Controlled Retrospective Cohort Study

Objective: It is essential to understand whether coronary artery ectasia (CAE) progresses over time because the patients might be under the risk of coronary rupture, and stent implant should be avoided if ectatic changes progress.Methods: A consecutive series of 99 CAE patients who had undergone coronary angiography at least twice were enrolled and followed up for 1–16 years until they received a second angiogram. Subjects were divided into two groups (1–5 vs. 5–16 years of follow-up), then the basic clinical characteristics and coronary artery images were compared over time.Results: (1) All CAE patients exhibited atherosclerosis, and a majority presented with acute myocardial infarction. Most baseline clinical characteristics were relatively stable. (2) Atherosclerosis (indicated by the distribution of stenosis in coronary vessels) and the Gensini scores progressed significantly. Ectasia extent showed minimal changes as indicated by blood vessel involvement, Markis type, coronary blood flow, ectasia diameter, and ectasia length. (3) Multilinear regression analysis revealed that the underlying factors related to stenosis evolution indicated by fold of Gensini score were: longer time interval, lower baseline Gensini score, and higher hypersensitive C-reactive protein concentration. (4) There was a relationship between the ectatic diameter and the extent of stenosis.Conclusions: For CAE patients with atherosclerosis followed for 1–16 years, there was minimal CAE progression, while the atherosclerosis progressed and the ectasia extent was related to degree of stenosis. The results indicate that prevention and treatment of atherosclerotic changes might have more clinical significance than addressing ectatic changes.

Internationalizing Malawian Higher Education: towards more beneficial academic mobility.

Aim: This study investigated the intentions, opportunities, and barriers to engaging in a meaningful internationalization of higher education in Malawi.Methods: This was cross-sectional research that was done between June and October 2021. Using a purposive (judgmental) sampling, we recruited 212 respondents from various institutions of higher education in Malawi. Multilinear regression analysis was used to analyze the factors with the P-value set at 0.05 level of statistical significance. Results: The results indicated that the majority of the respondents were males (63.7%) who fell into 30 years age bracket. Further, the results from the multilinear regression analysis indicate that Institutional collaboration (ß=0.326, p=0.000, CI=0.27—0.383), clear Policy on Mobility (ß=0.146, p=0.0.004, CI=0.047-0.246), experience (ß=0.083, p=0.117, CI=-0.021-0.186), academic rank (ß=0.114, p=0.000, CI=0.069-0.159) were positively statistically significant variables, whereas on the other hand, Occupation (ß=-0.131, p=0.002, CI=-0.213-0.49), academic qualification (ß=-0.106, p=0.013, CI=-0.19-0.023 and mobilityImportance (ß=-0.116, p=0.022, CI=-0.215-0.017) were negatively significant variables respectively.Conclusion and Recommendations: institutions need to invest in international and inter-institutional collaboration, clarify policy direction regarding academic mobility, keep track and linkages with mobile faculty, create a conducive social and formal institutional culture that attracts back mobile faculty, and reduce staff turnover.

Malawian Higher Education: towards a more internationalized system.

Aim: This study investigated the intentions, opportunities, and barriers to engaging in a meaningful internationalization of higher education in Malawi. Methods: This was cross-sectional research that was done between June and October 2021. Using a purposive (judgmental) sampling, we recruited 212 respondents from various institutions of higher education in Malawi. Multilinear regression analysis was used to analyze the factors with the P-value set at 0.05 level of statistical significance. Results: The results indicated that the majority of the respondents were males (63.7%) who fell into 30 years age bracket. Further, the results from the multilinear regression analysis indicate that Institutional collaboration (ß=0.326, p=0.000, CI=0.27—0.383), clear Policy on Mobility (ß=0.146, p=0.0.004, CI=0.047-0.246), experience (ß=0.083, p=0.117, CI=-0.021-0.186), academic rank (ß=0.114, p=0.000, CI=0.069-0.159) were positively statistically significant variables, whereas on the other hand, Occupation (ß=-0.131, p=0.002, CI=-0.213-0.49), academic qualification (ß=-0.106, p=0.013, CI=-0.19-0.023 and mobilityImportance (ß=-0.116, p=0.022, CI=-0.215-0.017) were negatively significant variables respectively. Conclusion and Recommendations: institutions need to invest in international and inter-institutional collaboration, clarify policy direction regarding academic mobility, keep track and linkages with mobile faculty, create a conducive social and formal institutional culture that attracts back mobile faculty, and reduce staff turnover.

The effect of educational attainment, length of work experience on the self-efficacy of teachers and employees

The study aims to determine the effect of educational attainment, length of work experience on self-efficacy and also to determine the difference of self-efficacy of employees based on the educational attainment and the length of work experience. To support the theories of the study, literature was reviewed. The study used a descriptive correlational research design and the questionnaires were used to gather the data. The population of the study was all employees of the Divine Word College of Laoag, Ilocos Norte, Philippines. The Multilinear regression analysis was used to determine the correlation and the analysis of variance (ANOVA) was used to determine the difference of self-efficacy among employees based on educational attainment and the length of work experience. The study found that the self-efficacy of employees was high and there is a correlation between educational attainment and self-efficacy and the length of work experience and self-efficacy. It is also found that there is a significant difference in self-efficacy among employees based on educational attainment and the length of work experience. Thus, based on the findings, then the hypotheses of the study are accepted.

Heterogeneous Catalysis of African Pear Seed Oil and Modelling of Some Thermo-Physical Properties of its Biodiesel

The heterogeneous catalysis of African pear seed oil (APO) and modelling of some thermo-physical properties of the biodiesel was carried out. The oil was extracted with petroleum ether solvent and characterized with Association of Analytical Chemist (AOAC). The catalysts were synthesized by thermal, acid and alkaline activation of clay. The catalysts were characterized and used to transesterify the APO. The biodiesel produced were characterized using American Society for Testing Materials ASTM D6571 and some the thermo-physical properties such as density, kinematic viscosity and cetane number were modelled using multilinear regression analysis of Polymath version 5.0. The 52% yield of oil from the African pear seeds using the petroleum ether was comparable with yields obtained from other nonedible seeds. The transesterification of the oil was significantly affected by increase in process variables but the yield of methyl ester decreased beyond 3 h reaction time, 3 wt% catalyst concentration, 10:1 methanol/oil molar ratio, 60 oC reaction temperature and 300 rpm agitation speed. The physicochemical properties of the biodiesel produced meet the ASTM standard and were within the acceptable limits. The biodiesel produced via transesterification of APO using thermally, acid and alkaline activated catalyst have similar properties and can be blended to form a homogeneous fuel. The coefficients of determination are close to 1 while the root mean square value is less than 0.2. This shows that the multilinear regression can model the thermo-physical properties of the biodiesel.

Smile Attractiveness Evaluation of Patients Selected for a U.S.-Based Board Certification Examination

Objectives The aims of the study were to assess smile attractiveness of a collection of 68 smiling photographs of successfully treated cases submitted to the American Board of Orthodontics (ABO) clinical examination and identify variables that influence the assessment. Materials and Methods A panel of 81 non-Caucasian assessors from various clinical disciplines were instructed to score the smile attractiveness on a visual analog scale from 1 (least attractive) to 10 (most attractive) and to select which components contributed to a lesser attractive smile. The mean, standard deviations (SDs), and quartiles of the smile attractiveness were obtained with descriptive statistics. Multilinear regression analysis was performed to investigate the scores of the perceived quality of smile attractiveness when the clinical disciplines and gender of the assessors were the factors taken into consideration. Receiver operating characteristic (ROC) curve was generated to establish the relationship between smile attractiveness and the achievement of a perfect smile. Results The mean (SD) rating of each clinical photograph of the anterior occlusion on smiling ranged from 3.11 (1.47) as the least attractive smile to 7.59 (1.45) as the most attractive smile. The overall mean (SD) score for smile attractiveness was 5.30 (1.10). Problems associated with teeth, gingiva, and lips corresponded with a reduction of the smile attractiveness score by 1.56, 1.82, and 1.47, respectively. Gender was not associated with smile attractiveness ratings. Orthodontists, periodontists, and prosthodontists demonstrated no difference in the ratings, while plastic surgeons were more critical than orthodontists regarding smile attractiveness. Conclusions The study suggested that only 2 out of 68 AOB validated treatment finishes had a perfect and attractive smile.

Transiency of postoperative cervical kyphosis seen after surgical correction of sagittal malalignment in adult spinal deformity patients

Objective In this study, we evaluated factors affecting changes in cervical lordosis after deformity correction and during follow-up period in adult spinal deformity (ASD) patients with severe sagittal imbalance. Methods Seventy-nine patients, with an average age of 71.6 years, who underwent long-segment fixation from T10 to S1 with sacropelvic fixation were included. We performed a comparative analysis of the radiographic parameters after surgery (Post) and at the last follow-up (Last). We calculated the Pearson’s correlation coefficient and performed multilinear regression analysis to predict independent parameters for Post and Last cervical lordosis (CL), T1 slope (T1S), and thoracic kyphosis (TK). Results Hyperlordotic changes of -23.3° in CL before surgery was reduced to -7° after surgery, and Last CL had increased to -15.3°. T1S was reduced from 27° before surgery to 14.4° after surgery and had increased to 18.8° at the last follow-up. Through multilinear regression analysis, we found that Post CL and T1S were more significantly affected by the amount of LL correction (p = .045 and .049). The effect of Last T1S was significantly associated with the Last CL; the effect of Last TK, with the Last T1S; and the effect of Post PI-LL, with the Last TK (p < .05). Conclusion The postoperative kyphotic change in CL in ASD patients with preoperative cervical hyperlordosis is not permanent and is affected by drastic LL correction and SVA restoration. To achieve spinopelvic harmony proportional to the difference in LL relative to PI, TK becomes modified over time to increase T1S and CL, in an effort to achieve optimal spine curvature.

Cue-Based Feeding as Intervention to Achieve Full Oral Feeding in Preterm Infants Primarily Managed with Bubble CPAP

Objective Cue-based feeding aims at matching introduction of per oral (PO) feeding with physiological readiness of preterm infants to facilitate PO intake and avoid oral aversion. It was claimed that cue-based feeding may lead to delay in the initiation or achieving full PO feeding in clinical setting primarily using bubble nasal continuous positive airway pressure (CPAP). The study aimed to examine the association of cue-based feeding with time of introduction and completing oral feeding in infants primarily managed with bubble CPAP. Study Design A retrospective analysis where outcomes of preterm infants ≤32 weeks' gestational age (GA) and ≤2,000 g birth weight (BW) were compared after a practice change from volume-based feeding advancement to cue-based feeding. Continuous variables were compared by using t-test and multilinear regression analysis to control for confounding variables. Results Of the 311 preterm infants who met inclusion and exclusion criteria, 194 were in the cue-based feeding group and 117 were in the volume-based advancement historical comparison group. There were no differences between groups regarding demographic or clinical variables. Postmenstrual age (PMA) of initial feeding assessment was less in the cue-based feeding group. Age of first PO feeding and when some PO was achieved every feed was mildly delayed in the cue-based feeding compared with comparison group, 34 (±1.3) versus 33.7 (±1.2) weeks, and 36.2 (±2.3) versus 36.0 (±2.4) weeks, (p < 0.01) respectively. However, the age of achieving full PO did not differ between groups, 36.8 (±2.2) versus 36.4 (±2.4) weeks (p = 0.13). There was no difference between groups regarding growth parameters at 36 weeks' PMA or at discharge. Similar results were obtained when examining subcategories of infants ≤1,000 g and 1,001 to 2,000 g. Conclusion Cue-based feeding may not be associated with a delay in achieving full oral feeding or prolongation of the length of stay in preterm infants managed with CPAP. Key Points