2,930 research outputs found
An Improved Volumetric Estimation Using Polynomial Regression
The polynomial regression (PR) technique is used to estimate the parameters of the dependent variable having a polynomial relationship with the independent variable. Normality and nonlinearity exhibit polynomial characterization of power terms greater than 2. Polynomial Regression models (PRM) with the auxiliary variables are considered up to their third order interactions. Preliminary, multicollinearity between the independent variables is minimized and statistical tests involving the Global, Correlation Coefficient, Wald, and Goodness-of-Fit tests, are carried out to select significant variables with their possible interactions. Comparisons between the polynomial regression models (PRM) are made using the eight selection criteria (8SC). The best regression model is identified based on the minimum value of the eight selection criteria (8SC). The use of an appropriate transformation will increase in the degree of a statistically valid polynomial, hence, providing a better estimation for the model
The Malaysian Polypropylene Industry Outlook In Facing ASEAN Free Trade Area (AFTA) Deregulation
The objective of this study is to focus specifically on the Malaysian polypropylene industry’s performance in order to further understand the current situation. As the future of the plastics industry is becoming more competitive due to the uncertainties of the global economy, it is hoped that this study could help to assist the Malaysian polypropylene industry to understand the future potential challenges better. Another aspect of the future challenges for the industry is the lifting of the trade barrier within the ASEAN countries. By early 2003, the ASEAN Free Trade Area (AFTA) has imposed in the ASEAN regions and there will be little or no tariff at all between the ten ASEAN countries. Based on the survey’s results, the Malaysian polypropylene industry is still very much dependent on the domestic market. The overall domestic market share commands about 60% of the total business. The trend to expand the export market is still in progress and in line with the overall Malaysian plastics industry. At the moment, only the large polypropylene industries are very aggressive in capturing the export market. If the current market segmentation of the overall industry is maintained, the AFTA deregulation could affect the future outlook of the industry as the alternative domestic market is not available in time in case of any penetration happens to this major market segment. As the small and medium polypropylene industries are very much dependent on the domestic market, they could be the first segment of the industry that would face the immediate effect or challenges of AFTA to the industry.
Analytical Solutions of Heat Transfer and Film Thickness with Slip Condition Effect in Thin-Film Evaporation for Two-Phase Flow in Microchannel
Physical and mathematical model has been developed to predict the two-phase flow and heat transfer in a microchannel with evaporative heat transfer. Sample solutions to the model were obtained for both analytical analysis and numerical analysis. It is assumed that the capillary pressure is neglected (Morris, 2003). Results are provided for liquid film thickness, total heat flux, and evaporating heat flux distribution. In addition to the sample calculations that were used to illustrate the transport characteristics, computations based on the current model were performed to generate results for comparisons with the analytical results of Wang et al. (2008) and Wayner Jr. et al. (1976). The calculated results from the current model match closely with those of analytical results of Wang et al. (2008) and Wayner Jr. et al. (1976). This work will lead to a better understanding of heat transfer and fluid flow occurring in the evaporating film region and develop an analytical equation for evaporating liquid film thickness
A Study Of Motivation In Business Start-Ups Among Malay Entrepreneurs
The effect of entrepreneurships in developing economies was studied widely in prior researches, since entrepreneurs contribute significantly in economics development. The purpose of this study is to explore and understand Malay entrepreneurs in the eastern region of Peninsular Malaysia; who are the majority ethnic group in the area. The study is concentrated on the motivation factors that influenced their decision to start up new businesses. This study also examined problems faced by those entrepreneurs, both during start up stage and during present operation. Basic variables on entrepreneurs’ background and their business characteristics were taken into account. The motivational factors were examined using a modified model from Scheinberg and MacMillan. The primary data collections methods were structured interviews and surveys. “Statistical Package for the Social Science” (SPSS) was used in analyzing the data. Frequency and descriptive analysis were used to examine the basic variables and problems facing the entrepreneurs. Factor analysis was applied to determine the motivation factors. In addition, ANOVA and MANOVA were used to test the hypotheses developed. The study shows that majority of Malay entrepreneurs are male. One third of the entrepreneurs are well educated up to the tertiary level. Almost all of them are married and has worked in three different fields prior to starting their own business. They were involved in operating small business for others, worked as Government servants or in private firms. A majority of their parents operate their own business. Major problems in conducting business lies in stiff competition from others and also insufficient initial capital. Seven motivational factors were determined to have influenced Malay entrepreneurs to start up business. The most influential factors are spiritual liability, personal development and satisfaction, and financial security. Other important factors are opportunities, freedom, accommodation and escapism. Meanwhile, five hypotheses were developed for this study. The result shows that the level of education of entrepreneurs is significant with reference to the motivational factors. On the other hand, gender, previous work and parents’ occupation are of no significance. However, combination of gender and level of education showed certain level of significance with reference to their motivational factors.
Rationale and Design of an Online Educational Program Using Game-Based Learning to Improve Nutrition and Physical Activity Outcomes Among University Students in the United Kingdom.
OBJECTIVE: To assess the impact of an online game-based educational program on nutrition knowledge and dietary and physical activity habits among university students in the United Kingdom. DESIGN: Randomized controlled trial with pre- and postintervention comparisons. SETTING: Two higher education settings in London, UK. SUBJECTS: Current undergraduate and postgraduate students of two universities (n = 88) aged 18-34 years are randomly allocated to an intervention (n = 44) or a control group (n = 44). INTERVENTION: The intervention group will receive access to an educational website and online quizzes with gamification elements, including information about healthy eating and physical activity. The control group will receive no information. Duration of the intervention will be 10 weeks. MEASURES OF OUTCOME: Primary outcome is nutrition knowledge. Secondary outcomes include dietary and activity habits. Nutrition knowledge and dietary and activity habits will be assessed using questionnaires. Weekly steps will be counted using pedometers. Assessment of anthropometric and metabolic risk factors will take place. ANALYSIS: Quantitative analysis will investigate changes in nutrition knowledge between the two groups of the study population. Linear regression analysis will be used, if the data follow the normal distribution (otherwise binomial regression analysis), to examine whether field of study, residence status, body mass index (BMI), and demographic factors affect nutrition knowledge. Associations between changes in knowledge and dietary and physical activity behavior will be assessed by correlations. CONCLUSIONS/IMPLICATIONS: The study will provide insights with regard to the design and use of online game-playing as a cost-effective approach to improve nutritional knowledge among university students
Physicochemical characterization of the endotoxins from Coxiella burnetii strain Priscilla in relation to their bioactivities
BACKGROUND: Coxiella burnetii is the etiological agent of Q fever found worldwide. The microorganism has like other Gram-negative bacteria a lipopolysaccharide (LPS, endotoxin) in its outer membrane, which is important for the pathogenicity of the bacteria. In order to understand the biological activity of LPS, a detailed physico-chemical analysis of LPS is of utmost importace. RESULTS: The lipid A moiety of LPS is tetraacylated and has longer (C-16) acyl chains than most other lipid A from enterobacterial strains. The two ester-linked 3-OH fatty acids found in the latter are lacking. The acyl chains of the C. burnetii endotoxins exhibit a broad melting range between 5 and 25°C for LPS and 10 and 40°C for lipid A. The lipid A moiety has a cubic inverted aggregate structure, and the inclination angle of the D-glucosamine disaccharide backbone plane of the lipid A part with respect to the membrane normal is around 40°. Furthermore, the endotoxins readily intercalate into phospholipid liposomes mediated by the lipopolysaccharide-binding protein (LBP). The endotoxin-induced tumor necrosis factor α (TNFα) production in human mononuclear cells is one order of magnitude lower than that found for endotoxins from enterobacterial strains, whereas the same activity as in the latter compounds is found in the clotting reaction of the Limulus amebocyte lysate assay. CONCLUSIONS: Despite a considerably different chemical primary structure of the C. burnetii lipid A in comparison with enterobacterial lipid A, the data can be well understood by applying the previously presented conformational concept of endotoxicity, a conical shape of the lipid A moiety of LPS and a sufficiently high inclination of the sugar backbone plane with respect to the membrane plane. Importantly, the role of the acyl chain fluidity in modulating endotoxicity now becomes more evident
Intraoperative monitoring of visual evoked potentials in patients undergoing transsphenoidal surgery for pituitary adenoma: a systematic review
BACKGROUND:
Transsphenoidal surgery is the gold standard for pituitary adenoma resection. Although rare, a serious complication of surgery is worsened vision post-operatively.
OBJECTIVE:
To determine whether, in patients undergoing transsphenoidal surgery for pituitary adenoma, intraoperative monitoring of visual evoked potentials (VEP) is a safe, reproducible, and effective technological adjunct in predicting postoperative visual function.
METHODS:
The PubMed and OVID platforms were searched between January 1993 and December 2020 to identify publications that (1) featured patients undergoing transsphenoidal surgery for pituitary adenoma, (2) used intraoperative optic nerve monitoring with VEP and (3) reported on safety or effectiveness. Reference lists were cross-checked and expert opinion sought to identify further publications.
RESULTS:
Eleven studies were included comprising ten case series and one prospective cohort study. All employed techniques to improve reliability. No safety issues were reported. The only comparative study included described a statistically significant improvement in post-operative visual field testing when VEP monitoring was used. The remaining case-series varied in conclusion. In nine studies, surgical manipulation was halted in the event of a VEP amplitude decrease suggesting a widespread consensus that this is a warning sign of injury to the anterior optic apparatus.
CONCLUSIONS:
Despite limited and low-quality published evidence regarding intra-operative VEP monitoring, our review suggests that it is a safe, reproducible, and increasingly effective technique of predicting postoperative visual deficits. Further studies specific to transsphenoidal surgery are required to determine its utility in protecting visual function in the resection of complex pituitary tumours
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MicroRNA-148a controls epidermal and hair follicle stem/progenitor cells by modulating the activities of Rock1 and Elf5
Skin and hair development is regulated by complex programs of gene activation and silencing and microRNA-dependent modulation of gene expression to maintain normal skin and hair follicle development, homeostasis, and cycling. In this study, we show that miR-148a, through its gene targets, plays an important role in regulating skin homeostasis and hair follicle cycling. RNA and protein analysis of miR-148a and its gene targets were analyzed using a combination of in vitro and in vivo experiments. We show that the expression of miR-148a markedly increases during telogen (bulge and hair germ stem cell compartments). Administration of antisense miR-148a inhibitor into mouse skin during the telogen phases of the postnatal hair cycle results in accelerated anagen development and altered stem cell activity in the skin. We also show that miR-148a can regulate colony-forming abilities of hair follicle bulge stem cells as well as control keratinocyte proliferation/differentiation processes. RNA and protein analysis revealed that miR-148a may control these processes by regulating the expression of Rock1 and Elf5 in vitro and in vivo. These data provide an important foundation for further analyses of miR-148a as a crucial regulator of these genes target in the skin and hair follicles and its importance in maintaining stem/progenitor cell functions during normal tissue homeostasis and regeneration
Effectiveness of an integrated diabetes care package at primary healthcare facilities: a cluster randomised trial in Pakistan
Background: There were an estimated 7 million people living with diabetes in Pakistan in 2014, and this is predicted to reach 11.4 million by 2030.
Aim: To assess if an integrated care package can achieve better control of diabetes.
Design & setting: The pragmatic cluster randomised controlled trial (cRCT) was conducted from December 2014–June 2016 at 14 primary healthcare facilities in Sargodha district. Opportunistic screening, diagnostic testing, and patient recording processes were introduced in both the control 'testing, treating, and recording' (TTR) arm, and the intervention 'additional case management' (ACM) arm, which also included a clinical care guide and pictorial flipbook for lifestyle education, associated clinician training, and mobile phone follow-up.
Method: Clinics were randomised on a 1:1 basis (sealed envelope lottery method) and 250 patients recruited in the ACM arm and 245 in the TTR-only arm (age ≥25 years and HbA1c >7%). The primary outcome was mean change in HbA1c (%) from baseline to 9-month follow-up. Patients and staff were not blinded.
Results: The primary outcome was available for n = 238/250 (95.2%) participants in the ACM arm and n = 219/245 (89.4%) participants in the TTR-only arm (all clusters). Cluster level mean outcome was -2.26 pp (95% confidence intervals [CI] = -2.99 to -1.53) for the ACM arm, and -1.44 pp (95% CI = -2.34 to -0.54) for the TTR-only arm. Cluster level mean ACM–TTR difference (covariate-unadjusted) was -0.82 pp (95% CI = -1.86 to 0.21; P = 0.11).
Conclusion: The ACM intervention in public healthcare facilities did not show a statistically significant effect on HbA1c reduction compared to the control (TTR-only) arm. Future evaluation should assess changes after a longer follow-up period, and minimal care enhancement in the comparator (control) arm
Contingency Analysis of a Power Grid with the Participation of Utility-Scale Solar PV Units: A Case Study from Sarawak, Malaysia
Integrating renewable energy resources (RER)
into the power grid may jeopardize the whole power system if the penetration level or solar PV uncertainty is not thoroughly managed. The critical impact on the behaviour of power system can be observed during the line outage in a power grid connected with large-scale RER. Therefore, contingency analysis (CA) is crucial to assess such hybrid power grid. This paper proposes a framework based on CA to assess the simultaneous effect of large-scale solar photovoltaic (PV) power plants integrated with the existing power grid, particularly, in the aspects of implementing effective measuring indices. Simulation studies have been carried out on a practical power system, which was modelled by considering the probability of solar irradiance at different locations in Sarawak. The study presented in this paper can provide an
insight to identify the level of insecurity for a large-scale deployment of solar PV systems in Sarawak
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