512 research outputs found
Psychometric Properties of an Instrument Developed to Assess Students’ Evaluation of Teaching in Higher Education
Student evaluation of teaching is a global predominant practice in higher education institutions. Therefore, a major university in Jordan developed a questionnaire for students’ use in evaluating their instructors’ teaching effectiveness. Since student evaluation of teaching is an important process, the present study tried to examine the psychometric properties of the instrument. Item-total correlations showed acceptable internal consistency. In addition, a two-factor structure of the scale (teaching effectiveness and course attributes) was supported by exploratory factor analysis and confirmatory factor analysis from two independent samples. Convergent validity was supported by a moderate correlation coefficient between course averages of students’ ratings on the first factor and course averages of students’ final grades in each course. Finally, students’ responses on the factor that captures teaching effectiveness were found to have very high internal consistency (Cronbach’s alpha of 0.96). However, this instrument lacks evidences of content validity and convergent validity. Therefore, it is important to be cautious in evaluating faculty members and making promotion decisions that is based solely on the scores obtained using this instrument.
Monitoring spindle orientation: Spindle position checkpoint in charge
Every cell division in budding yeast is inherently asymmetric and counts on the correct positioning of the mitotic spindle along the mother-daughter polarity axis for faithful chromosome segregation. A surveillance mechanism named the spindle position checkpoint (SPOC), monitors the orientation of the mitotic spindle and prevents cells from exiting mitosis when the spindle fails to align along the mother-daughter axis. SPOC is essential for maintenance of ploidy in budding yeast and similar mechanisms might exist in higher eukaryotes to ensure faithful asymmetric cell division. Here, we review the current model of SPOC activation and highlight the importance of protein localization and phosphorylation for SPOC function
A stochastic Model for Predicting Irrigation Water Requirements (IWR)
The main objective of this paper is to develop a stochastic time series model with trend, periodic and irregular components using a ten years IWR decade data for three different types of cotton crops cultivated in Gezira Scheme, SUDAN. The model was applied to cotton Brackat and then used to Shmbat & Akala cotton. In the analysis of IWR time series the correlogram technique was used to detect the periodicity which then smoothed by Fourier series method. The series is then tested for stationary and the dependent part of irregular component is found to be well expressed by the first order autoregressive model for all the crops. The developed model superimposes a periodic-deterministic process and an irregular componen
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Studying location privacy in mobile applications: 'predator vs. prey' probes
Assessment of Air Pollutants Emissions from a Cement Plant: A Case Study in Jordan
This paper presents predictions of air pollutants (dust, SO2, NOx and CO) emitted from a cement plant that will be constructed in Wadi Alabyad area located about 100 km south of Amman, Jordan. The Gaussian air pollution model is used and the predicted concentrations of the air pollutants are compared with the Jordanian air quality standards (JS 1140/2006). It is found that the month of September represents the worst-case scenario where the atmospheric stability condition is classified as A and the average wind speed is 1.7 m/s. The predicted SO2 hourly and the 24-hour concentrations -when using fuel oil- reached 0.8 ppm and 0.42 ppm, consequently, at a distance of 750 m from the plant, which exceed the standard values of 0.3 ppm and 0.14 pmm, consequently. In case of natural gas as source of energy, the SO2 concentration is predicted to be negligible. The hourly concentration of NOx is 0.32 ppm at a distance of 750 m from the plant exceeding the standard limit of 0.21 ppm. It is found that the maximum TSP 24-hour concentration will be expected to reach 359.61 μg/m3 exceeding the standard value of 260 μg/m3. The TSP, PM10 and PM2.5 concentrations exceeded the values set by the standard near the vicinity of the cement plant at a distance closer than 300 m. The proposed mitigation measures should limit the ambient air pollutant concentrations to be in compliance with the standard values
Clinical and computed tomographic evaluation of portland cement pulpotomy in primary molar: A case report
The present case describes the clinical & radiographic outcome of a Portland Cement pulpotomy. The 5 years old girl presenting extensive carious exposure in her mandibular left 2nd deciduous molar and was suffering pain in her left lower jaw only on exposure to cold for last 2 days. She was ultimately diagnosed clinic-radio-graphically as a case of irreversible pulpitis. Coronal pulpotomy procedure was carried out in the responsible tooth and Portland cement (PC) was applied as a medicament after pulpotomy. At the 3 & 6-months follow-up appointments, treated tooth was asymptomatic clinically and radiographic examinations revealed no sign of periradicular pathosis in the pulpotomized teeth. Additionally, the formation of a dentin bridge immediately below the PC in the treated tooth was confirmed by RVG and CBCT
Antimicrobial activity of bBanana (Musa paradisiaca L.) peels against food borne pathogenic microbes
Banana (Musa paradisiaca L.) peels are usually considered as wastes and are
discarded during the processing, which eventually contribute to polluting the
environment. Hence, this study was aimed to evaluate the antimicrobial activity of two
different varieties of M. paradisiaca peels, i.e., Nangka (M. paradisiaca variety Nangka)
and Tanduk (M. paradisiaca variety Tanduk) with regard to generate safe and cheap
antimicrobials as well as address pollution related issues due to such wastes.
Antimicrobial study was carried out on the extracts using disc diffusion and broth
micro-dilution methods. The best activity through disc diffusion method for bacteria
and fungi was demonstrated by Tanduk peel’s ethanol and dichloromethane extracts
against S. aureus (30 mm) and C. krusei (10 mm), respectively. However, the least active
bacteria and fungi were found to be V. parahaemolyticus and C. albicans, respectively.
The minimum inhibitory concentration (MIC) values ranged from 6.25 to 100 mg/mL.
Tanduk peel’s ethanol extract exhibited the lowest MIC and minimum bactericidal
concentration (MBC) values against B. cepacia (6.25 mg/mL) whereas for fungi, Tanduk
peel’s dichloromethane extract exhibited lowest MIC and minimum fungicidal
concentration (MFC) values against C. albicans (25 mg/mL). The results of MBC or MFC
showed that some extracts were bactericidal or fungicidal while others were bacteriostatic
or fungistatic against certain microbes. Banana peel waste’s extracts could be potential
antimicrobial alternatives and may be effective to utilize as a natural source of
antimicrobial agent in pharmaceutical industries.
Key words: Musa paradisiaca L., Nangka, Tanduk, Antimicrobial activity, MIC, MBC, MFC
Adaptive sharing for online social networks: a trade-off between privacy risk and social benefit
Online social networks such as Facebook allow users to control which friend sees what information, but it can be a laborious process for users to specify every receiver for each piece of information they share. Therefore, users usually group their friends into social circles, and select the most appropriate social circle to share particular information with. However, social circles are not formed for setting privacy policies, and even the most appropriate social circle still cannot adapt to the changes of users’ privacy requirements influenced by the changes in context. This problem drives the need for better privacy control which can adaptively filter the members in a selected social circle to satisfy users’ requirements while maintaining users’ social needs. To enable such adaptive sharing, this paper proposes a utility-based trade-off framework that models users’ concerns (i.e. potential privacy risks) and incentives of sharing (i.e. potential social benefits), and quantifies users’ requirements as a trade- off between these two types of utilities. By balancing these two metrics, our framework suggests a subset of a selected circle that aims to maximise users’ overall utility of sharing. Numerical simulation results compare the outcome of three sharing strategies in randomly changing contexts
Solubility and Dissolution Enhancement of Atorvastatin Calcium using Phospholipid Solid Dispersion Technique
Atorvastatin (ATR) is a poorly water-soluble anti-hyperlipidemic drug. The drug belongs to the class II group according to the biopharmaceutical classification system (BCS) with low bioavailability due to its low solubility. Solid dispersion is an effective technique for enhancing the solubility and dissolution of drugs. Phospholipid solid dispersion (PSD) using phosphatidylcholine (PC) as a carrier with or without adsorbent (magnesium aluminum silicate, silicon dioxide 15nm, silicon dioxide 30nm, calcium silicate) was used to prepare ATR PSD using different drug: PC: adsorbent ratios by solvent evaporation method. The resulted PSD was evaluated for its percentage yield, drug content, solubility, dissolution rate, Fourier transformation infrared spectroscopy (FTIR), powder X-ray diffraction study (PXRD), and differential scanning calorimetry (DSC). The prepared (PSD) showed improvement in drug solubility in all prepared formulas. The best result was obtained with F5 (ATR: PC: MAS 1:3:4). The solubility was increased by 21 folds compared to the pure drug with enhanced dissolution and decrease crystallinity
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