Chemical constituents of Pandanus species / Hannis Fadzillah Mohsin

The Pandanus (family: Pandanaceae) are Asia Pacific plants with approximately 800 species. They are used traditionally for various purposes. Researchers investigate the medicinal values of these plants and interestingly, they provide scientific evidences showing that the plant extracts exhibited biopharmaceutical properties. Thus, this study aims to investigate the plant concerning the phytochemical aspect through its chromatographic profile and analysis using spectroscopy, crystallography and microscopy. This study was conducted on six locally available Pandanus species, namely P. pygmaeus, P. sanderi, P. tectorius, P. dubius, P. conoideus and P. amaryllifolius. Out of these species, only P. amaryllifolius was studied by Malaysian scientists. Meanwhile, three other species (P. tectorius, P. dubius and P. conoideus) were examined by the Philippines and Indonesian counterparts. This work was also emphasized on another two pandans (P. pygmaeus and P. sanderi), which have never been studied before. Thus, the samples were extracted in relatively small scale (less than one kilogram) and the solvents were recycled during the crude extraction. The extractions were based on both acid base and normal procedures, depending upon the targeted compounds. As for the fractionation and isolation, a range of chromatographic techniques were performed such as Silica Gel Column Chromatography (SGCC), preparative Thin Layer Chromatography (TLC), both normal and reverse phase medium, plus high performance liquid chromatographies (HPLC), utilizing ultraviolet detector. Nearly ninety moieties were successfully separated, exclusively based on the HPLC chromatograms. The identification and characterization of pure substituents were accomplished by using the standard Nuclear Magnetic Resonance (NMR) spectroscopic analysis, Time-of-Flight Liquid Chromatography-Mass Spectrometry (TOF LC-MS) and X-ray crystallography of pure crystals. However, merely seven chemical entities were fully recognized from this Pandanus study. Three molecules from P. pygmaeus consist of stigmasterol, lignan and a novel pandan alkaloid, practically called as Pygmaeusamine. Two compounds from P. sanderi include one saponin (lanostane-type) and saponoside (b-sitosterol glucoside), respectively. Initial discovery included a compound which was comparable to a tirucallane-type triterpene. However, after a detailed inspection from the X-ray crystallography asessment, it was revealed that the compound has a different carbon skeleton from previously isolated triterpene from Pandanus species and was classified as a lanostane-type triterpene. In the case of P. tectorius, two chemical components were known as a steroid alkaloid and an esterified triterpenoid. Meanwhile, the root of P. amaryllifolius possibly contains the same alkaloid as found in P. tectorius. Still, the isolated moieties from P. dubius and P. conoideus were partially elucidated and cannot be completely characterized due to the insufficient amount of pure samples. In addition, the microscopic analysis revealed the presence of raphide-type crystals of calcium oxalate. In short, this is the first documented occurrence of novel Pandanus alkaloid, steroid alkaloid and saponoside from Pandanus

OSH In School pupuk kesedaran pelajar tentang keselamatan dan kesihatan

Pejabat Pengurusan Keselamatan dan Kesihatan Pekerjaan (OSHMO), Universiti Malaysia Pahang (UMP) mengadakan program kerjasama dengan Sekolah Menengah Sains Sultan Haji Ahmad Shah (SEMSAS) Kuantan dalam OSH in School bagi berkongsi ilmu berkaitan kesedaran keselamatan dan kesihatan pekerjaan (KKK) pada 27 Ogos 2016 yang lalu

Gender and body side differences of glenoid morphometry

Background: Glenoid cavity orientation is crucial for the biomechanics of the glenohumeral joint. Reproducible data of the exact orientation and positioning of the glenoid cavity is important to evaluate various shoulder conditions. It is also useful as proper preoperative planning prior to replacement procedure and to minimize unfavourable implications of prosthetic failure. Among possible complications include prosthesis loosening, glenohumeral instability, tears of the rotator cuff, periprosthetic fracture, infection, neural injury, and dysfunction of the deltoid. The important parameters of glenoid morphometry are glenoid length, width, glenoid version and glenoid inclination. Aim of study: The aims of this study were to use multiplanar reconstructed CT images as the modality to determine the normal glenoid morphology among patients who underwent CT thorax in Hospital Universiti Sains Malaysia, to compare side and gender differences. Methods and Materials: This study was a cross sectional study. A total of 88 CT thorax were analyzed from 2009 to 2014 for non orthopaedic indications in Department of Radiology, Hospital Universiti Sains Malaysia (HUSM), Kubang Kerian, Kelantan. Results: A total of 176 glenoid cavities were measured. The mean glenoid length in male were 4.03cm (SD 0.28) and in female 3.45cm (SD 0.27). The mean for the glenoid width in male were 2.25cm (SD 0.23) and in female 1.95cm (SD 0.23).. The average glenoid version angle in male was 4.25 (SD 4.20) and in female was 4.97 (SD 5.41). The average glenoid inclination in male was 11.4 (SD 3.55) and in female was 8.77 (SD 4.26). There was significant difference in glenoid length and glenoid inclination between right and left scapula. However no significant difference observed in glenoid width and glenoid version between two sides. Significant difference also noted in mean value of glenoid dimension and glenoid inclination between male and female. However no significant difference reported in glenoid version of different gender. Conclusion: The dimensions of the glenoid observed in the present study were different from other studies done on other populations. The difference was found in glenoid length and inclination between right and left scapula. The glenoid dimension and inclination are significantly larger in male than female

Integral Backstepping Control for Stabilizing an Underactuated X4-AUV

Autonomous Underwater vehicles (AUV) is one of an unmanned underwater vehicle (UUV) that work independently and can be control automatically on board without requiring a cable. The autonomous capability has great important tasks due to navigate in abyss zones and dangerous underwater mission. However, in order to stabilize the system consists of four control inputs and six degree of freedoms (DOFs) is difficult tasks because of the nonlinear dynamic and model uncertainties. This paper presents the stabilization of underactuated X4-AUV using nonlinear control techniques, integral backstepping. The key idea of integral backstepping is to design a virtual controller for each subsystem by associate with integral of tracking error. The effectiveness of the proposed control technique demonstrates by simulation

Influence of internal heat source on double-diffusive Soret induced convection in a binary fluid

The neutral convection in a double-diffusive fluid layer subject to the internal heat source (internal heating) and thermodiffusion or also known as Soret effect is studied analytically. The influence of the internal heating is supplied by an internal volumetric source with a uniform distribution. Results show that the presence of internal heating in the binary fluid layer which is fluid layer heated and salted has a significant influence on the neutral convection where increasing the internal heating will destabilize the fluid system. Despite the destabilizing factor, an increase of the Solutal Rayleigh number spikes the critical Rayleigh number and thus ensures greater stability of the system. The instability gets fluctuate depending on values of Soret parameter in the presence of internal heating

Stabilization of convective instability in micropolar fluid model by feedback control strategy subjected to internal heat source

This investigation reports on a stability analysis of Rayleigh-Benard convection in a horizontal of micropolar fluid layer heated from below. The effect of a feedback control strategy on the onset of steady convection in the presence of internal heat source is investigated theoretically using Galerkin technique. The eigenvalues are obtained for free-free, rigid-rigid, free-rigid boundary combination with isothermal temperature boundary condition. The influence of various micropolar parameters on the onset of convection has also been analyzed. The onset of motion is found to depend on the feedback control parameter, K and internal heat source, Q and the micropolar parameter Ni

Convection on binary fluid with cross diffusive coefficients and vertical magnetic field

This study deals theoretically with the effect of cross diffusion coefficients viz., Soret and Dufour effects subjected to uniform vertical magnetic field on the onset of stationary convection in a horizontal layer of binary fluid model. The upper surface of a binary fluid layer is non-deformable and the lower surface is assumed to be rigid and heated from below. In this investigation, the bounding system of the model are considered to be rigid-rigid and free-rigid which described the upper and free surfaces of the model. The eigenvalue equations of the perturbed state obtained from the normal mode analysis are solved by using the Galerkin method. The influences of magnetic field and cross diffusion parameter in binary fluid model are analyzed on the onset of convection. The results show that the effect of increasing the magnetic field strength is always to stabilize the binary fluid model although the onset of convection gets advanced when the Soret parameter is increase

Empirical evidence on examining the performance of accounting major / Nor Syafinaz Shaffee, Dr Normah Ahmad and Fazni Mohd Fadzillah

Students' performance in Costing 1 (MAF220) had been fluctuating. The failure rate frequently exceed the required standard of the Faculty of Accountancy where the failure rate should be less than 20%. Thus, a study was carried out to explore the characteristics of students taking up Costing 1 (MAF220) at UiTM (Perlis). Questionnaires were distributed to final year students of April 2010. Attributes set in the questionnaire were based on the previous researches whom had associated personal attribute, intention, prior exposure, disruption and gender differences for the cause of variation in students' performance. This study has found that students' performances and attrbutes influence their intention to further their study in cost-related studies (CIMA). Further study should look into how significant the attributes could influence the performance of students in MAF220 and thus, could teachercentred or student-centred learning be implemented

Analisis Pengaruh Biaya Reparasi, Biaya Penyusutan, dan Biaya Pemasaran Terhadap Kinerja Keuangan PT. Telekomunikasi Indonesia ( TELKOM )

Each company seeks to optimally achieve their planned goals, both short-term goals and long-term goals. In the activities of the company, all parts such as marketing, operations, human resources, and finance will be a unity of work that must support each other in the process of achieving goals, both social and economic. The purpose of writing this thesis is to determine the effect of reparation costs, depreciation costs, and marketing costs in PT. Telkom finance. Population of this study is the data budget operational costs and income statement data obtained from PT. Telekomunikasi Indonesia Tbk in 2012 until 2016, with purposive sampling sampling technique hence obtained sample of this research is financial report from year 2012 until 2016. Analyze used in this research is classical assumption test, multiple linear regression analysis, hypothesis testing, and coefficient of determination. Based on the results of the study and discussion can be made the following conclusions: (1) The cost of reparation has a positive but insignificant effect on your performance, (2) Depreciation Cost has positive but not significant impact on financial performance, and (3) Marketing Cost has positive and significant effect to financial performance

The stability of soret induced convection in doubly diffusive fluid layer with feedback control

Linear stability analysis is performed to study the Soret induced convection in a doubly diffusive fluid layer heated from below. The effect of a feedback control on the onset of steady convection is investigated theoretically using Galerkin technique. The eigenvalues are obtained for Free-Free, Rigid-Rigid, Rigid-Free boundaries combined with isothermal temperature boundary condition. The influence of various doubly diffusive parameters on the onset of convection has also been analyzed. It is found that the onset of motion can be stabilized by using the feedback control in all cases