Showing papers by "University of Bahrain published in 2017"

An International Consortium Update: Pathophysiology, Diagnosis, and Treatment of Polycystic Ovarian Syndrome in Adolescence.

Abstract: This paper represents an international collaboration of paediatric endocrine and other societies (listed in the Appendix) under the International Consortium of Paediatric Endocrinology (ICPE) aiming to improve worldwide care of adolescent girls with polycystic ovary syndrome (PCOS)1. The manuscript examines pathophysiology and guidelines for the diagnosis and management of PCOS during adolescence. The complex pathophysiology of PCOS involves the interaction of genetic and epigenetic changes, primary ovarian abnormalities, neuroendocrine alterations, and endocrine and metabolic modifiers such as anti-Mullerian hormone, hyperinsulinemia, insulin resistance, adiposity, and adiponectin levels. Appropriate diagnosis of adolescent PCOS should include adequate and careful evaluation of symptoms, such as hirsutism, severe acne, and menstrual irregularities 2 years beyond menarche, and elevated androgen levels. Polycystic ovarian morphology on ultrasound without hyperandrogenism or menstrual irregularities should not be used to diagnose adolescent PCOS. Hyperinsulinemia, insulin resistance, and obesity may be present in adolescents with PCOS, but are not considered to be diagnostic criteria. Treatment of adolescent PCOS should include lifestyle intervention, local therapies, and medications. Insulin sensitizers like metformin and oral contraceptive pills provide short-term benefits on PCOS symptoms. There are limited data on anti-androgens and combined therapies showing additive/synergistic actions for adolescents. Reproductive aspects and transition should be taken into account when managing adolescents.

Hippocampal and prefrontal processing of network topology to simulate the future

Abstract: Topological networks lie at the heart of our cities and social milieu. However, it remains unclear how and when the brain processes topological structures to guide future behaviour during everyday life. Using fMRI in humans and a simulation of London (UK), here we show that, specifically when new streets are entered during navigation of the city, right posterior hippocampal activity indexes the change in the number of local topological connections available for future travel and right anterior hippocampal activity reflects global properties of the street entered. When forced detours require re-planning of the route to the goal, bilateral inferior lateral prefrontal activity scales with the planning demands of a breadth-first search of future paths. These results help shape models of how hippocampal and prefrontal regions support navigation, planning and future simulation.

Structural, Optical, and Magnetic Properties of Zn-Doped CoFe2O4 Nanoparticles.

Abstract: The effect of Zn-doping in CoFe2O4 nanoparticles (NPs) through chemical co-precipitation route was investigated in term of structural, optical, and magnetic properties. Both XRD and FTIR analyses confirm the formation of cubic spinel phase, where the crystallite size changes with Zn content from 46 to 77 nm. The Scherrer method, Williamson-Hall (W-H) analysis, and size-strain plot method (SSPM) were used to study of crystallite sizes. The TEM results were in good agreement with the results of the SSP method. SEM observations reveal agglomeration of fine spherical-like particles. The optical band gap energy determined from diffuse reflectance spectroscopy (DRS) varies increases from 1.17 to 1.3 eV. Magnetization field loops reveal a ferromagnetic behavior with lower hysteresis loop for higher Zn content. The magnetic properties are remarkably influenced with Zn doping; saturation magnetization (Ms) increases then decreases while both coercivity (HC) and remanent magnetization (Mr) decrease continuously, which was associated with preferential site occupancy and the change in particle size.

Enhanced anti-cancer and antimicrobial activities of curcumin nanoparticles.

Abstract: Background Curcumin (diferuloylmethane) is a polyphenol derived from the plant Curcuma longa, commonly called turmeric. Extensive research over the last 50 years has demonstrated that these polyphenols play an important role in the maintenance of health and prevention of diseases, in addition to its therapeutic benefits such as anti-tumor, anti-inflammatory, and anti-oxidant activities. Materials and methods This study is devoted to the enhancement of the solubility and bioavailability of curcumin nanoparticles prepared by a process based on a wet-milling technique and then examine in vitro against prostate cancer cell line 3 (PC3), human embryonic kidney cell line (HEK), human erythrocytes (red blood cells (RBCs)), and against fourth different bacterial strains two gram-positive (Micrococcus luteus ATCC 9341, Staphylococcus aureus ATCC 29213), two gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853). Results The cell viability curve, the half maximal inhibitory concentration (IC50), and the minimum bactericidal concentration (MBC) were evaluated. Nanocurcumin displayed significant activity against cancer cell line (PC3) and low toxicity against normal cells (HEK) compared with parent curcumin in favor of PC3 (P 0.05). On the other hand, the results demonstrate that, the MBCs of nanocurcumin were lower than curcumin for all different bacterial strains. Moreover, the selected gram-positive bacteria had higher sensitivity than the selected gram-negative bacteria for both curcumin and nanocurcumin. In conclusion, all these findings not only indicate that nanocurcumin safe compound has a potent ability as anti-cancer and antimicrobial activities, but also well justify the avail of using nanocurcumin as prostate cells PC3 anti-cancer, and antimicrobial agent for nanocurcumin are markedly improved by decreasing particle size to the nano-scale regime.

Toxicity effect of graphene oxide on growth and photosynthetic pigment of the marine alga Picochlorum sp. during different growth stages.

Abstract: Graphene oxide (GO), a recently discovered material, has been investigated for many applications in various fields. Thus, an immense awareness should be paid on the potential effects of the material on the environment as huge quantities of GO may get to the environment. Aquatic organisms, marine algae as an example, are exposed to such material when disposed to the environment. Accordingly, it is significant to assess the probable interactions of GO with algae in evaluating its possible environmental risks. In this study, we have examined the effect of different concentrations of GO on Picochlorum sp. during the different growth phases. The results showed that the toxicity of GO increases with increasing its concentration. The lowest concentration (0.5 mg L−1) was found to improve the algae growth and pigment content of Picochlorum sp. In contrast, higher GO concentrations had a negative consequence on the growth of algae and photosynthetic pigment concentration.

Nanostructured ZnO-based biosensor: DNA immobilization and hybridization

Abstract: An electrochemical DNA biosensor was successfully fabricated by using (3-aminopropyl) triethoxysilane (APTES) with zinc oxide (ZnO) nanorods synthesized using microwave-assisted chemical bath deposition method on thermally oxidized SiO2 thin films. The structural quality and morphology of the ZnO nanorods were determined by employing scanning electron microscopy (SEM) and X-ray diffraction (XRD), which show a hexagonal wurtzite structure with a preferred orientation along the (101) direction. The surface of the SiO2 thin films was chemically modified with ZnO. Label-free detection DNA immobilization and hybridization were performed using potassium hexacyanoferrate with cyclic voltammetry (CV) measurements. The capacitance, permittivity, and conductivity profiles of the fabricated sensor clearly indicate DNA immobilization and hybridization. Results show that the capacitance values of bare, ZnO- modified surface immobilization, and target DNA hybridization were 46 × 10− 12 F, 47 × 10− 8 F, 27 μF, and 17 μF, respectively, at 1 Hz. The permittivity measurement increased from 3.94 × 103 to 251 × 103 and 165 × 103 at the frequency range of approximately 200 to 1 Hz for bare and DNA immobilization and hybridization, respectively. The measured conductivity values for the bare, ZnO, immobilized, and hybridization device were 2.4 × 10− 9, 10 × 10− 8, 1.6 × 10− 7, and 1.3 × 10− 7 S cm− 1, respectively.

Effect of growth time on Ti-doped ZnO nanorods prepared by low-temperature chemical bath deposition.

Abstract: Ti-doped ZnO nanorod arrays were grown onto Si substrate using chemical bath deposition (CBD) method at 93 °C. To investigate the effect of time deposition on the morphological, and structural properties, four Ti-doped ZnO samples were prepared at various deposition periods of time (2, 3.5, 5, and 6.5 h). FESEM images displayed high-quality and uniform nanorods with a mean length strongly dependent upon deposition time; i.e. it increases for prolonged growth time. Additionally, EFTEM images reveal a strong erosion on the lateral side for the sample prepared for 6.5 h as compared to 5 h. This might be attributed to the dissolution reaction of ZnO with for prolonged growth time. XRD analysis confirms the formation of a hexagonal wurtzite-type structure for all samples with a preferred growth orientation along the c-axis direction. The (100) peak intensity was enhanced and then quenched, which might be the result of an erosion on the lateral side of nanorods as seen in EFTEM. This study confirms the important role of growth time on the morphological features of Ti-doped ZnO nanorods prepared using CBD.

The psychometric properties of an Arabic version of the Personality Inventory for DSM-5 (PID-5) across three Arabic-speaking Middle Eastern countries

Abstract: The nature and extent of the influence of culture on psychopathology have long been studied, with a central emphasis on whether abnormal behavior is etic (universalized) or emic (cultural based). This study aimed to examine the psychometric properties (factorial structure, inter-correlations, reliability, and criterion validity) of an Arabic translation of the Personality Inventory for DSM-5 across three Arabic-speaking countries (Bahrain, Kuwait, and Qatar; N = 710). The results of first-order 25-factor CFAs indicated generally acceptable to good fit for the Arabic version of the PID-5. In addition, the results of higher-order five factors CFAs (using the five domains) indicated a generally acceptable fit. Furthermore, the 25 facets of the PID-5 had moderate to high reliability using Cronbach’s alpha. Finally, the five domains of the PID-5 had strong inter-correlations and expected associations with the FFM model of personality. Therefore, this study replicated the adequate psychometric propertie...

Audit Committee Characteristics and Earnings Management: The Case of Bahrain

Abstract: This study examines the effectiveness of some a udit committee ( AC) characteristics to monitor management behavior with the respect to their incentives to manage earnings. Bahraini listed companies on Bahrain Bursa for the year 2012 to 2014 have been investigated to analyze the relationship between AC characteristics and earnings management. The AC characteristics examined are AC independence, AC size, AC meetings and AC financial experts. M ultivariate regression model is used to examine the relationship between earnings management as dependent variable and AC characteristics as independent variables and other firm-specific attributes, as control variables. As a small developing market, Bahrain’s unique business environment and context offer a good opportunity and provides a useful setting for examining the effectiveness of AC characteristics in detecting and preventing earnings management practices. The results show that discretionary accruals as a proxy for earnings management is negatively associated with AC size and AC financial experts, but positively associated audit firm size as control variable. However, the results do not show a significant relationship between AC independence, AC meetings, company size, leverage and earnings management. This study extends the literature on the monitoring function of the AC on earnings management, and contributes geographically to the financial reporting process and earnings management literatures by analyzing data from an emerging market and providing useful information for the corporations, accounting profession and the regulators on the effective practice of ACs.

Complexity of Cyber Security Architecture for IoT Healthcare Industry: A Comparative Study

Abstract: In recent years a wide range of wearable IoT healthcare applications have been developed and deployed. The rapid increase in wearable devices allows the transfer of patient personal information between different devices, at the same time personal health and wellness information of patients can be tracked and attacked. There are many techniques that are used for protecting patient information in medical and wearable devices. In this research a comparative study of the complexity for cyber security architecture and its application in IoT healthcare industry has been carried out. The objective of the study is for protecting healthcare industry from cyber attacks focusing on IoT based healthcare devices. The design has been implemented on Xilinx Zynq-7000, targeting XC7Z030 - 3fbg676 FPGA device.

Structural and magnetic properties and DFT analysis of ZnO:(Al,Er) nanoparticles

Abstract: The structural, optical and electrical properties of un-doped and (Al,Er) co-doped zinc oxide (ZnO) powders synthesized by hydrothermal method were investigated. The obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive spectroscopy and magnetic measurements. XRD results reveal that the incorporation of Al and Er in ZnO matrix leads to the formation of a nanostructured hexagonal (wurtzite) ZnO structure and α-Al2O3 secondary phase. High-resolution transmission electron microscopy image also shows the hexagonal shape of the ZnO nanoparticles. The magnetic behavior of the nanoparticles changes with concentration of dopant elements due to the competition between oxygen vacancies, secondary phase effect and exchange interaction between dopant elements.

A Green approach: synthesis, characterization and opto-magnetic properties of MgxMn1−xFe2O4 spinel nanoparticles

Abstract: MnFe2O4 nanoparticles of different crystallite size were prepared by varying the different concentrations of Mg2+ dopant ions using microwave assisted combustion method. The structural properties of the ferrite and modified ferrite were characterized by XRD (X-ray powder diffraction), Rietveld analysis, FT-IR (Fourier transforms infra red spectroscopy), HR-SEM (high resolution scanning electron microscopy), UV–Visible spectroscopy, PL (photoluminescence spectroscopy), and VSM (vibrating sample magnetometer). The concentration of the dopant metal ions plays an important role in phase, purity, morphology, optical and magnetic properties. X-ray diffraction and the HR-SEM analysis indicate that all the samples are single phase, crystalline and homogeneous in nature. The presence of metal oxides is confirmed by FT-IR analysis. The band gap energy of the samples has been studied using UV–Visible DRS measurements and the effect of Mg2+ doping on absorption spectra is also investigated. The band gap energy of the sample decreases with increasing the concentration of the dopant ions. The PL spectrum shows the emission peak at 565 nm with an excitation wavelength of 414 nm. The considerable decrease in saturation magnetization and increase in the coercivity value is determined using vibrating sample magnetometer.

Examination of factors influencing students and faculty behavior towards m-learning acceptance: An empirical study

Abstract: Purpose Mobile learning is a unique form of learning which uses the distinct features of mobile devices. The purpose of this paper is to investigate the present state of student and faculty perception towards m-learning at open and distance educational institutes in Pakistan. Design/methodology/approach The paper presents a conceptual model based on TAM, which explains factors influencing student and faculty perception towards m-learning acceptance. M-learning acceptance mainly depends on personal attitude, so this study focusses on individual context. Primary data from students and faculty including tutors (n=612, students =448, faculty/tutors=162) was collected through a properly designed questionnaire by using purposive convenient sampling technique during Autumn 2015 semester. Structural equation modelling was used to analyse the collected data. Findings The results indicate that student and faculty skill readiness and self-efficacy influence perceived ease of use and perceived usefulness, where these two factors along with prior experience positively influence behavioural intension (BI) to accept mobile learning. Furthermore study results specifically provide factors which positively influence BI either directly or indirectly. Research limitations/implications The study was limited to AIOU. Originality/value The study specifically provides factors which influence BI either directly or indirectly.

Assessment of spatial variations of particulate matter (PM10 and PM2.5) in Bahrain identified by air quality index (AQI)

Abstract: The rapid urbanization, industrialization, modernization, and the frequent Middle Eastern dust storms have negatively impacted the ambient air quality in Bahrain. The objective of this study is to identify the most critical atmospheric air pollutants with emphasis on their potential risk to health based on calculated AQI (air quality index) values using EPA approach. The air quality datasets of particulate matters (PM10 and PM2.5), ozone (O3), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) were measured in January 2012 and August 2012 using five mobile air quality monitoring stations located at different governorates. The results of this study demonstrated that PM10 and PM2.5 are the most critical air pollutants in Bahrain with PM2.5 prevailing during January 2012 and PM10 prevailing during August 2012. The corresponding AQI categories were utilized to evaluate spatial variability of particulate matters in five governorates. The impact of meteorological factors such as ambient air temperature, wind speed, relative humidity, and total precipitation on ambient air quality were discussed. The analysis demonstrated that the highest PM10 concentrations were observed in the Northern Governorate while the highest PM2.5 concentrations were observed in the Capital, Central, and Northern Governorates during August 2012. It was observed that the levels of PM2.5 pollution were higher within proximity of the industrial zone. The results suggested that the average PM2.5/PM10 ratio in August 2012 was lower than in January 2012 due to the Aeolian processes. This study concludes that higher wind speed, total precipitation, relative humidity rates, and lower ambient air temperature in January 2012 assisted with the dissipation of particulate matter thus lowering the pollution levels of both PM10 and PM2.5 in comparison to August 2012.

The impact of indexing approaches on Arabic text classification

Abstract: This paper investigates the impact of using different indexing approaches full-word, stem, and root when classifying Arabic text. In this study, the naive Bayes classifier is used to construct the multinomial classification models and is evaluated using stratified k-fold cross-validation k ranges from 2 to 10. It is also uses a corpus that consists of 1000 normalized Arabic documents. The results of one experiment in this study show that significant accuracy improvements have occurred when the full-word form is used in most k-folds. Further experiments show that the classifier has achieved the highest accuracy in the eight-fold by using 7/8-1/8 train-test ratio, despite the indexing approach being used. The overall results of this study show that the classifier has achieved the maximum micro-average accuracy 99.36%, either by using the full-word form or the stem form. This proves that the stem is a better choice to use when classifying Arabic text, because it makes the corpus dataset smaller and this will enhance both the processing time and storage utilization, and achieve the highest level of accuracy.