Resampling the peak, some dos and don'ts

Resampling techniques are used widely within the ERP community to assess statistical significance and especially in the deception detection literature. Here, we argue that because of statistical bias, bootstrap should not be used in combination with methods like peak-to-peak. Instead, permutation tests provide a more appropriate alternative

An investigation into university teachers’ and students' perceptions of problem solving in physics in higher education in Saudi Arabia

This study was conducted to investigate university teachers’ and students' perceptions of problem solving in physics in higher education in Saudi Arabia. The current study took into consideration the sociocultural notion that context is an important contributor to the learning process and impacts on the interaction between people. This study focused on aspects of the context, such as community, school, university, language, syllabus and classroom practices, that influence students’ learning of problem-solving in physics. An explanatory sequential mixed methods approach was used to collect data using two questionnaires (the Force Concept Inventory test and the Mechanics Base Line Test), semi-structured interviews, classroom observations and think aloud protocols. The study sample consisted of 31 participants in total, including ten preparatory-year students, eleven first-year students, five preparatory-year teachers and five first-year teachers. The findings revealed that students found difficulty in understanding problems; they did not seem to know how to implement the steps of problem-solving (understanding the problem, devising the plan, carrying out the plan and looking back). Moreover, this study revealed that a number of social and cultural aspects played an essential role in influencing these students’ learning of problem-solving in physics. The study also revealed that students were fearful of asking their teachers questions when they did not understand. Likewise, this study emphasised the important role of providing a safe classroom environment to create social interaction between students and their teachers, and between students themselves, in order to enable students to think and access assistance to their performance, whether from their teacher or peers. Subsequently, this assistance improved students’ understanding in physics lectures and their understanding of physics problems. Also, the study highlighted that a number of linguistic issues, such as the teacher’s dialect or the use of English as medium of instruction, were an obstacle to students’ understanding of mechanics problems, thereby causing an additional cognitive burden. In addition, this study found that students seemed not to have the opportunity to get assistance, such as in the form of feedback or questioning from their teachers, due to the huge number of students in the class, which prevented teachers from guiding students’ thinking while solving physics problems. It was also found that students’ comprehension of Newtonian concepts was inadequate for successful problem-solving due to a lack of basic physics knowledge

Metabolite profiling of the chemosphere of the macroalga ulva (ulvales, chlorophyta) and its associated bacteria

The eukaryotic green marine algae Ulva spp. (Chlorophyta), are usually associated with marine bacteria and exhibit therefore microbe-dependent growth and morphotypes. Ulva spp. might actively affect their microbiome by releasing specific compounds in its chemosphere. For instance, algal oxylipins including polyunsaturated aldehydes (PUAs) derived from polyunsaturated acids (PUFAs) might play an important structuring role for the microbiome. In the present study, Ulva spp. collected at various sampling sites in the lagoon of the Ria Formosa (Portugal) have been studied with respect to (1) their ability to produce polyunsaturated aldehydes and (2) their ability to communicate with their surrounding bacteria via infochemicals. Lipoxygenase/hydroperoxidelyase mediated transformations convert polyunsaturated fatty acids into various oxylipins. These fatty acid transformations are highly diverse in marine algae and play a crucial role in e.g., signaling, chemical defense, and stress response often mediated through polyunsaturated aldehydes (PUAs). In this study, Ulva spp. were surveyed for PUAs. Ulva species with sea-lettuce like morphotype were demonstrated to produce elevated amounts of volatile C10-polyunsaturated aldehydes (2,4,7-decatrienal and 2,4-decadienal) upon tissue damage in contrast to Ulva species with tube-like morphotype. Moreover, morphogenetic and phylogenetic analyses of the collected Ulva species revealed chemotaxonomic significance of the perspective biosynthetic pathways. The aldehydes are derived from omega-3 and omega-6 polyunsaturated fatty acids (PUFA) with 20 or 18 carbon atoms including eicosapentaenoic acid (C20:5 n-3), arachidonic acid (C20:4 n-6), stearidonic acid (C18:4 n-3), and gamma-linolenic acid (C18:3 n-6). As first evidences in this study, it was found that lipoxygenase-mediated (11-LOX and 9-LOX) eicosanoid and octadecanoid pathways catalyze the transformation of C20- and C18-polyunsaturated fatty acids into PUAs and concomitantly into short chain hydroxylated fatty acids. Ulva mutabilis Føyn (sl) with tube-like morphotype was used as an objective to investigate the chemical mediated interaction (infochemicals) within the chemosphere of tripartite community consisting of U. mutabilis and its associated marine bacteria i.e., Roseobacter and Cytophaga species. In the absence of these bacteria (axenic conditions), U. mutabilis forms callus-like colonies. However, the combination of the two bacterial strains, Roseobacter sp. and Cytophaga sp. can completely restore the morphogenesis of U. mutabilis forming a symbiotic tripartite community. The exo-metabolome of the chemosphere of this tripartite community was surveyed along with the biological metadata. Two different approaches and cultivation conditions i.e., sterile 25 L bioreactor cultures and non-sterile 200 L outdoor aquacultures were conducted which cultures were inoculated with axenic seven days old germlings. Indeed, it was feasible to observe the whole life cycle of the gametophyte under these conditions when the appropriate bacteria were inoculated as well. Hereby, the medium did not need to be changed. Bioassays revealed that U. mutabilis passed through three statuses of gametogenesis inducibility which can be distinguished whether Ulva is able to onset the gametogenesis: (1) gametogenesis is not inducible, (2) gametogenesis can be induced or (3) it starts even spontaneously. The nutrient depletion over the reproductive cycle shows that the utilization rate of nitrate as a limiting growth factor was significantly high during the inducible status, when the macroalgae was growing. The waterborne metabolites were extracted by solid phase extraction. The samples were directly analyzed by ultra-high performance liquid chromatography (UHPLC) and by gas chromatography (after derivatization) coupled with a time-of-flight mass spectrometer (TOF-MS). Interestingly, discriminant analysis proofed that all waterborne metabolites obtained either from GC-MS or LC-MS were corresponding to the inducibility status of gametogenesis of U. mutabilis in both cultivation conditions. Even more interesting, many unknown biomarkers were found to be common in both bioreactor cultures and aquaculture, insuring the high probability of using these biomarkers as indicators to determine the growth phases corresponding to the status of gametogenesis inducibility in U. mutabilis under any cultivation condition in future land based aquacultures. Moreover, the present study revealed remarkable metabolic fingerprints which might due to the adaptation of U. mutabilis to changes in its surrounding environment. For instance, the algal biomarker 2,4,6-tribromophenol was detected in the chemosphere of the tripartite community under sterile cultivation (bioreactor) but not in the well-defined bacterial community under non-sterile cultivation (aquaculture). In summary, the changes of the metabolite profile between the growth phases were significant. Therefore, various statues in algal growth and life cycle can be predicted based on the dynamics of waterborne metabolites. This knowledge will be essential in order to maintain land based aquacultures providing economical relevant amounts of biomasses

The cost of space independence in P300-BCI spellers.

Background: Though non-invasive EEG-based Brain Computer Interfaces (BCI) have been researched extensively over the last two decades, most designs require control of spatial attention and/or gaze on the part of the user. Methods: In healthy adults, we compared the offline performance of a space-independent P300-based BCI for spelling words using Rapid Serial Visual Presentation (RSVP), to the well-known space-dependent Matrix P300 speller. Results: EEG classifiability with the RSVP speller was as good as with the Matrix speller. While the Matrix speller’s performance was significantly reliant on early, gaze-dependent Visual Evoked Potentials (VEPs), the RSVP speller depended only on the space-independent P300b. However, there was a cost to true spatial independence: the RSVP speller was less efficient in terms of spelling speed. Conclusions: The advantage of space independence in the RSVP speller was concomitant with a marked reduction in spelling efficiency. Nevertheless, with key improvements to the RSVP design, truly space-independent BCIs could approach efficiencies on par with the Matrix speller. With sufficiently high letter spelling rates fused with predictive language modelling, they would be viable for potential applications with patients unable to direct overt visual gaze or covert attentional focus

Are Humans Safe in Public Places? Expansion of Protection Motivation Theory in the Gulf Cooperation Council Countries

Objectives: People regularly face safety threats that are often ignored in day to day life. The knowledge and understanding of the risks posed through unhealthy activities are essential. This realization can change behavior in ways that are effective in mitigating risk. The study aimed to determine the importance of protection motivation theory in studies conducted in Saudi Arabia, Kuwait, the United Arab Emirates, Qatar, Bahrain, and Oman evaluating the safety and health concerns of people living in the region. Methods: This study reviews previous studies that analyzed social protection motivation theory constructs to analyze and improve the health and safety in these countries. Results: Several studies were identi ed, indicating that the protection motivation theory is important in motivating individuals to change behavior. Conclusion: Protection motivation theory is a useful construct to understand and mitigate risk. It can aid in developing preventive measures to enhance individual safety

Risk analysis of business intelligence in cloud computing

© 2015 IEEE. The paper discusses the issues of risk analysis of Business Intelligence on the basis of Cloud platforms. The study gives an account on various aspects of the issue such as benefits and risks, financial appliance, and a factual process of data analysis. The paper attempts to address the issue in terms of empirical knowledge as long as numerous organizations face difficulties concerning appropriate application of Business Intelligence in the Cloud environment for purposes of risk forecasting and assessment

THE INTER-RELATIONSHIP BETWEEN COMMODITY ENERGY PRICES AND STOCK MARKET VOLATILITY IN SAUDI-ARABIA

Background and Purpose: The present study examines the inter-relationship that exists between commodity energy price as well as stock market volatility in Saudi-Arabia. The focus of the study is to test if changes in commodities energy prices (oil related) cause significant changes in the stock market volatility of Saudi Arabia.   Methodology: This study made use of a generalized autoregressive conditional heteroscedasticity model which has exogenous variables (GARCH-X), thus able to employ the commodity energy price inform of an exogenous so as to test the conditional variance of the Saudi-Arabia stock market return.   Findings: The findings from the estimated model provide evidence that only the ARCH and GARCH parameters are significant while the exogenous variables are insignificant. It is concluded that other factors affect the volatility of the Saudi-Arabia stock market, but not the commodity energy price.   Contributions: This study recommends that, policy makers, investors, and regulators should give emphasis on macro-economic variables and volatility interdependence with other correlated markets, especially during energy price shock that affected the volatility of Saudi-Arabia stock market.    Keywords: Energy price, GARCH-X, Saudi Arabia, stock market, volatility.   Cite as: Alsufyani, M., & Sarmidi, T. (2020). The inter-relationship between commodity energy prices and stock market volatility in Saudi-Arabia. Journal of Nusantara Studies, 5(1), 270-293. http://dx.doi.org/10.24200/jonus.vol5iss1pp270-29

Migration of cloud services and deliveries to higher education

This paper discusses the adoption of cloud computing in education. It emphasizes the view that cloud computing is vital in the education sector because of its ability to reduce the overall costs of IT infrastructure installation and maintenance, improvement of efficiency, and the sharing of IT resources among students. The flexibility of cloud computing and its reliability makes it more appropriate for use in the educational environment. The Leeds Beckett University cloud project utilizes the SAS Educational Value-Added Assessment System, which gives lecturers the opportunity to deliver accurate content to students while monitoring their progress. Contemporary educational institutions must look forward to improve their research and education through cloud computing

An Adaptive Common Control Channel MAC with Transmission Opportunity in IEEE 802.11ac

Spectral utilization is a major challenge in wireless ad hoc networks due in part to using limited network resources. For ad hoc networks, the bandwidth is shared among stations that can transmit data at any point in time. It  is important to maximize the throughput to enhance the network service. In this paper, we propose an adaptive multi-channel access with transmission opportunity protocol for multi-channel ad hoc networks, called AMCA-TXOP. For the purpose of coordination, the proposed protocol uses an adaptive common control channel over which the stations negotiate their channel selection based on the entire available bandwidth and then switch to the negotiated channel. AMCA-TXOP requires a single radio interface so that each station can listen to the control channel, which can overhear all agreements made by the other stations. This allows parallel transmission to multiple stations over various channels, prioritizing data traffic to achieve the quality-of-service requirements. The proposed approach can work with the 802.11ac protocol, which has expanded the bandwidth to 160 MHz by channel bonding. Simulations were conducted to demonstrate the throughput gains that can be achieved using the AMCA-TXOP protocol. Moreover, we compared our protocol with  the IEEE 802.11ac standard protocols

The Relationship between Preoperative Educational Session and Anxiety Level among Women Undergoing Cesarean Section: A Scoping Review

Context: Anxiety is felt in women undergoing elective cesarean section. In obstetric patients, literature has reported a higher level of preoperative anxiety than in the general surgical population. One of the commonest surgical procedures in obstetrics is Caesarean section (CS). Preoperative anxiety has been described as being associated with several adverse physiological and psychological effects.Aim: This review aimed to determine the relationship between preoperative educational sessions and anxiety levels among women undergoing cesarean section. Methods: The search strategy of this study relies on some of the electronic bibliographic databases under the Medicine, Nursing, and Health Sciences departments. Various databases have been used to include different perspectives in the findings, CINAHL, Ovid MEDLINE, Pub Med, and Embase databases were used to collect primary articles for this study.Results: The current review of the literature included seven quantitative studies that fulfill the inclusion criteria. The included studies revealed the intervention used as mental health training (one study), video is used in three studies, and health instruction in five studies, with two studies using both video and health instruction. In terms of the effect of preoperative sessions on anxiety levels, four out of seven studies reported a decrease in the anxiety level while the remaining three studies reported a non-significant effect of educational intervention in decreasing the women’s anxiety. Conclusion: Most of the reviewed studies indicated that preoperative education intervention could positively impact anxiety levels among women undergoing CS making the reviewed theme open for further randomized control intervention studying