Annual cycle of the Benguela Jet

Includes bibliographical referencesThe Benguela Jet is a north-westward flowing current in the southern Benguela region. It is known to have an important influence on the fish recruitment yet little is known about the physical properties of the jet. In this study the ability of satellite data (SST and altimetry) to resolve the Jet was investigated. Following this, the annual cycle of the Benguela Jet was investigated using monthly climatological means computed from both remotely sensed and model output data (from the Regional Ocean Modelling System). Two altimeter tracks were identified as best suited to study the Benguela Jet: the Topex-A / Jason-1A Track number 209 which crosses the Benguela Jet current in its northern region off the Cape Columbine and the Topex-B / Jason-1B track number 31, which crosses the Benguela Jet current in the southern region. The month of January and July were chosen due to the fact that they represent the peaks of summer and winter. The surface geostrophic currents derived from both the model and satellite data reproduced the existence of the jet current off Cape Columbine and the Cape Peninsula. The jet was narrow and strong in January off Cape Columbine and off the Cape Peninsula and was situated farther offshore based on the model, relative to the altimeter data. Outputs from the numerical model showed that in July the jet was confined to the coast and was stronger off the Cape Peninsula (0.5 m.s-1) compared to Cape Columbine (0.4 m.s-1). A comparison between the regions of strong velocity gradient and the position of the upwelling front were in agreement in depicting the position of the jet. Altimetry, which suffers from imitation in coastal regions, could not reveal the jet in July due to its proximity to the shore at this season. The offshore boundary of the jet is resolved by altimetry in January. The interannual variability of the Benguela Jet has been identified

Learning Preferences and Support Opportunities for Online African Doctoral Students

Researchers in this qualitative study interviewed a mix of 14 African students and alumni on their doctoral experience. Interviews included questions on what motivated them, the challenges they faced, and suggestions for future students. Data were collected via telephone interview and transcriptions were analyzed inductively using the In Vivo method. Key findings included a need for better financial assistance, improved technology access and targeted support. Learning preferences identified were spread across a variety of modalities. Specific aspects of the academic residency experience were identified as essential for progress and completion. Participants also provided several recommendations to support international students’ success. Supported by the Ackerman Research Grant in Education Leadership Recommended Citation Adeoye, B. F., & Lynn, L. K. (2020, October 1-2). Learning preferences and support opportunities for online African doctoral students [Poster presentation]. Walden University Research Conference 2020 (online). https://scholarworks.waldenu.edu/researchconference/2020/posters/47

A survey of the resources senior secondary school teachers use in teaching vocabulary in Ibadan North, Nigeria

This study surveyed the resources senior secondary school English language teachers use in teaching vocabulary in Ibadan North. The descriptive research design of the survey type was employed in the study. Using the purposive sampling technique, all the two hundred and twenty-four (224) English and Literature-in-English teachers in the study area as at the time of this study constituted the sample based on the intervening variables of gender, qualification, school type and experience. Only one hundred and ninety-six (196) questionnaires were properly filled and returned. A reliability coefficient of r = 0.90 was obtained using the Pearson Product Moment Correlation Statistics. This showed that the items were of high stake. Findings revealed that the teachers seemed to make more frequent use of non-human instructional resources for teaching vocabulary than the human instructional resources. Also, there were no significant differences on teachers’ qualification, school type and experience except for gender. It was concluded that, aside from teachers’ gender, no other variable had any influence on the resources used for the teaching of vocabulary in senior secondary schools in Ibadan North. It was thus recommended that teachers should employ both human and non-human teaching resources during the teaching and learning of vocabulary

Depth encoded input polarisation independent swept source cross-polarised optical coherence tomography probe

Within the last decades, several studies have been published that prove the benefit of polarisation sensitive optical coherence (psOCT) tomography for the field of biomedical diagnostics. However, polarisation sensitive imaging typically requires careful control of the polarisation state of the input illumination, which leads to bulky and delicate systems. While psOCT provides quantitative information, it is mostly sufficient to analyse the images qualitatively in the field of biomedical diagnostics. Therefore, a reduced form of this technique, cross-polarised optical coherence tomography (cpOCT), moves into the focus of interest that serves to visualise the birefringence properties of a sample. Despite the low requirements for the illumination's polarisation, most of the proposed systems still include complex illumination control mechanisms. Here, we propose a common path probe based endoscopic system with an lateral resolution of 30 µm and a sensitivity of 103 dB comprising a commercially available swept-source OCT system and a free-space module which does not require any polarisation controlling elements. A Faraday mirror substitutes the complex polarisation control apparatus. We demonstrate the independence of the approach from the polarisation state of the light source by monitoring the illumination power in the orthogonal channels while varying the source polarisation. Furthermore, we validate the ability of the system to reveal the birefringence properties of different samples, starting from a quarter-wave plate, since its properties are fully characterised. Additionally, we present imaging results from several tissues to demonstrate its feasibility for the field of biomedical diagnostics