“Brothers Gonna Work It Out:” Understanding the Pedagogic Performance of African American Male Teachers Working with African American Male Students

Drawing from ethnographic data, this paper explores how African American male teachers working with African American male students performed their pedagogy. This paper highlights how teachers’ understanding of African American males social and educational needs shaped their pedagogical performance. Interestingly however, teachers’ performance was contingent on the diverse ways they imagined African American males should engage within their social and political worlds. These findings suggest then that African American male teachers’ pedagogic performances were both complex and multifaceted.     

A Ṭā’ifa in Exile: Sayf al-Dawla and the Survival of the Banū Hūd

In 1145–1146, Sayf al-Dawla returned to al-Andalus to create an independent kingdom and return the Banū Hūd of Zaragoza to prominence. His task was a difficult one, not least because he’d spent a decade serving the Christian king Alfonso VII. After a year of campaigning, Sayf al-Dawla secured a base of support in Murcia. However, he died shortly after his coronation in a battle with Christian allies who were allegedly sent by Alfonso to help him. In addition to providing an explanation for the battle and his death, the article examines how Sayf al-Dawla promoted the legitimacy of his state through his coinage, adherence to Andalusī traditions, and a network of fellow exiles. It interprets the Zaragozan ?ā’ifa as a moveable faction rather than a fixed geographical entity and connects Sayf al-Dawla’s kingdom to later movements to demonstrate how his actions preserved the Banū Hūd’s prestige in Andalusī imaginations.     

China-ASEAN Relations in Higher Education: An Analytical Framework

China’s dramatic economic rise has tended to overshadow other wider perspectives on the developing China and Association of Southeast Asian Nations (ASEAN) relationship, including in higher education. The article examines contemporary relations between China and ASEAN, set against the longer term development of cultural and trade relations. It is argued that, notwithstanding current territorial disputes, and a history of discrimination against ethnic Chinese in several parts of ASEAN, prospects for a deepening of relations in higher education remain strong. Singapore, Malaysia, and Vietnam are selected as three instances of the developing relationship in higher education and some of the links traced, with the former assessed as best placed to take advantage of its China relations in higher education. The developing sense of regionalism is seen as likely to further enhance China-ASEAN relations in higher education.     

Interstimulus interval and viewing time effects in monkey list memory

Two rhesus monkeys were tested in 6- and 10-item list memory tasks for performance changes as a function of the exposure duration of the list stimuli and the interstimulus interval (ISI) between successive list stimuli. Accuracy increased with longer item exposure duration and tended to decrease with longer ISI duration. Humans, by contrast, typically show increases in accuracy with ISI, a result taken as evidence of rehearsal. The decrease in accuracy for monkeys suggests that they were not using rehearsal processes in these list memory experiments. Further tests in which choice accuracy with predictable ISIs was compared with choice accuracy with unpredictable ISIs also yielded no evidence of rehearsal by the monkeys. This apparent absence of rehearsal mechanisms in monkeys, in situations also shown to support human rehearsal, is discussed as a potential difference in the visual working memory processes of the two species.     

The influence of an afternoon nap on the endurance performance of trained runners

The effectiveness of a nap as a recovery strategy for endurance exercise is unknown and therefore the present study investigated the effect of napping on endurance exercise performance. Eleven trained male runners completed this randomised crossover study. On two occasions, runners completed treadmill running for 30?min at 75% ?O_2max in the morning, returning that evening to run for 20?min at 60% ?O_2max, and then to exhaustion at 90% ?O_2max. On one trial, runners had an afternoon nap approximately 90?min before the evening exercise (NAP) whilst on the other, runners did not (CON). All runners napped (20?±?10?min), but time to exhaustion (TTE) was not improved in all runners (NAP 596?±?148?s vs. CON 589?±?216?s, P?=?.83). Runners that improved TTE after the nap slept less at night than those that did not improve TTE (night-time sleep 6.4?±?0.7?h vs. 7.5?±?0.4?h, P?r^{2 ?} =??0.76, P?=?.001). In runners that improved TTE, ratings of perceived exertion (RPE) were lower during the TTE on NAP than CON compared to runners that did not improve (?0.4?±?0.6 vs. 0?±?0, P?=?.05). Reduced exercising sense of effort (RPE) may account for the improved TTE after the nap. In conclusion, a short afternoon nap improves endurance performance in runners that obtain less than 7?h night-time sleep.     

Incentive learning and the motivational control of instrumental performance by thirst

The role of incentive learning in instrumental performance following a shift in the degree of water deprivation was analyzed in three experiments. In Experiments 1A and IB, rats trained to perform an instrumental action reinforced with either sucrose or maltodextrin solutions when in a high-deprivation state were subsequently shifted to a low-deprivation state and tested in extinction. This within-state shift in water deprivation reduced instrumental performance only when the animals had been exposed to the reinforcer in the low-deprivation state prior to instrumental training. In Experiment 2, a concurrent training procedure was used to assess whether the change in the value of the reinforcer brought about by preexposurewas mediated by the contingency between the instrumental action and the reinforcer. Preexposure to the reinforcer under the low-deprivation state produced a selective reduction of the performance of the action upon which it was contingent during training when testing was conducted in extinction following a shift from the high- to the low-deprivation state. These experiments provide evidence that animals have to learn about the incentive value of a reinforcer in a particular motivational state through exposure to the reinforcer in that state.     

A Person-Centered Approach to Students' Evaluations of Perceived Fear Appeals and Their Association With Engagement

A person-centered approach was employed to investigate how students' evaluation of perceived teacher utility value messages, i.e., fear appeals, as a threat and as a challenge, combined within individuals and how these combinations related to student engagement. Two studies were conducted with students in their final two years of secondary education. Empirically distinct clusters emerged at two time points in the academic year. Evaluating the message in the fear appeal at a higher level of challenge than threat was beneficial. Unexpectedly, high threat was associated with high engagement, as long as high challenge was also present, however, this combination was also related to high emotional disaffection. Moderate threat combined with moderate challenge had the most detrimental relationship with student engagement. Educational interventions should aim to increase the likelihood of a challenge evaluation.     

Geometrical effects in microfluidic-based microarrays for rapid, efficient single-cell capture of mammalian stem cells and plant cells

In this paper, a detailed numerical and experimental investigation into the optimisation of hydrodynamic micro-trapping arrays for high-throughput capture of single polystyrene (PS) microparticles and three different types of live cells at trapping times of 30 min or less is described. Four different trap geometries (triangular, square, conical, and elliptical) were investigated within three different device generations, in which device architecture, channel geometry, inter-trap spacing, trap size, and trap density were varied. Numerical simulation confirmed that (1) the calculated device dimensions permitted partitioned flow between the main channel and the trap channel, and further, preferential flow through the trap channel in the absence of any obstruction; (2) different trap shapes, all having the same dimensional parameters in terms of depth, trapping channel lengths and widths, main channel lengths and widths, produce contrasting streamline plots and that the interaction of the fluid with the different geometries can produce areas of stagnated flow or distorted field lines; and (3) that once trapped, any motion of the trapped particle or cell or a shift in its configuration within the trap can result in significant increases in pressures on the cell surface and variations in the shear stress distribution across the cell’s surface. Numerical outcomes were then validated experimentally in terms of the impact of these variations in device design elements on the percent occupancy of the trapping array (with one or more particles or cells) within these targeted short timeframes. Limitations on obtaining high trap occupancies in the devices were shown to be primarily a result of particle aggregation, channel clogging and the trap aperture size. These limitations could be overcome somewhat by optimisation of these device design elements and other operational variables, such as the average carrier fluid velocity. For example, for the 20 μm polystyrene microparticles, the number of filled traps increased from 32% to 42% during 5–10 min experiments in devices with smaller apertures. Similarly, a 40%–60% reduction in trapping channel size resulted in an increase in the amount of filled traps, from 0% to almost 90% in 10 min, for the human bone marrow derived mesenchymal stem cells, and 15%–85% in 15 min for the human embryonic stem cells. Last, a reduction of the average carrier fluid velocity by 50% resulted in an increase from 80% to 92% occupancy of single algae cells in traps. Interestingly, changes in the physical properties of the species being trapped also had a substantial impact, as regardless of the trap shape, higher percent occupancies were observed with cells compared to single PS microparticles in the same device, even though they are of approximately the same size. This investigation showed that in microfluidic single cell capture arrays, the trap shape that maximizes cell viability is not necessarily the most efficient for high-speed single cell capture. However, high-speed trapping configurations for delicate mammalian cells are possible but must be optimised for each cell type and designed principally in accordance with the trap size to cell size ratio.