The Measurement of Eye Movements in Mild Traumatic Brain Injury: A Structured Review of an Emerging Area

Mild traumatic brain injury (mTBI), or concussion, occurs following a direct or indirect force to the head that causes a change in brain function. Many neurological signs and symptoms of mTBI can be subtle and transient, and some can persist beyond the usual recovery timeframe, such as balance, cognitive or sensory disturbance that may pre-dispose to further injury in the future. There is currently no accepted definition or diagnostic criteria for mTBI and therefore no single assessment has been developed or accepted as being able to identify those with an mTBI. Eye-movement assessment may be useful, as specific eye-movements and their metrics can be attributed to specific brain regions or functions, and eye-movement involves a multitude of brain regions. Recently, research has focused on quantitative eye-movement assessments using eye-tracking technology for diagnosis and monitoring symptoms of an mTBI. However, the approaches taken to objectively measure eye-movements varies with respect to instrumentation, protocols and recognition of factors that may influence results, such as cognitive function or basic visual function. This review aimed to examine previous work that has measured eye-movements within those with mTBI to inform the development of robust or standardized testing protocols. Medline/PubMed, CINAHL, PsychInfo and Scopus databases were searched. Twenty-two articles met inclusion/exclusion criteria and were reviewed, which examined saccades, smooth pursuits, fixations and nystagmus in mTBI compared to controls. Current methodologies for data collection, analysis and interpretation from eye-tracking technology in individuals following an mTBI are discussed. In brief, a wide range of eye-movement instruments and outcome measures were reported, but validity and reliability of devices and metrics were insufficiently reported across studies. Interpretation of outcomes was complicated by poor study reporting of demographics, mTBI-related features (e.g., time since injury), and few studies considered the influence that cognitive or visual functions may have on eye-movements. The reviewed evidence suggests that eye-movements are impaired in mTBI, but future research is required to accurately and robustly establish findings. Standardization and reporting of eye-movement instruments, data collection procedures, processing algorithms and analysis methods are required. Recommendations also include comprehensive reporting of demographics, mTBI-related features, and confounding variables

An Examination of Culturally Relevant Pedagogy and Antibias-Antiracist Curriculm in a Montessori Setting

The research consisted of a qualitative case study of three urban public Montessori schools with a population of 51% or more of students of color and a commitment of 2 years or more of CRP-ABAR within a Montessori setting. The theoretical framework used for the study was the critical race theory, which is the conceptual foundation for examining inequities in public education. This research dissertation had a focus on gaining an insight into the perceptions of administrators, teachers, and parents toward CRP-ABAR in Montessori schools by examining the practices in three public Montessori schools. The possible connections to student outcomes, such as behavioral referrals, suspension rates, and academic achievement for students of color were explored to determine if any connections exist between CRP-ABAR and outcomes for students of color within a public Montessori setting. Three major themes emerged of the perceptions of administrators, teachers, and parents about the impact of the CRP-ABAR in a Montessori setting. The CRP-ABAR could be delivered through a curriculum-oriented approach or a systemic-oriented approach and the CRP-ABAR connects to Montessori through peace-global education and the prepared teacher-environment. The CRP-ABAR practices impact students of color primarily through social emotional growth with limited academic outcomes. Even with an intentional focus and diversity training, many non-Black teachers’ perceptions of students of color included deficit theory thinking. Some parents believed racism is being dismantled through the curriculum and celebrations of diversity. Other parents identified some teachers-staff with underpinning instances of biases and insensitivity

Modelling the X-ray spectra of high velocity outflows from quasars

High velocity outflows from supermassive black holes have been invoked to explain the recent identification of strong absorption features in the hard X-ray spectra of several quasars. Here, Monte Carlo radiative transfer calculations are performed to synthesise X-ray spectra from models of such flows. It is found that simple, parametric bi-conical outflow models with plausible choices for the wind parameters predict spectra that are in good qualitative agreement with observations in the 2 - 10 keV band. The influence on the spectrum of both the mass-loss rate and opening angle of the flow are considered: the latter is important since photon leakage plays a significant role in establishing an ionization gradient within the flow, a useful discriminant between spherical and conical outflow for this and other applications. Particular attention is given to the bright quasar PG1211+143 for which constraints on the outflow geometry and mass-loss rate are discussed subject to the limitations of the currently available observational data.Comment: 15 pages, 8 figures. Accepted for publication by MNRA

Working with external partners to support climate change education through a focus on design

In this paper we reflect on the opportunities and potential pitfalls encountered when schools work in partnership with external organisations. To illustrate wider issues, we examine the implementation of a pilot project aimed at introducing the role of design in the context of climate change in the primary setting. Our data comprise observational field notes of activities in situ, interviews with participating teachers, focus groups with children, and interviews with designers who led the activities across five different schools in England. In reviewing the data, we highlight the need for partners to build upon each other’s skills, genuinely co‐creating activities and co‐leading lessons. Most importantly, we call for all climate change initiatives to be grounded in children’s realities and provide ample opportunities for children to be agentic

Effect of grazing on ship rat density in forest fragments of lowland Waikato, New Zealand

Ship rat (Rattus rattus) density was assessed by snap-trapping during summer and autumn in eight indigenous forest fragments (mean 5 ha) in rural landscapes of Waikato, a lowland pastoral farming district of the North Island, New Zealand. Four of the eight were fenced and four grazed. In each set of four, half were connected with hedgerows, gullies or some other vegetative corridor to nearby forest and half were completely isolated. Summer rat density based on the number trapped in the first six nights was higher in fenced (mean 6.5 rats ha–1) than in grazed fragments (mean 0.5 rats ha–1; P = 0.02). Rats were eradicated (no rats caught and no rat footprints recorded for three consecutive nights) from all eight fragments in January–April 2008, but reinvaded within a month; time to eradication averaged 47 nights in fenced and 19 nights in grazed fragments. A second six-night trapping operation in autumn, 1–3 months after eradication, found no effect of fencing (P = 0.73). Connectedness to an adjacent source of immigrants did not influence rat density within a fragment in either season (summer P = 0.25, autumn P = 0.67). An uncalibrated, rapid (one-night) index of ship rat density, using baited tracking tunnels set in a 50 × 50 m grid, showed a promising relationship with the number of rats killed per hectare over the first six nights, up to tracking index values of c. 30% (corresponding to c. 3–5 rats ha–1). The index will enable managers to determine if rat abundance is low enough to achieve conservation benefits. Our results confirm a dilemma for conservation in forest fragments. Fencing protects vegetation, litter and associated ecological processes, but also increases number of ship rats, which destroy seeds, invertebrates and nesting birds. Maximising the biodiversity values of forest fragments therefore requires both fencing and control of ship rats

Effect of ambient temperature during acute aerobic exercise on short-term appetite, energy intake, and plasma acylated ghrelin in recreationally active males

Ambient temperature during exercise may affect energy intake regulation. Compared with a temperate (20 °C) environment, 1 h of running followed by 6 h of rest tended to decrease energy intake from 2 ad libitum meals in a hot (30 °C) environment but increase energy intake in a cool (10 °C) environment (p = 0.08). Core temperature changes did not appear to mediate this trend; whether acylated ghrelin is involved is unclear. Further research is warranted to clarify these findings

The Acute Effects of Swimming on Appetite, Food Intake, and Plasma Acylated Ghrelin

Swimming may stimulate appetite and food intake but empirical data are lacking. This study examined appetite, food intake, and plasma acylated ghrelin responses to swimming. Fourteen healthy males completed a swimming trial and a control trial in a random order. Sixty min after breakfast participants swam for 60 min and then rested for six hours. Participants rested throughout the control trial. During trials appetite was measured at 30 min intervals and acylated ghrelin was assessed periodically (0, 1, 2, 3, 4, 6, and 7.5 h. N = 10). Appetite was suppressed during exercise before increasing in the hours after. Acylated ghrelin was suppressed during exercise. Swimming did not alter energy or macronutrient intake assessed at buffet meals (total trial energy intake: control 9161 kJ, swimming 9749 kJ). These findings suggest that swimming stimulates appetite but indicate that acylated ghrelin and food intake are resistant to change in the hours afterwards

Acute exercise increases feeding latency in healthy normal weight young males but does not alter energy intake

This study investigated the acute influence of exercise on eating behaviour in an ecologically valid setting whereby healthy active males were permitted complete ad libitum access to food. Ten healthy males completed two, 8 h trials (exercise and control) in a randomised-crossover design. In the exercise trials participants consumed a breakfast snack and then rested for 1 h before undertaking a 60 min run (72% of V˙O2 max) on a treadmill. Participants then rested in the laboratory for 6 h during which time they were permitted complete ad libitum access to a buffet meal. The timing of meals, energy/macronutrient intake and eating frequency were assessed. Identical procedures were completed in the control trial except no exercise was performed. Exercise increased the length of time (35 min) before participants voluntarily requested to eat afterwards. Despite this, energy intake at the first meal consumed, or at subsequent eating episodes, was not influenced by exercise (total trial energy intake: control 7426 kJ, exercise 7418 kJ). Neither was there any difference in macronutrient intake or meal frequency between trials. These results confirm that food intake remains unaffected by exercise in the immediate hours after but suggest that exercise may invoke a delay before food is desired

Bee Threat Elicits Alarm Call in African Elephants

Unlike the smaller and more vulnerable mammals, African elephants have relatively few predators that threaten their survival. The sound of disturbed African honeybees Apis meliffera scutellata causes African elephants Loxodonta africana to retreat and produce warning vocalizations that lead other elephants to join the flight. In our first experiment, audio playbacks of bee sounds induced elephants to retreat and elicited more head-shaking and dusting, reactive behaviors that may prevent bee stings, compared to white noise control playbacks. Most importantly, elephants produced distinctive “rumble” vocalizations in response to bee sounds. These rumbles exhibited an upward shift in the second formant location, which implies active vocal tract modulation, compared to rumbles made in response to white noise playbacks. In a second experiment, audio playbacks of these rumbles produced in response to bees elicited increased headshaking, and further and faster retreat behavior in other elephants, compared to control rumble playbacks with lower second formant frequencies. These responses to the bee rumble stimuli occurred in the absence of any bees or bee sounds. This suggests that these elephant rumbles may function as referential signals, in which a formant frequency shift alerts nearby elephants about an external threat, in this case, the threat of bees