Observations of red-giant variable stars by Aboriginal Australians

Aboriginal Australians carefully observe the properties and positions of stars, including both overt and subtle changes in their brightness, for subsistence and social application. These observations are encoded in oral tradition. I examine two Aboriginal oral traditions from South Australia that describe the periodic changing brightness in three pulsating, red-giant variable stars: Betelgeuse (Alpha Orionis), Aldebaran (Alpha Tauri), and Antares (Alpha Scorpii). The Australian Aboriginal accounts stand as the only known descriptions of pulsating variable stars in any Indigenous oral tradition in the world. Researchers examining these oral traditions over the last century, including anthropologists and astronomers, missed the description of these stars as being variable in nature as the ethnographic record contained several misidentifications of stars and celestial objects. Arguably, ethnographers working on Indigenous Knowledge Systems should have academic training in both the natural and social sciences.Comment: The Australian Journal of Anthropology (2018

Dissociable Components of Cognitive Control: An Event-Related Potential (ERP) Study of Response Inhibition and Interference Suppression

Background: Cognitive control refers to the ability to selectively attend and respond to task-relevant events while resisting interference from distracting stimuli or prepotent automatic responses. The current study aimed to determine whether interference suppression and response inhibition are separable component processes of cognitive control. Methodology/Principal Findings: Fourteen young adults completed a hybrid Go/Nogo flanker task and continuous EEG data were recorded concurrently. The incongruous flanker condition (that required interference suppression) elicited a more centrally distributed topography with a later N2 peak than the Nogo condition (that required response inhibition). Conclusions/Significance: These results provide evidence for the dissociability of interference suppression and response inhibition, indicating that taxonomy of inhibition is warranted with the integration of research evidence from neuroscience

Teacher Wellbeing: The Importance of Teacher–Student Relationships

Many studies have examined the importance of teacher-student relationships for the development of children. Much less is known, however, about how these relationships impact the professional and personal lives of teachers. This review considers the importance of teacher-student relationships for the wellbeing of teachers guided by the Transactional Model of Stress and Coping of Lazarus (1991). Based on theories on interpersonal relationships, it is postulated that teachers have a basic need for relatedness with the students in their class that originates from the close proximity between teacher and student. It is discussed that teachers internalize experiences with students in representational models of relationships that guide emotional responses in daily interactions with students, and changes teacher wellbeing in the long run. In addition, the notion of mental representations of relationships at different levels of generalization could offer a window to understand how individual teacher-student relationships may affect the professional and personal self-esteem of teachers. Lastly, it is argued that the influence of student misbehavior on teacher stress may be more fully understood from a relationship perspective. The review shows that few studies have directly tested these propositions and offers suggestions for future research

An empirical model for the de novo formation of PCDD/F in medical waste incinerators

Tests in a 10 kg h pilot scale incinerator burning medical waste showed that the amounts of PCCD/F formed when cooling from 900 °C to ambient were almost proportional to the residence time in the 400-200 °C range. This suggests that gas-phase adsorption control rather than kinetic control was operating. A generalized model of PCCD/F formation was developed for a chlorine-rich gas phase, based on diffusion of HCI to the fly ash surface. It was necessary to incorporate a 'sticking factor' α, which specifies the fraction of molecules that are retained on the ash surface and subsequently enter into reaction. The calculation combines rates for the formation and destruction mechanisms that are effective in the range of 400-225 °C. Application of the model requires knowledge of the cooling regime, the specific surface area of fly ash, its concentration at the sampling point, and the initial surface concentration of PCCD/F. It assumes that all the PCCD/F emitted from waste incinerators is associated with the fly ash. The model satisfactorily simulates the upper temperature window for PCCD/F formation and the effect of cooling regime on rate. When tested on a number of commercial incinerators with varying levels of gas cleaning efficiency, the value of α was found to depend on the downstream cleaning facilities, being 4-5 x 10 for gas cleaning systems involving only solids removal (wet scrubbing) and 1-3 x 10 for those utilizing adsorption processes for gas-phase components as well (lime, carbon). The latter appears to be the true value for surface formation processes. The presence of sulfur in the fuel forces the value of α downward.Tests in a 10 kg h pilot scale incinerator burning medical waste showed that the amounts of PCCD/F formed when cooling from 900°C to ambient were almost proportional to the residence time in the 400-200°C range. This suggests that gas-phase adsorption control rather than kinetic control was operating. A generalized model of PCCD/F formation was developed for a chlorine-rich gas phase, based on diffusion of HCl to the fly ash surface. It was necessary to incorporate a 'sticking factor' α, which specifies the fraction of molecules that are retained on the ash surface and subsequently enter into reaction. The calculation combines rates for the formation and destruction mechanisms that are effective in the range of 400-225°C. Application of the model requires knowledge of the cooling regime, the specific surface area of fly ash, its concentration at the sampling point, and the initial surface concentration of PCCD/F. It assumes that all the PCCD/F emitted from waste incinerators is associated with the fly ash. The model satisfactorily simulates the upper temperature window for PCCD/F formation and the effect of cooling regime on rate. When tested on a number of commercial incinerators with varying levels of gas cleaning efficiency, the value of α was found to depend on the downstream cleaning facilities, being 4-5 × 10 for gas cleaning systems involving only solids removal (wet scrubbing) and 1-3 × 10 for those utilizing adsorption processes for gas-phase components as well (lime, carbon). The latter appears to be the true value for surface formation processes. The presence of sulfur in the fuel forces the value of α downward