Reducing prolonged sedentary time using a treadmill desk acutely improves cardiometabolic risk markers in male and female adults

This study evaluated the acute effects of interrupting prolonged sitting with an accumulated 2 h of light-intensity walking on postprandial cardiometabolic risk markers. In this randomised crossover trial, 24 participants (twelve males) aged 18–55 years took part in two, 6.5 h conditions: 1) prolonged sitting (SIT) and 2) sitting interrupted hourly with 20 min light-intensity treadmill desk walking at between 1.2–3.5 km/h^?1 (INT-SIT). Standardized meals were provided at 0 h and 3 h. Blood samples and blood pressure measures were taken hourly. Statistical analyses were completed using linear mixed models. Postprandial incremental area under the curve responses (mmol/L?6.5 h) for glucose (4.52 [3.47, 5.56] and 6.66 [5.62, 7.71] for INT-SIT and SIT, respectively) and triglycerides (1.96 [0.96, 2.96] and 2.71 [1.70, 3.71] for INT-SIT and SIT, respectively) were significantly lower in INT-SIT than SIT. Mean systolic and diastolic blood pressure responses were lower by 3% and 4%, respectively, in INT-SIT than SIT (P < 0.05). There was no significant condition x sex interaction effect for any outcomes (P > 0.05). These findings suggest that interrupting sitting with an accumulated 2 h of light-intensity walking acutely improves cardiometabolic risk levels in males and females compared with prolonged sitting.     

Reflecting on the Use of Writing to Promote Mathematical Learning: An Examination of Preservice Mathematics Teachers' Perspectives

We examine preservice mathematics teachers' conceptions of writing as a tool for learning mathematics before and after participation in and reflection on writing tasks. We describe the use of two targeted activities incorporated into a secondary methods course: writing to learn mathematics (WTLM) and reflection on that writing. Prior to participation in these activities, the preservice teachers expressed reluctance toward the use of writing in mathematics and uncertainty as to how writing could be useful in mathematics, while accepting that some possible benefits might exist for students' procedural learning. Following participation in these activities, the preservice teachers expressed a willingness to accept writing as a useful tool for supporting an expanded view of teaching and learning mathematics. Specifically, the preservice teachers considered writing as a way to build connections between mathematics and other subjects, a means to assess student understanding of mathematics, and a beneficial support for student conceptual learning.     

Using Metaphor Theory to Examine Conceptions of Energy in Biology,Chemistry, and Physics

Energy is one of the most important unifying themes in science. Yet the way energy is conceptualized varies depending on context. In this paper, the discourse used to explain the role of energy in systems from biology, chemistry, and physics is examined from the perspective of metaphor theory. Six substance metaphors for energy are identified in pedagogical discourse (i.e., textbooks and the science education literature): energy as a substance that can be accounted for, can flow, can be carried, can change forms, can be lost, and can be an ingredient, a product or stored in some way. Each of these conceptual metaphors highlight and obscure various characteristics of energy, and provide a set of frameworks that each afford a different understanding of the energy concept.     

Online Versus Face-to-Face Training of Critical Time Intervention: A Matching Cluster Randomized Trial

This study examined the effectiveness of online education to providers who serve people experiencing homelessness, comparing online and face-to-face training of Critical Time Intervention (CTI), an evidence-based case management model. The authors recruited 184 staff from nineteen homeless service agencies to participate in one of two training conditions: (a) Online Training + Community of Practice or (b) Face-to-Face Training + Telephone Consultation. Each group received twenty-four hours of instruction and support. Through baseline, follow-up, and nine-month posttraining surveys, the authors examined satisfaction, knowledge gains, knowledge retention, and readiness to implement CTI. Although satisfaction rates were higher among participants in the face-to-face group, the two training conditions produced comparable pre/postknowledge gains. Furthermore, both groups showed increased knowledge retention scores at nine-month follow-up, with the online group scoring higher than the face-to-face group.