The construction of common treadmills significantly affects biomechanical and metabolic variables

ABSTRACT

Surface compliance has been shown to affect leg stiffness and energetics. It is unknown if compliance differences between common treadmills would elicit such changes. Therefore, the purpose of this study was to determine if compliance design differences of common treadmills would affect the mechanics and energetics of running. Eleven runners ran at moderate, self-selected, matched belt speeds for three minutes on two treadmills: compliant (CT) and rigid (RT) decks. During the last minute of each trial, oxygen consumption and six markers describing the torso, thigh, shank and foot, and one marker to determine treadmill deflection were recorded. Leg stiffness, continuous relative phase (CRP) and CRP variability were calculated. Compared to RT, running on CT resulted in a significantly more compliant leg (8.591 kN?m^?1 > 9.063 kN?m^?1), lower oxygen consumption (34.69 ml?kg^?1?min^?1 < 36.86 ml?kg^?1?min^?1), different coordination patterns and greater variability, particularly during the push-off phase. These results are inconsistent with the literature because the deck of CT rebounds back at the runner during the absorption phase and away from the runner during the push-off phase. Therefore, care should be taken when using treadmills for research and comparing mechanical and energetic measures between studies.     

Short lesson plan associated with increased acceptance of evolutionary theory and potential change in three alternate conceptions of macroevolution in undergraduate students

Undergraduates commonly harbor alternate conceptions about evolutionary biology; these alternate conceptions often persist, even after intensive instruction, and may influence acceptance of evolution. We interviewed undergraduates to explore their alternate conceptions about macroevolutionary patterns and designed a 2-h lesson plan to present evidence that life has evolved. We identified three alternate conceptions during our interviews: that newly derived traits would be more widespread in extant species than would be ancestral traits, that evolution proceeds solely by anagenesis, and that lineages must become more complex over time. We also attempted to measure changes in the alternate conceptions and levels of acceptance of evolutionary theory in biology majors and nonmajors after exposure to the lesson plan. The instrument used to assess understanding had flaws, but our results are suggestive of mixed effects: we found a reduction in the first alternate conception, no change in the second, and reinforcement of the third. We found a small, but significant, increase in undergraduate acceptance of evolutionary theory in two trials of the lesson plan (Cohen's d effect sizes of 0.51 and 0.19). These mixed results offer guidance on how to improve the lesson and show the potential of instructional approaches for influencing acceptance of evolution.     

Cultural Persistence,Political Resistance,and Hope in the Community and School-Based Art of a Puerto Rican Diaspora Neighborhood

The authors describe themes of cultural persistence, political resistance, and hope in the art of one Puerto Rican neighborhood in the Midwestern United States. The themes are described across three contexts: community mural art, poetry from students in an alternative high school, and poetry from seventh grade students in a neighborhood middle school. In describing currents of Puerto Rican identity-making, resistance to gentrification, and struggles against local oppression that are evident in all three contexts, the authors argue that as they name their worlds, students commit acts of social justice through their perpetuation of historical and cultural themes situated within a tradition of community activism.     

Principals may inflate teacher evaluation scores to achieve important goals

Educational Assessment, Evaluation and Accountability - A concerning attribute of teacher evaluations across countries is the systemic leniency of principals during classroom observations. However,...     

Sickle Cell Trait Presenting as Chronic Calcific Pancreatitis with Pseudocyst- A Case Report

Sickle cell disease is known to cause acute pancreatitis either due to gall stones obstructing the pancreatic duct or by vaso-occlusive mechanism. However chronic pancreatitis is a very rare complication in sickle cell anemia. We report a case of sickle cell trait presenting with chronic pancreatitis with pseudo cyst. USG abdomen and CT abdomen confirmed the diagnosis of chronic calcific pancreatitis with pseudocyst. Etiological work up for other causes did not reveal anything except sickle cell trait. This case represents a rare association between chronic calcific pancreatitis and sickle cell trait.     

Artistic Learning in Relation to Young Children’s Chorotopos: An In-Depth Approach to Early Childhood Visual Culture Education

The paper reports on a study of young children and the nature of their art learning based on the in-depth approach and in the context of chorotopos (space-place, area, landscape, region, village or town). The sample includes 50 children drawn from three classrooms in three early childhood settings in the area of Thessaloniki and Chalkidiki, Greece. Classroom observation notes, audio-taped analysis, photographic material and the artworks of children were used to find out the influences of the programs to young children’s art learning. Findings indicate that artistic activities in relation to their chorotopos and in-depth exploration of materials made children more situated to their own environment and enabled them to understand the potential expressiveness of materials and their inherent meaning. Teachers’ role was decisive in providing special “scaffolding” to further the exploratory process in an interactive environment of learning. The findings highlight the significance of learning in, through and about art by allowing children to experience their personal environment through objects and materials encountered in their chorotopos, to appreciate its richness and to see themselves as part of it.

Consumer learning for university students: a case for a curriculum

This article indicates how the application of a simplified version of the analytical abstraction method (AAM) was used in curriculum development for consumer learning at one higher education institution in South Africa. We used a case study design and qualitative research methodology to generate data through semi‐structured interviews with eight learning facilitators at the Cape Peninsula University of Technology. This data set forms the basis of the reported research. Application of basic‐ and higher‐level analysis resulted in the identification of patterns that confirmed the need for consumer learning and informed the situation analysis with regard to a ‘readiness climate’ at the institution. We also gained insight into aspects that need to be considered during curriculum development for consumer learning as the AAM has proved to be a useful guiding tool in developing a structured explanatory framework for curriculum development. The article concludes with the view that the promotion of consumer learning in university curricula has been under‐researched and that, despite current efforts, university curricula are slow to adopt consumer learning as a critical learning outcome. We suggest several possibilities that might assist in overcoming this inertia.     

Building Systems from Scratch: an Exploratory Study of Students Learning About Climate Change

Science and computational practices such as modeling and abstraction are critical to understanding the complex systems that are integral to climate science. Given the demonstrated affordances of game design in supporting such practices, we implemented a free 4-day intensive workshop for middle school girls that focused on using the visual programming environment, Scratch, to design games to teach others about climate change. The experience was carefully constructed so that girls of widely differing levels of experience were able to engage in a cycle of game design. This qualitative study aimed to explore the representational choices the girls made as they took up aspects of climate change systems and modeled them in their games. Evidence points to the ways in which designing games about climate science fostered emergent systems thinking and engagement in modeling practices as learners chose what to represent in their games, grappled with the realism of their respective representations, and modeled interactions among systems components. Given the girls’ levels of programming skill, parts of systems were more tractable to create than others. The educational purpose of the games was important to the girls’ overall design experience, since it influenced their choice of topic, and challenged their emergent understanding of climate change as a systems problem.     

Measuring clearance mechanics based on dynamic leg length

The aim of this study was to quantify clearance mechanics during gait. Seventeen children diagnosed with hemiplegic cerebral palsy underwent a three-dimensional gait analysis evaluation. Dynamic leg lengths were measured from the hip joint center to the heel, to the ankle joint center and to the forefoot throughout the gait cycle. Significant asymmetry was observed during stance, initial and terminal swing phases, where the hemiplegic limb was found shorter by using a paired t-test at 51 sample points (p < .05). The hemiplegic side was restricted in achieving maximal length during terminal swing. The ratio between the maximal dynamic leg length during the stance phase to minimal dynamic leg length during the swing phase was found higher on the non-involved side and lower on the hemiplegic side (p < .05). Quantifying clearance mechanics based on dynamic leg length can provide an additional insight into the analysis of gait patterns and might assist in detecting time of abnormal kinematic deviations.     

Urban park design + love for nature: Interventions for visitor experiences and social networking

Affect or emotion for nature can prime environmentally friendly attitudes and behaviors, but for one’s love of nature to grow she must physically experience and communicate about nature with others. This study aimed to identify urban park designs that could increase affect for nature in park visitors by stimulating their desire to communicate about and experience nature. Participants included 33 visitors at four urban parks in a mid-sized US city who were interviewed on location. Social network theory (SNT) served as the methodological framework for interpreting why, how, and with whom visitors’ communicated their nature experiences, as well as the design elements that led to increased love for nature. Analysis of the interviews confirmed findings from similar studies, while contributing new insight to how visitors’ use mobile technology to communicate about nature and build bonds with their social network. The conclusion offers ways for scholars and practitioners to improve urban park design so as to increase visitors’ affect, communication about, and action for nature.