Our aim was to comprehensively validate the 1-min sit-to-stand (STS) test in chronic obstructive pulmonary disease (COPD) patients and explore the physiological response to the test.We used data from two longitudinal studies of COPD patients who completed inpatient pulmonary rehabilitation programmes. We collected 1-min STS test, 6-min walk test (6MWT), health-related quality of life, dyspnoea and exercise cardiorespiratory data at admission and discharge. We assessed the learning effect, test-retest reliability, construct validity, responsiveness and minimal important difference of the 1-min STS test.In both studies (n=52 and n=203) the 1-min STS test was strongly correlated with the 6MWT at admission (r=0.59 and 0.64, respectively) and discharge (r=0.67 and 0.68, respectively). Intraclass correlation coefficients (95% CI) between 1-min STS tests were 0.93 (0.83-0.97) for learning effect and 0.99 (0.97-1.00) for reliability. Standardised response means (95% CI) were 0.87 (0.58-1.16) and 0.91 (0.78-1.07). The estimated minimal important difference was three repetitions. End-exercise oxygen consumption, carbon dioxide output, ventilation, breathing frequency and heart rate were similar in the 1-min STS test and 6MWT.The 1-min STS test is a reliable, valid and responsive test for measuring functional exercise capacity in COPD patients and elicited a physiological response comparable to that of the 6MWT.

In our classroom experiences as teachers, we are often baffled when students correctly answer questions in one setting and then can't answer seemingly identical questions in another. Obviously, their understanding of the material is not as strong as we would like. But are we asking the relevant questions when we come to this conclusion? Do the students fundamentally not know the material? Do they know it but not recognize appropriate circumstances in which to use it? And how should our instruction and evaluation of their knowledge depend on the answers to these questions?We have begun to address these questions at the University of Maryland using the methods and tools of physics education research.1 Our approach combines the study of student difficulties with physics with the design of instructional materials and environments that help students improve their understanding. This approach can lead to educational environments that help students overcome their difficulties. 2 We report here on our study of student understanding of the physics of mechanical waves. Understanding wave physics is important for making sense of physical optics, quantum mechanics, and electromagnetic radiation. Previous research has shown that students have fundamental difficulties with some of the basic concepts of wave physics. 1 Sense Making and Mental ModelsTo describe and understand our observations of student reasoning we need a framework and a language. In the University of Maryland Physics Education Research Group, we use the idea of mental models borrowed from the cognitive science and learning theory literature in order to interpret how students make sense of physics. 3,4 We use the term to mean the patterns of association and physical analogies that guide spontaneous responses and reasoning in unfamiliar situations. Mental models are less specific and less rigorous than physical models and are often not explicitly verbalized or consciously used.For example, we have found that many students answering questions dealing with the propagation speed and superposition of mechanical waves appear to use a guiding analogy of waves that is reasonably complete and coherent, but at odds with physical reality. We call this the Particle Pulses Mental Model. We observe that many students do not think of the forces and interactions internal to a mechanical waves system as we do in the physical model of waves when we derive the wave equation or discuss its physical meaning. Instead, many students mistakenly use analogies with Newtonian particle mechanics and ideas of force, energy, and collisions between objects to describe the physics of waves. These analogies play an important role in how students come to an understanding of wave physics and how we test and probe their understanding in our classrooms. Research Context and MethodsOur investigations were done in the second semester of a three-semester university physics course at the University of Maryland. The course includes three hours of lecture a week, a traditional laboratory, and a small g...

The minimal clinically important difference (MCID) defines to what extent change on a health status instrument is clinically relevant, which aids scientists and physicians in measuring therapy effects. This is the first study that aimed to establish the MCID of the Clinical chronic obstructive pulmonary disease (COPD) Questionnaire (CCQ), the COPD Assessment Test (CAT) and the St George’s Respiratory Questionnaire (SGRQ) in the same pulmonary rehabilitation population using multiple approaches. In total, 451 COPD patients participated in a 3-week Pulmonary Rehabilitation (PR) programme (58 years, 65% male, 43 pack-years, GOLD stage II/III/IV 50/39/11%). Techniques used to assess the MCID were anchor-based approaches, including patient-referencing, criterion-referencing and questionnaire-referencing, and the distribution-based methods standard error of measurement (SEM), 1.96SEM and half standard deviation (0.5s.d.). Patient- and criterion-referencing led to MCID estimates of 0.56 and 0.62 (CCQ); 3.12 and 2.96 (CAT); and 8.40 and 9.28 (SGRQ). Questionnaire-referencing suggested MCID ranges of 0.28–0.61 (CCQ), 1.46–3.08 (CAT) and 6.86–9.47 (SGRQ). The SEM, 1.96SEM and 0.5s.d. were 0.29, 0.56 and 0.46 (CCQ); 3.28, 6.43 and 2.80 (CAT); 5.20, 10.19 and 6.06 (SGRQ). Pooled estimates were 0.52 (CCQ), 3.29 (CAT) and 7.91 (SGRQ) for improvement. MCID estimates differed depending on the method used. Pooled estimates suggest clinically relevant improvements needing to exceed 0.40 on the CCQ, 3.00 on the CAT and 7.00 on the SGRQ for moderate to very severe COPD patients. The MCIDs of the CAT and SGRQ in the literature might be too low, leading to overestimation of treatment effects for patients with COPD.

Students are taught several models of conductivity, both at the introductory and the advanced level. From early macroscopic models of current flow in circuits, through the discussion of microscopic particle descriptions of electrons flowing in an atomic lattice, to the development of microscopic non-localized band diagram descriptions in advanced physics courses, they need to be able to distinguish between commonly used, though sometimes contradictory, physical models. In investigations of student reasoning about models of conduction, we find that students often are unable to account for the existence of free electrons in a conductor and create models that lead to incorrect predictions and responses contradictory to expert descriptions of the physics. We have used these findings as a guide to creating curriculum materials that we show can be effective helping students to apply the different conduction models more effectively.

MCP-1 expression is increased in angiotensin II-dependent models of hypertensive nephrosclerosis and is temporally and spatially related to MPhi infiltration. The angiotensin II type 1 receptor mediates the induction of MCP-1.