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Sara Baratchi Francisco J. Tovar-Lopez Khashayar Khoshmanesh Megan S. Grace William Darby Juhura Almazi Arnan Mitchell Peter McIntyre 《Biomicrofluidics》2014,8(4)
Shear stress is the major mechanical force applied on vascular endothelial cells by blood flow, and is a crucial factor in normal vascular physiology and in the development of some vascular pathologies. The exact mechanisms of cellular mechano-transduction in mammalian cells and tissues have not yet been elucidated, but it is known that mechanically sensitive receptors and ion channels play a crucial role. This paper describes the use of a novel and efficient microfluidic device to study mechanically-sensitive receptors and ion channels in vitro, which has three independent channels from which recordings can be made and has a small surface area such that fewer cells are required than for conventional flow chambers. The contoured channels of the device enabled examination of a range of shear stresses in one field of view, which is not possible with parallel plate flow chambers and other previously used devices, where one level of flow-induced shear stress is produced per fixed flow-rate. We exposed bovine aortic endothelial cells to different levels of shear stress, and measured the resulting change in intracellular calcium levels ([Ca2+]i) using the fluorescent calcium sensitive dye Fluo-4AM. Shear stress caused an elevation of [Ca2+]i that was proportional to the level of shear experienced. The response was temperature dependant such that at lower temperatures more shear stress was required to elicit a given level of calcium signal and the magnitude of influx was reduced. We demonstrated that shear stress-induced elevations in [Ca2+]i are largely due to calcium influx through the transient receptor potential vanilloid type 4 ion channel. 相似文献
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There is increasing enthusiasm for teaching approaches that combine mathematics and biology. The call for integrating more quantitative work in biology education has led to new teaching tools that improve quantitative skills. Little is known, however, about whether increasing interdisciplinary work can lead to adverse effects, such as the development of broader but shallower skills or the possibility that math anxiety causes some students to disengage in the classroom, or, paradoxically, to focus so much on the mathematics that they lose sight of its application for the biological concepts in the center of the unit at hand. We have developed and assessed an integrative learning module and found disciplinary learning gains to be equally strong in first-year students who actively engaged in embedded quantitative calculations as in those students who were merely presented with quantitative data in the context of interpreting biological and biostatistical results. When presented to advanced biology students, our quantitative learning tool increased test performance significantly. We conclude from our study that the addition of mathematical calculations to the first year and advanced biology curricula did not hinder overall student learning, and may increase disciplinary learning and data interpretation skills in advanced students. 相似文献
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Alexa Valiente 《英语沙龙》2013,(7):10-11
工作不仅仅是维持人的生存的手段,更可以体现一个人的社会价值,所以一份工作的好坏在很大程度上决定一个人一生的质量。如何选择工作以及如何选择一个好工作,自然是大学生包括诸多仍然在工作中迷茫前进的职场人不断思考的问题。本期带来的职场调查总结了2013年各大职业的评估报告,在这个毕业季,送给所有准备踏上职场的年轻人! 相似文献
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Educational Psychology Review - This systematic review investigated how successful children/adolescents with poor literacy skills learn a foreign language compared with their peers with typical... 相似文献
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Research Study on an Applied Interdisciplinary Product Development Course for College Sophomores 
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下载免费PDF全文 Margaret D. Condrasky Alexa Weeks McCay Duncan Darby Julia L. Sharp Sarah F. Griffin 《Journal of Food Science Education》2018,17(2):66-71
This research compares the industry readiness, product development skill level, and overall knowledge gains of students taking an undergraduate research course (treatment) to those who did not (control). This 2‐semester Applied Interdisciplinary Product Development (AIPD) course for sophomores brought together interdisciplinary teams of food science, nutrition, and packaging science students in a hands‐on setting to create healthy food products for children, complete with retail packaging. A Subject Knowledge Assessment (SKA) was used to evaluate the mean percent difference value (MPDV) of food science, nutrition, packaging science, and general product development knowledge gained through the course. SKA results indicated that the MPDV were significantly different (α = 0.05) between the treatment and comparison groups in the overall score and in every subject area score except packaging science. Data from an Exit Questionnaire (EQ) was used for evaluation of attitudes pertaining to product development knowledge and skills, department engagement, and pedagogy. EQ results indicated that mean scores between the treatment and comparison groups were significantly different (α = 0.05) in 7 of the 9 statements on product development knowledge and skills, both statements pertaining to pedagogy, and the statement pertaining to department engagement. Overall, the research project was considered a successful intervention for educating sophomores at the University. Overall, the research project was considered a successful intervention for educating sophomores in the Food, Nutrition and Packaging Science department at Clemson University. The student‐lead teams were held to a greater degree of accountability for their success in terms of education gleaned and value of experience gained as metric for the University and other IFT Accredited programs. 相似文献
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Lynn A. Darby Ph.D. Jennifer L. Marsh M.Ed. Patricia A. Shewokis Ph.D. Roberta L. Pohlman Ph.D. 《Measurement in physical education and exercise science》2013,17(3):131-148
To adhere to the principle of “exercise specificity” exercise testing should be completed using the same physical activity that is performed during exercise training. The present study was designed to assess whether aerobic step exercisers have a greater maximal oxygen consumption (max VO2) when tested using an activity specific, maximal step exercise test (SET; arms and legs) versus a maximal running test (legs only). Female aerobic step exercisers (N=18; 20.7 ± 1.5 years) performed three maximal graded exercise tests (GXTs): 2 SETs; 1 treadmill test (TMT). The SET consisted of six 3-min progressive stages of alternate lead, basic step, basic step with biceps curls, knee raise with pull-down, repeater knee with pull-down, lateral lunge with pull-down, and side squat with shoulder presses. Stepping rate was 32 steps· min?1 on an 8-in (20.32 cm) step for stages 1–3, and a 10-in (25.4 cm) step for stages 4–6. Submaximal and maximal heart rate (HR) and oxygen consumption (VO2) were recorded at the end of each stage. Test–retest reliability for the first five stages of the SET ranged from .91 to .97 for HR, and from .84 to .96 for VO2. Maximal HR was significantly greater (p =.0001) for the SET (200 ± 6.2 beats·min?1) as compared to the TMT (193 ± 7.9 beats·min?1). No significant difference was found for max VO2 (42.9 ± 8.5, 41.2 ± 5.9 ml·kg?1·min?1, p =.14). The SET was a valid and reliable protocol for assessing responses of these aerobic step exercisers; however, max VO2 from a TMT did not differ significantly from the SET. Conversely, max HR obtained from the criterion TMT was 7 beats·min?1 lower than from the SET. If a training HR for step exercise (arms and legs exercise) is prescribed based on the max HR from treadmill exercise (legs only), then the training HR should be calculated from a TMT max HR that has been increased by 7 beats·min?1 to obtain an intensity of step exercise comparable to that of running. 相似文献