The development of a conceptual framework and tools to assess undergraduates' principled use of models in cellular biology     

Richmond G  Merritt B  Urban-Lurain M  Parker J 《CBE life sciences education》2010,9(4):441-452

Recent science education reform has been marked by a shift away from a focus on facts toward deep, rich, conceptual understanding. This requires assessment that also focuses on conceptual understanding rather than recall of facts. This study outlines our development of a new assessment framework and tool-a taxonomy- which, unlike existing frameworks and tools, is grounded firmly in a framework that considers the critical role that models play in science. It also provides instructors a resource for assessing students' ability to reason about models that are central to the organization of key scientific concepts. We describe preliminary data arising from the application of our tool to exam questions used by instructors of a large-enrollment cell and molecular biology course over a 5-yr period during which time our framework and the assessment tool were increasingly used. Students were increasingly able to describe and manipulate models of the processes and systems being studied in this course as measured by assessment items. However, their ability to apply these models in new contexts did not improve. Finally, we discuss the implications of our results and the future directions for our research.  相似文献   

Bioinformatics and the Undergraduate Curriculum Essay     

Mark Maloney  Jeffrey Parker  Mark LeBlanc  Craig T. Woodard  Mary Glackin  Michael Hanrahan 《CBE life sciences education》2010,9(3):172-174

Recent advances involving high-throughput techniques for data generation and analysis have made familiarity with basic bioinformatics concepts and programs a necessity in the biological sciences. Undergraduate students increasingly need training in methods related to finding and retrieving information stored in vast databases. The rapid rise of bioinformatics as a new discipline has challenged many colleges and universities to keep current with their curricula, often in the face of static or dwindling resources. On the plus side, many bioinformatics modules and related databases and software programs are free and accessible online, and interdisciplinary partnerships between existing faculty members and their support staff have proved advantageous in such efforts. We present examples of strategies and methods that have been successfully used to incorporate bioinformatics content into undergraduate curricula.  相似文献   

Child adaptational development in contexts of interparental conflict over time     

Davies PT  Sturge-Apple ML  Winter MA  Cummings EM  Farrell D 《Child development》2006,77(1):218-233

This multi-method study sought to identify parameters of developmental change and stability of child reaction patterns to interparental conflict in the context of family relations in a sample of 223 6-year-old children and their parents followed over the course of one year. Consistent with the sensitization hypothesis, interparental withdrawal and hostility each consistently and uniquely predicted child distress reactions to conflict even after analytically controlling for parental warmth. Associations were found across multiple domains of child responding (i.e., overt negative affect, subjective negative affect, internal representations) and both concurrent and prospective, autoregressive analyses. Results of the autoregressive path analyses indicated moderate stability in each of the domains of conflict reactivity over the 1-year longitudinal period.  相似文献   

Racial self-categorization in adolescence: multiracial development and social pathways     

Hitlin S  Scott Brown J  Elder GH 《Child development》2006,77(5):1298-1308

Research on multiracial individuals is often cross-sectional, obscuring the fluid nature of multiracial self-categorization across time. Pathways of racial self-identification are developed from a nationally representative sample of adolescents aged 14-18, measured again 5 years later. A significant proportion of multiracial adolescents change racial self-identification across time. Youth who ever report being multiracial are 4 times as likely to switch self-identification as to report consistent multiracial identities. Across this time, more multiracial adolescents either add a racial category (diversify) or subtract one (consolidate) than maintain consistent multiracial self-categorization. Exploratory multinomial analyses show few differences between these pathways on select psychological and social characteristics. Results lend quantitative support to qualitative studies indicating the fluidity of racial self-categorization.  相似文献   

An integrated, multiparametric flow cytometry chip using ��microfluidic drifting�� based three-dimensional hydrodynamic focusing     

Xiaole Mao  Ahmad Ahsan Nawaz  Sz-Chin Steven Lin  Michael Ian Lapsley  Yanhui Zhao  J. Philip McCoy  Wafik S. El-Deiry  Tony Jun Huang 《Biomicrofluidics》2012,6(2):024113-024113-9

In this work, we demonstrate an integrated, single-layer, miniature flow cytometry device that is capable of multi-parametric particle analysis. The device integrates both particle focusing and detection components on-chip, including a “microfluidic drifting” based three-dimensional (3D) hydrodynamic focusing component and a series of optical fibers integrated into the microfluidic architecture to facilitate on-chip detection. With this design, multiple optical signals (i.e., forward scatter, side scatter, and fluorescence) from individual particles can be simultaneously detected. Experimental results indicate that the performance of our flow cytometry chip is comparable to its bulky, expensive desktop counterpart. The integration of on-chip 3D particle focusing with on-chip multi-parametric optical detection in a single-layer, mass-producible microfluidic device presents a major step towards low-cost flow cytometry chips for point-of-care clinical diagnostics.  相似文献   

An integrated, multiparametric flow cytometry chip using "microfluidic drifting" based three-dimensional hydrodynamic focusing     

Mao X  Nawaz AA  Lin SC  Lapsley MI  Zhao Y  McCoy JP  El-Deiry WS  Huang TJ 《Biomicrofluidics》2012,6(2):24113-241139

In this work, we demonstrate an integrated, single-layer, miniature flow cytometry device that is capable of multi-parametric particle analysis. The device integrates both particle focusing and detection components on-chip, including a "microfluidic drifting" based three-dimensional (3D) hydrodynamic focusing component and a series of optical fibers integrated into the microfluidic architecture to facilitate on-chip detection. With this design, multiple optical signals (i.e., forward scatter, side scatter, and fluorescence) from individual particles can be simultaneously detected. Experimental results indicate that the performance of our flow cytometry chip is comparable to its bulky, expensive desktop counterpart. The integration of on-chip 3D particle focusing with on-chip multi-parametric optical detection in a single-layer, mass-producible microfluidic device presents a major step towards low-cost flow cytometry chips for point-of-care clinical diagnostics.  相似文献   

Relationship between leg stiffness and lower body injuries in professional Australian football   总被引：2，自引：2，他引：0  

Pruyn EC  Watsford ML  Murphy AJ  Pine MJ  Spurrs RW  Cameron ML  Johnston RJ 《Journal of sports sciences》2012,30(1):71-78

Leg stiffness is a modifiable mechanical property that may be related to soft tissue injury risk. The purpose of this study was to examine mean leg stiffness and bilateral differences in leg stiffness across an entire professional Australian Football League (AFL) season, and determine whether this parameter was related to the incidence of lower body soft tissue injury. The stiffness of the left and right legs of 39 professional AFL players (age 24.4 ± 4.4 years, body mass 87.4 ± 8.1 kg, stature 1.87 ± 0.07 m) was measured using a unilateral hopping test at least once per month throughout the season. Injury data were obtained directly from the head medical officer at the football club. Mean leg stiffness and bilateral differences in leg stiffness were compared between the injured and non-injured players. There was no difference between the season mean leg stiffness values for the injured (219.3 ± 16.1 N x m(-1) x kg(-1)) and non-injured (217.4 ± 14.9 N x m(-1) x kg(-1); P = 0.721) groups. The injured group (7.5 ± 3.0%) recorded a significantly higher season mean bilateral difference in leg stiffness than the non-injured group (5.5 ± 1.3%; P = 0.05). A relatively high bilateral difference in leg stiffness appears to be related to the incidence of soft tissue injury in Australian football players. This information is of particular importance to medical and conditioning staff across a variety of sports.  相似文献   

Prediction of segmental lean mass using anthropometric variables in young adults     

Scafoglieri A  Tresignie J  Provyn S  Marfell-Jones M  Reilly T  Bautmans I  Clarys JP 《Journal of sports sciences》2012,30(8):777-785

The aim of the present study was to develop and cross-validate anthropometrical prediction equations for segmental lean tissue mass (SLM). One hundred and seventeen young healthy Caucasians (67 men and 50 women; mean age: 31.9 ± 10.0 years; Body Mass Index: 24.3 ± 3.2 kg · m(-2)) were included. Body mass (BM), stretch stature (SS), 14 circumferences (CC), 13 skinfolds (SF) and 4 bone breadths (BB) were used as anthropometric measurements. Segmental lean mass of both arms, trunk and both legs were measured by dual energy X-ray absorptiometry as the criterion method. Three prediction equations for SLM were developed as follows: arms = 40.394(BM) + 169.836(CCarm-tensed) + 399.162(CCwrist) - 85.414(SFtriceps) - 39.790(SFbiceps) - 7289.190, where Adj.R (2) = 0.97, P < 0.001, and standard error of estimate (SEE) = 355 g;trunk = 181.530(BM) + 155.037(SS) + 534.818(CCneck) + 175.638(CCchest) - 88.359(SFchest) - 147.232(SFsupraspinale) - 46522.165, where Adj.R(2) = 0.97, P < 0.001, and SEE = 1077g; and legs = 55.838(BM) + 88.356(SS) + 235.579(CCmid-thigh) + 278.595(CCcalf) + 288.984(CCankle) - 84.954(SFfront-thigh) - 53.009(SFmedial calf) - 28522.241, where Adj.R (2) = 0.96, P < 0.001, and SEE = 724 g. Cross-validation statistics showed no significant differences (P < 0.05) between observed and predicted SLM. Root mean squared errors were smallest for arms (362 g), followed by legs (820 g) and trunk (1477 g). These new prediction equations allow an accurate estimation of segmental lean mass in groups of young adults, but estimation errors of 8 to 14% can occur in certain individuals.  相似文献   

Distance reached in the Anteromedial Reach Test as a function of learning and leg length     

Bent NP  Rushton AB  Wright CC  Batt ME 《Research quarterly for exercise and sport》2012,83(2):188-195

The anteromedial reach test (ART) is a new outcome measure for assessing dynamic knee stability in anterior cruciate ligament-injured patients. The effect of learning and leg length on distance reached in the ART was examined. Thirty-two healthy volunteers performed 15 trials of the ART on each leg. There was a moderate correlation (r = .44-.50) between reach distance and leg length, therefore reach distances were normalized for leg length. Normalized reach distance increased significantly over the 15 trials (p < .01), reaching a plateau after 8 trials, identified by a moving average graph. It is recommended that participants be afforded eight practice trials and that reach distances be normalized by expressing them as a percentage of leg length.  相似文献   

The influence of hydration on anaerobic performance: a review     

Kraft JA  Green JM  Bishop PA  Richardson MT  Neggers YH  Leeper JD 《Research quarterly for exercise and sport》2012,83(2):282-292

This review examines the influence of dehydration on muscular strength and endurance and on single and repeated anaerobic sprint bouts. Describing hydration effects on anaerobic performance is difficult because various exercise modes are dominated by anaerobic energy pathways, but still contain inherent physiological differences. The critical level of water deficit (approximately 3-4%; mode dependent) affecting anaerobic performance is larger than the deficit (approximately 2%) impairing endurance performance. A critical performance-duration component (> 30 s) may also exist. Moderate dehydration (approximately 3% body weight; precise threshold depends on work/recovery ratio) impairs repeated anaerobic bouts, which place an increased demand on aerobic metabolism. Interactions between dehydration level, dehydration mode, testing mode, performance duration, and work/recovery ratio during repeated bouts make the dehydration threshold influencing anaerobic performance mode dependent.  相似文献