Optofluidic tunable microlens by manipulating the liquid meniscus using a flared microfluidic structure

We have designed, demonstrated, and characterized a simple, novel in-plane tunable optofluidic microlens. The microlens is realized by utilizing the interface properties between two different fluids: CaCl(2)solution and air. A constant contact angle of ～90° is the pivotal factor resulting in the outward bowing and convex shape of the CaCl(2) solution-air interface. The contact angle at the CaCl(2) solution-air interface is maintained by a flared structure in the polydimethylsiloxane channel. The resulting bowing interface, coupled with the refractive index difference between the two fluids, results in effective in-plane focusing. The versatility of such a design is confirmed by characterizing the intensity of a traced beam experimentally and comparing the observed focal points with those obtained via ray-tracing simulations. With the radius of curvature conveniently controlled via fluid injection, the resulting microlens has a readily tunable focal length. This ease of operation, outstandingly low fluid usage, large range tunable focal length, and in-plane focusing ability make this lens suitable for many potential lab-on-a-chip applications such as particle manipulation, flow cytometry, and in-plane optical trapping.     

Reproducibility, accuracy and concordance of Accutrend Plus for measuring circulating lipid concentration in adults

Introduction

The determination of lipid biomarkers by capillary sampling may be useful in the screening, diagnosis and/or personal management of hyperlipidemia and cardiovascular risk. It remains unclear whether the use of the Accutrend^® Plus system is appropriate. This study aimed to assess its reproducibility, accuracy and concordance for blood lipid profiling in adults.

Materials and methods:

Fasting capillary total cholesterol (TC) and triglyceride (TG) concentration on Accutrend^® Plus were compared with their venous analogues obtained by a laboratory reference method in sixty-one adults (27 men and 34 women, aged 33.0 years). Supplementary capillary sampling was performed at two consecutive days taking into account macro-nutrient intake.

Results:

The day-to-day reproducibility of the Accutrend^® Plus system proved to be high for TC (ICC = 0.85, P < 0.001), but moderate for TG (ICC = 0.68, P < 0.001). Strong correlations (r ≥ 0.80, P < 0.001) with the reference method were found for TC and TG. Mean difference (limits of agreement) were: 0.26 mmol/L (−0.95, 1.47) for TC, and −0.16 mmol/L (−1.29, 0.98) for TG. The concordance for subject classification according to the National Cholesterol Education Program (NCEP) guidelines was significant (P < 0.001), with substantial agreement for TC (κ_w = 0.67), and moderate agreement for TG (κ_w = 0.50).

Conclusions:

Day-to-day reproducibility of the Accutrend^® Plus device for TC and TG is not optimal and lacks accuracy when compared to the reference laboratory method. The concordance between both methods for classifying subjects according to the NCEP is inadequate. Accutrend^® Plus device should not be interchangeably used as a substitution for the standard laboratory methods in the diagnosis of hyperlipidemia.     

心肺耐力:体质健康的核心要素——以美国有氧中心纵向研究为例

从20世纪40年代开始的体力活动与冠心病发病及死亡风险的研究使人们开始关注体力活动、心肺耐力与健康及疾病风险间的关联。特别是近些年来世界范围内体力活动不足问题日益加剧,体力活动与心肺耐力,以及心肺耐力在人体健康状况及疾病死亡风险中的重要作用尤其受到关注,成为公共健康与运动科学领域最活跃的研究方向之一。心肺耐力作为人群体力活动水平的一个客观生理指标,与各人群全死因死亡率及心血管疾病死亡率高度相关,是体质健康各组成部分的核心要素。以Steven N Blair教授在美国Cooper研究所主持开展的有氧中心纵向研究(ACLS)的系列成果为主要参考资料,综述体力活动、心肺耐力与人群健康及疾病风险间的关联,并讨论前瞻性流行病学研究在体力活动与公共健康研究领域的重要功能,揭示心肺耐力在体质健康各要素中的核心地位。     

Children's Social Goals and Self-Efficacy Perceptions as Influences on Their Responses to Ambiguous Provocation

This study examined whether children who vary in their behavioral responses (aggression vs. withdrawal vs. problem solving) to ambiguous provocation but who are similar in their attributional processes differ in their social goals and self-efficacy perceptions. In response to 10 hypothetical situations involving ambiguous provocation, fourth- and fifth-grade students ( n = 781) indicated whether or not the protagonist intended to cause the harm and reported how they would respond to the protagonist's action. Newly developed measures assessed children's situated social goals and self-efficacy perceptions. Results indicated that the aggressive, withdrawn, and problem-solving responders differed in their social goals and self-efficacy perceptions. The strength of the findings, compared to earlier work on children's goals and self-efficacy perceptions, suggests the importance of a situated social-cognitive assessment in which children's thoughts are measured in a specific kind of social situation and are related to their reported behavior in the same type of situation.     

Differences in Pride and Shame in Maltreated and Nonmaltreated Preschoolers

This study examined the expression of shame and pride in maltreated and nonmaltreated preschool children. 84 4–5-year-old children and their mothers participated in the study: 42 had a history of child maltreatment and 42 served as matched controls. Children were presented with easy and difficult tasks and their emotional responses of shame and pride were observed. No shame was shown when subjects succeeded on the tasks and no pride was shown when they failed. Maltreating mothers offered more negative feedback, particularly to their daughters, than nonmaltreating mothers. Maltreated girls showed more shame when they failed and less pride when they succeeded than nonmaltreated girls. The relation between differential socialization practices and the self-conscious emotions is explored as it relates to observed gender differences in emotionality and self-concept.     

In search of a happy medium in instructional technology research: Issues concerning external validity,media replications,and learner control

Due in part to the diverse characteristics and training of its researchers, the field of instructional technology is currently plagued by much uncertainty regarding meaningful research questions and accepted paradigms for investigating them. Major areas in which these uncertainties are manifested concern the degree of emphasis to be placed on basic versus developmental research and considerations involving the separation of media from methods in research designs. To help researchers achieve a “happier medium” in balancing instructional technology goals with the performance of well-designed and scientifically sound studies, greater attention to three concerns is advocated: the external validity of studies to increase the relevance of findings to applied technologies; usage of media replications to test the generalizability of findings obtained with individual media and to demonstrate delivery applications; and learner control as a potentially effective and practical means of adapting validated instructional strategies to individuals. Each of these issues is discussed in relation to research conducted by the authors and to suggested designs for future studies. The authors would like to thank Robert D. Tennyson for his helpful suggestions regarding an earlier draft.     

Private Speech of Learning Disabled and Normally Achieving Children in Classroom Academic and Laboratory Contexts

Learning disabled (LD) children are often targets for cognitive-behavioral interventions designed to train them in effective use of a self-directed speech. The purpose of this study was to determine if, indeed, these children display immature private speech in the naturalistic classroom setting. Comparisons were made of the private speech, motor accompaniment to task, and attention of LD and normally achieving classmates during academic seatwork. Setting effects were examined by comparing classroom data with observations during academic seatwork and puzzle solving in the laboratory. Finally, a subgroup of LD children symptomatic of attention-deficit hyperactivity disorder (ADHD) was compared with pure LD and normally achieving controls to determine if the presumed immature private speech is a function of a learning disability or externalizing behavior problems. Results indicated that LD children used more task-relevant private speech than controls, an effect that was especially pronounced for the LD/ADHD subgroup. Use of private speech was setting- and task-specific. Implications for intervention and future research methodology are discussed.     

Spelling improvement for college students who are dyslexic

Academic problems of the dyslexic child often persist in adult life. Such problems as spelling can interfere with the performance of such adult learners in college. Federal legislation requires reasonable accommodation for these students. At some colleges, this consists of allowing use of tape recorders in lectures and sometimes allowing extra time on examinations. Remediation of reading, writing, and spelling among dyslexic college students is often not addressed. This study reports the use of a modified Orton-Gillingham approach in comparison with a nonphonetic approach and with a group receiving no remediation. The results indicate a significant increase in spelling performance for the group receiving the modified Orton-Gillingham remediation. This contrasts with no significant change in the group receiving nonphonetic remediation and in the control group (no remediation), and indicates that adulthood is not too late for appropriate intervention for the dyslexic student. Colleges offering such intervention and the students receiving it will benefit from improved performance.     

Contextual cues and the retrieval of competing memories of goal events

In Experiment 1, four groups of rats were initially trained on a discrimination which established a stimulus as a signal for reinforcement. That signal was then presented during subsequent partial reinforcement training in a way that could potentially interfere with retrieval of the memory of nonreinforcement (S^N) on the preceding trial either because (1) thestorage and retrieval contexts for S^N were different (retrieval failure hypothesis), or (2) the memory of reinforcement produced by the signal acted as a competing memory (competing memory hypothesis). Experiment 1 supported the competing memory hypothesis. In Experiment 2, we investigated the effect of stimulus change on the capacity of the context to retrieve a competing memory of a temporally remote reinforcement event with which the context was strongly associated. Retrieval of a competing memory was impaired by differences between the storage and retrieval contexts in a manner analogous to the effect of context on retrieval of a reinforcement event memory from an immediately preceding trial.