Asymptotic behavior of solutions of some semilinear functional differential and integro-differential equations with infinite delay in Banach spaces

We prove in this paper the existence and uniqueness of mild solutions to some functional differential and functional integro-differential equations with infinite delay in Banach spaces which approach almost automorphic functions at infinity. We also discuss the existence of S-asymptotically $\omega \text{-}\mathrm{periodic}$ mild solutions. The results are new.     

Robust block second order sliding mode control for a quadrotor

This paper presents the design of a controller based on the block control technique combined with the super twisting control algorithm for trajectory tracking of a quadrotor helicopter. A first order exact differentiator is used in order to estimate the virtual control inputs, which simplifies the control law design. In addition, the wind parameter resulting from the aerodynamic forces is also estimated in order to ensure robustness against these unmatched perturbations. The stability and finite time convergence of the exact differentiator have been recently proved by means of Lyapunov functions, and therefore the stability analysis of the proposed controller has been carried out along the same lines. The performance and effectiveness of the proposed controller are tested in a simulation study taking into account external disturbances.     

Appropriate intellectual property protection and economic growth in countries at different levels of development

This paper examines how the role of patents and utility models in innovation and economic growth varies by level of economic development. Using a panel dataset of over 70 countries, we find that patent protection is an important determinant of innovation and that patentable innovations contribute to economic growth in developed countries, but not in developing. Instead, in developing economies, a minor form of intellectual property rights (IPRs) - namely utility models - is conducive to innovation and growth, controlling for other factors. Using Korean firm level data as a case study, we find that utility model innovations contribute to firm performance when firms are technologically lagging and that those minor innovations can be a learning device and thus a stepping stone for developing more patentable inventions later on. Upon reaching higher levels of technological capabilities, firms become more reliant upon patents and less on utility models. Thus the lesson here is that patent protection enhances innovation and economic growth in countries where the capacity to conduct innovative research exists. Where this capacity is weaker, a system that provides incentives to conduct minor, incremental inventions is more conducive to growth. The significance of this paper is to emphasize the importance not just of the strength of IPRs but of the appropriate type of IPRs for economic development.     

Firms’ genetic characteristics and competence-enlarging strategies: A comparison between academic and non-academic high-tech start-ups

This paper argues that academic high-tech start-ups exhibit peculiar “genetic characteristics” that leave an enduring imprint on firm development. We formulate a series of hypotheses on the effects of such genetic characteristics on the post-entry strategies that academic high-tech start-ups adopt to enlarge their initial competence endowments. In the empirical section, we use matched-pair statistical techniques and run several regressions to test the theoretical hypotheses. Our findings contribute to the literature on the antecedents of the strategies adopted by academic high-tech start-ups. They also allow us to derive implications for academic entrepreneurs, university managers and policy makers.     

建构跨学科的中国环境与资源社会学

环境社会学与自然资源社会学是关于社会与自然界相互关系的两个主要研究传统。目前关于这两个分支学科的讨论主要是局限在美国学术界内,而其对于其它国家环境和社会研究学科建设的借鉴作用尚未引起足够的重视,这正是本文在中国的学术背景中提出环境社会学与自然资源社会学相互融合问题的原因所在。环境社会学在中国正处于重要的学科建设阶段,垮学科的中国环境与资源社会学在投身中国"资源节约型、环境友好型"社会的建设中完全有希望实现环境社会学与自然资源社会学的实质融合。     

Kinematic changes during learning the longswing on high bar

The purpose of this study is to provide evidence of technique changes during learning a sports-specific skill, the looped bar longswing (LLS). Thirteen male participants with no previous high bar experience took part in a training study. Kinematic data were collected using a CODA motion analysis system (200 Hz) during eight weekly testing sessions. Analyses focused on the amplitude of swing and the functional phase (FP) actions, defined by the rapid flexion to extension of the shoulders and extension to flexion of the hips as the performer passed through the lower vertical. Three groups were identified based on the number of sessions it took each participant to perform the LLS (G1: most successful, G2: intermediate, and G3: least successful). All participants were able to significantly increase swing amplitude over the training period (p < 0.05). For each participant the hip FP started significantly: later for G1, earlier for G2, and did not change for G3. Extension actions at the shoulders were dissimilar to those reported for elite gymnasts performing the longswing. The FP of the hips provides a mechanism to distinguish between the learners of different skill levels. The study has provided support for a single-subject design when investigating technique changes during learning.     

Using Simulation and Patient Role Play to Teach Electrocardiographic Rhythms to Physical Therapy Students

Purpose

The aims of the study were to differentiate: (1) physical therapy (PT) students’ preferred method for learning electrocardiographic (ECG) recognition utilizing standardized patient (SP) and human patient simulation (HPS) approaches, (2) the impact of HPS or SP on confidence in interpreting ECG, and 3) the effect of HPS or SP on students’ ability to make clinical decisions based upon ECG interpretation.

Methods

“Three educational methods were employed to teach ECG recognition to two different years of novice PT students enrolled in a cardiopulmonary physical therapy class. First, all students had a traditional lecture on ECG. Following the lecture, two problem-based learning (PBL) approaches were utilized. One approach used a SP and paper ECG strips, and the second approach utilized HPS with simulated ECG monitoring.”¹ Following the two PBL approaches, a post instructional survey regarding the learning experiences was conducted. Following instruction, each cohort (n = 24, n = 29) of PT students was given a mixed methods survey about their experience.

Results

Survey return rate amongst both cohorts was 77%. Independent sample of individual cohort and paired t-tests of combined data comparing HPS to SP revealed a strong preference for HPS (p = 0.003 (2008 cohort) and p = 0.0001 (2010 cohort)) and combined cohort (p = 0.0001). There were no significant differences in responses between cohorts or preference between the HPS method and the use of SP and HPS combined. Additionally, 75% of respondents either strongly agreed or agreed that they felt confident with their skill in ECG interpretation as presented with HPS or SP. 90% either strongly agreed or agreed that they understood how the ECG relates to patient treatment. Summative assessment utilizing HPS revealed that students were competent in their performance in ECG recognition and clinical decision making related to patient treatment.¹

Conclusion

Data support that HPS was the preferred method to improve student confidence in ECG recognition and interpretation.Key Words: human patient simulation, electrocardiography, critical care management, educational technology     

Triangulating Clinically Meaningful Change in the Six-minute Walk Test in Individuals with Chronic Heart Failure: A Systematic Review

Purpose

The purpose of the present review was to use existing, published data to provide an estimate of the amount of change in six-minute walk test distance (Δ6MWT) that represents a clinically meaningful change in individuals with chronic heart failure (CHF).

Methods

The present review included two separate literature searches of the CINAHL and Medline databases for articles that: (1) reported the intraclass correlation coefficient (ICC) of the 6MWT in individuals with CHF, and (2) used the 6MWT along with either aerobic capacity or health-related quality of life (HRQL) as study endpoints in randomized controlled trials (RCTs) of exercise-based intervention for individuals with CHF. The ICCs were used to calculate the minimum detectable difference (MDD) at the 95% confidence interval for each included study. The Δ6MWT associated with aerobic capacity and HRQL within-group effect sizes for the intervention and control groups in each included RCT was analyzed using receiver operating characteristic (ROC) curves.

Results

Thirteen articles reported the ICC for the 6MWT. The mean (standard deviation) MDD calculated based on these data was 43.1(16.8) m. Eighteen RCTs measured the 6MWT and either aerobic capacity and/or HRQL. A Δ6MWT of 40–45 m was associated with at least moderate aerobic capacity and HRQL effect sizes in the intervention groups. The Δ6MWT thresholds that discriminated between intervention and control groups using ROC curves revealed the following sensitivity/specificity for the respective thresholds: 19 m, 94.4/83.3%, 32 m, 83.3/94.4%, and 48 m 44.4/100% (AUC = .935, p = .009, CI_95% .855, 1.015).

Conclusions

A Δ6MWT of approximately 45 m appears to exceed measurement error and be associated with significant changes in either aerobic capacity and/or HRQL.Key Words: heart failure, six-minute walk test, clinically meaningful change, minimum detectable difference     

Putting proficiency: contributions of the pelvis and trunk

Putting proficiency is a key determinant of golfing success and yet minimal biomechanical research has been published on this important skill. Little is known about the motion and coordination of the pelvis and trunk during the putting motion. The purpose of this study was to present detailed three-dimensional (3D) kinematic profiles of the pelvis and trunk during the putting motion, and to determine if differences in kinematics exist between proficient and non-proficient golfers. A 3D analysis (100 Hz) was conducted on 10 single figure handicap golfers using a six-camera motion capture system. Participants completed 18 putts (2 m) towards a cup in an indoor facility and were subsequently divided into two groups based on putting proficiency (Proficient: >79%; Non-proficient: <79%). Variables assessed were the linear movements of the centre of mass (COM) and head, and the angular movements of the pelvis and trunk. Effect size statistics showed that the Proficient putters tended to move predominantly in the frontal plane (towards the target), while the non-proficient putters moved more sagittally. In addition, the Non-proficient putters recorded greater movement variability. The implications of this study suggest that putting proficiency is enhanced when the COM moves towards the target.     

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