Enhanced single-cell printing by acoustophoretic cell focusing

Recent years have witnessed a strong trend towards analysis of single-cells. To access and handle single-cells, many new tools are needed and have partly been developed. Here, we present an improved version of a single-cell printer which is able to deliver individual single cells and beads encapsulated in free-flying picoliter droplets at a single-bead efficiency of 96% and with a throughput of more than 10 beads per minute. By integration of acoustophoretic focusing, the cells could be focused in x and y direction. This way, the cells were lined-up in front of a 40 μm nozzle, where they were analyzed individually by an optical system prior to printing. In agreement with acoustic simulations, the focusing of 10 μm beads and Raji cells has been achieved with an efficiency of 99% (beads) and 86% (Raji cells) to a 40 μm wide center region in the 1 mm wide microfluidic channel. This enabled improved optical analysis and reduced bead losses. The loss of beads that ended up in the waste (because printing them as single beads arrangements could not be ensured) was reduced from 52% ± 6% to 28% ± 1%. The piezoelectric transducer employed for cell focusing could be positioned on an outer part of the device, which proves the acoustophoretic focusing to be versatile and adaptable.     

Introducing novel approaches for examining the variability of individuals’ physical activity

Tudor-Locke and colleagues previously assessed steps/day for 1 year. The aim of this study was to use this data set to introduce a novel approach for the investigation of whether individual’s physical activity exhibits periodicity fluctuating round a mean and, if so, the degree of fluctuation and whether the mean changes over time. Twenty-three participants wore a pedometer for 365 days, recorded steps/day and whether the day was a workday. Fourier transform of each participant’s daily steps data showed the physical activity had a periodicity of 7 days in half of the participants, matching the periodicity of the workday pattern. Activity level remained stable in half of the participants, decreased in ten participants and increased in two. In conclusion, the 7-day periodicity of activity in half of the participants and correspondence with the workday pattern suggest a social or environmental influence. The novel analytical approach introduced herein allows the determination of the periodicity of activity, the degree of variability in activity that is tolerated during day-to-day life and whether the activity level is stable. Results from the use of these methodologies in larger data sets may enable a more focused approach to the design of interventions that aim to increase activity.     

Tracking of physical activity in pubertal boys with different BMI over two-year period

We examined the tracking of physical activity (PA) measured by accelerometers and subjective self- and parental reports in normal weight and overweight and obese pubertal boys over two-year period. In total, 156 boys with mean (±SD) age of 11.53 ± 0.76 at baseline and with mean age of 13.94 ± 0.74 at 2 year follow-up were studied. At baseline and approximately two years later, the boys completed self-report questionnaire and wore an accelerometer for seven consecutive days. On the basis of first year assessment’s body mass index (BMI), the children were grouped as normal weight and overweight and obese groups according to BMI cut-offs. Tracking correlations of objectively measured PA and subjectively measured PA were fairly similar across the 12–14 year-old-boys weight groups over two year period. Tracking correlations of objectively measured PA and subjectively measured PA were not significantly different over two-year period between both BMI groups. The results of the study show that pubertal boys objectively measured PA decreased over two-year period and so the boys started to be less active in their pubertal period.     

The Dutch motor skills assessment as tool for talent development in table tennis: a reproducibility and validity study

A motor skills assessment could be helpful in talent development by estimating essential perceptuo-motor skills of young players, which are considered requisite to develop excellent technical and tactical qualities. The Netherlands Table Tennis Association uses a motor skills assessment in their talent development programme consisting of eight items measuring perceptuo-motor skills specific to table tennis under varying conditions. This study aimed to investigate this assessment regarding its reproducibility, internal consistency, underlying dimensions and concurrent validity in 113 young table tennis players (6–10 years). Intraclass correlation coefficients of six test items met the criteria of 0.7 with coefficients of variation between 3% and 8%. Cronbach’s alpha valued 0.853 for internal consistency. The principal components analysis distinguished two conceptually meaningful factors: “ball control” and “gross motor function.” Concurrent validity analyses demonstrated moderate associations between the motor skills assessment’s results and national ranking; boys r = ?0.53 (P < 0.001) and girls r = ?0.45 (P = 0.015). In conclusion, this evaluation demonstrated six test items with acceptable reproducibility, good internal consistency and good prospects for validity. Two test items need revision to upgrade reproducibility. Since the motor skills assessment seems to be a reproducible, objective part of a talent development programme, more longitudinal studies are required to investigate its predictive validity.     

Argentina and the 1984 Los Angeles Olympics

The election of Raúl Alfonsín in October of 1983 represented the return of democracy to Argentina after more than seven years of a military dictatorship that left the country in a terribly distressed state. Since the dictatorship had joined the boycott of the 1980 Moscow Olympics led by the USA, for Argentina, the 1984 Los Angeles Olympics meant both coming back to the Olympic fold and the first such festival under the new democratic government. This paper explores Argentina's trajectory towards, and construction of, its participation in the country's first post-dictatorship Olympics. In doing so, this paper reveals why participation in the 1984 Los Angeles Olympics was not a priority for the incoming administration and why such participation was not conceived as a potential emissary capable of reaffirming on the global Olympic stage the hard fought, yet still emerging, democracy of Argentina. In addition, it reveals not only the determination of the Alfonsín administration to make his sport policy work but also its aspirations, complexity and ambiguities.     

论CBA篮球运动员的职业道德特点与发展对策

文章运用文献研究和逻辑分析的方法,对我国现阶段CBA运动员职业道德现状进行了审视,总结出现阶段CBA运动员职业道德具有运动员人生观和价值观多样化、运动员竞技体育精神缺乏、运动员职业道德失范形式多样化等几个特点。在此基础上,进一步提出发展CBA篮球运动员职业道德建设的几种途径：（1）完善各项CBA联赛规章制度;（2）加强CBA运动员职业道德教育;（3）建立CBA职业联赛职业道德监督机构;（4）营造良好的职业篮球舆论环境;（5）加强CBA运动员的文化教育,以期能够对我国职业篮球的总体发展提供一个理论上的借鉴。     

给排水专业学生科研创新能力培养模式研究

水环境的变化给传统工科给排水专业带来新的挑战,现行给排水专业人才培养模式需要调整,以满足学生对科研创新能力的需求。该文从实验课程内容改进、实施本科生导师制、本科生科技创新项目等方面对给排水专业本科生科研创新能力培养中出现的一些问题进行了分析,并结合华侨大学给排水专业情况探讨了本科生科研创新能力的培养模式。     

我国银行系P2P模式发展存在的问题及对策

随着我国互联网金融的火爆,P2P平台的快速发展,我国传统银行业受到一定的冲击。我国九家商业银行也相应推出自有的P2P平台,称为银行系P2P。银行系P2P一推出便受到广大投资者的追捧。但其收益率较低,管理模式滞后,风险控制体系不健全也是银行系P2P急需提升的短板。逐步提升产品收益、创新经营管理模式、健全风险控制体系是我国银行系P2P的当务之急。