Efficient sample preparation in immuno-matrix-assisted laser desorption/ionization mass spectrometry using acoustic trapping

Acoustic trapping of minute bead amounts against fluid flow allows for easy automation of multiple assay steps, using a convenient aspirate/dispense format. Here, a method based on acoustic trapping that allows sample preparation for immuno-matrix-assisted laser desorption/ionization mass spectrometry using only half a million 2.8 μm antibody covered beads is presented. The acoustic trapping is done in 200 × 2000 μm² glass capillaries and provides highly efficient binding and washing conditions, as shown by complete removal of detergents and sample processing times of 5-10 min. The versatility of the method is demonstrated using an antibody against Angiotensin I (Ang I), a peptide hormone involved in hypotension. Using this model system, the acoustic trapping was efficient in enriching Angiotensin at 400 pM spiked in plasma samples.     

On the determinants of employment-related organised education and informal learning

This paper analyses the distribution of employment-related organised education and informal learning in the Canadian workforce. The paper draws on a large-scale survey, the Changing Nature of Work and Lifelong Learning (WALL), which was based on structured and standardised telephone interviews with a representative sample of 5783 Canadian members of the employed labour force. In exploring the determinants facilitating employment-related informal learning, three analytical categories of factors derived from previous research on learning participation were used: individual-level factors, job characteristics and workplace environment. The analyses focus on differences in individuals, jobs and workplace characteristics among adult workers who acquired or improved their job-related skills through different training pathways. In addition, analyses were performed to compare the extent to which these factors differ in their influence on learning decisions among workers who combine both organised education and informal learning and those who receive only informal learning. The results indicate that important predictors of participation in employment-related organised education and informal learning are age, educational attainment, learning skills, occupational class, education-job relation, degree of autonomy, degree of labour intensity, principal area of production and organisation size.     

How Will We Understand What We Teach? - Primary Student Teachers’ Perceptions of their Development of Knowledge and Attitudes Towards Physics

The research outlined in this paper investigated how student teachers perceived the development of their knowledge and attitudes towards physics through video recorded practical workshops based on experiments and subsequent group discussions. During an 8-week physics course, 40 primary science student teachers worked in groups of 13–14 on practical experiments and problem-solving skills in physics. The student teachers were video recorded in order to follow their activities and discussions during the experiments. In connection with every workshop, the student teachers participated in a seminar conducted by their physics teachers and a primary science teacher; they watched the video recording in order to reflect on their activities and how they communicated their conceptions in their group. After the 8 weeks of coursework a questionnaire including a storyline was used to elicit the student teachers’ perceptions of their development of subject matter knowledge from the beginning to the end of the course. Finally, five participants were interviewed after the course. The results provided insight into how aspects such as self-confidence and the meaningfulness of knowledge for primary teaching were perceived as important factors for the primary science student teachers’ development of subject matter knowledge as well as a positive attitude towards physics.     

Selective cell capture and analysis using shallow antibody-coated microchannels

Demand for analysis of rare cells such as circulating tumor cells in blood at the single molecule level has recently grown. For this purpose, several cell separation methods based on antibody-coated micropillars have been developed (e.g., Nagrath et al., Nature 450, 1235–1239 (2007)). However, it is difficult to ensure capture of targeted cells by these methods because capture depends on the probability of cell-micropillar collisions. We developed a new structure that actively exploits cellular flexibility for more efficient capture of a small number of cells in a target area. The depth of the sandwiching channel was slightly smaller than the diameter of the cells to ensure contact with the channel wall. For cell selection, we used anti-epithelial cell adhesion molecule antibodies, which specifically bind epithelial cells. First, we demonstrated cell capture with human promyelocytic leukemia (HL-60) cells, which are relatively homogeneous in size; in situ single molecule analysis was verified by our rolling circle amplification (RCA) method. Then, we used breast cancer cells (SK-BR-3) in blood, and demonstrated selective capture and cancer marker (HER2) detection by RCA. Cell capture by antibody-coated microchannels was greater than with negative control cells (RPMI-1788 lymphocytes) and non-coated microchannels. This system can be used to analyze small numbers of target cells in large quantities of mixed samples.     

The stroke has only a minor influence on direction consistency in golf putting among elite players

In the golf instructional literature, the putting stroke is typically given higher priority than green reading and aiming. The main purpose of this study was to assess the importance of the putting stroke for direction consistency in golf putting. Kinematic stroke parameters were recorded from 71 elite golf players (mean handicap = 1.8, s = 4.2) on 1301 putts from about 4 m. Of the different factors deciding stroke direction consistency, face angle was found to be the most important (80%), followed by putter path (17%) and impact point (3%). This suggests that improvements in consistency of putter path and impact point will have very little effect on overall putting direction consistency and should not be prioritized in the training of elite players. In addition, mean stroke direction variability for an elite player (European Tour) was found to be 0.39 degrees, which is good enough to hole about 95% of all 4-m putts. In practice, however, top professionals in tournaments only hole about 17% of 4-m putts. We conclude that the putting stroke of elite golfers has a relatively minor influence on direction consistency.     

A new method for recording the temporal pattern of stride during treadmill running

The aim of this study was to investigate the reliability of a new infrared light based method (IR₄₀) for recording temporal stride patterns during treadmill running. The IR₄₀ device, emitting a tight web of 40 infrared light beams 10 mm above the treadmill running surface, was compared to a previously validated electro-pneumatic contact shoe (CS) method while nine well-trained athletes ran at 2.8, 3.3, 3.9, 4.4, 5.0, and 5.6 m s⁻¹. Disconnection and reconnection of the IR beams marked the stance phase. The sampling rate was 500 Hz for both methods. The stance phase duration was on average 11.5 (±8.4) ms longer with the IR₄₀ than with the CS depending on earlier touch down (8.3 ± 6.2 ms) and delayed toe off (3.2 ± 5.3 ms) registrations. Significantly different stance phases were recorded between all velocities and for both methods. Thus, despite the fact that the IR₄₀ systematically measured a somewhat longer stance phase duration than CS, the IR₄₀ is nonetheless useful for temporal stride analysis during treadmill running.     

Knee angular displacement and extensor muscle activity in telemark skiing and in ski-specific strength exercises

Much of the training of competitive telemark skiers is performed as dry-land exercises. The specificity of these exercises is important for optimizing the training effect. Our aim here was to study the activation of the knee extensor musculature and knee angular displacement during competitive telemark skiing and during dry-land strength training exercises to determine the specificity of the latter. Specificity was analysed with respect to angular amplitude, angular velocity, muscle action and electromyographic (EMG) activity. Five male telemark skiers of national and international standard volunteered to participate in the study, which consisted of two parts: (1) skiing a telemark ski course and (2) specific dry-land strength training exercises for telemark skiing (telemark jumps and barbell squats). The angular displacement of the right knee joint was recorded with an electrogoniometer. A tape pressure sensor was used to measure pressure between the sole of the foot and the bottom of the right ski boot. Electromyographic activity in the right vastus lateralis was recorded with surface electrodes. The EMG activity recorded during maximum countermovement jumps was used to normalize the EMG activity during telemark skiing, telemark jumps and barbell squats. The results showed that knee angular displacement during telemark skiing and dry-land telemark jumps had four distinct phases: a flexion (F1) and extension (E1) phase during the thrust phase of the outside ski/leg in the turn/jump and a flexion (F2) and extension (E2) phase when the leg was on the inside of the turn/jump. The vastus lateralis muscle was activated during F1 and E1 in the thrust phase during telemark skiing and telemark jumps. The overall net knee angular amplitude was significantly greater (P < 0.05) for telemark jumps than for telemark skiing. Barbell squats showed a knee angular amplitude significantly greater than that in telemark skiing (P < 0.05). The mean knee angular velocity of the F1 and E1 phases during telemark skiing was about 0.47 rad x s(-1); during barbell squats, it was about 1.22 rad x s(-1). The angular velocity during telemark jumps was 2.34 and 1.59 rad x s(-1) in the F1 and E1 phase, respectively. The normalized activation level of the EMG bursts during telemark skiing, telemark jumps and barbell squats was 70-80%. In conclusion, the muscle action and level of activation in the vastus lateralis during the F1 and E1 phases were similar during telemark skiing and dry-land exercises. However, the dry-land exercises showed a larger knee extension and flexion amplitude and angular velocity compared with telemark skiing. It appears that an adjustment of knee angular velocity during barbell squats and an adjustment of knee angle amplitude during both telemark jumps and barbell squats will improve specificity during training.     

Work-time profile,blood lactate concentration and rating of perceived exertion in the 1998 Greco-Roman Wrestling World Championship

The aim of this study was to examine work-time profiles, blood lactate concentrations and perceived exertion among Greco-Roman wrestlers in the 1998 World Championship. Forty-two senior wrestlers from nine nations were studied in 94 matches. Each match was recorded with a video camera (Panasonic AG 455, film rate: 25 Hz) and analysed for duration of work (wrestling) and rest (interrupt) periods. Blood lactate concentration was determined with an electrochemical device (Analox P-LM5) and a rating of perceived exertion scale (Borg) was used to estimate general exertion and exertion in the extremity and trunk muscles. The mean duration of the matches was 427 s (range 324-535 s), with mean durations of work and rest of 317 and 110 s, respectively. The mean periods of work and rest were 37.2 and 13.8 s, respectively. Mean blood lactate concentration was 14.8 mmol x 1(-1) (range 6.9-20.6). The difference in mean blood lactate concentration between the first- and final-round matches was not significant (P > 0.05). Blood lactate concentration was significantly higher (P < 0.04) in matches of long duration than in those of short duration. The mean general rating of perceived exertion for all matches was 13.8 according to the scale used. Most of the wrestlers (53.3%) perceived exertion to be highest in the flexors of the forearm, followed by the deltoids (17.4%) and the biceps brachii muscles (12.0%). In addition to a relatively high rating of perceived exertion in the arm muscles, this indicates a high specific load on the flexor muscles of the forearm.     

A resourcification manifesto: Understanding the social process of resources becoming resources

In times of major global interconnectedness and environmental change, the pressure to identify, create, and exploit new resources is certain to intensify. Given that there are unavoidable trade-offs, conflicts, and arenas for violence involved when increasingly more material and immaterial things are turned into resources, we call for explicit research on the very process – a process that we label resourcification. The concept of resourcification shifts attention from essentialist queries about the nature of resources to a focus on the social processes through which things are turned into resources. In search of a better understanding of resources in the Anthropocene and, in particular, an understanding about the way resources emerge and are used, resourcification offers a new conceptual framework that allows for a systematic search for knowledge about the diversity of contexts, conditions, modes, and temporalities of resourcification. This Resourcification Manifesto offers a theoretical and empirical framework for a radical and disruptive approach to innovation, sustainability, and management studies and policies.