Application of Instrumented Paddles in Measuring On-Water Kinetics of Front and Back Paddlers in K2 Sprint Kayaking Crews of Various Ability Levels.

This study used instrumented paddles to obtain on-water kinetic variables of two-seater (K2) crews during sprint kayaking. A total of 74 male kayakers of various ability levels (national team: 9, recreational club: 38, school team: 27) comprising 39 K2 crews were recruited. Both the front and back paddlers were provided with an instrumented paddle to perform 200-m maximal effort paddling in a reservoir. Force, power, and temporal variables were extracted from the paddle data. Difference among groups were compared using a factorial Analysis of Variance. Results showed that the force, power, and temporal characteristics of the front and back paddlers were similar during maximal effort sprint kayaking. Proficient kayakers produced greater kinetic outputs than less proficient kayakers, while the coordination strategy based on timing differences at key events between the two crew members in a K2 boat was similar across ability levels. These data can be useful for coaches, sport scientists, and athletes in planning and monitoring the training.

Development and validation of the incontinence associated dermatitis knowledge, attitude and practice questionnaire.

AIM: This study aimed to develop and test the validity and reliability of the Knowledge, Attitudes and Practices of Incontinence-associated Dermatitis Questionnaire (KAP-IAD-Q) for Nurses. METHODS: A psychometric validation design was employed. Phase I of the study entailed the development of items through an extensive literature review and a double Delphi procedure with 11 experts specialised in wound, ostomy and continence to examine content validity of the KAP-IAD-Q. Phase II involved administering the KAP-IAD-Q to a convenience sample of 263 Registered Nurses from a public hospital in Singapore to evaluate its construct validity, internal consistency and test-retest reliability. RESULTS: The instrument showed acceptable content validity (S-CVI = 0.85). Exploratory factor analysis showed all 22 items demonstrated strong factor loadings >0.4 and the four factors KAP-IAD-Q explained 58.1% of total variance. The four factors were☹1) knowledge om IAD aetiology and identification, (2) knowledge on IAD risk factors; (3) attitudes, and (4) practices. The overall internal consistency was excellent (Cronbach's α = 0.913). The KAP-IAD-Q showed good overall test-retest reliability as well (ICC = 0.89 (95% CI 0.69-0.96, p < 0.001). CONCLUSION: The KAP-IAD-Q demonstrated good psychometric properties and is effective in measuring levels of IAD-related KAP among nurses. Further confirmation of the proposed factor structure is recommended. Future research should explore determinants of nurses' KAP and associations between IAD knowledge, attitudes and practices.

Kayaking paddle blade compression load distribution sensing system based on optical fiber with a polydimethylsiloxane membrane.

This paper proposed a novel real-time compression load measurement system for a kayaking paddle based on optical fiber technology. The optical fiber sensor, fiber Bragg grating, is embedded in a 2 mm polydimethylsiloxane membrane, which serves as a pressure mat that can be easily attached/detached to/from the kayaking paddle. The proposed system is proposed for measuring and evaluating both handgrip loading and paddle blade load distribution during on-water kayaking, e.g., peak compression load distribution pattern and duration of the paddle blade in real time. Both indoor prototype experiment results and on-water experimental data on an expert paddler were presented to demonstrate the application potential of the proposed system.

Transcriptome analysis for the identification of cellular markers related to trabecular meshwork differentiation.

BACKGROUND: Development of primary open-angle glaucoma (POAG) is associated with the malfunctioning trabecular meshwork (TM). Cell therapy offers great potential for the treatment of POAG, but requires the generation of functional TM cells in vitro to replace the lost/dysfunctional cells. TM differentiation in vitro from various stem cell types must be monitored by the expression of specific markers. However, no single definitive marker of the TM has been identified. RESULTS: To identify robust markers of TM differentiation, we performed global transcriptome profiling using high-density oligonucleotide microarray on ex vivo TM tissue and cultured TM progenitors. Corneal and scleral tissues were also used in the analysis. After removal of genes expressed in the cornea and sclera, 18 genes were identified that were differentially expressed in the TM relative to the other samples. CDH23, F5, KCNAB1, FGF9, SPP1, and HEY1 were selected among the genes highly expressed in the TM, together with BDNF which was repressed, compared to progenitors for further investigation. Expression analysis by qPCR verified the differential expression and immunofluorescence of the anterior segment confirmed strong expression in the TM. CONCLUSIONS: Three independent cohort of expression studies have identified novel markers, fitting in identifying TM cells and in evaluating directed TM differentiation in vitro.

Overall Preference of Running Shoes Can Be Predicted by Suitable Perception Factors Using a Multiple Regression Model.

OBJECTIVE: This study examined (a) the strength of four individual footwear perception factors to influence the overall preference of running shoes and (b) whether these perception factors satisfied the nonmulticollinear assumption in a regression model. BACKGROUND: Running footwear must fulfill multiple functional criteria to satisfy its potential users. Footwear perception factors, such as fit and cushioning, are commonly used to guide shoe design and development, but it is unclear whether running-footwear users are able to differentiate one factor from another. METHODS: One hundred casual runners assessed four running shoes on a 15-cm visual analogue scale for four footwear perception factors (fit, cushioning, arch support, and stability) as well as for overall preference during a treadmill running protocol. RESULTS: Diagnostic tests showed an absence of multicollinearity between factors, where values for tolerance ranged from .36 to .72, corresponding to variance inflation factors of 2.8 to 1.4. The multiple regression model of these four footwear perception variables accounted for 77.7% to 81.6% of variance in overall preference, with each factor explaining a unique part of the total variance. CONCLUSION: Casual runners were able to rate each footwear perception factor separately, thus assigning each factor a true potential to improve overall preference for the users. The results also support the use of a multiple regression model of footwear perception factors to predict overall running shoe preference. APPLICATION: Regression modeling is a useful tool for running-shoe manufacturers to more precisely evaluate how individual factors contribute to the subjective assessment of running footwear.

Neural development in human embryonic stem cells-applications of lentiviral vectors.

The derivation of neural lineages from human embryonic stem cells (hESCs) in vitro is based largely on exposure of hESCs to exogenous signals and substrates, designed to mimic conditions in the developing embryo. However, selection of specific lineages and the discovery of gene function in human neural development may be enhanced by the ability to intrinsically regulate gene expression. Recombinant lentiviral vectors provide an efficient method to stably introduce genes into hESC and their differentiating derivatives. Here we review the methods used to derive neural cells from hESCs, transduction of these cells with lentiviral vectors, and improvements that have been made to the vectors to enhance viral integration and transgene expression. Finally, we explore prospects for future uses of lentiviral vectors in hESC research, including their applications in library screening for drug development, zinc finger nucleases for gene editing and optogenetics to interrogate cellular pathways and function.

The Role of Vision in Maintaining Stroke Synchronization in K2 Crew-Boat Kayaking.

This study investigated the role of vision in maintaining stroke synchronization in crew-boat sprint kayaking. Sixteen sprint kayakers from a national team were paired into eight two-seater (K2) crews. Each crew paddled at high intensity with the back paddler's eyes open or closed in a randomized order. Using video analysis, stroke synchronization was quantified by the timing offsets between the front and back paddlers at four key positions of the stroke. All crews could paddle continuously without capsize or stopping under both visual conditions. In the absence of vision, neither 200-m performance time (p = 0.23, d = 0.47, small effect size) nor stroke rate (p = 0.41, d = 0.31, small effect size) was severely affected. There were no significant effects of vision on stroke synchronization offsets between the front and back paddlers across all key positions (all p > 0.05). Highly skilled paddlers likely relied on the kinesthetic perception to maintain the boat synchronization when visual information was not available.

Rapid flood and damage mapping using synthetic aperture radar in response to Typhoon Hagibis, Japan.

During the aftermath of Typhoon Hagibis, we made flood and damage proxy maps, rapidly derived from synthetic aperture radar (SAR) data using change detection approaches. The maps have large spatial coverage over the Tokyo, Fukushima, Ibaraki, Iwate, and Nagano prefectures of Japan. The maps are also largely in agreement with various validation sources including aerial imagery, optical imagery and news sources. Apart from visual maps, we provide flood and damage extents in various formats compatible with geographic information system (GIS) applications. The data may potentially be used for applications such as typhoon risk modelling, investigating spatial correlations of typhoon impacts, and comparing alternative flood or damage mapping techniques.

A Video-Based Method to Quantify Stroke Synchronisation in Crew Boat Sprint Kayaking.

The study aimed to quantify stroke synchronisation in two-seater crew boat sprint kayaking (K2) using a video-based method, and to assess the intra- and inter-rater reliabilities of this method. Twelve sub-elite sprint kayakers (six males and six females) from a national team were paired into six single-gender K2 crews. The crews were recorded at 120 Hz with a sagittal-view video camera during 200-m time trials. Video analysis identified four meaningful positions of a stroke (catch, immersion, extraction and release). The timing difference (termed "offset") between the front and back paddlers, within each K2, at each stroke position was calculated, with zero offset indicating perfect synchronisation. Results showed almost perfect intra-rater reliability of this method. The intra-class correlation (ICC) ranged from .87 to 1.00, and standard error of measurement ( SEM) from 0 to 5 milliseconds (ms). Inter-rater reliability was substantial to almost perfect (ICC .72 - .94, SEM 2 - 6 ms). On average, 35 strokes were analysed for each crew and the mean offset was 17 ms, or 5.7% of water phase duration. Crews were more synchronised at the catch (11 ms, 3.8%) than the release (21 ms, 7.2%). However, the stroke synchronisation profiles of the six sub-elite crews varied considerably from each other. For example, the best performing male and female crews had directly contrasting profiles. This suggests that there is no universal stroke synchronisation profile for well-trained sprint kayakers. This video-based method may aid future investigations on improving performance.

Personality, biographical characteristics, and job interview success: a longitudinal study of the mediating effects of interviewing self-efficacy and the moderating effects of internal locus of causality.

In this study, the authors developed and tested a model of performance in job interviews that examines the mediating role of interviewing self-efficacy (I-SE; job applicants' beliefs about their interviewing capabilities) in linking personality and biographical background with interview success and the moderating role of locus of causality attributions in influencing the relationship between interview success and subsequent I-SE. The authors tested their model (over 5 months' duration) with matched data from 229 graduating seniors, firms, and university records. Hierarchical regression analyses demonstrated I-SE mediated the effects of Extraversion, Conscientiousness, and leadership experience on interview success. Locus of causality attributions for interview outcomes moderated the relationship between interview success and subsequent I-SE. Theoretical and practical implications are discussed.

Using gait parameters to detect fatigue and responses to ice slurry during prolonged load carriage.

This study examined (1) if changes in gait characteristics could indicate the exertional heat stress experienced during prolonged load carriage, and (2) if gait characteristics were responsive to a heat mitigation strategy. In an environmental chamber replicating tropical climatic conditions (ambient temperature 32°C, 70% relative humidity), 16 males aged 21.8 (1.2) years performed two trials of a work-rest cycle protocol consisting two bouts of 4-km treadmill walks with 30-kg load at 5.3km/h separated by a 15-min rest period. Ice slurry (ICE) or room temperature water (29°C) as a control (CON) was provided in 200-ml aliquots. The fluids were given 10min before the start, at the 15(th) and 30(th) min of each work cycle, and during each rest period. Spatio-temporal gait characteristics were obtained at the start and end of each work-rest cycle using a floor-based photocell system (OptoGait) and a high-speed video camera at 120Hz. Repeated-measure analysis of variance (trial×time) showed that with time, step width decreased (p=.024) while percent crossover steps increased (p=.008) from the 40(th) min onwards. Reduced stance time variability (-11.1%, p=.029) step width variability (-8.2%, p=.001), and percent crossover step (-18.5%, p=.010) were observed in ICE compared with CON. No differences in step length and most temporal variables were found. In conclusion, changes in frontal plane gait characteristics may indicate exertional heat stress during prolonged load carriage, and some of these changes may be mitigated with ice slurry ingestion.

Identification and characterization of mesenchymal stem cells derived from the trabecular meshwork of the human eye.

Mesenchymal stem cells (MSC) have been isolated from several adult human tissues. Their propensity to differentiate into cell types of connective tissue, such as osteocytes, chondrocytes, and adipocytes, suggests that MSC may function as a reserve of progenitor cells that repair and maintain healthy adult tissues. Dysfunction of the trabecular meshwork (TM), a connective tissue at the anterior region of the human eye that regulates intraocular pressure, plays a major role in the pathogenesis of glaucoma. The mechanobiology and pharmacological aspects of the TM tissue have been relatively well studied in disease states. Less well understood is if there are progenitor cells within the TM that contribute to maintenance of this tissue. In this study, we have identified and characterized an expandable population of cells that have stem cell-like properties. In particular, these cells express the markers CD73, CD90, and CD105, which are typically associated with MSC. Thus, we have named these cells TM-MSC. As further evidence that these cells are MSC, they were differentiated in vitro into adipocytes, osteocytes, and chondrocytes. Through genomic characterization, we show that TM-MSC have gene expression patterns most similar to MSC derived from other tissues. TM-MSC express genes found on adult TM tissue, suggesting that TM-MSC are progenitor cells that serve to maintain a healthy TM.