1,673 research outputs found

    Web Surveys In Business Research: Use, Design And Construction Issues

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    Online surveys have the potential to dramatically improve the distribution of surveys, reduce the cost of administering surveys and increase survey response rates.  This can lead to an overall improvement in the quality of the research being conducted.  We first discuss the advantages and potential problems associated with online surveys.  We then discuss survey website design issues and provide guidance regarding the use of various features.  We also discuss  several website construction considerations.  Finally, we report on several viable approaches for building an online survey system, which range from inexpensive and technically challenging to expensive and easy to use and build. 

    Identification of a Cell Surface Protein with a Role in Stimulating Human Keratinocyte Proliferation, Expressed During Development and Carcinogenesis

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    In an attempt to define cell surface molecules with an important role in the development of squamous cell carcinomas (SCCs), we generated monoclonal antibodies (MoAbs) to a human keratinocyte cell line (FEP18-11-T1) capable of giving rise to SCCs in nude mice. MoAb 10G7 was selected for further study because it bound to a cell surface component preferentially expressed by this cell line as compared with normal human foreskin keratinocytes. This MoAb recognizes a cell surface protein (10G7 antigen) that is not detectable on normal keratinocytes in the foreskin in vivo, but whose expression is induced when the keratinocytes are dissociated from this tissue and placed in culture. Interestingly, the 10G7 antigen is downregulated upon keratinocyte differentiation in vitro. Consistent with its expression in hyper-proliferative epithella in vitro, 10G7 antigen exhibited a classic oncofetal pattern of expression in vivo. Thus, although no reactivity was obtained with MoAb 10G7 in the epithelia of normal foreskin or cervical tissue, strong reactivity was detected in epithelia from genital lesions ranging from benign warts to invasive SCCs. Epidermis from developing fetal tissue also exhibited strong reactivity with MoAb 10G7. We have been able to demonstrate that this MoAb is capable of stimulating FEP18–11-T1 keratinocyte proliferation in vitro in a concentration-dependent manner in the absence of growth factors, suggesting that the 10G7 antigen may play an important role in regulating cellular proliferation during development and in carcinogenesis in epithelial tissues

    Is there a social gradient of sarcopenia? A meta-analysis and systematic review protocol

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    Introduction: Sarcopenia (or loss of muscle mass and function) is a relatively new area within the field of musculoskeletal research and medicine. Investigating whether there is a social gradient, including occupation type and income level, of sarcopenia, as observed for other diseases, will contribute significantly to the limited evidence base for this disease. This new information may inform the prevention and management of sarcopenia and widen the evidence base to support existing and future health campaigns. Methods and analysis: We will conduct a systematic search of the databases PubMed, Ovid, CINAHL, Scopus and EMBASE to identify articles that investigate associations between social determinants of health and sarcopenia in adults aged 50 years and older. Eligibility of the selected studies will be determined by two independent reviewers. The methodological quality of eligible studies will be assessed according to predetermined criteria. Established statistical methods to identify and control for heterogeneity will be used, and where appropriate, we will conduct a meta-analysis. In the event that heterogeneity prevents numerical synthesis, a best evidence analysis will be employed. This systematic review protocol adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols reporting guidelines and will be registered with the International Prospective Register of Systematic Reviews (PROSPERO). Ethics and dissemination: This systematic review will use published data, thus ethical permissions will not be required. In addition to peer-reviewed publication, our results will be presented at (inter)national conferences relevant to the field of sarcopenia, ageing and/or musculoskeletal health and disseminated both electronically and in print. PROSPERO registration number: CRD4201707225

    Reliability of Tibialis Anterior Muscle Voluntary Activation Using the Interpolated Twitch Technique and the Central Activation Ratio in People with Stroke

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    Voluntary activation (VA) is measured by applying supramaximal electrical stimulation to a muscle during a maximal voluntary contraction (MVC). The amplitude of the evoked muscle twitch is used to determine any VA deficit, and indicates incomplete central neural drive to the motor units. People with stroke experience VA deficits and greater levels of central fatigue, which is the decrease in VA that occurs following exercise. This study investigated the between-session reliability of VA and central fatigue of the tibialis anterior muscle (TA) in people with chronic stroke (n = 12), using the interpolated twitch technique (ITT), adjusted-ITT, and central activation ratio (CAR) methods. On two separate sessions, supramaximal electrical stimulation was applied to the TA when it was at rest and maximally activated, at the start and end of a 30-s isometric dorsiflexor MVC. The most reliable measures of VA were obtained using the CAR calculation on transformed data, which produced an ICC of 0.92, and a lower bound confidence interval in the good range (95% CI 0.77 to 0.98). Reliability was lower for the CAR calculation on non-transformed data (ICC 0.82, 95% CI 0.63 to 0.91) and the ITT and adjusted-ITT calculations on transformed data (ICCs 0.82, 95% CIs 0.51 to 0.94), which had lower bound confidence intervals in the moderate range. The two ITT calculations on non-transformed data demonstrated the poorest reliability (ICCs 0.62, 95% CI 0.25 to 0.74). Central fatigue measures demonstrated very poor reliability. Thus, the reliability for VA in people with chronic stroke ranged from good to poor, depending on the calculation method and statistical analysis method, whereas the reliability for central fatigue was very poor

    Characteristics of the Contingent Negative Variation during Lower Limb Functional Movement with an Audio-Visual Cue

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    Background: The contingent negative variation (CNV) is a negative shift in electroencephalography (EEG) related to the planning and execution of an externally cued movement task. The CNV has the potential to be applied within stroke rehabilitation; however, there is insufficient knowledge about the CNV characteristics under movement conditions relevant to rehabilitation. This study explores the CNV characteristics during a functional movement task (versus a simple movement task) and when using an audio-visual cue that has been previously evaluated for its usability in stroke rehabilitation (versus a simple visual cue). Methods: Thirty healthy participants performed five randomized movement tasks: simple ankle dorsiflexion with a visual cue (1), audio-visual cue (2), and auditory-only cue (3), and sit-to-stand with a visual (4) and audio-visual cue (5). Fifty repetitions of each movement were performed while continuous EEG was recorded. The band-passed and Laplacian-filtered (Cz) EEG was averaged for each condition and the peak negativity (PN) latency and amplitude were identified. Results: PN latency was significantly later during sit-to-stand with the audio-visual cue versus the visual cue (p = 0.027). PN amplitude was significantly larger during sit-to-stand versus ankle dorsiflexion, with both visual and audio-visual cues (p < 0.0001). Conclusion: The CNV changes under more complex movement conditions. Assumptions about the MRCP from simple laboratory recordings should not be generalized to the rehabilitation setting

    Converting From 3.6 and 4.5 Micron Fluxes to Stellar Mass

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    We use high spatial resolution maps of stellar mass and infrared flux of the Large Magellanic Cloud (LMC) to calibrate a conversion between 3.6 and 4.5 micron fluxes and stellar mass, M_* = 10^{5.65} * F_{3.6}^{2.85} * F_{4.5}^{-1.85} * (D/0.05)^2 M_solar, where fluxes are in Jy and D is the luminosity distance to the source in Mpc, and to provide an approximate empirical estimate of the fractional internal uncertainty in M_* of 0.3*sqrt{N/10^6}, where N is the number of stars in the region. We find evidence that young stars and hot dust contaminate the measurements, but attempts to remove this contamination using data that is far superior than what is generally available for unresolved galaxies resulted in marginal gains in accuracy. The scatter among mass estimates for regions in the LMC is comparable to that found by previous investigators when modeling composite populations, and so we conclude that our simple conversion is as precise as possible for the data and models currently available. Our results allow for a reasonably bottom-heavy initial mass function, such as Salpeter or heavier, and moderately disfavor lighter versions such as a diet-Salpeter or Chabrier initial mass function.Comment: 7 pages, 6 figures, to be published in the Astronomical Journa

    Validity and Reliability of a Smartphone App for Gait and Balance Assessment

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    Advances in technology provide an opportunity to enhance the accuracy of gait and balance assessment, improving the diagnosis and rehabilitation processes for people with acute or chronic health conditions. This study investigated the validity and reliability of a smartphone-based application to measure postural stability and spatiotemporal aspects of gait during four static balance and two gait tasks. Thirty healthy participants (aged 20–69 years) performed the following tasks: (1) standing on a firm surface with eyes opened, (2) standing on a firm surface with eyes closed, (3) standing on a compliant surface with eyes open, (4) standing on a compliant surface with eyes closed, (5) walking in a straight line, and (6) walking in a straight line while turning their head from side to side. During these tasks, the app quantified the participants’ postural stability and spatiotemporal gait parameters. The concurrent validity of the smartphone app with respect to a 3D motion capture system was evaluated using partial Pearson’s correlations (r(p)) and limits of the agreement (LoA%). The within-session test–retest reliability over three repeated measures was assessed with the intraclass correlation coefficient (ICC) and the standard error of measurement (SEM). One-way repeated measures analyses of variance (ANOVAs) were used to evaluate responsiveness to differences across tasks and repetitions. Periodicity index, step length, step time, and walking speed during the gait tasks and postural stability outcomes during the static tasks showed moderate-to-excellent validity (0.55 ≤ r(p) ≤ 0.98; 3% ≤ LoA% ≤ 12%) and reliability scores (0.52 ≤ ICC ≤ 0.92; 1% ≤ SEM% ≤ 6%) when the repetition effect was removed. Conversely, step variability and asymmetry parameters during both gait tasks generally showed poor validity and reliability except step length asymmetry, which showed moderate reliability (0.53 ≤ ICC ≤ 0.62) in both tasks when the repetition effect was removed. Postural stability and spatiotemporal gait parameters were found responsive (p < 0.05) to differences across tasks and test repetitions. Along with sound clinical judgement, the app can potentially be used in clinical practice to detect gait and balance impairments and track the effectiveness of rehabilitation programs. Further evaluation and refinement of the app in people with significant gait and balance deficits is needed

    Excessive daytime sleepiness and falls among older men and women: cross-sectional examination of a population-based sample

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    Background: Excessive daytime sleepiness (EDS) has been associated with an increased risk for falls among clinical samples of older adults. However, there is little detailed information among population-representative samples. The current study aimed to assess the relationship between EDS and falls among a cohort of population-based older adults. Methods: This study assessed 367 women aged 60-93years (median 72, interquartile range 65-79) and 451 men aged 60-92years (median 73, interquartile range 66-80) who participated in the Geelong Osteoporosis Study between the years 2001 and 2008. Falls during the prior year were documented via self-report, and for men, falls risk score was obtained using an Elderly Fall Screening Test (EFST). Sleepiness was assessed using the Epworth Sleepiness Scale (ESS), and scores of&ge;10 indicated EDS. Differences among those with and without EDS in regard to falls were tested using logistic regression models. Results: Among women, 50 (13.6 %) individuals reported EDS. Women with EDS were more likely to report a fall, and were more likely to report the fall occurring outside. EDS was similarly associated with an increased risk of a fall following adjustment for use of a walking aid, cases of nocturia and antidepressant medication use (adjusted OR&isin;=&isin;2.54, 95 % CI 1.24-5.21). Multivariate modelling revealed antidepressant use (current) as an effect modifier (p&isin;&lt;&isin;.001 for the interaction term). After stratifying the data by antidepressant medication use, the association between EDS and falls was sustained following adjustment for nocturia among antidepressant non-users (adjusted OR&isin;=&isin;2.63, 95 % CI 1.31-5.30). Among men, 72 (16.0 %) individuals reported EDS. No differences were detected for men with and without EDS in regard to reported falls, and a trend towards significance was noted between EDS and a high falls risk as assessed by the EFST (p&isin;=&isin;0.06), however, age explained this relationship (age adjusted OR&isin;=&isin;2.20, 95 % CI 1.03-1.10). Conclusions: For women, EDS is independently associated with at least one fall during the previous year, and this is more likely to occur whilst located outside. Amelioration of EDS may assist in improving functional outcomes among these individuals by reducing the risk for falls

    Electroencephalographic recording of the movement-related cortical potential in ecologically-valid movements:A scoping review

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    The movement-related cortical potential (MRCP) is a brain signal that can be recorded using surface electroencephalography (EEG) and represents the cortical processes involved in movement preparation. The MRCP has been widely researched in simple, single-joint movements, however, these movements often lack ecological validity. Ecological validity refers to the generalizability of the findings to real-world situations, such as neurological rehabilitation. This scoping review aimed to synthesize the research evidence investigating the MRCP in ecologically valid movement tasks. A search of six electronic databases identified 102 studies that investigated the MRCP during multi-joint movements; 59 of these studies investigated ecologically valid movement tasks and were included in the review. The included studies investigated 15 different movement tasks that were applicable to everyday situations, but these were largely carried out in healthy populations. The synthesized findings suggest that the recording and analysis of MRCP signals is possible in ecologically valid movements, however the characteristics of the signal appear to vary across different movement tasks (i.e., those with greater complexity, increased cognitive load, or a secondary motor task) and different populations (i.e., expert performers, people with Parkinson’s Disease, and older adults). The scarcity of research in clinical populations highlights the need for further research in people with neurological and age-related conditions to progress our understanding of the MRCPs characteristics and to determine its potential as a measure of neurological recovery and intervention efficacy. MRCP-based neuromodulatory interventions applied during ecologically valid movements were only represented in one study in this review as these have been largely delivered during simple joint movements. No studies were identified that used ecologically valid movements to control BCI-driven external devices; this may reflect the technical challenges associated with accurately classifying functional movements from MRCPs. Future research investigating MRCP-based interventions should use movement tasks that are functionally relevant to everyday situations. This will facilitate the application of this knowledge into the rehabilitation setting
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