scholarly journals Reducing Aerodynamic Drag by Adopting a Novel Road-Cycling Sprint Position

2019 ◽  
Vol 14 (6) ◽  
pp. 733-738 ◽  
Author(s):  
Paul F.J. Merkes ◽  
Paolo Menaspà ◽  
Chris R. Abbiss
Keyword(s):  
Regression Analysis ◽  
Aerodynamic Drag ◽  
Barometric Pressure ◽  
Standing Position ◽  
Road Cycling ◽  
Significant Difference ◽  
Main Effect ◽  
Road Cyclists ◽  
Road Gradient ◽  
Sprint Velocity

Purpose: To assess the influence of seated, standing, and forward-standing cycling sprint positions on aerodynamic drag (CdA) and the reproducibility of a field test of CdA calculated in these different positions. Methods: A total of 11 recreational male road cyclists rode 250 m in 2 directions at around 25, 32, and 40 km·h−1 and in each of the 3 positions, resulting in a total of 18 efforts per participant. Riding velocity, power output, wind direction and velocity, road gradient, temperature, relative humidity, and barometric pressure were measured and used to calculate CdA using regression analysis. Results: A main effect of position showed that the average CdA of the 2 d was lower for the forward-standing position (0.295 [0.059]) compared with both the seated (0.363 [0.071], P = .018) and standing positions (0.372 [0.077], P = .037). Seated and standing positions did not differ from each other. Although no significant difference was observed in CdA between the 2 test days, a poor between-days reliability was observed. Conclusion: A novel forward-standing cycling sprint position resulted in 23% and 26% reductions in CdA compared with a seated and standing position, respectively. This decrease in CdA could potentially result in an important increase in cycling sprint velocity of 3.9–4.9 km·h−1, although these results should be interpreted with caution because poor reliability of CdA was observed between days.

Body balance in a free-standing position in road and off-road cyclists

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
Paulina Hebisz ◽  
Rafal Hebisz ◽  
Marek Zaton
Keyword(s):  
Sagittal Plane ◽  
Standing Position ◽  
The Body ◽  
Free Standing ◽  
Body Balance ◽  
Eyes Closed ◽  
Road Cycling ◽  
Progressive Exercise ◽  
Before And After ◽  
Road Cyclists

AbstractBackground: The purpose of this study was to compare body balance in road and off-road cyclists, immediately before and after the racing season.Material/Methods: Twenty individuals participated in the study and they were divided into two groups: specialists in road-cycling (n = 10) and in off-road cycling (n = 10). Immediately before and after the five-month racing season stabilographic trials were carried out (at rest and after progressive exercise). In assessing body balance the distance and velocity of the centre shifts (in the anterior-posterior and left-right direction) were analysed. The tests were performed with the cyclists’ eyes open, eyes closed, and in feedback.Results: After the racing season, in the off-road cyclists’ group, distance and velocity of the centre of pressure shifts increased after a progressive exercise.Conclusions: In the off-road cyclists’ group the balance of the body in the sagittal plane deteriorated after the racing season. Moreover, after the racing season off-road cyclists were characterized by a worse balance of the body, compared to road cyclists

scholarly journals Does perceived self-regulation affect target commitment?

2020 ◽  
Vol 17 (4) ◽  
pp. 1047-1053
Author(s):  
Serhat Turan ◽  
Zülbiye Kaçay
Keyword(s):  
Regression Analysis ◽  
Linear Regression Analysis ◽  
Self Regulation ◽  
General Information ◽  
Goal Commitment ◽  
School Students ◽  
School Sports ◽  
Significant Difference ◽  
Main Effect ◽  
Manova Analysis

The aim of this study was to investigate the effect of perceived self-regulation levels on target commitment of secondary school students participating and no-participating in inter-school sports competitions. “General Information Form”, “Perceived Self-Regulation Scale (PSRS) and “Goal Commitment Scale (GCS)” were used to collect the data. The sample group consisted of 313 (male = 130, female = 183) students studying at secondary level. Pearson Moment Correlation test, Manova analysis and simple linear regression analysis were used for data analysis. As a result of the analysis, the main effect of the variables of gender and participating in inter-school sports competitions was not determined to be statistically significant for PSRS and GCS. As a result of the regression analysis, it was determined that perceived self-regulation predicted the target commitment positively and statistically significant. Also, it was determined that there was a positive and significant difference between PSRS and GCS. In this study, it was determined that participating in inter-school sports competitions did not significantly affect perceived self-regulation and target commitment levels. It is recommended that the study should be applied to students who do regular sports and students who do not do regular sports.

Seated Versus Standing Cycling in Competitive Road Cyclists: Uphill Climbing and Maximal Oxygen Uptake

1996 ◽  
Vol 21 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Hirofumi Tanaka ◽  
David R. Bassett Jr. ◽  
Shane K. Best ◽  
Kenny R. Baker Jr.
Keyword(s):  
Heart Rate ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Perceived Exertion ◽  
Body Position ◽  
Standing Position ◽  
Rating Of Perceived Exertion ◽  
Hill Climbing ◽  
Significant Difference ◽  
Road Cyclists

Seven competitive road cyclists (M ± SE = 23.7 ± 1.5 yr, 70.5 ± 1.7 kg) participated to determine the effects of cycling body position on physiological responses during uphill cycling and maximal oxygen uptake [Formula: see text]. There was no significant difference in [Formula: see text] between seated and standing positions on a cycle ergometer (66.4 ± 1.6 vs. 66.4 ± 1.7 ml∙kg−1∙min−1). When the subjects rode their own bicycle on a treadmill, oxygen uptake and heart rate were significantly (p < 0.05) higher during standing when subjects bicycled at 20.0 km∙h−1 (4% grade), but no difference was observed when riding at 12.3 km−1 (10% grade). Leg RPE was significantly (p < 0.05) lower for standing position up a 10% grade. The results suggest that the standing position is less economical during moderate hill climbing, but during steep hill climbing, it results in a decreased sensation of effort in the legs. Key words: bicycling, heart rate, rating of perceived exertion

scholarly journals The prognostic and diagnostic significance of the neutrophil-to-lymphocyte ratio in hepatocellular carcinoma: a prospective controlled study

2021 ◽  
Author(s):  
Philip J. Johnson ◽  
Sofi Dhanaraj ◽  
Sarah Berhane ◽  
Laura Bonnett ◽  
Yuk Ting Ma
Keyword(s):  
Hepatocellular Carcinoma ◽  
Regression Analysis ◽  
Prognostic Factor ◽  
Cox Regression ◽  
Prognostic Models ◽  
Controlled Study ◽  
Cox Regression Analysis ◽  
Neutrophil Lymphocyte Ratio ◽  
Lymphocyte Ratio ◽  
Significant Difference

Abstract Background The neutrophil–lymphocyte ratio (NLR), a presumed measure of the balance between neutrophil-associated pro-tumour inflammation and lymphocyte-dependent antitumour immune function, has been suggested as a prognostic factor for several cancers, including hepatocellular carcinoma (HCC). Methods In this study, a prospectively accrued cohort of 781 patients (493 HCC and 288 chronic liver disease (CLD) without HCC) were followed-up for more than 6 years. NLR levels between HCC and CLD patients were compared, and the effect of baseline NLR on overall survival amongst HCC patients was assessed via multivariable Cox regression analysis. Results On entry into the study (‘baseline’), there was no clinically significant difference in the NLR values between CLD and HCC patients. Amongst HCC patients, NLR levels closest to last visit/death were significantly higher compared to baseline. Multivariable Cox regression analysis showed that NLR was an independent prognostic factor, even after adjustment for the HCC stage. Conclusion NLR is a significant independent factor influencing survival in HCC patients, hence offering an additional dimension in prognostic models.

scholarly journals Comparison of intravenous sedation using midazolam during dental treatment in elderly patients with/without dementia: a prospective, controlled clinical trial

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuichi Tatsuno ◽  
Yoshinari Morimoto ◽  
Megumi Hayashi ◽  
Takatoshi Iida
Keyword(s):  
Regression Analysis ◽  
Cognitive Impairment ◽  
Elderly Patients ◽  
Multiple Regression Analysis ◽  
Multiple Regression ◽  
Intravenous Sedation ◽  
Negative Group ◽  
Severe Dementia ◽  
Positive Group ◽  
Significant Difference

AbstractThe effects of intravenous sedation with midazolam on the cerebral function of elderly patients with severe dementia are unclear. This study aimed to evaluate its effects on parameters such as brainwaves and cerebral blood flow (CBF) and compare them between elderly individuals with dementia and without cognitive impairment. Ten patients with severe dementia and 10 without cognitive impairment were registered. The bispectral index (BIS) and normalized tissue hemoglobin index (nTHI), which reflects CBF using near-infrared spectroscopy, were measured. Midazolam was administered until a Modified Observer’s Assessment of Alertness/Sedation score of 2 was reached. The chi-squared, Mann–Whitney U, Wilcoxon signed-rank, and Friedman tests and multiple regression analysis were used for comparisons. Whereas a similar decline in BIS values was observed in both groups after midazolam administration (P < 0.018), there was a significant decrease by 9% in the nTHI of the dementia-positive group (P < 0.013). However, there was no significant difference in the nTHI between the dementia-positive and dementia-negative group according to the multiple regression analysis (P = 0.058). In the dementia-negative group, none of the measured values differed from the baseline values. In the dementia-positive group, sedation with midazolam resulted in a 9% decrease in the CBF.

scholarly journals Impact of Violent Experiences and Social Support on R-NSSI Behavior among Middle School Students in China

2021 ◽  
Vol 18 (7) ◽  
pp. 3347
Author(s):  
Kun Liu ◽  
Xueyan Yang ◽  
Moye Xin
Keyword(s):  
Social Support ◽  
Influencing Factors ◽  
Empirical Support ◽  
Female Students ◽  
Male Students ◽  
Male And Female ◽  
Self Injury ◽  
Significant Difference ◽  
Main Effect ◽  
Nonsuicidal Self Injury

Repetitive nonsuicidal self-injury (R-NSSI) is an extreme manifestation of nonsuicidal self-injury (NSSI) behavior that causes bodily harm and emotional and personality disorders. It is a growing concern, especially among adolescents; therefore, this study aims to provide empirical support for effective interventions on R-NSSI behavior among adolescents in China. We used data of about 1180 students from a survey conducted in seven middle schools in Xi’an, China, and applied multiple logistic regression to analyze NSSI and R-NSSI among male and female students, including their influencing factors. We found no significant difference between male and female students’ R-NSSI; however, regarding influencing factors, male students had more violent experiences and less social support than female students. Parental and familial factors played the most prominent role in social support. Social support was found to be a main-effect mechanism in the effect of violent experiences on R-NSSI among male students, whereas the mechanism had both a main effect and a certain buffer effect among female students. R-NSSI was found to be more prevalent among younger children, children with siblings, and those with romantic relationship experiences. We also found that healthy adolescent development involves the participation of families and schools. Health education should be conducted according to the students’ sex and characteristics.

Donepezil Combined with DL-3-n-Butylphthalide Delays Cognitive Decline in Patients with Mild to Moderate Alzheimer’s Disease: A Multicenter, Prospective Cohort Study

2021 ◽  
Vol 80 (2) ◽  
pp. 673-681
Author(s):  
Jin Wang ◽  
Xiaojuan Guo ◽  
Wenhui Lu ◽  
Jie Liu ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Logistic Regression ◽  
Regression Analysis ◽  
Cohort Study ◽  
Prospective Cohort ◽  
Daily Living ◽  
Multivariate Logistic Regression Analysis ◽  
Multivariate Logistic Regression ◽  
Significant Difference

Background: Vascular factors and mitochondria dysfunction contribute to the pathogenesis of Alzheimer’s disease (AD). DL-3-n-butylphthalide (NBP) has an effect in protecting mitochondria and improving microcirculation. Objective: The aim was to investigate the effect of donepezil combined NBP therapy in patients with mild-moderate AD. Methods: It was a prospective cohort study. 92 mild-moderate AD patients were classified into the donepezil alone group (n = 43) or the donepezil combined NBP group (n = 49) for 48 weeks. All patients were evaluated with Alzheimer’s Disease Assessment Scale-Cognitive subscale (ADAS-cog), Clinician’s Interview-Based Impression of Change plus caregiver input (CIBIC-plus), Alzheimer’s Disease Cooperative Study-Activities of Daily Living (ADCS-ADL), and Neuropsychiatric Inventory (NPI) every 12 weeks. All patients were monitored for adverse events (AEs). The efficacy was analyzed using multivariate logistic regression analysis. Results: The multivariate logistic regression analysis showed that the changes of ADAS-cog score (OR = 2.778, 95% CI: [1.087, 7. 100], p = 0.033) and ADCS-ADL score (OR = 2.733, 95% CI: [1.002, 7.459], p = 0.049) had significant difference between donepezil alone group and donepezil combined NBP group, while the changes of NPI (OR = 1.145, 95% CI: [0.463, 2.829], p = 0.769), MMSE (OR = 1.563, 95% CI: [0.615, 3.971], p = 0.348) and CIBIC-plus (OR = 2.593, 95% CI: [0.696, 9.685], p = 0.156) had no significant difference. The occurrence of AEs was similar in the two groups. Conclusion: Over the 48-week treatment period, donepezil combined NBP group had slower cognitive decline and better activities of daily living in patients with mild to moderate AD. These indicated that the multi-target therapeutic effect of NBP may be a new choice for AD treatment.

Müller-Weiss Disease: The Descriptive Factors of Failure Conservative Treatment

2021 ◽  
pp. 107110072110028
Author(s):  
Thos Harnroongroj ◽  
Theerawoot Tharmviboonsri ◽  
Bavornrit Chuckpaiwong
Keyword(s):  
Regression Analysis ◽  
Conservative Treatment ◽  
Demographic Characteristics ◽  
Classification Systems ◽  
Clinical Severity ◽  
P Value ◽  
Level Of Evidence ◽  
Factors Associated ◽  
Radiographic Parameters ◽  
Significant Difference

Background: Conservative treatment is the first-line approach for Müller-Weiss disease (MWD). However, factors associated with the failure of conservative treatment have never been reported. Our objectives were to compare the differences in demographic and radiographic parameters between “successful” and “failure” conservative treatment in patients with MWD and identify descriptive factors associated with failure conservative treatment. Methods: We retrospectively reviewed 68 patients with MWD divided into 29 “failure” and 39 “successful” conservative treatment groups. Demographic characteristics, Foot and Ankle Outcome Score (FAOS), visual analog scale (VAS) scores for pain and walking disability, and radiographic parameters such as calcaneal pitch, lateral Meary, anteroposterior (AP) Meary angle, and talonavicular-naviculocuneiform arthritis were compared. Logistic regression analysis was performed to identify descriptive factors of failure conservative treatment. A P value <.05 was considered a statistically significant difference. Results: We found more severe VAS pain and walking disability scores and FAOS for the pain, activities of daily living, and quality of life subscales in the failure group ( P < .05). Regression analysis demonstrated 2 significant descriptive factors associated with failure conservative treatment: abducted AP Meary angle >13.0 degrees and radiographic talonavicular arthritis. No demographic characteristics were found to be associated with failure conservative treatment. Conclusion: Midfoot abduction (AP Meary angle, >13 degrees) and radiographic talonavicular arthritis were factors associated with failure conservative treatment in MWD and should be determined concurrently with the clinical severity. Classification systems for MWD should include these factors. Level of evidence: Level III, retrospective comparative study.

scholarly journals Clinical benefits, referral practice and cost implications of an in-hospital pain service: results of a service evaluation in a London teaching hospital

2016 ◽  
Vol 11 (1) ◽  
pp. 36-45 ◽  
Author(s):  
Maya Sussman ◽  
Elizabeth Goodier ◽  
Izabella Fabri ◽  
Jessica Borrowman ◽  
Sarah Thomas ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Pain Management ◽  
Teaching Hospital ◽  
Rating Scale ◽  
Service Evaluation ◽  
Rank Test ◽  
Future Research ◽  
Binary Logistic Regression Analysis ◽  
Significant Difference ◽  
Referral Practice

Background: In-hospital pain services (IPS) are commonplace, but evidence of efficacy is inadequate, and patients’ pain management in any hospital ward remains problematic. This service evaluation aimed to measure the effect of a contemporary IPS, its appropriate use and cost-efficacy. Methods: Records of 249 adults reviewed by the IPS in an inner London Teaching Hospital over an 8-month period were analysed for demographic data, interventions, workload and change in pain intensity measured by numerical rating scale (NRS). Non-parametric tests were used to evaluate differences between initial and final NRS. Spearman’s rank correlation analysis was used to create a correlation matrix to evaluate associations between all identified independent variables with the change in NRS. All strongly correlated variables (ρ > 0.5) were subsequently included in a binary logistic regression analysis to identify predictors of pain resolution greater than 50% NRS and improvement rather than deterioration or no change in NRS. Finally, referral practice and cost of inappropriate referrals were estimated. Referrals were thought to be inappropriate when pain was not optimised by the referring team; they were identified using a set algorithm. Results: Initial median NRS and final median NRS were significantly different when a Wilcoxon signed-rank test was applied to the whole cohort; Z = –5.5 (p = 0.000). Subgroup analysis demonstrated no significant difference in the ‘mild’ pain group; z = –1.1 (p = 0.253). Regression analysis showed that for every unit increase in initial NRS, there was a 62% chance of general and a 33% chance of >50% improvement in final NRS. An estimated annual cost-saving potential of £1546 to £4558 was found in inappropriate referrals and patients experiencing no benefit from the service. Discussion: Results suggest that patients with moderate to severe pain benefit most from IPS input. Also pain management resources are often distributed inefficiently. Future research is required to develop algorithms for easy identification of potential treatment responders.

Comparison of stirrup lengths chosen for flatwork by novice and experienced riders

2018 ◽  
Vol 14 (4) ◽  
pp. 223-230 ◽  
Author(s):  
M. Andrews-Rudd ◽  
C. Farmer-Day ◽  
H.M. Clayton ◽  
J.M. Williams ◽  
D.J. Marlin
Keyword(s):  
Standing Position ◽  
Knee Angle ◽  
Leg Length ◽  
Greater Trochanter ◽  
Significant Difference ◽  
And Function ◽  
Leg Position ◽  
Combined Data

Although stirrups may be considered an essential part of equestrian equipment, there is little research describing their use and function. The aim of the present study was to compare stirrup lengths chosen for flatwork by novice and experienced riders, and to measure the associated leg position and knee angles. Ten novice and ten experienced riders, with kinematic markers attached to their greater trochanter, lateral femoral epicondyle, and lateral fibular malleolus, mounted three horses and a mechanical horse. The riders selected an appropriate stirrup length for flatwork by adjusting the unnumbered stirrup leathers. Stirrup length was measured and expressed as a percentage of the rider’s leg length measured from the greater trochanter to the floor when standing. Lateral photographs were taken from both sides with the riders mounted on each horse in a standing position. The kinematic markers were digitised to measure knee angle and ankle position relative to the hip in the anteroposterior direction. Within riders, there was no significant difference in stirrup length between the three live horses or between the mechanical horse and live horse. Experienced riders consistently selected a significantly longer stirrup length as a percentage of their leg length compared with novice riders (combined data for live horses and mechanical horse; P=0.005). Experienced riders demonstrated a significantly larger knee angle (combined data for live horses and mechanical horse) compared with novice riders (118±8° and 109±7°, respectively; P=0.016). Novice riders had a significantly larger knee angle on the mechanical horse compared with the live horse (115±9° versus 107±9°, respectively; P=0.003). The relatively longer stirrup length selected by experienced riders is thought to reflect the development of an independent seat, which implies the ability to move the legs independently of the pelvis. The chair seat adopted by novice riders on the mechanical horse could be considered counter to improving their equitation skills.

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