Incremental Speed Research Articles

Differences in Player Position Running Velocity at Lactate Thresholds Among Male Professional German Soccer Players.

This study investigated the differences in running velocities at specific lactate thresholds among male German soccer players. One hundred fifty-two professional (3rd league: n = 78; 4th league: n = 74) male soccer players (mean ± SD; age: 24.7 ± 4.37 years, body mass: 80.8 ± 7.33 kg, body height: 1.83 ± 0.06 m) volunteered for the investigation. Players were categorized as goalkeepers, central defenders, central midfielders, wings and forward. Players completed a treadmill test, at incremental speeds, to determine running velocity at different blood lactate concentrations (v2 = 2 mmol/l; v4 = 4 mmol/l; and v6 = 6 mmol/l). In addition, the largest difference between positions for running velocity was found at the lactate threshold v2 (p = 0.005). The running data revealed that only goalkeepers had significantly lower velocities at the lactate thresholds compared to outfield players. The central midfielders showed the highest average performance level at the lactate thresholds (v2: 12.5 ± 1.20 km/h; v4: 15.2 ± 1.14 km/h; and v6: 16.6 ± 1.14 km/h). In conclusion, this study provides soccer and position-specific reference data for the running performance of male professional German soccer players to evaluate the endurance performance in a standardized way. In this context, future research should extend the database for the first and second leagues. Further research assessing running performance during competition matches over the entire season is required to validate the endurance test performance data.

Validity and Reliability of a 10 Hz GPS for Assessing Variable and Mean Running Speed.

Our purpose was to assess the 10 Hz Viper GPS devices’ validity and reliability (STATSport) in both instantaneous and mean speed measuring in accelerations and decelerations in straight-line running conditions. Eight amateur team sport players participated in the study, performing firstly 21 x 40 m sprints at submaximal incremental speed, and secondly 21 x 40 m sprints, with the first stage consisting of submaximal incremental speed, and the second stage of subsequent submaximal decreasing speed. Criteria systems used to evaluate the GPS validity were a radar gun for instantaneous speed, and timing-gates for mean speed. Reliability was measured with two GPS devices carried by the same athlete, running 10 x (20 m + 20 m) sprints with a 180º change of direction and a 10 s inter-set rest interval. Results showed an agreement between GPS devices and the criteria systems measuring instantaneous speed (r = 0.98; standardized mean bias (SMB) = -0.07; standard typical error (STE) = 0.22) and mean speed (r = 0.99; SMB = 0.38; STE = 0.17). The reliability study presented a nearly perfect correlation between devices, a trivial SMB and a small STE (r = 0.97; SMB = 0.04; STE = 0.23). 10 Hz GPS devices are an adequate solution to monitor straight-line running speed in acceleration and deceleration conditions, but we would like to draw attention to the small errors and bias detected, such as the speed overestimation compared with timing gates.

Physical activity estimation from accelerometry.

Objective physical activity (PA) quantification is traditionally achieved using lightweight accelerometers accounting for activity frequency, intensity and duration. The accelerometer data are usually converted into activity counts and these counts can be used on their own to quantify the intensity and duration of a PA period or they can serve as features for energy expenditure computation or activity classification. This paper investigates the way how Actigraph counts are computed. Several points are discussed regarding bandpass filtering and amplitude non-linearities that may hamper some analysis. Experimental data were used 1) to assess reconstructed filter performances to replicate ActiGraph counts during an urban-circuit involving 20 subjects wearing an ActiGraph GT3X+ and 2) explain filter limitations (e.g. plateauphenomenon) thanks to a treadmill test with incremental speed (n=4). This study reproduces well ActiLife filter and reveals the impact of band-pass filtering on ActiLife count conversion. These results provide some keys to interpret knowingly ActiLife count based studies.

Lightweight sandwich fiber-welded foam-like nonwoven fabrics/graphene composites for electromagnetic shielding

With the remarkable increment speed of consumer electronics, shielding materials qualified for favourable minimal thickness, mechanical behaviors and efficient conduction path are imperiously demanded. To manufacture desired shielding materials qualified for favourable mechanical behaviors and efficient conduction path, we designed a foam-like nonwoven multiscale composite with welding-network, sandwich and random orientation combined architectures for the first time. A 0.5-mm-thick epoxy composite exhibits an outstanding shielding effectiveness of 65 dB, and the specific electromagnetic interference shielding effectiveness reaches to ∼23103.4 dB cm2 g−1, which surpassed that in reported literature. The continuous backbone with sandwich microstructure enables the epoxy composites to be mechanically robust with the tensile MPa of 349. The exceptional mechanical performance exhibited an alternative approach to exploit potentials of carbon fiber-based nonwoven fabrics for developing advanced multifunctional materials.

Relationship between Repeated Sprint Ability and Aerobic Fitness in College Volleyball Players

The main purpose of this study was to investigate the relationship between physiological variables related to aerobic fitness and repeated sprint ability (RSA) in college volleyball players. Sixteen male volleyball players (21.1±1.4 years) took part in the study. Players first performed an incremental treadmill run test to determine their maximal oxygen uptake (VO2max ), ventilatory threshold (VT), peak incremental test speed and time to exhaustion. After at least 48 hours, subjects performed an RSA test consisting of 10 × 20-m sprints interspersed with 20 seconds of active recovery, to determine the mean sprint time (RSAmean), the best sprint time (RSAbest) and the fatigue index (FI). RSAmean was significantly negatively correlated with VO 2max (r= −0.73, p 0.05). The results of this study demonstrated that high VO 2max as well as VT has an important contribution to performance during repeated-sprint efforts. These findings suggest that training practices for the development of aerobic components may improve also RSA.

Spontaneously hypertensive rats have greater impairments in regulating abdominal temperature than brain cortex temperature following physical exercise.

This study aimed to evaluate the changes in brain (Tbrain) and abdominal (Tabd) temperatures in spontaneously hypertensive rats (SHRs) following fatiguing exercise. Male normotensive Wistar rats (NWRs) and SHRs were used at 16 weeks of age. Their arterial pressure was measured by tail plethysmography prior to the experiments to confirm the hypertensive status of the SHRs. Then, the rats underwent implantation of an abdominal temperature sensor to measure Tabd and a guide cannula in the frontal cortex to enable the insertion of a thermistor to measure Tbrain. After a familiarization period, each animal was subjected to incremental speed exercises until fatigue in either a temperate (25 °C) or warm (32 °C) environment, followed by a 60-min post-exercise period at the same temperature at which they exercised. Tbrain, Tabd and tail-skin temperature (Tskin) were measured every min throughout the experiments. SHRs exhibited higher Tabd values than NWRs, and these higher values were transiently and persistently observed at 25 °C and 32 °C, respectively. For example, at 32 °C, Tabd was 0.84 °C higher in SHRs at the 25th min (large effect size). In contrast, regardless of the ambient temperature, SHRs exhibited similar Tbrain values as NWRs, indicating preserved Tbrain regulation following exercise in hypertensive rats. SHRs presented higher Tskin during the last half of the post-exercise period at 25 °C, whereas no inter-group differences were observed at 32 °C. In conclusion, the present results highlight that SHRs, an animal model that mimics uncontrolled essential hypertension in humans, exhibited greater impairments in regulating Tabd than Tbrain during the post-exercise period.

Impact of Cardiac Resynchronization Therapy on Left Ventricular Unloading in Patients with Implanted Left Ventricular Assist Devices

Cardiac resynchronization therapy (CRT) and left ventricular assist devices (LVADs) are common heart failure therapies; however, little is known regarding the concomitant use of these devices. We aim to evaluate unloading differences in LVAD patients with and without active biventricular pacing. Left ventricular assist device patients with and without CRT prospectively underwent ramp hemodynamic/echocardiographic testing. Patients with >95% biventricular pacing comprised the active CRT pacing group; all others (no device, implantable cardioverter defibrillator only, CRT without biventricular pacing) were categorized into the non-CRT pacing group. Invasive hemodynamics and echocardiographic characteristics (left ventricular end-diastolic/systolic diameter and valvular regurgitation) were measured at baseline and at incremental speed changes. Unloading slopes were calculated using linear regression modeling for individual hemodynamics and echocardiographic characteristics across speeds. Among 62 LVAD patients (age 59.6 ± 11.4 years, 60% male), 25 had active CRT pacing. There was no significant difference in echocardiographic or hemodynamic characteristics at baseline or final set speeds between CRT groups. Similarly, no significant differences were noted in the unloading characteristics. In LVAD patients, active biventricular pacing is unlikely to improve echocardiographic or hemodynamic characteristics.

COMPARATIVE ANALYSIS OF EVALUATION MODELS EFFECTIVENESS OF INVESTMENTS IN INNOVATION PROJECTS (PART 1)

The article describes the main models and methodological tools for evaluating the effectiveness of investment and innovation measures and mechanisms that have been developed and applied in the economic environment since the mid-twentieth century. The article discusses two directions in the assessment of investments: the direction of market evaluation of the introduction of innovation / investment and the direction of the assessment of the effectiveness of capital investment (investment) in the development of new technology (innovation), which was used in the conditions of non-market (planned) economic system. The article has characteristics about the advantages and disadvantages of both areas. The direction of further development of investment efficiency assessment models is outlined. Keywords: net present value, discounting, economic efficiency of capital investments, reduced costs, indicator of the speed of specific increment in value.

A3301 A Novel hierarchical medical system improved the effect of hypertension management in Shenzhen Futian, China

Objectives: This study aimed to implement a novel hierarchical medical system of hypertension, and improved the effect of hypertension management in Futian, China. Methods: To establish a novel hierarchical medical system of hypertension by series of measures: taking the Futian hospital for prevention and treatment of Chronic Disease as the bridge of regional hierarchical medical system to develop and implement the strategy of hypertension management, building regional medical association, promulgating hierarchical medical programme, setting up a discipline alliance, enhancing the ability of health care, modifying two-way referral service process. Results: A novel hierarchical medical system of hypertension in Futian was established successfully since July 2016, in which the hospital for prevention and treatment of Chronic Disease played a important role as the bridge to difference level medical institution and hypertension management.Evaluation shown that The number of patients with hypertension attending community health center increased by 18.2% and 26.9% compared with the same period before implementation of hierarchical medical system. The increment speed of standardized management for hypertension and diabetes patients were more than 3 times and 2.18 times compared with the same period before implementation of hierarchical medical system. The patients’ satisfaction for the medical system was high. Conclusion: The novel hierarchical medical system of hypertension in Shenzhen Futian, China is satisfactory to improved the effect of hypertension management, which is high quality model of hierarchical medical system, and is worth extending to other place.

Research Analysis of Big Data and Cloud Computing with Emerging Impact of Testing

Big Data has increased much focus from the scholastic world and the IT business. In the advanced and figuring world, all together is created and gathered at a rate that quickly surpasses the limit go. Right now, more than 2 billion individuals worldwide are associated with the Internet, and more than 5 billion people possess cell phones. By 2020, 50 billion gadgets are relied upon to be associated with the Internet. Now, anticipated information creation will be 44 times more prominent than that in 2009. As data is exchanged and shared at light speed on optic fiber and remote systems, the volume of information and the speed of market development increment. In any case, the quick development rate of such substantial information creates various difficulties, for example, the fast development of information, exchange speed, different information, and security. In any case, Big Data is still in its outset arrange, and the space has not been checked on all in all. Distributed computing has opened up new open doors for testing offices. New innovation and social network patterns are making an ideal tempest of chance, empowering cloud to change inside tasks, Customer connections and industry esteem chains. To guarantee high caliber of cloud applications being worked on, designer must perform testing to analyze the quality and exactness whatever they plan. In this examination paper, we address a testing natural engineering with important key advantages, to perform execution of experiments and utilized testing strategies to improve nature of cloud applications.

Decoupling Between Diastolic Pulmonary Arterial Pressure and Pulmonary Arterial Wedge Pressure at Incremental Left Ventricular Assist Device (LVAD) Speeds Is Associated With Worse Prognosis After LVAD Implantation

Decoupling between diastolic pulmonary arterial pressure (dPAP) and pulmonary arterial wedge pressure (PAWP) is an index of pulmonary vasculature remodeling and provides prognostic information. Furthermore, decoupling may change during incremental left ventricular assist device (LVAD) speed changes. In this prospective study, patients underwent an echocardiographic and hemodynamic ramp test after LVAD implantation and were followed for 1 year. The change in decoupling (dPAP - PAWP) between the lowest and highest LVAD speeds during the ramp test was calculated. Survival and heart failure admission rates were assessed by means of Kaplan-Meier analysis. Eighty-seven patients were enrolled in the study: 54 had a Heartmate II LVAD (60.8 ± 9.3 years of age and 34 male) and 33 had an HVAD LVAD (58.6 ± 13.2 years of age and 20 male). Patients who experienced greater changes in decoupling (Δdecoupling >3 mm Hg) had a persistently elevated dPAP at incremental LVAD speed and had worse 1-year heart failure readmission-free survival compared with the group without significant changes in the degree of decoupling (41% vs 75%; P = .001). An increase in decoupling between dPAP and PAWP at incremental LVAD speed changes was associated with worse prognosis in LVAD patients.

Seasonal variations in body composition, maximal oxygen uptake, and gas exchange threshold in cross-country skiers.

IntroductionIn order to ensure that athletes achieve their highest performance levels during competitive seasons, monitoring their long-term performance data is crucial for understanding the impact of ongoing training programs and evaluating training strategies. The present study was thus designed to investigate the variations in body composition, maximal oxygen uptake (VO2max), and gas exchange threshold values of cross-country skiers across training phases throughout a season.Materials and methodsIn total, 15 athletes who participate in international cross-country ski competitions voluntarily took part in this study. The athletes underwent incremental treadmill running tests at 3 different time points over a period of 1 year. The first measurements were obtained in July, during the first preparation period; the second measurements were obtained in October, during the second preparation period; and the third measurements were obtained in February, during the competition period. Body weight, body mass index (BMI), body fat (%), as well as VO2max values and gas exchange threshold, measured using V-slope method during the incremental running tests, were assessed at all 3 time points. The collected data were analyzed using SPSS 20 package software. Significant differences between the measurements were assessed using Friedman’s twoway variance analysis with a post hoc option.ResultsThe athletes’ body weights and BMI measurements at the third point were significantly lower compared with the results of the second measurement (p<0.001). Moreover, the incremental running test time was significantly higher at the third measurement, compared with both the first (p<0.05) and the second (p<0.01) measurements. Similarly, the running speed during the test was significantly higher at the third measurement time point compared with the first measurement time point (p<0.05). Body fat (%), time to reach the gas exchange threshold, running speed at the gas exchange threshold, VO2max, amount of oxygen consumed at gas exchange threshold level (VO2GET), maximal heart rate (HRmax), and heart rate at gas exchange threshold level (HRGET) values did not significantly differ between the measurement time points (p>0.05).ConclusionVO2max and gas exchange threshold values recorded during the third measurements, the timing of which coincided with the competitive season of the cross-country skiers, did not significantly change, but their incremental running test time and running speed significantly increased while their body weight and BMI significantly decreased. These results indicate that the cross-country skiers developed a tolerance for high-intensity exercise and reached their highest level of athletic performance during the competitive season.

Influence of coolant mass flow rate on the endwall conjugate heat transfer

The switch from diffusive combustion to premixed combustion in a modern gas turbine will change the combustor exit temperature profile to a more uniform one. As a result, the temperature near the inner and outer shroud of the turbine vane will increase which is a big challenge for the endwall cooling. Two typical vane endwall configurations with different cooling arrangements are investigated both experimentally and numerically in this study. One endwall has film cooling method only while the other has both film cooling and impingement cooling. The coolant to mainstream mass flow ratio (MFR) changes from 0.8% to 2.5% in the numerical investigation. The numerical method is validated by the experimental data. Detailed analysis of the coolant mass flow rate effect on the endwall conjugate heat transfer is conducted based on the numerical results. The results indicate that the speed of the overall effectiveness increment slows down when the MFR increases. As the MFR increases, the advantage of the combination of film and impingement enlarges. The warming effect of the coolant increases as the MFR increases which leads to a lower coolant discharge temperature.

Decoupling Between Diastolic Pulmonary Artery and Pulmonary Capillary Wedge Pressures at Incremental LVAD Speeds is a Poor Prognostic Factor Following LVAD Implantation

Decoupling Between Diastolic Pulmonary Artery and Pulmonary Capillary Wedge Pressures at Incremental LVAD Speeds is a Poor Prognostic Factor Following LVAD Implantation

Performance Characteristics Comparison of CNG Port and CNG Direct Injection in Spark Ignition Engine

A comparative performance analysis is being carried out on a four cylinder, four stroke cycle, spark ignition engine having displacement volume 1297cc. The cylinder head of original gasoline based engine was modified by drilling holes from upper surfaces of head to individual combustion chamber to convert the engine in a CNG direct injection engine. The CNG port injection (CNG-PI) system and CNG direct injection (CNG-DI) system were incorporated with the single engine. The engine was retrofitted to run on both CNG-PI and CNG-DI system alternately with common CNG tank and other engine loading and measurement system. The engine was equipped with electrical dynamometer having rheostat type loading. The CNG direct injection system was incorporated with various sensors and engine ECU. The operating parameters can be obtained on computer screen by loading the computer with engine through switch box. The engine was run over the speed range of 1000 rpm to 3000 rpm with incremental speed of 300 rpm. The performance parameters were calculated from observations and recorded for both CNG-PI and CNG-DI system. The experimental investigation exhibits that, the average 7-8% reduction in BSFC while the engine was running with CNG-DI system as compared to that of CNG-PI system. Also the engine produced 8-9% higher brake torque and hence higher brake power. The engine gives 6-7% higher brake thermal efficiency with CNG-DI system as compared to CNG-PI system.

Cardiorespiratory Optimal Point in Professional Soccer Players: A Novel Submaximal Variable During Exercise

Abstract Background: Maximal oxygen consumption (VO2max) and ventilatory threshold (VT) obtained during a cardiopulmonary exercise test (CPX) are used in the evaluation of athletes. However, the identification of these variables may sometimes be unreliable, which limits their use. In contrast, the cardiorespiratory optimal point (COP) is a submaximal variable derived from CPX with objective measurement and prognostic significance. However, its behavior in athletes is unknown. Objective: To describe the behavior of COP in professional soccer players and its association with VO2max and VT. Methods: VO2max, VT and COP were obtained retrospectively from 198 soccer players undergoing maximal treadmill CPX using ramp protocol. COP was defined as the lowest value of the ventilation/oxygen consumption ratio in a given minute of the CPX. The soccer players were stratified according to their field position: goalkeeper, center-defender, left/right-back, midfielder and forwarder. Continuous variables were compared using unpaired Student t test or ANOVA, or Mann-Whitney test or Kruskal-Wallis test depending on their distribution, and categorical variables were compared using chi-square test. Pearson correlation was used to test the association between COP and other ventilatory variables. A level of 5% was used for statistical significance. Results: COP (mean ± SD) was 18.2 ± 2.1 and was achieved at a speed 4.3 ± 1.4 km.h-1 lower than that achieved at the VT. While VO2max (62.1 ± 6.2 mL.kg-1.min-1) tended to be lower in goalkeepers (p < 0.05), the COP did not vary according to field position (p = 0.41). No significant association was observed between COP and VO2max (r = 0.032, p = 0.65) or between COP and VT (r = -0.003, p = 0.96). Conclusion: COP can be easily determined during submaximal exercise performed with incremental speed in soccer players and does not vary according to the athlete’s field position. The absence of association with VO2max and VT indicates that COP provides distinct and complementary information to these variables. Future studies are needed to determine the practical implications of COP in assessing athletes. (Int J Cardiovasc Sci. 2018; [online].ahead print, PP.0-0)

The physiological demand of a loaded march at five incremental speeds

The physiological demand of a loaded march at five incremental speeds

Cannula and Pump Positions Are Associated With Left Ventricular Unloading and Clinical Outcome in Patients With HeartWare Left Ventricular Assist Device

BackgroundCannula and pump positions are associated with clinical outcomes such as device thrombosis in patients with HeartMate II; however, clinical implications of HVAD (HeartWare International, Framingham, Massachusetts) cannula position are unknown. This study aims to assess the relationship among cannula position, left ventricular (LV) unloading, and patient prognosis. Methods and resultsTwenty-seven HVAD patients (60.0 ± 12.6 years of age and 19 males [70%]) underwent ramp test. Device position was quantified from chest X-ray parameters obtained at the time of the hemodyamic ramp test: (1) cannula coronal angle, (2) pump depth, (3) cannula sagittal angle, and (4) pump area. Lower cannula coronal angle was associated with LV unloading (as measured by smaller LV diastolic dimension and lower pulmonary capillary wedge pressure). Smaller pump area was associated with LV dynamic unloading, as assessed by steeper negative slopes of LV diastolic dimension and pulmonary capillary wedge pressure during incremental rotational speed change. Cannula coronal angle ≤65° was associated with reduced heart failure readmission rate (hazard ratio, 10.33; P = .007 by log-rank test). ConclusionHVAD cannula and pump positions are associated with LV unloading and improved clinical outcomes. Prospective studies evaluating surgical techniques to ensure optimal device positioning and its effects on clinical outcomes are warranted.

Optimization of Formability Parameters In Incremental Sheet Metal Forming Process

The Conventional forming process, without die and punch press, cannot be completed for desired product output and it leads to higher cost of setup forming process in industries, especially in automotive and sheet metal industries. To come over this cost factor, there is need of unique process for forming of sheet metal which eliminates higher setup cost of die and punch press. Considering lead time for process starting, it also takes higher lead time in conventional process which also effects on ultimate manufacturing cost. Surface quality and wall thickness mainly depends on the input parameters during forming process. This study aims to optimize surface roughness and wall thickness through incremental forming on AA6063 Aluminium alloy at room temperature by controlling the effects of forming parameters. To conclude the optimum process parameters in ISF, Taguchi method of DOE with L9 orthogonal array was developed for different process parameter factors such as feed rate, speed of spindle, wall angle, and step depth increment.

Pump Speed Optimization in Stable Patients with a Left Ventricular Assist Device.

Optimal left ventricular assist device (LVAD) functioning and preservation of right ventricular (RV) function are major survival determinants in destination therapy (DT)-LVAD recipients. Currently, the indication for routine pump speed optimization in stable patients and its effect on RV function at follow-up remain underexplored. Hemodynamically stable patients (N = 17, age 61 [interquartile range {IQR} 51-66] years; 13 [77%] male) underwent a routine speed ramp test. Echocardiographic images were obtained at incremental speed settings to determine optimal pump speed. In 8 patients (47%), LVAD speed could be optimized. In these patients, RV fractional area change (26% [IQR 23-31] to 35% [IQR 27-45], p = 0.04) and RV longitudinal peak systolic strain (-13% [IQR -16 to -9] to -17% [IQR -18 to -11], p = 0.02) at 3 months follow-up improved without RV dilatation. Furthermore, N-terminal pro-brain natriuretic peptide level decreased (3,162 [IQR 1,336-4,487] ng/L to 2,294 [IQR 1,157-3,810] ng/L, p = 0.02). No significant follow-up changes were found in patients without indication for speed adjustment. In conclusion, routine evaluation of optimal LVAD speed reveals the potential of speed optimization in a substantial proportion of stable LVAD-DT patients and can improve RV function.