Energy cost and energy sources in karate

Energy costs and energy sources in karate (wado style) were studied in eight male practitioners (age 23.8 years, mass. 72.3 kg, maximal oxygen consumption (VO_2max) 36.8 ml · min^–1 · kg^–1) performing six katas (formal, organized movement sequences) of increasing duration (from approximately. 10 s to approximately 80 s). Oxygen consumption (VO₂) was determined during pre-exercise rest, the exercise period and the first 270 s of recovery in five consecutive expired gas collections. A blood sample for lactate (la^–) analysis was taken 5 min after the end of exercise. The overall amount of O₂ consumed during the exercise and in the following recovery increased linearly with the duration of exercise (t) from approximately 1.51 (for t equal to 10.5 s (SD 1.6)) to approximately 5.81, for t equal to 81.5 s (SD 1.0). The energy release from la^– production (VO_21a ^–) calculated assuming that an increase of 1 mmol · l^–1 la^– corresponded to a VO₂ of 3 mlO₂ · kg^–1 was negligible for t equal to or less than 20 s and increased to 17.3 ml · kg^–1 (la^– = 5.8 mmol · l^–1 above resting values) for t equal approximately to 80 s. The overall energy requirement (VO_2eq) as given by the sum of VO₂ and VO_2la ^– was described by VO_2eq = 0.87 + 0.071 · t (n = 64; r ² = 0.91), where VO_2eq is in litres and t in seconds. This equation shows that the metabolic power (VO_2eq · t ^–1) for this karate style is very high: from approximately 9.51 · min^–1 for t equal to 10 s to approximately 4.91 · min^–1 for t equal to 80 s, i.e. from 3.5 to 1.8 times the subjects' VO_2max. The fraction of VO_2eq derived from the amount of O₂ consumed during the exercise increased from 11% for t equal to 10 s to 41 % for t equal to 80 s whereas VO_21a ^– was negligible far t equal to or less than 20 s and increased to 13 % o for t equal to 80 s. The remaining fraction (from 90% for t equal to 10 s to 46% for t equal to 80 s), corresponding to the amount of O₂ consumed in the recovery after exercise, is derived from anaerobic alactic sources, i.e. from net splitting of high energy phosphates during the exercise.     

Toward an energy budget model of photosynthesis predicting world productivity

In order to provide an initial estimate of the probable potential (no lack of soil water, fertilizer, pest and disease controls, advanced cultivation techniques, etc.) agricultural and primary productive ceilings of this planet, a series of deductive models of optimum net photosynthesis is constructed. The concern is with the generalized global trends of productivities representing many types of plants. Because a worldwide treatment of productivity is preferred at this time, a relatively simple, basic model had to be utilized in order to stay within reasonable limits of financial contraints. The findings presented in the body of the text thus represent a tentative economic answer to a pressing question of mankind.Four models have been developed: 1 for a high-efficiency C₄ plant, 2 for a C₃ type agricultural crop, 3 for a broadleaf woody species and 4 for a needleleaf species. The prediction of the leaf temperature is considered the crux of the testing of the energy budget portion of the models.     

The spring-mass model and the energy cost of treadmill running

During running, the behaviour of the support leg was studied by modelling the runner using an oscillating system composed of a spring (the leg) and of a mass (the body mass). This model was applied to eight middle-distance runners running on a level treadmill at a velocity corresponding to 90% of their maximal aerobic velocity [mean 5.10 (SD 0.33) m · s⁻¹]. Their energy cost of running (C _r ), was determined from the measurement of O₂ consumption. The work, the stiffness and the resonant frequency of both legs were computed from measurements performed with a kinematic arm. The C _r was significantly related to the stiffness (P < 0.05, r = −0.80) and the absolute difference between the resonant frequency and the step frequency (P < 0.05, r = 0.79) computed for the leg producing the highest positive work. Neither of these significant relationships were obtained when analysing data from the other leg probably because of the work asymmetry observed between legs. It was concluded that the spring-mass model is a good approach further to understand mechanisms underlying the interindividual differences in C _r . Accepted: 18 August 1997     

The energy cost of running increases with the distance covered

The net energy cost of running per unit of body mass and distance (Cr, ml O2.kg-1.km-1) was determined on ten amateur runners before and immediately after running 15, 32 or 42 km on an indoor track at a constant speed. The Cr was determined on a treadmill at the same speed and each run was performed twice. The average value of Cr, as determined before the runs, amounted to 174.9 ml O2.kg-1.km-1, SD 13.7. After 15 km, Cr was not significantly different, whereas it had increased significantly after 32 or 42 km, the increase ranging from 0.20 to 0.31 ml O2.kg-1.km-1 per km of distance (D). However, Cr before the runs decreased, albeit at a progressively smaller rate, with the number of trials (N), indicating an habituation effect (H) to treadmill running. The effects of D alone were determined assuming that Cr increased linearly with D, whereas H decreased exponentially with increasing N, i.e. Cr = Cr0 + a D + He-bN. The Cr0, the "true" energy cost of running in nonfatigued subjects accustomed to treadmill running, was assumed to be equal to the average value of Cr before the run for N equal to or greater than 7 (171.1 ml O2.kg-1.km-1, SD 12.7; n = 30).(ABSTRACT TRUNCATED AT 250 WORDS)     

A method to calculate the cumulative energy demand (CED) of lignite extraction

For the utilisation of an energy carrier such as lignite, the whole life cycle including necessary energy supply processes have to be considered. Therefore using the ‘Cumulative Energy Demand’ (CED) is especially suited to determine and compare the energy intensity of processes. The goal of the CED is to calculate the total primary energy input for the generation of a product, taking into account the pertinent front-end process chains. So the CED is in many steps similar to the LCA, especially in the ‘inventory analysis step’. The statements of the CED for energy supply-systems are concerned with the (primary) energy-efficiency of the energy supply and pointing out the life cycle steps with high energy-resources demand. Due to the great environmental impacts of energy supply and use which have to be laboriously assessed in LCA, the CED provides a useful, additional, energy-related ‘screening-indicator’ to LCA. This case study analyses the extraction of lignite in an opencast mine in West-Germany as the first step of energy carrier provision. Our data for the inventory analysis arise from a measuring campaign about the period of one year. The results underline the great energy demand of lignite extraction in West-Germany. With reference to the energy contents of lignite, the fraction of primary energy demands for its’ mining amounts to about 6.2%. This accounts to 93.8 % of the lignite energy content being available as usable energy for further processes, which is obviously worse than other studies have shown.     

The energy cost of walking or running on sand

Oxygen uptake (VO2) at steady state, heart rate and perceived exertion were determined on nine subjects (six men and three women) while walking (3-7 km.h-1) or running (7-14 km.h-1) on sand or on a firm surface. The women performed the walking tests only. The energy cost of locomotion per unit of distance (C) was then calculated from the ratio of VO2 to speed and expressed in J.kg-1.m-1 assuming an energy equivalent of 20.9 J.ml O2-1. At the highest speeds C was adjusted for the measured lactate contribution (which ranged from approximately 2% to approximately 11% of the total). It was found that, when walking on sand, C increased linearly with speed from 3.1 J.kg-1.m-1 at 3 km.h-1 to 5.5 J.kg-1.m-1 at 7 km.h-1, whereas on a firm surface C attained a minimum of 2.3 J.kg-1.m-1 at 4.5 km.h-1 being greater at lower or higher speeds. On average, when walking at speeds greater than 3 km.h-1, C was about 1.8 times greater on sand than on compact terrain. When running on sand C was approximately independent of the speed, amounting to 5.3 J.kg-1.m-1, i.e. about 1.2 times greater than on compact terrain. These findings could be attributed to a reduced recovery of potential and kinetic energy at each stride when walking on sand (approximately 45% to be compared to approximately 65% on a firm surface) and to a reduced recovery of elastic energy when running on sand.     

The cost of enzyme synthesis in the genetics of energy balance and physiological performance

The study of metabolism has traditionally focused upon factors that influence metabolic rate, at levels of both the metabolic pathway and the whole organism. This paper focuses on the cost, and thereby the efficiency, of metabolic processes. The genotype-dependent cost of enzyme turnover is proposed as a biochemical genetic mechanism for relating genetic variation at single genes to phenotypic variation in quantitative traits of energy metabolism. Decreased costs of maintenance metabolism can accompany artificial selection for increased production (e.g. growth, reproduction, etc.) and lower maintenance is correlated with multiple locus heterozygosity in outbred populations. In both cases, high production has been associated with lower rates of protein turnover. Several factors influence the ATP-equivalent cost of enzyme turnover. These factors are used to calculate the cost of turnover for a single enzyme. This cost can conservatively constitute up to several percent of the total daily mass-specific energy demands of maintenance metabolism. Genetic variants of an enzyme can differ in the cost of turnover. These differences can constitute the basis for metabolic changes associated with artificial selection for production and the metabolic differences that are associated with individual levels of heterozygosity. The metabolic and evolutionary significance of genotype-dependent turnover costs is a function of individual energy balance. The strength of selection against increases in cost will be an inverse function of individual energy balance and is therefore influenced by both environmental and genetic factors.     

External loading does not change energy cost and mechanics of rollerski skating

The purpose of this study was to examine the effects of external loading on the energy cost and mechanics of roller ski skating. A group of 13 highly skilled male cross-country skiers roller skied at 19.0 ( SD 0.1) km · h⁻¹ without additional load and with loads of 6% and 12% body mass (m _b). Oxygen uptake (V˙O₂), knee and ankle joint kinematics, roller-ski electromyogram (EMG) of the vastus lateralis and gastrocnemius lateralis muscles, and roller ski velocity were recorded during the last 40 s of each 4-min period of roller skiing. One-way repeated measures ANOVA revealed that the V˙O₂ expressed relative to total mass (m _tot), joint kinetics, eccentric-to-concentric ratio of the integrated EMG, velocity changes within a cycle, and cycle rate did not change significantly with load. The subsequent analysis of the effect of load on each resistance opposing motion suggested that the power to sustain changes in translational kinetic energy, potential energy, and overcoming rolling resistance increased proportionately with the load. The lack of a significant change in V˙O₂/m _tot with external loading was associated with a lack of marked change in external mechanical power relative to m _tot. The existence of an EMG signal during the eccentric phase prior to the thrust (concentric phase), as well as the lack of significant delay between the two phases, showed that a stretch-shortening cycle (SSC) occurs in roller ski skating. Taken together, the present results would suggest that external loading up to 12% m _b does not increase storage and release of elastic energy of lower limb muscles during SSC in roller ski skating. Accepted: 20 March 1998     

External load can alter the energy cost of prolonged exercise

The present study was undertaken to examine the energy cost of prolonged walking while carrying a backpack load. Six trained subjects were tested while walking for 120 min on a treadmill at a speed of 1.25 m.s-1 and 5% elevation with a well fitted backpack load of 25 and 40 kg alternately. Carrying 40 kg elicited a significantly higher (p less than 0.01) energy cost than 25 kg. Furthermore, whereas carrying 25 kg resulted in a constant energy cost, 40 kg yielded a highly significant (p less than 0.05) increase in energy cost over time. The study implies that increase in load causes physical fatigue, once work intensity is higher than 50% maximal work capacity. This is probably due to altered locomotion biomechanics which in turn lead to the increase in energy cost. Finally, the prediction model which estimates energy cost while carrying loads should be used with some caution when applied to heavy loads and long duration of exercise, since it might underestimate the actual energy cost.     

The energy cost of common tasks in rural Nepal: levels of energy expenditure compatible with sustained physical activity

Three hundred and six measurements of energy expenditure by indirect calorimetry of sitting at rest and self-paced activity were made on 41 men, 48 women and 6 adolescents in a mountain village of Nepal. Except for walking and carrying uphill, measured activities fell within the range of values for light to moderate effort, despite appearing physically demanding. Villagers tended to reduce travel speed when carrying heavy loads (54-102% of body mass on various inclines), averaging a moderate level of energy expenditure which could be sustained throughout the day. Such moderately demanding work was also assumed by pregnant, lactating women and young adolescents. Pregnant women worked more slowly at some tasks, but did not differentiate themselves from their non-pregnant, non-lactating counterparts for travel on the mountain side.     

Reproduction and the energy cost of defense in a Batesian mimicry complex

Summary The amount of energy invested in reproduction and in defense was examined in a Batesian mimicry complex consisting of the modelEleodes obscura and the mimicStenomorpha marginata (both Coleoptera: Tenebrionidae). Models live up to 4 y as adults while mimic adults live only 3 mo. The energy content of the eggs of the model and mimic was determined by microbomb calorimetry. The energy content of the defensive secretions produced by the model was determined by computational chemistry and MNDO computer programming. Contrary to the predictions of some life-history theory, the long-lived model annually produces many small eggs each of low energetic content, while the short-lived mimic annually produces fewer, larger eggs each of high energetic content. However, in terms of total energy, the long-lived model has an annual investment in reproduction equal to that of the short-lived mimic. During the 3 mo of co-ocurrence of models and mimics within a year, an average individual model's cost in using defensive secretions against potential predators is 12% of the amount of energy tied up in the eggs that it produces within the year. The annual cost of defense for the model is 18% of the energy contained in the mean number of eggs produced. When the energy allocated to eggs is added to that allocated to defense, the model has an annual investiment that is greater than the annual investment in reproduction by the mimic. Although the energy invested in defense by the model is small relative to the energy invested in egg production, it buys the model considerable protection from predation. Nevertheless, the cost of defense does not explain the deviations from the predictions of life-history theory.     

Non-indigenous insect species in Israel and adjacent areas

Non-indigenous species cause great damage worldwide. Non-indigenous insects are known as harmful in many regions, but few comprehensive works have investigated non-indigenous insects as a group. We compiled a comprehensive database of established non-indigenous (ENI) insects in Israel and adjacent regions to investigate how they arrived, their biological characteristics, and the attributes of areas they invade. Of 218 species of ENI insects in this region, 124 are widespread. Most species came as stowaways, but 38 were brought intentionally for biological control. Most ENI insects in this region are in the Coleoptera, Diptera, Hymenoptera, Lepidoptera, and Homoptera. Species from various orders differ in their tendency to be localized or widespread, and in biogeographic origins. The distribution of species among orders differs between native and ENI insects. The Coastal Plain houses the most ENI insect species and the Negev and Judean deserts the fewest. Most ENI insects spread from the Coastal Plain to other regions. Absence of roads, settlements and presence of nature reserves are negatively correlated with occurrence of ENI species. Seventy-nine species are categorized as pests that damage produce, merchandise, forestry, etc. Despite a general dearth of knowledge on impacts of ENI insects on natural systems, 42 species are known to feed on native plants, some of conservation concern. Biological control agents are usually more limited in their distribution than other ENI insects. Further research, legislation, and enforcement are required to minimize effects of these species on agriculture and natural habitats.     

Influence of the oxygen uptake slow component on the aerobic energy cost of high-intensity submaximal treadmill running in humans

During high-intensity running, the oxygen uptake (V˙O₂) kinetics is characterised by a slow component which delays the attainment of the steady-state beyond the 3rd min of exercise. To assess if the aerobic energy cost of running measured at the 3rd min (C ₃) adequately reflects the variability of the true aerobic energy cost measured during the steady-state (C _ss), 13 highly-trained runners completed sessions of square-wave running at intensities above 80% maximal oxygen uptake (V˙O_2max) on a level treadmill. To evaluate the time at which the steady-state V˙O₂ was attained (t _ss), the V˙O₂ responses were described using a general double-exponential equation and t _ss was defined as the time at which V˙O₂ was less than 1% below the asymptotic value given by the model. All the subjects achieved a steady state for intensities equal to or greater than 92% V˙O_2max, and 8 out of 13 achieved it at 99% V˙O_2max. In all cases, t _ss was less than 13 min. For intensities greater than 85% V˙O_2max, C _ss was significantly higher than C ₃ and was positively related to %V˙O_2max (r= 0.44; P < 0.001) while C ₃ remained constant. The C ₃ only explained moderately the variability of C _ss (0.39 < r ² < 0.72, depending on the velocity or the (relative intensity at which the relationship was calculated). Moreover, the excess aerobic energy cost of running the (difference between C _ss and C ₃) was well predicted by age (0.90 < r ² < 0.93). Therefore, when the aerobic profile of runners is evaluated, it is recommended that their running efficiencies at velocities which reflect their race intensities should be determined, with V˙O₂ data being measured at the true steady-state. Accepted: 1 June 1998     

山地麻蜥主要贮能部位水分含量和能值的年变化

研究了安徽宿州山地麻蜥主要贮能部位水分含量和能值的年变化。蜥蜴分别于2001年9-11月和2002年3—8月逐月捕回,经测量、称重后解剖分离为躯干(包括尾)、肝脏和腹脂肪体三组分。所有样品65℃恒温干燥至恒重,用索氏脂肪提取器测定脂肪含量,微电脑热量计测定能值。本研究结果显示：雄体躯干、肝脏水分含量显著高于雌体,躯干、肝脏水分含量的月间差异显著;雄体躯干、脱脂躯干能值显著高于雌体,躯干、脱脂躯干能值的月间差异显著;雄体肝脏能值、脱脂肝脏能值以及腹脂肪体能值显著低于雌体,肝脏能值、脱脂肝脏能值以及腹脂肪体能值的月间差异显著。上述结果表明,山地麻蜥躯干、肝脏以及腹脂肪体能值的年变化与繁殖和冬眠关系密切,繁殖期雄体适度贮能有利于提高运动的敏捷性;雌体适度贮能有利于增加繁殖输出,提高野外生存和适应性。     

Response of tree biomass and wood litter to disturbance in a Central Amazon forest

We developed an individual-based stochastic-empirical model to simulate the carbon dynamics of live and dead trees in a Central Amazon forest near Manaus, Brazil. The model is based on analyses of extensive field studies carried out on permanent forest inventory plots, and syntheses of published studies. New analyses included: (1) growth suppression of small trees, (2) maximum size (trunk base diameter) for 220 tree species, (3) the relationship between growth rate and wood density, and (4) the growth response of surviving trees to catastrophic mortality (from logging). The model simulates a forest inventory plot, and tracks recruitment, growth, and mortality of live trees, decomposition of dead trees (coarse litter), and how these processes vary with changing environmental conditions. Model predictions were tested against aggregated field data, and also compared with independent measurements including maximum tree age and coarse litter standing stocks. Spatial analyses demonstrated that a plot size of ~10 ha was required to accurately measure wood (live and dead) carbon balance. With the model accurately predicting relevant pools and fluxes, a number of model experiments were performed to predict forest carbon balance response to perturbations including: (1) increased productivity due to CO₂ fertilization, (2) a single semi-catastrophic (10%) mortality event, (3) increased recruitment and mortality (turnover) rates, and (4) the combined effects of increased turnover, increased tree growth rates, and decreased mean wood density of new recruits. Results demonstrated that carbon accumulation over the past few decades observed on tropical forest inventory plots (~0.5 Mg C ha^–1 year^–1) is not likely caused by CO₂ fertilization. A maximum 25% increase in woody tissue productivity with a doubling of atmospheric CO₂ only resulted in an accumulation rate of 0.05 Mg C ha^–1 year^–1 for the period 1980–2020 for a Central Amazon forest, or an order of magnitude less than observed on the inventory plots. In contrast, model parameterization based on extensive data from a logging experiment demonstrated a rapid increase in tree growth following disturbance, which could be misinterpreted as carbon sequestration if changes in coarse litter stocks were not considered. Combined results demonstrated that predictions of changes in forest carbon balance during the twenty-first century are highly dependent on assumptions of tree response to various perturbations, and underscores the importance of a close coupling of model and field investigations.     

Utilization of energy for growth in lambs of the breed german merino landsheep

Based on energy deposition and energy intake the utilization of energy for fat and protein deposition and the mean energy utilization for growth as well as the energy requirement for maintenance were estimated in this study. Fifty-four male and 54 female lambs were fed at three feeding levels and slaughtered at various body weights (BW): 18, 30, 45, and 55 kg. Based on the method of the comparative slaughter technique the total body of each animal was analysed. From the data of empty-body gain, fat, protein and energy deposition in the different fattening periods was calculated. The utilization of metabolizable energy for growth and maintenance was estimated by a multiple linear regression model. In this regression model, a utilization of energy for fat deposition of 71% and for protein deposition of 30% was determined (R² = 0.869). The requirement for maintenance was 520 kJ·kg BW ^{? 0.75}·d ^{? 1}. A slightly higher requirement for maintenance was determined for female lambs. The study indicated that the used regression model can be recommended to estimate the utilization of energy and the requirement for maintenance in growing lambs.     

Comments on the through-space singlet energy transfers and energy migration (exciton) in the light harvesting systems

Recent findings on the photophysical investigations of several cofacial bisporphyrin dyads for through space singlet and triplet energy transfers raised several serious questions about the mechanism of the energy transfers and energy migration in the light harvesting devices, notably LH II, in the heavily studied purple photosynthetic bacteria. The key issue is that for simple cofacial or slipped dyads with controlled geometry using rigid spacers or spacers with limited flexibilities, the fastest possible rates for singlet energy transfer for three examples are in the 10 x 10(9)s(-1) (i.e. just in the 100 ps time scale) for donor-acceptor distances approaching 3.5-3.6 A. The reported time scale for energy transfers between different bacteriochlorophylls, notably B800*-->B850, is in the picosecond time scale despite the long Mg...Mg separation of approximately 18 A. Such a short rate drastically contrasts with the well accepted F?rster theory. This article reviews the modern knowledge of the structure, bacteriochlorophyll a transition moments, and photophysical processes and dynamics in LH II, and compares these parameters with the recently investigated model bisporphyrin dyads build upon octa-etio-porphyrin chromophores and rigid and semi-rigid spacers. The recently discovered role of the rhodopin glucoside residue called carotenoid will be commented as the possible relay for energy transfer, including the possibility of uphill processes at room temperature. In this context, the concept of energy migration, called exciton, may also be affected by relays and uphill processes. Also, it is becoming more and more apparent that the presence of an irreversible electron transfer reaction at the reaction center, i.e. electron transfer from the special pair to the phyophytin macrocycle and so on, renders the rates for energy transfer and migration more rapid precluding all possibility of back transfers.     

Energy cost of front-crawl swimming in women

The purpose of this study was to examine the relationship between the energy cost of swimming per unit distance (Cs) at different velocities (v) and performance level, body size and swimming technique in women. A total of 58 females swimmers were studied. Three performance levels (A, B, C) were determined, ranging from the slower (A) to the faster (B, C). At level C and at 1.1 m.s-1, Cs,1.1 was reduced by 7% when directly compared to level B. The Cs,1.1 was reduced by 10% when calculated per unit of height (h) and by 37% when calculated per unit of h and hydrostatic lift (HL). For the whole group of swimmers, the equation regression was Cs,1.1 = 0.27 h-2.38 HL - 7.5 (r = 0.53, P less than 0.01). To evaluate the specific influence of arm length two groups of long- and short-armed swimmers were selected among swimmers of similar h and performance. The Cs was significantly higher (P less than 0.05) by 12%, SD 2.2%, for short-armed than for long-armed swimmers. To evaluate the influence of different types of swimming technique, two other groups of similar performance and anthropometric characteristics were selected. The Cs was significantly higher (P less than 0.05) by 12%, SD 4.5% for swimmers using for preference their legs rather than their arms. The Cs of the sprinters was 15.7%, SD 2% higher than that of the long-distance swimmers. For all groups, Cs increased with v on average by 8% to 11% every 0.1 m.s-1. These findings showed that Cs variations of these women were close to those previously demonstrated for men. The Cs depends on performance level, body size, buoyancy, swimming technique and v.     

Energy cost of running in similarly trained men and women

The energy demand of running on a treadmill was studied in different groups of trained athletes of both sexes. We have not found any significant differences in the net energy cost (C) during running (expressed in J.kg-1.m-1) between similarly trained groups of men and women. For men and women respectively in adult middle distance runners C = 3.57 +/- 0.15 and 3.65 +/- 0.20, in adult long-distance runners C = 3.63 +/- 0.18 and 3.70 +/- 0.21, in adult canoeists C = 3.82 +/- 0.34 and 3.80 +/- 0.24, in young middle-distance runners C = 3.84 +/- 0.18 and 3.78 +/- 0.26 and in young long-distance runners C = 3.85 +/- 0.12 and 3.80 +/- 0.24. This similarity may be explained by the similar training states of both sexes, resulting from the intense training which did not differ in its relative intensity and frequency between the groups of men and women. A negative relationship was found between the energy cost of running and maximal oxygen uptake (VO2max) expressed relative to body weight (for men r = -0.471, p less than 0.001; for women r = -0.589, p less than 0.001). In contrast, no significant relationship was found in either sex between the energy cost of running and VO2max. We conclude therefore that differences in sports performance between similarly trained men and women are related to differences in VO2max.kg-1. The evaluation of C as an additional characteristic during laboratory tests may help us to ascertain, along with other parameters, not only the effectiveness of the training procedure, but also to evaluate the technique performed.