Beta-adrenergic blockade does not prevent the lactate response to exercise after acclimatization to high altitude

1994 ◽  
Vol 76 (2) ◽  
pp. 610-615 ◽  
Author(s):  
R. S. Mazzeo ◽  
G. A. Brooks ◽  
G. E. Butterfield ◽  
A. Cymerman ◽  
A. C. Roberts ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Control Group ◽  
Adrenergic Blockade ◽  
Arterial O2 Saturation ◽  
Response To Exercise ◽  
Peak Blood

We examined the extent to which epinephrine influences blood lactate adjustments to exercise during both acute (AC) and chronic (CH) high-altitude exposure. Eleven male sea level residents were divided into a control group (n = 5) receiving a placebo or a drug group (n = 6) receiving 240 mg/day of propranolol. All subjects were studied at rest and during 45 min of submaximal exercise (approximately 50% of sea level maximal O2 uptake) at sea level (SL) and within 4 h of exposure to and after 3 wk residence at 4,300 m (summit of Pikes Peak). Blood samples were collected from the femoral artery for epinephrine and lactate concentration. Exercising blood lactate concentration was significantly different across all altitude conditions such that AC > CH > SL (P < 0.05). For a given arterial O2 saturation, mean exercising blood lactates were lower for the beta-blocked group compared with controls; however, both groups demonstrated similar patterns across all conditions. Epinephrine levels during exercise followed a similar pattern to that of lactate, averaging 0.67, 0.43, and 0.29 ng/ml for AC, CH, and SL, respectively. The correlation between lactate and epinephrine was 0.93 and 0.84 for control and beta-blocked subjects, respectively. Whereas during exercise epinephrine was consistently higher for the beta-blocked group than controls, this difference was only significant during CH exposure. The epinephrine response was related to the extent of hypoxia in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Peak blood lactate and blood lactate vs. workload during acclimatization to 5,050 m and in deacclimatization

1996 ◽  
Vol 80 (2) ◽  
pp. 685-692 ◽  
Author(s):  
B. Grassi ◽  
M. Marzorati ◽  
B. Kayser ◽  
M. Bordini ◽  
A. Colombini ◽  
...  
Keyword(s):  
Sea Level ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Acid Base ◽  
Acid Base Status ◽  
Per Se ◽  
The Right ◽  
Peak Blood ◽  
Peak Blood Lactate

Peak blood lactate ([Labl]peak) and blood lactate concentration ([Labl]) vs. workload (W) relationships during acclimatization to altitude and in the deacclimatization were evaluated in 10 Caucasian lowlanders at sea level (SL0); after approximately 1 wk (Alt1wk), 3 wk (Alt3wk), and 5 wk (Alt5wk) at 5,050 m; and weekly during the first 5 wk after return to sea level (SL1wk-SL5wk). Incremental bicycle ergometer exercises (30 W added every 4 min up to exhaustion) were performed. At Alt1wk and at Alt5wk, the experiments were repeated in hypobaric normoxia (Alt1wk-O2 and Alt5wk-O2). [Labl] was determined at rest and during the last approximately 30 s of each W. [Labl]peak was taken as the highest [Labl] during recovery. Acid-base status (pH and concentration of HCO-3 in arterialized capillary blood) was determined at rest. Mean [Labl]peak values were 11.5 (SL0), 8.0 (Alt1wk), 6.4 (Alt3wk), 6.3 (Alt5wk), 8.0 (SL1wk), 9.4 (SL2wk), 10.8 (SL3wk), 11.3 (SL4wk), and 11.6 (SL5wk) mM. At Alt1wk-O2 and Alt5wk-O2, peak W increased, compared with Alt1wk and Alt5wk, whereas no changes were observed for [Labl]peak. [Labl] vs. W was shifted to the left (i.e., higher [Labl] values were found for the same W) at Alt1wk compared with SL0 and partially shifted back to the right (i.e., lower [Labl] values were found for the same W) at Alt3wk and Alt5wk. At Alt1wk-O2 and Alt5wk-O2, [Labl] vs. W values were superimposed on that at SL0. At SL1wk-SL5wk, [Labl] vs. W values were shifted to the right compared with that at SL0. At Alt1wk, a condition of respiratory alkalosis was found, which was only partially compensated for during acclimatization. At SL1wk, the acid-base status was back to normal. We conclude that 1) the reduced [Labl]peak at altitude is still present for 2-3 wk after return from altitude; is not attributable to reduced peak W nor to hypoxia per se, nor to a reduced buffer capacity; alternatively, it could be related to some central determinants of fatigue. 2) The [Labl] vs. W leftward shift at altitude was due to hypoxia per se. 3) The factor(s) responsible for the [Labl] vs. W partial rightward shift during acclimatization could still be effective during the first weeks after return to sea level.

Optimal Adrenergic Support in Septic Shock Due to Peritonitis

2003 ◽  
Vol 98 (4) ◽  
pp. 888-896 ◽  
Author(s):  
Qinghua Sun ◽  
Zizhi Tu ◽  
Suzana Lobo ◽  
George Dimopoulos ◽  
Nathalie Nagy ◽  
...  
Keyword(s):  
Septic Shock ◽  
Cardiac Output ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
The Other ◽  
Control Group ◽  
Lower Blood

Background The authors evaluated optimal adrenergic support using norepinephrine, dopamine, and dobutamine in a clinically relevant model of septic shock. Methods Twenty-eight mature, female, anesthetized sheep (weight, 30.5 +/- 3.6 kg) underwent cecal ligation and perforation and were randomized into four groups of seven animals to be treated with norepinephrine, dopamine-norepinephrine, dobutamine-norepinephrine, or no adrenergic agent. In all groups, lactated Ringer's solution was administered to restore cardiac filling pressures to baseline. In the norepinephrine group, norepinephrine (0.5-5 microg. kg(-1). min(-1)) was titrated to maintain mean arterial pressure between 75-85 mmHg. In the dopamine-norepinephrine group, dopamine was given first, and norepinephrine was added only when mean arterial pressure remained below 75 mmHg despite the infusion of 20 microg. kg(-1). min(-1) dopamine. In the dobutamine-norepinephrine group, dobutamine was started at the same time as norepinephrine and titrated up to 20 microg. kg(-1). min(-1) to get a 15% increase in cardiac output. Results The dobutamine-norepinephrine group had greater cardiac output; superior mesenteric blood flow, oxygen delivery (Do(2)), and oxygen consumption ([OV0312]o(2)); and lower blood lactate concentration and partial pressure of carbon dioxide (Pco(2)) gap than the controls did. Cumulative urine output was significantly higher in the dobutamine-norepinephrine group than in the other groups. Survival time was significantly longer in the dobutamine-norepinephrine (24 +/- 4 h), dopamine- norepinephrine (24 +/- 6 h), and norepinephrine (20 +/- 1 h) groups than the control group (17 +/- 2 h; P &lt; 0.05 vs. other groups), and significantly longer in the combined dopamine-norepinephrine and dobutamine-norepinephrine groups (24 +/- 5 h) than in the norepinephrine alone group (P &lt; 0.05). Histologic examination of lung biopsies revealed less severe lesions in the dobutamine-norepinephrine group than in the control and norepinephrine alone groups. Anatomic alterations in the lung, liver, and small intestine were less severe in the dobutamine-norepinephrine group than in the other groups. Conclusions In this prolonged septic shock model, association of norepinephrine with either dopamine or dobutamine resulted in the longest survival and the least severe pulmonary lesions. The combination of dobutamine with norepinephrine was associated with a better myocardial performance, greater Do(2) and [OV0312]o(2), lower blood lactate concentration and Pco(2) gap, and less anatomic injury.

scholarly journals La privación de sueño no afecta la resistencia aeróbica ni la concentración de lactato en sangre de jóvenes deportistas (Sleep deprivation does not affect aerobic resistance or blood lactate concentration of young athletes)

Retos ◽  
2018 ◽  
pp. 221-223
Author(s):  
Jorge Alberto Aburto Corona ◽  
Tatiana Miranda Núñez ◽  
Alicia Bárcenas Ugalde ◽  
Roberto Espinoza Gutiérrez ◽  
Emilio Manuel Arrayales Millán
Keyword(s):  
Sleep Deprivation ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Aerobic Performance ◽  
Control Group ◽  
Experimental Conditions ◽  
Male Athletes ◽  
Physical Test ◽  
Significant Difference

El objetivo de este estudio fue determinar si la resistencia aeróbica y la concentración de lactato en sangre, pueden ser influenciados por la privación parcial o total del sueño en un grupo de deportistas. Se reclutaron 13 deportistas masculinos (21.8 ± 2.9 años de edad) los cuales fueron sometidos a tres condiciones experimentales: dormir cuatro horas (D4H), no dormir (0H) y una condición contol de dormir ocho horas (D8H). No se encontraron diferencias estadísticamente significativas en la resistencia aeróbica (p=.845). De la misma manera, no se halló diferencia significativa en la concentración de lactato en sangre (p>.05). Estos resultados señalan que la privación parcial (dormir cuatro horas) o total (no dormir) del sueño, previo a una prueba física, no es un factor que influya en el rendimiento aeróbico ni en la concentración de lactato en sangre en comparación a la cantidad de horas de sueño recomendadas (dormir ocho horas).Abstract. The purpose of this study was to determinate if aerobic performance and blood lactate concentration are influenced by partial or total sleep deprivation. Thirteen male athletes (age: 21.8 ± 2.9 y.o) were randomly assigned to three experimental conditions: sleep four hours (D4H), no sleep (0H), and sleep eigth hours (D8H, control group). No significant difference was found in the aerobic performance (p=.845). Similarly, there was no sifnificant difference in blood lactate concentration (p>.05). This results suggest that partial (sleep four hours) or total (no sleep) sleep deprivation before a physical test are not a factor influencing aerobic performance or blood lactate concentration compared to the amount of recommended hours of sleep (sleep eight hours).

Interleukin-6 response to exercise and high-altitude exposure: influence of α-adrenergic blockade

2001 ◽  
Vol 91 (5) ◽  
pp. 2143-2149 ◽  
Author(s):  
Robert S. Mazzeo ◽  
Danielle Donovan ◽  
Monika Fleshner ◽  
Gail E. Butterfield ◽  
Stacy Zamudio ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Interleukin 6 ◽  
Moderate Intensity ◽  
Adrenergic Blockade ◽  
Moderate Intensity Exercise ◽  
Exercise Tests ◽  
Altitude Exposure ◽  
Excretion Rates ◽  
Response To Exercise

Interleukin-6 (IL-6), an important cytokine involved in a number of biological processes, is consistently elevated during periods of stress. The mechanisms responsible for the induction of IL-6 under these conditions remain uncertain. This study examined the effect of α-adrenergic blockade on the IL-6 response to acute and chronic high-altitude exposure in women both at rest and during exercise. Sixteen healthy, eumenorrheic women (aged 23.2 ± 1.4 yr) participated in the study. Subjects received either α-adrenergic blockade (prazosin, 3 mg/day) or a placebo in a double-blinded, randomized fashion. Subjects participated in submaximal exercise tests at sea level and on days 1 and 12 at altitude (4,300 m). Resting plasma and 24-h urine samples were collected throughout the duration of the study. At sea level, no differences were found at rest for plasma IL-6 between groups (1.5 ± 0.2 and 1.2 ± 0.3 pg/ml for placebo and blocked groups, respectively). On acute ascent to altitude, IL-6 levels increased significantly in both groups compared with sea-level values (57 and 84% for placebo and blocked groups, respectively). After 12 days of acclimatization, IL-6 levels remained elevated for placebo subjects; however, they returned to sea-level values in the blocked group. α-Adrenergic blockade significantly lowered the IL-6 response to exercise both at sea level (46%) and at altitude (42%) compared with placebo. A significant correlation ( P = 0.004) between resting IL-6 and urinary norepinephrine excretion rates was found over the course of time while at altitude. In conclusion, the results indicate a role for α-adrenergic regulation of the IL-6 response to the stress of both short-term moderate-intensity exercise and hypoxia.

Long-Sprint Abilities in Soccer: Ball Versus Running Drills

2017 ◽  
Vol 12 (9) ◽  
pp. 1256-1263 ◽  
Author(s):  
Carlo Castagna ◽  
Lorenzo Francini ◽  
Susana C.A. Póvoas ◽  
Stefano D’Ottavio
Keyword(s):  
Blood Lactate ◽  
External Load ◽  
Perceived Exertion ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Cardiovascular Effects ◽  
Rating Of Perceived Exertion ◽  
Soccer Players ◽  
Physiological Diversity ◽  
Peak Blood

Purpose:To examine the acute effects of generic drills (running drills [RDs]) and specific (small-sided-games [SSGs]) long-sprint-ability (LSA) drills on internal and external load of male soccer players. Methods:Fourteen academy-level soccer players (mean ± SD age 17.6 ± 0.61 y, height 1.81 ± 0.63 m, body mass 69.53 ± 4.65 kg) performed four 30-s LSA bouts for maintenance (work:rest 1:2) and production (1:5) with RDs and SSGs. Players’ external load was tracked with GPS technology (20-Hz), and heart rate (HR), blood lactate concentration (BLc), and rating of perceived exertion (RPE) were used to characterize players’ internal load. Individual peak BLc was assessed with a 30-s all-out test on a nonmotorized treadmill (NMT). Results:Compared with SSGs, the RDs had a greater effect on external load and BLc (large and small, respectively). During SSGs players covered more distance with high-intensity decelerations (moderate to small). Muscular RPE was higher (small to large) in RDs than in SSGs. The production mode exerted a moderate effect on BLc while the maintenance condition elicited higher cardiovascular effects (small to large). Conclusion:The results of this study showed the superiority of generic over specific drills in inducing LSA-related physiological responses. In this regard production RDs showed the higher postexercise BLc. Individual peak blood lactate responses were found after the NMT 30-s all-out test, suggesting this drill as a valid option to RDs. The practical physiological diversity among the generic and specific LSA drills here considered enable fitness trainers to modulate prescription of RD and SSG drills for LSA according to training schedule.

The Assessment of Children’s Anaerobic Performance Using Modifications of the Wingate Anaerobic Test

1997 ◽  
Vol 9 (1) ◽  
pp. 80-89 ◽  
Author(s):  
Michael Chia ◽  
Neil Armstrong ◽  
David Childs
Keyword(s):  
Blood Lactate ◽  
Peak Power ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Mean Power ◽  
Wingate Anaerobic Test ◽  
Power Outputs ◽  
Anaerobic Test ◽  
Peak Blood ◽  
Peak Blood Lactate

Twenty-five girls and 25 boys (mean age 9.7 ± 0.3 years) each completed a 20- and 30-s Wingate Anaerobic Test (WAnT). Oxygen uptake during the WAnTs, and postexercise blood lactate samples were obtained. Inertia and load-adjusted power variables were higher (18.6–20.1% for peak, and 6.7–7.5% for mean power outputs, p < .05) than the unadjusted values for both the 20- and 30-s WAnTs. The adjusted peak power values were higher (7.7–11.6%, p < .05) in both WAnTs when integrated over 1-s than over 5-s time periods. The aerobic contributions to the tests were lower (p < .05) in the 20-s WAnT (13.7–35.7%) than in the 30-s WAnT (17.7–44.3%) for assumed mechanical efficiencies of 13% and 30%. Postexercise blood lactate concentration after the WAnTs peaked by 2 min. No gender differences (p > .05) in anaerobic performances or peak blood lactate values were detected.

Evaluation of Blood Lactate Concentration in Dogs Receiving Whole Blood Transfusion

2020 ◽  
Author(s):  
B. Zakarevičiūtė ◽  
D. Juodžentė ◽  
B. Karvelienė ◽  
S. Čechovičienė ◽  
V. Riškevičienė
Keyword(s):  
Blood Transfusion ◽  
Blood Lactate ◽  
Whole Blood ◽  
Blood Cells ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Control Group ◽  
Patient Status ◽  
Group I ◽  
Life Saving

Background: A blood transfusion is a routine, life-saving procedure used to replace blood cells or blood products. The current study was aimed to assess whether the blood lactate concentration has a prognostic value of successful blood transfusion.Methods: During the period 2018-2019 group I dogs (n=19) received whole blood transfusion and twenty dogs were assigned to the control group (group II). Blood samples in group I were obtained from cephalic vein before blood transfusion (T0), then after it was finished (4hr±20 min) (T1) and 24hr±20 min after the T0 (T2).Result: The level of blood lactate reached the normal level after blood transfusion in T1 and T2. The clearance of lactate had a moderate negative correlation with packed cell volume (PCV) and red blood cells (RBC). There was no significant correlation between survival rate and blood lactate level. The survivals 24hr after transfusion (T2) had five times higher count of reticulocytes (RETIC) then non-survivals. Serial blood lactate measurement can improve the prediction of successful blood transfusion and it is useful in monitoring the patient status 24hr post blood transfusion, but it doesn’t have the predictive value of survival.

scholarly journals Energetic and Biomechanical Contributions for Longitudinal Performance in Master Swimmers

2020 ◽  
Vol 5 (2) ◽  
pp. 37
Author(s):  
Daniel A. Marinho ◽  
Maria I. Ferreira ◽  
Tiago M. Barbosa ◽  
José Vilaça-Alves ◽  
Mário J. Costa ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Swimming Performance ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Stroke Index ◽  
Front Crawl ◽  
Stroke Length ◽  
Propelling Efficiency ◽  
Peak Blood ◽  
Peak Blood Lactate

Background: The current study aimed to verify the changes in performance, physiological and biomechanical variables throughout a season in master swimmers. Methods: Twenty-three master swimmers (34.9 ± 7.4 years) were assessed three times during a season (December: M1, March: M2, June: M3), in indoor 25 m swimming pools. An incremental 5 × 200 m test was used to evaluate the speed at 4 mmol·L−1 of blood lactate concentration (sLT), maximal oxygen uptake (VO2max), peak blood lactate ([La-]peak) after the test, stroke frequency (SF), stroke length (SL), stroke index (SI) and propelling efficiency (ηp). The performance was assessed in the 200 m front crawl during competition. Results: Swimming performance improved between M1, M2 (2%, p = 0.03), and M3 (4%, p < 0.001). Both sLT and VO2max increased throughout the season (4% and 18%, p < 0.001, respectively) but not [La-]peak. While SF decreased 5%, SL, SI and ηp increased 5%, 7%, and 6% (p < 0.001) from M1 to M3. Conclusions: Master swimmers improved significantly in their 200 m front crawl performance over a season, with decreased SF, and increased SL, ηp and SI. Despite the improvement in energetic variables, the change in performance seemed to be more dependent on technical than energetic factors.

Decreased reliance on lactate during exercise after acclimatization to 4,300 m

1991 ◽  
Vol 71 (1) ◽  
pp. 333-341 ◽  
Author(s):  
G. A. Brooks ◽  
G. E. Butterfield ◽  
R. R. Wolfe ◽  
B. M. Groves ◽  
R. S. Mazzeo ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Acute Exposure ◽  
O2 Consumption ◽  
Arterial Lactate ◽  
Healthy Men ◽  
Subsequent Decrease ◽  
Appearance Rate

We hypothesized that the increased exercise arterial lactate concentration on arrival at high altitude and the subsequent decrease with acclimatization were caused by changes in blood lactate flux. Seven healthy men [age 23 +/- 2 (SE) yr, wt 72.2 +/- 1.6 kg] on a controlled diet were studied in the postabsorptive condition at sea level, on acute exposure to 4,300 m, and after 3 wk of acclimatization to 4,300 m. Subjects received a primed-continuous infusion of [6,6–2D]glucose (Brooks et al. J. Appl. Physiol. 70:919–927, 1991) and [3–13C]lactate and rested for a minimum of 90 min followed immediately by 45 min of exercise at 101 +/- 3 W, which elicited 51.1 +/- 1% of the sea level peak O2 consumption (VO2peak; 65 +/- 2% of both acute altitude and acclimatization). During rest at sea level, lactate appearance rate (Ra) was 0.52 +/- 0.03 mg.kg-1.min-1; this increased sixfold during exercise to 3.24 +/- 0.19 mg.kg-1.min-1. On acute exposure, resting lactate Ra rose from sea level values to 2.2 +/- 0.2 mg.kg-1.min-1. During exercise on acute exposure, lactate Ra rose to 18.6 +/- 2.9 mg.kg-1.min-1. Resting lactate Ra after acclimatization (1.77 +/- 0.25 mg.kg-1.min-1) was intermediate between sea level and acute exposure values. During exercise after acclimatization, lactate Ra (9.2 +/- 0.7 mg.kg-1.min-1) rose from resting values but was intermediate between sea level and acute exposure values. The increased exercise arterial lactate concentration response on arrival at high altitude and subsequent decrease with acclimatization are due to changes in blood lactate appearance.(ABSTRACT TRUNCATED AT 250 WORDS)

Muscle accounts for glucose disposal but not blood lactate appearance during exercise after acclimatization to 4,300 m

1992 ◽  
Vol 72 (6) ◽  
pp. 2435-2445 ◽  
Author(s):  
G. A. Brooks ◽  
E. E. Wolfel ◽  
B. M. Groves ◽  
P. R. Bender ◽  
G. E. Butterfield ◽  
...  
Keyword(s):  
Blood Glucose ◽  
High Altitude ◽  
Sea Level ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Acute Exposure ◽  
Glucose Disposal ◽  
O2 Uptake ◽  
Arterial Lactate ◽  
Subsequent Decrease

We hypothesized that the increased blood glucose disappearance (Rd) observed during exercise and after acclimatization to high altitude (4,300 m) could be attributed to net glucose uptake (G) by the legs and that the increased arterial lactate concentration and rate of appearance (Ra) on arrival at altitude and subsequent decrease with acclimatization were caused by changes in net muscle lactate release (L). To evaluate these hypotheses, seven healthy males [23 +/- 2 (SE) yr, 72.2 +/- 1.6 kg], on a controlled diet were studied in the postabsorptive condition at sea level, on acute exposure to 4,300 m, and after 3 wk of acclimatization to 4,300 m. Subjects received a primed-continuous infusion of [6,6–D2]glucose (Brooks et al., J. Appl. Physiol. 70: 919–927, 1991) and [3–13C]lactate (Brooks et al., J. Appl. Physiol. 71:333–341, 1991) and rested for a minimum of 90 min, followed immediately by 45 min of exercise at 101 +/- 3 W, which elicited 51.1 +/- 1% of the sea level peak O2 uptake (65 +/- 2% of both acute altitude and acclimatization peak O2 uptake). Glucose and lactate arteriovenous differences across the legs and arms and leg blood flow were measured. Leg G increased during exercise compared with rest, at altitude compared with sea level, and after acclimatization. Leg G accounted for 27–36% of Rd at rest and essentially all glucose Rd during exercise. A shunting of the blood glucose flux to active muscle during exercise at altitude is indicated. With acute altitude exposure, at 5 min of exercise L was elevated compared with sea level or after acclimatization, but from 15 to 45 min of exercise the pattern and magnitude of L from the legs varied and followed neither the pattern nor the magnitude of responses in arterial lactate concentration or Ra. Leg L accounted for 6–65% of lactate Ra at rest and 17–63% during exercise, but the percent Ra from L was not affected by altitude. Tracer-measured lactate extraction by legs accounted for 10–25% of lactate Rd at rest and 31–83% during exercise. Arms released lactate under all conditions except during exercise with acute exposure to high altitude, when the arms consumed lactate. Both active and inactive muscle beds demonstrated simultaneous lactate extraction and release. We conclude that active skeletal muscle is the predominant site of glucose disposal during exercise and at high altitude but not the sole source of blood lactate during exercise at sea level or high altitude.

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