Soluble Trace Elements and Total Mercury in Arctic Alaskan Snow

Ultraclean field and laboratory procedures were used to examine trace element concentrations in northern Alaskan snow. Sixteen soluble trace elements and total mercury were determined in snow core samples representing the annual snowfall deposited during the 1993-94 season at two sites in the Prudhoe Bay oil field and nine sites in the Arctic National Wildlife Refuge (Arctic NWR). Results indicate there were two distinct point sources for trace elements in the Prudhoe Bay oil field- a source associated with oil and gas production and a source associated with municipal solid-waste incineration. Soluble trace element concentrations measured in snow from the Arctic NWR resembled concentrations of trace elements measured elsewhere in the Arctic using clean sample-collection and processing techniques and were consistent with deposition resulting from widespread arctic atmospheric contamination. With the exception of elements associated with sea salts, there were no orographic or east-west trends observed in the Arctic NWR data, nor were there any detectable influences from the Prudhoe Bay oil field, probably because of the predominant easterly and northeasterly winds on the North Slope of Alaska. However, regression analysis on latitude suggested significant south-to-north increases in selected trace element concentrations, many of which appear unrelated to the sea salt contribution.Des techniques ultra-propres utilisées sur le terrain et en laboratoire ont permis d'étudier les concentrations en éléments traces dans la neige de l'Alaska septentrional. Seize éléments traces solubles et le mercure total ont été mesurés dans des carottes de neige représentant la chute nivale annuelle de la saison 1993-94 à deux emplacements du champ pétrolifère de Prudhoe Bay et à neuf emplacements du refuge faunique national Arctique. Les résultats révèlent qu'il existe deux sources ponctuelles distinctes d'éléments traces découverts dans le champ pétrolifère de Prudhoe Bay, l'une reliée à la production de pétrole et de gaz et l'autre reliée à l'incinération des déchets municipaux solides. Les concentrations en éléments traces solubles mesurées dans la neige du refuge faunique national Arctique s'apparentaient aux concentrations en éléments traces mesurées ailleurs dans l'Arctique à l'aide de techniques propres de prélèvement et de traitement des carottes. Ces concentrations correspondent bien à des dépôts engendrés par une pollution atmosphérique généralisée dans l'Arctique. À l'exception des éléments associés aux sels marins, on n'a observé aucune tendance orographique ou est-ouest dans les données du refuge faunique national Arctique, de même qu'on n'a pas décelé d'influences perceptibles dues au champ pétrolifère de Prudhoe Bay, probablement en raison des vents prédominants d'est et du nord-est sur le versant nord de l'Alaska. L'analyse de régression sur la latitude suggère cependant une augmentation importante en allant du sud au nord dans les concentrations en certains éléments traces, dont beaucoup ne semblent pas reliées à l'apport de sel marin

Comparison of High-Intensity vs. High-Volume Resistance Training on the BDNF Response to Exercise

This study compared the acute and chronic response of circulating plasma brain-derived neurotrophic factor (BDNF) to high-intensity low-volume (HI) and low-intensity high volume (HV) resistance training. Twenty experienced resistance-trained men (23.5 ± 2.6 y, 1.79 ± 0.05 m, 75.7 ± 13.8 kg) volunteered for this study. Before the resistance training program (PRE), participants performed an acute bout of exercise using either the HI [3-5 reps; 90% of one repetition maximum (1RM)] or HV (10–12 reps; 70% 1RM) training paradigm. The acute exercise protocol was repeated after 7 wk of training (POST). Blood samples were obtained at rest (BL), immediately (IP), 30 min (30P), and 60 min (60P) post exercise at PRE and POST. A three-way repeated measure ANOVA was used to analyze acute changes in BDNF concentrations during HI and HV resistance exercise and the effect of 7 wk of training. No training × time × group interaction in BDNF was noted (P = 0.994). Significant main effects for training (P = 0.050) and time (P \u3c 0.001) in BDNF were observed. Significant elevations in BDNF concentrations were seen from BL at IP (P = 0.001), 30P (P \u3c 0.001), and 60P (P \u3c 0.001) in both HI and HV combined during PRE and POST. BDNF concentrations were also observed to increase from PRE to POST when collapsed across groups and time. No significant group × training interaction (P = 0.342), training (P = 0.105), or group (P = 0.238) effect were noted in the BDNF area under the curve response. Results indicate that BDNF concentrations are increased after an acute bout of resistance exercise, regardless of training paradigm, and are further increased during a 7-wk training program in experienced lifters

Improving muscle strength and size: the importance of training volume, intensity, and status

Increases in muscle size and strength are influenced by the mechanical and metabolic stresses imposed by resistance training. Mechanical stress is induced by the use of high-intensity training and it is believed it activates a larger percentage of muscle fibers. Conversely, metabolic stress is generated by high training volumes with moderate intensities using short rest intervals. This training paradigm results in greater fatigue and potentially stimulates a greater anabolic hormone response to exercise. Although evidence exists for both strategies, it still remains inconclusive whether one training paradigm is more advantageous than the other regarding muscle hypertrophy development. In untrained adults, the novelty of most resistance training programs may be sufficient to promote hypertrophy and strength gains, whereas greater training intensity may be more beneficial for trained adults. However, the body of well-designed research in this advanced population is limited. Therefore, the purpose of this brief review is to discuss the merits and limitations of the current evidence

High-intensity interval training and beta-hydroxy-beta-methylbutyric free acid improves aerobic power and metabolic thresholds

Background: Previous research combining Calcium beta-hydroxy-beta-methylbutyrate (CaHMB) and running high-intensity interval training (HIIT) have shown positive effects on aerobic performance measures. The purpose of this study was to examine the effect of beta-hydroxy-beta-methylbutyric free acid (HMBFA) and cycle ergometry HIIT on maximal oxygen consumption (VO(2)peak), ventilatory threshold (VT), respiratory compensation point (RCP) and time to exhaustion (T-max) in college-aged men and women. Methods: Thirty-four healthy men and women (Age: 22.7 +/- 3.1 yrs; VO(2)peak: 39.3 +/- 5.0 ml center dot kg(-1)center dot min(-1)) volunteered to participate in this double-blind, placebo-controlled design study. All participants completed a series of tests prior to and following treatment. A peak oxygen consumption test was performed on a cycle ergometer to assess VO(2)peak, Tmax, VT, and RCP. Twenty-six participants were randomly assigned into either a placebo (PLA-HIIT) or 3 g per day of HMBFA (BetaTor (TM) ) (HMBFA-HIIT) group. Eight participants served as controls (CTL). Participants in the HIIT groups completed 12 HIIT (80-120% maximal workload) exercise sessions consisting of 5-6 bouts of a 2: 1 minute cycling work to rest ratio protocol over a four-week period. Body composition was measured with dual energy x-ray absorptiometry (DEXA). Outcomes were assessed by ANCOVA with posttest means adjusted for pretest differences. Results: The HMBFA-HIIT intervention showed significant (p \u3c 0.05) gains in VO(2)peak, and VT, versus the CTL and PLA-HIIT group. Both PLA-HIIT and HMBFA-HIIT treatment groups demonstrated significant (p \u3c 0.05) improvement over CTL for Tmax, and RCP with no significant difference between the treatment groups. There were no significant differences observed for any measures of body composition. An independent-samples t-test confirmed that there were no significant differences between the training volumes for the PLA-HIIT and HMBFA-HIIT groups. Conclusions: Our findings support the use of HIIT in combination with HMBFA to improve aerobic fitness in college age men and women. These data suggest that the addition of HMBFA supplementation may result in greater changes in VO(2)peak and VT than HIIT alone

Fundamental study of adhesion of corrugated board. Project 2696-4, report one : a progress report to Fourdrinier Kraft Board Institute, Inc.

"January 15, 1969.""Institute of Paper Chemistry: Gerald R. Hoffman ... Joseph J. Becher ... John W. Swanson ... R. C. McKee.

High-intensity interval training and beta-hydroxy-beta-methylbutyric free acid improves aerobic power and metabolic thresholds

Background: Previous research combining Calcium beta-hydroxy-beta-methylbutyrate (CaHMB) and running high-intensity interval training (HIIT) have shown positive effects on aerobic performance measures. The purpose of this study was to examine the effect of beta-hydroxy-beta-methylbutyric free acid (HMBFA) and cycle ergometry HIIT on maximal oxygen consumption (VO(2)peak), ventilatory threshold (VT), respiratory compensation point (RCP) and time to exhaustion (T-max) in college-aged men and women. Methods: Thirty-four healthy men and women (Age: 22.7 +/- 3.1 yrs; VO(2)peak: 39.3 +/- 5.0 ml center dot kg(-1)center dot min(-1)) volunteered to participate in this double-blind, placebo-controlled design study. All participants completed a series of tests prior to and following treatment. A peak oxygen consumption test was performed on a cycle ergometer to assess VO(2)peak, Tmax, VT, and RCP. Twenty-six participants were randomly assigned into either a placebo (PLA-HIIT) or 3 g per day of HMBFA (BetaTor (TM) ) (HMBFA-HIIT) group. Eight participants served as controls (CTL). Participants in the HIIT groups completed 12 HIIT (80-120% maximal workload) exercise sessions consisting of 5-6 bouts of a 2: 1 minute cycling work to rest ratio protocol over a four-week period. Body composition was measured with dual energy x-ray absorptiometry (DEXA). Outcomes were assessed by ANCOVA with posttest means adjusted for pretest differences. Results: The HMBFA-HIIT intervention showed significant (p \u3c 0.05) gains in VO(2)peak, and VT, versus the CTL and PLA-HIIT group. Both PLA-HIIT and HMBFA-HIIT treatment groups demonstrated significant (p \u3c 0.05) improvement over CTL for Tmax, and RCP with no significant difference between the treatment groups. There were no significant differences observed for any measures of body composition. An independent-samples t-test confirmed that there were no significant differences between the training volumes for the PLA-HIIT and HMBFA-HIIT groups. Conclusions: Our findings support the use of HIIT in combination with HMBFA to improve aerobic fitness in college age men and women. These data suggest that the addition of HMBFA supplementation may result in greater changes in VO(2)peak and VT than HIIT alone

An evaluation of drainage aids in corrugating medium and linerboard finishes. Project 2926, report one : a progress report to Fourdrinier Kraft Board Institute, Inc.

"General.""December 23, 1970.""The Institute of Paper Chemistry, Gerald R Hoffman, research assistant, Joseph J. Becher, research associate, John W. Swanson, director, Division of Natural Materials and Systems, Robert C. McKee, chairman, Container Section.

Effects of beta-Hydroxy-beta-methylbutyrate Free Acid Ingestion and Resistance Exercise on the Acute Endocrine Response

Objective. To examine the endocrine response to a bout of heavy resistance exercise following acute beta-hydroxy-beta-methylbutyrate free acid (HMB-FA) ingestion. Design. Twenty resistance trained men were randomized and consumed either 1 g of HMB-FA (BetaTor) or placebo (PL) 30 min prior to performing an acute heavy resistance exercise protocol. Blood was obtained before (PRE), immediately after (IP), and 30 min after exercise (30P). Circulating concentrations of testosterone, growth hormone (GH), insulin-like growth factor (IGF-1), and insulin were assayed. Data were analyzed with a repeated measures ANOVA and area under the curve (AUC) was analyzed by the trapezoidal rule. Results. The resistance exercise protocol resulted in significant elevations from PRE in testosterone (P \u3c 0.01), GH (P \u3c 0.01), and insulin (P = 0.05) at IP, with GH (P \u3c 0.01) and insulin (P \u3c 0.01) remaining elevated at 30P. A significant interaction was noted between groups in the plasma GH response at IP, which was significantly higher following HMB-FA compared to PL (P \u3c 0.01). AUC analysis revealed an elevated GH and IGF-1 response in the HMB-FA group compared to PL. Conclusion. HMB-FA prior to resistance exercise augments the GH response to high volume resistance exercise compared to PL. These findings provide further support for the potential anabolic benefits associated with HMB supplementation

Efficacy of phosphatidic acid ingestion on lean body mass, muscle thickness and strength gains in resistance-trained men

Background: Phosphatidic acid (PA) has been reported to activate the mammalian target of rapamycin (mTOR) signaling pathway and is thought to enhance the anabolic effects of resistance training. The purpose of this pilot study was to examine if oral phosphatidic acid administration can enhance strength, muscle thickness and lean tissue accruement during an 8-week resistance training program. Methods: Sixteen resistance-trained men were randomly assigned to a group that either consumed 750 mg of PA (n = 7, 23.1 +/- 4.4 y; 176.7 +/- 6.7 cm; 86.5 +/- 21.2 kg) or a placebo (PL, n = 9, 22.5 +/- 2.0 y; 179.8 +/- 5.4 cm; 89.4 +/- 13.6 kg) group. During each testing session subjects were assessed for strength (one repetition maximum [1-RM] bench press and squat) and body composition. Muscle thickness and pennation angle were also measured in the vastus lateralis of the subject\u27s dominant leg. Results: Subjects ingesting PA demonstrated a 12.7% increase in squat strength and a 2.6% increase in LBM, while subjects consuming PL showed a 9.3% improvement in squat strength and a 0.1% change in LBM. Although parametric analysis was unable to demonstrate significant differences, magnitude based inferences indicated that the Delta change in 1-RM squat showed a likely benefit from PA on increasing lower body strength and a very likely benefit for increasing lean body mass (LBM). Conclusions: Results of this study suggest that a combination of a daily 750 mg PA ingestion, combined with a 4-day per week resistance training program for 8-weeks appears to have a likely benefit on strength improvement, and a very likely benefit on lean tissue accruement in young, resistance trained individuals

Excess Post-Exercise Oxygen Consumption (Epoc) Following Multiple Effort Sprint and Moderate Aerobic Exercise

The purpose of this study was to investigate the effects of 30-second all-out sprint interval exercise (SIE) vs. moderate aerobic exercise (MA) on excess post-exercise oxygen consumption (EPOC). Six recreationally-trained males (age=23.3 +/- 1.4 yrs, weight=81.8 +/- 9.9 kg, height=180.8 +/- 6.3 cm) completed a sprint interval exercise session consisting of three repeated 30-second Wingate cycling tests separated by four minutes (duration similar to 11minutes) as well as a moderate aerobic exercise session consisting of 30-minute cycling at 60% heart rate reserve (HRR) in a random counterbalanced design. Baseline oxygen consumption (VO2) was determined by an average VO2 from the final five minutes of a 30-minute supine rest period prior to each trial. Following each protocol, VO2 was measured for 30 minutes or until baseline measures were reached. EPOC was determined by subtracting baseline VO2 from post-exercise VO2 measurements. Energy expenditure (kJ) was determined by multiplying kJ per liter of oxygen by the average VO2 during recovery. EPOC values were significantly higher in SIE (7.5 +/- 1.3 L) than MA (1.8 +/- 0.7 L). SIE produced a higher recovery caloric expenditure (156.9 kJ) compared to MA (41.0 kJ) and remained significantly elevated (p=.024) over resting levels during the entire recovery period (30 minutes) compared to MA (6 minutes, p=.003). The energy required to recover from three repeated maximal effort 30-second Wingate cycling tests was greater than 30 minutes of moderate aerobic exercise. Future studies should examine the chronic effects of maximal effort sprint training protocol on cardiovascular fitness and body composition