The ecology of exercise: mechanisms underlying Individual variation in behavior, activity, and performance: an introduction to symposium

Wild animals often engage in intense physical activity while performing tasks vital for their survival and reproduction associated with foraging, avoiding predators, fighting, providing parental care, and migrating. In this theme issue we consider how viewing these tasks as “exercise”—analogous to that performed by human athletes—may help provide insight into the mechanisms underlying individual variation in these types of behaviors and the importance of physical activity in an ecological context. In this article and throughout this issue, we focus on four key questions relevant to the study of behavioral ecology that may be addressed by studying wild animal behavior from the perspective of exercise physiology: (1) How hard do individual animals work in response to ecological (or evolutionary) demands?; (2) Do lab-based studies of activity provide good models for understanding activity in free-living animals and individual variation in traits?; (3) Can animals work too hard during “routine” activities?; and (4) Can paradigms of “exercise” and “training” be applied to free-living animals? Attempts to address these issues are currently being facilitated by rapid technological developments associated with physiological measurements and the remote tracking of wild animals, to provide mechanistic insights into the behavior of free-ranging animals at spatial and temporal scales that were previously impossible. We further suggest that viewing the behaviors of non-human animals in terms of the physical exercise performed will allow us to fully take advantage of these technological advances, draw from knowledge and conceptual frameworks already in use by human exercise physiologists, and identify key traits that constrain performance and generate variation in performance among individuals. It is our hope that, by highlighting mechanisms of behavior and performance, the articles in this issue will spur on further synergies between physiologists and ecologists, to take advantage of emerging cross-disciplinary perspectives and technologies

Sequence-selective DNA recognition and enhanced cellular up-take by peptide–steroid conjugates

Several GCN4 bZIP TF models have previously been designed and synthesized. However, the synthetic routes towards these constructs are typically tedious and difficult. We here describe the substitution of the Leucine zipper domain of the protein by a deoxycholic acid derivative appending the two GCN4 binding region peptides through an optimized double azide–alkyne cycloaddition click reaction. In addition to achieving sequence specific dsDNA binding, we have investigated the potential of these compounds to enter cells. Confocal microscopy and flow cytometry show the beneficial influence of the steroid on cell uptake. This unique synthetic model of the bZIP TF thus combines sequence specific dsDNA binding properties with enhanced cell-uptake. Given the unique properties of deoxycholic acid and the convergent nature of the synthesis, we believe this work represents a key achievement in the field of TF mimicry

Рациональная организация учебного процесса как фактор здоровьесбережения студента

The aim of this study was to determine the training effects of an upper-body training program involving resistance exercise and high-intensity arm cranking on peak handcycling performance, propulsion efficiency, and biomechanical characteristics of wheelchair propulsion in able-bodied men. The training group (n = 10) received a 4-week upper-body resistance training (RT), 70% of 1 repetition maximum, 3 sets of 10 repetitions, 8 exercise stations, 2 times per week, combined with high-intensity interval training (HIIT) 2 times per week. High-intensity interval training consisted of arm-crank exercise, 7 intervals of 2 minutes at 80–90% of peak heart rate (HRpeak) with 2-minute active rest at 50–60% of HRpeak. The control group (n = 10) received no training. Both groups performed a preincremental and postincremental handcycling test until volitional exhaustion to evaluate fitness and a 4-minute submaximal wheelchair propulsion test at comfortable speed (CS), 125 and 145% of CS, to evaluate gross mechanical efficiency (GE), fraction of effective force (FEF), percentage of peak oxygen consumption (% V[Combining Dot Above]O2peak), and propulsion characteristics. Repeated-measures analysis of variance was performed (p < 0.05). Training resulted in a 28.2 ± 16.5% increase in peak power output, 13.3 ± 7.5% increase in V[Combining Dot Above]O2peak, 5.6 ± 0.9% increase in HRpeak, and 3.8 ± 1.5% decrease in HRrest. No training effects on FEF, GE, % V[Combining Dot Above]O2peak, and push characteristics were identified. In conclusion, the combined RT and arm-cranking HIIT improved fitness. However, it seems that this training did not result in improvements in propulsion efficiency and push characteristics. Additional wheelchair skill training may be needed to fully benefit from this advantage in daily life propulsion

Regulation of skeletal muscle fatty acid metabolism following acute and chronic exercise

This thesis investigated the effects of acute and chronic exercise on skeletal muscle lipolysis, fatty acid transport and oxidative capacity. The first study examined the importance of acute hormonal stimulation of hormone sensitive lipase (HSL) activity during the onset of exercise at ~65% VO2peak and ~90% VO2peak. Arterial epinephrine (EPI) increased (p < 0.05) post-exercise at 65% and 90% VO2peak. HSL activity increased following 1 min of exercise at both intensities. Cyclic AMP content, which has been associated with hormonal regulation of HSL, was augmented following exercise. The results indicated that increases in arterial EPI concentration during the onset of moderate and high intensity exercise increase cyclic AMP content which is associated with the phosphorylation of Ser 660 activating HSL. The second study examined the potency of seven high intensity aerobic interval training (HIIT) sessions on skeletal muscle and whole body fat metabolism in women. Each session consisted of ten, 4-min bouts at ~90% VO2 peak with 2-min rest between intervals. Training increased VO2 peak by 13%, whole body fat oxidation during exercise increased 36% and muscle mitochondrial enzyme maximal activities by 20-32%. Total muscle FABPpm content increased (25%), while FAT/CD36 content was unchanged following training. HIIT appears to stimulate improvements in whole body and skeletal muscle fat metabolism with only seven hours of training in two weeks. The third study determined if training altered total skeletal muscle, sarcolemmal and mitochondrial fatty acid transport protein contents in women. Ten females completed six weeks of HIIT. Training resulted in (1) a 48% and 13% increase in total FABPpm and FAT/CD36 content, respectively. (2) a 23% increase in FABPpm content and no change in FAT/CD36 content on the sarcolemma, (3) and a 51% increase in mitochondrial FAT/CD36 content (per g mitochondria), with no change in FABPpm content. This is the first study to show that exercise training in humans can increase sarcolemmal and mitochondrial content of fatty acid transport proteins. These results suggest that adaptations in whole body fat oxidation following training are in part due to a redistribution of fatty acid transport proteins to the sarcolemma and mitochondria enhancing transport capacity

Randomized controlled trial of postoperative exercise rehabilitation program after lumbar spine fusion: study protocol

Abstract Background Lumbar spine fusion (LSF) effectively decreases pain and disability in specific spinal disorders; however, the disability rate following surgery remains high. This, combined with the fact that in Western countries the number of LSF surgeries is increasing rapidly it is important to develop rehabilitation interventions that improve outcomes. Methods/design In the present RCT-study we aim to assess the effectiveness of a combined back-specific and aerobic exercise intervention for patients after LSF surgery. One hundred patients will be randomly allocated to a 12-month exercise intervention arm or a usual care arm. The exercise intervention will start three months after surgery and consist of six individual guidance sessions with a physiotherapist and a home-based exercise program. The primary outcome measures are low back pain, lower extremity pain, disability and quality of life. Secondary outcomes are back function and kinesiophobia. Exercise adherence will also be evaluated. The outcome measurements will be assessed at baseline (3&#8201;months postoperatively), at the end of the exercise intervention period (15&#8201;months postoperatively), and after a 1-year follow-up. Discussion The present RCT will evaluate the effectiveness of a long-term rehabilitation program after LSF. To our knowledge this will be the first study to evaluate a combination of strength training, control of the neutral lumbar spine position and aerobic training principles in rehabilitation after LSF. Trial registration ClinicalTrials.gov Identifier NCT00834015peerReviewe

A peptide with alternating lysines can act as a highly specific Z-DNA binding domain

Many nucleic acid binding proteins use short peptide sequences to provide specificity in recognizing their targets, which may be either a specific sequence or a conformation. Peptides containing alternating lysine have been shown to bind to poly(dG–d5meC) in the Z conformation, and stabilize the higher energy form [H. Takeuchi, N. Hanamura, H. Hayasaka and I. Harada (1991) FEBS Lett., 279, 253–255 and H. Takeuchi, N. Hanamura and I. Harada (1994) J. Mol. Biol., 236, 610–617.]. Here we report the construction of a Z-DNA specific binding protein, with the peptide KGKGKGK as a functional domain and a leucine zipper as a dimerization domain. The resultant protein, KGZIP, induces the Z conformation in poly(dG–d5meC) and binds to Z-DNA stabilized by bromination with high affinity and specificity. The binding of KGZIP is sufficient to convert poly(dG–d5meC) from the B to the Z form, as shown by circular dichroism. The sequence KGKGKGK is found in many proteins, although no functional role has been established. KGZIP also has potential for engineering other Z-DNA specific proteins for future studies of Z-DNA in vitro and in vivo

Temporary Electrostatic Impairment of DNA Recognition: Light‐Driven DNA Binding of Peptide Dimers

This is the peer reviewed version of the following article: Jiménez‐Balsa, A. , Pazos, E. , Martínez‐Albardonedo, B. , Mascareñas, J. L. and Vázquez, M. E. (2012), Temporary Electrostatic Impairment of DNA Recognition: Light‐Driven DNA Binding of Peptide Dimers. Angew. Chem. Int. Ed., 51: 8825-8829, which has been published in final form at https://doi.org/10.1002/anie.201201627. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsAppending negatively charged Glu8 tails to a peptide dimer derived from the GCN4 transcription factor leads to an effective suppression of its DNA binding. The specific DNA recognition can be restored by irradiation with UV light by using a photolabile linker between the acidic tail and the DNA binding peptideConsolider Ingenio. Grant Numbers: SAF2010‐20822‐C02, CTQ2009‐14431/BQU, CSD2007‐00006 Xunta de Galicia. Grant Numbers: INCITE09 209 084PR, PGIDIT08CSA‐047209PR, GRC2010/12 MINECOS