Chronic low back pain is a worldwide burden that is not being abated with our current knowledge and treatment of the condition. The fear-avoidance model is used to explain the relationship between ...pain and disability in patients with chronic low back pain. However there are gaps in empirical support for pathways proposed within this model, and no evidence exists as to whether physical activity moderates these pathways.
This was a cross-sectional study of 218 people with chronic low back pain. Multiple mediation analyses were conducted to determine the role of fear, catastrophizing, depression, and anxiety in the relationship between pain and disability. Separate analyses were performed with physical activity as the moderator. Individuals were classified as performing regular structured physical activity if they described on average once per week for > 30-minutes an activity classified at least moderate intensity (≥ 4-6 METs), activity prescribed by an allied health professional for their back pain, leisure time sport or recreation, or self-directed physical activity such as resistance exercise.
Fear, catastrophizing, and depression significantly mediated the relationship between pain and disability (p<0.001). However the mediating effect of catastrophizing was conditional upon weekly physical activity. That is, the indirect effect for catastrophizing mediating the relationship between pain and disability was only significant for individuals reporting weekly physical activity (B = 1.31, 95% CI 0.44 to 2.23), compared to individuals reporting no weekly physical activity (B = 0.21, 95% CI -0.50 to 0.97). Catastrophizing also mediated the relationship between pain and fear (B = 0.37, 95% CI 0.15 to 0.62), with higher scores explaining 53% of the total effect of pain on fear.
These results support previous findings about the importance of fear and depression as factors that should be targeted in low back pain patients to reduce back pain related disability. We have also extended understanding for the mediating effect of catastrophizing on back pain related disability. Back pain patients engaged with regular physical activity may require counselling with regards to negative pain perceptions.
The purpose of this randomized controlled trial was to determine the effects of resistance training (RT) on markers of inflammation and immune function in breast cancer survivors. Thirty-nine breast ...cancer survivors were randomly assigned to a RT (
n
= 20) or control (
n
= 19) group. RT performed supervized exercise three times per week. Natural killer cell (NK) and natural killer T-cell (NKT) function, and markers of inflammation (serum TNF-α, IL-6, IL-10, and CRP) were measured before and after training. Changes in NK and NKT cell function were analyzed using ANCOVA, with the change score the dependent variable, and the baseline value of the same variable the covariate. Effect sizes (ES) were calculated via partial eta-squared. We found a significant reduction, and large associated ESs, in the RT group compared to the control group for change in NK cell expression of TNF-α (
p
= 0.005, ES = 0.21) and NKT cell expression of TNF-α (
p
= 0.04, ES = 0.12). No differences were observed in any serum marker. Significant improvements in all measurements of strength were found in RT compared to control (
p
< 0.001; large ESs ranging from 0.32 to 0.51). These data demonstrate that RT has a beneficial effect on the NK and NKT cell expression of TNF-α indicating that RT may be beneficial in improving the inflammatory profile in breast cancer survivors.
The reaction NH3 + NH2 ⇄ N2H3 + H2 (R1) has been identified as a key step to explain experimental results for pyrolysis and oxidation of ammonia. However, no direct experimental or theoretical ...evidence for the reaction has been reported. In the present work, the reaction was studied by ab initio theory and by reinterpretation of experimental data. We could not locate a transition state for R1 occurring as a direct process, but alternative mechanisms yielded an upper bound to k 1 of 1.5 × 1013 exp(−58.9 kcal mol–1/RT) cm3 mol–1 s–1 over 1000–2500 K, several orders of magnitude lower than values applied in modeling. Consistent with the theoretical work, re-evaluation of NH3 pyrolysis data supported a very low value of k 1. However, this finding opens up a novel unresolved issue. Current kinetic models cannot capture the NH3 oxidation behavior in a number of laminar flow reactor and jet-stirred reactor experiments without adopting an improbably high value for k 1. Important oxidation steps might be underestimated or missing from mechanisms.
To examine changes in hamstring muscle fatigue and central motor output during a 90-minute simulated soccer match, and the concomitant changes in hamstring maximal torque and rate of torque ...development.
Eight amateur male soccer players performed a 90-minute simulated soccer match, with measures performed at the start of and every 15-minutes during each half. Maximal torque (Nm) and rate of torque development (RTD; Nm.s-1) were calculated from maximal isometric knee flexor contractions performed at 10° of flexion. Hamstring peripheral fatigue was assessed from changes in the size and shape of the resting twitch (RT). Hamstring central motor output was quantified from voluntary activation (%) and normalized biceps femoris (BF) and medial hamstrings (MH) electromyographic amplitudes (EMG/M).
Maximal torque was reduced at 45-minutes by 7.6±9.4% (p<0.05). RTD in time intervals of 0-25, 0-50, and 0-75 ms post-contraction onset were reduced after 15-minutes in the first-half between 29.6 to 46.2% (p<0.05), and were further reduced at the end of the second-half (p<0.05). Maximal EMG/M was reduced for biceps femoris only concomitant to the time-course of reductions in maximal torque (p = 0.007). The rate of EMG rise for BF and MH was reduced in early time periods (0-75 ms) post-contraction onset (p<0.05). No changes were observed for the size and shape of the RT, indicating no hamstring peripheral fatigue.
Centrally mediated reductions in maximal torque and rate of torque development provide insight into factors that may explain hamstring injury risk during soccer. Of particular interest were early reductions during the first-half of hamstring rate of torque development, and the decline in maximal EMG/M of biceps femoris in the latter stages of the half. These are important findings that may help explain why the hamstrings are particularly vulnerable to strain injury during soccer.
Mystical experiences can bring an overwhelming sense that deeper realities have been contacted or that the everyday world has been apprehended as it truly is. Philosophical study of the experiences ...has not given much attention to their metaphysical significance, especially to the insights they may offer on fundamental issues such as the nature of reality, self, consciousness, and time. There are reasons for the neglect, and in the present article I consider two major theoretical obstacles to finding metaphysical significance in the experiences: a radical form of contextualism and a reductionist approach to neuroscience. With these obstacles addressed, there is room to consider how mystical experience and metaphysics can be brought into dialogue, a task facilitated by the contemporary resurgence of interest in alternatives to materialist metaphysics and a renewed interest in mystical experience encouraged by psychedelic research.
The idea of institutional religious freedom has become increasingly controversial, especially in the United States, and pressure for such freedom has been growing. The notion that institutions, ...including commercial ones, can have religious freedom rights has been described as unprecedented. However, the notion of such religious freedom has deep historical roots in a wide range of settings, is deeply intertwined with the growth of free societies, and is tied to the nature of religions themselves. This also applies to religious commercial institutions, which are far more widespread than commonly recognized. I focus particularly on what is it about such institutions that needs protecting and emphasize that what is central is the particular practice that typifies the organization. It needs the freedom to be what it is and to live out a religious commitment. If this calling is denied or subverted, then the institution loses its raison d’être. One of the principal reasons for forbidding government discrimination on matters such as religion is precisely so that private institutions will be able to appropriately employ staff and carry out policies according to their own particular beliefs as to what supports their distinctive mission. Governmental neutrality is intended to be a foundation for a lively and diverse societal pluralism, not for society to become a mirror of the government itself.
Over the last 50 years, German energy policy has ranged from strong enthusiasm for both coal and nuclear energy to deep skepticism. The most dramatic changes with respect to energy policies have ...occurred as a response to nuclear accidents, yet the accidental and unintended effects of coal policies are also important in influencing the trajectory. The newly emerging climate debate prevented the coal industry from acting as a substitute for the diminishing share of nuclear power. In 2011 the conservative government announced the Energiewende (‘energy transformation’) and decided to reduce the amount of fossil fuels from 80% of the energy supply to 20% by 2050. However, while the verdict on nuclear was unequivocal with a final phase-out date of 2022, the share of coal in the electricity market did not decrease and the amount of carbon dioxide released into the air slightly increased from 2011 to 2013. There are growing conflicts over the immediate costs and practicalities of coal replacement. Consequently, the future of coal in Germany is still relatively open and contested.
•German energy policy has ranged from enthusiasm about coal and nuclear to skepticism.•Policy has been driven by protest, planning, contingency and opportunity seeking.•Policy has resulted in paradoxes and unintended effects.•Nuclear energy seems to be finished but coal may linger on.
Research on d-aspartic acid (DAA) has demonstrated increases in total testosterone levels in untrained men, however research in resistance-trained men demonstrated no changes, and reductions in ...testosterone levels. The long-term consequences of DAA in a resistance trained population are currently unknown.
To evaluate the effectiveness of DAA to alter basal testosterone levels over 3 months of resistance training in resistance-trained men.
Randomised, double-blind, placebo controlled trial in healthy resistance-trained men, aged 18-36, had been performing regular resistance training exercise for at least 3 d.w-1 for the previous 2 years. Randomised participants were 22 men (d-aspartic acid n = 11; placebo n = 11) (age, 23.8±4.9 y, training age, 3.2±1.5 y).
D-aspartic acid (6 g.d-1, DAA) versus equal-weight, visually-matched placebo (PLA). All participants performed 12 weeks of supervised, periodised resistance training (4 d.w-1), with a program focusing on all muscle groups.
Basal hormones, total testosterone (TT), free testosterone (FT), estradiol (E2), sex-hormone-binding globulin (SHBG) and albumin (ALB); isometric strength; calf muscle cross-sectional area (CSA); calf muscle thickness; quadriceps muscle CSA; quadriceps muscle thickness; evoked V-wave and H-reflexes, were assessed at weeks zero (T1), after six weeks (T2) and after 12 weeks (T3).
No change in basal TT or FT were observed after the intervention. DAA supplementation (n = 10) led to a 16%, 95% CI -27%, -5% reduction in E2 from T1-T3 (p<0.01). The placebo group (n = 9) demonstrated improvements in spinal responsiveness (gastrocnemius) at the level of the alpha motoneuron. Both groups exhibited increases in isometric strength of the plantar flexors by 17%, 95% CI 7%, 28% (p<0.05) as well as similar increases in hypertrophy in the quadriceps and calf muscles.
The results of this paper indicate that DAA supplementation is ineffective at changing testosterone levels, or positively affecting training outcomes. Reductions in estradiol and the blunting of peripheral excitability appear unrelated to improvements from resistance training.
Australian New Zealand Clinical Trials Registry ACTRN12617000041358.
This study measured gluteus medius (GM) strength and endurance before and after a 2 h prolonged standing task in previously asymptomatic individuals, to compare between individuals who did and did ...not report pain in the low back. Twenty-four participants without a history of low back pain stood in a constrained area for 2
h. Before and after the standing protocol, participant’s maximal hip abduction strength (N) and side-bridge endurance (seconds and GM myoelectric fatigue) were measured. Continuous surface EMG was collected from GM during the 2-h protocol for analysis of bilateral co-activation. Pain in the low back was rated every 15
min with a visual analog scale (VAS). Seventeen of 24 (71%) previously asymptomatic participants developed pain in the low back during the standing protocol. These participants had lower side-bridge endurance (
p
=
.002), and higher gluteus medius (GM) co-activation (
p
=
.002) compared to participants who did not develop pain in the low back. Hip abduction strength decreased for both groups following prolonged standing, with no between groups’ difference. Lower side-bridge endurance and hip abduction strength were significantly associated with higher GM co-activation (adjusted
r
2
=
.34), but not pain levels. Side-bridge endurance and GM co-activation, but not hip abduction strength, may have utility in identifying participants likely to develop pain in the low back during prolonged standing. The best training program for increasing GM endurance is unclear.
In two concurrent studies, we aimed to a) confirm the acute effect of 0.3 g·kg-1 body weight (BW) sodium bicarbonate (NaHCO3) supplementation on central and peripheral mechanisms associated with ...explosive power (Study 1) and b) determine whether chronic NaHCO3 supplementation would improve the adaptive response of the neuromuscular system during a 10-week resistance training program (Study 2).
Eight resistance trained participants volunteered after providing written consent. The experimental design consisted of a week of baseline testing, followed by ten weeks of training with progress measures performed in Week 5. Study 1 involved neuromuscular measurements before and after the leg extension portion of a power based training session performed in Week 1. Changes in maximal torque (MVT) and rates of torque development (RTD), along with other variables derived from femoral nerve stimulation (e.g. voluntary activation, neural recruitment) were analysed to determine the extent of fatigue under NaHCO3 or placebo conditions. Changes in these same variables, coupled with functional 1-repetition maximum leg extension strength, were measured in Study 2 from baseline (Week 0) to Week 5, and again at Week 10.
In Study 1, we observed a decline after the leg extension task in both MVT (~ 30%) and rates of torque production (RTD) irrespective of acid-base status, however the decline in maximal RTD (RTDMAX) was nearly 20% less in the NaHCO3 condition when compared to placebo (mean difference of 294.8 ± 133.4 Nm·s-1 (95% CI -583.1 to -6.5 Nm, p < 0.05)). The primary finding in Study 2, however, suggests that introducing NaHCO3 repeatedly during a 10-week RT program does not confer any additional benefit to the mechanisms (and subsequent adaptive processes) related to explosive power production.
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