Soil penetration by maize roots is negatively related to ethylene-induced thickening

Radial expansion is a classic response of roots to a mechanical impedance that has generally been assumed to aid penetration. We analysed the response of maize nodal roots to impedance to test the hypothesis that radial expansion is not related to the ability of roots to cross a compacted soil layer. Genotypes varied in their ability to cross the compacted layer, and those with a steeper approach to the compacted layer or less radial expansion in the compacted layer were more likely to cross the layer and achieve greater depth. Root radial expansion was due to cortical cell size expansion, while cortical cell file number remained constant. Genotypes and nodal root classes that exhibited radial expansion in the compacted soil layer generally also thickened in response to exogenous ethylene in hydroponic culture, that is, radial expansion in response to ethylene was correlated with the thickening response to impedance in soil. We propose that ethylene insensitive roots, that is, those that do not thicken and can overcome impedance, have a competitive advantage under mechanically impeded conditions as they can maintain their elongation rates. We suggest that prolonged exposure to ethylene could function as a stop signal for axial root growth

Aerobic interval training and continuous training equally improve aerobic exercise capacity in patients with coronary artery disease:The SAINTEX-CAD study

AbstractBackgroundExercise-based cardiac rehabilitation increases peak oxygen uptake (peak VO2), which is an important predictor of mortality in cardiac patients. However, it remains unclear which exercise characteristics are most effective for improving peak VO2 in coronary artery disease (CAD) patients. Proof of concept papers comparing Aerobic Interval Training (AIT) and Moderate Continuous Training (MCT) were conducted in small sample sizes and findings were inconsistent and heterogeneous. Therefore, we aimed to compare the effects of AIT and Aerobic Continuous Training (ACT) on peak VO2, peripheral endothelial function, cardiovascular risk factors, quality of life and safety, in a large multicentre study.MethodsTwo-hundred CAD patients (LVEF >40%, 90% men, mean age 58.4±9.1years) were randomized to a supervised 12-week cardiac rehabilitation programme of three weekly sessions of either AIT (90–95% of peak heart rate (HR)) or ACT (70–75% of peak HR) on a bicycle. Primary outcome was peak VO2; secondary outcomes were peripheral endothelial function, cardiovascular risk factors, quality of life and safety.ResultsPeak VO2 (ml/kg/min) increased significantly in both groups (AIT 22.7±17.6% versus ACT 20.3±15.3%; p-time<0.001). In addition, flow-mediated dilation (AIT+34.1% (range –69.8 to 646%) versus ACT+7.14% (range –66.7 to 503%); p-time<0.001) quality of life and some other cardiovascular risk factors including resting diastolic blood pressure and HDL-C improved significantly after training. Improvements were equal for both training interventions.ConclusionsContrary to earlier smaller trials, we observed similar improvements in exercise capacity and peripheral endothelial function following AIT and ACT in a large population of CAD patients

QCD in the nuclear medium and effects due to Cherenkov gluons

The equations of in-medium gluodynamics are proposed. Their classical lowest order solution is explicitly shown for a color charge moving with constant speed. For nuclear permittivity larger than 1 it describes emission of Cherenkov gluons resembling results of classical electrodynamics. The values of the real and imaginary parts of the nuclear permittivity are obtained from the fits to experimental data on the double-humped structure around the away-side jet obtained at RHIC. The dispersion of the nuclear permittivity is predicted by comparing the RHIC, SPS and cosmic ray data. This is important for LHC experiments. Cherenkov gluons may be responsible for the asymmetry of dilepton mass spectra near rho-meson, observed in the SPS experiment with excess in the low-mass wing of the resonance. This feature is predicted to be common for all resonances. The "color rainbow" quantum effect might appear according to higher order terms of in-medium QCD if the nuclear permittivity depends on color.Comment: 29 p., 4 figs; for "Phys. Atom. Nucl." volume dedicated to 80th birthday of L.B. Okun; minor corrections on pp. 11 and 13 in v

Factors associated with patients self-reported adherence to prescribed physical activity in routine primary health care

<p>Abstract</p> <p>Background</p> <p>Written prescriptions of physical activity have increased in popularity. Such schemes have mostly been evaluated in terms of efficacy in clinical trials. This study reports on a physical activity prescription referral scheme implemented in routine primary health care (PHC) in Sweden. The aim of this study was to evaluate patients' self-reported adherence to physical activity prescriptions at 3 and 12 months and to analyse different characteristics associated with adherence to these prescriptions.</p> <p>Methods</p> <p>Prospective prescription data were obtained for the general population in 37 of 42 PHC centres in Östergötland County, during 2004. The study population consisted of 3300.</p> <p>Results</p> <p>The average adherence rate to the prescribed activity was 56% at 3 months and 50% at 12 months. In the multiple logistic regression models, higher adherence was associated with higher activity level at baseline and with prescriptions including home-based activities.</p> <p>Conclusions</p> <p>Prescription from ordinary PHC staff yielded adherence in half of the patients in this PAR scheme follow-up.</p

Differential Effects of Aerobic Exercise, Resistance Training and Combined Exercise Modalities on Cholesterol and the Lipid Profile:Review, Synthesis and Recommendations

There is a direct relationship between chronically elevated cholesterol levels (dyslipidaemia) and coronary heart disease. A reduction in total cholesterol is considered the gold standard in preventative cardiovascular medicine. Exercise has been shown to have positive impacts on the pathogenesis, symptomatology and physical fitness of individuals with dyslipidaemia, and to reduce cholesterol levels. The optimal mode, frequency, intensity and duration of exercise for improvement of cholesterol levels are, however, yet to be identified. This review assesses the evidence from 13 published investigations and two review articles that have addressed the effects of aerobic exercise, resistance training and combined aerobic and resistance training on cholesterol levels and the lipid profile. The data included in this review confirm the beneficial effects of regular activity on cholesterol levels and describe the impacts of differing volumes and intensities of exercise upon different types of cholesterol. Evidence-based exercise recommendations are presented, aimed at facilitating the prescription and delivery of interventions in order to optimize cholesterol levels

Correlates of physical activity among community-dwelling adults aged 50 or over in six low- and middle-income countries

Background: Considering that physical activity is associated with healthy ageing and helps to delay, prevent, or manage a plethora of non-communicable diseases in older adults, there is a need to investigate the factors that influence physical activity participation in this population. Thus, we investigated physical activity correlates among community-dwelling older adults (aged ≥50 years) in six low- and middle-income countries. Methods: Cross-sectional data were analyzed from the World Health Organization’s Study on Global Ageing and Adult Health. Physical activity was assessed by the Global Physical Activity Questionnaire. Participants were dichotomized into low (i.e., not meeting 150 minutes of moderate physical activity per week) and moderate-to-high physically active groups. Associations between physical activity and a range of correlates were examined using multivariable logistic regressions. Results: The overall prevalence (95%CI) of people not meeting recommended physical activity levels in 34,129 participants (mean age 62.4 years, 52.1% female) was 23.5% (22.3%-24.8%). In the multivariable analysis, older age and unemployment were significant sociodemographic correlates of low physical activity. Individuals with low body mass index (<18.5kg/m2), bodily pain, asthma, chronic back pain, chronic obstructive pulmonary disease, hearing problems, stroke, visual impairment, slow gait, and weak grip strength were less likely to meet physical activity targets in the overall sample (P<0.05). The associations varied widely between countries. Conclusion: Our data illustrates that a multitude of factors influence physical activity target achievement in older adults, which can inform future interventions across low- and middle-income countries to assist people of this age group to engage in regular physical activity. Future prospective cohort studies are also required to investigate the directionality and mediators of the relationships observed