576 research outputs found
Auswirkungen von Schnitt-und Weidenutzung auf die Ertragsbildung und den Stickstoffgehalt verschiedener Futterleguminosen.
The objective of this study was to compare the agronomic performance of different forage legume species submitted to different management systems, i.e. grazing, silage-cut and simulated grazing to find alternatives for white clover. The experiment was established in 2003 and 2004 as binary swards with perennial ryegrass (Lolium perenne L.) as the companion grass with three replicates in two different sites on the experimental station âLindhofâ of the University of Kiel. Legume species were arranged within each management system as completely randomised blocks. Results of agro-nomic performance of the first production years in 2004 and 2005 (DM-yield, botanical composition, N-yield, N-content) are presented for white clover swards (Trifolium repens L.), red clover swards (Trifolium pratense L.), lucerne swards (grazing type, Medicago sativa L.) and birdsfoot trefoil swards (Lotus corniculatus L.). Considering both years the birdsfoot trefoil/grass-swards were the only ones which produced significantly less DM-yield (736 g DM m² a-1) under simulated grazing than the white clover/grass-swards (805 g DM m2 a-1). While under grazing all legume/grass-swards produced a significant lower DM-yield compared to the white clover/grass-swards, no significant differences can be found under the silage-cut system. Considering the N-yield, birdsfoot trefoil/grass-swards were the only legume/grass-swards which pro-duced a significant lower N-yield under the 5-cut system (14.1 g N m² a-1) as well as under grazing (15.7 g N m² a-1) compared to the white clover/grass-swards (26 g N m² a-1 and 21.9 g N m² a-1 respectively). Considering the botanical composition of the different legume/grass-swards all legume species had a significant higher propor-tion of total DM-yield under cutting compared to white clover in 2004. Comparisons between systems showed that beside the white clover/grass-swards all legume/grass-swards had a significant lower legume proportion under grazing in comparison to the cutting systems. Because of the comparable agronomic performance of the red clo-ver/grass-swards and lucerne/grass-swards, both legume species could be used as alternatives for white clover under cutting, while the birdsfoot trefoil/grass-swards should be considered carefully because of their low agronomic performance. Whereas white clover showed the highest performance under the grazing system, none of the different legume species present an alternative for white clover
Einfluss der Grßnlandnutzung auf die PPO-Aktivität in Rotklee
Several studies show that polyphenol oxidase (PPO) in red clover reduces proteolysis and increases nitrogen use efficiency of the ruminant, but not much is known about factors affecting PPO activity in red clover plants. PPO activity was analysed in red clover plants from legume-grass mixtures subjected to three different management systems. The cutting frequency (3 or 5 cuts) caused only minor differences in PPO activity, whereas a significant increase in PPO activity could be proved for the rota-tional grazing system (RG), compared to the simulated grazing system (SG, 5 cuts) with equal use frequency. Results indicate a metabolic adaptation of the red clover plants due to the grazing process itself, leading to a control factor which has to be considered in case of red clover nutrition properties
Ice skating promotes postural control in children
High fall rates causing injury and enormous financial costs are reported for children. However, only few studies investigated the effects of balance training in children and these studies did not find enhanced balance performance in postural (transfer) tests. Consequently, it was previously speculated that classical balance training might not be stimulating enough for children to adequately perform these exercises. Therefore, the aim of this study is to evaluate the influence of ice skating as an alternative form of balance training. Volunteers of an intervention (nâ=â17; INT: 13.1âÂąâ0.4 years) and a control group (nâ=â13; CON: 13.2âÂąâ0.3 years) were tested before and after training in static and dynamic postural transfer tests. INT participated in eight sessions of ice skating during education lessons, whereas CON participated in normal physical education. Enhanced balance performance was observed in INT but not in CON when tested on an unstable free-swinging platform (PâPâ<â0.001). This is the first study showing significantly enhanced balance performance after ice skating in children. More importantly, participating children improved static and dynamic balance control in postural tasks that were not part of the training
Neck muscle vibration can improve sensorimotor function in patients with neck pain
Background: context People with neck pain display a diminished joint position sense and disturbed postural control, which is thought to be a result of impaired somatosensory afferent activity and/or integration. Afferent processing can be artificially manipulated by vibration and was shown to reduce motor performance in healthy subjects. However, the effect of vibration on sensorimotor function in neck pain patients is scarcely investigated.Purpose: To assess the effect of neck muscle vibration on joint position sense and postural control in neck pain subjects and healthy controls.Study design: Case control study.Patient sample: Thirteen neck pain patients and 10 healthy controls participated in the present study.Outcome measurements: Cervical joint position sense and dynamic and static postural stability.Methods: Short-term, targeted neck muscle vibration with 100 Hz was applied after baseline measurement.Results: Vibration had opposite effects in patients and healthy subjects. Patients showed improved joint position sense (p<.01) and reduced dynamic postural sway (p<.05) after vibration, whereas vibration resulted in reduced joint position sense acuity (p<.05) and a nonsignificant increase in postural sway in healthy controls.Conclusions: This is the first study showing an improved motor performance after neck muscle vibration in patients with neck pain. Thus, vibration may be used to counteract sensorimotor impairment of the cervical spine. Potential underlying mechanisms are discussed
Proteinqualität verschiedener Rotkleegenotypen unter Berßcksichtigung der spezifischen Polyphenoloxidase-Aktivität
Increasing protein quality of forages in ruminant nutrition may contribute to reduce nitrogen losses in specialized dairy farms in Europe. Red clover is known to have high polyphenol oxidase (PPO) activity among forage legumes. The enzyme oxidizes phenols to quinones. These highly reactive quinones form stabilized quinone-protein-complexes, protecting protein from fast degradation. The objective of this study was to investigate the effect of the specific PPO activity on the protein fractions of twelve red clover genotypes in two management systems (without and with mechanical stress) in pure red clover swards. The results showed that genotype seem to be of minor importance compared to the variation in PPO activity induced by mechanical stress and particular by cut. Furthermore, with increasing specific PPO activity fraction A decreased and fraction C increased slightly. However, specific PPO activity was poorly related to the protein fractions, expressed by a low R²
Non-physical practice improves task performance in an unstable, perturbed environment: motor imagery and observational balance training
For consciously performed motor tasks executed in a defined and constant way, both motor imagery (MI) and action observation (AO) have been shown to promote motor learning. It is not known whether these forms of non-physical training also improve motor actions when these actions have to be variably applied in an unstable and unpredictable environment. The present study therefore investigated the influence of MI balance training (MI_BT) and a balance training combining AO and MI (AO+MI_BT) on postural control of undisturbed and disturbed upright stance on unstable ground. As spinal reflex excitability after classical (i.e., physical) balance training (BT) is generally decreased, we tested whether non-physical BT also has an impact on spinal reflex circuits. Thirty-six participants were randomly allocated into an MI_BT group, in which participants imagined postural exercises, an AO+MI_BT group, in which participants observed videos of other people performing balance exercises and imagined being the person in the video, and a non-active control group (CON). Before and after 4 weeks of non-physical training, balance performance was assessed on a free-moving platform during stance without perturbation and during perturbed stance. Soleus H-reflexes were recorded during stable and unstable stance. The post-measurement revealed significantly decreased postural sway during undisturbed and disturbed stance after both MI_BT and AO+MI_BT. Spinal reflex excitability remained unchanged. This is the first study showing that non-physical training (MI_BT and AO+MI_BT) not only promotes motor learning of ârigidâ postural tasks but also improves performance of highly variable and unpredictable balance actions. These findings may be relevant to improve postural control and thus reduce the risk of falls in temporarily immobilized patients
Enhanced jump performance when providing augmented feedback compared to an external or internal focus of attention
Factors such as an external focus of attention (EF) and augmented feedback (AF) have been shown to improve performance. However, the efficacy of providing AF to enhance motor performance has never been compared with the effects of an EF or an internal focus of attention (IF). Therefore, the aim of the present study was to identify which of the three conditions (AF, EF or IF) leads to the highest performance in a countermovement jump (CMJ). Nineteen volunteers performed 12 series of 8 maximum CMJs. Changes in jump height between conditions and within the series were analysed. Jump heights differed between conditions (PÂ PÂ <Â 0.001) within-series effects of higher jump heights at the end of the series in AF (+1.60%) and lower jump heights at the end of the series in EF (â1.79%) and IF (â1.68%) were observed. Muscle activity did not differ between conditions. The differences between conditions and within the series provide evidence that AF leads to higher performance and better progression within one series than EF and IF. Consequently, AF seems to outperform EF and IF when maximising jump height
Human Rights-Based Evaluation in German and International Development Cooperation: Literature Review
This literature review aims to summarise current knowledge on a human rights-based approach (HRBA) to evaluation and improve the basis for further conceptual discussions on this approach. To this end, we reviewed strategies and (publicly available) guidelines of multilateral and bilateral development actors, relevant tools for human rights in monitoring and evaluation, research articles, and evaluation reports published between 2014 and 2021
Surround inhibition in the primary motor cortex is task-specifically modulated in non-professional musicians but not in healthy controls during real piano playing
Research has indicated that at the onset of a finger movement, unwanted contractions of adjacent muscles are prevented by inhibiting the cortical areas representing these muscles. This so-called surround inhibition (SI) seems relevant for the performance of selective finger movements but may not be necessary for tasks involving functional coupling between different finger muscles. Therefore, the present study compared SI between isolated finger movement and complex selective finger movements while playing a three-finger sequence on the piano in nine non-professional musicians and 10 untrained control participants. Transcranial magnetic stimulation (TMS) was applied to the contralateral motor cortex to assess SI in the first dorsal interosseous (FDI), abductor pollicis brevis (APB) and abductor digiti minimi (ADM) during the movement preparation and the late phasic phases. The results reveal stronger SI during the preparation phase than during the phasic phase (30.6% vs. 10.7%; PâŻâŻâŻ0.05). Thus, musicians were able to modulate SI between conditions whereas control participants revealed constant levels of SI. Therefore, it may be assumed that long-term training as observed in skilled musicians is accompanied by task-specific effects on SI modulation potentially relating to the ability to perform selective and complex finger movements
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