Effect of vegetation type on throughfall deposition and seepage flux.

This paper compares different vegetation types (coniferous and deciduous forest, grassed and pure heathland) in terms of input (throughfall deposition) and output (seepage flux) in a region with intermediate nitrogen load (+/-20kg Nha(-1)y(-1) via bulk precipitation) in comparable conditions in north Belgium. Coniferous forest (two plots Pinus sylvestris and two plots Pinus nigra) received significantly higher nitrogen and sulphur throughfall deposition than deciduous forest and heathland. Grassed and pure heathland had significantly highest throughfall quantities of Ca(2+) and Mg(2+), respectively. The observed differences in throughfall deposition between the different vegetation types were not univocally reflected in the ion seepage flux. Considerable seepage fluxes of NO(3)(-), SO(4)(2-), Ca(2+) and Al(III) were only found under the P. nigra plots. We discuss our hypothesis that the P. nigra forests already evolved to a situation of N saturation, while the other vegetation types did not.

Postural abnormalities and contraversive pushing following right hemisphere brain damage.

We investigated the presence of postural abnormalities in a consecutive sample of stroke patients, with either left or right brain damage, in relation to their perceived body position in space. The presence or absence of posture-related symptoms was judged by two trained therapists and subsequently analysed by hierarchical classes analysis (HICLAS). The subject classes resulting from the HICLAS model were further validated with respect to posture-related measurements, such as centre of gravity position and head position, as well as measurements related to the postural body scheme, such as the perception of postural and visual verticality. The results of the classification analysis clearly demonstrated a relation between the presence of right brain damage and abnormalities in body geometry. The HICLAS model revealed three classes of subjects: The first class contained almost all the patients without neglect and without any signs of contraversive pushing. They were mainly characterised by a normal body axis in any position. The second class were all neglect patients but predominantly without any contraversive pushing. The third class contained right brain damaged patients, all showing neglect and mostly exhibiting contraversive pushing. The patients in the third class showed a clear resistance to bringing the weight over to the ipsilesional side when the therapist attempted to make the subject achieve a vertical posture across the midline. The clear correspondence between abnormalities of the observed body geometry and the tilt of the subjective postural and visual vertical suggests that a patient's postural body geometry is characterised by leaning towards the side of space where he/she feels aligned with an altered postural body scheme. The presence of contraversive pushing after right brain damage points in to a spatial higher-order processing deficit underlying the higher frequency and severity of the axial postural abnormalities found after right brain lesions.

Contraversive pushing and inattention of the contralesional hemispace.

The aim of this study was to investigate, in 114 stroke patients, the frequency of occurrence of a largely unknown neurological disorder, characterized by a postural imbalance due to a 'pushing away' reaction of the body towards the contralesional side of space, in function of hemispheric lesion localization and gender. The study also investigate the relation of this contraversive pushing with active movement, somatosensory perception deficits and, in particular, inattention of contralesional hemispace and body. The similarity of the presence of contraversive pushing and the syndrome of spatial hemineglect together with a gender-related differentiation suggest the existence of a "pusher syndrome", in which the pathophysiology points in the direction of a spatial higher-order processing deficit, related to spatial inattention, underlying the higher frequency and severity of contraversive pushing after right brain lesions.

Effect of a therapeutic intervention for the hemiplegic upper limb in the acute phase after stroke: a single-blind, randomized, controlled multicenter trial.

BACKGROUND AND PURPOSE: Arm function recovery is notoriously poor in stroke patients. The effect of treatment modalities, particularly those directed at improving upper limb function, has been studied primarily in chronic stroke patients. The purpose of this study was to investigate the effect of a specific therapeutic intervention on arm function in the acute phase after stroke. METHODS: In a single-blind, randomized, controlled multicenter trial, 100 consecutive patients were allocated to either an experimental group that received an additional treatment of sensorimotor stimulation or to a control group. The intervention was applied for 6 weeks. Patients were evaluated for level of impairment (Brunnström-Fugl-Meyer test) and disability (Action Research Arm test, Barthel Index) before, midway, and after the intervention period and at follow-up 6 and 12 months after stroke. RESULTS: Patients in the experimental group performed better on the Brunnström-Fugl-Meyer test than those in the control group throughout the study period, but differences were significant only at follow-up. Results on the Action Research Arm test and Barthel Index revealed no effect at the level of disability. The effect of the therapy was attributed to the repetitive stimulation of muscle activity. The treatment was most effective in patients with a severe motor deficit and hemianopia or hemi-inattention. No adverse effects due to the intervention were found. CONCLUSIONS: Adding a specific intervention during the acute phase after stroke improved motor recovery, which was apparent 1 year later. These results emphasize the potential beneficial effect of therapeutic interventions for the arm.