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Copyright of Letras (0459-1283) is the property of Universidad Pedagogica Experimental Libertador and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

OBJECTIVE: To characterize the lateral stepping strategies for postural correction in patients with Parkinson's disease (PD) and the effect of their anti-parkinson medication. DESIGN: Observational study. SETTING: Outpatient neuroscience laboratory. PARTICIPANTS: Thirteen participants with idiopathic PD in their on (PD on) and off (PD off) levodopa state and 14 healthy elderly controls. INTERVENTIONS: Movable platform with lateral translations of 12 cm at 14.6 cm/s ramp velocity. MAIN OUTCOME MEASURES: The incidence and characteristics of 3 postural strategies were observed: lateral side-step, crossover step, or no step. Corrective stepping was characterized by latency to step after perturbation onset, step velocity, and step length and presence of an anticipatory postural adjustment (APA). Additionally, percentages of trials resulting in falls were identified for each group. RESULTS: Whereas elderly control participants never fell, PD participants fell in 24% and 35% of trials in the on and off medication states, respectively. Both PD and control participants most often used a lateral side-step strategy; 70% (control), 67% (PD off), and 73% (PD on) of all trials, respectively. PD participants fell most often when using a crossover strategy (75% of all crossover trials) or no-step strategy (100% of all no-step trials). In the off medication state, PD participants' lateral stepping strategies were initiated later than controls (370+/-37 ms vs 280+/-10 ms, P<.01), and steps were smaller (254+/-20 mm vs 357+/-17 mm, P<.01) and slower (0.99+/-0.08 m/s vs 1.20+/-0.07 m/s, P<.05). No differences were found between the PD off versus PD on state in the corrective stepping characteristics. Unlike control participants, PD participants often (56% of side-step strategy trials) failed to activate an APA before stepping, although their APAs, when present, were of similar latency and magnitude as for control participants. Levodopa on or off state did not significantly affect falls, APAs, or lateral step latency, velocity, or amplitude (P>.05). CONCLUSIONS: PD participants showed significantly more postural instability and falls than age-matched controls when stepping was required for postural correction in response to lateral disequilibrium. Although PD participants usually used a similar lateral stepping strategy as controls in response to lateral translations, lack of an anticipatory lateral weight shift, and bradykinetic characteristics of the stepping responses help explain the greater rate of falls in participants with PD. Differences were not found between the levodopa on and off states. The results suggest that rehabilitation aimed at improving lateral stability in PD should include facilitating APAs before a lateral side-stepping strategy with faster and larger steps to recover equilibrium. Copyright © 2008 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation [ABSTRACT FROM AUTHOR]

Copyright of Revue Historique (0035-3264) is the property of Presses Universitaires de France and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Issues in Ethnology Anthropology is the property of Issues in Ethnology Anthropology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In Australia, periodic waterlogging throughout the cotton growing season can cause production losses of up to 10%. There is limited information on the genetic variation in cotton for waterlogging tolerance. The aim of this study was to identify methods to evaluate physiological responses under waterlogging conditions that may lead to identifying waterlogging tolerant and sensitive cotton cultivars. A field experiment was conducted in Narrabri, north-western New South Wales using thirteen upland cotton (Gossypium hirsutum L.) cultivars (Georgia King, McNair 1032, PD93057, LA 887, Codetec 401, DP 16, DP 90, Coker 315, CIM 443, Gohar 87, Sicot 71, Sicot 73 and Sicot 80) and one Gossypium barbadense cultivar (Pima A-8) originating from diverse environmental regions. Parameters measured to assess response to waterlogging included: SPAD (leaf colour) readings, leaf nutritional status, leaf photosynthetic rate, plant and root morphology, and final yield. Leaf SPAD readings, nitrogen and potassium concentrations were reduced in waterlogged treatments compared to the respective controls, and varied with cultivar. Leaf phosphorus, calcium, magnesium, manganese and sulphur concentrations were reduced in the waterlogged treatment compared to the respective controls in all cultivars. Waterlogging increased leaf total iron concentration in all cultivars. No aerenchyma on cotton roots were observed in this study. Leaf SPAD readings, nitrogen and potassium concentrations suggested that the most waterlogging tolerant cultivars were Gohar 87, Pima A-8, Sicot 71, Sicot 73 and Sicot 80 which originate from production on heavy clays, and the most susceptible were Georgia King, LA 887, DP 16, DP 90 and CIM 443 which originate from production on lighter texture soils. This study helped to target those measurements that may be of most use to screen for waterlogging tolerance. [ABSTRACT FROM AUTHOR]

Abstract: King LA, Horak FB. Lateral stepping for postural correction in Parkinson’s disease. Objective: To characterize the lateral stepping strategies for postural correction in patients with Parkinson’s disease (PD) and the effect of their anti-parkinson medication. Design: Observational study. Setting: Outpatient neuroscience laboratory. Participants: Thirteen participants with idiopathic PD in their on (PD on) and off (PD off) levodopa state and 14 healthy elderly controls. Interventions: Movable platform with lateral translations of 12cm at 14.6cm/s ramp velocity. Main Outcome Measures: The incidence and characteristics of 3 postural strategies were observed: lateral side-step, crossover step, or no step. Corrective stepping was characterized by latency to step after perturbation onset, step velocity, and step length and presence of an anticipatory postural adjustment (APA). Additionally, percentages of trials resulting in falls were identified for each group. Results: Whereas elderly control participants never fell, PD participants fell in 24% and 35% of trials in the on and off medication states, respectively. Both PD and control participants most often used a lateral side-step strategy; 70% (control), 67% (PD off), and 73% (PD on) of all trials, respectively. PD participants fell most often when using a crossover strategy (75% of all crossover trials) or no-step strategy (100% of all no-step trials). In the off medication state, PD participants’ lateral stepping strategies were initiated later than controls (370±37ms vs 280±10ms, P<.01), and steps were smaller (254±20mm vs 357±17mm, P<.01) and slower (0.99±0.08m/s vs 1.20±0.07m/s, P<.05). No differences were found between the PD off versus PD on state in the corrective stepping characteristics. Unlike control participants, PD participants often (56% of side-step strategy trials) failed to activate an APA before stepping, although their APAs, when present, were of similar latency and magnitude as for control participants. Levodopa on or off state did not significantly affect falls, APAs, or lateral step latency, velocity, or amplitude (P>.05). Conclusions: PD participants showed significantly more postural instability and falls than age-matched controls when stepping was required for postural correction in response to lateral disequilibrium. Although PD participants usually used a similar lateral stepping strategy as controls in response to lateral translations, lack of an anticipatory lateral weight shift, and bradykinetic characteristics of the stepping responses help explain the greater rate of falls in participants with PD. Differences were not found between the levodopa on and off states. The results suggest that rehabilitation aimed at improving lateral stability in PD should include facilitating APAs before a lateral side-stepping strategy with faster and larger steps to recover equilibrium. [Copyright &y& Elsevier]