Publications (3)1.21 Total impact
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ABSTRACT: Retrospective case series. To describe an injury mechanism and a series of patients with spine fractures after passing over speed humps in a motor vehicle. The use of speed humps as an effective measure to reduce the rate of traffic accidents is still a matter of discussion. Furthermore, their use in mass transport routes may cause spine injuries among passengers in motor vehicles. Review of the database in our medical records, identifying all the patients with spine fractures that occurred after passing over speed humps while in a motor vehicle, from January 1, 1997 to April 30, 2008 in the Hospital del Trabajador de Santiago, Chile. Of a sample of 46 patients with 52 fractures-none of them with neurologic impairment-37 female patients (80.4%) and 9 male patients (19.6%) with an average age of 48.5 years (16 to 70 y), 67.4% (31 of 46) presented comorbidities. Six patients presented 2 spine fractures, all of them at adjacent levels. Forty-four individuals (95.7%) were injured in a bus: 42 of 44 patients (95.5%) were seated on the last row, whereas the remaining 2 patients were bus drivers. All patients had type A Association for Osteosynthesis/Association for the Study of Internal Fixation fractures, 30/52 (57.7%) subtype A1 and 20/52 (38.5%) subtype A3. L1 was the most frequently fractured vertebra (23/52, 44.2%), followed by T12 (11/52, 21.2%). Ten patients (21.7%) required surgical treatment. The average time out of work was 104.3 days; 3 patients (6.5%) received workers' compensation for chronic lumbar pain. The mean follow-up time was 78.6 months (24 to 159). Seating in a motor vehicle, particularly on the last row in a bus, as it passes over a speed hump may cause severe traumatic spine injuries. These fractures occur more frequently at the thoracolumbar junction and treatment may require surgery.Journal of spinal disorders & techniques 12/2010; 24(6):386-9. · 1.21 Impact Factor
Article: Electrical signaling, stomatal conductance, ABA and ethylene content in avocado trees in response to root hypoxia.[show abstract] [hide abstract]
ABSTRACT: Avocado (Persea americana Mill.) trees are among the most sensitive of fruit tree species to root hypoxia as a result of flooded or poorly drained soil. Similar to drought stress, an early physiological response to root hypoxia in avocado is a reduction of stomatal conductance. It has been previously determined in avocado trees that an extracellular electrical signal between the base of stem and leaves is produced and related to reductions in stomatal conductance in response to drought stress. The current study was designed to determine if changes in the extracellular electrical potential between the base of the stem and leaves in avocado trees could also be detected in response to short-term (min) or long-term (days) root hypoxia, and if these signals could be related to stomatal conductance (gs), root and leaf ABA and ACC concentrations, ethylene emission from leaves and leaf abscission. In contrast to previous observations for drought-stressed trees, short-term or long-term root hypoxia did not stimulate an electrical potential difference between the base of the stem and leaves. Short-term hypoxia did not result in a significant decrease in gs compared with plants in the control treatment, and no differences in ABA concentration were found between plants subjected to hypoxia and control plants. Long-term hypoxia in the root zone resulted in a significant decrease in gs, increased leaf ethylene and increased leaf abscission. The results indicate that for avocado trees exposed to root hypoxia, electrical signals do not appear to be the primary root-to-shoot communication mechanism involved in signaling for stomatal closure as a result of hypoxia in the root zone.Plant signaling & behavior 03/2009; 4(2):100-8.
Article: Estudio de la masa forestal y su dinamismo en parcelas de diferentes tipos ecológicos de bosques naturales de las tierras bajas venezolanas / por J. P. Veillon, Víctor W. Konrad, Nicolás García[show abstract] [hide abstract]
ABSTRACT: "Proyecto F0-39-76 Financiado por Instituto de Silvilcultura y el Consejo de Desarrollo y Humanistíco de la Universidad de Los Andes" Incluye bibliografíaSERBIULA (sistema Librum 2.0).