21 research outputs found
Trilhas e seu papel ecológico: o que temos aprendido e quais as perspectivas para a restauração de ecossistemas?
Assessment and monitoring of recreation impacts and resource conditions on mountain summits: Examples from the Northern Forest, USA
Mountain summits present a unique challenge to manage sustainably: they are ecologically important and, in many circumstances, under high demand for recreation and tourism activities. This article presents recent advances in the assessment of resource conditions and visitor disturbance in mountain summit environments, by drawing on examples from a multiyear, interdisciplinary study of summits in the northeastern United States. Primary impact issues as a consequence of visitor use, such as informal trail formation, vegetation disturbance, and soil loss, were addressed via the adaption of protocols from recreation ecology studies to summit environments. In addition, new methodologies were developed that provide measurement sensitivity to change previously unavailable through standard recreation monitoring protocols. Although currently limited in application to the northeastern US summit environments, the methods presented show promise for widespread application wherever summits are in demand for visitor activities
Distributed robotic target acquisition using bluetooth communication
This paper presents a distributed multi-robot system designed to solve a team-based search and destroy task. The project was divided into two phases. The initial phase was used to demonstrate the use of Bluetooth communication for coordinated robotic search. The second (current) phase of the project attempts to integrate these early developments. This integration allows two seeker robots to locate and coordinate an attack on a target (enemy). The goal of the first phase was to develop a robot communication strategy using Bluetooth for the Honeybee task. The goal of the second phase was to take the communication strategy and use it in the team-based search and destroy task. A secondary goal in the current phase was to convert a model tank into a robust autonomous vehicle. We present the details of the phases, the progress made towards achieving the goals, and the directions we plan to take after the current phase is complete
Spinal cord repair in MS: Does mitochondrial metabolism play a role?(e–Pub ahead of print)
OBJECTIVE: To investigate the mechanisms of spinal cord repair and their relative contribution to clinical recovery in patients with multiple sclerosis (MS) after a cervical cord relapse, using spinal cord (1)H-magnetic resonance spectroscopy (MRS) and volumetric imaging. METHODS: Fourteen patients with MS and 13 controls underwent spinal cord imaging at baseline and at 1, 3, and 6 months. N-acetyl-aspartate (NAA) concentration, which reflects axonal count and metabolism in mitochondria, and the cord cross-sectional area, which indicates axonal count, were measured in the affected cervical region. Mixed effect linear regression models investigated the temporal evolution of these measures and their association with clinical changes. Ordinal logistic regressions identified predictors of recovery. RESULTS: Patients who recovered showed a sustained increase in NAA after 1 month. In the whole patient group, a greater increase of NAA after 1 month was associated with greater recovery. Patients showed a significant decline in cord area during follow-up, which did not correlate with clinical changes. A worse recovery was predicted by a longer disease duration at study entry. CONCLUSIONS: The partial recovery of N-acetyl-aspartate levels after the acute event, which is concurrent with a decline in cord cross-sectional area, may be driven by increased axonal mitochondrial metabolism. This possible repair mechanism is associated with clinical recovery, and is less efficient in patients with longer disease duration. These insights into the mechanisms of spinal cord repair highlight the need to extend spinal cord magnetic resonance spectroscopy to other spinal cord disorders, and explore therapies that enhance recovery by modulating mitochondrial activity