Living on the edge: Lower thermal quality but greater survival probability at a high altitude mountain for the mesquite lizard (Sceloporus grammicus).

A 20-month recapture analysis of 1001 individually marked mesquite lizards (Sceloporus grammicus) suggests that variation in thermal quality across three altitudes influences survival probability. Each additional unit of deviation from the temperature selected by these lizards in previous laboratory experiments (i.e. decreased thermal quality) meant an increase of roughly 1.01% in survival probability. Survival probabilities ranged from 0.80 to 0.90 at the lowest elevation site (2600 m), from 0.76 to 0.87 at the middle elevation site (3100 m) and from 0.90 to 0.94 at the highest elevation site (4150 m). These results suggest that in poor thermal quality environments mesquite lizards may employ thermoregulatory strategies (behavioral, physiological and/or morphological) to decrease their metabolic expenditure and their exposure to predators, maximizing survival. These findings highlight the relevance of thermal quality of the habitat in determining survival probability of ectotherms.

Evolución de las complicaciones neurológicas en la cirugía de deformidades vertebrales en la infancia

Introducción: Se llevó a cabo un estudio retrospectivo descriptivo con el propósito de evaluar cómo evolucionaron los pacientes que sufrieron trastornos neurológicos a causa de una cirugía de las cifoescoliosis en la infancia. Materiales y Métodos: Se evaluó a 9 pacientes sin alteraciones neurológicas previas, que presentaron complicaciones neurológicas luego de un procedimiento quirúrgico por escoliosis o cifosis, operados en nuestra institución, durante un período de 10 años. Resultados: Las etiologías de las deformidades fueron: 4 escoliosis idiopáticas, 2 escoliosis congénitas, una secundaria a neurofibromatosis de tipo 1, una cifosis idiopática y una poslaminectomía por miofibrosarcomatosis. Cinco pacientes tuvieron episodios neurofisiológicos intraquirúrgicos. Todos requirieron, al menos, una segunda intervención quirúrgica para solucionar su patología de base. La lesión neurológica fue: lesión radicular (un caso) y lesión del cordón medular (8 casos); 6 sufrieron una lesión medular completa (75%) que se manifestó como una paresia bilateral y 2 (25%), una lesión medular incompleta con monoparesia, sólo 2 quedaron con vejiga neurogénica. Conclusión: La detección temprana de una complicación neurológica, su diagnóstico etiológico y la resolución quirúrgica mejoran la evolución neurológica del paciente, y evitan la secuela o disminuyen su gravedad.(AU)

Background: A retrospective descriptive study was performed to assess the outcome of neurological complications due to kyphosis or scoliosis surgery in children. Methods: Nine patients who suffered neurological complication during kyphosis and/or scoliosis deformity surgery operated on our institution from May 2003 to June 2013 were evaluated. Results: Etiologies observed were: 4 idiopathic scolioses, 2 congenital scolioses, one associated with neurofibromatosis type 1, one idiopathic kyphosis and one myofibrosarcomatosis post-laminectomy surgery. Five patients presented intraoperative neurological changes. All patients needed at least a second surgical intervention to solve the spine deformity. The topographic classification of the neurological injury was: radicular injury (one patient); spinal cord injury (8 patients), 6 presented complete spinal injury (75%) which manifested with bilateral paresis and 2 patients (25%) suffered an incomplete spinal injury with monoparesis, only 2 stayed with neurogenic bladder. Conclusion: Early detection of a neurological complication, its etiological diagnosis and surgical resolution improve neurological outcome, avoiding or reducing its sequel.(AU)