The relevance of a right scale for sampling when studying high-resolution behavioral dynamics.

Many species used in behavioral studies are small vertebrates with high metabolic rates and potentially enhanced temporal resolution of perception. Nevertheless, the selection of an appropriate scales to evaluate behavioral dynamics has received little attention. Herein, we studied the temporal organization of behaviors at fine-grain (i.e. sampling interval ≤1s) to gain insight into dynamics and to rethink how behavioral events are defined. We statistically explored high-resolution Japanese quail (Coturnix japonica) datasets encompassing 17 defined behaviors. We show that for the majority of these behaviors, events last predominately <300ms and can be shorter than 70ms. Insufficient sampling resolution, even in the order of 1s, of behaviors that involve spatial displacement (e.g. walking) yields distorted probability distributions of event durations and overestimation of event durations. Contrarily, behaviors without spatial displacement (e.g. vigilance) maintain non-Gaussian, power-law-type distributions indicative of long-term memory, independently of the sampling resolution evaluated. Since data probability distributions reflect underlying biological processes, our results highlight the importance of quantification of behavioral dynamics based on the temporal scale pertinent to the species, and data distribution. We propose a hierarchical model that links diverse types of behavioral definitions and distributions, and paves the way towards a statistical framework for defining behaviors.

A decade (2001-2010) of genetic testing for pheochromocytoma and paraganglioma.

The identification of 9 susceptibility genes for paraganglioma/pheochromocytoma between 2001 and 2010 has led to the development of routine genetic tests. To study the evolution in genetic screening for paraganglioma/pheochromocytoma over the past decade, we carried out a retrospective study on the tests performed in our laboratory from January 2001 to December 2010. A genetic test for paraganglioma/pheochromocytoma was assessed for 2 499 subjects, 1 620 index cases, and 879 presymptomatic familial genetic tests. A germline mutation in a PGL/PCC susceptibility gene was identified in 363 index cases (22.4%): 269 in SDHx genes (137 in SDHB, 100 in SDHD, 30 in SDHC, 2 in SDHA), 64 in VHL, 23 in RET, and 7 in TMEM127. A presymptomatic paraganglioma/pheochromocytoma test was positive in 427 subjects. Advances in molecular screening techniques led to an increase in the total number of mutation-carriers diagnosed each year. Overall, during the last decade, our laboratory identified a germline mutation in 44.7% of patients with a suspect hereditary PGL/PCC and in 8% of patients with an apparently sporadic PGL/PCC. During the past decade, the discoveries of new paraganglioma/pheochromocytoma susceptibility genes and the subsequent progress of molecular screening techniques have enabled us to diagnose a hereditary paraganglioma/pheochromocytoma in about 22% of patients tested in routine practice. This genetic testing is of major importance for the follow-up of affected patients and for the genetic counselling of their families.