An automatic breath collecting and sampling system, which is preferably carried by the subject, or otherwise kept with him or near him, for the recommended duration of the collection period. A transfer characteristic between an acoustical signal impinging on the converters and the result signal is dependent on the arrival direction of the acoustical signals at the converters. The distance between peaks of the correlation function represents the payload. A method of using a sink extender comprises mounting the sink extender comprising a sink that drains into a flexible hose and at least one tool holder to a support surface; running the hose to a traditional sink such that water may drain from the sink to the traditional sink by gravity; securing a wet tool to the at least one tool holder such that the tool drains into the sink. This invention further provides methods for inducing differentiation of floor plate cell, motor neuron, generating ventral neurons and treatments for alleviating abnormalities associated with the vhh-1 protein.