Experimental problems in the application of the Berg-Barrett Method to the observation of dislocations in metal single crystals are discussed. The problem of background noise caused by fluorescence from the specimen and inelastic scattering is considered. A criterion for selecting an appropriate filter to discriminate against the background noise is presented. The problem of multiple images is ...

Living cells often need to extract information from biochemical signals that are noisy. We study how accurately cells can measure chemical concentrations with signaling networks that are linear. For stationary signals of long duration, they can reach, but not beat, the Berg-Purcell limit, which relies on uniformly averaging in time the fluctuations in the input signal. For short times or nonsta...

Adaptation is not required to explain the long-term response of axons to molecular gradients Jun Xu1, William J. Rosoff1, Jeffrey S. Urbach2 and Geoffrey J. Goodhill3,* Department of Neuroscience, Georgetown University Medical Center, 3900 Reservoir Road NW, Washington, DC 20007, USA Department of Physics, Georgetown University, 37th and O Streets NW, Washington, DC 20057, USA Queensland Brain ...

Purpose. To compare between the effects of balance-based torso weighting and tailored physical therapy program in improving balance postural control ataxic MS patients. Methods. Ninety patients diagnosed as multiple sclerosis with impaired were selected from outpatient clinic two hospitals. The randomly assigned into groups, group (A: n = 30) received torso-based (B; 60) program. Both groups co...