ANK2 autism mutation targeting giant ankyrin-B promotes axon branching and ectopic connectivity

Giant ankyrin-B (ankB) is a neurospecific alternatively spliced variant of ANK2, a high-confidence autism spectrum disorder (ASD) gene. We report that a mouse model for human ASD mutation of giant ankB exhibits increased axonal branching in cultured neurons with ectopic CNS axon connectivity, as well as with a transient increase in excitatory synapses during postnatal development. We elucidate a mechanism normally limiting axon branching, whereby giant ankB localizes to periodic axonal plasma membrane domains through L1 cell-adhesion molecule protein, where it couples microtubules to the plasma membrane and prevents microtubule entry into nascent axon branches. Giant ankB mutation or deficiency results in a dominantly inherited impairment in selected communicative and social behaviors combined with superior executive function. Thus, gain of axon branching due to giant ankB-deficiency/mutation is a candidate cellular mechanism to explain aberrant structural connectivity and penetrant behavioral consequences in mice as well as humans bearing ASD-related ANK2 mutations

Myelopathy associated with decompression sickness: A report of six cases

Four scuba divers and 2 professional deep sea divers developed spinal cord symptoms due to decompression sickness. Symptoms developed during or immediately after ascent in 4 cases and were delayed in 2. In 2 cases new symptoms appeared during a jet flight. In 4 cases paraparesis was associated with a sensory level in the mid or low dorsal region indicating the thoracic cord as the major site of involvement. In the other 2 cases the clinical findings were suggestive of combined lesions in the lower cervical and lumbar cord. Therapeutic recompression led to improvement in each case. Three cases who were re-examined after intervals of 3 to 7 years each showed residual corticospinal and minor sensory signs. One of these cases met with a violent death 3.5 years after the acute episode; examination of the cord showed multifocal white matter degeneration in the posterior and lateral columns between C7 and T4 with secondary ascending and descending tract degeneration. The mechanism of spinal cord damage in decompression sickness is discussed

Design and performance of a custom ASIC digitizer for wire chamber readout in 65 nm CMOS technology

We present the design and performance of a prototype ASIC digitizer for integrated wire chamber readout, implemented in 65 nm commercial CMOS technology. Each channel of the 4-channel prototype is composed of two 16-bit Time-to-Digital Converters (TDCs), one 8-bit Analog-to-Digital Converter (ADC), a front-end preamplifier and shaper, plus digital and analog buffers that support a variety of digitization chains. The prototype has a multiplexed digital backend that executes a state machine, distributes control and timing signals, and buffers data for serial output. Laboratory bench tests measure the absolute TDC resolution between 74 ps and 480 ps, growing with the absolute delay, and a relative time resolution of 19 ps. Resolution outliers due to cross-talk between clock signals and supply or reference voltages are seen. After calibration, the ADC displays good linearity and noise performance, with an effective number of bits of 6.9. Under normal operating conditions the circuit consumes 32 mW per channel. Potential design improvements to address the resolution drift and tails are discussed