Deacetoxy/deacetylcephalosporin C synthase (acDAOC/DACS) from Acremonium chrysogenum is a bifunctional enzyme that catalyzes both the ring-expansion of penicillin N to deacetoxycephalosporin C (DAOC) and the hydroxylation of the latter to deacetylcephalosporin C (DAC). Three residues N305, R307 and R308 located in close proximity to the C-terminus of acDAOC/DACS were each mutated to leucine. Th...

Dopaminergic amacrine cells (DACs) are among the most well-characterized neurons in the mammalian retina, and their connections to AII amacrine cells have been described in detail. However, the stratification of DAC dendrites differs based on their location in the inner plexiform layer (IPL), raising the question of whether all AII lobules are modulated by dopamine release from DACs. The presen...

Introduction Instrumentation, waveform generation, data acquisition, feedback control systems and other application areas are beginning to utilize 16-bit data converters. More specifically, 16bit digital-to-analog converters (DACs) have seen increasing use. New components (see the sidebar “Components for 16-Bit Digital-to-Analog Conversion” on page 31) have made 16-bit DACs a practical design a...

Some basic observations are made about the static accuracy of ADCs and DACs with full digital correction. First, the accuracy of flash ADCs is considered. It is pointed out that the loss in effective resolution due to component mismatch is only about 1 bit, independently of the mismatch level (unless the mismatch is very small). Second, the accuracy of current steering DACs is considered. It is...

Recently, a line of evidence has demonstrated that the vertebrate retina possesses a novel retrograde signaling pathway. In this pathway, phototransduction is initiated by the photopigment melanopsin, which is expressed in a small population of retinal ganglion cells. These ganglion cell photoreceptors then signal to dopaminergic amacrine cells (DACs) through glutamatergic synapses, influencing...

We evaluated the structure and validity of the Upward Appearance Comparison Scale (UPACS) and Downward Appearance Comparison Scale (DACS) (O'Brien et al., 2009) in Chinese samples. In Study 1, principal component analysis on an initial sample (427 women, 123 men) and confirmatory factor analysis on another sample (447 women, 121 men) found that a 15-item, two component model had the best overal...

As the work for managing a whole LAN effectively without limited purposes, there are works of Policy-based network management (PBNM). The existing PBNM is defined in some organizations including the Internet Engineering Task Force (IETF). However, it has structural problems. For example, communications sent from many clients concentrate on a communication control mechanism called PEP (Policy En...

In parallel with massive genomic data production, data sharing practices have rapidly expanded over the last decade. To ensure authorized access to data, access review by data access committees (DACs) has been utilized as one potential solution. Here we discuss core elements to be integrated into the fabric of access review by both established and emerging DACs in order to foster fair, efficien...

Dopamine (DA) is a neuromodulator that in the retina adjusts the circuitry for visual processing in dim and bright light conditions. It is synthesized and released from retinal interneurons called dopaminergic amacrine cells (DACs), whose basic physiology is not yet been fully characterized. To investigate their cellular and input properties as well as light responses, DACs were targeted for wh...

This paper considers the viability of compact low-resolution low-power mini digital-to-analog converters (mini-DACs) for use in large arrays of neural type cells, where programmable weights are required. Transistors are biased in weak inversion in order to yield small currents and low power consumptions, a necessity when building large size arrays. One important drawback of weak inversion opera...