Simulations of charge transfer in Electron Multiplying Charge Coupled Devices

Electron Multiplying Charge Coupled Devices (EMCCDs) are a variant of traditional CCD technology well suited to applications that demand high speed operation in low light conditions. On-chip signal amplification allows the sensor to effectively suppress the noise introduced by readout electronics, permitting sub-electron read noise at MHz pixel rates. The devices have been the subject of many detailed studies concerning their operation, however there has not been a study into the transfer and multiplication process within the EMCCD gain register. Such an investigation has the potential to explain certain observed performance characteristics, as well as inform further optimisations to their operation. In this study, the results from simulation of charge transfer within an EMCCD gain register element are discussed with a specific focus on the implications for serial charge transfer efficiency (CTE). The effects of operating voltage and readout speed are explored in context with typical operating conditions. It is shown that during transfer, a small portion of signal charge may become trapped at the semiconductor-insulator interface that could act to degrade the serial CTE in certain operating conditions

Seasonal acclimatization to temperature in cardueline finches

1. Seasonal variation in body constituents and utilization of lipid, protein, and carbohydrate during cold stress in American goldfinches were studied to determine relations of these functions to the pronounced seasonal shift in thermogenic capacity documented in a previous study (Dawson and Carey, 1976).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47119/1/360_2004_Article_BF00686746.pd

The Apocalypse in the early church Christ, eschaton, and millennium

SIGLEAvailable from British Library Document Supply Centre- DSC:D175413 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Coincidence of immune-mediated diseases driven by TH1 and TH2 subsets suggests a common aetiology. A population-based study using computerized General Practice data

Background The recent rise in the prevalence of immune‐mediated diseases has been attributed to environmental factors such as a lack of microbial challenge, or dietary change, that deviate the overall balance between mutually antagonistic subsets of T helper (Th) cells. Objective An alternative proposal is that recent environmental changes have resulted in an immune system that is more likely to produce both Th1 and Th 2 responses against benign antigens. The prediction of this hypothesis, that Th1 and Th 2‐mediated diseases are not mutually exclusive, and may be positively associated, is tested here in a whole population. Methods Data from General Practices participating in the Scottish Continuous Morbidity Recording (CMR) project were used to determine the coincidence of the major Th 2‐mediated atopic diseases; asthma, eczema and allergic rhinitis, with the Th1‐mediated autoimmune conditions; type I diabetes, rheumatoid arthritis and psoriasis. We also identified the prescription rates of inhaled therapy for asthma in patients with Th1‐mediated disease. Results There was a significant increase in the risk of presenting with a Th1‐mediated autoimmune condition in patients with a history of allergic disease (standardized prevalence ratio (95% confidence interval) 1.28 (1.18–1.37)). Likewise, the standardized prevalence ratios of presenting with either eczema (1.67 (1.48–1.87)) or allergic rhinitis (1.22 (1.02–1.44)) were significantly increased in subjects with a history of Th1‐mediated disease. There was a particularly strong association between current psoriasis and current eczema (standardized prevalence ratio of psoriasis in subjects with eczema 2.88, 95% confidence interval (CI) 2.38–3.45). There was also a significant increase in prescriptions for inhaled asthma therapy in patients with Th1 disease. Conclusion It is concluded that Th1‐ and Th 2‐mediated diseases are significantly associated in a large General Practice population. This finding supports the proposal that autoimmune and atopic diseases share risk factors that increase the propensity of the immune system to generate both Th1‐ and Th 2‐mediated inappropriate responses to non‐pathological antigens