Analysis of Factors Relating to Companion Rabbits Relinquished to Two United Kingdom Rehoming Centers

Rabbits are a common companion animal in the United Kingdom, and some reports have suggested that large numbers are relinquished to rehoming centers each year. This study aimed to investigate the characteristics of rabbits relinquished to 2 UK rehoming centers and explore reasons given for relinquishment. The centers contributed data for all rabbits who entered their center during 2013 (n = 205). Most rabbits (59.5%) were relinquished by a guardian. Similar numbers of males and females were relinquished, and a larger number of rabbits were not neutered (72.4%) and adults (56%). Most rabbits were healthy on arrival (61.5%). The most common reasons for relinquishment were: “too many rabbits/unplanned litters” (30.3%) and “housing problems” (23.8%). Rabbit-related reasons accounted for 12.2% of rabbits relinquished. Reasons for relinquishment were associated with 1 of the recorded rabbit characteristics. Further detailed studies are needed to explore the dynamics of companion rabbit ownership and factors that affect the breakdown of rabbit–guardian relationships in the United Kingdom.     

13C NMR investigation of the anomeric specificity of CMP-N-acetylneuraminic acid synthetase from Escherichia coli.

The anomeric specificity of Escherichia coli CMP-N-acetylneuraminic acid (CMP-NeuAc) synthetase was investigated by NMR using 13C-labeled N-acetylneuraminic acid (NeuAc). Consumption of the beta-anomer of [2-13C]N-acetylneuraminic acid was observed upon addition of enzyme, with a concomitant appearance of an anomeric resonance for CMP-N-acetylneuraminic acid. Inhibition by substrate analogues the anomeric oxygen was determined in a similar manner using [2-13C,(50 atom %)18O]N-acetylneuraminic acid. An upfield shift of 1.5 Hz in the anomeric resonance of both the [13C]NeuAc substrate and CMP-[13C]NeuAc product was observed due to the 18O substitution. This result implies conservation of the NeuAc oxygen. Results of steady-state kinetic analysis suggest a sequential-type mechanism and therefore no covalent intermediate. Thus, CMP-beta-NeuAc is probably formed by a direct transfer of the anomeric oxygen of beta-NeuAc to the alpha-phosphate of CTP.     

Single-molecule detection with total internal reflection excitation: comparing signal-to-background and total signals in different geometries.

Excitation of fluorescence with total internal reflection (TIR) excitation yields very low background scattered light and good signal-to-background contrast. The background and its associated noise can be made low enough to detect single fluorescent molecules under ambient conditions. In this paper, different TIR geometries were compared for excitation and detection of single rhodamine 6G (R6G) molecules at air-silica interfaces and single B-phycoerythrin proteins at water-silica interfaces. Through-objective, objective-coverslip, and prism-based TIR geometries were investigated. The signal-to-background ratio (SBR) and the number of photons detected before photobleaching (Nb) were optimum in different geometries. The greatest image contrast was obtained when using prism-TIR (SBR = 11.5), but the largest number of detected signal photoelectrons was obtained by using through-objective TIR for R6G-air-silica ( = 10(4)). The results were discussed in terms of the TIR field enhancements and the modified dipole emission pattern near a dielectric interface. The SBR and total detected photons are important parameters for designing photon-limited experiments.     

Human intestinal tissue-resident memory T cells comprise transcriptionally and functionally distinct subsets

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