Controlling the Frequency-Temperature Sensitivity of a Cryogenic Sapphire Maser Frequency Standard by Manipulating Fe3+ Spins in the Sapphire Lattice

To create a stable signal from a cryogenic sapphire maser frequency standard, the frequency-temperature dependence of the supporting Whispering Gallery mode must be annulled. We report the ability to control this dependence by manipulating the paramagnetic susceptibility of Fe3+ ions in the sapphire lattice. We show that the maser signal depends on other Whispering Gallery modes tuned to the pump signal near 31 GHz, and the annulment point can be controlled to exist between 5 to 10 K depending on the Fe3+ ion concentration and the frequency of the pump. This level of control has not been achieved previously, and will allow improvements in the stability of such devices.Comment: 17 pages, 10 figure

Routine hand hygiene audit by direct observation: has nemesis arrived?

Infection prevention and control experts have expended valuable health service time developing and implementing tools to audit health workers' hand hygiene compliance by direct observation. Although described as the ‘gold standard’ approach to hand hygiene audit, this method is labour intensive and may be inaccurate unless performed by trained personnel who are regularly monitored to ensure quality control. New technological devices have been developed to generate ‘real time’ data, but the cost of installing them and using them during routine patient care has not been evaluated. Moreover, they do not provide as much information about the hand hygiene episode or the context in which hand hygiene has been performed as direct observation. Uptake of hand hygiene products offers an inexpensive alternative to direct observation. Although product uptake would not provide detailed information about the hand hygiene episode or local barriers to compliance, it could be used as a continuous monitoring tool. Regular inspection of the data by infection prevention and control teams and clinical staff would indicate when and where direct investigation of practice by direct observation and questioning of staff should be targeted by highly trained personnel to identify local problems and improve practice

Hybrid electron spin resonance and whispering gallery mode resonance spectroscopy of Fe3+ in sapphire

The development of a new era of quantum devices requires an understanding of how paramagnetic dopants or impurity spins behave in crystal hosts. Here, we describe a spectroscopic technique which uses traditional electron spin resonance (ESR) combined with the measurement of a large population of electromagnetic whispering gallery modes. This allows the characterization of the physical parameters of paramagnetic impurity ions in the crystal at low temperatures. We present measurements of two ultrahigh-purity sapphires cooled to 20 mK in temperature, and determine the concentration of Fe3 ions and their frequency sensitivity to a dc magnetic field. Our method is different from ESR in that it is possible to track the resonant frequency of the ion from zero applied magnetic field to any arbitrary value, allowing excellent measurement precision. This high precision reveals anisotropic behavior of the Zeeman splitting. In both crystals, each Zeeman component demonstrates a different g factor

The center of the partition algebra

In this paper we show that the center of the partition algebra , in the semisimple case, is given by the subalgebra of supersymmetric polynomials in the normalised Jucys-Murphy elements. For the non-semisimple case, such a subalgebra is shown to be central, and in particular it is large enough to recognise the block structure of . This allows one to give an alternative description for when two simple -modules belong to the same block

Core components for effective infection prevention and control programmes: new WHO evidence-based recommendations

Abstract Health care-associated infections (HAI) are a major public health problem with a significant impact on morbidity, mortality and quality of life. They represent also an important economic burden to health systems worldwide. However, a large proportion of HAI are preventable through effective infection prevention and control (IPC) measures. Improvements in IPC at the national and facility level are critical for the successful containment of antimicrobial resistance and the prevention of HAI, including outbreaks of highly transmissible diseases through high quality care within the context of universal health coverage. Given the limited availability of IPC evidence-based guidance and standards, the World Health Organization (WHO) decided to prioritize the development of global recommendations on the core components of effective IPC programmes both at the national and acute health care facility level, based on systematic literature reviews and expert consensus. The aim of the guideline development process was to identify the evidence and evaluate its quality, consider patient values and preferences, resource implications, and the feasibility and acceptability of the recommendations. As a result, 11 recommendations and three good practice statements are presented here, including a summary of the supporting evidence, and form the substance of a new WHO IPC guideline

Validity of hand hygiene compliance measurement by observation: A systematic review

BACKGROUND: Hand hygiene is monitored by direct observation to improve practice, but this approach can potentially cause information, selection, and confounding bias, threatening the validity of findings. The aim of this study was to identify and describe the potential biases in hand hygiene compliance monitoring by direct observation; develop a typology of biases and propose improvements to reduce bias; and increase the validity of compliance measurements. METHODS: This systematic review of hospital-based intervention studies used direct observation to monitor health care workers' hand hygiene compliance. RESULTS: Seventy-one publications were eligible for review. None was free of bias. Selection bias was present in all studies through lack of data collection on the weekends (n = 61, 86%) and at night (n = 46, 65%) and observations undertaken in single-specialty settings (n = 35, 49%). We observed inconsistency of terminology, definitions of hand hygiene opportunity, criteria, tools, and descriptions of the data collection. Frequency of observation, duration, or both were not described or were unclear in 58 (82%) publications. Observers were trained in 56 (79%) studies. Inter-rater reliability was measured in 26 (37%) studies. CONCLUSIONS: Published research of hand hygiene compliance measured by direct observation lacks validity. Hand hygiene should be measured using methods that produce a valid indication of performance and quality. Standardization of methodology would expedite comparison of hand hygiene compliance between clinical settings and organizations

Changing the paradigm: messages for hand hygiene education and audit from cluster analysis

BACKGROUND: Hand hygiene is considered to be the foremost infection prevention measure. How healthcare workers accept and make sense of the hand hygiene message is likely to contribute to the success and sustainability of initiatives to improve performance, which is often poor. METHODS: A survey of nurses in critical care units in three National Health Service trusts in England was undertaken to explore opinions about hand hygiene, use of alcohol hand rubs, audit with performance feedback, and other key hand-hygiene-related issues. Data were analysed descriptively and subjected to cluster analysis. RESULTS: Three main clusters of opinion were visualized, each forming a significant group: positive attitudes, pragmatism and scepticism. A smaller cluster suggested possible guilt about ability to perform hand hygiene. CONCLUSION: Cluster analysis identified previously unsuspected constellations of beliefs about hand hygiene that offer a plausible explanation for behaviour. Healthcare workers might respond to education and audit differently according to these beliefs. Those holding predominantly positive opinions might comply with hand hygiene policy and perform well as infection prevention link nurses and champions. Those holding pragmatic attitudes are likely to respond favourably to the need for professional behaviour and need to protect themselves from infection. Greater persuasion may be needed to encourage those who are sceptical about the importance of hand hygiene to comply with guidelines. Interventions to increase compliance should be sufficiently broad in scope to tackle different beliefs. Alternatively, cluster analysis of hand hygiene beliefs could be used to identify the most effective educational and monitoring strategies for a particular clinical setting

RECOVER Guidelines: Newborn Resuscitation in Dogs and Cats. Clinical Guidelines

Objective: To present evidence- and consensus-based guidelines for resuscitation of newborn puppies and kittens. Design: Prioritized clinical questions pertaining to newborn resuscitation and in the Population–Intervention–Comparator– Outcome (PICO) format were used to inform systematic literature searches by information specialists, to extract research findings from relevant publications and synthesize them into evidence, to assess this evidence for quality, and, finally, to develop draft treatment recommendations. These steps were followed by a consensus process and a community commenting period prior to finalization of the project. These RECOVER Newborn Resuscitation Guidelines are a concise summary of the newborn resuscitation process to provide clear and actionable clinical instructions to veterinary professionals. Setting: Transdisciplinary, international collaboration in university, specialty, and emergency practice. Results: A total of 28 PICO questions pertaining to resuscitation of puppies and kittens at birth were addressed in this project. This resulted in 59 treatment recommendations that delineate an iterative approach to newborn resuscitation starting with airway clearance, tactile stimulation, and temperature control, as well as positive pressure ventilation, and instruct on more advanced measures such as CPR. An algorithm displays the flow of assessments and actions over the course of the resuscitation process

Measurement of fundamental thermal noise limit in a cryogenic sapphire frequency standard using bimodal maser oscillations

We report observations of the Schawlow-Townes noise limit in a cryogenic sapphire secondary frequency standard. The effect causes a fundamental limit to the frequency stability, and was measured through the novel excitation of a bimodal maser oscillation of a Whispering Gallery doublet at $12.04 GHz$. The beat frequency of $10 kHz$ between the oscillations enabled a sensitive probe for this measurement of fractional frequency instability of $10^{-14}\tau^{-1/2}$ with only 0.5 $pW$ of output power.Comment: Published in PRL 100, 233901 (2008