Duo modules

Let R be a ring. An R-module M is called a (weak) duo module provided every (direct summand) submodule of M is fully invariant. It is proved that if R is a commutative domain with field of fractions K then a torsion-free uniform R-module is a duo module if and only if every element k in K such that kM is contained in M belongs to R. Moreover every non-zero finitely generated torsion-free duo R-module is uniform. In addition, if R is a Dedekind domain then a torsion R-module is a duo module if and only if it is a weak duo module and this occurs precisely when the P-primary component of M is uniform for every maximal ideal P of R

The Magnetic Field Gradiometer

This report has two principal goals. First, to present a general review of magnetic field gradiometers and, second, to provide new data concerning these gradiometers, including new information about their response to magnetic dipole fields. A system of nomenclature is introduced that is consistent with the mathematical concept of gradient and which provides a basis for discussions of the different functions of magnetic field gradiometers and differential magnetometers. The distinction between component gradiometers and total field gradiometers is also stressed.Office of Naval TechnologyNaval Postgraduate SchoolOffice of Naval ResearchAdditional support for this work was provided by the Office of Naval Research through Contracts No.N00014-75-C-1095 and N00014-77-C-0292.Approved for public release; distribution unlimited

The Magnetic Field Gradiometer

Final Technical Report No. E723-1This report has two principal goals: First, to present a general review of magnetic field gradiometers and, second, to provide new data concerning these gradiometers, including new information about their response to magnetic dipole fields. A system of nomenclature is introduced that is consistent with the mathematical concept of gradient and which provides a basis for discussions of the different functions of magnetic field gradiometers and differential magnetometers. The distinction between component gradiometers and total field gradiometers is also stressed. An historical review provides an opportunity to describe the different characteristics of the many kinds of magnetic field gradiometers that have been developed since the first report of such a gradiometer in 1925: rotating induction loop, fixed induction loop, fluxgate, proton precession, optically pumped, and superconducting gradiometers are discussed. It is pointed out how the great sensitivity of superconducting gradiometers, and possibly other varieties of modern magnetic field gradiometers, may invalidate the popular 'source-free' asssumption under particular circumstances. Further, because these high sensitivities will make the gradiometers more susceptible to the geomagnetic field gradient, expressions are derived for the components of this gradient and some representative numerical values are calculated. The response of both component and total field gradiometers to dipole sources is considered for a number of different source-gradiometer configurations. On a more speculative note, two varieties of rotating component gradiometers are discussed, with particular attention being given to their possibly unique characteristics. The report ends by recapitulating the many applications of magnetic field gradiometers, particularly in such important areas as medicine, energy production, and defense, and by stressing the need for gradiometer-related basic research.Office of Naval TechnologyNaval Postgraduate SchoolOffice of Naval ResearchN00228-81-C-AB56Approved for public release; distribution is unlimited

Idiopathic chondrolysis, of the hip - A case report

A report of a case of idiopathic chondrolysis of the right hip in a 13-year-old Black girl is presented. Radiographs and microbiological and biochemical investigations excluded all other diseases. Cartilage and synovium were removed at biopsy of the right hip. Macroscopic and histopathological studies showed the typical features of idiopathic chondrolysis. Transmission electron microscopy confirmed the histological findings. Scanning electron microscopy highlighted the irregular pitted and fibrillated surface of the cartilage. Immunofluorescent studies. on cartilage and synovium were negative. The possible pathogenesis of the disease is discussed, but the cause still remains unknown

Mechanisms of termination and prevention of atrial fibrillation by drug therapy

Atrial fibrillation (AF) is a disorder of the rhythm of electrical activation of the cardiac atria. It is the most common cardiac arrhythmia, has multiple aetiologies, and increases the risk of death from stroke. Pharmacological therapy is the mainstay of treatment for AF, but currently available anti-arrhythmic drugs have limited efficacy and safety. An improved understanding of how anti-arrhythmic drugs affect the electrophysiological mechanisms of AF initiation and maintenance, in the setting of the different cardiac diseases that predispose to AF, is therefore required. A variety of animal models of AF has been developed, to represent and control the pathophysiological causes and risk factors of AF, and to permit the measurement of detailed and invasive parameters relating to the associated electrophysiological mechanisms of AF. The purpose of this review is to examine, consolidate and compare available relevant data on in-vivo electrophysiological mechanisms of AF suppression by currently approved and investigational anti-arrhythmic drugs in such models. These include the Vaughan Williams class I–IV drugs, namely Na+ channel blockers, β-adrenoceptor antagonists, action potential prolonging drugs, and Ca2+ channel blockers; the “upstream therapies”, e.g., angiotensin converting enzyme inhibitors, statins and fish oils; and a variety of investigational drugs such as “atrial-selective” multiple ion channel blockers, gap junction-enhancers, and intracellular Ca2+-handling modulators. It is hoped that this will help to clarify the main electrophysiological mechanisms of action of different and related drug types in different disease settings, and the likely clinical significance and potential future exploitation of such mechanisms. Keywords: Atrial fibrillation; Cardiac arrhythmia mechanisms: reentry, afterdepolarisations; In-vivo animal models; Pathological electrical remodelling; Pharmacological treatment; Anti-arrhythmic drug mechanisms Abbreviations: ACE, angiotensin-converting enzyme; AF, atrial fibrillation; AFCL, AF cycle length; APD, action potential duration; DAD, delayed afterdepolarisation; EAD, early afterdepolarisation; ERP, effective refractory period; ICaL, L-type Ca2+ current; ICaT, T-type Ca2+ current; If, funny current; IK1, inward rectifier K+ current; IKACh, acetylcholine-activated K+ current; IKr, rapid delayed rectifier K+ current; IKS, slow delayed rectifier K+ current; IKur, ultra-rapid delayed rectifier K+ current; INa, Na+ current; INa/Ca, Na+-Ca2+ exchanger current; INa/H, Na+-H+ exchanger current; INaL, late INa; ISKCa, small conductance Ca2+-activated K+ current; ITO, transient outward K+ curren

Noise Pollution in the Operating Room

Introduction: Noise pollution in the operating room (OR) poses a threat to both patients and providers. Sound levels often exceed recommended standards set forth by the National Institute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA). The purpose of this project was to examine current evidence and implement education for student registered nurse anesthetists (SRNAs) regarding noise pollution in the OR. The education module emphasized the effect of increased noise levels on the delivery of an anesthetic, with a focus on resultant sequelae. Methods: A literature review produced 117 articles, of which thirty-five were included for analysis. Systematic reviews, randomized and non-randomized control trials, cohort studies, case studies, qualitative studies and expert opinion were all considered. A research based education module was delivered to SRNAs. A pre-test and post-test methodology was utilized to assess the efficacy of the education module for SRNAs. Analysis of Results: Results generated from the education module illustrate a knowledge deficient of student registered nurse anesthetists pertaining to noise reduction, cognitive demand, and attention allocation. Post-test scores (M=90%) for SRNAs who completed the education module were significantly greater than pre-test scores (M=60%).  t(39)= 10.1, p = 1.88 x 10-12. Recommendations for Practice: Noise pollution is a complex, multifactorial problem. The physical, psychological and emotional effects of noise pollution are the inability to critically think, impaired team communication, chronic hearing loss, increased incidence of cardiovascular disease, and medical error. Emphasis placed on sustaining and integrating noise reduction education into curriculum schemas of nurse anesthesia programs is prudent. Educational content delivered to all anesthesia providers and the interdisciplinary care team in the operating room would be a comprehensive plan. Although several national initiatives are in place to reduce noise, it is imperative that knowledge is shared and interventions implemented to protect both provider and patient. Furthermore, there should be a collaboration amongst a variety of surgical specialties to continue research pertaining to the production of noise in the operating room. Keywords: Anesthesia, Noise, Noise pollution, Operating room, Occupational safet

Raman spectroscopy of human teeth using integrated optical spectrometers

We have designed an arrayed-waveguide grating in silicon oxynitride technology for the detection of Raman signals from tooth enamel in the spectral region between 890 nm and 912 nm. The detected signals for both parallel and cross polarizations are used to distinguish between healthy and carious regions on the tooth surface of extracted human teeth. Our experimental results are in very good agreement with those achieved using conventional Raman spectrometers. Our results represent a step toward the realization of compact, hand-held, integrated spectrometers

Compositional closure for Bayes Risk in probabilistic noninterference

We give a sequential model for noninterference security including probability (but not demonic choice), thus supporting reasoning about the likelihood that high-security values might be revealed by observations of low-security activity. Our novel methodological contribution is the definition of a refinement order and its use to compare security measures between specifications and (their supposed) implementations. This contrasts with the more common practice of evaluating the security of individual programs in isolation. The appropriateness of our model and order is supported by our showing that our refinement order is the greatest compositional relation --the compositional closure-- with respect to our semantics and an "elementary" order based on Bayes Risk --- a security measure already in widespread use. We also relate refinement to other measures such as Shannon Entropy. By applying the approach to a non-trivial example, the anonymous-majority Three-Judges protocol, we demonstrate by example that correctness arguments can be simplified by the sort of layered developments --through levels of increasing detail-- that are allowed and encouraged by compositional semantics

We haven't got a seat on the bus for you or All the seats are mine: Narratives and career transitions in professional golf

In this article we explore how the stories an athlete tells throughout life in sport affect her career transition experiences. We base our enquiry on a social constructionist conception of narrative theory which holds that storytelling is integral to the creation and maintenance of identity and sense of self. Life stories were gathered through interviews with two professional women golfers (Christiana and Kandy) over a six‐year period. Through a narrative analysis of structure and form we explored each participant’s stories of living in and withdrawing from professional golf. We suggest Christiana told monological performance‐oriented stories which, while aligning with the culture of elite sport, resulted in an exclusive athletic identity and foreclosure of alternative selves and roles. On withdrawal, Christiana experienced narrative wreckage, identity collapse, mental health difficulties and considerable psychological trauma. In contrast, Kandy told dialogical discovery‐oriented stories which, while being in tension with the dominant performance narrative, created and sustained a multidimensional identity and self. Her stories and identity remained intact, authentic and continuous on withdrawal from tournament golf and she experienced few psychological problems