WorldWideScience

Sample records for excluding manometric artefacts

  1. Video manometry of the sphincter of Oddi: a new aid for interpreting manometric tracings and excluding manometric artefacts

    DEFF Research Database (Denmark)

    Madácsy, L; Middelfart, H V; Matzen, Peter

    2000-01-01

    was to develop a new method sphincter of Oddi video manometry-based on simultaneous ESOM and real-time endoscopic image analysis, and to investigate the usefulness of video manometry for detecting manometric artefacts during ESOM. PATIENTS AND METHODS: Seven consecutive patients who had undergone cholecystectomy.......5+/-2.4/min (range: 1-12/min). On the ESOM tracing, 78% of the duodenal contractions had a corresponding pressure wave with an average duration of 2.8+/-0.4 seconds and an amplitude of 71.9+/-16.7 mm Hg. Other artefacts on the ESOM tracings, such as catheter movements, pseudocontractions, hyperventilation......, or retching, were also easily recognized using simultaneous ESOM and real-time endoscopic image analysis. CONCLUSIONS: Video manometry of the sphincter of Oddi is a promising new method for improving the analysis and documentation of ESOM tracings. It has several advantages over the conventional technique...

  2. Video manometry of the sphincter of Oddi: a new aid for interpreting manometric tracings and excluding manometric artefacts

    DEFF Research Database (Denmark)

    Madácsy, L; Middelfart, H V; Matzen, Peter

    2000-01-01

    of Oddi phasic contractions were identified, with an average amplitude of 153.9+/-85.0 mm Hg and a duration of 7.9+/-1.2 seconds. Visual analysis of the real-time endoscopic images, replayed in cine loop by the computer, revealed 236 separate duodenal contractions, with an average frequency of 3...

  3. Triggering Artefacts

    DEFF Research Database (Denmark)

    Mogensen, Preben Holst; Robinson, Mike

    1995-01-01

    The paper presents a general critique of the use of conceptual frameworks in design, illustrated by the well known synchronous/asynchronous, co-located/non-co-located framework. It argues that while frameworks are a necessary and inevitable starting point for design, the business of tailoring...... and adapting them to specific situations need not be ad hoc.Triggering artefacts are a way of systematically challenging both designers' preunderstandings and the conservatism of work practice. Experiences from the Great Belt tunnel and bridge project are used to illustrate howtriggering artefacts change...

  4. Negotiating meaning through artefacts

    DEFF Research Database (Denmark)

    Tavella, Elena

    2015-01-01

    analyzes a workshop transcript to assess the extent to which stakeholders’ appropriation of artefacts supports them in engaging in negotiation of meaning with action implications. Moreover, how artefacts and negotiation of meaning shape one another is identified. The data suggest that appropriating...... artefacts helps stakeholders negotiate meaning effectively, but appropriation occurs at varying intensities depending on the issue of concern, the artefact used and who appropriates it....

  5. Manometric artefacts suggesting compression of the duodenum by the superior mesenteric artery in healthy humans

    NARCIS (Netherlands)

    Schwartz, M. P.; Samsom, M.; Smout, A. J.

    2001-01-01

    Multi-channel manometry offers the opportunity to study intestinal motor activity with high spatiotemporal resolution. We report tonic and phasic intraluminal pressure changes in the mid-portion of the horizontal part of the duodenum. In 10 healthy volunteers, we recorded 2 h of interdigestive

  6. Improved manometric setup for the accurate determination of supercritical carbon dioxide sorption

    NARCIS (Netherlands)

    Van Hemert, P.; Bruining, H.; Rudolph, E.S.J.; Wolf, K.H.A.A.; Maas, J.G.

    2009-01-01

    An improved version of the manometric apparatus and its procedures for measuring excess sorption of supercritical carbon dioxide are presented in detail with a comprehensive error analysis. An improved manometric apparatus is necessary for accurate excess sorption measurements with supercritical

  7. Facts about artefacts in diagnostic pathology.

    Science.gov (United States)

    Pattari, S K; Dey, P

    2002-01-01

    Literal meaning of artefact given by 'Oxford Advanced Learner Dictionary' is 'a thing made by people'. In medical science 'the fact' is not true; but we observe routinely is called artefact. We face various types of artefacts in daily reporting of pathology specimen. Many times artefacts hinder the actual diagnosis. The artefacts i. e. fixation artefact, processing artefact, staining artefact, mounting artefact, air bubbles etc. can cause difficulty in diagnosis and a pathologist should be trained to identify those artefacts.

  8. Manometric determination of supercritical gas sorption in coal

    NARCIS (Netherlands)

    Van Hemert, P.

    2009-01-01

    The characteristics of the manometric method are investigated so that it can be used to obtain accurate data of sorption of supercritical gas in coal. Furthermore, data of the sorption of carbon dioxide, methane and nitrogen in coal at in situ conditions have been determined. Accurate data are

  9. Symbol: artefact and model

    DEFF Research Database (Denmark)

    Galle, Per

    2000-01-01

    In preparation of an analysis of product modelling in terms of communication, this report presents a brief analysis of symbols; that is, the entities by means of which communication takes place. Symbols are defined in such a way as to admit artefacts and models (the latter including linguistic...... utterances as well as scale models) as special cases....

  10. Interpreting manometric signals for propulsion in the gut

    Science.gov (United States)

    Sinnott, M. D.; Cleary, P. W.; Dinning, P. G.; Arkwright, J. W.; Costa, M.

    2015-09-01

    Propulsion of intestinal contents involves coordinated contractions and relaxations of the muscle controlled by polarised enteric neural reflex pathways. Due to the inaccessibility of the small and large bowel, obtaining detailed manometric measurements in the gut or visualizing the movement of digesta is difficult in vivo. Computational modelling that incorporates the complex interactions between gut content and wall contractility has the potential to explain the mechanisms behind propulsive motor patterns and aid the interpretation of manometric measurements. We present here a biomechanical computational model of coupled wall flexure and flow dynamics in a virtual segment of intestine. The model uses the smoothed particle hydrodynamics method which permits coupling of the fluid/solid motion and wall deformation in a natural way. Peristaltic waves of contraction and relaxation, similar to those observed in physiological experiments, were applied to the gut wall of the model. A catheter containing manometric sensors was also incorporated into the model to derive representative pressure readings. The sensitivity of the model to input parameters including wall stiffness, viscosity of content and degree of muscular contraction is also presented. The results show that there is a rapid rise in pressure of fluid content trapped between the catheter and the contracting wall. The peristaltic wave travels along the length of the virtual segment of intestine passing over each sensor. The bolus, formed by the peristaltic contraction, grows in size and longitudinal extent until the bolus size reaches steady state. The wall force and the peak fluid pressure both scale proportionally with the change in muscle length, indicating that manometric data provide a reliable means for measuring the strength of contractions. Changes in stiffness of the wall and viscosity of contents result in predictable changes in the parameters of peristalsis. The model can be thus applied to manometry

  11. CO2 - Laser Intestinal Anastomosis Histological And Manometric Study

    Science.gov (United States)

    Rabau, Micha Y.; Goldman, Gideon; Bar-Nea, Lilian; Wiznitzer, Theodor; Rochkind, Semion

    1988-06-01

    Low energy CO2 laser was used to perform intestinal anastomosis by means of tissue welding in 10 Wistar rats. The post operative course in the studied animals was uneventful. The integrity of the anastomosis was investigated manometrically, immediately upon completion of the anasto-mosis and twenty days later. Ten Wistar rats served as control in which conventional interrupted one-layer anastomosis was performed. The results show a significant superior-ity (Phistological examinations up to 90 days following surgery revealed complete healing and epithelialization of the anastomotic site. The technical details of the CO2 laser anastomosis are described.

  12. Signes et artefacts.

    Directory of Open Access Journals (Sweden)

    Samuel Périgois

    2006-04-01

    Full Text Available Les opérations de requalification des centres des petites villes se sont multipliées depuis deux décennies. Cet article analyse comment le réaménagement des centres-villes s’inscrit dans un processus de patrimonialisation qui participe à une nouvelle conception de l’urbanité à travers une mise en scène des espaces centraux. Cette mise en scène des espaces publics passe par la multiplication de signes d’ancienneté. On peut distinguer des modalités différentes selon que les artefacts mobilisés renvoient à l’histoire du lieu, à des éléments hérités du passé et réinscrits dans l’espace ou qu’ils relèvent d’une ancienneté générique telle qu’elle s’est popularisée dans l’usage des mobiliers urbains « de style » — comme les candélabres « tradition » et bornes en fonte symbolisant l’appartenance à une urbanité d’apparence. Ce phénomène identitaire particulier vise à produire une urbanité, au moins physique. Cette artefactualisation amène à une redéfinition de la patrimonialisation. La tendance actuelle à la substitution d’« objets patrimoines » par des signes rappelant leur existence passée et les artefacts simulant de l’ancienneté et suscitant de l’historicité mobilisent les notions d’ambiance, d’esthétique et de « simulacre » selon le terme utilisé par Jean Baudrillard. La combinaison des références au patrimoine local et à l’ancien générique participe d’une mise en scène plus globale visant à inscrire le centre dans le temps long et à la production esthétique d’une néo-archéo urbanité « petite ville ». Refitting operations of downtown areas of small cities have increased for two decades. This article analyzes how this restructuring falls under a process of “patrimonialisation” which takes part in a new design of “urbanity” through a setting in scene of central spaces. This setting in scene of public spaces finds expression in

  13. Anatomic abnormalities are common potential explanations of manometric esophagogastric junction outflow obstruction

    National Research Council Canada - National Science Library

    DeLay, K; Austin, G. L; Menard‐Katcher, P

    2016-01-01

    ...) diagnosis associated with a myriad of conditions and of uncertain clinical implication. We compared clinical and manometric features of EGJOO classified as either idiopathic or related to anatomic conditions...

  14. Material culture - artefacts and daily life

    DEFF Research Database (Denmark)

    Roesdahl, Else; Verhaeghe, Frans

    2011-01-01

    A survey of main groups of medieval portable artefacts, with a focus on north-western and central Europe (including Scandinavia), and a discussion of methods and interpretations in artefact studies......A survey of main groups of medieval portable artefacts, with a focus on north-western and central Europe (including Scandinavia), and a discussion of methods and interpretations in artefact studies...

  15. Artefact detection in neonatal EEG.

    Science.gov (United States)

    Stevenson, N J; O'Toole, J M; Korotchikova, I; Boylan, G B

    2014-01-01

    Artefact detection is an important component of any automated EEG analysis. It is of particular importance in analyses such as sleep state detection and EEG grading where there is no null state. We propose a general artefact detection system (GADS) based on the analysis of the neonatal EEG. This system aims to detect both major and minor artefacts (a distinction based primarily on amplitude). As a result, a two-stage system was constructed based on 14 features extracted from EEG epochs at multiple time scales: [2, 4, 16, 32]s. These features were combined in a support vector machine (SVM) in order to determine the presence of absence of artefact. The performance of the GADS was estimated using a leave-one-out cross-validation applied to a database of hour long recordings from 51 neonates. The median AUC was 1.00 (IQR: 0.95-1.00) for the detection of major artefacts and 0.89 (IQR: 0.83-0.95) for the detection of minor artefacts.

  16. Importancia de la Manometría Anorrectalen la Infancia

    Directory of Open Access Journals (Sweden)

    Daisy Naranjo Hernández

    1999-09-01

    Full Text Available RESUMEN Al registrar cambios de presión en órganos musculares huecos, el estudio manométrico anorrectal ha permitido llegar a conclusiones acerca del mecanismo de continencia anorrectal, la función esfinteriana y la sensación rectal. Se utilizó el método de catéteres perfundidos y balón intrarrectal para el estímulo por distensión. Se estudiaron 340 pacientes, 214 masculinos y 126 femeninos, con una edad promedio de 6,5 años. Se formaron 3 grupos: I. Constipación crónica, II. Crónica más encopresis y III. Incontinencia anal. Entre las variables manométricas que se estudiaron: presencia o no del reflejo rectoanal inhibitorio inducido (RRII, presión de reposo, longitud, tanto por ciento de relajación del mismo y volumen crítico capaz de desencadenar respuesta esfinteriana. Se realizó estudio de colon por enema y se halló mayor correlación entre megacolon radiográfico y el mayor porcentaje de ausencia manométrica del RRAI. El grupo II mostró mayor valor de presión basal del EAI con un menor tanto por ciento de relajación y un mayor número de casos con ausencia del RRAI. En el grupo III se obtuvo el valor más bajo de presión basal del EAI mayor por ciento de relajación y mayor número de casos con ausencia del EAI. Se demuestra la importancia del estudio en el manejo integral del niño con afecciones anorrectales, el que fue indispensable en el diagnóstico de la enfermedad de Hirschprung. Su empleo se recomienda en todos los servicios de Gastroenterología Pediátrica.On registering pressure changes in the muscular hollow organs, the anorectal manometric study has allowed to reach conclusions about the mechanism of anorectal continence, the sphincteral function and the anorectal sensation. The method of perfused catheters and intrarectal balloon was used to attain the stimulus by distention. 340 patients, 214 males and 126 females with an average age of 6.5 years old, were studied. Patients were divided into 3 groups

  17. Manometric and mass spectrometric analysis of fluids in geological materials

    Energy Technology Data Exchange (ETDEWEB)

    Jean-Louis, Zimmermann; Albert, Jambon; Gilbert, Guyetand

    1988-01-01

    It has been shown that the use of coupled manometric and mass spectrometric methods enables the analysis of volatile species from rocks with a very good accuracy. A separaton line using cold traps, oxidation (CO to CO/sub 2/) and reduction (H/sub 2/O to H/sub 2/) furnaces permits to separate several fractions. The detection limits are 0.5 to 1.x10/sup -7/ mol H/sub 2/O, 0.3x10/sup -7/ mol CO/sub 2/ and about 0.2x10/sup -7/ mol for H/sub 2/, N/sub 2/, CO, CH/sub 4/ and Ar. Conjunction of crushing, stepwise heating and size fraction analysis permit to distinguish between fluid inclusions, dissolved (trapped) gases and adsorbed gases. Analysis of organic matter is very difficult. Light species may be extracted by crushing as exemplified by the quartz analyses. Heavier non volatile species are decomposed when moderately heated, and destroyed when temperature exceeds 500/sup 0/C. H/sub 2/ and CO detected after thermal extraction when organic compounds are present in the sample reflect organic decomposition rather than any thermodynamic equilibrium attained upon rock formation. (4 figs, 3 tabs, 37 refs)

  18. Artefacts and the performance of an exhibition

    DEFF Research Database (Denmark)

    Svabo, Connie

    2008-01-01

    The article explores the role of mediating artefacts in children's encounters with a museum of natural history. Using actor network theory it explores how a specific artefact shapes the way users relate to exhibited objects and how the artefact guides users' movements in the exhibition. The media...

  19. Development of A MEMS Based Manometric Catheter for Diagnosis of Functional Swallowing Disorders

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, H Y [Centre for Advanced Manufacturing Research, University of South Australia, Adelaide (Australia); Hariz, A J [School of Electrical and Information Engineering, University of South Australia (Australia); Omari, T [Centre for Paediatric and Adolescent Gastroenterology, Women' s and Children' s Hospital, Adelaide (Australia); Teng, M F [Centre for Advanced Manufacturing Research, University of South Australia, Adelaide (Australia); Sii, D [Centre for Advanced Manufacturing Research, University of South Australia, Adelaide (Australia); Chan, S [Centre for Advanced Manufacturing Research, University of South Australia, Adelaide (Australia); Lau, L [Centre for Advanced Manufacturing Research, University of South Australia, Adelaide (Australia); Tan, S [Centre for Advanced Manufacturing Research, University of South Australia, Adelaide (Australia); Lin, G [Centre for Advanced Manufacturing Research, University of South Australia, Adelaide (Australia); Haskard, M [School of Electrical and Information Engineering, University of South Australia (Australia); Mulcahy, D; Bakewell, M [Centre for Paediatric and Adolescent Gastroenterology, Women' s and Children' s Hospital, Adelaide (Australia)

    2006-04-01

    Silicon pressure sensors based on micro-electro-mechanical-systems (MEMS) technologies are gaining popularity for applications in bio-medical devices. In this study, a silicon piezo-resistive pressure sensor die is used in a feasibility study of developing a manometric catheter for functional swallowing disorders diagnosis. The function of a manometric catheter is to measure the peak and intrabolus pressures along the esophageal segment during the swallowing action. Previous manometric catheters used the water perfusion technique to measure the pressure changes. This type of catheter is reusable, large in size and the pressure reading is recorded by an external transducer. Current manometric catheters use a solid state pressure sensor on the catheter itself to measure the pressure changes. This type of catheter reduces the discomfort to the patient but it is reusable and is very expensive. We carried out several studies and experiments on the MEMS-based pressure sensor die, and the results show the MEMS-based pressure sensors have a good stability and a good linearity output response, together with the advantage of low excitation biasing voltage and extremely small size. The MEMS-based sensor is the best device to use in the new generation of manometric catheters. The concept of the new MEMS-based manometric catheter consists of a pressure sensing sensor, supporting ring, the catheter tube and a data connector. Laboratory testing shows that the new calibrated catheter is capable of measuring pressure in the range from 0 to 100mmHg and maintaining stable condition on the zero baseline setting when no pressure is applied. In-vivo tests are carried out to compare the new MEMS based catheter with the current version of catheters used in the hospital.

  20. [ECG artefacts after electrode misplacements].

    Science.gov (United States)

    Thaler, T; Rudiger, A

    2009-01-07

    Artefacts due to electrode misplacement occur in 0.4 to 4% of all performed electrocardiograms (ECG). They can lead to the clinically important false diagnosis of myocardial ischemia. Lateral and inferior myocardial ischemia can be mimicked by an electrode exchange between right and left arm and between right arm and left leg, respectively. Misplaced anterior leads suggest damage of the anterior wall. ECG criteria proposed in this review article will help to identify such artefacts. They include abnormal QRS axis (-90 degrees to +180 degrees), positive P-waves in aVR, negative P-waves in I or II, low voltage in lead I, II or III as well as an irregular R-wave progression in V1 to V6.

  1. Radiocarbon dating of iron artefacts

    Energy Technology Data Exchange (ETDEWEB)

    Cresswell, R. [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics

    1997-12-31

    Iron artefacts are generally dated by association or on stylistic grounds. This may not give a true indication of the date of manufacture, or may not be possible if the piece is out of context, ambiguous in style, or a copy. Obtaining a direct date on the artefact would be preferable. During the processes of manufacture, carbon is incorporated into the iron from the fuel source. If the fuel is of a material containing contemporaneous carbon, i.e. has an ambient radiocarbon signature, e.g. charcoal, then we may reliably radiocarbon date the artefact by extracting this carbon. Care must be taken, however, to ensure that re-working has not introduced multiple sources of carbon that would give an erroneous date. Detailed chemical analysis must precede radiocarbon analysis. Sample size is determined by carbon content, and before the advent of accelerator mass spectrometry, several tens of grams of carbon were required for radiocarbon dating (van der Merwe, 1969), prohibiting this method except for high-carbon cast-irons and bulk samples, e.g. caches of nails. AMS permits the analysis of sub-gram pieces of iron (Cresswell, 1991), thereby permitting the analysis of museum pieces with only minimal loss of material, and small fragments of iron recovered from archaeological sites. A few examples are given to illustrate these points. Paper no. 41; Extended abstract. 6 refs.

  2. Transforming Artefacts into Digital Heritage

    DEFF Research Database (Denmark)

    Otto, Ton; Hardy, Dianna

    2016-01-01

    a genuine transformation of the artefacts that opens up new possibilities of use. These include providing access to and facilitating the reappropriation of cultural knowledge stored elsewhere, maintaining and developing a living digital cultural heritage, and gathering, sharing and transferring knowledge...... that is available within Aboriginal communities. In this paper we examine different types of digital repositories and we assess their suitability for use by Aboriginal communities. We classify a number of institutional archiving systems and analyse in some detail two interactive systems that were specifically...... designed for use by Aboriginal communities. The paper ends with a set of recommendations for designing digital databases for Indigenous usage....

  3. The proper use of artefacts : A philosophical theory of the social constitution of artefact functions

    NARCIS (Netherlands)

    Scheele, M.

    2005-01-01

    Artefacts are humanly designed objects with a function. Their proper function is what they are for. This book develops a theory of these functions on the basis of the idea that artefacts are used in a social context. Current theories of artefact functions are inadequate to deal with this special

  4. Role of stationary esophageal manometry in clinical practice: Manometric results in patients with gastroesophageal reflux, dysphagia or non-cardiac chest pain Papel de la manometría esofágica estacionaria en la práctica clínica: Resultados manométricos en pacientes con reflujo gastroesofágico, disfagia y dolor torácico no cardiaco

    Directory of Open Access Journals (Sweden)

    C. Ciriza de los Ríos

    2004-09-01

    Full Text Available The present study was carried out to evaluate the diagnostic usefulness of stationary esophageal manometry in 263 patients divided into three groups: 150 patients with reflux symptoms, 68 with dysphagia, and 45 with non-cardiac chest pain. Patients with endoscopic abnormalities were excluded. Standard manometry was performed following the station pull-through technique. In the group of patients with reflux symptoms 40.7% had a normal manometry and 57.3% had abnormalities, being the most frequent (43% hypotensive lower esophageal sphincter. In the dysphagia group, 20.6% of manometries were normal and 79.4% were abnormal, of which achalasia was the most frequent disorder (53.7%. In the case of non-cardiac chest pain, 42.2% of patients had a normal manometry and 57.8% an abnormal one, of which hypotensive lower esophageal sphincter was the most frequent abnormality. A significant higher proportion of manometric alterations were found in the dysphagia group compared to reflux symptoms and non-cardiac chest pain (p El presente estudio ha sido realizado para evaluar la utilidad diagnóstica de la manometría esofágica estacionaria en 263 pacientes divididos en 3 grupos: 150 pacientes con síntomas de reflujo gastroesofágico, 68 con disfagia y 45 con dolor torácico no cardiaco. Se excluyeron los pacientes con alteraciones endoscópicas. La manometría se realizó según la técnica de retirada estacionaria. Entre los pacientes con síntomas de reflujo gastroesofágico, el 40,7% tuvieron una manometría normal y el 57,3% presentaron alteraciones, siendo la presencia de un esfínter esofágico inferior hipotenso la alteración más frecuente (43%. En el grupo de disfagia, el 20,6% de las manometrías fueron normales y el 79,4% anormales, siendo la achalasia el trastorno motor más frecuente (53,7%. En el grupo con dolor torácico no cardiaco, el 42,2% de los pacientes tuvieron manometría normal y el 57,8% anormal, siendo esfínter esofágico inferior

  5. A short overview of MRI artefacts

    African Journals Online (AJOL)

    Enrique

    Abstract. Many different artefacts can occur during magnetic resonance imaging. (MRI), some affecting the diagnostic quality, while others may be confused with pathology. An artefact is a fea- ture appearing in an image that is not present in the original object. Arte- facts can be classified as patient- related, signal ...

  6. A short overview of MRI artefacts

    African Journals Online (AJOL)

    Enrique

    diffuse image noise (Fig. 1). Ghost image intensity increases with ampli- tude of movement and the signal intensity from the moving tissue. Several methods can be used to reduce motion artefacts, including patient immobilisation,1 cardiac and respiratory gating,2 signal suppression of the tissue causing the artefact,1.

  7. Manometric Biofeedback Effectiveness on Urinary Incontinence and Quality of Life: A Non-Randomized Control Trial

    Directory of Open Access Journals (Sweden)

    Marcos E Fernandez-Cuadros

    2017-04-01

    Full Text Available Objectives This study aimed at examining if a 6-session protocol of tonic-phasic exercises using manometric biofeedback (BFB is capable of improving quality of life (QoL and muscular strength in patients with urinary incontinence (UI. Methods A prospective quasi-experimental before-after study was performed on 31 patients with Urinary Incontinence (UI referred to the rehabilitation department of Santa Cristina’s University hospital, Madrid, Spain. The study was performed from January to December 2016. At initial evaluation, affiliation of data, predisposing factors, and type of UI were recorded. Patients were given lifestyle recommendations and international consultation on incontinence questionnaire short form (ICIQ-SF/ incontinence quality-of-life measure (I-QOL questionnaires/scales to be fulfilled at the beginning/end of treatment. Manometric evaluation was recorded at initial/final evaluation by MYOMED ® 932. Manometric-BFB protocol consisted of a 30-minute session of tonic/phasic exercises (15 minutes each, 2 times a week for up to 6 sessions, supervised by a physiotherapist. Results Mean age was 52 ± 12.1 years. Overall, 96.7% (n = 31 of the participants were females. Maximum and mean strength of pelvic floor contraction was 24 ± 17.72 and 4.9 ± 4.1 mmHg, and increased significantly after treatment to 35 ± 20.85 and 7.45 ± 4.92 mmHg (P < 0.01. The mean ICIQ-SF score was 9.13 ± 5.18 and decreased significantly to 6.13 ± 4.75 (P = 0.003. The mean I-QoL score increased significantly from 70.33 ± 22.12 to 81.25 ± 16.72 (P = 0.0017. The I-QoL Limiting Behaviour (LB-subscale raised from 68.38 ± 23.33 to 80 ± 16.56 (P = 0.0015; I-QoL Psychosocial Impact (PI-subscale increased from 77.43 ± 24.51 to 80 ± 17.47 (p = 0.0152; and I-QoL social embarrassment (SE-subscale incremented from 60.72 ± 22.37 to 74.37 ± 20.86 (P = 0.0007. Conclusions Manometric-BFB protocol is capable of decreasing UI and to improve QoL and manometric values

  8. Organisational learning is crystallised into artefacts

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege

    1996-01-01

    In this note I understand organisational learning in terms of manifest crystallisation of collective experience into artefacts, and I attempt to integrate an engineering and an emancipatory perspective. A Danish music festival serves as an example.......In this note I understand organisational learning in terms of manifest crystallisation of collective experience into artefacts, and I attempt to integrate an engineering and an emancipatory perspective. A Danish music festival serves as an example....

  9. An excluded diagnosis

    Directory of Open Access Journals (Sweden)

    Paolo Ghiringhelli

    2007-12-01

    Full Text Available We describe a 50-years-old patient with septic fever of unidentifiable source, following resection for rectal adenocarcinoma. He has been in treatment for sepsi two months before. Blood coltures, an accurate amanestic analysis and a transesophageal echocardiography were the major tools for the diagnosis of this disease. After the diagnosis of infective endocarditis had been excluded, antibiotic treatment (with teicoplanin and rifampicine was given for the presence of Staphylococcus epidermidis. The previous pacemaker system was removed and a DDD pacemaker was implanted.

  10. The manometric sorptomat—an innovative volumetric instrument for sorption measurements performed under isobaric conditions

    Science.gov (United States)

    Kudasik, Mateusz

    2016-03-01

    The present paper discusses the concept of measuring the process of sorption by means of the volumetric method, developed in such a way as to allow measurements performed under isobaric conditions. On the basis of the concept in question, a prototype of a sorption instrument was built: the manometric sorptomat. The paper provides a detailed description of the idea of the instrument, and of the way it works. In order to evaluate the usefulness of the device in sorption measurements carried out under laboratory conditions, comparative studies were conducted, during which the results of sorption measurements obtained with the developed instrument were compared with the results Mateusz obtained with a reference device. The objects of comparison were the sorption capacities of hard coal samples, calculated on the basis of the established courses of the methane sorption process. The results were regarded as compatible if the compared values fell within the range of the measurement uncertainty of the two devices. For the sake of the comparative studies, fifteen granular samples of hard coal—representing the 0.20-0.25 mm grain fraction and coming from various mines of the Upper Silesian Coal Basin—were used. After comparing the results obtained with the original manometric sorptomat with the results obtained with the gravimetric reference device, it was observed that the compatibility of measurements of sorption capacities was over 90%, based on the defined criterion of the measurement compatibility.

  11. Explicating the Sustainable Design of Technical Artefacts

    DEFF Research Database (Denmark)

    Vissonova, Karina

    2016-01-01

    afforded by the properties of artefacts. The study is a conceptual analysis and as such belongs to the field of epistemology of design. It offers three contributions to the design discipline: (1) a proposition of the definition of the sustainable design kind; (2) a proposition of the concept of technical......Sustainable design of technical artefacts is referred to as if it were a kind of design with some specific characteristics. However, in design research and practice alike, there appears to be a lack of shared conceptions of what such a design might entail. Furthermore, we have no clear grounds...... for evaluating what makes the sustainable design solutions permissible. The lack of shared conceptions is largely due to ambiguities associated with the notion of sustainability. In response to these challenges, the aim of my study is to offer a definition of sustainable design of technical artefacts. I argue...

  12. Being Included and Excluded

    DEFF Research Database (Denmark)

    Korzenevica, Marina

    2016-01-01

    Following the civil war of 1996–2006, there was a dramatic increase in the labor mobility of young men and the inclusion of young women in formal education, which led to the transformation of the political landscape of rural Nepal. Mobility and schooling represent a level of prestige that rural...... politics. It analyzes how formal education and mobility either challenge or reinforce traditional gendered norms which dictate a lowly position for young married women in the household and their absence from community politics. The article concludes that women are simultaneously excluded and included from...... people regard as a prerequisite for participating in local community politics. Based on a fieldwork in two villages of Panchthar district in eastern Nepal, this article explores how these changes strengthen or weaken women’s political agency and how this is reflected in their participation in community...

  13. Model output: fact or artefact?

    Science.gov (United States)

    Melsen, Lieke

    2015-04-01

    As a third-year PhD-student, I relatively recently entered the wonderful world of scientific Hydrology. A science that has many pillars that directly impact society, for example with the prediction of hydrological extremes (both floods and drought), climate change, applications in agriculture, nature conservation, drinking water supply, etcetera. Despite its demonstrable societal relevance, hydrology is often seen as a science between two stools. Like Klemeš (1986) stated: "By their academic background, hydrologists are foresters, geographers, electrical engineers, geologists, system analysts, physicists, mathematicians, botanists, and most often civil engineers." Sometimes it seems that the engineering genes are still present in current hydrological sciences, and this results in pragmatic rather than scientific approaches for some of the current problems and challenges we have in hydrology. Here, I refer to the uncertainty in hydrological modelling that is often neglected. For over thirty years, uncertainty in hydrological models has been extensively discussed and studied. But it is not difficult to find peer-reviewed articles in which it is implicitly assumed that model simulations represent the truth rather than a conceptualization of reality. For instance in trend studies, where data is extrapolated 100 years ahead. Of course one can use different forcing datasets to estimate the uncertainty of the input data, but how to prevent that the output is not a model artefact, caused by the model structure? Or how about impact studies, e.g. of a dam impacting river flow. Measurements are often available for the period after dam construction, so models are used to simulate river flow before dam construction. Both are compared in order to qualify the effect of the dam. But on what basis can we tell that the model tells us the truth? Model validation is common nowadays, but validation only (comparing observations with model output) is not sufficient to assume that a

  14. Freeze-drying process design by manometric temperature measurement: design of a smart freeze-dryer.

    Science.gov (United States)

    Tang, Xiaolin Charlie; Nail, Steven L; Pikal, Michael J

    2005-04-01

    To develop a procedure based on manometric temperature measurement (MTM) and an expert system for good practices in freeze drying that will allow development of an optimized freeze-drying process during a single laboratory freeze-drying experiment. Freeze drying was performed with a FTS Dura-Stop/Dura-Top freeze dryer with the manometric temperature measurement software installed. Five percent solutions of glycine, sucrose, or mannitol with 2 ml to 4 ml fill in 5 ml vials were used, with all vials loaded on one shelf. Details of freezing, optimization of chamber pressure, target product temperature, and some aspects of secondary drying are determined by the expert system algorithms. MTM measurements were used to select the optimum shelf temperature, to determine drying end points, and to evaluate residual moisture content in real-time. MTM measurements were made at 1 hour or half-hour intervals during primary drying and secondary drying, with a data collection frequency of 4 points per second. The improved MTM equations were fit to pressure-time data generated by the MTM procedure using Microcal Origin software to obtain product temperature and dry layer resistance. Using heat and mass transfer theory, the MTM results were used to evaluate mass and heat transfer rates and to estimate the shelf temperature required to maintain the target product temperature. MTM product dry layer resistance is accurate until about two-thirds of total primary drying time is over, and the MTM product temperature is normally accurate almost to the end of primary drying provided that effective thermal shielding is used in the freeze-drying process. The primary drying times can be accurately estimated from mass transfer rates calculated very early in the run, and we find the target product temperature can be achieved and maintained with only a few adjustments of shelf temperature. The freeze-dryer overload conditions can be estimated by calculation of heat/mass flow at the target product

  15. Artefacts: Minecraft meets Collaborative Interactive Evolution

    DEFF Research Database (Denmark)

    Patrascu, Cristinel; Risi, Sebastian

    2016-01-01

    does not only allow players to collaborate by building larger structures from evolved objects but also to continue evolution of others’ artefacts. Results from playtests on three different game iterations indicate that players generally enjoy playing the game and are able to discover a wide variety...

  16. Fitts' law as a design artefact

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege

    1994-01-01

    Fitts' law is described and discussed as an example of use of theory in human-computer interaction design. The dichotomy between academic theory and applied theory is rejected and replaced by a radical pragmatic notion of theories as design artefacts. Different roles of theory in design...

  17. Measuring femoral lesions despite CT metal artefacts : A cadaveric study

    NARCIS (Netherlands)

    Malan, D.F.; Botha, C.P.; Kraaij, G.; Joemai, R.M.S.; Van der Heide, H.J.L.; Nelissen, R.G.H.H.; Valstar, E.R.

    2011-01-01

    Objective Computed tomography is the modality of choice for measuring osteolysis but suffers from metal-induced artefacts obscuring periprosthetic tissues. Previous papers on metal artefact reduction (MAR) show qualitative improvements, but their algorithms have not found acceptance for clinical

  18. Investigating effects of different artefact types on motor imagery BCI

    DEFF Research Database (Denmark)

    Frølich, Laura; Winkler, Irene; Muller, Klaus-Robert

    2015-01-01

    Artefacts in recordings of the electroencephalogram (EEG) are a common problem in Brain-Computer Interfaces (BCIs). Artefacts make it difficult to calibrate from training sessions, resulting in low test performance, or lead to artificially high performance when unintentionally used for BCI control...... that muscle, but not ocular, artefacts adversely affect BCI performance when all 119 EEG channels are used. Artefacts have little influence when using 48 centrally located EEG channels in a configuration previously found to be optimal....

  19. Contextualising the Curriculum through Local Floodplain Artefacts at ...

    African Journals Online (AJOL)

    A collection of floodplain artefacts was prepared in readiness for display, and this article reports on how such artefacts can be used in localised curriculum work for teaching and learning purposes. The study used a participatory action approach in which school personnel participated in the collection of artefacts. It was found ...

  20. Artefact in forensic medicine: scrotal mummification.

    Science.gov (United States)

    Patel, F

    2003-12-01

    Misinterpretation of postmortem artefacts in forensic medical practice may result in a misdiagnosis of criminal activity. Forensic physicians at the scene can liaise with forensic pathologists and visit the mortuary in the company of the crime scene investigators or scenes-of-crime officers to ensure all relevant facts are identified. In this case a postmortem change created by partial dessication of the scrotal skin was misinterpreted as a suspicious injury.

  1. Computer Simulation of Multidimensional Archaeological Artefacts

    Directory of Open Access Journals (Sweden)

    Vera Moitinho de Almeida

    2012-11-01

    Our project focuses on the Neolithic lakeside site of La Draga (Banyoles, Catalonia. In this presentation we will begin by providing a clear overview of the major guidelines used to capture and process 3D digital data of several wooden artefacts. Then, we shall present the use of semi-automated relevant feature extractions. Finally, we intend to share preliminary computer simulation issues.

  2. Macular pseudohaemorrhage secondary to Allen Dot artefact.

    Science.gov (United States)

    Michaels, Luke; Alexander, Philip; Newsom, Richard

    2015-01-05

    A 34-year-old highly myopic (-11.00 D) woman presented to eye clinic with a 3 day history of right eye paracentral blurring. Visual acuities were 6/6 bilaterally. Clinical examination was normal. Fundus photography showed the classic appearance of a macular haemorrhage. This is a recognised complication of high myopia and would have accounted for the patient's symptoms. However, further photography showed that the haemorrhage seemed to 'jump' around the fundus and was even present in the fellow eye. The apparent haemorrhage was revealed to be an imaging artefact. The 'Allen Dot' is a 6 mm black mask incorporated into retinal cameras to reduce reflection. Rarely, in highly myopic eyes, optical artefact can result. To the best of our knowledge, we are the first in the literature to report artefacts from the Allen Dot masquerading as ophthalmic disease. This case re-iterates the importance of clinical examination, especially in high myopes, given the current trend towards virtual clinics. 2015 BMJ Publishing Group Ltd.

  3. Designing the e-Participation Artefact

    DEFF Research Database (Denmark)

    Sanford, Clive Carlton; Rose, Jeremy

    2008-01-01

    When e-participation is considered in the context of applied research, researchers support government institutions by enabling technology for citizens who participate in policy-making. Governments' e-participation agendas involve a variety of different design activities; for example, designing new...... administrative procedures, computer literacy programs, or creating new laws. Design science aids the creation and evaluation of artefacts that are intended to find solutions to identified problems in a rigorous way. We therefore characterise three different types of e-participation design activities...

  4. Optical artefact characterization and correction in volumetric scintillation dosimetry

    Science.gov (United States)

    Robertson, Daniel; Hui, Cheukkai; Archambault, Louis; Mohan, Radhe; Beddar, Sam

    2014-01-01

    The goals of this study were (1) to characterize the optical artefacts affecting measurement accuracy in a volumetric liquid scintillation detector, and (2) to develop methods to correct for these artefacts. The optical artefacts addressed were photon scattering, refraction, camera perspective, vignetting, lens distortion, the lens point spread function, stray radiation, and noise in the camera. These artefacts were evaluated by theoretical and experimental means, and specific correction strategies were developed for each artefact. The effectiveness of the correction methods was evaluated by comparing raw and corrected images of the scintillation light from proton pencil beams against validated Monte Carlo calculations. Blurring due to the lens and refraction at the scintillator tank-air interface were found to have the largest effect on the measured light distribution, and lens aberrations and vignetting were important primarily at the image edges. Photon scatter in the scintillator was not found to be a significant source of artefacts. The correction methods effectively mitigated the artefacts, increasing the average gamma analysis pass rate from 66% to 98% for gamma criteria of 2% dose difference and 2 mm distance to agreement. We conclude that optical artefacts cause clinically meaningful errors in the measured light distribution, and we have demonstrated effective strategies for correcting these optical artefacts. PMID:24321820

  5. 3D artefact for concurrent scale calibration in Computed Tomography

    DEFF Research Database (Denmark)

    Stolfi, Alessandro; De Chiffre, Leonardo

    2016-01-01

    A novel artefact for calibration of the scale in 3D X-ray Computed Tomography (CT) is presented. The artefact comprises a carbon fibre tubular structure on which a number of reference ruby spheres are glued. The artefact is positioned and scanned together with the workpiece inside the CT scanner...... providing a reference system for measurement. The artefact allows a considerable reduction of time by compressing the full process of calibration, scanning, measurement, and re-calibration, into a single process. The method allows a considerable reduction of the amount of data generated from CT scanning....... A prototype was calibrated and its applicability demonstrated....

  6. The impact of digital image processing artefacts mimicking pathological features associated with restorations.

    Science.gov (United States)

    Brettle, D; Carmichael, F

    2011-08-26

    Image processing of digital X-ray images is known to have the potential to produce artefacts that may mimic pathology. A study was conducted at a UK dental radiology conference to demonstrate this effect in dentistry. Sixteen digital X-rays of single teeth containing restorations were randomly presented in both unprocessed and processed formats to an auditorium of 42 participants. Participants interactively scored each image on a scale from 1-5 where 1 was definitely no pathology and 5 was definitely pathology. The display conditions were confirmed for each participant using a validated threshold contrast test. The results show that 52% (81/157) of responses at level 1 for the unprocessed images changed to levels 4 or 5 after image processing. This study illustrates the potential for image processing artefacts to mimic pathology particularly at high contrast boundaries and introduces the risk of unnecessary interventions. In order to minimise this risk, it is recommended that for digital radiographs containing pathology relating to high contrast boundaries, non-related high contrast features such as unrelated restorations or tooth/bone margins are also considered to exclude the possibility of artefact. If there is doubt, reference should be made to the unprocessed data.

  7. Re-scripting interactive artefacts with feminine values

    DEFF Research Database (Denmark)

    Rasmussen, Majken Kirkegaard; Petersen, Marianne Graves

    2012-01-01

    This paper takes up the challenge, of developing value-centred interaction design as an approach to avoiding stereotypic presumptions about femininity when designing artefacts. We suggest that utilizing a feminine value perspective to design artefacts can create a richer profusion of ways to view...

  8. Stone artefact production and exchange among the northern Lesser Antilles

    NARCIS (Netherlands)

    Knippenberg, Sebastiaan

    2006-01-01

    This work discusses the exchange of stone materials and artefacts among the northern Lesser Antilles during the Ceramic Age (500 BC - AD 1492). Through the systematic analysis of source materials and a comparison of these with lithic artefacts, the provenance of a significant portion of stone

  9. Deviations in delineated GTV caused by artefacts in 4DCT

    DEFF Research Database (Denmark)

    Persson, Gitte Fredberg; Nygaard, Ditte Eklund; Brink, Carsten

    2010-01-01

    Four-dimensional computed tomography (4DCT) is used for breathing-adapted radiotherapy planning. Irregular breathing, large tumour motion or interpolation of images can cause artefacts in the 4DCT. This study evaluates the impact of artefacts on gross tumour volume (GTV) size....

  10. Contextualising the Curriculum through local floodplain artefacts at ...

    African Journals Online (AJOL)

    of learners, teachers and community members through the use of floodplain artefacts. School managers could also draw .... because local communities, in collaboration with schools, can innovatively articulate issues in their surroundings for .... The genre (major family grouping of the artefact); and. • The vernacular language ...

  11. GIS as an Artefact in Geography Education: Some Future Challenges

    DEFF Research Database (Denmark)

    Madsen, Lene Møller; Winsløw, Carl

    2007-01-01

    can be used to inform our understanding of the actual and potential roles of GIS in the education of geographers. Our conclusion is that there is a need to recognise GIS as an artefact interwoven with the professional development of becoming a geographer and to start researching the challenges...... this artefact offers to education and teaching....

  12. Emergent Artefacts of Ethnography and Processual Engagements of design

    DEFF Research Database (Denmark)

    Wallace, Jamie

    2012-01-01

    Relating to processes of design and creativity, the use of artefacts are contrasted between two different disciplines. Pointing to possible challenges, the study considers how collaborative innovation depends upon the interplay between entwined and emergent artefact worlds and their related skill...

  13. Artefact specification, design, and production as a process of communication

    DEFF Research Database (Denmark)

    Galle, Per

    1999-01-01

    The co-operative process of specifying, designing, and producing an artefact is analysed in terms of communication among the agents involved. By way of introduction, I offer a brief analysis of communication in general, outlining conditions for its success, while avoiding simplistic assumptions...... for the success of communication carry over to the artefact production process. The purpose of the analysis is to provide a conceptual background for the study of various aspects of artefact production, such as design, or the development of computer-based tools for collaborative design, product modelling...... about communication as literal ‘transmission’ or ‘sharing’ of ideas. It is then explained how the initial artefact specification, the design representation, and ultimately the artefact itself can all be seen as symbolic expressions of ideas that are communicated, and it is shown how the conditions...

  14. The materiality of materials and artefacts used in science classrooms

    DEFF Research Database (Denmark)

    Cowie, Bronwen; Otrel-Cass, Kathrin; Moreland, Judy

    materials as natural objects in this world and artefacts as manmade objects. We are aware that in a classroom material objects and artefacts shape, and are shaped by classroom practice through the way they selectively present scientific explanations. However, materials and artefacts have no intrinsic...... and constrain forms of action and insights that are likely to “emerge” (Wells, 2003). Methods The study's teachers considered that students enjoy and benefit from “hands–on” learning activities and many commented that tasks and interactions incorporated the use of materials. These included material objects...... such as fossils, plant samples and artefacts like test tubes, worksheets and digital tools along with written inscriptions produced during interactions and that served as artefacts in subsequent interactions (Roehl, 2012). Data sources Data were generated via classroom observation using video, student work sample...

  15. Clinical learning environments: place, artefacts and rhythm.

    Science.gov (United States)

    Sheehan, Dale; Jowsey, Tanisha; Parwaiz, Mariam; Birch, Mark; Seaton, Philippa; Shaw, Susan; Duggan, Alison; Wilkinson, Tim

    2017-10-01

    Health care practitioners learn through experience in clinical environments in which supervision is a key component, but how that learning occurs outside the supervision relationship remains largely unknown. This study explores the environmental factors that inform and support workplace learning within a clinical environment. An observational study drawing on ethnographic methods was undertaken in a general medicine ward. Observers paid attention to interactions among staff members that involved potential teaching and learning moments that occurred and were visible in the course of routine work. General purpose thematic analysis of field notes was undertaken. A total of 376 observations were undertaken and documented. The findings suggest that place (location of interaction), rhythm (regularity of activities occurring in the ward) and artefacts (objects and equipment) were strong influences on the interactions and exchanges that occurred. Each of these themes had inherent tensions that could promote or inhibit engagement and therefore learning opportunities. Although many learning opportunities were available, not all were taken up or recognised by the participants. We describe and make explicit how the natural environment of a medical ward and flow of work through patient care contribute to the learning architecture, and how this creates or inhibits opportunities for learning. Awareness of learning opportunities was often tacit and not explicit for either supervisor or learner. We identify strategies through which tensions inherent within space, artefacts and the rhythms of work can be resolved and learning opportunities maximised. © 2017 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

  16. Filling defect artefacts in magnetic resonance urography

    Energy Technology Data Exchange (ETDEWEB)

    Girish, G.; Chooi, W.K.; Morcos, S.K. [Department of Diagnostic Imaging, Northern General Hospital, Sheffield Teaching Hospitals NHS Trust, S5 7AU, Sheffield (United Kingdom)

    2004-01-01

    The aim of this study was to determine the prevalence of filling defect artefacts (FDA) in magnetic resonance urography (MRU). Retrospectively, we assessed MRU examinations of 45 patients with neurogenic bladder dysfunction (21 men, 24 women; mean age 35 years, age range 18-71 years). The MRU was performed 30 min after intramuscular injection of 20 mg frusemide using heavily T2-weighted fast-spin-echo techniques [axial, thick coronal slab, coronal maximum intensity projection (MIP) images] with fat saturation. The images were reviewed by two observers to determine the presence of filling defects and dilatation of pelvicalyceal system and ureters. The filling defects were classified into central, eccentric and complete. Clinical course and plain films were reviewed to determine significance of the detected filling defects. True filling defects were observed in 5 patients (11%) and all due to stones seen on the plain radiograph of the abdomen. Filling defects artefacts (FDAs) were seen in 23 patients (51%; 17 pelvicalyceal system, 17 upper third of ureters, 7 mid ureters and 1 distal ureter). No stones were seen on the plain radiograph of these patients and they had a favourable clinical course for over 24 months. The true filling defects were large in size, eccentric in position and seen in more than one sequence of the MRU examination (axial, n=5; slab, n=5; and MIP, n=4). Four (80%) of the patients with true defects and 21 (91%) of those with FDAs had dilatation of the pelvicalyceal system and ureters. The FDAs were small in size, centrally placed (74%) and always seen in axial images, rarely in slab images (2 cases) and not seen in MIP images. Artefactual filling defects can be seen in MRU examinations. The cause of the FDAs is not fully explained and could be secondary to turbulent and fast flow of the urine. Some of the FDAs seen in the calyces could be due to the tips of the papillae. Awareness of such defects obviates misinterpretation and prevents

  17. Multiple height calibration artefact for 3D microscopy

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Carli, Lorenzo; Eriksen, Rasmus Solmer

    2011-01-01

    A novel artefact for calibration of the height in 3D microscopy is presented. The artefact comprises three steps having a common vertical axis, which allows z-coordinate calibration at different magnifications without requiring repositioning. The artefact is suitable for transferring traceability...... to 3D techniques at the micrometer and nanometer scale, e.g. 3D SEM, confocal microscopes etc. Two different series of samples were fabricated using EDM with three steps of 2–5–7μm, and 20–50–70μm, respectively, from a 3mm diameter carbide wire. The artefact steps were calibrated on a stylus instrument...... according to ISO 5436 and measured on 3D microscopes....

  18. Metal artefacts in MRI-guided brachytherapy of cervical cancer

    Directory of Open Access Journals (Sweden)

    Abraam S. Soliman

    2016-08-01

    Full Text Available The importance of assessing the metal-induced artefacts in magnetic resonance imaging (MRI-guided brachytherapy is growing along with the increasing interest of integrating MRI into the treatment procedure of cervical cancer. Examples of metal objects in use include intracavitary cervical applicators and interstitial needles. The induced artefacts increase the uncertainties in the clinical workflow and can be a potential obstacle for the accurate delivery of the treatment. Overcoming this problem necessitates a good understanding of its originating sources. Several efforts are recorded in the literature to quantify the extent of such artefacts, in phantoms and in clinical practice. Here, we elaborate on the origin of metal-induced artefacts in the light of brachytherapy applications, while summarizing recent efforts that have been made to assess and overcome the induced distortions.

  19. Pulmonary MRA: differentiation of pulmonary embolism from truncation artefact.

    Science.gov (United States)

    Bannas, Peter; Schiebler, Mark L; Motosugi, Utaroh; François, Christopher J; Reeder, Scott B; Nagle, Scott K

    2014-08-01

    Truncation artefact (Gibbs ringing) causes central signal drop within vessels in pulmonary magnetic resonance angiography (MRA) that can be mistaken for emboli, reducing diagnostic accuracy for pulmonary embolism (PE). We propose a quantitative approach to differentiate truncation artefact from PE. Twenty-eight patients who underwent pulmonary computed tomography angiography (CTA) for suspected PE were recruited for pulmonary MRA. Signal intensity drops within pulmonary arteries that persisted on both arterial-phase and delayed-phase MRA were identified. The percent signal loss between the vessel lumen and central drop was measured. CTA served as the reference standard for presence of pulmonary emboli. A total of 65 signal intensity drops were identified on MRA. Of these, 48 (74%) were artefacts and 17 (26%) were PE, as confirmed by CTA. Truncation artefacts had a significantly lower median signal drop than PE on both arterial-phase (26% [range 12-58%] vs. 85% [range 53-91%]) and delayed-phase MRA (26% [range 11-55%] vs. 77% [range 47-89%]), p < 0.0001 for both. Receiver operating characteristic (ROC) analyses revealed a threshold value of 51% (arterial phase) and 47% signal drop (delayed phase) to differentiate between truncation artefact and PE with 100% sensitivity and greater than 90% specificity. Quantitative signal drop is an objective tool to help differentiate truncation artefact and pulmonary embolism in pulmonary MRA. • Inexperienced readers may mistake truncation artefacts for emboli on pulmonary MRA • Pulmonary emboli have non-uniform signal drop • 51% (arterial phase) and 47% (delayed phase) cut-off differentiates truncation artefact from PE • Quantitative signal drop measurement enables more accurate pulmonary embolism diagnosis with MRA.

  20. Computed tomographic beam-hardening artefacts: mathematical characterization and analysis.

    Science.gov (United States)

    Park, Hyoung Suk; Chung, Yong Eun; Seo, Jin Keun

    2015-06-13

    This paper presents a mathematical characterization and analysis of beam-hardening artefacts in X-ray computed tomography (CT). In the field of dental and medical radiography, metal artefact reduction in CT is becoming increasingly important as artificial prostheses and metallic implants become more widespread in ageing populations. Metal artefacts are mainly caused by the beam-hardening of polychromatic X-ray photon beams, which causes mismatch between the actual sinogram data and the data model being the Radon transform of the unknown attenuation distribution in the CT reconstruction algorithm. We investigate the beam-hardening factor through a mathematical analysis of the discrepancy between the data and the Radon transform of the attenuation distribution at a fixed energy level. Separation of cupping artefacts from beam-hardening artefacts allows causes and effects of streaking artefacts to be analysed. Various computer simulations and experiments are performed to support our mathematical analysis. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  1. Pulmonary MRA: Differentiation of pulmonary embolism from truncation artefact

    Energy Technology Data Exchange (ETDEWEB)

    Bannas, Peter [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University Hospital Hamburg-Eppendorf, Department of Radiology, Hamburg (Germany); Schiebler, Mark L.; Motosugi, Utaroh; Francois, Christopher J. [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); Reeder, Scott B. [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin-Madison, Department of Biomedical Engineering, Madison, WI (United States); University of Wisconsin-Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin-Madison, Department of Medicine, Madison, WI (United States); Nagle, Scott K. [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin-Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin-Madison, Department of Pediatrics, Madison, WI (United States)

    2014-08-15

    Truncation artefact (Gibbs ringing) causes central signal drop within vessels in pulmonary magnetic resonance angiography (MRA) that can be mistaken for emboli, reducing diagnostic accuracy for pulmonary embolism (PE). We propose a quantitative approach to differentiate truncation artefact from PE. Twenty-eight patients who underwent pulmonary computed tomography angiography (CTA) for suspected PE were recruited for pulmonary MRA. Signal intensity drops within pulmonary arteries that persisted on both arterial-phase and delayed-phase MRA were identified. The percent signal loss between the vessel lumen and central drop was measured. CTA served as the reference standard for presence of pulmonary emboli. A total of 65 signal intensity drops were identified on MRA. Of these, 48 (74 %) were artefacts and 17 (26 %) were PE, as confirmed by CTA. Truncation artefacts had a significantly lower median signal drop than PE on both arterial-phase (26 % [range 12-58 %] vs. 85 % [range 53-91 %]) and delayed-phase MRA (26 % [range 11-55 %] vs. 77 % [range 47-89 %]), p < 0.0001 for both. Receiver operating characteristic (ROC) analyses revealed a threshold value of 51 % (arterial phase) and 47 % signal drop (delayed phase) to differentiate between truncation artefact and PE with 100 % sensitivity and greater than 90 % specificity. Quantitative signal drop is an objective tool to help differentiate truncation artefact and pulmonary embolism in pulmonary MRA. (orig.)

  2. Measuring femoral lesions despite CT metal artefacts: a cadaveric study

    Energy Technology Data Exchange (ETDEWEB)

    Malan, Daniel F. [Leiden University Medical Center, Department of Orthopaedics, Leiden (Netherlands); Delft University of Technology, Department of Mediamatics, EEMCS, P.O. Box 5031, Delft (Netherlands); Botha, Charl P. [Delft University of Technology, Department of Mediamatics, EEMCS, P.O. Box 5031, Delft (Netherlands); Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Kraaij, Gert; Heide, Huub J.L. van der; Nelissen, Rob G.H.H. [Leiden University Medical Center, Department of Orthopaedics, Leiden (Netherlands); Joemai, Raoul M.S. [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Valstar, Edward R. [Leiden University Medical Center, Department of Orthopaedics, Leiden (Netherlands); Delft University of Technology, Department of Biomechanical Engineering, Delft (Netherlands)

    2012-05-15

    Computed tomography is the modality of choice for measuring osteolysis but suffers from metal-induced artefacts obscuring periprosthetic tissues. Previous papers on metal artefact reduction (MAR) show qualitative improvements, but their algorithms have not found acceptance for clinical applications. We investigated to what extent metal artefacts interfere with the segmentation of lesions adjacent to a metal femoral implant and whether metal artefact reduction improves the manual segmentation of such lesions. We manually created 27 periprosthetic lesions in 10 human cadaver femora. We filled the lesions with a fibrotic interface tissue substitute. Each femur was fitted with a polished tapered cobalt-chrome prosthesis and imaged twice - once with the metal, and once with a substitute resin prosthesis inserted. Metal-affected CTs were processed using standard back-projection as well as projection interpolation (PI) MAR. Two experienced users segmented all lesions and compared segmentation accuracy. We achieved accurate delineation of periprosthetic lesions in the metal-free images. The presence of a metal implant led us to underestimate lesion volume and introduced geometrical errors in segmentation boundaries. Although PI MAR reduced streak artefacts, it led to greater underestimation of lesion volume and greater geometrical errors than without its application. CT metal artefacts impair image segmentation. PI MAR can improve subjective image appearance but causes loss of detail and lower image contrast adjacent to prostheses. Our experiments showed that PI MAR is counterproductive for manual segmentation of periprosthetic lesions and should be used with care. (orig.)

  3. Assessing MRI susceptibility artefact through an indicator of image distortion

    Directory of Open Access Journals (Sweden)

    Illanes Alfredo

    2016-09-01

    Full Text Available Susceptibility artefacts in magnetic resonance imaging (MRI caused by medical devices can result in a severe degradation of the MR image quality. The quantification of susceptibility artefacts is regulated by the ASTM standard which defines a manual method to assess the size of an artefact. This means that the estimated artefact size can be user dependent. To cope with this problem, we propose an algorithm to automatically quantify the size of such susceptibility artefacts. The algorithm is based on the analysis of a 3D surface generated from the 2D MR images. The results obtained by the automatic algorithm were compared to the manual measurements performed by study participants. The results show that the automatic and manual measurements follow the same trend. The clear advantage of the automated algorithm is the absence of the inter- and intra-observer variability. In addition, the algorithm also detects the slice containing the largest artefact which was not the case for the manual measurements.

  4. Artefact formation during acid hydrolysis of saponins from Medicago spp.

    Science.gov (United States)

    Tava, Aldo; Biazzi, Elisa; Mella, Mariella; Quadrelli, Paolo; Avato, Pinarosa

    2017-06-01

    Artefact compounds obtained during acid hydrolysis of saponins from Medicago spp. (Fabaceae), have been monitored and evaluated by GC-FID. Their identification has been performed by GC-MS and 1H and 13C NMR. Saponins with different substituents on the triterpenic pentacyclic aglycones were considered, and their hydrolysis products were detected and quantified during 10 h of time course reaction. From soyasapogenol B glycoside the well known soyasapogenols B, C, D and F were obtained together with a previously undescribed sapogenol artefact identified as 3β,22β,24-trihydroxyolean-18(19)-en and named soyasapogenol H. From a zanhic acid saponin two major artefact compounds identified as 2β,3β,16α-trihydroxyolean-13(18)-en-23,28-dioic acid and 2β,3β,16α-trihydroxyolean-28,13β-olide-23-oic acid were obtained, together with some zanhic acid. Other compounds, detected in very small amount in the reaction mixture, were also tentatively identified based on their GC-MS and UV spectra. The other most characteristic saponins in Medicago spp., hederagenin, bayogenin and medicagenic acid glycosides, under acidic condition of hydrolysis, released instead the correspondent aglycones and generated a negligible amount of artefacts. Nature of artefacts and mechanism of their formation, involving a stable tertiary carbocation, is here proposed and discussed for the first time. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Excluding interlopers from asteroid families

    Science.gov (United States)

    Novakovic, B.; Radovic, V.

    2014-07-01

    from AstDys database. Next, all family members that do not meet adopted criteria (based on physical and spectral characteristics) are excluded from the initial catalogue. Finally, the HCM analysis is performed again using the improved catalogue. Results: We apply this approach to the Themis family. In the first step the HCM links 3061 asteroids to the family. Among them we identify 113 potential interlopers. After removing interlopers, in the second run of the HCM, the total number of members has decreased to 2847. Thus, 101 extra objects have been excluded from the membership list (see Figure).

  6. Mapping SOA Artefacts onto an Enterprise Reference Architecture Framework

    Science.gov (United States)

    Noran, Ovidiu

    Currently, there is still no common agreement on the service-Oriented architecture (SOA) definition, or the types and meaning of the artefacts involved in the creation and maintenance of an SOA. Furthermore, the SOA image shift from an infrastructure solution to a business-wide change project may have promoted a perception that SOA is a parallel initiative, a competitor and perhaps a successor of enterprise architecture (EA). This chapter attempts to map several typical SOA artefacts onto an enterprise reference framework commonly used in EA. This is done in order to show that the EA framework can express and structure most of the SOA artefacts and therefore, a framework for SOA could in fact be derived from an EA framework with the ensuing SOA-EA integration benefits.

  7. Deviations in delineated GTV caused by artefacts in 4DCT

    DEFF Research Database (Denmark)

    Persson, Gitte Fredberg; Nygaard, Ditte Eklund; Brink, Carsten

    2010-01-01

    BACKGROUND AND PURPOSE: Four-dimensional computed tomography (4DCT) is used for breathing-adapted radiotherapy planning. Irregular breathing, large tumour motion or interpolation of images can cause artefacts in the 4DCT. This study evaluates the impact of artefacts on gross tumour volume (GTV......-expiration GTV size (GTVexp) was considered as reference for GTV size. Intra-session delineation error was estimated by re-delineation of GTV in eight of the 4DCT scans. RESULTS: In 16 of the 4DCT scans the maximum deviations from GTVexp were larger than could be explained by delineation error. The deviations...... in GTV size throughout the 4DCT scans. Awareness of the error introduced by artefacts is important especially if radiotherapy planning is based on a single 4DCT bin....

  8. Augmenting Everyday Artefacts to Support Social Interaction Among Senior Peers

    DEFF Research Database (Denmark)

    Nazzi, Elena; Sokoler, Tomas

    2015-01-01

    Novel technological possibilities emerge when tangible and social computing come together. This paper explores the potential of such technology when designing for seniors and their social interaction. Our research is guided by the concept of twitterIDo, which is to make seniors’ everyday activities...... more visible by augmenting everyday artefacts to communicate the ongoing activity they are used for. We engaged a local community of seniors in a living lab to explore the possibilities of twitterIDo in real life situations. This paper presents a series of interactive prototypes of everyday artefacts...... and displays designed to start a dialogue with the seniors on how twitterIDo-technology may fit into their everyday situations. Our findings point out how augmented everyday artefacts can make a positive difference when designing technology in a domain such the one of seniors’ and their social interaction...

  9. Fish scale artefact on an intraoral imaging receptor.

    Science.gov (United States)

    Buchanan, Allison; Morales, Carla; Looney, Stephen; Kalathingal, Sajitha

    2017-12-01

    To describe an artefact, termed the fish scale artefact, present on an intraoral imaging receptor. Thirty brand new DIGORA Optime photostimulable phosphor (PSP) plates (Soredex/Orion Corp., Helsinki, Finland) were imaged using the dental digital quality assurance radiographic phantom (Dental Imaging Consultants LLC, San Antonio, TX). All PSP plates were scanned at the same spatial resolution (dpi) using the high resolution mode. Two evaluators assessed all 30 plates. Each evaluator assessed the 30 PSP plates separately for purposes of establishing interrater reliability, and then together in order to obtain the gold standard result. The fish scale artefact was detected on 46.7% of the PSP plates. The kappa coefficient for interrater reliability was 0.86 [95% CI (0.69-1.00)], indicating excellent interrater reliability. For Evaluator 1, sensitivity was 0.85 [95% CI (0.55-0.98)]; specificity was 0.94 [CI (0.71-1.00)] and overall accuracy was 0.90 [95% CI (0.73-0.98)]. For Evaluator 2, sensitivity was 1.00 [95% CI (0.75-1.00)]; specificity was 0.94 [CI (0.71-1.00)] and overall accuracy was 0.97 [95% CI (0.83-1.00)]. These results indicate excellent agreement with the gold standard for both evaluators. Utilizing a comprehensive quality assurance protocol, we identified a fish scale artefact inherent to the image receptor. Additional research is needed to determine if the artefact remains static over time or if it increases over time. Likewise, research to determine the potential sources contributing to an increase in the artefact is needed.

  10. Sustainable Interactions: Studies in the Design of Energy Awareness Artefacts

    Energy Technology Data Exchange (ETDEWEB)

    Broms, Loove

    2011-07-01

    This thesis presents a collection of experimental designs that approach the problem of growing electricity consumption in homes. From the perspective of design, the intention has been to critically explore the design space of energy awareness artefacts to reinstate awareness of energy use in everyday practice. The design experiments were used as vehicles for thinking about the relationship between physical form, interaction, and social practice. The rationale behind the concepts was based on a small-scale ethnography, situated interviews, and design experience. Moreover, the thesis compares designer intention and actual user experiences of a prototype that was installed in nine homes in a residential area in Stockholm for three months. This was done in order to elicit tacit knowledge about how the concept was used in real-world domestic settings, to challenge everyday routines, and to enable both users and designers to critically reflect on artefacts and practices. From a design perspective, contributions include design approaches to communicating energy use: visualizations for showing relationships between behaviour and electricity consumption, shapes and forms to direct action, means for turning restrictions caused by energy conservation into central parts of the product experience, and ways to promote sustainable behaviour with positive driving forces based on user lifestyles. The general results indicate that inclusion is of great importance when designing energy awareness artefacts; all members of the household should be able to access, interact with, and reflect on their energy use. Therefore, design-related aspects such as placement and visibility, as well as how the artefact might affect the social interactions in the home, become central. Additionally, the thesis argues that these types of artefacts can potentially create awareness accompanied by negative results such as stress. A challenge for the designer is to create artefacts that communicate and

  11. Indigenous african artefacts: Can they serve as tangible programming objects?

    CSIR Research Space (South Africa)

    Smith, Adrew C

    2010-05-01

    Full Text Available to be found at markets and shops are purposefully made for the tourist, often artificially aged to increase its monetary value. This can be explained as follows: To most Africans a new object has the most spiritual power, and it is for this reason... that when a new artefact is offered on the market it was probably made, not for actual use but, for the tourist. The tourist attaches more value to an object which has actually been used and would prefer to purchase a thoroughly used artefact. Those who...

  12. Metal artefact reduction for accurate tumour delineation in radiotherapy

    DEFF Research Database (Denmark)

    Kovacs, David Gergely; Rechner, Laura A.; Appelt, Ane L.

    2017-01-01

    Background and purpose: Two techniques for metal artefact reduction for computed tomography were studied in order to identify their impact on tumour delineation in radiotherapy. Materials and methods: Using specially designed phantoms containing metal implants (dental, spine and hip) as well...

  13. Persuasiveness, Personalization & Productive Workplace Practices with IT-Knowledge Artefacts

    DEFF Research Database (Denmark)

    Fischer, Louise Harder; Pries-Heje, Lene

    2016-01-01

    work. We see a possible way forward for improving workplace practices with IT-knowledge artefact based applications, by combining new insight of how different personality traits prefer different knowledge sharing processes with new insight on personalizing persuasive technology. We explore new research...

  14. On the Systematic Conformance Check of Software Artefacts

    NARCIS (Netherlands)

    van Dijk, H.W.; Graaf, Bas; Boerman, Rob; Morrison, R.; Oquendo, F.

    In this paper we present a systematic check of the conformance of the implemented and the intended software architecture. Nowadays industry is confronted with rapidly evolving embedded systems. In order to effectively reuse design artefacts such as requirements, architectural views and analysis, as

  15. Simulated field maps for susceptibility artefact correction in interventional MRI.

    Science.gov (United States)

    Kochan, Martin; Daga, Pankaj; Burgos, Ninon; White, Mark; Cardoso, M Jorge; Mancini, Laura; Winston, Gavin P; McEvoy, Andrew W; Thornton, John; Yousry, Tarek; Duncan, John S; Stoyanov, Danail; Ourselin, Sébastien

    2015-09-01

    Intraoperative MRI (iMRI) is a powerful modality for acquiring images of the brain to facilitate precise image-guided neurosurgery. Diffusion-weighted MRI (DW-MRI) provides critical information about location, orientation and structure of nerve fibre tracts, but suffers from the "susceptibility artefact" stemming from magnetic field perturbations due to the step change in magnetic susceptibility at air-tissue boundaries in the head. An existing approach to correcting the artefact is to acquire a field map by means of an additional MRI scan. However, to recover true field maps from the acquired field maps near air-tissue boundaries is challenging, and acquired field maps are unavailable in historical MRI data sets. This paper reports a detailed account of our method to simulate field maps from structural MRI scans that was first presented at IPCAI 2014 and provides a thorough experimental and analysis section to quantitatively validate our technique. We perform automatic air-tissue segmentation of intraoperative MRI scans, feed the segmentation into a field map simulation step and apply the acquired and the simulated field maps to correct DW-MRI data sets. We report results for 12 patient data sets acquired during anterior temporal lobe resection surgery for the surgical management of focal epilepsy. We find a close agreement between acquired and simulated field maps and observe a statistically significant reduction in the susceptibility artefact in DW-MRI data sets corrected using simulated field maps in the vicinity of the resection. The artefact reduction obtained using acquired field maps remains better than that using the simulated field maps in all evaluated regions of the brain. The proposed simulated field maps facilitate susceptibility artefact reduction near the resection. Accurate air-tissue segmentation is key to achieving accurate simulation. The proposed simulation approach is adaptable to different iMRI and neurosurgical applications.

  16. Leadership identity:using artefacts (and storytelling) to discover new insights.

    OpenAIRE

    Watton, Emma Louisa; Parry, Ken

    2016-01-01

    Artefacts are used in management education to reflect upon the experiences of participants. Story-telling has a leadership influence that is long recognised in the leadership literature. However, artefacts and story-telling have not been used concurrently in leadership and management development programmes. We used artefacts combined with story-telling to help participants understand their leadership identity. Louisa’s story and artefact are the basis of this research. We found that the story...

  17. Replica calibration artefacts for optical 3D scanning of micro parts

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Carmignato, S.; Cantatore, Angela

    2009-01-01

    This work deals with development of calibration artefacts produced by using hard replica materials, achieving high quality geometrical reproduction of suitable reference artefacts, high stability, and high surface cooperativeness. An investigation was carried out using a replica material for dental...... applications to reproduce the geometry of a step artefact, a miniature step gauge, and a curve standard for optical measuring machines. The replica artefacts were calibrated using a tactile coordinate measuring machine and measured on two different optical scanners. Replication quality and applicability...

  18. ECG movement artefacts can be greatly reduced with the aid of a movement absorbing device

    DEFF Research Database (Denmark)

    Harrison, Adrian Paul; Wandall, Kirsten; Thorball, Jørgen

    2007-01-01

    movement artefacts, were measured on a healthy human subject. Results show a greatly improved stability of the ECG signal recorded using an electrode holder capable of absorbing movement artefacts during periods of lead disturbance, and highlight the movement artefacts that develop when the recording lead...

  19. Quantitative image analysis for the detection of motion artefacts in coronary artery computed tomography

    NARCIS (Netherlands)

    Kristanto, Wisnumurti; van Ooijen, Peter M.; Dikkers, Riksta; Greuter, Marcel J.; Zijlstra, Felix; Oudkerk, Matthijs

    Multi detector-row CT (MDCT), the current preferred method for coronary artery disease assessment, is still affected by motion artefacts. To rule out motion artefacts, qualitative image analysis is usually performed. Our study aimed to develop a quantitative image analysis for motion artefacts

  20. Influence of software product management maturity on usage of artefacts in agile software development

    NARCIS (Netherlands)

    Wagenaar, G.; Overbeek, S.J.; Lucassen, G.G.; Brinkkemper, S.; Schneider, K.

    2017-01-01

    Context: Agile software development (ASD) uses ‘agile’ artefacts such as user stories and product backlogs as well as ‘non-agile’ artefacts, for instance designs and test plans. Rationales for incorporating especially non-agile artefacts by an agile team mainly remain unknown territory. Goal: We

  1. Use of manometric temperature measurements (MTM) to characterize the freeze-drying behavior of amorphous protein formulations.

    Science.gov (United States)

    Johnson, Robert E; Oldroyd, Megan E; Ahmed, Saleem S; Gieseler, Henning; Lewis, Lavinia M

    2010-06-01

    The freeze-drying behavior and cake morphology of a model protein in an amorphous formulation were studied at varying protein concentrations using conservative (-25 degrees C) and aggressive (+25 degrees C) shelf temperatures at constant chamber pressure during primary drying. The two cycles were characterized by manometric temperature measurements (MTM) in a SMART freeze dryer that estimates the sublimation rate (dm/dt), product temperature at the freeze-drying front (T(p-MTM)) and product resistance (R(p)) during a run. The calculated sublimation rates (dm/dt) were 3-4 times faster in the aggressive cycle compared to the conservative cycle. For conservatively dried cakes R(p) increased with both dry layer thickness and protein concentration. For aggressively dried cakes (where freeze-drying occurs at the edge of microcollapse), R(p) also increased with protein concentration but was independent of the dry layer thickness. The sublimation rate was influenced by R(p), dry layer thickness and T(p-MTM) in the conservative cycle, but was governed mainly by T(p-MTM) in the aggressive cycle, where R(p) is independent of the dry layer thickness. The aggressively dried cakes had a more open and porous structure compared to their conservatively dried counterparts. (c) 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  2. Effect of sacral magnetic stimulation on the anorectal manometric activity: a new modality for examining sacro-rectoanal interaction.

    Science.gov (United States)

    Kubota, Masayuki; Okuyama, Naoki; Hirayama, Yutaka; Kobayashi, Kumiko; Satoh, Kanako

    2007-08-01

    We examined the interaction between the sacral neural system and the anorectal activity using a technique comprising repetitive magnetic stimulation. Thirteen control children without any bowel dysmotility (age range; 3 month old to 15 year old), 20 patients with chronic constipation (1 month old to 14 year old), and nine pre-operative patients with Hirschsprung's disease (1 month old to 6 year old) were examined. Magnetic stimulation was applied at the S3 level using the MagPro (Medtronic) device while simultaneously performing manometric recordings of the anorectal activity. In the 13 controls and the 20 patients with chronic constipation, the rectoanal reflex was demonstrated by balloon rectal dilatation. The sphincter response to magnetic stimulation was biphasic in the controls, consisting of an initial rise followed by a decrease in the sphincter pressure, while it varied among the patients with chronic constipation including a biphasic response in 16 patients, no response in three patients, and only a transient rise in pressure in one patient. In nine pre-operative patients with Hirschsprung's disease, no rectoanal reflex was observed, however, the sphincter pressure increased due to magnetic stimulation in six patients, while three patients exhibited no recordable responses. These results suggest that the repetitive magnetic stimulation technique is a valuable modality for investigating the neural interaction between the sacral nervous system and the anorectum.

  3. Analysis artefacts of the INS-IGF2 fusion transcript

    DEFF Research Database (Denmark)

    Wernersson, Rasmus; Frogne, Thomas; Rescan, Claude

    2015-01-01

    Background: In gene expression analysis, overlapping genes, splice variants, and fusion transcripts are potential sources of data analysis artefacts, depending on how the observed intensity is assigned to one, or more genes. We here exemplify this by an in-depth analysis of the INS-IGF2 fusion...... proteomics analysis we could not demonstrate INS-IGF2 protein in samples of human islets nor in EndoC-βH1. Conclusions: Sequence features, such as fusion transcripts spanning multiple genes can lead to unexpected results in gene expression analysis, and care must be taken in generating and interpreting...... is >20,000 fold lower than INS in human beta cells, and we suggest an explanation to the nature of the artefacts which have previously led to overestimation of the gene expression level in selected studies. We reinvestigated the previous reported findings of detection of INS-IGF2 using antibodies both...

  4. Investigation on a Roman copper alloy artefact from Pompeii (Italy).

    Science.gov (United States)

    Baraldi, Pietro; Baraldi, Cecilia; Ferrari, Giorgia; Foca, Giorgia; Marchetti, Andrea; Tassi, Lorenzo

    2006-01-01

    A selection of samples, obtained from a particular copper-alloy domestic artefact of Roman style from Pompeii, has been analysed by using different techniques (IR, Raman, SEM-EDX, FAAS), in order to investigate the chemical nature and composition of the metals utilised for such manufacturing pieces. The surface analysis of the bright red metallic microfragments conducted by different analytical techniques, emphasises the presence of pure unalloyed copper and confirms the absence of other metallic species on the upper layers. On the contrary, the mapping analysis of the section of the laminar metal of the investigated sample shows a consistent enrichment in tin content. Finally, destructive analysis by FAAS confirms that the artefact looks like a bronze metal alloy, with a medium Sn content of about 6.5%.

  5. Stratigraphy, artefact industries and hominid associations for Sterkfontein, member 5.

    Science.gov (United States)

    Kuman, K; Clarke, R J

    2000-06-01

    A revised stratigraphy for the early hominid site of Sterkfontein (Gauteng Province, South Africa) reveals a complex distribution of infills in the main excavation area between 2.8 and 1.4 m.y.a, as well as deposits dating to the mid to late Pleistocene. New research now shows that the Member 4 australopithecine breccia (2.8-2.6 Ma) extends further west than was previously thought, while a late phase of Member 4 is recognized in a southern area. The artefact-bearing breccias were defined sedimentologically as Member 5, but one supposed part of these younger breccias, the StW 53 infill, lacks in situ stone tools, although it does appear to post-date 2.6 Ma when artefacts first appear in the archaeological record. The StW 53 hominid, previously referred to Homo habilis, is here argued to be Australopithecus. The first artefact-bearing breccia of Member 5 is the Oldowan Infill, estimated at 2-1.7 Ma. It occupies a restricted distribution in Member 5 east and contains an expedient, flake-based tool industry associated with a few fossils of Paranthropos robustus. An enlarged cave opening subsequently admitted one or more Early Acheulean infills associated in Member 5 west with Homo ergaster. The artefacts attest to a larger site accumulation between ca. 1.7 and 1.4 Ma, with more intensive use of quartzite over quartz and a subtle but important shift to large flakes and heavier-duty tools. The available information on palaeoenvironments is summarized, showing an overall change from tropical to sub-tropical gallery forest, forest fringe and woodland conditions in Member 4 to more open woodland and grassland habitats in the later units, but with suggestions of a wet localized topography in the Paranthropus -bearing Oldowan Infill. Copyright 2000 Academic Press.

  6. 7 CFR 58.137 - Excluded milk.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Excluded milk. 58.137 Section 58.137 Agriculture... Milk § 58.137 Excluded milk. A plant shall not accept milk from a producer if: (a) The milk has been in...) Three of the last five milk samples have exceeded the maximum bacterial estimate of 500,000 per ml...

  7. Removing Ocular Movement Artefacts by a Joint Smoothened Subspace Estimator

    Directory of Open Access Journals (Sweden)

    Ronald Phlypo

    2007-01-01

    Full Text Available To cope with the severe masking of background cerebral activity in the electroencephalogram (EEG by ocular movement artefacts, we present a method which combines lower-order, short-term and higher-order, long-term statistics. The joint smoothened subspace estimator (JSSE calculates the joint information in both statistical models, subject to the constraint that the resulting estimated source should be sufficiently smooth in the time domain (i.e., has a large autocorrelation or self predictive power. It is shown that the JSSE is able to estimate a component from simulated data that is superior with respect to methodological artefact suppression to those of FastICA, SOBI, pSVD, or JADE/COM1 algorithms used for blind source separation (BSS. Interference and distortion suppression are of comparable order when compared with the above-mentioned methods. Results on patient data demonstrate that the method is able to suppress blinking and saccade artefacts in a fully automated way.

  8. Clinical and manometric evaluation of women with chronic anal fissure before and after internal subcutaneous lateral sphincterotomy

    Directory of Open Access Journals (Sweden)

    Silvana Marques e Silva

    2012-06-01

    Full Text Available OBJECTIVE: To evaluate clinical and manometric parameters of chronic anal fissure females undergoing lateral internal sphincterotomy (LIS. METHODS: A total of eight women with chronic anal fissure who underwent LIS were included in this study. The preoperative assessment was performed one week before surgery and included general and anorectal examination, anorectal manometry, and Jorge Wexner questionnaire. The post operative follow up was made every 15 days until complete healing. Jorge Wexner questionnaires and anorectal manometry were repeated at 1 month and 3 months after the surgery. Time to healing, manometric changes and complications were assessed. RESULTS: All patients had preoperative increased anal resting pressure. The resting pressures and anal canal length were significantly decreased 3 months after surgery. Patients' complaints of itching and bleeding were also reduced. Fissures healed in 7 patients and median healing time was 45 days. No complications were observed due to the procedure. One patient had transient incontinence to flatus. CONCLUSION: Lateral internal sphincterotomy provided clinical improvement and reduced resting pressure of the internal anal sphincter in women with chronic anal fissure.OBJETIVO: Avaliar a evolução clínica e manométrica de mulheres com fissura anal crônica submetidas à esfincterotomia lateral interna subcutânea. MÉTODOS: Estudo prospectivo com oito pacientes. A avaliação inicial foi realizada por meio de questionários, exame físico e manometria anorretal na semana anterior ao procedimento cirúrgico. Durante o período pós-operatório, as pacientes foram avaliadas clinicamente a cada 15 dias, até a cicatrização completa. Os questionários e a manometria anorretal foram repetidos 1 mês e 3 meses após a operação. Foi avaliado o tempo para cicatrização da fissura, as alterações manométricas e as complicações decorrentes do procedimento. RESULTADOS: Todas as pacientes

  9. Metabolic cold adaptation of polar fish based on measurements of aerobic oxygen consumption: fact or artefact? Artefact!

    DEFF Research Database (Denmark)

    Steffensen, John Fleng

    2002-01-01

    Whether metabolic cold adaptation in polar fish, based on measurements of aerobic standard metabolic rate, is a fact or an artefact has been a dispute since Holeton asked the question in 1974. So far polar fish had been considered to be metabolically cold adapted because they were reported to have...... a considerably elevated resting oxygen consumption, or standard metabolic rate, compared with oxygen consumption values of tropical or temperate fish extrapolated to similar low polar temperatures. Recent experiments on arctic and Antarctic fish, however, do not show elevated resting aerobic oxygen consumption...... values, or standard metabolic rate, and hence it is concluded that that metabolic cold adaptation in the traditional sense is an artefact....

  10. The effects of misinterpretation of an artefact on multidetector row CT scans in children.

    Science.gov (United States)

    du Plessis, Anne-Marie; Theron, Salomine; Andronikou, Savvas

    2009-02-01

    Artefacts reflect problems with radiographic technique rather than true pathology. These may be misinterpreted as pathology with serious consequences. An artefact caused such problems in one paediatric imaging department. To determine the incidence, and consequences of misinterpretation, of a CT artefact in a paediatric imaging department. A retrospective review of images and reports of paediatric CT scans over a set period with a known artefact was performed. Reports were correlated with reviewers' evaluation of the presence of artefact and reviewed for correct identification of artefact, misinterpretation as pathology, and action taken as a result. A total of 74 CT scans had been performed over the study period and an artefact detected by reviewers on 32 (43%). Six (18.75%) of these were misinterpreted as pathology, of which three (9.4%) were reported as tuberculous granulomas, two (6.2%) as haemorrhages and one (3.1%) as an unknown hyperdensity. Two patients (6.2%) had subsequent MRI studies performed, and treatment for tuberculosis was continued in one patient (3.1%). No initial report identified the artefact. One-fifth of the scans with the artefact were misinterpreted as pathology and half of these misinterpretations led to further action. Artefacts result in false diagnoses and unnecessary investigations; vigilance is needed.

  11. Trials of electronet fencing to exclude coyotes

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is on the trials of using electronet fencing to exclude coyotes for the protection of black-footed ferrets in Montana. Reintroduction of black-tailed...

  12. AFSC/ABL: 2009 Chinook Excluder Samples

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project genetically analyzed 1,620 chinook salmon samples from the 2009 spring salmon excluder device test. These samples were collected over a short period of...

  13. Generalized mathematical representation of the soft tissue artefact.

    Science.gov (United States)

    Dumas, R; Camomilla, V; Bonci, T; Cheze, L; Cappozzo, A

    2014-01-22

    While reconstructing skeletal movement using stereophotogrammetry, the relative movement between a skin marker and the underlying bone is regarded as an artefact (soft tissue artefact: STA). Similarly, the consequent pose, size and shape variations that affect a cluster of markers associated with a bony segment, or any arbitrary change of configuration in the marker local positions as representative of the skin envelope shape variation, may also be looked upon as an STA. Bone pose estimators able to compensate for these artefacts must embed relevant a priori knowledge in the form of an STA mathematical model. Prior to tackling this modeling exercise, an appropriate definition and mathematical representation of the STA time histories must be accomplished. Relevant appropriateness is based on the degree of approximation of the STA reconstruction and on the number of parameters involved. The objective of this study was to propose a generalized mathematical representation of the STA which would be applicable for most plausible definitions of it. To this purpose, a modal approach was used that, most importantly, allows for the splitting of a given STA into additive components (modes). For each STA definition, these modes may be ranked according to the contribution that each of them gives to the reconstruction of the STA. In this way, the STA definition leading to the minimum number of modes, and, therefore, of parameters, that provides an adequate approximation for further purposes can be selected, allowing a trade-off between complexity and effectiveness of the STA model. Using information available in the literature and data provided by an ex-vivo experiment, it is shown that the modes corresponding to the different STA definitions (individual marker displacements, marker-cluster geometrical transformations, and skin envelope shape variations) can be ranked and selected leading, respectively, to a large, moderate or low number of parameters embedded in the STA

  14. Plasma cleaning and analysis of archeological artefacts from Sipan

    Energy Technology Data Exchange (ETDEWEB)

    Saettone, E A O [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Matta, J A S da [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Alva, W [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Chubaci, J F O [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Fantini, M C A [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Galvao, R M O [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Kiyohara, P [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil); Tabacniks, M H [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo, CEP 05508-900 (Brazil)

    2003-04-07

    A novel procedure using plasma sputtering in an electron-cyclotron-resonance device has been applied to clean archeological MOCHE artefacts, unearthed at the Royal Tombs of Sipan. After successful cleaning, the pieces were analysed by a variety of complementary techniques, namely proton-induced x-ray emission, Rutherford backscattering spectroscopy, x-ray diffraction, electron microscopy, and inductively coupled plasma mass spectroscopy. With these techniques, it has been possible to not only determine the profiles of the gold and silver surface layers, but also to detect elements that may be relevant to explain the gilding techniques skillfully developed by the metal smiths of the MOCHE culture.

  15. Reduction of metallic coil artefacts in computed tomography body imaging: effects of a new single-energy metal artefact reduction algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Kidoh, Masafumi; Utsunomiya, Daisuke; Ikeda, Osamu; Tamura, Yoshitaka; Oda, Seitaro; Yuki, Hideaki; Nakaura, Takeshi; Hirai, Toshinori; Yamashita, Yasuyuki [Kumamoto University, Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto (Japan); Funama, Yoshinori [Kumamoto University, Department of Medical Physics, Faculty of Life Sciences, Kumamoto (Japan); Kawano, Takayuki [Kumamoto University Graduate School, Department of Neurosurgery, Faculty of Life Sciences Research, Kumamoto (Japan)

    2016-05-15

    We evaluated the effect of a single-energy metal artefact reduction (SEMAR) algorithm for metallic coil artefact reduction in body imaging. Computed tomography angiography (CTA) was performed in 30 patients with metallic coils (10 men, 20 women; mean age, 67.9 ± 11 years). Non-SEMAR images were reconstructed with iterative reconstruction alone, and SEMAR images were reconstructed with the iterative reconstruction plus SEMAR algorithms. We compared image noise around metallic coils and the maximum diameters of artefacts from coils between the non-SEMAR and SEMAR images. Two radiologists visually evaluated the metallic coil artefacts utilizing a four-point scale: 1 = extensive; 2 = strong; 3 = mild; 4 = minimal artefacts. The image noise and maximum diameters of the artefacts of the SEMAR images were significantly lower than those of the non-SEMAR images (65.1 ± 33.0 HU vs. 29.7 ± 10.3 HU; 163.9 ± 54.8 mm vs. 10.3 ± 19.0 mm, respectively; P < 0.001). Better visual scores were obtained with the SEMAR technique (3.4 ± 0.6 vs. 1.0 ± 0.0, P < 0.001). The SEMAR algorithm significantly reduced artefacts caused by metallic coils compared with the non-SEMAR algorithm. This technique can potentially increase CT performance for the evaluation of post-coil embolization complications. (orig.)

  16. Correlação entre achados manométricos e sintomatologia na incontinência fecal Correlation between manometric findings and symptomatology in fecal incontinence

    Directory of Open Access Journals (Sweden)

    Flávia Balsamo

    2011-03-01

    Full Text Available Foram estudados 92 pacientes com sintomatologia de incontinência fecal, no período de julho de 2005 a fevereiro de 2009. Os sintomas de incontinência foram classificados de acordo com o Cleveland Clinic Incontinence Score e os pacientes foram submetidos à manometria anorretal. Foram avaliados: idade, sexo, cirurgia prévia, sintomatologia e achado manométrico. Observou-se que o aumento da intensidade da sintomatologia de incontinência fecal está relacionado à diminuição progressiva das pressões de repouso. O mesmo não foi constatado com as pressões de contração na amostra estudadaWe have studied 92 patients with fecal incontinence symptoms, from July 2005 to February 2009. They were classified on the Cleveland Clinic Incontinence Score and all of them have undergone on manometric examination. Sex, age, previous surgery, symptomatology, and manometric findings were analyzed. We have concluded that the increase of incontinence symptoms is related to the progressive decrease on resting pressures. The same was not found with squeeze pressures in the studied sample

  17. An experimental case of wood-working use-wear on quartzite artefacts

    Directory of Open Access Journals (Sweden)

    Jiying Liu

    2016-12-01

    Full Text Available Use-wear analysis has become an essential method for the functional study of lithic artefacts from prehistoric archaeological assemblages. On the basis of earlier research, this article discusses experiments and analyses of use-wear on quartzite artefacts caused by wood-working. The raw materials of the artefacts were collected from the Wulanmulun Site, Inner Mongolia. The woodworking techniques include scraping, drilling, and chopping. Scarring sizes are mostly medium and small. Scarring terminations are mainly feathered; stepped terminations are caused by scraping and chopping wood. Scarring mainly appears as run-together distributions. Medium and heavy rounding is found on the edges of the artefacts.

  18. What is the Right to Exclude Immigrants?

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2010-01-01

    of states. The right to exclude claimed by states is analysed and it is shown to differ both conceptually and normatively from rights to impose political authority within a territory. The paper finally indicates how this analysis might broaden the focus of debates about immigration and suggest alternative......It is normally taken for granted that states have a right to control immigration into their territory. When immigration is raised as a normative issue two questions become salient, one about what the right to exclude is, and one about whether and how it might be justified. This paper considers...... the first question. The paper starts by noting that standard debates about immigration have not addressed what the right to exclude is. Standard debates about immigration furthermore tend to result either in fairly strong cases for open borders or in denials that considerations of justice apply...

  19. Low immigrant mortality in England and Wales: a data artefact?

    Science.gov (United States)

    Wallace, Matthew; Kulu, Hill

    2014-11-01

    Previous research shows low mortality for most immigrants compared to natives in host countries. This advantage is often attributed to health selection processes in migration and to protective health behaviours. Little research has examined the role of data quality, especially the registration of moves. Registration errors relating to moves between origin and host countries can mismatch deaths and risk populations, leading to denominator bias and an under-estimation of migrant mortality (data artefact). The paper investigates the mortality of immigrants in England and Wales from 1971 to 2001 using the Office for National Statistics Longitudinal Study (ONS LS), a 1% sample of the population of England and Wales. We apply parametric survival models to study the mortality of 450,000 individuals. We conduct sensitivity analysis to assess the impact of entry and exit uncertainty on immigrant mortality rates. The analysis shows that most international migrants have lower mortality than natives in England and Wales. Differences largely persist when we adjust models to entry and exit uncertainty and they become pronounced once we control for individual socioeconomic characteristics. This study supports low mortality among immigrants and shows that results are not a data artefact. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. The origin of emeralds embedded in archaeological artefacts in Slovenia

    Directory of Open Access Journals (Sweden)

    Albina Kržič

    2013-06-01

    Full Text Available Roman gold jewellery, which was excavated in Ptuj (Poetovio and consists of a necklace, earrings and a braceletwith embedded emeralds, is part of the Slovenian archaeological artefacts collections. Crystallographic characteristics,inclusions, luminous phenomena and geological characteristics were determined in order to establish theorigin of the emeralds. Chemical composition of the emeralds was determined non-destructively using the methodsof proton-induced X-rays and gamma rays (PIXE/PIGE. The results were compared with reference emeraldsfrom Habachtal in Austria and with green beryls from the Ural Mts. Literature data for emeralds from Egypt andmodern-day Afghanistan area were used to interpret the results. Specifically, these sites were known for emeraldsbeing mined for jewellery in Roman times. It was assumed that emeralds from archaeological artefacts originatedfrom Habachtal in Austria, given that this site was the nearest to the place where found. But the emeralds fromthe necklace and earrings in fact came from Egyptian deposits. The origin of emeralds from the bracelet could nothave been determined absolutely reliably due to the lack of comparative materials; they may originate from a site inmodern-day Afghanistan or from Egypt, but certainly not from the same site as the previously mentioned emeraldsin the necklace and earrings.

  1. fMRI Artefact Rejection and Sleep Scoring Toolbox

    Directory of Open Access Journals (Sweden)

    Yves Leclercq

    2011-01-01

    Full Text Available We started writing the “fMRI artefact rejection and sleep scoring toolbox”, or “FAST”, to process our sleep EEG-fMRI data, that is, the simultaneous recording of electroencephalographic and functional magnetic resonance imaging data acquired while a subject is asleep. FAST tackles three crucial issues typical of this kind of data: (1 data manipulation (viewing, comparing, chunking, etc. of long continuous M/EEG recordings, (2 rejection of the fMRI-induced artefact in the EEG signal, and (3 manual sleep-scoring of the M/EEG recording. Currently, the toolbox can efficiently deal with these issues via a GUI, SPM8 batching system or hand-written script. The tools developed are, of course, also useful for other EEG applications, for example, involving simultaneous EEG-fMRI acquisition, continuous EEG eye-balling, and manipulation. Even though the toolbox was originally devised for EEG data, it will also gracefully handle MEG data without any problem. “FAST” is developed in Matlab as an add-on toolbox for SPM8 and, therefore, internally uses its SPM8-meeg data format. “FAST” is available for free, under the GNU-GPL.

  2. Polyelectrolyte solutions: Excluded-volume considerations

    Science.gov (United States)

    Mattoussi, Hedi; Karasz, Frank E.

    1993-12-01

    We provide experimental evidence for the electrostatically related excluded-volume effects on the colligative properties and the single chain behavior of polyelectrolyte solutions in the dilute regime. The data are compared to the theory developed by Fixman, Skolnick, Odijk, and Houwaart. Good agreement between these theoretical considerations and the experimental data is observed.

  3. 21 CFR 1308.22 - Excluded substances.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Excluded substances. 1308.22 Section 1308.22 Food and Drugs DRUG ENFORCEMENT ADMINISTRATION, DEPARTMENT OF JUSTICE SCHEDULES OF CONTROLLED SUBSTANCES... may, under the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 301), be lawfully sold over the counter...

  4. Replica calibration artefacts for optical 3D scanning of micro parts

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo; Carmignato, S.; Cantatore, Angela

    2009-01-01

    applications to reproduce the geometry of a step artefact, a miniature step gauge, and a curve standard for optical measuring machines. The replica artefacts were calibrated using a tactile coordinate measuring machine and measured on two different optical scanners. Replication quality and applicability...

  5. A Philosophical Framework for Enhancing the Understanding of Artefacts in the Technology Classroom

    Science.gov (United States)

    Rauscher, Willem

    2016-01-01

    Technology teachers should have a sound understanding and knowledge of artefacts in order to assist learners in the designing, making and evaluating of artefacts. Unfortunately, technology teachers in South African schools seem to have a poor grasp of the complexity of this important part of knowledge that is specific to technology. As a result,…

  6. Settings and artefacts relevant for Doppler ultrasound in large vessel vasculitis.

    Science.gov (United States)

    Terslev, L; Diamantopoulos, A P; Døhn, U Møller; Schmidt, W A; Torp-Pedersen, S

    2017-07-20

    Ultrasound is used increasingly for diagnosing large vessel vasculitis (LVV). The application of Doppler in LVV is very different from in arthritic conditions. This paper aims to explain the most important Doppler parameters, including spectral Doppler, and how the settings differ from those used in arthritic conditions and provide recommendations for optimal adjustments. This is addressed through relevant Doppler physics, focusing, for example, on the Doppler shift equation and how angle correction ensures correctly displayed blood velocity. Recommendations for optimal settings are given, focusing especially on pulse repetition frequency (PRF), gain and Doppler frequency and how they impact on detection of flow. Doppler artefacts are inherent and may be affected by the adjustment of settings. The most important artefacts to be aware of, and to be able to eliminate or minimize, are random noise and blooming, aliasing and motion artefacts. Random noise and blooming artefacts can be eliminated by lowering the Doppler gain. Aliasing and motion artefacts occur when the PRF is set too low, and correct adjustment of the PRF is crucial. Some artefacts, like mirror and reverberation artefacts, cannot be eliminated and should therefore be recognised when they occur. The commonly encountered artefacts, their importance for image interpretation and how to adjust Doppler setting in order to eliminate or minimize them are explained thoroughly with imaging examples in this review.

  7. X-ray CT high-density artefact suppression in the presence of bones

    Energy Technology Data Exchange (ETDEWEB)

    Wei Jikun [School of Health Sciences, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051 (United States); Chen Laigao [BioImaging Center of Emphasis, Pfizer Global Research and Development, 2800 Plymouth RD, Ann Arbor, MI 48105 (United States); Sandison, George A [School of Health Sciences, 550 Stadium Mall Drive, West Lafayette, IN 47907-2051 (United States); Liang Yun [Department of Radiology, Indiana University Medical School, Indianapolis, IN 46202 (United States); Xu, Lisa X [School of Mechanical Engineering, 585 Purdue Mall, West Lafayette, IN 47907-2040 (United States)

    2004-12-21

    This paper presents a novel method of reducing x-ray CT high-density artefacts generated by metal objects when abundant bone structures are present in the region of interest. This method has an advantage over previously proposed methods since it heavily suppresses the metal artefacts without introducing extra bone artefacts. The method of suppression requires that bone pixels are isolated and segmented by thresholding. Then artificial CT numbers are assigned to the bone pixels so that their projection profiles are smooth and thus can be properly simulated by a polynomial interpolation. The projection profile of the metal object is then removed to fully suppress the artefacts. The resulting processed profile is fed to a reconstruction routine and the previously preserved bone pixels added back. The new method utilizes two important features of the CT image with metal artefacts: (a) metal and bone pixels are not severely affected by the high-density artefacts and (b) the high-density artefacts can be located in specific projection channels in the profile domain, although they are spread out in the image domain. This suppression method solves the problem of CT image artefacts arising from metal objects in the body. It has the potential to greatly improve diagnostic CT imaging in the presence of these objects and treatment planning that utilizes CT for patients with metal applicators (e.g., brachytherapy for cervix cancer and prostate cryotherapy)

  8. Understanding sudden environmental and societal change through coupled geochronological and artefact shape analyses

    DEFF Research Database (Denmark)

    Hoggard, Christian Steven; Sauer, Florian Rudolf; Zernack, Anke Verena

    Over the last twenty years, advances in geometric morphometric methodologies have revolutionised how archaeologists understand changes in artefact shape and form (size plus shape) throughout the Quaternary period. Such methodologies provide a high resolution of artefact coverage, and allow a crit...

  9. Definition, classification and retrospective analysis of photostimulable phosphor image artefacts and errors in intraoral dental radiography.

    Science.gov (United States)

    Çalışkan, Armağan; Sumer, A Pinar

    2017-03-01

    To detect and determine image error and artefact types in intraoral radiographs obtained with photostimulable phosphor (PSP) technology, place them in an appropriate classification and retrospectively analyze the PSP-specific image errors and artefacts. The causes and solutions of PSP-specific errors and artefacts have also been discussed. The radiographic database of Ondokuz Mayis University, Faculty of Dentistry, Department of Dentomaxillofacial Radiology, was used for this study. Different types of image errors and artefacts observed on intraoral radiographs during 2014-15 were detected and defined. A total of 2100 intraoral radiographs were individually evaluated for the distribution of PSP-specific image artefacts. There were 34 image error and artefact types detected and classified into 4 groups according to the causative factors. The most common PSP-specific image artefacts were found in fading with a ratio of 44.1% for the ambient light-related group, peeling of the plate borders with a ratio of 53.4% for the PSP plate-related group and straight line with a ratio of 42.2% for the scanner-related group. The determination and definition of the image errors and artefacts with clarification of their causes and solutions are important for the improvement of radiographic quality and the reduction of the retake ratio.

  10. The use of F-K filter in the elimination of artefacts from a shallow ...

    African Journals Online (AJOL)

    The use of F-K filter in the elimination of artefacts from a shallow seismic reflection data in Zaria, Nigeria. ... The processing of the seismic data if not well handled often leads to migration artefacts which could be misconstrued as a seismic event. The field procedure employed for the geophysical survey was the split spread ...

  11. Laryngeal mask airway (LMA) artefact resulting in MRI misdiagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Schieble, Thomas [University of Medicine and Dentistry of New Jersey, Department of Anesthesiology, New Jersey Medical School, Newark, NJ (United States); Maimonides Medical Center, Department of Anesthesiology, Brooklyn, NY (United States); Patel, Anuradha; Davidson, Melissa [University of Medicine and Dentistry of New Jersey, Department of Anesthesiology, New Jersey Medical School, Newark, NJ (United States)

    2008-03-15

    We report a 7-year-old child who underwent brain MRI for a known seizure disorder. The technique used for general anesthesia included inhalation induction followed by placement of a laryngeal mask airway (LMA) for airway maintenance. Because the reviewing radiologist was unfamiliar with the use of an LMA during anesthesia, and because the attending anesthesiologist did not communicate his technique to the radiologist, an MRI misdiagnosis was reported because of artefact created by the in situ LMA. As a result of this misdiagnosis the child was subjected to unnecessary subsequent testing to rule out a reported anatomic abnormality induced by the LMA. Our case illustrates the need for coordination of patient care among hospital services. (orig.)

  12. A model of the soft tissue artefact rigid component.

    Science.gov (United States)

    Camomilla, V; Bonci, T; Dumas, R; Chèze, L; Cappozzo, A

    2015-07-16

    When using stereophotogrammetry and skin-markers, the reconstruction of skeletal movement is affected by soft-tissue artefact (STA). This may be described by considering a marker-cluster as a deformable shape undergoing a geometric transformation formed by a non-rigid (change in size and shape) and a rigid component (translation and rotation displacements). A modal decomposition of the STA, relative to an appropriately identified basis, allows the separation of these components. This study proposes a mathematical model of the STA that embeds only its rigid component and estimates the relevant six mode amplitudes as linear functions of selected proximal and distal joint rotations during the analysed task. This model was successfully calibrated for thigh and shank using simultaneously recorded pin- and skin-marker data of running volunteers. The root mean square difference between measured and model-estimated STA rigid component was 1.1(0.8)mm (median (inter-quartile range) over 3 subjects × 5 trials × 33 markers coordinates), and it was mostly due to the wobbling not included in the model. Knee joint kinematics was estimated using reference pin-marker data and skin-marker data, both raw and compensated with the model-estimated STA. STA compensation decreased inaccuracy on average from 6% to 1% for flexion/extension, from 43% to 18% for the other two rotations, and from 69% to 25% for the linear displacements. Thus, the proposed mathematical model provides an STA estimate which can be effectively used within optimal bone pose and joint kinematics estimators for artefact compensation, and for simulations aimed at their comparative assessments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Clean Water Act (excluding Section 404)

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-15

    This Reference Book contains a current copy of the Clean Water Act (excluding Section 404) and those regulations that implement the statutes and appear to be most relevant to US Department of Energy (DOE) activities. The document is provided to DOE and contractor staff for informational purposes only and should not be interpreted as legal guidance. Updates that include important new requirements will be provided periodically. Questions concerning this Reference Book may be directed to Mark Petts, EH-231 (202/586-2609).

  14. Factors controlling headspace pressure in a manual manometric BMP method can be used to produce a methane output comparable to AMPTS.

    Science.gov (United States)

    Himanshu, H; Voelklein, M A; Murphy, J D; Grant, J; O'Kiely, P

    2017-08-01

    The manual manometric biochemical methane potential (mBMP) test uses the increase in pressure to calculate the gas produced. This gas production may be affected by the headspace volume in the incubation bottle and by the overhead pressure measurement and release (OHPMR) frequency. The biogas and methane yields of cellulose, barley, silage and slurry were compared with three incubation bottle headspace volumes (50, 90 and 180ml; constant 70ml total medium) and four OHPMR frequencies (daily, each third day, weekly and solely at the end of experiment). The methane yields of barley, silage and slurry were compared with those from an automated volumetric method (AMPTS). Headspace volume and OHPMR frequency effects on biogas yield were mediated mainly through headspace pressure, with the latter having a negative effect on the biogas yield measured and relatively little effect on methane yield. Two mBMP treatments produced methane yields equivalent to AMPTS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. How useful is esophageal high resolution manometry in diagnosing gastroesophageal junction disruption: causes affecting this disruption and its relationship with manometric alterations and gastroesophageal reflux

    Directory of Open Access Journals (Sweden)

    Constanza Ciriza-de-los-Ríos

    2014-01-01

    Full Text Available Background: High-resolution manometry (HRM is a breakthrough in the morphological study of the gastroesophageal junction (GEJ and its degrees of disruption. Objectives: a Assessment of risk factors involved in the disruption of the GEJ in patients with gastroesophageal reflux (GER symptoms; b the relationship between the type of GEJ and GER demonstrated by 24 hours pH-monitoring; and c identification of the alterations in the manometric parameters related to the morphology of the GEJ. Methods: One hundred and fifteen patients with symptoms of GER studied with HRM and classified by the type of GEJ (type I: Normal; type II: Sliding; type III: Hiatal hernia. Twenty four hour pH-monitoring without proton pump inhibitors was performed in all of them. Epidemiological aspects, manometric parameters (Chicago 2012 classification and the pH-monitoring results were evaluated. Results: Age (OR 1.033 [1.006-1.060]; p = 0.16, BMI (OR 1.097 [1.022-1.176]; p = 0. 01 and abdominal perimeter (OR 1.034 [1.005-1.063]; p = 0.0215 were independent risk factors for the GEJ type III (area under the curve 0.70. Disruption of the GEJ was associated with a lower resting pressure (p = 0.006, greater length (p < 0.001 and greater esophageal shortening (p < 0.001. Abnormal acidic reflux was found in the total period (p = 0.015, standing (p = 0.022 and supine (p = 0.001 in patients with GEJ type II and III with respect to type I. Conclusions: Increased age, overweight and central obesity pose a higher risk of GEJ type III (hiatal hernia. The greater disruption of the GEJ is associated with lower resting pressure, esophageal shortening, and higher acid exposure in the pH-monitoring.

  16. Rejecting deep brain stimulation artefacts from MEG data using ICA and mutual information.

    Science.gov (United States)

    Abbasi, Omid; Hirschmann, Jan; Schmitz, Georg; Schnitzler, Alfons; Butz, Markus

    2016-08-01

    Recording brain activity during deep brain stimulation (DBS) using magnetoencephalography (MEG) can potentially help clarifying the neurophysiological mechanism of DBS. The DBS artefact, however, distorts MEG data significantly. We present an artefact rejection approach to remove the DBS artefact from MEG data. We developed an approach consisting of four consecutive steps: (i) independent component analysis was used to decompose MEG data to independent components (ICs); (ii) mutual information (MI) between stimulation signal and all ICs was calculated; (iii) artefactual ICs were identified by means of an MI threshold; and (iv) the MEG signal was reconstructed using only non-artefactual ICs. This approach was applied to MEG data from five Parkinson's disease patients with implanted DBS stimulators. MEG was recorded with DBS ON (unilateral stimulation of the subthalamic nucleus) and DBS OFF during two experimental conditions: a visual attention task and alternating right and left median nerve stimulation. With the presented approach most of the artefact could be removed. The signal of interest could be retrieved in both conditions. In contrast to existing artefact rejection methods for MEG-DBS data (tSSS and S(3)P), the proposed method uses the actual artefact source, i.e. the stimulation signal, as reference signal. Using the presented method, the DBS artefact can be significantly rejected and the physiological data can be restored. This will facilitate research addressing the impact of DBS on brain activity during rest and various tasks. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Iterative metal artefact reduction (MAR) in postsurgical chest CT: comparison of three iMAR-algorithms.

    Science.gov (United States)

    Aissa, Joel; Boos, Johannes; Sawicki, Lino Morris; Heinzler, Niklas; Krzymyk, Karl; Sedlmair, Martin; Kröpil, Patric; Antoch, Gerald; Thomas, Christoph

    2017-11-01

    The purpose of this study was to evaluate the impact of three novel iterative metal artefact (iMAR) algorithms on image quality and artefact degree in chest CT of patients with a variety of thoracic metallic implants. 27 postsurgical patients with thoracic implants who underwent clinical chest CT between March and May 2015 in clinical routine were retrospectively included. Images were retrospectively reconstructed with standard weighted filtered back projection (WFBP) and with three iMAR algorithms (iMAR-Algo1 = Cardiac algorithm, iMAR-Algo2 = Pacemaker algorithm and iMAR-Algo3 = ThoracicCoils algorithm). The subjective and objective image quality was assessed. Averaged over all artefacts, artefact degree was significantly lower for the iMAR-Algo1 (58.9 ± 48.5 HU), iMAR-Algo2 (52.7 ± 46.8 HU) and the iMAR-Algo3 (51.9 ± 46.1 HU) compared with WFBP (91.6 ± 81.6 HU, p algorithms, respectively. iMAR-Algo2 and iMAR-Algo3 reconstructions decreased mild and moderate artefacts compared with WFBP and iMAR-Algo1 (p algorithms led to a significant reduction of metal artefacts and increase in overall image quality compared with WFBP in chest CT of patients with metallic implants in subjective and objective analysis. The iMARAlgo2 and iMARAlgo3 were best for mild artefacts. IMARAlgo1 was superior for severe artefacts. Advances in knowledge: Iterative MAR led to significant artefact reduction and increase image-quality compared with WFBP in CT after implementation of thoracic devices. Adjusting iMAR-algorithms to patients' metallic implants can help to improve image quality in CT.

  18. Geoarchaeological approaches to Palaeolithic surface artefact distributions and hominin landscape use in SW Saudi Arabia

    Science.gov (United States)

    Inglis, Robyn; Sinclair, Anthony; Fanning, Patricia; Alsharekh, Abdullah; Bailey, Geoff

    2017-04-01

    The vast majority of Palaeolithic archaeological material in arid and semi-arid regions exists in the form of scatters of stone tools across the surface of present-day landscapes. This is particularly the case in the Saharo-Arabian desert belt, a region vital to understanding the global dispersal of hominins from Africa. These surface artefacts possess little stratigraphic context, but comprise the only record we possess to examine spatial behavioural patterning and landscape use by hominin populations. Interpretation of the observed spatial distribution of artefacts is far from straightforward. Surface artefact distributions result from a complex interplay of varying human behaviours over time. Also, geomorphological processes affect the preservation, exposure and visibility of the artefacts, as well as alter the presence and location of attractive resources. The SURFACE project employs an interdisciplinary approach to understanding the distribution of Palaeolithic artefacts in SW Saudi Arabia. By combining remote sensing, geomorphological fieldwork, archaeological survey and GIS analyses, the project is developing a geomorphological context for the artefacts that guides survey to areas of high archaeological potential, as well as allowing the robust interpretation of the observed artefact distribution in a dynamic landscape in terms of past landscape use. This paper will present the ongoing multi-scalar approaches employed by the project to Palaeolithic landscapes, particularly focussing on the site of Wadi Dabsa, Asir Province, where Lower and Middle Palaeolithic artefacts have been found in association with extensive tufa deposits. Investigation in early 2017 at the site will apply SURFACE's methods to understand the present-day artefact distributions at the exposure, and their relationship to the tufa deposition, as well as their potential to inform on Palaeolithic activity and landscape use at the site.

  19. Exploring preferences and non-use values for hidden archaeological artefacts

    DEFF Research Database (Denmark)

    Lundhede, Thomas; Bille, Trine; Hasler, Berit

    2013-01-01

    This paper presents a choice experiment study of a proposed wetland restorationproject which aims to preserve archaeological artefacts from Stone Age villages which are presently buried within the topsoil. Wetland restoration can avoid destruction of the artefacts due to agricultural cultivation...... is for ensuring permanent protection of archaeological artefacts, rather than biological diversity and recreational opportunities. The results are discussed in relation to the Prospect Theory:people value a loss of cultural heritage higher than a gain of new cultural goods or services. This insight is of general...

  20. Exploring Preferences and Non-use Values for Hidden Archaeological Artefacts

    DEFF Research Database (Denmark)

    Lundhede, Thomas; Bille, Trine; Hasler, Berit

    2013-01-01

    This paper presents a choice experiment study of a proposed wetland restoration project which aims to preserve archaeological artefacts from Stone Age villages which are presently buried within the topsoil. Wetland restoration can avoid destruction of the artefacts due to agricultural cultivation...... is for ensuring permanent protection of archaeological artefacts, rather than biological diversity and recreational opportunities. The results are discussed in relation to the Prospect Theory: people value a loss of cultural heritage higher than a gain of new cultural goods or services. This insight is of general...

  1. Emulation: From Digital Artefact to Remotely Rendered Environments

    Directory of Open Access Journals (Sweden)

    Dirk von Suchodoletz

    2009-12-01

    Full Text Available Emulation used as a long-term preservation strategy offers the potential to keep digital objects in their original condition and experience them within their original computer environment. However, having just an emulator in place is not enough. To apply emulation as a fully fledged strategy, an automated and user-friendly approach is required. This cannot be done without knowledge and contextual information of the original software. This paper combines the existing concept of a view path, which captures the contextual information of software, together with new insights into improving the concept with extra metadata. It provides regularly updated instructions for archival management to preserve and access its artefacts. The view-path model requires extensions to the metadata set of the primary object of interest and depends on additionally stored secondary objects for environment recreation like applications or operating systems. This article also addresses a strategy of rendering digital objects by running emulation processes remotely. The advantage of this strategy is that it improves user convenience while maximizing emulation capability.

  2. Queueing process with excluded-volume effect.

    Science.gov (United States)

    Arita, Chikashi

    2009-11-01

    We introduce an extension of the M/M/1 queueing process with a spatial structure and excluded-volume effect. The rule of particle hopping is the same as for the totally asymmetric simple exclusion process (TASEP). A stationary-state solution is constructed in a slightly arranged matrix product form of the open TASEP. We obtain the critical line that separates the parameter space depending on whether the model has the stationary state. We calculate the average length of the model and the number of particles and show the monotonicity of the probability of the length in the stationary state. We also consider a generalization of the model with backward hopping of particles allowed and an alternate joined system of the M/M/1 queueing process and the open TASEP.

  3. 34 CFR 85.950 - Excluded Parties List System

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Excluded Parties List System 85.950 Section 85.950... (NONPROCUREMENT) Definitions § 85.950 Excluded Parties List System Excluded Parties List System (EPLS) means the... entitled, “List of Parties Excluded or Disqualified from Federal Procurement and Nonprocurement Programs...

  4. Automatic detection of EEG artefacts arising from head movements using EEG and gyroscope signals.

    Science.gov (United States)

    O'Regan, Simon; Faul, Stephen; Marnane, William

    2013-07-01

    Contamination of EEG signals by artefacts arising from head movements has been a serious obstacle in the deployment of automatic neurological event detection systems in ambulatory EEG. In this paper, we present work on categorizing these head-movement artefacts as one distinct class and on using support vector machines to automatically detect their presence. The use of additional physical signals in detecting head-movement artefacts is also investigated by means of support vector machines classifiers implemented with gyroscope waveforms. Finally, the combination of features extracted from EEG and gyroscope signals is explored in order to design an algorithm which incorporates both physical and physiological signals in accurately detecting artefacts arising from head-movements. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  5. Automatic artefact removal in a self-paced hybrid brain- computer interface system.

    Science.gov (United States)

    Yong, Xinyi; Fatourechi, Mehrdad; Ward, Rabab K; Birch, Gary E

    2012-07-27

    A novel artefact removal algorithm is proposed for a self-paced hybrid brain-computer interface (BCI) system. This hybrid system combines a self-paced BCI with an eye-tracker to operate a virtual keyboard. To select a letter, the user must gaze at the target for at least a specific period of time (dwell time) and then activate the BCI by performing a mental task. Unfortunately, electroencephalogram (EEG) signals are often contaminated with artefacts. Artefacts change the quality of EEG signals and subsequently degrade the BCI's performance. To remove artefacts in EEG signals, the proposed algorithm uses the stationary wavelet transform combined with a new adaptive thresholding mechanism. To evaluate the performance of the proposed algorithm and other artefact handling/removal methods, semi-simulated EEG signals (i.e., real EEG signals mixed with simulated artefacts) and real EEG signals obtained from seven participants are used. For real EEG signals, the hybrid BCI system's performance is evaluated in an online-like manner, i.e., using the continuous data from the last session as in a real-time environment. With semi-simulated EEG signals, we show that the proposed algorithm achieves lower signal distortion in both time and frequency domains. With real EEG signals, we demonstrate that for dwell time of 0.0s, the number of false-positives/minute is 2 and the true positive rate (TPR) achieved by the proposed algorithm is 44.7%, which is more than 15.0% higher compared to other state-of-the-art artefact handling methods. As dwell time increases to 1.0s, the TPR increases to 73.1%. The proposed artefact removal algorithm greatly improves the BCI's performance. It also has the following advantages: a) it does not require additional electrooculogram/electromyogram channels, long data segments or a large number of EEG channels, b) it allows real-time processing, and c) it reduces signal distortion.

  6. Removal of BCG artefact from concurrent fMRI-EEG recordings based on EMD and PCA.

    Science.gov (United States)

    Javed, Ehtasham; Faye, Ibrahima; Malik, Aamir Saeed; Abdullah, Jafri Malin

    2017-11-01

    Simultaneous electroencephalography (EEG) and functional magnetic resonance image (fMRI) acquisitions provide better insight into brain dynamics. Some artefacts due to simultaneous acquisition pose a threat to the quality of the data. One such problematic artefact is the ballistocardiogram (BCG) artefact. We developed a hybrid algorithm that combines features of empirical mode decomposition (EMD) with principal component analysis (PCA) to reduce the BCG artefact. The algorithm does not require extra electrocardiogram (ECG) or electrooculogram (EOG) recordings to extract the BCG artefact. The method was tested with both simulated and real EEG data of 11 participants. From the simulated data, the similarity index between the extracted BCG and the simulated BCG showed the effectiveness of the proposed method in BCG removal. On the other hand, real data were recorded with two conditions, i.e. resting state (eyes closed dataset) and task influenced (event-related potentials (ERPs) dataset). Using qualitative (visual inspection) and quantitative (similarity index, improved normalized power spectrum (INPS) ratio, power spectrum, sample entropy (SE)) evaluation parameters, the assessment results showed that the proposed method can efficiently reduce the BCG artefact while preserving the neuronal signals. Compared with conventional methods, namely, average artefact subtraction (AAS), optimal basis set (OBS) and combined independent component analysis and principal component analysis (ICA-PCA), the statistical analyses of the results showed that the proposed method has better performance, and the differences were significant for all quantitative parameters except for the power and sample entropy. The proposed method does not require any reference signal, prior information or assumption to extract the BCG artefact. It will be very useful in circumstances where the reference signal is not available. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Spectral methods to distinguish ventricular fibrillation from artefact in implantable cardioverter-defibrillators.

    Science.gov (United States)

    Mollerus, Michael E; Renier, Colleen; Lipinski, Margaret

    2011-09-01

    Despite the proven benefit of implantable cardioverter-defibrillators (ICDs), inappropriate shocks remain a significant problem. Recent trends have shown an increased incidence of lead failure and an increased exposure of devices to extreme electromagnetic interference environments. The goal of the current study is to evaluate the spectral characteristics of ventricular fibrillation (VF) detected in an ICD at time of defibrillation threshold testing and use of the findings to predict event types from a population of clinical VF and artefact events. A modelling group was created from induced VF and artefact events at time of ICD implantation and DFT testing. Power spectral density evaluation was performed on each event and used to calculate an energy ratio (ER; the ratio of energy under the first three harmonics to the entire spectrum). The model was then applied to a database of clinical VF and artefact events to determine its sensitivity and specificity. The far-field ER of the modelling group was significantly larger for VF (0.888 ± 0.110) than artefact (0.265 ± 0.156, P 0.526, the far-field ER had a sensitivity of 100% [confidence interval (CI) 100-100%] and a specificity of 92.4% (CI 84.9-98.5%) to distinguish clinical VF from clinical artefact. Far-field signal during VF detected by an ICD has a distinct spectral pattern that can distinguish VF from artefact.

  8. Migration of free-surface-related multiples: Removing artefacts using a water-layer model

    Science.gov (United States)

    Hu, Hao; Wang, Yibo; Chang, Xu; Xie, Songlei

    2015-01-01

    The migration of free-surface-related multiples has been developed for seismic data processing because such multiples can be utilised for imaging and sometimes provide additional subsurface illumination. Recently, the simultaneous migration of primaries and free-surface-related multiples has been proposed as an attractive approach for avoiding the costly prediction of multiples. However, the migration artefacts of multiples, generated by mismatched events, pollute the stacked image and degrade the image quality. We developed a new approach to attenuate the distinct migration artefacts of multiples using water-layer-related multiples. In addition to the original data, the only additional information required by this approach is the water-layer model, which can be acquired easily and accurately from sonar or the stacked profile. By using the predicted water-layer multiples, the distinct migration artefacts can be imaged and then subtracted from the migration image of multiples. Numerical experiments illustrate that the proposed approach can suppress most distinct artefacts in the migration of multiples while preserving the advantages. The proposed approach is an effective tool for the removal of artefacts from the migration of multiples and can be applied to different types of migration operators to produce better-illuminated images with fewer artefacts.

  9. ARTEFACT MOBILE DATA MODEL TO SUPPORT CULTURAL HERITAGE DATA COLLECTION AND INTERPRETATION

    Directory of Open Access Journals (Sweden)

    Z. S. Mohamed-Ghouse

    2012-07-01

    Full Text Available This paper discusses the limitation of existing data structures in mobile mapping applications to support archaeologists to manage the artefact (any object made or modified by a human culture, and later recovered by an archaeological endeavor details excavated at a cultural heritage site. Current limitations of data structure in the mobile mapping application allow archeologist to record only one artefact per test pit location. In reality, more than one artefact can be excavated from the same test pit location. A spatial data model called Artefact Mobile Data Model (AMDM was developed applying existing Relational Data Base Management System (RDBMS technique to overcome the limitation. The data model was implemented in a mobile database environment called SprintDB Pro which was in turn connected to ArcPad 7.1 mobile mapping application through Open Data Base Connectivity (ODBC. In addition, the design of a user friendly application built on top of AMDM to interpret and record the technology associated with each artefact excavated in the field is also discussed in the paper. In summary, the paper discusses the design and implementation of a data model to facilitate the collection of artefacts in the field using integrated mobile mapping and database approach.

  10. Social Analysis in Development Interventions: Policy Artefact or Constructive Transformation?

    Directory of Open Access Journals (Sweden)

    SUSANNA PRICE

    2012-02-01

    Full Text Available Recently attention has focused on the role of social researchers in the processes of construction and transmission of knowledge about global poverty and its reduction. This paper examines some of the formative efforts by pioneering social researchers in development institutions to step into the realm of policy making to construct processes for project preparation and management through social analysis. Before 1970 development planners invoked ‘social' or ‘human' factors only as an excuse to explain away project failures - they designed and implemented development projects in the absence of any strategies or regulatory frameworks for managing their social impacts. Recognizing that project investments represent induced change and constitute a social process in themselves, pioneering social researchers constructed policies and procedures to introduce sociological content and method into the project cycle and so re-order social outcomes. Were such constructs merely policy artefacts? Even as the constructs helped to shift the statements of the development discourse towards ‘people oriented' poverty reduction, new modalities appeared which tested the limits of the agreed methods. Institutions may forget, neglect, contest or re-write the documents if in perceived conflict with the institutional ‘core business'. Yet those pioneering efforts created institutional space for, and understanding of, social analysis, with a measure of flow-on international recognition. Tracking social analysis in several international institutions and in a significant emerging economy, China, this paper highlights not only a history full of lessons to be learned where social analysis is not practiced systematically but also outlines some future challenges.

  11. [Treatment of adenomyosis (excluding pregnancy project)].

    Science.gov (United States)

    Pelage, L; Fenomanana, S; Brun, J-L; Levaillant, J-M; Fernandez, H

    2015-05-01

    In this review we aimed to update the possibilities of adenomyosis treatment in women excluding those with a desire for pregnancy. Adenomyosis is defined as the presence of endometrial tissue within the myometrium and frequently underestimated. Over the last decades, its pathophysiology has been better known. The diagnosis is essentially based on clinical symptoms like menorrhagia and dysmenorrhea. Transvaginal ultrasound and magnetic resonance imaging are the main tools of the radiologic diagnosis. However, the definitive diagnosis is histological. The most effective treatment remains hysterectomy; however it is expensive, radical and at risk of morbidity compared with medical or surgical conservative management. The literature has reported several series of patients undergoing various treatments, thus allowing different therapeutic options. The levonorgestrel-releasing intrauterine device showed its efficacy alone or in combination with hysteroscopic treatment. Oral progestins, GnRH agonists are useful at short term or in preoperative condition. Some conservative treatments like focused ultrasound therapies or uterus-sparing operative treatment stay under evaluation and seems to be effective. Embolization has been the subject of several studies and must be outlined. Furthermore, several molecules, such as modulators of progesterone receptors and the aromatase inhibitors have been recently studied and are perhaps future treatments. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  12. Neutron resonance data exclude random matrix theory

    Science.gov (United States)

    Koehler, P. E.; Bečvář, F.; Krtička, M.; Guber, K. H.; Ullmann, J. L.

    2013-02-01

    Almost since the time it was formulated, the overwhelming consensus has been that random matrix theory (RMT) is in excellent agreement with neutron resonance data. However, over the past few years, we have obtained new neutron-width data at Oak Ridge and Los Alamos National Laboratories that are in stark disagreement with this theory. We also have reanalyzed neutron widths in the most famous data set, the nuclear data ensemble (NDE), and found that it is seriously flawed, and, when analyzed carefully, excludes RMT with high confidence. More recently, we carefully examined energy spacings for these same resonances in the NDE using the $\\Delta_{3}$ statistic. We conclude that the data can be found to either confirm or refute the theory depending on which nuclides and whether known or suspected p-wave resonances are included in the analysis, in essence confirming results of our neutron-width analysis of the NDE. We also have examined radiation widths resulting from our Oak Ridge and Los Alamos measurements, and find that in some cases they do not agree with RMT. Although these disagreements presently are not understood, they could have broad impact on basic and applied nuclear physics, from nuclear astrophysics to nuclear criticality safety.

  13. Neutron resonance data exclude random matrix theory

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, P.E. [Physics Division, Oak Ridge National Laboratory, MailStop 6356, Oak Ridge, Tennessee 37831 (United States); Becvar, F.; Krticka, M. [Charles University, Faculty of Mathematics and Physics, 180 00 Prague 8 (Czech Republic); Guber, K.H. [Reactor and Nuclear Systems Division, Oak Ridge National Laboratory, Mail Stop 6356, Oak Ridge, Tennessee 37831 (United States); Ullmann, J.L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2013-02-15

    Almost since the time it was formulated, the overwhelming consensus has been that random matrix theory (RMT) is in excellent agreement with neutron resonance data. However, over the past few years, we have obtained new neutron-width data at Oak Ridge and Los Alamos National Laboratories that are in stark disagreement with this theory. We also have reanalyzed neutron widths in the most famous data set, the nuclear data ensemble (NDE), and found that it is seriously flawed, and, when analyzed carefully, excludes RMT with high confidence. More recently, we carefully examined energy spacings for these same resonances in the NDE using the {Delta}{sub 3} statistic. We conclude that the data can be found to either confirm or refute the theory depending on which nuclides and whether known or suspected p-wave resonances are included in the analysis, in essence confirming results of our neutron-width analysis of the NDE. We also have examined radiation widths resulting from our Oak Ridge and Los Alamos measurements, and find that in some cases they do not agree with RMT. Although these disagreements presently are not understood, they could have broad impact on basic and applied nuclear physics, from nuclear astrophysics to nuclear criticality safety. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Prototype metal artefact reduction algorithm in flat panel computed tomography - evaluation in patients undergoing transarterial hepatic radioembolisation.

    Science.gov (United States)

    Hamie, Qeumars Mustafa; Kobe, Adrian Raoul; Mietzsch, Leif; Manhart, Michael; Puippe, Gilbert Dominique; Pfammatter, Thomas; Guggenberger, Roman

    2018-01-01

    To investigate the effect of an on-site prototype metal artefact reduction (MAR) algorithm in cone-beam CT-catheter-arteriography (CBCT-CA) in patients undergoing transarterial radioembolisation (RE) of hepatic masses. Ethical board approved retrospective study of 29 patients (mean 63.7±13.7 years, 11 female), including 16 patients with arterial metallic coils, undergoing CBCT-CA (8s scan, 200 degrees rotation, 397 projections). Image reconstructions with and without prototype MAR algorithm were evaluated quantitatively (streak-artefact attenuation changes) and qualitatively (visibility of hepatic parenchyma and vessels) in near- (3cm) of artefact sources (metallic coils and catheters). Quantitative and qualitative measurements of uncorrected and MAR corrected images and different artefact sources were compared RESULTS: Quantitative evaluation showed significant reduction of near- and far-field streak-artefacts with MAR for both artefact sources (p0.05). Inhomogeneities of attenuation values were significantly higher for metallic coils compared to catheters (pprototype MAR algorithm improves image quality in proximity of metallic coil and catheter artefacts. • Metal objects cause artefacts in cone-beam computed tomography (CBCT) imaging. • These artefacts can be corrected by metal artefact reduction (MAR) algorithms. • Corrected images show significantly better visibility of nearby hepatic vessels and tissue. • Better visibility may facilitate image interpretation, save time and radiation exposure.

  15. Evaluation of manometric temperature measurement (MTM), a process analytical technology tool in freeze drying, part III: heat and mass transfer measurement.

    Science.gov (United States)

    Tang, Xiaolin Charlie; Nail, Steven L; Pikal, Michael J

    2006-01-01

    This article evaluates the procedures for determining the vial heat transfer coefficient and the extent of primary drying through manometric temperature measurement (MTM). The vial heat transfer coefficients (Kv) were calculated from the MTM-determined temperature and resistance and compared with Kv values determined by a gravimetric method. The differences between the MTM vial heat transfer coefficients and the gravimetric values are large at low shelf temperature but smaller when higher shelf temperatures were used. The differences also became smaller at higher chamber pressure and smaller when higher resistance materials were being freeze-dried. In all cases, using thermal shields greatly improved the accuracy of the MTM Kv measurement. With use of thermal shields, the thickness of the frozen layer calculated from MTM is in good agreement with values obtained gravimetrically. The heat transfer coefficient "error" is largely a direct result of the error in the dry layer resistance (ie, MTM-determined resistance is too low). This problem can be minimized if thermal shields are used for freeze-drying. With suitable use of thermal shields, accurate Kv values are obtained by MTM; thus allowing accurate calculations of heat and mass flow rates. The extent of primary drying can be monitored by real-time calculation of the amount of remaining ice using MTM data, thus providing a process analytical tool that greatly improves the freeze-drying process design and control.

  16. Separating drought effects from roof artefacts on ecosystem processes in a grassland drought experiment

    Science.gov (United States)

    Vogel, Anja; Fester, Thomas; Eisenhauer, Nico; Scherer-Lorenzen, Michael; Schmid, Bernhard; Weisser, Wolfgang W.; Weigelt, Alexandra

    2013-04-01

    Given the predictions of increasing risk of long drought periods under various climate change scenarios, there have been numerous experimental field studies simulating drought using transparent roofs in different ecosystems and regions. Such roofs may, however, have unknown side effects, here called artefacts, on the response variables potentially confounding experimental results and misleading conclusions. Knowing the ecosystem response to such roof artefacts is therefore indispensible to correctly predict the effects of drought on the composition and functioning of ecosystems. We therefore aimed at filling this gap by studying the relevance of roof artefacts in a temperate grassland ecosystem. We compared pure drought effects to roof artefacts by measuring the response of three ecosystem properties (aboveground biomass, litter decomposition and plant metabolite profiles). We realized three treatments: a drought treatment simulated by means of transparent roofs, an unroofed control treatment receiving natural rainfall and a roofed control, with rain water applied according to ambient conditions. The roof constructions in our experiment caused a slight change in air (+0.14 °C during night) and soil (-0.45°C on warm days, +0.25 °C on cold nights) temperatures while photosynthetically active radiation was decreased (-16%) on bright days. Aboveground plant community biomass was reduced in the drought treatment (-41%), but there was no significant difference between the roofed and unroofed control, thus there was no measurable response of aboveground biomass to roof artefacts, but a considerable response to drought. Compared to the unroofed control, litter decomposition was decreased both in the drought treatment (-26%) and in the roofed control treatment (-18%), suggesting a response of litter decomposition to roof artefacts in addition to drought. Similarly, aboveground metabolite profiles in the model plant species Medicago x varia were significantly different

  17. Optimization of metal artefact reduction (MAR) sequences for MRI of total hip prostheses.

    Science.gov (United States)

    Toms, A P; Smith-Bateman, C; Malcolm, P N; Cahir, J; Graves, M

    2010-06-01

    To describe the relative contribution of matrix size and bandwidth to artefact reduction in order to define optimal sequence parameters for metal artefact reduction (MAR) sequences for MRI of total hip prostheses. A phantom was created using a Charnley total hip replacement. Mid-coronal T1-weighted (echo time 12ms, repetition time 400ms) images through the prosthesis were acquired with increasing bandwidths (150, 300, 454, 592, and 781Hz/pixel) and increasing matrixes of 128, 256, 384, 512, 640, and 768 pixels square. Signal loss from the prosthesis and susceptibility artefact was segmented using an automated tool. Over 90% of the achievable reduction in artefacts was obtained with matrixes of 256x256 or greater and a receiver bandwidth of approximately 400Hz/pixel or greater. Thereafter increasing the receiver bandwidth or matrix had little impact on reducing susceptibility artefacts. Increasing the bandwidth produced a relative fall in the signal-to-noise ratio (SNR) of between 49 and 56% for a given matrix, but, in practice, the image quality was still satisfactory even with the highest bandwidth and largest matrix sizes. The acquisition time increased linearly with increasing matrix parameters. Over 90% of the achievable metal artefact reduction can be realized with mid-range matrices and receiver bandwidths on a clinical 1.5T system. The loss of SNR from increasing receiver bandwidth, is preferable to long acquisition times, and therefore, should be the main tool for reducing metal artefact. Copyright 2010 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  18. Electrically evoked compound action potentials artefact rejection by independent component analysis: procedure automation.

    Science.gov (United States)

    Akhoun, Idrick; McKay, Colette; El-Deredy, Wael

    2015-01-15

    Independent-components-analysis (ICA) successfully separated electrically-evoked compound action potentials (ECAPs) from the stimulation artefact and noise (ECAP-ICA, Akhoun et al., 2013). This paper shows how to automate the ECAP-ICA artefact cancellation process. Raw-ECAPs without artefact rejection were consecutively recorded for each stimulation condition from at least 8 intra-cochlear electrodes. Firstly, amplifier-saturated recordings were discarded, and the data from different stimulus conditions (different current-levels) were concatenated temporally. The key aspect of the automation procedure was the sequential deductive source categorisation after ICA was applied with a restriction to 4 sources. The stereotypical aspect of the 4 sources enables their automatic classification as two artefact components, a noise and the sought ECAP based on theoretical and empirical considerations. The automatic procedure was tested using 8 cochlear implant (CI) users and one to four stimulus electrodes. The artefact and noise sources were successively identified and discarded, leaving the ECAP as the remaining source. The automated ECAP-ICA procedure successfully extracted the correct ECAPs compared to standard clinical forward masking paradigm in 22 out of 26 cases. ECAP-ICA does not require extracting the ECAP from a combination of distinct buffers as it is the case with regular methods. It is an alternative that does not have the possible bias of traditional artefact rejections such as alternate-polarity or forward-masking paradigms. The ECAP-ICA procedure bears clinical relevance, for example as the artefact rejection sub-module of automated ECAP-threshold detection techniques, which are common features of CI clinical fitting software. Copyright © 2014. Published by Elsevier B.V.

  19. Excluding the Excluded : New Labour’s Penchant for Punishment

    OpenAIRE

    Bell, Emma

    2011-01-01

    New Labour’s emphasis on personal responsibility leads it to shun any definition of the socially excluded as the passive victims of socio-economic circumstances. It encourages them to act positively to re-integrate themselves into “mainstream” society by participating in welfare-to-work schemes etc. Importantly, this involves an acceptance of a certain value system as promoted by the government. Refusal to accept these values - often taken to denote membership of an underclass (increasingly u...

  20. SOURCES OF ARTEFACTS IN SYNTHETIC APERTURE RADAR INTERFEROMETRY DATA SETS

    Directory of Open Access Journals (Sweden)

    K. Becek

    2012-07-01

    Full Text Available In recent years, much attention has been devoted to digital elevation models (DEMs produced using Synthetic Aperture Radar Interferometry (InSAR. This has been triggered by the relative novelty of the InSAR method and its world-famous product—the Shuttle Radar Topography Mission (SRTM DEM. However, much less attention, if at all, has been paid to sources of artefacts in SRTM. In this work, we focus not on the missing pixels (null pixels due to shadows or the layover effect, but rather on outliers that were undetected by the SRTM validation process. The aim of this study is to identify some of the causes of the elevation outliers in SRTM. Such knowledge may be helpful to mitigate similar problems in future InSAR DEMs, notably the ones currently being developed from data acquired by the TanDEM-X mission. We analysed many cross-sections derived from SRTM. These cross-sections were extracted over the elevation test areas, which are available from the Global Elevation Data Testing Facility (GEDTF whose database contains about 8,500 runways with known vertical profiles. Whenever a significant discrepancy between the known runway profile and the SRTM cross-section was detected, a visual interpretation of the high-resolution satellite image was carried out to identify the objects causing the irregularities. A distance and a bearing from the outlier to the object were recorded. Moreover, we considered the SRTM look direction parameter. A comprehensive analysis of the acquired data allows us to establish that large metallic structures, such as hangars or car parking lots, are causing the outliers. Water areas or plain wet terrains may also cause an InSAR outlier. The look direction and the depression angle of the InSAR system in relation to the suspected objects influence the magnitude of the outliers. We hope that these findings will be helpful in designing the error detection routines of future InSAR or, in fact, any microwave aerial- or space

  1. 48 CFR 9.404 - Excluded Parties List System.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Excluded Parties List... ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 9.404 Excluded Parties List System. (a) The General Services Administration (GSA)— (1) Operates the web-based Excluded Parties...

  2. 29 CFR 1471.950 - Excluded Parties List System

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Excluded Parties List System 1471.950 Section 1471.950... GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 1471.950 Excluded Parties List System Excluded Parties List System (EPLS) means the list maintained and disseminated by the General Services...

  3. 26 CFR 1.1563-2 - Excluded stock.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Excluded stock. 1.1563-2 Section 1.1563-2...) INCOME TAXES Certain Controlled Corporations § 1.1563-2 Excluded stock. (a) Certain stock excluded. For purposes of sections 1561 through 1563 and the regulations thereunder, the term “stock” does not include...

  4. Metallic artefacts in MR imaging: effects of main field orientation and strength

    Energy Technology Data Exchange (ETDEWEB)

    Guermazi, A.; Miaux, Y.; Zaim, S.; Peterfy, C.G.; White, D.; Genant, H.K

    2003-04-01

    AIM: To determine the effect of metallic implant positioning on magnetic resonance (MR) imaging artefacts, and to determine the optimal imaging parameters for minimization of metallic artefacts. MATERIALS AND METHODS: In a phantom and in three joints with non-ferromagnetic metallic implants imaged at 1.5 and/or at 0.2 T, we examined the influence of the static magnetic field (B{sub 0}) strength and orientation, frequency-encoding direction, and type of imaging sequence on metallic artefacts. RESULTS: The impact of artefacts caused by metallic objects depends mainly on the relationship between the anatomy of interest and the orientation of the object relative to the direction of B{sub 0}. The main field strength plays a less important role, but its orientation depends on the type of MR imager. CONCLUSION: MR artefacts can be easily minimized by optimally positioning patients with metallic implants in the magnet. Knowledge of how this influences MR imaging is helpful in patient selection and guiding limb positioning.

  5. Automated Detection of Motion Artefacts in MR Imaging Using Decision Forests

    Directory of Open Access Journals (Sweden)

    Benedikt Lorch

    2017-01-01

    Full Text Available The acquisition of a Magnetic Resonance (MR scan usually takes longer than subjects can remain still. Movement of the subject such as bulk patient motion or respiratory motion degrades the image quality and its diagnostic value by producing image artefacts like ghosting, blurring, and smearing. This work focuses on the effect of motion on the reconstructed slices and the detection of motion artefacts in the reconstruction by using a supervised learning approach based on random decision forests. Both the effects of bulk patient motion occurring at various time points in the acquisition on head scans and the effects of respiratory motion on cardiac scans are studied. Evaluation is performed on synthetic images where motion artefacts have been introduced by altering the k-space data according to a motion trajectory, using the three common k-space sampling patterns: Cartesian, radial, and spiral. The results suggest that a machine learning approach is well capable of learning the characteristics of motion artefacts and subsequently detecting motion artefacts with a confidence that depends on the sampling pattern.

  6. Characterization and correction of cupping effect artefacts in cone beam CT

    Science.gov (United States)

    Hunter, AK; McDavid, WD

    2012-01-01

    Objective The purpose of this study was to demonstrate and correct the cupping effect artefact that occurs owing to the presence of beam hardening and scatter radiation during image acquisition in cone beam CT (CBCT). Methods A uniform aluminium cylinder (6061) was used to demonstrate the cupping effect artefact on the Planmeca Promax 3D CBCT unit (Planmeca OY, Helsinki, Finland). The cupping effect was studied using a line profile plot of the grey level values using ImageJ software (National Institutes of Health, Bethesda, MD). A hardware-based correction method using copper pre-filtration was used to address this artefact caused by beam hardening and a software-based subtraction algorithm was used to address scatter contamination. Results The hardware-based correction used to address the effects of beam hardening suppressed the cupping effect artefact but did not eliminate it. The software-based correction used to address the effects of scatter resulted in elimination of the cupping effect artefact. Conclusion Compensating for the presence of beam hardening and scatter radiation improves grey level uniformity in CBCT. PMID:22378754

  7. Motion Artefacts in MRI: a Complex Problem with Many Partial Solutions

    Science.gov (United States)

    Zaitsev, Maxim; Maclaren, Julian.; Herbst, Michael

    2015-01-01

    Subject motion during magnetic resonance imaging (MRI) has been problematic since its introduction as a clinical imaging modality. While sensitivity to particle motion or blood flow can be used to provide useful image contrast, bulk motion presents a considerable problem in the majority of clinical applications. It is one of the most frequent sources of artefacts. Over 30 years of research have produced numerous methods to mitigate or correct for motion artefacts, but no single method can be applied in all imaging situations. Instead, a ‘toolbox’ of methods exists, where each tool is suitable for some tasks, but not for others. This article reviews the origins of motion artefacts and presents current mitigation and correction methods. In some imaging situations, the currently available motion correction tools are highly effective; in other cases, appropriate tools still need to be developed. It seems likely that this multifaceted approach will be what eventually solves the motion sensitivity problem in MRI, rather than a single solution that is effective in all situations. This review places a strong emphasis on explaining the physics behind the occurrence of such artefacts, with the aim of aiding artefact detection and mitigation in particular clinical situations. PMID:25630632

  8. Quality Enhancement and Nerve Fibre Layer Artefacts Removal in Retina Fundus Images by Off Axis Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Giancardo, Luca [ORNL; Meriaudeau, Fabrice [ORNL; Karnowski, Thomas Paul [ORNL; Li, Yaquin [University of Tennessee, Knoxville (UTK); Tobin Jr, Kenneth William [ORNL; Chaum, Edward [University of Tennessee, Knoxville (UTK)

    2011-01-01

    Retinal fundus images acquired with non-mydriatic digital fundus cameras are a versatile tool for the diagnosis of various retinal diseases. Because of the ease of use of newer camera models and their relative low cost, these cameras are employed worldwide by retina specialists to diagnose diabetic retinopathy and other degenerative diseases. Even with relative ease of use, the images produced by these systems sometimes suffer from reflectance artefacts mainly due to the nerve fibre layer (NFL) or other camera lens related reflections. We propose a technique that employs multiple fundus images acquired from the same patient to obtain a single higher quality image without these reflectance artefacts. The removal of bright artefacts, and particularly of NFL reflectance, can have great benefits for the reduction of false positives in the detection of retinal lesions such as exudate, drusens and cotton wool spots by automatic systems or manual inspection. If enough redundant information is provided by the multiple images, this technique also compensates for a suboptimal illumination. The fundus images are acquired in straightforward but unorthodox manner, i.e. the stare point of the patient is changed between each shot but the camera is kept fixed. Between each shot, the apparent shape and position of all the retinal structures that do not exhibit isotropic reflectance (e.g. bright artefacts) change. This physical effect is exploited by our algorithm in order to extract the pixels belonging to the inner layers of the retina, hence obtaining a single artefacts-free image.

  9. Removing artefacts from TMS-EEG recordings using independent component analysis: importance for assessing prefrontal and motor cortex network properties.

    Science.gov (United States)

    Rogasch, Nigel C; Thomson, Richard H; Farzan, Faranak; Fitzgibbon, Bernadette M; Bailey, Neil W; Hernandez-Pavon, Julio C; Daskalakis, Zafiris J; Fitzgerald, Paul B

    2014-11-01

    The combination of transcranial magnetic stimulation and electroencephalography (TMS-EEG) is emerging as a powerful tool for causally investigating cortical mechanisms and networks. However, various artefacts contaminate TMS-EEG recordings, particularly over regions such as the dorsolateral prefrontal cortex (DLPFC). The aim of this study was to substantiate removal of artefacts from TMS-EEG recordings following stimulation of the DLPFC and motor cortex using independent component analysis (ICA). 36 healthy volunteers (30.8 ± 9 years, 9 female) received 75 single TMS pulses to the left DLPFC or left motor cortex while EEG was recorded from 57 electrodes. A subset of 9 volunteers also received 50 sham pulses. The large TMS artefact and early muscle activity (-2 to ~15 ms) were removed using interpolation and the remaining EEG signal was processed in two separate ICA runs using the FastICA algorithm. Five sub-types of TMS-related artefacts were manually identified: remaining muscle artefacts, decay artefacts, blink artefacts, auditory-evoked potentials and other noise-related artefacts. The cause of proposed blink and auditory-evoked potentials was assessed by concatenating known artefacts (i.e. voluntary blinks or auditory-evoked potentials resulting from sham TMS) to the TMS trials before ICA and evaluating grouping of resultant independent components (ICs). Finally, we assessed the effect of removing specific artefact types on TMS-evoked potentials (TEPs) and TMS-evoked oscillations. Over DLPFC, ICs from proposed muscle and decay artefacts correlated with TMS-evoked muscle activity size, whereas proposed TMS-evoked blink ICs combined with voluntary blinks and auditory ICs with auditory-evoked potentials from sham TMS. Individual artefact sub-types characteristically distorted each measure of DLPFC function across the scalp. When free of artefact, TEPs and TMS-evoked oscillations could be measured following DLPFC stimulation. Importantly, characteristic TEPs

  10. METHODOLOGY TO CREATE DIGITAL AND VIRTUAL 3D ARTEFACTS IN ARCHAEOLOGY

    Directory of Open Access Journals (Sweden)

    Calin Neamtu

    2016-12-01

    Full Text Available The paper presents a methodology to create 3D digital and virtual artefacts in the field of archaeology using CAD software solution. The methodology includes the following steps: the digitalization process, the digital restoration and the dissemination process within a virtual environment. The resulted 3D digital artefacts have to be created in files formats that are compatible with a large variety of operating systems and hardware configurations such as: computers, graphic tablets and smartphones. The compatibility and portability of these 3D file formats has led to a series of quality related compromises to the 3D models in order to integrate them on in a wide variety of application that are running on different hardware configurations. The paper illustrates multiple virtual reality and augmented reality application that make use of the virtual 3D artefacts that have been generated using this methodology.

  11. The Identification and Treatment of a Unique Cache of Organic Artefacts from Menorca's Bronze Age

    Directory of Open Access Journals (Sweden)

    Howard Wellman

    1996-05-01

    Full Text Available A unique cache of organic artefacts was excavated in March 1995 from Cova d'es Carritx, Menorca, a sealed cave system that was used as a mortuary in the late second or early first millennia BC. This deposit included a set of unique conical tubes made of bovine horn sheath, stuffed with hair or other fibres, and capped with wooden disks. Other materials were found in association with the tubes, including a copper-tin alloy rod. The decision to display some of the tubes required a degree of consolidative strengthening which would conflict with conservation aims of preserving the artefacts essentially unchanged for future study. The two most complete artefacts were treated by localised consolidation (with Paraloid B-72, while the other two were left untreated. The two consolidated tubes were provided with display-ready mounts, while the others were packaged to minimise the effects of handling and long-term storage.

  12. An Evaluation View of an Ensemble Artefact for Decision Support using Action Design Research

    Directory of Open Access Journals (Sweden)

    Dale MacKrell

    2016-11-01

    Full Text Available This paper investigates the integration of content, context and process (CCP into the Action Design Research (ADR framework to account for the interplay of organisational issues in artefact design and development. The investigation is conducted through a case study in which successive ICT student teams incrementally build, over several semesters, a tailored, low cost business intelligence (BI system as an ensemble artefact for an organisation in the not-for-profit (NFP sector. During project development, CCP’s human-centred approach to evaluation complements ADR’s more prescribed technology-driven software testing. The integration of CCP into ADR as an evaluation view offers an holistic approach to assessing an ensemble artefact. The resultant conceptual framework is presented as a model with an explication of unexpected design and research outcomes.

  13. Preliminary Results of Ocular Artefacts Identification in EEC Series by Neural Network

    Directory of Open Access Journals (Sweden)

    M. Kofronova

    1996-06-01

    Full Text Available The human electroencephalogram (EEG, is record of the electrical activity of the brain and contains useful diagnostic information on a variety of neurological disorders. Normal EEG signal are usually registered from electrodes placed on the scalp, and are often very small in amplitude, of 20 µV. The EEG, like all biomedical signals, is very susceptible to a variety of large signal contamination or artefacts (signals of other than brain activity which reduce its clinical usefulness. For example, blinking or moving eyes produces large electrical potentials around the eyes called the electrooculogram (EOG. The EOG spreads across the scalp to contaminate the EEG, when it is referred to as an ocular artefact (OA. This paper includes method of identification portion of the EEG record where ocular artefact appears and classification its type by neural network.

  14. Problem Solving of Low Data Throughput on Mobile Devices by Artefacts Prebuffering

    Directory of Open Access Journals (Sweden)

    Krejcar Ondrej

    2009-01-01

    Full Text Available The paper deals with a problem of low data throughput on wirelessly connected mobile devices and a possibility to solve this problem by prebuffering of selected artefacts. The basics are in determining the problem parts of a mobile device and solve the problem by a model of data prebuffering-based system enhancement for locating and tracking users inside the buildings. The framework uses a WiFi network infrastructure to allow the mobile device determine its indoor position. User location is used for data prebuffering and for pushing information from a server to PDAs. All server data are saved as artefacts with its indoor position information. Accessing prebuffered data on a mobile device can significantly improve a response time needed to view large multimedia data. The solution was tested on a facility management information system built on purpose with a testing collection of about hundred large size artefacts.

  15. What Then Happens When Interaction is Not Possible: The Virtuosic Interpretation of Ergodic Artefacts

    Directory of Open Access Journals (Sweden)

    Miguel Carvalhais

    2015-11-01

    Full Text Available Procedural systems allow unique modes of authorship and singular aesthetic experiences. As creators and users of these systems, we need to be aware that their aesthetic potential is not solely defined by interaction but that interpretation, and the capacity to understand and simulate the processes taking place within these artefacts is highly significant. This paper argues that although direct interaction is usually the most discernible component in the relationship between ergodic artefacts and their users, ergodicity does not necessarily imply interaction. Non-interactive procedural artefacts may allow the development of ergodic experiences through interpretation, and the probing of the system by its reader through simulations. We try to set the grounds for designing towards virtuosic interpretation, an activity that we may describe as the ergodic experience developed by means of mental simulation through the development of theories of systems.

  16. The XRF mapping of archaeological artefacts as the key to understanding of the past.

    Science.gov (United States)

    Kozak, L; Niedzielski, P; Jakubowski, K; Michałowski, A; Krzyżanowska, M; Teska, M; Wawrzyniak, M; Kot, K; Piotrowska, M

    2016-04-07

    The article describes the X-ray fluorescence (XRF) studies on the chemical composition of archaeological artefacts. The mapping of the concentration of selected elements has been used to recognise the way of object production and the use. The obtained data allowed to obtain the new information, which is impossible to gain by use of different methods. 'The data obtained from the chemical composition of the particular parts of the objects may be used for the interpretation of the manufacturing technology or the primal form of the objects. Additionally, the knowledge obtained from the chemical composition of the different parts of the artefacts may be essential for the selection of the protection and conservation methods. The present studies can be useful to improve knowledge about the level of former craftsmanship. These knowledge allow us to exam archaeological artefacts in a new light, and these findings can also broaden the archaeological knowledge horizons and provide good bases for further detailed studies.

  17. A motion artefact study and locally deforming objects in computerized tomography

    Science.gov (United States)

    Hahn, Bernadette N.

    2017-11-01

    Movements of the object during the data collection in computerized tomography can introduce motion artefacts in the reconstructed image. They can be reduced by employing information about the dynamic behaviour within the reconstruction step. However, inaccuracies concerning the movement are inevitable in practice. In this article, we give an explicit characterization of what is visible in an image obtained by a reconstruction algorithm with incorrect motion information. Then, we use this result to study in detail the situation of locally deforming objects, i.e. individual parts of the object have a different dynamic behaviour. In this context, we prove that additional artefacts arise due to the global nature of the Radon transform, even if the motion is exactly known. Based on our analysis, we propose a numerical scheme to reduce these artefacts in the reconstructed image. All our results are illustrated by numerical examples.

  18. Non-invasive NMR stratigraphy of a multi-layered artefact: an ancient detached mural painting.

    Science.gov (United States)

    Di Tullio, Valeria; Capitani, Donatella; Presciutti, Federica; Gentile, Gennaro; Brunetti, Brunetto Giovanni; Proietti, Noemi

    2013-10-01

    NMR stratigraphy was used to investigate in situ, non-destructively and non-invasively, the stratigraphy of hydrogen-rich layers of an ancient Nubian detached mural painting. Because of the detachment procedure, a complex multi-layered artefact was obtained, where, besides layers of the original mural painting, also the materials used during the procedure all became constitutive parts of the artefact. NMR measurements in situ enabled monitoring of the state of conservation of the artefact and planning of minimum representative sampling to validate results obtained in situ by solid-state NMR analysis of the samples. This analysis enabled chemical characterization of all organic materials. Use of reference compounds and prepared specimens assisted data interpretation.

  19. Improved artefact removal from EEG using Canonical Correlation Analysis and spectral slope.

    Science.gov (United States)

    Janani, Azin S; Grummett, Tyler S; Lewis, Trent W; Fitzgibbon, Sean P; Whitham, Emma M; DelosAngeles, Dylan; Bakhshayesh, Hanieh; Willoughby, John O; Pope, Kenneth J

    2018-01-31

    Contamination of scalp measurement by tonic muscle artefacts, even in resting positions, is an unavoidable issue in EEG recording. These artefacts add significant energy to the recorded signals, particularly at high frequencies. To enable reliable interpretation of subcortical brain activity, it is necessary to detect and discard this contamination. We introduce a new automatic muscle-removal approach based on the traditional Blind Source Separation-Canonical Correlation Analysis (BSS-CCA) method and the spectral slope of its components. We show that CCA-based muscle-removal methods can discriminate between signals with high correlation coefficients (brain, mains artefact) and signals with low correlation coefficients (white noise, muscle). We also show that typical BSS-CCA components are not purely from one source, but are mixtures from multiple sources, limiting the performance of BSS-CCA in artefact removal. We demonstrate, using our paralysis dataset, improved performance using BSS-CCA followed by spectral-slope rejection. This muscle removal approach can reduce high-frequency muscle contamination of EEG, especially at peripheral channels, while preserving steady-state brain responses in cognitive tasks. This approach is automatic and can be applied on any sample of data easily. The results show its performance is comparable with the ICA method in removing muscle contamination and has significantly lower computational complexity. We identify limitations of the traditional BSS-CCA approach to artefact removal in EEG, propose and test an extension based on spectral slope that makes it automatic and improves its performance, and results in performance comparable to competitors such as ICA-based artefact removal. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Characterization of measurement artefacts in fluoroptic temperature sensors: implications for laser thermal therapy at 810 nm.

    Science.gov (United States)

    Davidson, Sean R H; Vitkin, I Alex; Sherar, Michael D; Whelan, William M

    2005-04-01

    Fluoroptic sensors are used to measure interstitial temperatures but their utility for monitoring laser interstitial thermal therapy (LITT) is unclear because these sensors exhibit a measurement artefact when exposed to the near-infrared (NIR) treatment light. This study investigates the cause of the artefact to determine whether fluoroptic sensors can provide reliable temperature measurements during LITT. The temperature rise measured by a fluoroptic sensor irradiated in non-absorbing media (air and water) was considered an artefact. Temperature rise was measured as a function of distance from a laser source. Two different sensor designs and several laser powers were investigated. A relationship between fluence rate and measurement artefact in water was determined and coupled with a numerical simulation of LITT in liver to estimate the error in temperature measurements made by fluoroptic sensors in tissue in proximity to the laser source. The effect of ambient light on the performance of sensors capped with a transparent material ("clear-capped sensors") was also investigated. The temperature rise recorded in air by both clear- and black-capped fluoroptic sensors decreased with distance from a laser source in a manner similar to fluence rate. Sensor cap material, laser power, and the thermal properties of the surrounding medium affected the magnitude of the artefact. Numerical simulations indicated that the accuracy of a clear-capped fluoroptic sensor used to monitor a typical LITT treatment in liver is > 1 degrees C provided the sensor is further than approximately 3 mm from the source. It was also shown that clear-capped fluoroptic sensors are affected by ambient light. The measurement artefact experienced by both black-capped and clear-capped fluoroptic sensors irradiated by NIR light scales with fluence rate and is due to direct absorption of the laser light, which results in sensor self-heating. Clear-capped fluoroptic sensors can be used to accurately

  1. Automatic artefact removal in a self-paced hybrid brain- computer interface system

    Directory of Open Access Journals (Sweden)

    Yong Xinyi

    2012-07-01

    Full Text Available Abstract Background A novel artefact removal algorithm is proposed for a self-paced hybrid brain-computer interface (BCI system. This hybrid system combines a self-paced BCI with an eye-tracker to operate a virtual keyboard. To select a letter, the user must gaze at the target for at least a specific period of time (dwell time and then activate the BCI by performing a mental task. Unfortunately, electroencephalogram (EEG signals are often contaminated with artefacts. Artefacts change the quality of EEG signals and subsequently degrade the BCI’s performance. Methods To remove artefacts in EEG signals, the proposed algorithm uses the stationary wavelet transform combined with a new adaptive thresholding mechanism. To evaluate the performance of the proposed algorithm and other artefact handling/removal methods, semi-simulated EEG signals (i.e., real EEG signals mixed with simulated artefacts and real EEG signals obtained from seven participants are used. For real EEG signals, the hybrid BCI system’s performance is evaluated in an online-like manner, i.e., using the continuous data from the last session as in a real-time environment. Results With semi-simulated EEG signals, we show that the proposed algorithm achieves lower signal distortion in both time and frequency domains. With real EEG signals, we demonstrate that for dwell time of 0.0s, the number of false-positives/minute is 2 and the true positive rate (TPR achieved by the proposed algorithm is 44.7%, which is more than 15.0% higher compared to other state-of-the-art artefact handling methods. As dwell time increases to 1.0s, the TPR increases to 73.1%. Conclusions The proposed artefact removal algorithm greatly improves the BCI’s performance. It also has the following advantages: a it does not require additional electrooculogram/electromyogram channels, long data segments or a large number of EEG channels, b it allows real-time processing, and c it reduces signal distortion.

  2. MR susceptibility artefact associated with the use of Barricade coils for treatment of intracranial aneurysms.

    Science.gov (United States)

    Gontu, Vamsi; McConachie, Norman

    2015-04-01

    Magnetic resonance angiography (MRA) is commonly used to follow up patients after endovascular treatment for intracranial aneurysms. Magnetic resonance artefacts from coil constructs may impair image quality and jeopardise the evaluation of the effectiveness of treatment and review of adjacent vasculature. We present here a technical note on the usage of Barricade coils recently introduced at our institution. The MRA artefacts associated with these coils may make it impossible to ascertain aneurysm closure and anatomy. Hence these patients would need to be recalled for digital subtraction angiograms for a complete neuroradiological follow-up. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  3. Reducing beam hardening effects and metal artefacts using Medipix3RX: With applications from biomaterial science

    CERN Document Server

    Rajendran, K; de Ruiter, N J A; Chernoglazov, A I; Panta, R K; Butler, A P H; Butler, P H; Bell, S T; Anderson, N G; Woodfield, T B F; Tredinnick, S J; Healy, J L; Bateman, C J; Aamir, R; Doesburg, R M N; Renaud, P F; Gieseg, S P; Smithies, D J; Mohr, J L; Mandalika, V B H; Opie, A M T; Cook, N J; Ronaldson, J P; Nik, S J; Atharifard, A; Clyne, M; Bones, P J; Bartneck, C; Grasset, R; Schleich, N; Billinghurst, M

    2014-01-01

    This paper discusses methods for reducing beam hardening effects using spectral data for biomaterial applications. A small-animal spectral scanner operating in the diagnostic energy range was used. We investigate the use of photon-processing features of the Medipix3RX ASIC in reducing beam hardening and associated artefacts. A fully operational charge summing mode was used during the imaging routine. We present spectral data collected for metal alloy samples, its analysis using algebraic 3D reconstruction software and volume visualisation using a custom volume rendering software. Narrow high energy acquisition using the photon-processing detector revealed substantial reduction in beam hardening effects and metal artefacts.

  4. Automatic artefact removal in a self-paced hybrid brain- computer interface system

    Science.gov (United States)

    2012-01-01

    Background A novel artefact removal algorithm is proposed for a self-paced hybrid brain-computer interface (BCI) system. This hybrid system combines a self-paced BCI with an eye-tracker to operate a virtual keyboard. To select a letter, the user must gaze at the target for at least a specific period of time (dwell time) and then activate the BCI by performing a mental task. Unfortunately, electroencephalogram (EEG) signals are often contaminated with artefacts. Artefacts change the quality of EEG signals and subsequently degrade the BCI’s performance. Methods To remove artefacts in EEG signals, the proposed algorithm uses the stationary wavelet transform combined with a new adaptive thresholding mechanism. To evaluate the performance of the proposed algorithm and other artefact handling/removal methods, semi-simulated EEG signals (i.e., real EEG signals mixed with simulated artefacts) and real EEG signals obtained from seven participants are used. For real EEG signals, the hybrid BCI system’s performance is evaluated in an online-like manner, i.e., using the continuous data from the last session as in a real-time environment. Results With semi-simulated EEG signals, we show that the proposed algorithm achieves lower signal distortion in both time and frequency domains. With real EEG signals, we demonstrate that for dwell time of 0.0s, the number of false-positives/minute is 2 and the true positive rate (TPR) achieved by the proposed algorithm is 44.7%, which is more than 15.0% higher compared to other state-of-the-art artefact handling methods. As dwell time increases to 1.0s, the TPR increases to 73.1%. Conclusions The proposed artefact removal algorithm greatly improves the BCI’s performance. It also has the following advantages: a) it does not require additional electrooculogram/electromyogram channels, long data segments or a large number of EEG channels, b) it allows real-time processing, and c) it reduces signal distortion. PMID:22838499

  5. A Comparative Performance Analysis of FDM Machines Based on a Calibration Artefact

    DEFF Research Database (Denmark)

    D'Angelo, Greta; Nielsen, Jakob Skov; Rasmussen, Jeppe

    2014-01-01

    During the past ten years Additive Manufacturing (AM) technologies have been constantly developing in terms of materials and processes. This allows the use of the AM not only during the preproduction but also for the manufacturing of final components for commercial use [1], [2]. However one...... and there are no standards to compare them with. To overcome this problem, a method to evaluate the performance of AM machine tools based on the printing of an artefact and the subsequent measuring of its features is proposed and shown. This paper shows a validation of the method by means of a laser interferometer....... Furthermore, different AM machines are tested using the printed artefact....

  6. Effect of anatomical region on the formation of metal artefacts produced by dental implants in cone beam computed tomographic images.

    Science.gov (United States)

    Machado, Alessiana Helena; Fardim, Karolina Aparecida Castilho; de Souza, Camila Furtado; Sotto-Maior, Bruno Salles; Assis, Neuza Maria Souza Picorelli; Devito, Karina Lopes

    2018-01-10

    To quantitatively compare metal artefacts produced by implants in different maxillomandibular regions on cone beam CT (CBCT) images. A total of 200 implants selected from CBCT examinations were divided into four groups: Group 1 (n = 50)-implants located in the anterior maxilla; Group 2 (n = 50)-implants located in the posterior maxilla; Group 3 (n = 50)-implants located in the anterior mandible and Group 4 (n = 50)-implants located in the posterior mandible. The implants were further classified as isolated or adjacent to other implants. Three axial reconstructions were selected for each sampled implant (apical, middle and cervical). On each slice, the artefacts produced by the implants were counted. The Mann-Whitney test was used to compare the variables between groups. The Kruskal-Wallis and Student-Newman-Keuls tests were used to compare the axial reconstructions. The mandible showed a greater number of artefacts than the maxilla (apical image: p = 0.0024; middle image: p < 0.0001). The anterior region produced more artefacts than the posterior region (apical image: p = 0.0105; middle image: p < 0.0316). There was no significant difference in the number of artefacts between isolated and adjacent implants, and the cervical image was most affected by artefacts. Dental implants always produce metal artefacts in CBCT images, and these artefacts are affected by the anatomical location in the dental arch.

  7. Artefact expression associated with several cone-beam computed tomographic machines when imaging root filled teeth.

    Science.gov (United States)

    Vasconcelos, K F; Nicolielo, L F P; Nascimento, M C; Haiter-Neto, F; Bóscolo, F N; Van Dessel, J; EzEldeen, M; Lambrichts, I; Jacobs, R

    2015-10-01

    To evaluate the characteristic artefact patterns associated with teeth root filled with Gutta-percha when scanned with four cone-beam CT devices. Whilst using soft tissue simulation, ten root filled human premolars were placed in empty sockets in a dry human skull. Subsequently, the skull was scanned using 3D Accuitomo 170(®) , WhiteFox(®) , Cranex 3D(®) and Scanora 3D(®) following clinical protocols with the highest resolution and artefact reduction. After proper image registration in OnDemand3D(®) software (Cybermed, Seoul, Korea), each image slice was evaluated by three trained and calibrated dentomaxillofacial radiologists, which scored absence (0) and presence (1) of cupping artefact, hypodense halos and streak artefacts. Kappa test was performed for intra- and interobserver agreement. A moderate to perfect agreement for each observer (intra-observer κ = 0.5-1.0) was found. Agreement between the different observers was moderate to almost perfect for the different artefact patterns (interobserver κ = 0.55-0.9). Cupping artefact was the most prevalent (70%), followed by a hypodense halo (35%) and streak artefacts (16%). The Chi-squared test revealed significantly more streaks in axial slices (P teeth. Continuous efforts are needed to improve CBCT reconstruction algorithms, with a specific focus on reducing artefacts induced by dense dental materials, whilst striving for enhanced image quality at low-radiation doses. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  8. Statistical iterative reconstruction for streak artefact reduction when using multidetector CT to image the dento-alveolar structures

    Science.gov (United States)

    Hayakawa, Y; Kober, C

    2014-01-01

    Objectives: When metallic prosthetic appliances and dental fillings exist in the oral cavity, the appearance of metal-induced streak artefacts is not avoidable in CT images. The aim of this study was to develop a method for artefact reduction using the statistical reconstruction on multidetector row CT images. Methods: Adjacent CT images often depict similar anatomical structures. Therefore, reconstructed images with weak artefacts were attempted using projection data of an artefact-free image in a neighbouring thin slice. Images with moderate and strong artefacts were continuously processed in sequence by successive iterative restoration where the projection data was generated from the adjacent reconstructed slice. First, the basic maximum likelihood–expectation maximization algorithm was applied. Next, the ordered subset–expectation maximization algorithm was examined. Alternatively, a small region of interest setting was designated. Finally, the general purpose graphic processing unit machine was applied in both situations. Results: The algorithms reduced the metal-induced streak artefacts on multidetector row CT images when the sequential processing method was applied. The ordered subset–expectation maximization and small region of interest reduced the processing duration without apparent detriments. A general-purpose graphic processing unit realized the high performance. Conclusions: A statistical reconstruction method was applied for the streak artefact reduction. The alternative algorithms applied were effective. Both software and hardware tools, such as ordered subset–expectation maximization, small region of interest and general-purpose graphic processing unit achieved fast artefact correction. PMID:24754471

  9. From Governing through Data to Governmentality through Data: Artefacts, Strategies and the Digital Turn

    Science.gov (United States)

    Souto-Otero, Manuel; Beneito-Montagut, Roser

    2016-01-01

    The article argues that current discussions about governance through data in education can be fruitfully extended through: (1) the establishment of connections with wider debates about the role of commensuration processes and governmentality in the recreation of education systems; (2) greater emphasis on the "artefacts" through which…

  10. The Sensual and the Conceptual: Artefact-Mediated Kinesthetic Actions and Semiotic Activity

    Science.gov (United States)

    Radford, Luis; Demers, Serge; Guzman, Jose; Cerulli, Michele

    2004-01-01

    In this paper we deal with the problem of the genetic relationship between the sensual and the conceptual in knowledge formation. Transcript and videotape analyses of two small groups of a regular Grade 11 mathematics class shed some light on the dialectics between semiotic activity and artefact-mediated kinesthetic actions. The analyses point to…

  11. Beyond tokenistic participation: using representational artefacts to enable meaningful public participation in health service design.

    Science.gov (United States)

    Morrison, Cecily; Dearden, Andy

    2013-10-01

    A number of recent policies promote public participation in health service design. Yet, a growing literature has articulated a gap between policy aims and actual practice resulting in public participation becoming tokenistic. Drawing on theory from participatory design, we argue that choosing appropriate artefacts to act as representations can structure discussions between public participants and health professionals in ways that both groups find meaningful and valid. Through a case study of a service improvement project in outpatient services for older people, we describe three representational artefacts: emotion maps, stories, and tracing paper, and explain how they helped to mediate interactions between public participants and health professionals. We suggest that using such representational artefacts can provide an alternative approach to participation that stands in contrast to the current focus on the professionalisation of public participants. We conclude that including participatory designers in projects, to chose or design appropriate representational artefacts, can help to address the policy-practice gap of including public participants in health service design. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  12. Development of nondestructive inspection tools for cultural heritage artefacts with 3D THz imaging

    DEFF Research Database (Denmark)

    Dandolo, Corinna Ludovica Koch

    by the fact that often a large portion of an method that handles these problems allowing a clear representation of each subsurface layer in the artwork is presented. Thus, insights about the artistic technique and preservation state of real valuable artefacts were obtained non-invasively, where the 3D...

  13. Entangled ontologies: a sociophilosophical analysis of technological artefacts, subjects, and bodies

    OpenAIRE

    Schyfter, Pablo

    2009-01-01

    Social studies of technology and particularly the sociology of technology have long explored the reticulations between technology and social life. More specifically, the sociology of technology has contributed numerous studies addressing the relationship between technological artefacts and the social order. Following this tradition, feminist studies of technology have developed robust analyses of technology and subjectivity, with particular attention given to questions of gender i...

  14. Decreasing incidence of adenotonsillar problems in Dutch general practice: real or artefact?

    NARCIS (Netherlands)

    Biermans, M.C.J.; Theuns-Lamers, E.H.M.; Spreeuwenberg, P.; Verheij, R.A.; Wouden, J.C. van der; Vries-Robbé, P.F. de; Zielhuis, G.A.

    2009-01-01

    Background: The incidence of hypertrophy and recurrent infections of the tonsils/adenoids appears to be decreasing in the Netherlands. It is uncertain whether this is a `real' decrease in the incidence of disease or an `artefact'. Aim: To investigate possible causes of the decreasing incidence of

  15. The role of action knowledge in the comprehension of artefacts--a PET study

    DEFF Research Database (Denmark)

    Gerlach, Christian; Law, I; Gade, A

    2002-01-01

    Activation of the left ventral premotor cortex (PMv) has in previous imaging studies been associated with the processing of visually presented artefacts. It has been suggested that this activation reflects processing of action knowledge and that action knowledge contributes to the comprehension o...

  16. 3D Visualization of Cultural Heritage Artefacts with Virtual Reality devices

    Science.gov (United States)

    Gonizzi Barsanti, S.; Caruso, G.; Micoli, L. L.; Covarrubias Rodriguez, M.; Guidi, G.

    2015-08-01

    Although 3D models are useful to preserve the information about historical artefacts, the potential of these digital contents are not fully accomplished until they are not used to interactively communicate their significance to non-specialists. Starting from this consideration, a new way to provide museum visitors with more information was investigated. The research is aimed at valorising and making more accessible the Egyptian funeral objects exhibited in the Sforza Castle in Milan. The results of the research will be used for the renewal of the current exhibition, at the Archaeological Museum in Milan, by making it more attractive. A 3D virtual interactive scenario regarding the "path of the dead", an important ritual in ancient Egypt, was realized to augment the experience and the comprehension of the public through interactivity. Four important artefacts were considered for this scope: two ushabty, a wooden sarcophagus and a heart scarab. The scenario was realized by integrating low-cost Virtual Reality technologies, as the Oculus Rift DK2 and the Leap Motion controller, and implementing a specific software by using Unity. The 3D models were implemented by adding responsive points of interest in relation to important symbols or features of the artefact. This allows highlighting single parts of the artefact in order to better identify the hieroglyphs and provide their translation. The paper describes the process for optimizing the 3D models, the implementation of the interactive scenario and the results of some test that have been carried out in the lab.

  17. Persistent Artefacts in an Online Classroom: The Value of a Dynamic Learning Archive

    Science.gov (United States)

    Berry, Stuart C.

    2016-01-01

    This paper summarizes a multi-year research project that examines the use and value of visible and persistent artefacts within an online learning environment. This study is framed within elements of a business management theory. Changes to an online learning environment are documented as well as an examination of the impact of these changes on the…

  18. Mediation of Artefacts, Tools and Technical Objects: An International and French Perspective

    Science.gov (United States)

    Impedovo, Maria Antonietta; Andreucci, Colette; Ginestié, Jacques

    2017-01-01

    In this article we present a review of literature on the concept of Artefact, Tool and Technical Object in the light of sociocultural approach. Particular attention is given to present and discuss the French research tradition on the Technical Object and Technological education. The aim is to give a broad perspective to explore the mediation…

  19. Prospective ECG triggering reduces prosthetic heart valve-induced artefacts compared with retrospective ECG gating on 256-slice CT.

    Science.gov (United States)

    Symersky, Petr; Habets, Jesse; Westers, Paul; de Mol, Bas A J M; Prokop, Mathias; Budde, Ricardo P J

    2012-06-01

    Multidetector computed tomography (MDCT) has diagnostic value for the evaluation of prosthetic heart valve (PHV) dysfunction but it is hampered by artefacts. We hypothesised that image acquisition using prospective triggering instead of retrospective gating would reduce artefacts related to pulsating PHV. In a pulsatile in vitro model, a mono- and bileaflet PHV were imaged using 256 MDCT at 60, 75 and 90 beats per minute (BPM) with either retrospective gating (120 kV, 600 mAs, pitch 0.2, CTDI(vol) 39.8 mGy) or prospective triggering (120 kV, 200 mAs, CTDI(vol) 13.3 mGy). Two thresholds (>175 and <-45HU), derived from the density of surrounding structures, were used for quantification of hyper- and hypodense artefacts. Image noise and artefacts were compared between protocols. Prospective triggering reduced hyperdense artefacts for both valves at every BPM (P = 0.001 all comparisons). Hypodense artefacts were reduced for the monoleaflet valve at 60 (P = 0.009), 75 (P = 0.016) and 90 BPM (P = 0.001), and for the bileaflet valves at 60 (P = 0.001), 90 (P = 0.001) but not at 75 BPM (P = 0.6). Prospective triggering reduced image noise at 60 (P = 0.001) and 75 (P < 0.03) but not at 90 BPM. Compared with retrospective gating, prospective triggering reduced most artefacts related to pulsating PHV in vitro. • Computed tomographic images are often degraded by prosthetic heart valve-induced artefacts • Prospective triggering reduces prosthetic heart valve-induced artefacts in vitro • Artefact reduction at 90 beats per minute occurs without image noise reduction • Prospective triggering may improve CT image quality of moving hyperdense structures.

  20. The influence of metal artefacts on the range of ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Jaekel, Oliver; Reiss, Petra [German Cancer Research Center - Deutsches Krebsforschungszentrum, Division for Medical Physics in Radiotherapy (E040), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)

    2007-02-07

    The influence of artefacts due to metal implants on the range of ion beams is investigated, using a geometrically well-defined head and pelvic phantom together with inserts from steel, titanium and tungsten. The ranges along various beam paths including artefacts were calculated from the TPS and compared to known calculations for phantoms without any insert. In the head phantom, beams intersecting the streak artefacts lead to errors in the range of around or below 1%, which is mainly due to a cancellation of various effects. Beams through the metal or close to it show an underestimation of 3.5% of the range for tungsten. For the pelvic phantom, a large underestimation of the range is observed for a lateral path through the metal insert. In the case of tungsten and steel, range errors of -5% and -18% are observed, respectively. Such beam paths are typically used for pelvic tumours in radiotherapy with ion beams. For beams in the anterior-posterior direction through the inserts, an overestimation of ion ranges of up to 3% for titanium and 8% for steel is expected, respectively. Beam paths outside the metal insert show a large cancellation for the lateral beams (leading to errors of around 1% only) and somewhat higher errors for anterior-posterior beams (around 3% for titanium and 6% for steel). The analysis of CT data of patients with dental implants of gold as compared to patients with healthy teeth also showed a significant effect of the artefacts on the distribution of HU in the data, namely a redistribution of HU to higher and lower values as compared to patients with healthy teeth. The corresponding mean range variation was a 2.5% reduction in the data with artefacts as compared to the data without artefacts. It is concluded that beam paths through metal implants should generally be avoided in proton and ion therapy. In this case, the underestimation of ion range due to artefacts alone may amount to 3% for dental fillings and up to 5% and 18% for hip prosthesis

  1. CT metal artefact reduction of total knee prostheses using angled gantry multiplanar reformation.

    Science.gov (United States)

    Lewis, Mark; Toms, Andoni P; Reid, Karen; Bugg, William

    2010-08-01

    This study was designed to determine whether or not acquiring CT images of total knee prostheses by using an angled gantry and multiplanar reformation can reduce beam hardening artefact. A CT phantom was created with a total knee prosthesis suspended in gelatine with a known attenuation. CT data was acquired with a gantry angled at 0 degrees, 5 degrees, 10 degrees and 15 degrees in both craniocaudal oblique planes. Axial images where then reformatted from these datasets. Two independent observers selected regions of interest to measure the mean and standard deviation (SD) of attenuation in the gelatine for all reformatted axial images. Artefact was measured as SD of the background attenuation and areas under the curve of SD for each gantry angle acquisition were compared. Inter-observer reliability was excellent (ICC=0.89, CI 0.875-0.908). The most accurate mean attenuation values for tissues around a TKR were obtained with a CT gantry using 10 degrees to 15 degrees anteroinferior to posterosuperior angulation. The smallest area under the curve for SD of attenuation for the whole prosthesis, and the femoral component in isolation, was obtained with a 5 degrees gantry angle in the same direction. The smallest area under the curve for the tibial component in isolation occurred with a gantry angle of 15 degrees. We conclude that acquiring CT data with a gantry angle can reduce metal artefact around a TKR. Optimal overall metal artefact reduction can be achieved with a small angle from anteroinferior to posterosuperior. Further selective artefact reduction around the tibial component can be achieved with larger angles. Crown Copyright 2010. Published by Elsevier B.V. All rights reserved.

  2. Extracting the social relevance of artefact distribution in Roman military forts

    Directory of Open Access Journals (Sweden)

    Penelope M. Allison

    2005-04-01

    Full Text Available 'Engendering Roman Spaces' is a research project concerned with using artefact assemblage analyses to better understand spatial and gender relationships in the early Roman Empire and to produce more engendered perspectives of Roman society. This paper discusses the methodology and analyses being used in this project to investigate social behaviour within Roman military forts and fortresses of the 1st and 2nd centuries CE through analyses of the spatial distribution of artefacts at these sites. The processes involved include digitising previously published maps and artefact catalogues from Roman military sites to create searchable databases and GIS maps. They also include the classification of the artefacts according to a number of functional and gender-associated categories (e.g. combat equipment, male and female dress, toilet etc. so that the spatial distributions of the relevant activities can be plotted. This data is then used to interpret the spatial relationships of these activities and the people involved in them. The double legionary fortress of Vetera I, on the Lower Rhine, has been used to exemplify these processes. This fortress was excavated in the early 20th century and the artefacts were comprehensively published in 1995 (N. Hanel, Vetera I: Die Funde aus den römischen Lagern auf dem Fürstenberg bei Xanten. Rheinische Ausgrabungen 35, Rheinland-Verlag, Cologne and Dr Rudolf Halbert, Bonn, 1995. The paper includes descriptions of the methods and software employed in the digitisation of relevant material from these volumes, the formation of relational databases, and the importation of this data and of site maps into a GIS programme. To illustrate these processes and to present some of the results, the paper also includes a number of examples of the analyses carried out, together with interactive GIS maps of these analyses.

  3. 48 CFR 609.404 - Excluded parties list system.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Excluded parties list system. 609.404 Section 609.404 Federal Acquisition Regulations System DEPARTMENT OF STATE COMPETITION... Excluded parties list system. A/OPE shall accomplish the agency responsibilities prescribed in FAR 9.404(c...

  4. 20 CFR 404.1313 - World War II service excluded.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false World War II service excluded. 404.1313... DISABILITY INSURANCE (1950- ) Wage Credits for Veterans and Members of the Uniformed Services World War II Veterans § 404.1313 World War II service excluded. Your service was not in the active service of the United...

  5. 8 CFR 1241.20 - Aliens ordered excluded.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Aliens ordered excluded. 1241.20 Section 1241.20 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded Aliens...

  6. The Value of the Right to Exclude: An Empirical Assessment

    NARCIS (Netherlands)

    J.M. Klick (Jonathan); G. Parchomovsky (Gideon)

    2016-01-01

    markdownabstractProperty theorists have long deemed the right to exclude fundamental and essential for the efficient use and allocation of property. Recently, however, proponents of the progressive property movement have called into question the centrality of the right to exclude, suggesting that it

  7. Artefacts in multimodal imaging of titanium, zirconium and binary titanium-zirconium alloy dental implants: an in vitro study.

    Science.gov (United States)

    Smeets, Ralf; Schöllchen, Maximilian; Gauer, Tobias; Aarabi, Ghazal; Assaf, Alexandre T; Rendenbach, Carsten; Beck-Broichsitter, Benedicta; Semmusch, Jan; Sedlacik, Jan; Heiland, Max; Fiehler, Jens; Siemonsen, Susanne

    2017-02-01

    To analyze and evaluate imaging artefacts induced by zirconium, titanium and titanium-zirconium alloy dental implants. Zirconium, titanium and titanium-zirconium alloy implants were embedded in gelatin and MRI, CT and CBCT were performed. Standard protocols were used for each modality. For MRI, line-distance profiles were plotted to quantify the accuracy of size determination. For CT and CBCT, six shells surrounding the implant were defined every 0.5 cm from the implant surface and histogram parameters were determined for each shell. While titanium and titanium-zirconium alloy induced extensive signal voids in MRI owing to strong susceptibility, zirconium implants were clearly definable with only minor distortion artefacts. For titanium and titanium-zirconium alloy, the MR signal was attenuated up to 14.1 mm from the implant. In CT, titanium and titanium-zirconium alloy resulted in less streak artefacts in comparison with zirconium. In CBCT, titanium-zirconium alloy induced more severe artefacts than zirconium and titanium. MRI allows for an excellent image contrast and limited artefacts in patients with zirconium implants. CT and CBCT examinations are less affected by artefacts from titanium and titanium-zirconium alloy implants compared with MRI. The knowledge about differences of artefacts through different implant materials and image modalities might help support clinical decisions for the choice of implant material or imaging device in the clinical setting.

  8. Comparison and Combination of Dual-Energy- and Iterative-Based Metal Artefact Reduction on Hip Prosthesis and Dental Implants.

    Directory of Open Access Journals (Sweden)

    Malte N Bongers

    Full Text Available To compare and combine dual-energy based and iterative metal artefact reduction on hip prosthesis and dental implants in CT.A total of 46 patients (women:50%,mean age:63±15years with dental implants or hip prostheses (n = 30/20 were included and examined with a second-generation Dual Source Scanner. 120kV equivalent mixed-images were derived from reconstructions of the 100/Sn140kV source images using no metal artefact reduction (NOMAR and iterative metal artefact reduction (IMAR. We then generated monoenergetic extrapolations at 130keV from source images without IMAR (DEMAR or from source images with IMAR, (IMAR+DEMAR. The degree of metal artefact was quantified for NOMAR, IMAR, DEMAR and IMAR+DEMAR using a Fourier-based method and subjectively rated on a five point Likert scale by two independent readers.In subjects with hip prosthesis, DEMAR and IMAR resulted in significantly reduced artefacts compared to standard reconstructions (33% vs. 56%; for DEMAR and IMAR; respectively, p<0.005, but the degree of artefact reduction was significantly higher for IMAR (all p<0.005. In contrast, in subjects with dental implants only IMAR showed a significant reduction of artefacts whereas DEMAR did not (71%, vs. 8% p<0.01 and p = 0.1; respectively. Furthermore, the combination of IMAR with DEMAR resulted in additionally reduced artefacts (Hip prosthesis: 47%, dental implants 18%; both p<0.0001.IMAR allows for significantly higher reduction of metal artefacts caused by hip prostheses and dental implants, compared to a dual energy based method. The combination of DE-source images with IMAR and subsequent monoenergetic extrapolation provides an incremental benefit compared to both single methods.

  9. First pass cable artefact correction for cardiac C-arm CT imaging

    Science.gov (United States)

    Haase, C.; Schäfer, D.; Kim, M.; Chen, S. J.; Carroll, J. D.; Eshuis, P.; Dössel, O.; Grass, M.

    2014-07-01

    Cardiac C-arm CT imaging delivers a tomographic region-of-interest reconstruction of the patient's heart during image guided catheter interventions. Due to the limited size of the flat detector a volume image is reconstructed, which is truncated in the cone-beam (along the patient axis) and the fan-beam (in the transaxial plane) direction. To practically address this local tomography problem correction methods, like projection extension, are available for first pass image reconstruction. For second pass correction methods, like metal artefact reduction, alternative correction schemes are required when the field of view is limited to a region-of-interest of the patient. In classical CT imaging metal artefacts are corrected by metal identification in a first volume reconstruction and generation of a corrected projection data set followed by a second reconstruction. This approach fails when the metal structures are located outside the reconstruction field of view. When a C-arm CT is performed during a cardiac intervention pacing leads and other cables are frequently positioned on the patients skin, which results in propagating streak artefacts in the reconstruction volume. A first pass approach to reduce this type of artefact is introduced and evaluated here. It makes use of the fact that the projected position of objects outside the reconstruction volume changes with the projection perspective. It is shown that projection based identification, tracking and removal of high contrast structures like cables, only detected in a subset of the projections, delivers a more consistent reconstruction volume with reduced artefact level. The method is quantitatively evaluated based on 50 simulations using cardiac CT data sets with variable cable positioning. These data sets are forward projected using a C-arm CT system geometry and generate artefacts comparable to those observed in clinical cardiac C-arm CT acquisitions. A C-arm CT simulation of every cardiac CT data set without

  10. A knowledge-based method for reducing attenuation artefacts caused by cardiac appliances in myocardial PET/CT

    Science.gov (United States)

    Hamill, James J.; Brunken, Richard C.; Bybel, Bohdan; Di Filippo, Frank P.; Faul, David D.

    2006-06-01

    Attenuation artefacts due to implanted cardiac defibrillator leads have previously been shown to adversely impact cardiac PET/CT imaging. In this study, the severity of the problem is characterized, and an image-based method is described which reduces the resulting artefact in PET. Automatic implantable cardioverter defibrillator (AICD) leads cause a moving-metal artefact in the CT sections from which the PET attenuation correction factors (ACFs) are derived. Fluoroscopic cine images were measured to demonstrate that the defibrillator's highly attenuating distal shocking coil moves rhythmically across distances on the order of 1 cm. Rhythmic motion of this magnitude was created in a phantom with a moving defibrillator lead. A CT study of the phantom showed that the artefact contained regions of incorrect, very high CT values and adjacent regions of incorrect, very low CT values. The study also showed that motion made the artefact more severe. A knowledge-based metal artefact reduction method (MAR) is described that reduces the magnitude of the error in the CT images, without use of the corrupted sinograms. The method modifies the corrupted image through a sequence of artefact detection procedures, morphological operations, adjustments of CT values and three-dimensional filtering. The method treats bone the same as metal. The artefact reduction method is shown to run in a few seconds, and is validated by applying it to a series of phantom studies in which reconstructed PET tracer distribution values are wrong by as much as 60% in regions near the CT artefact when MAR is not applied, but the errors are reduced to about 10% of expected values when MAR is applied. MAR changes PET image values by a few per cent in regions not close to the artefact. The changes can be larger in the vicinity of bone. In patient studies, the PET reconstruction without MAR sometimes results in anomalously high values in the infero-septal wall. Clinical performance of MAR is assessed by two

  11. Office of Inspector General List of Excluded Individuals and Entities

    Data.gov (United States)

    U.S. Department of Health & Human Services — The objective is to ensure that providers who bill Federal health care programs do not submit claims for services furnished, ordered or prescribed by an excluded...

  12. Plastic and other artefacts on South African beaches: Temporal trends in abundance and composition

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, P.G.; Moloney, C.L. (Univ. of Cape Town, Rondebosch (South Africa))

    Floating plastic objects and other artefacts have three main impacts on the marine environment: (1) they are ingested by and entangle many marine animals; (2) they increase the amount of substratum available for epiphytic organisms; and (3) when stranded, they reduce the aesthetic appeal and tourism potential of beaches. These impacts can have serious ecological and economic consequences, and recently have been the focus of international concern. It is often assumed that the density of plastic at sea is increasing, but there are few actual measures of temporal changes in the abundance and composition of artefacts. Such measures are needed to assess the dynamics of marine debris and to determine the efficacy of measures introduced to reduce the amount of marine debris. The authors present preliminary measures of trends in plastic abundance off South Africa, estimated from sampling both micro- and macro-plastic particles stranded at a range of beaches over a five-year period.

  13. Reflection contributions to the dispersion artefact in FTIR spectra of single biological cells.

    Science.gov (United States)

    Bassan, Paul; Byrne, Hugh J; Lee, Joe; Bonnier, Franck; Clarke, Colin; Dumas, Paul; Gazi, Ehsan; Brown, Michael D; Clarke, Noel W; Gardner, Peter

    2009-06-01

    Fourier transform infrared spectra of a single cell in transflection geometry are seen to vary significantly with position on the cell, showing a distorted derivative-like lineshape in the region of the optically dense nucleus. A similar behaviour is observable in a model system of the protein albumin doped in a potassium bromide disk. It is demonstrated that the spectrum at any point is a weighted sum of the sample reflection and transmission and that the dominance of the reflection spectrum in optically dense regions can account for some of the spectral distortions previously attributed to dispersion artefacts. Rather than being an artefact, the reflection contribution is ever present in transflection spectra and it is further demonstrated that the reflection characteristics can be used for cellular mapping.

  14. The brain-artefact interface (BAI): a challenge for archaeology and cultural neuroscience.

    Science.gov (United States)

    Malafouris, Lambros

    2010-06-01

    Cultural neuroscience provides a new approach for understanding the impact of culture on the human brain (and vice versa) opening thus new avenues for cross-disciplinary collaboration with archaeology and anthropology. Finding new meaningful and productive unit of analysis is essential for such collaboration. But what can archaeological preoccupation with material culture and long-term change contribute to this end? In this article, I introduce and discuss the notion of the brain-artefact interface (BAI) as a useful conceptual bridge between neuroplastisty and the extended mind. I argue that a key challenge for archaeology and cultural neuroscience lies in the cross-disciplinary understanding of the processes by which our plastic enculturated brains become constituted within the wider extended networks of non-biological artefacts and cultural practices that delineate the real spatial and temporal boundaries of the human cognitive map.

  15. Modelling optical scattering artefacts for varying pathlength in a gel dosimeter phantom

    Energy Technology Data Exchange (ETDEWEB)

    Bosi, Stephen G [Department of Radiation Oncology, Prince of Wales Hospital, Randwick, NSW 2031 (Australia); Brown, Saxby; Sarabipour, Sarvenaz; Baldock, Clive [Institute of Medical Physics, School of Physics, University of Sydney, NSW 2006 (Australia); De Deene, Yves [Division of Radiotherapy, University Hospital of Ghent, de Pintelaan 185, 9000 Ghent (Belgium)], E-mail: s.bosi@physics.usyd.edu.au

    2009-01-21

    A gelatin phantom containing an optically scattering funnel-shaped region of elevated optical density (OD) was used to examine light-scattering-induced artefacts in a cone-beam optical CT scanner used for gel dosimetry. To simulate polymer gel dosimeters, the opacity was introduced by adding a colloidal scatterer to the gelatin. Scatter results in an underestimate of OD (hence dose). In line profiles of OD taken from 3D reconstructions of the funnel, those profiles with a long pathlength through high OD regions exhibited a 'dishing' (or 'cupping') artefact, while those of short pathlength exhibited the opposite effect-'doming'. These phenomena are accounted for by a model that includes the effect of stray, scattered light.

  16. The development of equipment for the technical assessment of respiratory motion induced artefacts in MRI

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, P.C.; Davies, S.C.; Zananiri, F.V.; Follett, D.H.; Halliwell, M.; Wells, P.N.T. (Bristol General Hospital (United Kingdom)); Bean, J.P. (Imperial College of Science, Technology and Medicine, London (United Kingdom). Dept. of Electrical Engineering)

    1993-02-01

    A device and technique to study the effects of respiratory motion on the quality of magnetic resonance images is proposed. The construction of the device enables a variety of test objects to be mounted and used in the evaluation of imaging parameters that may be affected by motion. The equipment is constructed of cast acrylic and the movement is actuated and controlled pneumatically thus ensuring that there are no interactions with the magnetic field and radiofrequency detection system to cause further image artefacts. Separate studies have been performed, using ultrasound, to assess the degree and rate of movement of organs owing to respiration in order to derive the motion parameters for the apparatus. Preliminary results indicate that the technique produces motion induced artefacts simulating those which are the result of the effects of respiration. (author).

  17. Prediction of beam hardening artefacts in computed tomography using Monte Carlo simulations

    DEFF Research Database (Denmark)

    Thomsen, M.; Bergbäck Knudsen, Erik; Willendrup, Peter Kjær

    2015-01-01

    We show how radiological images of both single and multi material samples can be simulated using the Monte Carlo simulation tool McXtrace and how these images can be used to make a three dimensional reconstruction. Good numerical agreement between the X-ray attenuation coefficient in experimental...... and simulated data can be obtained, which allows us to use simulated projections in the linearisation procedure for single material samples and in that way reduce beam hardening artefacts. The simulations can be used to predict beam hardening artefacts in multi material samples with complex geometry......, illustrated with an example. Linearisation requires knowledge about the X-ray transmission at varying sample thickness, but in some cases homogeneous calibration phantoms are hard to manufacture, which affects the accuracy of the calibration. Using simulated data overcomes the manufacturing problems...

  18. Corrosion of archaeological iron artefacts compared to modern iron at the waterlogged site Nydam, Denmark

    DEFF Research Database (Denmark)

    Matthiesen, Henning; Hilbert, Lisbeth Rischel; Gregory, David

    2004-01-01

    loss, corrosion potential, electrochemical impedance spectroscopy and electrical resistivity. 3) Measurements of environmental parameter such as water level, redox potential, oxygen concentration, soil pH, and the concentration of a range of dissolved species in the pore water. This presentation shows...... focuses solely on the iron objects. A three-pronged approach has been used in the studies in Nydam: Studies of the excavated artefacts, including the compositon of corrosion products and a mapping of their exact state of preservation. 2) Use of modern iron samples placed in the soil for studies of weight...... some of the results obtained during the seven years of studies at the site. It is demonstrated how the three pronged approach is useful in understanding not only the current corrosion rate and threats against the artefacts but also the corrosion history, i.e. when were the deterioration patterns...

  19. The surface of cultural heritage artefacts: physicochemical investigations for their knowledge and their conservation.

    Science.gov (United States)

    Aucouturier, Marc; Darque-Ceretti, Evelyne

    2007-10-01

    This tutorial review intends to show, through demonstrative examples chosen from the recent literature, how surface characterisation conducted by modern investigation methods leads to very rich information on a cultural heritage artefact's history, fabrication techniques and conservation state. Application of surface science to conservation science is of great help for the definition of a conservation and restoration policy for museum and archaeological objects. A brief description of the investigation methods is given, together with relevant references for more detailed information.

  20. Defining the IT artefact in social media for eparticipation: An ensemble view

    OpenAIRE

    Johannessen, Marius Rohde; Munkvold, Bjørn E.

    2012-01-01

    Social media has become a popular outlet for various eParticipation activities, such as online campaigning by political parties. However, research so far has shown that political parties often have limited success with their efforts. Much is yet unclear as to the results and possible applications of social media use. This paper contributes to clarify the underlying concepts of social media, by analysing the social media IT artefact as a socio-technical object. We propose and defin...

  1. Electrocardiographic artefacts mimicking atrial tachycardia resulted in unnecessary diagnostic and therapeutic measures

    OpenAIRE

    Y-Hassan, Shams; Sylv?n, Christer

    2013-01-01

    Electrocardiographic (ECG) artefacts may closely simulate both supraventricular and ventricular tachycardias. We describe a case initially diagnosed as rapid atrial fibrillation, based on 12-lead surface ECG (especially the limb leads) and monitor tracing. The arrhythmia was resistant to beta blockers. Because of the at times apparently regular rhythm, an esophageal ECG recording was performed, and adenosine was administered. When the presumed atrial fibrillation terminated after sodium pento...

  2. VTrace-A Tool for Visualizing Traceability Links Among Software Artefacts for an Evolving System

    OpenAIRE

    Satish, C.J.; M, Anand

    2017-01-01

    Traceability Management plays a key role in tracing the life of a requirement through all the specifications produced during the development phase of a software project. A lack of traceability information not only hinders the understanding of the system but also will prove to be a bottleneck in the future maintenance of the system. Projects that maintain traceability information during the development stages somehow fail to upgrade their artefacts or maintain traceability among the different ...

  3. An Introduction To Multi-Battery Factor Analysis: Overcoming Method Artefacts.

    Directory of Open Access Journals (Sweden)

    Gavin T L Brown

    2007-05-01

    Full Text Available Examination of participants' responses to factor or scale scores provides useful insights, but analysis of such scores from multiple measures or batteries is sometimes confounded by methodological artefacts. This paper provides a short primer into the use of multi-trait, multi-method (MTMM correlational analysis and multi-battery factor analysis (MBFA. The principles of both procedures are outlined and a case study is provided from the author's research into 233 teachers' responses to 22 scale scores drawn from five batteries. The batteries were independently developed measures of teachers' thinking about the nature and purpose of assessment, teaching, learning, curriculum, and teacher efficacy. Detailed procedures for using Cudeck's (1982 MBFACT software are provided. Both MTMM and MBFA analyses identified an appropriate common trait across the five batteries, whereas joint factor analysis of the 22 scale scores confounded the common trait with a battery or method artefact. When researchers make use of multiple measures, they ought to take into account the impact of method artefacts when analyzing scale scores from multiple batteries. The multi-battery factor analysis procedure and MBFACT software provide a robust procedure for exploring how scales inter-relate.

  4. Evaluation of efficacy of metal artefact reduction technique using contrast media in Computed Tomography

    Science.gov (United States)

    Yusob, Diana; Zukhi, Jihan; Aziz Tajuddin, Abd; Zainon, Rafidah

    2017-05-01

    The aim of this study was to evaluate the efficacy of metal artefact reduction using contrasts media in Computed Tomography (CT) imaging. A water-based abdomen phantom of diameter 32 cm (adult body size) was fabricated using polymethyl methacrylate (PMMA) material. Three different contrast agents (iodine, barium and gadolinium) were filled in small PMMA tubes and placed inside a water-based PMMA adult abdomen phantom. The orthopedic metal screw was placed in each small PMMA tube separately. These two types of orthopedic metal screw (stainless steel and titanium alloy) were scanned separately. The orthopedic metal crews were scanned with single-energy CT at 120 kV and dual-energy CT at fast kV-switching between 80 kV and 140 kV. The scan modes were set automatically using the current modulation care4Dose setting and the scans were set at different pitch and slice thickness. The use of the contrast media technique on orthopedic metal screws were optimised by using pitch = 0.60 mm, and slice thickness = 5.0 mm. The use contrast media can reduce the metal streaking artefacts on CT image, enhance the CT images surrounding the implants, and it has potential use in improving diagnostic performance in patients with severe metallic artefacts. These results are valuable for imaging protocol optimisation in clinical applications.

  5. Composition and microstructure of Roman metallic artefacts of Southwestern Iberian Peninsula

    Science.gov (United States)

    Valério, P.; Voráčová, E.; Silva, R. J. C.; Araújo, M. F.; Soares, A. M. M.; Arruda, A. M.; Pereira, C.

    2015-10-01

    The Roman invasion introduces new alloys and metallurgical practices in Iberian Peninsula. The southwestern end of this region has many evidences of connections with the Roman World, but there are no studies about the manufacture and use of copper-based artefacts during this period. Therefore, a set of about 20 ornaments, tools and small attachments recovered at the Roman sites of Monte Molião and Cidade das Rosas was studied by an analytical approach combining micro-EDXRF, optical microscopy, SEM-EDS and Vickers microhardness testing. The artefact composition shows a good correlation with function, namely pure copper for nails and rivets, low-tin bronze (2-6 wt% Sn) for basic tools, high-tin bronze (14 wt% Sn) for fibulae and high-lead bronze (19 wt% Pb) for a decorated jug handle. The manufacture also depends on function because most artefacts were subjected to thermomechanical processing, except the ornaments that would not benefit from post-casting work. Brass and gunmetal were only present in the site with a later chronology. A metallurgy visibly ruled by economical, aesthetical and technological concerns reinforces the evidences about the total integration of Southwestern Iberian Peninsula in the Roman World, but further studies will be essential to determine the evolution of copper-based alloys in Lusitania under Roman influence.

  6. Synchronizing the transcranial magnetic pulse with electroencephalographic recordings effectively reduces inter-trial variability of the pulse artefact

    DEFF Research Database (Denmark)

    Tomasevic, Leo; Takemi, Mitsuaki; Siebner, Hartwig Roman

    2017-01-01

    BACKGROUND: Electroencephalography (EEG) can capture the cortical response evoked by transcranial magnetic stimulation (TMS). The TMS pulse provokes a large artefact, which obscures the cortical response in the first milliseconds after TMS. Removing this artefact remains a challenge. METHODS: We...... were tested at 10 and 20 kHz using the head phantom. We also tested the effect of a soft sheet placed between the stimulation coil and recording electrodes in both human and melon. RESULTS & CONCLUSION: Synchronizing TMS and data acquisition markedly reduced trial-to-trial variability of the pulse......-to-trial variability renders it possible to create an artefact template for off-line filtering. Template-based subtraction of the artefact from the EEG signals is a prerequisite to effectively recover the immediate physiological response in the stimulated cortex and inter-connected areas....

  7. A multi-channel opto-electronic sensor to accurately monitor heart rate against motion artefact during exercise

    National Research Council Canada - National Science Library

    Alzahrani, Abdullah; Hu, Sijung; Azorin-Peris, Vicente; Barrett, Laura; Esliger, Dale; Hayes, Matthew; Akbare, Shafique; Achart, Jérôme; Kuoch, Sylvain

    2015-01-01

    This study presents the use of a multi-channel opto-electronic sensor (OEPS) to effectively monitor critical physiological parameters whilst preventing motion artefact as increasingly demanded by personal healthcare...

  8. Comparison and Combination of Dual-Energy- and Iterative-Based Metal Artefact Reduction on Hip Prosthesis and Dental Implants

    Science.gov (United States)

    Bongers, Malte N.; Schabel, Christoph; Thomas, Christoph; Raupach, Rainer; Notohamiprodjo, Mike; Nikolaou, Konstantin; Bamberg, Fabian

    2015-01-01

    Purpose To compare and combine dual-energy based and iterative metal artefact reduction on hip prosthesis and dental implants in CT. Material and Methods A total of 46 patients (women:50%,mean age:63±15years) with dental implants or hip prostheses (n = 30/20) were included and examined with a second-generation Dual Source Scanner. 120kV equivalent mixed-images were derived from reconstructions of the 100/Sn140kV source images using no metal artefact reduction (NOMAR) and iterative metal artefact reduction (IMAR). We then generated monoenergetic extrapolations at 130keV from source images without IMAR (DEMAR) or from source images with IMAR, (IMAR+DEMAR). The degree of metal artefact was quantified for NOMAR, IMAR, DEMAR and IMAR+DEMAR using a Fourier-based method and subjectively rated on a five point Likert scale by two independent readers. Results In subjects with hip prosthesis, DEMAR and IMAR resulted in significantly reduced artefacts compared to standard reconstructions (33% vs. 56%; for DEMAR and IMAR; respectively, pIMAR (all pIMAR showed a significant reduction of artefacts whereas DEMAR did not (71%, vs. 8% pIMAR with DEMAR resulted in additionally reduced artefacts (Hip prosthesis: 47%, dental implants 18%; both pIMAR allows for significantly higher reduction of metal artefacts caused by hip prostheses and dental implants, compared to a dual energy based method. The combination of DE-source images with IMAR and subsequent monoenergetic extrapolation provides an incremental benefit compared to both single methods. PMID:26600188

  9. Neutron-based analyses of three Bronze Age metal objects: a closer look at the Buggenum, Jutphaas and Escharen artefacts

    OpenAIRE

    POSTMA HANS; AMKREUTZ LUC; FONTIJN D.; Kamermans, H.; Kockelmann, W.; SCHILLEBEECKX PETER; VISSER DIRK

    2017-01-01

    Three important Bronze Age copper-alloy artefacts from the permanent exhibition of the National Museum of Antiquity in Leiden (NL) have been studied by neutron-based methods. These artefacts are known as the Buggenum sword, the Jutphaas dirk, and the Escharen double axe. All three objects have been studied with neutron resonance capture analysis (NRCA), a non-destructive method to determine the bulk elemental compositions. The Buggenum sword is also studied with time-of-flight neutron diffrac...

  10. Synchronizing the transcranial magnetic pulse with electroencephalographic recordings effectively reduces inter-trial variability of the pulse artefact.

    Science.gov (United States)

    Tomasevic, Leo; Takemi, Mitsuaki; Siebner, Hartwig Roman

    2017-01-01

    Electroencephalography (EEG) can capture the cortical response evoked by transcranial magnetic stimulation (TMS). The TMS pulse provokes a large artefact, which obscures the cortical response in the first milliseconds after TMS. Removing this artefact remains a challenge. We delivered monophasic and biphasic TMS to a melon as head phantom and to four healthy participants and recorded the pulse artefact at 5 kHz with a TMS-compatible EEG system. Pulse delivery was either synchronized or non-synchronized to the clock of the EEG recording system. The effects of synchronization were tested at 10 and 20 kHz using the head phantom. We also tested the effect of a soft sheet placed between the stimulation coil and recording electrodes in both human and melon. Synchronizing TMS and data acquisition markedly reduced trial-to-trial variability of the pulse artefact in recordings from the phantom or from the scalp. Reduced trial-to-trial variability was also observed at high sampling frequencies. The use of a soft sheet reduced the variability in recordings on the head phantom, but not in human participants. Effective reduction of the trial-to-trial variability renders it possible to create an artefact template for off-line filtering. Template-based subtraction of the artefact from the EEG signals is a prerequisite to effectively recover the immediate physiological response in the stimulated cortex and inter-connected areas.

  11. Influence of chest compression artefact on capnogram-based ventilation detection during out-of-hospital cardiopulmonary resuscitation.

    Science.gov (United States)

    Leturiondo, Mikel; de Gauna, Sofía Ruiz; Ruiz, Jesus M; Julio Gutiérrez, J; Leturiondo, Luis A; González-Otero, Digna M; Russell, James K; Zive, Dana; Daya, Mohamud

    2017-12-12

    Capnography has been proposed as a method for monitoring the ventilation rate during cardiopulmonary resuscitation (CPR). A high incidence (above 70%) of capnograms distorted by chest compression induced oscillations has been previously reported in out-of-hospital (OOH) CPR. The aim of the study was to better characterize the chest compression artefact and to evaluate its influence on the performance of a capnogram-based ventilation detector during OOH CPR. Data from the MRx monitor-defibrillator were extracted from OOH cardiac arrest episodes. For each episode, presence of chest compression artefact was annotated in the capnogram. Concurrent compression depth and transthoracic impedance signals were used to identify chest compressions and to annotate ventilations, respectively. We designed a capnogram-based ventilation detection algorithm and tested its performance with clean and distorted episodes. Data were collected from 232 episodes comprising 52654 ventilations, with a mean (±SD) of 227 (±118) per episode. Overall, 42% of the capnograms were distorted. Presence of chest compression artefact degraded algorithm performance in terms of ventilation detection, estimation of ventilation rate, and the ability to detect hyperventilation. Capnogram-based ventilation detection during CPR using our algorithm was compromised by the presence of chest compression artefact. In particular, artefact spanning from the plateau to the baseline strongly degraded ventilation detection, and caused a high number of false hyperventilation alarms. Further research is needed to reduce the impact of chest compression artefact on capnographic ventilation monitoring. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Gradient Artefact Correction and Evaluation of the EEG Recorded Simultaneously with fMRI Data Using Optimised Moving-Average

    Science.gov (United States)

    Wu, Yan; Besseling, René M. H.; Lamerichs, Rolf; Aarts, Ronald M.

    2016-01-01

    Over the past years, coregistered EEG-fMRI has emerged as a powerful tool for neurocognitive research and correlated studies, mainly because of the possibility of integrating the high temporal resolution of the EEG with the high spatial resolution of fMRI. However, additional work remains to be done in order to improve the quality of the EEG signal recorded simultaneously with fMRI data, in particular regarding the occurrence of the gradient artefact. We devised and presented in this paper a novel approach for gradient artefact correction based upon optimised moving-average filtering (OMA). OMA makes use of the iterative application of a moving-average filter, which allows estimation and cancellation of the gradient artefact by integration. Additionally, OMA is capable of performing the attenuation of the periodic artefact activity without accurate information about MRI triggers. By using our proposed approach, it is possible to achieve a better balance than the slice-average subtraction as performed by the established AAS method, regarding EEG signal preservation together with effective suppression of the gradient artefact. Since the stochastic nature of the EEG signal complicates the assessment of EEG preservation after application of the gradient artefact correction, we also propose a simple and effective method to account for it. PMID:27446943

  13. Gradient Artefact Correction and Evaluation of the EEG Recorded Simultaneously with fMRI Data Using Optimised Moving-Average

    Directory of Open Access Journals (Sweden)

    José L. Ferreira

    2016-01-01

    Full Text Available Over the past years, coregistered EEG-fMRI has emerged as a powerful tool for neurocognitive research and correlated studies, mainly because of the possibility of integrating the high temporal resolution of the EEG with the high spatial resolution of fMRI. However, additional work remains to be done in order to improve the quality of the EEG signal recorded simultaneously with fMRI data, in particular regarding the occurrence of the gradient artefact. We devised and presented in this paper a novel approach for gradient artefact correction based upon optimised moving-average filtering (OMA. OMA makes use of the iterative application of a moving-average filter, which allows estimation and cancellation of the gradient artefact by integration. Additionally, OMA is capable of performing the attenuation of the periodic artefact activity without accurate information about MRI triggers. By using our proposed approach, it is possible to achieve a better balance than the slice-average subtraction as performed by the established AAS method, regarding EEG signal preservation together with effective suppression of the gradient artefact. Since the stochastic nature of the EEG signal complicates the assessment of EEG preservation after application of the gradient artefact correction, we also propose a simple and effective method to account for it.

  14. Comparison and Combination of Dual-Energy- and Iterative-Based Metal Artefact Reduction on Hip Prosthesis and Dental Implants.

    Science.gov (United States)

    Bongers, Malte N; Schabel, Christoph; Thomas, Christoph; Raupach, Rainer; Notohamiprodjo, Mike; Nikolaou, Konstantin; Bamberg, Fabian

    2015-01-01

    To compare and combine dual-energy based and iterative metal artefact reduction on hip prosthesis and dental implants in CT. A total of 46 patients (women:50%,mean age:63±15years) with dental implants or hip prostheses (n = 30/20) were included and examined with a second-generation Dual Source Scanner. 120kV equivalent mixed-images were derived from reconstructions of the 100/Sn140kV source images using no metal artefact reduction (NOMAR) and iterative metal artefact reduction (IMAR). We then generated monoenergetic extrapolations at 130keV from source images without IMAR (DEMAR) or from source images with IMAR, (IMAR+DEMAR). The degree of metal artefact was quantified for NOMAR, IMAR, DEMAR and IMAR+DEMAR using a Fourier-based method and subjectively rated on a five point Likert scale by two independent readers. In subjects with hip prosthesis, DEMAR and IMAR resulted in significantly reduced artefacts compared to standard reconstructions (33% vs. 56%; for DEMAR and IMAR; respectively, pdental implants only IMAR showed a significant reduction of artefacts whereas DEMAR did not (71%, vs. 8% pprosthesis: 47%, dental implants 18%; both pdental implants, compared to a dual energy based method. The combination of DE-source images with IMAR and subsequent monoenergetic extrapolation provides an incremental benefit compared to both single methods.

  15. Reduced artefacts and improved assessment of hyperintense brain lesions with BLADE MR imaging in patients with neurofibromatosis type 1

    Energy Technology Data Exchange (ETDEWEB)

    Kalle, Thekla von; Fabig-Moritz, Claudia; Mueller-Abt, Peter; Zieger, Michael; Winkler, Peter [Department of Paediatric Radiology, Stuttgart (Germany); Blank, Bernd [Haematology and Immunology, Department of Paediatric Oncology, Stuttgart (Germany); Wohlfarth, Katrin [Siemens Healthcare Sector, Erlangen (Germany)

    2009-11-15

    Assessment of small brain lesions in children is often compromised by pulsation, flow or movement artefacts. MRI with a rotating blade-like k-space covering (BLADE, PROPELLER) can compensate for these artefacts. We compared T2-weighted FLAIR images that were acquired with different k-space trajectories (conventional Cartesian and BLADE) to evaluate the impact of BLADE technique on the delineation of small or low-contrast brain lesions. The subject group comprised 26 children with neurofibromatosis type 1 (NF 1), who had been routinely scanned at 1.5 T for optic pathway gliomas with both techniques and who had the typical hyperintense brain lesions seen in NF 1. Four experienced radiologists retrospectively compared unlabelled 4-mm axial images with respect to the presence of artefacts, visibility of lesions, quality of contour and contrast. Both techniques were comparable in depicting hyperintense lesions as small as 2 mm independent of contrast and edge definition. Pulsation and movement artefacts were significantly less common with BLADE k-space trajectory. In 7 of 26 patients (27%), lesions and artefacts were rated as indistinguishable in conventional FLAIR, but not in BLADE FLAIR images. BLADE imaging significantly improved the depiction of lesions in T2-W FLAIR images due to artefact reduction especially in the posterior fossa. (orig.)

  16. Excluded-volume effects in the diffusion of hard spheres

    KAUST Repository

    Bruna, Maria

    2012-01-03

    Excluded-volume effects can play an important role in determining transport properties in diffusion of particles. Here, the diffusion of finite-sized hard-core interacting particles in two or three dimensions is considered systematically using the method of matched asymptotic expansions. The result is a nonlinear diffusion equation for the one-particle distribution function, with excluded-volume effects enhancing the overall collective diffusion rate. An expression for the effective (collective) diffusion coefficient is obtained. Stochastic simulations of the full particle system are shown to compare well with the solution of this equation for two examples. © 2012 American Physical Society.

  17. Helicobacter pylori infection has no impact on manometric and pH-metric findings in adolescents and young adults with gastroesophageal reflux and antral gastritis: eradication results to no significant clinical improvement

    Directory of Open Access Journals (Sweden)

    Ioannis Xinias

    2013-02-01

    Full Text Available The relationship between Helicobacter pylori (Hp gastritis and gastroesophageal reflux disease (GERD remains controversial. The aim was to investigate the association between Hp infection and gastroesophageal reflux (GER and the impact of Hp eradication on esophageal acid exposure and motility in adolescents and young adults with Hp gastritis and GERD. Sixty-four patients with symptoms suggestive for GERD, of which 40 Hp-positive (group A and 24 Hp-negative (group B, underwent endoscopy-biopsy, esophageal manometry and 24-hour pH-metry. All group A patients received eradication treatment and were re-evaluated six months later again with 24-hour pH-metry, esophageal manometry, endoscopy-biopsy and clinical assessment. At inclusion, there were no significant differences between the two groups regarding sex, age, grade of endoscopic esophagitis, manometric and pH-metry findings. All Hp-positive patients had an antral predominant gastritis. Eradication of Hp was successful in all patients, and gastritis and esophagitis were healed in all patients. The mean lower esophageal sphincter pressure (LESP increased significantly from 11.25 mmHg before to 11.71 mmHg after eradication (P<0.05. A significant decrease in reflux index was observed (mean RI 6.02% before versus 4.96% after eradication (P<0.05. However clinical symptoms of GER improved not significantly after 6 months follow up. Conclusively, in children and young adults with GER symptoms and GERD, the presence or absence of Hp has no impact on manometric and pH-metric findings. Eradication of Hp infection results in increase in LESP with a consequent decrease in esophageal acid exposure but not significant clinical improvement.

  18. 5 CFR 2634.203 - Persons excluded by rule.

    Science.gov (United States)

    2010-01-01

    ... FINANCIAL DISCLOSURE, QUALIFIED TRUSTS, AND CERTIFICATES OF DIVESTITURE Persons Required To File Public Financial Disclosure Reports § 2634.203 Persons excluded by rule. (a) In general. Any individual or group of... not affect adversely the integrity of the Government or the public's confidence in the integrity of...

  19. 40 CFR 240.201 - Solid wastes excluded.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Solid wastes excluded. 240.201 Section 240.201 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES GUIDELINES FOR THE THERMAL PROCESSING OF SOLID WASTES Requirements and Recommended Procedures § 240.201 Solid...

  20. 42 CFR 412.25 - Excluded hospital units: Common requirements.

    Science.gov (United States)

    2010-10-01

    ... decreased at any time during a cost reporting period if the hospital notifies its fiscal intermediary and... chief medical officer of the hospital in which it is located. (B) It maintains admission and discharge... 42 Public Health 2 2010-10-01 2010-10-01 false Excluded hospital units: Common requirements. 412...

  1. 8 CFR 1240.38 - Fingerprinting of excluded aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Fingerprinting of excluded aliens. 1240.38 Section 1240.38 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS PROCEEDINGS TO DETERMINE REMOVABILITY OF ALIENS IN THE UNITED STATES Exclusion of...

  2. The public space and the right to exclude

    Directory of Open Access Journals (Sweden)

    Verónica Urzúa Bastida

    2012-03-01

    Full Text Available This paper raises that the notion of «public space», as is currently used, legitimize, at the same time is the base of what might be called the right to exclude. This is not happening by law, but culture. To argue this, there will develop three ideas: comfort, planning and civic order, presents in the above mentioned notion.

  3. 26 CFR 1.410(b)-6 - Excludable employees.

    Science.gov (United States)

    2010-04-01

    ... section 861(a)(3)) is treated as an excludable employee. (2) Special treaty rule. In addition, an employee... year (for purposes of this paragraph (f)(1)(v), a plan that uses the elapsed time method of determining... provided for such term by 29 CFR 2530.200b-2 under the general method of crediting service for the employee...

  4. 29 CFR 548.305 - Excluding certain additions to wages.

    Science.gov (United States)

    2010-07-01

    ... excluded are: modest housing, bonuses or prizes of various sorts, tuition paid by the employer for the... business. It may also include such things as payment by the employer of the employee's social security tax...-of-living bonus of $260 each calendar quarter, or $20 per week. The employee works overtime in only 2...

  5. University Benefits Survey. Part I (All Benefits Excluding Pensions).

    Science.gov (United States)

    University of Western Ontario, London.

    Results of a 1986 survey of benefits, excluding pensions, for 17 Ontario, Canada, universities are presented. Information is provided on the following areas: whether the university self- administers insurance plans, communication of benefits, proposed changes in benefits, provision of accidental death and dismemberment insurance, maternity leave…

  6. University Benefits Survey. Part 1 (All Benefits Excluding Pensions).

    Science.gov (United States)

    University of Western Ontario, London.

    Results of a 1983 survey of benefits, excluding pensions, for 17 Ontario, Canada, universities are presented. Information is provided on the following areas: whether the university self-administers insurance plans, communication of benefits, proposed changes in benefits, provision of life and dismemberment insurance, maternity leave policy,…

  7. The use of radiation in the study of cultural heritage artefacts

    Science.gov (United States)

    Creagh, Dudley; Otieno-Alego, Vincent; Treasure, Alana; Kubik, Maria; Hallam, David

    2017-08-01

    Patrons of art galleries and museums, tourists visiting historic buildings, and sightseers viewing archaeological sites are generally unaware of the extent to which science and technology has contributed to the value of what they see. Many countries rely on cultural tourism to generate national wealth. The use of radiation of many kinds to assist in the conservation/restoration of cultural heritage artefacts is described in this paper. In particular, the paper will describe studies of the pigments used in historic Australian Indigenous art, the degradation of manuscripts written using iron-gall inks, the protection of statues against corrosion and the selection of lubricants for use in old machinery.

  8. PHOTOGRAPHER-FRIENDLY WORK-FLOWS FOR IMAGE-BASED MODELLING OF HERITAGE ARTEFACTS

    Directory of Open Access Journals (Sweden)

    N. Martin-Beaumont

    2013-07-01

    Full Text Available Because of its low-cost and ease in use, 3D reconstruction from sets of images has an great potential for enhancing cultural heritage documentation, conservation and valuation. However, these technologies, from image acquisition to final 3D model obtaining, are often difficult to master for non-expert people. Our work consists in developing a series of acquisition protocols for the museum's photographs. The end-goal being to enable those professionals to generate efficiently and easily 3D models of heritage artefact.

  9. Minimally destructive DNA extraction from archaeological artefacts made from whale baleen

    DEFF Research Database (Denmark)

    Sinding, Mikkel Holger Strander; Gilbert, Tom; Grønnow, Bjarne

    2012-01-01

    Here we demonstrate the successful extraction and amplification of target species DNA from artefacts made of whale baleen collected from excavations of past palaeo-Eskimo and Inuit cultures in Greenland. DNA was successfully extracted and amplified from a single baleen bristle of 1.5 cm length...... genetic studies. We conclude that genetic investigation of historical baleen collections can contribute to our knowledge of the prehistoric population genetics of baleen whales, for example by quantifying the impact of modern whaling on the genetic diversity of bowhead whales....

  10. Channelling can affect concentrations of metabolic intermediates at constant net flux: artefact or reality?

    Science.gov (United States)

    Cornish-Bowden, A; Cárdenas, M L

    1993-04-01

    We show that if a metabolic intermediate is directly transferred ('channelled') from an enzyme that catalyses its production to another that uses it as substrate, there is no change in its free concentration compared with a system with the same net flux in which there is no direct transfer. Thus the widespread idea that channelling provides a mechanism for decreasing metabolite concentrations at constant flux is false. Results from computer simulation that suggest otherwise [Mendes, P., Kell, D. B. & Westerhoff, H. V. (1992) Eur. J. Biochem. 204, 257-266] are artefacts either of variations in flux or of alterations in opposite directions of the activities of the relevant enzymes.

  11. Suppression of high-density artefacts in x-ray CT images using temporal digital subtraction with application to cryotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Baissalov, R.; Sandison, G.A.; Rewcastle, J.C. [Department of Medical Physics, Tom Baker Cancer Center, Calgary, Canada, T2N 4N2 2 Department of Physics and Astronomy, University of Calgary, Calgary T2N 2N4 (Canada); Donnelly, B.J. [Department of Surgery, Tom Baker Cancer Center, Calgary, Canada, T2N 4N2 4 Department of Surgery, Foothills Hospital, Calgary T2N 2T7 (Canada); Saliken, J.C. [Department of Surgery, Tom Baker Cancer Center, Calgary T2N 4N2 (Canada); Department of Diagnostic Imaging, Foothills Hospital, Calgary T2N 2T7 (Canada); McKinnon, J.G. [Department of Surgery, Foothills Hospital, Calgary T2N 2T7 (Canada); Muldrew, K. [Department of Surgery, Faculty of Medicine, University of Calgary, Calgary T2N 2T7 (Canada)

    2000-05-01

    Image guidance in cryotherapy is usually performed using ultrasound. Although not currently in routine clinical use, x-ray CT imaging is an alternative means of guidance that can display the full 3D structure of the iceball, including frozen and unfrozen regions. However, the quality of x-ray CT images is compromised by the presence of high-density streak artefacts. To suppress these artefacts we applied temporal digital subtraction (TDS). This TDS method has the added advantage of improving the grey-scale contrast between frozen and unfrozen tissue in the CT images. Two sets of CT images were taken of a phantom material, cryoprobes and a urethral warmer (UW) before and during the cryoprobe freeze cycle. The high-density artefacts persisted in both image sets. TDS was performed on these two image sets using the corresponding mask image of unfrozen material and the same geometrical configuration of the cryoprobes and the UW. The resultant difference image had a significantly reduced artefact content. Thus TDS can be used to significantly suppress or eliminate high-density CT streak artefacts without reducing the metallic content of the cryoprobes. In vivo study needs to be conducted to establish the utility of this TDS procedure for CT assisted prostate or liver cryotherapy. Applying TDS in x-ray CT guided cryotherapy will facilitate estimation of the number and location of all frozen and unfrozen regions, potentially making cryotherapy safer and less operator dependent. (author)

  12. Evaluation of a prototype correction algorithm to reduce metal artefacts in flat detector computed tomography of scaphoid fixation screws.

    Science.gov (United States)

    Filli, Lukas; Marcon, Magda; Scholz, Bernhard; Calcagni, Maurizio; Finkenstädt, Tim; Andreisek, Gustav; Guggenberger, Roman

    2014-12-01

    The aim of this study was to evaluate a prototype correction algorithm to reduce metal artefacts in flat detector computed tomography (FDCT) of scaphoid fixation screws. FDCT has gained interest in imaging small anatomic structures of the appendicular skeleton. Angiographic C-arm systems with flat detectors allow fluoroscopy and FDCT imaging in a one-stop procedure emphasizing their role as an ideal intraoperative imaging tool. However, FDCT imaging can be significantly impaired by artefacts induced by fixation screws. Following ethical board approval, commercially available scaphoid fixation screws were inserted into six cadaveric specimens in order to fix artificially induced scaphoid fractures. FDCT images corrected with the algorithm were compared to uncorrected images both quantitatively and qualitatively by two independent radiologists in terms of artefacts, screw contour, fracture line visibility, bone visibility, and soft tissue definition. Normal distribution of variables was evaluated using the Kolmogorov-Smirnov test. In case of normal distribution, quantitative variables were compared using paired Student's t tests. The Wilcoxon signed-rank test was used for quantitative variables without normal distribution and all qualitative variables. A p value of FDCT for metal artefacts induced by scaphoid fixation screws may facilitate intra- and postoperative follow-up imaging. Flat detector computed tomography (FDCT) is a helpful imaging tool for scaphoid fixation. The correction algorithm significantly reduces artefacts in FDCT induced by scaphoid fixation screws. This may facilitate intra- and postoperative follow-up imaging.

  13. Artefact on CT brain images caused by the presence of air bubbles in the cooling oil of the X-ray tube.

    Science.gov (United States)

    Trieu, Nelson; Xia, Ryan; Loneragan, Robert; Ridley, Lloyd; Trieu, Joseph

    2017-04-01

    We report a series of patients who had computed tomography (CT) of their brains which showed an uncommon artefact caused by excess air bubbles in the cooling oil around the X-ray tube. In November and December 2015, it was recognised that artefacts appearing on CT brain images acquired at our department were caused by a scanner fault. The test images were reviewed and the service engineer for the CT scanner was questioned about the artefact cause. A retrospective audit was then performed of images acquired on the CT scanner from December 2015 back to the date that the CT scanner was last serviced in September 2015 to identify any other scans affected by the artefact. Seven patients were identified whose CT brain scans showed the artefact. The artefact manifested in the form of an ill-defined low density area in varying locations. The artefact also appeared on CT phantom test images. It was discovered to be caused by the presence of excess air bubbles within the cooling oil of the X-ray tube. The fault was then rectified. The artefact described may not be easily recognised and could lead to misinterpretation and unnecessary investigation. We aim to promote awareness of this artefact and to reinforce the importance of frequent quality control testing of CT systems. © 2016 The Royal Australian and New Zealand College of Radiologists.

  14. Explorative Materiality and Knowledge. The Role of Creative Exploration and Artefacts in Design Research

    Directory of Open Access Journals (Sweden)

    Kristina Niedderer

    2013-08-01

    Full Text Available Juxtaposing the nature of design and the foundations of research in the traditional science and humanities disciplines puts their differences into sharp relief. The comparison highlights the key characteristics of design – its creative and experiential nature – which any design research must take into account, as well as the theoretical foundations of research. The aim of this article is to develop an understanding of the ontological, epistemological and methodological issues of design research, and to offer a framework that can embrace equally the notions of creativity and experiential knowledge, and of academic rigour. Furthermore,the potential roles of the design process and artefact within research are examined within this theoretical framework, which suggests that design processes and artefacts can – if appropriately framed – play an important partin the research process, facilitating an approach commensurate with the aims ofdesign enquiry. A case study of the Niedderer’s own work serves to illustratethe balance and integration of theory and (creative practice within the research process, and how this integration can enable a multi-layered contribution to the theoretical and practical advancement of the field.

  15. fNIRS response during walking - Artefact or cortical activity? A systematic review.

    Science.gov (United States)

    Vitorio, R; Stuart, S; Rochester, L; Alcock, L; Pantall, A

    2017-12-01

    This systematic review aims to (i) evaluate functional near infrared spectroscopy (fNIRS) walking study design in young adults, older adults and people with Parkinson's disease (PD); (ii) examine signal processing techniques to reduce artefacts and physiological noise in fNIRS data; and (iii) provide evidence-based recommendations for fNIRS walking study design and signal analysis techniques. An electronic search was undertaken. The search request detailed the measurement technique, cohort and walking task. Thirty-one of an initial yield of 73 studies satisfied the criteria. Protocols and methods for removing artefacts and noise varied. Differences in fNIRS signals between studies were found in rest vs. walking, speed of walking, usual vs. complex walking and easy vs. difficult tasks. In conclusion, there are considerable technical and methodological challenges in conducting fNIRS studies during walking which can introduce inconsistencies in study findings. We provide recommendations for the construction of robust methodologies and suggest signal processing techniques implementing a theoretical framework accounting for the physiology of haemodynamic responses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Integrated approach to the characterization and conservation of artefacts of the Brazilian colonial period

    Science.gov (United States)

    Angelini, E.; Grassini, S.; Solorzano, G.; Do Nascimento Campos, G.; de Caro, T.

    2006-06-01

    Several common-use artifacts (coins, faience, cult objects, etc.) coming from two excavations sites near Rio de Janeiro, two sugar farms Historico do Rochedo and Cruzeiro, have been the subject of this investigation, which aimed to integrate physico-chemical characterizations with the identification of degradation mechanisms, and the proposal of innovative conservation methods, such as PECVD deposition of SiO2-like films for protection of metallic artifacts. For the microchemical, micromorphological and microstructural analysis, optical microscopy-OM, X-ray diffraction XRD, X-ray fluorescence-XRF, and scanning electron microscopy equipped with electron microprobe-SEM+EDS have been employed. A cleaning step followed by a consolidation step has been carried out on glassy artefacts, while on metallic artefacts the mechanical cleaning has been followed by a stabilization treatment when necessary. For long-term protection the deposition by PECVD of SiO2-like films has been performed on a series of copper-based alloys in a home made reactor fed with an tetraethoxysilane-oxygen-argon mixture. The coatings show a good barrier effect against the diffusion of water and oxygen from the environment to the metal surface, that increases with increasing the oxygen to monomer ratio in the feeding gas mixture and the input power density. Moreover, the coating adhesion increases if the deposition process is performed after a hydrogen plasma treatment.

  17. Removing eye blink artefacts from EEG-A single-channel physiology-based method.

    Science.gov (United States)

    Zhang, Shenghuan; McIntosh, Julia; Shadli, Shabah M; Neo, Phoebe S-H; Huang, Zhiyi; McNaughton, Neil

    2017-11-01

    EEG signals are often contaminated with artefacts, particularly with large signals generated by eye blinks. Deletion of artefact can lose valuable data. Current methods of removing the eye blink component to leave residual EEG, such as blind source component removal, require multichannel recording, are computationally intensive, and can alter the original EEG signal. Here we describe a novel single-channel method using a model based on the ballistic physiological components of the eye blink. This removes the blink component, leaving uncontaminated EEG largely unchanged. Processing time allows its use in real-time applications such as neurofeedback training. Blink removal had a success rate of over 90% recovered variance of original EEG when removing synthesised eye blink components. Fronto-lateral sites were poorer (∼80%) than most other sites (92-96%), with poor fronto-polar results (67%). When compared with three popular independent component analysis (ICA) methods, our method was only slightly (1%) better at frontal midline sites but significantly (>20%) better at lateral sites with an overall advantage of ∼10%. With few recording channels and real-time processing, our method shows clear advantages over ICA for removing eye blinks. It should be particularly suited for use in portable brain-computer-interfaces and in neurofeedback training. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Respiratory Artefact Removal in Forced Oscillation Measurements: A Machine Learning Approach.

    Science.gov (United States)

    Pham, Thuy T; Thamrin, Cindy; Robinson, Paul D; McEwan, Alistair L; Leong, Philip H W

    2017-08-01

    Respiratory artefact removal for the forced oscillation technique can be treated as an anomaly detection problem. Manual removal is currently considered the gold standard, but this approach is laborious and subjective. Most existing automated techniques used simple statistics and/or rejected anomalous data points. Unfortunately, simple statistics are insensitive to numerous artefacts, leading to low reproducibility of results. Furthermore, rejecting anomalous data points causes an imbalance between the inspiratory and expiratory contributions. From a machine learning perspective, such methods are unsupervised and can be considered simple feature extraction. We hypothesize that supervised techniques can be used to find improved features that are more discriminative and more highly correlated with the desired output. Features thus found are then used for anomaly detection by applying quartile thresholding, which rejects complete breaths if one of its features is out of range. The thresholds are determined by both saliency and performance metrics rather than qualitative assumptions as in previous works. Feature ranking indicates that our new landmark features are among the highest scoring candidates regardless of age across saliency criteria. F1-scores, receiver operating characteristic, and variability of the mean resistance metrics show that the proposed scheme outperforms previous simple feature extraction approaches. Our subject-independent detector, 1IQR-SU, demonstrated approval rates of 80.6% for adults and 98% for children, higher than existing methods. Our new features are more relevant. Our removal is objective and comparable to the manual method. This is a critical work to automate forced oscillation technique quality control.

  19. Empowering the digitally excluded: learning initiatives for (invisible groups

    Directory of Open Access Journals (Sweden)

    Jane Seale

    2012-12-01

    Full Text Available There is growing evidence that some digitally excluded groups of learners are receiving more attention than others. Discussions regarding why some digitally excluded learners are more visible than others and therefore worthy of more committed digital inclusion interventions raises important questions about how we define and conceptualise digital inclusion and digital inclusion practice; particularly in relation to empowerment. In this article, we draw on a range of research, practice and policy literature to examine two important questions: what is empowerment and in whose hands does empowerment lie? We argue that empowerment involves making informed choices about technology use, but that learners often require support- human intervention- to make these choices. However, current digital inclusion research has failed to produce a detailed critique of what constitutes empowering support from educational institutions and their staff. A lack of open and reflexive accounts of practice means that we are no closer to identifying and understanding the kinds of empowering practices that are required to challenge the kinds of prejudices, stereotypes, risk-aversiveness and low aspirations associated with the most invisible of digitally excluded learners.

  20. The Study of Prehistoric Artefacts in National Context: Belgian Archaeologists and the Problem of Ancient Stone Implements

    Directory of Open Access Journals (Sweden)

    Matthew R. Goodrum

    2013-09-01

    Full Text Available During the early nineteenth century European archaeologists were formulating new ideas about the significance of ancient stone artefacts. Some, such as Christian Thomsen in Copenhagen, believed that in Scandinavia, a Stone Age had preceded the Bronze and Iron Ages. In France some excavations had retrieved stone artefacts from deep levels of peat and cave deposits that suggested that these objects were of very great antiquity. While the collection and study of stone artefacts occurred across much of Europe, there were regional variations in their interpretation. Assisted by local institutions and motivated by patriotism, Belgian archaeologists who participated in this research, had much in common with their colleagues elsewhere in Europe, but the nature of local archaeological sites and the ideas of local researchers had an impact on the development and contributions of Belgian prehistoric archaeology.

  1. Recording evoked potentials during deep brain stimulation: development and validation of instrumentation to suppress the stimulus artefact.

    Science.gov (United States)

    Kent, A R; Grill, W M

    2012-06-01

    The clinical efficacy of deep brain stimulation (DBS) for the treatment of movement disorders depends on the identification of appropriate stimulation parameters. Since the mechanisms of action of DBS remain unclear, programming sessions can be time consuming, costly and result in sub-optimal outcomes. Measurement of electrically evoked compound action potentials (ECAPs) during DBS, generated by activated neurons in the vicinity of the stimulating electrode, could offer insight into the type and spatial extent of neural element activation and provide a potential feedback signal for the rational selection of stimulation parameters and closed-loop DBS. However, recording ECAPs presents a significant technical challenge due to the large stimulus artefact, which can saturate recording amplifiers and distort short latency ECAP signals. We developed DBS-ECAP recording instrumentation combining commercial amplifiers and circuit elements in a serial configuration to reduce the stimulus artefact and enable high fidelity recording. We used an electrical circuit equivalent model of the instrumentation to understand better the sources of the stimulus artefact and the mechanisms of artefact reduction by the circuit elements. In vitro testing validated the capability of the instrumentation to suppress the stimulus artefact and increase gain by a factor of 1000 to 5000 compared to a conventional biopotential amplifier. The distortion of mock ECAP (mECAP) signals was measured across stimulation parameters, and the instrumentation enabled high fidelity recording of mECAPs with latencies of only 0.5 ms for DBS pulse widths of 50 to 100 µs/phase. Subsequently, the instrumentation was used to record in vivo ECAPs, without contamination by the stimulus artefact, during thalamic DBS in an anesthetized cat. The characteristics of the physiological ECAP were dependent on stimulation parameters. The novel instrumentation enables high fidelity ECAP recording and advances the potential use

  2. Investigating the effect of modifying the EEG cap lead configuration on the gradient artefact in simultaneous EEG-fMRI

    Directory of Open Access Journals (Sweden)

    Karen J Mullinger

    2014-07-01

    Full Text Available EEG data recorded during simultaneous fMRI are contaminated by large voltages generated by time-varying magnetic field gradients. Correction of the resulting gradient artefact (GA generally involves low-pass filtering to attenuate the high-frequency voltage fluctuations of the GA, followed by subtraction of a GA template produced by averaging over repeats of the artefact waveforms. This average artefact subtraction (AAS process relies on the EEG amplifier having a large enough dynamic range to characterise the artefact voltages and on invariance of the artefact waveform over repeated image acquisitions. Saturation of the amplifiers and changes in subject position can leave unwanted residual GA after AAS. Previous modelling work suggested that modifying the lead layout and the exit position of the cable bundle on the EEG cap could reduce the GA amplitude.Here, we used simulations and experiments to evaluate the effect of modifying the lead paths on the magnitude of the GA and on the residual artefact after AAS. The modelling work showed that for wire paths following great circles, the smallest overall GA occurs when the leads converge at electrode Cz. The performance of this new cap design was compared with a standard cap in experiments on a spherical agar phantom and human subjects. Using gradient pulses applied separately along the three Cartesian axes, we found that the GA due to the foot-head gradient was most significantly reduced relative to a standard cap for the phantom, whereas the anterior-posterior GA was most attenuated for human subjects. In addition, there was an overall 37% reduction in the RMS GA amplitude produced by a standard EPI sequence when comparing the two caps on the phantom. In contrast, the subjects showed an 11% increase in the average RMS of the GA. This work shows that the optimal design reduces the GA on a spherical phantom however; these gains are not translated to human subjects, probably due to the differences in

  3. Recording evoked potentials during deep brain stimulation: development and validation of instrumentation to suppress the stimulus artefact

    Science.gov (United States)

    Kent, A R; Grill, W M

    2012-01-01

    Deep brain stimulation (DBS) is an effective treatment for movement disorders, but the selection of stimulus parameters is a clinical burden and often yields sub-optimal outcomes for patients. Measurement of electrically evoked compound action potentials (ECAPs) during DBS could offer insight into the type and spatial extent of neural element activation and provide a potential feedback signal for the rational selection of stimulus parameters and closed-loop DBS. However, recording ECAPs presents a significant technical challenge due to the large stimulus artefact, which can saturate recording amplifiers and distort short latency ECAP signals. We developed DBS-ECAP recording instrumentation combining commercial amplifiers and circuit elements in a serial configuration to reduce the stimulus artefact and enable high fidelity recording. We used an electrical circuit equivalent model of the instrumentation to understand better the sources of the stimulus artefact and the mechanisms of artefact reduction by the circuit elements. In vitro testing validated the capability of the instrumentation to suppress the stimulus artefact and increase gain by a factor of 1,000 to 5,000 compared to a conventional biopotential amplifier. The distortion of mock ECAP (mECAP) signals was measured across stimulation parameters, and the instrumentation enabled high fidelity recording of mECAPs with latencies of only 0.5 ms for DBS pulse widths of 50 to 100 μs/phase. Subsequently, the instrumentation was used to record in vivo ECAPs, without contamination by the stimulus artefact, during thalamic DBS in an anesthetized cat. The characteristics of the physiological ECAP were dependent on stimulation parameters. The novel instrumentation enables high fidelity ECAP recording and advances the potential use of the ECAP as a feedback signal for the tuning of DBS parameters. PMID:22510375

  4. Enhanced x-ray imaging for a thin film cochlear implant with metal artefacts using phase retrieval tomography

    Energy Technology Data Exchange (ETDEWEB)

    Arhatari, B. D. [Department of Physics, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Coherent X-ray Science, Melbourne (Australia); Harris, A. R.; Paolini, A. G. [School of Psychological Science, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Electromaterials Science, Melbourne (Australia); Peele, A. G. [Department of Physics, La Trobe University, Victoria 3086 (Australia); ARC Centre of Excellence for Coherent X-ray Science, Melbourne (Australia); Australian Synchrotron, Victoria 3168 (Australia)

    2012-06-01

    Phase retrieval tomography has been successfully used to enhance imaging in systems that exhibit poor absorption contrast. However, when highly absorbing regions are present in a sample, so-called metal artefacts can appear in the tomographic reconstruction. We demonstrate that straightforward approaches for metal artefact reconstruction, developed in absorption contrast tomography, can be applied when using phase retrieval. Using a prototype thin film cochlear implant that has high and low absorption components made from iridium (or platinum) and plastic, respectively, we show that segmentation of the various components is possible and hence measurement of the electrode geometry and relative location to other regions of interest can be achieved.

  5. Excluded volume effect enhances the homology pairing of model chromosomes

    Science.gov (United States)

    Takamiya, Kazunori; Yamamoto, Keisuke; Isami, Shuhei; Nishimori, Hiraku; Awazu, Akinori

    To investigate the structural dynamics of the homology pairing of polymers, we mod- eled the scenario of homologous chromosome pairings during meiosis in Schizosaccharomyces pombe, one of the simplest model organisms of eukaryotes. We consider a simple model consist- ing of pairs of homologous polymers with the same structures that are confined in a cylindrical container, which represents the local parts of chromosomes contained in an elongated nucleus of S. pombe. Brownian dynamics simulations of this model showed that the excluded volume effects among non-homological chromosomes and the transitional dynamics of nuclear shape serve to enhance the pairing of homologous chromosomes.

  6. An automated algorithm to identify and reject artefacts for quantitative EEG analysis during sleep in patients with sleep-disordered breathing.

    Science.gov (United States)

    D'Rozario, Angela L; Dungan, George C; Banks, Siobhan; Liu, Peter Y; Wong, Keith K H; Killick, Roo; Grunstein, Ronald R; Kim, Jong Won

    2015-05-01

    Large quantities of neurophysiological electroencephalogram (EEG) data are routinely collected in the sleep laboratory. These are underutilised due to the burden of managing artefact contamination. The aim of this study was to develop a new tool for automated artefact rejection that facilitates subsequent quantitative analysis of sleep EEG data collected during routine overnight polysomnography (PSG) in subjects with and without sleep-disordered breathing (SDB). We evaluated the accuracy of an automated algorithm to detect sleep EEG artefacts against artefacts manually scored by three experienced technologists (reference standard) in 40 PSGs. Spectral power was computed using artefact-free EEG data derived from (1) the reference standard, (2) the algorithm and (3) raw EEG without any prior artefact rejection. The algorithm showed a high level of accuracy of 94.3, 94.7 and 95.8% for detecting artefacts during the entire PSG, NREM sleep and REM sleep, respectively. There was good to moderate sensitivity and excellent specificity of the algorithm detection capabilities during sleep. The EEG spectral power for the reference standard and algorithm was significantly lower than that of the raw, unprocessed EEG signal. These preliminary findings support an automated way to process EEG artefacts during sleep, providing the opportunity to investigate EEG-based markers of neurobehavioural impairment in sleep disorders in future studies.

  7. Reduction of artefacts caused by hip implants in CT-based attenuation-corrected PET images using 2-D interpolation of a virtual sinogram on an irregular grid

    NARCIS (Netherlands)

    Abdoli, Mehrsima; de Jong, Johan R.; Pruim, Jan; Dierckx, Rudi A. J. O.; Zaidi, Habib

    2011-01-01

    Purpose Metallic prosthetic replacements, such as hip or knee implants, are known to cause strong streaking artefacts in CT images. These artefacts likely induce over-or underestimation of the activity concentration near the metallic implants when applying CT-based attenuation correction of positron

  8. Diffusion of multiple species with excluded-volume effects

    KAUST Repository

    Bruna, Maria

    2012-01-01

    Stochastic models of diffusion with excluded-volume effects are used to model many biological and physical systems at a discrete level. The average properties of the population may be described by a continuum model based on partial differential equations. In this paper we consider multiple interacting subpopulations/species and study how the inter-species competition emerges at the population level. Each individual is described as a finite-size hard core interacting particle undergoing Brownian motion. The link between the discrete stochastic equations of motion and the continuum model is considered systematically using the method of matched asymptotic expansions. The system for two species leads to a nonlinear cross-diffusion system for each subpopulation, which captures the enhancement of the effective diffusion rate due to excluded-volume interactions between particles of the same species, and the diminishment due to particles of the other species. This model can explain two alternative notions of the diffusion coefficient that are often confounded, namely collective diffusion and self-diffusion. Simulations of the discrete system show good agreement with the analytic results. © 2012 American Institute of Physics.

  9. HLA region excluded by linkage analyses of early onset periodontitis

    Energy Technology Data Exchange (ETDEWEB)

    Sun, C.; Wang, S.; Lopez, N.

    1994-09-01

    Previous studies suggested that HLA genes may influence susceptibility to early-onset periodontitis (EOP). Segregation analyses indicate that EOP may be due to a single major gene. We conducted linkage analyses to assess possible HLA effects on EOP. Fifty families with two or more close relatives affected by EOP were ascertained in Virginia and Chile. A microsatellite polymorphism within the HLA region (at the tumor necrosis factor beta locus) was typed using PCR. Linkage analyses used a donimant model most strongly supported by previous studies. Assuming locus homogeneity, our results exclude a susceptibility gene within 10 cM on either side of our marker locus. This encompasses all of the HLA region. Analyses assuming alternative models gave qualitatively similar results. Allowing for locus heterogeneity, our data still provide no support for HLA-region involvement. However, our data do not statistically exclude (LOD <-2.0) hypotheses of disease-locus heterogeneity, including models where up to half of our families could contain an EOP disease gene located in the HLA region. This is due to the limited power of even our relatively large collection of families and the inherent difficulties of mapping genes for disorders that have complex and heterogeneous etiologies. Additional statistical analyses, recruitment of families, and typing of flanking DNA markers are planned to more conclusively address these issues with respect to the HLA region and other candidate locations in the human genome. Additional results for markers covering most of the human genome will also be presented.

  10. Bronze Age metal artefacts found on Cyprus - metal from Anatolia and the Western Mediterranean

    Directory of Open Access Journals (Sweden)

    Stos-Gale, Zofia A.

    2010-12-01

    Full Text Available Hundreds of Bronze Age metal artefacts excavated on archaeological sites in Cyprus have been analysed for their lead isotope and elemental composition in the Isotrace Laboratory, University of Oxford, in the years 1982-2002. In parallel, but in particular after 1995, hundreds of samples of minerals and slags collected from the mines and smelting sites around the Troodos Mountains were also analysed. Most of the results were published in various articles over the years, but the interpretation of some of the lead isotope data needs a current revision in view of new research conducted in Spain, Sardinia and southern France. It has been known that the lead isotope data for metal artefacts from the Cypriot Bronze Age sites shows that not all of the copper is consistent with origin from the Cypriot ores. In addition, the lead and silver artefacts found there must have been imported, because there are no lead or silver ores on Cyprus. The re-evaluation of the data shows that about 11 % of the analysed metal artefacts are consistent with the origin from the deposits in the Aegean and Turkey, while about 14 % with sources in the Western Mediterranean. This paper discusses in detail the current interpretation of the research into the sources of imported metal found in the Bronze Age context on Cyprus.

    Cientos de objetos de metal de la Edad del Bronce excavados en yacimientos de Chipre han sido analizados para conocer su composición elemental y sus isótopos de plomo en el Isotrace Laboratory de la Universidad de Oxford entre los años 1982 y 2002. Especialmente con posterioridad a 1995 cientos de muestras de minerales y escorias recogidas de minas y sitios de reducción de minerales localizadas en el entorno de las montañas de Troodos también fueron analizadas. La mayoría de los resultados fueron publicados en varios artículos a lo largo del tiempo, pero la interpretación de algunos análisis de isótopos de plomo necesitan de una revisión a

  11. The material variance of the Dead Sea Scrolls: On texts and artefacts

    Directory of Open Access Journals (Sweden)

    Eibert Tigchelaar

    2016-05-01

    Full Text Available What does a sacred text look like? Are religious books materially different from other books? Does materiality matter? This article deals with three different aspects of material variance attested amongst the Dead Sea Scrolls, Ancient Jewish religious text fragments, of which were found in the Judean Desert. I suggest that the substitution of the ancient Hebrew script by the everyday Aramaic script, also for Torah and other religious texts, was intentional and programmatic: it enabled the broader diffusion of scriptures in Hellenistic and Roman Judea. The preponderant use of parchment for religious texts rather than papyrus may be a marker of identity. The many small scrolls which contained only small parts of specific religious books (Genesis, Psalms may have been produced as religious artefacts which express identity in the period when Judaism developed into a religion of the book. Keywords: Dead Sea Scrolls; Judaism; Manuscripts

  12. Interaction of pulse laser radiation of 532 nm with model coloration layers for medieval stone artefacts

    Energy Technology Data Exchange (ETDEWEB)

    Colson, J. [University of Vienna, Department of Physical Chemistry, A-1090 Vienna (Austria); Nimmrichter, J. [Austrian Federal Office for the Care of Monuments, Department for Conservation and Restoration, Arsenal, Objekt 15, Tor 4, A-1030 Vienna (Austria); Kautek, W., E-mail: wolfgang.kautek@univie.ac.at [University of Vienna, Department of Physical Chemistry, A-1090 Vienna (Austria)

    2014-05-01

    Multilayer polychrome coatings on medieval and Renaissance stone artefacts represent substantial challenges in laser cleaning. Therefore, polychromic models with classical pigments, minium (Pb{sub 2}{sup 2+}Pb{sup 4+}O{sub 4}), zinc white (ZnO), and lead white ((PbCO{sub 3}){sub 2}·Pb(OH){sub 2}) in an acrylic binder, were irradiated with a Q-switched Nd:YAG laser emitting at 532 nm. The studied medieval pigments exhibit strongly varying incubation behaviours directly correlated to their band gap energies. Higher band gaps beyond the laser photon energy of 2.3 eV require more incubative generation of defects for resonant transitions. A matching of the modification thresholds after more than four laser pulses was observed. Laser cleaning with multiple pulsing should not exceed ca. 0.05 J/cm{sup 2} when these pigments coexist in close spatial proximity.

  13. Influence of metallic dental implants and metal artefacts on dose calculation accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Maerz, Manuel; Koelbl, Oliver; Dobler, Barbara [Regensburg University Medical Center, Department of Radiotherapy, Regensburg (Germany)

    2014-10-31

    Metallic dental implants cause severe streaking artefacts in computed tomography (CT) data, which inhibit the correct representation of shape and density of the metal and the surrounding tissue. The aim of this study was to investigate the impact of dental implants on the accuracy of dose calculations in radiation therapy planning and the benefit of metal artefact reduction (MAR). A second aim was to determine the treatment technique which is less sensitive to the presence of metallic implants in terms of dose calculation accuracy. Phantoms consisting of homogeneous water equivalent material surrounding dental implants were designed. Artefact-containing CT data were corrected using the correct density information. Intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans were calculated on corrected and uncorrected CT data and compared to 2-dimensional dose measurements using GafChromic trademark EBT2 films. For all plans the accuracy of dose calculations is significantly higher if performed on corrected CT data (p = 0.015). The agreement of calculated and measured dose distributions is significantly higher for VMAT than for IMRT plans for calculations on uncorrected CT data (p = 0.011) as well as on corrected CT data (p = 0.029). For IMRT and VMAT the application of metal artefact reduction significantly increases the agreement of dose calculations with film measurements. VMAT was found to provide the highest accuracy on corrected as well as on uncorrected CT data. VMAT is therefore preferable over IMRT for patients with metallic implants, if plan quality is comparable for the two techniques. (orig.) [German] Zahnimplantate aus Metall verursachen in Computertomographiedaten (CT) streifenfoermige Artefakte. Diese verhindern eine korrekte Zuordnung von Form und Dichteeigenschaften des Metalls und des umgebenden Gewebes. Ziel dieser Studie war es, den Einfluss von Zahnimplantaten auf die Genauigkeit der Dosisberechnung in der

  14. Photoelectric artefact from optogenetics and imaging on microelectrodes and bioelectronics: New Challenges and Opportunities.

    Science.gov (United States)

    Kozai, Takashi D Y; Vazquez, Alberto L

    2015-07-07

    Bioelectronics, electronic technologies that interface with biological systems, are experiencing rapid growth in terms of technology development and applications, especially in neuroscience and neuroprosthetic research. The parallel growth with optogenetics and in vivo multi-photon microscopy has also begun to generate great enthusiasm for simultaneous applications with bioelectronic technologies. However, emerging research showing artefact contaminated data highlight the need for understanding the fundamental physical principles that critically impact experimental results and complicate their interpretation. This review covers four major topics: 1) material dependent properties of the photoelectric effect (conductor, semiconductor, organic, photoelectric work function (band gap)); 2) optic dependent properties of the photoelectric effect (single photon, multiphoton, entangled biphoton, intensity, wavelength, coherence); 3) strategies and limitations for avoiding/minimizing photoelectric effects; and 4) advantages of and applications for light-based bioelectronics (photo-bioelectronics).

  15. Archaeometric study of artefacts from firing places of Longola-Poggiomarino protohystoric settlement site (Naples, Italy)

    Science.gov (United States)

    Balassone, G.; di Maio, G.; Barca, D.; Mormone, A.

    2009-04-01

    The Longola-Poggiomarino protohistoric village was discovered at west of Naples (southern Italy) in the year 2000, during the construction of a purification plant. It is located nearby the harbour of the Roman town of Pompeii and its age spans from the late Middle Bronze Age to the 6th century B.C., when the site was definitely abandoned (Cicirelli et al., 2006). This is a noteworthy discovery in southern Italy and in Europe, due to the peculiarity of its riverine location and the way in which it was constructed. In fact the village was built on many artificial small islands surrounded by a navigable canal network; hence it is surnamed "The prehistoric Venice". It is characterized by numerous evidences of human activities, like houses, pirogues, numerous objects and some handicraft working areas, where artefacts for domestic artisan and ornamental use were made (Salari et al., 2006). A great abundance of ceramics and metallic objects (made of diversified materials like lead, bronze, iron and gold) has been found, pointing to several distinct working/smelting sites throughout the village (Balassone et al., 2009). In these working sites, fair evidences of heating have been detected on several materials. In this work we characterized the compositional features of fifteen samples coming from firing places found at Longola, by means of a multi-analytical approach. Likely use of these findings could be coverings of burnt pavements, bricks or heat resistant vessel. The research aim is to contribute to the scenario reconstruction of this archaeological site by the knowledge of some production techniques, firing temperatures and provenance of raw materials. The microstructural features and modal mineralogy of the findings were determined by optical microscopy. X-ray diffraction, SEM-EDS and FTIR spectroscopy were used to determine and characterize overall mineral constituents and their quantitative composition. Representative findings were also analyzed for their whole

  16. Two benzaldehyde derivatives and their artefacts from a gorgonian-derived Eurotium sp. fungus.

    Science.gov (United States)

    Chen, Min; Zhao, Qing; Hao, Jun-Di; Wang, Chang-Yun

    2017-02-01

    Two new benzaldehyde derivatives, named 3'-OH-tetrahydroauroglaucin (1) and(3'S*,4'R*)-6-(3',5-epoxy-4'-hydroxy-1'-heptenyl)-2-hydroxy-3-(3''-methyl-2''-butenyl)benzaldehyde (2), were isolated from a gorgonian-derived Eurotium sp. fungus. Their structures were determined by extensive spectroscopic analysis including NMR and MS spectra. Dissolved 1 in CDCl3 for several days could be detected its 2H-chromene skeleton derivatives (1a/1b), a pair of enantiomers with opposite configurations at C-3'. Compound 2 was also found to chemically convert to a pair of epimers non-enzymatically. The plausible mechanism to form the 2H-chromene artefacts with racemisation at C-3' undergoing nucleophilic substitution (SN1) was proposed.

  17. EVALUATING AND REFINING THE ‘ENTERPRISE ARCHITECTURE AS STRATEGY’ APPROACH AND ARTEFACTS

    Directory of Open Access Journals (Sweden)

    M. De Vries

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Enterprise Architecture (EA is a new discipline that has emerged from the need to create a holistic view of an enterprise, and thereby to discover business/IT integration and alignment opportunities across enterprise structures. Previous EA value propositions that merely focus on IT cost reductions will no longer convince management to invest in EA. Today, EA should enable business strategy in the organisation to create value. This resides in the ability to do enterprise optimisation through process standardisation and integration. In order to do this, a new approach is required to integrate EA into the strategy planning process of the organisation.
    This article explores the use of three key artefacts – operating models, core diagrams, and an operating maturity assessment as defined by Ross, Weill & Robertson [1] – as the basis of this new approach. Action research is applied to a research group to obtain qualitative feedback on the practicality of the artefacts.

    AFRIKAANSE OPSOMMING: Ondernemingsargitektuur (OA is ’n nuwe dissipline wat ontstaan het uit die behoefte om ’n holistiese perspektief van ’n onderneming te skep om sodoende besigheid/IT-integrasie en - belyningsgeleenthede regoor ondernemingstrukture te ontdek. Vorige OA waardeaanbiedings wat hoofsaaklik gefokus het op IT kostebesparings sal bestuur nie meer kan oorreed om in OA te belê nie. Vandag behoort OA bevoegdheid te gee aan ondernemingstrategie om werklik waarde te skep. Hierdie bevoegdheid lê gesetel in ondernemingsoptimering deur middel van prosesstandaardisasie en -integrasie. ’n Nuwe benadering word benodig ten einde OA te integreer met die strategiese beplanningsproses van die organisasie.
    Hierdie artikel ondersoek die gebruik van drie artefakte – operasionele modelle, kerndiagramme, en operasionele volwassenheidsassessering soos gedefinieer deur Ross, Weill & Robertson [1] – as die basis van hierdie nuwe benadering

  18. A new method for joint susceptibility artefact correction and super-resolution for dMRI

    Science.gov (United States)

    Ruthotto, Lars; Mohammadi, Siawoosh; Weiskopf, Nikolaus

    2014-03-01

    Diffusion magnetic resonance imaging (dMRI) has become increasingly relevant in clinical research and neuroscience. It is commonly carried out using the ultra-fast MRI acquisition technique Echo-Planar Imaging (EPI). While offering crucial reduction of acquisition times, two limitations of EPI are distortions due to varying magnetic susceptibilities of the object being imaged and its limited spatial resolution. In the recent years progress has been made both for susceptibility artefact correction and increasing of spatial resolution using image processing and reconstruction methods. However, so far, the interplay between both problems has not been studied and super-resolution techniques could only be applied along one axis, the slice-select direction, limiting the potential gain in spatial resolution. In this work we describe a new method for joint susceptibility artefact correction and super-resolution in EPI-MRI that can be used to increase resolution in all three spatial dimensions and in particular increase in-plane resolutions. The key idea is to reconstruct a distortion-free, high-resolution image from a number of low-resolution EPI data that are deformed in different directions. Numerical results on dMRI data of a human brain indicate that this technique has the potential to provide for the first time in-vivo dMRI at mesoscopic spatial resolution (i.e. 500μm) a spatial resolution that could bridge the gap between white-matter information from ex-vivo histology (≍1μm) and in-vivo dMRI (≍2000μm).

  19. A novel approach for removing the hook effect artefact from Electrical Bioimpedance spectroscopy measurements

    Science.gov (United States)

    Buendia, R.; Seoane, F.; Gil-Pita, R.

    2010-04-01

    Very often in Electrical Bioimpedance (EBI) spectroscopy measurements the presence of stray capacitances creates a measurement artefact commonly known as Hook Effect. Such an artefact creates a hook-alike deviation of the EBI data noticeable when representing the measurement on the impedance plane. Such Hook Effect is noticeable at high frequencies but it also causes a data deviation at lower measurement frequencies. In order to perform any accurate analysis of the EBI spectroscopy data, the influence of the Hook Effect must be removed. An established method to compensate the hook effect is the well known Td compensation, which consists on multiplying the obtained spectrum, Zmeas(ω) by a complex exponential in the form of exp[jωTd]. Such a method cannot correct entirely the Hook Effect since the hook-alike deviation occurs a broad frequency range in both magnitude and phase of the measured impedance, and by using a scalar value for Td. First a scalar only modifies the phase of the measured impedance and second, a single value can truly corrects the Hook Effect only at a single frequency. In addition, the process to select a value for the scalar Td by an iterative process with the aim to obtain the best Cole fitting lacks solid scientific grounds. In this work the Td compensation method is revisited and a modified approach for correcting the Hook Effect including a novel method for selecting the correcting values is proposed. The initial validation results confirm that the proposed method entirely corrects the Hook Effect at all frequencies.

  20. Correction of motion artefacts and pseudo colour visualization of multispectral light scattering images for optical diagnosis of rheumatoid arthritis

    Science.gov (United States)

    Minet, Olaf; Scheibe, Patrick; Beuthan, Jürgen; Zabarylo, Urszula

    2010-02-01

    State-of-the-art image processing methods offer new possibilities for diagnosing diseases using scattered light. The optical diagnosis of rheumatism is taken as an example to show that the diagnostic sensitivity can be improved using overlapped pseudo-coloured images of different wavelengths, provided that multispectral images are recorded to compensate for any motion related artefacts which occur during examination.

  1. Portable XRF on Prehistoric Bronze Artefacts: Limitations and Use for the Detection of Bronze Age Metal Workshops

    DEFF Research Database (Denmark)

    Nørgaard, Heide Wrobel

    2017-01-01

    Two different scientific analyses—one destructive and one non destructive—were conducted on two separate groups of bronze ornaments dating from 1500–1100 BC to investigate, amongst other traits, the metal composition of their copper-tin alloys. One group of artefacts was sampled, and polished thi...

  2. Artefacts in 24-h pharyngeal and oesophageal pH monitoring: Is simplification of pH data analysis feasible?

    NARCIS (Netherlands)

    Mathus-Vliegen, E. M. H.; Smit, C. F.; Devriese, P. P.

    2004-01-01

    Background: Ambulatory 24-h dual-channel pharyngeal and oesophageal pH monitoring is the standard test for measuring gastro-oesophageal and gastropharyngeal reflux. Artefacts caused by the intake of food may result in falsely positive gastropharyngeal reflux, which necessitates a manual review of

  3. Dynamic miniature lighting system with low correlated colour temperature and high colour rendering index for museum lighting of fragile artefacts

    DEFF Research Database (Denmark)

    Thorseth, Anders; Corell, Dennis Dan; Poulsen, Peter Behrensdorff

    2013-01-01

    of historical artefacts in display cases at museums and other exhibitions, which can replace 3-5 Watt incandescent light bulbs with a correlated colour temperature (CCT) from 2000 K to 2400 K. The solution decreases the energy consumption by up to 80 %, while maintaining colour rendering indices (Ra) above 90...

  4. Coronary CT angiography in patients with implanted cardiac devices: initial experience with the metal artefact reduction technique.

    Science.gov (United States)

    Tatsugami, Fuminari; Higaki, Toru; Sakane, Hiroaki; Fukumoto, Wataru; Iida, Makoto; Baba, Yasutaka; Fujioka, Chikako; Kihara, Yasuki; Tsushima, So; Awai, Kazuo

    2016-11-01

    Single-energy metal artefact reduction (SEMAR), a new technique that can now be used in routine CT examinations, has recently become applicable to volume data acquired with electrocardiography gating. We evaluated the effect of this technique on the visualization of the coronary arteries in patients harboring cardiac devices. We subjected 8 patients (7 males, 1 female; mean age 65.5 ± 11.3 years) with implanted cardiac devices to coronary CT angiography on a 320-slice CT scanner (Aquilion ONE Vision(™); Toshiba Medical Systems Corp., Tokyo, Japan). Image data sets were reconstructed with and without SEMAR. Two radiologists visually evaluated the image quality based on metal artefacts from the electronic device leads using a four-point scale (1 = vessel not visible to 4 = minimal or no metal artefacts). Images with a score of 3 or 4 were considered diagnostic. In both SEMAR and non-SEMAR data sets, 94 coronary artery segments were available for evaluation. Without SEMAR, 11 segments (11.7%) were rated as non-diagnostic; SEMAR improved the image quality of 9 of the 11 segments (81.8%), and the images became diagnostic. SEMAR reduced metal artefacts from the electronic device leads and improved the image quality of the coronary arteries in patients with cardiac devices. Advances in knowledge: SEMAR has recently become applicable to volume data acquired with electrocardiography gating. SEMAR reduces metal artefacts elicited by electronic device leads and improves the image quality of the coronary arteries in patients with cardiac devices.

  5. FT-Raman and FT-Infrared investigations of archaeological artefacts from Foeni Neolithic site (Banat, Romania

    Directory of Open Access Journals (Sweden)

    Simona Cîntă Pînzaru

    2008-08-01

    Full Text Available An impressive collection of chert artefacts from the Foeni Neolithic archaeological site (Timiş County, Banat region, Romania is hosted by the Banat Museum in Timişoara. A representative set of seven specimens was non-destructively investigated using FT-Raman and ATR-FT-IR spectroscopy. The research was carried out for checking if these readily-available, non-destructive, fast, and cheap methods, which do not require preliminary sample preparation could provide significant information for characterizing the mineral composition of chert artefacts. Based on vibrational data, it was confirmed that the raw material was represented by microcrystalline quartz and moganite, with local concentrations of accessory minerals (calcite, dolomite, and clay minerals. In spite of their wide macroscopic heterogeneity (colour, transparency, based on single point FT-Raman measurements the chert artefacts could not be assigned to distinctive groups of raw silica materials, in order to provide specific arguments for provenance studies. However, the presence of specific accessory minerals (dolomite, illite pointed to distinctive genetic conditions in the case of one lithic material. Sets of measurements (mapping are required for statistically characterizing each artefact specimen. IR data were less significant, due to the rough surface texture of the specimens in contact with the ZnSe crystal of the ATR-FT-IR module. However, illite was identified based solely on its contribution to the IR spectrum. This pioneering study on chert artefacts from Romania based on optical spectroscopic methods shows that there are good premises for a systematic investigation of highly-valuable museum collections, in particular in terms of chert geology.

  6. Evaluation of a prototype correction algorithm to reduce metal artefacts in flat detector computed tomography of scaphoid fixation screws

    Energy Technology Data Exchange (ETDEWEB)

    Filli, Lukas; Finkenstaedt, Tim; Andreisek, Gustav; Guggenberger, Roman [University Hospital of Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); Marcon, Magda [University Hospital of Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Udine, Institute of Diagnostic Radiology, Department of Medical and Biological Sciences, Udine (Italy); Scholz, Bernhard [Imaging and Therapy Division, Siemens AG, Healthcare Sector, Forchheim (Germany); Calcagni, Maurizio [University Hospital of Zurich, Division of Plastic Surgery and Hand Surgery, Zurich (Switzerland)

    2014-12-15

    The aim of this study was to evaluate a prototype correction algorithm to reduce metal artefacts in flat detector computed tomography (FDCT) of scaphoid fixation screws. FDCT has gained interest in imaging small anatomic structures of the appendicular skeleton. Angiographic C-arm systems with flat detectors allow fluoroscopy and FDCT imaging in a one-stop procedure emphasizing their role as an ideal intraoperative imaging tool. However, FDCT imaging can be significantly impaired by artefacts induced by fixation screws. Following ethical board approval, commercially available scaphoid fixation screws were inserted into six cadaveric specimens in order to fix artificially induced scaphoid fractures. FDCT images corrected with the algorithm were compared to uncorrected images both quantitatively and qualitatively by two independent radiologists in terms of artefacts, screw contour, fracture line visibility, bone visibility, and soft tissue definition. Normal distribution of variables was evaluated using the Kolmogorov-Smirnov test. In case of normal distribution, quantitative variables were compared using paired Student's t tests. The Wilcoxon signed-rank test was used for quantitative variables without normal distribution and all qualitative variables. A p value of < 0.05 was considered to indicate statistically significant differences. Metal artefacts were significantly reduced by the correction algorithm (p < 0.001), and the fracture line was more clearly defined (p < 0.01). The inter-observer reliability was ''almost perfect'' (intra-class correlation coefficient 0.85, p < 0.001). The prototype correction algorithm in FDCT for metal artefacts induced by scaphoid fixation screws may facilitate intra- and postoperative follow-up imaging. (orig.)

  7. Persistent Artefacts in an Online Classroom: The Value of a Dynamic Learning Archive | Artefacts persistants dans une salle de classe en ligne : la valeur d’une archive dynamique de l’apprentissage

    Directory of Open Access Journals (Sweden)

    Stuart C. Berry

    2016-04-01

    Full Text Available This paper summarizes a multi-year research project that examines the use and value of visible and persistent artefacts within an online learning environment. This study is framed within elements of a business management theory. Changes to an online learning environment are documented as well as an examination of the impact of these changes on the learning process. The study also shows the impact of learner engagement with artefacts over the life of multiple iterations of a course within this socially networked online learning space. Two significant outcomes emerged: 1. How the use of a socially networked online learning environment can offer a rich and supportive place for teaching and learning; and 2. That students in this study support the inclusion of an archive containing artefacts from learners in prior iterations of a course. The connection between the inclusion of this archive and the impact of a socially networked online learning environment will be demonstrated throughout. Cet article résume un projet de recherche sur plusieurs années, examinant l’utilisation et la valeur des artefacts visibles et persistants au sein d’un environnement d’apprentissage en ligne. Cette étude a été structurée selon des éléments d’une théorie de la gestion des affaires. Les modifications à l’environnement d’apprentissage en ligne sont documentées, ainsi que l’examen de l’incidence de ces modifications sur le processus d’apprentissage. L’étude montre aussi l’impact de l’engagement de l’apprenant avec les artefacts sur plusieurs itérations d’un cours dans un espace d’apprentissage en ligne doté de réseaux sociaux. Deux résultats importants ont émergé : 1. un espace d’apprentissage en ligne doté de réseaux sociaux peut offrir un endroit riche et soutenant pour l’enseignement et l’apprentissage; et 2. les étudiants dans cette étude sont favorables à l’inclusion d’une archive rassemblant les

  8. Towards a Knowledge Communication Perspective on Designing Artefacts Supporting Knowledge Work

    Directory of Open Access Journals (Sweden)

    Niclas Eberhagen

    2015-02-01

    Full Text Available The designing of computer-based artefacts to support knowledge work is far from a straightforward rational process. Characteristics of knowledge work have a bearing upon how developers (or designers, together with users, come to approach and capture the rich and tacit knowing of the practice. As all knowledge work is about the production of knowledge, transforming it, so is the design practice for developing artefacts to occupy space within that same practice. There is a need for providing a conceptual language to better reflect the nature of this design work that goes beyond those dressed in the managerial (or rational language of planned activities and deliverables. Towards this end, a conceptual frame is presented that makes several important aspects of the design practice visible. The frame brings together both nature of design work and characteristics of knowledge work to extend the frame of knowledge in user-developer communication of Kensing and Munk-Madsen. Thereby, providing a means to focus attention and dress debate on what situated designing is. By using explicit concepts, such as types knowledge domains embedded in the design situation, the transitional paths between them, and design engagements, it arms practitioners with specific linguistic constructs to direct attention and efforts in planning and organizing development undertakings.Purpose – the purpose of this work is to present and argue for a perspective on designing of computer-based artefacts supporting knowledge work. This is done to inform practitioners, directing their attention and dressing debate, and providing a conceptual language to better capture design activities in planning and organizing development undertakings.Design/Methodology/Approach – The approach presented in this article is conceptual in so far that a model or frame providing linguistic constructs is constructed and argued, building upon scholarly work of knowledge communication and drawing upon

  9. In vitro artefact assessment of a new MR-compatible microwave antenna and a standard MR-compatible radiofrequency ablation electrode for tumour ablation

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Ruediger; Rempp, Hansjoerg; Eibofner, Frank; Kessler, David-Emanuel; Weiss, Jakob; Nikolaou, Konstantin; Clasen, Stephan [Eberhard Karls University, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Blumenstock, Gunnar [Eberhard Karls University, Department of Clinical Epidemiology and Applied Biometry, Tuebingen (Germany); Pereira, Philippe L. [SLK-Kliniken Heilbronn GmbH, Department of Radiology, Minimally Invasive Therapies, and Nuclear Medicine, Heilbronn (Germany)

    2016-03-15

    To evaluate and compare artefact configuration and diameters in a magnetic resonance (MR)-compatible prototype microwave (MW) applicator and a standard MR-compatible radiofrequency (RF) applicator for MR-guided tumour ablation. Both applicators were tested in a phantom study at 1.5T with three sequences: T1-weighted three-dimensional volume interpolated breath-hold examination (VIBE), T1-weighted fast low angle shot (FLASH), T2-weighted turbo spin echo (TSE). Applicator orientation to main magnetic field (B{sub 0}) and slice orientation were varied. Needle tip location error (TLE) was assessed, and artefact diameters were calculated. Influence of imaging parameters on artefacts was assessed with analysis of variance (ANOVA) and post hoc testing. MW applicator: the shaft artefact diameter measured 2.3 +/- 0.8 mm. Tip artefact diameter and length measured 2.2 ± 0.8 mm and 2.4 ± 1.3 mm, respectively. A prominent oval artefact (diameter: 16.5 +/- 1.8 mm, length: 19.1 +/- 2.5 mm) appeared close to the tip. TLE: -.3 +/- 0.6 mm. RF applicator: shaft and tip diameter measured 8.9 +/- 4.7 mm and 9.0 +/-.0 mm, respectively. TLE: -0.1 +/- 0.8 mm. Minimal artefacts were measured with RF applicator orientation parallel to B{sub 0} (P < 0.0001), whereas no such influence was found for MW applicator. For both applicators, significantly large artefacts were measured with T1 FLASH (P = 0.03). The MW applicator's artefact is satisfactory and seems useable for MR-guided ablation procedures. (orig.)

  10. Investigating the minimum scan parameters required to generate free-breathing motion artefact-free fast-helical CT.

    Science.gov (United States)

    Thomas, David H; Tan, Jun; Neylon, Jack; Dou, Tai; O'Connell, Dylan; McNitt-Gray, Michael; Lee, Percy; Lamb, James; Low, Daniel A

    2018-02-01

    A recently proposed "5DCT" protocol uses deformable registration of free-breathing fast-helical CT scans to generate a breathing motion model. In order to allow accurate registration, free-breathing images are required to be free of doubling-artefacts, which arise when tissue motion is greater than scan speed. Using a unique set of digital phantoms based on patient data and verified with a motion phantom, this work identifies the minimum scanner parameters required to successfully generate free-breathing artefact-free fast-helical scans. A motion phantom and 5 patients were imaged 25 times under free-breathing conditions in alternating directions with a 64-slice CT scanner employing a low-dose fast-helical protocol. A series of high temporal resolution (0.1 s) 5DCT scan data sets was generated in each case. A simulated CT scanner was used to "image" each free-breathing data set. Various CT scanner detector widths and rotation times were simulated, and verified using the motion phantom results. Motion-induced artefacts were quantified in patient images using structural similarity maps to determine the similarity between axial slices. Increasing amounts of motion-induced artefacts were observed with increasing rotation times >0.2 s for 16 mm detector configuration. The current generation of 16-slice CT scanners, which are present in the majority of Radiation Oncology departments, are not capable of generating free-breathing sorting artefact-free images required for 5DCT. Advances in knowledge: A recently proposed "5DCT" protocol uses deformable registration of free-breathing fast-helical CT scans to generate a breathing motion model. In order to allow accurate registration, free-breathing images are required to be free of doubling-artefacts, which arise when tissue motion is greater than scan speed. The results suggest that the current generation of 16-slice CT scanners, present in the majority of Radiation Oncology departments, are not capable of generating

  11. Beam hardening artefacts in computed tomography with photon counting, charge integrating and energy weighting detectors: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Shikhaliev, Polad M [Department of Radiological Sciences, University of California, Irvine, CA 92697 (United States)

    2005-12-21

    Photon counting x-ray imaging provides efficient rejection of the electronics noise, no pulse height (Swank) noise, less noise due to optimal photon energy weighting and the possibility of energy resolved image acquisition. These advantages apply also to CT when projection data are acquired using a photon counting detector. However, photon counting detectors assign a weighting factor of 1 to all detected photons whereas the weighting factor of a charge integrating detector is proportional to the energy of the detected photon. Therefore, data collected by photon counting and charge integrating detectors represent the 'hardening' of the photon beam passed through the object differently. This affects the beam hardening artefacts in the reconstructed CT images. This work represents the first comparative evaluation of the effect of photon counting, charge integrating and energy weighting photon detectors on beam hardening artefacts in CT. Beam hardening artefacts in CT images were evaluated for 20 cm and 14 cm diameter water cylinders with bone and low contrast inserts, at 120 kVp and 90 kVp x-ray tube voltages, respectively. It was shown that charge integrating results in 1.8% less beam hardening artefacts from bone inserts (i.e., CT numbers in the 'shadow' of the bone are less by 1.8% as compared to CT numbers over the periphery of the image), as compared to photon counting. However, optimal photon energy weighting, which provides highest SNR, results in 7.7% higher beam hardening artefacts from bone inserts as compared to photon counting. The magnitude of the 'cupping' artefacts was lower by 1% for charge integrating and higher by 6.1% for energy weighting acquisitions as compared to photon counting. Only the photon counting systems provide an accurate representation of the beam hardening effect due to its flat energy weighting. Because of their energy dependent weighting factors, the charge integrating and energy weighting systems do

  12. Determinants of prosocial behavior in included versus excluded contexts

    Directory of Open Access Journals (Sweden)

    Esther eCuadrado

    2016-01-01

    Full Text Available Prosocial behavior is increasingly becoming necessary as more and more individuals experience exclusion. In this context it is important to understand the motivational determinants of prosocial behavior. Here we report two experiments which analyzed the influence of dispositional (prosocialness; rejection sensitivity and motivational variables (prosocial self-efficacy; prosocial collective efficacy; trust; anger; social affiliation motivation on prosocial behavior under neutral contexts (Study 1, and once under inclusion or exclusion conditions (Study 2. Both studies provided evidence for the predicted mediation of prosocial behavior. Results in both neutral and inclusion and exclusion conditions supported our predictive model of prosocial behavior. In the model dispositional variables predicted motivational variables, which in turn predicted prosocial behavior. We showed that the investigated variables predicted prosocial behavior; this suggests that to promote prosocial behavior one could (1 foster prosocialness, prosocial self and collective efficacy, trust in others and affiliation motivation and (2 try to reduce negative feelings and the tendency to dread rejection in an attempt to reduce the negative impact that these variables have on prosocial behavior. Moreover, the few differences that emerged in the model between the inclusion and exclusion contexts suggested that in interventions with excluded individuals special care emphasis should be placed on addressing rejection sensitivity and lack of trust.

  13. Should the Standard Count Be Excluded from Neutron Probe Calibration?

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhuanfang

    2017-10-12

    About 6 decades after its introduction, the neutron probe remains one of the most accurate methods for indirect measurement of soil moisture content. Traditionally, the calibration of a neutron probe involves the ratio of the neutron count in the soil to a standard count, which is the neutron count in the fixed environment such as the probe shield or a specially-designed calibration tank. The drawback of this count-ratio-based calibration is that the error in the standard count is carried through to all the measurements. An alternative calibration is to use the neutron counts only, not the ratio, with proper correction for radioactive decay and counting time. To evaluate both approaches, the shield counts of a neutron probe used for three decades were analyzed. The results show that the surrounding conditions have a substantial effect on the standard count. The error in the standard count also impacts the calculation of water storage and could indicate false consistency among replicates. The analysis of the shield counts indicates negligible aging effect of the instrument over a period of 26 years. It is concluded that, by excluding the standard count, the use of the count-based calibration is appropriate and sometimes even better than ratio-based calibration. The count-based calibration is especially useful for historical data when the standard count was questionable or absent

  14. Comparative Laser Spectroscopy Diagnostics for Ancient Metallic Artefacts Exposed to Environmental Pollution

    Science.gov (United States)

    Ciupiński, Łukasz; Fortuna-Zaleśna, Elżbieta; Garbacz, Halina; Koss, Andrzej; Kurzydłowski, Krzysztof J.; Marczak, Jan; Mróz, Janusz; Onyszczuk, Tomasz; Rycyk, Antoni; Sarzyński, Antoni; Skrzeczanowski, Wojciech; Strzelec, Marek; Zatorska, Anna; Żukowska, Grażyna Z.

    2010-01-01

    Metal artworks are subjected to corrosion and oxidation processes due to reactive agents present in the air, water and in the ground that these objects have been in contact with for hundreds of years. This is the case for archaeological metals that are recovered from excavation sites, as well as artefacts exposed to polluted air. Stabilization of the conservation state of these objects needs precise diagnostics of the accrued surface layers and identification of original, historical materials before further protective treatments, including safe laser cleaning of unwanted layers. This paper presents analyses of the chemical composition and stratigraphy of corrosion products with the use of laser induced breakdown spectroscopy (LIBS) and Raman spectroscopy. The discussion of the results is supported by material studies (SEM-EDS, XRF, ion-analyses). The tests were performed on several samples taken from original objects, including copper roofing from Wilanów Palace in Warsaw and Karol Poznański Palace in ŁódŸ, bronze decorative figures from the Wilanów Palace gardens, and four archaeological examples of old jewellery (different copper alloys). Work has been performed as a part of the MATLAS project in the frames of EEA and Norway Grants (www.matlas.eu) and the results enable the comparison of the methodology and to elaborate the joint diagnostic procedures of the three project partner independent laboratories. PMID:22399915

  15. Apps as Artefacts: Towards a Critical Perspective on Mobile Health and Medical Apps

    Directory of Open Access Journals (Sweden)

    Deborah Lupton

    2014-10-01

    Full Text Available Although over 100,000 health and medical mobile apps have been placed on the market, few critical social analyses have been yet undertaken of the role of these apps in healthcare, preventive health and health promotion. In this article I present an argument for approaching the study of mobile apps as sociocultural artefacts, focusing specifically on those that have been developed on health and medical topics. This perspective acknowledges that apps are digital objects that are the products of human decision-making, underpinned by tacit assumptions, norms and discourses already circulating in the social and cultural contexts in which they are generated, marketed and used. First, I provide the context, by discussing the gradual digitisation of health and medical information since the advent of the Internet and the emergence of health and medical apps as one of the latest developments. Second, I discuss how a critical perspective may be employed to analyse the social, cultural and political dimensions of health and medical apps. Finally I illustrate how such an approach may be applied by giving a case study of an analysis of the top 10 ranked health and medical apps on the Apple App Store on one day, outlining some major themes and discourses that emerge.

  16. The characterisation of non-evaporable getters by Auger electron spectroscopy Analytical potential and artefacts

    CERN Document Server

    Scheuerlein, C; Taborelli, M

    2002-01-01

    The surfaces of getter materials are particularly difficult to analyse because of their high chemical reactivity. The results obtained can be strongly influenced by the experimental set-up and procedures. In this paper the experimental influence on the Auger electron spectroscopy results is discussed, based on the measurements of more than 100 different non-evaporable getter (NEG) materials. There are four typical changes in the Auger electron spectra when a NEG becomes activated. The oxygen peak intensity decreases, the shape of the metal peaks changes, the carbon peak shape changes shape and intensity and a chlorine peak occurs. All these changes are affected by instrumental artefacts. The Zr-MNV peak shape changes occurring during the reduction of ZrO2 are well suited to determine the onset of NEG activation, while the slope with which the O-KLL peak intensity decreases in a certain temperature range is a better criterion for the determination of the temperature at which activation is complete. The O-KLL i...

  17. Comparative Laser Spectroscopy Diagnostics for Ancient Metallic Artefacts Exposed to Environmental Pollution

    Directory of Open Access Journals (Sweden)

    Łukasz Ciupiński

    2010-05-01

    Full Text Available Metal artworks are subjected to corrosion and oxidation processes due to reactive agents present in the air, water and in the ground that these objects have been in contact with for hundreds of years. This is the case for archaeological metals that are recovered from excavation sites, as well as artefacts exposed to polluted air. Stabilization of the conservation state of these objects needs precise diagnostics of the accrued surface layers and identification of original, historical materials before further protective treatments, including safe laser cleaning of unwanted layers. This paper presents analyses of the chemical composition and stratigraphy of corrosion products with the use of laser induced breakdown spectroscopy (LIBS and Raman spectroscopy. The discussion of the results is supported by material studies (SEM-EDS, XRF, ion-analyses. The tests were performed on several samples taken from original objects, including copper roofing from Wilanów Palace in Warsaw and Karol Poznański Palace in Łódź, bronze decorative figures from the Wilanów Palace gardens, and four archaeological examples of old jewellery (different copper alloys. Work has been performed as a part of the MATLAS project in the frames of EEA and Norway Grants (www.matlas.eu and the results enable the comparison of the methodology and to elaborate the joint diagnostic procedures of the three project partner independent laboratories.

  18. An unusual MR signal reduction artefact in an incompletely thawed cadaver spine specimen

    Energy Technology Data Exchange (ETDEWEB)

    Kurmis, Andrew P. [Bone and Joint Research Laboratory, Division of Tissue Pathology, Institute of Medical and Veterinary Science and Hanson Institute, South Australia (Australia); School of Medicine, Flinders University, South Australia (Australia)], E-mail: andrew.kurmis@flinders.edu.au; Slavotinek, John P. [Department of Medical Imaging, Flinders Medical Centre, South Australia (Australia); Barber, Christine; Smith, Lachlan [Bone and Joint Research Laboratory, Division of Tissue Pathology, Institute of Medical and Veterinary Science and Hanson Institute, South Australia (Australia); Fazzalari, Nicola L. [Bone and Joint Research Laboratory, Division of Tissue Pathology, Institute of Medical and Veterinary Science and Hanson Institute, South Australia (Australia); Department of Pathology, University of Adelaide, South Australia (Australia)

    2009-02-15

    Objective: Within the contemporary constraints associated with in vivo use for research purposes, preservation of macroscopic human tissue specimens is of critical importance. Simple sub-zero freezing remains the method-of-choice for medium-term storage of such material. Despite widespread use, few papers have described the effects of this preservation method on resultant images, or the impact of inadequate tissue thawing. Materials and methods: A series of post-mortem-harvested human lumbar spine specimens were undergoing conventional MR imaging as part of a larger project exploring non-invasive hydration status assessment of the intervertebral disc. Results: A complex central signal reduction artefact was noted during scanning of one specimen, resembling an isotherm distribution. Subtle inadequacies in core specimen thawing lead to an initially confusing pattern of central signal dampening. Conclusions: These findings demonstrate the impact of sub-optimal specimen preparation on image signal characteristics and highlight the importance of appropriate thawing methods of frozen tissue specimens prior to imaging.

  19. Irradiation treatment for the protection and conservation of cultural heritage artefacts in Croatia

    Science.gov (United States)

    Katušin-Ražem, Branka; Ražem, Dušan; Braun, Mario

    2009-07-01

    The application of irradiation treatment for the protection of cultural heritage artefacts in Croatia was made possible by the development of radiation processing procedures at the Radiation Chemistry and Dosimetry Laboratory of the Ruđer Bo\\vsković Institute. After the upgrading of the 60Co gamma irradiation source in the panoramic irradiation facility in 1983 it became possible to perform both research and pilot plant-scale irradiations for sterilization, pasteurization and decontamination of various materials, including medical supplies, pharmaceuticals, cosmetics and foods, but also for disinfestation of cultural heritage artefects. The demand for irradiation treatment of cultural heritage objects has particularly increased as the increasing number of these objects, especially polychromic wooden sculptures, were requiring salvation, restauration and conservation as a consequence of direct and indirect damages inflicted to them during the war in Croatia, 1991-1995. The irradiation facility at the Ruđer Bo\\vsković Institute is briefly described and an account of its fifteen years' activities in the irradiation treatment of cultural heritage objects is given. Some case studies performed in cooperation with the Croatian Conservation Institute and other interested parties are presented, as well as some cases of protective and curative treatments for disinfestation and decontamination. International cooperations and activities are also mentioned.

  20. Irradiation treatment for the protection and conservation of cultural heritage artefacts in Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Katusin-Razem, Branka [Department of Chemistry, Ruder Boskovic Institute, Bijenicka cesta 54, P.O. Box 180, HR-10002 Zagreb (Croatia)], E-mail: brazem@irb.hr; Razem, Dusan [Department of Chemistry, Ruder Boskovic Institute, Bijenicka cesta 54, P.O. Box 180, HR-10002 Zagreb (Croatia); Braun, Mario [Croatian Conservation Institute, Zagreb (Croatia)

    2009-07-15

    The application of irradiation treatment for the protection of cultural heritage artefacts in Croatia was made possible by the development of radiation processing procedures at the Radiation Chemistry and Dosimetry Laboratory of the Ruder Boskovic Institute. After the upgrading of the {sup 60}Co gamma irradiation source in the panoramic irradiation facility in 1983 it became possible to perform both research and pilot plant-scale irradiations for sterilization, pasteurization and decontamination of various materials, including medical supplies, pharmaceuticals, cosmetics and foods, but also for disinfestation of cultural heritage artefects. The demand for irradiation treatment of cultural heritage objects has particularly increased as the increasing number of these objects, especially polychromic wooden sculptures, were requiring salvation, restauration and conservation as a consequence of direct and indirect damages inflicted to them during the war in Croatia, 1991-1995. The irradiation facility at the Ruder Boskovic Institute is briefly described and an account of its fifteen years' activities in the irradiation treatment of cultural heritage objects is given. Some case studies performed in cooperation with the Croatian Conservation Institute and other interested parties are presented, as well as some cases of protective and curative treatments for disinfestation and decontamination. International cooperations and activities are also mentioned.

  1. Cell respiration under hypoxia: facts and artefacts in mitochondrial oxygen kinetics.

    Science.gov (United States)

    Scandurra, Francesca M; Gnaiger, Erich

    2010-01-01

    When oxygen supply to tissues is limiting, mitochondrial respiration and ATP production are compromised. To assess the bioenergetic consequences under normoxia and hypoxia, quantitative evaluation of mitochondrial oxygen kinetics is required. Using high-resolution respirometry, the "apparent K (m)" for oxygen or p (50) of respiration in 32D cells was determined at 0.05 +/- 0.01 kPa (0.4 mmHg, 0.5 microM, 0.25% air saturation). Close agreement with p (50) of isolated mitochondria indicates that intracellular gradients are small in small cells at routine activity. At intracellular p (O2) respiration is limited by >2% with a p (50) of 0.05 kPa. Over-estimation of p (50) at 0.4 kPa (3 mmHg) would imply significant (>17%) oxygen limitation of respiration under intracellular normoxia. Based on a critical review, we conclude that p (50) ranges from 0.01 to 0.10 kPa in mitochondria and small cells in the absence of inhibitors of cytochrome c oxidase, whereas experimental artefacts explain the controversial >200-fold range of p (50) in the literature on mitochondrial oxygen kinetics.

  2. Supporting BPMN choreography with system integration artefacts for enterprise process collaboration

    Science.gov (United States)

    Nie, Hongchao; Lu, Xudong; Duan, Huilong

    2014-07-01

    Business Process Model and Notation (BPMN) choreography modelling depicts externally visible message exchanges between collaborating processes of enterprise information systems. Implementation of choreography relies on designing system integration solutions to realise message exchanges between independently developed systems. Enterprise integration patterns (EIPs) are widely accepted artefacts to design integration solutions. If the choreography model represents coordination requirements between processes with behaviour mismatches, the integration designer needs to analyse the routing requirements and address these requirements by manually designing EIP message routers. As collaboration scales and complexity increases, manual design becomes inefficient. Thus, the research problem of this paper is to explore a method to automatically identify routing requirements from BPMN choreography model and to accordingly design routing in the integration solution. To achieve this goal, recurring behaviour mismatch scenarios are analysed as patterns, and corresponding solutions are proposed as EIP routers. Using this method, a choreography model can be analysed by computer to identify occurrences of mismatch patterns, leading to corresponding router selection. A case study demonstrates that the proposed method enables computer-assisted integration design to implement choreography. A further experiment reveals that the method is effective to improve the design quality and reduce time cost.

  3. Not all that glitters is gold - Electron microscopy study on uptake of gold nanoparticles in Daphnia magna and related artefacts

    DEFF Research Database (Denmark)

    Jensen, Louise Helene Søgaard; Skjolding, Lars Michael; Thit, Amalie

    2017-01-01

    techniques are used to investigate internalization of 10 nm gold nanoparticles in Daphnia magna gut lumen and gut epithelial cells upon 24h exposure and outline potential artefacts, i.e. high contract precipitates from sample preparation related to these techniques. Light sheet microscopy confirmed......, permitting only single particles through. Structures resembling nanoparticles were also observed inside gut cells. As elemental analysis could not verify these to be gold they were likely artifacts from the preparation, such as osmium and iron. Importantly, gold nanoparticles were in fact found inside...... holocrine cells with disrupted membranes. Thus, false positive observations of nanoparticle internalization may result from either preparation artefacts or by mistaking disrupted cells for intact. These findings emphasize the importance of cell integrity and combining elemental analysis...

  4. Polder maps: improving OMIT maps by excluding bulk solvent.

    Science.gov (United States)

    Liebschner, Dorothee; Afonine, Pavel V; Moriarty, Nigel W; Poon, Billy K; Sobolev, Oleg V; Terwilliger, Thomas C; Adams, Paul D

    2017-02-01

    The crystallographic maps that are routinely used during the structure-solution workflow are almost always model-biased because model information is used for their calculation. As these maps are also used to validate the atomic models that result from model building and refinement, this constitutes an immediate problem: anything added to the model will manifest itself in the map and thus hinder the validation. OMIT maps are a common tool to verify the presence of atoms in the model. The simplest way to compute an OMIT map is to exclude the atoms in question from the structure, update the corresponding structure factors and compute a residual map. It is then expected that if these atoms are present in the crystal structure, the electron density for the omitted atoms will be seen as positive features in this map. This, however, is complicated by the flat bulk-solvent model which is almost universally used in modern crystallographic refinement programs. This model postulates constant electron density at any voxel of the unit-cell volume that is not occupied by the atomic model. Consequently, if the density arising from the omitted atoms is weak then the bulk-solvent model may obscure it further. A possible solution to this problem is to prevent bulk solvent from entering the selected OMIT regions, which may improve the interpretative power of residual maps. This approach is called a polder (OMIT) map. Polder OMIT maps can be particularly useful for displaying weak densities of ligands, solvent molecules, side chains, alternative conformations and residues both in terminal regions and in loops. The tools described in this manuscript have been implemented and are available in PHENIX.

  5. The politics of corruption, inequality, and the socially excluded.

    Science.gov (United States)

    Santos Salas, Anna

    2013-07-01

    In this article, the production of knowledge in the context of socially excluded people exposed to inequality, oppression, and exploitation is problematized. The analysis follows Enrique Dussel's philosophical exegesis of the politics of power and corruption and his vision of a critical transformation of the social political order. The argument is also informed by the work of critical educator Paulo Freire, who elucidates the conditions of oppression and marginalization and highlights the importance of conscientization to develop a critical awareness of these conditions. Hannah Arendt's work on the politics of understanding totalitarianism also assists in the elucidation of the machinery that operates behind oppression to sustain power and inequality. The article emphasizes the need to recognize the inequality of conditions that exists between the producer of knowledge and those who live through inequality and oppression in their lived corporality. A critical transformation of the process of production of knowledge is needed to both acknowledge the conditions that sustain this endeavour in the first place and avoid the corruption of knowledge. A work of conscientization is also necessary among knowledge producers to undertake a critical analysis of inequality that exposes the corruption of power. This analysis needs to examine and unmask the hidden mechanisms that perpetuate inequality and oppression and serve only the interests of a few. The abysmal gaps between the wealthy and the poor within and among countries bespeak a degree of human indifference that reflects a most serious and complex phenomenon that perverts something profoundly human in our societies. © 2013 John Wiley & Sons Ltd.

  6. Proximal placement of lateral thigh skin markers reduces soft tissue artefact during normal gait using the Conventional Gait Model.

    Science.gov (United States)

    Cockcroft, John; Louw, Quinette; Baker, Richard

    2016-11-01

    A primary source of measurement error in gait analysis is soft-tissue artefact. Hip and knee angle measurements, regularly used in clinical decision-making, are particularly prone to pervasive soft tissue on the femur. However, despite several studies of thigh marker artefact it remains unclear how lateral thigh marker height affects results using variants of the Conventional Gait Model. We compared Vicon Plug-in Gait hip and knee angle estimates during gait using a proximal and distal thigh marker placement for ten healthy subjects. Knee axes were estimated by optimizing thigh rotation offsets to minimize knee varus-valgus range during gait. Relative to the distal marker, the proximal marker produced 37% less varus-valgus range and 50% less hip rotation range (p < 0.001), suggesting that it produced less soft-tissue artefact in knee axis estimates. The thigh markers also produced different secondary effects on the knee centre estimate. Using whole gait cycle optimization, the distal marker showed greater minimum and maximum knee flexion (by 6° and 2° respectively) resulting in a 4° reduction in range. Mid-stance optimization reduced distal marker knee flexion by 5° throughout, but proximal marker results were negligibly affected. Based on an analysis of the Plug-in Gait knee axis definition, we show that the proximal marker reduced sensitivity to soft-tissue artefact by decreasing collinearity between the points defining the femoral frontal plane and reducing anteroposterior movement between the knee and thigh markers. This study suggests that a proximal thigh marker may be preferable when performing gait analysis using the Plug-in Gait model.

  7. FT-Raman and FT-Infrared investigations of archaeological artefacts from Foeni Neolithic site (Banat, Romania)

    OpenAIRE

    Simona Cîntă Pînzaru; Dana Pop; Loredana Nemeth

    2008-01-01

    An impressive collection of chert artefacts from the Foeni Neolithic archaeological site (Timiş County, Banat region, Romania) is hosted by the Banat Museum in Timişoara. A representative set of seven specimens was non-destructively investigated using FT-Raman and ATR-FT-IR spectroscopy. The research was carried out for checking if these readily-available, non-destructive, fast, and cheap methods, which do not require preliminary sample preparation could provide significant information for ch...

  8. Synergistic effects of additives to benzotriazole solutions applied as corrosion inhibitors to archaeological copper and copper alloy artefacts.

    OpenAIRE

    Golfomitsou, S.

    2006-01-01

    Benzotriazole (BTA) is a corrosion inhibitor extensively used for the stabilisation of active corrosion of archaeological copper and copper alloys. However, BTA often fails to effectively retard corrosion when applied on heavily corroded artefacts. Although there are numerous studies about its mode of action on clean copper, there is no comprehensive understanding about the way it is bonded to corroded copper. This thesis aimed to understand and compare BTA and its mode of action on clean and...

  9. Development, implementation and evaluation of a dedicated metal artefact reduction method for interventional flat-detector CT.

    Science.gov (United States)

    Prell, D; Kalender, W A; Kyriakou, Y

    2010-12-01

    The purpose of this study was to develop, implement and evaluate a dedicated metal artefact reduction (MAR) method for flat-detector CT (FDCT). The algorithm uses the multidimensional raw data space to calculate surrogate attenuation values for the original metal traces in the raw data domain. The metal traces are detected automatically by a three-dimensional, threshold-based segmentation algorithm in an initial reconstructed image volume, based on twofold histogram information for calculating appropriate metal thresholds. These thresholds are combined with constrained morphological operations in the projection domain. A subsequent reconstruction of the modified raw data yields an artefact-reduced image volume that is further processed by a combining procedure that reinserts the missing metal information. For image quality assessment, measurements on semi-anthropomorphic phantoms containing metallic inserts were evaluated in terms of CT value accuracy, image noise and spatial resolution before and after correction. Measurements of the same phantoms without prostheses were used as ground truth for comparison. Cadaver measurements were performed on complex and realistic cases and to determine the influences of our correction method on the tissue surrounding the prostheses. The results showed a significant reduction of metal-induced streak artefacts (CT value differences were reduced to below 22 HU and image noise reduction of up to 200%). The cadaver measurements showed excellent results for imaging areas close to the implant and exceptional artefact suppression in these areas. Furthermore, measurements in the knee and spine regions confirmed the superiority of our method to standard one-dimensional, linear interpolation.

  10. Estudo manométrico do esôfago distal de gatos anestesiados com tiopental sódico Manometric study of the distal esophagus of cats anesthetized with sodic thiopental

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo Meirelles dos Santos

    2004-06-01

    Full Text Available OBJETIVO: Obter o padrão de normalidade da pressão e comprimento do esfíncter inferior do esôfago (EIE em gatos anestesiados com tiopental e analisar a viabilidade prática do anestésico para uso neste tipo de investigação sobre atividade motora do esôfago de felinos. MÉTODOS: Em 12 gatos anestesiados com tiopental sódico foram realizados estudos manométricos do EIE, com leitura por perfusão em três canais radiais. Foram avaliadas as pressões e comprimentos do EIE. RESULTADOS: Os valores médios da pressão e comprimento do EIE foram 33,52 ± 12,42 mmHg e 1,6 ± 0,4 cm, respectivamente. CONCLUSÃO: Foi possível estabelecer valor de referência para a pressão e comprimento do EIE de felinos, com uma contenção e retorno confortáveis para o animal, utilizando o tiopental sódico como agente anestésico.PURPOSE: To obtain the normality standard of the lower esophageal sphincter (LES of cats anesthetized with tiopental and at analysing the practical viability of the anesthetic use in felines esophagus motor activity investigation. METHODS: Manometric studies of LES were performed in 12 cats anestetized with tiopental with perfusion reading in three radial channels. LES pressures and lengths were measured. RESULTS: The mean values of LES pressure and lengths were 33,52 ± 12,42 mmHg and 1,6 ± 0,4 cm respectively. CONCLUSION: A LES reference value for felines pressure and length was determined. Acommodation and return were comfortable for the animals with the use of sodic tiopental as an anesthetic agent.

  11. Value of monoenergetic dual-energy CT (DECT) for artefact reduction from metallic orthopedic implants in post-mortem studies.

    Science.gov (United States)

    Filograna, Laura; Magarelli, Nicola; Leone, Antonio; Guggenberger, Roman; Winklhofer, Sebastian; Thali, Michael John; Bonomo, Lorenzo

    2015-09-01

    The aim of this ex vivo study was to assess the performance of monoenergetic dual-energy CT (DECT) reconstructions to reduce metal artefacts in bodies with orthopedic devices in comparison with standard single-energy CT (SECT) examinations in forensic imaging. Forensic and clinical impacts of this study are also discussed. Thirty metallic implants in 20 consecutive cadavers with metallic implants underwent both SECT and DECT with a clinically suitable scanning protocol. Extrapolated monoenergetic DECT images at 64, 69, 88, 105, 120, and 130 keV and individually adjusted monoenergy for optimized image quality (OPTkeV) were generated. Image quality of the seven monoenergetic images and of the corresponding SECT image was assessed qualitatively and quantitatively by visual rating and measurements of attenuation changes induced by streak artefact. Qualitative and quantitative analyses showed statistically significant differences between monoenergetic DECT extrapolated images and SECT, with improvements in diagnostic assessment in monoenergetic DECT at higher monoenergies. The mean value of OPTkeV was 137.6 ± 4.9 with a range of 130 to 148 keV. This study demonstrates that monoenergetic DECT images extrapolated at high energy levels significantly reduce metallic artefacts from orthopedic implants and improve image quality compared to SECT examination in forensic imaging.

  12. Magnetic resonance imaging acquisition techniques intended to decrease movement artefact in paediatric brain imaging: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Woodfield, Julie [University of Edinburgh, Child Life and Health, Edinburgh (United Kingdom); Kealey, Susan [Western General Hospital, Department of Neuroradiology, Edinburgh (United Kingdom)

    2015-08-15

    Attaining paediatric brain images of diagnostic quality can be difficult because of young age or neurological impairment. The use of anaesthesia to reduce movement in MRI increases clinical risk and cost, while CT, though faster, exposes children to potentially harmful ionising radiation. MRI acquisition techniques that aim to decrease movement artefact may allow diagnostic paediatric brain imaging without sedation or anaesthesia. We conducted a systematic review to establish the evidence base for ultra-fast sequences and sequences using oversampling of k-space in paediatric brain MR imaging. Techniques were assessed for imaging time, occurrence of movement artefact, the need for sedation, and either image quality or diagnostic accuracy. We identified 24 relevant studies. We found that ultra-fast techniques had shorter imaging acquisition times compared to standard MRI. Techniques using oversampling of k-space required equal or longer imaging times than standard MRI. Both ultra-fast sequences and those using oversampling of k-space reduced movement artefact compared with standard MRI in unsedated children. Assessment of overall diagnostic accuracy was difficult because of the heterogeneous patient populations, imaging indications, and reporting methods of the studies. In children with shunt-treated hydrocephalus there is evidence that ultra-fast MRI is sufficient for the assessment of ventricular size. (orig.)

  13. Adaptive removal of gradients-induced artefacts on ECG in MRI: a performance analysis of RLS filtering.

    Science.gov (United States)

    Sansone, Mario; Mirarchi, Luciano; Bracale, Marcello

    2010-05-01

    One of the main vital signs used in patient monitoring during Magnetic Resonance Imaging (MRI) is Electro-Cardio-Gram (ECG). Unfortunately, magnetic fields gradients induce artefacts which severely affect ECG quality. Adaptive Noise Cancelling (ANC) is one of the preferred techniques for artefact removal. ANC involves the adaptive estimation of the impulse response of the system constituted by the MRI equipment, the patient and the ECG recording device. Least Mean Square (LMS) adaptive filtering has been traditionally employed because of its simplicity: anyway, it requires the choice of a step-size parameter, whose proper value for the specific application must be estimated case by case: an improper choice could yield slow convergence and unsatisfactory behaviour. Recursive Least Square (RLS) algorithm has, potentially, faster convergence while not requiring any parameter. As far as the authors' knowledge, there is no systematic analysis of performances of RLS in this scenario. In this study we evaluated the performance of RLS for adaptive removal of artefacts induced by magnetic field gradients on ECG in MRI, in terms of efficacy of suppression. Tests have been made on real signals, acquired via an expressly developed system. A comparison with LMS was made on the basis of opportune performance indices. Results indicate that RLS is superior to LMS in several respects.

  14. Pyramid approach for the reduction of parallax-related artefacts in optical recordings of moving translucent volumes.

    Science.gov (United States)

    Flotho, Philipp; Romero-Santiago, Alejandro; Schwerdtfeger, Karsten; Hulser, Matthias; Haab, Lars; Strauss, Daniel J

    2017-07-01

    Functional optical imaging (OI) of intrinsic signals (like blood oxygenation coupled reflection changes) and of extrinsic properties of voltage sensitive probes (like voltage-sensitive dyes (VSD)) forms a group of invasive neuroimaging techniques, that possess up to date the highest temporal and spatial resolution on a meso- to macroscopic scale. There are different sources that contribute to the OI signal of which many are noise. In our previous works, we have used dense optical flow for the reduction of movement artefacts. The translucent surface of the cortex allows contributions from multiple depths. Due to the depth offield (DOF) effect, we get an implicit relation of depth and 2D frequency components. In this work, we introduce registration on the levels of a Laplacian pyramid to remove movement artefacts which have different motion components in different spatial frequency bands. This aims to resolve artefacts that remain after normal registration and are caused e.g. by parallax motion, dead pixels or dust on the sensor and other high frequent, moving particles on the cortex surface without the compromise of using high smoothness weights.

  15. Value of monoenergetic dual-energy CT (DECT) for artefact reduction from metallic orthopedic implants in post-mortem studies

    Energy Technology Data Exchange (ETDEWEB)

    Filograna, Laura [University of Zurich, Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, Zurich (Switzerland); Catholic University of Rome, School of Medicine, University Hospital ' ' A. Gemelli' ' , Department of Radiological Sciences, Rome (Italy); Magarelli, Nicola; Leone, Antonio; Bonomo, Lorenzo [Catholic University of Rome, School of Medicine, University Hospital ' ' A. Gemelli' ' , Department of Radiological Sciences, Rome (Italy); Guggenberger, Roman; Winklhofer, Sebastian [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Thali, Michael John [University of Zurich, Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, Zurich (Switzerland)

    2015-09-15

    The aim of this ex vivo study was to assess the performance of monoenergetic dual-energy CT (DECT) reconstructions to reduce metal artefacts in bodies with orthopedic devices in comparison with standard single-energy CT (SECT) examinations in forensic imaging. Forensic and clinical impacts of this study are also discussed. Thirty metallic implants in 20 consecutive cadavers with metallic implants underwent both SECT and DECT with a clinically suitable scanning protocol. Extrapolated monoenergetic DECT images at 64, 69, 88, 105, 120, and 130 keV and individually adjusted monoenergy for optimized image quality (OPTkeV) were generated. Image quality of the seven monoenergetic images and of the corresponding SECT image was assessed qualitatively and quantitatively by visual rating and measurements of attenuation changes induced by streak artefact. Qualitative and quantitative analyses showed statistically significant differences between monoenergetic DECT extrapolated images and SECT, with improvements in diagnostic assessment in monoenergetic DECT at higher monoenergies. The mean value of OPTkeV was 137.6 ± 4.9 with a range of 130 to 148 keV. This study demonstrates that monoenergetic DECT images extrapolated at high energy levels significantly reduce metallic artefacts from orthopedic implants and improve image quality compared to SECT examination in forensic imaging. (orig.)

  16. 75 FR 49528 - Freescale Semiconductor, Inc., Networking and Multimedia Group (“NMG”) Excluding the Multimedia...

    Science.gov (United States)

    2010-08-13

    ... Employment and Training Administration Freescale Semiconductor, Inc., Networking and Multimedia Group (``NMG'') Excluding the Multimedia Applications Division Including On- Site Leased Workers of Synergy Services..., applicable to workers of Freescale Semiconductor, Inc., Networking and Multimedia Group (``NMG''), excluding...

  17. Artefacts induced by coiled intracranial aneurysms on 3.0-Tesla versus 1.5-Tesla MR angiography--An in vivo and in vitro study.

    Science.gov (United States)

    Schaafsma, Joanna D; Velthuis, Birgitta K; Vincken, Koen L; de Kort, Gerard A P; Rinkel, Gabriel J E; Bartels, Lambertus W

    2014-05-01

    To compare metal-induced artefacts from coiled intracranial aneurysms on 3.0-Tesla and 1.5-Tesla magnetic resonance angiography (MRA), since concerns persist on artefact enlargement at 3.0Tesla. We scanned 19 patients (mean age 53; 16 women) with 20 saccular aneurysms treated with coils only, at 1.5 and 3.0Tesla according to standard clinical 3D TOF-MRA protocols containing a shorter echo-time but weaker read-out gradient at 3.0Tesla in addition to intra-arterial digital subtraction angiography (IA-DSA). Per modality two neuro-radiologists assessed the occlusion status, measured residual flow, and indicated whether coil artefacts disturbed this assessment on MRA. We assessed relative risks for disturbance by coil artefacts, weighted kappa's for agreement on occlusion levels, and we compared remnant sizes. For artefact measurements, a coil model was created and scanned with the same protocols followed by 2D MR scans with variation of echo-time and read-out gradient strength. Coil artefacts disturbed assessments less frequently at 3.0Tesla than at 1.5Tesla (RR: 0.3; 95%CI: 0.1-0.8). On 3.0-Tesla MRA, remnants were larger than on 1.5-Tesla MRA (difference: 0.7mm; 95%CI: 0.3-1.1) and larger than on IA-DSA (difference: 1.0mm; 95%CI: 0.6-1.5) with similar agreement on occlusion levels with IA-DSA for both field strengths (κ 0.53; 95%CI: 0.23-0.84 for 1.5-Tesla MRA and IA-DSA; κ 0.47; 95%CI: 0.19-0.76 for 3.0-Tesla MRA and IA-DSA). Coil model artefacts were smaller at 3.0Tesla than at 1.5Tesla. The echo-time influenced artefact size more than the read-out gradient. Artefacts were not larger, but smaller at 3.0Tesla because a shorter echo-time at 3.0Tesla negated artefact enlargement. Despite smaller artefacts and larger remnants at 3.0Tesla, occlusion levels were similar for both field strengths. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Are osseous artefacts a window to perishable material culture? Implications of an unusually complex bone tool from the Late Pleistocene of East Timor.

    Science.gov (United States)

    O'Connor, S; Robertson, G; Aplin, K P

    2014-02-01

    We report the discovery of an unusually complex and regionally unique bone artefact in a Late Pleistocene archaeological assemblage (c. 35 ka [thousands of years ago]) from the site of Matja Kuru 2 on the island of Timor, in Wallacea. The artefact is interpreted as the broken butt of a formerly hafted projectile point, and it preserves evidence of a complex hafting mechanism including insertion into a shaped or split shaft, a complex pattern of binding including lateral stabilization of the cordage within a bilateral series of notches, and the application of mastic at several stages in the hafting process. The artefact provides the earliest direct evidence for the use of this combination of hafting technologies in the wider region of Southeast Asia, Wallacea, Melanesia and Australasia, and is morphologically unparallelled in deposits of any age. By contrast, it bears a close morphological resemblance to certain bone artefacts from the Middle Stone Age of Africa and South Asia. Examination of ethnographic projectile technology from the region of Melanesia and Australasia shows that all of the technological elements observed in the Matja Kuru 2 artefact were in use historically in the region, including the unusual feature of bilateral notching to stabilize a hafted point. This artefact challenges the notion that complex bone-working and hafting technologies were a relatively late innovation in this part of the world. Moreover, its regional uniqueness encourages us to abandon the perception of bone artefacts as a discrete class of material culture, and to adopt a new interpretative framework in which they are treated as manifestations of a more general class of artefacts that more typically were produced on perishable raw materials including wood. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  19. Body physique and heart rate variability determine the occurrence of stair-step artefacts in 64-slice CT coronary angiography with prospective ECG-triggering.

    Science.gov (United States)

    Husmann, Lars; Herzog, Bernhard A; Burkhard, Nina; Tatsugami, Fuminari; Valenta, Ines; Gaemperli, Oliver; Wyss, Christophe A; Landmesser, Ulf; Kaufmann, Philipp A

    2009-07-01

    The purpose of this study was to describe and characterize the frequency and extent of stair-step artefacts in computed tomography coronary angiography (CTCA) with prospective electrocardiogram (ECG)-triggering and to identify their determinants. One hundred and forty three consecutive patients (55 women, mean age 57 +/- 13 years) underwent 64-slice CTCA using prospective ECG-triggering. Occurrence of stair-step artefacts in CTCA of the thoracic wall and the coronary arteries was determined and maximum offset was measured. If stair-step artefacts occurred in both cases, a difference between thoracic wall and coronary artery offset of 0.6 mm or greater was attributed to additional motion of the heart. Mean effective radiation dose was 2.1 +/- 0.7 mSv (range 1.0-3.5 mSv). Eighty-nine patients (62%) had stair-step artefacts in CTCA of the coronary arteries (mean offset of 1.7 +/- 1.1 mm), while only 77 patients had thoracic wall stair-step artefacts (mean offset of 1.0 +/- 0.3 mm; significantly different, P < 0.001). Stair-step artefacts in CTCA of the thoracic wall were determined by BMI and weight (P < 0.01), while artefacts in CTCA of the coronary arteries were associated with heart rate variability (P < 0.05). Stair-step artefacts in CTCA with prospective ECG-triggering are determined by (a) motion of the entire patient during table travel, particularly in large patients and (b) by motion of the heart, particularly when heart rates are variable.

  20. Casino Self- and Forced Excluders' Gambling Behavior Before and After Exclusion.

    Science.gov (United States)

    Kotter, Roxana; Kräplin, Anja; Bühringer, Gerhard

    2017-11-11

    Casino exclusion programs are intended to prevent or limit gambling-related harm. Although previous research showed that self-exclusion is associated with reduced gambling, it remains unknown whether self- and forced excluded subjects show different patterns of gambling behavior and if exclusion from casino gambling affects all gambling activities. The present study retrospectively investigated (1) the role of voluntariness of exclusion for the first time, and (2) general gambling behavior of excluded individuals before and after exclusion. A total of N = 215 casino excluders (self-excluders: n = 187, forced excluders: n = 28) completed an online survey or a face-to-face interview up to 8 years after enrollment. Self- and forced excluders showed similar rates of abstinence (self-excluders: 19.3%, forced excluders: 28.6%) and reduction (self-excluders: 67.4%, forced excluders: 60.7%), even though forced excluders reported a significantly greater initial gambling intensity compared to self-excluders (e.g., pre-exclusion gambling time; self-excluders: 3.2 days/week, forced excluders: 4.3 days/week). Overall, results indicated that 20.5% of excluders stopped all gambling activities and another 66.5% reduced their gambling. Those who continued gambling significantly reduced this behavior in every segment, except for gambling halls. Findings indicate that self- and forced exclusion are associated with similarly reduced gambling behavior, even in non-excluded segments. However, unchanged gambling in gambling halls emphasizes the importance to implement consistent exclusion programs over all gambling segments.

  1. 21 CFR 1308.26 - Excluded veterinary anabolic steroid implant products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Excluded veterinary anabolic steroid implant... SCHEDULES OF CONTROLLED SUBSTANCES Excluded Veterinary Anabolic Steroid Implant Products § 1308.26 Excluded veterinary anabolic steroid implant products. (a) Products containing an anabolic steroid, that are expressly...

  2. On the artefactual parasitic eubacteria clan in conditioned logdet phylogenies: heterotachy and ortholog identification artefacts as explanations.

    Science.gov (United States)

    Sangaralingam, Ajanthah; Susko, Edward; Bryant, David; Spencer, Matthew

    2010-11-09

    Phylogenetic reconstruction methods based on gene content often place all the parasitic and endosymbiotic eubacteria (parasites for short) together in a clan. Many other lines of evidence point to this parasites clan being an artefact. This artefact could be a consequence of the methods used to construct ortholog databases (due to some unknown bias), the methods used to estimate the phylogeny, or both.We test the idea that the parasites clan is an ortholog identification artefact by analyzing three different ortholog databases (COG, TRIBES, and OFAM), which were constructed using different methods, and are thus unlikely to share the same biases. In each case, we estimate a phylogeny using an improved version of the conditioned logdet distance method. If the parasites clan appears in trees from all three databases, it is unlikely to be an ortholog identification artefact.Accelerated loss of a subset of gene families in parasites (a form of heterotachy) may contribute to the difficulty of estimating a phylogeny from gene content data. We test the idea that heterotachy is the underlying reason for the estimation of an artefactual parasites clan by applying two different mixture models (phylogenetic and non-phylogenetic), in combination with conditioned logdet. In these models, there are two categories of gene families, one of which has accelerated loss in parasites. Distances are estimated separately from each category by conditioned logdet. This should reduce the tendency for tree estimation methods to group the parasites together, if heterotachy is the underlying reason for estimation of the parasites clan. The parasites clan appears in conditioned logdet trees estimated from all three databases. This makes it less likely to be an artefact of database construction. The non-phylogenetic mixture model gives trees without a parasites clan. However, the phylogenetic mixture model still results in a tree with a parasites clan. Thus, it is not entirely clear whether

  3. A new geoarchaeology of Aboriginal artefact deposits in western NSW, Australia: establishing spatial and temporal geomorphic controls on the surface archaeological record

    Science.gov (United States)

    Fanning, Patricia C.; Holdaway, Simon J.; Rhodes, Ed J.

    2008-10-01

    Surface deposits of stone artefacts are the most common feature of the Australian Aboriginal archaeological record, but they remain difficult for archaeologists to interpret. Among the many reasons is a lack of understanding of geomorphic processes that have exposed the artefacts at the surface. We describe research on the geomorphic environments in arid Australia from which we have developed a new geoarchaeological framework for describing and analysing surface artefact deposits. Optically Stimulated Luminescence dating of sediments upon which the artefacts currently rest demonstrates that the landscape, and the archaeological record it preserves, is spatially and temporally discontinuous. Exposure and/or burial of artefacts is controlled by geomorphic processes operating on timescales ranging from a few decades to thousands of years and spatial scales of tens to many thousands of square meters. These same processes, operating on similar scales, also determine whether or not artefact scatters are preserved in the contemporary landscape or in the sedimentary record of past landscapes, and hence whether or not they become part of the archaeological record. Models of settlement behavior in hunter-gatherer peoples that are largely derived from analysis of surface 'sites' must take account of these discontinuities.

  4. Avaliação manométrica anal pré e pós tratamento da fissura anal crônica com nifedipina tópica 0,2% The role of nifedipine 0,2% in cronic anal fissure-manometric study pre and post treatment

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora Prolungatti Cesar

    2007-06-01

    Full Text Available No tratamento da fissura anal, novas drogas têm sido utilizadas, dentre elas os bloqueadores de canais de cálcio. O objetivo desta pesquisa foi à avaliação manométrica de pacientes com fissura anal crônica após tratamento com nifedipina tópica 0,2%, correlacionando com a cicatrização e a dor. Trata-se de estudo prospectivo realizado em pacientes atendidos no ambulatório de Coloproctologia do Hospital Universitário de Taubaté. Os pacientes foram submetidos ao exame manométrico antes e após 30 dias da utilização de nifedipina tópica gel 0,2% três vezes ao dia no ânus e margem anal. Para a análise estatística foi utilizado o teste de Mann-Whitney considerando significante, se pIn the treatment of the anal fissure, calcium channel blockers are among the new drugs which have been used. The objective of this research was the manometric evaluation of patients with chronic anal fissure after topic treatment with 0.2% nifedipine and correlation with the healing and pain. This is a prospective study of patients from Coloproctology Clinic of the University of Taubaté Hospital. The patients had been submitted to a manometric examination before and after 30 days of the use of topic 0.2% nifedipine gel three times a day in the anus and anal edge. For the statistics analysis Mann-Whitney test was applied to a significance of p= 0,05. Ten patients did not exihibit manometric alteration associated with nifedipina treatment, however 50% of them reported improvement of the symptoms and 40% depicted healing of the fissure. The results demonstrated that nifedipine was effective and safe for anal fissure treatment and considering the functional point of view it did not cause injuries as well. The manometric evaluation did not demonstrate alterations in the anal pressure; however, it was observed that 50% of the patients had improvement in pain and 40% in healing.

  5. Living archaeology: artefacts of specific nest site fidelity in wild chimpanzees.

    Science.gov (United States)

    Stewart, F A; Piel, A K; McGrew, W C

    2011-10-01

    Savanna chimpanzees are known to re-use areas of the landscape for sleep, and patterns of chimpanzee sleeping site re-use are proposed as a referential model for early hominin archaeological site formation. We recorded the prevalence of deformed but healed branches and remnants of dead branches found around fresh nests at the savanna site of Issa in Ugalla, Tanzania. These old nest scars were found in 79% of 112 beds. We also randomly selected potential nesting locations for a subset of 32 beds within the same trees, and found nest scars in only 19% of these "control" locations. We then monitored 275 nests for up to 19 months for decay, regeneration of new branches, and re-use. Of these 275 nest locations, 24% were re-used within the first nine months of monitoring, and most re-use occurred when the nest had already decayed and was not easily visible from the ground. After 18 months, the proportion of specific nest positions re-used increased to 48%. This fidelity is likely a result of the creation of ideally-shaped support structures and supple new growth for mattress material with successive use of nest locations. We propose that specific nest site re-use may not be a direct product of environmental determination, but a result of "niche construction" through formation of good building sites within trees. Environmental modification through construction behaviour may have influenced both chimpanzee and early hominin ranging, and thus leaves behind recognisable patterns of artefact deposition across the landscape. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Identifying scientific artefacts in biomedical literature: the Evidence Based Medicine use case.

    Science.gov (United States)

    Hassanzadeh, Hamed; Groza, Tudor; Hunter, Jane

    2014-06-01

    Evidence Based Medicine (EBM) provides a framework that makes use of the current best evidence in the domain to support clinicians in the decision making process. In most cases, the underlying foundational knowledge is captured in scientific publications that detail specific clinical studies or randomised controlled trials. Over the course of the last two decades, research has been performed on modelling key aspects described within publications (e.g., aims, methods, results), to enable the successful realisation of the goals of EBM. A significant outcome of this research has been the PICO (Population/Problem-Intervention-Comparison-Outcome) structure, and its refined version PIBOSO (Population-Intervention-Background-Outcome-Study Design-Other), both of which provide a formalisation of these scientific artefacts. Subsequently, using these schemes, diverse automatic extraction techniques have been proposed to streamline the knowledge discovery and exploration process in EBM. In this paper, we present a Machine Learning approach that aims to classify sentences according to the PIBOSO scheme. We use a discriminative set of features that do not rely on any external resources to achieve results comparable to the state of the art. A corpus of 1000 structured and unstructured abstracts - i.e., the NICTA-PIBOSO corpus - is used for training and testing. Our best CRF classifier achieves a micro-average F-score of 90.74% and 87.21%, respectively, over structured and unstructured abstracts, which represents an increase of 25.48 percentage points and 26.6 percentage points in F-score when compared to the best existing approaches. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Is it so bad? Energy consumption and changes in stocks of energy-converting artefacts

    Energy Technology Data Exchange (ETDEWEB)

    Bladh, Mats (Department of Thematic Studies, Technology and Social Change, Linkoeping University (Sweden))

    2011-07-01

    The development of total energy consumption is important in a world with limited resources. It is the result of two basic tendencies working in opposite directions: growth in use (such as more cars) and improvements in energy efficiency (such as more fuel-efficient engines). Since the 1970s energy consumption has stagnated in Sweden. This means that increasing supply has been counteracted by measures improving overall energy efficiency to a larger degree than before. How can longterm development in energy consumption be analysed? This paper proposes a change-of-stock model as a tool for such analyses. In order to show the fruitfulness of this approach, historical data on cars, dwellings and lamps in Sweden are used. The basic idea is that changes in composition, size and use of stocks of these energy converters explain energy consumption. Gains in efficiency can be reached in two ways, either through changing technological path (such as electric cars instead of petrol-driven cars) or improvements within the path taken (such as fuel-efficient combustion engines). As the existence of path dependence is assumed here, it is expected that the latter will dominate. But does that mean small gains in energy saved? Results from the cases in this paper show considerable gains of efficiency in fuel consumption in private cars, and heating efficiency in multi-dwelling houses. Thus, incremental changes are important, but are partially offset by changes in characteristics of the artefacts. Radical changes, such as the factual change from air to rail transportation, and a counterfactual double switch from gasoline to electric cars and from electric heating to district heating, as well as probable gains from the phase-out of incandescent lamps, show even bigger gains. Both incremental and radical changes are the subject of counteracting tendencies, of a broader nature than that associated with rebound effects, such as more cars per inhabitant and fewer people in each dwelling. The

  8. Image artefact propagation in motion estimation and reconstruction in interventional cardiac C-arm CT

    Science.gov (United States)

    Müller, K.; Maier, A. K.; Schwemmer, C.; Lauritsch, G.; De Buck, S.; Wielandts, J.-Y.; Hornegger, J.; Fahrig, R.

    2014-06-01

    The acquisition of data for cardiac imaging using a C-arm computed tomography system requires several seconds and multiple heartbeats. Hence, incorporation of motion correction in the reconstruction step may improve the resulting image quality. Cardiac motion can be estimated by deformable three-dimensional (3D)/3D registration performed on initial 3D images of different heart phases. This motion information can be used for a motion-compensated reconstruction allowing the use of all acquired data for image reconstruction. However, the result of the registration procedure and hence the estimated deformations are influenced by the quality of the initial 3D images. In this paper, the sensitivity of the 3D/3D registration step to the image quality of the initial images is studied. Different reconstruction algorithms are evaluated for a recently proposed cardiac C-arm CT acquisition protocol. The initial 3D images are all based on retrospective electrocardiogram (ECG)-gated data. ECG-gating of data from a single C-arm rotation provides only a few projections per heart phase for image reconstruction. This view sparsity leads to prominent streak artefacts and a poor signal to noise ratio. Five different initial image reconstructions are evaluated: (1) cone beam filtered-backprojection (FDK), (2) cone beam filtered-backprojection and an additional bilateral filter (FFDK), (3) removal of the shadow of dense objects (catheter, pacing electrode, etc) before reconstruction with a cone beam filtered-backprojection (cathFDK), (4) removal of the shadow of dense objects before reconstruction with a cone beam filtered-backprojection and a bilateral filter (cathFFDK). The last method (5) is an iterative few-view reconstruction (FV), the prior image constrained compressed sensing combined with the improved total variation algorithm. All reconstructions are investigated with respect to the final motion-compensated reconstruction quality. The algorithms were tested on a mathematical

  9. Iterative metal artefact reduction in CT: can dedicated algorithms improve image quality after spinal instrumentation?

    Science.gov (United States)

    Aissa, J; Thomas, C; Sawicki, L M; Caspers, J; Kröpil, P; Antoch, G; Boos, J

    2017-05-01

    To investigate the value of dedicated computed tomography (CT) iterative metal artefact reduction (iMAR) algorithms in patients after spinal instrumentation. Post-surgical spinal CT images of 24 patients performed between March 2015 and July 2016 were retrospectively included. Images were reconstructed with standard weighted filtered back projection (WFBP) and with two dedicated iMAR algorithms (iMAR-Algo1, adjusted to spinal instrumentations and iMAR-Algo2, adjusted to large metallic hip implants) using a medium smooth kernel (B30f) and a sharp kernel (B70f). Frequencies of density changes were quantified to assess objective image quality. Image quality was rated subjectively by evaluating the visibility of critical anatomical structures including the central canal, the spinal cord, neural foramina, and vertebral bone. Both iMAR algorithms significantly reduced artefacts from metal compared with WFBP (panalysis showed that both iMAR algorithms led to an improvement in visualisation of soft-tissue structures (median iMAR-Algo1=3; interquartile range [IQR]:1.5-3; iMAR-Algo2=4; IQR: 3.5-4) and bone structures (iMAR-Algo1=3; IQR:3-4; iMAR-Algo2=4; IQR:4-5) compared to WFBP (soft tissue: median 2; IQR: 0.5-2 and bone structures: median 2; IQR: 1-3; palgorithms reduced artefacts compared with WFBP, however, the iMAR algorithm with dedicated settings for large metallic implants was superior to the algorithm specifically adjusted to spinal implants. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  10. Challenging the 'offshore hypothesis' for fossiliferous chert artefacts in southwestern Australia and consideration of inland trade routes

    Science.gov (United States)

    O'Leary, Michael J.; Ward, Ingrid; Key, Marcus M.; Burkhart, Mackenze S.; Rawson, Chris; Evans, Noreen

    2017-01-01

    Surface scatters containing Eocene chert artefacts are a widespread cultural site type along the Swan Coastal Plain; however, no source rock for the chert is known to exist locally. In the absence of chert outcrops onshore, archaeologists have argued for an offshore source that was subsequently flooded during post-glacial sea level rise. Support for this theory has been the decline or absence of Eocene chert artefacts in deposits younger than 6000 years BP, and the apparent decrease in chert assemblage inland from the contemporary coastline, which may call into question a distal eastern source. This paper presents an alternative theory whereby chert was sourced from the Nullarbor Plain (∼1000 km to the east) and traded east as well as west across southern Australia. Evidence to support this theory includes (1) absence of Eocene age sedimentary strata outcropping on the continental shelf, (2) faunal evidence showing bryozoans imbedded in the Swan Coastal Plain chert, with similar environmental affinities to bryozoans embedded in chert outcropping along the Nullarbor Plain sea cliffs, and (3) geochemical evidence showing a similar geochemical fingerprint between artefacts from the Nullarbor Plain and Swan Coastal Plain. With a peak in fossiliferous chert use around the Last Glacial Maximum, these findings have significant ethnographic implications supporting long distance trade to the east rather than local sourcing of lithic resources by isolated Aboriginal groups. These findings also have chronological implications relating to the use of Eocene fossiliferous chert as a chronological marker for Late Pleistocene to early-Holocene age deposits in southwest Western Australia, albeit with source accessibility following post-glacial sea-level rise still a main factor in the decline in chert use.

  11. Not all that glitters is gold - Electron microscopy study on uptake of gold nanoparticles in Daphnia magna and related artefacts

    DEFF Research Database (Denmark)

    Jensen, Louise Helene Søgaard; Skjolding, Lars Michael; Thit, Amalie

    2017-01-01

    Increasing use of engineered nanoparticles has led to extensive research into their potential hazards to the environment and human health. Cellular uptake from the gut is sparsely investigated and microscopy techniques applied for uptake studies can result in misinterpretations. Various microscopy...... techniques are used to investigate internalization of 10 nm gold nanoparticles in Daphnia magna gut lumen and gut epithelial cells upon 24h exposure and outline potential artefacts, i.e. high contract precipitates from sample preparation related to these techniques. Light sheet microscopy confirmed...

  12. The Fundamentals Regarding the Usage of the Concept of Interface for the Modeling of the Software Artefacts

    Directory of Open Access Journals (Sweden)

    Dorin Bocu

    2016-03-01

    Full Text Available This paper presents the conceptual foundations of a software system’s solution modelling activity, which is formally based on two essential concepts: the artefact and the interface. This  modelling activity envisions  two  objectives: the  explicit emphasis on the  interfaces’ importance in the software engineering, and the preparation of the  framework inside which  the  loop structure-behaviour can be formalized considering the inherent benefits for the  modelling activity in  general, and  for  the  modelling activity automation in particular.

  13. Metal artefact suppression at 3 T MRI: comparison of MAVRIC-SL with conventional fast spin echo sequences in patients with Hip joint arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Kretzschmar, Martin; Nardo, Lorenzo; Han, Misung M.; Heilmeier, Ursula; Sam, Craig; Joseph, Gabby B.; Krug, Roland; Link, Thomas M. [University of California San Francisco, Musculoskeletal Quantitative Imaging Research Group, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Koch, Kevin M. [Medical Collage of Wisconsin, Departments of Biophysics and Radiology, Milwaukee, WI (United States)

    2015-08-15

    The aim of our study was to evaluate the clinical feasibility and diagnostic value of a new MRI metal artefact reduction pulse sequence called MAVRIC-SL in a 3 T MRI environment. Two MAVRIC-SL sequences obtained in 61 patients with symptomatic total hip replacement were compared with standard FSE-STIR sequences optimized for imaging around metal. Artefact size was measured on the slice of greatest extent. Image quality, fat saturation, image distortion, visibility of anatomical structures, and detectability of joint abnormalities were visually assessed and graded on qualitative scales. Differences between MAVRIC-SL and FSE sequences were tested with the Wilcoxon signed-rank test. MAVRIC-SL sequences at 3 T showed significantly smaller metal artefacts compared to FSE-STIR sequences (p < 0.0001). The general image quality of MAVRIC-SL sequences was reduced with regard to spatial resolution, noise and contrast (p = 0.001), and fat saturation (p < 0.0001). The reduction of artefact size and image distortion significantly improved visualization of joint anatomy (p < 0.0001) and diagnostic confidence regarding implant-associated abnormalities (p = 0.0075 to <0.0001). Although the image quality of MAVRIC-SL sequences is limited at 3 T, its clinical application is feasible and provides important additional diagnostic information for the workup of patients with symptomatic hip replacement through substantially reduced metal artefacts. (orig.)

  14. Influence of the artefact reduction algorithm of Picasso Trio CBCT system on the diagnosis of vertical root fractures in teeth with metal posts.

    Science.gov (United States)

    Bezerra, I S Q; Neves, F S; Vasconcelos, T V; Ambrosano, G M B; Freitas, D Q

    2015-01-01

    To assess the influence of the artefact reduction algorithm (AR) available on the Picasso Trio 3D(®) imaging system (Vatech, Hwaseong, Republic of Korea) on image quality [greyscale values, contrast-to-noise ratio (CNR) and artefact formation] and diagnosis of vertical root fractures (VRFs) in the teeth with intracanal metal posts. 30 uniradicular teeth had their crowns removed and their roots endodontically treated to receive intracanal metal posts. In 20 teeth, both complete (n = 10) and incomplete (n = 10) VRFs were created. Each tooth was scanned twice, with and without AR activation. The mean and variation of greyscale values, as well as CNR, were calculated for all images. Subsequently, an evaluator compared the amount of artefact (cupping, white streaks and dark bands) in all images. Five evaluators rated for VRF presence using a five-point scale. Mean greyscale values and CNR were significantly decreased in images acquired with the AR. The usage of the algorithm promoted an overall reduction of image artefacts. Regarding the diagnosis of complete and incomplete VRFs, the use of the AR had an overall negative impact on specificity and accuracy. While indeed reducing artefact formation, the use of the AR, instead of improving the impact on the diagnosis of VRFs in teeth with intracanal metal posts, had a negative impact on the diagnosis.

  15. Reduction of artefacts caused by missing ray-sum data in optical-CT imaging of implants in gel dosimeters

    Science.gov (United States)

    Asena, A.; Smith, S. T.; Kairn, T.; Crowe, S. B.; Franich, R. D.; Trapp, J. V.

    2017-05-01

    This study demonstrates the degradation in image quality, and subsequent dose evaluation inaccuracies, that are encountered when an optical-CT system reconstructs an image slice of a gel dosimeter containing an opaque implant, and evaluates the feasibility of a simple correction method to improve the accuracy of radiotherapy dose distribution measurements under these circumstances. MATLAB was used to create a number of different virtual phantoms and treatment plans along with their synthetic projections and reconstructed data sets. The results have illustrated that accurately evaluating 3D gel dose distributions in the vicinity of high-Z interfaces is not possible using the filtered back projection method, without correction, as there are serious artefacts throughout the dose volume that are induced by the missing ray-sum data. Equivalent artefacts were present in physical measurements of irradiated PAGAT gel containers when read by an optical-CT system. An interpolation correction performed prior to reconstruction via the filtered back projection algorithm has been shown to significantly improve dose evaluation accuracy to within approximately 15 mm of the opacity. With careful placement of the implant within the gel sample, and use of the linear interpolation method described in this study, there is the potential for more accurate optical CT imaging of gels containing opaque objects.

  16. Different Views about the Nature of Gender-Related Asymmetries in Tasks Based on Biological or Artefact Categories

    Directory of Open Access Journals (Sweden)

    Guido Gainotti

    2010-01-01

    Full Text Available Sex-related asymmetries in the ability to process different semantic categories have been reported both in normal subjects and in brain-damaged patients, but the nature of these asymmetries is still controversial. Some authors suggest that these differences might be due to social-role related familiarity factors, whereas others attribute them to inborn neural differences rooted in evolution. Drawing in part on this second line of thought, some authors have suggested that gender-related asymmetries might be due to differences in stimulus processing between men and women, namely, to the tendency of females to focus mainly on perceptual features and of males to focus equally on both perceptual and functional features. To test this hypothesis, we asked 53 male and 65 female undergraduate students to evaluate the relevance of a number of perceptual and functional features in the representation of various kinds of biological and artefact categories. Contrary to the hypothesis, evaluation of the weight of different sources of knowledge in representing living and artefact categories was similar in males and females.

  17. CT contrast enhancement following renal cryoablation – artefact or treatment failure?

    DEFF Research Database (Denmark)

    Nielsen, Tommy Kjærgaard; Østraat, Øyvind; Andersen, Gratien

    Introduction and objective: Renal cryoablation is a valid treatment option for localized pT1a renal cancer. Treatment success is typically defined as absence of contrast enhancement (CE) and a decrease in size of the cryoablated renal mass (i.e. cryolesion) on follow-up imaging. We investigated...... (LCA) or percutaneous cryoablation (PCA) from August 2005 to August 2012 at Aarhus University Hospital. Six patients were excluded from analysis due to MRI follow-up. During routine postoperative CT follow-up, contrast enhancement of the cryolesion was identified in 34 of the 107 patients (32......, PADUA- score and level of contrast enhancement was significantly (penhancement pattern and number of cryoprobes used were not significantly different between the two groups. In patients where...

  18. Application of dual-energy CT to suppression of metal artefact caused by pedicle screw fixation in radiotherapy: a feasibility study using original phantom

    Science.gov (United States)

    Wang, Tianyuan; Ishihara, Takeaki; Kono, Atsushi; Yoshida, Naoki; Akasaka, Hiroaki; Mukumoto, Naritoshi; Yada, Ryuichi; Ejima, Yasuo; Yoshida, Kenji; Miyawaki, Daisuke; Kakutani, Kenichiro; Nishida, Kotaro; Negi, Noriyuki; Minami, Toshiaki; Aoyama, Yuuichi; Takahashi, Satoru; Sasaki, Ryohei

    2017-08-01

    The objective of the present study was the determination of the potential dosimetric benefits of using metal-artefact-suppressed dual-energy computed tomography (DECT) images for cases involving pedicle screw implants in spinal sites. A heterogeneous spinal phantom was designed for the investigation of the dosimetric effect of the pedicle-screw-related artefacts. The dosimetric comparisons were first performed using a conventional two-directional opposed (AP-PA) plan, and then a volumetric modulated arc therapy (VMAT) plan, which are both used for the treatment of spinal metastases in our institution. The results of Acuros® XB dose-to-medium (Dm) and dose-to-water (Dw) calculations using different imaging options were compared with experimental measurements including the chamber and film dosimetries in the spinal phantom. A dual-energy composition image with a weight factor of  -0.2 and a dual-energy monochromatic image (DEMI) with an energy level of 180 keV were found to have superior abilities for artefact suppression. The Dm calculations revealed greater dosimetric effects of the pedicle screw-related artefacts compared to the Dw calculations. The results of conventional single-energy computed tomography showed that, although the pedicle screws were made from low-Z titanium alloy, the metal artefacts still have dosimetric effects, namely, an average (maximum) Dm error of 4.4% (5.6%) inside the spinal cord for a complex VMAT treatment plan. Our findings indicate that metal-artefact suppression using the proposed DECT (DEMI) approach is promising for improving the dosimetric accuracy near the implants and inside the spinal cord (average (maximum) Dm error of 1.1% (2.0%)).

  19. Respiratory-motion artefacts in liver MRI following injection of gadoxetate disodium and gadobenate dimeglumine: an intra-individual comparative study in cirrhotic patients.

    Science.gov (United States)

    Furlan, A; Close, O N; Borhani, A A; Wu, Y H; Heller, M T

    2017-01-01

    To perform an intra-individual comparison of the frequency of respiratory-motion artefacts on magnetic resonance imaging (MRI) in cirrhotic patients following injection of gadoxetate disodium and gadobenate dimeglumine. Ninety-five cirrhotic patients (61 men and 34 women, mean age 58 years) underwent liver MRI with intravenous administration of gadoxetate disodium and gadobenate dimeglumine at different times (interval between studies, 189±83 days). Three readers scored the severity of respiratory-motion artefacts on the three-dimensional (3D) gradient-echo (GRE) images acquired before and after contrast medium injection. McNemar's test was used to assess the difference in frequency of new respiratory-motion artefacts and transient severe motion (TSM) artefacts between gadoxetate disodium and gadobenate dimeglumine MRI studies. The association between clinical and technical features and the occurrence of TSM on gadoxetate disodium MRI studies was investigated. On arterial phase images, new respiratory-motion artefacts were present in 32/95 (34%) cases after injection of gadoxetate disodium, while only seen in 2/95 (2%) cases after injection of gadobenate dimeglumine (pTSM was present in 6/95 (6%) cases after injection of gadoxetate disodium, and in 0/95 (0%) case after injection of gadobenate dimeglumine. No clinical or technical features were associated with the occurrence of TSM. In cirrhotic patients, respiratory-motion artefacts on arterial phase 3D GRE images are more frequently seen after injection of gadoxetate disodium than after injection of gadobenate dimeglumine. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  20. 20 CFR 404.1323 - Post-World War II service excluded.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Post-World War II service excluded. 404.1323... DISABILITY INSURANCE (1950- ) Wage Credits for Veterans and Members of the Uniformed Services Post-World War II Veterans § 404.1323 Post-World War II service excluded. Your service was not in the active service...

  1. 8 CFR 241.21 - Stay of deportation of excluded alien.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Stay of deportation of excluded alien. 241.21 Section 241.21 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS APPREHENSION AND DETENTION OF ALIENS ORDERED REMOVED Deportation of Excluded Aliens (for Hearings Commenced...

  2. 22 CFR 40.102 - Guardian required to accompany excluded alien.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Guardian required to accompany excluded alien. 40.102 Section 40.102 Foreign Relations DEPARTMENT OF STATE VISAS REGULATIONS PERTAINING TO BOTH... Guardian required to accompany excluded alien. INA 212(a)(9)(B) is not applicable at the time of visa...

  3. Bias towards dementia: are hip fracture trials excluding too many patients? A systematic review

    NARCIS (Netherlands)

    Hebert-Davies, Jonah; Laflamme, G.-Yves; Rouleau, Dominique; Bhandari, Mohit; Devereaux, Philip J.; Guyatt, Gordon; Heetveld, Martin J.; Jeray, Kyle; Liew, Susan; Richardson, Martin J.; Schemitsch, Emil H.; Swiontkowski, Marc; Tornetta, Paul; Walter, Stephen; Mohit, Bhandari; Sprague, Sheila; Viveiros, Helena; Simunovic, Nicole; Swinton, Marilyn; Heels-Ansdell, Diane; Buckingham, Lisa; Duraikannan, Aravin; Swiontkowski, Marc F.; Agel, Julie; van Lieshout, Esther M. M.; Zielinski, Stephanie M.; Goslings, J. Carel; Haverlag, Robert; Ponsen, M. J.; de Rijcke, P. A. R.; Koppert, C. L.; Buijk, Steven E.; Groenendijk, Richard P. R.; Dawson, I.; de Rycke, P. A. R.; Tetteroo, G. W. M.; Bruijninckx, M. M. M.; Doornebosch, P.; deGraaf, E. J. R.; Patka, Peter; Eversdijk, Martin; Peters, Rolf; van Waes, Oscar; den Hartog, Dennis; van Waes, O.; Oprel, P.; Gasthuis, Kennemer; Visser, Gijs A.; Stockmann, Heyn; Silvis, Rob; Snellen, J. P.; Rybroek, A.; Scheepers, J. J. G.; Vermeulen, Erik G. J.; Siroen, M. P. C.; Vuylsteke, Ronald; Brom, H. L. F.; Ryna, H.; van Laarhoven, H. A. J.; Haag, Den; Rhemrev, S.; Bosman, C. H. R.; van Otterloo, Alexander Mol; Hoogendoorn, Jochem; Idenburg, Floris; de Vries, A. C.; Meylaerts, S. A. G.; Roukema, Gert R.; Josaputra, H.; Keller, Paul; de Rooij, P. P.; Kuiken, H.; Boxma, H.; Cleffken, B. I.; Liem, Ronald; Poolman, Rudolf W.; Simons, Maarten P.; van der Heijden, F. H. W. M.; Willems, W. J.; de Meulemeester, Frank R. A. J.; van der Hart, Cor; Tarkan, K.; Festen, S.; de Nies, F.; Out, N. J. M.; Bosma, J.; de Graaf Gasthuis, Reinier; van der Elst, Maarten; van der Pol, Carmen C.; van't Reit, Martyne; Karsten, T. M.; de Vries, M. R.; Stassen, P. S.; Schep, N.; Schmidt, Ben; Hoffman, W. H.; Segers, J. M.; Zijl, Jacco; Verhoeven, Bart; Smits, Anke; Theunissen, Evert B. M.; Wille, J.; Govaert, Lonnek; Wittich, Phillippe; Brauw, Maurits; Wille, Jan; Ritchie, Ewan D.; Wittish, H.; Wessel, R. N.; Hammacher, E. R.; Ziekenhuis, Elisabeth; Verhofstad, Michiel H. J.; Meijer, Joast M. R.; van Egmond, Teun; van den Heijden, F. H. W. M.; Campo, Martin; Verhagen, Ronald; van Kampen, A.; Biert, J.; van Vugt, Arie B.; Edwards, Michael; Blokhuis, Taco; Frolke, Jan Paul M.; Geeraidts, L.; de Waal Malefyt, M. C.; Schreurs, B.; Simmermacher, Roger K. J.; van Mulken, Jeroen; van Gaalen, Steven M.; Bronovo, Ziekenhuis; Bronkhorst, Maarten W. G. A.; Guicherit, O. R.; Frihagen, Frede; Nordsletten, Lars; Kibsgaard, Thomas; Haug, Knut Jorgen; Lona, Tariei; Ugland, Stein; Nilsen, Kenneth; Brekke, Anne Christin; Vesterhus, Elise Berg; Tetsworth, Kevin; Weinrauch, Patrick; Pincus, Paul; Donald, Geoff; yang, Steven; Halliday, Brett; Gervais, Trevor; Holt, Michael; Flynn, Annette; Pirpiris, Marinis; Love, David; Bucknill, Andrew; Farrugia, Richard J.; Dowrick, Adam; Donohue, Craig; Bedi, Harvinder; Li, Doug; Edwards, Elton; Csonguray, Steven; Miller, Russell; Wang, Otis; Chia, Andrew; Jain, Arvind; Mammen, Mathan; Moaveni, Ash; Murdock, Zoe; Sage, Claire; Bahadur, Tegh; Jain, Anil Kumar; Pankaj, Amite; Pesantez, Rodrigo; Martinez, Adriana; Novoa, Catherine; Buckley, Richard E.; Duffy, Paul; Korley, Robert; Johnston, Kelly; Puloski, Shannon; Carcary, Kimberly; Avram, Victoria; Bicknell, Ryan; Yach, Jeff; Bardana, Davide; Wood, Gavin; Lambert, Sue; Sanders, David W.; Howard, Jamie; Macleod, Mark; Lawendy, Abdel; Bartley, Debra; Laney, Tim; Tieszer, Christina; Peterson, Devin; Zalzal, Paul; Naumetz, Victor; Brien, Heather; Weening, Brad; Wai, Eugene K.; Papp, Steven; Roffey, Darren; McCormack, Robert; Stone, Trevor; Perey, Bertrand; Viskontas, Darius; Boyer, Dory; Moola, Farhad; Zomar, Mauri; Moon, Karyn; McKee, Michael; Hall, Jeremy; Ahn, Henry; Vicente, Milena R.; Wild, Lisa M.; Kreder, Hans J.; Stephen, David J. G.; Nousianinen, Markku; Kunz, Monica; Syed, Khalid; Azad, Tania; Coles, Chad; Leighton, Ross; Johnstone, David; Glazebrook, Mark; Alexander, David; Coady, Cathy; Trask, Kelly; Dobbin, Gwendolyn; Oliver, Todd M.; Jones, Vicky; Ronan, James; Brown, Desmond T.; Carlilse, Hope; Shaughnessy, Lisa; Schwappach, John; Davis, Craig A.; Weingarten, Peter; Weinerman, Stewart; Newman, Heike; Baker, Janell; Browner, Kieran; Hurley, Meghan; Payton, Krystal; Zura, Robert; Manson, Maria J.; Goetz, David; Broderick, Scott J.; Porter, Scott; Pace, Thomas; Tanner, Stephanie L.; Snider, Becky; Schmidt, Andrew H.; Haas, Jonathan; Templeman, David; Westberg, Jerald R.; Mullis, Brian; Ertl, J. P.; Shively, Karl; Frizzel, Valda; Moore, Molly M.; Marcantonio, Andrew J.; Iorio, Richard; Lobo, Margaret; Kain, Michael; Specht, Lawrence; Tilzey, John; Garfi, John; Prayson, Michael J.; Laughlin, Richard; Rubino, Joe; Lawless, Mathew; DiPaola, Matt; Gayton, Chris; Dulaney-Cripe, Liz; Vallier, Heather A.; Wilber, John; Wilber, Roger G.; Sontich, John H.; Patterson, Brendan; Dolenc, Andrea; Robinson, Chalitha; DePaolo, Charles J.; Alosky, Rachel; Shell, E.; Keeve, Jonathan P.; Anderson, Chris; McDonald, Michael; Hoffman, Jodi; Baele, Joseph; Weber, Tim; Edison, Matt; Musapatika, Dana; Jones, Clifford; Ringler, James; Endres, Terrance; Gelbke, Martin; Jabara, Michael; Sietsema, Debra L.; Engerman, Susan M.; Switzer, Julie A.; Li, Mangnai; Marston, Scott; Cole, Peter; Vang, Sandy X.; Ly, Thuan; Anderson, Sarah; Foley, Amy; McBeth, Jessica; Comstock, Curt; Ziran, Navid; Shaer, James; Hileman, Barbara; Karges, David; Cannada, Lisa; Kuldjanov, Djoldas; Watson, John Tracy; Mills, James Jackman Emily; Hill, Leslie; Simon, Tiffanya; Abdelgawad, Amr; Shunia, Juan; Jenkins, Mark; Zumwalt, Mimi; Romero, Amanda West; Lowe, Jason; Goldstein, Jessica; Zamorano, David P.; Lawson, Deanna; Archdeacon, Michael; Wyrick, John; Hampton, Shelley; Lewis, Courtland G.; Ademi, Arben; Sullivan, Raymond; Caminiti, Stephanie; Graves, Matthew; Smith, Lori; Della Rocca, Gregory J.; Crist, Brett D.; Murtha, Yvonne; Anderson, Linda K.; Kliewer, Toni K.; McPherson, Melinda K.; Sullivan, Kelly M.; Jarrett, Sharon L.; Sagebien, Carlos; Seuffert, Patricia; Mehta, Samir; Esterhai, John; Ahn, Jaimo; Tjoumakaris, Fotios; Horan, Annamarie D.; Kaminski, Christine; Tarkin, Ivan; Siska, Peter; Luther, Arlene; Irrgang, James; Farrell, Dana J.; Gorczyca, John T.; Gross, Jonathan M.; Kates, Stephen Lloyd; Colosi, Jen; Hibsch, Nancy; Noble, Krista; Neu, Sarah; Agarwal, Animesh; Wright, Rebecca; Hsu, Joseph R.; Randall, Gayle M.; Ficke, James R.; Charlton, Michael; Fan, Mary; Garcia, Socorro H.; Obremskey, William T.; Richards, Justin Edward; Robinson, Kenya; Carroll, Eben; Kulp, Brenda; Guyatt, Gordon H.; Devereaux, Philip James; Einhorn, Thomas A.; Koval, Ken J.; Tetsworth, Kevin D.; Culgin, Sarah; Desjardin, Heather; Beimers, Lijkele; de Vries, Jasper; Zurcher, Arthur W.; Albers, G. H. Rob; Rademakers, Maarten; Breugem, Stefan; van der Haven, Ibo; Damen, Peter Jan; Bulstra, Gythe H.; Somford, P.; Haverkamp, Daniël; Gasthuis, Onze Lieve Vrouwe; Molekamp, Willem Jan Kleyn; Kleipool, E. B.; Keizer, Stefan B.; Swen, Jan-Willem A.; Nelissen, Eelco M.; Hollander, Peter H. C. den; Metsaars, Weineke; Thomassen, J. W.; Fontijne, W. Peter J.; Wiersma, Saskia C.; Boetes, Bastiaan; JT, Edgar; Ziekenhuis, Spaarne; Nolte, Peter A.; de Jong, Tjitte; van Noort, Arthur; Vergroesen, Diederik A.; van den Bekerom, Michel P. J.; Schutte, Bernard G.; Schuman, Lein; Hillen, Robert Jan; Cheung, John; van der Heide, Huub J. L.; Nagels, Jochem; Krips, Rover; Mullers, J. Bernard; Schüller, Hans; Ziekenhuis, Amphia; van den Hout, Joost A. A. M.; Joosten, Adrianus J. P.; van der Broek, Chris M.; Bolder, Stefan B. T.; Eygendaal, Denise; Moonen, Adrianus F. C. M.; van Geenen, Rutger C. I.; Hoebink, Eric A.; Wagenmakers, Robert; van Helden, Wouter; Kooijman, Rob; Postema, Roelf R.; Lampe, Harald I. H.; Ziekenhuizen, Gelre; Bolhuis, Hugo W.; Bullens, Pieter H. J.; Hogervorst, Mike; de Kroon, Karin E.; Jansen, Rob H.; Raven, Eric E. J.; van Jonbergen, Hans-Peter W.; Reuver, Joost M.; Barnaart, Alexander F. W.; Roerdink, W. Herbert; van Erve, Ruud H. G. P.; Koorevaar, Rinco; Frima, Anthony Hans; Flikweert, Elvira R.; Falke, Mark L. M.; Kurek, Frans J.; Slingerland, Adrianus C. H.; Vallei, Gelderse; van Dijk, Jan P.; van Helden, Wouter H.; Mauer-Hansen, Espen; Boee, Berte; Clarke-Jensen, Jon; Brekke, Anne Christine; Vestergaard, Elise Berg; Carr, Ashley; Russ, Matthias; Li, Douglas; Doig, Stephen; Laflamme, Yves; Fernandes, Julio C.; Poirier, Marie-France; Bogoch, Earl; Kreder, Hans; Axelrod, Terry; Jenkinson, Richard; Wadey, Veronica; Nousiainen, Markku; Stephen, David; Macnevin, Melanie; Richardson, Glen C.; Biddulph, Michael; Gross, Michael; Dunbar, Michael; Dobbin, Gwen; Zarin, Jeffrey; Parvataneni, Hari; Baker, Janell K.; Roberson, James R.; Erens, Greg; Montelione, Anita; Woodard, Shawndra; Ertl, Janos; Cummings, Judd; Worman, Ripley; Webster, Mark; Parr, Andrew; Frizzell, Valda; Moore, Molly; Wilk, Richard; Torchia, Michael; Cross, William; Sems, Andrew; Taunton, Michael; Sanchez-Satelo, Joaquin; Sierrz, Rafsel; Timm, Kimberly; Foreman, Barbara; DePaolo, Charles; Hill, Rocky; Lewis, Coutland; Srivastava, Ajay; Bakeman, James; Sietsema, Deb; Strathy, Gregg; Johnson, Paul; Peter, Kathleen; Morton, Maeghan E.; Parvizi, Javad; Austin, Matthew; Morrison, Tiffany; Mont, Michael; Copeland, Carol; Delanois, Ronald; Khanuja, Harpal; Weddington, Shaquita; Bacon, Madeline; Mullen, Marylou; Kanlic, Enes; Abdelgawad, Amr Atef; Shunia, Juan Gerardo; Horan, Annamarie

    2012-01-01

    Patients with hip fractures are older and often present many co-morbidities, including dementia. These patients cannot answer quality of life questionnaires and are generally excluded from trials. We hypothesized that a significant number of patients are being excluded from these studies and this

  4. 38 CFR 17.260 - Patient care costs to be excluded from direct costs.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Patient care costs to be excluded from direct costs. 17.260 Section 17.260 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS MEDICAL Grants for Exchange of Information § 17.260 Patient care costs to be excluded from...

  5. 40 CFR 1048.20 - What requirements from this part apply to excluded stationary engines?

    Science.gov (United States)

    2010-07-01

    ... of another company you choose to designate. (3) State the engine displacement (in liters) and maximum... to excluded stationary engines? 1048.20 Section 1048.20 Protection of Environment ENVIRONMENTAL...-IGNITION ENGINES Overview and Applicability § 1048.20 What requirements from this part apply to excluded...

  6. 41 CFR 101-30.302 - Types of items excluded from cataloging.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Types of items excluded...-FEDERAL CATALOG SYSTEM 30.3-Cataloging Items of Supply § 101-30.302 Types of items excluded from...) Items procured in foreign markets for use in overseas activities of Federal agencies. (e) Printed forms. ...

  7. 26 CFR 31.3402(e)-1 - Included and excluded wages.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Included and excluded wages. 31.3402(e)-1... SOURCE Collection of Income Tax at Source § 31.3402(e)-1 Included and excluded wages. (a) If a portion of... not more than 31 consecutive days constitutes wages, and the remainder does not constitute wages, all...

  8. Preventing Inclusion? Inclusive Early Childhood Education and the Option to Exclude

    Science.gov (United States)

    Cologon, Kathy

    2014-01-01

    While there is increasing international commitment to inclusive education, as outlined in the United Nations Convention on the Rights of Persons with Disabilities (CRPD), many children remain excluded at school. One marginalised and frequently excluded group of people are people who experience disability. In the recently released first report on…

  9. Motion-related artefacts in EEG predict neuronally plausible patterns of activation in fMRI data

    Science.gov (United States)

    Jansen, Marije; White, Thomas P.; Mullinger, Karen J.; Liddle, Elizabeth B.; Gowland, Penny A.; Francis, Susan T.; Bowtell, Richard; Liddle, Peter F.

    2012-01-01

    The simultaneous acquisition and subsequent analysis of EEG and fMRI data is challenging owing to increased noise levels in the EEG data. A common method to integrate data from these two modalities is to use aspects of the EEG data, such as the amplitudes of event-related potentials (ERP) or oscillatory EEG activity, to predict fluctuations in the fMRI data. However, this relies on the acquisition of high quality datasets to ensure that only the correlates of neuronal activity are being studied. In this study, we investigate the effects of head-motion-related artefacts in the EEG signal on the predicted T2*-weighted signal variation. We apply our analyses to two independent datasets: 1) four participants were asked to move their feet in the scanner to generate small head movements, and 2) four participants performed an episodic memory task. We created T2*-weighted signal predictors from indicators of abrupt head motion using derivatives of the realignment parameters, from visually detected artefacts in the EEG as well as from three EEG frequency bands (theta, alpha and beta). In both datasets, we found little correlation between the T2*-weighted signal and EEG predictors that were not convolved with the canonical haemodynamic response function (cHRF). However, all convolved EEG predictors strongly correlated with the T2*-weighted signal variation in various regions including the bilateral superior temporal cortex, supplementary motor area, medial parietal cortex and cerebellum. The finding that movement onset spikes in the EEG predict T2*-weighted signal intensity only when the time course of movements is convolved with the cHRF, suggests that the correlated signal might reflect a BOLD response to neural activity associated with head movement. Furthermore, the observation that broad-spectral EEG spikes tend to occur at the same time as abrupt head movements, together with the finding that abrupt movements and EEG spikes show similar correlations with the T2

  10. Human presence in the central Netherlands during early MIS 6 (∼170-190 Ka): Evidence from early Middle Palaeolithic artefacts in ice-pushed Rhine-Meuse sediments

    NARCIS (Netherlands)

    Balen, R.T. van; Busschers, F.S.

    2010-01-01

    Part of the gravelly deposits of a combined Rhine-Meuse river of Middle Pleistocene age in the central Netherlands contains early Middle Palaeolithic artefacts. Although not in their original position, a significant part of these artefacts is hardly abraded, indicating limited fluvial transport. The

  11. Metal artefact reduction for patients with metallic dental fillings in helical neck computed tomography: comparison of adaptive iterative dose reduction 3D (AIDR 3D), forward-projected model-based iterative reconstruction solution (FIRST) and AIDR 3D with single-energy metal artefact reduction (SEMAR).

    Science.gov (United States)

    Yasaka, Koichiro; Kamiya, Kouhei; Irie, Ryusuke; Maeda, Eriko; Sato, Jiro; Ohtomo, Kuni

    To compare the differences in metal artefact degree and the depiction of structures in helical neck CT, in patients with metallic dental fillings, among adaptive iterative dose reduction three dimensional (AIDR 3D), forward-projected model-based iterative reconstruction solution (FIRST) and AIDR 3D with single-energy metal artefact reduction (SEMAR-A). In this retrospective clinical study, 22 patients (males, 13; females, 9; mean age, 64.6 ± 12.6 years) with metallic dental fillings who underwent contrast-enhanced helical CT involving the oropharyngeal region were included. Neck axial images were reconstructed with AIDR 3D, FIRST and SEMAR-A. Metal artefact degree and depiction of structures (the apex and root of the tongue, parapharyngeal space, superior portion of the internal jugular chain and parotid gland) were evaluated on a four-point scale by two radiologists. Placing regions of interest, standard deviations of the oral cavity and nuchal muscle (at the slice where no metal exists) were measured and metal artefact indices were calculated (the square root of the difference of the squares of them). In SEMAR-A, metal artefact was significantly reduced and depictions of all structures were significantly improved compared with those in FIRST and AIDR 3D (p ≤ 0.001, sign test). Metal artefact index for the oral cavity in AIDR 3D/FIRST/SEMAR-A was 572.0/477.7/88.4, and significant differences were seen between each reconstruction algorithm (p metal artefact and better depiction of structures than AIDR 3D and FIRST.

  12. Nanoparticles of Sr(OH)2: synthesis in homogeneous phase at low temperature and application for cultural heritage artefacts

    Science.gov (United States)

    Ciliberto, E.; Condorelli, G. G.; La Delfa, S.; Viscuso, E.

    2008-07-01

    This paper concerns the synthesis and the characterization of nanometer particles of Sr(OH)2, a moderately high water soluble hydroxide (Ksp= 3.2×10-4 at 25 °C). The reported process yields strontium hydroxide nanoparticles starting from low cost raw materials in aqueous medium (homogeneous phase) at low temperature (below 100 °C) by chemical precipitation from salt solutions, involving very simple operational steps and avoiding the use of organic solvents. Observations by X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive X-Ray (EDX) and Fourier transform infrared spectroscopy (FTIR) indicate that the particles are well-crystallized and have nanometer dimensions (˜ 30 nm in diameter). Moreover, experimental evidence shows the potential use of this material for the protection and the consolidation of wall paintings (frescoes), paper, stone, wood and other artistic artefacts.

  13. Exploring young children’s artefact engagements as premises for creating purposeful intergenerational knowledge of digitalized everyday life

    DEFF Research Database (Denmark)

    Chimirri, Niklas Alexander

    ’s digitalization focuses primarily on children’s learning and thus becoming the future workforce, as well as on digital artefacts’ potentials for pedagogical staff to closely and comprehensively document and monitor this becoming. Meanwhile, single municipalities and institutions relate differently to this top....... It is acknowledged, though, that dissent also always implies an alternative hope as well as temporary stabilizations of meaning. Therefore, it is of crucial importance to not only inquire into dissenting practices and knowledges, but also to how these relate to consenting practices and knowledges. Pivotally...... engagement with how and why children more generally engage with any kind of sociomaterial artefact, creating joint knowledge through both dissensus and consensus. In order to ground digitalization in children’s as well as adults’ (well)being, the paper proposes that the analytical focus must be put on which...

  14. Assessing the role of artefact design within the Middle Palaeolithic repertoire: determining the behavioural potential of blade production strategies

    DEFF Research Database (Denmark)

    Hoggard, Christian Steven

    2017-01-01

    the functional analysis through a goodness-of-fit test, to explain whether a working hypothesis grounded on ‘performance attributes’ (Skibo and Schiffer, 2001) and artefact design could explain the change from a predominantly Levallois method of blade production in the Early Middle Palaeolithic...... the importance of three factors: social transmission and cultural tradition (Bordian-centric models), site-function and adaptation (Binfordian-centric models), and diachronic change andchronology. In many of these investigations and analyses into the Middle Palaeolithic, little emphasis is placed...... on commonalities and differences in blank-type, product desirability and their behavioural potential given their morphology. While function may not account for all aspects of technological variability, analyses of functional performance may explain chronological changes in various core volume management strategies...

  15. The usefulness of ultrasound colour-Doppler twinkling artefact for detecting urolithiasis compared with low dose nonenhanced computerized tomography

    DEFF Research Database (Denmark)

    Winkel, Rikke Rass; Kalhauge, Anna; Fredfeldt, Knud-Erik

    2012-01-01

    This prospective study evaluates the usefulness of the twinkling artefact (TA) seen on colour-Doppler ultrasound (US) in diagnosing urolithiasis. US and standard computed tomography (CT) were performed blinded on 105 patients. B-mode US and colour-Doppler used separately and in combination showed...... 55% sensitivity and 99% specificity (positive predictive value [PPV] 67% and negative predictive value [NPV] 98%). Of CT verified stones, 61% were ≤3 mm. TAs were present in 74% of the B-mode stones (43% of all CT verified stones). Patients with CT verified stone disease had significantly more TAs......, US and US with colour-Doppler TA can be useful as complementary techniques for detecting stones....

  16. Performance Investigation of a Handheld 3d Scanner to Define Good Practices for Small Artefact 3d Modeling

    Science.gov (United States)

    Lachat, E.; Landes, T.; Grussenmeyer, P.

    2017-08-01

    Handheld 3D scanners can be used to complete large scale models with the acquisition of occluded areas or small artefacts. This may be of interest for digitization projects in the field of Cultural Heritage, where detailed areas may require a specific treatment. Such sensors present the advantage of being easily portable in the field, and easily usable even without particular knowledge. In this paper, the Freestyle3D handheld scanner launched on the market in 2015 by FARO is investigated. Different experiments are described, covering various topics such as the influence of range or color on the measurements, but also the precision achieved for geometrical primitive digitization. These laboratory experiments are completed by acquisitions performed on engraved and sculpted stone blocks. This practical case study is useful to investigate which acquisition protocol seems to be the more adapted and leads to precise results. The produced point clouds will be compared to photogrammetric surveys for the purpose of their accuracy assessment.

  17. Provenance analysis of Roman stone artefacts from sedimentary rocks from the archaeological site near Mošnje, NW Slovenia

    Directory of Open Access Journals (Sweden)

    Snježana Miletić

    2016-08-01

    Full Text Available This study deals with the macroscopic and microfacies characterisation of Roman stone artefacts excavated in 2006 from a Roman villa rustica near Mošnje (NW Slovenia with the aim of defiing their provenance. A total of 28 representative fids (querns, mortars, whetstones, tooled and rounded stones, a fragment of stone slab, mosaic tesserae and two architectural elements - one with a relief made of clastic and carbonate sedimentary rocks were examined. Comparison was made with rock samples taken from quarries and gravel bars close to the archaeological site, as well as from larger distance to the site. The majority of artefact sampled is composed of Upper Palaeozoic quartz sandstones, which are found as pebbles in gravel bars close to the archaeological site; while 2 samples were from Quaternary coarse grained clastic rocks which can be found in local glacio-flvial sediments. Other fids were made of four different Mesozoic shallow-water limestones which outcrop in different areas of Central and SW Slovenia. The nearest Lower Jurassic biopelmicritic limestones are found at the western periphery of Ljubljana in Podutik. Cretaceous miliolid limestones and biocalcarenitic limestones with rudists are common in the successions of the Dinaric Carbonate Platform in SW Slovenia (for example, on the Trieste-Komen Plateau, NE Italy and SW Croatia. This indicates that the limestones for architectural elements, stone mortars and tesserae were brought to Mošnje from distant locations. Smaller stone tools are likely to have been made at the location of the archaeological site from material gathered locally, mostly pebbles from clastic rocks, which were accessible and suitable for tooling.

  18. Comparative assessment of knee joint models used in multi-body kinematics optimisation for soft tissue artefact compensation.

    Science.gov (United States)

    Richard, Vincent; Cappozzo, Aurelio; Dumas, Raphaël

    2017-09-06

    Estimating joint kinematics from skin-marker trajectories recorded using stereophotogrammetry is complicated by soft tissue artefact (STA), an inexorable source of error. One solution is to use a bone pose estimator based on multi-body kinematics optimisation (MKO) embedding joint constraints to compensate for STA. However, there is some debate over the effectiveness of this method. The present study aimed to quantitatively assess the degree of agreement between reference (i.e., artefact-free) knee joint kinematics and the same kinematics estimated using MKO embedding six different knee joint models. The following motor tasks were assessed: level walking, hopping, cutting, running, sit-to-stand, and step-up. Reference knee kinematics was taken from pin-marker or biplane fluoroscopic data acquired concurrently with skin-marker data, made available by the respective authors. For each motor task, Bland-Altman analysis revealed that the performance of MKO varied according to the joint model used, with a wide discrepancy in results across degrees of freedom (DoFs), models and motor tasks (with a bias between -10.2° and 13.2° and between -10.2mm and 7.2mm, and with a confidence interval up to ±14.8° and ±11.1mm, for rotation and displacement, respectively). It can be concluded that, while MKO might occasionally improve kinematics estimation, as implemented to date it does not represent a reliable solution to the STA issue. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Convergence characteristics of two algorithms in non-linear stimulus artefact cancellation for electrically evoked potential enhancement.

    Science.gov (United States)

    Parsa, V; Parker, P; Scott, R

    1998-03-01

    Somatosensory evoked potentials (SEPs) are a sub-class of evoked potentials (EPs) that are very useful in diagnosing various neuromuscular disorders and in spinal cord and peripheral-nerve monitoring. Most often, the measurements of these signals are contaminated by stimulus-evoked artefact. Conventional stimulus-artifact (SA) reduction schemes are primarily hardware-based and rely on some form of input blanking during the SA phase. This procedure can result in partial SEP loss if the tail of the SA interferes with the SEP. Adaptive filters offer an attractive solution to this problem by iteratively reducing the SA waveform while leaving the SEP intact. Owing to the inherent non-linearities in the SA generation system, non-linear adaptive filters (NAFs) are most suitable. SA reduction using NAFs based on truncated second-order Volterra expansion series is investigated. The focus is on the performance of two main adaptation algorithms, the least mean square (LMS) and recursive least squares (RLS) algorithms, in the context of non-linear adaptive filtering. A comparison between the convergence and performance characteristics of these two algorithms is made by processing both simulated and experimental SA data. It is found that, in high artefact-to-noise ratio (ANR) SA cancellation, owing to the large eigenvalue spreads, the RLS-based NAF is more efficient than the LMS-based NAF. However, in low-ANR scenarios, the RLS- and LMS-based NAFs exhibit similar convergence properties, and the computational simplicity of the LMS-based NAFs makes them the preferred option.

  20. Modelo experimental de fundoplicatura gastroesofágica em ratos: estudo manométrico e histológico do esôfago Experimental model of gastric-esophageal fundoplication in rats: manometric and histological study of the esophagus

    Directory of Open Access Journals (Sweden)

    Sérgio Luis Rocha

    2004-04-01

    Full Text Available OBJETIVO: O presente estudo objetiva avaliar alguns aspectos decorrentes da fundoplicatura em ratos, com técnica de Nissen, através da análise histológica do esôfago distal e estudo manométrico do esfíncter esofágico inferior (EEI, bem como da avaliação da variação do peso dos ratos submetidos ao procedimento, com diferentes dias de evolução. MÉTODOS: Utilizaram-se 70 ratos Wistar, machos, com idade entre 100 e 130 dias e peso entre 250 e 300 g, divididos em dois grupos. O grupo experimento foi composto por 60 ratos, subdivididos em 6 subgrupos de acordo com o tempo de aferição manométrica pós-operatória: 02, 07, 14, 21, 28 e 40 dias, e submetido a fundoplicatura com posterior análise manométrica do EEI e histológica do esôfago distal. O grupo controle foi composto pelos 10 animais restantes, submetido apenas a laparotomia com manipulação da região es��fago-gástrica, e realizaram-se as mesmas análises. RESULTADOS: Evidenciou-se na análise histológica, edema estatisticamente significativo (p=0,0000 nos subgrupos 02 e 07 dias, acompanhado de perda de peso. Observou-se significância estatística no estudo manométrico em todos os subgrupos comparados ao controle (p t c=+2,132. CONCLUSÃO: Após fundoplicatura de Nissen em ratos, a pressão no EEI não retorna aos níveis do controle até o 40º pós-operatório. O edema correlacionado à perda de peso e ao aumento da pressão no EEI pode ser a principal variável relacionada à possível disfagia.PURPOSE: The aim of this experimental study is to evaluate the outcomes of having Nissen fundoplication done on rats through the histological analysis of the distal esophagus and manometric study of the lower esophageal sphincter (LES, as well as the evaluation of weight variation of the rats subjected to this procedure, in distinct days after surgery. METHODS: Have been used 70 male Wistar rats, at the ages of 100 to 130 days , weighing from 250 to 300 grams and divided

  1. Blasphemy As Violence: Trying to Understand the Kind of Injury That Can Be Inflicted by Acts and Artefacts That Are Construed As Blasphemy

    NARCIS (Netherlands)

    Baumgartner, C.|info:eu-repo/dai/nl/304835250

    2013-01-01

    This article suggests an understanding of blasphemy as violence that enables us to identify various kinds of injury that can be inflicted by blasphemous acts and artefacts. Understanding blasphemy as violence can take three forms: physical violence, indirect intersubjective violence, and

  2. The effect of metal artefact reduction on CT-based attenuation correction for PET imaging in the vicinity of metallic hip implants : a phantom study

    NARCIS (Netherlands)

    Harnish, Roy; Prevrhal, Sven; Alavi, Abass; Zaidi, Habib; Lang, Thomas F.

    To determine if metal artefact reduction (MAR) combined with a priori knowledge of prosthesis material composition can be applied to obtain CT-based attenuation maps with sufficient accuracy for quantitative assessment of F-18-fluorodeoxyglucose uptake in lesions near metallic prostheses. A custom

  3. The social construction of facts and artefacts: or How the sociology of science and the sociology of technology might benefit each other

    NARCIS (Netherlands)

    Pinch, Trevor J.; Bijker, Wiebe E.

    1984-01-01

    The need for an integrated social constructivist approach towards the study of science and technology is outlined. Within such a programme both scientific facts and technological artefacts are to be understood as social constructs. Literature on the sociology of science, the science-technology

  4. Quantitative analysis of orthopedic metal artefact reduction in 64-slice computed tomography scans in large head metal-on-metal total hip replacement, a phantom study

    NARCIS (Netherlands)

    Boomsma, Martijn F.; Warringa, Niek; Edens, Mireille A.; Mueller, Dirk; Ettema, Harmen B.; Verheyen, Cees C. P. M.; Maas, Mario

    2016-01-01

    Purpose: Quantification of the effect of O-MAR on decreasing metal artefacts caused by large head metal on metal total hip arthroplasty (MoM THA) in a dedicated phantom setup of the hip. Background: Pathological reactions of the hip capsule on Computed tomography (CT) can be difficult to diagnose

  5. NNDSS - Table II. Salmonellosis (excluding typhoid fever and paratyphoid fever) to Shigellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Salmonellosis (excluding typhoid fever and paratyphoid fever) to Shigellosis - 2018. In this Table, provisional cases of selected notifiable...

  6. Listening to excluded young people's perspectives on how digital technologies support and challenge their lives

    OpenAIRE

    Sue Cranmer

    2010-01-01

    Listening to excluded young people’s perspectives on how digital technologies support and challenge their lives This article reports on the perspectives of young people who have been excluded from school on how ICTs support and challenge them in their everyday lives. Qualitative in-depth semistructured interviews were carried out with 13 young people at a Pupil Referral Unit (PRU). The analysis provides a nuanced account of young people’s online activities for those who are already experie...

  7. Equation of State for the Two-component Van der Waals Gas with Relativistic Excluded Volumes

    OpenAIRE

    Zeeb, Gebhard; Bugaev, Kyrill A.; Reuter, Philipp T.; Stöcker, Horst

    2002-01-01

    A canonical partition function for the two-component excluded volume model is derived, leading to two different van der Waals approximations. The one is known as the Lorentz-Berthelot mixture and the other has been proposed recently. Both models are analysed in the canonical and grand canonical ensemble. In comparison with the one-component van der Waals excluded volume model the suppression of particle densities is reduced in these two-component formulations, but in two essentially different...

  8. Reducing the effects of metal artefact using high keV monoenergetic reconstruction of dual energy CT (DECT) in hip replacements.

    Science.gov (United States)

    Lewis, Mark; Reid, Karen; Toms, Andoni P

    2013-02-01

    The aim of this study was to determine whether high keV monoenergetic reconstruction of dual energy computed tomography (DECT) could be used to overcome the effects of beam hardening artefact that arise from preferential deflection of low energy photons. Two phantoms were used: a Charnley total hip replacement set in gelatine and a Catphan 500. DECT datasets were acquired at 100, 200 and 400 mA (Siemens Definition Flash, 100 and 140 kVp) and reconstructed using a standard combined algorithm (1:1) and then as monoenergetic reconstructions at 10 keV intervals from 40 to 190 keV. Semi-automated segmentation with threshold inpainting was used to obtain the attenuation values and standard deviation (SD) of the streak artefact. High contrast line pair resolution and background noise were assessed using the Catphan 500. Streak artefact is progressively reduced with increasing keV monoenergetic reconstructions. Reconstruction of a 400 mA acquisition at 150 keV results in reduction in the volume of streak artefact from 65 cm(3) to 17 cm(3) (74 %). There was a decrease in the contrast to noise ratio (CNR) at higher tube voltages, with the peak CNR seen at 70-80 keV. High contrast spatial resolution was maintained at high keV values. Monoenergetic reconstruction of dual energy CT at increasing theoretical kilovoltages reduces the streak artefact produced by beam hardening from orthopaedic prostheses, accompanied by a modest increase in heterogeneity of background image attenuation, and decrease in contrast to noise ratio, but no deterioration in high contrast line pair resolution.

  9. Algorithms that eliminate the effects of calibration artefact and trial-imposed offsets of Masimo oximeter in BOOST-NZ trial.

    Science.gov (United States)

    Zahari, Marina; Lee, Dominic Savio; Darlow, Brian Alexander

    2016-10-01

    The displayed readings of Masimo pulse oximeters used in the Benefits Of Oxygen Saturation Targeting (BOOST) II and related trials in very preterm babies were influenced by trial-imposed offsets and an artefact in the calibration software. A study was undertaken to implement new algorithms that eliminate the effects of offsets and artefact. In the BOOST-New Zealand trial, oxygen saturations were averaged and stored every 10 s up to 36 weeks' post-menstrual age. Two-hundred and fifty-seven of 340 babies enrolled in the trial had at least two weeks of stored data. Oxygen saturation distribution patterns corresponding with a +3 % or -3 % offset in the 85-95 % range were identified together with that due to the calibration artefact. Algorithms involving linear and quadratic interpolations were developed, implemented on each baby of the dataset and validated using the data of a UK preterm baby, as recorded from Masimo oximeters with the original software and a non-offset Siemens oximeter. Saturation distributions obtained were compared for both groups. There were a flat region at saturations 85-87 % and a peak at 96 % from the lower saturation target oximeters, and at 93-95 and 84 % respectively from the higher saturation target oximeters. The algorithms lowered the peaks and redistributed the accumulated frequencies to the flat regions and artefact at 87-90 %. The resulting distributions were very close to those obtained from the Siemens oximeter. The artefact and offsets of the Masimo oximeter's software had been addressed to determine the true saturation readings through the use of novel algorithms. The implementation would enable New Zealand data be included in the meta-analysis of BOOST II trials, and be used in neonatal oxygen studies.

  10. Reducing the effects of metal artefact using high keV monoenergetic reconstruction of dual energy CT (DECT) in hip replacements

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Mark [Norfolk and Norwich University Hospital, Norwich (United Kingdom); Norwich Radiology Academy, Norwich (United Kingdom); Reid, Karen [Norfolk and Norwich University Hospital, Norwich (United Kingdom); Toms, Andoni P. [Norfolk and Norwich University Hospital and University of East Anglia, Norwich (United Kingdom)

    2013-02-15

    The aim of this study was to determine whether high keV monoenergetic reconstruction of dual energy computed tomography (DECT) could be used to overcome the effects of beam hardening artefact that arise from preferential deflection of low energy photons. Two phantoms were used: a Charnley total hip replacement set in gelatine and a Catphan 500. DECT datasets were acquired at 100, 200 and 400 mA (Siemens Definition Flash, 100 and 140 kVp) and reconstructed using a standard combined algorithm (1:1) and then as monoenergetic reconstructions at 10 keV intervals from 40 to 190 keV. Semi-automated segmentation with threshold inpainting was used to obtain the attenuation values and standard deviation (SD) of the streak artefact. High contrast line pair resolution and background noise were assessed using the Catphan 500. Streak artefact is progressively reduced with increasing keV monoenergetic reconstructions. Reconstruction of a 400 mA acquisition at 150 keV results in reduction in the volume of streak artefact from 65 cm{sup 3} to 17 cm{sup 3} (74 %). There was a decrease in the contrast to noise ratio (CNR) at higher tube voltages, with the peak CNR seen at 70-80 keV. High contrast spatial resolution was maintained at high keV values. Monoenergetic reconstruction of dual energy CT at increasing theoretical kilovoltages reduces the streak artefact produced by beam hardening from orthopaedic prostheses, accompanied by a modest increase in heterogeneity of background image attenuation, and decrease in contrast to noise ratio, but no deterioration in high contrast line pair resolution. (orig.)

  11. Medicare Star excludes diabetes patients with poor CVD risk factor control.

    Science.gov (United States)

    Schmittdiel, Julie; Raebel, Marsha; Dyer, Wendy; Steiner, John; Goodrich, Glenn; Karter, Andy; Nichols, Gregory

    2014-12-01

    CMS recently added medication adherence to antihypertensives, antihyperlipidemics, and oral antihyperglycemics to its Medicare Star quality measures. These CMS metrics exclude patients with Star adherence metrics and assessed the relationship of both Star-defined adherence and exclusion from Star metrics with CVD risk factor control. Cross-sectional, population-based analysis of 129,040 patients with diabetes aged ≥65 years in 2010 from 3 Kaiser Permanente regions. We estimated adjusted risk ratios to assess the relationship between achieving Star adherence and being excluded from Star adherence metrics, with CVD risk factor control (glycated hemoglobin [A1C]Star metrics excluded 27% of patients with diabetes prescribed oral medications. Star-defined nonadherence was negatively associated with CVD risk factor control (risk ratio [RR], 0.95, 0.84, 0.96 for A1C, LDL-C, and SBP control, respectively; PStar metrics due to early nonadherence was also strongly associated with poor control (RR, 0.83, 0.56, 0.87 for A1C, LDL-C, and SBP control, respectively; PStar adherence measures underestimate the prevalence of medication nonadherence in diabetes and exclude patients at high risk for poor CVD outcomes. Up to 3 million elderly patients with diabetes may be excluded from these measures nationally. Quality measures designed to encourage effective medication use should focus on all patients treated for CVD risk.

  12. [Viral load test conducive to excluding negative subjects from suspects in HIV antibody detections].

    Science.gov (United States)

    Hei, Fa-Xin; Zhang, Qi-Yun; Sun, Wei-Dong; Zhang, Qin; Ye, Jing-Rong; Liu, Hai-Lin; Lu, Hong-Yan

    2008-01-01

    To study whether plasma viral load testing is helpful to exclude ones free from Human immunodeficiency virus (HIV) infections from suspects in HIV antibody detections. 19 Specimens, which showed disconcordant results of the two HIV EIA testing (S/CO test, were selected. Viral load of the specimens were detected. A six-month follow up survey in detecting HIV antibody was conducted in these subjects. None of these 19 cases was observed to be positive HIV viral loads and there was no any progress in WB bands development during the follow-up period. The possibility of HIV infection could be excluded. When the specimens react with very low intensity in both EIA and WB, negative viral load result is conducive to exclude negative subjects from suspects in HIV antibody detections.

  13. Synchrotron Radiation Effects in the IR Solenoid Flux Excluder(LCC-0007)

    Energy Technology Data Exchange (ETDEWEB)

    Tenenbaum, P

    2004-04-22

    We examine the emittance dilution due to synchrotron radiation in the fringing fields at the end of the ''flux excluder'' solenoid which protects the final doublet quadrupoles from the main detector solenoid field, and also the effect of SR in the main solenoid field itself.Because the deflection due to the excluder fringe field is opposite in polarity from that of the main solenoid, the resulting dispersive rays cancel at the IP; as a result the synchrotron radiation from the two magnetic fields produces only a small dilution of the vertical spot size. The contribution to the spot size from the finite opening angle of the synchrotron flux is found to be comparable to the contribution from solenoidal dispersion, and both are acceptable. We conclude that SR considerations do not rule out use of a flux excluder, and that the range of crossing angles and solenoidal fields available is large.

  14. Listening to excluded young people’s perspectives on how digital technologies support and challenge their lives

    National Research Council Canada - National Science Library

    Sue Cranmer

    2010-01-01

    Listening to excluded young people’s perspectives on how digital technologies support and challenge their lives This article reports on the perspectives of young people who have been excluded from school on how ICTs support...

  15. Schedules of Controlled Substances: Table of Excluded Nonnarcotic Products: Vicks® VapoInhaler®.

    Science.gov (United States)

    2016-02-08

    This final rule adopts the interim final rule, with a correction to spelling of the manufacturer's name that was published in the Federal Register on October 27, 2015. The Drug Enforcement Administration is amending the table of Excluded Nonnarcotic Products to update the listing for Vicks® VapoInhaler®, containing 50 mg levmetamfetamine in a nasal decongestant inhaler, marketed by The Procter & Gamble Company. This over-the-counter, non-narcotic drug product is excluded from provisions of the Controlled Substances Act.

  16. Study of SEM preparation artefacts with correlative microscopy: Cell shrinkage of adherent cells by HMDS-drying.

    Science.gov (United States)

    Katsen-Globa, Alisa; Puetz, Norbert; Gepp, Michael M; Neubauer, Julia C; Zimmermann, Heiko

    2016-11-01

    One of the often reported artefacts during cell preparation to scanning electron microscopy (SEM) is the shrinkage of cellular objects, that mostly occurs at a certain time-dependent stage of cell drying. Various methods of drying for SEM, such as critical point drying, freeze-drying, as well as hexamethyldisilazane (HMDS)-drying, were usually used. The latter becomes popular since it is a low cost and fast method. However, the correlation of drying duration and real shrinkage of objects was not investigated yet. In this paper, cell shrinkage at each stage of preparation for SEM was studied. We introduce a shrinkage coefficient using correlative light microscopy (LM) and SEM of the same human mesenchymal stem cells (hMSCs). The influence of HMDS-drying duration on the cell shrinkage is shown: the longer drying duration, the more shrinkage is observed. Furthermore, it was demonstrated that cell shrinkage is inversely proportional to cultivation time: the longer cultivation time, the more cell spreading area and the less cell shrinkage. Our results can be applicable for an exact SEM quantification of cell size and determination of cell spreading area in engineering of artificial cellular environments using biomaterials. SCANNING 38:625-633, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  17. Non-destructive characterisation and classification of ceramic artefacts using pEDXRF and statistical pattern recognition

    Directory of Open Access Journals (Sweden)

    Gajić-Kvaščev Maja D

    2012-09-01

    Full Text Available Abstract Background Portable energy dispersive X-ray fluorescence (pEDXRF spectrometry analysis was applied for the characterisation of archaeological ceramic findings from three Neolithic sites in Serbia. Two dimension reduction techniques, principal component analysis (PCA and scattering matrices-based dimension reduction were used to examine the possible classification of those findings, and to extract the most discriminant features. Results A decision-making procedure is proposed, whose goal is to classify unknown ceramic findings based on their elemental compositions derived by pEDXRF spectrometry. As a major part of decision-making procedure, the possibilities of two dimension reduction methods were tested. Scattering matrices-based dimension reduction was found to be the more efficient method for the purpose. Linear classifiers designed based on the desired output allowed for 7 of 8 unknown samples from the test set to be correctly classified. Conclusions Based on the results, the conclusion is that despite the constraints typical of the applied analytical technique, the elemental composition can be considered as viable information in provenience studies. With a fully-developed procedure, ceramic artefacts can be classified based on their elemental composition and well-known provenance.

  18. Soft tissue artefacts of skin markers on the lower limb during cycling: Effects of joint angles and pedal resistance.

    Science.gov (United States)

    Li, Jia-Da; Lu, Tung-Wu; Lin, Cheng-Chung; Kuo, Mei-Ying; Hsu, Horng-Chaung; Shen, Wu-Chung

    2017-09-06

    Soft tissue artefacts (STA) are a major error source in skin marker-based measurement of human movement, and are difficult to eliminate non-invasively. The current study quantified in vivo the STA of skin markers on the thigh and shank during cycling, and studied the effects of knee angles and pedal resistance by using integrated 3D fluoroscopy and stereophotogrammetry. Fifteen young healthy adults performed stationary cycling with and without pedal resistance, while the marker data were measured using a motion capture system, and the motions of the femur and tibia/fibula were recorded using a bi-plane fluoroscopy-to-CT registration method. The STAs with respect to crank and knee angles over the pedaling cycle, as well as the within-cycle variations, were obtained and compared between resistance conditions. The thigh markers showed greater STA than the shank ones, the latter varying linearly with adjacent joint angles, the former non-linearly with greater within-cycle variability. Both STA magnitudes and within-cycle variability were significantly affected by pedal resistance (presistance and muscle contractions. The current data will be helpful for a better choice of marker positions for data collection, and for developing methods to compensate for both stable and variation components of the STA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A Multi-Channel Opto-Electronic Sensor to Accurately Monitor Heart Rate against Motion Artefact during Exercise

    Directory of Open Access Journals (Sweden)

    Abdullah Alzahrani

    2015-10-01

    Full Text Available This study presents the use of a multi-channel opto-electronic sensor (OEPS to effectively monitor critical physiological parameters whilst preventing motion artefact as increasingly demanded by personal healthcare. The aim of this work was to study how to capture the heart rate (HR efficiently through a well-constructed OEPS and a 3-axis accelerometer with wireless communication. A protocol was designed to incorporate sitting, standing, walking, running and cycling. The datasets collected from these activities were processed to elaborate sport physiological effects. t-test, Bland-Altman Agreement (BAA, and correlation to evaluate the performance of the OEPS were used against Polar and Mio-Alpha HR monitors. No differences in the HR were found between OEPS, and either Polar or Mio-Alpha (both p > 0.05; a strong correlation was found between Polar and OEPS (r: 0.96, p < 0.001; the bias of BAA 0.85 bpm, the standard deviation (SD 9.20 bpm, and the limits of agreement (LOA from −17.18 bpm to +18.88 bpm. For the Mio-Alpha and OEPS, a strong correlation was found (r: 0.96, p < 0.001; the bias of BAA 1.63 bpm, SD 8.62 bpm, LOA from −15.27 bpm to +18.58 bpm. These results demonstrate the OEPS to be capable of carrying out real time and remote monitoring of heart rate.

  20. An investigation of head movement with a view to minimising motion artefact during SPECT and PET imaging of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, H.; Clarke, G.H.; Guy, R. [RMIT, Melbourne, VIC (Australia). Department of Medical Radiations Science; McKay, W.J. [Austin and Repatriation Medical Centre, Heidelberg, VIC (Australia). Department of Nuclear Medicine and Centre for Positron Emission Tomography

    1998-06-01

    Full text: Motion artefact has long been recognised as a major cause of image degradation. Single Photon Emission Computerised Tomography (SPECT) and Positron Emission Tomography (PET) of the brain are playing an important role in the diagnosis and management of several neurological disorders. If these imaging modalities are to contribute fully to medical imaging it is essential that the improved spatial resolution of these systems is not compromised by patient movement. Thirty volunteer subjects have been examined using a simple video technique and the video images were used to classify and measure head movements which may occur during brain imaging. All subjects demonstrated angular movement within the transverse plane or rotation of the head. Angular movement within the sagittal plane or flexion/extension of the neck occurred in 69% of subjects and 72% of subjects exhibited translational movement of the sagittal plane. There was no movement of the coronal plane; nor was there any translational movement of the sagittal plane. These results suggest that when positioning the patient`s head for brain imaging a system of head restraint which minimises rotation of the head should be used if image quality is to be maintained

  1. On artefact-free reconstruction of low-energy (30–250 eV) electron holograms

    Energy Technology Data Exchange (ETDEWEB)

    Latychevskaia, Tatiana, E-mail: tatiana@physik.uzh.ch; Longchamp, Jean-Nicolas; Escher, Conrad; Fink, Hans-Werner

    2014-10-15

    Low-energy electrons (30–250 eV) have been successfully employed for imaging individual biomolecules. The most simple and elegant design of a low-energy electron microscope for imaging biomolecules is a lensless setup that operates in the holographic mode. In this work we address the problem associated with the reconstruction from the recorded holograms. We discuss the twin image problem intrinsic to inline holography and the problem of the so-called biprism-like effect specific to low-energy electrons. We demonstrate how the presence of the biprism-like effect can be efficiently identified and circumvented. The presented sideband filtering reconstruction method eliminates the twin image and allows for reconstruction despite the biprism-like effect, which we demonstrate on both, simulated and experimental examples. - Highlights: • Radiation damage-free imaging of individual biomolecules. • Elimination of the twin image in inline holograms. • Circumventing biprism-like effect in low-energy electron holograms. • Artefact-free reconstructions of low-energy electron holograms.

  2. Ross filter pairs for metal artefact reduction in x-ray tomography: a case study based on imaging and segmentation of metallic implants

    Science.gov (United States)

    Arhatari, Benedicta D.; Abbey, Brian

    2018-01-01

    Ross filter pairs have recently been demonstrated as a highly effective means of producing quasi-monoenergetic beams from polychromatic X-ray sources. They have found applications in both X-ray spectroscopy and for elemental separation in X-ray computed tomography (XCT). Here we explore whether they could be applied to the problem of metal artefact reduction (MAR) for applications in medical imaging. Metal artefacts are a common problem in X-ray imaging of metal implants embedded in bone and soft tissue. A number of data post-processing approaches to MAR have been proposed in the literature, however these can be time-consuming and sometimes have limited efficacy. Here we describe and demonstrate an alternative approach based on beam conditioning using Ross filter pairs. This approach obviates the need for any complex post-processing of the data and enables MAR and segmentation from the surrounding tissue by exploiting the absorption edge contrast of the implant.

  3. How could the Viking Sun compass be used with sunstones before and after sunset? Twilight board as a new interpretation of the Uunartoq artefact fragment.

    Science.gov (United States)

    Bernáth, Balázs; Farkas, Alexandra; Száz, Dénes; Blahó, Miklós; Egri, Adám; Barta, András; Akesson, Susanne; Horváth, Gábor

    2014-06-08

    Vikings routinely crossed the North Atlantic without a magnetic compass and left their mark on lands as far away as Greenland, Newfoundland and Baffin Island. Based on an eleventh-century dial fragment artefact, found at Uunartoq in Greenland, it is widely accepted that they sailed along chosen latitudes using primitive Sun compasses. Such instruments were tested on sea and proved to be efficient hand-held navigation tools, but the dimensions and incisions of the Uunartoq find are far from optimal in this role. On the basis of the sagas mentioning sunstones, incompatible hypotheses were formed for Viking solar navigation procedures and primitive skylight polarimetry with dichroic or birefringent crystals. We describe here a previously unconceived method of navigation based on the Uunartoq artefact functioning as a 'twilight board', which is a combination of a horizon board and a Sun compass optimized for use when the Sun is close to the horizon. We deduced an appropriate solar navigation procedure using a twilight board, a shadow-stick and birefringent crystals, which bring together earlier suggested methods in harmony and provide a true skylight compass function. This could have allowed Vikings to navigate around the clock, to use the artefact dial as a Sun compass during long parts of the day and to use skylight polarization patterns in the twilight period. In field tests, we found that true north could be appointed with such a medieval skylight compass with an error of about ±4° when the artificially occluded Sun had elevation angles between +10° and -8° relative to the horizon. Our interpretation allows us to assign exact dates to the gnomonic lines on the artefact and outlines the schedule of the merchant ships that sustained the Viking colony in Greenland a millennium ago.

  4. The impact of Digitalization on Business Models: How IT Artefacts, Social Media, and Big Data Force Firms to Innovate Their Business Model

    OpenAIRE

    Bouwman, Harry; de Reuver, Mark; Nikou, Shahrokh

    2017-01-01

    Digital technology has forced entrepreneurs to reconsider their business models (BMs). Although research on entrepreneurial intention and business models is gaining attention, there is still a large knowledge gap on both fields. In this paper, we specifically address the impact of digitalization on business model innovation (BMI). Based on data collected from 338 European small- to medium-sized enterprises (SMEs) actively using IT artefacts, social media, or big data to innovate their busines...

  5. Cadmium tolerance and accumulation in Excluder Thlaspi arvense and various accessions of hyperaccumulator Noccaea caerulescens

    NARCIS (Netherlands)

    Seregin, I.V.; Kozhevnikova, A.D.; Zhukovskaya, V.; Schat, H.

    2015-01-01

    Cadmium (Cd) accumulation and tolerance were analyzed in hyperaccumulator Noccaea caerulescens F.K. Mey and excluder Thlaspi arvense L. Five accessions of N. caerulescens (La Calamine (LC, Belgium), Saint Félix de Palliéres (SF, France), Col du Mas de l’Aire (CMA, France), Ganges (GA, France) from

  6. 20 CFR 668.650 - Can INA grantees exclude segments of the eligible population?

    Science.gov (United States)

    2010-04-01

    ... eligible population? 668.650 Section 668.650 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION... population? (a) No, INA grantees cannot exclude segments of the eligible population. INA grantees must document in their Two Year Plan that a system is in place to afford all members of the eligible population...

  7. Excluding Ethical Issues from U.S. History Textbooks: 911 and the War on Terror

    Science.gov (United States)

    Romanowski, Michael H.

    2009-01-01

    This research study examined nine secondary American history textbooks regarding their treatment of 9/11 and related events. The analysis centered on both the knowledge included and excluded from the discussion in each book. Particular attention was given to the moral and ethical issues relevant to 9/11. Findings show that textbooks vary in their…

  8. 75 FR 13678 - Schedules of Controlled Substances; Table of Excluded Nonnarcotic Products: Nasal Decongestant...

    Science.gov (United States)

    2010-03-23

    ... Excluded Nonnarcotic Products: Nasal Decongestant Inhalers Manufactured by Classic Pharmaceuticals, LLC... (containing 50 mg Levmetamfetamine) manufactured by Classic Pharmaceuticals, LLC and marketed under various..., which may be lawfully sold over the counter without a prescription under the Federal Food, Drug, and...

  9. Acting on Observed Social Exclusion: Developmental Perspectives on Punishment of Excluders and Compensation of Victims

    Science.gov (United States)

    Will, Geert-Jan; Crone, Eveline A.; van den Bos, Wouter; Güroglu, Berna

    2013-01-01

    This study examined punishment of excluders and compensation of victims after observing an instance of social exclusion at various phases of adolescent development. Participants (n = 183; age 9 to 22 years) were first included in a virtual ball-tossing game, Cyberball, and then "observed" the exclusion of a peer. Subsequently, they…

  10. NGO Provision of Basic Education: Alternative or Complementary Service Delivery to Support Access to the Excluded?

    Science.gov (United States)

    Rose, Pauline

    2009-01-01

    This paper focuses on approaches by non-government organisations (NGOs) to reach primary school-aged children excluded from access to the conventional state education system. It highlights recent shifts in international literature and agency priorities from the portrayal of NGO provision as a (non-formal) "alternative" to (formal) state…

  11. 7 CFR 205.310 - Agricultural products produced on an exempt or excluded operation.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Agricultural products produced on an exempt or excluded operation. 205.310 Section 205.310 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) ORGANIC FOODS PRODUCTION AC...

  12. Walk the Talk? The Effect of Voting and Excludability in Public Goods Experiments

    Directory of Open Access Journals (Sweden)

    Hans J. Czap

    2010-01-01

    Full Text Available The purpose of this paper is to investigate the effect of voting and excludability on individual contributions to group projects. We conducted two experiments on excludable and nonexcludable public goods, which provided several important results. First, contrary to our expectations, subjects are generally contributing more to the non-excludable compared to the excludable public good. Second, participating in a vote to choose a public project per se makes no difference in contributions. However, if the project that the individual voted for also gets selected by the group, they contribute significantly more to that project. Third, empathy and locus of control are important driving forces of participation in common projects. Our results have implications on the procedural design of obtaining funding for public projects. First, the public should get involved and have a say in the determination of which project should be realized. Second, it might well pay off to attempt to develop a consensus among the population and obtain near unanimous votes, because in our experiment, subjects discriminate between the project they voted for and the project chosen by the majority. Third, the policy proposers should stress the other-regarding interest of the public good rather than just pecuniary incentives.

  13. 46 CFR 148.04-13 - Ferrous metal borings, shavings, turnings, or cuttings (excluding stainless steel).

    Science.gov (United States)

    2010-10-01

    ... (excluding stainless steel). 148.04-13 Section 148.04-13 Shipping COAST GUARD, DEPARTMENT OF HOMELAND... stainless steel). (a) This section applies to the stowage and transportation in bulk of hazardous materials... steel). However, unmanned barges on which the article is stowed for or transported on a voyage entirely...

  14. ALTERNATIVE FORMULATIONS TO REDUCE CFC USE IN U.S. EXEMPTED AND EXCLUDED AEROSOL PRODUCTS

    Science.gov (United States)

    The report examines products exempted and excluded from those affected by the 1978 ban on the use of chlorofluorocarbons (CFCs) as aerosol propellants, the present consumption of CFCs still utilized for these products in the U.S., and alternative formulations which may be used to...

  15. 26 CFR 1.401(a)(26)-6 - Excludable employees.

    Science.gov (United States)

    2010-04-01

    ... nonresident aliens) may be treated as an excludable employee. (ii) Special treaty rule. In addition, an...), a plan that uses the elapsed time method of determining years of service may use either 91... general method of crediting service for the employee. If one of the equivalencies set forth in 29 CFR 2530...

  16. 40 CFR 1039.20 - What requirements from this part apply to excluded stationary engines?

    Science.gov (United States)

    2010-07-01

    ... name and trademark of another company you choose to designate. (3) State the engine displacement (in... to excluded stationary engines? 1039.20 Section 1039.20 Protection of Environment ENVIRONMENTAL... COMPRESSION-IGNITION ENGINES Overview and Applicability § 1039.20 What requirements from this part apply to...

  17. Influence of streambank fencing on the environmental quality of cattle-excluded pastures.

    Science.gov (United States)

    Miller, J J; Chanasyk, D S; Curtis, T; Willms, W D

    2010-01-01

    Limited information exists on the effect of streambank fencing on riparian zone pastures. The objective of this study was to test the hypothesis that 4 to 6 yr of streambank fencing would improve the environmental quality of the cattle-excluded pasture compared with the grazed pasture and cause the fenced pasture to act as a buffer or filter strip. Rangeland health, vegetative and soil properties, and rainfall simulation runoff were measured in the cattle-excluded and adjacent grazed native pastures along the fenced reach of the Lower Little Bow River in southern Alberta, Canada, for 3 yr (2005-2007). Rangeland health was improved (health score increase from 55 to 72%); vegetation cover (13-21%) and standing litter (38-742%) were increased; and bare soil (72-93%) and soil bulk density (6-8%) were decreased under cattle exclusion, indicating an improvement in environmental quality from streambank fencing. In contrast, other vegetation (total and live basal area, fallen litter) and soil properties (soil water and soil C, N, and P) were not improved by cattle exclusion. Cattle exclusion significantly (P fenced pasture may act as a buffer for certain runoff variables. In contrast, other runoff variables (turbidity, electrical conductivity, pH, concentrations and loads of total suspended solids, and certain N and P fractions) in the cattle-excluded pasture were generally not improved by streambank fencing. Overall, streambank fencing improved the quality of certain environmental variables within the cattle-excluded pasture.

  18. Unanimous versus partial rejection: How the number of excluders influences the impact of ostracism in children

    NARCIS (Netherlands)

    Sandstrom, M.J.; Deutz, M.H.F.; Lansu, T.A.M.; Noorden, T.H.J. van; Karremans, J.C.T.M.; Cillessen, A.H.N.

    2017-01-01

    Previous research has shown that ostracism - the experience of being ignored and excluded - has negative effects on all of us, young and old. Using a Cyberball paradigm, the present research replicates the effects of ostracism on the moods (anger, anxiety, happiness, and anger) and fundamental needs

  19. Unanimous versus partial rejection : How the number of excluders influences the impact of ostracism in children

    NARCIS (Netherlands)

    Sandstrom, Marlene J.; Deutz, Marike H F; Lansu, Tessa A M; van Noorden, Tirza H J; Karremans, Johan C.; Cillessen, Antonius H N

    Previous research has shown that ostracism-the experience of being ignored and excluded-has negative effects on all of us, young and old. Using a Cyberball paradigm, the present research replicates the effects of ostracism on the moods (anger, anxiety, happiness, and anger) and fundamental needs

  20. Ontario Universities Benefits Survey, 1987-88. Part I: Benefits Excluding Pensions.

    Science.gov (United States)

    University of Western Ontario, London.

    Results of the 1987-1988 survey of benefits, excluding pensions, for 17 Ontario, Canada, universities are presented. Information is provided on the following areas: administration and insurance plans, communication of benefits, proposed changes in benefits, provision of life and dismemberment insurance, maternity leave policy, Ontario health…

  1. Endoscopic findings in the excluded stomach after Roux-en-Y gastric bypass surgery.

    Science.gov (United States)

    Kuga, Rogerio; Safatle-Ribeiro, Adriana V; Faintuch, Joel; Ishida, Robson K; Furuya, Carlos K; Garrido, Arthur B; Cecconello, Ivan; Ishioka, Shinichi; Sakai, Paulo

    2007-10-01

    After gastric bypass surgery performed because of morbid obesity, the excluded stomach can rarely be endoscopically examined. With the advent of a new apparatus and technique, possible mucosal changes can be routinely accessed and monitored, thus preventing potential benign and malignant complications. Prospective observational study in a homogeneous population with nonspecific symptoms. Outpatient clinic of a large public academic hospital. Forty consecutive patients (mean +/- SD age, 44.5 +/- 10.0 y ears; 85.0% women) were seen at a mean +/- SD of 77.3 +/- 19.4 months after Roux-en-Y gastric bypass surgery. Elective double-balloon enteroscopy of the excluded stomach was performed. Rate of successful intubation, endoscopic findings, and complications. The excluded stomach was reached in 35 of 40 patients (87.5%). Mean +/- SD time to enter the organ was 24.9 +/- 14.3 minutes (range, 5-75 minutes). Endoscopic findings were normal in 9 patients (25.7%), whereas in 26 (74.3%), various types of gastritis (erythematous, erosive, hemorrhagic erosive, and atrophic) were identified, primarily in the gastric body and antrum. No cancer was documented in the present series. Tolerance was good, and no complications were recorded during or after the intervention. The double-balloon method is useful and practical for access to the excluded stomach. Although cancer was not noted, most of the studied population had gastritis, including moderate and severe forms. Surveillance of the excluded stomach is recommended after Roux-en-Y gastric bypass surgery performed because of morbid obesity.

  2. Long-Term Outcome of the GORE EXCLUDER AAA Endoprosthesis for Treatment of Infrarenal Aortic Aneurysms.

    Science.gov (United States)

    Poublon, Claire G; Holewijn, Suzanne; van Sterkenburg, Steven M M; Tielliu, Ignace F J; Zeebregts, Clark J; Reijnen, Michel M P J

    2017-05-01

    To evaluate long-term outcome of GORE EXCLUDER AAA Endoprosthesis (W.L. Gore & Associates, Inc, Flagstaff, Arizona) for elective treatment of infrarenal aortic aneurysms and to evaluate performance of different generations of the device. A retrospective analysis was performed of 248 patients undergoing elective endovascular aneurysm repair with the GORE EXCLUDER between January 2000 and December 2015 in 2 hospitals. Primary endpoint was reintervention-free survival. Secondary endpoints were technical success, overall survival, rupture-free survival, endoleaks, sac diameter change (> 5 mm), limb occlusion, and migration (> 5 mm). Median follow-up time was 26 months (range, 1-190 months). Assisted primary technical success was 96.8%. Reintervention-free survival for 5 and 10 years was 85.2% and 75.6%, respectively. Independent risk factors for reintervention were technical success (P < .001), type I endoleak (P < .001), and type II endoleak (P = .003). Late adverse events requiring reintervention included rupture (0.4%), limb occlusion (0.4%), and stent migration (0.4%). Type Ia (4.8%), Ib (2.8%), II (35.9%), and V (6.5%) endoleaks were reported throughout follow-up. Sac growth was more prevalent with the original GORE EXCLUDER compared with the low permeability GORE EXCLUDER (P = .001) and in the presence of type I, II, and V endoleaks (P < .05). Three conversions (1.2%) were performed. Overall survival at 5 and 10 years was 68.4% and 49.0%, with no reported aneurysm-related deaths. Treatment with the GORE EXCLUDER is effective with acceptable reintervention rates in the long-term and few device-related adverse events or ruptures up to 10 years. Observed late adverse events and new-onset endoleaks emphasize the need for long-term surveillance. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  3. Addressing dichotomous data for participants excluded from trial analysis: a guide for systematic reviewers.

    Directory of Open Access Journals (Sweden)

    Elie A Akl

    Full Text Available Systematic reviewer authors intending to include all randomized participants in their meta-analyses need to make assumptions about the outcomes of participants with missing data.The objective of this paper is to provide systematic reviewer authors with a relatively simple guidance for addressing dichotomous data for participants excluded from analyses of randomized trials.This guide is based on a review of the Cochrane handbook and published methodological research. The guide deals with participants excluded from the analysis who were considered 'non-adherent to the protocol' but for whom data are available, and participants with missing data.Systematic reviewer authors should include data from 'non-adherent' participants excluded from the primary study authors' analysis but for whom data are available. For missing, unavailable participant data, authors may conduct a complete case analysis (excluding those with missing data as the primary analysis. Alternatively, they may conduct a primary analysis that makes plausible assumptions about the outcomes of participants with missing data. When the primary analysis suggests important benefit, sensitivity meta-analyses using relatively extreme assumptions that may vary in plausibility can inform the extent to which risk of bias impacts the confidence in the results of the primary analysis. The more plausible assumptions draw on the outcome event rates within the trial or in all trials included in the meta-analysis. The proposed guide does not take into account the uncertainty associated with assumed events.This guide proposes methods for handling participants excluded from analyses of randomized trials. These methods can help in establishing the extent to which risk of bias impacts meta-analysis results.

  4. TSH alone is not sufficient to exclude all patients with a functioning thyroid nodule from undergoing testing to exclude thyroid cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hurtado-Lopez, Luis-Mauricio; Monroy-Lozano, Blanca-Estela [General Hospital of Mexico, Mexico City (Mexico); Martinez-Duncker, Carlos [Hospital Infantil de Mexico Federico Gomez, Medicina Nuclear Molecular, Mexico City, DF (Mexico)

    2008-06-15

    The purpose of the study was to analyze whether the thyroid-stimulating hormone (TSH) alone avoids tests to exclude malignancy in all patients with functional thyroid nodules (FTN). Sixty-nine patients with FTN on {sup 99m}Tc scintigraphy, radioiodine uptake test (RIU), {sup 99m}Tc thyroid uptake, TSH assay, T3, and T4 obtained within 48 h were retrospectively identified out of 2,356 thyroid scans performed from January 2000 to April 2007. FTNs were classified as causing total, partial, or no inhibition of the thyroid as group 1, 2, or 3, respectively. TSH was subnormal in 21 of 69 (30.43%) patients. In group 1 (N = 23, 33.3%), TSH was subnormal, normal, and high in eight, nine, and six patients; in group 2 (N = 17, 24.6%), TSH was subnormal, normal, and high in four, six, and seven patients, and in group 3 (N = 29, 42%), TSH was subnormal, normal, and high in 9, 13, and 7 patients, respectively. TSH was significantly lower in group 1. In T3, T4, {sup 99m}Tc thyroid uptake, and RIU, there were no differences between the three groups. Only 30.43% of patients had subnormal TSH. TSH alone cannot avoid tests to exclude malignancy in all patients with FTN. FTN existence can only be accurately assessed by thyroid scintigraphy. The current incidence of FTN may be unknown because scintigraphy is not routinely performed in all patients with thyroid nodules. Thyroid scintigraphy of patients with high TSH can detect diseases such as Hashimoto's thyroiditis and identify patients with FTN in whom no further diagnostic procedures would be needed in patients with normal TSH levels with nondiagnostic fine-needle aspiration results. (orig.)

  5. Decreased CSF-flow artefacts in T2 imaging of the cervical spine with periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER/BLADE)

    Energy Technology Data Exchange (ETDEWEB)

    Ragoschke-Schumm, Andreas; Schmidt, Peter; Mayer, Thomas E. [Friedrich-Schiller-University, Department of Neuroradiology, Institute for Diagnostic and Interventional Radiology, University Clinic, Jena (Germany); Schumm, Julia [Friedrich-Schiller-University, Clinic of Internal Medicine I, Jena (Germany); Reimann, Georg; Mentzel, Hans-Joachim; Kaiser, Werner A. [Friedrich-Schiller-University, Institute for Diagnostic and Interventional Radiology, University Clinic, Jena (Germany)

    2011-01-15

    The cervical spine is prone to artefacts in T2 MR-imaging due to patient movements and cerebrospinal fluid flow. The periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER/BLADE) acquisition method was developed to reduce motion artefacts. We sought to determine if T2-BLADE is superior to T2-TSE with conventional k-space reading. Twenty-five patients were examined using a 1.5 T MR-scanner. T2-weighted imaging of the cervical spine in sagittal and axial orientation using conventional or BLADE k-space reading was performed. Spinal cord, subarachnoid space, vertebrae and discs were evaluated by two independent observers using a scale from 0 (non-diagnostic) to 3 (excellent). Interobserver correlation was assessed as Cohen's kappa. Results of Mann-Whitney U test with p < 0.05 were regarded as significant. Furthermore, the investigators were asked for subjective evaluation in consensus. Overall interobserver accuracy of {kappa} = 0.91 was obtained. Comparison of sagittal images showed better values for all investigated structures in T2-BLADE: spinal cord (TSE/BLADE: 1.52/2.04; p < 0.001), subarachnoid space (1.36/2.06; p < 0.001) and vertebrae/discs (1.66/2.86; p < 0.001). Comparison of axial images showed better values in T2-BLADE for spinal cord (1.68/1.86; p = 0.149) and vertebrae/discs (1.0/1.96: p < 0.001) while subarachnoid space was better to be evaluated in conventional T2-TSE (1.94/1.12; p < 0.001). In sagittal orientation, motion- and CSF-flow artefacts were reduced in T2-BLADE. In axial orientation, however, CSF-flow artefacts were pronounced in T2-BLADE. The image quality of the sagittal T2-BLADE sequences was significantly better than the T2-TSE and acquired in less time. In axial orientation, increased CSF-flow artefacts may reduce accuracy of structures in the subarachnoid space. (orig.)

  6. Life Expectancy in Germany Based on the 2011 Census: Was the Healthy Migrant Effect Merely an Artefact?

    Directory of Open Access Journals (Sweden)

    Felix zur Nieden

    2016-08-01

    Full Text Available The Federal Statistical Office’s 2010/12 general life table is the first to provide results on life expectancy based on census data for reunified Germany. This article therefore examines the question of how the revisions of the population figures from the 2011 census affected the measured life expectancy. To do so, we analysed both the official life tables based on the old intercensal population updates before the census and those based on the population data from the 2011 census. The method used to calculate the census-adjusted 2010/12 general life table was also transferred to separate life tables drawn up for the German and the foreign population. In this way, findings on the so-called “healthy migrant effect” can be discussed, ruling out possible errors in the intercensal population updates. These errors had previously been cited as the main causes for a distinctly longer life expectancy among the foreign population compared with the German population. As expected, a census-based calculation for the total population and for the German population resulted in only minor revisions to the life expectancy figures. The use of the census results does, however, distinctly alter the life expectancy of foreign women and men. An advantage of over 5 years in life expectancy at birth, measured on the basis of the old population data, needs to be revised to about 2.9 years for men and 2.1 years for women based on the 2011 census. The healthy migrant effect therefore cannot be traced back solely to data artefacts from the old intercensal population updates – even with revised data, the foreign population shows marked survival advantages.

  7. The snowball effect: friendship moderates escalations in depressed affect among avoidant and excluded children.

    Science.gov (United States)

    Bukowski, William M; Laursen, Brett; Hoza, Betsy

    2010-11-01

    A three-wave longitudinal study conducted with preadolescent boys and girls (N = 231 at Time 1 [T1]) was used to assess the hypotheses that aspects of social withdrawal would be predictors of a "snowball" cascade of depressed affect, and that friendship experiences would moderate these effects. Consistent with these hypotheses, multilevel modeling showed that measures of avoidance and exclusion at T1 were associated with concurrent levels of depressed affect and were antecedent to escalating trajectories of depressed affect over time. These accelerating growth curves fit a snowball cascade model. The analyses also showed the protective effects of friendship. Specifically, the snowball effect was limited to avoidant and excluded children who were friendless. Depressed affect did not increase among avoidant and excluded children who were friended.

  8. Trust and cooperation in the public sphere: why Roma people should not be excluded?

    Directory of Open Access Journals (Sweden)

    Dragoş DRAGOMAN

    2014-05-01

    Full Text Available The recent political developments in Romania and other Central and East European countries, marked by rising populism and political extremism, shed light on the essential issue of building a free, tolerant and inclusive public sphere, which is willing to let arguments to be decisive instead of power, status, race or wealth. The current tendencies of socially excluding Roma, indiscriminately taken by populists for unjustified social burden and intolerable racial difference, are a warning for more radical political action that could undermine on the long-run the effort to set up a democratic public space. Excluding from start an entire minority would only encourage future exclusions based on ideology, ethnicity or religion, according to the narrow definition populists use to give to the concept of ‘people’.

  9. Using coronary calcification to exclude an ischemic etiology for cardiomyopathy: A validation study and systematic review.

    Science.gov (United States)

    Premaratne, Manuja; Shamsaei, Mohabbat; Chow, Jonathan D H; Haddad, Tony; Erthal, Fernanda; Curran, Helen; Yam, Yeung; Szczotka, Agnieszka; Mielniczuk, Lisa; Wells, George A; Beanlands, Rob S; Hossain, Alomgir; Chow, Benjamin J W

    2017-03-01

    Preliminary data suggests the absence of coronary artery calcification (CAC) excludes ischemic etiologies of cardiomyopathy. We prospectively validate and perform a systematic review to determine the utility of an Agatston score=0 to exclude the diagnosis of ischemic cardiomyopathy. Patients with newly diagnosed LV dysfunction were prospectively enrolled. Patients underwent CAC imaging and were followed until an etiologic diagnosis of cardiomyopathy was made. Eighty-two patients were enrolled in the study and underwent CAC imaging with 81.7% patients having non-ischemic cardiomyopathy. An Agatston score=0 successfully excluded an ischemic etiology for cardiomyopathy with a specificity of 100% (CI: 74.7-100%) and a positive predictive value of 100% (CI: 85.0%-100%). A systematic literature review was performed and studies were deemed suitable for inclusion if: 1) patients with CHF, cardiomyopathy or LV dysfunction were enrolled, 2) underwent CAC imaging and patients were assessed for an Agatston score=0 or the absence of CAC, and 3) the final etiologic diagnosis (ischemic or non-ischemic) was provided. Eight studies provided sufficient information to calculate operating characteristics for an Agatston score=0 and were combined with our validation cohort for a total of 754 patients. An Agatston score=0 excluded ischemic cardiomyopathy with specificity and positive predictive values of 98.4% (CI: 95.6-99.5%), and 98.3% (CI: 95.5-99.5%), respectively. In patients with cardiomyopathy of unknown etiology, an Agatston score=0 appears to rule out an ischemic etiology. A screening CAC may be a simple and cost-effective method of triaging patients, identifying those who do and do not need additional CAD investigations. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Schoolchildren's consumption of competitive foods and beverages, excluding à la carte.

    Science.gov (United States)

    Kakarala, Madhuri; Keast, Debra R; Hoerr, Sharon

    2010-09-01

    Competitive foods/beverages are those in school vending machines, school stores, snack bars, special sales, and items sold à la carte in the school cafeteria that compete with United States Department of Agriculture (USDA) meal program offerings. Grouping à la carte items with less nutritious items allowed in less regulated venues may obfuscate analysis of the school competitive food environment. Excluding à la carte items from competitive foods, the objectives were to: (1) assess competitive food use by gender, ethnicity, eligibility for free or reduced-price meals, and participation in school meals programs, (2) determine differences between grade levels in energy intakes obtained from food sources, (3) determine the nutrient intake derived from competitive foods for students who consumed them, and (4) determine energy-adjusted differences in 24-hour nutrient intakes of protein, calcium, iron, and other selected nutrients between competitive food consumer and nonconsumers. Competitive foods/beverages use, excluding à la carte items, was examined using the third School Nutrition Dietary Assessment Study (SNDA III), a nationally representative sample of 2309 schoolchildren in grades 1 to 12. Mean nutrient intakes were adjusted for energy intake and other covariates, and differences between consumers and nonconsumers of competitive items were determined using analysis of variance and sudaan. Excluding à la carte items, 22% of schoolchildren consumed competitive items in a representative school day and use was highest in high school. Consumers of competitive items other than à la carte had significantly higher mean energy, sugar intakes, and lower sodium, dietary fiber, B vitamins, and iron intakes than nonconsumers. Use of competitive foods/beverages, excluding à la carte, was detrimental to children's diet quality.

  11. Ionic Asymmetry and Solvent Excluded Volume Effects on Spherical Electric Double Layers: A Density Functional Approach

    Energy Technology Data Exchange (ETDEWEB)

    Medasani, Bharat; Ovanesyan, Zaven; Thomas, Dennis G.; Sushko, Maria L.; Marucho, Marcelo

    2014-05-29

    In this article we present a classical density functional theory for electrical double layers of spherical macroions that extends the capabilities of conventional approaches by accounting for electrostatic ion correlations, size asymmetry and excluded volume effects. The approach is based on a recent approximation introduced by Hansen-Goos and Roth for the hard sphere excess free energy of inhomogeneous fluids (J. Chem. Phys. 124, 154506). It accounts for the proper and efficient description of the effects of ionic asymmetry and solvent excluded volume, especially at high ion concentrations and size asymmetry ratios including those observed in experimental studies. Additionally, we utilize a leading functional Taylor expansion approximation of the ion density profiles. In addition, we use the Mean Spherical Approximation for multi-component charged hard sphere fluids to account for the electrostatic ion correlation effects. These approximations are implemented in our theoretical formulation into a suitable decomposition of the excess free energy which plays a key role in capturing the complex interplay between charge correlations and excluded volume effects. We perform Monte Carlo simulations in various scenarios to validate the proposed approach, obtaining a good compromise between accuracy and computational cost. We use the proposed computational approach to study the effects of ion size, ion size asymmetry and solvent excluded volume on the ion profiles, integrated charge, mean electrostatic potential, and ionic coordination number around spherical macroions in various electrolyte mixtures. Our results show that both solvent hard sphere diameter and density play a dominant role in the distribution of ions around spherical macroions, mainly for experimental water molarity and size values where the counterion distribution is characterized by a tight binding to the macroion, similar to that predicted by the Stern model.

  12. Clean Water Act (excluding Section 404). Environmental guidance program reference book: Revision 6

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-15

    This Reference Book contains a current copy of the Clean Water Act (excluding Section 404) and those regulations that implement the statutes and appear to be most relevant to US Department of Energy (DOE) activities. The document is provided to DOE and contractor staff for informational purposes only and should not be interpreted as legal guidance. Updates that include important new requirements will be provided periodically. Questions concerning this Reference Book may be directed to Mark Petts, EH-231 (202/586-2609).

  13. A discrete fibre dispersion method for excluding fibres under compression in the modelling of fibrous tissues.

    Science.gov (United States)

    Li, Kewei; Ogden, Ray W; Holzapfel, Gerhard A

    2018-01-01

    Recently, micro-sphere-based methods derived from the angular integration approach have been used for excluding fibres under compression in the modelling of soft biological tissues. However, recent studies have revealed that many of the widely used numerical integration schemes over the unit sphere are inaccurate for large deformation problems even without excluding fibres under compression. Thus, in this study, we propose a discrete fibre dispersion model based on a systematic method for discretizing a unit hemisphere into a finite number of elementary areas, such as spherical triangles. Over each elementary area, we define a representative fibre direction and a discrete fibre density. Then, the strain energy of all the fibres distributed over each elementary area is approximated based on the deformation of the representative fibre direction weighted by the corresponding discrete fibre density. A summation of fibre contributions over all elementary areas then yields the resultant fibre strain energy. This treatment allows us to exclude fibres under compression in a discrete manner by evaluating the tension-compression status of the representative fibre directions only. We have implemented this model in a finite-element programme and illustrate it with three representative examples, including simple tension and simple shear of a unit cube, and non-homogeneous uniaxial extension of a rectangular strip. The results of all three examples are consistent and accurate compared with the previously developed continuous fibre dispersion model, and that is achieved with a substantial reduction of computational cost. © 2018 The Author(s).

  14. Excluded-Mean-Variance Neural Decision Analyzer for Qualitative Group Decision Making

    Directory of Open Access Journals (Sweden)

    Ki-Young Song

    2012-01-01

    Full Text Available Many qualitative group decisions in professional fields such as law, engineering, economics, psychology, and medicine that appear to be crisp and certain are in reality shrouded in fuzziness as a result of uncertain environments and the nature of human cognition within which the group decisions are made. In this paper we introduce an innovative approach to group decision making in uncertain situations by using a mean-variance neural approach. The key idea of this proposed approach is to compute the excluded mean of individual evaluations and weight it by applying a variance influence function (VIF; this process of weighting the excluded mean by VIF provides an improved result in the group decision making. In this paper, a case study with the proposed excluded-mean-variance approach is also presented. The results of this case study indicate that this proposed approach can improve the effectiveness of qualitative decision making by providing the decision maker with a new cognitive tool to assist in the reasoning process.

  15. Social work and artefacts

    DEFF Research Database (Denmark)

    Høybye-Mortensen, Line Matilde

    2015-01-01

    Socialarbejderes brug af artefakter—altså objekter såsom papir, computer og plastikmodeller—i klientrelationer bliver sjældent undersøgt. Som oftest fokuserer forskningen på interpersonelle relationer, målgrupper, professionelle kompetencer og indsatstyper samt metoder i socialt arbejde. I en und...

  16. Artefacts that talk

    DEFF Research Database (Denmark)

    Hasse, Cathrine

    2013-01-01

    -phenomenology and cultural– historical activity theory to capture the embodied, cultural and historical learning processes initiated when technologies engage with humans in professional work life. Moreover, the article invokes the concept of relational agency as useful for capturing how staff may question the distribution...... of expertise between humans and machines...

  17. The reports of thick discs' deaths are greatly exaggerated. Thick discs are NOT artefacts caused by diffuse scattered light

    Science.gov (United States)

    Comerón, S.; Salo, H.; Knapen, J. H.

    2018-02-01

    Recent studies have made the community aware of the importance of accounting for scattered light when examining low-surface-brightness galaxy features such as thick discs. In our past studies of the thick discs of edge-on galaxies in the Spitzer Survey of Stellar Structure in Galaxies - the S4G - we modelled the point spread function as a Gaussian. In this paper we re-examine our results using a revised point spread function model that accounts for extended wings out to more than 2\\farcm5. We study the 3.6 μm images of 141 edge-on galaxies from the S4G and its early-type galaxy extension. Thus, we more than double the samples examined in our past studies. We decompose the surface-brightness profiles of the galaxies perpendicular to their mid-planes assuming that discs are made of two stellar discs in hydrostatic equilibrium. We decompose the axial surface-brightness profiles of galaxies to model the central mass concentration - described by a Sérsic function - and the disc - described by a broken exponential disc seen edge-on. Our improved treatment fully confirms the ubiquitous occurrence of thick discs. The main difference between our current fits and those presented in our previous papers is that now the scattered light from the thin disc dominates the surface brightness at levels below μ 26 mag arcsec-2. We stress that those extended thin disc tails are not physical, but pure scattered light. This change, however, does not drastically affect any of our previously presented results: 1) Thick discs are nearly ubiquitous. They are not an artefact caused by scattered light as has been suggested elsewhere. 2) Thick discs have masses comparable to those of thin discs in low-mass galaxies - with circular velocities vc< 120 km s-1 - whereas they are typically less massive than the thin discs in high-mass galaxies. 3) Thick discs and central mass concentrations seem to have formed at the same epoch from a common material reservoir. 4) Approximately 50% of the up

  18. Unicompartmental knee arthroplasty MRI: impact of slice-encoding for metal artefact correction MRI on image quality, findings and therapy decision

    Energy Technology Data Exchange (ETDEWEB)

    Agten, Christoph A.; Pfirrmann, Christian W.A.; Sutter, Reto [Balgrist University Hospital, Radiology Department, Zurich (Switzerland); University of Zurich, Faculty of Medicine, Zurich (Switzerland); Grande, Filippo del [Regional Hospital, Radiology, Lugano (Switzerland); Fucentese, Sandro F.; Blatter, Samuel [University of Zurich, Faculty of Medicine, Zurich (Switzerland); Balgrist University Hospital, Orthopedics, Zurich (Switzerland)

    2015-07-15

    To evaluate the impact of slice-encoding for metal artefact correction (SEMAC) on image quality, findings, and therapy decision in patients with unicompartmental knee arthroplasty (UKA). Forty-five painful UKAs were examined at 1.5T-MRI (STIR, proton-density(PD)-weighted sequence, each with SEMAC and high-bandwidth). Artefact size, image quality, anatomic depiction, and clinically relevant findings were compared between SEMAC and high-bandwidth (2 readers). In 30 patients, therapy decision was retrospectively assessed by two orthopaedic surgeons without MRI, with high-bandwidth-MRI, and with SEMAC-MRI. SEMAC reduced mean artefact size for STIR (11.8 cm{sup 2} vs. 37.7 cm{sup 2}) and PD (16.8 cm{sup 2} vs. 18.9 cm{sup 2}), p < 0.0005 for both comparisons. SEMAC showed more blurring than high-bandwidth, p < 0.0005. STIR-SEMAC revealed more bone marrow oedema (29 vs. 18 patients, p = 0.001, 30 vs. 13 patients, p < 0.0005, for reader 1 and 2 respectively). PD-SEMAC was worse in detecting meniscal lesions (6 missed, p = 0.031, 9 missed, p = 0.004, by reader 1 and 2 respectively) than PD-high-bandwidth. Revision-surgery was chosen in 12 and 11 patients without MRI (surgeon 1 and 2), with high-bandwidth-MRI in 15 and 14 patients, and with SEMAC-MRI in 19 and 14 patients. STIR-SEMAC was useful in detecting bone marrow oedema and influenced the orthopaedic surgeons' decisions towards surgery, while PD-SEMAC showed no clinical benefit. (orig.)

  19. Metallic artefact reduction with monoenergetic dual-energy CT: systematic ex vivo evaluation of posterior spinal fusion implants from various vendors and different spine levels

    Energy Technology Data Exchange (ETDEWEB)

    Guggenberger, R.; Winklhofer, S.; Andreisek, G.; Alkadhi, H.; Stolzmann, P. [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Osterhoff, G.; Wanner, G.A. [University Hospital Zurich, Department of Surgery, Division of Trauma Surgery, Zurich (Switzerland); Fortunati, M. [The Spine Center, Thun (Switzerland)

    2012-11-15

    To evaluate optimal monoenergetic dual-energy computed tomography (DECT) settings for artefact reduction of posterior spinal fusion implants of various vendors and spine levels. Posterior spinal fusion implants of five vendors for cervical, thoracic and lumbar spine were examined ex vivo with single-energy (SE) CT (120 kVp) and DECT (140/100 kVp). Extrapolated monoenergetic DECT images at 64, 69, 88, 105 keV and individually adjusted monoenergy for optimised image quality (OPTkeV) were generated. Two independent radiologists assessed quantitative and qualitative image parameters for each device and spine level. Inter-reader agreements of quantitative and qualitative parameters were high (ICC = 0.81-1.00, {kappa} = 0.54-0.77). HU values of spinal fusion implants were significantly different among vendors (P < 0.001), spine levels (P < 0.01) and among SECT, monoenergetic DECT of 64, 69, 88, 105 keV and OPTkeV (P < 0.01). Image quality was significantly (P < 0.001) different between datasets and improved with higher monoenergies of DECT compared with SECT (V = 0.58, P < 0.001). Artefacts decreased significantly (V = 0.51, P < 0.001) at higher monoenergies. OPTkeV values ranged from 123-141 keV. OPTkeV according to vendor and spine level are presented herein. Monoenergetic DECT provides significantly better image quality and less metallic artefacts from implants than SECT. Use of individual keV values for vendor and spine level is recommended. (orig.)

  20. Looking for the Signal: A guide to iterative noise and artefact removal in X-ray tomographic reconstructions of porous geomaterials

    Science.gov (United States)

    Bruns, S.; Stipp, S. L. S.; Sørensen, H. O.

    2017-07-01

    X-ray micro- and nanotomography has evolved into a quantitative analysis tool rather than a mere qualitative visualization technique for the study of porous natural materials. Tomographic reconstructions are subject to noise that has to be handled by image filters prior to quantitative analysis. Typically, denoising filters are designed to handle random noise, such as Gaussian or Poisson noise. In tomographic reconstructions, noise has been projected from Radon space to Euclidean space, i.e. post reconstruction noise cannot be expected to be random but to be correlated. Reconstruction artefacts, such as streak or ring artefacts, aggravate the filtering process so algorithms performing well with random noise are not guaranteed to provide satisfactory results for X-ray tomography reconstructions. With sufficient image resolution, the crystalline origin of most geomaterials results in tomography images of objects that are untextured. We developed a denoising framework for these kinds of samples that combines a noise level estimate with iterative nonlocal means denoising. This allows splitting the denoising task into several weak denoising subtasks where the later filtering steps provide a controlled level of texture removal. We describe a hands-on explanation for the use of this iterative denoising approach and the validity and quality of the image enhancement filter was evaluated in a benchmarking experiment with noise footprints of a varying level of correlation and residual artefacts. They were extracted from real tomography reconstructions. We found that our denoising solutions were superior to other denoising algorithms, over a broad range of contrast-to-noise ratios on artificial piecewise constant signals.

  1. Is metal artefact reduction mandatory in cardiac PET/CT imaging in the presence of pacemaker and implantable cardioverter defibrillator leads?

    Energy Technology Data Exchange (ETDEWEB)

    Ghafarian, Pardis [Shahid Beheshti University, Department of Radiation Medicine, Tehran (Iran, Islamic Republic of); Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Tehran University of Medical Sciences, Research Center for Science and Technology in Medicine, Tehran (Iran, Islamic Republic of); Aghamiri, S.M.R. [Shahid Beheshti University, Department of Radiation Medicine, Tehran (Iran, Islamic Republic of); Ay, Mohammad R. [Tehran University of Medical Sciences, Research Center for Science and Technology in Medicine, Tehran (Iran, Islamic Republic of); Tehran University of Medical Sciences, Department of Medical Physics and Biomedical Engineering, Tehran (Iran, Islamic Republic of); Tehran University of Medical Sciences, Research Institute for Nuclear Medicine, Tehran (Iran, Islamic Republic of); Rahmim, Arman [Johns Hopkins University, Department of Radiology, Baltimore, MD (United States); Schindler, Thomas H. [Geneva University, Cardiovascular Center, Nuclear Cardiology, Geneva (Switzerland); Ratib, Osman [Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland)

    2011-02-15

    Cardiac PET/CT imaging is often performed in patients with pacemakers and implantable cardioverter defibrillator (ICD) leads. However, metallic implants usually produce artefacts on CT images which might propagate to CT-based attenuation-corrected (CTAC) PET images. The impact of metal artefact reduction (MAR) for CTAC of cardiac PET/CT images in the presence of pacemaker, ICD and ECG leads was investigated using both qualitative and quantitative analysis in phantom and clinical studies. The study included 14 patients with various leads undergoing perfusion and viability examinations using dedicated cardiac PET/CT protocols. The PET data were corrected for attenuation using both artefactual CT images and CT images corrected using the MAR algorithm. The severity and magnitude of metallic artefacts arising from these leads were assessed on both linear attenuation coefficient maps ({mu}-maps) and attenuation-corrected PET images. CT and PET emission data were obtained using an anthropomorphic thorax phantom and a dedicated heart phantom made in-house incorporating pacemaker and ICD leads attached at the right ventricle of the heart. Volume of interest-based analysis and regression plots were performed for regions related to the lead locations. Bull's eye view analysis was also performed on PET images corrected for attenuation with and without the MAR algorithm. In clinical studies, the visual assessment of PET images by experienced physicians and quantitative analysis did not reveal erroneous interpretation of the tracer distribution or significant differences when PET images were corrected for attenuation with and without MAR. In phantom studies, the mean differences between tracer uptake obtained without and with MAR were 10.16{+-}2.1% and 6.86{+-}2.1% in the segments of the heart in the vicinity of metallic ICD or pacemaker leads, and were 4.43{+-}0.5% and 2.98{+-}0.5% in segments far from the leads. Although the MAR algorithm was able to effectively improve

  2. The effect of excluding juveniles on apparent adult olive baboons (Papio anubis) social networks

    Science.gov (United States)

    Fedurek, Piotr; Lehmann, Julia

    2017-01-01

    In recent years there has been much interest in investigating the social structure of group living animals using social network analysis. Many studies so far have focused on the social networks of adults, often excluding younger, immature group members. This potentially may lead to a biased view of group social structure as multiple recent studies have shown that younger group members can significantly contribute to group structure. As proof of the concept, we address this issue by investigating social network structure with and without juveniles in wild olive baboons (Papio anubis) at Gashaka Gumti National Park, Nigeria. Two social networks including all independently moving individuals (i.e., excluding dependent juveniles) were created based on aggressive and grooming behaviour. We used knockout simulations based on the random removal of individuals from the network in order to investigate to what extent the exclusion of juveniles affects the resulting network structure and our interpretation of age-sex specific social roles. We found that juvenile social patterns differed from those of adults and that the exclusion of juveniles from the network significantly altered the resulting overall network structure. Moreover, the removal of juveniles from the network affected individuals in specific age-sex classes differently: for example, including juveniles in the grooming network increased network centrality of adult females while decreasing centrality of adult males. These results suggest that excluding juveniles from the analysis may not only result in a distorted picture of the overall social structure but also may mask some of the social roles of individuals belonging to different age-sex classes. PMID:28323851

  3. Method for excluding salt and other soluble materials from produced water

    Science.gov (United States)

    Phelps, Tommy J [Knoxville, TN; Tsouris, Costas [Oak Ridge, TN; Palumbo, Anthony V [Oak Ridge, TN; Riestenberg, David E [Knoxville, TN; McCallum, Scott D [Knoxville, TN

    2009-08-04

    A method for reducing the salinity, as well as the hydrocarbon concentration of produced water to levels sufficient to meet surface water discharge standards. Pressure vessel and coflow injection technology developed at the Oak Ridge National Laboratory is used to mix produced water and a gas hydrate forming fluid to form a solid or semi-solid gas hydrate mixture. Salts and solids are excluded from the water that becomes a part of the hydrate cage. A three-step process of dissociation of the hydrate results in purified water suitable for irrigation.

  4. Chip-excluding in Lathe Cutting 1st. Report : Chip Form Geometry I

    OpenAIRE

    小尾, 誠; 岩里, 茂; 丹沢, 常正

    1981-01-01

    The cfficiency of chip-excluding in lathe cutting is very often determined by chip forms. So, the relation between the chip form and cutting conditions must be explained from the point of view of not only practical experiences but also theoretical studies. Here in the paper, the basic equation for chip forms has been derived analytically and the chip forms are simulated on the basis of an assumption that the chip is formed by certain herahedrons which are piled. By this study the following re...

  5. 5 CFR 919.420 - May I approve a transaction with an excluded or disqualified person at a lower tier?

    Science.gov (United States)

    2010-01-01

    ... excluded or disqualified person at a lower tier? 919.420 Section 919.420 Administrative Personnel OFFICE OF... a transaction with an excluded or disqualified person at a lower tier? If a transaction at a lower tier is subject to your approval, you as an agency official may not approve— (a) A covered transaction...

  6. 31 CFR 19.420 - May I approve a transaction with an excluded or disqualified person at a lower tier?

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false May I approve a transaction with an excluded or disqualified person at a lower tier? 19.420 Section 19.420 Money and Finance: Treasury Office... transaction with an excluded or disqualified person at a lower tier? If a transaction at a lower tier is...

  7. 20 CFR 10.818 - How is a provider notified of OWCP's intent to exclude him or her?

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false How is a provider notified of OWCP's intent to exclude him or her? 10.818 Section 10.818 Employees' Benefits OFFICE OF WORKERS' COMPENSATION... How is a provider notified of OWCP's intent to exclude him or her? The Regional Director shall...

  8. 20 CFR 30.718 - How is a provider notified of OWCP's intent to exclude him or her?

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false How is a provider notified of OWCP's intent to exclude him or her? 30.718 Section 30.718 Employees' Benefits OFFICE OF WORKERS' COMPENSATION... OWCP's intent to exclude him or her? The Regional Director shall initiate the exclusion process by...

  9. 9 CFR 130.16 - User fees for veterinary diagnostic serology tests performed at NVSL (excluding FADDL) or at...

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for veterinary diagnostic serology tests performed at NVSL (excluding FADDL) or at authorized sites. 130.16 Section 130.16 Animals... USER FEES § 130.16 User fees for veterinary diagnostic serology tests performed at NVSL (excluding...

  10. 9 CFR 130.19 - User fees for other veterinary diagnostic services or materials provided at NVSL (excluding FADDL).

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for other veterinary... User fees for other veterinary diagnostic services or materials provided at NVSL (excluding FADDL). (a) User fees for other veterinary diagnostic services or materials available from NVSL (excluding FADDL...

  11. Prejudice in practitioners who work with socially excluded people in Andalusia: A dual process approach

    Directory of Open Access Journals (Sweden)

    José-Luis Álvarez-Castillo

    2016-12-01

    Full Text Available It is assumed that the professional profile of those who work with socially excluded people is not compatible with the maintenance of prejudices against the group they help. The current study tested this hypothesis regarding the Dual Process Cognitive-Motivational Model of Duckitt (2001 and Duckitt and Sibley (2010. Data from 565 Andalusian professionals were collected in a cross-sectional survey, using measures of socio-demographics, personality, values, ideological attitudes, political position, and prejudice. The model fitted to data reproduced the basic relations in the hypothesized model, although its explanatory power was limited. Prejudice was significantly explained by both paths (authoritarianism and dominance, leading to the conclusion that the reduced level of prejudice held by professionals corresponds to the perception of socially excluded people as a dissident group. This suggests that professional identity as a broad construct may moderate the variance in prejudice. Finally, these findings also suggest that the professional development of social workers should be promoted.

  12. MRI of the breast in patients with DCIS to exclude the presence of invasive disease

    Energy Technology Data Exchange (ETDEWEB)

    Deurloo, Eline E. [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Radiology, Amsterdam (Netherlands); Sriram, Jincey D.; Rutgers, Emiel J.T. [Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Surgery, Amsterdam (Netherlands); Teertstra, Hendrik J.; Loo, Claudette E. [Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Radiology, Amsterdam (Netherlands); Wesseling, Jelle [Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Pathology, Amsterdam (Netherlands); Gilhuijs, Kenneth G.A. [Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Radiology, Amsterdam (Netherlands); University Medical Center Utrecht, Department of Radiology, Image Sciences Institute, Utrecht (Netherlands)

    2012-07-15

    Core biopsy underestimates invasion in more than 20% of patients with preoperatively diagnosed ductal carcinoma in situ (DCIS) without evidence of invasion (pure DCIS). The aim of the current study was to evaluate the efficacy of preoperative magnetic resonance imaging (MRI) to discriminate between patients with DCIS who are at high risk of invasive breast cancer and patients at low risk. One hundred and twenty-five patients, preoperatively diagnosed with pure DCIS (128 lesions; 3 bilateral) by core-needle biopsy, were prospectively included. Clinical, mammographic, histological (core biopsy) and MRI features were assessed. All patients underwent breast surgery. Analyses were performed to identify features associated with presence of invasion. Eighteen lesions (14.1%) showed invasion on final histology. Seventy-three lesions (57%) showed suspicious enhancement on MRI with a type 1 (n = 12, 16.4%), type 2 (n = 19, 26.0%) or type 3 curve, respectively (n = 42, 57.5%). At multivariate analysis, the most predictive features for excluding presence of invasive disease were absence of enhancement or a type 1 curve on MRI (negative predictive value 98.5%; A{sub Z} 0.80, P = 0.00006). Contrast medium uptake kinetics at MRI provide high negative predictive value to exclude presence of invasion and may be useful in primary surgical planning in patients with a preoperative diagnosis of pure DCIS. (orig.)

  13. A comparison of trapping techniques (Coleoptera: Carabidae, Buprestidae, Cerambycidae, and Curculionoidea excluding Scolytinae)

    Science.gov (United States)

    Skvarla, Michael J.; Dowling, Ashley P. G.

    2017-01-01

    Beetles (Coleoptera) are a charismatic group of insects targeted by collectors and often used in biodiversity surveys. As part of a larger project, we surveyed a small (4 hectare) plot in the Boston Mountains of Arkansas using 70 traps of 12 trap types and Berlese–Tullgren extraction of leaf litter and identified all Buprestidae, Carabidae, Cerambycidae, and Curculionoidea (Anthribidae, Attelabidae, Brachyceridae, Brentidae, and Curculionidae excluding Scolytinae) to species. This resulted in the collection of 7,973 specimens representing 242 species arranged in 8 families. In a previous publication, we reported new state records and the number of specimens collected per species. In this publication, we used these data to determine the most effective collection method for four beetle groups: Carabidae, Cerambycidae, Curculionoidea (excluding Scolytinae), and Buprestidae. We found that the combination of pitfall and Malaise traps was most effective for Carabidae, Cerambycidae, and Curculionoidea, but that the combination of Malaise and green Lindgren funnel traps was most effective at collecting Buprestidae. Species accumulation curves did not become asymptotic and extrapolated rarefaction curves did not become asymptotic until 350–1,000 samples, suggesting that much more effort is required to completely inventory even a small site. Additionally, seasonal activity is presented for each species and the similarity and overlap between collecting dates and seasons is discussed for each family. PMID:28042105

  14. Tuberculosis peer educators: personal experiences of working with socially excluded communities in London.

    Science.gov (United States)

    Croft, L A; Hayward, A C; Story, A

    2013-10-01

    Peer education is a relatively unexplored intervention for tuberculosis (TB) control, particularly among socially excluded communities. In London, peer educators are used to raise awareness of TB and promote uptake of radiological screening among people using homeless and/or drug and alcohol treatment services. To understand the motivation and personal impact of being a peer educator on people with experience of anti-tuberculosis treatment, homelessness and addiction. In-depth semi-structured interviews with peer educators were recorded and transcribed, and then analysed using a grounded theory approach to identify themes. Reflexivity and thick description were used to support transparency of findings. Becoming a peer educator supports individuals in making sense of past experiences and renewing their sense of self. The role places value on personal experience and the communication approach this supports. The project environment is an important motivator, providing the peer with structure, social support and respect. Being a peer educator with experience of homelessness and addiction can be beneficial and empowering and help long-term recovery. Peers are an underused resource for strengthening TB control among socially excluded populations. There is a need for further research into the contribution of peers to TB control, including analyses of economic effectiveness.

  15. The Gore Excluder AAA endoprosthesis with C3 delivery system: results in high-volume centers.

    Science.gov (United States)

    Krajcer, Z

    2014-02-01

    The use of endovascular aortic aneurysm repair (EVAR) has increased dramatically, chiefly because of its low perioperative morbidity compared with open surgery. Challenges to the success of EVAR remain, however, with the most important being features of the patient's infrarenal aortic neck anatomy that make optimal placement of the endoprosthesis difficult. These features include a short, wide, severely angulated, or reverse-tapered neck and the presence of calcifications or thrombus. Suboptimal endograft positioning may necessitate use of aortic cuffs, thereby increasing the time and cost of an EVAR procedure, or increase the likelihood of graft migration, which can lead to endoleaks and additional interventions. Efforts to improve outcomes of EVAR and expand its application in patients with challenging aortic neck anatomy have focused on the development of endografts and delivery systems with innovative designs. The low-permeability Gore Excluder AAA endoprosthesis with C3 delivery system, which became available in Europe and the United States in 2010, represents one such design. The C3 system allows the proximal end of the endoprosthesis to be reconstrained after insertion so that the device can, if necessary, be rotated or moved cranially or caudally. Repositioning may facilitate contralateral gate cannulation and placement of the endograft closer to the lowest renal artery (without covering its orifice), thereby possibly decreasing the risk of inadequate sealing and consequent graft migration and endoleaks. Early clinical studies of the Gore Excluder AAA endoprosthesis with C3 delivery system have yielded promising results.

  16. Computer assisted strain-gauge plethysmography is a practical method of excluding deep venous thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, A.J.P.; Chakraverty, S.; Wright, J

    2001-01-01

    AIM: To evaluate a computed strain-gauge plethysmograph (CSGP) as a screening tool to exclude above knee deep venous thrombosis (DVT). METHODS: The first phase took place in the Radiology department. One hundred and forty-nine patients had both Doppler ultrasound and CSGP performed. Discordant results were resolved by venography where possible. The second phase took place in an acute medical admissions ward using a modified protocol. A further 173 patients had both studies performed. The results were collated and analysed. RESULTS: Phase 1. The predictive value of a negative CSGP study was 98%. There were two false-negative CSGP results (false-negative rate 5%), including one equivocal CSGP study which had deep venous thrombosis on ultrasound examination. Two patients thought to have thrombus on ultrasound proved not to have acute thrombus on venography. Phase 2. The negative predictive value of CSGP using a modified protocol was 97%. There were two definite and one possible false-negative studies (false-negative rate 4-7%). CONCLUSION: Computer strain-gauge plethysmograph can provide a simple, cheap and effective method of excluding lower limb DVT. However, its use should be rigorously assessed in each hospital in which it is used. Goddard, A.J.P., Chakraverty, S. and Wright, J. (2001)

  17. Stainless-steel wires exclude gulls from a wastewater treatment plant

    Science.gov (United States)

    Clark, Daniel E.; Koenen, Kiana K. G.; MacKenzie, Kenneth G.; Pereira, Jillian W.; DeStefano, Stephen

    2013-01-01

    There is growing concern about the prevalence of pathogens and antibiotic-resistant bacteria in the environment and the role wildlife plays in their transmission and dissemination. Gulls feeding at wastewater treatment plants may provide a route for transmission of pathogens and bacteria to public water supplies or other critical areas. The authors identified gulls routinely feeding at a wastewater treatment plant in Millbury, Mass., and tested the effectiveness of overhead stainless-steel wires in excluding gulls from the plant. The number of gulls in certainstructures was compared before and after wiring and during an experimental approach using simultaneous treatments and controls. Stainless-steel wires spaced at 0.9-3.3 m (3-10 ft) effectively prevented gulls from using treatment structures (p 24 months. Materials costs to wire all structures was about $5,700, and labor costs were $4,020. Overhead stainless-steel wires can provide a long-term, cost-efficient method of excluding ring-billed gulls from wastewater treatment plants.

  18. A systematic review of clinical trials of treatments for the congenital ichthyoses, excluding ichthyosis vulgaris.

    Science.gov (United States)

    Hernández-Martin, Angela; Aranegui, Beatriz; Martin-Santiago, Ana; Garcia-Doval, Ignacio

    2013-10-01

    The ichthyoses comprise a group of inherited disorders of keratinization. Because of the need for lifelong treatment, it is important that therapies are beneficial, safe, and well tolerated. We sought to review the evidence on existing treatments for the congenital ichthyoses, excluding ichthyosis vulgaris. We undertook a systematic review using the methodology of the Cochrane Collaboration. Articles published in MEDLINE, EMBASE, and CENTRAL and registered clinical trials were screened. Randomized controlled trials involving patients with the inherited ichthyoses, either syndromic or nonsyndromic but excluding ichthyosis vulgaris, were considered. Six trials met the inclusion criteria. Topical treatments including 5% urea, 20% propylene glycol alone or in combination with 5% lactic acid, calcipotriol ointment, and liarozole 5% cream showed therapeutic benefit. Oral liarozole, a retinoic acid metabolism blocking agent, showed no advantage over oral acitretin. Most studies were performed on a small sample of patients and lacked methodological and reporting quality. The small number of trials and the nearly constant positive results make publication bias likely. The absence of standardization of outcome measures precluded the comparison of studies. Topical treatments including emollients, calcipotriol ointment, and liarozole cream seem to have therapeutic benefit and a good safety profile, although the use of topical calcipotriol is limited by a maximum weekly dose of 100 g. The advantage of oral liarozole over acitretin is uncertain. Multicenter trials comparing oral and topical interventions and evaluation of long-term outcomes are needed. Copyright © 2013 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  19. Unanimous versus partial rejection: How the number of excluders influences the impact of ostracism in children.

    Science.gov (United States)

    Sandstrom, Marlene J; Deutz, Marike H F; Lansu, Tessa A M; van Noorden, Tirza H J; Karremans, Johan C; Cillessen, Antonius H N

    2017-04-01

    Previous research has shown that ostracism-the experience of being ignored and excluded-has negative effects on all of us, young and old. Using a Cyberball paradigm, the present research replicates the effects of ostracism on the moods (anger, anxiety, happiness, and anger) and fundamental needs (belongingness, control, meaningful existence, and self-esteem) of children (Study 1) and then extends the literature by examining the role of the number of ostracizers and inclusive members in this process by randomly assigning children to conditions varying in degree of ostracism (Study 2). Results of both studies showed that experiencing ostracism strongly and negatively affected all moods and fundamental needs-with the exception of anxiety. Study 2 in addition showed that the ratio of excluders to inclusive group members had different effects across outcomes. In all cases, complete ostracism produced the worst outcomes, suggesting that the presence of even a single ally reduces children's distress. For sadness, unanimous ostracism seemed particularly toxic. In some cases, facing two ostracizers produced significantly worse outcomes than only one, suggesting that consensual rejection might drive the negative effects on happiness, and sense of belonging, control, and meaningful existence. For self-esteem, only one ostracizer (in the presence of two inclusive members) was sufficient to induce a negative effect. Aggr. Behav. 43:190-203, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Matching excluded-volume hadron-resonance gas models and perturbative QCD to lattice calculations

    Science.gov (United States)

    Albright, M.; Kapusta, J.; Young, C.

    2014-08-01

    We match three hadronic equations of state at low energy densities to a perturbatively computed equation of state of quarks and gluons at high energy densities. One of them includes all known hadrons treated as point particles, which approximates attractive interactions among hadrons. The other two include, in addition, repulsive interactions in the form of excluded volumes occupied by the hadrons. A switching function is employed to make the crossover transition from one phase to another without introducing a thermodynamic phase transition. A χ2 fit to accurate lattice calculations with temperature 100coupling and the hard core radius of protons and neutrons, which turns out to be 0.62±0.04 fm. The most physically reasonable models include the excluded-volume effect. Not only do they include the effects of attractive and repulsive interactions among hadrons, but they also achieve better agreement with lattice QCD calculations of the equation of state. The equations of state constructed in this paper do not result in a phase transition, at least not for the temperatures and baryon chemical potentials investigated. It remains to be seen how well these equations of state will represent experimental data on high-energy heavy-ion collisions when implemented in hydrodynamic simulations.

  1. Removal of pulse artefact from EEG data recorded in MR environment at 3T. Setting of ICA parameters for marking artefactual components: application to resting-state data.

    Science.gov (United States)

    Maggioni, Eleonora; Arrubla, Jorge; Warbrick, Tracy; Dammers, Jürgen; Bianchi, Anna M; Reni, Gianluigi; Tosetti, Michela; Neuner, Irene; Shah, N Jon

    2014-01-01

    Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) allow for a non-invasive investigation of cerebral functions with high temporal and spatial resolution. The main challenge of such integration is the removal of the pulse artefact (PA) that affects EEG signals recorded in the magnetic resonance (MR) scanner. Often applied techniques for this purpose are Optimal Basis Set (OBS) and Independent Component Analysis (ICA). The combination of OBS and ICA is increasingly used, since it can potentially improve the correction performed by each technique separately. The present study is focused on the OBS-ICA combination and is aimed at providing the optimal ICA parameters for PA correction in resting-state EEG data, where the information of interest is not specified in latency and amplitude as in, for example, evoked potential. A comparison between two intervals for ICA calculation and four methods for marking artefactual components was performed. The performance of the methods was discussed in terms of their capability to 1) remove the artefact and 2) preserve the information of interest. The analysis included 12 subjects and two resting-state datasets for each of them. The results showed that none of the signal lengths for the ICA calculation was highly preferable to the other. Among the methods for the identification of PA-related components, the one based on the wavelets transform of each component emerged as the best compromise between the effectiveness in removing PA and the conservation of the physiological neuronal content.

  2. Negative effects overpower the positive of kelp to exclude invertebrates from the understorey community.

    Science.gov (United States)

    Connell, Sean D

    2003-09-01

    Marine macroalgal forests are one of the most widespread and studied habitats on subtidal coasts, but there remain challenges in understanding why many sessile invertebrates are anomalously absent from understorey communities. In a series of experiments on recruitment of invertebrates, I partitioned the habitat-modifying effects of kelp into their positive and negative effects. Experiments revealed that a reduction of light intensity and removal of sediment by canopies acted to facilitate recruitment, but physical abrasion by the canopy acted as a negative force to overpower these positive effects. Understorey assemblages, therefore, represent biased subsets of taxa from a local pool capable of colonization. On balance, negative effects acted to exclude invertebrates from the understorey community. The asymmetric strength of negative effects not only explains the enigma of exclusion but also indicates that, when it exists, understorey coexistence with canopy plants must reflect a more even match between positive and negative effects.

  3. Dyslexic adults can learn from repeated stimulus presentation but have difficulties in excluding external noise.

    Directory of Open Access Journals (Sweden)

    Rachel L Beattie

    Full Text Available We examined whether the characteristic impairments of dyslexia are due to a deficit in excluding external noise or a deficit in taking advantage of repeated stimulus presentation. We compared non-impaired adults and adults with poor reading performance on a visual letter detection task that varied two aspects: the presence or absence of background visual noise, and a small or large stimulus set. There was no interaction between group and stimulus set size, indicating that the poor readers took advantage of repeated stimulus presentation as well as the non-impaired readers. The poor readers had higher thresholds than non-impaired readers in the presence of high external noise, but not in the absence of external noise. The results support the hypothesis that an external noise exclusion deficit, not a perceptual anchoring deficit, impairs reading for adults.

  4. Excluded and behaving unethically: social exclusion, physiological responses, and unethical behavior.

    Science.gov (United States)

    Kouchaki, Maryam; Wareham, Justin

    2015-03-01

    Across 2 studies, we investigated the ethical consequences of physiological responses to social exclusion. In Study 1, participants who were socially excluded were more likely to engage in unethical behavior to make money and the level of physiological arousal experienced during exclusion--measured using galvanic skin response--mediated the effects of exclusion on unethical behavior. Likewise, in Study 2, results from a sample of supervisor-subordinate dyads revealed a positive relationship between experience of workplace ostracism and unethical behaviors as rated by the immediate supervisors. This relationship was mediated by employees' reports of experienced physiological arousal. Together, the results of these studies demonstrate that physiological arousal accompanies social exclusion and provides an explanatory mechanism for the increased unethical behavior in both samples. Theoretical implications of these findings for research on ethical behavior and social exclusion in the workplace are discussed. PsycINFO Database Record (c) 2015 APA, all rights reserved.

  5. [Immunophenotyping of B chronic lymphoproliferative syndromes (CLL excluded): confrontation with the histology].

    Science.gov (United States)

    El Borgi, Wijden; Ben Salah, Nawel; Ben Lakhal, Fatma; Makni, Lamia; Gouider, Emna; Hafsia, Raouf

    2013-01-01

    Immunophenotyping is a major tool for the diagnosis of the chronic lymphoïd leukaemia (CLL). Its interest remains limited in the classification of the other B chronic lymphoproliférative syndromes (B-CLPS). We evaluate the place of the flow cytometry (CMF) in the diagnosis and classification of the non CLL B-CLPS. The cases with Matutes score of 4 or more are excluded. A confrontation of the results to the histology is made. 28 cases of non CLL B-CLPS are diagnosed. CMF shows a κ monoclonal population in 15 cases and λ in 13 cases. A co-expression CD19+CD5 + is found in 11 cases concording with an atypic CLL or a mantel cell lymphoma in 6 cases with Matutes score of 3. In 5 cases, we concluded to non CLL B-CLPS (Matutesconfrontation of the histology results remains essential.

  6. A simple and fast method to exclude high Plasmodium falciparum parasitaemia in travellers with imported malaria.

    Science.gov (United States)

    van Gool, Tom; van Wolfswinkel, Marlies E; Koelewijn, Rob; van Thiel, Pieter P A M; Jacobs, Jan; van Hellemond, Jaap J; van Genderen, Perry J J

    2011-10-14

    Counts of malaria parasites in peripheral blood are important to assess severity of Plasmodium falciparum malaria. Thin and thick smears are routinely used for this purpose. In this study the Binax NOW Malaria Test, an easy-to-perform rapid diagnostic test, with Histidine Rich Protein-2 (HRP-2) and aldolase as diagnostic markers, was used for semi-quantitative assessment of parasitaemia of P. falciparum. In 257 patients with imported P. falciparum malaria, reactivity of aldolase increased with higher parasitaemia. In all patients with a parasitaemia above 50,000 asexual parasites/μl (> 1%) co-reactivity of HRP-2 and aldolase was observed. Absence of aldolase reactivity in the presence of HRP-2 was a reliable predictive marker to exclude high (> 1%) parasitaemia in P. falciparum malaria. Assessment of HRP-2 and aldolase co-reactivity can be of help in clinical decision making in the acute care setting of returning travellers suspected of having malaria.

  7. Comparing Legal Approaches: Mental Disorders as Grounds for Excluding Criminal Responsibility

    Directory of Open Access Journals (Sweden)

    Carl-Friedrich Stuckenberg

    2016-08-01

    Full Text Available The effect of mental disorders on criminal responsibility seems to be more or less the same in all jurisdictions. However, upon a closer look, the details of the regulatory schemes and the practical effects vary considerably and this discord has increased even more in the past 30 years. This article undertakes a brief comparative survey with a focus on substantive criminal law in order to sketch a normative matrix which shows that there are three basic approaches to deal with mental disorders as grounds for excluding criminal responsibility. While psychiatry has made considerable progress over the past 150 years, in providing more humane treatment to mentally ill persons, it is a disturbing observation that the criminal law appears to be significantly less tolerant towards mentally disturbed offenders in modern times than during the previous two millennia.

  8. Excluded-volume effects for a hadron gas in Yang-Mills theory

    CERN Document Server

    Alba, Paolo; Nada, Alessandro; Panero, Marco; Stöcker, Horst

    2016-01-01

    When the multiplicities of particles produced in heavy-ion collisions are fitted to the hadron-resonance-gas model, excluded-volume effects play a significant role. In this work, we study the impact of such effects onto the equation of state of pure Yang-Mills theory at low temperatures, comparing the predictions of the statistical model with lattice results. In particular, we present a detailed analysis of the SU(2) and SU(3) Yang-Mills theories: we find that, for both of them, the best fits to the equilibrium thermodynamic quantities are obtained when one assumes that the volume of different glueball states is inversely proportional to their mass. The implications of these findings for QCD are discussed.

  9. Excluded and avoided: racial microaggressions targeting Asian international students in Canada.

    Science.gov (United States)

    Houshmand, Sara; Spanierman, Lisa B; Tafarodi, Romin W

    2014-07-01

    This qualitative study explored East and South Asian international students' (N = 12) experiences with racial microaggressions at one Canadian university. Data were collected through unstructured, individual interviews. Using a modified version of the consensual qualitative research method (Hill, Thompson, & Williams, 1997), we identified six racial microaggressions themes: (a) excluded and avoided, (b) ridiculed for accent, (c) rendered invisible, (d) disregarded international values and needs, (e) ascription of intelligence, and (f) environmental microaggressions (structural barriers on campus). In addition, we used the same approach to identify themes pertaining to the ways in which students coped with racial microaggressions: (a) engaging with own racial and cultural groups, (b) withdrawing from academic spheres, and (c) seeking comfort in the surrounding multicultural milieu. Microaggressions and coping themes differed based on country of origin and language proficiency. Implications for research and practice are discussed.

  10. Experience with the GORE EXCLUDER iliac branch endoprosthesis for common iliac artery aneurysms.

    Science.gov (United States)

    van Sterkenburg, Steven M M; Heyligers, Jan M M; van Bladel, Mathijs; Verhagen, Hence J; Eefting, Daniël; van Sambeek, Marc R; Zeebregts, Clark J; Reijnen, Michel M P J

    2016-06-01

    In this study, we analyzed the procedural success and early outcome of endovascular treatment of a multicenter cohort of patients with common iliac artery (CIA) aneurysms treated with the new GORE EXCLUDER (W. L. Gore & Associates, Flagstaff, Ariz) iliac branch endoprosthesis (IBE). A retrospective cohort analysis was performed in 13 sites in The Netherlands. Anatomic, demographic, procedural, and follow-up data were assessed from hospital records. From November 2013 to December 2014, 51 CIA aneurysms were treated with an IBE in 46 patients. The median diameter of the treated aneurysm was 40.5 (range, 25.0-90.0) mm. The mean procedural time was 198 ± 56 minutes. All but one implantation were successful; two type Ib endoleaks were noticed, resulting in a procedural success rate of 93.5%. The two type Ib endoleaks spontaneously disappeared at 30 days. There was no 30-day mortality. Ipsilateral buttock claudication was present in only two cases at 30 days and disappeared during follow-up. The incidence of reported erectile dysfunction was low and severe ischemic complications were absent. After a mean follow-up of 6 months, data on 17 treated aneurysms were available. Two showed a stable diameter, whereas 15 showed a mean decrease of 3.9 ± 2.2 mm (P < .001). Reinterventions were performed in two patients (7.1%). The 6-month primary patency of the internal component of the IBE device was 94%. The use of the GORE EXCLUDER IBE device for CIA aneurysms is related to high procedural success, high patency rates, and low reintervention rates at short-term follow-up. Prospective data with longer follow-up are awaited to establish the role of the device in the treatment algorithm of CIA aneurysms. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  11. Accountability and the pressures to exclude: A cautionary tale from England.

    Directory of Open Access Journals (Sweden)

    E. Rustique-Forrester

    2005-04-01

    Full Text Available Recent studies have produced conflicting findings about whether test-based rewards and sanctions create incentives that improve student performance, or hurdles that increase dropout and pushout rates from schools. This article reports the findings from a study that examined the impact of England's accountability reforms and investigated whether the confluent pressures associated with increased testing, school ranking systems, and other sanctions contributed to higher levels of student exclusion (expulsion and suspension. The study found that England's high-stakes approach to accountability, combined with the dynamics of school choice and other curriculum and testing pressures led to a narrowing of the curriculum, the marginalization of low-performing students, and a climate perceived by teachers to be less tolerant of students with academic and behavioral difficulties. A comparison of higher- and lower-excluding schools, however, found that these effects were more pronounced in the higher-excluding schools, which lacked strong systems and internal structures for supporting staff communication, teacher collaboration, and students' individual needs. The study offers an international perspective on recent trends toward greater accountability in education, pointing to a complex inter-relationship between the pressures of national policies and the unintended consequences on schools' organizational and teachers' instructional capacities. The study's findings raise particular implications for the United States and show that in the design of accountability systems, attention must be paid to how the pressures from accountability will affect the capacity of schools and teachers to respond to students who are low-performing and struggling academically.

  12. Increasing the efficiency of bacterial transcription simulations: When to exclude the genome without loss of accuracy

    Directory of Open Access Journals (Sweden)

    McMillen David R

    2008-09-01

    Full Text Available Abstract Background Simulating the major molecular events inside an Escherichia coli cell can lead to a very large number of reactions that compose its overall behaviour. Not only should the model be accurate, but it is imperative for the experimenter to create an efficient model to obtain the results in a timely fashion. Here, we show that for many parameter regimes, the effect of the host cell genome on the transcription of a gene from a plasmid-borne promoter is negligible, allowing one to simulate the system more efficiently by removing the computational load associated with representing the presence of the rest of the genome. The key parameter is the on-rate of RNAP binding to the promoter (k_on, and we compare the total number of transcripts produced from a plasmid vector generated as a function of this rate constant, for two versions of our gene expression model, one incorporating the host cell genome and one excluding it. By sweeping parameters, we identify the k_on range for which the difference between the genome and no-genome models drops below 5%, over a wide range of doubling times, mRNA degradation rates, plasmid copy numbers, and gene lengths. Results We assess the effect of the simulating the presence of the genome over a four-dimensional parameter space, considering: 24 min Conclusion Exclusion of the genome is shown to yield less than 5% difference in transcript numbers over wide ranges of values, and computational speed is improved by two to 24 times by excluding explicit representation of the genome.

  13. Oral Challenge without Skin Testing Safely Excludes Clinically Significant Delayed-Onset Penicillin Hypersensitivity.

    Science.gov (United States)

    Confino-Cohen, Ronit; Rosman, Yossi; Meir-Shafrir, Keren; Stauber, Tali; Lachover-Roth, Idit; Hershko, Alon; Goldberg, Arnon

    Penicillins are the drug family most commonly associated with hypersensitivity reactions. Current guidelines recommend negative skin tests (ST) before re-administering penicillins to patients with previous nonimmediate reactions (NIR). The objective of this study was to examine whether ST are necessary before re-administering penicillin to patients with NIR. Patients with NIR to penicillins starting longer than 1 hour after last dose administration or starting any time after the first treatment day or patients with vague recollection of their reaction underwent penicillin ST. Disregarding ST results, patients were challenged with the relevant penicillins. One-tenth of the therapeutic dose followed by the full dose was administered at 1-hour interval and patients continued taking the full dose for 5 days. A total of 710 patients with alleged BL allergy were evaluated. Patients with a history of immediate reaction (52, 7.3%) or cephalosporin allergy (16, 2.2%) were excluded. Of the remaining 642 patients, 62.3% had negative ST, 5.3% positive ST, and 32.4% equivocal ST. A total of 617 (96.1%) patients were challenged. Immediate reaction was observed in 9 patients (1.5%): 1-positive ST, 7-negative ST, and 1-equivocal ST (P = .7). Late reaction to the first-day challenge occurred in 24 patients (4%). An at-home challenge was continued by 491 patients. Complete 5-day and partial challenges were well tolerated by 417 (85%) and 44 patients (8.9%), respectively, disregarding ST results. Thirty patients (6.1%) developed mild reactions to the home challenge regardless of their ST results. A 5-day oral challenge without preceding ST is safe and sufficient to exclude penicillin allergy after NIR developing during penicillin treatment. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  14. Template-based automatic breast segmentation on MRI by excluding the chest region.

    Science.gov (United States)

    Lin, Muqing; Chen, Jeon-Hor; Wang, Xiaoyong; Chan, Siwa; Chen, Siping; Su, Min-Ying

    2013-12-01

    Methods for quantification of breast density on MRI using semiautomatic approaches are commonly used. In this study, the authors report on a fully automatic chest template-based method. Nonfat-suppressed breast MR images from 31 healthy women were analyzed. Among them, one case was randomly selected and used as the template, and the remaining 30 cases were used for testing. Unlike most model-based breast segmentation methods that use the breast region as the template, the chest body region on a middle slice was used as the template. Within the chest template, three body landmarks (thoracic spine and bilateral boundary of the pectoral muscle) were identified for performing the initial V-shape cut to determine the posterior lateral boundary of the breast. The chest template was mapped to each subject's image space to obtain a subject-specific chest model for exclusion. On the remaining image, the chest wall muscle was identified and excluded to obtain clean breast segmentation. The chest and muscle boundaries determined on the middle slice were used as the reference for the segmentation of adjacent slices, and the process continued superiorly and inferiorly until all 3D slices were segmented. The segmentation results were evaluated by an experienced radiologist to mark voxels that were wrongly included or excluded for error analysis. The breast volumes measured by the proposed algorithm were very close to the radiologist's corrected volumes, showing a % difference ranging from 0.01% to 3.04% in 30 tested subjects with a mean of 0.86% ± 0.72%. The total error was calculated by adding the inclusion and the exclusion errors (so they did not cancel each other out), which ranged from 0.05% to 6.75% with a mean of 3.05% ± 1.93%. The fibroglandular tissue segmented within the breast region determined by the algorithm and the radiologist were also very close, showing a % difference ranging from 0.02% to 2.52% with a mean of 1.03% ± 1.03%. The total error by adding the

  15. Should children with overweight or obesity be excluded from height references?

    Science.gov (United States)

    Júlíusson, Pétur B; Brannsether, Bente; Kristiansen, Hege; Hoppenbrouwers, Karel; Bjerknes, Robert; Roelants, Mathieu

    2015-11-01

    Growth reference charts are usually based on measurements of children free from a medical condition that affects growth. However, samples collected during the past decades often contain a large proportion of overweight or obese children. Because obesity increases linear growth, the question arises to what extent the percentiles curves for length/height are affected by the presence of children with overweight or obesity. Data from two cross-sectional samples of 2-year-old to 18-year-old children were analysed: 12,252 Belgian children, measured in 2002-2004, and 6159 Norwegian children, measured in 2003-2006. The LMS method was used to estimate height-for-age curves with and without children considered overweight or obese according to the International Obesity Task Force thresholds. The prevalence of overweight (including obesity) and obesity was 13.0% and 2.8% in the Belgian and 13.8% and 2.3% in the Norwegian sample. Children were taller when overweight (+0.49 and 0.43 SD, in the Belgian and Norwegian sample, respectively) or obese (+0.73 and 0.72 SD in the Belgian and Norwegian sample, respectively). Effect sizes were smaller in younger and older children, which points to an advanced age of maturation as a possible cause. Excluding overweight and obese children had only a minor impact on the growth curves with largest difference in mean height SD scores -0.09 in the Belgian and -0.12 in the Norwegian sample with a corresponding increase of up to 0.5% and 1.2% in number of children >+2 SD. Current Belgian and Norwegian growth references for length/height were found to be largely unaffected by the current proportion of overweight and obese children. There is, therefore, no need for revised height charts that exclude overweight or obese children. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  16. Underestimating intraspecific variation: the problem with excluding Sts 19 from Australopithecus africanus.

    Science.gov (United States)

    Ahern, J C

    1998-04-01

    Two analyses conclude that Sts 19 cannot be accommodated within the Australopithecus africanus hypodigm (Kimbel and Rak [1993] In Kimbel and Martin [eds.]: Species, Species Concepts, and Primate Evolution. New York: Plenum, pp. 461-484; Sarmiento [1993] Am. J. Phys. Anthropol. [Suppl.] 16:173). Both studies exclude Sts 19 because it possesses synapomorphies with Homo. Furthermore, according to Kimbel and Rak (1993), including Sts 19 in A. africanus results in an unacceptably high degree of polymorphism. This study aims to refute the null hypothesis that Sts 19 belongs to A. africanus. Twelve basicranial characters, as defined and implemented in Kimbel and Rak's study, were scored for casts of seven A. africanus and seven Homo habilis basicranial specimens. These characters were also examined on specimens from a large (N = 87) sample of African pongids. Contrary to Kimbel and Rak's (1993) findings, the null hypothesis is not refuted. The degree of polymorphism among A. africanus with Sts 19 included is less than that seen in Pan troglodytes. In addition, Sts 19 shares only one apomorphy with Homo. However, when treated metrically, Sts 19's morphology for this character is not significantly divergent from other A. africanus specimens.

  17. Strategies to exclude subjects who conceal and fabricate information when enrolling in clinical trials

    Directory of Open Access Journals (Sweden)

    Eric G. Devine

    2017-03-01

    Full Text Available Clinical trials within the US face an increasing challenge with the recruitment of quality candidates. One readily available group of subjects that have high rates of participation in clinical research are subjects who enroll in multiple trials for the purpose of generating income through study payments. Aside from issues of safety and generalizability, evidence suggests that these subjects employ methods of deception to qualify for the strict entrance criteria of some studies, including concealing information and fabricating information. Including these subjects in research poses a significant risk to the integrity of data quality and study designs. Strategies to limit enrollment of subjects whose motivation is generating income have not been systematically addressed in the literature. The present paper is intended to provide investigators with a range of strategies for developing and implementing a study protocol with protections to minimize the enrollment of subjects whose primary motivation for enrolling is to generate income. This multifaceted approach includes recommendations for advertising strategies, payment strategies, telephone screening strategies, and baseline screening strategies. The approach also includes recommendations for attending to inconsistent study data and subject motivation. Implementing these strategies may be more or less important depending upon the vulnerability of the study design to subject deception. Although these strategies may help researchers exclude subjects with a higher rate of deceptive practices, widespread adoption of subject registries would go a long way to decrease the chances of subjects enrolling in multiple studies or more than once in the same study.

  18. Innovation Chinese rice wine brewing technology by bi-acidification to exclude rice soaking process.

    Science.gov (United States)

    Wei, Xiao Lu; Liu, Shuang Ping; Yu, Jian Shen; Yu, Yong Jian; Zhu, Sheng Hu; Zhou, Zhi Lei; Hu, Jian; Mao, Jian

    2017-04-01

    As a traditional fermented alcoholic beverage of China, Chinese rice wine (CRW) had a long history of more than 5000 years. Rice soaking process was the most crucial step during CRW brewing process, because rice soaking quality directly determined the quality of CRW. However, rice soaking water would cause the eutrophication of water bodies and waste of water. The longer time of rice soaking, the higher the content of biogenic amine, and it would have a huge impact on human health. An innovation brewing technology was carried out to exclude the rice soaking process and the Lactobacillus was added to make up for the total acid. Compared to the traditional brewing technology, the new technology saved water resources and reduced environmental pollution. The concentration of biogenic amine was also decreased by 27.16%, which improving the security of the CRW. The esters increased led to more soft-tasted CRW and less aging time; the quality of CRW would be improved with less alcohol. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  19. CONTRIBUTION TO THE KNOWLEDGE OF THE ARACHNIDS IN THE YUCATAN PENINSULA, MEXICO (EXCLUDING ARANAE AND ACARI

    Directory of Open Access Journals (Sweden)

    Hugo Delfin Gonzalez

    2017-08-01

    Full Text Available The Chelicerata are the second group of arthropods with the highest diversity after insects and they can inhabit almost all types of environments. The most current classification recognizes 11 orders and estimates in the number of species vary from 52,000 to 100,000. We have made an extensive literature review on the diversity of arachnids in the Yucatan Peninsula (YP (excluding spiders and ticks. In Mexico there are 834 known species which represent 6% of the worldwide diversity. In the YP 63 records were found (58 species and 5 genera of arachnids, which represent 6.8% of the Mexican species. According to our research, 28 of the 58 species (48% in the YP were also record in other parts of Mexico, the continent and the world. Undoubtedly, the state of Yucatan is the best represented of the YP. In order to have a better understanding of the diversity of arachnid species is important to promote biological compendiums and sampling programs, which will improve the representation of this group and probably increasing the number of local species.

  20. Excluding the poor from accessing biomedical literature: a rights violation that impedes global health.

    Science.gov (United States)

    Yamey, Gavin

    2008-01-01

    Most biomedical journals charge readers a hefty access toll to read the full text version of a published research article. These tolls bring enormous profits to the traditional corporate publishing industry, but they make it impossible for most people worldwide--particularly in low and middle income countries--to access the biomedical literature. Traditional publishers also insist on owning the copyright on these articles, making it illegal for readers to freely distribute and photocopy papers, translate them, or create derivative educational works. This article argues that excluding the poor from accessing and freely using the biomedical research literature is harming global public health. Health care workers, for example, are prevented from accessing the information they need to practice effective medicine, while policymakers are prevented from accessing the essential knowledge they require to build better health care systems. The author proposes that the biomedical literature should be considered a global public good, basing his arguments upon longstanding and recent international declarations that enshrine access to scientific and medical knowledge as a human right. He presents an emerging alternative publishing model, called open access, and argues that this model is a more socially responsive and equitable approach to knowledge dissemination.

  1. Genome-wide association study of handedness excludes simple genetic models

    Science.gov (United States)

    Armour, J AL; Davison, A; McManus, I C

    2014-01-01

    Handedness is a human behavioural phenotype that appears to be congenital, and is often assumed to be inherited, but for which the developmental origin and underlying causation(s) have been elusive. Models of the genetic basis of variation in handedness have been proposed that fit different features of the observed resemblance between relatives, but none has been decisively tested or a corresponding causative locus identified. In this study, we applied data from well-characterised individuals studied at the London Twin Research Unit. Analysis of genome-wide SNP data from 3940 twins failed to identify any locus associated with handedness at a genome-wide level of significance. The most straightforward interpretation of our analyses is that they exclude the simplest formulations of the ‘right-shift' model of Annett and the ‘dextral/chance' model of McManus, although more complex modifications of those models are still compatible with our observations. For polygenic effects, our study is inadequately powered to reliably detect alleles with effect sizes corresponding to an odds ratio of 1.2, but should have good power to detect effects at an odds ratio of 2 or more. PMID:24065183

  2. Two-year-olds exclude novel objects as potential referents of novel words based on pragmatics.

    Science.gov (United States)

    Grassmann, Susanne; Stracke, Marén; Tomasello, Michael

    2009-09-01

    Many studies have established that children tend to exclude objects for which they already have a name as potential referents of novel words. In the current study we asked whether this exclusion can be triggered by social-pragmatic context alone without pre-existing words as blockers. Two-year-old children watched an adult looking at a novel object while saying a novel word with excitement. In one condition the adult had not seen the object beforehand, and so the children interpreted the adult's utterance as referring to the gazed-at object. In another condition the adult and child had previously played jointly with the gazed-at object. In this case, children less often assumed that the adult was referring to the object but rather they searched for an alternative referent--presumably because they inferred that the gazed-at object was old news in their common ground with the adult and so not worthy of excited labeling. Since this inference based on exclusion is highly similar to that underlying the Principle of Contrast/Mutual Exclusivity, we propose that this principle is not purely lexical but rather is based on children's understanding of how and why people direct one another's attention to things either with or without language.

  3. A simple and fast method to exclude high Plasmodium falciparum parasitaemia in travellers with imported malaria

    Directory of Open Access Journals (Sweden)

    Jacobs Jan

    2011-10-01

    Full Text Available Abstract Background Counts of malaria parasites in peripheral blood are important to assess severity of Plasmodium falciparum malaria. Thin and thick smears are routinely used for this purpose. Methods In this study the Binax NOW® Malaria Test, an easy-to-perform rapid diagnostic test, with Histidine Rich Protein-2 (HRP-2 and aldolase as diagnostic markers, was used for semi-quantitative assessment of parasitaemia of P. faciparum. Results In 257 patients with imported P. falciparum malaria, reactivity of aldolase increased with higher parasitaemia. In all patients with a parasitaemia above 50,000 asexual parasites/μl (> 1% co-reactivity of HRP-2 and aldolase was observed. Absence of aldolase reactivity in the presence of HRP-2 was a reliable predictive marker to exclude high (> 1% parasitaemia in P. falciparum malaria. Conclusions Assessment of HRP-2 and aldolase co-reactivity can be of help in clinical decision making in the acute care setting of returning travellers suspected of having malaria.

  4. The 'empowered client' in vocational rehabilitation: the excluding impact of inclusive strategies.

    Science.gov (United States)

    van Hal, Lineke B E; Meershoek, Agnes; Nijhuis, Frans; Horstman, Klasien

    2012-09-01

    In vocational rehabilitation, empowerment is understood as the notion that people should make an active, autonomous choice to find their way back to the labour process. Following this line of reasoning, the concept of empowerment implicitly points to a specific kind of activation strategy, namely labour participation. This activation approach has received criticism for being paternalistic, disciplining and having a one-sided orientation on labour participation. Although we share this theoretical criticism, we want to go beyond it by paying attention to the practical consequences of understanding empowerment as an activation strategy. Inspired by the field of Science and Technology Studies, we will explore the meaning of empowerment and activation in concrete practices of vocational rehabilitation in the Netherlands. Our analysis is based on the narratives of people with a work disability about their lives and the vocational rehabilitation programmes they participated in. We present five illustrative cases that how empowerment is 'done' in the practice of vocational rehabilitation and its unintended effects. Our analysis demonstrates that activation strategies seem to be caught in a paradox: instead of including people in society, they have excluding consequences. Vocational rehabilitation professionals can go beyond this paradox by learning from the ways in which empowerment is 'done' by clients in vocational rehabilitation programmes.

  5. Re-Appraisal of Estrogen Receptor Negative/Progesterone Receptor Positive (ER-/PR+) Breast Cancer Phenotype: True Subtype or Technical Artefact?

    Science.gov (United States)

    Foley, Niamh M; Coll, J M; Lowery, A J; Hynes, S O; Kerin, M J; Sheehan, M; Brodie, C; Sweeney, K J

    2017-09-11

    Expression of the ER and PR receptors is routinely quantified in breast cancer as a predictive marker of response to hormonal therapy. Accurate determination of ER and PR status is critical to the optimal selection of patients for targeted therapy. The existence of an ER-/PR+ subtype is controversial, with debate centred on whether this represents a true phenotype or a technical artefact on immunohistochemistry (IHC). The aim of this study was to investigate the true incidence and clinico-pathological features of ER-/PR+ breast cancers in a tertiary referral symptomatic breast unit. Clinico-pathological data were collected on invasive breast cancers diagnosed between 1995 and 2005. IHC for ER and PR receptors was repeated on all cases which were ER-/PR+, with the same paraffin block used for the initial diagnostic testing. Concordance between the diagnostic and repeat IHC was determined using validated testing. Complete data, including ER and PR status were available for 697 patients diagnosed during the study period. On diagnostic IHC, the immunophenotype of the breast tumours was: ER+/PR+ in 396 (57%), ER-/PR- in 157 (23%), ER+/PR- in 88 (12%) and ER-/PR+ in 56 (8.6%) patients. On repeat IHC of 48/56 ER-/PR+ tumours 45.8% were ER+/PR+, 6% were ER+/PR- and 43.7% were ER-/PR- None of the cases were confirmed to be ER-/PR+. The ER-/PR+ phenotypic breast cancer is likely to be the result of technical artefact. Prompt reassessment of patients originally assigned to this subtype who re-present with symptoms should be considered to ensure appropriate clinical management.

  6. [Potentially excluded population from health coverage and health impact since Royal Decree 16/2012: The Central Catalonia experience].

    Science.gov (United States)

    Álamo-Junquera, Dolores; Sala, Núria; Millet, Joan-Pau; Ortega-Gutiérrez, Lluïsa; Planas-Giner, Albert; Rovira, Carol; Comet, Dolors

    2015-01-01

    To assess the proportion of population potentially excluded from healthcare coverage since the Royal Decree-Law 16/2012. To describe the use of health services, the distribution of chronic and infectious diseases, and the pharmaceutical costs in 2012 of the persons potentially excluded compared to the those who maintain their coverage. An observational analytical cross-sectional study was designed and conducted on a Primary Care based population in the Central Catalonia Management Area of the Institut Català de la Salut PARTICIPANTS AND MAIN MEASUREMENTS: Individuals potentially excluded since the application of the Royal Decree-Law 16/2012 were selected and compared with individuals who maintained their healthcare coverage, randomly matched by sex, age and Primary Care service. The information obtained included the use of health services, the distribution of chronic and infectious diseases, and the pharmaceutical costs during the year 2012. A total of 1,699 individuals were identified as potentially excluded from healthcare coverage, 0.53% of the total of population (51.4% men), with a median of age of 34years (interquartile range, 28-43). The use of healthcare services, the chronic morbidity recorded, and the pharmaceutical costs during the year 2012 of the excluded individuals was lower than those of the non-excluded ones (P<.001). On the other hand, the infectious morbidity was higher in the excluded individuals (P<.001). The results of the study suggests that this legislative measure does not seem to be justified for medical or economic reasons. It could also cause public health problems and contribute to the risk of social fracture. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  7. Gas-induced susceptibility artefacts on diffusion-weighted MRI of the rectum at 1.5 T - Effect of applying a micro-enema to improve image quality.

    Science.gov (United States)

    van Griethuysen, Joost J M; Bus, Elyse M; Hauptmann, Michael; Lahaye, Max J; Maas, Monique; Ter Beek, Leon C; Beets, Geerard L; Bakers, Frans C H; Beets-Tan, Regina G H; Lambregts, Doenja M J

    2018-02-01

    Assess whether application of a micro-enema can reduce gas-induced susceptibility artefacts in Single-shot Echo Planar Imaging (EPI) Diffusion-weighted imaging of the rectum at 1.5 T. Retrospective analysis of n = 50 rectal cancer patients who each underwent multiple DWI-MRIs (1.5 T) from 2012 to 2016 as part of routine follow-up during a watch-and-wait approach after chemoradiotherapy. From March 2014 DWI-MRIs were routinely acquired after application of a preparatory micro-enema (Microlax ® ; 5 ml; self-administered shortly before acquisition); before March 2014 no bowel preparation was given. In total, 335 scans were scored by an experienced reader for the presence/severity of gas-artefacts (on b1000 DWI), ranging from 0 (no artefact) to 5 (severe artefact). A score ≥3 (moderate-severe) was considered a clinically relevant artefact. A random sample of 100 scans was re-assessed by a second independent reader to study inter-observer effects. Scores were compared between the scans performed without and with a preparatory micro-enema using univariable and multivariable logistic regression taking into account potential confounding factors (age/gender, acquisition parameters, MRI-hardware, rectoscopy prior to MRI). Clinically relevant gas-artefacts were seen in 24.3% (no micro-enema) vs. 3.7% (micro-enema), odds ratios were 0.118 in univariable and 0.230 in multivariable regression (P = 0.0005 and 0.0291). Mean severity score (±SD) was 1.19 ± 1.71 (no-enema) vs 0.32 ± 0.77 (micro-enema), odds ratios were 0.321 (P < 0.0001) and 0.489 (P = 0.0461) in uni- and multivariable regression, respectively. Inter-observer agreement was excellent (κ0.85). Use of a preparatory micro-enema shortly before rectal EPI-DWI examinations performed at 1.5 T MRI significantly reduces both the incidence and severity of gas-induced artefacts, compared to examinations performed without bowel preparation. Copyright © 2017 Elsevier B.V. All rights

  8. Template-based automatic breast segmentation on MRI by excluding the chest region

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Muqing [Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697-5020 and National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Department of Biomedical Engineering, School of Medicine, Shenzhen University, 518060 China (China); Chen, Jeon-Hor [Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697-5020 and Department of Radiology, E-Da Hospital and I-Shou University, Kaohsiung 82445, Taiwan (China); Wang, Xiaoyong; Su, Min-Ying, E-mail: msu@uci.edu [Tu and Yuen Center for Functional Onco-Imaging, Department of Radiological Sciences, University of California, Irvine, California 92697-5020 (United States); Chan, Siwa [Department of Radiology, Taichung Veterans General Hospital, Taichung 40407, Taiwan (China); Chen, Siping [National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, Department of Biomedical Engineering, School of Medicine, Shenzhen University, 518060 China (China)

    2013-12-15

    Purpose: Methods for quantification of breast density on MRI using semiautomatic approaches are commonly used. In this study, the authors report on a fully automatic chest template-based method. Methods: Nonfat-suppressed breast MR images from 31 healthy women were analyzed. Among them, one case was randomly selected and used as the template, and the remaining 30 cases were used for testing. Unlike most model-based breast segmentation methods that use the breast region as the template, the chest body region on a middle slice was used as the template. Within the chest template, three body landmarks (thoracic spine and bilateral boundary of the pectoral muscle) were identified for performing the initial V-shape cut to determine the posterior lateral boundary of the breast. The chest template was mapped to each subject's image space to obtain a subject-specific chest model for exclusion. On the remaining image, the chest wall muscle was identified and excluded to obtain clean breast segmentation. The chest and muscle boundaries determined on the middle slice were used as the reference for the segmentation of adjacent slices, and the process continued superiorly and inferiorly until all 3D slices were segmented. The segmentation results were evaluated by an experienced radiologist to mark voxels that were wrongly included or excluded for error analysis. Results: The breast volumes measured by the proposed algorithm were very close to the radiologist's corrected volumes, showing a % difference ranging from 0.01% to 3.04% in 30 tested subjects with a mean of 0.86% ± 0.72%. The total error was calculated by adding the inclusion and the exclusion errors (so they did not cancel each other out), which ranged from 0.05% to 6.75% with a mean of 3.05% ± 1.93%. The fibroglandular tissue segmented within the breast region determined by the algorithm and the radiologist were also very close, showing a % difference ranging from 0.02% to 2.52% with a mean of 1.03% ± 1

  9. Limb muscle sound speed estimation by ultrasound computed tomography excluding receivers in bone shadow

    Science.gov (United States)

    Qu, Xiaolei; Azuma, Takashi; Lin, Hongxiang; Takeuchi, Hideki; Itani, Kazunori; Tamano, Satoshi; Takagi, Shu; Sakuma, Ichiro

    2017-03-01

    Sarcopenia is the degenerative loss of skeletal muscle ability associated with aging. One reason is the increasing of adipose ratio of muscle, which can be estimated by the speed of sound (SOS), since SOSs of muscle and adipose are different (about 7%). For SOS imaging, the conventional bent-ray method iteratively finds ray paths and corrects SOS along them by travel-time. However, the iteration is difficult to converge for soft tissue with bone inside, because of large speed variation. In this study, the bent-ray method is modified to produce SOS images for limb muscle with bone inside. The modified method includes three steps. First, travel-time is picked up by a proposed Akaike Information Criterion (AIC) with energy term (AICE) method. The energy term is employed for detecting and abandoning the transmissive wave through bone (low energy wave). It results in failed reconstruction for bone, but makes iteration convergence and gives correct SOS for skeletal muscle. Second, ray paths are traced using Fermat's principle. Finally, simultaneous algebraic reconstruction technique (SART) is employed to correct SOS along ray paths, but excluding paths with low energy wave which may pass through bone. The simulation evaluation was implemented by k-wave toolbox using a model of upper arm. As the result, SOS of muscle was 1572.0+/-7.3 m/s, closing to 1567.0 m/s in the model. For vivo evaluation, a ring transducer prototype was employed to scan the cross sections of lower arm and leg of a healthy volunteer. And the skeletal muscle SOSs were 1564.0+/-14.8 m/s and 1564.1±18.0 m/s, respectively.

  10. Oscillometric casual blood pressure normative standards for Swedish children using ABPM to exclude casual hypertension.

    Science.gov (United States)

    Krmar, Rafael T; Holtbäck, Ulla; Bergh, Anita; Svensson, Eva; Wühl, Elke

    2015-04-01

    Casual blood pressure (CBP) is considered a reliable proxy for cardiovascular health. Although the auscultatory technique is the reference standard method for measuring CBP, oscillometric devices are increasingly being used in children. We sought to establish oscillometric CBP normative standards for Swedish children. Cross-sectional oscillometric CBP readings were obtained by the Welch Allyn Spot Vital Signs 420 monitor and measured according to the International Guidelines' recommendations. Participants with elevated oscillometric CBP levels underwent verification by the auscultatory method. Ambulatory blood pressure monitoring (ABPM) was used to exclude casual hypertension. Data on 1,470 (772 males) apparently healthy Swedish schoolchildren aged 6-16 years were analyzed and sex-specific reference charts normalized to age or height were constructed. Systolic and diastolic CBP values were significantly higher with age, height, height standard deviation score (SDS), body mass index (BMI), and BMI SDS. Gender differences for systolic CBP were present starting from age of 15 years and revealed significantly higher values in boys than in girls, whereas for diastolic CBP, the differences were apparent at the age of 12 years, with higher values in girls. Increased BMI and BMI SDS were positively associated with CBP levels. Positive parental history of hypertension turned out to be a risk factor for higher systolic and diastolic CBP across all ages. Our normative standard for CBP can be used for blood pressure screening and control programs in Swedish children. The use of ABPM should be considered to confirm the diagnosis of casual hypertension. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Why are people with mental illness excluded from the rational suicide debate?

    Science.gov (United States)

    Hewitt, Jeanette

    2013-01-01

    The topic of rational suicide is often approached with some trepidation by mental health professionals. Suicide prevention strategies are more likely to be seen as the domain of psychiatry and a wealth of psychiatric literature is devoted to identifying and managing suicide risk. Whether or not suicide can be deemed permissible is ostensibly linked to discussions of autonomy and mental capacity, and UK legislation directs that a patient's wishes must be respected with regard to treatment refusal where decisional capacity is intact. In the context of the care and treatment of those with physical disorders, extreme and untreatable physical suffering is likely to be accepted as rational grounds for suicide, where the person possesses cognitive coherence and an ability to realistically appreciate the consequences of his or her actions. In the case of those with serious mental disorder, the grounds for accepting that suicide is rational are however less clear-cut. Serious mental illness is typically conceived of as a coercive pressure which prevents rational deliberation and as such, the suicides of those with serious mental illness are considered to be substantially non-voluntary acts arising from constitutive irrationality. Therefore, where an appropriate clinician judges that a person with serious mental disorder is non-autonomous, suicide prevention is likely to be thought legally and morally justified. There are arguably, two questionable assumptions in the position that psychiatry adopts: Firstly, that psychogenic pain is in some way less real than physical pain and secondly, that mental illness invariably means that a desire to die is irrational and inauthentic. If it can be shown that some people with serious mental illness can be rational with regard to suicide and that psychological pain is of equal significance as physical suffering, then it may be possible to conclude that some persons with serious mental illness should not by definition be excluded from the

  12. Initial results of the management of aortoiliac aneurysms with GORE® Excluder® Iliac Branched Endoprosthesis.

    Science.gov (United States)

    Schönhofer, S; Mansour, R; Ghotbi, R

    2015-12-01

    We prospectively observed the outcomes of all patients (N.=15) with an aortoiliac and a common iliac artery aneurysm who were electively treated with the GORE® Excluder® Iliac Branched Endoprosthesis (IBE) with regard to clinical, anatomical and radiological results. We evaluated operative mortality, aneurysm rupture rate and aneurysm related mortality as well as conversion to open surgery, incidence of endoleak, rate of aneurysm migration, aneurysm enlargement, graft patency, reintervention rate and the clinical outcome. Postoperative follow-up included a computed tomography angiography (CTA) before discharge, clinical evaluation and Duplex ultrasound or CTA 3 weeks after the intervention and Duplex ultrasound every 3 months afterwards. Mean patient age was 79 years (range 61-83 years); f/m: 1/2; mean follow-up was 9 months; 80% of the patients presented 2 or more major comorbidities and 1/3 were considered to be not eligible for open repair. Mean hospitalization time was 5 days. Technical success rate was 93.3% (intent-to-treat basis). Mortality within 30 days was 0%; there were no ruptures; type II endoleak directly after the procedure occurred in 20%, dropping to 13.3% after 3 months. We defined the initial technical success in absence of type I endoleaks. The initial technical success rate was 100%. No IBE occlusion or type Ia, Ib or III endoleak was observed during the postoperative follow-up (mean follow-up: 9 months). All of the internal iliac side branches remained patent. Reintervention rate, buttock claudication rate and pelvic complication rate were 0%. The GORE® IBE provides a new and safe alternative for the management of complete endovascular repair of an extensive aortoiliac or common iliac aneurysm while maintaining pelvic blood flow in iliac branched devices. Due to the lower complexity if compared to previous endovascular or hybrid methods, it should be performed in every anatomically suitable case.

  13. Normal pancreatic exocrine function does not exclude MRI/MRCP chronic pancreatitis findings.

    Science.gov (United States)

    Alkaade, Samer; Cem Balci, Numan; Momtahen, Amir Javad; Burton, Frank

    2008-09-01

    Abnormal pancreatic function tests have been reported to precede the imaging findings of chronic pancreatitis. Magnetic resonance imaging (MRI) with magnetic resonance cholangiopancreatography (MRCP) is increasingly accepted as the primary imaging modality for the detection of structural changes of early mild chronic pancreatitis. The aim of this study was to evaluate MRI/MRCP findings in patients with symptoms consistent with chronic pancreatitis who have normal Secretin Endoscopic Pancreatic Function test. A retrospective study of 32 patients referred for evaluation of chronic abdominal pain consistent with chronic pancreatitis and reported normal standard abdominal imaging (ultrasound, computed tomography, or MRI). All patients underwent Secretin Endoscopic Pancreatic Function testing and pancreatic MRI/MRCP at our institution. We reviewed the MRI/MRCP images in patients who had normal Secretin Endoscopic Pancreatic Function testing. MRI/MRCP images were assessed for pancreatic duct morphology, gland size, parenchymal signal and morphology, and arterial contrast enhancement. Of the 32 patients, 23 had normal Secretin Endoscopic Pancreatic Function testing, and 8 of them had mild to marked spectrum of abnormal MRI/MRCP findings that were predominantly focal. Frequencies of the findings were as follows: pancreatic duct stricture (n=3), pancreatic duct dilatation (n=3), side branch ectasia (n=4), atrophy (n=5), decreased arterial enhancement (n=5), decreased parenchymal signal (n=1), and cavity formation (n=1). The remaining15 patients had normal pancreatic structure on MRI/MRCP. Normal pancreatic function testing cannot exclude abnormal MRI/MRCP especially focal findings of chronic pancreatitis. Further studies needed to verify significance of these findings and establish MRI/MRCP imaging criteria for the diagnosis of chronic pancreatitis.

  14. Friedreich's ataxia GAA.TTC duplex and GAA.GAA.TTC triplex structures exclude nucleosome assembly.

    Science.gov (United States)

    Ruan, Haihe; Wang, Yuh-Hwa

    2008-11-07

    Both chromatin structure and formation of triplex DNA at expanded GAA TTC repeats have been shown to regulate the FXN gene silencing, which causes Friedreich's ataxia. Recent studies have suggested that the presence of heterochromatin at the long expanded GAA TTC repeats, which is enriched in hypoacetylated histones, deters the transcription of the FXN gene. However, neither direct histone binding nor the effect of histone acetylation on the GAA TTC duplex or the GAA GAA TTC triplex has been measured in vitro. In this study, GAA TTC repeating DNAs derived from the human FXN gene, and the GAA GAA TTC triplex, were examined for their ability to assemble single nucleosomes and nucleosome arrays. Competitive nucleosome reconstitution assays demonstrated that the GAA TTC duplex excludes nucleosomes (53% decrease compared to the pUC control DNA) and that the GAA GAA TTC triplex further lowers the nucleosome assembly efficiency (82% decrease compared to the duplex DNA). The difference in assembly efficiency is amplified more significantly when hypoacetylated histones are used, compared to assembly with hyperacetylated histones. By analyzing the formation of nucleosome arrays on GAA TTC-containing plasmids, the triplex structure was shown to destabilize the ability of adjacent sequences to assemble nucleosomes. These results provide the first direct binding measurements for the GAA TTC duplex and the GAA GAA TTC triplex, and on the effect of histone acetylation, towards dissecting the role of chromatin structure in silencing of the FXN gene. These findings suggest that these sequences could profoundly alter local chromatin structure, and the discrepancy between in vivo and in vitro results supports recent studies showing that, in addition to DNA sequences, other factors such as epigenetic marks could be involved in the mechanism for inhibition of FXN gene expression.

  15. Analysis of biomechanical parameters extracted from anorectal manometry of fecally-continent and incontinent patients Análisis de parámetros biomecánicos extraídos de la manometría recto-anal de pacientes con continencia e incontinencia fecal Análise de parâmetros biomecânicos extraídos da manometria anorretal de pacientes continentes e com incontinência fecal

    Directory of Open Access Journals (Sweden)

    Bianca Espindola

    2012-12-01

    Full Text Available OBJECTIVE: to evaluate the average resulting area from the Pressure x Time curves resulting from the manometric anorectal exam and compare it with the support capacity of voluntary squeeze. Materials and METHODS: the data set was represented by data from 11 exams from continent patients and eight exams from patients with grade III fecal incontinence. The manometric curves were delineated, and the areas and support capacity of voluntary squeeze calculated, by means of the R computer language and the algorithm developed. RESULTS: the resulting averages for support capacity of voluntary squeeze in continent patients and patients with grade III fecal incontinence were 33.07 seconds and 30.76 seconds (p>0.05 and the averages for area were 2362.04 mmHg x second and 947.92 mmHg x second (pOBJETIVO: evaluar el área media resultante proveniente de las curvas Presión versus Tiempo pertenecientes al examen manometría rectal y afrontarla con la capacidad de sustentación. Materiales y MÉTODOS: la casuística fue representada por datos de 11 exámenes de pacientes moderados y ocho exámenes de pacientes con incontinencia fecal grado III. Por medio del lenguaje computacional R y del algoritmo desarrollado fueron delineadas las curvas manométricas y calculadas las áreas y capacidades de sustentación. RESULTADOS: los medios resultantes de la capacidad de sustentación de pacientes moderados y con incontinencia fecal grado III fueron 33,07 segundos y 30,76 segundos (p>0,05 y las de la área, 2362,04 mmHg x según y 947,92 mmHg x según (pOBJETIVO: avaliar a área média resultante, proveniente das curvas pressão versus tempo, pertencentes ao exame manometria anorretal e confrontá-la com a capacidade de sustentação. MATERIAIS E MÉTODOS: a casuística foi representada por dados de 11 exames de pacientes continentes e oito exames de pacientes com incontinência fecal grau III. Por meio da linguagem computacional R e do algoritmo desenvolvido foram

  16. Effects of excluding a set of random effects on prediction error variance of breeding value.

    Science.gov (United States)

    Cantet, R J

    1997-01-12

    The effects of excluding a set of random effects (U-effects) uncorrelated to breeding values (BV) on prediction error variance (PEV) is studied analytically. Two situations are considered for model comparison: (a) existence of a 'true' model, (b) uncertainty about which of the competing models is 'true'. Models compared are the 'long' one, which includes BV + U-effects, and the 'short' one which includes BV's as the only random systematic effect. Expressions for PEV(BV) were obtained for the long model (PEVL); the short model (PEVS); and the short model assuming the long model is the correct one (PEVSI). It is shown that in general PEVS ≤ PEVL ≤ PEVSI. Results are exemplified by means of an example including a computer simulation. RESUMEN: En este trabajo se estudia analiticamente el efecto de excluir una variable aleatoria (efecto U) no correlacionada con el valor de cría (BV), sobre la varianza del error de predicción de este último (PEV(BV)). Para ello se utilizan dos enfoques de comparación de modelos: (a) existencia de un modelo 'verdadero', (b) incertidumbre respecto de cuál de ambos modelos alternativos es el correcto. Los modelos que se comparan son: el 'largo', que incluye BV+U, y el 'corto', el cuál solo incluye BV. Se obtienen las expresiones para PEV(BV) en las siguientes situaciones: (1) en el modelo largo (PEVL), (2) en el modelo corto (PEVS), y (3) en el modelo corto pero asumiendo que el largo es el verdadero (PEVSI). Se demuestra que en general PEVS ≤ PEVL ≤ PEVSI. Los resultados obtenidos son ilustrados mediante un ejemplo que incluye una simulación estocástica. ZUSAMMENFASSUNG: Veränderung der Fehlervarianz der Zuchtwertvoraussage durch Vernachlässigung einer Gruppe zufäliger Wirkungen. Es wird die Auswirkung der Ausschaltung einer Gruppe zufälliger Wirkungen (U-effects), die mit Zuchtwerten (BV) nicht korreliert sind, auf die Varianz des Voraussage-Fehlers (PEV) analytisch untersucht. Zwei Modelle werden betrachtet: (a

  17. 28 CFR 74.4 - Individuals excluded from compensation pursuant to section 108(B) of the Act.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Individuals excluded from compensation pursuant to section 108(B) of the Act. 74.4 Section 74.4 Judicial Administration DEPARTMENT OF JUSTICE... emancipated minors, on the date they departed the United States for Japan are subject to an irrebuttable...

  18. 21 CFR 1.327 - Who is excluded from all or part of the regulations in this subpart?

    Science.gov (United States)

    2010-04-01

    ... products to all other buyers. (4) A “retail food establishment” includes grocery stores, convenience stores... establishment and not the entire business, which may own numerous retail stores. (g) Persons who manufacture... from all of the requirements in this subpart. A restaurant/retail facility is excluded from all of the...

  19. 34 CFR 85.420 - May I approve a transaction with an excluded or disqualified person at a lower tier?

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false May I approve a transaction with an excluded or disqualified person at a lower tier? 85.420 Section 85.420 Education Office of the Secretary, Department of... lower tier? If a transaction at a lower tier is subject to your approval, you as an agency official may...

  20. 2 CFR 180.420 - May I approve a transaction with an excluded or disqualified person at a lower tier?

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false May I approve a transaction with an excluded or disqualified person at a lower tier? 180.420 Section 180.420 Grants and Agreements OFFICE OF... person at a lower tier? If a transaction at a lower tier is subject to your approval, you as a Federal...

  1. 22 CFR 208.420 - May I approve a transaction with an excluded or disqualified person at a lower tier?

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false May I approve a transaction with an excluded or disqualified person at a lower tier? 208.420 Section 208.420 Foreign Relations AGENCY FOR INTERNATIONAL... lower tier? If a transaction at a lower tier is subject to your approval, you as an agency official may...

  2. 45 CFR 2506.5 - If a debt is not excluded from these regulations, may it be compromised, suspended, terminated...

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false If a debt is not excluded from these regulations, may it be compromised, suspended, terminated, or waived? 2506.5 Section 2506.5 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE COLLECTION...

  3. Mortality of patients excluded from the Danish Verapamil Infarction Trail II. The DAVIT-II Study Group

    DEFF Research Database (Denmark)

    Madsen, J K; Hansen, J F

    1993-01-01

    The 18 month mortality rate in 2180 patients excluded from the Danish Verapamil Infarction Trail II (DAVIT II) was 25.6%. In non-consenters (n = 368) this was 15.0% compared with 13.85 in 897 placebo-treated patients (hazard ratio 1.09 [P = 0.60] when adjusting for sex and age). The increased...

  4. 9 CFR 130.17 - User fees for other veterinary diagnostic laboratory tests performed at NVSL (excluding FADDL) or...

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for other veterinary... FEES USER FEES § 130.17 User fees for other veterinary diagnostic laboratory tests performed at NVSL (excluding FADDL) or at authorized sites. (a) User fees for veterinary diagnostics tests performed at the...

  5. 9 CFR 130.18 - User fees for veterinary diagnostic reagents produced at NVSL or other authorized site (excluding...

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for veterinary diagnostic reagents produced at NVSL or other authorized site (excluding FADDL). 130.18 Section 130.18 Animals and... § 130.18 User fees for veterinary diagnostic reagents produced at NVSL or other authorized site...

  6. Data, Data Everywhere--But Not All the Numbers that Count? Mapping Alternative Provisions for Students Excluded from School

    Science.gov (United States)

    Thomson, Pat; Russell, Lisa

    2009-01-01

    It is now mandatory for English schools to ensure that young people, under 16 years of age, who are excluded from school are placed in an education and training programme within 12 days. The programme must be at least half time, and should offer a meaningful and balanced curriculum. The "Every Child Matters" agenda also suggests that…

  7. A new manometric method for measuring carbon dioxide production ...

    African Journals Online (AJOL)

    This paper describe a technique for carbon dioxide (CO2) measurement based on the displacement of acidifying liquid in burette at constant pressure. It was adapted to allow the growth of ... The CO2 production rate was higher with the parental strain (6.5 mM/ h) than with the variants. The amount of CO2 produced was ...

  8. Model Misspecification When Excluding Instrumental Variables From PS Models in Settings Where Instruments Modify the Effects of Covariates on Treatment

    Science.gov (United States)

    Wyss, Richard; Ellis, Alan R.; Lunt, Mark; Brookhart, M. Alan; Glynn, Robert J.; Stürmer, Til

    2014-01-01

    Theory and simulations show that variables affecting the outcome only through exposure, known as instrumental variables (IVs), should be excluded from propensity score (PS) models. In pharmacoepidemiologic studies based on automated healthcare databases, researchers will sometimes use a single PS model to control for confounding when evaluating the effect of a treatment on multiple outcomes. Because these “full” models are not constructed with a specific outcome in mind, they will usually contain a large number of IVs for any individual study or outcome. If researchers subsequently decide to evaluate a subset of the outcomes in more detail, they can construct reduced “outcome-specific” models that exclude IVs for the particular study. Accurate estimates of PSs that do not condition on IVs, however, can be compromised when simply excluding instruments from the full PS model. This misspecification may have a negligible impact on effect estimates in many settings, but is likely to be more pronounced for situations where instruments modify the effects of covariates on treatment (instrument-confounder interactions). In studies evaluating drugs during early dissemination, the effects of covariates on treatment are likely modified over calendar time and IV-confounder interaction effects on treatment are likely to exist. In these settings, refitting more flexible PS models after excluding IVs and IV-confounder interactions can work well. The authors propose an alternative method based on the concept of marginalization that can be used to remove the negative effects of controlling for IVs and IV-confounder interactions without having to refit the full PS model. This method fits the full PS model, including IVs and IV-confounder interactions, but marginalizes over values of the instruments. Fitting more flexible PS models after excluding IVs or using the full model to marginalize over IVs can prevent model misspecification along with the negative effects of balancing

  9. Clarifying the use of aggregated exposures in multilevel models: self-included vs. self-excluded measures.

    Directory of Open Access Journals (Sweden)

    Etsuji Suzuki

    Full Text Available Multilevel analyses are ideally suited to assess the effects of ecological (higher level and individual (lower level exposure variables simultaneously. In applying such analyses to measures of ecologies in epidemiological studies, individual variables are usually aggregated into the higher level unit. Typically, the aggregated measure includes responses of every individual belonging to that group (i.e. it constitutes a self-included measure. More recently, researchers have developed an aggregate measure which excludes the response of the individual to whom the aggregate measure is linked (i.e. a self-excluded measure. In this study, we clarify the substantive and technical properties of these two measures when they are used as exposures in multilevel models.Although the differences between the two aggregated measures are mathematically subtle, distinguishing between them is important in terms of the specific scientific questions to be addressed. We then show how these measures can be used in two distinct types of multilevel models-self-included model and self-excluded model-and interpret the parameters in each model by imposing hypothetical interventions. The concept is tested on empirical data of workplace social capital and employees' systolic blood pressure.Researchers assume group-level interventions when using a self-included model, and individual-level interventions when using a self-excluded model. Analytical re-parameterizations of these two models highlight their differences in parameter interpretation. Cluster-mean centered self-included models enable researchers to decompose the collective effect into its within- and between-group components. The benefit of cluster-mean centering procedure is further discussed in terms of hypothetical interventions.When investigating the potential roles of aggregated variables, researchers should carefully explore which type of model-self-included or self-excluded-is suitable for a given situation

  10. Cryo-scanning electron microscopy investigation of the Octopus Vulgaris arm structures for the design of an octopus-like arm artefact.

    Science.gov (United States)

    Minnocci, Antonio; Cianchetti, Matteo; Mazzolai, Barbara; Sebastiani, Luca; Laschi, Cecilia

    2015-12-01

    Octopus vulgaris is a cephalopod of the Octopodidae family. It has four pairs of arms and two rows of suckers which perform many functions, including bending and elongation. For this reason the octopus was chosen as model to develop a new generation of soft-body robots. In order to explain some of the fine structures of the octopus arm in relation to its specific ability, we examined the external and internal structures of O. vulgaris arms in a frozen-hydrated state using cryo-scanning electron microscopy. The arms showed skin with a very complex design that is useful to elongation, and a pore pattern distribution on their surface which is functional to cutaneous oxygen uptake. The analysis of freeze-fractured frozen-hydrated arm samples allowed us to describe the developmental differences in the relative proportion of the areas of axial nerve cord, intrinsic and extrinsic musculature, in relation to the growth of the arms and of the increase in functional capability. In the suckers, we analyzed the shedding mechanisms in the outer part of the infundibulum and described the outer and inner characteristics of the denticles, showing in detail their pore system, which is fundamental for their ability to explore the environment. These results are discussed by considering their possible application in the design of new octopus-like artefacts, which will be able to take advantage of some of these ultrastructure characteristics and achieve advanced bioinspired functionalities. © 2015 Wiley Periodicals, Inc.

  11. Hands-on defibrillation and electrocardiogram artefact filtering technology increases chest compression fraction and decreases peri-shock pause duration in a simulation model of cardiac arrest.

    Science.gov (United States)

    Fernando, Shannon M; Cheskes, Sheldon; Howes, Daniel

    2016-07-01

    Reducing pauses during cardiopulmonary resuscitation (CPR) compressions result in better outcomes in cardiac arrest. Artefact filtering technology (AFT) gives rescuers the opportunity to visualize the underlying electrocardiogram (ECG) rhythm during chest compressions, and reduces the pauses that occur before and after delivering a shock. We conducted a simulation study to measure the reduction of peri-shock pause and impact on chest compression fraction (CCF) through AFT. In a simulator setting, participants were given a standardized cardiac arrest scenario and were randomly assigned to perform CPR/defibrillation using the protocol from one of three experimental arms: 1) Standard of Care (pauses for rhythm analysis and shock delivery); 2) AFT (no pauses for rhythm analysis, but a pause for defibrillation); or 3) AFT with hands-on defibrillation (no pauses for rhythm analysis or defibrillation). The primary outcomes were CCF and peri-shock pause duration, with secondary outcomes of pre- and post-shock pause duration. AFT with hands-on defibrillation was found to have the highest CCF (86.4%), as compared to AFT alone (83.8%, pdefibrillation was associated with a reduced peri-shock pause (2.6 seconds) as compared to AFT alone (5.3 seconds, pdefibrillation.

  12. A Lateglacial archaeological site in the far north-west of Europe at Rubha Port an t-Seilich, Isle of Islay, western Scotland: Ahrensburgian-style artefacts, absolute dating and geoarchaeology

    DEFF Research Database (Denmark)

    Mithen, Steven; Wicks, Karen; Pirie, Anne

    2015-01-01

    -west of the European landmass, Scotland, has remained an unexplained exception to this pattern. Although the recently described Hamburgian artefacts from Howburn and an assemblage belonging to the arch-backed point complex from Kilmelfort Cave have established at least a sporadic human presence during earlier stages......The exact pattern, process and timing of the human re-colonization of northern Europe after the end of the last Ice Age remain controversial. Recent research has provided increasingly early dates for at least pioneer explorations of latitudes above 54°N in many regions, yet the far north...... with technological and typological characteristics similar to those of the continental Ahrensburgian at a locality in western Scotland. A preliminary analysis of associated tephra, pollen and phytoliths, along with microstratigraphic analysis, suggest the artefacts represent one or more episodes of human activity...

  13. Calibrating the X-ray attenuation of liquid water and correcting sample movement artefacts during in operando synchrotron X-ray radiographic imaging of polymer electrolyte membrane fuel cells.

    Science.gov (United States)

    Ge, Nan; Chevalier, Stéphane; Hinebaugh, James; Yip, Ronnie; Lee, Jongmin; Antonacci, Patrick; Kotaka, Toshikazu; Tabuchi, Yuichiro; Bazylak, Aimy

    2016-03-01

    Synchrotron X-ray radiography, due to its high temporal and spatial resolutions, provides a valuable means for understanding the in operando water transport behaviour in polymer electrolyte membrane fuel cells. The purpose of this study is to address the specific artefact of imaging sample movement, which poses a significant challenge to synchrotron-based imaging for fuel cell diagnostics. Specifically, the impact of the micrometer-scale movement of the sample was determined, and a correction methodology was developed. At a photon energy level of 20 keV, a maximum movement of 7.5 µm resulted in a false water thickness of 0.93 cm (9% higher than the maximum amount of water that the experimental apparatus could physically contain). This artefact was corrected by image translations based on the relationship between the false water thickness value and the distance moved by the sample. The implementation of this correction method led to a significant reduction in false water thickness (to ∼0.04 cm). Furthermore, to account for inaccuracies in pixel intensities due to the scattering effect and higher harmonics, a calibration technique was introduced for the liquid water X-ray attenuation coefficient, which was found to be 0.657 ± 0.023 cm(-1) at 20 keV. The work presented in this paper provides valuable tools for artefact compensation and accuracy improvements for dynamic synchrotron X-ray imaging of fuel cells.

  14. Should Controls With Respiratory Symptoms Be Excluded From Case-Control Studies of Pneumonia Etiology? Reflections From the PERCH Study.

    Science.gov (United States)

    Higdon, Melissa M; Hammitt, Laura L; Deloria Knoll, Maria; Baggett, Henry C; Brooks, W Abdullah; Howie, Stephen R C; Kotloff, Karen L; Levine, Orin S; Madhi, Shabir A; Murdoch, David R; Scott, J Anthony G; Thea, Donald M; Driscoll, Amanda J; Karron, Ruth A; Park, Daniel E; Prosperi, Christine; Zeger, Scott L; O'Brien, Katherine L; Feikin, Daniel R

    2017-06-15

    Many pneumonia etiology case-control studies exclude controls with respiratory illness from enrollment or analyses. Herein we argue that selecting controls regardless of respiratory symptoms provides the least biased estimates of pneumonia etiology. We review 3 reasons investigators may choose to exclude controls with respiratory symptoms in light of epidemiologic principles of control selection and present data from the Pneumonia Etiology Research for Child Health (PERCH) study where relevant to assess their validity. We conclude that exclusion of controls with respiratory symptoms will result in biased estimates of etiology. Randomly selected community controls, with or without respiratory symptoms, as long as they do not meet the criteria for case-defining pneumonia, are most representative of the general population from which cases arose and the least subject to selection bias. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  15. Joint kinematics estimation using a multi-body kinematics optimisation and an extended Kalman filter, and embedding a soft tissue artefact model.

    Science.gov (United States)

    Bonnet, Vincent; Richard, Vincent; Camomilla, Valentina; Venture, Gentiane; Cappozzo, Aurelio; Dumas, Raphaël

    2017-09-06

    To reduce the impact of the soft tissue artefact (STA) on the estimate of skeletal movement using stereophotogrammetric and skin-marker data, multi-body kinematics optimisation (MKO) and extended Kalman filters (EKF) have been proposed. This paper assessed the feasibility and efficiency of these methods when they embed a mathematical model of the STA and simultaneously estimate the ankle, knee and hip joint kinematics and the model parameters. A STA model was used that provides an estimate of the STA affecting the marker-cluster located on a body segment as a function of the kinematics of the adjacent joints. The MKO and the EKF were implemented with and without the STA model. To assess these methods, intra-cortical pin and skin markers located on the thigh, shank, and foot of three subjects and tracked during the stance phase of running were used. Embedding the STA model in MKO and EKF reduced the average RMS of marker tracking from 12.6 to 1.6mm and from 4.3 to 1.9mm, respectively, showing that a STA model trial-specific calibration is feasible. Nevertheless, with the STA model embedded in MKO, the RMS difference between the estimated and the reference joint kinematics determined from the pin markers slightly increased (from 2.0 to 2.1deg) On the contrary, when the STA model was embedded in the EKF, this RMS difference was slightly reduced (from 2.0 to 1.7deg) thus showing a better potentiality of this method to attenuate STA effects and improve the accuracy of joint kinematics estimate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Evaluation of virtual monoenergetic imaging algorithms for dual-energy carotid and intracerebral CT angiography: Effects on image quality, artefacts and diagnostic performance for the detection of stenosis.

    Science.gov (United States)

    Leithner, Doris; Mahmoudi, Scherwin; Wichmann, Julian L; Martin, Simon S; Lenga, Lukas; Albrecht, Moritz H; Booz, Christian; Arendt, Christophe T; Beeres, Martin; D'Angelo, Tommaso; Bodelle, Boris; Vogl, Thomas J; Scholtz, Jan-Erik

    2018-02-01

    To investigate the impact of traditional (VMI) and noise-optimized virtual monoenergetic imaging (VMI+) algorithms on quantitative and qualitative image quality, and the assessment of stenosis in carotid and intracranial dual-energy CTA (DE-CTA). DE-CTA studies of 40 patients performed on a third-generation 192-slice dual-source CT scanner were included in this retrospective study. 120-kVp image-equivalent linearly-blended, VMI and VMI+ series were reconstructed. Quantitative analysis included evaluation of contrast-to-noise ratios (CNR) of the aorta, common carotid artery, internal carotid artery, middle cerebral artery, and basilar artery. VMI and VMI+ with highest CNR, and linearly-blended series were rated qualitatively. Three radiologists assessed artefacts and suitability for evaluation at shoulder height, carotid bifurcation, siphon, and intracranial using 5-point Likert scales. Detection and grading of stenosis were performed at carotid bifurcation and siphon. Highest CNR values were observed for 40-keV VMI+ compared to 65-keV VMI and linearly-blended images (P evaluation at shoulder and bifurcation height. Suitability was significantly higher in VMI+ and VMI compared to linearly-blended images for intracranial and ICA assessment (P performance. 40-keV VMI+ showed improved quantitative image quality compared to 65-keV VMI and linearly-blended series in supraaortic DE-CTA. VMI and VMI+ provided increased suitability for carotid and intracranial artery evaluation with excellent assessment of stenosis, but did not translate into increased diagnostic performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Assessment of the lower limb soft tissue artefact at marker-cluster level with a high-density marker set during walking.

    Science.gov (United States)

    Barré, Arnaud; Aissaoui, Rachid; Aminian, Kamiar; Dumas, Raphaël

    2017-09-06

    The estimation of joint kinematics from skin markers is hindered by the soft tissue artefact (STA), a well-known phenomenon although not fully characterized. While most assessments of the STA have been performed based on the individual skin markers displacements, recent assessments were based on the marker-cluster geometrical transformations using, e.g., principal component or modal analysis. However, these marker-clusters were generally made of 4-6 markers and the current findings on the STA could have been biased by the limited number of skin makers analysed. The objective of the present study was therefore to confirm them with a high-density marker set, i.e. 40 markers placed on the segments. A larger number of modes than found in the literature was required to describe the STA. Nevertheless, translations and rotations of the marker-cluster remained the main STA modes, archetypally the translation along the proximal-distal and anterior-posterior axes for the shank and the translation along the proximal-distal axis and the rotation about the medial-lateral axis for the thigh. High correlations were also found between the knee flexion angle and the amplitude of these modes for the thigh whereas moderate ones were found for the shank. These findings support the current re-orientation of the STA compensation methods, from bone pose estimators which typically address the non-rigid components of the marker-cluster to kinematic-driven rigid-component STA models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Linkage analysis of primary open-angle glaucoma excludes the juvenile glaucoma region on chromosome 1q

    Energy Technology Data Exchange (ETDEWEB)

    Wirtz, M.K.; Acott, T.S.; Samples, J.R. [Casey Eye Institute, Portland, OR (United States)]|[Oregon Health Sciences Univ., Portland, OR (United States)] [and others

    1994-09-01

    The gene for one form of juvenile glaucoma has been mapped to chromosome 1q21-q31. This raises the possibility of primary open-angle glaucoma (POAG) also mapping to this region if the same defective gene causes both diseases. To ask this question linkage analysis was performed on a large POAG kindred. Blood samples or skin biopsies were obtained from 40 members of this family. Individuals were diagnosed as having POAG if they met two or more of the following criteria: (1) Visual field defects compatible with glaucoma on automated perimetry; (2) Optic nerve head and/or nerve fiber layer analysis compatible with glaucomatous damage; (3) high intraocular pressures (> 20 mm Hg). Patients were considered glaucoma suspects if they only met one criterion. These individuals were excluded from the analysis. Of the 40 members, seven were diagnosed with POAG; four were termed suspects. The earliest age of onset was 38 years old, while the average age of onset was 65 years old. We performed two-point and multipoint linkage analysis, using five markers which encompass the region 1q21-q31; specifically, D1S194, D1S210, D1S212, D1S191 and LAMB2. Two-point lod scores excluded tight linkage with all markers except D1S212 (maximum lod score of 1.07 at theta = 0.0). In the multipoint analysis, including D1S210-D1S212-LAMB2 and POAG, the entire 11 cM region spanned by these markers was excluded for linkage with POAG; that is, lod scores were < -2.0. In conclusion, POAG in this family does not map to chromosome 1q21-q31 and, thus, they carry a gene that is distinct from the juvenile glaucoma gene.

  19. Diagnostic accuracy of plasma NT-proBNP levels for excluding cardiac abnormalities in the very elderly

    Directory of Open Access Journals (Sweden)

    Westendorp Rudi GJ

    2010-11-01

    Full Text Available Abstract Background In the elderly the diagnosis of chronic heart failure is often challenging and the availability of echocardiography can be limited. Plasma levels of NT-proBNP are valuable tools to diagnose patients with heart failure. However, the performance of this biomarker to detect cardiac abnormalities in the very elderly remains unclear. The aims of this study were to investigate the relation between NT-proBNP and cardiac abnormalities and to evaluate the use of NT-proBNP to exclude structural and functional cardiac abnormalities in a community-based sample of "well-functioning" nonagenarians. Methods A diagnostic cross-sectional study embedded within the Leiden 85-plus Study in the municipality of Leiden, the Netherlands. Plasma NT-proBNP levels were measured and 2-dimensional echocardiography was performed in a subgroup of 80 well-functioning nonagenarians. Linear regression analysis was used to explore the relation between NT-proBNP and cardiac abnormalities and ROC curve analysis was used to assess the performance of NT-proBNP to exclude cardiac abnormalities. The upper limit of the lowest tertile of NT-proBNP was used as a cut-off value. Results NT-proBNP levels were associated with abnormal left ventricular (LV dimensions, LV systolic and diastolic function, left atrial enlargement and valvular heart disease. LV mass, E/A ratio and degree of aortic regurgitation were identified as independent predictors of NT-proBNP. NT-proBNP levels were higher with greater number of echocardiographic abnormalities (P Conclusions In this convenience sample of well-functioning nonagenarians NT-proBNP was related to a wide variety of functional and structural echocardiographic abnormalities. Moreover, NT-proBNP could be used to exclude echocardiographic abnormalities in well-functioning nonagenarians and might be used to indicate who needs to be referred for further cardiovascular examination.

  20. A pragmatic randomized controlled trial of computerized CBT (SPARX) for symptoms of depression among adolescents excluded from mainstream education.

    Science.gov (United States)

    Fleming, Theresa; Dixon, Robyn; Frampton, Christopher; Merry, Sally

    2012-10-01

    Adolescents excluded from mainstream education have high mental health needs. The use of computerized Cognitive Behavioural Therapy (cCBT) has not been investigated with this group. To test the efficacy of the SPARX cCBT programme for symptoms of depression among adolescents in programmes for students excluded or alienated from mainstream education. Adolescents (32; 34% Maori, 38% Pacific Island, 56% male) aged 13-16 with Child Depression Rating Scale Revised (CDRS-R) scores indicating possible through to almost certain depressive disorder were randomized to SPARX to be completed over the following 5 weeks (n = 20) or to waitlist control (n = 12). Assessments were at baseline, 5 weeks and 10 weeks. Those in the wait condition were invited to complete SPARX after the 5 week assessment. Most participants (n = 26, 81%) completed at least 4 levels of SPARX and 22 (69%) completed all 7 levels. Among the 30 (94%) participants who began treatment as randomized and provided 5-week data, significant differences were found between cCBT and wait groups on the CDRS-R (baseline to 5-week mean change -14.7 versus -1.1, pDepression Scale (-4.6 vs. +3.2 p = .05) but not on other self-rating psychological functioning scales. In intent-to-treat analyses CDRS-R changes and remission remained significant. Gains were maintained at 10-week follow-up. SPARX appears to be a promising treatment for students with symptoms of depression who are in alternative schooling programmes for those excluded from mainstream education.

  1. How does the use of mobile phones by 16-24 year old socially excluded women affect their capabilities?

    OpenAIRE

    Faith, Rebecca

    2016-01-01

    This research looks at the impact of mobile phone use on the lives and opportunities of 16-24 year-old socially excluded women, using a novel, cross-disciplinary framework of the capability approach and affordances. \\ud \\ud Fieldwork took the form of semi-structured interviews in 2013-14 with 30 women between the ages of 16-24, and four youth workers. The instrumental affordances of mobile phones are examined to understand whether they provide a means to address issues relating to work, healt...

  2. Type specimens of Hymenoptera deposited in the Museu de Zoologia da Universidade de São Paulo, Brazil (excluding Aculeata

    Directory of Open Access Journals (Sweden)

    Helena C. Onody

    2014-01-01

    Full Text Available The present paper lists the type specimens of Hymenoptera, excluding Aculeata, deposited in the Museu de Zoologia da Universidade de São Paulo, Brazil. We record all labels contents and also additional information from MZSP registers, published material, and other available sources. High resolution photographs of holotypes, lectotypes and syntypes are available through links to Specimage - the image database of The Ohio State University, where they are archived. The collection comprises a total of 332 type-specimens (32 holotypes, 266 paratypes, 12 syntypes, 20 paralectotypes and two lectotypes of eight superfamilies, 18 families, 31 subfamilies, 43 genera and 83 species.

  3. 2 CFR 801.137 - Who in the Department of Veterans Affairs may grant an exception to allow an excluded person to...

    Science.gov (United States)

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Who in the Department of Veterans Affairs may grant an exception to allow an excluded person to participate in a covered transaction? 801.137... Veterans Affairs may grant an exception to allow an excluded person to participate in a covered transaction...

  4. Routine screening for postnatal depression in a public health family service unit: a retrospective study of self-excluding women.

    Science.gov (United States)

    Grussu, Pietro; Quatraro, Rosa Maria

    2015-01-01

    At this time, there is limited scientific knowledge about women who exclude themselves from screening programs for postnatal depression. In this retrospective descriptive study, we have sought to investigate the socio-demographic and psycho-social factors of women who withdraw from PND screening of their own accord. Study participants were 525 women attending antenatal classes who later took part in institutional routine screening for PND at the Consultorio Familiare Service of the National Health Service, Italy. The PND screening program consisted of the completion of the postpartum depression predictors inventory-revised and psychological well-being (PWB) questionnaires within eight to nine months of pregnancy, and Edinburgh Postnatal Depression Scale, GHQ-12 and PWB within six to eight weeks after childbirth. The Responders group was made up of 346 subjects - 65.9% of the total sample - who completed the entire program of screening for PND. The Non-Responders group, on the other hand, consisted of 179 subjects - 34.1% of the total sample - who, after childbirth, withdrew from the screening program. Compared to the Responders group, the Non-Responders group showed a greater number of subjects with marital dissatisfaction, and with unemployment as a stressful event. Health professionals who detect marital dissatisfaction and/or unemployment as a stressful event in pregnant women should bear in mind that these individuals, besides being at high risk for depression after delivery, will also tend to exclude themselves from screening for PND.

  5. ECG artefacts after electrode misplacements

    National Research Council Canada - National Science Library

    Thaler, T; Rudiger, A

    2009-01-01

    ...). They can lead to the clinically important false diagnosis of myocardial ischemia. Lateral and inferior myocardial ischemia can be mimicked by an electrode exchange between right and left arm and between right arm and left leg, respectively...

  6. Artefacts for optical surface measurement

    Science.gov (United States)

    Robson, Stuart; Beraldin, J.-Angelo; Brownhill, Andrew; MacDonald, Lindsay

    2011-07-01

    Flexible manufacturing technologies are supporting the routine production of components with freeform surfaces in a wide variety of materials and surface finishes. Such surfaces may be exploited for both aesthetic and performance criteria for a wide range of industries, for example automotive, aircraft, small consumer goods and medial components. In order to ensure conformance between manufactured part and digital design it is necessary to understand, validate and promote best practice of the available measurement technologies. Similar, but currently less quantifiable, measurement requirements also exist in heritage, museum and fine art recording where objects can be individually hand crafted to extremely fine levels of detail. Optical 3D measurement systems designed for close range applications are typified by one or more illumination sources projecting a spot, line or structured light pattern onto a surface or surfaces of interest. Reflections from the projected light are detected in one or more imaging devices and measurements made concerning the location, intensity and optionally colour of the image. Coordinates of locations on the surface may be computed either directly from an understanding of the illumination and imaging geometry or indirectly through analysis of the spatial frequencies of the projected pattern. Regardless of sensing configuration some independent means is necessary to ensure that measurement capability will meet the requirements of a given level of object recording and is consistent for variations in surface properties and structure. As technologies mature, guidelines for best practice are emerging, most prominent at the current time being the German VDI/VDE 2634 and ISO/DIS 10360-8 guidelines. This considers state of the art capabilities for independent validation of optical non-contact measurement systems suited to the close range measurement of table top sized manufactured or crafted objects.

  7. Diabetic artefacts in forensic practice.

    Science.gov (United States)

    Murty, O P

    2009-05-01

    A case is presented where confusion arose about skin lesions and whether they were diabetic or electrical in origin. The deceased was a known diabetic and hypertensive man. A middle-aged person in early fifties was found unconscious in the cell and judicial autopsy was performed. He was facing trial for capital punishment of being allegedly involved in drug trafficking and money laundering. He had few marks over his fingers and foot which were considered to be electric marks produced in electric torture. also had fracture of skull and ischemic necrosis of right side of cerebrum; and contrecoup lesions. Findings are documented with photographs of the lesions. The article also depicts photographs of the scene where the victim had fallen and sustained skull fracture.

  8. Tertiary Artefactness at the Interface

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege

    2006-01-01

    In this chapter I discuss how an aesthetic approach to computing can contribute to the further development of the branch of computing dealing with human use of interactive technology. It is my hypothesis that human-computer interaction can advance if redefined as an aesthetic discipline. More...... specifically, I look into Wartofsky's account on the history of perception, and the function of art in this. The potential of this account in relation to human-computer interaction is to place experience and culture as first order aspects to be integrated with the traditional foci on cognition and work...

  9. Excluding the typical patient

    DEFF Research Database (Denmark)

    Odlaug, Brian Lawrence; Weinhandl, Eric; Mancebo, Maria C

    2014-01-01

    Over the past 30 years, clinical trials have resulted in several successful pharmacotherapies for obsessive-compulsive disorder (OCD), yet patients in clinical settings often report inadequate response. This study compares clinical characteristics of treatment-seeking OCD patients to the inclusion...

  10. Open lateral internal anal sphincterotomy under local anesthesia as the gold standard in the treatment of chronic anal fissures: A prospective clinical and manometric study Esfinterotomía lateral interna abierta con anestesia local como gold standard en el tratamiento de la fisura anal crónica: Estudio prospectivo clínico y manométrico a largo plazo

    Directory of Open Access Journals (Sweden)

    A. Sánchez Romero

    2004-12-01

    hipertonía esfinteriana (mecanismo etiopatogénico fundamental de la fisura, permitiendo por tanto, disminuir la proctalgia y así la curación de la fisura. Material y métodos: realizamos un estudio prospectivo de 120 pacientes intervenidos por fisura anal crónica con esfinterotomía lateral interna abierta con anestesia local (20 cc mepivacaína al 2% tratados ambulatoriamente en la consulta de la Unidad de Proctología entre los años 1998-2001. No se requirió estudios preoperatorios, preparación con enemas, profilaxis antibiótica, accesos venosos, ingreso ni observación hospitalaria. Los pacientes fueron revisados a la 1ª semana, 2º mes, 6º mes y al año. Resultados: complicaciones precoces (1ª semana: 3 hematoma-equimosis de la herida (2,5%, 3 hemorragias autolimitadas (2,5%. No encontramos trombosis hemorroidales, fístulas, abscesos perianales ni mortalidad. Complicaciones tardías (2º mes: 9 pacientes con incontinencia (7,5% y 3 pacientes (2,5% con recurrencia de la fisura. Al 6º mes, la incontinencia disminuyó al 5% (6 pacientes, y aparecieron 3 pacientes más con recurrencia de la fisura (2,5%. Al año se mantuvo la tasa de incontinencia del 5% (a gases y líquidos y aparecieron otros 3 pacientes con recurrencia de la fisura (2,5%. Recurrencia global del 7,5%. Los hallazgos en la manometría fueron, PMB (presión máxima basal pre-tratamiento similar a la PMB en pacientes con recurrencia de la fisura, así como la PMB del grupo control similar a la PMB de pacientes con curación. La PMB en pacientes incontinentes fue más baja que la PMB en pacientes continentes (55 ± 7 frente a 80,7 ± 21. La diferencia entre la PMCV (presión máxima de contracción voluntaria en pacientes incontinentes y pacientes continentes no fue estadísticamente significativa. Conclusiones: la esfinterotomía lateral interna abierta con anestesia local tiene una tasa de curación a largo plazo y unos índices de morbilidad equiparables a otras técnicas, por lo que puede

  11. Normative and counter-normative stress messages and symptom reporting: implications for health promotion and a methodological artefact for stress research.

    Science.gov (United States)

    Ferguson, Eamonn; Lawrence, Claire

    2013-05-01

    are at best ineffective. Demonstrating for the first time that only when the stress-coping-symptom links are made explicit do the theoretical associations observed in the literature emerge. This may be a potential methodological artefact in stress research that needs to be controlled. © 2013 The British Psychological Society.

  12. The effect of metal artefact reduction on CT-based attenuation correction for PET imaging in the vicinity of metallic hip implants: A phantom study

    Science.gov (United States)

    Harnish, Roy; Prevrhal, Sven; Alavi, Abass; Zaidi, Habib; Lang, Thomas

    2014-01-01

    Background To determine if metal artefact reduction (MAR) combined with a priori knowledge of prosthesis material composition can be applied to obtain CT-based attenuation maps with sufficient accuracy for quantitative assessment of 18F-fluorodeoxyglucose uptake in lesions near metallic prostheses. Methods A custom hip prosthesis phantom with a lesion-sized cavity filled with 0.2 ml 18F-FDG solution having an activity of 3.367 MBq adjacent to a prosthesis bore was imaged twice with a chrome-cobalt steel hip prosthesis and a plastic replica, respectively. Scanning was performed on a clinical hybrid PET/CT system equipped with an additional external 137Cs transmission source. PET emission images were reconstructed from both phantom configurations with CT-based attenuation correction (CTAC) and with CT-based attenuation correction using MAR (MARCTAC). To compare results with the attenuation-correction method extant prior to the advent of PET/CT, we also carried out attenuation correction with 137Cs transmission-based attenuation correction (TXAC). CTAC and MARCTAC images were scaled to attenuation coefficients at 511 keV using a tri-linear function that mapped the highest CT values to the prosthesis alloy attenuation coefficient. Accuracy and spatial distribution of the lesion activity was compared between the three reconstruction schemes. Results Compared to the reference activity of 3.37 MBq, the estimated activity quantified from the PET image corrected by TXAC was 3.41 MBq. The activity estimated from PET images corrected by MARCTAC was similar in accuracy at 3.32 MBq. CTAC corrected PET images resulted in nearly 40% overestimation of lesion activity at 4.70 MBq. Comparison of PET images obtained with the plastic and metal prostheses in place showed that CTAC resulted in a marked distortion of the 18F-FDG distribution within the lesion, whereas application of MARCTAC and TXAC resulted in lesion distributions similar to those observed with the plastic replica

  13. Relationship between growth and standard metabolic rate: measurement artefacts and implications for habitat use and life-history adaptation in salmonids.

    Science.gov (United States)

    Rosenfeld, Jordan; Van Leeuwen, Travis; Richards, Jeffrey; Allen, David

    2015-01-01

    Mass-specific standard metabolic rate (SMR, or maintenance metabolism) varies greatly among individuals. Metabolism is particularly sensitive to variation in food consumption and growth creating the potential for significant bias in measured SMR for animals that are growing (e.g. juveniles) or of uncertain nutritional status. Consequently, interpreting individual variation in metabolism requires a sound understanding of the potentially confounding role of growth and the relative importance of fixed (genetic) vs. environmental drivers of SMR variation. We review the role of growth in measured SMR variation in juvenile salmonids, with the goals of (i) understanding the contribution of growth (and food consumption) to SMR variation through ontogeny, (ii) understanding the relative contributions of tissue maintenance and biosynthesis (overhead costs of growth) to apparent SMR variation, and (iii) using intrinsic growth effects on SMR to model how alternate life-history strategies may influence growth and measured SMR in juvenile salmonids. SMR measures on juveniles, even when post-absorptive, may be inflated by delayed growth-associated overhead costs, unless juveniles are on a maintenance ration (i.e. not growing). Empirical measurements of apparent SMR in food restricted vs. satiated 2-5 g juvenile salmon demonstrate that estimates may be inflated by as much as 67% due to delayed overhead costs of growth, even when SMR measurements are taken 35 h post-feeding. These results indicate that a substantial component of variation in apparent SMR among juvenile salmonids may be associated with (i) environmentally driven variation in ration (where elevated SMR measurements are an artefact of delayed growth overhead costs), (ii) intrinsic (genetic) or plastic organ-system trade-offs related to increasing investment in metabolically expensive digestive tissue responsible for processing food and (iii) intrinsic (genetic) variation in maximum body size and growth among

  14. Mild extraction methods using aqueous glucose solution for the analysis of natural dyes in textile artefacts dyed with Dyer's madder (Rubia tinctorum L.).

    Science.gov (United States)

    Ford, Lauren; Henderson, Robert L; Rayner, Christopher M; Blackburn, Richard S

    2017-03-03

    efficient process that preserves these sensitive molecules and is a step-change in analysis of madder dyed textiles as it can provide further information about historical dye preparation and dyeing processes that current methods cannot. The method also efficiently extracts glycosides in artificially aged samples, making it applicable for museum textile artefacts. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Preliminary Experience with the GORE(®) EXCLUDER(®) Iliac Branch Endoprosthesis for Common Iliac Aneurysm Endovascular Treatment.

    Science.gov (United States)

    Millon, Antoine; Della Schiava, Nellie; Arsicot, Matthieu; De Lambert, Alberic; Feugier, Patrick; Magne, Jean Luc; Lermusiaux, Patrick

    2016-05-01

    The aim of this study is to assess the safety and the short-term results of endovascular treatment of common iliac artery (CIA) aneurysms using the new GORE EXCLUDER iliac branch endoprosthesis (IBE) device. The study is a retrospective with prospective follow-up nonrandomized, single-arm evaluation. Patients with a CIA aneurysm (diameter >30 mm) extending to the iliac bifurcation underwent endovascular treatment with the Gore IBE. Anatomic and procedural data were collected. Computed tomography angiography (CTA) was performed within the 30 days after the procedure and every 6 month. Thirty-day and at least 6-months outcomes were investigated. From February 2014 to December 2014, 10 male patients with aneurysmal CIA (mean age 75 years old) underwent consecutive endovascular treatment with the Gore IBE. The CIA aneurysm (mean diameter 43.2 mm, range 32-49) treated with the Gore IBE was associated with an abdominal aortic aneurysm (AAA) in 5 patients. One patient had a previous AAA open repair. CIA aneurysm was bilateral in 5 patients. Preliminary procedure of internal iliac artery embolization was performed in 3 patients. Technical success rate of the Gore IBE implantation was 100% with a median fluoroscopy time of 35 min (range 12-64, ±16) and median contrast load of 150 mL (range 100-250, ±45). No perioperative complications were observed. Median length of stay was 4 days (range 3-7, ±2). One aortic type Ia endoleak was observed on the postoperative CT scan requiring an aortic extension at day 3. Branch patency was observed in all 10 patients at 1 month and 9 patients at 6 month. All CIA aneurysms were excluded without type Ib or type III endoleak. The technical success and short-term results demonstrate encouraging results and clinical benefits of the new GORE EXCLUDER IBE. A longer follow-up is needed to assess midterm and long-term results. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Oral health of children from rural excluded villages (Trancas and Calchaqui valleys. Tucumán, Argentina).

    Science.gov (United States)

    Delgado, A M; Molina, N; Totongi, M; Bordoni, N; Fernandez, C

    1999-01-01

    The general hypothesis of the study was to evaluate strategically important rural areas to confirm their characteristics of "excluded population" and identify the priorities to allocate human and financial resources of the international co-operation project. The aim of this study was to establish the degree of development of villages in the Trancas and Calchaqui valleys, and the oral health of children living in areas involved in an integral study on excluded villages in the northwest of Argentina. These villages are considered a priority in the UNIR Project; they are thus strategically important as a link with countries of the MERCOSUR. Data on living conditions were obtained through direct inquiries (Project UNIR, W. K. Kellogg Foundation/University of Tucumán) and from data supplied by the Ministry of Economy, by the Ministry of Culture and Education and by the SIEMPRO project of the Secretariat of Social Development of the Ministry of Health. The Human Development Index (HDI) was calculated as World Bank criteria (1995), The studies on dental conditions were carried out in all the children between 12 and 14 years old, that is a total of 58 in the Trancas Valley and 212 in the Calchaqui Valley. (1) The HDI was 0.731 for the province, 0.56 for the Trancas Valley and 0.51 for Calchaqui valley. (2) The results are above the values for the country in the first case, and below the average country values for the valleys. (3) The percentage of BNN families reached 92%. The results for oral health show: (4) the DMFT were 6.34 +/- 0.07 in the Trancas Valley and 7.47 +/- 0.276 in the Calchaquí valley. (5) Carious teeth (CT) were the most important component of this index. (6) The absence of a specific and preventive assistance. (a) Children between 12 and 14 living in the Valleys of Trancas and Calchaqui (Tucumán, Argentina) are affected by severe levels of caries, with values above the national and province means. (b) The human development index is below that of the

  17. Linkage analysis excludes the glaucoma locus on 1q from involvement in autosomal dominant glaucoma with iris hypoplasia

    Energy Technology Data Exchange (ETDEWEB)

    Heon, E.; Sheth, B.P.; Kalenak, J.W. [and others

    1994-09-01

    Genetic factors have been implicated in a variety of types of glaucoma including primary open-angle glaucoma, infantile glaucoma, pigmentary glaucoma, and juvenile open-angle glaucoma. We previously mapped the disease-causing gene for one type of juvenile open angle glaucoma to chromosome 1q21-31. Weatherill and Hart (1969) and Pearce (1983) each noted the association of iris hypoplasia and early-onset autosomal dominant glaucoma. We recently had the opportunity to study a large family (12 affected members) with this phenotype. Affected individuals developed glaucoma at an average age of 30 years. These patients also have a strikingly underdeveloped iris stroma which causes a peculiar eye color. Linkage analysis was able to completely exclude the 1q glaucoma locus from involvement in the disorder that affects this family. A complete clinical description of the family and linkage results at additional candidate loci will be presented.

  18. Race, treatment preferences, and hospice enrollment. Eligibility criteria may exclude patients with the greatest needs for care

    Science.gov (United States)

    Fishman, Jessica; O'Dwyer, Peter; Lu, Hien L.; Henderson, Hope; Asch, David A.; Casarett, David J.

    2009-01-01

    Background The requirement that patients give up curative treatment makes hospice enrollment unappealing for some patients, and may particularly limit use among African American patients. Objectives To determine whether African-American patients with cancer are more likely than white patients are to have preferences for cancer treatment that exclude them from hospice, and whether they are less likely to want specific hospice services. Methods 283 patients receiving treatment for cancer at six oncology clinics within the University of Pennsylvania Cancer Network completed conjoint interviews measuring their perceived need for five hospice services and their preferences for continuing cancer treatment. Patients were followed for six months or until death. Results African American patients had stronger preferences for continuing their cancer treatments on a 7-point scale even after adjusting for age, sex, finances, education, ECOG performance status, quality of life, and physical and psychological symptom burden (adjusted means 4.75 vs. 3.96; β coefficient 0.82; 95% confidence interval 0.22-1.41; p=0.007). African-American patients also had greater perceived needs for hospice services after adjusting for these characteristics (adjusted means 2.31 vs. 1.83) (β coefficient 0.51; 95% confidence interval 0.11-0.92; p=0.01). However, this effect disappeared after adjusting for household finances. Conclusions Hospice eligibility criteria may exclude African-American patients disproportionately despite greater perceived needs for hospice services in this population. The mechanisms driving this health disparity likely include both cultural differences and economic characteristics, and consideration should be given to redesigning hospice eligibility criteria. PMID:19107761

  19. Race, treatment preferences, and hospice enrollment: eligibility criteria may exclude patients with the greatest needs for care.

    Science.gov (United States)

    Fishman, Jessica; O'Dwyer, Peter; Lu, Hien L; Henderson, Hope R; Henderson, Hope; Asch, David A; Casarett, David J

    2009-02-01

    The requirement that patients give up curative treatment makes hospice enrollment unappealing for some patients and may particularly limit use among African-American patients. The current study was conducted to determine whether African-American patients with cancer are more likely than white patients to have preferences for cancer treatment that exclude them from hospice and whether they are less likely to want specific hospice services. Two hundred eighty-three patients who were receiving treatment for cancer at 6 oncology clinics within the University of Pennsylvania Cancer Network completed conjoint interviews measuring their perceived need for 5 hospice services and their preferences for continuing cancer treatment. Patients were followed for 6 months or until death. African-American patients had stronger preferences for continuing their cancer treatments on a 7-point scale even after adjusting for age, sex, finances, education, Eastern Cooperative Oncology Group performance status, quality of life, and physical and psychologic symptom burden (adjusted mean score, 4.75 vs 3.96; beta coefficient, 0.82; 95% confidence interval, 0.22-1.41 [P = .007]). African-American patients also had greater perceived needs for hospice services after adjusting for these characteristics (adjusted mean score, 2.31 vs 1.83; beta coefficient, 0.51; 95% confidence interval, 0.11-0.92 [P = .01]). However, this effect disappeared after adjusting for household finances. Hospice eligibility criteria may exclude African-American patients disproportionately despite greater perceived needs for hospice services in this population. The mechanisms driving this health disparity likely include both cultural differences and economic characteristics, and consideration should be given to redesigning hospice eligibility criteria. (c) 2008 American Cancer Society.

  20. The accuracy of transcranial Doppler in excluding intracranial hypertension following acute brain injury: a multicenter prospective pilot study.

    Science.gov (United States)

    Rasulo, Frank A; Bertuetti, Rita; Robba, Chiara; Lusenti, Francesco; Cantoni, Alfredo; Bernini, Marta; Girardini, Alan; Calza, Stefano; Piva, Simone; Fagoni, Nazzareno; Latronico, Nicola

    2017-02-27

    Untimely diagnosis of intracranial hypertension may lead to delays in therapy and worsening of outcome. Transcranial Doppler (TCD) detects variations in cerebral blood flow velocity which may correlate with intracranial pressure (ICP). We investigated if intracranial hypertension can be accurately excluded through use of TCD. This was a multicenter prospective pilot study in patients with acute brain injury requiring invasive ICP (ICPi) monitoring. ICP estimated with TCD (ICPtcd) was compared with ICPi in three separate time frames: immediately before ICPi placement, immediately after ICPi placement, and 3 hours following ICPi positioning. Sensitivity and specificity, and concordance correlation coefficient between ICPi and ICPtcd were calculated. Receiver operating curve (ROC) and the area under the curve (AUC) analyses were estimated after measurement averaging over time. A total of 38 patients were enrolled, and of these 12 (31.6%) had at least one episode of intracranial hypertension. One hundred fourteen paired measurements of ICPi and ICPtcd were gathered for analysis. With dichotomized ICPi (≤20 mmHg vs >20 mmHg), the sensitivity of ICPtcd was 100%; all measurements with high ICPi (>20 mmHg) also had a high ICPtcd values. Bland-Altman plot showed an overestimation of 6.2 mmHg (95% CI 5.08-7.30 mmHg) for ICPtcd compared to ICPi. AUC was 96.0% (95% CI 89.8-100%) and the estimated best threshold was at ICPi of 24.8 mmHg corresponding to a sensitivity 100% and a specificity of 91.2%. This study provides preliminary evidence that ICPtcd may accurately exclude intracranial hypertension in patients with acute brain injury. Future studies with adequate power are needed to confirm this result.