Pulsar Timing and its Application for Navigation and Gravitational Wave Detection

Pulsars are natural cosmic clocks. On long timescales they rival the precision of terrestrial atomic clocks. Using a technique called pulsar timing, the exact measurement of pulse arrival times allows a number of applications, ranging from testing theories of gravity to detecting gravitational waves. Also an external reference system suitable for autonomous space navigation can be defined by pulsars, using them as natural navigation beacons, not unlike the use of GPS satellites for navigation on Earth. By comparing pulse arrival times measured on-board a spacecraft with predicted pulse arrivals at a reference location (e.g. the solar system barycenter), the spacecraft position can be determined autonomously and with high accuracy everywhere in the solar system and beyond. We describe the unique properties of pulsars that suggest that such a navigation system will certainly have its application in future astronautics. We also describe the on-going experiments to use the clock-like nature of pulsars to "construct" a galactic-sized gravitational wave detector for low-frequency (f_GW ~1E-9 - 1E-7 Hz) gravitational waves. We present the current status and provide an outlook for the future.Comment: 30 pages, 9 figures. To appear in Vol 63: High Performance Clocks, Springer Space Science Review

Variation in spatial dependencies across the cortical mantle discriminates the functional behaviour of primary and association cortex

Recent theories of cortical organisation suggest features of function emerge from the spatial arrangement of brain regions. For example, association cortex is located furthest from systems involved in action and perception. Association cortex is also ‘interdigitated’ with adjacent regions having different patterns of functional connectivity. It is assumed that topographic properties, such as distance between regions, constrains their functions, however, we lack a formal description of how this occurs. Here we use variograms, a quantification of spatial autocorrelation, to profile how function changes with the distance between cortical regions. We find function changes with distance more gradually within sensory-motor cortex than association cortex. Importantly, systems within the same type of cortex (e.g., fronto-parietal and default mode networks) have similar profiles. Primary and association cortex, therefore, are differentiated by how function changes over space, emphasising the value of topographical features of a region when estimating its contribution to cognition and behaviour

Automatic Recognition of Affective Body Movement in a Video Game Scenario

This study aims at recognizing the affective states of players from non-acted, non-repeated body movements in the context of a video game scenario. A motion capture system was used to collect the movements of the participants while playing a Nintendo Wii tennis game. Then, a combination of body movement features along with a machine learning technique was used in order to automatically recognize emotional states from body movements. Our system was then tested for its ability to generalize to new participants and to new body motion data using a sub-sampling validation technique. To train and evaluate our system, online evaluation surveys were created using the body movements collected from the motion capture system and human observers were recruited to classify them into affective categories. The results showed that observer agreement levels are above chance level and the automatic recognition system achieved recognition rates comparable to the observers' benchmark. © 2012 ICST Institute for Computer Science, Social Informatics and Telecommunications Engineering

Avaliação da qualidade de vida, da dor nas costas, da funcionalidade e de alterações da coluna vertebral de estudantes de fisioterapia

O objetivo deste estudo foi avaliar a qualidade de vida, dor nas costas, funcionalidade e as alterações da coluna vertebral de estudantes de fisioterapia. Participaram 42 universitários, sendo avaliada a coluna vertebral por meio do arcômetro, a dor nas costas por meio de um questionário multidimensional de dor, a qualidade de vida por meio do questionário SF-36 e funcionalidade a partir do Roland-Morris. Foi realizada estatística descritiva e teste qui-quadrado (α=0,05). Os resultados demonstraram: prevalência de alterações nas curvaturas da coluna vertebral de 38,1%; (n=16); alta prevalência de dor nas costas (69%; n=29); baixa prevalência de comprometimento da funcionalidade (3,4%; n=1); que não há associação entre as alterações nas curvaturas da coluna vertebral e funcionalidade e dor nas costas; e que os escores dos domínios do SF-36 foram maiores que 45, exceto o domínio "dor", cujo escore aproximado foi de 35. Conclui-se que quanto menor os níveis de intensidade da dor melhor o nível de qualidade de vida

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Combining asymmetrical flow field-flow fractionation with light-scattering and inductively coupled plasma mass spectrometric detection for characterization of nanoclay used in biopolymer nanocomposites

International audienceIt is expected that biopolymers obtained from renewable resources will in due course become fully competitive with fossil fuel-derived plastics as food packaging materials. In this context, biopolymer nanocomposites are a field of emerging interest since such materials can exhibit improved mechanical and barrier properties and be more suitable for a wider range of food packaging applications. Natural or synthetic clay nanofillers are being investigated for this purpose in the current NanoPack project funded by the Danish Strategic Research Council. In order to detect and chracterize the size of clay nanoparticulates, an analytical system combining asymmetrical flow field-flow fractionation (AF4) with multi angle light scattering detection (MALS) and inductively coupled plasma mass spectrometry (ICP-MS) is presented here. In a migration study we tested a biopolymer nanocomposite consisting of polylactide (PLA) with 5 % Cloisite®30B, a derivatised montmorillonite clay, as filler. Based on AF4-MALS analyses we found that particles ranging from 50 to 800 nm in radius indeed migrated into the 95 % ethanol used as food simulant. The full hyphenated AF4-MALS-ICP-MS system showed however, that none of the characteristic clay minerals were detectable, and we conclude that clay nanoparticles was absent in the migrate. Finally, by means of centrifugation experiments, a platelet aspect ratio of 320 was calculated for montmorillonite clay using AF4-MALS for platelet size measurements

Joint WHO/ISH workshop on efficacy and radiation safety in interventional radiology

Mit der staendigen Weiterentwicklung der Technik und der Eroeffnung neuer Anwendungsgebiete vergroessert sich der Einsatzbereich der interventionellen Radiologie (IR) betraechtlich. Durch diese hochkomplizierten Verfahren koennen oft grosse chirurgische Eingriffe vermieden werden; das ist von enormen Nutzen fuer den Patienten. Andererseits sind bei der IR lange Durchleuchtungszeiten noetig und - weil oft hoechste Bildqualitaet gebraucht wird - teilweise sehr hohe Dosisleistung. Dazu kommen noch Kino-Serien und eine grosse Zahl von Einzelaufnahmen. Aus diesen Gruenden ist der Strahlenpegel fuer Patient und Personal sehr hoch. Um ueber Moeglichkeiten der Verminderung des Strahlenrisikos von IR-Massnahmen zu beraten, erscheinen interdisziplinaere Gespraeche notwendig zwischen Vertretern der Roentgengeraete-Industrie, der Medizinphysiker und der Kliniker, um nach Wegen zu suchen, wie man unnoetige Strahlenbelastung fuer Patienten und Personal vermeiden kann. Das war das Ziel eines Workshops ueber IR, der gemeinsam von der Weltgesundheitsorganisation und dem Institut fuer Strahlenhygiene des Bundesamtes fuer Strahlenschutz im Oktober 1995 veranstaltet wurde. Es sollte ein Diskussionsforum sein ueber Themen, die mit der IR zusammenhaengen, um verbesserte Verfahren anzuregen. Es sollte eine Gelegenheit sein, um den Stand von Wissenschaft und Technik darzustellen, effizientere klinische Verfahren vorzuschlagen, ueber Verfahren der Ausbildung und Fortbildung und ueber geraetetechnische Entwicklungen zu diskutieren. Verbesserter Strahlenschutz fuer Patient und Personal war das generelle Ziel des Workshops. Dieser Band enthaelt die Vortraege, die am ersten Tag des Workshops gehalten wurden. (orig./DG)With the constantly developing technology and the opening of new fields of application, the implementation of Interventional Radiology (IR) is increasing considerably. These sophisticated procedures can frequently replace open surgery, and this is of enormous benefit for the patient. On the other hand, IR involves prolonged application of fluoroscopy and - due to the need for excellent image quality - partly very high dose-rate levels. Additionally, cine-series, and alsogreat numbers of single radiographs are necessary. Accordingly, the levels of exposure to patients and staff are very high. In order to consider possible reduction of the radiation risks of IR procedures interdiciplinary talks between representatives of manufacturers of X-ray equipment, hospital physicists and the clinical community would seem necessary in order to find ways of avoiding unproductive radiation exposure to the patient and to clinical staff. This was the aim of a workshop on IR, which was jointly organized by the World Health Organization and the Institute of Radiation Hygiene of the Federal Office for Radiation Protection in Germany in October 1995. It was intended as a forum for the discussion of issues related to IR, and to forster improved application, that is to say as an opportunity: To present the state of the art; to work out proposals for more efficient clinical protocols; to discuss on schemes of education and training and on equipment-related developments. Improvement of radiation safety for both patients and staff, was the general aim of the workshop. This volume contains the presentations given on the first day of the workshop. (orig./DG)SIGLEAvailable from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman