Application of semidefinite programming to maximize the spectral gap produced by node removal

The smallest positive eigenvalue of the Laplacian of a network is called the spectral gap and characterizes various dynamics on networks. We propose mathematical programming methods to maximize the spectral gap of a given network by removing a fixed number of nodes. We formulate relaxed versions of the original problem using semidefinite programming and apply them to example networks.Comment: 1 figure. Short paper presented in CompleNet, Berlin, March 13-15 (2013

Erasmus MC at CLEF eHealth 2016: Concept recognition and coding in French texts

We participated in task 2 of the CLEF eHealth 2016 chal-lenge. Two subtasks were addressed: entity recognition and normalization in a corpus of French drug labels and Medline titles, and ICD-10 coding of French death certificates. For both subtasks we used a dictionary-based approach. For entity recognition and normalization, we used Peregrine, our open-source indexing engine, with a dictionary based on French terms in the Unified Medical Language System (UMLS) supplemented with English UMLS terms that were translated into French with automatic translators. For ICD-10 coding, we used the Solr text tagger, together with one of two ICD-10 terminologies derived from the task training ma-terial. To reduce the number of false-positive detections, we implemented several post-processing steps. On the challenge test set, our best system obtained F-scores of 0.702 and 0.651 fo

Gurga Chiya and Tepe Marani: new excavations in the Shahrizor plain, Iraqi Kurdistan

Gurga Chiya and Tepe Marani are small, adjacent mounds located close to the town of Halabja in the southern part of the Shahrizor Plain, one of the most fertile regions of Iraqi Kurdistan. Survey and excavation at these previously unexplored sites is beginning to produce evidence for human settlement spanning the sixth to the fourth millennia, c. 5600–3300 cal. b.c. In Mesopotamian chronology this corresponds to the Late Neolithic through to Chalcolithic periods; the Halaf, Ubaid, and Uruk phases of conventional culture history. In Iraqi Kurdistan, documentation of these periods—which witnessed many important transformations in prehistoric village life—is currently very thin. Here we offer a preliminary report on the emerging results from the Shahrizor Plain, with a particular focus on the description of material culture (ceramic and lithic assemblages), in order to establish a benchmark for further research. We also provide a detailed report on botanical remains and accompanying radiocarbon dates, which allow us to place this new evidence in a wider comparative framework. A further, brief account is given of Late Bronze Age material culture from the upper layers at Gurga Chiya. We conclude with observations on the significance of the Shahrizor Plain for wider research into the later prehistory of the Middle East, and the importance of preserving and investigating its archaeological record

Experimental study of the robust global synchronization of Brockett oscillators

International audienceThis article studies the experimental synchronization of a family of a recently proposed oscillator model, i.e. the Brockett oscillator [Brockett, 2013]. Due to its structural property, Brockett oscillator can be considered as a promising benchmark nonlinear model for investigating synchronization and the consensus phenomena. Our experimental setup consists of analog circuit realizations of a network of Brockett oscillators. Experimental results obtained in this work correspond to the prior theoretical findings

Distributed Adaptive Attitude Synchronization of Multiple Spacecraft

This paper addresses the distributed attitude synchronization problem of multiple spacecraft with unknown inertia matrices. Two distributed adaptive controllers are proposed for the cases with and without a virtual leader to which a time-varying reference attitude is assigned. The first controller achieves attitude synchronization for a group of spacecraft with a leaderless communication topology having a directed spanning tree. The second controller guarantees that all spacecraft track the reference attitude if the virtual leader has a directed path to all other spacecraft. Simulation examples are presented to illustrate the effectiveness of the results.Comment: 13 pages, 11 figures. To appear in SCIENCE CHINA Technological Science

Bellis prostrata Pomel (Asteraceae), a new species for Morocco

Investigations conducted in temporary wetlands of the coastal Meseta of W Morocco (Benslimane region) lead to the discovery of Bellis prostrata in a small endoreic temporary pool (ca. 1 ha) of the quartzitic-limestone plateau of Benslimane

Rising Annual Costs of Dizziness Presentations to U.S. Emergency Departments

Objectives Dizziness and vertigo account for roughly 4% of chief symptoms in the emergency department ( ED ). Little is known about the aggregate costs of ED evaluations for these patients. The authors sought to estimate the annual national costs associated with ED visits for dizziness. Methods This cost study of adult U.S. ED visits presenting with dizziness or vertigo combined public‐use ED visit data (1995 to 2009) from the National Hospital Ambulatory Medical Care Survey ( NHAMCS ) and cost data (2003 to 2008) from the Medical Expenditure Panel Survey ( MEPS ). We calculated total visits, test utilization, and ED diagnoses from NHAMCS . Diagnosis groups were defined using the Healthcare Cost and Utilization Project's Clinical Classifications Software ( HCUP ‐ CCS ). Total visits and the proportion undergoing neuroimaging for future years were extrapolated using an autoregressive forecasting model. The average ED visit cost‐per‐diagnosis‐group from MEPS were calculated, adjusting to 2011 dollars using the Hospital Personal Health Care Expenditures price index. An overall weighted mean across the diagnostic groups was used to estimate total national costs. Year 2011 data are reported in 2011 dollars. Results The estimated number of 2011 US ED visits for dizziness or vertigo was 3.9 million (95% confidence interval [ CI ] = 3.6 to 4.2 million). The proportion undergoing diagnostic imaging by computed tomography ( CT ), magnetic resonance imaging ( MRI ), or both in 2011 was estimated to be 39.9% (39.4% CT , 2.3% MRI ). The mean per‐ ED ‐dizziness‐visit cost was $1,004 in 2011 dollars. The total extrapolated 2011 national costs were$3.9 billion. HCUP ‐ CCS key diagnostic groups for those presenting with dizziness and vertigo included the following (fraction of dizziness visits, cost‐per‐ ED ‐visit, attributable annual national costs): otologic/vestibular (25.7%; $768;$757 million), cardiovascular (16.5%, $1,489;$941 million), and cerebrovascular (3.1%; $1059;$127 million). Neuroimaging was estimated to account for about 12% of the total costs for dizziness visits in 2011 ( CT scans $360 million, MRI scans$110 million). Conclusions Total U.S. national costs for patients presenting with dizziness to the ED are substantial and are estimated to now exceed $4 billion per year (about 4% of total ED costs). Rising costs over time appear to reflect the rising prevalence of ED visits for dizziness and increased rates of imaging use. Future economic studies should focus on the specific breakdown of total costs, emphasizing areas of high cost and use that might be safely reduced. Resumen Incremento Anual de los Costes de las Atenciones por Mareo en los Servicios de Urgencias de Estados Unidos Objectivos El mareo y el vértigo suman aproximadamente el 4% de los motivos de consulta en el servicio de urgencias ( SU ). Se conoce poco sobre los costes globales de las evaluaciones del SU en estos pacientes. Se buscó estimar los costes anuales nacionales asociados con las visitas al SU por mareo. Metodología Este estudio de costes de visitas al SU de adultos norteamericanos que acudieron con mareo o vértigo combinó los datos públicos de las visitas a los SU (1995 a 2009) recogidos por el National Hospital Ambulatory Medical Care Survey ( NHAMCS ) y los costes (2003 a 2008) recogidos por el Medical Expenditure Panel Survey ( MEPS ). Se calcularon el total de visitas, el uso de pruebas diagnósticas y los diagnósticos del SU del NHAMCS . Los grupos diagnósticos se definieron según el Healthcare Cost and Utilization Project's Clinical Classifications Software ( HCUP ‐ CCS ). Los datos del año 2011 se documentaron en dólares de 2011. El total de visitas y la proporción de neuroimagen llevada a cabo en los futuros años se extrapoló usando un modelo predictivo autorregresivo. La media del coste por visita al SU por grupo diagnóstico del MEPS se calculó, ajustándose a dólares de 2011, mediante el índice de precios de los Hospital Personal Health Care Expenditures. Se utilizó una media ponderada global entre los grupos diagnósticos para estimar los costes totales nacionales. Resultados El número de visitas al SU en Estados Unidos en 2011 por mareo o vértigo fue de 3,9 millones ( IC 95% = 3,6 a 4,2 millones). El porcentaje de pruebas diagnósticas de imagen llevadas a cabo por tomografía computarizada ( TC ), resonancia magnética ( RM ) o ambas en 2011 se estimó en un 39,9% (39,4% TC , 2,3% RM ). La media de coste por visita al SU por mareo fue de 1.004 dólares de 2011. Los costes totales, extrapolados para todo el país, fueron de 3.900 millones de dólares. Los grupos diagnósticos HCUP ‐ CCS para aquéllos que presentaron mareo o vértigo incluyeron los siguientes (proporción de visitas por mareo; coste por visita al SU ; costes anuales nacionales atribuibles): otológico/vestibular (25,7%; 768 dólares; 757 millones de dólares), cardiovascular (16,5%, 1.489 dólares; 941 millones de dólares) y cerebrovascular (3,1%; 1.059 dólares; 127 millones de dólares). Se estimó una suma en la neuroimagen del 12% del total de costes para las visitas por mareo en 2011 (360 millones de dólares para la TC y 110 millones de dólares para la RM ). Conclusiones Los costes totales en Estados Unidos para los pacientes que acuden por mareo al SU son sustanciales, y se estima que sobrepasan en estos momentos los 4.000 millones de dólares por año (aproximadamente un 4% de los costes totales del SU ). El incremento de los costes con el paso del tiempo parece reflejar el crecimiento de la prevalencia de las visitas al SU por mareo y el aumento de porcentajes de utilización de la neuroimagen. Futuros estudios económicos deberían centrarse en el desglose de los costes totales, y hacer énfasis en las áreas de alto uso y coste que pueden ser reducidas sin riesgo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99059/1/acem12168.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/99059/2/acem12168-sup-0001-DataSupplementS1.pd

Thermo-mechanical analysis of dental silicone polymers

Soft lining materials are used to replace the inner surface of a conventional complete denture, especially for weak elderly patients, with delicate health who cannot tolerate the hard acrylic denture base. Most of these patients have fragile supporting mucosa, excessive residual ridge resorption, particularly on the mandibular arch. The application of a soft liner to the mandibular denture allows absorbing impact forces during mastication and relieving oral mucosa. Actually, the silicone rubbers constitute the main family of commercialised soft lining materials. This study was conducted to understand the relationships between the mechanical properties and the physical structure of polysiloxanes. For this purpose, a series of polysiloxanes of various chemical compositions have been investigated. The evolution of their physical structure as a function of temperature has been followed by differential scanning calorimetry (DSC). In order to facilitate comparisons, the mechanical modulus has been analysed upon the same heating rate using dynamic mechanical analysis (DMA). Polysiloxanes actually commercialised as soft denture liners are three-dimensional networks: the flexibility of chains allows a crystalline organisation in an amorphous phase leading to the low value of the shear modulus. The dynamic mechanical analysis shows that they are used in the rubbery state. So, polysiloxanes have steady mechanical properties during physiological utilisation

Distributed information consensus filters for simultaneous input and state estimation

This paper describes the distributed information filtering where a set of sensor networks are required to simultaneously estimate input and state of a linear discrete-time system from collaborative manner. Our research purpose is to develop a consensus strategy in which sensor nodes communicate within the network through a sequence of Kalman iterations and data diffusion. A novel recursive information filtering is proposed by integrating input estimation error into measurement data and weighted information matrices. On the fusing process, local system state filtering transmits estimation information using the consensus averaging algorithm, which penalizes the disagreement in a dynamic manner. A simulation example is provided to compare the performance of the distributed information filtering with optimal Gillijins–De Moor’s algorithm