Effect of Time-of-Flight and Regularized Reconstructions on Quantitative Measurements and Qualitative Assessments in Newly Diagnosed Prostate Cancer With 18F-Fluorocholine Dual Time Point PET/MRI.

Recent technical advances in positron emission tomography/magnetic resonance imaging (PET/MRI) technology allow much improved time-of-flight (TOF) and regularized iterative PET reconstruction regularized iterative reconstruction (RIR) algorithms. We evaluated the effect of TOF and RIR on standardized uptake values (maximum and peak SUV [SUVmax and SUVpeak]) and their metabolic tumor volume dependencies and visual image quality for 18F-fluorocholine PET/MRI in patients with newly diagnosed prostate cancer. Fourteen patients were administered with 3 MBq/kg of 18F-fluorocholine and scanned dynamically for 30 minutes. Positron emission tomography images were divided to early and late time points (1-6 minutes summed and 7-30 minutes summed). The values of the different SUVs were documented for dominant PET-avid lesions, and metabolic tumor volume was estimated using a 50% isocontour and SUV threshold of 2.5. Image quality was assessed via visual acuity scoring (VAS). We found that incorporation of TOF or RIR increased lesion SUVs. The lesion to background ratio was not improved by TOF reconstruction, while RIR improved the lesion to background ratio significantly ( P < .05). The values of the different VAS were all significantly higher ( P < .05) for RIR images over TOF, RIR over non-TOF, and TOF over non-TOF. In conclusion, our data indicate that TOF or RIR should be incorporated into current protocols when available

Harmonization of space-borne infra-red sensors measuring sea surface temperature

Sea surface temperature (SST) is observed by a constellation of sensors, and SST retrievals are commonly combined into gridded SST analyses and climate data records (CDRs). Differential biases between SSTs from different sensors cause errors in such products, including feature artefacts. We introduce a new method for reducing differential biases across the SST constellation, by reconciling the brightness temperature (BT) calibration and SST retrieval parameters between sensors. We use the Advanced Along-Track Scanning Radiometer (AATSR) and the Sea and Land Surface Temperature Radiometer (SLSTR) as reference sensors, and the Advanced Very High Resolution Radiometer (AVHRR) of the MetOp-A mission to bridge the gap between these references. Observations across a range of AVHRR zenith angles are matched with dual-view three-channel skin SST retrievals from the AATSR and SLSTR. These skin SSTs act as the harmonization reference for AVHRR retrievals by optimal estimation (OE). Parameters for the harmonized AVHRR OE are iteratively determined, including BT bias corrections and observation error covariance matrices as functions of water-vapor path. The OE SSTs obtained from AVHRR are shown to be closely consistent with the reference sensor SSTs. Independent validation against drifting buoy SSTs shows that the AVHRR OE retrieval is stable across the reference-sensor gap. We discuss that this method is suitable to improve consistency across the whole constellation of SST sensors. The approach will help stabilize and reduce errors in future SST CDRs, as well as having application to other domains of remote sensing

Les métamorphoses pâlissantes dans les textes traduits : étude sur le jaune et le blond.

Ante la poca atención que reciben en la producción científica en español las “figuras de traducción” (existencia de una serie de fenómenos que se repiten, independientemente de los idiomas y traductores implicados), nuestro objetivo básico es describir el proceder de los traductores cuando verbalizan lo que ven, sienten, perciben y comprenden del mundo evocado en el texto que traducen. Intentamos así aportar un esclarecimiento del fenómeno de la comprensión lectora (las reducciones realizadas por los lectores) para asentar el sentido de los enunciados literarios, y al mismo tiempo de la actividad traductora. Para ello, el artículo plantea analizar el breve espacio que da cuenta de la aprensión e identificación de los colores en el discurso mediante la revisión de la traducción del color amarillo y el matiz rubio en un corpus de textos literarios franceses y españoles (552 ítems analizados) para intentar delimitar las situaciones en las que surgen las traducciones literales de este cromatismo, y las situaciones para las que los traductores proponen distintos tipos de alejamiento, aplicando su propio “filtro de color”. Permite observar estrategias recurrentes en las alteraciones de amarillo y rubio en los textos traducidos, manifestando mayoritariamente una intensificación del realismo -que tiende a adecuar los adjetivos seleccionados a la realidad habitualmente observada (atenuación del color amarillo en determinadas situaciones: naturaleza otoñal, tez, pelo, etc.)-, o bien una respuesta (casi) automática a prácticas de lectura codificadas -preferencia de dorado como equivalente de rubio en situaciones relacionadas con objetos o elementos de la naturaleza-. Nuestra conclusión básica es que la reorganización pictórica presente en las novelas analizadas tiende a acentuar los estereotipos y los modelos realistas, en detrimento de cierta singularidad cromática propuesta por los distintos autores. Consecuentemente los traductores pierden de vista el traslado a la escritura de la imaginación creadora en los textos originales, y en las traducciones privilegian la dimensión referencial del lenguaje en detrimento de su función poética, privilegian un texto más inmediatamente legible e inteligible, designando así un tipo de discurso lícito para la lectura eficaz de enunciados ficticios

Oxidation Resistance of Thermal Barrier Coatings Based on Hollow Alumina Particles

International audienc

Median eminence blood flow influences food intake by regulating ghrelin access to the metabolic brain

Central integration of peripheral appetite-regulating signals ensures maintenance of energy homeostasis. Thus, plasticity of circulating molecule access to neuronal circuits involved in feeding behavior plays a key role in the adaptive response to metabolic changes. However, the mechanisms involved remain poorly understood despite their relevance for therapeutic development. Here, we investigated the role of median eminence mural cells, including smooth muscle cells and pericytes, in modulating gut hormone effects on orexigenic/anorexigenic circuits. We found that conditional activation of median eminence vascular cells impinged on local blood flow velocity and altered ghrelin-stimulated food intake by delaying ghrelin access to target neurons. Thus, activation of median eminence vascular cells modulates food intake in response to peripheral ghrelin by reducing local blood flow velocity and access to the metabolic brain.</p

A Resident Perspective on Adding Value as Radiologists

During the annual 46th annual American Alliance of Academic Chief Residents in Radiology (A3CR2) meeting in New Orleans, chief residents discussed the role of residents within American College of Radiology 3.0 campaign. Our discussion was directed toward the evolving role of fourth-year radiology residents and how we might improve their training to better prepare them to add value as both leaders and radiologists. The ideas resulting from our Problem Solving session were divided into three categories: clinical presence in the wards and subspecialty clinics; visibility to clinicians and patients; and the education of medical students, residents, and advanced practice clinicians to aid in realizing the long-term goals of Imaging 3.0

Propagation en contexte arrière-arc : premiers résultats de la campagne ProFeTi (Bassin Nord-Fidjien, Pacifique SW)

Au centre du bassin Nord-Fidjien, le segment d'accrétion NS, qui se propage vers le Nord aux dépens du segment N15 depuis au moins 1 Ma, a été échantillonné pendant la campagne ProFeTi du NO Alis. Malgré sa position arrière-arc, aucune contamination géochimique caractéristique d'une subduction n'est perceptible. L'échantillonnage étudié montre que les réservoirs magmatiques de ce segment en propagation évoluent dans une perpétuelle dynamique de recherche d'équilibre thermique et chimique, perturbée par les actions conjuguées suivantes : l'éloignement de la pointe du propagateur par rapport aux zones de réalimentations focalisées sous le centre du segment, des réalimentations successives par des liquides primitifs évoluant avec l'état de maturité du propagateur, et un effet de paroi froide provenant du segment N15, dans lequel la lithosphère de la pointe du segment NS se propage. (Résumé d'auteur

Multiple-scale neuroendocrine signals connect brain and pituitary hormone rhythms

International audienceSignificance The hypothalamo–pituitary axis controls a wide range of homeostatic processes, including growth, stress, and reproduction. Despite this fact, the hypothalamic neuron firing patterns that lead to slowly evolving pituitary hormone rhythms remain enigmatic. Here, we used in vivo amperometric recordings in freely behaving mice to investigate how tuberoinfundibular neurons release dopamine (DA) at the median eminence (ME) to control pituitary prolactin secretion. Using this approach, we show that DA release occurs as multiple locally generated and time-scaled secretory events, which are integrated over a range of minutes across the ME. These results provide a broad physiological mechanism for the dialogue that occurs between the brain and pituitary to dictate hormone rhythms over multiple timescales, from ultradian to seasonal