Producing Chart Data from Interferometric Sonars on Small AUVs

High frequency (100kHz to 500kHz) ‗interferometric‘ or phase measuring sonars are a common tool for boat-mounted hydrographic surveys. Recent improvements in sonar and positioning technology have led to improved data quality: 2005 saw the first interferometric survey accepted for charting by the UK Hydrographic office. In parallel with this there have been significant advances in man-portable autonomous underwater vehicles (AUVs). These technologies can be combined: there are now growing numbers of small AUVs running interferometric bathymetry surveys worldwide. The ability to access hazardous areas, provide cost-effective force-multiplication, and acquire higher resolution data from deeper water has proven very attractive.This paper discusses the influences on data quality when acquiring swath bathymetric data using interferometric sonars on small AUVs, including how the data can be processed and qualified for hydrographic charting. Commercial AUV capabilities are illustrated using data collected by a 7-inch diameter Gavia AUV (Teledyne Gavia, Iceland) carrying a 500kHz GeoSwath sonar (GeoAcoustics, UK). Error budgets are discussed, showing that existing technology is capable of achieving IHO S-44 Ed.5 Special Order surveys, within certain operational limits and using appropriate survey planning and data processing.Possible future improvements in data analysis methods are mentioned, including the use of SLAM (Simultaneous Localisation and Mapping) methods to improve navigation. This is illustrated using sample data processed in CleanSweep software (OIC Inc., Hawaii).Los sonares ―interferométricos‖ de alta frecuencia (100kHz a 500kHz) o que miden las fases son un instrumento común para los levantamientos hidrográficos montados en las barcas. Las mejoras recientes en tecnología han dado como resultado diferencias en la calidad de los datos: en el 2005 se aceptó el primer levantamiento interferométrico para su uso en cartografía por el Servicio Hidrográ-fico del Reino Unido. Paralelamente a esto ha habido mejoras en la tecnología portátil de Vehículos Submarinos Autónomos (AUV - Autonomous Underwater Vehicle). Hay ahora cada vez más cantidades de pequeños AUVs que efectúan levantamientos batimétricos en el mundo entero. La posibilidad de acceso a zonas peligrosas proporciona una multiplicación de las fuerzas rentable, y la adquisición de datos de una resolución mayor procedentes de aguas más profundas ha resultado muy atractiva.Este documento describe la ruta desde el vehículo lanzador a los datos que pueden ser cartografia-dos, concentrándose en el modo en el que los datos batimétricos de banda barrida adquiridos mediante sonares interferométricos en pequeños AUVs pueden ser procesados y aptos para la cartografía hidrográfica. Las capacidades de los AUVs comerciales se ilustran utilizando los datos recogidos con un AUV Gavia (Teledyne Gavia, Islandia) de 7 pulgadas de diámetro que transporta un sonar de barrido de 500kHz (de GeoAcoustics, RU). Se discuten los factores de error, que mues-tran que la tecnología existente puede llevar a cabo levantamientos de una Clase Especial según la Ed. 5 de la Norma S-44 de la OHI, dentro de ciertos límites operativos.Se mencionan las posibles mejoras futuras en los métodos de análisis de datos, incluyendo el uso de métodos de Localización y Cartografía Simultáneas (SLAM - Simultaneous Localisation and Map-ping) para mejorar la navegación. Esto se ilustra utilizando datos de muestras procesados en el pro-grama CleanSweep (OIC Inc., Hawaii).Les sonars ―interférométriques‖ à haute fréquence (de 100kHz à 500kHz) ou de mesure de phases sont un outil répandu pour la réalisation de levés hydrographiques à bord des navires. Des améliora-tions récentes dans le domaine de la technologie ont permis de faire des bonds en avant en matière de qualité des données. En 2005, le premier levé interférométrique a été agréé pour la cartographie par le Service hydrographique du Royaume-Uni. Il y a eu parallèlement des améliorations relatives à la technologie des véhicules sous-marins autonomes portables (AUV). Il existe maintenant un nombre croissant de petits AUV qui réalisent des levés bathymétriques dans le monde entier. La possibilité d‘accéder à des zones dangereuses, de multiplier les forces de façon rentable et d‘acquérir des données à plus haute résolution dans des eaux plus profondes s‘est révélée très intéressante.Ce document décrit le parcours suivi depuis la mise à la mer du véhicule jusqu‘aux données qui sont utilisées pour les cartes et se concentre sur la manière dont les données bathymétriques à large couverture acquises par sonars interférométriques à bord d‘AUV peuvent être traitées et admises pour la reproduction cartographique des données hydrographiques. Les capacités commerciales des AUV sont illustrées par les données recueillies par un AUV Gavia de 7 pouces de diamètre (Teledyne Gavia, Islande) embarquant un sonar GeoSwath de 500 kHz (GeoAcoustics, RU). Les budgets d‘erreur, qui montrent que la technologie existante est capable d‘obtenir des levés d’ordre spécial conformément à la 5ème édition de la publication S-44 de l’OHI dans le cadre de certaines limites opérationnelles, y sont discutés.De futurs progrès éventuels dans les méthodes d‘analyse des données sont mentionnés, y compris l‘utilisation de la méthode SLAM (Cartographie et localisation simultanée) afin d‘améliorer la navigation. Ceci est illustré par l‘exemple du traitement des données à l‘aide du logiciel CleanSweep software (OIC Inc., Hawaï)

Assessing model performance for counterfactual predictions

Counterfactual prediction methods are required when a model will be deployed in a setting where treatment policies differ from the setting where the model was developed, or when the prediction question is explicitly counterfactual. However, estimating and evaluating counterfactual prediction models is challenging because one does not observe the full set of potential outcomes for all individuals. Here, we discuss how to tailor a model to a counterfactual estimand, how to assess the model's performance, and how to perform model and tuning parameter selection. We also provide identifiability results for measures of performance for a potentially misspecified counterfactual prediction model based on training and test data from the same (factual) source population. Last, we illustrate the methods using simulation and apply them to the task of developing a statin-na\"{i}ve risk prediction model for cardiovascular disease

Self-rated health and socio-economic status among older adults in Northern Iceland

Publisher's version (útgefin grein)Little is known about self-rated health (SRH) of older people living in more remote and Arctic areas. Iceland is a high-income country with one of the lowest rates of income inequality in the world, which may influence SRH. The research aim was to study factors affecting SRH, in such a population living in Northern Iceland. Stratified random sample according to the place of residency, age and gender was used and data collected via face-to-face interviews. Inclusion criteria included community-dwelling adults ≥65 years of age. Response rate was 57.9% (N = 175), average age 74.2 (sd 6.3) years, range 65–92 years and 57% were men. The average number of diagnosed diseases was 1.5 (sd 1.3) and prescribed medications 3.0 (sd 1.7). SRH ranged from 5 (excellent) to 1 (bad), with an average of 3.26 (sd 1.0) and no difference between the place of residency. Lower SRH was independently explained by depressed mood (OR = 0.88, 95% CI = 0.80–0.96), higher body mass index (OR = 0.93, 95% CI = 0.87–0.99), number of prescribed medications (OR = 0.88, 95% CI = 0.78–1.00) and perception of inadequate income (OR = 0.45, 95% CI = 0.21–0.98). The results highlight the importance of physical and mental health promotion for general health and for ageing in place and significance of economic factors as predictors of SRH.This work was supported by the Háskólinn á Akureyri [R-1803]; Icelandic Regional Development Institute (Byggðastofnun) [102022].Peer Reviewe

C-KIT Signaling Depends on Microphthalmia-Associated Transcription Factor for Effects on Cell Proliferation

The development of melanocytes is regulated by the tyrosine kinase receptor c-KIT and the basic-helix-loop-helix-leucine zipper transcription factor Mitf. These essential melanocyte survival regulators are also well known oncogenic factors in malignant melanoma. Despite their importance, not much is known about the regulatory mechanisms and signaling pathways involved. In this study, we therefore sought to identify the signaling pathways and mechanisms involved in c-KIT mediated regulation of Mitf. We report that c-KIT stimulation leads to the activation of Mitf specifically through the c-KIT phosphorylation sites Y721 (PI3 kinase binding site), Y568 and Y570 (Src binding site). Our study not only confirms the involvement of Ras-Erk signaling pathway in the activation of Mitf, but also establishes that Src kinase binding to Y568 and Y570 of c-KIT is required. Using specific inhibitors we observe and verify that c-KIT induced activation of Mitf is dependent on PI3-, Akt-, Src-, p38- or Mek kinases. Moreover, the proliferative effect of c-KIT is dependent on Mitf in HEK293T cells. In contrast, c-KIT Y568F and Y721F mutants are less effective in driving cell proliferation, compared to wild type c-KIT. Our results reveal novel mechanisms by which c-KIT signaling regulates Mitf, with implications for understanding both melanocyte development and melanoma

The Ahuachapan geothermal field, El Salvador: Reservoir analysis

These are appendices F through I of the Ahuachapan Geothermal Field Reservoir Analysis. The volume contains: well logs, water chemistry plots, gas chemistry plots, temperature plots, and flow plots. (JEF

Mutation in Archain 1, a Subunit of COPI Coatomer Complex, Causes Diluted Coat Color and Purkinje Cell Degeneration

Intracellular trafficking is critical for delivering molecules and organelles to their proper destinations to carry out normal cellular functions. Disruption of intracellular trafficking has been implicated in the pathogenesis of various neurodegenerative disorders. In addition, a number of genes involved in vesicle/organelle trafficking are also essential for pigmentation, and loss of those genes is often associated with mouse coat-color dilution and human hypopigmentary disorders. Hence, we postulated that screening for mouse mutants with both neurological defects and coat-color dilution will help identify additional factors associated with intracellular trafficking in neuronal cells. In this study, we characterized a mouse mutant with a unique N-ethyl-N-nitrosourea (ENU)–induced mutation, named nur17. nur17 mutant mice exhibit both coat-color dilution and ataxia due to Purkinje cell degeneration in the cerebellum. By positional cloning, we identified that the nur17 mouse carries a T-to-C missense mutation in archain 1 (Arcn1) gene which encodes the δ subunit of the coat protein I (COPI) complex required for intracellular trafficking. Consistent with this function, we found that intracellular trafficking is disrupted in nur17 melanocytes. Moreover, the nur17 mutation leads to common characteristics of neurodegenerative disorders such as abnormal protein accumulation, ER stress, and neurofibrillary tangles. Our study documents for the first time the physiological consequences of the impairment of the ARCN1 function in the whole animal and demonstrates a direct association between ARCN1 and neurodegeneration

Leukocyte Tyrosine Kinase Functions in Pigment Cell Development

A fundamental problem in developmental biology concerns how multipotent precursors choose specific fates. Neural crest cells (NCCs) are multipotent, yet the mechanisms driving specific fate choices remain incompletely understood. Sox10 is required for specification of neural cells and melanocytes from NCCs. Like sox10 mutants, zebrafish shady mutants lack iridophores; we have proposed that sox10 and shady are required for iridophore specification from NCCs. We show using diverse approaches that shady encodes zebrafish leukocyte tyrosine kinase (Ltk). Cell transplantation studies show that Ltk acts cell-autonomously within the iridophore lineage. Consistent with this, ltk is expressed in a subset of NCCs, before becoming restricted to the iridophore lineage. Marker analysis reveals a primary defect in iridophore specification in ltk mutants. We saw no evidence for a fate-shift of neural crest cells into other pigment cell fates and some NCCs were subsequently lost by apoptosis. These features are also characteristic of the neural crest cell phenotype in sox10 mutants, leading us to examine iridophores in sox10 mutants. As expected, sox10 mutants largely lacked iridophore markers at late stages. In addition, sox10 mutants unexpectedly showed more ltk-expressing cells than wild-type siblings. These cells remained in a premigratory position and expressed sox10 but not the earliest neural crest markers and may represent multipotent, but partially-restricted, progenitors. In summary, we have discovered a novel signalling pathway in NCC development and demonstrate fate specification of iridophores as the first identified role for Ltk