66 research outputs found

    Digital data logging and processing, Derbyshire Survey, 1997

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    In 1997, the Deep Submergence Group (DSG) of the Woods Hole Oceanographic Institution (WHOI) surveyed the wreckage field of the M.V. Derbyshire. The motivation for the survey and its results are described elsewhere (Williams et al, 1998). The purpose of this report is to describe the digital data logging and processing systems that were used by the Deep Submergence Group during the survey. The report is divided into four sections: this Introduction, a description of the collection mechanisms, a description of the processing schemes and series of appendices. The appendices include a glossary of terms, a description of data formats, and a comparison of electronic still camera processing choices. Readers desiring information on the equipment used, on the operations, or on the analysis effort performed by the on-board Inspection and Verification (I & V) Team or by the Assessors ashore are directed to (Williams et al, 1998), (Ballard, 1993) and (Bowen, et al, 1993).Funding was provided by the National Science Foundation under Grant No. OCE-9627160 and a Memorandum of Agreement between the United States Government and the United Kingdom Department of the Environment, Transport and the Regions

    NDSF technical operations via telecommunications

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    In 2015, the Woods Hole Oceanographic Institution (WHOI) commissioned an external study concerning the use of modern telecommunications and telepresence technologies in the potential reduction of manpower in National Deep Submergence Operations. That study has been completed, and the final report is attached as Appendix A.Funding was provided by the Nereus Legacy Fund at the Woods Hole Oceanographic Institutio

    A 3D stereo camera system for precisely positioning animals in space and time

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    PLT was supported by the Scottish Funding Council (grant HR09011) through the Marine Alliance for Science and Technology for Scotland.Here, we describe a portable stereo camera system that integrates a GPS receiver, an attitude sensor and 3D stereo photogrammetry to rapidly estimate the position of multiple animals in space and time. We demonstrate the performance of the system during a field test by simultaneously tracking the individual positions of six long-finned pilot whales, Globicephala melas. In shore-based accuracy trials, a system with a 50-cm stereo baseline had an average range estimation error of 0.09 m at a 5-m distance increasing up to 3.2 at 50 m. The system is especially useful in field situations where it is necessary to follow groups of animals travelling over relatively long distances and time periods whilst obtaining individual positions with high spatial and temporal resolution (up to 8 Hz). These positions provide quantitative estimates of a variety of key parameters and indicators for behavioural studies such as inter-animal distances, group dispersion, speed and heading. This system can additionally be integrated with other techniques such as archival tags, photo-identification methods or acoustic playback experiments to facilitate fieldwork investigating topics ranging from natural social behaviour to how animals respond to anthropogenic disturbance. By grounding observations in quantitative metrics, the system can characterize fine-scale behaviour or detect changes as a result of disturbance that might otherwise be difficult to observe.PostprintPeer reviewe

    Mesobot : An Autonomous Underwater Vehicle for Tracking and Sampling Midwater Targets

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    Mesobot, a new class of autonomous underwater vehicle, will address specific unmet needs for observing slow-moving targets in the midwater ocean. Mesobot will track targets such as zooplankton, fish, and descending particle aggregates using a control system based on stereo cameras and a combination of thrusters and a variable buoyancy system. The vehicle will also be able to collect biogeochemical and environmental DNA (eDNA) samples using a pumped filter sampler

    Enhanced Platelet-activating Factor synthesis facilitates acute and delayed effects of ethanol intoxicated thermal burn injury

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    Thermal burn injuries in patients alcohol intoxicated result in greater morbidity and mortality. Murine models combining ethanol and localized thermal burn injury reproduce the systemic toxicity seen in human subjects, which consists of both acute systemic cytokine production with multiple organ dysfunction, as well as a delayed systemic immunosuppression. However, the exact mechanisms for these acute and delayed effects are unclear. These studies sought to define the role of the lipid mediator Platelet-activating factor (PAF) in the acute and delayed effects of intoxicated burn injury. Combining ethanol and thermal burn injury resulted in increased enzymatic PAF generation in a keratinocyte cell line in vitro, human skin explants ex vivo, as well as in murine skin in vivo. Further, the acute increase in inflammatory cytokines such as IL-6, and the systemic immunosuppressive effects of intoxicated thermal burn injury, were suppressed in mice lacking PAF receptors. Together, these studies provide a potential mechanism and novel treatment strategies for the augmented toxicity and immunosuppressive effects of thermal burn injury in the setting of acute ethanol exposure, which involves the pleotropic lipid mediator PAF

    Submeter bathymetric mapping of volcanic and hydrothermal features on the East Pacific Rise crest at 9°50′N

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    Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 8 (2007): Q01006, doi:10.1029/2006GC001333.Recent advances in underwater vehicle navigation and sonar technology now permit detailed mapping of complex seafloor bathymetry found at mid-ocean ridge crests. Imagenex 881 (675 kHz) scanning sonar data collected during low-altitude (~5 m) surveys conducted with DSV Alvin were used to produce submeter resolution bathymetric maps of five hydrothermal vent areas at the East Pacific Rise (EPR) Ridge2000 Integrated Study Site (9°50′N, “bull's-eye”). Data were collected during 29 dives in 2004 and 2005 and were merged through a grid rectification technique to create high-resolution (0.5 m grid) composite maps. These are the first submeter bathymetric maps generated with a scanning sonar mounted on Alvin. The composite maps can be used to quantify the dimensions of meter-scale volcanic and hydrothermal features within the EPR axial summit trough (AST) including hydrothermal vent structures, lava pillars, collapse areas, the trough walls, and primary volcanic fissures. Existing Autonomous Benthic Explorer (ABE) bathymetry data (675 kHz scanning sonar) collected at this site provide the broader geologic context necessary to interpret the meter-scale features resolved in the composite maps. The grid rectification technique we employed can be used to optimize vehicle time by permitting the creation of high-resolution bathymetry maps from data collected during multiple, coordinated, short-duration surveys after primary dive objectives are met. This method can also be used to colocate future near-bottom sonar data sets within the high-resolution composite maps, enabling quantification of bathymetric changes associated with active volcanic, hydrothermal and tectonic processes.This work was supported by an NSF Ridge2000 fellowship to V.L.F. and a Woods Hole Oceanographic Institution fellowship supported by the W. Alan Clark Senior Scientist Chair (D.J.F.). Funding was also provided by the Censsis Engineering Research Center of the National Science Foundation under grant EEC-9986821. Support for field and laboratory studies was provided by the National Science Foundation under grants OCE-9819261 (D.J.F. and M.T.), OCE-0096468 (D.J.F. and T.S.), OCE-0328117 (SMC), OCE-0525863 (D.J.F. and S.A.S.), OCE-0112737 ATM-0427220 (L.L.W.), and OCE- 0327261 and OCE-0328117 (T.S.). Additional support was provided by The Edwin Link Foundation (J.C.K.)

    Protein Aggregation and Protein Instability Govern Familial Amyotrophic Lateral Sclerosis Patient Survival

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    The nature of the “toxic gain of function” that results from amyotrophic lateral sclerosis (ALS)-, Parkinson-, and Alzheimer-related mutations is a matter of debate. As a result no adequate model of any neurodegenerative disease etiology exists. We demonstrate that two synergistic properties, namely, increased protein aggregation propensity (increased likelihood that an unfolded protein will aggregate) and decreased protein stability (increased likelihood that a protein will unfold), are central to ALS etiology. Taken together these properties account for 69% of the variability in mutant Cu/Zn-superoxide-dismutase-linked familial ALS patient survival times. Aggregation is a concentration-dependent process, and spinal cord motor neurons have higher concentrations of Cu/Zn-superoxide dismutase than the surrounding cells. Protein aggregation therefore is expected to contribute to the selective vulnerability of motor neurons in familial ALS

    PaLM 2 Technical Report

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    We introduce PaLM 2, a new state-of-the-art language model that has better multilingual and reasoning capabilities and is more compute-efficient than its predecessor PaLM. PaLM 2 is a Transformer-based model trained using a mixture of objectives. Through extensive evaluations on English and multilingual language, and reasoning tasks, we demonstrate that PaLM 2 has significantly improved quality on downstream tasks across different model sizes, while simultaneously exhibiting faster and more efficient inference compared to PaLM. This improved efficiency enables broader deployment while also allowing the model to respond faster, for a more natural pace of interaction. PaLM 2 demonstrates robust reasoning capabilities exemplified by large improvements over PaLM on BIG-Bench and other reasoning tasks. PaLM 2 exhibits stable performance on a suite of responsible AI evaluations, and enables inference-time control over toxicity without additional overhead or impact on other capabilities. Overall, PaLM 2 achieves state-of-the-art performance across a diverse set of tasks and capabilities. When discussing the PaLM 2 family, it is important to distinguish between pre-trained models (of various sizes), fine-tuned variants of these models, and the user-facing products that use these models. In particular, user-facing products typically include additional pre- and post-processing steps. Additionally, the underlying models may evolve over time. Therefore, one should not expect the performance of user-facing products to exactly match the results reported in this report
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