675 research outputs found

    Holonomy Spin Foam Models: Definition and Coarse Graining

    Full text link
    We propose a new holonomy formulation for spin foams, which naturally extends the theory space of lattice gauge theories. This allows current spin foam models to be defined on arbitrary two-complexes as well as to generalize current spin foam models to arbitrary, in particular finite groups. The similarity with standard lattice gauge theories allows to apply standard coarse graining methods, which for finite groups can now be easily considered numerically. We will summarize other holonomy and spin network formulations of spin foams and group field theories and explain how the different representations arise through variable transformations in the partition function. A companion paper will provide a description of boundary Hilbert spaces as well as a canonical dynamic encoded in transfer operators.Comment: 36 pages, 12 figure

    Acoustic doppler current profiling in the Western Pacific during the WOCE P10 cruise, November/December 1993

    Get PDF
    The objective of this cruise was to occupy a hydrographic section nominally along 149E from Papua New Guinea to the shelf off the coast of Japan near Yokohama as part of the one-time WOCE Hydrographic Programe survey of the Pacific Ocean, line P10. This report describes the processing of shipboard acoustic Doppler current profier (ADCP) data that were collected during this cruise. New GPS-based heading measurements ("Ashtech heading"). which increase the accuracy of the ADCP, are covered in detail. A subset of the processed data from the New Guinea Coastal Undercurrent and from the Kuroshio is presented.Funding was provided by the National Science Foundation through Grant No. OCE93-06689

    The acute phase protein, haptoglobin : a potential parameter in welfare assessment?

    Get PDF
    Physiological parameters are important measures in animal welfare assessment. To assess the amount of stress an animal experiences, stress hormones like cortisol are frequently used. However, measuring cortisol has major disadvantages due to its rapid reactivity and decline and many influencing factors. Other potential alternative markers are acute phase proteins, since stress is known to affect the immune system. A pilot study was conducted to investigate the response of the acute phase protein, plasma haptoglobine (HP), in pigs subjected to a stressor (food deprivation) and to examine the correlation between HP levels and average daily growth (ADG). Forty grower pigs (25.1 ± 4.4 kg, mean ± SD) (sex and former pen mates balanced), were allocated to 4 conventional pens, 2 treatment (T) and 2 control (C) groups (10 pigs per pen). After 10 days of adaptation the experiment started and ran for 3 weeks. In the 2nd week, T groups were repeatedly subjected to an 8-hour food deprivation (day 1, 3, 5 and 7 of week 2), C groups had normal, unrestricted, access to food. Pigs were weighed twice a week and blood was collected once a week (every 5th day). Mean levels of plasma HP of C and T groups showed large variation between individuals (C groups, week 2: 1.84 ± 3.11 mg/ml; T groups, week 2: 1.40 ± 1.16 mg/ml). No significant differences (Kruskal-Wallis test) in HP levels or growth were found between the C and T groups or between the different weeks within the T groups. Significant negative weak to moderate correlations were found between ADG and HP levels (HP week 1 and ADG week 1: rs = -0.47, p=0.005; HP week 2 and ADG total; rs= -0.60, p=0.015; HP week 3 and ADG total: rs = -0.43, p=0.025; average HP total and ADG total: rs= -0.41, p=0.017). Large variations in HP levels between individuals were shown and no effect of treatment on HP levels or growth was found. Possibly, food deprivation had no apparent stress eliciting effect. Despite these results, interesting correlations between the level of HP and ADG were found, corroborating the inverse relationship between the acute phase response and growth. To further investigate the relation of the acute phase response and stress a successive experiment will be conducted in which we apply a stronger stressor (mixing pigs) and combine the physiological data with behavior

    On the Expansions in Spin Foam Cosmology

    Get PDF
    We discuss the expansions used in spin foam cosmology. We point out that already at the one vertex level arbitrarily complicated amplitudes contribute, and discuss the geometric asymptotics of the five simplest ones. We discuss what type of consistency conditions would be required to control the expansion. We show that the factorisation of the amplitude originally considered is best interpreted in topological terms. We then consider the next higher term in the graph expansion. We demonstrate the tension between the truncation to small graphs and going to the homogeneous sector, and conclude that it is necessary to truncate the dynamics as well.Comment: 17 pages, 4 figures, published versio

    Increasing frequency of mid‐depth salinity maximum intrusions in the Middle Atlantic Bight

    Get PDF
    © The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gawarkiewicz, G., Fratantoni, P., Bahr, F., & Ellertson, A. Increasing frequency of mid‐depth salinity maximum intrusions in the Middle Atlantic Bight. Journal of Geophysical Research: Oceans, 127(7), (2022): e2021JC018233, https://doi.org/10.1029./2021jc018233.Shelfbreak exchange processes have been studied extensively in the Middle Atlantic Bight. An important process occurring during stratified conditions is the Salinity Maximum Intrusion. These features are commonly observed at the depth of the seasonal pycnocline, and less frequently at the surface and bottom. Data collected from NOAA's National Marine Fisheries Service Ecosystem Monitoring program as well as data collected from the fishing industry in Rhode Island show that the middepth intrusions are now occurring much more frequently than was reported in a previous climatology of the intrusions (Lentz, 2003, https://doi.org/10.1029/2003JC001859). The intrusions have a greater salinity difference from ambient water and penetrate large distances shoreward of the shelf break relative to the earlier climatology. The longer term data from the Ecosystem Monitoring program indicates that the increase in frequency occurred in 2000, and thus may be linked to a recent regime shift in the annual formation rate of Warm Core Rings by the Gulf Stream. Given the increased frequency of these salty intrusions, it will be necessary to properly resolve this process in numerical simulations in order to account for salt budgets for the continental shelf and slope.Data collection for the Shelf Research Fleet and salary for G. Gawarkiewicz, F. Bahr, and A. Ellertson were provided by the van Beuren Charitable Foundation of Newport, RI. G. Gawarkiewicz, F. Bahr, and A. Ellertson were also supported in analysis of this data by NSF grant OCE-1851261

    OC449-09 Data Report : St. Thomas, USVI to Bermuda, December 1-10, 2008

    Get PDF
    Data collected during multiple surveys of hydrography, velocity, and biological quantities are presented from a 9-day cruise aboard the R/V Oceanus near the island of St. Thomas, USVI and a subsequent transit to Bermuda during December, 2008. This cruise (OC449-09) was undertaken primarily to field test a newly acquired towed-undulating body, the Scanfish. The Scanfish and a second towed body, the Video Plankton Recorder (VPR), were used to survey hydrographic, optical, and biological properties north and south of St. Thomas. Conductivity-Temperature-Depth (CTD) casts and plankton net-tows were made at locations along the survey transects for inter-comparison. The VPR was also used to profile conditions between St. Thomas and Bermuda during transit. An overview of the cruise is given along with descriptions of the data collection methods, processing steps taken, and data products available for distribution.Funding for this research was provided by the King Abdullah University of Science and Technology (KAUST) under a cooperative research agreement with Woods Hole Oceanographic Institution

    Auricular Acupuncture with Laser

    Get PDF
    Auricular acupuncture is a method which has been successfully used in various fields of medicine especially in the treatment of pain relief. The introduction of lasers especially low-level lasers into medicine brought besides the already existing stimulation with needles and electricity an additional technique to auricular acupuncture. This literature research looks at the historical background, the development and the anatomical and neurological aspects of auricular acupuncture in general and auricular laser acupuncture in detail. Preliminary scientific findings on auricular acupuncture with laser have been described in detail and discussed critically in this review article. The results of the studies have shown evidence of the effect of auricular laser acupuncture. However, a comparison of these studies was impossible due to their different study designs. The most important technical as well as study parameters were described in detail in order to give more sufficient evidence and to improve the quality of future studies

    Subduction in the subtropical gyre : Seasoar cruises data report

    Get PDF
    The overall objective of the Subduction Accelerated Research Initiative (ARI) was to bring together several techniques to address the formation and evolution of newly formed water masses. The Seasoar component provided surveys of temperature and salinity to help determine the spatial varability of the temperature, salinity and density fields in both the active frontal regions and in the vicinity of subducting water tagged by bobbers. Data were collected in the eastern North Atlantic Ocean in spring 1991, winter 1992, winter 1993 and spring 1994. "Star" patterns were used to study the mesoscale varability. Temperature, pressure and thickness for each pattern were objectively mapped on potential density surfaces of 26.5, 26.7 and 26.9 kg/m3. Acoustic Doppler Current Profies (ADCP) maps were also created for the the two shallower density surfaces. We describe the Seasoar data collected during the four cruises. A CD-Rom includes 1- and 3-second conductivity-temperature-depth (CTD), cruise navigation, ADCP and Seasoar engineering data, as well as color figures of these data. This data report can also be viewed using an internet information browser (i.e., Mosaic, Netscape) using the provided CD-Rom.Funding was provided by the Office of Naval Research through Grants Nos, N00014-91-J-1585, N00014-90-J-1425. and N00014-90-J-1508

    Shelfbreak frontal structure and processes north of Cape Hatteras in winter

    Get PDF
    Author Posting. © Sears Foundation for Marine Research, 2008. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 66 (2008): 755-799.The circulation north of Cape Hatteras is complicated by the proximity of the shelfbreak front, the Gulf Stream, and convergent shelf flow from the Middle and South Atlantic Bights. A three-week cruise in this region in January/February, 2005 was undertaken in order to study the structure of the shelfbreak front as it terminates near Cape Hatteras and to quantify the freshwater transport from the Middle Atlantic Bight shelf into the Gulf Stream. Two strongly contrasting conditions were identified. Early in the cruise, the Gulf Stream directly abutted the shelfbreak at Cape Hatteras and drove a northward flow over the continental shelf as far north as 35°45′N. All of the Middle Atlantic Bight shelf water terminated by 35°30′N. Ten days later, the Gulf Stream had moved away from the shelfbreak south of Cape Hatteras and strong winds from the north were present. During this time, the shelfbreak frontal jet was strong (maximum southward velocity of approximately 0.5 m s-1 with a Rossby number of 2) and abruptly turned eastward and offshore between 35°35′N and 35°45′N. Freshwater transport eastward from the shelfbreak jet was 7.4 mSv and southward over the shelf was 19.9 mSv, giving a total freshwater transport of 27.3 mSv. This likely represents an upper bound due to the strong wind forcing. Implications of these results for the freshwater budget of the Middle Atlantic Bight shelf, stability properties of the shelfbreak front in this region, and the formation of “Ford water” in the Gulf Stream are discussed.Support for the Rutgers satellite archive is provided by NSF, ONR and NOAA. This work was supported under NSF Grant Number OCE-0327249

    WHOI Hawaii Ocean Timeseries Station (WHOTS) : WHOTS-3 mooring turnaround cruise report

    Get PDF
    The Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Timeseries (HOT) Site (WHOTS), 100 km north of Oahu, Hawaii, is intended to provide long-term, high-quality air-sea fluxes as a coordinated part of the HOT program and contribute to the goals of observing heat, fresh water, and chemical fluxes at a site representative of the oligotrophic North Pacific Ocean. The approach is to maintain a surface mooring outfitted for meteorological and oceanographic measurements at a site near 22.75N 158W by successive mooring turnarounds. These observations will be used to investigate air-sea interaction processes related to climate variability. The first WHOTS mooring (WHOTS-1) was deployed in August 2004. WHOTS-1 was recovered and WHOTS-2 deployed in July 2005. This report documents recovery of the WHOTS-2 mooring and deployment of the third mooring (WHOTS-3) at the same site. Both moorings used Surlyn foam buoys as the surface element and were outfitted with two Air-Sea Interaction Meteorology (ASIMET) systems. Each system measures, records, and transmits via Argos satellite, the surface meteorological variables necessary to compute air-sea fluxes of heat, moisture, and momentum. WHOTS-2 was equipped with one Iridium data transmitter, and WHOTS-3 had two Iridium data transmitters. In cooperation with R. Lukas of the University of Hawaii, the upper 155 m of the morrings were outfitted with oceanographic sensors for the measurement of temperature, conductivity, and velocity. The WHOTS mooring turnaround was done on the Scripps Institution of Oceanography ship Revelle, Cruise AMAT-07, by the Upper Ocean Processes Group of the Woods Hole Oceanographic Institution and Roger Lukas’group at the University of Hawaii. The cruise took place between 22 and 29 June 2006. Operations on site were initiated with an intercomparison of shipboard meteorological observations with the WHOTS-2 buoy. Dr. Frank Bradley, CSIRO, Australia, assisted with these comparisons. This was followed by recovery of the WHOTS-2 mooring on 24 June. A number of recovered instruments were calibrated by attaching them to the rosette frame of the CTD. Shallow CTD profiles were taken every two hours for 12 hours on the 25th of June. A fish trap was deployed on June 25th by John Yeh, a University of Hawaii graduate student. The WHOTS-3 mooring was deployed on 26 June at approximately 22°46'N, 157°54'W in 4703 m of water. A ship-buoy intercomparison period and series of shallow CTDs followed along with a second deployment of the fishtrap. A NOAA Teacher-At-Sea, Diana Griffiths, and a NOAA Hollings Scholar, Terry Smith, participated in the cruise. This report describes the mooring operations, some of the pre-cruise buoy preparations and CTD casts taken during the cruise, the fish trap deployments, and the experiences of the Teacher-at-Sea and Hollings Scholar.Funding was provided by the National Oceanic and Atmospheric Administration under grant No. NA17RJ1223 for the Cooperative Institute for Climate and Ocean Research (CICOR)
    corecore