1,136 research outputs found
Length of hospital stay following temporary pacing post-transcatheter valve replacement
Transcatheter valve replacement (TVR) provides a minimally invasive method of valve replacement. During TVR, conduction abnormalities can develop, but only some will require permanent pacing, and use of temporary pacing provides immediate support until a decision of temporary pacing is made. Henry Ford Health System has two methods of pacing lead placement: balloon tipped leads and screw-in leads. Currently, the impact of different types of temporary pacing leads on recovery time is still unknown. This project investigated the differences in the length of hospital and ICU stay between patients who received the balloon tipped and screw-in leads. Data was collected from 144 patients who underwent TVR and was analyzed for differences between these two patient groups. We had 44 patients with a balloon tipped lead and 104 patients with a screw in lead. Of the patients who received balloon tipped leads, average length of stay was 10.4 days and number of ICU days was 4.3. For the patients who received Screw in leads, average length of stay was 6.7 days and average number of ICU days was 1.2. Both the length of hospital stay (
The surface density of Extremely Red Objects in high-z quasar fields
We report on a study of the surface density of Extremely Red Objects (EROs)
in the fields of 13 radio-loud quasars at 1.8 < z < 3.0 covering a total area
of 61.7 sqr arcmin. There is a large variation in the ERO surface density from
field to field, and as many as 30--40 % of the fields have roughly 4--5 times
more EROs than what is expected from a random distribution. The average surface
density exceeds the value found in large random-field surveys by a factor of
2--3, a result which is significant at the >3 sigma level. Hence, it appears
that the quasar lines of sight are biassed towards regions of high ERO density.
This might be caused by clusters or groups of galaxies physically associated
with the quasars. However, an equally likely possibility is that the observed
ERO excess is part of overdensities in the ERO population along the line of
sight to the quasars. In this case, the non-randomness of quasar fields with
respect to EROs may be explained in terms of gravitational lensing.Comment: 6 pages, 2 figures, to appear in "Radio galaxies: past, present and
future", eds. M. Jarvis et al., Leiden, November 200
Amino acid stable N isotope estimations reveal uniform diazotrophic contributions across zooplankton size fractions in the subtropical N Atlantic
presentacionNatural abundance of stable N isotopes (d15N) in both individual amino acids and bulk organic matter of size-fractionated plankton samples were compared to analyze the differential impact of nitrogen fixation through the food web, in a transect across the subtropical North Atlantic. Low d15N values in the central and western regions were consistent with the prevalence of nitrogen fixation, while maximum d15N values tracked the influence of West African upwelling in the eastern zone. Compound-specific amino acid isotope data (CSI-AA) revealed relatively low variability in the impact of diazotrophic nitrogen within the different plankton size fractions, while d15N of bulk organic matter showed higher variability with size. Moreover, CSI-AA results also indicated a greater importance of diazotrophy than suggested by bulk d15N values. Trophic position estimates using CSI-AA showed the expected general increase with mean plankton size class and varied in a relatively narrow range (1.8 to 2.5), with the lowest values in the central zone. Using isotopic δ15N values of individual amino acids (in particular Phe and Thr), as well as reconstructed total protein d15N values, a set of new relationships with bulk plankton d15N was determined, aimed to improve the use CSI-AA data in tracing direct plankton contributions to organic nitrogen pools in the ocean. These new results represent the most detailed investigation of CSI-AA data in zooplankton size classes to date, and point to a key role of large zooplankton in the transmission of the diazotrophic nitrogen up oceanic food webs.Malaspina-2010(CSD2008-00077), NSF Grant OCE-113181
The Canary Basin contribution to the seasonal cycle of the Atlantic Meridional Overturning Circulation at 26°N
This study examines the seasonal cycle of the Atlantic Meridional Overturning Circulation (AMOC) and its eastern boundary contributions. The cycle has a magnitude of 6 Sv, as measured by the RAPID/MOCHA/WBTS project array at 26°N, which is driven largely by the eastern boundary. The eastern boundary variations are explored in the context of the regional circulation around the Canary Islands. There is a 3 month lag between maximum wind forcing and the largest eastern boundary transports, which is explained in terms of a model for Rossby wave generated at the eastern boundary. Two dynamic processes take place through the Lanzarote Passage (LP) in fall: the recirculation of the Canary Current and the northward flow of the Intermediate Poleward Undercurrent. In contrast, during the remaining seasons the transport through the LP is southward due to the Canary Upwelling Current. These processes are linked to the seasonal cycle of the AMOC
Bacterially mediated removal of phosphorus and cycling of nitrate and sulfate in the waste stream of a "zero-discharge" recirculating mariculture system
Simultaneous removal of nitrogen and phosphorus by microbial biofilters has been used in a variety of water treatment systems including treatment systems in aquaculture. In this study, phosphorus, nitrate and sulfate cycling in the anaerobic loop of a zero-discharge, recirculating mariculture system was investigated using detailed geochemical measurements in the sludge layer of the digestion basin. High concentrations of nitrate and sulfate, circulating in the overlying water (~15 mM), were removed by microbial respiration in the sludge resulting in a sulfide accumulation of up to 3 mM. Modelling of the observed S and O isotopic ratios in the surface sludge suggested that, with time, major respiration processes shifted from heterotrophic nitrate and sulfate reduction to autotrophic nitrate reduction. The much higher inorganic P content of the sludge relative to the fish feces is attributed to conversion of organic P to authigenic apatite. This conclusion is supported by: (a) X-ray diffraction analyses, which pointed to an accumulation of a calcium phosphate mineral phase that was different from P phases found in the feces, (b) the calculation that the pore waters of the sludge were highly oversaturated with respect to hydroxyapatite (saturation index = 4.87) and (c) there was a decrease in phosphate (and in the Ca/Na molar ratio) in the pore waters simultaneous with an increase in ammonia showing there had to be an additional P removal process at the same time as the heterotrophic breakdown of organic matter
The Size Distributions of Asteroid Families in the SDSS Moving Object Catalog 4
Asteroid families, traditionally defined as clusters of objects in orbital
parameter space, often have distinctive optical colors. We show that the
separation of family members from background interlopers can be improved with
the aid of SDSS colors as a qualifier for family membership. Based on an
~88,000 object subset of the Sloan Digital Sky Survey Moving Object Catalog 4
with available proper orbital elements, we define 37 statistically robust
asteroid families with at least 100 members using a simple Gaussian
distribution model in both orbital and color space. The interloper rejection
rate based on colors is typically ~10% for a given orbital family definition,
with four families that can be reliably isolated only with the aid of colors.
About 50% of all objects in this data set belong to families, and this fraction
varies from about 35% for objects brighter than an H magnitude of 13 and rises
to 60% for objects fainter than this. The fraction of C-type objects in
families decreases with increasing H magnitude for H > 13, while the fraction
of S-type objects above this limit remains effectively constant. This suggests
that S-type objects require a shorter timescale for equilibrating the
background and family size distributions via collisional processing. The size
distributions for 15 families display a well-defined change of slope and can be
modeled as a "broken" double power-law. Such "broken" size distributions are
twice as likely for S-type familes than for C-type families, and are dominated
by dynamically old families. The remaining families with size distributions
that can be modeled as a single power law are dominated by young families. When
size distribution requires a double power-law model, the two slopes are
correlated and are steeper for S-type families.Comment: 50 pages, 16 figures, accepted for publication in Icaru
BRST Analysis of Physical States for 2D (Super) Gravity Coupled to (Super) Conformal Matter
We summarize some recent results on the BRST analysis of physical states of
2D gravity coupled to c<=1 conformal matter and the supersymmetric
generalization.Comment: 11 page
- …