New views of the spherical Bouguer gravity anomaly

This paper presents a number of new concepts concerning the gravity anomaly. First, it identifies a distinct difference between a surface (2-D) gravity anomaly (the difference between actual gravity on one surface and normal gravity on another surface) and a solid (3-D) gravity anomaly defined in the fundamental gravimetric equation. Second, it introduces the 'no topography' gravity anomaly (which turns out to be the complete spherical Bouguer anomaly) as a means to generate a quantity that is smooth, thus suitable for gridding, and harmonic, thus suitable for downward continuation. It is understood that the possibility of downward continuing a smooth gravity anomaly would simplify the task of computing an accurate geoid. It is also shown that the planar Bouguer anomaly is not harmonic, and thus cannot be downward continued

The rigorous determination of orthometric heights

The main problem of the rigorous definition of the orthometric height is the evaluation of the mean value of the Earth’s gravity acceleration along the plumbline within the topography. To find the exact relation between rigorous orthometric and Molodensky’s normal heights, the mean gravity is decomposed into: the mean normal gravity, the mean values of gravity generated by topographical and atmospheric masses, and the mean gravity disturbance generated by the masses contained within geoid. The mean normal gravity is evaluated according to Somigliana–Pizzetti’s theory of the normal gravity field generated by the ellipsoid of revolution. Using the Bruns formula, the mean values of gravity along the plumbline generated by topographical and atmospheric masses can be computed as the integral mean between the Earth’s surface and geoid. Since the disturbing gravity potential generated by masses inside the geoid is harmonic above the geoid, the mean value of the gravity disturbance generated by the geoid is defined by applying the Poisson integral equation to the integral mean. Numerical results for a test area in the Canadian Rocky Mountains show that the difference between the rigorously defined orthometric height and the Molodensky normal height reaches 0.5 m

Assessment of Density Variations of Marine Sediments with Ocean and Sediment Depths

We analyze the density distribution of marine sediments using density samples taken from 716 drill sites of the Deep Sea Drilling Project (DSDP). The samples taken within the upper stratigraphic layer exhibit a prevailing trend of the decreasing density with the increasing ocean depth (at a rate of −0.05 g/cm3 per 1 km). Our results confirm findings of published studies that the density nonlinearly increases with the increasing sediment depth due to compaction. We further establish a 3D density model of marine sediments and propose theoretical models of the ocean-sediment and sediment-bedrock density contrasts. The sediment density-depth equation approximates density samples with an average uncertainty of about 10% and better represents the density distribution especially at deeper sections of basin sediments than a uniform density model. The analysis of DSDP density data also reveals that the average density of marine sediments is 1.70 g/cm3 and the average density of the ocean bedrock is 2.9 g/cm3

Correspondence: No substantial long-term bias in the Cenozoic benthic foraminifera oxygen-isotope record

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Soluble Triggering Receptor Expressed on Myeloid Cells 1 Is Released in Patients with Stable Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is increasingly recognized as a systemic disease that is associated with increased serum levels of markers of systemic inflammation. The triggering receptor expressed on myeloid cells 1 (TREM-1) is a recently identified activating receptor on neutrophils, monocytes, and macrophage subsets. TREM-1 expression is upregulated by microbial products such as the toll-like receptor ligand lipoteichoic acid of Gram-positive or lipopolysaccharides of Gram-negative bacteria. In the present study, sera from 12 COPD patients (GOLD stages I–IV, FEV1 51 ± 6%) and 10 healthy individuals were retrospectively analyzed for soluble TREM-1 (sTREM-1) using a newly developed ELISA. In healthy subjects, sTREM-1 levels were low (median 0.25 ng/mL, range 0–5.9 ng/mL). In contrast, levels of sTREM-1 in sera of COPD patients were significantly increased (median 11.68 ng/mL, range 6.2–41.9 ng/mL, P<.05). Furthermore, serum levels of sTREM-1 showed a significant negative correlation with lung function impairment. In summary, serum concentrations of sTREM-1 are increased in patients with COPD. Prospective studies are warranted to evaluate the relevance of sTREM-1 as a potential marker of the disease in patients with COPD

736–3 Costs and Complications of Non-thoracotomy Defibrillator Systems: Impact of Health Care Financing Administration Guidelines

Non-thoracotomy implantable defibrillator (ICD) systems have been shown to have lower costs and fewer complications than thoracotomy systems. Recent interpretation of Health Care Financing Administration regulations has challenged reimbursement for investigational devices or combinations of components not approved by the Food and Drug Administration (“off-label”). We compared the costs and complications associated with approved pulse generator/lead systems (CPI 1600/Endotak, CPl 1705/Endotak and Medtronic 7217/Transvene, n=136) with investigational and “off-label” systems (CPI 1625/Endotak, CPI 1715/Endotak, Medtronic 7219/Transvene and Ventritex V100 or V110/TVL and Vl00/Endotak, n=79). Age [63±12 years versus 63±11 years (mean±SD)] and ejection fraction (31±15% versus 31±11%) were similar for patients with approved and investigational systems, respectively. However, total hospital charges including preoperative care and evaluation, implant procedure and hardware, postoperative testing and revisions were $64±19,000 for approved devices versus$57±16,000 for non-approved devices (p=0.02) despite higher overall costs of newer pulse generators and leads. Total length of stay was 17±10 days versus 14±8 days (p=0.03) and complications including lead dislodgement, increased defibrillation threshold, hematoma and infection were 25/136 versus 4/77 (p&lt;0.005) for approved and investigational or “off-label” systems, respectively. Based on data provided by the manufacturers, anticipated average battery longevity is 3.8 years for approved systems and 5.5 years for investigational or “off-label” systems.ConclusionsThe prudent use of current investigational or “off-label” nonthoracotomy ICD systems is more cost-effective and is associated with fewer complications than approved ICD systems. When increased battery longevity is considered, long term costs of non-thoracotomy ICD therapy may be improved dramatically with the use of investigational or “off-label” systems. Review of reimbursement regulations may be warranted

New free-air and Bouguer gravity fields of Taiwan from multiple platforms and sensors

We construct 1' × 1' grids of free-air and Bouguer gravity anomalies around Taiwan with well-defined error estimates for quality assessment. The grids are compiled from land, airborne and shipborne gravity measurements, augmented with altimeter gravity at sea. Three sets of relative land gravity measurements are network-adjusted and outlier-edited, yielding accuracies of 0.03–0.09 mGal. Three airborne gravity sets are collected at altitudes 5156 and 1620 m with accuracies of 2.57–2.79 mGal. Seven offshore shipborne gravity campaigns around Taiwan and its offshore islands yield shallow-water gravity values with 0.88–2.35 mGal accuracies. All data points are registered with GPS-derived geodetic coordinates at cm–dm accuracies, allowing for precise gravity reductions and computing gravity disturbances. The various datasets are combined by the band-limited least-squares collocation in a one-step procedure. In the eastern mountainous (or offshore) region, Bouguer anomalies and density contrasts without considering the oceanic (or land) topographic contribution are underestimated. The new grids show unprecedented tectonic features that can revise earlier results, and can be used in a broad range of applications