Distinguishing f(R) theories from general relativity by gravitational lensing effect

The post-Newtonian formulation of a general class of f(R) theories is set up to 3rd order approximation. It turns out that the information of a specific form of f(R) gravity is encoded in the Yukawa potential, which is contained in the perturbative expansion of the metric components. Although the Yukawa potential is canceled in the 2nd order expression of the effective refraction index of light, detailed analysis shows that the difference of the lensing effect between the f(R) gravity and general relativity does appear at the 3rd order when $\sqrt{f''(0)/f'(0)}$ is larger than the distance $d_0$ to the gravitational source. However, the difference between these two kinds of theories will disappear in the axially symmetric spacetime region. Therefore only in very rare case the f(R) theories are distinguishable from general relativity by gravitational lensing effect at the 3rd order post-Newtonian approximation.Comment: 14 page

Invertebrate larval availability during summer upwelling and downwelling on the inner continental shelf off New Jersey

This study examined the effects of wind-driven, cross-shelf circulation on invertebrate larval supply to benthic habitats on the inner continental shelf off Tuckerton, New Jersey, USA. Study sites were located along an inshore/offshore transect in the LEO-15 research area at Beach Haven Ridge, a 12–20 m deep, shore-oblique sand ridge. Meroplankton was sampled using Moored, Automated, Serial Zooplankton Pumps which were programmed to take 250-l samples, ~1 m above the bottom, every 4 h. Upwelling and downwelling conditions were characterized using wind data from the nearby meteorological tower at the Rutgers University Marine Field Station, and bottom temperatures from LEO-15 node data and the pump sites. Studies were carried out during July in 1996 –1998 because previous recruitment studies showed that July was when larval surfclams, Spisula solidissima, were abundant and their settlement maximal. The study was repeated over three years to sample multiple upwelling/downwelling sequences. Although the study focused primarily on the dominant S. solidissima larvae, other meroplankton were also enumerated. Short-lived pulses (12 h or less) of highest larval surfclam concentrations (up to 3000 sample -1, sample volume = 250 l) often coincided with the initial arrival of warm water at the bottom at the initiation of downwelling, indicating a patchy larval distribution that is probably related to high larval concentrations near fronts. On one date in July 1998, very high concentrations of surfclam and pholad bivalve larvae coincided with the arrival of warm, relatively low salinity water. This pattern suggested a larval concentrating mechanism near an estuarine front, perhaps from the Hudson River plume. Sampling during multiple upwelling/downwelling events over the three summers revealed a close correlation between peaks in larval concentration of bivalves and gastropods coinciding with the arrival of downwelled warm water at the bottom at inner shelf sites

4-(4-Chloro­phen­yl)-5-(4-nitro­phen­yl)-3-phenyl-4H-1,2,4-triazole

The title compound, C20H13ClN4O2, was synthesized by the condensation of 4-nitro­benzohydrazide and N-(4-chlorophen­yl)­benzimidoyl chloride in N,N-dimethyl­acetamide. The asymmetric unit contains two independent mol­ecules. In one molecule, the triazole ring is oriented at dihedral angles of 23.1 (5), 85.4 (1) and 10.5 (1)° with respect to the phenyl, chlorophenyl and nitrophenyl rings, respectively. In the other molecule, the corresponding dihedral angles are 29.8 (9), 73.4 (7) and 16.4 (3)°

Ketamine Inhibits Lung Fluid Clearance through Reducing Alveolar Sodium Transport

Ketamine is a broadly used anaesthetic for analgosedation. Accumulating clinical evidence shows that ketamine causes pulmonary edema with unknown mechanisms. We measured the effects of ketamine on alveolar fluid clearance in human lung lobes ex vivo. Our results showed that intratracheal instillation of ketamine markedly decreased the reabsorption of 5% bovine serum albumin instillate. In the presence of amiloride (a specific ENaC blocker), fluid resolution was not further decreased, suggesting that ketamine could decrease amiloride-sensitive fraction of AFC associated with ENaC. Moreover, we measured the regulation of amiloride-sensitive currents by ketamine in A549 cells using whole-cell patch clamp mode. Our results suggested that ketamine decreased amiloride-sensitive Na+ currents (ENaC activity) in a dose-dependent fashion. These data demonstrate that reduction in lung ENaC activity and lung fluid clearance following administration of ketamine may be the crucial step of the pathogenesis of resultant pulmonary edema

Coverage Analysis for Cellular-Connected Random 3D Mobile UAVs with Directional Antennas

This letter proposes an analytical framework to evaluate the coverage performance of a cellular-connected unmanned aerial vehicle (UAV) network in which UAV user equipments (UAV-UEs) are equipped with directional antennas and move according to a three-dimensional (3D) mobility model. The ground base stations (GBSs) equipped with practical down-tilted antennas are distributed according to a Poisson point process (PPP). With tools from stochastic geometry, we derive the handover probability and coverage probability of a random UAV-UE under the strongest average received signal strength (RSS) association strategy. The proposed analytical framework allows to investigate the effect of UAV-UE antenna beamwidth, mobility speed, cell association, and vertical motions on both the handover probability and coverage probability. We conclude that the optimal UAV-UE antenna beamwidth decreases with the GBS density, and the omnidirectional antenna model is preferred in the sparse network scenario. What's more, the superiority of the strongest average RSS association over the nearest association diminishes with the increment of GBS density.Comment: 5 pages, 5 figures, submitted to IEEE Wireless Communications Letter