Whole-system metabolism and CO₂ fluxes in a Mediterranean Bay dominated by seagrass beds (Palma Bay, NW Mediterranean)

The relationship between whole-system metabolism estimates based on planktonic and benthic incubations (bare sediments and seagrass, Posidonia oceanica meadows), and CO2 fluxes across the air-sea interface were examined in the Bay of Palma (Mallorca, Spain) during two cruises in March and June 2002. Moreover, planktonic and benthic incubations were performed at monthly intervals from March 2001 to October 2002 in a seagrass vegetated area of the bay. From the annual study, results showed a contrast between the planktonic compartment, which was heterotrophic during most of the year, except for occasional bloom episodes, and the benthic compartment, which was slightly autotrophic. Whereas the seagrass community was autotrophic, the excess organic carbon production therein could only balance the excess respiration of the planktonic compartment in shallow waters (<10 m) relative to the maximum depth of the bay (55 m). This generated a horizontal gradient from autotrophic or balanced communities in the shallow, seagrass-covered areas of the bay, to strongly heterotrophic communities in deeper areas, consistent with the patterns of CO2 fields and fluxes across the bay observed during the two extensive cruises in 2002. Finally, dissolved inorganic carbon and oxygen budgets provided NEP estimates in fair agreement with those derived from direct metabolic estimates based on incubated samples over the Posidonia oceanica meadow

Conformal linear gravity in de Sitter space II

From the group theoretical point of view, it is proved that the theory of linear conformal gravity should be written in terms of a tensor field of rank-3 and mixed symmetry [Binegar, et al, Phys. Rev. D 27, (1983) 2249]. We obtained such a field equation in de Sitter space [Takook, et al, J. Math. Phys. 51, (2010) 032503]. In this paper, a proper solution to this equation is obtained as a product of a generalized polarization tensor and a massless scalar field and then the conformally invariant two-point function is calculated. This two-point function is de Sitter invariant and free of any pathological large-distance behavior.Comment: 16 pages, no figure, published versio

Supersymmetric solutions of PT-/non-PT-symmetric and non-Hermitian Screened Coulomb potential via Hamiltonian hierarchy inspired variational method

The supersymmetric solutions of PT-symmetric and Hermitian/non-Hermitian forms of quantum systems are obtained by solving the Schrodinger equation for the Exponential-Cosine Screened Coulomb potential. The Hamiltonian hierarchy inspired variational method is used to obtain the approximate energy eigenvalues and corresponding wave functions.Comment: 13 page

Whole-system metabolism and CO2 fluxes in a Mediterranean Bay dominated by seagrass beds (Palma Bay, NW Mediterranean)

Planktonic and benthic incubations (bare and Posidonia oceanica vegetated sediments) were performed at monthly intervals from March 2001 to October 2002 in a seagrass vegetated area of the Bay of Palma (Mallorca, Spain). Results showed a contrast between the planktonic compartment, which was on average near metabolic balance (-4.6 +/- 5.9 mmol O-2 m(-2) d(-1)) and the benthic compartment, which was autotrophic (17.6 +/- 8.5 mmol O-2 m(-2) d(-1)). During two cruises in March and June 2002, planktonic and benthic incubations were performed at several stations in the bay to estimate the whole-system metabolism and to examine its relationship with partial pressure of CO2 (pCO(2)) and apparent oxygen utilisation (AOU) spatial patterns. Moreover, during the second cruise, when the residence time of water was long enough, net ecosystem production (NEP) estimates based on incubations were compared, over the Posidonia oceanica meadow, to rates derived from dissolved inorganic carbon ! (DIC) and oxygen (O-2) mass balance budgets. These budgets provided NEP estimates in fair agreement with those derived from direct metabolic estimates based on incubated samples over the Posidonia oceanica meadow. Whereas the seagrass community was autotrophic, the excess organic carbon production therein could only balance the planktonic heterotrophy in shallow waters relative to the maximum depth of the bay ( 55 m). This generated a horizontal gradient from autotrophic or balanced communities in the shallow seagrass-covered areas, to strongly heterotrophic communities in deeper areas of the bay. It seems therefore that, on an annual scale in the whole bay, the organic matter production by the Posidonia oceanica may not be sufficient to fully compensate the heterotrophy of the planktonic compartment, which may require external organic carbon inputs, most likely from land