SUMMARY: New data force us to raise previous estimates of oceanic denitrification. Our revised estimate of ~ 450 Tg N yr -1 (Tg = 10 12 g) produces an oceanic fixed N budget with a large deficit ) that can be explained only by positing an ocean that has deviated far from a steady-state, the need for a major upwards revision of fixed N inputs, particularly nitrogen fixation, or both. Oceanic denitrification can be significantly altered by small re-distributions of carbon and dissolved oxygen. Since fixed N is a limiting nutrient, uncompensated changes in denitrification affect the ocean's ability to sequester atmospheric CO 2 via the "biological pump". We have also had to modify our concepts of the oceanic N 2 O regime to take better account of the extremely high N 2 O saturations that can arise in productive, low oxygen waters. Recent results from the western Indian Shelf during a period when hypoxic, suboxic and anoxic waters were present produced a maximum surface N 2 O saturation of > 8000%, a likely consequence of "stop and go" denitrification. The sensitivity of N 2 O production and consumption to small changes in the oceanic dissolved oxygen distribution and to the "spin-up" phase of denitrification suggests that the oceanic source term for N 2 O could change rapidly.

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Denitrification rates in sediments within the oxygen deficient waters off Mexico and from the Gulf of Maine were investigated on the basis of interstitial nutrient profiles. Nitrate fluxes into the sediments were calculated from gradients across the sediment‐water interface and vertical molecular diffusion coefficients and averaged 0.151 (Mexico) and 0.0920 (Gulf of Maine) pmol NO−3 cm−2 s−1. These are minimum values, since these gradients may have been underestimated. In the Gulf of Maine, bottom water irrigation by macrobenthos increases the nitrate supply well above this estimate. In addition, only 15‐22% of the expected ammonium is present in Gulf of Maine sediments perhaps because of removal by a rapid coupling of nitrification with denitrification. This large apparent loss of the regenerated ammonium appears to be ubiquitous in shelf sediments with oxygenated bottom water. The global denitrification rate in continental shelf sediments was reassessed to be >50 Tg N yr−1 (1 Tg = 1012 g), demonstrating that sediments are an important sink for oceanic nitrogen. Globally, current nitrogen losses from the oceans may exceed inputs by 60‐90 Tg N yr−1. Over the glacial‐interglacial cycle the global sedimentary denitrification rate probably varied commensurately with the changing continental shelf area. An oscillating oceanic nitrogen budget over these time scales could occur given the sequence of (1) scouring and dumping of terrestrial nitrogen into the oceans during glacial advance, (2) removal of oceanic combined nitrogen to the atmosphere by denitrification following glacial retreat, and (3) reincorporation of this N into terrestrial biomass during the interglacial period.

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The purpose of the study was to assess oral health and treatment needs among elderly in psychiatric institutions in a Danish county. The study serves as baseline for the evaluation of a newly established oral health care program in the county. The study population comprised the residents in eight institutions (n = 407). Two thirds of the residents were edentulous, 34% of the dentate had one or more root remnants, and 55% had untreated decay. The dentate with regular dental visiting habits had significantly less untreated decay than the irregular users. The oral hygiene was poor, but was not related to whether or not the elderly were assisted in daily oral hygiene. The evaluation of the program will show to what extent treatment takes place, and whether or not oral hygiene improves.

This article of top civil servants in Danish central and local government sheds new light on politicization. A survival analysis shows that since 1970, the risk that a top civil servant will be replaced has increased. There is no evidence of politicization in central government while city managers' risk of replacement increases both when a new mayor, representing another party and holding an absolute majority, and when the shift of mayor takes place within the same party. We interpret these results as evidence of the adaptability of the merit civil service and political executives' stronger insistence on their authority to make discretionary replacements.