[1] We use a geochemical box model to investigate the changes in marine N-fixation and denitrification required to match the observed sedimentary ı15N changes between 30 kyr B.P. and the late Holocene. This is achieved by optimizing a set of seven parameters that describe the strengths of three ocean-internal N feedbacks and the response of the oceanic N cycle to four external forcings. Scenari...

Nodule CO2 fixation via PEPC provides malate for bacteroids and oxaloacetate for N assimilation. The process is therefore of central importance for efficient nitrogen fixation. Nodule CO2 fixation is known to depend on external CO2 concentration. The hypothesis of the present paper was that nitrogen fixation in alfalfa plants is enhanced when the nodules are exposed to elevated CO2 concentratio...

BACKGROUND Clinically there are different fixation methods used for fixation of the posterior malleolar fractures (PMF), but the best treatment modality is still not clear. Few studies have concentrated on this issue, least of all using a biomechanical comparison. The purpose of this study was to carry out a computational comparative biomechanics of three different commonly used fixation constr...

Persons with amblyopia, especially those with strabismus, are known to exhibit abnormal fixational eye movements. In this paper, we compared six characteristics of fixational eye movements among normal control eyes (n=16), the non-amblyopic fellow eyes and the amblyopic eyes of anisometropic (n=14) and strabismic amblyopes (n=14). These characteristics include the frequency, magnitude of landin...

OBJECTIVE To evaluate fixation properties of a new intervertebral anchored fusion device and compare these with ventral locking plate fixation. STUDY DESIGN In vitro biomechanical evaluation. ANIMALS Cadaveric canine C4-C7 cervical spines (n = 9). METHODS Cervical spines were nondestructively loaded with pure moments in a nonconstraining testing apparatus to induce flexion/extension while...

Increases in global temperature are likely to have effects on the nitrogen cycle, including thosemediated through effects on legumes, which have a role in the N cycle by fixing N2. These effects may alter plant functioning and community structure, especially in N-limited ecosystems.Wemanipulated temperature and plant diversity in the field to investigate the effects of elevated temperature on a...

12 Benthic nitrogen (N2) fixation and sulfate reduction (SR) were investigated in the Peruvian 13 oxygen minimum zone (OMZ). Sediment samples, were retrieved by a multiple corer at six 14 stations (70 1025 m water depth) along a depth transect at 12°S, covering anoxic and 15 hypoxic bottom water conditions. Benthic N2 fixation was detected at all sites using the 16 acetylene reduction assay, wi...

BACKGROUND The acetabular component has remained the weakest link in hip arthroplasty regarding achievement of long-term survival. Primary fixation is a prerequisite for long-term performance. For this reason, we investigated the stability of a unique cementless titanium-coated elastic monoblock socket and the influence of supplementary screw fixation. PATIENT AND METHODS During 2006-2008, we...