Shells of the bivalve Arctica islandica are used to reconstruct paleo-environmental conditions (e.g. temperature) via biogeochemical proxies, i.e. biogenic components that are related closely to environmental parameters at the time of shell formation. Several studies have shown that proxies like element and isotope-ratios can be affected by shell growth and microstructure. Thus it is essential ...

The effect of hypercapnia on coronary vascular resistance (CVR) was studied in seven open-chest dogs. Coronary blood flow was supplied to the cannulated left main coronary artery from the femoral artery by a precision pump. Coronary arterial PCO2 was locally controlled with a small membrane oxygenator in the coronary perfusion circuit. Each PCO2 change was made at a constant coronary flow, and ...

Surface water partial pressure of CO2 (pCO2) variations in Drake Passage are examined using decade-long underway shipboardmeasurements. North of the Polar Front (PF), the observed pCO2 shows a seasonal cycle that peaks annually in August and dissolved inorganic carbon (DIC)–forced variations are significant. Just south of the PF, pCO2 shows a small seasonal cycle that peaks annually in February...

Alveolar hyperventilation is a characteristic feature of the interstitial lung diseases, yet its pathogenesis remains unknown. We examined the relationship between inflammatory alveolar acinar cell counts and the steady state, resting arterial PCO2 in patients with fibrosing alveolitis. To eliminate the influence of overwhelming mechanical lung restriction or resting hypoxemia, we studied 20 pa...

PURPOSE To determine whether angiotensin II (Ang II), a vasoconstrictive peptide, changes the relaxation effect of elevated partial pressure of carbon dioxide (PCO2) on pericytes. METHODS The contractile tone of cultured bovine retinal pericytes was measured when the ambient PCO2 was elevated in the absence or the presence of Ang II. All experiments were performed in the bicarbonate-buffered ...

Inadequate splanchnic tissue perfusion is relatively common during and after aortic surgery. We hypothesized that vasodilation caused by thoracic epidural analgesia improves splanchnic blood flow and tissue perfusion after aortic surgery. In this prospective, randomized, controlled study, we studied 20 patients undergoing elective aortic-femoral or aortic-iliac reconstruction surgery. Gastric a...

The arterial to end-tidal PCO2 difference (PaCO2-PE'CO2) was measured in five anaesthetized dogs during controlled ventilation at 0.25 Hz (15 b.p.m.) and during high frequency jet ventilation at 1, 3 and 5 Hz. Because of the slow response of the infra-red carbon dioxide analyser, satisfactory recordings of end-tidal carbon dioxide could not be obtained at frequencies greater than 1 Hz. The inte...

The effects of coastal acidification on the growth and toxicity of the saxitoxin-producing dinoflagellate Alexandrium fundyense were examined in culture and ecosystem studies. In culture experiments, Alexandrium strains isolated from Northport Bay NY, USA, and the Bay of Fundy, Canada, grew significantly faster (16 -190%; p<0.05) when exposed to elevated levels of pCO2 (~ 800- 1900μatm) compare...

[1] This paper examines the sensitivity of atmospheric pCO2 to changes in ocean biology that result in drawdown of nutrients at the ocean surface. We show that the global inventory of preformed nutrients is the key determinant of atmospheric pCO2 and the oceanic carbon storage due to the soft-tissue pump (OCSsoft). We develop a new theory showing that under conditions of perfect equilibrium bet...