Aquatic plants have been used as hydrological tracers in groundwater fed river systems. In nature, patterns in plant distribution have been attributed to ammonium (NH(4)) toxicity and phosphate (PO(4)) limitation, while some laboratory studies have focused on the role of the partial pressure of CO(2) (pCO(2)). The aims of this study were (i) to test whether plant distribution was more related t...

We studied the interactive effects of pCO(2) and growth light on the coastal marine diatom Thalassiosira pseudonana CCMP 1335 growing under ambient and expected end-of-the-century pCO(2) (750 ppmv), and a range of growth light from 30 to 380 µmol photons·m(-2)·s(-1). Elevated pCO(2) significantly stimulated the growth of T. pseudonana under sub-saturating growth light, but not under saturating ...

1 . A study of exercise physiology in 117 children aged 6-16 is described including the measurement of cardiac output by the Indirect (CO,) Fick Principle. 2. Computer produced graphs enabled various alternative values for arterial Pco, (Pa,co,) to be inserted simultaneously into the Fick equation for cardiac output and the Bohr equation for dead space. 3. Dead space could be estimated with rea...

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 Pco, was locally controlled with a small membrane oxygenator in the coronary perfusion circuit. Each Pco, change was made at a constant coronary flow, and ...

Ocean acidification (OA) has important implications for the persistence of coral reef ecosystems, due to potentially negative effects on biomineralization. Many coral reefs are dynamic with respect to carbonate chemistry, and experience fluctuations in pCO₂ that exceed OA projections for the near future. To understand the influence of dynamic pCO₂ on an important reef calcifier, we tested the r...

This study was designed to investigate the pathogenesis of type I (distal) renal tubular acidosis. Urinary and blood Pco(2) tensions were determined when the pH of the urine was equal to or exceeded the corresponding blood pH. This provided an indication of net hydrogen ion secretion in the distal nephron. In 16 normal subjects, the Pco(2) of the urine exceeded blood values (U-B Pco(2)) by 32.7...

OBJECTIVES This pilot study aimed to evaluate the feasibility and potential benefits of a novel biofeedback breathing training for achieving sustained increases in pCO(2) levels. METHODS Twelve asthma patients were randomly assigned to an immediate 4-week treatment group or waiting list control. Patients were instructed to modify their respiration in order to change levels of end-tidal pCO(2)...

objective(s): pcos (polycystic ovary syndrome) produces symptoms in approximately 5% to 10% of women of reproductive age (12–45 years old). it is thought to be one of the leading causes of female subfertility. this study aimed to confirm the role of nutrition containing omega-3 (polyunsaturated fatty acid) on control of experimental pco induced by estradiol-valerat in rats. materials and method...

To project how ocean acidification will impact biological communities in the future, it is critical to understand the potential for local adaptation and the physiological plasticity of marine organisms throughout their entire life cycle, as some stages may be more vulnerable than others. Coralline algae are ecosystem engineers that play significant functional roles in oceans worldwide and are c...

Posterior capsular opacification (PCO) is the most frequent complication of cataract surgery. Advances in surgical techniques, intraocular lens materials, and designs have reduced the PCO rate, but it is still a significant problem. The only effective treatment for PCO, Nd:YAG laser capsulotomy carries vision-related complications and risks and puts a significant financial burden on the health ...