Responses of macroalgae to CO2 enrichment cannot be inferred solely from their inorganic carbon uptake strategy

Increased plant biomass is observed in terrestrial systems due to rising levels of atmospheric CO2, but responses of marine macroalgae to CO2 enrichment are unclear. The 200% increase in CO2 by 2100 is predicted to enhance the productivity of fleshy macroalgae that acquire inorganic carbon solely as CO2 (non‐carbon dioxide‐concentrating mechanism [CCM] species—i.e., species without a carbon dioxide‐concentrating mechanism), whereas those that additionally uptake bicarbonate (CCM species) are predicted to respond neutrally or positively depending on their affinity for bicarbonate. Previous studies, however, show that fleshy macroalgae exhibit a broad variety of responses to CO2 enrichment and the underlying mechanisms are largely unknown. This physiological study compared the responses of a CCM species (Lomentaria australis) with a non‐CCM species (Craspedocarpus ramentaceus) to CO2 enrichment with regards to growth, net photosynthesis, and biochemistry. Contrary to expectations, there was no enrichment effect for the non‐CCM species, whereas the CCM species had a twofold greater growth rate, likely driven by a downregulation of the energetically costly CCM(s). This saved energy was invested into new growth rather than storage lipids and fatty acids. In addition, we conducted a comprehensive literature synthesis to examine the extent to which the growth and photosynthetic responses of fleshy macroalgae to elevated CO2 are related to their carbon acquisition strategies. Findings highlight that the responses of macroalgae to CO2 enrichment cannot be inferred solely from their carbon uptake strategy, and targeted physiological experiments on a wider range of species are needed to better predict responses of macroalgae to future oceanic change

Acupuncture for chronic low back pain: protocol for a multicenter, randomized, sham-controlled trial

<p>Abstract</p> <p>Background</p> <p>Use of acupuncture has widely increased in patients with chronic low back pain. However, the evidence supporting its efficacy remains unclear. In this article, we report the design and the protocol of a multi-center randomized sham-controlled trial to treat chronic low back pain. Our goal is to verify the effect of acupuncture on chronic low back pain.</p> <p>Methods/Design</p> <p>This study is a multi-center randomized sham-controlled trial with 2 parallel arms. Participants included in the study met the following criteria: 1) low back pain lasting for at least the last 3 months, 2) a documented ≥ 5 points on a 10 cm visual analog scale for bothersomeness of low back pain at the time of screening and 3) between 18 and 65 years of age. Participants were blinded to the real and sham acupuncture treatments. The real acupuncture treatment group received real acupuncture 2 times a week, during a total of 12 sessions over 6 weeks. The control group received sham acupuncture during the same period. In order to assess the primary and secondary outcome measures, the participants were asked to fill out a questionnaire at the baseline and 6, 8, 12 and 24 weeks after starting the treatments. The primary outcome was measured using the visual analog scale for bothersomeness of low back pain at 8 weeks after the initiation of treatments.</p> <p>Discussion</p> <p>The result of this trial (which will be available in 2010) will demonstrate the efficacy of using acupuncture to treat chronic low back pain.</p> <p>Trial registration</p> <p>This study is registered with the U.S. National Institutes of Health Clinical Trials registry: NCT00815529</p

Evolution récente des conceptions médicales de la sexualité féminine et de ses troubles

BORDEAUX2-BU Santé (330632101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF