Evidence against dust-mediated control of glacial-interglacial changes in atmospheric CO2.

The �iron fertilisation� hypothesis suggests controversially that atmospheric CO2 has been influenced by transport of iron-containing dust to the ocean surface1-3. Experiments in the Southern Ocean show that productivity, and subsequent CO2 drawdown, are enhanced by iron additions4. A carbon cycle model (forced by large values of Southern Ocean dust flux) indicates productivity changes during past glacial times could have reduced atmospheric CO2 by ~40ppm 5. However, Southern Ocean dust flux is very low at present and was increased, but still low, during past glaciations. Thus, as for the equatorial Pacific 1, 6, 7, distally-supplied, upwelled iron may be more significant than local dust-borne iron. Hence, Northern, not Southern, hemisphere dust may drive Southern Ocean productivity8,9. Here, we examine the flux and timing of N. Atlantic dust inputs in relation to the Vostok climate record. For the penultimate glaciation, two N. Atlantic dust peaks occurred. At 155 ka, the Atlantic dust flux was 2500x that at Vostok10, but declined well before the onset of the Vostok CO2 rise. The second dust peak, at 130ka, substantially post-dated the CO2 rise. Thus, low Southern Ocean dust fluxes, and this mismatch between N. hemisphere dust peaks and Southern Ocean climate change, appear not to support the suggested role of dust-mediated iron fertilisation in the Southern Ocean at Termination II

Systematic review of natural agents for the management of oral mucositis in cancer patients

For the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO)PURPOSE The aim of this study was to review the available literature and define clinical practice guidelines for the use of natural agents for the prevention and treatment of oral mucositis. METHODS A systematic review was conducted by the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society for Oral Oncology. The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. Based on the evidence level, one of the following three guideline determinations was possible: recommendation, suggestion, and no guideline possible. RESULTS A total of 49 papers across 15 interventions were examined. A new suggestion was developed in favor of systemic zinc supplements administered orally in the prevention of oral mucositis in oral cancer patients receiving radiation therapy or chemoradiation (Level III evidence). A recommendation was made against the use of intravenous glutamine for the prevention of oral mucositis in patients receiving high-dose chemotherapy prior to hematopoietic stem cell transplant (Level II evidence). No guideline was possible for any other agent, due to inadequate and/or conflicting evidence. CONCLUSIONS Of the various natural agents reviewed here, the available evidence supported a guideline only for two agents: a suggestion in favor of zinc and a recommendation against glutamine, in the treatment settings listed above. Well-designed studies of other natural agents are warranted.Noam Yarom, Anura Ariyawardana, Allan Hovan, Andrei Barasch, Virginia Jarvis, Siri Beier Jensen, Yehuda Zadik, Sharon Elad, Joanne Bowen, Rajesh V. Lall

Position Sensitive Single Wire Proportional Counter with Electrodes for Increasing Electric Field Strength

A position sensitive single wire proportional counter (PS-SWPC) with supplemental electrodes is studied for developing a focal plane detector of a magnetic spectrograph. These electrodes increase the electric field at the position away from the anode wire in the counter in order to accelerate the drift velocity of electrons generated by the incident radiation. Characteristics of electron drift and detection efficiency for filling gas mixtures (Ar-CH4 and Ne-CH4) are investigated. As a result, we obtained sufficient time characteristics for PS-SWPC