Concentration of floating biogenic material in convergence zones

Some organisms that live just below the sea surface (the neuston) are known more as a matter of curiosity than as critical players in biogeochemical cycles. The hypothesis of this work is that their existence implies that they receive some food from an upward flux of organic matter. The behaviour of these organisms and of the associated organic matter, hereafter mentioned as floating biogenic material (FBM) is explored using a global physical-biogeochemical coupled model, in which its generation is fixed to 1% of primary production, and decay rate is of the order of I month. The model shows that the distribution of FBM should depart rapidly from that of primary production.. and be more sensitive to circulation patterns than to the distribution of primary production. It is trapped in convergence areas, where it reaches concentrations larger by a factor 10 than in divergences, thus enhancing and inverting the contrast between high and low primary productivity areas. Attention is called on the need to better understand the biogeochemical processes in the first meter of the ocean, as they may impact the distribution of food for fishes, as well as the conditions for air-sea exchange and for the interpretation of sea color.

INVESTIGATING THE PRESENCE OF THE HISTORY OF SCIENCE IN UNIVERSITY GENERAL CHEMISTRY TEXTBOOKS

INVESTIGATING THE PRESENCE OF THE HISTORY OF SCIENCE IN UNIVERSITY GENERAL CHEMISTRY TEXTBOOKS. This paper aims at analyzing the history of science content of three general chemistry textbooks used in Brazilian universities: the translations of Kotz and Treichel's Chemistry & Chemical Reactivity, Atkins and Jones's Chemical Principles, and Garritz and Chamizo's Quimica. Results revealed different trends for the inclusion of history of science in chemistry teaching. Katz & Treichel and Atkins & Jones used history mainly as curiosity and ornament. Garritz & Chamizo adopted the historical approach as one of the organizing axis of their textbook. Nevertheless, the historical content of the three textbooks may be criticized from current historiographical standpoint.

Investigando a presença da história da ciência em livros didáticos de Química Geral para o ensino superior

This paper aims at analyzing the history of science content of three general chemistry textbooks used in Brazilian universities: the translations of Kotz and Treichel's Chemistry & Chemical Reactivity, Atkins and Jones's Chemical Principles, and Garritz and Chamizo's Química. Results revealed different trends for the inclusion of history of science in chemistry teaching. Kotz & Treichel and Atkins & Jones used history mainly as curiosity and ornament. Garritz & Chamizo adopted the historical approach as one of the organizing axis of their textbook. Nevertheless, the historical content of the three textbooks may be criticized from current historiographical standpoint.