Physical controls on carbon dioxide transfer velocity and flux in low-gradient river systems and implications for regional carbon budgets

Outgassing of carbon dioxide (CO(2)) from rivers and streams to the atmosphere is a major loss term in the coupled terrestrial-aquatic carbon cycle of major low-gradient river systems (the term ""river system"" encompasses the rivers and streams of all sizes that compose the drainage network in a river basin). However, the magnitude and controls on this important carbon flux are not well quantified. We measured carbon dioxide flux rates (F(CO2)), gas transfer velocity (k), and partial pressures (p(CO2)) in rivers and streams of the Amazon and Mekong river systems in South America and Southeast Asia, respectively. F(CO2) and k values were significantly higher in small rivers and streams (channels <100 m wide) than in large rivers (channels >100 m wide). Small rivers and streams also had substantially higher variability in k values than large rivers. Observed F(CO2) and k values suggest that previous estimates of basinwide CO(2) evasion from tropical rivers and wetlands have been conservative and are likely to be revised upward substantially in the future. Data from the present study combined with data compiled from the literature collectively suggest that the physical control of gas exchange velocities and fluxes in low-gradient river systems makes a transition from the dominance of wind control at the largest spatial scales (in estuaries and river mainstems) toward increasing importance of water current velocity and depth at progressively smaller channel dimensions upstream. These results highlight the importance of incorporating scale-appropriate k values into basinwide models of whole ecosystem carbon balance.

Implications of long-term land-use change for the hydrology and solute budgets of small catchments in Amazonia

The replacement of undisturbed tropical forest with cattle pasture has the potential to greatly modify the hydrology of small watersheds and the fluxes of solutes. We examined the fluxes of water, Cl(-), NO(3)(-)-N: SO(4)(2--)-S, NH(4)(+)-N, Na(+), K(+), Mg(2+) and Ca(2+) in different flow paths in similar to 1 ha catchments of undisturbed open tropical rainforest and a 20 year-old pasture established from forest in the southwestern Brazilian Amazon state of Rondonia. Storm flow discharge was 18% of incident rainfall in pasture, but only 1% in forest. Quickflow predominated over baseflow in both catchments and in both wet and dry seasons. In the pasture, groundwater and quickflow were important flow paths for the export of all solutes. In the forest, quickflow was important for NO(3)(-)-N export, but all other solutes were exported primarily by groundwater outflow. Both catchments were sinks for SO(4)(2-)-S and Ca(2+), and sources of Na(+). The pasture catchment also lost K(+) and Mg(2+) because of higher overland flow frequency and volume and to cattle excrement. These results show that forest clearing dramatically influences small watershed hydrology by increasing quickflow and water export to streams. They also indicate that tropical forest watersheds are highly conservative for most solutes but that pastures continue to lose important cations even decades after deforestation and pasture establishment. (c) 2008 Elsevier B.V. All rights reserved.

Listening to the Whispers of Matter Through Arabic Hermeticism: New Studies on the Book of the Treasure of Alexander

The Jabirian Corpus refers to the K. Thahirat Al-`Iskandar, ""The Book of the Treasure of Alexander"" (hereafter BTA), as one of several forgeries suggesting that alchemical secrets were hidden in inscriptions in various places. The book was neglected until 1926, when Julius Ruska discussed it in his work on the Emerald Tablet, placing the BTA within the literature related to the development of Arabic alchemy. His preliminary study became an essential reference and encouraged many scholars to work on the BTA in the following decades. Some years ago, we completed the first translation of the BTA into a Western language. The work was based on the acephalous Escorial manuscript, which we identified as a fourteenth-century copy of the BTA. This manuscript is peculiar, as part of it is encoded. After finishing our translation, we started to establish the text of the BTA. At present, the text is in process of fixation-to be followed by textual criticism-and has been the main focus of a thorough study of ours on medieval hermeticism and alchemy. A sample of the work currently in progress is presented in this paper: an analysis of the variations between different manuscripts along with a study and English translation of its alchemical chapter.

Book illustration, as (intersemiotic) translation: Pictures translating words

This article examines book illustrations through the prism of Translation Studies. It mainly suggests that the pictures in illustrated books are (intersemiotic) translations of the text and that, as such, they can be analyzed making use of the same tools applied to verbal interlingual translation. The first section deals with the theoretical bases upon which illustrations can be regarded as translations, concentrating on theories of re-creation, as illustration is viewed essentially as the re-creation of the text in visual form. One of the claims in this section is that, because illustration is carried out in very similar ways as interlingual translation itself, the term ""intersemiotic"" relates more to the (obvious) difference of medium. For this reason the word is most often referred to in parentheses. The second section discusses three particular ways through which illustrations can translate the text, namely, by reproducing the textual elements literally in the picture, by emphasizing a specific narrative element, and by adapting the pictures to a certain ideology or artistic trend. The example illustrations are extracted from different. kinds of publication and media, ranging from Virgil`s Aeneid, Lewis Carroll`s Alice in Wonderland and Mark Twain`s Adventures of Huckleberry Finn to an online comic version of Shakespeare`s Hamlet.

Accelerated testing of mold growth on traditional and recycled book paper

The growth of molds on paper containing cellulose is a frequent occurrence when the level of relative air humidity is high or when books become wet due to water leaks in libraries. The aim of this study is to differentiate the bioreceptivity of different types of book paper for different fungi. Laboratory tests were performed with strains of Aspergillus niger, Cladosporium sp., Chaetomium globosum and Trichoderma harzianum isolated from books. Four paper types were evaluated: couche Men (offset), recycled and a reference paper containing only cellulose. The tests were carried out in chambers with relative air humidity of 95% and 100%. Mold growth was greatest in the tests at 100% relative humidity. Results of stereoscopic microscopy observation showed that Cladosporium sp. grew in 74% of these samples, A. niger in 75%, T. harzianum in 72% and C. globosum in 60%. In the chambers with 95% air humidity Cladosporium sp. grew in only 9% of the samples, A. niger in 1%, T harzianum in 3% and C globosum did not grow in any sample. The most bioreceptive paper was couche and the least receptive was recycled paper. The composition of the recycled paper, however, varies depending on the types of waste materials used to make it. (C) 2011 Elsevier Ltd. All rights reserved.

Real map germs and higher open book structures

The paper focusses on the existence of higher open book structures defined by real map germs psi : (R(m), 0) -> (R(p), 0) such that Sing psi boolean AND psi(-1)(0) subset of {0}. A general existence criterion is proved, with view to weighted-homogeneous maps.