Report on the catalytic activity of 6-heteropolymolybdates as potential Fischer-Tropsch synthesis catalysts

Unsupported and supported decomposition products of 6-heteropolymolybdates were tested as possible Fischer-Tropsch synthesis catalysts. Depending on the heteroatom, the activity changes significantly and the best supported catalysts have higher activity (based on total metal loading) than previously investigated MoO2 and Mo2C catalysts.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26261/1/0000342.pd

How Did the West Usurp the Rest? Origins of the Great Divergence over the Longue Durée

Traditional explanations of the “rise of the West” have located the sources of Western supremacy in structural or long-term developmental factors internal to Europe. By contrast, revisionist accounts have emphasized the conjunctural and contingent aspects of Europe's ascendancy, while highlighting intersocietal conditions that shaped this trajectory to global dominance. While sharing the revisionist focus on the non-Western sources of European development, we challenge their conjunctural explanation, which denies differences between “West” and “East” and within Europe. We do so by deploying the idea of uneven and combined development (UCD), which redresses the shortcomings found on both sides of the debate: the traditional Eurocentric focus on the structural and immanent characteristics of European development and the revisionists’ emphasis on contingency and the homogeneity of Eurasian societies. UCD resolves these problems by integrating structural and contingent factors into a unified explanation: unevenness makes sense of the sociological differences that revisionists miss, while combination captures the aleatory processes of interactive and multilinear development overlooked by Eurocentric approaches. From this perspective, the article examines the sociologically generative interactions between European and Asian societies’ development over the longue durée and traces how the breakdown of feudalism and the rise of capitalism in Europe were fundamentally rooted in and conditioned by extra-European structures and agents. This then sets up our conjunctural analysis of a central yet underappreciated factor explaining Europe rise to global dominance: the disintegration of the Mughal Empire and Britain's colonization of India

Reversible association of ribulose-1, 5-bisphosphate carboxylase/oxygenase activase with the thylakoid membrane depends upon the ATP level and pH in rice without heat stress

Ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) activase (RCA) in the thylakoid membrane (TM) has been shown to play a role in protection and regulation of photosynthesis under moderate heat stress. However, the physiological significance of RCA bound to the TM (TM–RCA) without heat stress remains unknown. In this study, it is first shown, using experiments in vivo, that the TM–RCA varies in rice leaves at different development stages, under different environmental conditions, and in a rice mutant. Furthermore, it is shown that the amount of TM–RCA always increased when the Rubisco activation state and the pH gradient across the TM (ΔpH) decreased. It was then demonstrated in vitro that the RCA bound dynamically to TM and the amount of TM–RCA increased during Rubisco activation. A high level of ATP and a high pH value promoted the dissociation of RCA from the TM. Both the RCA association with and dissociation from the TM showed conformational changes related to the ATP level or pH as indicated by the changes in fluorescence intensity of 1-anilinonaphthalene-8-sulphonic acid (ANS) binding to RCA. These results suggest that the reversible association of RCA with the TM is ATP and pH (or ΔpH) dependent; it might be involved in the RCA activation of Rubisco, in addition to the previously discovered role in the protection and regulation of photosynthesis under heat stress

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Chloroplast function is orchestrated by the organelle's intricate architecture. By combining cryo-focused ion beam milling of vitreous Chlamydomonas cells with cryo-electron tomography, we acquired three-dimensional structures of the chloroplast in its native state within the cell. Chloroplast envelope inner membrane invaginations were frequently found in close association with thylakoid tips, and the tips of multiple thylakoid stacks converged at dynamic sites on the chloroplast envelope, implicating lipid transport in thylakoid biogenesis. Subtomogram averaging and nearest neighbor analysis revealed that RuBisCO complexes were hexagonally packed within the pyrenoid, with similar to 15 nm between their centers. Thylakoid stacks and the pyrenoid were connected by cylindrical pyrenoid tubules, physically bridging the sites of light-dependent photosynthesis and light-independent carbon fixation. Multiple parallel minitubules were bundled within each pyrenoid tubule, possibly serving as conduits for the targeted one-dimensional diffusion of small molecules such as ATP and sugars between the chloroplast stroma and the pyrenoid matrix

Sphagnum reproduction.

http://deepblue.lib.umich.edu/bitstream/2027.42/53369/1/1803.pdfDescription of 1803.pdf : Access restricted to on-site users at the U-M Biological Station

Succession at Stutsmanville Bog.

http://deepblue.lib.umich.edu/bitstream/2027.42/53368/1/1802.pdfDescription of 1802.pdf : Access restricted to on-site users at the U-M Biological Station

Responses of Mosses, Especially Hedwigia Ciliata and Mnium Cuspidatum, to Desiccation and Rehydration.

Experiments were performed to determine the mechanisms by which mosses survive dry conditions. Moss samples were desiccated over silica gel and rehydrated on filter paper soaked with distilled water. Desiccation damage was measured by analyzing cell and shoot survival after rehydration. Photosynthetic measurements were made with an open flow IRGA system. Photosynthetic pigments were extracted in 80% acetone and concentrations were calculated by conventional methods. The effects of desiccation and rehydration on 10 local moss species were examined; 4 species were desiccation-sensitive, 3 species were drought-evaders, surviving by producing new growth from severely damaged shoots, 2 species were desiccation-resistant and were not affected by the treatment. Drought-evasion was correlated with fluctuating water levels in the habitat; desiccation-resistance occurred in species from dry habitats. High variance in cell damage within the same clump of moss led to development of a st and ardized method of sampling cell damage; the technique involves counting a minimum of 10 cells in 6 locations on each leaf and 6 leaves on each of 10 shoots for each treatment. The results of this method correlate well with shoot survival (r = 0.98). Detailed experiments were performed on 2 species, Hedwigia ciliata and Mnium cuspidatum. Studies on cell survival, shoot survival, and time courses for desiccation and rehydration indicate that both species lose water at the same rate and to the same extent, that Hedwigia is desiccation-tolerant and that Mnium is desiccation-sensitive. Chlorophyll content decreases in Mnium after desiccation and rehydration, with preferential damage to chlorophyll a. Hedwigia appears to lose chlorophyll after desiccation and rehydration also, but the pigment composition of plants does not change, suggesting that Hedwigia has adaptations which protect the chlorophyll a from desiccation damage. Possible models for the mechanism of desiccation damage in Mnium and desiccation-tolerance in Hedwigia are presented.Ph.D.BotanyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/160046/1/8412258.pd