30 research outputs found

    Peasants' Choices? Indian Agriculture and the Limits of Commercialization in Nineteenth-Century Bihar

    Get PDF
    The article attempts to distinguish and locate choices in agricultural production, with special reference to Bihar, India, during the nineteenth century. On the one hand, it considers closely managed and extensively irrigated areas, long involved in trade under the overall control of 'landlords', and, on the other hand, the expanding production of opium, and also of indigo and sugar (so-called 'forced' commercialization), identifying common features and continuities of production and marketing. Particular the importance of advance payments and local intermediaries is stressed. Thus, in contrast with the more usual evolutionary models, based on unitary categories and modes, the essay illustrates ecological, customary, collective, and local political constraints upon agricultural decisions; and this leads to the identification in turn of their different kinds and levels

    Strategies for the hyperpolarization of acetonitrile and related Ligands by SABRE

    Get PDF
    (Chemical Equation Presented) We report on a strategy for using SABRE (signal amplification by reversible exchange) for polarizing 1H and 13C nuclei of weakly interacting ligands which possess biologically relevant and nonaromatic motifs. We first demonstrate this via the polarization of acetonitrile, using Ir(IMes)(COD)Cl as the catalyst precursor, and confirm that the route to hyperpolarization transfer is via the J-coupling network. We extend this work to the polarization of propionitrile, benzylnitrile, benzonitrile, and trans-3-hexenedinitrile in order to assess its generality. In the 1H NMR spectrum, the signal for acetonitrile is enhanced 8-fold over its thermal counterpart when [Ir(H)2(IMes)(MeCN)3]+ is the catalyst. Upon addition of pyridine or pyridine-d5, the active catalyst changes to [Ir(H)2(IMes)- (py)2(MeCN)]+ and the resulting acetonitrile 1H signal enhancement increases to 20- and 60-fold, respectively. In 13C NMR studies, polarization transfers optimally to the quaternary 13C nucleus of MeCN while the methyl 13C is hardly polarized. Transfer to 13C is shown to occur first via the 1H - 1H coupling between the hydrides and the methyl protons and then via either the 2J or 1J couplings to the respective 13Cs, of which the 2J route is more efficient. These experimental results are rationalized through a theoretical treatment which shows excellent agreement with experiment. In the case of MeCN, longitudinal two-spin orders between pairs of 1H nuclei in the three-spin methyl group are created. Two-spin order states, between the 1H and 13C nuclei, are also created, and their existence is confirmed for Me13CN in both the 1H and 13C NMR spectra using the Only Parahydrogen Spectroscopy protocol

    The solution structure of EMILIN1 globular C1q domain reveals a disordered insertion necessary for interaction with the alpha4beta1 integrin.

    No full text
    The extracellular matrix protein EMILIN1 (elastin microfibril interface located protein 1) is implicated in maintaining blood pressure homeostasis via the N-terminal elastin microfibril interface domain and in trophoblast invasion of the uterine wall via the globular C1q (gC1q) domain. Here, we describe the first NMR-based homology model structure of the human 52-kDa homotrimer of the EMILIN1 gC1q domain. In contrast to all of the gC1q (crystal) structures solved to date, the 10-stranded beta-sandwich fold of the gC1q domain is reduced to nine beta strands with a consequent increase in the size of the central cavity lumen. An unstructured loop, resulting from an insertion unique to EMILIN1 and EMILIN2 family members and located at the trimer apex upstream of the missing strand, specifically engages the alpha4beta1 integrin. Using both Jurkat T and EA.hy926 endothelial cells as well as site-directed mutagenesis, we demonstrate that the ability of alpha4beta1 integrins to recognize the trimeric EMILIN1 gC1q domain mainly depends on a single glutamic acid residue (Glu(933)). Static and flow adhesion of T cells and haptotactic migration of endothelial cells on gC1q is fully dependent on this residue. Thus, EMILIN1 gC1q-alpha4beta1 represents a unique ligand/receptor system, with a requirement for a 3-fold arrangement of the interaction site

    The solution structure of EMILIN1 globular C1q domain reveals a disordered insertion necessary for interaction with the alpha4beta1 integrin

    No full text
    The extracellular matrix protein EMILIN1 (elastin microfi- bril interface located protein 1) is implicated in maintaining blood pressure homeostasis via the N-terminal elastin microfi- bril interface domain and in trophoblast invasion of the uterine wall via the globular C1q (gC1q) domain. Here, we describe the first NMR-based homology model structure of the human 52-kDa homotrimer of the EMILIN1 gC1q domain. In contrast to all of the gC1q (crystal) structures solved to date, the 10-stranded \u2424-sandwich fold of the gC1q domain is reduced to nine \u2424 strands with a consequent increase in the size of the cen- tral cavity lumen. An unstructured loop, resulting from an inser- tion unique to EMILIN1 and EMILIN2 family members and located at the trimer apex upstream of the missing strand, spe- cifically engages the \u24234\u24241 integrin. Using both Jurkat T and EA.hy926 endothelial cells as well as site-directed mutagenesis, we demonstrate that the ability of \u24234\u24241 integrins to recognize the trimeric EMILIN1 gC1q domain mainly depends on a single glutamic acid residue (Glu933). Static and flow adhesion of T cells and haptotactic migration of endothelial cells on gC1q is fully dependent on this residue. Thus, EMILIN1 gC1q-\u24234\u24241 represents a unique ligand/receptor system, with a requirement for a 3-fold arrangement of the interaction site
    corecore