125 research outputs found

    The political economy machinery: toward a critical anthropology of development as a contested capitalist practice

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    This article discusses anthropology’s current mainstream understandings of development and offers a historical materialist alternative. According to these, development was and is either a discourse-backed anti-politics machine that strengthens the power of postcolonial governments or a category of practice, a universal that generates frictions when it clashes with local historical–cultural formations. The approach proposed here reintegrates the analysis of development into the anthropological analysis of capitalism’s uneven and contested histories and practices. A reassessment of World Bank reporting on Lesotho and an analysis of the Bank’s impact on the wider policies of development in postcolonial Mauritius, one of the twentieth century’s preeminent success stories of capitalist development, underlines that development is best understood as a political economy machinery that maintains and amends contested capitalist practices in an encounter with earlier global, national, and local historical–cultural formations

    Expression of ZIC genes in the development of the chick inner ear and nervous system

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    ZIC genes, vertebrate homologues of the Drosophila pair-rule gene odd-paired ( opa ), function in embryonic pattern formation, in the early stages of central nervous system neurogenesis and in cerebellar maturation. Mouse Zic genes are expressed in restricted, and in some cases overlapping, patterns during development, particularly in the central and peripheral nervous systems. We identified chick ZIC2 in a differential display analysis of the auditory system designed to find genes up-regulated after noise trauma. In this study, we examined the expression of chick ZIC1 , ZIC2 , and ZIC3 by in situ hybridization in normal inner ear development and in the tissues that influence its development, including the hindbrain, the neural crest, and the periotic mesenchyme. Between Hamburger and Hamilton stages 13 and 24, all three ZIC genes were found in the dorsal periotic mesenchyme adjacent to the developing inner ear. ZIC1 mRNA was expressed in the otocyst epithelium between stages 12 and 24, in some sensory tissue, as well as in a striped pattern in the floorplate of the hindbrain that appears to be complementary to that of Chordin, a gene known to regulate ZIC expression in frogs. Chick ZIC genes are also expressed in the neuroectoderm, paraxial mesenchyme, brain, spinal cord, neural crest, and/or the overlying ectoderm as well as the limb buds. In general, ZIC1 and ZIC2 expression patterns overlapped, although ZIC2 expression was less robust; ZIC3 expression was minimal. These observations suggest that ZIC genes, in addition to their known roles in brain development, may play an important role in the development of the chick inner ear. Developmental Dynamics 702–712, 2003. © 2003 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35173/1/10262_ftp.pd

    DAN directs endolymphatic sac and duct outgrowth in the avian inner ear

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    Bone morphogenetic proteins (BMPs) are expressed in the developing vertebrate inner ear and participate in inner ear axial patterning and the development of its sensory epithelium. BMP antagonists, such as noggin, chordin, gremlin, cerberus, and DAN (differential screening-selected gene aberrative in neuroblastoma) inhibit BMP activity and establish morphogenetic gradients during the patterning of many developing tissues and organs. In this study, the role of the BMP antagonist DAN in inner ear development was investigated. DAN-expressing cell pellets were implanted into the otocyst and the periotic mesenchyme to determine the effects of exogenous DAN on otic development. Similar to the effects on the inner ear seen after exposure of otocysts to the BMP4 antagonist noggin, semicircular canals were truncated or eliminated based upon the site of pellet implantation. Unique to the DAN implantations, however, were effects on the developing endolymphatic duct and sac. In DAN-treated inner ears, endolymphatic ducts and sacs were merged with the crus or grew into the superior semicircular canal. Both the canal and endolymphatic duct and sac effects were rescued by joint implantation of BMP4-expressing cells. Electroporation of DAN antisense morpholinos into the epithelium of stage 15–17 otocysts, blocking DAN protein synthesis, resulted in enlarged endolymphatic ducts and sacs as well as smaller semicircular canals in some cases. Taken together, these data suggest a role for DAN both in helping to regulate BMP activity spatially and temporally and in patterning and partitioning of the medial otic tissue between the endolymphatic duct/sac and medially derived inner ear structures. Developmental Dynamics 229:219–230, 2004. © 2003 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35175/1/10414_ftp.pd

    A Late Role for bmp2b in the Morphogenesis of Semicircular Canal Ducts in the Zebrafish Inner Ear

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    BACKGROUND:The Bone Morphogenetic Protein (BMP) genes bmp2 and bmp4 are expressed in highly conserved patterns in the developing vertebrate inner ear. It has, however, proved difficult to elucidate the function of BMPs during ear development as mutations in these genes cause early embryonic lethality. Previous studies using conditional approaches in mouse and chicken have shown that Bmp4 has a role in semicircular canal and crista development, but there is currently no direct evidence for the role of Bmp2 in the developing inner ear. METHODOLOGY/PRINCIPAL FINDINGS:We have used an RNA rescue strategy to test the role of bmp2b in the zebrafish inner ear directly. Injection of bmp2b or smad5 mRNA into homozygous mutant swirl (bmp2b(-/-)) embryos rescues the early patterning defects in these mutants and the fish survive to adulthood. As injected RNA will only last, at most, for the first few days of embryogenesis, all later development occurs in the absence of bmp2b function. Although rescued swirl adult fish are viable, they have balance defects suggestive of vestibular dysfunction. Analysis of the inner ears of these fish reveals a total absence of semicircular canal ducts, structures involved in the detection of angular motion. All other regions of the ear, including the ampullae and cristae, are present and appear normal. Early stages of otic development in rescued swirl embryos are also normal. CONCLUSIONS/SIGNIFICANCE:Our findings demonstrate a critical late role for bmp2b in the morphogenesis of semicircular canals in the zebrafish inner ear. This is the first demonstration of a developmental role for any gene during post-embryonic stages of otic morphogenesis in the zebrafish. Despite differences in the early stages of semicircular canal formation between zebrafish and amniotes, the role of Bmp2 in semicircular canal duct outgrowth is likely to be conserved between different vertebrate species

    Molecular characterization of conditionally immortalized cell lines derived from mouse early embryonic inner ear

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    Inner ear sensory hair cells (HCs), supporting cells (SCs), and sensory neurons (SNs) are hypothesized to develop from common progenitors in the early embryonic otocyst. Because little is known about the molecular signals that control this lineage specification, we derived a model system of early otic development: conditionally immortalized otocyst (IMO) cell lines from the embryonic day 9.5 Immortomouse. This age is the earliest stage at which the otocyst can easily be separated from surrounding mesenchymal, nervous system, and epithelial cells. At 9.5 days post coitum, there are still pluripotent cells in the otocyst, allowing for the eventual identification of both SN and HC precursors—and possibly an elusive inner ear stem cell. Cell lines derived from primitive precursor cells can also be used as blank canvases for transfections of genes that can affect lineage decisions as the cells differentiate. It is important, therefore, to characterize the “baseline state” of these cell lines in as much detail as possible. We characterized seven representative “precursor-like” IMO cell populations and the uncloned IMO cells, before cell sorting, at the molecular level by polymerase chain reaction (PCR) and immunocytochemistry (IHC), and one line (IMO-2B1) in detail by real-time quantitative PCR and IHC. Many of the phenotypic markers characteristic of differentiated HCs or SCs were detected in IMO-2B1 proliferating cells, as well as during differentiation for up to 30 days in culture. These IMO cell lines represent a unique model system for studying early stages of inner ear development and determining the consequences of affecting key molecular events in their differentiation. Developmental Dynamics 231:815–827, 2004. © 2004 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35177/1/20186_ftp.pd

    Sovereign risk and the bank lending channel in Europe.

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    ABSTRACT: The main purpose of this article is to analyze how sovereign risk influences the loan supply reaction of banks to monetary policy through the bank lending channel. Additionally, we aim to test whether this reaction differs in easy and tight monetary regimes. Using a sample of 3,125 banks from the euro zone between 1999 and 2012, we find that sovereign risk plays an important role in determining loan supply from banks during tight monetary regimes. Banks in higher sovereign risk countries reduce lending more during tight regimes. However, we find little evidence to support any relationship between sovereign risk and loan supply reaction to monetary policy expansions. These results are very interesting for the way monetary policy is conducted in Europe. Banking union, banking system strength, and the budget control of governments would be necessary measures to reduce the heterogeneous transmission of the monetary policy in the euro zone
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