249 research outputs found

    Firm-Specific Variation and Openness in Emerging Markets

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    This paper compares the comovement of individual stock returns across emerging markets. Campbell et al. (2001) and Morck et al. (2000) show that the US in the post war period saw rising firm specific stock return variations and thus declining comovement. We detect a similar, albeit weaker, pattern in most, but not all, emerging markets. We further find that higher firm-specific variation is associated with greater capital market openness, but not goods market openness. Moreover, this relationship is magnified by institutional integrity (good government). Goods market openness is associated with higher market-wide variation.http://deepblue.lib.umich.edu/bitstream/2027.42/40009/3/wp623.pd

    Firm-Specific Variation and Openness in Emerging Markets

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    This paper compares the comovement of individual stock returns across emerging markets. Campbell et al. (2001) and Morck et al. (2000) show that the US in the post war period saw rising firm specific stock return variations and thus declining comovement. We detect a similar, albeit weaker, pattern in most, but not all, emerging markets. We further find that higher firm-specific variation is associated with greater capital market openness, but not goods market openness. Moreover, this relationship is magnified by institutional integrity (good government). Goods market openness is associated with higher market-wide variation.

    Towards Feasible Instructor Intervention in MOOC discussion forums

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    Massive Open Online Courses allow numerous people from around the world to have access to knowledge that they otherwise have not. However, high student-to-instructor ratio in MOOCs restricts instructors’ ability to facilitate student learning by intervening in discussions forums, as they do in face-to-face classrooms. Instructors need automated guidance on when and how to intervene in discussion forums. Using a typology of pedagogical interventions derived from prior research, we annotate a large corpus of discussion forum contents to enable supervised machine learning to automatically identify interventions that promote student learning. Such machine learning models may allow building of dashboards to automatically prompt instructors on when and how to intervene in discussion forums. In the longer term, it may be possible to automate these interventions relieving instructors of this effort. Such automated approaches are essential for allowing good pedagogical practices to scale in the context of MOOC discussion forums

    Structural modification of fibroblast growth factor-binding heparan sulfate at a determinative stage of neural development

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    Heparan sulfate (HS) glycosaminoglycans are essential modulators of fibroblast growth factor (FGF) activity and appear to act by coupling particular forms of FGF to appropriate FGF receptors, During neural development, one particular HS proteoglycan is able to rapidly switch its potentiating activity from FGF-2, as neural precursor cell proliferation occurs, to FGF-1, as neuronal differentiation occurs, Using various analytical techniques, including chemical and enzymatic cleavage, low pressure chromatography, and strong anion-exchange high performance Liquid chromatography, we have analyzed the different HSs expressed during these crucial developmental stages, There are distinct alterations in patterns of 6-O-sulfation, total chain length, and the number of sulfated domains of the HS from the more mature embryonic brain, These changes correlate with a switch in the ability of the HS to potentiate the actions of FGF-1 in triggering: cell differentiation It thus appears that each HS pool is designed to function in the modulation of an intricate interaction with a specific growth factor and its cognate receptor, and suggests tightly regulated expression of specific, bioactive disaccharide sequences, The data can be used to construct a simple model of controlled variations in HS chain structure which have functional consequences at a crucial stage of neuronal maturation

    Mastomys natalensis and Lassa Fever, West Africa

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    PCR screening of 1,482 murid rodents from 13 genera caught in 18 different localities of Guinea, West Africa, showed Lassa virus infection only in molecularly typed Mastomys natalensis. Distribution of this rodent and relative abundance compared with M. erythroleucus correlates geographically with Lassa virus seroprevalence in humans

    Cellular metabolism constrains innate immune responses in early human ontogeny

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    Pathogen immune responses are profoundly attenuated in fetuses and premature infants, yet the mechanisms underlying this developmental immaturity remain unclear. Here we show transcriptomic, metabolic and polysome profiling and find that monocytes isolated from infants born early in gestation display perturbations in PPAR-γ-regulated metabolic pathways, limited glycolytic capacity and reduced ribosomal activity. These metabolic changes are linked to a lack of translation of most cytokines and of MALT1 signalosome genes essential to respond to the neonatal pathogen Candida. In contrast, they have little impact on house-keeping phagocytosis functions. Transcriptome analyses further indicate a role for mTOR and its putative negative regulator DNA Damage Inducible Transcript 4-Like in regulating these metabolic constraints. Our results provide a molecular basis for the broad susceptibility to multiple pathogens in these infants, and suggest that the fetal immune system is metabolically programmed to avoid energetically costly, dispensable and potentially harmful immune responses during ontogeny

    Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

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    Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t

    Reversible Decomposition of Secondary Phases in BaO Infiltrated LSM Electrodes-Polarization Effects

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    In operando Raman spectroscopy is used to study ceramic La0.85Sr0.15MnO3 +/-delta electrodes infiltrated with BaO. The aim of this work is to clarify why BaO infiltration reduces the polarization resistance in oxygen containing atmospheres. Prior to the in operando experiments, ex situ X-ray diffraction and Raman spectroscopy reveal the formation of a secondary phase, Ba3Mn2O8, on the electrode. During the in operando Raman investigation of the BaO-infiltrated La0.85Sr0.15MnO3 +/-delta electrodes, experiments are performed at 300 and 500 degrees C with oxygen partial pressure 0.1 atm and with -1 or +1 V applied potential. A changing electrode surface is observed during operation as the Ba3Mn2O8 secondary phase decomposes and manganese oxide accumulates on the electrode surface during cathodic polarization. The observed changes are reversible. These results suggest that the formation of Ba3Mn2O8 is responsible for the reduced polarization resistance observed at open circuit voltage (OCV) in an oxygen containing atmosphere. Furthermore, the results illustrate the dramatic differences between the electrode surface composition at OCV and during cathodic polarization. Overall, the results highlight the dynamic interactions between minor secondary phases and applied potential, a general effect that may be important for the high-performance frequently observed with ceramic electrodes prepared by infiltration

    Language education policy and practice in East and Southeast Asia

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    East and Southeast Asia represents a linguistically and culturally diverse region. For example, more than 700 languages are spoken in Indonesia alone. It is against this backdrop of diversity that the ten countries that comprise Association of South East Asian Nations (ASEAN) have recently signed the ASEAN Charter which, while calling for respect for the region's languages, cultures and religions also officially nominates English as ASEAN's working language. In this article, we examine the language education policies of the region and consider the implications of these policies for the maintenance of linguistic and cultural diversity on the one hand and the promotion of English and the respective national languages on the other. As ASEAN is closely connected to the three major countries of China, Japan and South Korea, as indicated by the ‘ASEAN + 3’ forum, we also include these countries here. We stress that, as space forbids an in-depth treatment of the language education policies of each of the 13 countries, we have chosen to describe and discuss in some depth the policies of 5 countries (China, Indonesia, Japan, the Philippines and Vietnam), as these provide a cross-section of language policy contexts and approaches in the region. We add brief notes on the policies of the remaining countries
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