5,176 research outputs found

    Earth's middle age

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    This research was funded through Natural Environment Research Council (grant NE/J021822/1) and the APC was paid through the RCUK OA block grant.Earth's middle age, extending from 1.7 to 0.75 Ga, was characterized by environmental, evolutionary, and lithospheric stability that contrasts with the dramatic changes in preceding and succeeding eras. The period is marked by a paucity of preserved passive margins, an absence of a significant Sr anomaly in the paleoseawater record and in the εHf(t) in detrital zircon, a lack of orogenic gold and volcanic-hosted massive sulfide deposits, and an absence of glacial deposits and iron formations. In contrast, anorthosites and kindred bodies are well developed and major pulses of Mo and Cu mineralization, including the world's largest examples of these deposits, are features of this period. These trends are attributed to a relatively stable continental assemblage that was initiated during assembly of the Nuna supercontinent by ca. 1.7 Ga and continued until breakup of its closely related successor, Rodinia, ca. 0.75 Ga. The overall low abundance of passive margins is consistent with a stable continental configuration, which also provided a framework for environmental and evolutionary stability. A series of convergent margin accretionary orogens developed along the edge of the supercontinent. Abundant anorthosites and related rocks developed inboard of the plate margin. Their temporal distribution appears to link with the secular cooling of the mantle, at which time the overlying continental lithosphere was strong enough to be thickened and to support the emplacement of large plutons into the crust, yet the underlying mantle was still warm enough to result in widespread melting of the lower thickened crust.Publisher PDFPeer reviewe

    Using big data for customer centric marketing

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    This chapter deliberates on “big data” and provides a short overview of business intelligence and emerging analytics. It underlines the importance of data for customer-centricity in marketing. This contribution contends that businesses ought to engage in marketing automation tools and apply them to create relevant, targeted customer experiences. Today’s business increasingly rely on digital media and mobile technologies as on-demand, real-time marketing has become more personalised than ever. Therefore, companies and brands are striving to nurture fruitful and long lasting relationships with customers. In a nutshell, this chapter explains why companies should recognise the value of data analysis and mobile applications as tools that drive consumer insights and engagement. It suggests that a strategic approach to big data could drive consumer preferences and may also help to improve the organisational performance.peer-reviewe

    Temporal relations between mineral deposits and global tectonic cycles

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    Natural Environment Research Council (grant NE/J021822/1) supported this research.Mineral deposits are heterogeneously distributed in both space and time, with variations reflecting tectonic setting, evolving environmental conditions, as in the atmosphere and hydrosphere, and secular changes in the Earth’s thermal history. The distribution of deposit types whose settings are tied to plate margin processes (e.g. orogenic gold, volcanic-hosted massive sulphide, Mississippi valley type Pb–Zn deposits) correlates well with the supercontinent cycle, whereas deposits related to intra-cratonic settings and mantle-driven igneous events, such as Ni–Cu–PGE deposits, lack a clear association. The episodic distribution of deposits tied to the supercontinent cycle is accentuated by selective preservation and biasing of rock units and events during supercontinent assembly, a process that encases the deposit within the assembled supercontinent and isolates it from subsequent removal and recycling at plate margins.Publisher PD

    Schooling and labor market impacts of a natural policy experiment

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    The authors use a nationally representative household survey to estimate returns to schooling in Venezuela from instrumental variables based on a supply-side intervention in the education market. These estimates apply to a subgroup of liquidity-constrained individuals, in the spirit of the Local Average Treatment Effect (LATE) literature. Returns to schooling estimates which apply to a subgroup of individuals affected by the policy intervention may be more interesting from a policy perspective than the return to the"average"individual. The authors use an instrument based on the 1980 education reform (the Organic Law of Education) which provided for nine years of compulsory basic education. They also obtain alternative estimates using father's education as an instrument, in an attempt to derive high and low estimates of returns to schooling in Venezuela. The estimates are consistent with recent findings suggesting that the effect of education, at least for certain subgroups affected by a policy intervention, is as large, or larger than what is suggested by OLS estimates.Curriculum&Instruction,Public Health Promotion,Health Monitoring&Evaluation,Teaching and Learning,Education Reform and Management,Gender and Education,Health Monitoring&Evaluation,Teaching and Learning,Curriculum&Instruction,Education Reform and Management

    Incidence analysis of public support to the private education sector in Cote d'Ivoire

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    This report analyzes the equity effects of public subsidization of private schools in Cote d'Ivoire, updates previous analyses, and attempts to assess how efficiently public spending is targeted. The subsidy per student in private (and public) schools increases at higher quintiles. Students from families in the highest quintile receive more than twice the subsidy received by students from families in the lowestquintile, compared with four times more in the case of students attending public schools. However, the subsidy system is progressive as there is a clear tendency for the share of family education expenditure covered by subsidies to decline at higher quintiles. This element of progressivity is stronger in the case of private school attendance.Primary Education,Public Health Promotion,Teaching and Learning,Health Monitoring&Evaluation,Gender and Education,Health Monitoring&Evaluation,Gender and Education,Primary Education,Teaching and Learning,Urban Services to the Poor

    Economic volatility and returns to education in Venezuela : 1992-2002

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    Preliminary evidence suggests that the rates of return to education in Venezuela have been declining since the 1970s. The authors rigorously estimate the returns to education in Venezuela for the period 1992-2002, and link them to earlier available estimates from the 1980s. They use consistent cross-sections from the"Encuesta de Hogares por Muestreo"(Household Survey) to document falling returns to schooling, and educational levels until the mid-1990s, followed by increased returns thereafter. The authors use quantile regression analysis to provide further insight into and within skill group changes in returns over time.Decentralization,Public Health Promotion,Curriculum&Instruction,Teaching and Learning,Health Monitoring&Evaluation,Teaching and Learning,Health Monitoring&Evaluation,Curriculum&Instruction,Primary Education,Agricultural Knowledge&Information Systems
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