1,200 research outputs found

    Measuring Ethnic Fractionalization in Africa

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    Pre-analysis plans: a stocktaking

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    The evidence-based community has championed the public registration of pre-analysis plans (PAPs) as a solution to the problem of research credibility, but without any evidence that PAPs actually bolster the credibility of research. We analyze a representative sample of 195 pre-analysis plans (PAPs) from the American Economic Association (AEA) and Evidence in Governance and Politics (EGAP) registration platforms to assess whether PAPs are sufficiently clear, precise and comprehensive to be able to achieve their objectives of preventing fishing and reducing the scope for post-hoc adjustment of research hypotheses. We also analyze a subset of 93 PAPs from projects that have resulted in publicly available papers to ascertain how faithfully they adhere to their pre-registered specifications and hypotheses. We find significant variation in the extent to which PAPs are accomplishing the goals they were designed to achieve

    Kenya's New Constitution

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    On 4 August 2010, Kenyans voted to adopt a new constitution, culminating a process that began as part of a resolution to the violent conflict that followed the December 2007 elections. By reducing executive power, devolving authority, and guaranteeing rights to women, minorities, and marginalized communities, the constitution has the potential to transform Kenyan politics. Political and logistical obstacles will, however, pose a challenge to implementation. Yet that the constitution has been adopted amidst a broader trend toward the institutionalization of political power in Africa—a context in which formal constitutional rules are increasingly consequential—provides cause for cautious optimism

    Multiple testing & optimization-based approaches with applications to genome-wide association studies

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    Many phenotypic traits are heritable, but the exact genetic causes are difficult to determine. A common approach for disentangling the different genetic factors is to conduct a "genome-wide association study" (GWAS), where each single nucleotide variant (SNV) is tested for association with a trait of interest. Many SNVs for complex traits have been found by GWAS, but to date they explain only a fraction of heritability of complex traits. In this dissertation, we propose novel optimization-based and multiple testing procedures for variant set tests. In the second chapter, we propose a novel variant set test, convex-optimized SKAT (cSKAT), that leverages multiple SNV annotations. The test generalizes SKAT to convex combinations of SKAT statistics constructed from functional genomic annotations. We differ from previous approaches by optimizing kernel weights with a multiple kernel learning algorithm. In cSKAT, the contribution of each variant to the overall statistic is a product of annotation values and kernel weights for annotation classes. We demonstrate the utility of our biologically-informed SNV weights in a rare-variant analysis of fasting glucose in the FHS. In the third chapter, we propose a sequential testing procedure for GWAS that joins tests of single SNVs and groups of SNVs (SNV-sets) with common biological function. The proposed procedure differs from previous procedures by testing genes and sliding 4kb intergenic windows rather than chromosomes or the whole genome. We also sharpen an existing tree-based multiple testing correction by incorporating correlation between SNVs, which is present in any SNV-set containing contiguous regions (such as genes). In the fourth chapter, we present a sequential testing procedure for SNV-sets that incorporates correlation between test statistics of the SNV-sets. At each step of the procedure, the multiplicity correction is the number of remaining independent tests, making no assumption about the null distribution of tests. We provide an estimator for the number of remaining independent tests based on previous work in single-SNV GWAS and demonstrate the estimator is valid for sequential procedures. We implement the proposed method for GWAS by sequentially testing chromosomes, genes, 4kb windows, and SNVs

    MODEL KEMITRAAN BISNIS DONAT MADU CIHANJUANG: Studi Deskriptif pada Mitra Usaha Donat Madu Cihanjuang Se-Bandung Raya

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    Latar belakang penelitian ini adalah untuk mengetahui model pengembangan bisnis yang dilakukan oleh Donat Madu Cihanjuang melalui model kemitraan. Dalam penelitian ini difokuskan pada model kemitraan pola waralaba sesuai yang diterapkan bisnis tersebut dengan subyek penelitian mitra usaha Donat Madu Cihanjuang yang berada di kawasan Bandung Raya. Penelitian ini bertujuan untuk mengetahui (1) Gambaran umum mengenai alur kerja kemitraan Donat Madu Cihanjuang se-Bandung Raya (2) Kualitas hubungan kemitraan (3) Efektifitas pemasaran masing-masing mitra usaha (4) Tingkat keberhasilan usaha masing-masing mitra usaha. Metode yang dilakukan dalam penelitian ini adalah metode deskriptif kuantitatif dan kualitatif. Teknik pengumpulan data yang dilakukan dalam penelitian ini melalui studi kepustakaan, observasi dan instrument angket. Data yang telah terkumpul kemudian dianalisis melalui tahap display data, verifikasi data dan penegasan kesimpulan. Hasil penelitian menunjukkan: (1) Ketepatan alur kemitraan pola waralaba berada pada kriteria tinggi (2) Kualitas hubungan kemitraan berada pada kriteria sangat tinggi (3) efektifitas pemasaran berada pada kriteria tinggi (4) Tingkat keberhasilan usaha berada pada kriteria tinggi. ---------- The background in this research is to find out about business model developing of Donat Madu Cihanjuang by means of partnership model. This research focusing to partnership model system franchise that appropriate and applying from this business. Subject in this research is Donat Madu Cihanjuang partners in Bandung Metropolitan area. This research aims to know about (1) activity groove partnership of Donat Madu Cihanjuang in Bandung Metropolitan area (2) Quality of partner relationship (3) Marketing product efectivity each labor partnership (4) Level of business success each labor partnership. This research using quantitative and qualitative descriptive method. The techniques of collection data by study literature, observation and questionnaire. The collected data were analyzed through the stage of data display, data verification, and finally through the assertion conclusion. This result show that are (1) activity groove partnership is in high criteria (2) Quality of partner relationship is in very high criteria (3) Marketing product efectivity is in high criteria (4) Level of business success is in high criteria

    Exposure Patterns in the Digital Domain: A Demographic Analysis of Media Use and Access in the United States

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    In this study we examine and extend knowledge in a relatively neglected area of diversity research in the digital domain: exposure diversity. Specifically, we assess how different demographic groups use digital devices to consume media content and connect with one another. Two hundred and ninety-seven participants were surveyed about the digital media devices they have and what they do with them. We analyzed access and use in terms of users’ age, gender, race, annual income, and education. Our results confirm the persistence of a digital divide with regard to exposure diversity and continue to verify earlier findings regarding significant differences in media use and access in different demographic groups

    On L(2,1)-coloring split, chordal bipartite, and weakly chordal graphs

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    AbstractAn L(2,1)-coloring, or λ-coloring, of a graph is an assignment of non-negative integers to its vertices such that adjacent vertices get numbers at least two apart, and vertices at distance two get distinct numbers. Given a graph G, λ is the minimum range of colors for which there exists a λ-coloring of G. A conjecture by Griggs and Yeh [J.R. Griggs, R.K. Yeh, Labelling graphs with a condition at distance 2, SIAM Journal on Discrete Mathematics 5 (1992) 586–595] states that λ is at most Δ2, where Δ is the maximum degree of a vertex in G. We prove that this conjecture holds for weakly chordal graphs. Furthermore, we improve the known upper bounds for chordal bipartite graphs, and for split graphs
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