Detecting multivariate differentially expressed genes

<p>Abstract</p> <p>Background</p> <p>Gene expression is governed by complex networks, and differences in expression patterns between distinct biological conditions may therefore be complex and multivariate in nature. Yet, current statistical methods for detecting differential expression merely consider the univariate difference in expression level of each gene in isolation, thus potentially neglecting many genes of biological importance.</p> <p>Results</p> <p>We have developed a novel algorithm for detecting multivariate expression patterns, named Recursive Independence Test (RIT). This algorithm generalizes differential expression testing to more complex expression patterns, while still including genes found by the univariate approach. We prove that RIT is consistent and controls error rates for small sample sizes. Simulation studies confirm that RIT offers more power than univariate differential expression analysis when multivariate effects are present. We apply RIT to gene expression data sets from diabetes and cancer studies, revealing several putative disease genes that were not detected by univariate differential expression analysis.</p> <p>Conclusion</p> <p>The proposed RIT algorithm increases the power of gene expression analysis by considering multivariate effects while retaining error rate control, and may be useful when conventional differential expression tests yield few findings.</p

Female labor supply and the demand for housing

female workers;labour supply;housing

A short note on joint welfare maximization assumptions

Non-cooperative game theoretical models of international environmental agreements (IEAs) use the assumption that coalition of signatories maximize their joint welfare. The joint maxi- mization assumption is compared with di®erent sharing pro¯t schemes such as Shapley value, Nash bargaining solution and Consensus Value. The results show that the joint welfare max- imization assumption is similar with Nash Bargaining solution.game theory, coalition formation, joint welfare maximization, Shapley value, Nash bargaining solution, Consensus Value, international environmental agreements

An Analysis of Adaptation as a Response to Climate Change

Climate change is likely to have relevant effects on our future socio-economic systems. It is therefore important to identify how markets and policy jointly react to expected climate change to protect our societies and well-being. This study addresses this issue by carrying out an integrated analysis of both optimal mitigation and adaptation at the global and regional level. Adaptation responses are disentangled into three different modes: reactive adaptation, proactive (or anticipatory) adaptation, and investments in innovation for adaptation purposes. The size, the timing, the relative contribution to total climate-related damage reduction, and the benefit-cost ratios of each of these strategies are assessed for the world as a whole, and for developed and developing countries in both a cooperative and a non-cooperative setting. The study also takes into account the role of price signals and markets in inducing and diffusing adaptation. This leads to two scenarios: A pessimistic one, in which policy-driven adaptation bears the burden, together with mitigation, of reducing climate damage; and an optimistic one, in which markets also autonomously contribute to reducing some damages by modifying sectoral structure, international trade flows, capital distribution and land allocation. For all scenarios, the costs and benefits of adaptation are assessed using WITCH, an integrated assessment, intertemporal optimization, forward-looking model. Extensive sensitivity analysis with respect to the size of climate damages and of the discount rate has also been carried out.Climate change impacts, mitigation, adaptation, integrated assessment model

Environmental Policy, Spatial Spillovers and the Emergence of Economic Agglomerations

We explain the spatial concentration of economic activity, in a model of economic geography, when the cost of environmental policy - which is increasing in the concentration of pollution - and an immobile production factor act as centrifugal forces, while positive knowledge spillovers and iceberg transportation costs act as centripetal forces. We study the agglomeration eects caused by trade-os between centripetal and centrifugal forces. The above eects govern rms� location decisions and, as a result, they dene the distribution of economic activity across space. We derive the rational expectations equilibrium, which results either in a monocentric or in a polycentric city, and the regulator�s optimum, which results in a bicentric city. We compare the outcomes and characterize the optimal spatial policies.Agglomeration, Space, Pollution, Environmental Policy, Knowledge Spillovers, Transportation Cost

Academic English and WIDA Level One Through Three ELs in the Mainstream: Professional Development Series for Increased Educational Equity for ELs at the Elementary and Middle School Levels

The guiding question addressed in this capstone project is, how can we ensure that WIDA level one through three English Learners (ELs) are maximizing their learning potential and being provided with equitable learning opportunities in the mainstream? The purpose of this project was to explore and compile available resources related to serving and supporting WIDA level one through three ELs in mainstream educational contexts. The goal of this project was to create a professional development series intended to guide mainstream teachers in beginning to better understand who their ELs are and implement appropriate linguistic supports to ensure they are able to access grade level content and cognitively challenging learning tasks as much as possible regardless of their current English language proficiency. This project first expounds on the history of ELs in the U.S. public education system, as well as issues related to second language acquisition, equity, and ELs in mainstream educational settings. Additionally, it introduces eight low prep and easy to adapt linguistic scaffolds that can be employed to better support ELs in mainstream classrooms. Last, it discusses common issues for ELs related to traditional assessment and provides suggestions of alternate forms of authentic assessment for ELs in the mainstream classroom. The outcome of this project is a small toolbox of resources mainstream teachers can use and adapt to support individual EL needs to begin increasing equitable learning opportunities in the mainstream

Environmental Policy, Spatial Spillovers and the Emergence of Economic Agglomerations

We explain the spatial concentration of economic activity, in a model of economic geography, when the cost of environmental policy - which is increasing in the concentration of emissions - and an immobile production factor act as centrifugal forces, while positive knowledge spillovers and iceberg transportation costs act as centripetal forces. We study the agglomeration effects caused by trade-offs between centripetal and centrifugal forces. The above effects govern firms’ location decisions and as a result, they define the distribution of economic activity across space. We derive the rational expectations equilibrium and the social optimum, compare the outcomes and characterize the optimal spatial policies.Agglomeration, Spatial Economics, Environmental Policy, Knowledge Spillovers, Transportation Cost

Applying Model-Driven Engineering to Development Scenarios for Web Content Management System Extensions

Web content management systems (WCMSs) such as WordPress, Joomla or Drupal have established themselves as popular platforms for instantiating dynamic web applications. Using a WCMS instance allows developers to add additional functionality by implementing installable extension packages. However, extension developers are challenged by dealing with boilerplate code, dependencies between extensions and frequent architectural changes to the underlying WCMS platform. These challenges occur in frequent development scenarios that include initial development and maintenance of extensions as well as migration of existing extension code to new platforms. A promising approach to overcome these challenges is represented by model-driven engineering (MDE). Adopting MDE as development practice, allows developers to define software features within reusable models which abstract the technical knowledge of the targeted system. Using these models as input for platform-specific code generators enables a rapid transformation to standardized software of high quality. However, MDE has not found adoption during extension development in the WCMS domain, due to missing tool support. The results of empirical studies in different domains demonstrate the benefits of MDE. However, empirical evidence of these benefits in the WCMS domain is currently lacking. In this work, we present the concepts and design of an MDE infrastructure for the development and maintenance of WCMS extensions. This infrastructure provides a domain-specific modelling language (DSL) for WCMS extensions, as well as corresponding model editors. In addition, the MDE infrastructure facilitates a set of transformation tools to apply forward and reverse engineering steps. This includes a code generator that uses model instances of the introduced DSL, an extension extractor for code extraction of already deployed WCMS extensions, and a model extraction tool for the creation of model instances based on an existing extension package. To ensure adequacy of the provided MDE infrastructure, we follow a structured research methodology. First, we investigate the representativeness of common development scenarios by conducting interviews with industrial practitioners from the WCMS domain. Second, we propose a general solution concept for these scenarios including involved roles, process steps, and MDE infrastructure facilities. Third, we specify functional and non-functional requirements for an adequate MDE infrastructure, including the expectations of domain experts. To show the applicability of these concepts, we introduce JooMDD as infrastructure instantiation for the Joomla WCMS which provides the most sophisticated extension mechanism in the domain. To gather empirical evidence of the positive impact of MDE during WCMS extension development, we present a mixed-methods empirical investigation with extension developers from the Joomla community. First, we share the method, results and conclusions of a controlled experiment conducted with extension developers from academia and industry. The experiment compares conventional extension development with MDE using the JooMDD infrastructure, focusing on the development of dependent and independent extensions. The results show a clear gain in productivity and quality by using the JooMDD infrastructure. Second, we share the design and observations of a semi-controlled tutorial with four experienced developers who had to apply the JooMDD infrastructure during three scenarios of developing new (both independent and dependent) extensions and of migrating existing ones to a new major platform version. The aim of this study was to obtain direct qualitative feedback about acceptance, usefulness, and open challenges of our MDE approach. Finally, we share lessons learned and discuss the threats to validity of the conducted studies

A Life-Cycle Model of Outmigration and Economic Assimilation of Immigrants in Germany

This paper estimates a structural dynamic life-cycle model of outmigration where, in each period, immigrants choose whether to work in the host country, not to work but remain in the host country, or outmigrate.The model incorporates several features of existing life-cycle theories of outmigration but distinguishes itself by introducing uncertainty in about future earnings and preferences which allows immigrants to revise their duration decisions throughout their migration experience.Because immigrants simultaneously face a migration and a work decision in each period, the economic assimilation rates commonly used to assess the performance of immigrants in the host economy are endogenously determined and estimated, a feature previously ignored in the literature.We overcome the problem of not directly observing outmigration movements by using panel attrition as a proxy variable and use a simple method to correct for the fact that part of the attrition is not a consequence of outmigration.Estimates are used to predict changes in life-cycle patterns of outmigration behavior.Estimation results indicate that outmigration does not depend exclusively on earnings differentials.Estimated assimilation rates are found to be robust to selection effects.Immigrants are found to be forward looking decision makers, and simulations show that predicted migration durations are very sensitive to changes in their economic environment and differ considerably from those of a myopic model.migration;dynamic programming;immigration;emigration;life cycles;Germany