Nonparametric maximum likelihood approach to multiple change-point problems

In multiple change-point problems, different data segments often follow different distributions, for which the changes may occur in the mean, scale or the entire distribution from one segment to another. Without the need to know the number of change-points in advance, we propose a nonparametric maximum likelihood approach to detecting multiple change-points. Our method does not impose any parametric assumption on the underlying distributions of the data sequence, which is thus suitable for detection of any changes in the distributions. The number of change-points is determined by the Bayesian information criterion and the locations of the change-points can be estimated via the dynamic programming algorithm and the use of the intrinsic order structure of the likelihood function. Under some mild conditions, we show that the new method provides consistent estimation with an optimal rate. We also suggest a prescreening procedure to exclude most of the irrelevant points prior to the implementation of the nonparametric likelihood method. Simulation studies show that the proposed method has satisfactory performance of identifying multiple change-points in terms of estimation accuracy and computation time.Comment: Published in at http://dx.doi.org/10.1214/14-AOS1210 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Perceived Fit between Green IS and Green SCM: Does it Matter?

From a task-technology fit perspective, green SCM and green IS are likely to have synergistic effects on corporate sustainability. Yet, the exact mechanisms through which their perceived alignment by employees may exert influences on organizational performances are unclear. This study captures potential enablement and coverage routes at different development stages of sustainability with fit-as-mediation and fit-as-moderation, respectively. The results based on the observations collected from more than 400 organizations in the USA and China suggest that the perceived fit gradually shifts from a moderator role to a mediator role as the two green endeavors integrate with each other

Agenda 21.

A Agenda 21 Brasileira é um processo e, ao mesmo tempo, instrumento de planejamento participativo para o desenvolvimento sustentável e que tem como eixo central a sustentabilidade, compatibilizando a conservação ambiental, a justiça social e o crescimento econômico. O documento e resultado de uma vasta consulta a população brasileira, sendo construída a partir das diretrizes da Agenda 21 global. Trata-se, portanto, de um instrumento fundamental para a construção da democracia ativa e da cidadania participativa no pais. A primeira fase foi a construção da Agenda 21 Brasileira. Esse processo, que se deu de 1996 a 2002, foi coordenado pela Comissão de Politicas de Desenvolvimento Sustentável e da Agenda 21 Nacional - CPDS e teve o envolvimento de cerca de 40.000 pessoas de todo o Brasil. O documento Agenda 21 Brasileira foi concluído em 2002. A partir de 2003, a Agenda 21 Brasileira não somente entrou na fase de implementação assistida pela CPDS, como também foi elevada a condição de Programa do Plano Plurianual, PPA 2004-2007, pelo atual governo. Como programa, ela adquire mais foça politica e institucional, passando a ser instrumento fundamental para a construção do Brasil Sustentável, estando coadunada com as diretrizes da politica ambiental do Governo-transversalidade, desenvolvimento sustentável, fortalecimento do Sistema e participação social, adotando referenciais importantes como a Carta da Terra. Portanto, a Agenda 21, que tem provado ser um guia eficiente para processos de união da sociedade, compreensão dos conceitos de cidadania e de sua aplicação, e hoje um dos grandes instrumentos de formação de politicas públicas no Brasil.Agenda 21 Brazilian is a process and, at the same time, instrument of participative planning for the sustainable development and that it has as central axle the sustentabilidade, compatibizando the ambient conservation, social justice and the economic growth. The document is resulted of a vast one consults the Brazilian population, being constructed from the lines of direction of global Agenda 21. It is treated, therefore, of a basic instrument for the construction of the active democracy and the participative citizenship in the Country. The first phase was the construction of Agenda 21 Brazilian. This process, that if gave of 1996 the 2002, was co-ordinated by the Commission of Politics of Sustainable Development and the National Agenda 21 - CPDS and had the envolvement of about 40.000 people of all Brazil. The document Agenda 21 Brazilian was concluded in 2002. From 2003, Agenda 21 Brazilian not only entered in the phase of implementation attended for the CPDS, as also condition of Program of the Puritanical Plan was raised a, PPA 2004-2007, for the current government. As program, it it acquires more force institutional politics and, starting to be basic instrument for the construction of Sustainable Brazil, being coadunate with the lines of direction of the ambient politics of the Government-transversaldade, sustainable development, fortalecimento of the System and social participation, adopting referenciais important as the Letter of the Land. Therefore, Agenda 21, that it has proven being an efficient guide for processes of union of the society, understanding of the concepts of citizenship and its application, is today one of the great instruments of formation of public politics in Brazi

PRL2 Controls Phagocyte Bactericidal Activity by Sensing and Regulating ROS

Although it is well-recognized that inflammation enhances leukocyte bactericidal activity, the underlying mechanisms are not clear. Here we report that PRL2 is sensitive to oxidative stress at inflamed sites. Reduced PRL2 in phagocytes causes increased respiratory burst activity and enhances phagocyte bactericidal activity. PRL2 (Phosphatase Regenerating Liver 2) is highly expressed in resting immune cells, but is markedly downregulated by inflammation. in vitro experiments showed that PRL2 was sensitive to hydrogen peroxide (H2O2), a common damage signal at inflamed sites. In response to infection, PRL2 knockout (KO) phagocytes were hyper activated, produced more reactive oxygen species (ROS) and exhibited enhanced bactericidal activity. Mice with PRL2 deficiency in the myeloid cell compartment were resistant to lethal listeria infection and cleared the bacteria more rapidly and effectively. Moreover, in vitro experiments demonstrated that PRL2 binds to GTPase Rac and regulates ROS production. Rac GTPases were more active in PRL2 (KO) phagocytes than in wild type cells after bacterium infection. Our findings indicate that PRL2 senses ROS at inflamed sites and regulates ROS production in phagocytes. This positive feedback mechanism promotes bactericidal activity of phagocytes and may play an important role in innate anti-bacterial immunity

Critical success factors of green innovation: Technology, organization and environment readiness

Many organizations carry out green innovation for sustainable development, but not all are successful. Based on the technology-organization-environment framework, this study examines how prepared enterprises are for green innovation in terms of technology readiness, organization readiness, and environment readiness. It hypothesizes that the necessary and sufficient conditions along each dimension enable and facilitate green innovation, leading to competitive advantage through the mediation of environmental performance and firm performance. To test the research model, survey observations were collected from 340 companies in China. Supporting the hypothesized relationships, the results show that the necessary and sufficient conditions of all dimensions make significant but somewhat different contributions to the success of green innovation. The measurement instrument and research framework provide a self-assessment tool for organizations to strategize the preparation and implementation of green innovation for optimal sustainability outcomes

The First Passage Time Problem for Mixed-Exponential Jump Processes with Applications in Insurance and Finance

This paper stidies the first passage times to constant boundaries for mixed-exponential jump diffusion processes. Explicit solutions of the Laplace transforms of the distribution of the first passage times, the joint distribution of the first passage times and undershoot (overshoot) are obtained. As applications, we present explicit expression of the Gerber-Shiu functions for surplus processes with two-sided jumps, present the analytical solutions for popular path-dependent options such as lookback and barrier options in terms of Laplace transforms and give a closed-form expression on the price of the zero-coupon bond under a structural credit risk model with jumps.Comment: Abstract and Applied Analysis (To appear

Lipopeptide-Coated Iron Oxide Nanoparticles as Potential Glycoconjugate-Based Synthetic Anticancer Vaccines

Although iron oxide magnetic nanoparticles (NPs) have been widely utilized in molecular imaging and drug delivery studies, they have not been evaluated as carriers for glycoconjugate-based anticancer vaccines. Tumor-associated carbohydrate antigens (TACAs) are attractive targets for the development of anticancer vaccines. Due to the weak immunogenicity of these antigens, it is highly challenging to elicit strong anti-TACA immune responses. With their high biocompatibilities and large surface areas, magnetic NPs were synthesized for TACA delivery. The magnetic NPs were coated with phospholipid-functionalized TACA glycopeptides through hydrophobic–hydrophobic interactions without the need for any covalent linkages. Multiple copies of glycopeptides were presented on NPs, potentially leading to enhanced interactions with antibody-secreting B cells through multivalent binding. Mice immunized with the NPs generated strong antibody responses, and the glycopeptide structures important for high antibody titers were identified. The antibodies produced were capable of recognizing both mouse and human tumor cells expressing the glycopeptide, resulting in tumor cell death through complement-mediated cytotoxicities. These results demonstrate that magnetic NPs can be a new and simple platform for multivalently displaying TACA and boosting anti-TACA immune responses without the need for a typical protein carrier

Lipopeptide-Coated Iron Oxide Nanoparticles as Potential Glycoconjugate-Based Synthetic Anticancer Vaccines

Although iron oxide magnetic nanoparticles (NPs) have been widely utilized in molecular imaging and drug delivery studies, they have not been evaluated as carriers for glycoconjugate-based anticancer vaccines. Tumor-associated carbohydrate antigens (TACAs) are attractive targets for the development of anticancer vaccines. Due to the weak immunogenicity of these antigens, it is highly challenging to elicit strong anti-TACA immune responses. With their high biocompatibilities and large surface areas, magnetic NPs were synthesized for TACA delivery. The magnetic NPs were coated with phospholipid-functionalized TACA glycopeptides through hydrophobic–hydrophobic interactions without the need for any covalent linkages. Multiple copies of glycopeptides were presented on NPs, potentially leading to enhanced interactions with antibody-secreting B cells through multivalent binding. Mice immunized with the NPs generated strong antibody responses, and the glycopeptide structures important for high antibody titers were identified. The antibodies produced were capable of recognizing both mouse and human tumor cells expressing the glycopeptide, resulting in tumor cell death through complement-mediated cytotoxicities. These results demonstrate that magnetic NPs can be a new and simple platform for multivalently displaying TACA and boosting anti-TACA immune responses without the need for a typical protein carrier