Search results for "NIP"
showing 10 items of 775 documents
A New Set of Quartic Trivariate Polynomial Equations for Stratified Camera Self-calibration under Zero-Skew and Constant Parameters Assumptions
2012
This paper deals with the problem of self-calibrating a moving camera with constant parameters. We propose a new set of quartic trivariate polynomial equations in the unknown coordinates of the plane at infinity derived under the no-skew assumption. Our new equations allow to further enforce the constancy of the principal point across all images while retrieving the plane at infinity. Six such polynomials, four of which are independent, are obtained for each triplet of images. The proposed equations can be solved along with the so-called modulus constraints and allow to improve the performance of existing methods.
Differential influence of two acanthocephalan parasites on the antipredator behaviour of their common intermediate host
2007
7 pages; International audience; Fish acanthocephalans can modify the antipredator behaviour of their intermediate hosts in response to cues from fish predators. However, it is still unclear whether such behavioural changes are adaptive, or are just the consequence of infection. We addressed this question through studying two acanthocephalans, Pomphorhynchus laevis and Polymorphus minutus, and their intermediate host, the amphipod Gammarus pulex. Pomphorhynchus laevis completes its cycle in a freshwater fish, whereas P. minutus exploits waterbirds as final hosts.We first assessed vulnerability of infected and uninfected gammarids to predation by bullheads, Cottus gobio. Pomphorhynchus laevi…
Is the host or the parasite the most locally adapted in an amphipod–acanthocephalan relationship? A case study in a biological invasion context
2007
8 pages; International audience; Manipulative endoparasites with complex life cycles can alter their intermediate host immunity and behaviour in ways that increase survival probability within the host body cavity and enhance successful transmission to the definitive host. These parasitic manipulations are variable among and within parasite species and may result from co-evolutionary processes, in which the parasite is constrained for adaptation to the local intermediate host. Hence, arrival of a new host species in a local host population may promote local parasite maladaptation. This study tested the occurrence of local adaptation in two distantly located populations of the acanthocephalan…
Intra-specific variability and biological relevance of P3N-PIPO protein length in potyviruses
2013
Background:Pipo was recently described as a new ORF encoded within the genome of the Potyviridae family members (PNAS 105:5897-5902, 2008). It is embedded within the P3 cistron and is translated in the +2 reading frame relative to the potyviral long ORF as the P3N-PIPO fusion protein. In this work, we first collected pipo nucleotide sequences available for different isolates of 48 Potyvirus species. Second, to determine the biological implications of variation in pipo length, we measured infectivity, viral accumulation, cell-to-cell and systemic movements for two Turnip mosaic virus (TuMV) variants with pipo alleles of different length in three different susceptible host species, and tested…
A Perturbation Approach to Continuous-Time Portfolio Selection Under Stochastic Investment Opportunities
2013
This paper studies portfolio selection in continuous-time models with stochastic investment opportunities. We consider asset allocation problems where preferences are specified as power utility derived from terminal wealth as well as consumption-savings problems with recursive utility Epstein-Zin preferences. The paper approximates the associated dynamic programming problem by perturbing the coefficients of the stochastic dynamics. We represent the Hamilton-Jacobi-Bellman equation as a series of partial differential equations that can be solved iteratively in closed-form through computer algebra software, at any desired accuracy.
Evaluation of carotenoids and furosine content in air dried carrots and parsnips pre-treated with pulsed electric field (PEF)
2019
Carrot and parsnip slices were subjected to hot drying at 50, 60 and 70 °C with or without pulsed electric field (PEF) pre-treatment at 0.9 kV/cm and 1000 and 10,000 pulses. The effect of drying on processed samples was assessed by analysis of carotenoids, the furosine value, total phenols and the Whiteness Index (WI). PEF pre-treatment is effective in reducing drying times, but the degree of cellular breakdown makes the compounds more susceptible to chemical and enzymatic reactions. In our condition PEF pre-treatment increased the carotenoid degradation and promoted the Maillard reaction above all at the highest temperature of 70 °C. The assessment of carotenoid stability, together with th…
Anxiété et manipulation parasitaire chez un invertébré aquatique : approches évolutive et mécanistique
2020
Trophically transmitted parasites induce changes in their host’s phenotype. These changes are supposed to increase transmission probability to definitive hosts through the predation of intermediate hosts. This phenomenon is known as ‘parasite manipulation’ has been hypothesized to be an adaptive trait of parasites for a long time. As manipulation involves predator-prey interactions, it is therefore necessary to understand how antipredatory behaviours are modulated by exogenous (predation pressure) and endogenous (infection, emotional state) factors. We tried to go into this phenomenon in depth, in amphipods, by responding toseveral questions : (1) what is the extent of the multidimensionali…
Ciencia y manipulación discursiva en Legiones y Falanges: «Características raciales del comunismo»
2016
Sobre todo en algunos contextos socio-políticos, la prensa puede ser vehículo de ideología e instrumento para manipular la consciencia de los lectores. Es lo que sucede en la revista Legiones y falanges (1940-43), voz de la joven dictadura fascista. En este trabajo, a través del análisis de un artículo del "psiquiatra del régimen", se demuestra cómo incluso el discurso científico se convierte en un medio imprescindible para la autolegitimación y justificación de las medidas represivas adoptadas por el gobierno.
Facebook’s Emotional Contagion Experiment as a Challenge to Research Ethics
2016
This article analyzes the ethical discussion focusing on the Facebook emotional contagion experiment published by the <em>Proceedings of the National Academy of Sciences</em> in 2014. The massive-scale experiment manipulated the News Feeds of a large amount of Facebook users and was successful in proving that emotional contagion happens also in online environments. However, the experiment caused ethical concerns within and outside academia mainly for two intertwined reasons, the first revolving around the idea of research as manipulation, and the second focusing on the problematic definition of informed consent. The article concurs with recent research that the era of social med…
Developing a matrix framework for protein transition towards more sustainable diets
2021
PurposeThe purpose of this study is to propose a matrix framework to understand the interdependencies of domains and scales of protein transition towards diets based on plants and alternative sources of proteins.Design/methodology/approachThe abductive research approach is used in building the framework, and the proposed framework is illustrated using the regional food system in Central Finland as an example. Focus groups and interviews were used to collect qualitative data from 28 respondents.FindingsThis study provides a framework for protein transition, with five domains and five scale levels. Interactions between public and private governance activities at different scales, domains and …