353 research outputs found
Resurrecting the alien director: Jean-Pierre Jeunet in Hollywood
This essay examines the critical reception of Jean-Pierre Jeunet's Alien Resurrection in the popular Anglo-American press, where the film was often discussed in terms that highlighted the director's status as an 'outsider'. The anxiety that the film elicits among critics, it is argued, is a function of the very abjection that is depicted graphically within the film: a fear of the unclassifiable and of the crossing of boundaries
Attempts to detect retrotransposition and de novo deletion of Alus and other dispersed repeats at specific loci in the human genome
Dispersed repeat elements contribute to genome instability by de novo insertion and unequal recombination between repeats. To study the dynamics of these processes, we have developed single DNA molecule approaches to detect de novo insertions at a single locus and Alu-mediated deletions at two different loci in human genomic DNA. Validation experiments showed these approaches could detect insertions and deletions at frequencies below 10(-6) per cell. However, bulk analysis of germline (sperm) and somatic DNA showed no evidence for genuine mutant molecules, placing an upper limit of insertion and deletion rates of 2 x 10(-7) and 3 x 10(-7), respectively, in the individuals tested. Such re-arrangements at these loci therefore occur at a rate lower than that detectable by the most sensitive methods currently available
Fully coupled simulations of non-colloidal monodisperse sheared suspensions
In this work we investigate numerically the dynamics of sheared suspensions in the limit of vanishingly small fluid and particle inertia. The numerical model we used is able to handle the multi-body hydrodynamic interactions between thousands of particles embedded in a linear shear flow. The presence of the particles is modeled by momentum source terms spread out on a spherical envelop forcing the Stokes equations of the creeping flow. Therefore all the velocity perturbations induced by the moving particles are simultaneously accounted for.
The statistical properties of the sheared suspensions are related to the velocity fluctuation of the particles. We formed averages for the resulting velocity fluctuation and rotation rate tensors. We found that the latter are highly anisotropic and that all the velocity fluctuation terms grow linearly with particle volume fraction. Only one off-diagonal term is found to be non zero (clearly related to trajectory symmetry breaking induced by the non-hydrodynamic repulsion force). We also found a strong correlation of positive/negative velocities in the shear plane, on a time scale controlled by the shear rate (direct interaction of two particles). The time scale required to restore uncorrelated velocity fluctuations decreases continuously as the concentration increases. We calculated the shear induced self-diffusion coefficients using two different methods and the resulting diffusion tensor appears to be anisotropic too.
The microstructure of the suspension is found to be drastically modified by particle interactions. First the probability density function of velocity fluctuations showed a transition from exponential to Gaussian behavior as particle concentration varies. Second the probability of finding close pairs while the particles move under shear flow is strongly enhanced by hydrodynamic interactions when the concentration increases
Decorated vertices with 3-edged cells in 2D foams: exact solutions and properties
The energy, area and excess energy of a decorated vertex in a 2D foam are
calculated. The general shape of the vertex and its decoration are described
analytically by a reference pattern mapped by a parametric Moebius
transformation. A single parameter of control allows to describe, in a common
framework, different types of decorations, by liquid triangles or 3-sided
bubbles, and other non-conventional cells. A solution is proposed to explain
the stability threshold in the flower problem.Comment: 13 pages, 17 figure
Velocity distribution of fluidized granular gases in presence of gravity
The velocity distribution of a fluidized dilute granular gas in the direction
perpendicular to the gravitational field is investigated by means of Molecular
Dynamics simulations. The results indicate that the velocity distribution can
be exactly described neither by a Gaussian nor by a stretched exponential law.
Moreover, it does not exhibit any kind of scaling. In fact, the actual shape of
the distribution depends on the number of monolayers at rest, on the
restitution coefficient and on the height at what it is measured. The role
played by the number of particle-particle collisions as compared with the
number of particle-wall collisions is discussed
Data and initial model set-up for the 2022 VPA stock assessment of the eastern Atlantic and Mediterranean bluefin tuna
This document presents the data and initial model set-up for the 2022 Stock Assessment for the
Eastern Atlantic and Mediterranean bluefin tuna stock. During the 2017 Data Preparatory
meetings, several changes in the data used for previous assessments have been presented, among
which the revision of the Task 1 and Task 2 statistics and the selection of the indices of abundance.
This led to completely revisiting the catch at age matrix and the model specifications for the 2017
assessment. For the present document, the data over the historical period (1968-2015) were
nearly identical, whereas the data for the years 2016-2020 and abundance indices were updated.
As agreed in previous meetings, the initial model specifications were kept identical to the 2017
assessment as no change has been agreed on since then
Review of the catch and catch-at-age estimation for the E-BFT catch inflated estimates 1998-2007
During the 2022 Eastern Atlantic and Mediterranean Bluefin Tuna Data Preparatory Meeting, the Bluefin Species Group (BFTSG) agreed to revise the assumptions and update the catch-atsize/catch-at-age (CAS/CAA) intersessionally by replacing the "NEI (inflated)" partial catches component (1998-2007) with a new set of combined Mediterranean size samples. An ad-hoc small group was formed to carry out this task and proposed an alternative CAS/CAA for the 2022 E-BFT stock assessment, this document summarizes these analyses. This document provides the revised CAS (version 2b), and two CAA based on the von Bertalanffy and the Richards growth
curves. The small group agreed that this revised CAS is a better estimate of the size distribution for the NEI-inflated catch and proposed to be adopted by the BFTSG, and aso recommended that this revision would be applied only to VPA (Virtual Population Analysis) and possibly ASAP (Age Structured Assessment Program)
Final data, explorations, model set-up and diagnostics for the 2022 VPA stock assessment of the eastern and Mediterranean Atlantic bluefin tuna stock
This document presents the modeling work done for the 2022 stock assessment for the Eastern and Mediterranean Bluefin tuna stock, during informal modeling subgroup meetings in June 2022. This document presents various runs built upon the base case for the 2017 stock assessment. These runs aim at addressing issues identified in the 2020 update assessment and aspects discussed during the
informal meetings held in june 2022, regarding the inclusion of updated catch at age data, improvement of model stability in relation to Fratio estimates, the selection of the age for the plus group, inclusion of the WMED_GBYP_AER index. Following several explorations, the present work contains two runs that displayed improved diagnostics compared to previous runs. These models have improved retrospective patterns and no problematic issue was found through jittering the random number generator, jittering the starting values for the terminal F estimate, bootstrapping
or through jackknife analysis
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