995 research outputs found
Shape computations without compositions
Parametric CAD supports design explorations through generative methods which compose and transform geometric elements. This paper argues that elementary shape computations do not always correspond to valid compositional shape structures. In many design cases generative rules correspond to compositional structures, but for relatively simple shapes and rules it is not always possible to assign a corresponding compositional structure of parts which account for all operations of the computation. This problem is brought into strong relief when design processes generate multiple compositions according to purpose, such as product structure, assembly, manufacture, etc. Is it possible to specify shape computations which generate just these compositions of parts or are there additional emergent shapes and features? In parallel, combining two compositions would require the associated combined computations to yield a valid composition. Simple examples are presented which throw light on the issues in integrating different product descriptions (i.e. compositions) within parametric CAD
Metabolitos secundarios de Berberís empetrifolia
Berberís empetrifolia Lam. ha sido parcialmente estudiada en cuanto a su contenido de alcaloides cuaternarios. Al reestudiar la corteza y madera de tallos subterráneos de esta planta fue posible aislar un alcaloide dimérico, la paquistanina, y el lignano siringarresinol. Este lignano parece ser un componente común a varias especies chilenas de Berberís; la paquistanina, por el contrario, es una base del tipo aporfinabencilisoquinolina que hasta ahora sólo habia sido encontrada en especies asiáticas del género
Shape exploration of designs in a style: toward generation of product designs
Generative specifications have been used to systematically codify established styles in several design fields including architecture and product design. We examine how designers explore new designs in the early stages of product development as they manipulate and interpret shape representations. A model of exploration is proposed with four types of shape descriptions (contour, decomposition, structure, and design) and the results of the exploration are presented. Generative rules are used to provide consistent stylistic changes first within a given decomposition and second through changing the structure. Style expresses both the analytical order of explanation and the synthetic complexity of exploration. The model of exploration is consistent with observations of design practice. The application of generative design methods demonstrates a logical pattern for early stage design exploration. The model provides the basis for tools to assist designers in exploring families of designs in a style and for following new interpretations that move the exploration from one family to another
Correlation Functions of Complex Matrix Models
For a restricted class of potentials (harmonic+Gaussian potentials), we
express the resolvent integral for the correlation functions of simple traces
of powers of complex matrices of size , in term of a determinant; this
determinant is function of four kernels constructed from the orthogonal
polynomials corresponding to the potential and from their Cauchy transform. The
correlation functions are a sum of expressions attached to a set of fully
packed oriented loops configurations; for rotational invariant systems,
explicit expressions can be written for each configuration and more
specifically for the Gaussian potential, we obtain the large expansion ('t
Hooft expansion) and the so-called BMN limit.Comment: latex BMN.tex, 7 files, 6 figures, 30 pages (v2 for spelling mistake
and added reference) [http://www-spht.cea.fr/articles/T05/174
Depart and approach procedures for UAS in a VFR environment
This paper assesses the depart and approach operations of Unmanned Aircraft Systems (UAS) in one of the most challenging scenarios: when flying under Visual Flight Rules (VFR). Inspired by some existing procedures for (manned) general aviation, some automatic and predefined procedures for UAS are proposed. Hence, standardized paths to specific waypoints close to the airport are defined for depart operations, just before starting the navigation phase. Conversely, and for the approach maneuvers, it is foreseen a first integration into a holding pattern near the landing runway (ideally above it) followed by a standard VFR airfield traffic pattern. This paper discusses the advantages of these operations which aim at minimizing possible conflicts with other existing aircraft while reducing the Pilot-in-Command workload. Finally, some preliminary simulations are shown where these procedures have been successfully tested with simulated surrounding traffic
On gonihedric loops and quantum gravity
We present an analysis of the gonihedric loop model, a reformulation of the
two dimensional gonihedric spin model, using two different techniques. First,
the usual regular lattice statistical physics problem is mapped onto a height
model and studied analytically. Second, the gravitational version of this loop
model is studied via matrix models techniques. Both methods lead to the
conclusion that the model has for all values of the parameters
of the model. In this way it is possible to understand the absence of a
continuous transition
The moderate drift towards less tetracycline-susceptible isolates of contagious agalactia causative agents might result from different molecular mechanisms.
©2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This document is the Accepted version of a Published Work that appeared in final form in Veterinary Microbiology. To access the final edited and published work see https://doi.org/10.1016/j.vetmic.2018.05.001Contagious agalactia is a mycoplasmosis that affects small ruminants, is associated with
loss of milk production and high morbidity rates, and is highly deleterious to dairy
industries. The etiological agents are four mycoplasma (sub)species, of which the
relative importance depends on the countries and the animal host. Tetracyclines are non 23 expensive, broad-spectrum antimicrobials and are often used to control mastitis in dairy
herds. However, the in vitro efficiency of tetracyclines against each of the etiological
agents of contagious agalactia has been poorly assessed.
The aims of this study were i) to compare the tetracycline susceptibilities of various
field isolates, belonging to different mycoplasma (sub)species and subtypes, collected
over the years from different clinical contexts in France or Spain, and ii) to investigate
the molecular mechanisms behind the decreased susceptibility of some isolates to
tetracyclines.
The Minimum Inhibitory Concentrations (MICs) of tetracyclines were determined in
vitro on a set of 120 isolates. Statistical analyses were run to define the significance of
any observed differences in MICs distribution. As mutations in the genes encoding the
ttracycline targets (rrs loci) are most often associated with increased tetracycline MICs
in animal mycoplasmas, these genes were sequenced.
The loss of susceptibility to tetracyclines after year 2010 is not significant and recent
MICs are higher in M. agalactiae, especially isolates from ovine mastitis cases, than in
other etiological agents of contagious agalactia. The observed increases in MICs were
not always associated with mutations in the rrs alleles which suggests the existence of
other resistance mechanisms yet to be decipher
Defining Rules for Kinematic Shapes with Variable Spatial Relations
Designing mechanisms can be a challenging problem, because the underlying kinematics involved are typically not intuitively incorporated into common techniques for design representation. Kinematic shapes and kinematic grammars build on the shape grammar and making grammar formalisms to enable a visually intuitive approach to model and explore mechanisms. With reference to the lower kinematic pairs this paper introduces kinematic shapes. These are connected shapes with parts which have variable spatial relations that account for the relative motion of the parts. The paper considers how such shapes can be defined, the role of elements shared by connected parts, and the motions that result. It also considers how kinematic shape rules can be employed to generate and explore the motion of mechanisms
MultiBaC: A strategy to remove batch effects between different omic data types
[EN] Diversity of omic technologies has expanded in the last years together with the number of omic data integration strategies. However, multiomic data generation is costly, and many research groups cannot afford research projects where many different omic techniques are generated, at least at the same time. As most researchers share their data in public repositories, different omic datasets of the same biological system obtained at different labs can be combined to construct a multiomic study. However, data obtained at different labs or moments in time are typically subjected to batch effects that need to be removed for successful data integration. While there are methods to correct batch effects on the same data types obtained in different studies, they cannot be applied to correct lab or batch effects across omics. This impairs multiomic meta-analysis. Fortunately, in many cases, at least one omics platform-i.e. gene expression- is repeatedly measured across labs, together with the additional omic modalities that are specific to each study. This creates an opportunity for batch analysis. We have developed MultiBaC (multiomic Multiomics Batch-effect Correction correction), a strategy to correct batch effects from multiomic datasets distributed across different labs or data acquisition events. Our strategy is based on the existence of at least one shared data type which allows data prediction across omics. We validate this approach both on simulated data and on a case where the multiomic design is fully shared by two labs, hence batch effect correction within the same omic modality using traditional methods can be compared with the MultiBaC correction across data types. 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