4,896 research outputs found

    Translations in the exponential Orlicz space with Gaussian weight

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    We study the continuity of space translations on non-parametric exponential families based on the exponential Orlicz space with Gaussian reference density.Comment: Submitted to GSI 2017, Pari

    Design and analysis of fractional factorial experiments from the viewpoint of computational algebraic statistics

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    We give an expository review of applications of computational algebraic statistics to design and analysis of fractional factorial experiments based on our recent works. For the purpose of design, the techniques of Gr\"obner bases and indicator functions allow us to treat fractional factorial designs without distinction between regular designs and non-regular designs. For the purpose of analysis of data from fractional factorial designs, the techniques of Markov bases allow us to handle discrete observations. Thus the approach of computational algebraic statistics greatly enlarges the scope of fractional factorial designs.Comment: 16 page

    Inference on errors in industrial parts: Kriging and variogram versus geometrical product specifications standard

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    This article focuses on the inference on the errors in manufactured parts controlled by using measurements devices. The characterization of the part surface topographies is core in several applications. A broad set of properties (tribological, optical, biological, mechanical, etc.) depends on the micro- and macrogeometry of the parts. Moreover, parts usually show typical deterministic geometric deviation pattern, referred to as manufacturing signatures, due to the specific manufacturing processes and process setup parameters adopted for their production. In several situations, the measurements may also be affected by systematic errors due to the measurement process, that might be caused, for example, by a poor part alignment during the measurement process. Measurement techniques and characterization methods have been standardized in the International Standard ISO 25178, defining parameters characterizing the surface topography and supplying methods and formula adapt to deal with this issue computationally. In the present article, we consider a type of spatial dependence between measured values at different points that suggest the use of the variogram to identify patterns in the parts. We offer a comparison, based on a real set of measures, between the latter approach and the conventional as a test of the efficient performance of our findings

    Inhibition, recovery and field responses of Astyanax fasciatus (Cuvier, 1819) brain cholinesterases upon exposure to azinphos-methyl

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    Pesticides used in agriculture are among the most important environmental pollutants. Organophosphate and carbamate insecticides, intensely used in deciduous fruit-trees, may be  transported to aquatic ecosystems by runoff. Northwest rural Montevideo possesses zones of fruit-tree farms, where azinphos-methyl is currently the most used pesticide. Despite the well-known neurotoxic properties of this agrochemical, studies of its effects on aquatic organisms are scarce in Uruguay. The main goal of this study was to evaluate effects on brain cholinesterases and erythrocyte micronuclei in Astyanax fasciatus exposed to azynphos-methyl in laboratory and field conditions. Dose-response curves showed concentration-dependent brain cholinesterase inhibitions and a LC50 (48-hour) of 2.31 mg L-1 for azinphos-methyl.  Fishes exposed for 48 hours to toxicant and then transferred to clear water recovered 80% of brain cholinesterase activity in 10 days. Field study indicated that A. fasciatus from a watershed with low contamination showed a brain cholinesterase specific activity of 62.2±5.1 Units.mg-1 protein (22ºC) 97.7 % of which was acetylcholinesterase. Specimens from a basin with intense fruticulture exhibited a spatial gradient: specimens collected downstream to the farms showed brain acetylcholinesterase activities 32% lower than fishes captured upstream. In conclusion, our data suggest that A. fasciatus is a suitable species for exotoxicological biomonitoring.Keywords: Acetylcholinesterase; Astyanax fasciatus; Aquatic Biomonitoring; Azinphos-methyl; Bioindicator; Brain cholinesterases; Fish; Organophosphate pesticide
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