557 research outputs found

    Genotype-by-environment interactions for female mate choice of male cuticular hydrocarbons in Drosophila simulans

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    This is the final version of the article. Available from Public Library of Science via the DOI in this record.Recent research has highlighted the potential importance of environmental and genotype-by-environment (G×E) variation in sexual selection, but most studies have focussed on the expression of male sexual traits. Consequently, our understanding of genetic variation for plasticity in female mate choice is extremely poor. In this study we examine the genetics of female mate choice in Drosophila simulans using isolines reared across two post-eclosion temperatures. There was evidence for G×Es in female choosiness and preference, which suggests that the evolution of female mate choice behaviour could differ across environments. However, the ranked order of preferred males was consistent across females and environments, so the same males are favoured by mate choice in spite of G×Es. Our study highlights the importance of taking cross-environment perspectives in order to gain a more comprehensive understanding of the operation of sexual selection.This work was funded by the Association for the Study of Animal Behaviour (DJH), the ESF and NERC (DJH and JH), and a Royal Society Fellowship and Equipment grant (JH). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Arabic Language WEKA-Based Dialect Classifier for Arabic Automatic Speech Recognition Transcripts

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    This paper describes an Arabic dialect identification system which we developed for the Discriminating Similar Languages (DSL) 2016 shared task. We classified Arabic dialects by using Waikato Environment for Knowledge Analysis (WEKA) data analytic tool which contains many alternative filters and classifiers for machine learning. We experimented with several classifiers and the best accuracy was achieved using the Sequential Minimal Optimization (SMO) algorithm for training and testing process set to three different feature-sets for each testing process. Our approach achieved an accuracy equal to 42.85% which is considerably worse in comparison to the evaluation scores on the training set of 80-90% and with training set 60:40 percentage split which achieved accuracy around 50%. We observed that Buckwalter transcripts from the Saarland Automatic Speech Recognition (ASR) system are given without short vowels, though the Buckwalter system has notation for these. We elaborate such observations, describe our methods and analyse the training dataset

    Effects of five years of frequent N additions, with or without acidity, on the growth and below-ground dynamics of a young Sitka spruce stand growing on an acid peat: implications for sustainability

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    International audienceA field manipulation study was established to demonstrate effects of simulated wet N and S deposition on a young (planted 1986) stand of Sitka spruce growing on a predominantly organic soil in an area of low (8?10 kg N ha-1 yr-1) background N deposition in the Scottish borders. From 1996, treatments (six) were applied to the canopies of ten-tree plots in each of four blocks. N was provided as NH4NO3, either with H2SO4 (pH 2.5) at 48 or 96 kg N ha-1 yr-1 inputs or without, at 48 kg N ha-1 yr-1 along with wet (rain water) and dry controls (scaffolding) and a S treatment (Na2SO4). Positive responses (+ >20% over 5 years) with respect to stem area increment were measured in response to N inputs, irrespective of whether acid was included. The positive response to N was not dose related and was achieved against falling base cation concentrations in the foliage, particularly with respect to K. The results suggest young trees are able to buffer the low nutrient levels and produce new growth when there is sufficient N. Inputs of 96 kg N ha-1 yr-1, in addition to ambient N inputs, on this site exceeded tree demand resulting in elevated foliar N, N2O losses and measurable soil water N. These excessive N inputs did not reduce stem area growth. Keywords: acid, canopy application, nitrogen, acid organic soil, simulated wet deposition, soil water, sulphur, young Sitka spruc

    High-precision control of static magnetic field magnitude, orientation, and gradient using optically pumped vapour cell magnetometry

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    An integrated system of hardware and software allowing precise definition of arbitrarily oriented magnetic fields up to |B| = 1 μT within a five-layer Mumetal shield is described. The system is calibrated with reference to magnetic resonance observed between Zeeman states of the 6S1/2 F = 4 133Cs ground state. Magnetic field definition over the full 4π solid angle is demonstrated with one-sigma tolerances in magnitude, orientation, and gradient of δ|B| = 0.94 nT, δθ = 5.9 mrad, and δ|∇B|=13.0δ|∇B|=13.0 pT/mm, respectively. This field control is used to empirically map Mx magnetometer signal amplitude as a function of the static field (B0) orientation

    Orientational effects on the amplitude and phase of polarimeter signals in double resonance atomic magnetometry

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    Double resonance optically pumped magnetometry can be used to measure static magnetic fields with high sensitivity by detecting a resonant atomic spin response to a small oscillating field perturbation. Determination of the resonant frequency yields a scalar measurement of static field (B_0) magnitude. We present calculations and experimental data showing that the on-resonance polarimeter signal of light transmitted through an atomic vapour in arbitrarily oriented B0B_0 may be modelled by considering the evolution of alignment terms in atomic polarisation. We observe that the amplitude and phase of the magnetometer signal are highly dependent upon B_0 orientation, and present precise measurements of the distribution of these parameters over the full 4 pi solid angle

    A feed-forward measurement scheme for periodic noise suppression in atomic magnetometry

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    We present an unshielded, double-resonance magnetometer in which we have implemented a feed-forward measurement scheme in order to suppress periodic magnetic noise arising from, and correlated with, the mains electricity alternating current line. The technique described here uses a single sensor to track ambient periodic noise and feed forward to suppress it in a subsequent measurement. This feed forward technique has shown significant noise suppression of electrical mains-noise features of up to 22 dB under the fundamental peak at 50 Hz, 3 dB at the first harmonic (100 Hz), and 21 dB at the second harmonic (150 Hz). This technique is software based, requires no additional hardware, and is easy to implement in an existing magnetometer
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