Invariant image reconstruction from irregular samples and hexagonal grid splines

We present an algorithm for the reconstruction of images from irregularly placed samples, using linear splines with control points on a hexagonal grid. Several spline approximations are computed for different transformations of the control point grid (e.g. translations and rotations). These approximations are then merged together after compensation of the transformations, yielding a high-quality invariant image reconstruction. Evaluations show that the use of hexagonal grids of the “invariance by integration” principle improves reconstruction quality. An application to image coding is also presented.     

Water retention and gas relative permeability of two industrial concretes

This experimental study aims at identifying the water retention properties of two industrial concretes to be used for long term underground nuclear waste storage structures. Together with water retention, gas transfer properties are identified at varying water saturation level, i.e. relative gas permeability is assessed directly as a function of water saturation level S_w. The influence of the initial de-sorption path and of the subsequent re-saturation are analysed both in terms of water retention and gas transfer properties. Also, the influence of concrete microstructure upon water retention and relative gas permeability is assessed, using porosity measurements, analysis of the BET theory from water retention properties, and MIP. Finally, a single relative gas permeability curve is proposed for each concrete, based on Van Genuchten–Mualem's statistical model, to be used for continuous modelling approaches of concrete structures, both during drying and imbibition.     

Influence of the Pathogen <Emphasis Type="Italic">Candidatus</Emphasis> Liberibacter Solanacearum on Tomato Host Plant Volatiles and Psyllid Vector Settlement

Candidatus Liberibacter solanacearum (CLso) is an unculturable bacterium vectored by the tomato potato psyllid (TPP) Bactericera cockerelli and has been associated with Zebra chip disease in potato and with other economically relevant symptoms observed in solanaceous crops. By altering their host and vector’s biological system, pathogens are able to induce changes that benefit them by increasing their transmission rate. Understanding these changes can enable better targeting of mechanisms to control pathogen outbreaks. Here, we explored how the CLso infectious status affects the volatile organic compounds (VOCs) of the tomato plant, and whether the CLso infectious status of TPP influences host plant settlement. These chemical and behavioral changes can ultimately affect the rate of encounter between the host and the vector. Results from headspace volatile collection of tomato plants showed that CLso infected tomato plants emitted a qualitatively and quantitatively different blend of VOCs compared to sham-infected plants. By a factorial experiment, we showed that CLso negative (CLso-) TPP preferred to settle 70 % more often on infected tomato plants, while CLso positive (CLso+) TPP were found 68 % more often on sham-infected tomato plants. These results provide new evidence in favor of both host and vector manipulation by CLso.     

Effect of phosphate source,rate and cadmium content and use of Penicillium bilaii on phosphorus,zinc and cadmium concentration in durum wheat grain

Field studies were conducted over 3 years at several locations in Alberta and Manitoba, Canada to evaluate the impact of phosphate fertiliser containing varying concentrations of Cd on grain yield and P, Zn and Cd concentration in durum wheat grain. The effect of a seed treatment with Penicillium bilaii, a phosphate‐solubilising fungus, was also examined. P bilaii had little effect on crop yield, nutrient concentration or the concentration of Cd in the grain under the conditions of this study. Fertilisation with monoammonium phosphate consistently increased Cd concentration and Cd/Zn ratio and decreased Zn concentration in durum wheat. Increases in Cd concentration in durum wheat were unrelated to Cd concentration in the fertiliser, although the concentration of Cd in the fertiliser sources varied from 0.2 to 186.0 µg g^?1. Increased Cd concentration with phosphate application may be related to high ionic strength, reduced pH and enhanced root proliferation in the microregion around the fertiliser granules. Enhanced root development in response to phosphate fertilisation may increase the accumulation of Cd. Reduction in Zn accumulation associated with phosphate application may also contribute to the increase in Cd concentration in durum grain, possibly through enhancement of Cd translocation to the grain. While reduction in Cd concentration in phosphate fertilisers will reduce long‐term Cd accumulation in soils, use of low‐Cd fertiliser at commercially practical levels of fertilisation is unlikely to reduce Cd concentration in durum wheat in the year of application. © 2002 Society of Chemical Industry     

Multi-Fidelity High-Throughput Optimization of Electrical Conductivity in P3HT-CNT Composites

Combining high-throughput experiments with machine learning accelerates materials and process optimization toward user-specified target properties. In this study, a rapid machine learning-driven automated flow mixing setup with a high-throughput drop-casting system is introduced for thin film preparation, followed by fast characterization of proxy optical and target electrical properties that completes one cycle of learning with 160 unique samples in a single day, a > 10 ×  improvement relative to quantified, manual-controlled baseline. Regio-regular poly-3-hexylthiophene is combined with various types of carbon nanotubes, to identify the optimum composition and synthesis conditions to realize electrical conductivities as high as state-of-the-art 1000 S cm⁻¹. The results are subsequently verified and explained using offline high-fidelity experiments. Graph-based model selection strategies with classical regression that optimize among multi-fidelity noisy input-output measurements are introduced. These strategies present a robust machine-learning driven high-throughput experimental scheme that can be effectively applied to understand, optimize, and design new materials and composites.     

Cardiac output response to dynamic exercise after atrial switch repair for transposition of the great arteries

Results from this study showed that patients who underwent successful operation for transposition of the great arteries had no appropriate increase in stroke volume in response to exercise of a nature similar to common recreational activities. The impairment, most likely due to disturbances in both venous return and ventricular systolic function, is compensated for by an increase in peripheral oxygen extraction; however, this increase may not be adequate with maturation or during prolonged exercise when cardiovascular constraints are more important.     

Effect of temperature on the water retention properties of two high performance concretes

This contribution aims at (1) determining experimentally the first desorption isotherms of two high performance concretes (based on CEM I and CEM V cements), at three different temperature levels T = 20, 50 and 80 °C, and (2) showing whether these may be simply described by adsorption and capillarity.Results at 20 °C compare well with recently published results; in particular, an important desorption is observed at high RH (≥ 98%). A simple pore network model, based on Kelvin–Laplace's capillary theory, is implemented, and shows the existence of two main de-saturation modes, one at high pore radii (capillary pores), the other for pore radii on the order of a few nanometers (C-S-H porosity), where desorption is shown to occur. A complementary drying mechanism is evidenced at 80 °C, which is attributed to ettringite and/or C-S-H degradation. Finally, proper numerical fitting of all isotherm data is achieved using the well-known three-parameter BSB model.     

阻燃剂的两难：细说外部引燃（上）

今年恰逢信息科技(IT)与消费类电子(CE)产品标准面临修订,同时我们也注意到,有一本涵盖这两项产品范畴的全新标准(IEC TS 62441)已进入最后审批阶段.其中,"外部引燃"(Extemal Ignition)成为最具争议的议题.     

防止潜在危险的安全工程一个设计安全产品的理想工具

随着IEC62368—1第一版（影音、信息与通讯技术设备安全标准）在2009年10月初拍扳成为最终国际标准草案（108／325／FDIS），其正式发布的时间指日可待。由于IEC62368—1所牵动的产业及影响范围甚广，因此我们建议产品研发或制造商能够及早为新标准的颁布做好准备，不妨从现在开始了解该标准涉及的全新安全思维一防止潜在危险的安全工程（Hazard—based Safety Engineering，简称HBSE）一这套追求更理想产品安全目标的工具。     

Are online discussions enough to constitute communities of practice in professional domain? A case study of ergonomics’ practice in France

The goal of our research is to characterise how online discussions may provide support to the construction of a Virtual Community of Practice, as a way to develop a profession. To do so, we investigate the functions (sharing information, resources or experience) and the nature of knowledge (e.g. methodology and trends of ergonomics) exchanged on Ergoliste, a French-speaking online mailing list dedicated to ergonomics, as well as the status of participants. Our results reveal that the list has both informative and formative functions as it deals with sharing/seeking information, resources and experience, mainly between experts and novices in ergonomics, exchanging about situated and circumstantiated aspects of practices. Finally, these results are complemented by interviews with list participants which on the one hand confirm the main functions of the list and, on the other hand, reveal divergence in the perception that list participants belonging to a “community” structured only around this list. This research opens some prospects for more longitudinal investigations of the contents of the list, to analyse more deeply how the list can be viewed as an efficient tool to co-elaborate knowledge about ergonomics and its development.