1,067 research outputs found

    Certification Systems for Machine Learning: Lessons from Sustainability

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    Concerns around machine learning’s societal impacts have led to proposals to certify some systems. While prominent governance efforts to date center around networking standards bodies such as the Institute of Electrical and Electronics Engineers (IEEE), we argue that machine learning certification should build on structures from the sustainability domain. Policy challenges of machine learning and sustainability share significant structural similarities, including difficult to observe credence properties, such as data collection characteristics or carbon emissions from model training, and value chain concerns, including core-periphery inequalities, networks of labor, and fragmented and modular value creation. While networking-style standards typically draw their adoption and enforcement from functional needs to conform to enable network participation, machine learning, despite its digital nature, does not benefit from this dynamic. We therefore apply research on certification systems in sustainability, particularly of commodities, to generate lessons across both areas, informing emerging proposals such as the EU’s AI Act

    Trifloxystrobin based seed treatment fungicides control seed rot and pre-emergence damping-off of canola, pulses, and corn

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    Non-Peer ReviewedActive ingredient Trifloxystrobin belongs to the strobilurin class of fungicides which possess improved safety and environmental characteristics. The objective of this research was to evaluate the efficacy of seed treatment fungicides based on Trifloxystrobin to control seed rot and pre-emergence damping off of canola, pulses, and corn crops. In 2004-2006, canola, pulses, and corn trials were conducted in Saskatchewan (Aberdeen, Allan, Indian Head, and Wakaw), Alberta (Vegreville), and Manitoba (High Bluff). The experimental design used was a randomized complete block design with four replications. Seed treatments fungicide tested were Trilex FL (trifloxystrobin [10g]/100 kg of seed); Trilex AL (trifloxystrobin [5g] + Allegiance FL (metalaxyl) [4g]/100 kg of seed); and Trilex FL (trifloxystrobin [5g]/100 kg of seed) tank mixed with Allegiance FL (metalaxyl) [2g]/100 kg of seed) Plants were counted at 14 to 28 days after planting. Data were analyzed using an ANOVA. Trifloxystrobin based seed treatment fungicides possessed excellent efficacy for controlling seed rot and pre-emergence damping-off of canola, pea, lentil, chickpea, and corn crops grown in soils infected with Rhizoctonia solani or Fusarium avenaceum

    Optical excitations in hexagonal nanonetwork materials

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    Optical excitations in hexagonal nanonetwork materials, for example, Boron-Nitride (BN) sheets and nanotubes, are investigated theoretically. The bonding of BN systems is positively polarized at the B site, and is negatively polarized at the N site. There is a permanent electric dipole moment along the BN bond, whose direction is from the B site to the N site. When the exciton hopping integral is restricted to the nearest neighbors, the flat band of the exciton appears at the lowest energy. The higher optical excitations have excitation bands similar to the electronic bands of graphene planes and carbon nanotubes. The symmetry of the flat exciton band is optically forbidden, indicating that the excitons related to this band will show quite long lifetime which will cause strong luminescence properties.Comment: 4 pages; 3 figures; proceedings of "XVIth International Winterschool on Electronic Properties of Novel Materials (IWEPNM2002)

    Synchronization and multi-mode dynamics of mutually coupled semiconductor lasers

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    Dynamics of coupled semiconductor lasers is investigated by numerical simulations. A realistic laser simulation engine is used to study the synchronization and dynamical regime in two mutually coupled Fabry-Perot and/or DFB lasers. Both, single- and multi-mode operation regimes are studied with emphasis on the role of the multiple laser-cavity modes. Our findings indicate that the two laser synchronize within each laser-cavity mode, while the synchronization across different cavity modes is significantly weaker

    Effect of Nb and Ti micro-additives and thermo-mechanical treatment of high-manganese steels with aluminium and silicon on their microstructure and mechanical properties

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    The r esults are based on two experimental high-manganese X98MnAlSiNbTi24-11 and X105MnAlSi24-11 steels subjected to thermo-mechanical treatment by hot-rolling on a semi-industrial processing line. The paper presents the results of diffraction and structural studies using scanning and transmission electron microscopy showing the role of Nb and Ti micro-additives in shaping high strength properties of high-manganese austenitic-ferritic steels with complex carbides. The performed investigations of two experimental steels allow to explain how the change cooling conditions after thermo-mechanical treatment of the analysed steels affects the change of their microstructure and mechanical properties. The obtained results allow assessing the impact of both the chemical composition and the applied thermo-mechanical treatment technology on the structural effects of strengthening of the newly developed steels

    Quantum Lattice Fluctuations and Luminescence in C_60

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    We consider luminescence in photo-excited neutral C_60 using the Su-Schrieffer-Heeger model applied to a single C_60 molecule. To calculate the luminescence we use a collective coordinate method where our collective coordinate resembles the displacement of the carbon atoms of the Hg(8) phonon mode and extrapolates between the ground state "dimerisation" and the exciton polaron. There is good agreement for the existing luminescence peak spacing and fair agreement for the relative intensity. We predict the existence of further peaks not yet resolved in experiment. PACS Numbers : 78.65.Hc, 74.70.Kn, 36.90+

    Polaron Excitations in Doped C60: Effects of Disorders

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    Effects on C60_{60} by thermal fluctuations of phonons, misalignment of C60_{60} molecules in a crystal, and other intercalated impurities (remaining C70_{70}, oxygens, and so on) are simulated by disorder potentials. The Su-Schrieffer-Heeger--type electron-phonon model for doped C60_{60} is solved with gaussian bond disorders and also with site disorders. Sample average is performed over sufficient number of disorder configurations. The distributions of bond lengths and electron densities are shown as functions of the disorder strength and the additional electron number. Stability of polaron excitations as well as dimerization patterns is studied. Polarons and dimerizations in lightly doped cases (C60−1,−2_{60}^{-1,-2}) are relatively stable against disorders, indicated by peak structures in distribution functions. In more heavily doped cases, the several peaks merge into a single peak, showing the breakdown of polaron structures as well as the decrease of the dimerization strength. Possibility of the observation of polaronic lattice distortions and electron structures in doped C60_{60} is discussed.Comment: Note: This manusript was accepted for publication in Physical Review B. Figures will be sent to you via snail (conventional) mai

    Charge-Stripe Order and Superconductivity in Ir1−xPtxTe2\mathrm{Ir_{1-x}Pt_xTe_2}

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    A combined resistivity and hard x-ray diffraction study of superconductivity and charge ordering in Ir1−xPtxTe2\mathrm{Ir_{1-x}Pt_xTe_2}, as a function of Pt substitution and externally applied hydrostatic pressure, is presented. Experiments are focused on samples near the critical composition xc∼0.045x_c\sim 0.045 where competition and switching between charge order and superconductivity is established. We show that charge order as a function of pressure in Ir0.95Pt0.05Te2\mathrm{Ir_{0.95}Pt_{0.05}Te_{2}} is preempted - and hence triggered - by a structural transition. Charge ordering appears uniaxially along the short crystallographic (1,0,1) domain axis with a (15,0,15)\mathrm{(\frac{1}{5},0,\frac{1}{5})} modulation. Based on these results we draw a charge-order phase diagram and discuss the relation between stripe ordering and superconductivity.Comment: 8 pages, 4 figures: Accepted in Scientific Report

    P424Short-term ACE Inhibition upregulates cardiac expression of SERCA2a and protects against ventricular arrhythmias in healthy rats

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    Introduction: Chronic angiotensin converting enzyme inhibitor (ACEIs) treatment can suppress arrhythmogenesis. To examine whether the effect is more immediate and independent of suppression of pathological remodelling, we tested the antiarrhythmic effect of short-term ACE inhibition in healthy normotensive rats. Methods and results: Wistar rats were administered with enalaprilat (ENA, i.p., 5 mg/kg every 12 h) or vehicle (CON) for two weeks. Cellular shortening was measured in isolated, electrically paced cardiomyocytes. Standard 12-lead electrocardiography was performed and, hearts of anesthetized open-chest rats were subjected to 6-min ischemia followed by 10-minute reperfusion to examine susceptibility to ventricular arrhythmias. Expressions of calcium regulating proteins (SERCA2a, cardiac sarco/endoplasmic reticulum Ca2+-ATPase; CSQ, calsequestrin; TRD, triadin; PLB, phospholamban; FKBP12.6, FK506-binding protein) were measured by Western blot and mRNA levels of L-type calcium channel (Cacna1c), ryanodine receptor (Ryr2) and potassium channels Kcnh2 and Kcnq1 were measured by qRT-PCR. ENA decreased systolic as well as diastolic blood pressure (by 20%, and by 31%, respectively, for both P<0.05) but enhanced shortening of cardiomyocytes at basal conditions (by 34%, P<0.05) and under beta-adrenergic stimulation (by 73%, P<0.05). Enalaprilat shortened QTc interval duration (CON: 78±1 ms vs. ENA: 72±2 ms; P<0.05) and significantly decreased the total duration of ventricular fibrillations (VF) and the number of VF episodes (P<0.05). Reduction in arrhythmogenesis was associated with a pronounced upregulation of SERCA2a and increased Cacna1c mRNA levels. Conclusion: Short-term ACEI treatment can provide protection against I/R injury-induced ventricular arrhythmias in healthy myocardium and this effect is associated with increased SERCA2a expression. CON ENA Calcium regulating proteins SERCA2a 100±20 304±13* CSQ 100±6 105±7 TRD 100±16 117±10 PLB 100±9 109±16 FKBP12 100±12 93±
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