763 research outputs found

    Genotypic variation in growth and physiological responses of common bean (Phaseolus vulgaris L.) seedlings to flooding

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    Tolerance to flooding stress in root regions of some common bean genotypes (Beyaz Fasulye, Boncuk Sırık, Kökez, Oturak and Sırık) was investigated in terms of morphological and physiological. Plants were grown in a plant growth chamber at 26/18°C (day/night) temperature with RH 70% and 450 m-2 s-1 light intensity. Seedlings were exposed to flooding stress for 3 days when the plants had developed 3 to 4 true leaves. The results obtained showed that root dry weight and leaf area were reduced significantly by flooding treatment. The changes in leaf area showed differences between genotypes. It was found that flooding treatment did not affect the leaf relative water content (RWC) value. Flooding treatment decreased total chlorophyll content significantly. It was observed that some increases and decreases in the total sugar and lipid peroxidation (MDA) contents in root and leaf parts depend on genotypes and treatment. Beside that cell membrane injury and influence of flooding for each genotype were determined measuring the electrical conductivity. It was determined that the tolerance to flooding of five evaluated common bean genotypes, were change depending on root and leaf part. The results also showed that different genotypes responded differently to excess water in the soil, which could be linked to variation in growth and physiological responses. According to the evaluation, these results possibly suggest that ‘Boncuk Sırık’ ‘was relatively tolerant genotype, whereas ‘Sırık’ and ‘Kökez’ were determined as more sensitive genotypes.Key words: Phaseolus vulgaris L., common bean, excess water stress, flooding, lipid peroxidation, membrane injury, waterlogging

    Frequency-tunable metamaterials using broadside-coupled split ring resonators

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    We present frequency tunable metamaterial designs at terahertz (THz) frequencies using broadside-coupled split ring resonator (BC-SRR) arrays. Frequency tuning, arising from changes in near field coupling, is obtained by in-plane horizontal or vertical displacements of the two SRR layers. For electrical excitation, the resonance frequency continuously redshifts as a function of displacement. The maximum frequency shift occurs for displacement of half a unit cell, with vertical displacement resulting in a shift of 663 GHz (51% of f0) and horizontal displacement yielding a shift of 270 GHz (20% of f0). We also discuss the significant differences in tuning that arise for electrical excitation in comparison to magnetic excitation of BC-SRRs

    Optically thin composite resonant absorber at the near-infrared band: a polarization independent and spectrally broadband configuration

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    Cataloged from PDF version of article.We designed, fabricated, and experimentally characterized thin absorbers utilizing both electrical and magnetic impedance matching at the near-infrared regime. The absorbers consist of four main layers: a metal back plate, dielectric spacer, and two artificial layers. One of the artificial layers provides electrical resonance and the other one provides magnetic resonance yielding a polarization independent broadband perfect absorption. The structure response remains similar for the wide angle of incidence due to the sub-wavelength unit cell size of the constituting artificial layers. The design is useful for applications such as thermal photovoltaics, sensors, and camouflage. (C)2011 Optical Society of Americ

    Ground truth deficiencies in software engineering: when codifying the past can be counterproductive

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    Many software engineering tools build and evaluate their models based on historical data to support development and process decisions. These models help us answer numerous interesting questions, but have their own caveats. In a real-life setting, the objective function of human decision-makers for a given task might be influenced by a whole host of factors that stem from their cognitive biases, subverting the ideal objective function required for an optimally functioning system. Relying on this data as ground truth may give rise to systems that end up automating software engineering decisions by mimicking past sub-optimal behaviour. We illustrate this phenomenon and suggest mitigation strategies to raise awareness

    Fenotypowe podgrupy zespołu policystycznych jajników mają różne objawy wewnątrznerkowej oporności

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    Objective: The polycystic ovary syndrome (PCOS) is known to be related with increased metabolic and cardiovascular risks. Various phenotypic subgroups of PCOS have been proven to have metabolic and endocrine disorders with varying degrees of severity. However, intra-renal vascular resistance, which is an indirect indication ofatherosclerosis, remains unknown in PCOS subgroups. In this study we examined whether PCOS subgroups have different intra-renal resistance symptoms. Material and Methods: 98 PCOS patients (diagnosed according to the Rotterdam criteria) 30 controls were ncluded in the study. The diagnosis of PCOS was established in the presence of at least two of the following criteria: 1- oligo and/or amenorrhea (OM); 2- clinic and/or biochemical signs of hyperandrogenism (HA); 3- polycystic ovarian morphology (PCO) detected by transvaginal ultrasonography. 37 patients (Group 1) met all three criteria (HA+OM+PCO), 29 patients (Group 2) met two of the criteria including hyperandrogenism (HA+OM or HA+PCO) and the remaining 32 patients (Group 3) had no hyperandrogenism but fulfilled the other two criteria; PCO+OM. Renal Doppler ultrasonography and hormonal/ biochemical analyses were carried out. The first outcome measure was designated as the differences in the renal resistive index (RRI) values of the groups, and the second outcome measure was designated as the relation of RRI with the insulin resistance and lipid profile. Results: In Group 1, the RRI and the homeostasis model assessment of insulin resistance (HOMA-IR) values were significantly higher than in Group 3 and controls (P < 0.031, P < 0.001, respectively, after adjusting for age and BMI). The RRI and HOMA-IR values in Group 3 were similar to those of the control group. It was determined that RRI has a positive correlation with HOMA-IR (r=0.784, PCel pracy: Zespół policystycznych jajników jest związany ze zwiększonym ryzykiem metabolicznym i sercowonaczyniowym. Fenotypowe podgrupy w obrębie zespołu PCO charakteryzują się zaburzeniami metabolicznymi i endokrynnymi o rożnym stopniu nasilenia. Jednak wewnątrznerkowa oporność naczyniowa, która jest pośrednim wykładnikiem miażdżycy, pozostaje nieznana w podgrupach zespołu PCO. W badaniu ocenialiśmy czy podgrupy zespołu PCO mają rożne objawy wewnątrznerkowej oporności. Materiał i metoda: do badania włączono 98 pacjentek z zespołem PCO (zdiagnozowanym według kryterium z Rotterdamu) oraz 30 pacjentek kontrolnych. Rozpoznanie zespołu PCO postawiono na podstawie obecności przynajmniej dwóch z poniżej wymienionych kryteriów: 1-oligo i/lub amenorrhea (OM); 2-kliniczne lub biochemiczne objawy hiperandrogenizmu (HA); 3-policystyczny obraz jajnikow (PCO) w przez pochwowym badaniu ultrasonograficznym. Grupę 1 stanowiło 37 pacjentek, które spełniły wszystkie kryteria diagnostyczne (HA+OM+PCO), grupa 2 to 29 pacjentek z dwoma kryteriami, w tym kryterium hiperandrogenizmu (HA+OM lub HA+PCO), pozostałe 32 pacjentki to grupa 3 – bez hiperandrogenizmu ale z dwoma pozostałymi kryteriami; PCO+OM. Przeprowadzono badanie dopplerowskie nerek i hormonalno-biochemiczną ocenę. Jako pierwszą zmierzono różnicę pomiędzy grupami w indeksie oporu nerkowego (RRI), następnie oceniono związek pomiędzy RRI a insulinoopornością i profilem lipidowym. Wyniki: W grupie 1, RRI i wskaźnik oceny insulinooporności (HOMA-IR) były istotnie wyższe niż w grupie 3 oraz kontrolnej (

    Providing tool-support for value-based decision-making: A usability assessment

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    Numerous companies worldwide make their decisions related to software projects/products in a value neutral way, using only earned value systems, which represent short-term goals. Better decisions can be made using a value-based approach, achieving cost-effective results and reliable construction and maintenance of products. However, moving from a value-neutral to a value-based paradigm can be a challenge. We provide toolsupport, which was co-created in collaboration with three software companies, to ease the paradigm shift. Our tool supports both individual and group-based decisions using several visualization mechanisms. Despite the co-creation process employed while developing the value tool, there are specific issues relating to its usability that must also be assessed in order to reduce any possible drawbacks for its adoption by industry. This paper details three usability studies that were carried out to assess the value tool’s usability. The results also suggest that the tool is ready to be taken into use in the industry.The research project is funded by the Finnish Funding Agency for Technology and Innovation (Tekes), under the FiDiPro VALUE project

    Estimating the value of decisions relating to managing and developing software-intensive products and projects

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    The software industry’s current decision-making relating to product/project management and development is largely done in a value neutral setting, in which cost is the primary driver for every decision taken. However, numerous studies have shown that the primary critical success factor that differentiates successful products/projects from failed ones lie in the value domain. Therefore, to remain competitive, innovative and to grow, companies must change from cost-based decision-making to value-based decision-making where the decisions taken are the best for that company’s overall value creation. Our vision to tackle this problem and to provide a solution for value estimation is to employ a combination of qualitative and machine learning solutions where a probabilistic model encompassing the knowledge from different stakeholders will be used to predict the overall value of a given decision relating to product management and development. This vision drives the goal of a 3-year research project funded by the Finnish Funding Agency for Technology and Innovation (Tekes), with the participation of several industry partners.This work is funded under Tekes FiDiPro number 40150/14

    Amygdala responses to emotionally valenced stimuli in older and younger adults

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    ABSTRACT—As they age, adults experience less negative emotion, come to pay less attention to negative than to positive emotional stimuli, and become less likely to remember negative than positive emotional materials. This profile of findings suggests that, with age, the amygdala may show decreased reactivity to negative information while maintaining or increasing its reactivity to positive information. We used event-related functional magnetic resonance imaging to assess whether amygdala activation in response to positive and negative emotional pictures changes with age. Both older and younger adults showed greater activation in the amygdala for emotional than for neutral pictures; however, for older adults, seeing positive pictures led to greater amygdala activation than seeing negative pictures, whereas this was not the case for younger adults. Older adults experience less negative affect than younger adults in both cross-sectional and longitudinal studies (Carstensen, Pasupathi

    Negative Even Grade mKdV Hierarchy and its Soliton Solutions

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    In this paper we provide an algebraic construction for the negative even mKdV hierarchy which gives rise to time evolutions associated to even graded Lie algebraic structure. We propose a modification of the dressing method, in order to incorporate a non-trivial vacuum configuration and construct a deformed vertex operator for sl^(2)\hat{sl}(2), that enable us to obtain explicit and systematic solutions for the whole negative even grade equations
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