1,171 research outputs found

    Early growth of field-grown swiss flint maize landraces

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    Mild cold stress (chilling) limits early growth of maize (Zea mays L.) in central and northern Europe. Introgression of chilling tolerance from landraces has been proposed, because the genetic basis for chilling tolerance of European Flint x Dent hybrids is small. Therefore, the aim of this study was a detailed characterization of the chilling toler¬ance of Swiss maize landraces, hypothesizing a relatively good performance in marginal thermal environments. The environments were set up by different sowing dates in two years. A functional growth analysis of the shoot from the one-leaf to the six-leaf stage was conducted with eight Swiss landraces and a check hybrid (Magister). The mean air temperature calculated across the six environments was above 15°C. Under these conditions, none of the landraces grew consistently better than Magister. Some landrace-specific relative growth reactions were observed compared to Magister, apparently due to strong changes in the temperature course. However, based on this study direct use of Swiss maize landraces in breeding for the improvement of chilling tolerance is not recom¬mended. More detailed investigations of promising landraces are proposed

    Early growth of field-grown swiss flint maize landraces

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    Mild cold stress (chilling) limits early growth of maize (Zea mays L.) in central and northern Europe. Introgression of chilling tolerance from landraces has been proposed, because the genetic basis for chilling tolerance of European Flint x Dent hybrids is small. Therefore, the aim of this study was a detailed characterization of the chilling toler¬ance of Swiss maize landraces, hypothesizing a relatively good performance in marginal thermal environments. The environments were set up by different sowing dates in two years. A functional growth analysis of the shoot from the one-leaf to the six-leaf stage was conducted with eight Swiss landraces and a check hybrid (Magister). The mean air temperature calculated across the six environments was above 15°C. Under these conditions, none of the landraces grew consistently better than Magister. Some landrace-specific relative growth reactions were observed compared to Magister, apparently due to strong changes in the temperature course. However, based on this study direct use of Swiss maize landraces in breeding for the improvement of chilling tolerance is not recom¬mended. More detailed investigations of promising landraces are proposed

    Adaptive Organization - Management Tool in Variable Environment

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    The article argues the notion of adaptive organization as the tool for management enterprises in variable environment. In an increasingly unstable market environment the need for decisive restructuring of enterprise management systems, perfection of all management functions, including the organization, which as a function of management, must adjust to changing conditions, that is to be adaptive. A main goal of adaptive organization of enterprise management systems is to overcome the functionalism. Thus the level of regulation the management process should decrease when variability of environment is growing. This inevitably raises the role of self-organization as in management process within enterprise as in chaotic processes in environment. If external circumstances dictate, the will of business owners or management of the companies must be to reorganize the company on the basis of decentralization. Objective parameters for assessing the need for the next step in the decentralization of the company is the share that in common transactions of the enterprise takes the unit. The current market environment is influenced of many unaccounted factors, but in the process of self-organization it moves to relatively stable states called attractors. Formally the evolution of such systems can be described by means of so-called Poincare maps. Enough successful example of an attractor that show process of variable fluctuations in sales in a supermarket on weekdays is shown in the article. As a highly successful example of an attractor show process of variable fluctuations in sales in a supermarket on weekdays. The data of these attractors are the reliable tool for planning and organizing activities.У статті розкривається поняття адаптивної організації як інструменту управління підприємствами в мінливому середовищі. В умовах все більш нестабільного ринкового середовища зростає необхідність у рішучій реструктуризації систем управління підприємствами, удосконалення всіх функцій управління, включаючи організацію, яка, як функція управління, повинна пристосовуватися до мінливих умов, тобто бути адаптивною. Основна мета адаптивної організації системи управління підприємствами є подолання її надмірного функціоналізму. Тому рівень регламентації процесу управління повинен знижуватися в міру того, як мінливість навколишнього середовища зростає. Це неминуче підвищує роль самоорганізації, як в процесі управління всередині підприємства, так і в хаотичних процесах у навколишньому середовищі. Зміна зовнішніх умов має формувати у власників бізнесу або керуючих компаній волю до реорганізації підприємства на основі децентралізації. Об'єктивним параметром для оцінки необхідності наступного кроку в процесі децентралізації компанії стає частка, яку в загальному обсязі транзакцій підприємства виконує його окремий підрозділ. Поточне ринкове середовище формується під впливом багатьох неврахованих факторів, але в процесі самоорганізації воно рухається до відносно стійких станів, названих атракторами. Формально розвиток таких систем можна описати за допомогою так званого точкового відображення Пуанкаре. У статті представлений досить успішний приклад атрактора, який відображає процес самоорганізації коливань обсягів продажу в супермаркетах по днях тижня. Параметри подібних атракторів формують надійну базу для планування та організації діяльності підприємства в мінливому середовищі.В статье раскрывается понятие адаптивной организации как инструмента управления предприятиями в переменной среде. В условиях все более нестабильной рыночной среды возрастает необходимость в решительной реструктуризации систем управления предприятием, совершенствование всех функций управления, включая организацию, которая, как функция управления, должна приспосабливаться к изменяющимся условиям, то есть быть адаптивной. Основная цель адаптивной организации систем управления предприятием является преодоление ее чрезмерного функционализма. Поэтому уровень регламентации процесса управления должен снижаться по мере того, как переменность окружающей среды нарастает. Это неизбежно повышает роль самоорганизации, как в процессе управления внутри предприятия, так и в хаотических процессах в окружающей среде. Изменение внешних условий должно формировать у владельцев бизнеса или управляющих компаний волю к реорганизации предприятия на основе децентрализации. Объективным параметром для оценки необходимости следующего шага в процессе децентрализации компании становится доля, которую в общем объеме транзакций предприятия выполняет его подразделение. Текущая рыночная среда формируется под влиянием многих неучтенных факторов, но в процессе самоорганизации она движется к относительно устойчивым состояниям, называемым аттракторами. Формально развитие таких систем можно описать в виде так называемого точечного отображения Пуанкаре. В статье представлен достаточно успешный пример аттрактора, который отображает процесс самоорганизации переменных колебаний объемов продаж в супермаркетах по дням недели. Параметры подобных аттракторов формируют надежную базу для планирования и организации деятельности предприятия в переменной среде

    A Pilot Study with a Novel Setup for Collaborative Play of the Humanoid Robot KASPAR with children with autism

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    This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.This article describes a pilot study in which a novel experimental setup, involving an autonomous humanoid robot, KASPAR, participating in a collaborative, dyadic video game, was implemented and tested with children with autism, all of whom had impairments in playing socially and communicating with others. The children alternated between playing the collaborative video game with a neurotypical adult and playing the same game with the humanoid robot, being exposed to each condition twice. The equipment and experimental setup were designed to observe whether the children would engage in more collaborative behaviours while playing the video game and interacting with the adult than performing the same activities with the humanoid robot. The article describes the development of the experimental setup and its first evaluation in a small-scale exploratory pilot study. The purpose of the study was to gain experience with the operational limits of the robot as well as the dyadic video game, to determine what changes should be made to the systems, and to gain experience with analyzing the data from this study in order to conduct a more extensive evaluation in the future. Based on our observations of the childrens’ experiences in playing the cooperative game, we determined that while the children enjoyed both playing the game and interacting with the robot, the game should be made simpler to play as well as more explicitly collaborative in its mechanics. Also, the robot should be more explicit in its speech as well as more structured in its interactions. Results show that the children found the activity to be more entertaining, appeared more engaged in playing, and displayed better collaborative behaviours with their partners (For the purposes of this article, ‘partner’ refers to the human/robotic agent which interacts with the children with autism. We are not using the term’s other meanings that refer to specific relationships or emotional involvement between two individuals.) in the second sessions of playing with human adults than during their first sessions. One way of explaining these findings is that the children’s intermediary play session with the humanoid robot impacted their subsequent play session with the human adult. However, another longer and more thorough study would have to be conducted in order to better re-interpret these findings. Furthermore, although the children with autism were more interested in and entertained by the robotic partner, the children showed more examples of collaborative play and cooperation while playing with the human adult.Peer reviewe

    Ultrafast spin dynamics and critical behavior in half-metallic ferromagnet : Sr_2FeMoO_6

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    Ultrafast spin dynamics in ferromagnetic half-metallic compound Sr_2FeMoO_6 is investigated by pump-probe measurements of magneto-optical Kerr effect. Half-metallic nature of this material gives rise to anomalous thermal insulation between spins and electrons, and allows us to pursue the spin dynamics from a few to several hundred picoseconds after the optical excitation. The optically detected magnetization dynamics clearly shows the crossover from microscopic photoinduced demagnetization to macroscopic critical behavior with universal power law divergence of relaxation time for wide dynamical critical region.Comment: 14 pages, 4 figures. Abstract and Figures 1 & 3 are correcte

    Decreased Compressional Sound Velocity Is an Indicator for Compromised Bone Stiffness in X-Linked Hypophosphatemic Rickets (XLH)

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    Objectives: To assess the diagnostic potential of bidirectional axial transmission (BDAT) ultrasound, and high-resolution peripheral quantitative computed tomography (HR-pQCT) in X-linked hypophosphatemia (XLH, OMIM #307800), a rare genetic disorder of phosphate metabolism caused by mutations in the PHEX gene. Methods: BDAT bone ultrasound was performed at the non-dominant distal radius (33% relative to distal head) and the central left tibia (50%) in eight XLH patients aged between 4.2 and 20.8 years and compared to twenty-nine healthy controls aged between 5.8 and 22.4 years. In eighteen controls, only radius measurements were performed. Four patients and four controls opted to participate in HR-pQCT scanning of the ultradistal radius and tibia. Results: Bone ultrasound was feasible in patients and controls as young as 4 years of age. The velocity of the first arriving signal (νFAS) in BDAT ultrasound was significantly lower in XLH patients compared to healthy controls: In the radius, mean νFAS of XLH patients and controls was 3599 ± 106 and 3866 ± 142 m/s, respectively (-6.9%; p < 0.001). In the tibia, it was 3578 ± 129 and 3762 ± 124 m/s, respectively (-4.9%; p = 0.006). HR-pQCT showed a higher trabecular thickness in the tibia of XLH patients (+16.7%; p = 0.021). Conclusions: Quantitative bone ultrasound revealed significant differences in cortical bone quality of young XLH patients as compared to controls. Regular monitoring of XLH patients by a radiation-free technology such as BDAT might provide valuable information on bone quality and contribute to the optimization of treatment. Further studies are needed to establish this affordable and time efficient method in the XLH patients

    Socially assistive robotics for post-stroke rehabilitation

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    BACKGROUND: Although there is a great deal of success in rehabilitative robotics applied to patient recovery post stroke, most of the research to date has dealt with providing physical assistance. However, new rehabilitation studies support the theory that not all therapy need be hands-on. We describe a new area, called socially assistive robotics, that focuses on non-contact patient/user assistance. We demonstrate the approach with an implemented and tested post-stroke recovery robot and discuss its potential for effectiveness. RESULTS: We describe a pilot study involving an autonomous assistive mobile robot that aids stroke patient rehabilitation by providing monitoring, encouragement, and reminders. The robot navigates autonomously, monitors the patient's arm activity, and helps the patient remember to follow a rehabilitation program. We also show preliminary results from a follow-up study that focused on the role of robot physical embodiment in a rehabilitation context. CONCLUSION: We outline and discuss future experimental designs and factors toward the development of effective socially assistive post-stroke rehabilitation robots

    Abelian gauge potentials on cubic lattices

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    The study of the properties of quantum particles in a periodic potential subject to a magnetic field is an active area of research both in physics and mathematics; it has been and it is still deeply investigated. In this review we discuss how to implement and describe tunable Abelian magnetic fields in a system of ultracold atoms in optical lattices. After discussing two of the main experimental schemes for the physical realization of synthetic gauge potentials in ultracold set-ups, we study cubic lattice tight-binding models with commensurate flux. We finally examine applications of gauge potentials in one-dimensional rings.Comment: To appear on: "Advances in Quantum Mechanics: Contemporary Trends and Open Problems", G. Dell'Antonio and A. Michelangeli eds., Springer-INdAM series 201

    Calcium phosphate particles stimulate interleukin-1β release from human vascular smooth muscle cells: A role for spleen tyrosine kinase and exosome release

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    Aims: Calcium phosphate (CaP) particle deposits are found in several inflammatory diseases including atherosclerosis and osteoarthritis. CaP, and other forms of crystals and particles, can promote inflammasome formation in macrophages leading to caspase-1 activation and secretion of mature interleukin-1β (IL-1β). Given the close association of small CaP particles with vascular smooth muscle cells (VSMCs) in atherosclerotic fibrous caps, we aimed to determine if CaP particles affected pro-inflammatory signalling in human VSMCs. Methods and results: Using ELISA to measure IL-1β release from VSMCs, we demonstrated that CaP particles stimulated IL-1β release from proliferating and senescent human VSMCs, but with substantially greater IL-1β release from senescent cells; this required caspase-1 activity but not LPS-priming of cells. Potential inflammasome agonists including ATP, nigericin and monosodium urate crystals did not stimulate IL-1β release from VSMCs. Western blot analysis demonstrated that CaP particles induced rapid activation of spleen tyrosine kinase (SYK) (increased phospho-Y525/526). The SYK inhibitor R406 reduced IL-1β release and caspase-1 activation in CaP particle-treated VSMCs, indicating that SYK activation occurs upstream of and is required for caspase-1 activation. In addition, IL-1β and caspase-1 colocalised in intracellular endosome-like vesicles and we detected IL-1β in exosomes isolated from VSMC media. Furthermore, CaP particle treatment stimulated exosome secretion by VSMCs in a SYK-dependent manner, while the exosome-release inhibitor spiroepoxide reduced IL-1β release. Conclusions: CaP particles stimulate SYK and caspase-1 activation in VSMCs, leading to the release of IL-1β, at least in part via exosomes. These novel findings in human VSMCs highlight the pro-inflammatory and procalcific potential of microcalcification

    Wandering as a sociomaterial practice : extending the theorization of GPS tracking in cognitive impairment

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    Electronic tracking through global positioning systems (GPSs) is used to monitor people with cognitive impairment who “wander” outside the home. This ethnographic study explored how GPS-monitored wandering was experienced by individuals, lay carers, and professional staff. Seven in-depth case studies revealed that wandering was often an enjoyable and worthwhile activity and helped deal with uncertainty and threats to identity. In what were typically very complex care contexts, GPS devices were useful to the extent that they aligned with a wider sociomaterial care network that included lay carers, call centers, and health and social care professionals. In this context, “safe” wandering was a collaborative accomplishment that depended on the technology’s materiality, affordances, and aesthetic properties; a distributed knowledge of the individual and the places they wandered through, and a collective and dynamic interpretation of risk. Implications for design and delivery of GPS devices and services for cognitive impairment are discussed
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