Distribution of some elements in Veronica scutellata L. from Bolu,Turkey: soil-plant interactions

Veronica scutellata L. occurs in moist and wet habitats, such as ponds, marshes and other wetlands. This study was conducted on this species to examine its mineral element uptake status in terms of interactions between soil and plant. Experimental materials were taken from the Southern coast of Black Sea at coordinates 40º36’N and 31º16’E at an altitude of 1400 m above sea level from Bolu – Turkey; using standard methods and plant (root, stem and leaf parts) and soil mineral element measurements (Al, B, Ca, Cu, Fe, K, Mg, Mn, Na, Ni and Zn) were done. During the study, ICP-OES was employed for the measurement of mineral elements. It was observed that considerable amounts of B, Ca, K, Mg, Mn, Na and Zn are accumulated by the plant

SISO RIS-Enabled Joint 3D Downlink Localization and Synchronization

We consider the problem of joint three-dimensional localization and synchronization for a single-input single-output (SISO) multi-carrier system in the presence of a reconfigurable intelligent surface (RIS), equipped with a uniform planar array. First, we derive the Cram\ue9r-Rao bounds (CRBs) on the estimation error of the channel parameters, namely, the angle-of-departure (AOD), composed of azimuth and elevation, from RIS to the user equipment (UE) and times-of-arrival (TOAs) for the path from the base station (BS) to UE and BS-RISUE reflection. In order to avoid high-dimensional search over the parameter space, we devise a low-complexity estimation algorithm that performs two 1D searches over the TOAs and one 2D search over the AODs. Simulation results demonstrate that the considered RIS-aided wireless system can provide submeter-level positioning and synchronization accuracy, materializing the positioning capability of Beyond 5G networks even with single-antenna BS and UE. Furthermore, the proposed estimator is shown to attain the CRB at a wide interval of distances between UE and RIS. Finally, we also investigate the scaling of the position error bound with the number of RIS elements

Approach to stress endocrine response: somatization in the context of gastroenterological symptoms: a systematic review

Background: Stress can be defined as an acute threat to the homeostasis of an organism, and in order to manage stress, and maintain stability, the allostatic systems activate an adaptive response. Stress has been shown to have both short - and long-term effects on the function of the gastrointestinal tract, but long-term exposure to stress is more likely to cause endocrine disorders. Objective: The aim of this study was to investigate the endocrine response to stress, and evaluate the relationship between somatization and gastrointestinal symptoms. Methods: A systematic literature search was conducted on several academic databases, which included, Pubmed, EBSCO and Science Direct. The search was performed using the keywords, \u201cendocrine response to stress\u201d, \u201csomatization\u201d and \u201cgastrointestinal symptoms\u201d. Results: The hypothalamic-pituitary-adrenal (HPA) axis is essential in controlling physiological stress responses. Dysfunction is related to several mental disorders, including anxiety and depression, or somatization. Symptoms associated with genetic, or other traumatic experiences of individuals under stress, can lead to a maladaptive response to stress. These stressful life events were found to be associated with digestive system-related chronic diseases. Gastrointestinal disorders significantly affect millions of people worldwide. Conclusion: This study examined how the endocrine system responds to stress, and the effect this has in causing stress-related gastrointestinal distresses. Our findings indicate that stress-related psychological disorders are strongly associated with the severity of gastrointestinal symptoms

RIS-Enabled SISO Localization under User Mobility and Spatial-Wideband Effects

Reconfigurable intelligent surface (RIS) is a promising technological enabler for the 6th generation (6G) of wireless systems with applications in localization and communication. In this paper, we consider the problem of positioning a single-antenna user in 3D space based on the received signal from a single-antenna base station and reflected signal from an RIS by taking into account the mobility of the user and spatial-wideband (WB) effects. To do so, we first derive the spatial-WB channel model under the far-field assumption, for orthogonal frequency-division multiplexing signal transmission with the user having a constant velocity. We derive the Cram\\u27er Rao bounds to serve as a benchmark. Furthermore, we devise a low-complexity estimator that attains the bounds in high signal-to-noise ratios. Our estimator neglects the spatial-WB effects and deals with the user mobility by estimating the radial velocities and compensating for their effects in an iterative fashion. We show that the spatial-WB effects can degrade the localization accuracy for large RIS sizes and large signal bandwidths as the direction of arrival or departure deviate from the RIS normal. In particular, for a 64 $\times$ 64 RIS, the proposed estimator is resilient against the spatial-WB effects up to 140 MHz bandwidth. Regarding user mobility, our results suggest that the velocity of the user influences neither the bounds nor the accuracy of our estimator. Specifically, we observe that the state of the user with a high speed (42 m/s) can be estimated virtually with the same accuracy as a static user

Semi-Passive 3D Positioning of Multiple RIS-Enabled Users

Reconfigurable intelligent surfaces (RISs) are set to be a revolutionary technology in the 6th generation of wireless systems. In this work, we study the application of RIS in a multi-user passive localization scenario, where we have one transmitter (TX) and multiple asynchronous receivers (RXs) with known locations. Classical approaches fail in this scenario due to lack of synchronization and lack of data association between multi-static measurements and users. To resolve this, we consider each user to be equipped with an RIS, and show that we can avoid the data association problem and estimate users\u27 3D position with submeter accuracy in a large area around the transmitter, using time-of-arrival measurements at the RXs. We develop a low-complexity estimator that attains the corresponding Cram\\u27er-Rao bound as well as a novel RIS phase profile design to remove inter-path interference

Pion wave functions from holographic QCD and the role of infrared renormalons in photon-photon collisions

In this article, we calculate the contribution of the higher-twist Feynman diagrams to the large-$p_T$ inclusive single pion production cross section in photon-photon collisions in case of the running coupling and frozen coupling approaches within holographic QCD. We compare the resummed higher-twist cross sections with the ones obtained in the framework of the frozen coupling approach and leading-twist cross section. Also, we show that in the context of frozen coupling approach a higher-twist contribution to the photon-photon collisions cross section is normalized in terms of the pion electromagnetic form factor.Comment: 21 pages, 15 figures. arXiv admin note: text overlap with arXiv:0709.2072 by other author

Near-field Localization with a Reconfigurable Intelligent Surface Acting as Lens

Exploiting wavefront curvature enables localization with limited infrastructure and hardware complexity. With the introduction of reconfigurable intelligent surfaces (RISs), new opportunities arise, in particular when the RIS is functioning as a lens receiver. We investigate the localization of a transmitter using a RIS-based lens in close proximity to a single receive antenna element attached to reception radio frequency chain. We perform a Fisher information analysis, evaluate the impact of different lens configurations, and propose a two-stage localization algorithm. Our results indicate that positional beamforming can lead to better performance when a priori location information is available, while random beamforming is preferred when a priori information is lacking. Our simulation results for a moderate size lens operating at 28 GHz showcased that decimeter-level accuracy can be attained within 3 meters to the lens

Eltrombopag for the treatment of immune thrombocytopenia: The aegean region of Turkey experience

Objective: Immune thrombocytopenia (ITP) is an immune-mediated disease characterized by transient or persistent decrease of the platelet count to less than 100x109/L. Although it is included in a benign disease group, bleeding complications may be mortal. With a better understanding of the pathophysiology of the disease, thrombopoietin receptor agonists, which came into use in recent years, seem to be an effective option in the treatment of resistant cases. This study aimed to retrospectively assess the efficacy, long-term safety, and tolerability of eltrombopag in Turkish patients with chronic ITP in the Aegean region of Turkey. Materials and Methods: Retrospective data of 40 patients with refractory ITP who were treated with eltrombopag in the Aegean region were examined and evaluated. Results: The total rate of response was 87%, and the median duration of response defined as the number of the platelets being over 50x109/L was 19.5 (interquartile range: 5-60) days. In one patient, venous sinus thrombosis was observed with no other additional risk factors due to or related to thrombosis. Another patient with complete response and irregular follow-up for 12 months was lost due to sudden death as the result of probable acute myocardial infarction. Conclusion: Although the responses to eltrombopag were satisfactory, patients need to be monitored closely for overshooting platelet counts as well as thromboembolic events. © 2015 Turkish Society of Hematology. All rights reserved

Exploring the entrepreneurial engineer from a value creation perspective

The Grand Societal Challenges, such as the Sustainable Development Goals and the recognition of entrepreneurship as a lifelong learning competence, are raising interest in the engineering field. For engineering students, this is an opportunity to experience sustainable value-creation through innovative entrepreneurial education. Accordingly, they should be educated on applying entrepreneurial competences in environments that are complex, uncertain, and have a value-laden character. From an educational design lens, designing entrepreneurial education for engineers from a value-creation perspective requires exploring and analysing desired states of future entrepreneurship education for engineers. Specifically, this implies understanding who the entrepreneurial engineers are and what their value-creation process looks like to be able to translate such understanding into future educational interventions.Approach: This paper shares the findings of a survey with open-ended questions shared among Faculty and professionals of the engineering industry. We gather data including (1) perspectives of entrepreneurship, (2) characteristics of the entrepreneurial engineer, (3) value creation process (4) desired contribution to society and (5) role of the entrepreneurial engineer when facing sustainable transitions and transformations.Results: We are currently developing and iterating the codebook based on 5 responses. Results reflect the findings of this process and are, therefore, in an early stage.Implications: This paper shares part of the findings of the PhD position of the 4TU project “Educating the Entrepreneurial Engineer”. These help in designing learning interventions for educating future Entrepreneurial Engineers, and they contribute to the overarching theme “The future of engineering education”.Value/Originality: The findings of the study contribute to setting the ground for future studies aimed at mapping how the 4TUs are currently fostering Entrepreneurial Engineers. Ultimately, these will add value in building a common curriculum strategy at the 4TUs and beyond for educating the future entrepreneurial engineer. The originality of this contribution lies in the inclusion of faculty and industry in the design process, contributing to bridge theory and practice

Exploring the entrepreneurial engineer from a value creation perspective

The Grand Societal Challenges, such as the Sustainable Development Goals and the recognition of entrepreneurship as a lifelong learning competence, are raising interest in the engineering field. For engineering students, this is an opportunity to experience sustainable value-creation through innovative entrepreneurial education. Accordingly, they should be educated on applying entrepreneurial competences in environments that are complex, uncertain, and have a value-laden character. From an educational design lens, designing entrepreneurial education for engineers from a value-creation perspective requires exploring and analysing desired states of future entrepreneurship education for engineers. Specifically, this implies understanding who the entrepreneurial engineers are and what their value-creation process looks like to be able to translate such understanding into future educational interventions.Approach: This paper shares the findings of a survey with open-ended questions shared among Faculty and professionals of the engineering industry. We gather data including (1) perspectives of entrepreneurship, (2) characteristics of the entrepreneurial engineer, (3) value creation process (4) desired contribution to society and (5) role of the entrepreneurial engineer when facing sustainable transitions and transformations.Results: We are currently developing and iterating the codebook based on 5 responses. Results reflect the findings of this process and are, therefore, in an early stage.Implications: This paper shares part of the findings of the PhD position of the 4TU project “Educating the Entrepreneurial Engineer”. These help in designing learning interventions for educating future Entrepreneurial Engineers, and they contribute to the overarching theme “The future of engineering education”.Value/Originality: The findings of the study contribute to setting the ground for future studies aimed at mapping how the 4TUs are currently fostering Entrepreneurial Engineers. Ultimately, these will add value in building a common curriculum strategy at the 4TUs and beyond for educating the future entrepreneurial engineer. The originality of this contribution lies in the inclusion of faculty and industry in the design process, contributing to bridge theory and practice