840 research outputs found
Lived experience of applied science graduates who complete the applied baccalaureate, The
2012 Spring.Includes bibliographical references.The enrollment and transfer behaviors of college students are diverse. As a result college students travel various pathways to the baccalaureate degree. The purpose of this qualitative study was to better understand the lived experience of students who entered higher education through an associate of applied science (AAS) program and then continued in higher education to earn a bachelor of applied science (BAS) degree. To explore this phenomenon, eight participants completed two in-depth interviews regarding their lived experience as students on this educational pathway. Five structures emerged from the data to frame the participants' experiences on the AAS to BAS pathway: disengagement, doubt, knowledge of something different, significant relationships, and transformation. These five structures interacted in discrete ways to characterize the participants' experiences as pushing through disillusionment related to education, the profession, and self. The participants' moving through three dimensions of disillusionment along the pathway formed the meaning and the essence of the phenomenon, dogged determinism. Dogged determinism denotes the willful attitude assumed by the participants as they pushed through their illusions. Dogged determinism explains how the direction chosen when the participants encountered their illusions was the most probable option for the participants, at that particular time, and under that set of circumstances
Pulse sequences for measuring exchange rates between proton species: From unlocalised NMR spectroscopy to chemical exchange saturation transfer imaging
Within the field of NMR spectroscopy, the study of chemical exchange processes through saturation transfer techniques has a long history. In the context of MRI, chemical exchange techniques have been adapted to increase the sensitivity of imaging to small fractions of exchangeable protons, including the labile protons of amines, amides and hydroxyls. The MR contrast is generated by frequency-selective irradiation of the labile protons, which results in a reduction of the water signal associated with transfer of the labile protons’ saturated magnetization to the protons of the surrounding free water. The signal intensity depends on the rate of chemical exchange and the concentration of labile protons as well as on the properties of the irradiation field. This methodology is referred to as CEST (chemical exchange saturation transfer) imaging. Applications of CEST include imaging of molecules with short transverse relaxation times and mapping of physiological parameters such as pH, temperature, buffer concentration and chemical composition due to the dependency of this chemical exchange effect on all these parameters. This article aims to describe these effects both theoretically and experimentally. In depth analysis and mathematical modelling are provided for all pulse sequences designed to date to measure the chemical exchange rate. Importantly, it has become clear that the background signal from semi-solid protons and the presence of the Nuclear Overhauser Effect (NOE), either through direct dipole-dipole mechanisms or through exchange-relayed signals, complicates the analysis of CEST effects. Therefore, advanced methods to suppress these confounding factors have been developed, and these are also reviewed. Finally, the experimental work conducted both in vitro and in vivo is discussed and the progress of CEST imaging towards clinical practice is presented
DESIGNING AND EVALUATING A PORTABLE LIDAR-BASED SLAM SYSTEM
Mobile Mapping Technology (MMT) has evolved rapidly over the past few decades, especially in using low-cost sensors. This progress is primarily attributed to the appearance of innovative simultaneous localization and mapping (SLAM) algorithms. This article focuses on evaluating the efficiency of a new LiDAR-based portable SLAM system for mapping in dynamic real-world environments. The work proposed a technical solution based on a Livox Avia LiDAR sensor enhanced by gimbal stabilization. The system, named Portable Livox-based Mapping system (PoLiMap), is compared to other similar solutions by acquiring data from various environments, including urban sceneries, underground tunnels and forested areas, and processing them using a modified FAST-LIO-SLAM algorithm. The research presented in the article contributes to the understanding of the capabilities of PoLiMap systems under various conditions and offers significant insight into its potential applications. Accuracy evaluation results prove that the proposed MMT system can successfully tackle various demanding environments and challenge the results of other more costly state-of-the-art portable mobile laser scanning methods
Study of the third order nonlinear optical properties of Zn1−xMgxSe and Cd1−xMgxSe crystals
Third order nonlinear optical susceptibilities χ<3> of ternary Zn1−xMgxSe and Cd1−xMgxSe crystals have been measured using standard degenerate four-wave mixing (DFWM) method at 532 nm. The nonlinear transmission technique has been applied to check if our crystals exhibit two-photon absorption. The studied Zn1−xMgxSe and Cd1−xMgxSe solid solutions were grown from the melt by the modified high-pressure Bridgman method. For both crystals the energy gap increases with increasing Mg content. In the case of Zn1−xMgxSe, it was found that the value of third order nonlinear optical susceptibility χ<3> decreases with increasing Mg content. An explanation of this behaviour results from the dependence of optical nonlinearities on the energy band gap Eg of the studied crystals. In the case of Cd1txMgxSe with low content of Mg, no response was observed for the studied wavelength since the energy gap in such crystals is smaller than the photon energy of the used laser radiation. It was also found that the value of third order nonlinear optical susceptibility χ<3> for Cd0.70Mg0.30Se is higher than for Zn0.67Mg0.33Se. This behaviour can be understood if one take into consideration that the free carrier concentration in Cd1−xMgxSe samples is about four orders of magnitude higher than that in Zn1txMgxSe ones with comparable Mg content respectively. It is commonly known that when the electric conductivity increases, the values of nonlinear optical properties increase. From the performed measurements one can conclude that the incorporation of Mg as constituent into ZnSe and CdSe crystals leads to a change of the third order nonlinear optical susceptibilities
Assessment of a clinically feasible Bayesian fitting algorithm using a simplified description of Chemical Exchange Saturation Transfer (CEST) imaging
System komunikacji alternatywnej i wspomagającej wraz ze stosowanymi znakami oraz wykorzystanie urządzenia sterowanego za pomocą oczu w Polsce
Patients who do not communicate verbally or speak in an understandable way are a serious problem in providing appropriate care to patients due to a lack of understanding of their needs. Therefore, it is important that nursing staff have the knowledge and skills of alternative and assistive communication to communicate with patients with speech disorders. The purpose of article is to present the current state of knowledge of the alternative and augmentative communication with special consideration the signs used in Poland with a practicular emphasis laid to the revelant description of the eye tracking device. The literature has been reviewed, including also in this relation topics: alternative and augmentative communication, examples of signs used in alternative communication in Poland and communication and eye tracking. Not everyone has the ability to communicate verbally with the environment. In relation to this problem the solution is the alternative and augmentative communication which uses signs and devices to enable the patient to communicate with other people. (JNNN 2020;9(1):39–45)Pacjenci nie komunikujący się werbalnie lub mówiący w sposób niezrozumiały stanowią istotny problem w zapewnieniu właściwej opieki chorych w wyniku braku zrozumienia ich potrzeb. Z tego względu istotne jest posiadanie przez personel pielęgniarski wiedzy i umiejętności w zakresie komunikacji alternatywnej i wspomagającej by porozumieć się z pacjentami z zaburzeniami mowy. Celem pracy jest przedstawienie dotychczasowego stanu wiedzy na temat systemu komunikacji alternatywnej i wspomagającej ze szczególnym uwzgędnieniem wykorzystywanych znaków w Polsce oraz opis urządzenia sterowanego za pomocą oczu. Dokonano przeglądu literatury w zakresie tematów: komunikacja alternatywna i wspomagająca, przykłady znaków stosowanych w komunikacji alternatywnej w Polsce oraz komunikacja za pomocą oczu. Nie każdy człowiek posiada zdolność do komunikowania się werbalnie z otoczeniem. W odniesieniu do tego problemu rozwiązaniem jest komunikacja alternatywna i wspomagająca, która stosuje między innymi znaki oraz urządzenia, dające pacjentowi możliwość komunikowania się z ludźmi. (PNN 2020;9(1):39–45
Pair condensation in the BCS-BEC crossover of ultracold atoms loaded onto a 2D square lattice
We investigate the crossover from the Bardeen-Cooper-Schrieffer (BCS) state
of weakly-bound Cooper pairs to the Bose-Einstein Condensate (BEC) of
strongly-bound molecular dimers in a gas of ultracold atoms loaded on a
two-dimensional optical lattice. By using the the mean-field BCS equations of
the emerging Hubbard model and the concept of off-diagonal-long-range-order for
fermions we calculate analytically and numerically the pair binding energy, the
energy gap and the condensate fraction of Cooper pairs as a function of
interaction strength and filling fractor of atoms in the lattice at zero
temperature.Comment: 7 pages, 5 figures, to be published in Phys. Rev.
Additive effects of the dopamine D2 receptor and dopamine transporter genes on the error-related negativity in young children
The error-related negativity (ERN) is a negative deflection in the event-related potential that occurs approximately 50ms following the commission of an error at fronto-central electrode sites. Previous models suggest dopamine plays a role in the generation of the ERN. We recorded event-related potentials (ERPs) while 279 children aged 5-7 years completed a simple Go/No-Go task; the ERN was examined in relation to the dopamine D2 receptor (DRD2) and dopamine transporter (DAT1) genes. Results suggest an additive effect of the DRD2 and DAT1 genotype on ERN magnitude such that children with at least one DRD2 A1 allele and children with at least one DAT1 9 allele have an increased (i.e. more negative) ERN. These results provide further support for the involvement of dopamine in the generation of the ERN. © 2012 Blackwell Publishing Ltd and International Behavioural and Neural Genetics Society
Potential use of the organic fraction of municipal solid waste in anaerobic co-digestion with wastewater in submerged anaerobic membrane technology
Food waste was characterized for its potential use as substrate for anaerobic co-digestion in a submerged anaerobic membrane bioreactor pilot plant that treats urban wastewater (WW). 90% of the particles had sizes under 0.5 mm after grinding the food waste in a commercial food waste disposer. COD, nitrogen and phosphorus concentrations were 100, 2 and 20 times higher in food waste than their average concentrations in WW, but the relative flow contribution of both streams made COD the only pollutant that increased significantly when both substrates were mixed. As sulphate concentration in food waste was in the same range as WW, co-digestion of both substrates would increase the COD/SO4-S ratio and favour methanogenic activity in anaerobic treatments. The average methane potential of the food waste was 421 +/- 15 mL CH4 g(-1) VS, achieving 73% anaerobic biodegradability. The anaerobic co-digestion of food waste with WW is expected to increase methane production 2.9-fold. The settleable solids tests and the particle size distribution analyses confirmed that both treatment lines of a conventional WWTP (water and sludge lines) would be clearly impacted,by the incorporation of food waste into its influent. Anaerobic processes are therefore preferred over their aerobic counterparts due to their ability to valorise the high COD content to produce biogas (a renewable energy) instead of increasing the energetic costs associated with the aeration process for aerobic COD oxidation. (C) 2016 Elsevier Ltd. All rights reserved.This research work was possible thanks to financial support from the Generalitat Valenciana (project PROMETEO/2012/029) which is gratefully acknowledged.Moñino Amorós, P.; Jiménez Douglas, E.; Barat Baviera, R.; Aguado García, D.; Seco Torrecillas, A.; Ferrer, J. (2016). Potential use of the organic fraction of municipal solid waste in anaerobic co-digestion with wastewater in submerged anaerobic membrane technology. Waste Management. 56:158-165. https://doi.org/10.1016/j.wasman.2016.07.021S1581655
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