1,640 research outputs found

    The single-particle density matrix and the momentum distribution of dark "solitons" in a Tonks-Girardeau gas

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    We study the reduced single-particle density matrix (RSPDM), the momentum distribution, natural orbitals and their occupancies, of dark "soliton" (DS) states in a Tonks-Girardeau gas. DS states are specially tailored excited many-body eigenstates, which have a dark solitonic notch in their single-particle density. The momentum distribution of DS states has a characteristic shape with two sharp spikes. We find that the two spikes arise due to the high degree of correlation observed within the RSPDM between the mirror points (xx and x-x) with respect to the dark notch at x=0x=0; the correlations oscillate rather than decay as the points xx and x-x are being separated.Comment: 9 pages, 8 figure

    Cellular Signaling Mechanisms of Hypocretin/Orexin

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    Publisher Copyright: © 2021 The Author(s).Orexin receptors (OXRs) are promiscuous G-protein-coupled receptors that signal via several G-proteins and, putatively, via other proteins. On which basis the signal pathways are selected and orchestrated is largely unknown. We also have an insufficient understanding of the kind of signaling that is important for specific types of cellular responses. OXRs are able to form complexes with several other G-protein-coupled receptors in vitro, and one possibility is that the complexing partners regulate the use of certain signal transducers. In the central nervous system neurons, the main acute downstream responses of OXR activation are the inhibition of K+ channels and the activation of the Na+/Ca2+ exchanger and non-selective cation channels of unknown identity. The exact nature of the intracellular signal chain between the OXRs and these downstream targets is yet to be elucidated, but the Gq-phospholipase C (PLC) protein kinase C pathway - which is a significant signaling pathway for OXRs in recombinant cells - may be one of the players in neurons. The Gq-PLC pathway may also, under certain circumstances, take the route to diacylglycerol lipase, which leads to the production of the potent endocannabinoid (eCB), 2-arachidonoyl glycerol, and thereby connects orexins with eCB signaling. In addition, OXRs have been studied in the context of neurodegeneration and cancer cell death. Overall, OXR signaling is complex, and it can change depending on the cell type and environment.Peer reviewe

    An architecture for presenting auditory awareness information in pervasive computing environments

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    Presented at the 12th International Conference on Auditory Display (ICAD), London, UK, June 20-23, 2006.In this paper we present how awareness can be supported in pervasive computing environments through auditory information. We introduce an application which uses soundscapes to support people's awareness of each other's presence in an office environment. We describe several techniques for construction and control of such soundscapes. Finally, we present an architecture for designing and controlling soundscapes. The architecture is based on managers, agents, evaluators, a blackboard information storage, and a control language, it emphasizes reusability and extensibility, and it is built upon a common system framework

    Summative assessment of clinical practice of student nurses : a review of the literature

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    Objectives: To describe assessment of nursing student’s clinical practice concerned nursing education. Design: Systematic review and synthesis of qualitative and quantitative studies. Data sources: The data were collected with the support of an information specialist from scientific databases Cinahl, PubMed, Medic, ISI Web of Science, Cochrane library and Eric published in January 2000 – May 2014. All of the included studies citations were also performed. Methods: 725 articles concerned with nurse student clinical practice assessment were identified. After inclusion and exclusion criteria were met 23 articles for selected for critical review. Two independent reviewers selected the studies according to the inclusion criteria. These articles were analyzed using content analysis. Results: Findings suggest that the assessment process of nursing students’ clinical practice lacks consistency, it is open to the subjective bias of the assessor and the quality of assessment varies greatly. Nursing students clinical assessment was divided into 3 themes: acts (things to do) before final assessment, the actual final assessment situation and the acts after the final assessment situation. Mentors and students need orientation to the assessment process and to the paperwork by teachers. Terminology on evaluation forms is sometimes so difficult to grasp, that the mentors did not understand what they mean. There is no consensus about written assignments’ ability to describe the students’ skills. Mentors have timing problems to ensure relevant assessment of student nurses. At the final interview students normally self assess their performance, the mentor assesses by interview and by written assignments whether the student has achieved the criteria and role of the teacher is to support the mentor and the student in appropriate assessment. The variety of patient treatment environments in which nursing students do their clinical practice periods is challenging also for the assessment of nursing students’ expertise. Mentors alone want that clinical practice is a positive experience and it might lead to higher grades than what nurse student competency earns. It is very rare that students fail their clinical practice, if the student does not achieve the clinical competencies they are allowed to have extra time in clinical areas until they will be assessed as competent. Conclusions: This systematic review provides a description of challenges in nursing students’ assessment in clinical settings. Further research needs to be carried out to have more knowledge of final assessment in the end of the clinical practice. Through further research it will be possible to have better methods for high quality assessment processes and feedback to nurse students. Quality in assessment provides better nurses and therefore better patient safety

    Ammatti-identiteetin vaikutus varhaiskasvatuksen tiimityön konflikteihin

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    Tiivistelmä. Tämän kandidaatintutkielman tavoitteena on kuvata ammatti-identiteetin vaikutusta varhaiskasvatuksen tiimityön konflikteihin varhaiskasvatus alalla tapahtuvien jatkuvien muutosten keskellä. Tutkielma on toteutettu kuvailevana kirjallisuuskatsauksena. Tutkielmassa perehdytään varhaiskasvatuksen historian kautta suurimpiin lakimuutoksiin sekä muutoksiin koulutuksissa, jotka ovat muovanneet varhaiskasvatuksen kenttää sellaiseksi kuin se on tänä päivänä. Tämän jälkeen kuvataan millaisena varhaiskasvatuksen tiimityön konfliktit näyttäytyvät tutkimuskirjallisuuden valossa. Lopuksi tarkastellaan ammatti-identiteetti käsitettä muutoksessa sekä ammatti-identiteetin muotoutumista. Tutkimuksen lähteinä on käytetty väitöskirjoja, kotimaisia ja kansainvälisiä artikkeleja, varhaiskasvatuslakia, varhaiskasvatussuunnitelman perusteita sekä tutkimusraportteja. Kirjallisuuskatsaus osoittaa varhaiskasvatuksen tiimityön konfliktien syiksi hoivan ja pedagogiikan vastakkainasettelun, alan jatkuvat muutokset, koulutusten jännittyneisyyden sekä epäselvän työjaon ja työkulttuurin. Tutkimustuloksena voidaan todeta, että ammatti-identiteetti vaikuttaa konflikteihin, kuten myös muutokset. Muutoksilla ja konflikteilla on vaikutus ammatti-identiteettiin ja sitä kautta uusien konfliktien syntymiseen

    Impacts of winter feeding of reindeer on vegetation and soil in the sub-Arctic: insights from a feeding experiment

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    The overall impacts of winter feeding, including the effects of both forage and reindeer (Rangifer tarandus), were studied in an experiment in the Hammastunturi herding cooperative (68°N), Finland, with 300 reindeer in a sub-xeric heath forest (35 ha) during March/April 2009 and 2010. The feeding practices on the 50 plots were: (1) feeding with grass silage+hay with leftovers cleared in the spring; (2) feeding with grass silage+hay with leftovers not cleared; and (3) feeding with pellets. In addition, (4) unfenced and (5) fenced control plots were included, on which the reindeer were not fed. No invasive plant species introduced through grass silage+hay were observed on the plots. The coverage of Deschampsia flexuosa increased on grass silage+hay plots after the first winter, and both coverage and height of the grass increased after the second winter. The coverage of Dicranum sp. and Pleurozium schreberi was lower on plots where reindeer were fed with grass silage (leftover silage not cleared) vs. controls. Some dwarf shrubs, e.g., Calluna vulgaris, showed a similar response after the second winter. The N content of Empetrum nigrum was higher on grass silage plots (leftover silage not cleared) after the first winter vs. controls. After two winters, the N content of both E. nigrum and Vaccinium myrtillus was increased. Of the soil variables studied, C/N decreased on grass silage+hay plots vs. fenced controls. We conclude that even a moderate level of feeding may cause changes that can lead to a gradual shift from nutrient-poor heath forest towards a more nutrient-rich type

    Hormander class of pseudo-differential operators on compact Lie groups and global hypoellipticity

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    In this paper we give several global characterisations of the Hormander class of pseudo-differential operators on compact Lie groups. The result is applied to give criteria for the ellipticity and the global hypoellipticity of pseudo-differential operators in terms of their matrix-valued full symbols. Several examples of the first and second order globally hypoelliptic differential operators are given. Where the global hypoelliptiticy fails, one can construct explicit examples based on the analysis of the global symbols.Comment: 20 page
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