1,099 research outputs found
The single-particle density matrix and the momentum distribution of dark "solitons" in a Tonks-Girardeau gas
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 ( and ) with respect to the dark notch at ; the
correlations oscillate rather than decay as the points and are being
separated.Comment: 9 pages, 8 figure
Summative assessment of clinical practice of student nurses : a review of the literature
Objectives: To describe assessment of nursing studentâs 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 â 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 studentsâ 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 assignmentsâ ability to describe the studentsâ 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 studentsâ 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 studentsâ 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
Cell deformation behavior in mechanically loaded rabbit articular cartilage 4Â weeks after anterior cruciate ligament transection
SummaryObjectiveChondrocyte stresses and strains in articular cartilage are known to modulate tissue mechanobiology. Cell deformation behavior in cartilage under mechanical loading is not known at the earliest stages of osteoarthritis. Thus, the aim of this study was to investigate the effect of mechanical loading on volume and morphology of chondrocytes in the superficial tissue of osteoarthritic cartilage obtained from anterior cruciate ligament transected (ACLT) rabbit knee joints, 4Â weeks after intervention.MethodsA unique custom-made microscopy indentation system with dual-photon microscope was used to apply controlled 2Â MPa force-relaxation loading on patellar cartilage surfaces. Volume and morphology of chondrocytes were analyzed before and after loading. Also global and local tissue strains were calculated. Collagen content, collagen orientation and proteoglycan content were quantified with Fourier transform infrared microspectroscopy, polarized light microscopy and digital densitometry, respectively.ResultsFollowing the mechanical loading, the volume of chondrocytes in the superficial tissue increased significantly in ACLT cartilage by 24% (95% confidence interval (CI) 17.2â31.5, PÂ <Â 0.001), while it reduced significantly in contralateral group tissue by â5.3% (95% CI â8.1 to â2.5, PÂ =Â 0.003). Collagen content in ACLT and contralateral cartilage were similar. PG content was reduced and collagen orientation angle was increased in the superficial tissue of ACLT cartilage compared to the contralateral cartilage.ConclusionsWe found the novel result that chondrocyte deformation behavior in the superficial tissue of rabbit articular cartilage is altered already at 4Â weeks after ACLT, likely because of changes in collagen fibril orientation and a reduction in PG content
The Healthy Context Paradox at a National/Country-Level: Is Victimisation associated with Worse Adjustment in Countries where the Average Level of Victimisation is Lower?
Recent research has highlighted the healthy context paradox (HCP), namely that the association between peer victimisation and psychological and social adjustment worsens in social contexts with lower average level of victimisation. Previous research has examined this phenomenon in relation to classroom- or school-level victimisation. We tested whether the HCP is applicable on a much wider scale, at national level. Besides country-level victimisation, we explored whether country-level economic inequality and social welfare protection moderate the victimisation-adjustment link. We used data from the HBSC 2013/2014 survey related to peer victimisation and five measures of health and wellbeing of 11-, 13- and 15-year-old boys and girls from 40 countries (Nâ=â198,646) in Europe and North America, complemented with information on economic inequality (Gini index, available for 33 countries) and social protection (decommodification index, available for 25 countries). We confirmed an expected within-country correlation between higher levels of victimisation and poorer health and wellbeing for each measure and across countries; however this association had significant between-country variability. For country-level victimisation, there was evidence of a significant HCP effect for the measures of peer support and life satisfaction â but not for feeling low, health, and liking school
Interfacial compatibility of polymer-based structures in electronics
Interfacial compatibility of dissimilar materials was investigated to achieve a better understanding of interfacial adhesion in metal/polymer/metal systems. Surface modifications of polymers were applied to improve the adhesion. The modified surfaces were characterised by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements accompanied by surface free energy evaluations. The pull-off test was employed to assess the interfacial adhesion strength. Further, to determine the controlling adhesion mechanism, the fracture surfaces exposed in the pull-off test were examined by microscopy. To achieve modification of certain bulk properties of one of the evaluated polymers (SU8 epoxy resin), new star-shaped oligomers were synthesised and reactively blended with it. Oligomers were characterised by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, size exclusion chromatography (SEC) and differential scanning calorimetry (DSC). Films of the blends were spin coated on a silicon wafer for characterisation of the refractive index and a novel non-destructive method was developed to measure selected thermal properties of the films. The information concerning interfacial compatibility obtained in this work is of great practical as well as theoretical importance.reviewe
CRISPR/Cas9 screening using unique molecular identifiers
Loss-of-function screening by CRISPR/Cas9 gene knockout with pooled, lentiviral guide libraries is a widely applicable method for systematic identification of genes contributing to diverse cellular phenotypes. Here, Random Sequence Labels (RSLs) are incorporated into the guide library, which act as unique molecular identifiers (UMIs) to allow massively parallel lineage tracing and lineage dropout screening. RSLs greatly improve the reproducibility of results by increasing both the precision and the accuracy of screens. They reduce the number of cells needed to reach a set statistical power, or allow a more robust screen using the same number of cells.Peer reviewe
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