Comparison between the lattice dynamics and molecular dynamics methods: Calculation results for MgSiO3 perovskite

The lattice dynamics (LD) and molecular dynamics (MD) methods have been used to calculate the structure, bulk modulus, and volume thermal expansivity of MgSiO3 perovskite, in order to investigate the reliability of the two simulation techniques over a wide range of temperature and pressure conditions. At an intermediate temperature of 500 K and zero pressure, the LD and MD values are in exellent agreement for both the structure and bulk modulus of MgSiO3 perovskite. At high temperatures and zero pressure, however, the LD method, which is based on the quasi-harmonic approximation, increasingly overestimates the molar volume of MgSiO3 perovskite because of the neglect of higher-order anharmonic terms. At the high temperatures and high pressures prevailing in the lower mantle, the errors in the LD values for both the molar volume and bulk modulus, relative to the MD values, are generally small or negligible. However, since anharmonicity decreases substantially with pressure but increases rapidly with temperature, the error in the LD simulated volume thermal expansivity is serious, especially in the lower pressure region

Transit Light Curves with Finite Integration Time: Fisher Information Analysis

Kepler has revolutionized the study of transiting planets with its unprecedented photometric precision on more than 150,000 target stars. Most of the transiting planet candidates detected by Kepler have been observed as long-cadence targets with 30 minute integration times, and the upcoming Transiting Exoplanet Survey Satellite (TESS) will record full frame images with a similar integration time. Integrations of 30 minutes affect the transit shape, particularly for small planets and in cases of low signal-to-noise. Using the Fisher information matrix technique, we derive analytic approximations for the variances and covariances on the transit parameters obtained from fitting light curve photometry collected with a finite integration time. We find that binning the light curve can significantly increase the uncertainties and covariances on the inferred parameters when comparing scenarios with constant total signal-to-noise (constant total integration time in the absence of read noise). Uncertainties on the transit ingress/egress time increase by a factor of 34 for Earth-size planets and 3.4 for Jupiter-size planets around Sun-like stars for integration times of 30 minutes compared to instantaneously-sampled light curves. Similarly, uncertainties on the mid-transit time for Earth and Jupiter-size planets increase by factors of 3.9 and 1.4. Uncertainties on the transit depth are largely unaffected by finite integration times. While correlations among the transit depth, ingress duration, and transit duration all increase in magnitude with longer integration times, the mid-transit time remains uncorrelated with the other parameters. We provide code in Python and Mathematica for predicting the variances and covariances at www.its.caltech.edu/~eprice

Spiritual intelligence as a method to improve spiritual care in nursing students

Spiritual care poorly addressed within nurse education (Cone & Giske 2018) but is important for person-centred practice (McCance & McCormack 2017). This study used a phenomenological approach (Van Manen 2014) to explore the experiences of nursing students that transformed their understanding of spiritual care. Ten students were interviewed and analysis used portraiture to paint a picture of each participant (Lawrence-Lightfoot 1997). Interpretation used phenomenological existential themes. Results highlighted that students needed components of spiritual intelligence to develop understanding of spiritual care and develop the virtues needed to achieve this. A Spiritual Intelligence in Nurse Education framework is proposed. Background 200 words (1400 characters) international relevance Student nurses find the topic of spiritual care challenging and they feel unprepared to deal with issues (Cone & Giske 2018). The societal context of religious affiliation is changing across the globe and some countries are becoming more secular. Secularisation has led to religious belief being privatised (Paley 2009), meaning that faith beliefs are discouraged in public life (Neagoe 2013). A more secular approach to nursing is evident in the United Kingdom as the Nursing and Midwifery Council Code (NMC 2015) actively discourages expression of personal beliefs. However, person-centred care is promoted (McCance & McCormack 2017) including spiritual care. This can lead to challenges for nurse educators about addressing spiritual care in an effective and sensitive manner. A meta-narrative literature review was undertaken to outline current knowledge of the topic area when commencing this research study. This produced papers from an international context and four key themes were developed: integrating spiritual care into the curriculum, self-awareness around spiritual issues, spiritual care as part of holistic care, and competency in spiritual care. Aims (200 words) The aim of this research study was to Explore undergraduate nursing students’ lived experiences that develop their understanding of spiritual care. The study focused on a number of areas including how students described terms such as spirituality and religiosity, experiences that had informed their understanding of spiritual care and factors that had helped or hindered their learning. Research methodology, methods, analysis, ethics (200 words) An interpretative phenomenological approach, based on Van Manen’s work (2014) has been utilised for this study. This methodology was chosen to explore experiences and Van Manen (2014) has a pragmatic focus to provide insights that are useful in a variety of nurse educational contexts. Data was collected using a semi-structured interview strategy which were recorded and transcribed. Ethical approval was agreed through Canterbury Christ Church University Ethics Committee Reference 16/FHW/16 003. Data was collected between September 2016 and May 2017; all university confidentiality procedures were adhered too. Analysis involved descriptive and interpretative phases. The conversations were described using portraiture (Lawrence-Lightfoot 1997) and interpreted using lifeworld phenomenological existential themes (Van Manan 2014) of lived body (corporality), lived time (temporality), lived space (spatiality), lived relations (relationality), materiality (lived things) and Technology (lived cyborg relations). Data from participants, literature and theory was used to produce a creative writing of the phenomenological insights to offer a different perspective into the topic area explored. Key findings, recommendations (200 words) A purposeful sample of ten undergraduate nursing students took part in the study. The findings showed that there were significant similarities with current literature as presented in the meta-narrative literature review. New insights from this study was the need to develop student nurses’ spiritual intelligence as a way to combine the cognitive, emotional and spiritual aspects (Zohar & Marshall 2000) when providing spiritual care. This included using a variety of teaching and learning strategies that enable student nurses to construct learning and deal with the complexity of spiritual care. A Spiritual Intelligence in Nurse Education Framework is proposed and discussed as a method to educate student nurses about the topic. The framework includes elements of meaning & purpose, transcendence, goals & decision making, and character, which builds on Emmons (1999) work, as key in developing understanding about spiritual care. Spiritual intelligence is poorly addressed in nursing literature with limited evidence available; such as Karimi-Moonaghi (2015) looking at clinical competency of nurses in Iran and Kaur et al (2015) relating spiritual intelligence to caring behaviours. This study suggests that spiritual intelligence may build the student nurses’ personal and professional values so may have implications for character and virtue development. Key points for knowledge development of selected theme (humanising education) (100 words) This paper discusses a spiritual intelligence in nurse education framework as a way to enhance personal and professional character to provide person centred care. Spiritual intelligence may be used to develop character virtues, such as courage, that are important in nursing practice. This spiritual intelligence in nursing education framework could be used as a scaffold to ensure a variety of teaching and learning strategies are used to enhance the attributes of nursing character and enable effective spiritual care delivery

Using phenomenology to explore student nurses experiences of spiritual care

Background Spiritual care is viewed as integral to holistic nursing practice but studies suggest that most nurses feel unprepared to deal with spiritual needs (Cooper et al 2013). Initial findings of this phenomenological study, where student nurses discuss their experiences of spiritual care, will be outlined in this presentation including exemplars that are relevant to critical care practice. Aim The presentation will discuss phenomenology as a methodological approach and initial findings around student nurses experiences that have transformed their understanding of spiritual care. Methodology Phenomenology (Van Manen 2014) was chosen for this study as it draws of the lived experience of participants to develop an understanding of the phenomena being explored. This approach fits with the research aim to understand aspects that transform students understanding of spiritual care. Students volunteered to participate in the study and were interviewed using a semi structured schedule to allow exploration of their experiences. Ethical approval was gained before starting data collection. Analysis The use of interpretative analysis will be discussed considering the benefits and limitations when used in phenomenological research (Todres & Holloway 2010). Exemplars from the study will be used to identify key issues around learning about spiritual care. Potential implications for critical care practice will be outlined. Results Phenomenological methods produced some rich descriptions exploring spiritual care. Currently, students are talking about practice based experiences as the main medium that changes their understanding of spiritual care. Students are influenced by good staff role models and individualised patient care. The trustworthiness of phenomenology as an approach will be discussed. Summary This presentation should enable delegates to consider the use of phenomenology as a research approach, particularly related to spiritual care practices. References Cooper, K.L.; Chang, E.; Sheehan, A.; Johnson, A. (2013) ‘The impact of spiritual care education upon preparing undergraduate nursing students to provide spiritual care’. Nurse Education Today. 33. 1057-1061 Todres, L. & Holloway, I. (2010) ‘Phenomenological Research’. In: Gerrish, K. & Lacey, A. (Eds) The Research Process in Nursing. 6th edition. Chichester: John Wiley & Sons. pp 177-187 Van Manen, M. (2014) Phenomenology of Practice. USA: Left Coast Press

On the detection of nearly optimal solutions in the context of single-objective space mission design problems

When making decisions, having multiple options available for a possible realization of the same project can be advantageous. One way to increase the number of interesting choices is to consider, in addition to the optimal solution x*, also nearly optimal or approximate solutions; these alternative solutions differ from x* and can be in different regions – in the design space – but fulfil certain proximity to its function value f(x*). The scope of this article is the efficient computation and discretization of the set E of e–approximate solutions for scalar optimization problems. To accomplish this task, two strategies to archive and update the data of the search procedure will be suggested and investigated. To make emphasis on data storage efficiency, a way to manage significant and insignificant parameters is also presented. Further on, differential evolution will be used together with the new archivers for the computation of E. Finally, the behaviour of the archiver, as well as the efficiency of the resulting search procedure, will be demonstrated on some academic functions as well as on three models related to space mission design

The responses of small and large firms to tight credit shocks : the case of 2008 through the lens of Gertler and Gilchrist (1994)

Do large firms and small firms behave differently when credit becomes more costly or harder to obtain? Past research has found that small firms are more likely to be credit-constrained and thus tend to be affected more negatively than large firms during such times. Recent findings from the 2007-2009 recession, however, raise questions about the roles of small and large firms during periods of tight creditBusiness cycles ; Recessions

Black hole collisions from Brill-Lindquist initial data: predictions of perturbation theory

The Misner initial value solution for two momentarily stationary black holes has been the focus of much numerical study. We report here analytic results for an astrophysically similar initial solution, that of Brill and Lindquist (BL). Results are given from perturbation theory for initially close holes and are compared with available numerical results. A comparison is made of the radiation generated from the BL and the Misner initial values, and the physical meaning is discussed.Comment: 11 pages, revtex3.0, 5 figure