6,324 research outputs found

    Application of CFD to sonic boom near and mid flow-field prediction

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    A 3-D parabolized Navier-Stokes (PNS) code was used to calculate the supersonic overpressures from three different geometries at near- and mid-flow fields. Wind tunnel data is used for code validation. Comparison of the computed results with different grid refinements is shown. It is observed that a large number of grid points is needed to resolve the tail shock/expansion fan interaction. Therefore, an adaptive grid approach is employed to calculate the flow field. The agreement between the numerical results and the wind tunnel data confirms that computational fluid dynamics can be applied to the problem of sonic boom prediction

    Cenozoic evolution of the eastern Black Sea: a test of depth-dependent stretching models

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    Subsidence analysis of the eastern Black Sea basin suggests that the stratigraphy of this deep, extensional basin can be explained by a predominantly pure-shear stretching history. A strain-rate inversion method that assumes pure-shear extension obtains good fits between observed and predicted stratigraphy. A relatively pure-shear strain distribution is also obtained when a strain-rate inversion algorithm is applied that allows extension to vary with depth without assuming its existence or form. The timing of opening of the eastern Black Sea, which occupied a back-arc position during the closure of the Tethys Ocean, has also been a subject of intense debate; competing theories called for basin opening during the Jurassic, Cretaceous or Paleocene/Eocene. Our work suggests that extension likely continued into the early Cenozoic, in agreement with stratigraphic relationships onshore and with estimates for the timing of arc magmatism. Further basin deepening also appears to have occurred in the last 20 myr. This anomalous subsidence event is focused in the northern part of the basin and reaches its peak at 15–10 Ma. We suggest that this comparatively localized shortening is associated with the northward movement of the Arabian plate. We also explore the effects of paleowater depth and elastic thickness on the results. These parameters are controversial, particularly for deep-water basins and margins, but their estimation is a necessary step in any analysis of the tectonic subsidence record stored in stratigraphy. <br/

    How Traits of Emotional Intelligence Affect Perceived Stress in Entry-Level Doctor of Occupational Therapy Students

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    Purpose: Students in an entry-level Doctor of Occupational Therapy (OTD) programs are subject to high levels of stress and emotional burnout. Effective management of stress impacts life satisfaction and academic performance. Emotional intelligence (EI) has been shown to relate to lower stress levels in allied health students. Despite this, little has been done to investigate the emotional demands of an occupational therapy education. Methods: Participants were a convenience sample of 51 entry-level Doctor of Occupational Therapy Students recruited from the Southwest and Midwest cohorts of an OTD program. The participants were surveyed approximately 30 days after beginning their semester curriculum. Participants included 43 females and 8 males (n=51) with an age range of 21-36 years old. The sample was composed of 18 first-year (OT1) students, 17 second-year (OT2), and 16 third-year (OT3) students. A cross-sectional survey design was used, and the Assessing Emotions Scale and the Perceived Stress Scale questionnaires were both used to gather self-reported data regarding emotional intelligence and perceived stress. Emotional intelligence was correlated with perceived stress scores using the Spearman Rho analysis on SPSS program 25. Additionally, Kruskal Wallis analysis was used to determine if PSS and EI scores were significantly related to the year in the program. Mann Whitney U analysis was used to determine if PSS and EI scores were significantly related to gender. Results: A significant moderate negative correlation was found in this sample between emotional intelligence and perceived stress (rs= -0.391 with p= 0.005). There were no other significant relationships between variables. Conclusion: These findings have applications for developing educational programming and curriculum that may help equip Doctor of Occupational Therapy Students with the skills they need to thrive in their future profession. Additionally, opportunities exist for OTD students to increase EI and improve stress management levels and improve overall wellness

    Phosphorylation of androgen receptors at serine 515 is a potential prognostic marker for triple negative breast cancer

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    1.7 million cases of breast cancer are diagnosed every year with 522,000 deaths. Molecular classifications of breast cancer have resulted in improved treatments. However, treatments for triple negative breast cancer (TNBC) are lacking. Analysis of molecular targets for TNBC is a priority. One potential candidate is androgen receptor (AR) phosphorylation. This study assessed the role of AR phosphorylation at ser81/ser515 and their two upstream effectors, cyclin-dependent kinase 1 (pCDK1) and extracellular-regulated kinase 1/2 (pERK1/2) in 332 ductal breast cancer patients by immunohistochemistry. pERK1/2 combined with AR-515 associated with improved cancer-specific survival (CSS, p = 0.038), decreased size (p = 0.001), invasive grade (p &lt; 0.001), necrosis (p = 0.003), b-lymphocytes (p = 0.020), molecular subtype (p &lt; 0.001) and estrogen receptor (ER)/progesterone receptor (PR)-status (p &lt; 0.001). The cohort was therefore stratified into ER+ve and ER-ve patients. In ER+ve tumours, pERK1/2 combined with AR-515 associated with improved CSS (p = 0.038), smaller size (p = 0.004), invasive grade (p = 0.001), decreased b-lymphocytes (p = 0.013) and increased plasma cells (p = 0.048). In contrast, in TNBC patients, phosphorylation of AR-515 associated with poorer CSS (p = 0.007). pERK1/2 combined with AR-515 associated with decreased inflammation (p = 0.003), increased tumour stroma (p = 0.003) and tumour budding (p = 0.011), with trends towards decrease CSS (p = 0.065) and macrophage levels (p = 0.093). In Conclusions, AR-515 may be an important regulator of inflammation in breast cancer potential via ERK1/2 phosphorylation. AR-515 is a potential prognostic marker and therapeutic target for TNBC

    Determinants of breastfeeding initiation among mothers in Kuwait

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    <p>Abstract</p> <p>Background</p> <p>Exclusive breastfeeding is recommended as the optimal way to feed infants for the first six months of life. While overall breastfeeding rates are high, exclusive breastfeeding is relatively uncommon among Middle Eastern women. The objective of this study was to identify the incidence of breastfeeding amongst women in the six governorates of Kuwait and the factors associated with the initiation of breastfeeding.</p> <p>Methods</p> <p>A sample of 373 women (aged 17-47 years), recruited shortly after delivery from four hospitals in Kuwait, completed a structured, interviewer-administered questionnaire. Multivariate logistic regression analysis was used to identify those factors independently associated with the initiation of breastfeeding.</p> <p>Results</p> <p>In total, 92.5% of mothers initiated breastfeeding and at discharge from hospital the majority of mothers were partially breastfeeding (55%), with only 30% of mothers fully breastfeeding. Prelacteal feeding was the norm (81.8%) and less than 1 in 5 infants (18.2%) received colostrum as their first feed. Only 10.5% of infants had been exclusively breastfed since birth, the remainder of the breastfed infants having received either prelacteal or supplementary infant formula feeds at some time during their hospital stay. Of the mothers who attempted to breastfeed, the majority of women (55.4%) delayed their first attempt to breastfeed until 24 hours or more after delivery. Breastfeeding at discharge from hospital was positively associated with paternal support for breastfeeding and negatively associated with delivery by caesarean section and with the infant having spent time in the Special Care Nursery.</p> <p>Conclusions</p> <p>The reasons for the high use of prelacteal and supplementary formula feeding warrant investigation. Hospital policies and staff training are needed to promote the early initiation of breastfeeding and to discourage the unnecessary use of infant formula in hospital, in order to support the establishment of exclusive breastfeeding by mothers in Kuwait.</p
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