285 research outputs found

    Anomalistic Disturbance Torques during the Entry Phase of the Mars Exploration Rover Missions: A Telemetry and Mars-Surface Investigation

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    Shortly after landing on Mars, post-flight analysis of the "Spirit" entry data suggested that the vehicle experienced large, anomalistic oscillations in angle-of-attack starting at about M=6. Similar analysis for "Opportunity " found even larger oscillations starting immediately after maximum dynamic pressure at M=14. Where angles-of-attack of 1-2 degrees were expected from maximum dynamic pressure to drogue deployment, the reconstructions suggested 4 to 9 degrees. The next Mars lander, 2007 Phoenix project, was concerned enough to recommend further exploration of the anomalies. Detailed analysis of "Opportunity" data found significant anomalies in the hypersonic aerodynamic torques. The analysis showed that these torques were essentially fixed in the spinning vehicle. Nearly a year after landing, the "Oportunity" rover took pictures of its aeroshell on the surface, which showed that portions of the aeroshell thermal blanket assembly still remained. This blanket assembly was supposed to burn off very early in the entry. An analysis of the aeroshell photographs led to an estimate of the aerodynamic torques that the remnants could have produced. A comparison of two estimates of the aerodynamic torque perturbations (one extracted from telemetry data and the other from Mars surface photographs) showed exceptional agreement. Trajectory simulations using a simple data derived torque perturbation model provided rigid body motions similar to that observed during the "Opportunity" entry. Therefore, the case of the anomalistic attitude behavior for the "Opportunity" EDL is now considered closed and a suggestion is put forth that a similar event occurred for the "Spirit" entry as well

    Placenta Percreta: A Report On Surviving Death From The Bleeding Disaster!

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    https://scholarlycommons.henryford.com/merf2020caserpt/1001/thumbnail.jp

    Placenta Percreta; A Report On Surviving Death From The Bleeding Disaster!

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    A 34 year old G6P5 diagnosed with placenta previa percreta (fig 1) in her 2nd trimester was reviewed by a multidisciplinary team. Baby delivery was planned at 34 weeks gestation by cesarean hysterectomy(CH) immediately preceded by bilateral ureteral stents for anticipated surgical complexity. Patient received combined spinal and epidural (not activated) for the ureteric stenting with an aim to use the epidural for post-operative analgesia followed by general anesthesia and establishment of invasive lines and monitoring prior to start of CH. Soon after baby delivery, patient became hypotensive from severe hemorrhage. Massive transfusion protocol was instituted. After completion of hysterectomy, patient continued to bleed from multiple intraabdominal sites. While surgical hemostasis remained a challenge, patient developed PEA arrest. CPR was started with return of spontaneous circulation (ROSC) after chest compression for 2 minutes and 1mg of epinephrine. Following this, abdomen was packed with a decision to close secondarily after interventional radiology (IR) assisted intervention if necessary and hemodynamic stabilization. Intraoperatively, patient received a total of 29pRBCs, 22FFP, 4platelet & 3Cryo units with 21 L of crystalloids, 3.25 L of 5% albumin and 1.8L of cell saver with an estimated blood loss of 25L. Tranexamic acid and prothrombin complex concentrate was given. Thromboelastogram (TEG) and lab based coagulation profile was used intraoperatively to guide blood component transfusion. Serial blood gas analyses guided volume and electrolyte correction. In the ICU patient improved with no neurological insult or DIC. On postop day 1 IR found no active extravasations and surgical abdominal closure was performed. Epidural catheter was used for postoperative pain control and was removed on day 4. Patient was discharged on postop day 10.https://scholarlycommons.henryford.com/merf2020caserpt/1124/thumbnail.jp

    Masculinity at work: The experiences of men in female dominated occupations

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    This paper presents the findings of a research project on the implications of men's non-traditional career choices for their experiences within the organization and for gender identity. The research is based on 40 in-depth interviews with male workers from four occupational groups: librarian-ship, cabin crew, nurses and primary school teachers. Results suggest a typology of male workers in female dominated occupations: seekers (who actively seek the career), finders (who find the occupation in the process of making general career decisions) and settlers (who settle into the career after periods of time in mainly male dominated occupations). Men benefit from their minority status through assumptions of enhanced leadership (the assumed authority effect), by being given differential treatment (the special consideration effect) and being associated with a more careerist attitude to work (the career effect). At the same time, they feel comfortable working with women (the zone of comfort effect). Despite this comfort, men adopt a variety of strategies to re-establish a masculinity that has been undermined by the 'feminine' nature of their work. These include re-labeling, status enhancement and distancing from the feminine. The dynamics of maintaining and reproducing masculinities within the non-traditional work setting are discussed in the light of recent theorising around gender, masculinity and work

    'What was your blood sugar reading this morning?': representing diabetes self-management on Facebook

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    Social networking sites have swiftly become a salient venue for the production and consumption of neoliberal health discourse by individuals and organisations. These platforms offer both opportunities for individuals to accrue coping resources and a means for organisations to promote their agendas to an online audience. Focusing specifically on diabetes, this article examines the representation of social actors and interactional styles on three organisational Pages on Facebook. Drawing on media and communication theories, we situate this linguistic analysis in relation to the communicative affordances employed by these organisations as they publish content online. Diabetes sufferers are represented as an at-risk group whose vulnerabilities can be managed through forms of participation specific to the respective organisation. More popular diabetes Pages draw on the opportunities for social interaction afforded by Facebook and combine informational and promotional content to foster communication between the organisation and its audience. By encouraging reflexive management of diabetes risks, these Pages contribute to the construction of ‘biological citizens’ who interweave habitual interactions on social networking sites with responsible self-care, consumption of health information and health activism

    Quantitative lipoprotein subclass and low molecular weight metabolite analysis in human serum and plasma by 1H NMR spectroscopy in a multilaboratory trial

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    We report an extensive 600 MHz NMR trial of a quantitative lipoprotein and small molecule measurements in human blood serum and plasma. Five centers with eleven 600 MHz NMR spectrometers were used to analyze 98 samples including: 20 QCs, 37 commercially sourced, paired serum and plasma samples and 2 National Institute of Science and Technology, NIST, reference material 1951c replicates. Samples were analyzed using rigorous protocols for sample preparation and experimental acquisition. A commercial lipoprotein subclass analysis was used to quantify 105 lipoprotein subclasses and 24 low molecular weight metabolites from the nuclear magnetic resonance, NMR, spectra. For all spectrometers, the instrument specific variance in measuring internal quality controls, QCs, was lower than the percentage described by the National Cholesterol Education Program, NCEP, criteria for lipid testing (triglycerides<2.7%, cholesterol<2.8%; LDL-cholesterol<2.8%; HDL-cholesterol<2.3%), showing exceptional reproducibility for direct quantitation of lipoproteins in both matrices. The average RSD for the 105 lipoprotein parameters in the 11 instruments was 4.6% and 3.9% for the two NIST samples while it was 38% and 40% for the 37 commercially sourced plasmas and sera, respectively, showing negligible analytical compared to biological variation. The coefficient of variance, CV, obtained for the quantification of the small molecules across the 11 spectrometers was below 15% for 20 out of the 24 metabolites analyzed. This study provides further evidence of the suitability of NMR for high-throughput lipoprotein subcomponent analysis and small molecule quantitation with the exceptional reproducibility required for clinical and other regulatory settings

    How and why are communities of practice established in the healthcare sector? A systematic review of the literature

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    Background: Communities of Practice (CoPs) are promoted in the healthcare sector as a means of generating and sharing knowledge and improving organisational performance. However CoPs vary considerably in the way they are structured and operate in the sector. If CoPs are to be cultivated to benefit healthcare organisations, there is a need to examine and understand their application to date. To this end, a systematic review of the literature on CoPs was conducted, to examine how and why CoPs have been established and whether they have been shown to improve healthcare practice. Methods. Peer-reviewed empirical research papers on CoPs in the healthcare sector were identified by searching electronic health-databases. Information on the purpose of establishing CoPs, their composition, methods by which members communicate and share information or knowledge, and research methods used to examine effectiveness was extracted and reviewed. Also examined was evidence of whether or not CoPs led to a change in healthcare practice. Results: Thirty-one primary research papers and two systematic reviews were identified and reviewed in detail. There was a trend from descriptive to evaluative research. The focus of CoPs in earlier publications was on learning and exchanging information and knowledge, whereas in more recently published research, CoPs were used more as a tool to improve clinical practice and to facilitate the implementation of evidence-based practice. Means by which members communicated with each other varied, but in none of the primary research studies was the method of communication examined in terms of the CoP achieving its objectives. Researchers are increasing their efforts to assess the effectiveness of CoPs in healthcare, however the interventions have been complex and multifaceted, making it difficult to directly attribute the change to the CoP. Conclusions: In keeping with Wenger and colleagues' description, CoPs in the healthcare sector vary in form and purpose. While researchers are increasing their efforts to examine the impact of CoPs in healthcare, cultivating CoPs to improve healthcare performance requires a greater understanding of how to establish and support CoPs to maximise their potential to improve healthcare

    Filter-based stochastic algorithm for global optimization

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    We propose the general Filter-based Stochastic Algorithm (FbSA) for the global optimization of nonconvex and nonsmooth constrained problems. Under certain conditions on the probability distributions that generate the sample points, almost sure convergence is proved. In order to optimize problems with computationally expensive black-box objective functions, we develop the FbSA-RBF algorithm based on the general FbSA and assisted by Radial Basis Function (RBF) surrogate models to approximate the objective function. At each iteration, the resulting algorithm constructs/updates a surrogate model of the objective function and generates trial points using a dynamic coordinate search strategy similar to the one used in the Dynamically Dimensioned Search method. To identify a promising best trial point, a non-dominance concept based on the values of the surrogate model and the constraint violation at the trial points is used. Theoretical results concerning the sufficient conditions for the almost surely convergence of the algorithm are presented. Preliminary numerical experiments show that the FbSA-RBF is competitive when compared with other known methods in the literature.The authors are grateful to the anonymous referees for their fruitful comments and suggestions.The first and second authors were partially supported by Brazilian Funds through CAPES andCNPq by Grants PDSE 99999.009400/2014-01 and 309303/2017-6. The research of the thirdand fourth authors were partially financed by Portuguese Funds through FCT (Fundação para CiĂȘncia e Tecnologia) within the Projects UIDB/00013/2020 and UIDP/00013/2020 of CMAT-UM and UIDB/00319/2020
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