Liquid rocket performance computer model with distributed energy release Interim final report, 15 Aug. 1969 - 15 Aug. 1970

Liquid propellant rocket engine performance computer program with distributed energy releas

Ultrasound morphology of carotid plaque and its link with lipid: protein content and 3d microstructure of the plaque.

the 22nd Meeting of the European Society of Neurosonology and Cerebral Hemodynamics (ESNCH), 19-21 May 2017. Berlin, Germany, and published in the International Journal of Stroke 12(1S): 57 (Poster 101), May 2017. ISSN: 1747-4930, eISSN: 1747-4949

Traffic Equations and Granular Convection

We investigate both numerically and analytically the convective instability of granular materials by two dimensional traffic equations. In the absence of vibrations the traffic equations assume two distinctive classes of fixed bed solutions with either a spatially uniform or nonuniform density profile. The former one exists only when the function V(\rho) that monitors the relaxation of grains assumes a cut off at the closed packed density, \rho_c, with V(\rho_c)=0, while the latter one exists for any form of V. Since there is little difference between the uniform and nonuniform solution deep inside the bed, the convective instability of the bulk may be studied by focusing on the stability of the uniform solution. In the presence of vibrations, we find that the uniform solution bifurcates into a bouncing solution, which then undergoes a supercritical bifurcation to the convective instability. We determine the onset of convection as a function of control parameters and confirm this picture by solving the traffic equations numerically, which reveals bouncing solutions, two convective rolls, and four convective rolls. Further, convective patterns change as the aspect ratio changes: in a vertically long container, the rolls move toward the surface, and in a horizontally long container, the rolls move toward the walls. We compare these results with those reported previously with a different continuum model by Hayakawa, Yue and Hong[Phys. Rev. Lett. 75,2328, 1995]. Finally, we also present a derivation of the traffic equations from Enskoq equation.Comment: 34 pages, 10 figure

Evaluating the effectiveness of agricultural adaptation to climate change in preindustrial society

The effectiveness of agricultural adaptation determines the vulnerability of this sector to climate change, particularly during the preindustrial era. However, this effectiveness has rarely been quantitatively evaluated, specifically at a large spatial and long-term scale. The present study covers this case of preindustrial society in AD 1500–1800. Given the absence of technological innovations in this time frame, agricultural production was chiefly augmented by cultivating more land (land input) and increasing labor input per land unit (labor input). Accordingly, these two methods are quantitatively examined. Statistical results show that within the study scale, land input is a more effective approach of mitigating climatic impact than labor input. Nonetheless, these observations collectively improve Boserup's theory from the perspective of a large spatial and long-term scale.postprin

Structuring specification in Z to build a unifying framework for hypertext systems

A report is given on work undertaken to produce a structured specification in Z of a model which aims to capture the essential abstractions of hypertext systems. The specification is presented in part and the potential value of this specification to the hypertext community is explored and discussed. We argue that this specification provides a framework for hypertext systems in that it provides: explicit and unambiguous definitions of hypertext terms, an explicit environment for the presentation, comparison and evaluation of hypertext systems and a foundation for future research and development in the field. Although there are many formal reference models of hypertext, we have found Z expressive enough to allow a unified account of a system and its operations. Our model does not restrict the specifier to any particular design, but provides a mathematical framework within which different models may be compared. Further, we were able to structure the specification in order that the model could be described initially at the highest level of abstract with complexity added at increasingly lower levels of abstraction. This structure

Gambling: Electronic friends or a threat to one's health and personal development?

Gambling has become quite common in Sweden. The Swedish National Institute of Public Health (2010) has reported that about 70% of the Swedish population has gambled at least once during the last 12 months. Half of the population had gambled with money by 18 years of age and about 11% had gambled for the first time when they were 12-years-old or younger. In the report from the Swedish National Institute of Public Health, gambling problems are related to health problems and risky alcohol consumption. The highest problem rate is found among men aged 18 to 24; almost 1 in 10 had some gambling problems. The share of problem gamblers is found to be twice as high among the under-age gamblers as it is among the population as a whole. Young people gamble less but develop gambling problems to a larger extent than adult gamblers. In this article young people's gambling and their gambling careers are analysed as a natural part of their internalisation of other adult habits

Supporting cancer research on real-world data: extracting colorectal cancer status and explicitly written TNM stages from free-text imaging and histopathology reports

Objectives: The ‘tumour, node, metastasis’ (TNM) classification of colorectal cancer (CRC) predicts prognosis and so is vital to consider in analyses of patterns and outcomes of care when using electronic health records. Unfortunately, it is often only available in free-text reports. This study aimed to develop regex-based text-processing algorithms that identify the reports describing CRC and extract the TNM staging at a low computational cost. Methods: The CRC and TNM extraction algorithms were iteratively developed using 58 634 imaging and pathology reports of patients with CRC from the Oxford University Hospitals (OUH) and Royal Marsden (RMH) NHS Foundation Trusts (FT), with additional input from Imperial College Healthcare and Christie NHS FTs. The algorithms were evaluated on a stratified random sample of 400 OUH development data reports and 400 newer ‘unseen’ OUH reports. The reports were annotated with the help of two clinicians. Results: The CRC algorithm achieved at least 93.0% positive predictive value (PPV), 72.1% sensitivity, 64.0% negative predictive value (NPV) and 90.1% specificity for primary CRC on pathology reports. On imaging reports, it demonstrated at least 78.0% PPV, 91.8% sensitivity, 93.0% NPV and 80.9% specificity. For the main T/N/M categories, the TNM algorithm achieved PPVs of at least 93.9% (T), 97.7% (N) and 97.2% (M), and sensitivities of 63.6% (T), 89.6% (N) and 64.8% (M). NPVs were at least 45.0% (T), 91.1% (N), 88.4% (M), and specificities 95.7% (T), 98.1% (N), 99.3% (M). Reductions in performance were mostly due to implicit staging. For extracting explicit TNM stages, current or historical, the algorithm made no errors on 400 pathology reports and six errors on 400 imaging reports. Conclusion: The TNM algorithm accurately extracts explicit TNM staging, but other methods are needed for retrieving implicit stages. The CRC algorithm is accurate on non-supplementary reports, but outputs need additional review if higher precision is required

Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar

<p>Abstract</p> <p>Background</p> <p>Strains of <it>Plasmodium falciparum </it>genetically resistant to chloroquine (CQ) due to the presence of <it>pfcrt </it>76T appear to have been recently introduced to the island of Madagascar. The prevalence of such resistant genotypes is reported to be low (< 3%) when evaluated by conventional PCR. However, these methods are insensitive to low levels of mutant parasites present in patients with polyclonal infections. Thus, the current estimates may be an under representation of the prevalence of the CQ-resistant <it>P. falciparum </it>isolates on the island. Previously, minority variant chloroquine resistant parasites were described in Malawian patients using an isotopic heteroduplex tracking assay (HTA), which can detect <it>pfcrt </it>76T-bearing <it>P. falciparum </it>minority variants in individual patients that were undetectable by conventional PCR. However, as this assay required a radiolabeled probe, it could not be used in many resource-limited settings.</p> <p>Methods</p> <p>This study describes a digoxigenin (DIG)-labeled chemiluminescent heteroduplex tracking assay (DIG-HTA) to detect <it>pfcrt </it>76T-bearing minority variant <it>P. falciparum</it>. This assay was compared to restriction fragment length polymorphism (RFLP) analysis and to the isotopic HTA for detection of genetically CQ-resistant parasites in clinical samples.</p> <p>Results</p> <p>Thirty one clinical <it>P. falciparum </it>isolates (15 primary isolates and 16 recurrent isolates) from 17 Malagasy children treated with CQ for uncomplicated malaria were genotyped for the <it>pfcrt </it>K76T mutation. Two (11.7%) of 17 patients harboured genetically CQ-resistant <it>P. falciparum </it>strains after therapy as detected by HTA. RFLP analysis failed to detect any <it>pfcrt </it>K76T-bearing isolates.</p> <p>Conclusion</p> <p>These findings indicate that genetically CQ-resistant <it>P. falciparum </it>are more common than previously thought in Madagascar even though the fitness of the minority variant <it>pfcrt </it>76T parasites remains unclear. In addition, HTAs for malaria drug resistance alleles are promising tools for the surveillance of anti-malarial resistance. The use of a non-radioactive label allows for the use of HTAs in malaria endemic countries.</p