261 research outputs found
The synthesis of monodisperse alkanes with long chains
No full textThis thesis discusses reasons for the interest in monodisperse long chain alkanes and describes attempts, past and present, to synthesise such molecules. Chapter 1 discusses why the synthesis of such molecules are important and the objectives of this project. Chapter 2 reviews the methods previous groups have devised to prepare pure samples of long chain alkanes. In particular, work carried out by Whiting et al. at Bristol, whose scheme formed the basis of the early work in Durham. Chapter 3 describes the work in Durham and improvements which were made to Whiting's method, allowing the synthesis of longer chain lengths and greater quantities of materials to be achieved. Chapter 4 provides a summary of the practical work carried out by the author. Chapter 5 gives experimental details of the work described in Chapter 4
What the Law Cannot Do: Samuel DeWitt Proctor\u27s Theological Response to An American Crisis, 1945-1997
No full textSamuel De Witt Proctor (1921-1997) accomplished many things in his life. He was an educator, administrator, ordained Baptist pastor, and author. He was educated at Virginia State University and Virginia Union University, the University of Pennsylvania, Crozer Theological Seminary, Yale University, and Boston University School of Theology. He served in different government capacities during the Kennedy and Johnson administrations, including stints as an associate director of the Peace Corps and Office of Economic Opportunity. His academic career included presidential posts at Virginia Union University and North Carolina A and T State University, teaching duties at Rutgers University, and lectures at various colleges and seminaries following his retirement. He also served churches in Providence, Rhode Island and Harlem, New York (successor to Adam Clayton Powell Jr. at the prominent Abyssinian Baptist Church). Proctor\u27s public ministry spanned six decades..
Tracking progress towards malaria elimination in China: estimates of reproduction numbers and their spatiotemporal variation
No full textChina reported zero locally-acquired malaria cases in 2017 and 2018. Understanding the spatio-temporal pattern underlying this decline, especially the relationship between locally-acquired and imported cases, can inform efforts to maintain elimination and prevent re-emergence. This is particularly pertinent in Yunnan province, where the potential for local transmission is highest. Using a geo-located individual-level dataset of cases recorded in Yunnan province between 2011 and 2016, we jointly estimate the case reproduction number, Rc, and the number of unobserved sources of infection. We use these estimates within spatio-temporal geostatistical models to map how transmission varied over time and space, estimate the timeline to elimination and the risk of resurgence. Our estimates suggest that, maintaining current intervention efforts, Yunnan is unlikely to experience sustained local transmission up to 2020. However, even with a mean Rc of 0.005 projected for the year 2019, locally-acquired cases are possible due to high levels of importation
Effects of fir-wood biochar on CH4 oxidation rates and methanotrophs in landfill cover soils packed at three different proctor compaction levels
No full textApplication of biochar to landfill cover soils can purportedly improve methane (CH4) oxidation rates, but understanding the combined effects of soil texture, compaction, and biochar on the activity and composition of the methanotrophs is limited. The amendment of wood biochar on two differently textured landfill cover soils at three compaction levels of the Proctor density was explored by analyzing changes in soil physical properties relevant to methane oxidation, the effects on CH4 oxidation rates, and the composition of the methanotrophic community. Loose soils with and without biochar were pre-incubated to equally elevate the CH4 oxidation rates. Hereafter, soils were compacted and re-incubated. Methane oxidation rates, gas diffusivity, water retention characteristics, and pore size distribution were analyzed on the compacted soils. The relative abundance of methanotrophic bacteria (MOB) was determined at the end of both the pre-incubation and incubation tests of the packed samples. Biochar significantly increased porosity at all compaction levels, enhancing diffusion coefficients. Also, a re-distribution in pore sizes was observed. Increased gas diffusivity from low compaction and amendment of biochar, though, did not reflect higher methane oxidation rates due to high diffusive oxygen fluxes over the limited height of the compacted soil specimens. All soils, with and without biochar, were strongly dominated by Type II methanotrophs. In the sandy soil, biochar amendment strongly increased MOB abundance, which could be attributed to a corresponding increase in the relative abundance of Methylocystis species, while no such response was observed in the clayey soil. Compaction did not change the community composition in either soil. Fir-wood biochar addition to landfill cover soils may not always enhance methanotrophic activity and hence reduce fugitive methane emissions, with the effect being soil-specific. However, especially in finer and more compacted soils, biochar amendment can maintain soil diffusivity above a critical level, preventing the collapse of methanotrophy.Geo-engineeringLarge Scale Energy StoragePattern Recognition and Bioinformatic
Adapting equation-free modeling techniques for modern infectious disease data
No full textNon UBCUnreviewedAuthor affiliation: Institute for Disease ModelingOthe
Nealloptes Gaud and Mouchet
No full textGenus Nealloptes Gaud and Mouchet Nealloptes petazophorus (Trouessart, 1886) Hosts and distribution. This species was described ex Aramus guarauna (L.) (Gruiformes: Aramidae) from “ Nouvelle-Grenade ” (Trouessart 1886). However, this species was repeatedly found on Threskiornis aethiopicus (Latham) (Pelecaniformes: Threskiornithidae) from Cameroon (M'balmayo) and Congo (Gaud & Mouchet 1957; Gaud 1982) and the latter author unambiguously said that the record from A. guarauna was the result of contamination. Remark. “ Nouvelle-Grenade ” is one of the old names used for the territory of Colombia, Panama and parts of Nicaragua, Venezuela, Ecuador, Peru, and Brazil.Published as part of Barreto, Mauricio, Burbano, María E., Proctor, Heather C., Mironov, Serge V. & Wauthy, Georges, 2012, Feather mites (Acariformes: Psoroptidia) from Colombia: Preliminary list with new records 3516, pp. 1-68 in Zootaxa 3516 on page 1
Tracking progress towards malaria elimination in China: Individual-level estimates of transmission and its spatiotemporal variation using a diffusion network approach
No full textIn order to monitor progress towards malaria elimination, it is crucial to be able to measure changes in spatio-temporal transmission. However, common metrics of malaria transmission such as parasite prevalence are under powered in elimination contexts. China has achieved major reductions in malaria incidence and is on track to eliminate, having reporting zero locally-acquired malaria cases in 2017 and 2018. Understanding the spatio-temporal pattern underlying this decline, especially the relationship between locally-acquired and imported cases, can inform efforts to maintain elimination and prevent re-emergence. This is particularly pertinent in Yunnan province, where the potential for local transmission is highest. Using a geo-located individual-level dataset of cases recorded in Yunnan province between 2011 and 2016, we introduce a novel Bayesian framework to model a latent diffusion process and estimate the joint likelihood of transmission between cases and the number of cases with unobserved sources of infection. This is used to estimate the case reproduction number, Rc. We use these estimates within spatio-temporal geostatistical models to map how transmission varied over time and space, estimate the timeline to elimination and the risk of resurgence. We estimate the mean Rc between 2011 and 2016 to be 0.171 (95% CI = 0.165, 0.178) for P. vivax cases and 0.089 (95% CI = 0.076, 0.103) for P. falciparum cases. From 2014 onwards, no cases were estimated to have a Rc value above one. An unobserved source of infection was estimated to be moderately likely (p>0.5) for 19/ 611 cases and high (p>0.8) for 2 cases, suggesting very high levels of case ascertainment. Our estimates suggest that, maintaining current intervention efforts, Yunnan is unlikely to experience sustained local transmission up to 2020. However, even with a mean of 0.005 projected up to 2020, locally-acquired cases are possible due to high levels of importation.</div
Agnotology
No full textRobert Proctor e Ian Bolin acuñaron el término agnotología para designar el estudio de la ignorancia. Este escrito propone superar la visión de la ignorancia como un vacío que puede ser llenado por el conocimiento e invita a pensar en las formas en que hoy se produce, en forma premeditada y estructural: por negligencia, miopía, secreto o supresión. El autor muestra que la creación deliberada de la ignorancia es una estrategia para engañar y sembrar dudas sobre los hechos observados y sobre el conocimiento científico, tomando como ejemplos el papel de los secretos comerciales, la actividad de las tabacaleras para negar la relación causal entre el consumo de cigarrillos y el cáncer y el papel del secreto militar. Por último analiza algunos casos en que la ignorancia es una expresión de valores morales, como la prohibición, en algunas universidades, de investigaciones cuyo único fin es el afán de lucro y, en algunas revistas científicas, de publicar trabajos financiados por ciertas fuentes, así como el rechazo de ciertas tecnologías por razones intelectuales y morales bien fundadas.Robert Proctor and Ian Bolin coined the term agnotology to designate the study of ignorance. This paper proposes to overcome the vision of ignorance as a void that can be filled by knowledge and invites us to think about the ways in which it is produced today, in a premeditated and structural way: through negligence, myopia, secrecy or suppression. The author shows that the deliberate creation of ignorance is a strategy to compromise and sow doubts about the observed facts and about scientific knowledge, taking as examples the role of trade secrets, the activity of tobacco companies to deny the causal relationship between the cigarette smoking and cancer and the role of military secret. Finally, some cases in ignorance is an expression of moral values, such as the prohibition, in some universities, of research whose sole purpose is the profit motive and, in some scientific journals, of publishing works financed by certain sources, as well as the rejection of certain technologies for well-founded intellectual and moral reasons
Numerical simulations of rotating axisymmetric sunspots
No full textA numerical model of axisymmetric convection in the presence of a vertical magnetic flux bundle and rotation about the axis is presented. The model contains a compressible plasma described by the non-linear MHD equations, with density and temperature gradients simulating the upper layer of the Sun's convection zone. The solutions exhibit a central magnetic flux tube in a cylindrical numerical domain, with convection cells forming collar flows around the tube. When the numerical domain is rotated with a constant angular velocity, the plasma forms a Rankine vortex, with the plasma rotating as a rigid body where the magnetic field is strong, as in the flux tube, while experiencing sheared azimuthal flow in the surrounding convection cells, forming a free vortex. As a result, the azimuthal velocity component has its maximum value close to the outer edge of the flux tube. The azimuthal flow inside the magnetic flux tube and the vortex flow is prograde relative to the rotating cylindrical reference frame. A retrograde flow appears at the outer wall. The most significant convection cell outside the flux tube is the location for the maximum value of the azimuthal magnetic field component. The azimuthal flow and magnetic structure are not generated spontaneously, but decay exponentially in the absence of any imposed rotation of the cylindrical domain
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