70 research outputs found
Delineation and physical separation of novel translocation breakpoints on chromosome 1p in two genetically closely associated childhood tumors
No full textSporadic childhood tumors associated with Beckwith-Wiedemann syndrome (BWS) all show abnormalities of the same region on chromosome 11. In addition to chromosome 11, other chromosome regions are affected in some of these tumor types. In this study we analyzed the region on chromosome 1p involved in the etiology of BWS-associated tumors, Wilms tumor, rhabdomyosarcoma, and hepatoblastoma. For this purpose we determined the location of two novel translocation breakpoints in this chromosome region in cells from a Wilms tumor and cells from a rhabdomyosarcoma. We constructed a map of the region and found that both breakpoints are separated by at least 875 kb. We identified a PAC clone which crosses the rhabdomyosarcoma breakpoint and found several exons within this clone. We established that this breakpoint is located proximal to the PAX7 gene and, therefore, identified a new region involved in the etiology of rhabdomyosarcoma
Numerical modelling of shallow jet flows: A case study of Waterdunen
No full textShallow jet flows are often coupled to high flow velocities and complex flow patterns. To properly ensure the stability of the barrier between both water bodies surrounding the jet, a scour analysis is often a necessity. Such analyses are inevitably coupled to the hydrodynamic processes occurring in jet flows, either in the form of loads on potential bed protections or equilibrium scour hole depths. Numerical models could assist in the design of bed protections by supplying accurate hydrodynamic input parameters for the design formulae or by predicting the hydrodynamic processes at play. Due to the limited computational power available, simplifications must be made within the numerical model to ensure reasonable computational costs. One of these simplifications is to resolve the flow in depth-averaged sense to create a 2DH model. To allow this simplification to be made, the performance of a 2DH model compared to a fully 3D model needs to be researched. By comparing simulations of a controlled environment and of a prototype scenario, insight in the predictive capabilities of the numerical models for possible other projects can be gained. This work aims to research the performance of 2DH and 3D numerical models regarding the reproduction of the hydrodynamic processes in shallow jets. First, it was investigated which hydrodynamic processes thrive at a prototype shallow jet by analysing measurement data available at Waterdunen. Afterwards, we systematically determine the performance of both a 2DH and 3D numerical model by setting up FINEL models both for a laboratory experiment of a shallow jet and for the shallow jet at Waterdunen. Insight in the predictive capabilities of 2DH and 3D numerical models for shallow jets can contribute to future design problems surrounding shallow jets. Information regarding the shallow jet at the seaside of the culvert at Waterdunen was obtained by Svasek Hydraulics, commissioned by the public government Waterschap Scheldestromen and the province of Zeeland, during a measurement campaign split into six individual measurement scenarios. Immediately at outflow from the culvert, the jet is subject to a 1:6 slope in streamwise direction. The geometry of the seaside channel is asymmetric, with 1:4 lateral slopes at either side of the channel. Furthermore, morphological changes as a result of the jet flow introduce an asymmetric topography in the channel. Visual observations during the measurement campaign indicated the flow can be characterized by an horizontal contraction over the longitudinal slope and an asymmetric flow profile depending on which casings were active within the culvert. The analysis of the measurement data shows the jet concentrates on the eastern side of the channel during all six scenarios. As a result, the recirculation zones on either side of the jet can be characterized as a small, non-dominant recirculation zone on the east side of the jet and a large, dominant recirculation zone on the west side of the jet. The streamlines show a continuous horizontal contraction until the flow hits the eastern side of the channel. Over the longitudinal slope, the flow seems to remain attached to the bottom rather than separating. However, due to a relatively large clearance of the ADCP measurements with respect to the bottom, this cannot be proven directly. It was decided to simulate the shallow jet of experiment 2.4.1 of van de Zande (2018) to investigate the performance of a 2DH and 3D numerical model for a laboratory simulation. In this experiment, the behaviour of an asymmetric shallow jet over a longitudinal slope at the point of the horizontal expansion was investigated. It was shown that both the 2DH and 3D numerical model were capable of reproducing the most dominant hydrodynamic processes within the jet. However, the accuracy with which the processes were reproduced differed significantly. The 2DH model reproduced too much curvature of the flow towards the lower wall of the flume compared to both the 3D model and the measurement data. As a result, the high flow velocities in the jet center were located further down in the channel. The flow velocities in the jet center were modelled with a maximum error of 12.4% in the 2DH model and 3.02% in the 3D model. The lower accuracy of the 2DH model is caused by the comparison between depth-averaged velocities and surface PIV velocities. Due to the additional curvature the recirculating velocities in the non-dominant recirculation zone were modelled too high by the 2DH model, with an error of up to 56.6% relative to the jet center velocity. In the 3D model, this error decreased to 18.9%. However, it was remarked the recirculating flow velocities in the PIV data were subject to clumping of tracer particles. The horizontal streamline contraction was simulated in the 2DH model, but can only be directly related to the changes in water depth. In both the 3D model and the measurements, this horizontal streamline contraction was shown to continue further downstream of the slope. It was concluded the horizontal streamline contraction is directly related to the vertical velocity profile, which was observed to differ from the standard log-profile both on the slope and downstream thereof. The 3D model was capable of reproducing the vertical velocity profile with a maximum relative error of 10%. In the numerical simulations at Waterdunen, both the 2DH and 3D models were shown to behave similarly. Both the 2DH and 3D numerical models were capable of reproducing the eastern concentration of the flow. However, the curvature of the jet further downstream was modelled more accurate in the 3D model. The better reproduction of the flow curvature in the 2DH model compared to the laboratory simulations is the result of the asymmetric inflow boundary, which allows the 2DH model to more easily resolve the flow curvature. Both models underestimate the flow velocities throughout the entire DOI. It was concluded this was caused by errors in the model input. Similar to the laboratory simulations, the 2DH model reproduced the horizontal streamline contraction over the slope but failed to reproduce the contraction further downstream. The 3D model was capable of reproducing the continuing streamline contraction. Furthermore, the 3D model reproduced vertical flow attachment over the slope, which complies well with the measurement data. It was concluded that a 3D numerical model can better reproduce the flow curvature in case of asymmetrical flows. Furthermore, the recirculating flow is better reproduced by a 3D model compared to a 2DH model. Finally, a 3D model is capable of accurately reproducing the vertical velocity profile, which supplies additional information of accurate flow velocities at the bed. However, on a prototype scale the differences between a 2DH and 3D numerical model are small. In channels with symmetrical boundaries, it is suggested to use a 3D numerical model in case the flow is subject to the Coanda-like effect. However, if the inflow into the channel is already asymmetrical, a 2DH numerical model can be considered to save computational effort. Nevertheless, when employing a 2DH model one should be wary of geometric and topographic asymmetries, as the effect of both factors on the flow symmetry is still unclear.Civil Engineering | Hydraulic Engineerin
De Jacobo minore, justo, apostolo; ejusque Epistola canonica, disputatio. Quam annuente ampliss. fac. phil. Praeside viro maxime reverendo atque celeberrimo, dn. mag. Gregorio Steenman, l. l. or. prof. reg. & ord. Modeste examinandam sistit Jacobus Sievonius, Nylandus. Die. XVII. Junii a:o MDCCXLV, hor. p. m. solitis. In Academiae Auraicae auditorio maximo.
No full textInvokaatio: I.N.J.Dedikaatio: Carolus Klick, Carl Hising, Johan Wilh. Hising, Andreas Lanaeus, Gabriel Kepplerus, Jacobus Sirelius, Henricus Johannes Kreij, Abrah. Finnonius, Jacobus Sievonius vanh.Painovuosi nimekkeestä.Arkit: 3 arkintunnuksetonta lehteä, A-B4.Toinen dedikaatio on saksankielinen
Analysis logica de pane epiusío [kreikkaa] Matth. VI. v. 11: quam indulgente ampliss. senat. philos. in inclyto ad Auram Athenaeo, sub patrocinio m. Joh. Haartman, philos. theor. jam def. th. prof. reg. & ord. Publicae bonorum censurae, qua par est modestia, submittit, S:ae R:ae: M:tis alumnus Andreas Lizelius Satacundia Fenno. Die D. v. 28. Martii MDCCXXXV. L. h. solitis
No full textInvocatio: [hepreaa].Dedicatio: Greg. Steenman, Nicolaus Idman, Johannes Hornborg, Israel Peldan, Johannes Carpelius, Henricus Eek, Esaias Wechter, Justus Nicol. Schultz.Grat.: Nicolaus Idman, H. J. Carpelius [ruots. runo], Daniel Idman [ruots. runo].Arkit: 2 arkintunnuksetonta lehteä, A8 B2.Painovuosi nimekkeestä
Long-distance Diesel 'Buses on the European Continent
No full text In this paper the author deals with the special requirements for Diesel 'buses used for long-distance travel on the European continent. These 'buses travel over flat and mountainous countries, covering distances of between 300–400 miles per day at a regular speed of 50–60 m.p.h., while between 70 and 75 m.p.h. must be maintained on German Reichs-Autobahnen. As they are regularly operated in the Alps they must have a high continuous output when working on long and steep gradients. The 'bus must be capable of climbing a gradient of approximately 20 per cent (1 in 5), and this necessitates a heavier transmission than is required in normal use. It is also essential that gear changing can be easily carried out. With steep gradients the normal braking system is not capable of doing all the work and it is therefore necessary to fit a special exhaust brake to the engine; details of this brake and the results obtained by fitting it are given. The influence of a throttle valve in the air intake is discussed. Light steering and a small turning circle are important when descending steep gradients, and the high front axle load of approximately 5,000 kg. when descending necessitates special springs and tyres. </jats:p
Liver: Hepatoblastoma
No full textReview on Liver: Hepatoblastoma, with data on clinics, and the genes involved
Genetics of Beckwith-Wiedemann syndrome-associated tumors: common genetic pathways
No full textA specific subset of solid childhood tumors-Wilms' tumor, adrenocortical carcinoma, rhabdomyosarcoma, and hepatoblastoma-is characterized by its association with Beckwith-Wiedemann syndrome. Genetic abnormalities found in these tumors affect the same chromosome region (11p15), which has been implicated in the etiology of Beckwith-Wiedemann syndrome. This suggests that the development of these tumors occurs along a common genetic pathway involving chromosome 11. To search for additional common genetic pathways, this article reviews the genetic data published for these tumors. It was found that, up until now, the only genetic abnormalities detected in all four tumors affect chromosome band 11p15 and the TP53 gene. In addition, there are several aberrations that occur in two or three of the neoplasms. It is concluded that, of the four tumors, the genetic relationship is most evident between Wilms' tumor and rhabdomyosarcom
Connecting theory and fiction: Margaret Atwood's novels and second wave feminism
No full textThis thesis undertakes an examination of the manner in which a novelist interacts with a contemporary theoretical discourse. I argue that the novelist and the theoretical discourse enter into a symbiotic relationship in which each influences and is influenced by the other. This process, I suggest, is simultaneous and complex. The thesis demonstrates how the prevailing theoretical discourse is absorbed by the contemporary author, is developed and redefined in conjunction with alternative concerns, and comes to permeate the narrative in an altered state. The novelist's new perspectives, frequently problematising theoretical claims, are then disseminated by the novel, promoting further discussion and development of the theoretical discourse. The thesis focuses on the novels of Margaret Atwood, considering them in relation to the history and development of second wave feminism. "Second wave feminism" is understood as an umbrella term that incorporates a wide variety of related but diverse and occasionally contradictory discourses, centring on the subjects of gender, femininity, and sexuality. The focus of the discussion is dual and presented simultaneously. Atwood's novels are analysed chronologically, and within the parameter of this analysis I demonstrate how her work has been influenced by earlier feminist theories, how it comments upon a variety of contemporary feminist ideas, and how it can be seen to anticipate further discussions within feminist discourse. Finally, I identify moments in Atwood's writing when alternative discourses compete with feminism to create new directions for feminist criticism. Examples of these discourses include Canadian nationalism, liberalism, communitarianism and environmentalism. The specificity of the novelist's interests and politics create a unique site of interaction for feminism which, I argue, benefits feminist theory by challenging, broadening and diversifying its focus. The thesis concludes that the symbiotic relationship of the theorist and the novelist is self-perpetuating and is also necessary and beneficial to both parties
Comparative genomic hybridization analysis of hepatoblastomas: additional evidence for a genetic link with Wilms tumor and rhabdomyosarcoma
No full textWe applied the technique of comparative genomic hybridization (CGH) to a series of 16 hepatoblastomas. Our goals were (1) to identify all quantitative chromosome abnormalities that appear in this type of tumor and (2) to compare the results with data from similar studies on other tumors associated with the Beckwith-Wiedemann syndrome (BWS). We found that the most commonly detected (> 30%) chromosome abnormalities were gains of chromosomes 1, 2, 7, 8, and 17. Losses of chromosomes were found in only a few cases. On comparing our results with those from studies on the BWS-associated tumors, Wilms tumor and rhabdomyosarcoma, it became clear that three chromosome regions, namely, 7q, 8q, and 17q, were the ones most commonly involved in all three types of tumors. These regions, therefore, may harbor genes that play a role in the etiology of BWS-associated tumors in genera
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