6,712 research outputs found
Oral History Interview with Scott Gaff
No full textTranscript, 68 pp.In this interview Scott Gaff, formerly of Lamb & Company, discusses a wide variety of subjects in computer graphics history. Gaff recounts his education and work experience at the University of Minnesota, and his testing of TERAK, Evans & Sutherland PS-300, and voice recognition CAD/CAM systems. Gaff describes his brief stint in 1984-1985 at the failed Minneapolis company Mainframe Productions—which specialized in graphics for television commercials—and rendering and other technical work on Silicon Graphics (SGI) workstations and PCs running Wavefront software at Minneapolis-based animation firm Lamb & Company between 1986 and 2001.Gaff, Scott. (2002). Oral History Interview with Scott Gaff. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/107300
Wavelength tunable 10-GHz 3-ps pulse source using a dispersion decreasing fiber-based nonlinear optical loop mirror
No full textWe experimentally demonstrate the use of a dispersion decreasing fiber (DDF)-based nonlinear optical loop mirror (NOLM) for the generation of wavelength tunable soliton-like pulses at a repetition rate of 10 GHz. We compress ~12 ps Gaussian pulses from an electro-absorption modulator (EAM) (followed by 125 m of DCF for preliminary linear dispersion compensation) into 3 ps pedestal-free pulses using both high-order soliton compression and nonlinear switching effects within an 8.5 km DDF-based loop mirror. The output pulses from the DDF-based NOLM show considerable pedestal reduction compared to those obtained by directly compressing the EAM seed pulses via a single passage through the DDF. Wavelength tuning of the compressed pulses over a ~15 nm bandwidth (from 1541 to 1556 nm) is demonstrated without a significant increase in pulse duration or degradation in pulse quality
Player agency in interactive narrative: audience, actor & author
No full textThe question motivating this review paper is, how can
computer-based interactive narrative be used as a constructivist learn-
ing activity? The paper proposes that player agency can be used to
link interactive narrative to learner agency in constructivist theory,
and to classify approaches to interactive narrative. The traditional
question driving research in interactive narrative is, ‘how can an in-
teractive narrative deal with a high degree of player agency, while
maintaining a coherent and well-formed narrative?’ This question
derives from an Aristotelian approach to interactive narrative that,
as the question shows, is inherently antagonistic to player agency.
Within this approach, player agency must be restricted and manip-
ulated to maintain the narrative. Two alternative approaches based
on Brecht’s Epic Theatre and Boal’s Theatre of the Oppressed are
reviewed. If a Boalian approach to interactive narrative is taken the
conflict between narrative and player agency dissolves. The question
that emerges from this approach is quite different from the traditional
question above, and presents a more useful approach to applying in-
teractive narrative as a constructivist learning activity
Influence of flow on the structure of bacterial biofilms.
No full textBacteria attached to surfaces in biofilms are responsible for the contamination of industrial processes and many types of microbial infections and disease. Once established, biofilms are notoriously difficult to eradicate. A more complete understanding of how biofilms form and behave is crucial if we are to predict, and ultimately control, biofilm processes. A major breakthrough in biofilm research came in the early 1990’s when confocal scanning laser microscopy (CSLM) showed that biofilms formed complex structures which could facilitate nutrient exchange. We have recently found that biofilms growing in turbulent flow can also be temporally complex. Structures such as cell clusters and ripples can migrate downstream along solid surfaces. Further, biofilm viscoelasticity allows the biofilm to structurally deform when exposed to varying shear stresses
Limits to growth and what keeps a biofilm finite
No full textTwo of the factors, shear erosion and diffusive mass transfer, which limit the growth of heterogeneous biofilms are considered. For permeable beds of particulates, with a regulated throughflow, equating shear induced erosion and biofilm growth, leads to estimates of biofilm thickness and activity which conform with experimental measurements. In the more open environments of pipes and channels, increased thickness of biofilm is not directly balanced by increased cell erosion from the biofilm surface. However increasing thickness leads to growth limitations as diffusion limits the rate of mass transfer to cells deep in the film. For heterogeneous biofilms , consisting of complex clusters intersected by channels, mass transfer into the biofilm is by a combination of advective flow in the channels and diffusive transfer in clusters. In this paper we have considered mass transfer into simplified cluster forms, that is cylinders and hemispheres. Using the concept of critical dimension we have explored some of the implications of these simplified structures. We discuss the limitation to this approach as fluid shear alters the form of these simplified clusters. The viscoelastic properties of the biofilm clusters are being investigated and should allow better prediction of the effect of lateral shear on simple forms. The advection in biofilm channels and the related mass transfer processes needs further investigation
Charisma and Spirituality in the Early Church: A Study of Messalianism and Pseudo-Macarius
No full textThe thesis is an investigation into the concept of Charisma and Spirituality in the Early Church with particular emphasis upon the writings of Ps-Macarius, and of a group of ascetics known as the Messalians, evident in the late fourth / early fifth centuries. The Macarian writings are
examined to see what they reveal about the experiential pneumatic theology of the Early Church, the relationship between Syrian and Hellenic traditions of Christian Rhetoric, and the relationship between Ps-Macarius and the Cappadocian Circle. The Macarian corpus as a whole is examined to assess its rhetorical influences and style. The rhetoric of the Macarian corpus is seen to illustrate a high degree of sophistication. This study also gives definition to two terms that have become imprecise and diverse in their use: 'enkrateia' (self-control), and
`Syrian Christianity'. By isolating the characteristics of enkratefa the definitive stages of an encratic lifestyle are identified. The breaking down of the term into enkrateia, radical enkrateta and exclusive enkrateta enables a much clearer discussion to take place as to the
nature of the encratic theology of a group or individual. The final element of this study is a consideration of the distinct Macarian imagery that is evident within the corpus. Two images are considered in detail, the 'flight of the soul' and 'sober intoxication'. Overall this study
shows the variety of influences upon Ps-Macarius, and the uniqueness of his expression. The influences upon Ps-Macarius include a context of endemic Syrian spirituality, a radical encratic lifestyle, a Hellenic rhetorical training, and a distinct interpretation of Platonic and Neo-
Platonic images, coupled to the wider Judaic / Mesopotamian influences of his Church. It is shown that Ps-Macarius represents an individual voice that is distinct and recognisable amongst the Fathers of the Church
Store-mediated calcium entry in the regulation of phosphatidylserine exposure in blood cells from Scott patients
No full textSummaryScott syndrome is a bleeding disorder, characterized by impaired surface exposure of procoagulant phosphatidylserine (PS) on platelets and other blood cells, following activation with Ca2+-elevating agents. Since store-mediated Ca2+ entry (SMCE) forms an important part of the Ca2+ response in various blood cells, it has been proposed that deficiencies in Ca2+ entry may relate to the impaired PS exposure in the Scott syndrome. Here, we have tested this hypothesis by investigating the relationship between Ca2+ fluxes and PS exposure in platelets as well as B-lymphoblasts derived from the original Scott patient (M.S.), a newly identified Welsh patient (V.W.) with similar bleeding symptoms, and two control subjects. Procoagulant activity of V.W. platelets in suspension, measured after stimulation with collagen/thrombin or Ca2+-ionophore, ionomycin, resulted in 52% or 17%, respectively, compared to that of correspondingly activated control platelets. Procoagulant activity of V.W. erythrocytes treated with Ca2+-ionophore resulted in less than 6% of the activity of control erythrocytes. Single-cell Ca2+ responses of M.S. and V.W. platelets, adhering to collagen, were similar to those of platelets from control subjects, while PS exposure was reduced to 7% and 15%, respectively, compared to controls. Stimulation of non-apoptotic B-lymphoblasts derived from both patients and controls with Ca2+-ionophore or agents causing Ca2+ mobilization and SMCE, resulted in similar Ca2+ responses. However, in lymphoblasts from M.S. and V.W. Ca2+-induced PS exposure was reduced to 7% and 13% of the control lymphoblasts, respectively. We conclude that i. patient V.W. is a new case of Scott syndrome, ii. Ca2+ entry in the platelets and lymphoblasts from both Scott patients is normal, and iii. elevated [Ca2+]i as caused by SMCE is not sufficient to trigger PS exposure.</jats:p
Nuclear translocation and signalling of L1-CAM in human carcinoma cells requires ADAM10 and presenilin/gamma-secretase activity
No full textL1-CAM (L1 cell-adhesion molecule), or more simply L1, plays an important role in the progression of human carcinoma. Overexpression promotes tumour-cell invasion and motility, growth in nude mice and tumour metastasis. It is feasible that L1-dependent signalling contributes to these effects. However, little is known about its mechanism in tumour cells. We reported previously that L1 is cleaved by ADAM (a disintegrin and metalloprotease) and that the cytoplasmic part is essential for L1 function. Here we analysed more closely the role of proteolytic cleavage in L1-mediated nuclear signalling. Using OVMz carcinoma cells and L1-transfected cells as a model, we found that ADAM10-mediated cleavage of L1 proceeds in lipid raft and non-raft domains. The cleavage product, L1-32, is further processed by PS (presenilin)/gamma-secretase to release L1-ICD, an L1 intracellular domain of 28 kDa. Overexpression of dominantnegative PS1 or use of a specific gamma-secretase inhibitor leads to an accumulation of L1-32. Fluorescence and biochemical analysis revealed a nuclear localization for L1-ICD. Moreover, inhibition of ADAM10 and/or gamma-secretase blocks nuclear translocation of L1-ICD and L1-dependent gene regulation. Overexpression of recombinant L1-ICD mediates gene regulation in a similar manner to full-length L1. Our results establish for the first time that regulated proteolytic processing by ADAM10 and PS/gamma-secretase is essential for the nuclear signalling of L1 in human carcinoma cell lines. Key words: a disintegrin and metalloprotease 10 (ADAM10), L1 cell-adhesion molecule (L1-CAM), nuclear translocation, presenilin (PS)/gamma-secretase activity, raft, signalling
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Gene of the issue: ANO6 and Scott Syndrome.
No full textScott Syndrome is a very rare inhibited bleeding disorder characterised by an isolated deficit in procoagulant activity in platelets and other blood cells, caused by a lack of phosphatidylserine (PS) exposure following activation.[1,2] It results from mutations in ANO6, which encodes the phospholipid scramblase protein, TMEM16F.[3
Depth-generalist corals occurring in shallow to deep habitats at Scott Reef.
No full text<p>(a) foliaceous <i>Pachyseris speciosa</i> (PS) and (b) branching <i>Seriatopora hystrix</i> (SH) at approximately 50 m in the central lagoon of South Scott Reef. Images: A. Heyward.</p
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