4,210 research outputs found
Iterated extended ultrapowers and supercompactness without choice
No full textAbstractWorking in ZF + DC with no additional use of the axiom of choice, we show how to iterate the extended ultrapower construction of Spector (1988, 1991). This generalizes the technique of iterated ultrapowers to choiceless set theory. As an application, we prove the following theorem: Assume V = LU[Pκ(λ)] + “κ is λ-supercompact with normal ultrafilter U” + DC. Then for every sufficiently large regular cardinal ρ, there exists a set-generic extension V[G] of the universe in which there exists for some σ a set S ⊆ Pρ(σ) for which one can define an elementary embedding j mapping V to LD[S], where D is the filter in V[G] generated by the closed unbounded filter (according to V) on Pρ(σ). Moreover, we have j(κ) = ρ, j(λ) = σ, j(Pκ(λ)) = S (which is Pρ(σ) according to LD[S]), and j(itU) = D ∩ LD[S] i s a normal ultrafilter in LD[S] on Pρ(σ)
Genetic and environmental risk factors for sexual distress and its association with female sexual dysfunction
No full textA. Burri, Q. Rahman and T. Spector (2011). Genetic and environmental risk factors for sexual distress and its association with female sexual dysfunction. Psychological Medicine, 41, pp 2435-2445. Copyright © Cambridge University Press 2011. http://dx.doi.org/10.1017/S003329171100049
Value Pluralism and the Two Concepts of Rights
No full textPhilosophers and legal theorists still disagree about the correct analysis of 'rights', both moral and legal. The 'Will Theory' and the 'Interest Theory' - the two main views - can each account for various features of rights, but neither of them is totally satisfactory. The controversy has now been running for decades and seems irresolvable. I will contend in this paper that the discussion of 'value pluralism' in the Berlinian tradition can illuminate the debate over the concept of rights.analysis of rights, moral rights, legal rights, will theory, interest theory, value pluralism, Isaiah Berlin
Space tourism and sustainable trajectory
No full textThe commercial spaceflight industry is progressing rapidly. Yet, there is a lack of research theorising what the spatio-temporal contours of sustainability look like if the biosphere, along with its finite resources and limited ability to sustain continued population growth, constitutes a boundary that can be readily transcended. Informed by the concept of sustainable trajectory, this paper presents a conceptual model that extends the traditional spatial (e.g. national, global) and temporal (e.g. near future, intergenerational) scales that sustainability discourses in geography are typically predicated upon. We conducted a critical narrative literature review to analyse the implications of space tourism in the context of sustainable trajectory. Our analysis highlights deep tensions between the perspectives of sustainability typically promulgated in academic spheres and the path dependencies currently being formed by private spaceflight companies.Full Tex
Educational design research
No full textMcKenney, S. & Reeves, T. (2013). Educational design research. In M. Spector, M. Merrill, J. Elen & M. Bischop (Eds.) Handbook of Research on Educational Communications & Technology, pp. 131-140. London: Springer.Educational design research is a genre of research in which the iterative development of solutions to practical and complex educational problems provides the setting for scientific inquiry. The solutions can be educational products, processes, programs or policies. Educational design research not only targets solving significant problems facing educational practitioners, but at the same time it seeks to discover new knowledge that can inform the work of others facing similar problems. Working systematically and simultaneously toward these dual goals is perhaps the most defining feature of educational design research. This chapter seeks to clarify the nature of educational design research by distinguishing it from other types of inquiry conducted in the field of educational communications and technology. Examples of design research conducted by different researchers working in the field of educational communications and technology are described. The chapter concludes with a discussion of several important issues facing educational design researchers as they pursue future work using this innovative research approach
Mechanisms of top-down facilitation in perception of visual objects studied by fMRI
No full textPrior knowledge regarding the possible identity of an object facilitates its recognition from a degraded visual input, though the underlying mechanisms are unclear. Previous work implicated ventral visual cortex but did not disambiguate whether activity-changes in these regions are causal to or merely reflect an effect of facilitated recognition. We used functional magnetic resonance imaging to study top-down influences on processing of gradually revealed objects, by preceding each object with a name that was congruent or incongruent with the object. Congruently primed objects were recognized earlier than incongruently primed, and this was paralleled by shifts in activation profiles for ventral visual, parietal, and prefrontal cortices. Prior to recognition, defined on a trial-by-trial basis, activity in ventral visual cortex rose gradually but equivalently for congruently and incongruently primed objects. In contrast, prerecognition activity was greater with congruent priming in lateral parietal, retrosplenial, and lateral prefrontal cortices, whereas functional coupling between parietal and ventral visual (and also left lateral prefrontal and parietal) cortices was enhanced in the same context. Thus, when controlling for recognition point and stimulus information, activity in ventral visual cortex mirrors recognition success, independent of condition. Facilitation by top-down cues involves lateral parietal cortex interacting with ventral visual areas, potentially explaining why parietal lesions can lead to deficits in recognizing degraded objects even in the context of top-down knowledge
Do you know the way to ... Web 2.0
No full textKirschner, P. A., & Wopereis, I. G. J. H. (2013). Do you know the way to ... Web 2.0? In J. M. Spector, B. B. Lockee, S. E. Smaldino, & M. C. Herring (Eds.), Learning, problem solving, and mindtools: Essays in honor of David H. Jonassen (pp. 88-104). New York, NY: Routledge.With the coming of age of the Millennials, teacher training programs may become complacent, thinking that while the previous generation of digital immigrants that went into teaching may be a lost cause, things will now be different with the influx of digital natives into the teaching profession. This, however, is anything but true. Though Millennials may never have known anything except a digital, connected world, they appear to have precious little knowledge of how the attainments of the digital world can be used – as mindtools – in education. Programs for teacher training, thus, still need to train (aspiring) teachers make use of both traditional and Web 2.0 information and communication technologies as mindtools for themselves and their students. On the one hand, teachers can use these tools to engage their students in individual, collaborative and collective critical thinking and knowledge creation activities. On the other hand, they can use them themselves to help further their own professional development and thinking. In the latter case mindtools can be applied for cooperation (e.g., between teachers, teacher educators, and student teachers) and collaboration (e.g., with other teachers, experts, designers, and so forth on pedagogical projects). In this chapter we focus on electronic networking technologies (Communities of Practice) and Web 2.0 applications (e.g., weblogs) as mindtools for teacher professional development
Technology enhanced formative assessment for 21st century learning
No full textThis is an Open Access article distributed under the terms of the Creative Commons Attribution 3.0 International License (https://creativecommons.org/licenses/by-nc-nd/3.0/). Original citation: Spector, J. M., Ifenthaler, D., Sampson, D., Yang, J. L., Mukama, E., Warusavitarana, A., …Gibson, D. C. (2016). Technology enhanced formative assessment for 21st century learning. Journal of Educational Technology and Society. 19(3), 58-71. Retrieved from http://www.ifets.info/journals/19_3/7.pdf Spector, J. M., Ifenthaler, D., Samspon, D., Yang, L., Mukama, E., Warusavitarana, A., Lokuge Dona, K., Eichhorn, K., Fluck, A., Huang, R., Bridges, S., Lu, J., Ren, Y., Gui, X., Deneen, C. C., San Diego, J., & Gibson, D. C. (2016 ABSTRACT This paper is based on the deliberations of the Assessment Working Group at EDUsummIT 2015 in Bangkok, Thailand. All of the members of Thematic Working Group 5 (TWG5) have contributed to this synthesis of potentials, concerns and issues with regard to the role of technology in assessment as, for and of learning in the 21 st century. The group decided to focus primarily on formative assessment rather than summative assessment and high stakes testing. Formative assessments and feedback provide an important opportunity to support and enhance student learning. Recognizing shifts in education towards blended and online learning with problembased and inquiry-based approaches led to considerations of technologies that could effectively support formative assessment and informative feedback to 21 st century learners. The paper concludes with a summary of conclusions and recommendations of the working group to be taken up in subsequent efforts
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Cell Cycle Dysregulation by Human Cytomegalovirus: Influence of the Cell Cycle Phase at the Time of Infection and Effects on Cyclin Transcription
No full textHuman cytomegalovirus (HCMV) infection inhibits cell cycle progression and alters the expression of cyclins E, A, and B (F. M. Jault, J.-M. Jault, F. Ruchti, E. A. Fortunato, C. Clark, J. Corbeil, D. D. Richman, and D. H. Spector, J. Virol. 69:6697–6704, 1995). In this study, we examined cell cycle progression, cyclin gene expression, and early viral events when the infection was initiated at different points in the cell cycle (G
0
, G
1
, and S). In all cases, infection led to cell cycle arrest. Cells infected in G
0
or G
1
phase also showed a complete or partial absence, respectively, of cellular DNA synthesis at a time when DNA synthesis occurred in the corresponding mock-infected cells. In contrast, when cells were infected near or during S phase, many cells were able to pass through S phase and undergo mitosis prior to cell cycle arrest. S-phase infection also produced a delay in the appearance of the viral cytopathic effect and in the synthesis of immediate-early and early proteins. Labeling of cells with bromodeoxyuridine immediately prior to HCMV infection in S phase revealed that viral protein expression occurred primarily in cells which were not engaged in DNA synthesis at the time of infection. The viral-mediated induction of cyclin E, maintenance of cyclin-B protein levels, and inhibitory effects on the accumulation of cyclin A were not significantly affected when infection occurred during different phases of the cell cycle (G
0
, G
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, and S). However, there was a delay in the observed inhibition of cyclin A in cells infected during S phase. This finding was in accord with the pattern of cell cycle progression and delay in viral gene expression associated with S-phase infection. Analysis of the mRNA revealed that the effects of the virus on cyclin E and cyclin A, but not on cyclin B, were primarily at the transcriptional level
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A model system for human cytomegalovirus-mediated modulation of human immunodeficiency virus type 1 long terminal repeat activity in brain cells
No full textPreviously, our laboratory showed that human cytomegalovirus (HCMV) activates human immunodeficiency virus type 1 (HIV-1) in brain-derived cells with limited HIV-1 gene expression but inhibits HIV-1 in cells fully permissive for replication of both viruses (F. M. Jault, S. A. Spector, and D. H. Spector, J. Virol. 68:959-973, 1994). To investigate these effects further, we developed a model system that uncouples HIV-1 gene expression from long terminal repeat (LTR) activity. Two monoclonal U373-MG astrocytoma/glioblastoma cell lines (LTRIG and LIGHIVDC) were generated, each containing an integrated copy of an LTR-chloramphenicol acetyltransferase (CAT) construct and the Escherichia coli lacI gene. LIGHIVDC also has an inducible HIV-1 genome controlled by a Rous sarcoma virus promoter with lac operator sequences. Basal LTR-mediated CAT activity is 65-fold higher in LIGHIVDC than in LTRIG, and this activity is further increased (20-fold) following incubation of LIGHIVDC with isopropyl-beta-D-thiogalactopyranoside (IPTG). Tat protein can be detected by immunostaining in LIGHIVDC. However, Rev-mediated transport and subsequent translation of the singly spliced and unspliced HIV-1 mRNAs is inefficient. In the absence of Tat, HCMV stimulated CAT activity approximately 20-fold, and this activation required HCMV gene expression but not viral DNA replication. LTR-directed transcription was unaffected by HCMV infection in LIGHIVDC but was inhibited in these cells when they contained increased Tat levels following IPTG induction. These results support the hypothesis that HCMV can induce the HIV-1 LTR when HIV-1 gene expression is minimal and that a threshold level of HIV-1 gene products is necessary for HCMV to inhibit this promoter
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