669 research outputs found
Designing the Threshold: A Close Reading of Olafur Eliasson’s Approach to ‘Inside’ and ‘Outside’
This article discusses Icelandic installation artist Olafur Eliasson’s approach of the threshold as a productive liminal space rather than as a static boundary between the inside and the outside. Often defined as the physical division between the interior and the exterior in architecture, the authors argue that by looking at Eliasson’s works in detail, the threshold’s inherent capacity of comprising a dynamic dialogue between inside and outside where one is determined by the other, unfolds. This paper proposes that designing the relationships between inside and outside involves subtle renegotiations and redefinitions of conventionalised notions of their boundaries and a resultant emergence of new design strategies. Eliasson designs thresholds in diverse ways that he analyses and provokes the spatial associations between inside and outside, interior and exterior. While in Eliasson`s work the categories of inside and outside remain mutually exclusive, they physically co-exist at the same time; deliberately refracted, juxtapositioned, connected or confounded in an experimental yet rigorous approach that employs different scales and common characteristics. Seventeen of his works are analysed and grouped into four different threshold design strategies that result in an object, an association, an event and an immersive space
Correspondence between geometrical and differential definitions of the sine and cosine functions and connection with kinematics
In classical physics, the familiar sine and cosine functions appear in two
forms: (1) geometrical, in the treatment of vectors such as forces and
velocities, and (2) differential, as solutions of oscillation and wave
equations. These two forms correspond to two different definitions of
trigonometric functions, one geometrical using right triangles and unit
circles, and the other employing differential equations. Although the two
definitions must be equivalent, this equivalence is not demonstrated in
textbooks. In this manuscript, the equivalence between the geometrical and the
differential definition is presented assuming no a priori knowledge of the
properties of sine and cosine functions. We start with the usual length
projections on the unit circle and use elementary geometry and elementary
calculus to arrive to harmonic differential equations. This more general and
abstract treatment not only reveals the equivalence of the two definitions but
also provides an instructive perspective on circular and harmonic motion as
studied in kinematics. This exercise can help develop an appreciation of
abstract thinking in physics.Comment: 6 pages including 1 figur
Conversion of the Mycotoxin Patulin to the Less Toxic Desoxypatulinic Acid by the Biocontrol Yeast Rhodosporidium kratochvilovae Strain LS11
Se describe en este artÃculo el descubrimiento de la degradación de la micotoxina patulina por una levaduraThe infection of stored apples by the fungus Penicillium expansum causes the contamination of fruits and fruit-derived
products with the mycotoxin patulin, which is a major issue in food safety. Fungal attack can be prevented by beneficial
microorganisms, so-called biocontrol agents. Previous time-course thin layer chromatography analyses showed that the aerobic
incubation of patulin with the biocontrol yeast Rhodosporidium kratochvilovae strain LS11 leads to the disappearance of the
mycotoxin spot and the parallel emergence of two new spots, one of which disappears over time. In this work, we analyzed the
biodegradation of patulin effected by LS11 through HPLC. The more stable of the two compounds was purified and characterized by
nuclear magnetic resonance as desoxypatulinic acid, whose formation was also quantitated in patulin degradation experiments. After
R. kratochvilovae LS11 had been incubated in the presence of 13C-labeled patulin, label was traced to desoxypatulinic acid, thus
proving that this compound derives from the metabolization of patulin by the yeast. Desoxypatulinic acid was much less toxic than
patulin to human lymphocytes and, in contrast to patulin, did not react in vitro with the thiol-bearing tripeptide glutathione. The
lower toxicity of desoxypatulinic acid is proposed to be a consequence of the hydrolysis of the lactone ring and the loss of functional
groups that react with thiol groups. The formation of desoxypatulinic acid from patulin represents a novel biodegradation pathway
that is also a detoxification process
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Characterisation of secondary metabolites associated with neutrophil apoptosis
We studied changes in secondary metabolites in human neutrophils undergoing constitutive or tumour necrosis factor (TNFalpha) stimulated apoptosis by a combination of high-performance liquid chromatography (HPLC) and NMR spectroscopy. Our results show that in contrast to freshly isolated neutrophils, neutrophil cells aged for 20 h in vitro had marked differences in the levels of a number of endogenous metabolites including lactate, amino acids and phosphocholine (PCho). There was no change in the concentration of taurine or glutamate and the ATP/ADP ratio was not affected. Levels of glutamine and lactate actually decreased. Identical changes were also observed in neutrophils stimulated to undergo apoptosis over a shorter time period (6 h) in the presence of TNFalpha and the phosphatidylinositol-3-kinase inhibitor wortmannin (WM). The changes in the concentration of PCho suggest possible activation of phospholipase associated with apoptosis or a selective failure of phosphatidycholine synthesis. The increased levels of apoptosis obtained with WM+TNFalpha, compared to TNFalpha by itself, suggest a synergistic effect by these compounds. The acceleration in rate of apoptosis probably arises from suppression by WM of pathway(s) that normally delay the onset of apoptosis. Changes in PCho and other endogenous metabolites, if proven to be characteristic of apoptosis in other cell systems, may permit non-invasive quantification of apoptosis.
Dynamic coordination in brain and mind
Our goal here is to clarify the concept of 'dynamic coordination', and to note major issues that it raises for the cognitive neurosciences. In general, coordinating interactions are those that produce coherent and relevant overall patterns of activity, while preserving the essential individual identities and functions of the activities coordinated. 'Dynamic coordination' is the coordination that is created on a moment-by-moment basis so as to deal effectively with unpredictable aspects of the current situation. We distinguish different computational goals for dynamic coordination, and outline issues that arise concerning local cortical circuits, brain systems, cognition, and evolution. Our focus here is on dynamic coordination by widely distributed processes of self-organisation, but we also discuss the role of central executive processes
Building Innovative Online Korean and Japanese Courses: A Pilot on Technology- Enhanced Curriculum Development
Our pilot project created blended/online courses to accommodate the growing needs of precollegiate and collegiate students interested in learning Korean and Japanese. In the initial phase, we conducted a survey of students’ experiences with and perceptions about blended/online Asian language learning. We found a general lack of familiarity with, and moderate resistance toward, online language learning modes. With learner attitudes in mind, we developed online modules for beginning Korean and Japanese courses. In this article, we report the survey results and the process of developing these innovative blended and online modalities of content delivery, focusing on the strengths of the modules and the unforeseen development challenges. The impacts that these technology-enhanced environments may have on student perceptions of transactional distance and tele-/copresence are explored. We suggest that transforming conventional East Asian language courses into blended/online modes is not only feasible but also beneficial for foreign language teaching and learning
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