194 research outputs found
Some remarks on first passage of Lévy processes, the American put and pasting principles
Full text linkThe purpose of this article is to provide, with the help of a fluctuation identity, a generic link between a number of known identities for the first passage time and overshoot above/below a fixed level of a Lévy process and the solution of Gerber and Shiu [Astin Bull. 24 (1994) 195–220], Boyarchenko and Levendorskii [Working paper series EERS 98/02 (1998), Unpublished manuscript (1999), SIAM J. Control Optim. 40 (2002) 1663–1696], Chan [Original unpublished manuscript (2000)], Avram, Chan and Usabel [Stochastic Process. Appl. 100 (2002) 75–107], Mordecki [Finance Stoch. 6 (2002) 473–493], Asmussen, Avram and Pistorius [Stochastic Process. Appl. 109 (2004) 79–111] and Chesney and Jeanblanc [Appl. Math. Fin. 11 (2004) 207–225] to the American perpetual put optimal stopping problem. Furthermore, we make folklore precise and give necessary and sufficient conditions for smooth pasting to occur in the considered problem
Dis-placing the East/West Binary: Aesthetic and Cultural Crossover in Film and Visual Culture, Cardiff, 2 November 2012
Full text linkWhen that other is Asia and the “Far East”, it always seems as if the European intellectual must speak in absolute terms, making this other an utterly incomprehensible, terrifying, and fascinating spectacle ... [T]he “native” is turned into an absolute entity in the form of an image (the “empty” Japanese ritual or “China loam”), whose silence becomes the occasion for our speech. (Chow 33, 34
One-carbon metabolism, insulin resistance, and fecundability in a Singapore prospective preconception cohort study
No full textBackground: one-carbon metabolism, which consists of the folate cycle, methionine cycle, and trans-sulphuration pathway, is associated with nucleotide synthesis. However, the association between one-carbon metabolites, metabolic status, and reproductive health remains poorly understood.Objectives: we examined the association between the one-carbon cycle plasma metabolites and fecundability and determined whether it is modified by metabolic health status, as assessed by insulin resistance (IR).Methods: this prospective cohort study utilized data from the Singapore PREconception Study of long-Term maternal and child Outcomes. Fasting blood samples were collected, and one-carbon cycle metabolites were measured. Fecundability was measured by time to pregnancy in menstrual cycles within a year of enrollment. We identified patterns in plasma one-carbon cycle metabolites using principal component (PC) analysis. We estimated fecundability ratios (FRs) and confidence intervals (CIs), with confounder adjustment using discrete-time proportional hazards models. IR was determined using the Homeostatic Model Assessment 2 Insulin Resistance score, classified into lower IR (<0.65) and higher IR (≥0.65). The role of IR was examined through interaction tests and stratification.Results: we identified 3 one-carbon cycle PCs. PC1, characterized by higher folate and lower homocysteine concentrations; PC2, characterized by higher concentrations of dimethylglycine, choline, methionine, and betaine; and PC3, characterized by higher concentrations of vitamins B2, B12, and B6. Each z-score increase in PC1 was associated with a 17% increase in fecundability (FR: 1.17; 95% CI: 1.03, 1.33). The association between PC1 and fecundability was more evident in women with lower IR (FR: 1.30; 95% CI: 1.08, 1.57) but was attenuated in those with higher IR (FR: 1.09; 95% CI: 0.92, 1.30), with a P-for-interaction of 0.127. PC2 and PC3 were not associated with fecundability.Conclusions: our findings suggest that higher folate and lower homocysteine concentrations, which reflected the interlinked folate and methionine cycles, were associated with higher fecundability in preconception women with lower IR but less so in those with higher IR.Clinical Trial Registration: this trial was registered at ClinicalTrials.gov as NCT03531658 (https://www.clinicaltrials.gov/study/NCT03531658)
Mobile Fantasy: Miyazaki’s Transnational Magic
No full textSince the 1960s, anime on both film and television has become a part of global screen culture. It is Miyazaki Hayao who may take the credit for being the most highly regarded anime filmmaker known across the world. The global popularity and success of his films encourage us to link his works to transnationalism. But is Miyazaki transnational only because of his global popularity? There is another perspective in which we may take Miyazaki’s transnationalism: through film aesthetics and narrative, for his works may be said to enable mobile fantasy. While discussing transnationalism, many film studies scholars focus on the discussion of film production, distribution, exhibition and reception in relation to economic globalization. Mette Hjort points out the complication and sometimes confusion in the way that transnationalism is defined. She argues the term transnationalism is often used to describe “a series of assumptions about the networked and globalized realities that are those of a contemporary situation.” These assumptions, however, do not define transnationalism explicitly. The reality of economic globalization is a space we are well aware of. I am more interested, however, in studying how cinematic transnationalization takes place in the space of an imaginary. Apart from political, cultural and economic enterprises, transnational magic is also embedded in film aesthetics, narrative and its psychological effects on audiences. It is in this connection that I propose a notion of what I will call mobile fantasy.
This chapter will first re-conceptualise the theory of transnational cinema in order to link transnationalism to a notion of imaginary space and to mobile fantasy. It will then focus on Miyazaki’s works as a case study, by looking into two main characteristics of his films – the question of a surreal world, and the theme of childhood
Functional Characterization of CTX-M-14 and CTX-M-15 β-Lactamases by <i>In Vitro</i> DNA Shuffling
No full textABSTRACT
This work investigated the molecular events driving the evolution of the CTX-M-type β-lactamases by the use of DNA shuffling of fragments of the
bla
CTX-M-14
and
bla
CTX-M-15
genes. Analysis of a total of 51 hybrid enzymes showed that enzymatic activity could be maintained in most cases, yet hybrids that were active possessed fewer amino acid substitutions than those that were inactive, suggesting that point mutations in the constructs rather than reshuffling of the fragments of the two target genes would more likely cause disruption of CTX-M activity. For example, the P
67
L and L
261
P changes in a CTX-M-14 fragment could completely abolish the activity of the enzyme on all antibiotics tested. Structural analysis showed that L
216
was located in the active-site β sheet and might interact with the adjacent hydrophobic residues to stabilize the active-site β sheet and maintain the integrity of the enzyme active site. Likewise, a single amino acid substitution, E
64
K, was found to exhibit a significant suppressive effect on CTX-M-15 activity. Structural analysis showed that E
64
might form a salt bridge with R
44
, disruption of which might affect CTX-M-15 activity. Further analysis of the structure-function relationship of a range of mutant enzymes confirmed that, as can be expected, unstable enzymes lose their activity and avoid selective events. These findings suggest that the distal pockets could also contribute to the activity of the enzymes and may be regarded as alternative targets for inhibitor development.
</jats:p
Cross-cultural equivalence of parental ratings of child difficulties during the pandemic:Findings from a six-site study
Full text linkObjectives: The Strengths and Difficulties Questionnaire (SDQ) has been shown to be invariant across informants, developmental stage and settings, but tests of cross-cultural equivalence are limited to adolescents’ self-reports. The COVID-19 pandemic makes this gap particularly pertinent, given the need to understand whether distinct government approaches (e.g., school closures) are uniquely associated with variability in children’s psychosocial outcomes and the reliance on parents’ ratings for young children. Methods: Within a Confirmatory Factor Analysis (CFA) framework, we tested the cross-cultural measurement invariance of the SDQ across six countries: Australia, China, Italy, Sweden, the UK and USA, using a sample of 1761 parents of 3- to 8-year-olds (M = 5.76, SD = 1.09). Results: A five-factors model showed good fit to the data and partial cross-cultural scalar invariance. In this sample, Swedish parents reported the fewest peer problems (Cohen’s d = .950) and the highest prosocial scores (Cohen’s d = .547), whilst British parents reported the greatest child emotional (Cohen’s d = .412) and hyperactivity problems (Cohen’s d = .535). Conclusions: The present results indicate that the parent-version of the SDQ is appropriate for use and comparison across different contexts during the pandemic
The effect of language dominance on radical awareness and statistical learning in Singaporean Chinese bilinguals
No full textThis study examined the effect of language dominance on Chinese radical awareness and visual
statistical learning abilities in Singaporean Chinese-English bilinguals. Language dominance was assessed using a self-report measure of language history, use, proficiency and attitudes. Chinese radical awareness was assessed using a picture naming task, which examined radical sensitivity, as well as an odd-one-out task, which assessed radical recognition. Statistical learning was assessed using visually presented stimuli within a triplet learning paradigm. Thirty-six healthy Singaporean Chinese bilinguals (M = 26.1, SD = 4.14) were split into two even groups, consisting of participants who were More English-Dominant (MED) and participants who were Less English-Dominant (LED). Independent samples t-tests identified a statistically significant effect of language dominance on visual statistical learning accuracy (p = .03, d = .66) and radical sensitivity (p = .04, d = .63). MED participants were found to have significantly higher visual statistical learning accuracy but lower Chinese radical sensitivity and recognition accuracy, as compared to LED participants. These results seem to suggest an effect of L1 language dominance on language processing in Singaporean bilinguals. Findings of this study can be used to establish a more comprehensive research base for understanding bilingual lexical access in visual word recognition.Bachelor of Arts in Psychology and Linguistics and Multilingual Studie
Book Review - Striking beauty: A philosophical look at the Asian Martial Arts. Barry Allen, Columbia University Press, 2015
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