93 research outputs found
Diurnal regulation of lipid metabolism and applications of circadian lipidomics
No full text10.1016/j.jgg.2014.04.001Journal of Genetics and Genomics415283-29
Functional Analysis of AtVAMP714 gene in Arabidopsis
No full textAn activation tagging screen was carried out to identify gain-of-function mutants showing potential auxin defects, with the aim of identifying the new genes regulating plant development. The conjoined (cnj) mutant isolated from the activation tagged screen exhibits duplication of the seedling axis. Sequencing the insertion locus revealed that the activation tag was positioned between ATP-binding protein and vesicle associated membrane protein genes. Cloned mutant locus and expression studies indicated that the vesicle associated membrane protein gene is upregulated in the activation tagging line. The aim of this work is to investigate the function of the vesicle associated membrane protein gene (AtVAMP714), which is a member of an R-SNARE protein family.
To determine the expression pattern of AtVAMP714, proAtVAMP714::GUS expression in seedlings was examined. GUS activity was observed in the hypocotyl and roots and the strongest expression was observed in the root vascular tissues. The AtVAMP714 gene is positively auxin regulated. VAMP714::GFP fusion protein localized to Golgi vesicles suggesting it may be involved in the Golgi secretory pathway. Auxin transport levels in roots and shoots found to be greatly reduced in AtVAMP714 overexpressors compared to the wild type plants. Quantitative real-time RT-PCR showed that transcript levels of IAA1 and IAA2 were significantly reduced in AtVAMP714 overexpressors. Immunolocalization of PIN1 and PIN2 showed strong defects in localization.
To characterize the development role of VAMP714, SALK null mutants of the AtVAMP714 gene were identified. The mutant phenotype showed an abnormal branching and short root phenotype and PIN1, PIN2 and PIN4 transcript levels were significantly reduced. Dominant negative transgenics of AtVAMP714 were also created as a method of knocking out the function of the protein and F2 generation plants were analysed for developmental defects. Consistent with the above results the dominant negative transgenics showed a short root phenotype with dwarfed, branchy shoots. PIN1 and PIN2 proteins were mislocalized in dominant negative transgenics. The results presented provide evidence for a role of AtVAMP714 in auxin transport through a requirement for correct PIN protein secretion and localization
Effects of total sleep deprivation on divided attention performance.
No full textDividing attention across two tasks performed simultaneously usually results in impaired performance on one or both tasks. Most studies have found no difference in the dual-task cost of dividing attention in rested and sleep-deprived states. We hypothesized that, for a divided attention task that is highly cognitively-demanding, performance would show greater impairment during exposure to sleep deprivation. A group of 30 healthy males aged 21-30 years was exposed to 40 h of continuous wakefulness in a laboratory setting. Every 2 h, subjects completed a divided attention task comprising 3 blocks in which an auditory Go/No-Go task was 1) performed alone (single task); 2) performed simultaneously with a visual Go/No-Go task (dual task); and 3) performed simultaneously with both a visual Go/No-Go task and a visually-guided motor tracking task (triple task). Performance on all tasks showed substantial deterioration during exposure to sleep deprivation. A significant interaction was observed between task load and time since wake on auditory Go/No-Go task performance, with greater impairment in response times and accuracy during extended wakefulness. Our results suggest that the ability to divide attention between multiple tasks is impaired during exposure to sleep deprivation. These findings have potential implications for occupations that require multi-tasking combined with long work hours and exposure to sleep loss
Changes in Plasma Lipids during Exposure to Total Sleep Deprivation
No full text10.5665/sleep.5142SLEEP38111683-1691United State
Competency-based Education Through Micro-credentials Offerings – A Pilot Study
No full textThis pilot study examined the implementation of Competency-Based Education (CBE) through micro-credentials at the Singapore Institute of Technology (SIT), focusing on the perspectives of learners, instructors, and employers. Despite a growing global interest in CBE, empirical research on its effectiveness remains limited. SIT’s Competency-Based Stackable Micro-credential (CSM) program offers modular, industry-relevant learning for working adults, with micro-credentials functioning as standalone qualifications or stackable units toward a full degree. Findings from learner surveys indicated that the content was highly relevant to real-world jobs, and the learning could be applied to work. Instructors recognized the relevance of CBE to industry needs, despite the increased demands associated with content development, delivery, and learner support. Employers observed improvements in employee competencies and workplace engagement. The findings underscore the potential of CBE micro-credentials to offer flexible, industry-focused education pathways when supported by robust frameworks and comprehensive learner support services.
Analysis and automatic identification of sleep stages using higher order spectra
No full text10.1142/S0129065710002589International Journal of Neural Systems206509-52
On two combinatorial problems arising from automata theory
No full textInternational audienceWe present some partial results on the following conjectures arising from automata theory. The first conjecture is the triangle conjecture due to Perrin and Schützenberger. Let A = {a, b} be a two-letter alphabet, d a positive integer and let B_d = {a^iba^j | 0 <= i+j <= d}. If X \subset B_d is a code, then |X| <= d+1. The second conjecture is due to Cerný and the author. Let A be an automaton with n states. If there exists a word of rank <= k in A, there exists such a word with length <= (n-k)^2
Logic on words
No full textFirst published in the Bulletin of the European Association of Theoretical Computer Science 54 (1994), 145-165.This dialog between Quisani, Yuri Gurevich's imaginary student, and the author, was published in the "Logic in Computer Science Column" of the EATCS Bulletin. It is first addressed to logicians. This dialog is an occasion to present the connections between Büchi's sequential calculus and the theory of finite automata. In particular, the essential role of first order formulæ is emphasized. The quantifier hierarchies on these formulæ are an occasion to present open problems
Newton’s Forward Difference Equation for Functions from Words to Words
No full textInternational audienceNewton's forward difference equation gives an expression of a function from ℕ to ℤ in terms of the initial value of the function and the powers of the forward difference operator. An extension of this formula to functions from A* to ℤ was given in 2008 by P. Silva and the author. In this paper, the formula is further extended to functions from A* into the free group over B.L'équation aux différences avant de Newton donne une expression d'une fonction de ℕ dans ℤ en termes de la valeur initiale de la fonction et des puissances de l'opérateur de difference avant. Une extension de cette formule aux fonctions de A* dans ℤ a été donnée en 2008 par P. Silva et l'auteur. Dans cet article, cette formule est à nouveau généralisée, cette fois aux fonctions de A* dans le groupe libre sur B
A Variety Theorem Without Complementation.
No full textthis paper is to show that such results are not isolated, but are instances of a result as general as Eilenberg's theorem. On the language side, we consider positive varieties of languages, which have the same properties as varieties of languages except they are not supposed to be closed under complement. On the algebraic side, varieties of finite semigroups are replaced by varieties of finite ordered semigroups. Our main result states there is a one-to-one correspondence between positive varieties of languages and varieties of finite ordered semigroups. Due to the lack of space, we shall just give a few examples of this correspondence and defer to future papers the detailed study of our new types of varieties. For instance, P. Weil and the author have shown that the theorems of Birkhoff and Reiterman can be extended to ordered semigroups by replacing equations by inequation
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