209 research outputs found
Vietnamese Students Abroad: A Research Framework
The purpose of this paper is threefold. First, a critique of the current literature on the acculturation experience of Vietnamese international students is provided. Second, a review of the distinctive cultural-historical traits of Vietnamese international students is presented, demonstrating their differences relative to other Asian sojourning groups as well as other Vietnamese migrant groups. A third purpose of this paper is to present a Vietnamesespecific psychological acculturation framework that might pave the theoretical foundation for investigations on the acculturation experience of Vietnamese international students. This framework is based upon Berry’s (1997) acculturation framework, and De Jong and Fawcett’s (1981) value-expectancy model
公共政策のモバイル市場発展に対するインパクト分析 : ベトナム事例
制度:新 ; 文部省報告番号:甲2480号 ; 学位の種類:博士(国際情報通信学) ; 授与年月日:2007/6/20 ; 早大学位記番号:新458
From Misfolded Recombinant Proteins in vitro to Pathological Agents in vivo
The pathogenesis of a disease involves a stochastic refolding of the etiologic protein into a misfolded infectious state known as prion. Recently, there has been renewed interest in the possibility that proteins causing neurodegeneration are all prions. The \u3b2-sheet rich pathological \u3b1-synuclein (\u3b1-syn) can cross from the neurons of transplanted patients into the grafted cells, and induce a change in the structure of \u3b1-syn in Parkinson\u2019s disease (PD) is an example. The convergence of studies showing the presence of prions in the pathogenesis of common neurodegenerative maladies has since been remarkable. Studies on synthetic prions showed that recombinant (rec) prion protein (PrP) is refolded into infectious conformations in vitro. This synthetic prion protein stimulates the conversion of cellular PrP into nascent pathological PrP and induces the accumulation of the isoform that causes neurodegeneration in vivo.
Using defined biophysical and biochemical conditions in vitro, we developed methods for the pathological conversion of recPrP into PrPSc, and we established whether synthetic pathological agents of rec human \u3b1-syn amyloids can be infectious, as Legname et al. showed for the first time in production of mammalian synthetic prions. The pathological conversion process of both PrP and \u3b1-syn required only purified recombinant proteins and common chemicals. We generated putative infectious materials that possess different conformational structures. Moreover, we designed a novel build-in screening methodology for amyloid preparations to achieve putative infectious materials using amyloid-infected-cell culture assay.
At fifth cell passage after single infection, prion amyloid fibrils from different preparations induced endogenous PrPC to convert into PrPSc in both non-infected mouse hypothalamic GT1 and mouse neuroblastoma N2a cell lines. Moreover, these variant synthetic proteinaceous infectious agents can replicate and be detected by protein misfolding cyclic amplification (PMCA). Through this methodology that was used to obtain synthetic mammalian prions, we also tested whether recombinant human \u3b1-syn amyloids can infect neuronal cell lines in vitro, and wild-type mice in vivo. A single exposure to amyloid fibrils of human \u3b1-syn was sufficient to induce aggregation of endogenous \u3b1-syn in human neuroblastoma SH-SY5Y cells, mouse hypothalamic GT1 cells and mouse brains. Interestingly, we found pathological phosphorylated \u3b1-syn in amyloid-infected cells and in neurons and neurites of mice. These results suggest that recombinant human \u3b1-syn amyloids can promote endogenous \u3b1-syn aggregation and pathological post-translational modification. Upon subsequent passages, mice inoculated with either human \u3b1-syn amyloid or diseased mouse brain homogenates showed marked neurological symptoms resembling those of PD, as well as neuropathological \u3b1-syn inclusions in neurons
Modélisation fréquentielle analytique de convertisseurs statiques en vue du dimensionnement de systèmes par optimisation
For the design of static energy conversion systems from power grids, harmonic standards have to berespected. To characterize them, frequency modeling approaches, either numerical or semi-analytical. Thesecond one is more advisable for the sizing by optimization of systems, where a fast model is required and manyconstraints have to be carried out. However, the main difficulties happen in the analytical modeling of powerelectronics structures, especially those with soft commutations.This thesis proposes a semi-analytical modeling approach where the solving of implicit equations iscarried out by Newton-Raphson or SQP. The convergence difficulties are analyzed in two viewpoints:numerically and according the operating mode of the static converters. Then, alternatives are proposed to solvethem.To illustrate the problematic, applications with diode rectifiers (widely used in railway electrical gridsubstations or airline electrical grid) are used. Especially, the sizing of power channel of « new generation» of anAirbus, is made by optimization, using the proposed modelling approach.Dans le cadre du dimensionnement des systèmes de conversion statique d’énergie implantés dans des réseaux électriques, il est important de respecter certaines normes harmoniques. Pour caractériser celles-ci, on doit utiliser des approches des modélisations fréquentielles : soit numérique, soit semi-analytique. La deuxième est préférable pour à une procédure de dimensionnement par optimisation de système, qui requiert un modèle rapide et peut accepter beaucoup de contraintes. Cependant, la difficulté principale apparaît lors de la modélisation analytique des structures d’électronique de puissance, notamment celles ayant de la commutation naturelle.Cette thèse propose une approche de modélisation semi-analytique où la résolution des équations implicites est faite par Newton-Raphson ou SQP. Cependant, cette approche pose des difficultés de convergence de la méthode utilisée du point de vue numérique et du point de vue du mode de fonctionnement du convertisseur statique. Ainsi, cette thèse propose différentes alternatives pour les résoudre.En terme d’illustrations, cette thèse s’appuie particulièrement sur des applications avec des redresseurs à diodes qui sont largement utilisés dans les sous-stations de réseaux ferroviaires ou dans les réseaux d’avion,Notamment, un canal de puissance typique d’un Airbus de « nouvelle génération » sert d’application du point de vue de dimensionnement par optimisation
REGNSKAP I KOMMUNENE: En empirisk studie av Trondheim kommune
Dybdebasert master, 120 studiepoeng.Kommunens hovedoppgaver er å bruke de midlene de rår over til å dele det ut til innbyggerne gjennom velferd og innenfor de rammene lovgivningen og de folkevalgte fastsetter. Hensikten med denne utredningen er å se nærmere på Trondheim kommunes årsrapport og komme med forslag til eventuelle forbedringer. Hvordan kommunen har brukt de midlene den har til rådighet skal også studeres. Siden privat- og offentlig sektor har ulike formål, så har de også ulike bokføringssystem. Fokuset i denne utredningen er årsrapporten til Trondheim kommune, hvordan den er utarbeide og hvordan tallene i årsrapporten ser ut. Utredningen inneholder flere analyser med ulike komponenter. Der jeg tar for meg hvillke regnskapsregler som brukes for bokføring i kommunene. For å vite det må jeg undersøke regnskapet til kommunene. Der har jeg funnet ut at kommuneregnskapet følger de kommunale regnskapsreglene samt GKRS. Kommuneregnskapet føres i samsvar med grunnleggende regnskapsprinsipper, kvalitetskravene, regnskapsregler, regnskapsstandarder og god kommunal regnskapsskikk. Det er disse som samlet sett kalles rammeverket for kommuneregnskapet
The local uniform convergence of positive harmonic function sequence
The Harnack distance on space and its conformal invariance were constructed and studied by Herron. In this paper, we obtain the Harnack distance on domains in . Then, we use this concept to investigate some properties of the positive harmonic function class. These results are obtained in the complex plane, so it is advantageous to take some tools of the complex analysis. The main result of this paper is the property of the local uniform convergence of the positive harmonic sequences on a domain in the complex plane.The Harnack distance on space and its conformal invariance were constructed and studied by Herron. In this paper, we obtain the Harnack distance on domains in . Then, we use this concept to investigate some properties of the positive harmonic function class. These results are obtained in the complex plane, so it is advantageous to take some tools of the complex analysis. The main result of this paper is the property of the local uniform convergence of the positive harmonic sequences on a domain in the complex plane
Improving Multi-task Learning via Seeking Task-based Flat Regions
Multi-Task Learning (MTL) is a widely-used and powerful learning paradigm for
training deep neural networks that allows learning more than one objective by a
single backbone. Compared to training tasks separately, MTL significantly
reduces computational costs, improves data efficiency, and potentially enhances
model performance by leveraging knowledge across tasks. Hence, it has been
adopted in a variety of applications, ranging from computer vision to natural
language processing and speech recognition. Among them, there is an emerging
line of work in MTL that focuses on manipulating the task gradient to derive an
ultimate gradient descent direction to benefit all tasks. Despite achieving
impressive results on many benchmarks, directly applying these approaches
without using appropriate regularization techniques might lead to suboptimal
solutions on real-world problems. In particular, standard training that
minimizes the empirical loss on the training data can easily suffer from
overfitting to low-resource tasks or be spoiled by noisy-labeled ones, which
can cause negative transfer between tasks and overall performance drop. To
alleviate such problems, we propose to leverage a recently introduced training
method, named Sharpness-aware Minimization, which can enhance model
generalization ability on single-task learning. Accordingly, we present a novel
MTL training methodology, encouraging the model to find task-based flat minima
for coherently improving its generalization capability on all tasks. Finally,
we conduct comprehensive experiments on a variety of applications to
demonstrate the merit of our proposed approach to existing gradient-based MTL
methods, as suggested by our developed theory.Comment: 29 pages, 11 figures, 6 table
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