Computer programs calculate potential and charge distributions in a plasma

Computer program determines the potential and charge distributions between two electrodes in a plasma. Solutions of the Vlasov equations for plane, cylindrical, and spherical geometries are determined and density distributions are found for each of these configurations over a range of conditions

On the theory of Krull rings and injective modules

In the first chapter we give an outline of classical KRULL rings as in SAMUEL (1964), BOURBAKI (1965) and FOSSUM (1973). In the second chapter we introduce two notions important to our treatment of KRULL theory. The first is injective modules and.the second torsion theories. We then look at injective modules over Noetherian rings as in MATLIS [1958] and then over KRULL rings as in BECK [1971]. We show that for a KRULL ring there is a torsion theory (N,M) where N is the pseudo-zero modules and M the set of N-torsion-free (BECK calls these co-divisorial) modules. From LAMBEK [1971] there is a full abelian sub category C, namely the category of N-torsion-free, N-divisible modules, with exact reflector. We show in C (I) every direct sum of injective modules is injective and (II) C has global dimension at most one. It is these two properties that we exploit in the third chapter to give another characterization of KRULL rings. Then we generalize this to rings with zero-divisors and find that (i) R has to be reduced (ii) the ring is KRULL if and only if it is a finite product of fields and KRULL domains (iii) the injective envelope of the ring is semi-simple artinian. We then generalize the ideas to rings of higher dimension

Consequences of Brief Periods of Sleep Loss on Hippocampus-Dependent Memory and Synaptic Plasticity

Hippocampal cellular and molecular processes critical for memory consolidation are affected by the amount and quality of sleep attained. Questions remain with regard to how sleep enhances memory, what parameters of sleep after learning are optimal for memory consolidation, and what underlying hippocampal molecular players are dysregulated by sleep deprivation to impair memory consolidation and plasticity. In this dissertation, I describe experiments that we performed to identify the time window where memory consolidation is sensitive to sleep loss as well as to characterize two potential molecular players targeted by sleep deprivation. Because consolidation appears to have a particular window where it is sensitive to sleep loss, we explore the parameters of this time window in Chapter 2. Our results suggest that a specific 3-hour period of sleep loss during consolidation disrupts both memory and plasticity. In the second portion of this dissertation, I examine the mechanisms by which sleep deprivation impairs hippocampus-dependent memory consolidation. In Chapter 3, we show that loss of the phosphodiesterase (PDE) 4A, an enzyme responsible for decreasing cAMP signaling, rescues spatial memory disrupted by sleep loss. These results further implicate cAMP signaling with the negative effects of sleep deprivation on memory. Obtaining adequate sleep is challenging in a society that values work around the clock. Therefore, the development of interventions to combat the negative cognitive effects of sleep deprivation is critical. However, a limited number of therapeutics exists that are able to enhance cognition in the face of insufficient sleep. The identification of the temporal characteristics of sleep loss and the molecular pathways implicated in the deleterious effects of sleep deprivation on memory could potentially yield new targets for the development of more effective drugs

Le centre d'apprentissage de langues: Représentations, motivations et réalités.

Au delà de son aspect matériel, la réalité d'un centre de langues est composée d'un 'espace' cognitif destiné à favoriser l'apprentissage. Les apprenants évoluent dans cet espace de manière plus ou moins autonome, le personnel du centre étant là pour les guider le cas échéant. Afin de trouver une organisation optimale, le personnel tente de prendre en compte les représentations et les motivations des étudiants, pour qui l'apprentissage dans un centre de langues est souvent une expérience nouvelle. Une évaluation du centre est nécessaire pour savoir comment ses ressources sont perçues et utilisées. Le dispositif mis en place peut ensuite être modifié pour favoriser l'émergence de stratégies propices à l'apprentissage. Nous présentons ici un exemple de cette réalité « interne » d'un centre de langues, où l'espace créé résulte de la rencontre entre réflexion didactique, supports matériels et comportements d'apprenants

Le centre d'apprentissage de langues: Représentations, motivations et réalités.

Au delà de son aspect matériel, la réalité d'un centre de langues est composée d'un 'espace' cognitif destiné à favoriser l'apprentissage. Les apprenants évoluent dans cet espace de manière plus ou moins autonome, le personnel du centre étant là pour les guider le cas échéant. Afin de trouver une organisation optimale, le personnel tente de prendre en compte les représentations et les motivations des étudiants, pour qui l'apprentissage dans un centre de langues est souvent une expérience nouvelle. Une évaluation du centre est nécessaire pour savoir comment ses ressources sont perçues et utilisées. Le dispositif mis en place peut ensuite être modifié pour favoriser l'émergence de stratégies propices à l'apprentissage. Nous présentons ici un exemple de cette réalité « interne » d'un centre de langues, où l'espace créé résulte de la rencontre entre réflexion didactique, supports matériels et comportements d'apprenants

Rural Entrepreneurship Success Factors: An Empirical Investigation in an Emerging Market

Small businesses in rural communities play a key role in achieving global sustainable economic development because they are the driving force of poverty reduction, job creation, resiliency, and economic development. This study examines the factors that drive the success or failure of small businesses in rural communities in an emerging market. The methodology is survey interview research using a logistic regression model to test the Lussier success vs failure prediction model with a sample of 230 businesses (successful n = 120, failed n = 110) from the rural communities in an emerging market. This study supports the Lussier model validity (p < 0.01) with a high overall accuracy of 71% in predicting a venture as successful or failed. Capital, industry experience, staffing, and marketing skills are the most significant (t-values < .05) factors that distinguish successful from failed rural businesses in an emerging market. The findings can help future, and nascent rural entrepreneurs avoid failure and successfully contribute to economic development. Implications for government agencies, public regulatory bodies, financial institutions, investors, suppliers, educators, professional institutions, and society, as well as limitations and future research, are presented. This study also contributes to the international validity of the Lussier model that can be used in both advanced and developing economies, and it contributes to the development of theory

On \u3cem\u3eK\u3c/em\u3e\u3cem\u3e\u3csub\u3es,t\u3c/sub\u3e\u3c/em\u3e-minors in Graphs with Given Average Degree

Let D(H) be the minimum d such that every graph G with average degree d has an H-minor. Myers and Thomason found good bounds on D(H) for almost all graphs H and proved that for \u27balanced\u27 H random graphs provide extremal examples and determine the extremal function. Examples of \u27unbalanced graphs\u27 are complete bipartite graphs Ks,t for a fixed s and large t. Myers proved upper bounds on D(Ks,t ) and made a conjecture on the order of magnitude of D(Ks,t ) for a fixed s and t → ∞. He also found exact values for D(K2,t) for an infinite series of t. In this paper, we confirm the conjecture of Myers and find asymptotically (in s) exact bounds on D(Ks,t ) for a fixed s and large t

A framework for understanding the quantitative demands of higher education

For many students entering higher education in South Africa there is an articulation gap between the demands of the curriculum and their competencies. This mismatch is particularly critical in the area of quantitative literacy (mathematical literacy, numeracy) and if not addressed, has negative consequences for equity of outcomes for higher education. There is a need to make explicit the quantitative literacy demands of the curriculum so that they can be examined critically and addressed by educational interventions and other curriculum changes. We describe our approach to characterizing the quantitative literacy demands in curricula in disciplines, by presenting a framework for analysing aspects of quantitative literacy events in the curriculum. This is useful for helping educators to recognize the demands on students' quantitative literacy (and assumptions about students' competencies) that are often implicit in their curricula, for the purpose of informing the design of education interventions and for developing test constructs

Smart Shopping Cart

Most of the people in this modern world spend the lot of time in departmental stores. It has been found that a lot of time is being wasted particularly at the billing section. Here by this paper represents a new methodology of smart shopping cart which saves the lot of time. The cart contains a sensor RFID tag, LCD module so that the product can be scanned in the cart and the final amount is displayed in the LCD placed in the trolley itself and there by pay only the cash at the counter. On swipe the credit cards. It will overcome the barcode technology which gets lot of problem during scanning. This proposed method is safe and secure. The cost of this project is also very low. This methodology helps both the shopper and shopkeeper