29 resultados para Linear forms in logarithms


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Our PhD study focuses on the role of aspectual marking in expressing simultaneity of events in Tunisian Arabic as a first language, French as a first language, as well as in French as a second language by Tunisian learners at different acquisitional stages. We examine how the explicit markers of on-goingness qa:’id and «en train de» in Tunisian Arabic and in French respectively are used to express this temporal relation, in competition with the simple forms, the prefixed verb form in Tunisian Arabic and the présent de l’indicatif in French. We use a complex verbal task of retelling simultaneous events sharing an interval on the time axis based on eight videos presenting two situations happening in parallel. Two types of simultaneity are exploited: perfect simultaneity (when the two situations are parallel to each other) and inclusion (one situation is framed by the second one). Our informants in French and in Tunisian Arabic have two profiles, highly educated and low educated speakers. We show that the participants’ response to the retelling task varies according to their profiles, and so does their use of the on-goingness devices in the expression of simultaneity. The differences observed between the two profile groups are explained by the degree to which the speakers have developed a habit of responding to tasks. This is a skill typically acquired during schooling. We notice overall that the use of qa:’id as well as of «en train de» is less frequent in the data than the use of the simple forms. However, qa:’id as well as «en train de» are employed to play discursive roles that go beyond the proposition level. We postulate that despite the shared features between Tunisian Arabic and French regarding marking the concept of on-goingness, namely the presence of explicit lexical, not fully grammaticalised markers competing with other non-marked forms, the way they are used in the discourse of simultaneous events shows clear differences. We explain that «en train de» plays a more contrastive role than qa:’id and its use in discourse obeys a stricter rule. In cases of the inclusion type of simultaneity, it is used to construe the ‘framing’ event that encloses the second event. In construing perfectly simultaneneous events, and when both «en train de» and présent de l’indicatif are used, the proposition with «en train de» generally precedes the proposition with présent de l’indicatif, and not the other way around. qa:id obeys, but to a less strict rule as it can be used interchangeably with the simple form regardless of the order of propositions. The contrastive analysis of French L1 and L2 reveals learners’ deviations from natives’ use of on-goingness devices. They generalise the use of «en train de» and apply different rules to the interaction of the different marked and unmarked forms in discourse. Learners do not master its role in discourse even at advanced stages of acquisition despite its possible emergence around the basic and intermediate varieties. We conclude that the native speakers’ use of «en train de» involves mastering its role at the macro-structure level. This feature, not explicitly available to learners in the input, might persistently present a challenge to L2 acquisition of the periphrasis.

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Orally disintegrating tablets (ODTs) offer many advantages over the conventional oral dosage forms in terms of convenience and ease of use. Over the last decade, substantial advances in the formulation of ODTs have been achieved in academia and industry that resulted in the emerging of a large number of patents. The aim of this review is to summarise the most recent patents in ODT formulations and highlight their motivations, inventive steps and significances in the development of ODT formulations. Five major techniques have been applied in manufacturing of ODTs, namely conventional tablet press, moulding, freeze drying, tablet loading and pulverization, with majority of the patents dedicated to the use of conventional tablet pressing. The patents have addressed various issues concerning the manufacturing of robust and practical ODT formulations by disclosing new manufacturing techniques, advantageous materials, and innovative formulation steps. However, future developments are required to reduce the cost and widening the application of the new manufacturing techniques, while simplifying and shortening the formulation steps will be crucial in the well established ones.

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In the general introduction of the road-accident phenomenon inside and outside Iran, the results of previous research-works and international conferences and seminars on road-safety have been reviewed. Also a sample-road between Tehran and Mashad has been investigated as a case-study. Examining the road-accident data and iriformation,first: the information presented in road-accident report-forms in developed countries is discussed and, second: the procedures for road-accident data collection in Iran are investigated in detail. The data supplied by Iran Road-Police Central Statistics Office, is analysed, different rates are computed, due comparisons with other nations are made, and the results are discussed. Also such analysis and comparisons are presented for different provinces of Iran. It is concluded that each province with its own natural, geographical, social and economical characteristics possesses its own reasons for the quality and quantity of road-accidents and therefore must receive its own appropriate remedial solutions. The question~ of "what is the cost of road-accidents", "why and how evaluate the cost", "what is the appropriate way of approach to such evaluation" are all discussed and then "the cost of road-accidents in Iran" based on two different approaches: "Gross National Output"and "court award" is computed. It is concluded that this cost is about 1.5 per cent of the country's national product. In Appendix 3 an impressive example is given of the trend of costs and benefits that can be attributed to investment in road-safety measures.

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This thesis is an examination of organisational issues faced by Third Sector organisations which undertake nonviolent direct action. A case study methodology is employed and data gathered from four organisations: Earth First!; genetiX Snowball; Greenpeace; and Trident Ploughshares. The argument commences with a review of the literature which shows that little is known of the organising of nonviolent direct action. Operational definitions of 'organisation' and 'nonviolent direct action' are drawn from the literature. 'Organisation' is conceptualised using new institutionalism. 'Nonviolent direct action' is conceptualised using new social movement theory. These concepts inform the case study methodology in the choice of case, the organisations selected and the data gathering tools. Most data were gathered by semi-structured interview and participant observation. The research findings result from theory-building arising from thick descriptions of the case in the four organisations. The findings suggest that nonviolent direct action is qualitatively different from terrorism or violence. Although there is much diversity in philosophies of nonviolence, the practice of nonviolent direct action has much in common across the four organisations. The argument is that nonviolent direct action is an institution. The findings also suggest that new institutionalism is a fruitful approach to studies of these organisations. Along with nonviolent direct action, three other institutions are identified: 'rules'; consensus decision-making; and 'affinity groups'. An unanticipated finding is how the four organisations are instances of innovation. Tentative theory is developed which brings together the seemingly incompatible concepts of institutions and innovation. The theory suggests preconditions and then stages in the development of new organisational forms in new social movements: innovation. The three pre-conditions are: the existence of an institutional field; an 'institution-broker' with access to different domains; and a shared 'problem' to resolve. The three stages are: unlocking existing knowledge and practice; bridging different domains of practice or different fields to add, develop or translocate those practices; and establishing those practices within their new combinations or novel locations. Participants are able to move into and between these new organisational forms because they consist of familiar and habitual institutional behaviour.

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Limitations in the performance of coherent transmission systems employing digital back-propagation due to four-wave mixing impairments are reported for the first time. A significant performance constraint is identified, originating from four-wave mixing between signals and amplified spontaneous emission noise which induces a linear increase in the standard deviation of the received field with signal power, and linear dependence on transmission distance.

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For a Switched Reluctance Motor (SRM), the flux linkage characteristic is the most basic magnetic characteristic, and many other quantities, including the incremental inductance, back emf, and electromagnetic torque can be determined indirectly from it. In this paper, two methods of measuring the flux linkage profile of an SRM from the phase winding voltage and current measurements, with and without rotor locking devices, are presented. Torque, incremental inductance and back emf characteristics of the SRM are then obtained from the flux linkage measurements. The torque of the SRM is also measured directly as a comparison, and the closeness of the calculated and directly measured torque curves suggests the validity of the method to obtain the SRM torque, incremental inductance and back emf profiles from the flux linkage measurements. © 2013 IEEE.

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Epilepsy is one of the most common neurological disorders, a large fraction of which is resistant to pharmacotherapy. In this light, understanding the mechanisms of epilepsy and its intractable forms in particular could create new targets for pharmacotherapeutic intervention. The current project explores the dynamic changes in neuronal network function in the chronic temporal lobe epilepsy (TLE) in rat and human brain in vitro. I focused on the process of establishment of epilepsy (epileptogenesis) in the temporal lobe. Rhythmic behaviour of the hippocampal neuronal networks in healthy animals was explored using spontaneous oscillations in the gamma frequency band (SγO). The use of an improved brain slice preparation technique resulted in the natural occurence (in the absence of pharmacological stimulation) of rhythmic activity, which was then pharmacologically characterised and compared to other models of gamma oscillations (KA- and CCh-induced oscillations) using local field potential recording technique. The results showed that SγO differed from pharmacologically driven models, suggesting higher physiological relevance of SγO. Network activity was also explored in the medial entorhinal cortex (mEC), where spontaneous slow wave oscillations (SWO) were detected. To investigate the course of chronic TLE establishment, a refined Li-pilocarpine-based model of epilepsy (RISE) was developed. The model significantly reduced animal mortality and demonstrated reduced intensity, yet high morbidy with almost 70% mean success rate of developing spontaneous recurrent seizures. We used SγO to characterize changes in the hippocampal neuronal networks throughout the epileptogenesis. The results showed that the network remained largely intact, demonstrating the subtle nature of the RISE model. Despite this, a reduction in network activity was detected during the so-called latent (no seizure) period, which was hypothesized to occur due to network fragmentation and an abnormal function of kainate receptors (KAr). We therefore explored the function of KAr by challenging SγO with kainic acid (KA). The results demonstrated a remarkable decrease in KAr response during the latent period, suggesting KAr dysfunction or altered expression, which will be further investigated using a variety of electrophysiological and immunocytochemical methods. The entorhinal cortex, together with the hippocampus, is known to play an important role in the TLE. Considering this, we investigated neuronal network function of the mEC during epileptogenesis using SWO. The results demonstrated a striking difference in AMPAr function, with possible receptor upregulation or abnormal composition in the early development of epilepsy. Alterations in receptor function inevitably lead to changes in the network function, which may play an important role in the development of epilepsy. Preliminary investigations were made using slices of human brain tissue taken following surgery for intratctable epilepsy. Initial results showed that oscillogenesis could be induced in human brain slices and that such network activity was pharmacologically similar to that observed in rodent brain. Overall, our findings suggest that excitatory glutamatergic transmission is heavily involved in the process of epileptogenesis. Together with other types of receptors, KAr and AMPAr contribute to epilepsy establishment and may be the key to uncovering its mechanism.

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The synthesis and crystal structure of a novel one-dimensional Cu(II) compound [Cu(1,2-bis(tetrazol-1-yl)ethane)3](ClO4)2 are described. The single-crystal X-ray structure determination was carried out at 298 K. The molecular structure consists of a linear chain in which the Cu(II) ions are linked by three N4,N4' coordinating bis(tetrazole) ligands in syn conformation. The Cu(II) ions are in a Jahn-Teller distorted octahedral environment (Cu(1)-N(11)=2.034(2) Å, Cu(1)-N(21)=2.041(2) Å and Cu(1)-N(31)=2.391(2) Å). The Cu⋯Cu separations are 7.420(3) Å.

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While the literature has suggested the possibility of breach being composed of multiple facets, no previous study has investigated this possibility empirically. This study examined the factor structure of typical component forms in order to develop a multiple component form measure of breach. Two studies were conducted. In study 1 (N = 420) multi-item measures based on causal indicators representing promissory obligations were developed for the five potential component forms (delay, magnitude, type/form, inequity and reciprocal imbalance). Exploratory factor analysis showed that the five components loaded onto one higher order factor, namely psychological contract breach suggesting that breach is composed of different aspects rather than types of breach. Confirmatory factor analysis provided further evidence for the proposed model. In addition, the model achieved high construct reliability and showed good construct, convergent, discriminant and predictive validity. Study 2 data (N = 189), used to validate study 1 results, compared the multiple-component measure with an established multiple item measure of breach (rather than a single item as in study 1) and also tested for discriminant validity with an established multiple item measure of violation. Findings replicated those in study 1. The findings have important implications for considering alternative, more comprehensive and elaborate ways of assessing breach.

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We report on a new vector model of an erbium-doped fibre laser mode locked with carbon nanotubes. This model goes beyond the limitations of the previously used models based on either coupled nonlinear Schrödinger or Ginzburg-Landau equations. Unlike the previous models, it accounts for the vector nature of the interaction between an optical field and an erbium-doped active medium, slow relaxation dynamics of erbium ions, linear birefringence in a fibre, linear and circular birefringence of a laser cavity caused by in-cavity polarization controller and light-induced anisotropy caused by elliptically polarized pump field. Interplay of aforementioned factors changes coherent coupling of two polarization modes at a long time scale and so results in a new family of vector solitons (VSs) with fast and slowly evolving states of polarization. The observed VSs can be of interest in secure communications, trapping and manipulation of atoms and nanoparticles, control of magnetization in data storage devices and many other areas.

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Endothelial dysfunction (EDF) reflects pathophysiologicalchanges in the phenotype and functions of endothelial cells that result fromand/or contribute to a plethora of cardiovascular diseases. We review the roleof hydrogen sulfide (H2S) in the pathogenesis of EDF, one of thefastest advancing research topics. Conventionally treated as an environmentpollutant, H2S is also produced in endothelial cells and participatesin the fine regulation of endothelial integrity and functions. Disturbed H2Sbioavailability has been suggested to be a novel indicator of EDF progress andprognosis. EDF manifests in different forms in multiple pathologies, buttherapeutics aimed at remedying altered H2S bioavailability maybenefit all.

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OBJECTIVE: To identify the cross-national prevalence of psychotic symptoms in the general population and to analyze their impact on health status. METHOD: The sample was composed of 256,445 subjects (55.9% women), from nationally representative samples of 52 countries worldwide participating in the World Health Organization's World Health Survey. Standardized and weighted prevalence of psychotic symptoms were calculated in addition to the impact on health status as assessed by functioning in multiple domains. RESULTS: Overall prevalences for specific symptoms ranged from 4.80% (SE = 0.14) for delusions of control to 8.37% (SE = 0.20) for delusions of reference and persecution. Prevalence figures varied greatly across countries. All symptoms of psychosis produced a significant decline in health status after controlling for potential confounders. There was a clear change in health impact between subjects not reporting any symptom and those reporting at least one symptom (effect size of 0.55). CONCLUSIONS: The prevalence of the presence of at least one psychotic symptom has a wide range worldwide varying as much as from 0.8% to 31.4%. Psychotic symptoms signal a problem of potential public health concern, independent of the presence of a full diagnosis of psychosis, as they are common and are related to a significant decrement in health status. The presence of at least one psychotic symptom is related to a significant poorer health status, with a regular linear decrement in health depending on the number of symptoms.

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Continuous progress in optical communication technology and corresponding increasing data rates in core fiber communication systems are stimulated by the evergrowing capacity demand due to constantly emerging new bandwidth-hungry services like cloud computing, ultra-high-definition video streams, etc. This demand is pushing the required capacity of optical communication lines close to the theoretical limit of a standard single-mode fiber, which is imposed by Kerr nonlinearity [1–4]. In recent years, there have been extensive efforts in mitigating the detrimental impact of fiber nonlinearity on signal transmission, through various compensation techniques. However, there are still many challenges in applying these methods, because a majority of technologies utilized in the inherently nonlinear fiber communication systems had been originally developed for linear communication channels. Thereby, the application of ”linear techniques” in a fiber communication systems is inevitably limited by the nonlinear properties of the fiber medium. The quest for the optimal design of a nonlinear transmission channels, development of nonlinear communication technqiues and the usage of nonlinearity in a“constructive” way have occupied researchers for quite a long time.

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This paper introduces a quantitative method for identifying newly emerging word forms in large time-stamped corpora of natural language and then describes an analysis of lexical emergence in American social media using this method based on a multi-billion word corpus of Tweets collected between October 2013 and November 2014. In total 29 emerging word forms, which represent various semantic classes, grammatical parts-of speech, and word formations processes, were identified through this analysis. These 29 forms are then examined from various perspectives in order to begin to better understand the process of lexical emergence.