Electronic properties of a quantum wire with arbitrary bending angle

The electron transmission and bound state properties of a quantum wire with a sharp bend at arbitrary angle are studied, extending results on the right angle sharp bend (the L¿shaped wire). These new results are compared to those of a similar structure, the circular bend wire. The possibility of using a bent wire to perform transistor action is also discussed.

Narrative discourse in interviews to linguistically mixed couples

This article deals with self-referential storytelling in sociolinguistic interviews. It analyzes the personal stories in ten interviews to linguistically heterogeneous couples. For this purpose, it is applied the model of linguistic analysis of drama (Bruner & Weisser 1991) and it identifies and interprets discursive markers of autobiographical storytelling. Therefore it takes into consideration the elements referred to agents and to their actions, to the sequences of events, to the canon or rule, and to the narrator's perspective. At the same time, it proposes to extend our approach to the existence itself of the participants. Resumen.-"Discurso narrativo en entrevistas a parejas lingüísticamente mixtas". Este artículo trata de las narraciones autorreferenciales en entrevistas sociolingüísticas sobre concepciones y usos de las lenguas en familias lingüísticamente mixtas. Analiza los relatos que aparecen en diez entrevistas a padres y madres que forman parejas lingüísticamente heterogéneas. Aplica el modelo de análisis lingüístico del dramatismo (Bruner & Weisser 1991). Identifica e interpreta los marcadores discursivos de la narración autobiográfica. Con este propósito considera los constituyentes que se refieren a los agentes y sus acciones, a las secuencias de sucesos, al canon o norma y a la perspectiva del narrador. Y propone la ampliación del estudio a los guiones de vida de lo actores. Palabras clave: entrevista, relato, narración, pareja, política lingüística de la familia, multilingüismo, marcador discursivo.

Entry Regulation Asymmetries and Gasoline Competition in a Mixed Motorway Network

Regulatory and funding asymmetries in the Spanish motorway network produce huge differences in the structure of gasoline markets by motorway type: free or toll. While competition is encouraged among gas stations on free motorways, the regulations for toll motorways allow private concessionaires to auction all gas stations to the same provider, thereby limiting competition and consolidating market power. This paper reports how this regulatory asymmetry results in higher prices and fewer gas stations. Specifically, we show that competition is constrained on toll motorways by the granting of geographical monopolies, resulting in a small number of rivals operating in close proximity to each other, and allowing gas stations to operate as local monopolies. The lack of competition would seem to account for the price differential between toll and free motorways. According to available evidence, deregulation measures affecting toll motorway concessions could help to mitigate price inefficiencies and increase consumer welfare.

Beyond pure public and pure private management models: Mixed firms in the European Airport Industry

The use of private funding and management enjoys an increasing trend in airports. The literature has not paid enough attention to the mixed management models in this industry, although many European airports take the form of mixed firms or Institutional PPP, where ownership is shared between public and private sectors. We examine the determinants of the degree of private participation in the European airport sector. Drawing on a sample of the 100 largest European airports we estimate a multivariate equation in order to determine the role of airport characteristics, fiscal variables and political factors on the extent of private involvement. Our results confirm the alignment between public and private interests in PPPs. Fiscal constraints and market attractiveness promote private participation. Integrated governance models and the share of network carriers prevent the presence of private ownership, while the degree of private participation appears to be pragmatic rather than ideological.

The Evolution of the European Regulatory Framework for Electronic Communications

The paper reviews the historical transformation of the European regulatory framework for electronic communications from the era dominated by state-owned enterprises to the presence of regulated competition. In the course of these developments, the vision of the roles of the public and private sectors in electronic communications changed in expected and unexpected ways. While the period is characterized by a shift toward less direct state intervention, the intensity of regulation has increased in many areas. Most recently, in the wake of the financial crisis, new forms of state intervention can be observed, including public investment in communications infrastructure and public-private partnerships. As a result of the reforms, Europe has been able to achieve major successes but it also suffered unanticipated setbacks compared to other regions. The European Union emerged as the global leader in mobile communications during the 1990s and was able to roll-out first-generation broadband access networks more rapidly than many of its peers. Recently, however, Europe as a whole has not performed as well in deploying next-generation networks and advanced mobile communications services. The paper offers a political-economic explanation for these developments and assesses their effects on the performance of the European electronic communications sector and the economy. From this analysis, the European model emerges as a unique institutional arrangement with peculiar advantages and disadvantages. Once these are recognized, sensible next steps to build the strengths while avoiding the weaknesses of the model can be seen more clearly.

New technologies and nursing: use and perception of primary healthcare nurses about electronic health record in Catalonia, Spain

This study was aimed to analyze and assess the use and perception of electronic health records (EHRs) by nurses. The study sample included 113 nurses from different shifts of primary health facilities in Catalonia, Spain, devoted to adult as well as pediatric outpatients using EHRs throughout the year 2010. A majority of the sample (87.5%) were women and 12.5% were men. The average age was 44.27 years and the average time working in primary healthcare was 47.15 months. A majority (80.4%) received specific training on the use of the EHR and 19.6% did not. The use of the application required side technical support (mean: 3.42) and it is considered necessary to learn more about the performance of the application (mean: 3.50). The relationship between the average ratings that nurses have about the EHR and age shows that there is no statistically significant linear relationship (r = - 0.002, p-value = 0.984). As to how long they have used the EHRs, there are significant differences (r= -0.304, p-value = 0.00), so the more time the nurse takes using the EHR, the greater degree of satisfaction is shown. In addition, there are significant differences between nurses" perceptions regarding the EHR and gender (t = - 0.421, p-value = 0.675). Nurses assessed as positive the contribution of the EHRs in their nursing care day work (average score: 2.55/5). Considering that the usability of the EHR device is assessed as satisfactory, the results of the perception of nurses show that we must also take into account the training and emphasize the need for a side technical support in the implementation process of the EHR. Doing so, the positive perception that nurses have in regard to information and communication technology in general and with respect to the EHR in particular may be increased.

New technologies and nursing: use and perception of primary healthcare nurses about electronic health record in Catalonia, Spain

This study was aimed to analyze and assess the use and perception of electronic health records (EHRs) by nurses. The study sample included 113 nurses from different shifts of primary health facilities in Catalonia, Spain, devoted to adult as well as pediatric outpatients using EHRs throughout the year 2010. A majority of the sample (87.5%) were women and 12.5% were men. The average age was 44.27 years and the average time working in primary healthcare was 47.15 months. A majority (80.4%) received specific training on the use of the EHR and 19.6% did not. The use of the application required side technical support (mean: 3.42) and it is considered necessary to learn more about the performance of the application (mean: 3.50). The relationship between the average ratings that nurses have about the EHR and age shows that there is no statistically significant linear relationship (r = - 0.002, p-value = 0.984). As to how long they have used the EHRs, there are significant differences (r= -0.304, p-value = 0.00), so the more time the nurse takes using the EHR, the greater degree of satisfaction is shown. In addition, there are significant differences between nurses" perceptions regarding the EHR and gender (t = - 0.421, p-value = 0.675). Nurses assessed as positive the contribution of the EHRs in their nursing care day work (average score: 2.55/5). Considering that the usability of the EHR device is assessed as satisfactory, the results of the perception of nurses show that we must also take into account the training and emphasize the need for a side technical support in the implementation process of the EHR. Doing so, the positive perception that nurses have in regard to information and communication technology in general and with respect to the EHR in particular may be increased.

Public and Private Production in a Mixed Delivery System: Regulation, Competition and Costs

Academics and policy makers are increasingly shifting the debate concerning the best form of public service provision beyond the traditional dilemma between pure public and pure private delivery modes, because, among other reasons, there is a growing body of evidence that casts doubt on the existence of systematic cost savings from privatization, while any competition seems to be eroded over time. In this paper we compare the relative merits of public and private delivery within a mixed delivery system. We study the role played by ownership, transaction costs, and competition on local public service delivery within the same jurisdiction. Using a stochastic cost frontier, we analyze the public-private urban bus system in the Barcelona Metropolitan Area. Our results suggest that private firms tendering the service have higher delivery costs than those incurred by the public firm, especially when transaction costs are taken into account. Tenders, therefore, do not help to reduce delivery costs. Our results suggest that under a mixed delivery scheme, which permits the co-existence of public and private production, the metropolitan government and the regulator can use private delivery to contain costs in the public firm and, at the same time, benefit from the greater flexibility of private firms for dealing with events not provided for under contract.

Asymptotic analysis of stock price densities and implied volatilities in mixed stochastic models

In this paper, we obtain sharp asymptotic formulas with error estimates for the Mellin con- volution of functions de ned on (0;1), and use these formulas to characterize the asymptotic behavior of marginal distribution densities of stock price processes in mixed stochastic models. Special examples of mixed models are jump-di usion models and stochastic volatility models with jumps. We apply our general results to the Heston model with double exponential jumps, and make a detailed analysis of the asymptotic behavior of the stock price density, the call option pricing function, and the implied volatility in this model. We also obtain similar results for the Heston model with jumps distributed according to the NIG law.

Foliar photochemical processes and carbon metabolism under favourable and adverse winter conditions in a Mediterranean mixed forest, Catalonia (Spain)

Evergreen trees in the Mediterranean region must cope with a wide range of environmental stresses from summer drought to winter cold. The mildness of Mediterranean winters can periodically lead to favourable environmental conditions above the threshold for a positive carbon balance, benefitting evergreen woody species more than deciduous ones. The comparatively lower solar energy input in winter decreases the foliar light saturation point. This leads to a higher susceptibility to photoinhibitory stress especially when chilly (< 12 C) or freezing temperatures (< 0 C) coincide with clear skies and relatively high solar irradiances. Nonetheless, the advantage of evergreen species that are able to photosynthesize all year round where a significant fraction can be attributed to winter months, compensates for the lower carbon uptake during spring and summer in comparison to deciduous species. We investigated the ecophysiological behaviour of three co-occurring mature evergreen tree species (Quercus ilex L., Pinus halepensis Mill., and Arbutus unedo L.). Therefore, we collected twigs from the field during a period of mild winter conditions and after a sudden cold period. After both periods, the state of the photosynthetic machinery was tested in the laboratory by estimating the foliar photosynthetic potential with CO2 response curves in parallel with chlorophyll fluorescence measurements. The studied evergreen tree species benefited strongly from mild winter conditions by exhibiting extraordinarily high photosynthetic potentials. A sudden period of frost, however, negatively affected the photosynthetic apparatus, leading to significant decreases in key physiological parameters such as the maximum carboxylation velocity (Vc,max), the maximum photosynthetic electron transport rate (Jmax), and the optimal fluorometric quantum yield of photosystem II (Fv/Fm). The responses of Vc,max and Jmax were highly species specific, with Q. ilex exhibiting the highest and P. halepensis the lowest reductions. In contrast, the optimal fluorometric quantum yield of photosystem II (Fv/Fm) was significantly lower in A. unedo after the cold period. The leaf position played an important role in Q. ilex showing a stronger winter effect on sunlit leaves in comparison to shaded leaves. Our results generally agreed with the previous classifications of photoinhibition-tolerant (P. halepensis) and photoinhibitionavoiding (Q. ilex) species on the basis of their susceptibility to dynamic photoinhibition, whereas A. unedo was the least tolerant to photoinhibition, which was chronic in this species. Q. ilex and P. halepensis seem to follow contrasting photoprotective strategies. However, they seemed equally successful under the prevailing conditions exhibiting an adaptive advantage over A. unedo. These results show that our understanding of the dynamics of interspecific competition in Mediterranean ecosystems requires consideration of the physiological behaviour during winter which may have important implications for long-term carbon budgets and growth trends.

The use of mixed methods research in the behavioral sciences field

Mixed methods research involves the combined use of quantitative and qualitative methods in the same research study, and it is becoming increasingly important in several scientific areas. The aim of this paper is to review and compare through a mixed methods multiple-case study the application of this methodology in three reputable behavioural science journals: the Journal of Organizational Behavior, Addictive Behaviors and Psicothema. A quantitative analysis was carried out to review all the papers published in these journals during the period 2003-2008 and classify them into two blocks: theoretical and empirical, with the latter being further subdivided into three subtypes (quantitative, qualitative and mixed). A qualitative analysis determined the main characteristics of the mixed methods studies identified, in order to describe in more detail the ways in which the two methods are combined based on their purpose, priority, implementation and research design. From the journals selected, a total of 1.958 articles were analysed, the majority of which corresponded to empirical studies, with only a small number referring to research that used mixed methods. Nonetheless, mixed methods research does appear in all the behavioural science journals studied within the period selected, showing a range of designs, where the sequential equal weight mixed methods research design seems to stand out.

The use of mixed methods research in interdisciplinary educational journals

Mixed methods research is becoming increasingly important in several scientific areas. The analysis of prevalence rates is a new line of research that has emerged in mixed methods research, and this methodological approach has only been applied carefully in a handful of journals. The purpose of this article was to analyse the prevalence of mixed methods research in interdisciplinary educational journals. Moreover, the main characteristics of the mixed methods articles identified were examined. This study used a mixed methods approach to analyse these aspects. Specifically, a partially mixed sequential equal status multiple-case study design was applied with a development mixed methods purpose. Three educational journals in different disciplines were reviewed from 2005 to 2010 (Academy of Management Learning and Education, Educational Psychology Review, Journal of the Learning Sciences). The findings show differences among the journals in the prevalence rates and characteristics of the mixed methods studies

Response of fine root respiration to variations in biotic and abiotic factors in a mixed Mediterranean forest affected by drought-induced secondary succession

Understanding the factors controlling fine root respiration (FRR) at different temporal scales will help to improve our knowledge about the spatial and temporal variability of soil respiration (SR) and to improve future predictions of CO2 effluxes to the atmosphere. Here we present a comparative study of how FRR respond to variability in soil temperature and moisture in two widely spread species, Scots pines (Pinus sylvestris L.) and Holm-oaks (HO; Quercus ilex L.). Those two species show contrasting water use strategies during the extreme summer-drought conditions that characterize the Mediterranean climate. The study was carried out on a mixed Mediterranean forest where Scots pines affected by drought induced die-back are slowly being replaced by the more drought resistant HO. FRR was measured in spring and early fall 2013 in excised roots freshly removed from the soil and collected under HO and under Scots pines at three different health stages: dead (D), defoliated (DP) and non-defoliated (NDP). Variations in soil temperature, soil water content and daily mean assimilation per tree were also recorded to evaluate FRR sensibility to abiotic and biotic environmental variations. Our results show that values of FRR were substantially lower under HO (1.26 ± 0.16 microgram CO2 /groot·min) than under living pines (1.89 ± 0.19 microgram CO2 /groot·min) which disagrees with the similar rates of soil respiration previously observed under both canopies and suggest that FRR contribution to total SR varies under different tree species. The similarity of FRR rates under HO and DP furthermore confirms other previous studies suggesting a recent Holm-oak root colonization of the gaps under dead trees. A linear mixed effect model approach indicated that seasonal variations in FRR were best explained by soil temperature (p<0.05) while soil moisture was not exerting any direct control over FRR, despite the low soil moisture values during the summer sampling. Plant assimilation rates were positively related to FRR explaining part of the observed variability (p<0.01). However the positive relations of FRR with plant assimilation occurred mainly during spring, when both soil moisture and plant assimilation rates were higher. Our results finally suggest that plants might be able to maintain relatively high rates of FRR during the sub-optimal abiotic and biotic summer conditions probably thanks to their capacity to re-mobilize carbon reserves and their capacity to passively move water from moister layers to upper layers with lower water potentials (where the FR were collected) by hydraulic lift.

El comentario de textos electrónicos = Commentary on electronic texts

When sat in front of a computer screen and keyboard, we read and write different kinds of texts (chats, blogs, websites,etc.) and do so differently (with links, photographs, icons, etc.). However, we still comment on as many texts as in the pastin both public and private spheres. After setting out some typical features of reading and writing electronic texts, we givesome examples of students' colloquial commentary out of school, list some of the commonest academic tasks and offersome ideas and make some recommendations for making progress in this field