Interplay of spectral efficiency, power and doppler spectrum for reference-signal-assisted wireless communication

Expressions relating spectral efficiency, power, and Doppler spectrum, are derived for Rayleigh-faded wireless channels with Gaussian signal transmission. No side information on the state of the channel is assumed at the receiver. Rather, periodic reference signals are postulated in accordance with the functioning of most wireless systems. The analysis relies on a well-established lower bound, generally tight and asymptotically exact at low SNR. In contrast with most previous studies, which relied on block-fading channel models, a continuous-fading model is adopted. This embeds the Doppler spectrum directly in the derived expressions, imbuing them with practical significance. Closed-form relationships are obtained for the popular Clarke-Jakes spectrum and informative expansions, valid for arbitrary spectra, are found for the low- and high-power regimes. While the paper focuses on scalar channels, the extension to multiantenna settings is also discussed.

Phylogenetic relationships in the subfamily Psychodinae (Diptera, Psychodidae)

Thanks to recent advances in molecular systematics, our knowledge of phylogenetic relationships within the order Diptera has dramatically improved. However, relationships at lower taxonomic levels remain poorly investigated in several neglected groups, such as the highly diversified moth-fly subfamily Psychodinae (Lower Diptera), which occurs in numerous terrestrial ecosystems. In this study, we aimed to understand the phylogenetic relationships among 52 Palearctic taxa from all currently known Palearctic tribes and subtribes of this subfamily, based on mitochondrial DNA. Our results demonstrate that in light of the classical systematics of Psychodinae, none of the tribes sensu Je?ek or sensu Vaillant is monophyletic, whereas at least five of the 12 sampled genera were not monophyletic. The results presented in this study provide a valuable backbone for future work aiming at identifying morphological synapomorphies to propose a new tribal classification.

Astrocyte-neuron metabolic relationships: for better and for worse.

In recent years, previously unsuspected roles of astrocytes have been revealed, largely owing to the development of new tools enabling their selective study in situ. These exciting findings add to the large body of evidence demonstrating that astrocytes play a central role in brain homeostasis, in particular via the numerous cooperative metabolic processes they establish with neurons, such as the supply of energy metabolites and neurotransmitter recycling functions. Furthermore, impairments in astrocytic function are increasingly being recognized as an important contributor to neuronal dysfunction and, in particular, neurodegenerative processes. In this review, we discuss recent evidence supporting important roles for astrocytes in neuropathological conditions such as neuroinflammation, amyotrophic lateral sclerosis and Alzheimer's disease. We also explore the potential for neuroprotective therapeutics based on the modulation of astrocytic functions.

Cooperatives and Contracting in Agriculture: The Case of West Liberty Foods, October 2005

The West Liberty Foods turkey cooperative was formed in 1996 to purchase the assets and assume operations of Louis Rich Foods (an investor-owned processing rm), which, at the time, announced the imminent shutdown of its West Liberty, Iowa, processing facility. We study the creation and performance of this �new generation� cooperative using eld interviews with grower members and company management. We describe changes, before and after the buyout, in the contractual apparatus used for procuring live turkeys, and in the communication requirements, work expectations, and nancial positions of growers. During the private ownership period, most of the inputs (except labor and facilities) were provided by the rm; there was substantial supervision of the growers' actions; growers faced little price and production risk; and growers' equity was due largely to ownership of land and other farm assets. Our interviews reveal that, after cooperative formation, growers were exposed to considerable additional risk; monitoring of growers by the rm was less intensive; grower time and effort commitments to turkey production increased substantially; and a signicant fraction of rm (cooperative) equity came from growers' willingness to leverage their farm and personal assets (and hence indirectly their existing relationships with local lenders). We argue that some of these changes are consistent with a nancial contract where asset pledging and its corollary risk generate higher work effort by growers and a reduction in agency rents. These economies likely compensate for an organizational deadweight loss traditionally associated with cooperative governance.

Alliance patterns over the course of short-term dynamic psychotherapy: The shape of productive relationships.

The shape of alliance processes over the course of psychotherapy has already been studied in several process-outcome studies on very brief psychotherapy. The present study applies the shape-of-change methodology to short-term dynamic psychotherapies and complements this method with hierarchical linear modeling. A total of 50 psychotherapies of up to 40 sessions were included. Alliance was measured at the end of each session. The results indicate that a linear progression model is most adequate. Three main patterns were found: stable, linear, and quadratic growth. The linear growth pattern, along with the slope parameter, was related to treatment outcome. This study sheds additional light on alliance process research, underscores the importance of linear alliance progression for outcome, and also fosters a better understanding of its limitations.

Personal and household care giving for adult children to parents and social stratification

Using SHARE database the paper explores the factors conditioning personalcare giving from adult children to their parents. Frequency and intensity ofpersonal care is contrasted with the reciprocal expectations that children haveabout wealth inheritance from their parents and with the opportunity costs of helping, as well as with the capacity of parents of getting help from othersources of personal care. The results may help to understand how inequalitiesin accessing to formal services relate with intergenerational solidarity.

International nursing : cultivating a culture of empowerment

International nursing has been a growing phenomenon throughout the globe. International nurses have been found to be an asset to healthcare organizations and an important part of the health care team. However, growing concern for the plight of international nurses facing obstacles such as professional stagnation and exploitation has spurred the development of strategies to mitigate and ameliorate the experiences of nurses working abroad. In this respect, the purpose of this study was to explore the management-influenced factors and the nurse team-influenced factors that promote the empowerment of the international nurse in the health care setting. The methodology used in this study was a systemic review. After a rigorous search for relevant empirical studies using OVID database, eight empirical research studies were selected using systematic review methodology to collect, analyze and synthesize data. The selected eight empirical studies were then subjected to a content analysis. The results suggested that the empowerment of an international nurse is inseparable from the empowerment of the health care organization. Based on the findings in this study, strategies to promote international nurses were found to mirror strategies evidenced to empower the nursing organization. Some of the management-influenced factors which were found to facilitate empowerment included a diversity rich work culture, transformational leadership at the management level, and a responsibility to foster the values of the organization. The team-influenced factors which were found to contribute to the empowerment of the international nurse included a united mutually-interdependent nurse team, shared accountability among the members of the nurse team, and the building of trust in work relationships. To conlude, this study indicates that efforts to empower international nurses without considering the work culture and the organization as a whole are futile because empowerment cannot take place in an environment that lacks antecedent conditions. Strategies to empower the international nurse should not focus on the deficits and special needs of the international nurse, but should focus on the similarities and commonalities of the nursing body. Empowerment of the international nurse mean open honest communication, supportive work environment, and a firm policy to quell disruptive elements that threaten the organization's values, mission, and philosophy of care.

Conocimiento de la ley y preparación del personal sanitario sobre el proceso asistencial de la muerte

Este estudio apunta a conocer la percepción que los profesionales de la salud (médicos, enfermeras y auxiliares de enfermería) tienen acerca de su preparación en el cuidado de los enfermos terminales y determinar sus conocimientos sobre la legislación de cuidados paliativos. Se ha realizado un estudio transversal, en un hospital de Granada (España), mediante la aplicación de un cuestionario ad hoc. Los resultados muestran que la mayoría del personal ha trabajado con pacientes en el final de su vida, pero sólo la mitad cree tener la formación adecuada para cuidarlos. Una parte considerable dice no conocer la legislación actual en cuidados paliativos. La mayoría de los profesionales plantearía la retirada de terapias para el mantenimiento de la vida y desconocen el mecanismo para informar sobre la cumplimentación del Testamento Vital, como indica el Plan de Cuidados Paliativos de Andalucía (España).

The Economic Effects of Christian Moralities

This article examines the different influences that Catholicism and Protestantism exert on economically relevant values. It argues that Catholic theology and practice facilitate personal transactions while Protestantism favors values and types of moral and legal enforcement better adapted for impersonal trade. Protestantism may thus be more conducive to economic growth through anonymous exchange while Catholicism may provide better support for personal contracting. Several components of this hypothesis are confirmed using statistical models with data from the 1998 ISSP international survey on religion. These show that Protestants are more trusting of anonymous counter parties, develop more reliable institutions for legal enforcement and are more willing to spend resources on monitoring and punishing other members of the community. Catholicism is more protective of the family and small-group relationships, and provides more tolerant and less motivating beliefs. Relatively smaller and less consistent differences appear in terms of worldly personal success and incentives.

Asessing public policies. The case of education in Europe and the interaction between personal and institutional factors

The paper deals with the comparative study of European citizens' satisfaction with the state of education in their respective countries. Individual and contextual effects are tested applying multilevel analysis. The results show that educational public policies (level of decentralization, degree of comprehensiveness and public spending) as well as the students' social environment (socioeconomic and cultural status) have a sound impact on the opinions about the state of education.

Weak and Strong Altruism in Trait Groups: Reproductive Suicide, Personal Fitness, and Expected Value

A simple variant of trait group selection, employing predators as the mechanism underlying group selection, supports contingent reproductive suicide as altruism (i.e., behavior lowering personal fitness while augmenting that of another) without kin assortment. The contingent suicidal type may either saturate the population or be polymorphic with a type avoiding suicide, depending on parameters. In addition to contingent suicide, this randomly assorting morph may also exhibit continuously expressed strong altruism (sensu Wilson 1979) usually thought restricted to kin selection. The model will not, however, support a sterile worker caste as such, where sterility occurs before life history events associated with effective altruism; reproductive suicide must remain fundamentally contingent (facultative sensu West Eberhard 1987; Myles 1988) under random assortment. The continuously expressed strong altruism supported by the model may be reinterpreted as probability of arbitrarily committing reproductive suicide, without benefit for another; such arbitrary suicide (a "load" on "adaptive" suicide) is viable only under a more restricted parameter space relative to the necessarily concomitant adaptive contingent suicide.

Consumer Satisfaction with Websites of Banks - The Moderating Effect of Consumer Technology Attractiveness

The websites are becoming the firms’ first contact interface with their clients. Hence, understanding customers’ online attitudes and behaviors have been capturing increased research attention. The extant research has pointed customers’ satisfaction with the websites as the main reason for customers’ online behaviors. This research has used mostly variables related to the characteristics of the websites as the predictors of customers’ website satisfaction. However, recent research shows that groups of individuals displaying distinctive characteristics react differently to the same context. Therefore, behavior may be considerably different among groups of customers. In this study, we develop a conceptual model of the influence of individual characteristics on the traditional website quality – website satisfaction relationship. We propose a model based on the construct of consumer technology attractiveness (CTA) to represent the genuine positive propensity of individuals toward technology. We further test the moderating effect of this construct on the commonly used predictors of customer’s website satisfaction using Hierarchical Multiple Regression. The empirical study was based on websites of banks operating in Portuguese market. The commercial banking industry is one of the Portuguese industries that better uses the Internet to establish relationships with clients. Data were collected through an online website satisfaction survey, participated by the lecturers and postgraduate students from four Portuguese Universities and Polytechnic Institutes. Our final sample comprised 276 valid questionnaires. Our study permits to conclude that the most commonly used antecedents of website overall satisfaction are still relevant for analyzing consumer’s satisfaction with the banks websites. We also conclude that CTA has a significant moderating effect on almost all customers’ website satisfaction variables used in the study. This study contributes to highlight the theoretical importance and significant influence of consumers’ personal characteristics on their online behavior. Moreover, for the practitioners, a better understanding of these individual characteristics will assist them in developing customized websites that will meet customers’ expectations. O estudo dos comportamentos dos consumidores em ambientes online tem vindo a ter um crescente interesse, uma vez que os websites estão a transformar-se num importante ponto de contacto entre as empresas e os seus clientes. A satisfação dos clientes com os websites tem sido apontada pela Literatura como o principal condicionante dos comportamentos online dos consumidores. No entanto, a investigação científica tem conseguido provar que grupos de indivíduos com características distintas reagem de forma diferente quando submetidos a contextos idênticos, o que poderá levar a diferenças significativas no comportamento online de consumidores pertencentes a diferentes grupos. Neste estudo desenvolvemos um modelo conceptual que reflecte a influência de características individuais na relação entre a qualidade e a satisfação com os websites. Propomos um modelo assente na atractividade tecnológica do consumidor (CTA), que representa a propensão genuína que os indivíduos possuem em relação à tecnologia. Testamos o efeito moderador deste conceito sobre as variáveis mais utilizadas nos estudos sobre a satisfação dos consumidores com os websites, utilizando a Regressão Múltipla Hierárquica. O estudo empírico baseou-se nos websites dos bancos que operam no mercado português, uma vez que este sector é um dos que melhor utiliza a Internet na sua relação com os clientes. Os dados foram recolhidos através de um questionário sobre satisfação com os websites, colocado online e dirigido a docentes e estudantes de programas de pós-graduações, mestrados e doutoramentos de quatro universidades e instituto politécnico portugueses, tendo resultado numa amostra final de 276 questionários validados estatisticamente. Este estudo permitiu concluir que as variáveis que são mais utilizadas como antecedentes da satisfação dos consumidores com os websites, continuam a ser igualmente válidas para a análise dos websites dos bancos. Também concluímos que a CTA tem efeitos moderadores significativos na grande maioria das variáveis utilizadas neste estudo. Assim, conseguimos realçar a importância teórica das características pessoais dos consumidores no seu comportamento online. Para os gestores, uma melhor compreensão destas características individuais permitir-lhes-á desenvolver websites customizados que irão satisfazer as expectativas dos seus clientes.

Phylogenetic structures of the Holarctic Sorex araneus group and its relationships with S-samniticus, as inferred from mtDNA sequences

The shrews of the Sorex araneus group, characterized by the sexual chromosome complex XY1, Y2 have been intensively studied by morphological, karyotypical, and biochemical analyses. Nevertheless, the phylogenetic relationships among the species belonging to the araneus complex are still under debate, as different approaches gave often contradictory results. In this paper, partial nucleotide sequences of the mitochondrial DNA cytochrome b gene (1011 bp) were determined for 6 species of the araneus group from Eurasia and North America. We also included in the data set the sequences of Sorex samniticus, whose relationships with the araneus group remain controversial. Three other species representing two major karyological groups were also examined. Both parsimony and distance trees strongly support the monophyly of the araneus group. Sorex sumniticus is significantly more closely related to the araneus complex than to the other species included in the analysis. Based on the branching pattern within the araneus group, an attempt has been made to reconstruct the colonization history of the Holarctic region.