147 research outputs found
Search Engine Advertising Adoption and Utilization: An Empirical Investigation of Inflectional Factors
© Taylor & Francis Group, LLC. Search engine advertising (SEA) is a prominent source of revenue for search engine companies, and also a solution for businesses to promote their visibility on the web. However, there is little academic research available about the factors and the extent to which they may influence businesses’ decision to adopt SEA. Building on Theory of Planned Behavior, Technology Acceptance Model, and Unified Theory of Acceptance and Use of Technology, this study develops a context-specific model for understanding the factors that influence the decision of businesses to use SEA. Using structural equation modeling and survey data collected from 142 businesses, this research finds that the intention of businesses to use SEA is directly influenced by four factors: (i) attitude toward SEA, (ii) subjective norms, (iii) perceived control over SEA, and (iv) perceived benefits of SEA in terms of increasing web traffic, increasing sales and creating awareness. Furthermore, the research we discover six additional factors that have an indirect influence: (i) trust in search engines, (ii) perceived risk of SEA, (iii) ability to manage keywords and bids, (iv) ability to analyze and monitor outcomes, (v) advertising expertise, and (vi) using external experts
Aplicación de la formulación basada en Bonds de la teorÃa peridinámica a la mecánica de fractura
El estudio de estructuras que presentan fisuras y la respuesta que brindan los materiales en estas circunstancias se puede realizar mediante los fundamentos que brinda la mecánica de fractura. La misma cuantifica la combinación crÃtica de tres variables: la tensión aplicada, la tenacidad a la fractura y el tamaño del defecto. La tenacidad es la propiedad del material que caracteriza el comportamiento ante la falla y su valor es medido con los denominados parámetros fractomecánicos, por lo que resulta fundamental para el diseño contra la fractura poder determinarlos. Dos de los parámetros fractomecánicos más utilizados son la energÃa especÃfica de fractura y el factor de intensidad de tensiones. La teorÃa peridinámica es una reformulación de la descripción matemática básica de la mecánica del continuo en la cual se utilizan las mismas ecuaciones exista o no una discontinuidad en el cuerpo ya que reemplaza la divergencia del tensor de tensiones por ecuaciones integrales en la ecuación de movimiento. Con el objetivo de explorar sus potencialidades, en este trabajo se aborda la aplicación de la teorÃa peridinámica para el cálculo de parámetros fractomecánicos estáticos, además del modelado de la propagación inestable de fisuras y el mapeo de la redistribución de la energÃa de deformación debido a la presencia de discontinuidades. También se propone una nueva ley constitutiva del material con el propósito de lograr una mejora del comportamiento simulado. Se comparan los resultados obtenidos con los brindados por la bibliografÃa y con los logrados por otros autores con otros métodos para la validación de la metodologÃa implementada y se discuten sus ventajas e inconvenientes.Publicado en: Mecánica Computacional vol. XXXV no.33Facultad de IngenierÃ
Revival of Philozoon Geddes for host-specialized dinoflagellates, ‘zooxanthellae’, in animals from coastal temperate zones of northern and southern hemispheres
The dinoflagellate family Symbiodiniaceae comprises numerous genera and species with large differences in diversity, ecology and
geographic distribution. An evolutionarily divergent lineage common in temperate symbiotic cnidarians and designated in the
literature by several informal names including ‘temperate–A’, AI, Phylotype A´ (A-prime) and ‘Mediterranean A’, is here assigned to
the genus Philozoon. This genus was proposed by Geddes (1882) in one of the earliest papers that recognized ‘yellow cells’ as distinct
biological entities separate from their animal and protist hosts. Using phylogenetic data from nuclear (rDNA), chloroplast (cp23S)
and mitochondrial genes (cob and cox1), as well as morphology (cell size), ecological traits (host affinity) and geographic
distributions, we emend the genus Philozoon Geddes and two of its species, P. medusarum and P. actiniarum, and describe six
new species. Each symbiont species exhibits high host fidelity for particular species of sea anemone, soft coral, stony coral and
a rhizostome jellyfish. Philozoon is most closely related to Symbiodinium (formerly Clade A), but, unlike its tropical counterpart,
occurs in hosts in shallow temperate marine habitats in northern and southern hemispheres including the Mediterranean Sea,
north-eastern Atlantic Ocean, eastern Australia, New Zealand and Chile. The existence of a species-diverse lineage adapted to
cnidarian hosts living in high latitude habitats with inherently wide fluctuations in temperature calls further attention to the
ecological and biogeographic reach of the Symbiodiniaceae
Parallel algebraic multilevel Schwarz preconditioners for a class of elliptic PDE systems
Algebraic multilevel preconditioners for algebraic problems arising from the discretization of a class of systems of coupled elliptic partial differential equations (PDEs) are presented. These preconditioners are based on modifications of Schwarz methods and of the smoothed aggregation technique, where the coarsening strategy and the restriction and prolongation operators are defined using a point-based approach with a primary matrix corresponding to a single PDE. The preconditioners are implemented in a parallel computing framework and are tested on two representative PDE systems. The results of the numerical experiments show the effectiveness and the scalability of the proposed methods. A convergence theory for the twolevel case is presented
The determinants and consequences of adult nursing staff turnover: a systematic review of systematic reviews.
BACKGROUND: Nurses leaving their jobs and the profession are an issue of international concern, with supply-demand gaps for nurses reported to be widening. There is a large body of existing literature, much of which is already in review form. In order to advance the usefulness of the literature for nurse and human resource managers, we undertook an overview (review of systematic reviews). The aim of the overview was to identify high quality evidence of the determinants and consequences of turnover in adult nursing. METHODS: Reviews were identified which were published between 1990 and January 2015 in English using electronic databases (the Cochrane Database of Systematic Reviews, MEDLINE, EMBASE, Applied Social Sciences Index and Abstracts, CINAHL plus and SCOPUS) and forward searching. All stages of the review were conducted in parallel by two reviewers. Reviews were quality appraised using the Assessment of Multiple Systematic Reviews and their findings narratively synthesised. RESULTS: Nine reviews were included. We found that the current evidence is incomplete and has a number of important limitations. However, a body of moderate quality review evidence does exist giving a picture of multiple determinants of turnover in adult nursing, with - at the individual level - nurse stress and dissatisfaction being important factors and -at the organisational level - managerial style and supervisory support factors holding most weight. The consequences of turnover are only described in economic terms, but are considered significant. CONCLUSIONS: In making a quality assessment of the review as well as considering the quality of the included primary studies and specificity in the outcomes they measure, the overview found that the evidence is not as definitive as previously presented from individual reviews. Further research is required, of rigorous research design, whether quantitative or qualitative, particularly against the outcome of actual turnover as opposed to intention to leave. TRIAL REGISTRATION: PROSPERO Registration 17 March 2015: CRD42015017613
Impact of internet of things (IoT) in disaster management: a task-technology fit perspective
YesDisaster management aims to mitigate the potential damage from the disasters, ensure immediate and suitable assistance to the victims, and attain effective and rapid recovery. These objectives require a planned and effective rescue operation post such disasters. Different types of information about the impact of the disaster are, hence, required for planning an effective and immediate relief operation. The IoT technology available today is quite mature and has the potential to be very useful in disaster situations. This paper analyzes the requirements for planning rescue operation for such natural disasters and proposes an IoT based solution to cater the identified requirements. The proposed solution is further validated using the task-technology fit (TTF) approach for analyzing the significance of the adoption of IoT technology for disaster management. Results from the exploratory study established the core dimensions of the task requirements and the TTF constructs. Results from the confirmatory factor analysis using PLS path modelling, further, suggest that both task requirements and IoT technology have significant impact on the IoT TTF in the disaster management scenario. This paper makes significant contributions in the development of appropriate constructs for modeling TTF for IoT Technology in the context of disaster management
Effects of the cannabinoid CB1 receptor antagonist rimonabant on distinct measures of impulsive behavior in rats
Rationale Pathological impulsivity is a prominent feature in several psychiatric disorders, but detailed understanding of the specific
neuronal processes underlying impulsive behavior is as yet lacking.
Objectives As recent findings have suggested involvement of the brain cannabinoid system in impulsivity, the present study aimed at further
elucidating the role of cannabinoid CB1 receptor activation in distinct measures of impulsive behavior.
Materials and methods The effects of the selective cannabinoid CB1 receptor antagonist, rimonabant (SR141716A) and agonist WIN55,212-2 were tested in various measures of impulsive behavior,
namely, inhibitory control in a five-choice serial reaction time task (5-CSRTT), impulsive choice in a delayed reward paradigm,
and response inhibition in a stop-signal paradigm.
Results In the 5-CSRTT, SR141716A dose-dependently improved inhibitory control by decreasing the number of premature responses. Furthermore,
SR141716A slightly improved attentional function, increased correct response latency, but did not affect other parameters.
The CB1 receptor agonist WIN55,212-2 did not change inhibitory control in the 5-CSRTT and only increased response latencies and errors
of omissions. Coadministration of WIN55,212-2 prevented the effects of SR141716A on inhibitory control in the 5-CSRTT. Impulsive
choice and response inhibition were not affected by SR141716A at any dose, whereas WIN55,212-2 slightly impaired response
inhibition but did not change impulsive choice.
Conclusions The present data suggest that particularly the endocannabinoid system seems involved in some measures of impulsivity and provides
further evidence for the existence of distinct forms of impulsivity that can be pharmacologically dissociated
Cumulative chi-squared statistics for the service quality improvement: new properties and tools for the evaluation
In service quality evaluation, data are often categorical variables with ordered
categories and collected in two way contingency table. The Taguchi’s statistic
is a measure of the association between these variables as a simple alternative to
Pearson’s test. An extension of this statistic for three way contingency tables handled
in two way mode is introduced.We highlight its several properties, the approximated
distribution, a decomposition according to orthogonal quantities reflecting
the main effects and the interaction terms, and an extension of cumulative correspondence
analysis based on it
- …