When outcome expectations become habitual: explaining vs. predicting new media technology use from a social cognitive perspective

This study examined the triadic relationship between expected outcomes, habit strength, and media technology use within the model of media attendance (Larose & Eastin, 2004). Mobile phone users (N = 664) were divided into two groups using a stratified random sampling method. Respondents of group one (n = 334) were surveyed on existing mobile phone use, respondents of group two (n = 310) were surveyed on the intention to use mobile video phone. On the basis of structural equation analysis, the results of this study support the assumption that within the model of media attendance existing media use is more likely to be explained by habit strength, and new media use is more likely to be predicted by outcome expectations

The interplay between short-term, mild physicochemical forcing and plankton dynamics in a coastal area

Two intensive surveys were conducted in the coastal waters of Barcelona (northwest Mediterranean) to assess short-term variations of biological parameters in relation to environmental conditions. Surveys lasted 1 week, with three to four samplings per day, and were carried out in autumn and spring. Rather than exploring extreme events, we aimed to study the effects of regular low or moderate perturbations, such as meteorological fronts, on the dynamics of the system. We focused on two attributes: wave height, as a proxy for mechanical energy entering the system, and nutrient inputs, whose variability in total load and relative composition is a central characteristic of coastal areas. The effects of the temporal coupling or uncoupling of both factors were examined. Sudden nutrient fluxes uncoupled from water motion tended to favor bacteria and heterotrophic nanoflagellates, while their concurrence with some water column mixing shaped a favorable scenario for large autotrophs. Ultimately, these two distinct biological responses pointed toward two main disturbance scenarios: episodes of nutrient enrichment uncoupled from mixing, mostly related to episodic water spills from the nearby city that contributed to high relative loads of ammonium and organic compounds; and episodes of increased wind caused by passing weather fronts that promoted some water column mixing and the entrainment of nutrients from bottom sediments or from adjacent water masses

Interactive television or enhanced televisiion? : the Dutch users interest in applications of ITV via set-top boxes

This paper is both an analysis of the phenomenon of interactive television with background concepts of interactivity and television and a report of an empirical investigation among Dutch users of set-top-box ITV. In the analytic part a distinction is made between levels of interactivity in the applications of ITV. Activities labelled as selection, customisation, transaction and reaction reveal low levels of interactivity. They may be called ‘enhanced television’. They are extensions of existing television programmes that keep their linear character. Activities called production and conversation have the potential of higher interactivity. They may lead to ‘real’ interactive television as the user input makes a difference to programmes. It is suggested that so-called hybrid ITV– TV combined with telephone and email reply channels- and (broadband) Internet ITV offer better opportunities for high interactivity than set-top-box ITV. \ud The empirical investigation shows that the demand of subscribers to set-top-box ITV in the Netherlands matches supply. They favour the less interactive applications of selection and reaction. Other striking results are that young subscribers appreciate interactive applications more than the older ones and that those with a low level of education prefer these applications more than high educated subscribers. No significant gender differences were found

Social psychological determinants of mobile communication technology use and adoption : a comparison of three models to explain and predict mobile communication technology behavior

This dissertation focuses on the social psychological determinants of mobile\ud communication technology use and adoption in an attempt to better understand\ud people’s behavior for adopting and using innovative information and\ud communication technologies. In particular, this study emphasizes the\ud comparison of three media use models to explain and predict media technology\ud behavior from different theoretical perspectives

Presenting the networked home: a content analysis of promotion material of Ambient Intelligence applications

Ambient Intelligence (AmI) for the home uses information and communication technologies to make users’ everyday life more comfortable. AmI is still in its developmental phase and is headed towards the first stages of diffusion. \ud Characteristics of AmI design can be observed, among others, in the promotion material of initial producers. A literature study revealed that AmI originally envisioned a central role for the user, convenience that AmI offers them and that attention should be paid to critical policy issues such as privacy and a potential loss of freedom. A content analysis of current promotion material of several high-tech companies revealed that these original ideas are not all reflected in the material. Attributes which were used most in the promotion material were ‘connectedness’, ‘control’, ‘easiness’ and ‘personalization’. An analysis of the pictures in the promotion material showed that almost half of the pictures contained no humans but appliances. These results only partly correspond to the original vision on AmI, since the emphasis is now on technology. The results represent a serious problem, since both users, as well as critical policy issues are underexposed in the current promotion material

Modulation of ecdysal cyst and toxin dynamics of two Alexandrium (Dinophyceae) species under small-scale turbulence

Some dinoflagellate species have shown different physiological responses to certain turbulent conditions. Here we investigate how two levels of turbulent kinetic energy dissipation rates (epsilon = 0.4 and 27 cm(2) s(-3)) affect the PSP toxins and ecdysal cyst dynamics of two bloom forming species, Alexandrium minutum and A. catenella. The most striking responses were observed at the high epsilon generated by an orbital shaker. In the cultures of the two species shaken for more than 4 days, the cellular GTX(1+4) toxin contents were significantly lower than in the still control cultures. In A. minutum this trend was also observed in the C(1+2) toxin content. For the two species, inhibition of ecdysal cyst production occurred during the period of exposure of the cultures to stirring (4 or more days) at any time during their growth curve. Recovery of cyst abundances was always observed when turbulence stopped. When shaking persisted for more than 4 days, the net growth rate significantly decreased in A. minutum (from 0.25 +/- 0.01 day(-1) to 0.19 +/- 0.02 day(-1)) and the final cell numbers were lower (ca. 55.4%) than in the still control cultures. In A. catenella, the net growth rate was not markedly modified by turbulence although under long exposure to shaking, the cultures entered earlier in the stationary phase and the final cell numbers were significantly lower (ca. 23%) than in the control flasks. The described responses were not observed in the experiments performed at the low turbulence intensities with an orbital grid system, where the population development was favoured. In those conditions, cells appeared to escape from the zone of the influence of the grids and concentrated in calmer thin layers either at the top or at the bottom of the containers. This ecophysiological study provides new evidences about the sensitivity to high levels of small-scale turbulence by two life cycle related processes, toxin production and encystment, in dinoflagellates. This can contribute to the understanding of the dynamics of those organisms in nature

The role of Eph receptors in cancer and how to target them: novel approaches in cancer treatment.

Introduction: Erythropoietin-producing human hepatocellular (Eph) receptors are among the largest family of tyrosine kinases that are divided into two classes: EphA and EphB receptors. Over the past two decades, their role in cancer has become more evident. Areas covered: There is a need for new anticancer treatments and more insight in the emerging role of Eph receptors in cancer. Molecular mechanisms underlying the pro-tumorigenic effects of Eph receptors could be exploited for future therapeutic strategies. This review describes the variability in expression levels and different effects on oncogenic and tumor suppressive downstream signaling of Eph receptors in various cancer types, and the small molecules, antibodies and peptides that target these receptors. Expert opinion: The complexity of Eph signaling is a challenge for the definition of clear targets for cancer treatment. Nevertheless, numerous drugs that target EphA2 and EphB4 are currently in clinical trials. However, some Eph targeted drugs also inhibit other tyrosine kinases, so it is unclear to what extent the targeting of Eph receptors contributes to their efficacy. Future research is warranted for an improved understanding of the full network in which Eph receptors function. This will be critical for the improvement of the anticancer effects of drugs that target the Eph receptors

Seasonal changes in planktonic bacterivory rates under the ice-covered coastal Arctic Ocean

Bacterivory was determined in surface waters of Franklin Bay, western Arctic, over a seasonal ice-covered period (winter-spring, 2003-2004). The objectives were to obtain information on the functioning of the microbial food web under the ice, during winter (from 21 December 2003 to 21 March 2004) and during spring (from 22 March 2004 to 29 May 2004), and to test whether bacterial losses would increase after the increase in bacterial production following the spring phytoplankton bloom. Chl a concentrations ranged from 0.04 to 0.36 mu g L(-1), increasing in March and reaching a peak in April. Bacterial biomass showed no consistent trend for the whole period, and protist biomass followed a pattern similar to that of Chl a. Bacterial production increased 1 week after Chl a concentrations started to increase, while bacterivory rates increased very slightly. Average bacterivory rates in winter (0.16 +/- 0.07 mu g C L(-1) d(-1)) were not significantly different from those in spring (0.29 +/- 0.24 mu g C L(-1) d(-1)). Average bacterial production, on the other hand, was similar to bacterivory rates in winter (0.19 +/- 0.38 mu g C L(-1) d(-1)), but higher than bacterivory in spring (0.93 +/- 0.28 mu g C L(-1) d(-1)). Therefore, bacterial production was controlled by grazers during winter and by substrate concentration in spring

[Corrigendum to] Effects of small-scale turbulence on lower trophic levels under different nutrient conditions [vol 32, pg 197, 2010]

Small-scale turbulence affects the pelagic food web and energy flow in marine systems and the impact is related to nutrient conditions and the assemblage of organisms present. We generated five levels of turbulence (2*10 29 to 1*10 24 W kg 21 ) in land-based mesocosms (volume 2.6 m 3 ) with and without additional nutrients (31:16:1 Si:N:P m M) to asses the effect of small-scale turbulence on the lower part of the pelagic food web under different nutrient conditions. The ecological influence of nutrients and small-scale turbulence on lower trophic levels was quantified using multivariate statistics (RDA), where nutrients accounted for 31.8% of the observed biological variation, while 7.2% of the variation was explained by small-scale turbulence and its interaction with nutrients. Chlorophyll a, primary production rates, bacterial production rates and diatom and dinoflagellate abundance were positively correlated to turbulence, regardless of nutrient conditions. Abundance of autotrophic flagellates, total phytoplankton and bacteria were positively correlated to turbulence only when nutrients were added. Impact of small-scale turbulence was related to nutrient con- ditions, with implications for oligotrophic and eutrophic situations. The effect on community level was also different compared to single species level. Microbial processes drive biogeochemical cycles, and nutrient-controlled effects of small-scale turbulence on such processes are relevant to foresee altered carbon flow in marine systems