2,156 research outputs found

    Aldosterone secretion and its relationship to the renin-angiotensin system in the rat

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    The European framework for regulating telecommunications - a 25-year appraisal

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    The European telecommunications sector has been radically transformed in the past 25 years: from a group of state monopolies to a set of increasingly competitive markets. In this paper we summarize how this process has unfolded -- for both fixed and mobile telecommunications -- by focusing on the evolution of the regulatory framework and by drawing some parallels with the evolution of the sector in the US. Given the major strategic importance of the sector, we highlight some of the challenges that lie ahead

    Social networks : the future for health care delivery

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    With the rapid growth of online social networking for health, health care systems are experiencing an inescapable increase in complexity. This is not necessarily a drawback; self-organising, adaptive networks could become central to future health care delivery. This paper considers whether social networks composed of patients and their social circles can compete with, or complement, professional networks in assembling health-related information of value for improving health and health care. Using the framework of analysis of a two-sided network – patients and providers – with multiple platforms for interaction, we argue that the structure and dynamics of such a network has implications for future health care. Patients are using social networking to access and contribute health information. Among those living with chronic illness and disability and engaging with social networks, there is considerable expertise in assessing, combining and exploiting information. Social networking is providing a new landscape for patients to assemble health information, relatively free from the constraints of traditional health care. However, health information from social networks currently complements traditional sources rather than substituting for them. Networking among health care provider organisations is enabling greater exploitation of health information for health care planning. The platforms of interaction are also changing. Patient-doctor encounters are now more permeable to influence from social networks and professional networks. Diffuse and temporary platforms of interaction enable discourse between patients and professionals, and include platforms controlled by patients. We argue that social networking has the potential to change patterns of health inequalities and access to health care, alter the stability of health care provision and lead to a reformulation of the role of health professionals. Further research is needed to understand how network structure combined with its dynamics will affect the flow of information and potentially the allocation of health care resources

    Dual-Target Cost in Visual Search for Multiple Unfamiliar Faces.

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    The efficiency of visual search for one (single-target) and either of two (dual-target) unfamiliar faces was explored to understand the manifestations of capacity and guidance limitations in face search. The visual similarity of distractor faces to target faces was manipulated using morphing (Experiments 1 and 2) and multidimensional scaling (Experiment 3). A dual-target cost was found in all experiments, evidenced by slower and less accurate search in dual- than single-target conditions. The dual-target cost was unequal across the targets, with performance being maintained on one target and reduced on the other, which we label "preferred" and "non-preferred" respectively. We calculated the capacity for each target face and show reduced capacity for representing the non-preferred target face. However, results show that the capacity for the non-preferred target can be increased when the dual-target condition is conducted after participants complete the single-target conditions. Analyses of eye movements revealed evidence for weak guidance of fixations in single-target search, and when searching for the preferred target in dual-target search. Overall, the experiments show dual-target search for faces is capacity- and guidance-limited, leading to superior search for 1 face over the other in dual-target search. However, learning faces individually may improve capacity with the second face. (PsycINFO Database Recor

    Double Excitations within Time-Dependent Density Functional Theory Linear Response

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    Within the adiabatic approximation, time-dependent density functional theory yields only single excitations. Near states of double excitation character, the exact exchange–correlation kernel has a strong dependence on frequency. We derive the exact frequency-dependent kernel when a double excitation mixes with a single excitation, well separated from the other excitations, in the limit that the electron–electron interaction is weak. Building on this, we construct a nonempirical approximation for the general case, and illustrate our results on a simple model

    Understanding the contribution of target repetition and target expectation to the emergence of the prevalence effect in visual search

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    Behavior in visual search tasks is influenced by the proportion of trials on which a target is presented (the target prevalence). Previous research has found that when target prevalence is low (2% prevalence), participants tend to miss targets, compared with higher prevalence levels (e.g., 50% prevalence). There is an ongoing debate regarding the relative contribution of target repetition and the expectation that a target will occur in the emergence of prevalence effects. In order to disentangle these two factors, we went beyond previous studies by directly manipulating participants’ expectations regarding how likely a target was to appear on a given trial. This we achieved without using cues or feedback. Our results indicated both target repetition and target expectation contribute to the emergence of the prevalence effect

    Plantain (\u3cem\u3ePlantago lanceolata\u3c/em\u3e) Outperforms Chicory (\u3cem\u3eCichorium intybus\u3c/em\u3e) under Moisture Stress in Glasshouse

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    Forage chicory (Cichorium intybus) and plantain (Plantago lanceolata) are now widely used throughout the world as high feed quality perennial herbage (Sanderson et al. 2003; Labreveux et al. 2006; Li et al. 2010; Golding et al. 2011; Hutton et al. 2011). Both are taprooted plants and are thus likely to confer a degree of drought tolerance through accessing water deeper in the soil profile (Kemp et al. 2010). Nie et al. (2008) reported chicory can tolerate moisture stress to a greater degree than plantain. However, overall little is known about the effect of moisture stress on plantain and chicory persistence under defoliated conditions. The objective was to compare plantain and chicory un-der moisture stress and defoliation under glasshouse conditions

    Reduced Electronic Spaces for Modeling Donor/Acceptor Interactions

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    Diabatic states for donor (D) and acceptor (A) interactions in electron transfer (ET) processes are formulated and evaluated, along with coupling elements (HDA) and effective D/A separation distances (rDA), for reduced electronic spaces of variable size, using the generalized Mulliken Hush model (GMH), applicable to an arbitrary state space and nuclear configuration, and encompassing Robin−Day class III and as well as class II situations. Once the electronic state space is selected (a set of n ≄ 2 adiabatic states approximated by an orbital space based on an effective 1-electron (1-e) Hamiltonian), the charge-localized GMH diabatic states are obtained as the eigenstates of the dipole moment operator, with rotations to yield locally adiabatic states for sites with multiple states. The 1-e states and energies are expressed in terms of Kohn−Sham orbitals and orbital energies. Addressing questions as to whether the estimate of HDA “improves” as one increases n, and in what sense the GMH approach “converges” with n, we carry out calculations for three mixed-valence binuclear Ru complexes, from which we conclude that the 2-state (2-st) model gives the most appropriate estimate of the effective coupling, similar (to within a rms deviation of ≀15%) to coupling elements obtained by superexchange correction of HDA values based on larger spaces (n = 3−6), and thus yielding a quasi-invariant value for HDA over the range explored in the calculations (n = 2−6). An analysis of the coupling and associated D and A states shows that the 2-st coupling involves crucial mixing with intervening bridge states (D and A “tails”), while increasingly larger state spaces for the same system yield increasingly more localized D and A states (and weaker coupling), with HDA tending to approach the limit of “bare” or “through space” coupling. These results help to reconcile seemingly contradictory assertions in the recent literature regarding the proper role of multistate frameworks in the formulation of coupling for both intra- and intermolecular ET systems.The present results are compared in detail with other reported results
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