581 research outputs found
Use of mental simulations to change theory of planned behaviour variables
Objectives. The predictive validity of the theory of planned behaviour iswell established, but much less is known about: (a) whether there are causal relationships between key components of the model and (b) how to go about changing the theory of planned behaviour variables. This study tested the ability of outcome and process simulations to change variables specified in the theory of planned behaviour in relation to blood donation.
Design. Participants (N ¼ 146) were randomized to one of four conditions: outcome simulation only, process simulation only, process-plus-outcome simulation and a
distractor control condition. The dependent variables were state anxiety, and intention attitude, subjective norm and perceived control from the theory of planned behaviour.
Methods. Participants were asked to empty their mind and visualize themselves: (a) after donating blood (outcome manipulation), (b) preparing to donate blood (process manipulation), (c) both preparing to donate blood and after having donated blood (process-plus-outcome manipulation) or (d) both preparing to get a high mark and after having got a high mark on their course (control condition). Following mental rehearsal, participants completed the dependent variables.
Results. There were no main effects of outcome simulation, but process simulation successfully increased intention, subjective norm and perceived control. There was also a significant outcome simulation x process simulation interaction for attitude. The effect of the process manipulation on intention was mediated by subjective norm and perceived control.
Conclusions. The findings show promise for the use of mental simulations in changing cognitions and further research is required to extend the present findings to
other health behaviours.</p
Evidence that process simulations reduce anxiety in patients receiving dental treatment: randomized exploratory trial
Process simulations – mental simulations that ask people to imagine the process of completing a task – have been shown to decrease anxiety in students facing hypothetical or psychological threats in the short term. The aim of the present study was to see whether process simulations could reduce anxiety in a sample of the general population attending a dental practice, and whether these effects could be sustained throughout treatment. Participants (N = 75) were randomized to an experimental condition where they were asked to simulate mentally the process of seeing the dentist, or to a control condition where they were asked to simulate mentally the outcome of seeing the dentist. Findings showed that participants in the experimental condition were significantly less anxious both before and after their consultations. Self-efficacy and self-esteem remained unchanged. This study suggests that process simulation is one active ingredient in anxiety treatment programs and further research is required to enhance its effects
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Basal rot of narcissus : understanding pathogenicity in fusarium oxysporum f. sp. narcissi
Fusarium oxysporum is a globally distributed soilborne fungal pathogen causing root rots, bulb rots, crown rots and vascular wilts on a range of horticultural plants. Pathogenic F. oxysporum isolates are highly host specific and are classified as formae speciales. Narcissus is an important ornamental crop and both the quality and yield of flowers and bulbs can be severely affected by a basal rot caused by F. oxysporum f. sp. narcissi (FON); 154 Fusarium isolates were obtained from different locations and Narcissus cultivars in the United Kingdom, representing a valuable resource. A subset of 30 F. oxysporum isolates were all found to be pathogenic and were therefore identified as FON. Molecular characterisation of isolates through sequencing of three housekeeping genes, suggested a monophyletic origin with little divergence. PCR detection of 14 Secreted in Xylem (SIX) genes, previously shown to be associated with pathogenicity in other F. oxysporum f. spp., revealed different complements of SIX7, SIX9, SIX10, SIX12 and SIX13 within FON isolates which may suggest a race structure. SIX gene sequences were unique to FON and SIX10 was present in all isolates, allowing for molecular identification of FON for the first time. The genome of a highly pathogenic isolate was sequenced and lineage specific (LS) regions identified which harboured putative effectors including the SIX genes. Real-time RT-PCR, showed that SIX genes and selected putative effectors were expressed in planta with many significantly upregulated during infection. This is the first study to characterise molecular variation in FON and provide an analysis of the FON genome. Identification of expressed genes potentially associated with virulence provides the basis for future functional studies and new targets for molecular diagnostics
The Seismic Signature of Upper-Mantle Plumes: Application to the Northern East African Rift
Several seismic and numerical studies proposed that below, some hotspots upper-mantle plumelets rise from a thermal boundary layer below 660 km depth, fed by a deeper plume source.We
recently found tomographic evidence of multiple upper-mantle upwellings, spaced by several 100 km, rising through the transition zone below the northern East African Rift. To better test this interpretation, we run 3-D numerical simulations of mantle convection for Newtonian and non-Newtonian rheologies, for both thermal instabilities rising from a lower boundary layer, and the destabilization of a thermal anomaly
placed at the base of the box (700–800 km depth). The thermal structures are converted to seismic velocities using a thermodynamic approach. Resolution tests are then conducted for the same P and S data distribution and inversion parameters as our traveltime tomography. The Rayleigh Taylor models predict
simultaneous plumelets in different stages of evolution rising from a hot layer located below the transition zone, resulting in seismic structure that looks more complex than the simple vertical cylinders that are
often anticipated. From the wide selection of models tested, we find that the destabilization of a 200 â—¦C, 100 km thick thermal anomaly with a non-Newtonian rheology, most closely matches the magnitude and the spatial and temporal distribution of the anomalies below the rift. Finally, we find that for reasonable upper-mantle viscosities, the synthetic plume structures are similar in scale and shape to the actual low-velocity anomalies, providing further support for the existence of upper-mantle plumelets below the
northern East African Rift
The debris disk - terrestrial planet connection
The eccentric orbits of the known extrasolar giant planets provide evidence
that most planet-forming environments undergo violent dynamical instabilities.
Here, we numerically simulate the impact of giant planet instabilities on
planetary systems as a whole. We find that populations of inner rocky and outer
icy bodies are both shaped by the giant planet dynamics and are naturally
correlated. Strong instabilities -- those with very eccentric surviving giant
planets -- completely clear out their inner and outer regions. In contrast,
systems with stable or low-mass giant planets form terrestrial planets in their
inner regions and outer icy bodies produce dust that is observable as debris
disks at mid-infrared wavelengths. Fifteen to twenty percent of old stars are
observed to have bright debris disks (at wavelengths of ~70 microns) and we
predict that these signpost dynamically calm environments that should contain
terrestrial planets.Comment: Contribution to proceedings of IAU 276: Astrophysics of Planetary
System
Accretion disc-stellar magnetosphere interaction: field line inflation and the effect on the spin-down torque
We calculate the structure of a force-free magnetosphere which is assumed to
corotate with a central star and which interacts with an embedded
differentially rotating accretion disc. The magnetic and rotation axes are
aligned and the stellar field is assumed to be a dipole. We concentrate on the
case when the amount of field line twisting through the disc-magnetosphere
interaction is large and consider different outer boundary conditions. In
general the field line twisting produces field line inflation (eg. Bardou &
Heyvaerts 1996) and in some cases with large twisting many field lines can
become open. We calculate the spin-down torque acting between the star and the
disc and we find that it decreases significantly for cases with large field
line twisting. This suggests that the oscillating torques observed for some
accreting neutron stars could be due to the magnetosphere varying between
states with low and high field line inflation. Calculations of the spin
evolution of T Tauri stars may also have to be revised in light of the
significant effect that field line twisting has on the magnetic torque
resulting from star-disc interactions.Comment: Accepted by MNRAS. 21 pages, 15 figures. LaTeX2e in the MN style.
PostScript files are also available from http://www-star.qmw.ac.uk/~va/ or by
e-mail: [email protected]
Progress toward curing HIV infection with hematopoietic cell transplantation.
HIV-1 infection afflicts more than 35 million people worldwide, according to 2014 estimates from the World Health Organization. For those individuals who have access to antiretroviral therapy, these drugs can effectively suppress, but not cure, HIV-1 infection. Indeed, the only documented case for an HIV/AIDS cure was a patient with HIV-1 and acute myeloid leukemia who received allogeneic hematopoietic cell transplantation (HCT) from a graft that carried the HIV-resistant CCR5-∆32/∆32 mutation. Other attempts to establish a cure for HIV/AIDS using HCT in patients with HIV-1 and malignancy have yielded mixed results, as encouraging evidence for virus eradication in a few cases has been offset by poor clinical outcomes due to the underlying cancer or other complications. Such clinical strategies have relied on HIV-resistant hematopoietic stem and progenitor cells that harbor the natural CCR5-∆32/∆32 mutation or that have been genetically modified for HIV-resistance. Nevertheless, HCT with HIV-resistant cord blood remains a promising option, particularly with inventories of CCR5-∆32/∆32 units or with genetically modified, human leukocyte antigen-matched cord blood
Effects of mangrove cover on coastal erosion during a hurricane in Texas, USA
We tested the hypothesis that mangroves provide better coastal protection than salt marsh vegetation using 10 1,008-m2 plots in which we manipulated mangrove cover from 0 to 100%. Hurricane Harvey passed over the plots in 2017. Data from erosion stakes indicated up to 26 cm of vertical and 970 cm of horizontal erosion over 70 months in the plot with 0% mangrove cover, but relatively little erosion in other plots. The hurricane did not increase erosion, and erosion decreased after the hurricane passed. Data from drone images indicated 196 m2 of erosion in the 0% mangrove plot, relatively little erosion in other plots, and little ongoing erosion after the hurricane. Transects through the plots indicated that the levee (near the front of the plot) and the bank (the front edge of the plot) retreated up to 9 m as a continuous function of decreasing mangrove cover. Soil strength was greater in areas vegetated with mangroves than in areas vegetated by marsh plants, or nonvegetated areas, and increased as a function of plot-level mangrove cover. Mangroves prevented erosion better than marsh plants did, but this service was nonlinear, with low mangrove cover providing most of the benefits
A decade (1982 to 1992) of pediatric cardiac transplantation and the impact of FK 506 immunosuppression
The decade from 1982 through 1992 witnessed tremendous growth in pediatric cardiac transplantation. At Children's Hospital of Pittsburgh 66 cardiac transplants were performed during this period (age range 7 hours to 18 years). The cause of cardiomyopathy was congenital (n = 30), cardiomyopathy (n = 29), myocarditis (n = 2), doxorubicin toxicity (n = 2), ischemic (n = 1), valvular (n = 1), and cardiac angiosarcoma (n = 1). Nine children (14 %) required mechanical circulatory support before transplantation: extracorporeal membrane oxygenation (n = 8) and Novacor left ventricular assist system (n = 1) (Baxter Healthcare Corp., Novacor Div., Oakland, Calif.). The mean follow-up time was 2 years (range 4 months to 8 years). The overall survival in the group was 67 %. In children with congenital heart disease (>6 months of age) the perioperative (30 day) mortality was 66 % before mid-1988 (n = 10) and 0 % since mid-1988 (n = 11). The late mortality (>30 days) in children with cardiomyopathy transplanted prior to mid-1988 was 66 % (n = 14) and 7 % since mid-1988 (n = 15). Since mid-1988 1- and 3-year survival was 82 % in children with congenital heart disease and 90 % in children with cardiomyopathy. Twenty-six children have had FK 506 as their primary immunosuppressive therapy since November 1989. Survival in this group was 82 % at 1 and 3 years. The actuarial freedom from grade 3A rejection in the FK group was 60 % at 3 and 6 months after transplantation versus 20 % and 12 %, respectively, in the 15 children operated on before the advent of FK 506, who were treated with cyclosporine-based triple-drug therapy (p < 0.001, Mantel-Cox and Breslow). Twenty of 24 children (83 %) in the FK 506 group are receiving no steroids. The prevalence of posttransplantation hypertension was 4 % in the FK 506 group versus 70 % in the cyclosporine group (p < 0.001, Fisher). Renal toxicity in children treated with FK 506 has been mild. Additionally, eight children have been switched to FK 506 because of refractory rejection and drug toxicity. FK 506 has not produced hirsutism, gingival hyperplasia, or abnormal facial bone growth. The absence of these debilitating side effects, together with the observed immune advantage and steroid-sparing effects of FK 506, hold tremendous promise for the young patient facing cardiac transplantation and a future wedded to immunosuppression
Critical values for Lawshe's content validity ratio: revisiting the original methods of calculation
YesThe content validity ratio originally proposed by Lawshe is widely used to quantify content validity and yet methods used to calculate the original critical values were never reported. Methods for original calculation of critical values are suggested along with tables of exact binomial probabilities
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