4,437 research outputs found
Changing driver behavior during floods: Testing a novel e-health intervention using implementation imagery
We tested the efficacy of a novel implementation imagery intervention (N = 460) in promoting safer intentions regarding driving into floodwater post-intervention, and at a four-week follow-up using a pre-registered randomized controlled design. Results showed that the intervention reduced intentions and subjective norms regarding driving into floodwater. The control condition also improved on intentions and subjective norms, but the changes appeared to only be maintained at the follow-up for the intervention group and the between group difference at the follow-up was not significant based on our pre-specified cutoff level for statistical significance of 0.01. Results also indicated that changes in intentions may be stronger for males than females. Further exploratory analyses indicated that the intervention showed greater effects on post-intervention intentions, subjective norms, perceived behavioral control, perceived severity, anticipated regret, barrier self-efficacy, and action planning in individuals who indicated a modest level of intention to drive into floodwater prior to the intervention
Probing Density Fluctuations using the FIRST Radio Survey
We use results of angular clustering measurements in 3000 sq. deg's of the
FIRST radio survey to infer information on spatial clustering. Measurements are
compared with CDM-model predictions. Clustering of FIRST sources with optical
ID's in the APM catalog are also investigated. Finally, we outline a
preliminary search for a weak lensing signal in the survey.Comment: 6 pages latex, 2 figures, to appear in Cosmology with the New Radio
Surveys (Kluwer
A new ultrafast and high-throughput mass spectrometric approach for the therapeutic drug monitoring of the multi-targeted anti-folate pemetrexed in plasma from lung cancer patients
An analytical assay has been developed and validated for ultrafast and high-throughput mass spectrometric determination of pemetrexed concentrations in plasma using matrix assisted laser desorption/ionization–triple quadrupole–tandem mass spectrometry. Patient plasma samples spiked with the internal standard methotrexate were measured by multiple reaction monitoring. The detection limit was 0.4 fmol/μL, lower limit of quantification was 0.9 fmol/μL, and upper limit of quantification was 60 fmol/μL, respectively. Overall observed pemetrexed concentrations in patient samples ranged between 8.7 (1.4) and 142.7 (20.3) pmol/μL (SD). The newly developed mass spectrometric assay is applicable for (routine) therapeutic drug monitoring of pemetrexed concentrations in plasma from non-small cell lung cancer patients
Planet Formation by Coagulation: A Focus on Uranus and Neptune
Planets form in the circumstellar disks of young stars. We review the basic
physical processes by which solid bodies accrete each other and alter each
others' random velocities, and we provide order-of-magnitude derivations for
the rates of these processes. We discuss and exercise the two-groups
approximation, a simple yet powerful technique for solving the evolution
equations for protoplanet growth. We describe orderly, runaway, neutral, and
oligarchic growth. We also delineate the conditions under which each occurs. We
refute a popular misconception by showing that the outer planets formed quickly
by accreting small bodies. Then we address the final stages of planet
formation. Oligarchy ends when the surface density of the oligarchs becomes
comparable to that of the small bodies. Dynamical friction is no longer able to
balance viscous stirring and the oligarchs' random velocities increase. In the
inner-planet system, oligarchs collide and coalesce. In the outer-planet
system, some of the oligarchs are ejected. In both the inner- and outer-planet
systems, this stage ends once the number of big bodies has been reduced to the
point that their mutual interactions no longer produce large-scale chaos.
Subsequently, dynamical friction by the residual small bodies circularizes and
flattens their orbits. The final stage of planet formation involves the clean
up of the residual small bodies. Clean up has been poorly explored.Comment: to appear in ARA&A (2004), 51 pages, 3 figure
Surface-initiated growth of copper using isonicotinic acid-functionalized aluminum oxide surfaces
Isonicotinate self-assembled monolayers (SAM) were prepared on alumina surfaces (A) using isonicotinic acid (iNA). These functionalized layers (iNA-A) were used for the seeded growth of copper films (Cu-iNA-A) by hydrazine hydrate-initiated electroless deposition. The films were characterized by scanning electron microscopy (SEM), electron-dispersive X-ray spectroscopy, atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and advancing contact angle measurements. The films are Cu0 but with surface oxidation, and show a faceted morphology, which is more textured (Rq = 460 ± 90 nm) compared to the SAM (Rq = 2.8 ± 0.5 nm). In contrast, growth of copper films by SnCl2/PdCl2 catalyzed electroless deposition, using formaldehyde (CH2O) as the reducing agent, shows a nodular morphology on top of a relatively smooth surface. No copper films are observed in the absence of the isonicotinate SAM. The binding of Cu2+ to the iNA is proposed to facilitate reduction to Cu0 and create the seed for subsequent growth. The films show good adhesion to the functionalized surface
Secondary Prevention of Suicide
Leo Sher and colleagues discuss recent research on interventions to prevent secondary suicide and discuss the additional research that is needed
Cooperation and Contagion in Web-Based, Networked Public Goods Experiments
A longstanding idea in the literature on human cooperation is that
cooperation should be reinforced when conditional cooperators are more likely
to interact. In the context of social networks, this idea implies that
cooperation should fare better in highly clustered networks such as cliques
than in networks with low clustering such as random networks. To test this
hypothesis, we conducted a series of web-based experiments, in which 24
individuals played a local public goods game arranged on one of five network
topologies that varied between disconnected cliques and a random regular graph.
In contrast with previous theoretical work, we found that network topology had
no significant effect on average contributions. This result implies either that
individuals are not conditional cooperators, or else that cooperation does not
benefit from positive reinforcement between connected neighbors. We then tested
both of these possibilities in two subsequent series of experiments in which
artificial seed players were introduced, making either full or zero
contributions. First, we found that although players did generally behave like
conditional cooperators, they were as likely to decrease their contributions in
response to low contributing neighbors as they were to increase their
contributions in response to high contributing neighbors. Second, we found that
positive effects of cooperation were contagious only to direct neighbors in the
network. In total we report on 113 human subjects experiments, highlighting the
speed, flexibility, and cost-effectiveness of web-based experiments over those
conducted in physical labs
The cost of promiscuity: sexual transmission of Nosema microsporidian parasites in polyandrous honey bees
Multiple mating (and insemination) by females with different males, polyandry, is widespread across animals, due to material and/or genetic benefits for females. It reaches particularly high levels in some social insects, in which queens can produce significantly fitter colonies by being polyandrous. It is therefore a paradox that two thirds of eusocial hymenopteran insects appear to be exclusively monandrous, in spite of the fitness benefits that polyandry could provide. One possible cost of polyandry could be sexually transmitted parasites, but evidence for these in social insects is extremely limited. Here we show that two different species of Nosema microsporidian parasites can transmit sexually in the honey bee Apis mellifera. Honey bee males that are infected by the parasite have Nosema spores in their semen, and queens artificially inseminated with either Nosema spores or the semen of Nosema-infected males became infected by the parasite. The emergent and more virulent N. ceranae achieved much higher rates of infection following insemination than did N. apis. The results provide the first quantitative evidence of a sexually transmitted disease (STD) in social insects, indicating that STDs may represent a potential cost of polyandry in social insects
Risk and Ethical Concerns of Hunting Male Elephant: Behavioural and Physiological Assays of the Remaining Elephants
BACKGROUND: Hunting of male African elephants may pose ethical and risk concerns, particularly given their status as a charismatic species of high touristic value, yet which are capable of both killing people and damaging infrastructure. METHODOLOGY/PRINCIPAL FINDINGS: We quantified the effect of hunts of male elephants on (1) risk of attack or damage (11 hunts), and (2) behavioural (movement dynamics) and physiological (stress hormone metabolite concentrations) responses (4 hunts) in Pilanesberg National Park. For eleven hunts, there were no subsequent attacks on people or infrastructure, and elephants did not break out of the fenced reserve. For three focal hunts, there was an initial flight response by bulls present at the hunting site, but their movements stabilised the day after the hunt event. Animals not present at the hunt (both bulls and herds) did not show movement responses. Physiologically, hunting elephant bulls increased faecal stress hormone levels (corticosterone metabolites) in both those bulls that were present at the hunts (for up to four days post-hunt) and in the broader bull and breeding herd population (for up to one month post-hunt). CONCLUSIONS/SIGNIFICANCE: As all responses were relatively minor, hunting male elephants is ethically acceptable when considering effects on the remaining elephant population; however bulls should be hunted when alone. Hunting is feasible in relatively small enclosed reserves without major risk of attack, damage, or breakout. Physiological stress assays were more effective than behavioural responses in detecting effects of human intervention. Similar studies should evaluate intervention consequences, inform and improve best practice, and should be widely applied by management agencies
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