Strain and correlation of self-organized Ge_(1-x)Mn_x nanocolumns embedded in Ge (001)

We report on the structural properties of Ge_(1-x)Mn_x layers grown by molecular beam epitaxy. In these layers, nanocolumns with a high Mn content are embedded in an almost-pure Ge matrix. We have used grazing-incidence X-ray scattering, atomic force and transmission electron microscopy to study the structural properties of the columns. We demonstrate how the elastic deformation of the matrix (as calculated using atomistic simulations) around the columns, as well as the average inter-column distance can account for the shape of the diffusion around Bragg peaks.Comment: 9 pages, 7 figure

Exploring Children’s Insights about Participating in Recreational Activities with Horses and Farm Animals: Social Emotional Experiences and Belief in Animal Mind

Research continues to shed light on the impact of children’s interactions with horses in equine-assisted, learning, and therapeutic contexts. However, we know relatively less about the impact of children’s recreational activities with horses and a diversity of farm animals. What is needed is research that explores how recreational programs involving activities with horses and farm animals are perceived by the child participants themselves. This pilot study sought to explore the insights of children who participated in a nine-week recreational program involving activities with horses and farm animals, with a focus on children’s social emotional experiences and belief in animal mind, which involves attributing to animals the ability to think, feel, and experience emotions. Prior to beginning the nine-week program and upon its conclusion, we interviewed eight children (5 girls; 3 boys; aged 9 to 11 years) who were referred to the pro-gram because they were living in socioeconomically disadvantaged homes. Children responded to open-ended questions about their belief in animal mind and social emotional experiences. Salient themes in children’s responses prior to and following their participation in the program were identified using qualitative content analysis. Overall, children’s responses revealed new insights into animal minds and positive social emotional experiences following their participa-tion in the program. Children’s responses also revealed the following themes as key aspects of their experience in the program: (1) new opportunities and interest in the program, (2) feeling more confident with horses and farm animals, (3) new social opportunities and support, and (4) sadness that the program was ending. These findings hold significance for human–animal interaction practitioners and educators interested in supporting children’s positive social and emotional experiences and stimulating children’s belief in animal mind and knowledge of and respect for the needs of diverse animals

Frequency-Dependent Streaming Potential of Porous Media—Part 2: Experimental Measurement of Unconsolidated Materials

Frequency-dependent streaming potential coefficient measurements have been made upon Ottawa sand and glass bead packs using a new apparatus that is based on an electromagnetic drive. The apparatus operates in the range 1 Hz to 1 kHz with samples of 25.4 mm diameter up to 150 mm long. The results have been analysed using theoretical models that are either (i) based upon vibrational mechanics, (ii) treat the geological material as a bundle of capillary tubes, or (iii) treat the material as a porous medium. The best fit was provided by the Pride model and its simplification, which is satisfying as this model was conceived for porous media rather than capillary tube bundles. Values for the transition frequency were derived from each of the models for each sample and were found to be in good agreement with those expected from the independently measured effective pore radius of each material. The fit to the Pride model for all four samples was also found to be consistent with the independently measured steady-state permeability, while the value of the streaming potential coefficient in the low-frequency limit was found to be in good agreement with other steady-state streaming potential coefficient data

Inadequate heart rate control despite widespread use of beta-blockers in outpatients with stable CAD: findings from the international prospective CLARIFY registry

Background: To use CLARIFY, a prospective registry of patients with stable CAD (45 countries), to explore heart rate (HR) control and beta-blocker use.<p></p> Methods: We analyzed the CLARIFY population according to beta-blocker use via descriptive statistics with Pearson's χ2 test for comparisons, as well as a multivariable stepwise model.<p></p> Results: Data on beta-blocker use was available for 32,914 patients, in whom HR was 68 ± 11 bpm; patients with angina, previous myocardial infarction, and heart failure had HRs of 69 ± 12, 68 ± 11, and 70 ± 12 bpm, respectively. 75% of these patients were receiving beta-blockers. Bisoprolol (34%), metoprolol tartrate (16%) or succinate (13%), atenolol (15%), and carvedilol (12%) were mostly used; mean dosages were 49%, 76%, 35%, 53%, and 45% of maximum doses, respectively. Patients aged < 65 years were more likely to receive beta-blockers than patients ≥ 75 years (P < 0.0001). Gender had no effect. Subjects with HR ≤ 60 bpm were more likely to be on beta-blockers than patients with HR ≥ 70 bpm (P < 0.0001). Patients with angina, previous myocardial infarction, heart failure, and hypertension were more frequently receiving beta-blockers (all P < 0.0001), and those with PAD and asthma/COPD less frequently (both P < 0.0001). Beta-blocker use varied according to geographical region (from 87% to 67%).<p></p> Conclusions: Three-quarters of patients with stable CAD receive beta-blockers. Even so, HR is insufficiently controlled in many patients, despite recent guidelines for the management of CAD. There is still much room for improvement in HR control in the management of stable CAD

Exchange bias in GeMn nanocolumns: the role of surface oxidation

We report on the exchange biasing of self-assembled ferromagnetic GeMn nanocolumns by GeMn-oxide caps. The x-ray absorption spectroscopy analysis of this surface oxide shows a multiplet fine structure that is typical of the Mn2+ valence state in MnO. A magnetization hysteresis shift |HE|~100 Oe and a coercivity enhancement of about 70 Oe have been obtained upon cooling (300-5 K) in a magnetic field as low as 0.25 T. This exchange bias is attributed to the interface coupling between the ferromagnetic nanocolumns and the antiferromagnetic MnO-like caps. The effect enhancement is achieved by depositing a MnO layer on the GeMn nanocolumns.Comment: 7 pages, 5 figure

Relationships between components of blood pressure and cardiovascular events in patients with stable coronary artery disease and hypertension

Observational studies have shown a J-shaped relationship between diastolic blood pressure (BP) and cardiovascular events in hypertensive patients with coronary artery disease. We investigated whether the increased risk associated with low diastolic BP reflects elevated pulse pressure (PP). In 22 672 hypertensive patients with coronary artery disease from the CLARIFY registry (Prospective Observational Longitudinal Registry of Patients With Stable Coronary Artery Disease), followed for a median of 5.0 years, BP was measured annually and averaged. The relationships between PP and diastolic BP, alone or combined, and the primary composite outcome (cardiovascular death or myocardial infarction) were analyzed using multivariable Cox proportional hazards models. Adjusted hazard ratios for the primary outcome were 1.62 (95% confidence interval [CI], 1.40–1.87), 1.00 (ref), 1.07 (95% CI, 0.94–1.21), 1.54 (95% CI, 1.32–1.79), and 2.34 (95% CI, 1.95–2.81) for PP<45, 45 to 54 (reference), 55 to 64, 65 to 74, and ≥75 mm Hg, respectively, and 1.50 (95% CI, 1.31–1.72), 1.00 (reference), and 1.58 (95% CI, 1.42–1.77) for diastolic BPs of <70, 70 to 79 (ref), and ≥80 mm Hg, respectively. In a cross-classification analysis between diastolic BP and PP, the relationship between diastolic BP and the primary outcome remained J-shaped when the analysis was restricted to patients with the lowest-risk PP (45–64 mm Hg), with adjusted hazard ratios of 1.53 (95% CI, 1.27–1.83), 1.00 (ref), and 1.54 (95% CI, 1.34–1.75) in the <70, 70 to 79 (reference), and ≥80 mm Hg subgroups, respectively. The J-shaped relationship between diastolic BP and cardiovascular events in hypertensive patients with coronary artery disease persists in patients within the lowest-risk PP range and is therefore unlikely to be solely the consequence of an increased PP reflecting advanced vascular disease

Insights into mixed contaminants interactions and its implication for heavy metals and metalloids mobility, bioavailability and risk assessment

Mobility of heavy metals at contaminated sites is mainly influenced by the soil physicochemical properties and environmental conditions, therefore assessing heavy metals (HMs) and metalloids fractionation can provide insights into their potential risk and the mechanisms that regulate bioavailability. A 12-months mesocosms experiment was setup to investigate the effect of physicochemical factors (pH, moisture, and temperature) and weathering (time) on HMs and metalloids fractionation in three different multi-contaminated soil matrices (low, medium, and high contamination) collected from a soil treatment facility located in the United Kingdom, and two rural contaminated soil samples. The study demonstrates that even though Pb and Zn were found associated with the exchangeable fraction in the soil with the highest contamination (total average Pb 3400 mg/kg, and total average Zn 2100 mg/kg in Soil C), neither the condition applied nor the weathering caused an increase in their mobility. Although it was expected that lower pH (4.5) would favours the dissociation of HMs and metalloids, no significant differences were observed, potentially due to the initial alkaline pH of the genuine-contaminated soil samples. The results show that even though total concentration of Pb, Cu, and Zn exceed the soil standards and guideline values, HMs were predominantly associated with the non-exchangeable fraction, while only 5% were dissolved in the pore water fraction (potentially bioavailable). In addition, the mobility and bioavailability of HMs remained constant over the 12 months monitoring, suggesting that these soils pose negligible risk to the environment

Single-block rockfall dynamics inferred from seismic signal analysis

International audienceSeismic monitoring of mass movements can significantly help to mitigate the associated hazards; however, the link between event dynamics and the seismic signals generated is not completely understood. To better understand these relationships, we conducted controlled releases of single blocks within a soft-rock (black marls) gully of the Rioux-Bourdoux torrent (French Alps). A total of 28 blocks, with masses ranging from 76 to 472 kg, were used for the experiment. An instrumentation combining video cameras and seismometers was deployed along the travelled path. The video cameras allow reconstructing the trajectories of the blocks and estimating their velocities at the time of the different impacts with the slope. These data are compared to the recorded seismic signals. As the distance between the falling block and the seismic sensors at the time of each impact is known, we were able to determine the associated seismic signal amplitude corrected for propagation and attenuation effects. We compared the velocity, the potential energy lost, the kinetic energy and the momentum of the block at each impact to the true amplitude and the radiated seismic energy. Our results suggest that the amplitude of the seismic signal is correlated to the momentum of the block at the impact. We also found relationships between the potential energy lost, the kinetic energy and the seismic energy radiated by the impacts. Thanks to these relationships, we were able to retrieve the mass and the velocity before impact of each block directly from the seismic signal. Despite high uncertainties, the values found are close to the true values of the masses and the velocities of the blocks. These relationships allow for gaining a better understanding of the physical processes that control the source of high-frequency seismic signals generated by rockfalls

Interactional Structure Applied to the Identification and Generation of Visual Interactive Behavior: Robots that (Usually) Follow the Rules

Peer reviewe