569 research outputs found

    Pourous liquid metal-elastomer composites

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    It is known that liquid metal-elastomer composites are promising soft conductors for skin-interfaced bioelectronics, soft robots, and other applications due to their large stretchability, ultrasoftness, high electrical conductivity, and mechanical-electrical decoupling. There is, however, a high level of deformation-induced leakage, which can result in smears on the skin, poor performance of the device, and short circuits in the circuit. By using phase separation, we describe the synthesis of porous liquid metal-elastomer composites with high leakage resistance and antimicrobial properties. Furthermore, these composites exhibit high stretchability, tissue-like compliance, high electrical conductivity, high breathability, and compatibility with magnetic resonance imaging. As a result of damping effects, porous structures can minimize leakage and reduce liquid metal usage. In addition to monitoring cardiac electrical and mechanical activity, skin-interfaced bioelectronics can deliver electrical stimulation in a mechanically imperceptible and electrically stable manner.Includes bibliographical references

    Weed Suppression in Only-Legume Cover Crop Mixtures

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    Weed suppression is a potential benefit of cover crop mixtures, as species diversity may allow for combining early and late-season competition with weeds. Here, we studied if this is possible for only-legume mixtures containing species with different growth rates, by testing two legumes, alsike clover (AC; Trifolium hybridum L.) and black medic (BM; Medicago lupulina L.) in two field trials sown in 2016 and 2017. Five AC:BM ratios (100:0, 67:33, 50:50, 33:67, and 0:100) were grown at three densities (50%, 100%, and 150% of recommended seed density). Cover crop and weed aboveground biomass (CCB and WB, respectively) were harvested three times, after establishment in spring (H1), in summer (H2), and in autumn after mulching (H3). Compared to fallow plots, all monocultures and mixtures showed early-season weed suppression in terms of biomass production and more efficiency over time with an average reduction of 42%, 52%, and 96% in 2016, and 39%, 55%, and 89% in 2017 at H1, H2, and H3, respectively. Out of 54 mixture treatments, only eight mixtures showed stronger weed suppression than monocultures. Mixtures reduced WB by 28%, as an average value, in 2017 compared to the respective monocultures, but not significantly in 2016, indicating that the crop diversity effect on weeds was dependent on the growing environment. Weed suppression was significantly higher at 100% and 150% seed density than 50%, but no significant differences were determined between 100% and 150% seed density. After mulching, no density effect was observed on CCB and WB. In conclusion, AC and BM can be used as a keystone species on weed suppression for sustainable agriculture as they possess plasticity to suppress weeds when higher biomass productivity is limited by environmental conditions. However, their diversity effects are time and condition dependent. Appropriate seed density and mulching can successfully be employed in weed management, but seed density may not have an effect after mulching

    Quasi-free Compton Scattering and the Polarizabilities of the Neutron

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    Differential cross sections for quasi-free Compton scattering from the proton and neutron bound in the deuteron have been measured using the Glasgow/Mainz tagging spectrometer at the Mainz MAMI accelerator together with the Mainz 48 cm ⊘\oslash ×\times 64 cm NaI(Tl) photon detector and the G\"ottingen SENECA recoil detector. The data cover photon energies ranging from 200 MeV to 400 MeV at θγLAB=136.2∘\theta^{LAB}_\gamma=136.2^\circ. Liquid deuterium and hydrogen targets allowed direct comparison of free and quasi-free scattering from the proton. The neutron detection efficiency of the SENECA detector was measured via the reaction p(γ,π+n)p(\gamma,\pi^+ n). The "free" proton Compton scattering cross sections extracted from the bound proton data are in reasonable agreement with those for the free proton which gives confidence in the method to extract the differential cross section for free scattering from quasi-free data. Differential cross sections on the free neutron have been extracted and the difference of the electromagnetic polarizabilities of the neutron have been obtained to be α−β=9.8±3.6(stat)12.1.1(syst)±2.2(model)\alpha-\beta= 9.8\pm 3.6(stat){}^{2.1}_1.1(syst)\pm 2.2(model) in units 10−4fm310^{-4}fm^3. In combination with the polarizability sum α+β=15.2±0.5\alpha +\beta=15.2\pm 0.5 deduced from photoabsorption data, the neutron electric and magnetic polarizabilities, αn=12.5±1.8(stat)−0.6+1.1±1.1(model)\alpha_n=12.5\pm 1.8(stat){}^{+1.1}_{-0.6}\pm 1.1(model) and βn=2.7∓1.8(stat)−1.1+0.6(syst)∓1.1(model)\beta_n=2.7\mp 1.8(stat){}^{+0.6}_{-1.1}(syst)\mp 1.1(model) are obtained. The backward spin polarizability of the neutron was determined to be γπ(n)=(58.6±4.0)×10−4fm4\gamma^{(n)}_\pi=(58.6\pm 4.0)\times 10^{-4}fm^4

    Association between Fatty Acid Composition in Hair and Energy Availability during Early Lactation in Simmental and German Holstein Cows

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    This study examined (1) if fatty acids in bovine hair are influenced by dietary energy levels and (2) if the relationship between energy availability and fatty acids in hair persists across breeds and farms. Sixty-two and 59 Fleckvieh (Simmental), and 55 German Holstein cows from three farms, respectively, were fed two levels of energy concentration of roughage (6.1 and 6.5 MJ net energy for lactation/kg dry matter) and two levels of concentrate supply (150 and 250 g/kg energy-corrected milk). The average body weight was 727 kg (Simmental) and 668 kg (Holstein). The average lactation number was 3.1. Hair samples were taken in lactation weeks 4 and 8. In Simmental cows, a lower energy deficit due to a relatively higher energy intake from high energy concentration of the roughage was associated with higher C18:2n-6 and C18:3n-3 contents in hair at week 8. In cows from all three farms, higher energy intake between lactation weeks 2 and 6 correlated with higher content of C18:2n-6 in hair samples taken in lactation weeks 4 and 8. No correlation was found for C12:0. These results provide the first evidence that increased energy intake increases the contents of C18:2n-6 in hair

    Quasi-free π0\pi^0 Photoproduction from the Bound Nucleon

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    Differential cross-sections for quasi-free π0\pi^0 photoproduction from the proton and neutron bound in the deuteron have been measured for Eγ=200−400E_\gamma= 200 - 400 MeV at θγlab=136.2∘\theta^{\rm lab}_\gamma = 136.2^\circ usind the Glasgow photon tagger at MAMI, the Mainz 48 cm ∅\varnothing ×\times 64 cm NaI(Tl) photon detector and the G\"ottingen SENECA recoil detector. For the proton measurements made with both liquid deuterium and liquid hydrogen targets allow direct comparison of "free" π0\pi^0 photoproduction cross-sections as extracted from the bound proton data with experimental free cross sections which are found to be in reasonable agreement below 320 MeV. At higher energies the "free" cross sections extracted from quasifree data are significantly smaller than the experimental free cross sections and theoretical predictions based on multipole analysis. For the first time, "free" neutron cross sections have been extracted in the Δ\Delta-region. They are also in agreement with the predictions from multipole analysis up to 320 MeV and significantly smaller at higher photon energies

    Correction: Signatures of Adaptation in Human Invasive Salmonella Typhimurium ST313 Populations from Sub-Saharan Africa.

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    Correction to: 7 Aug 2015: The PLOS Neglected Tropical Diseases Staff (2015) Correction: Correction: Signatures of Adaptation in Human Invasive Salmonella Typhimurium ST313 Populations from Sub-Saharan Africa. PLoS Negl Trop Dis 9(8): e0003970. doi: 10.1371/journal.pntd.0003970

    Survey of UK histopathology consultants’ attitudes towards academic and molecular pathology

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    Objective: Academic pathology is facing a crisis; an ongoing decline in academic pathology posts, a paucity of academic pathologist’s in-training and unfilled posts at a time when cellular pathology departments are challenged to deliver increasing numbers of molecular tests. The National Cancer Research Institute initiative in Cellular & Molecular Pathology commissioned a survey to assess attitudes of cellular pathology consultants towards research in order to understand barriers and identify possible solutions to improve this situation. As cellular pathology is encompassing an increasing number of diagnostic molecular tests, we also surveyed the current approach to and extent of training in molecular pathology. Methods: The survey was distributed to all UK-based consultant pathologists via the Pathological Society of Great Britain & Ireland and Royal College of Pathologist networks. Heads of Department were contacted separately to obtain figures for number of academic training and consultant posts. Results: 302 cellular pathologists completed the survey which represents approximately 21% of the total cellular histopathology workforce. Most respondents (89%) had been involved in research at some point; currently, 22% were undertaking research formally, and 41% on an informal basis. Of those previously involved in research, 57% stopped early in their consultant career. The majority of substantive academic posts were Professors of which 60% had been in post for >20 years. Most respondents (84%) used molecular pathology in diagnostic work, independent of where they worked or the length of time in post. Notably, 53% of consultants had not received molecular pathology training, particularly more senior consultants and consultants in district general hospitals. Conclusions: The survey reveals that the academic workforce is skewed towards senior individuals, many of whom are approaching retirement, with a missing cohort of ‘junior consultant’ academic pathologists to replace them. Most pathologists stop formal research activity at the beginning of a consultant career. While molecular pathology is an increasing part of a pathologist’s workload, the majority of consultant cellular pathologists have not received any formal molecular training

    Neutron polarizabilities investigated by quasi-free Compton scattering from the deuteron

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    Measuring Compton scattered photons and recoil neutrons in coincidence, quasi-free Compton scattering by the neutron has been investigated at MAMI (Mainz) at thetaγlab=136otheta^{lab}_\gamma=136^o in an energy range from 200 to 400 MeV. From the data a polarizability difference of αn−βn=9.8±3.6(stat)−1.1+2.1(syst)±2.2(model)\alpha_n - \beta_n = 9.8 \pm 3.6(stat)^{+2.1}_{-1.1}(syst)\pm 2.2(model) in units of 10−4fm310^{-4}fm^3 has been determined. In combination with the polarizability sum αn+βn=15.2±0.5\alpha_n+\beta_n= 15.2\pm 0.5 deduced from photo absorption data, the neutron electric and magnetic polarizabilities, αn=12.5±1.8(stat)−0.6+1.1(syst)±1.1(model)\alpha_n=12.5\pm 1.8(stat)^{+1.1}_{-0.6}(syst)\pm 1.1(model) and βn=2.7∓1.8(stat)−1.1+0.6(syst)∓1.1(model)\beta_n = 2.7\mp 1.8(stat)^{+0.6}_{-1.1}(syst)\mp 1.1(model), are obtained

    Neutron skin of 208^{208}Pb from Coherent Pion Photoproduction

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    Information on the size and shape of the neutron skin on 208^{208}Pb has been extracted from coherent pion photoproduction cross sections measured using the Crystal Ball together with the Glasgow tagger at the MAMI electron beam facility. On exploitation of an interpolated fit of a theoretical model to the measured cross sections the half-height radius and diffuseness of the neutron distribution are found to be 6.70±0.03(stat)\pm 0.03(stat) fm and 0.55±0.01(stat)\pm 0.01(stat)−0.03+0.02(sys)^{+0.02}_{-0.03}(sys) fm respectively, corresponding to a neutron skin thickness Δrnp\Delta r_{np}=0.15±0.03(stat)\pm 0.03(stat)−0.03+0.01(sys)^{+0.01}_{-0.03}(sys) fm. The results give the first successful extraction of a neutron skin with an electromagnetic probe and indicate the skin of 208^{208}Pb has a halo character. The measurement provides valuable new constraints on both the structure of nuclei and the equation of state for neutron-rich matter.Comment: 4 figures 5 pages. Version submitted to journal. Includes additional studies of systematic effects in the extracted diffuseness, which led to a small increase in the quoted systematic error. These additional studies are discussed in the revised manuscript. Also includes minor editorial improvements to the tex
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