1,249 research outputs found
Critical Behavior of Disordered Systems with a Free Surface
The behavior of homogeneous and disordered systems with a free boundary is
described on the basis of group theory in the two-loop approximation directly
in three-dimensional space. The effect of the free boundary on the regime of
the bulk critical behavior is revealed. It is shown that the boundedness of the
system slightly affects the regime of the bulk critical behavior in the case of
the ordinary transition, whereas this effect is more noticeable in the case of
the special transition. Surface critical phenomena are described for
homogeneous and disordered systems, and the critical exponents are calculated
in the two-loop approximation. It is shown that the effect of impurities is
insignificant in the special phase transition, whereas it is more noticeable in
the ordinary phase transition. The derived critical exponents are compared with
the computer-simulation results.Comment: 19 pages, 2 figure
Fresh perspectives for classic forest restoration challenges
Restoration ecology is a young scientific discipline whose limitations can compromise the recovery of ecosystem biodiversity and functions. Specifically for limitations on forest restoration, we first recommend considering measures prior to land use changes to deal with the common lack of efforts to anticipate and plan restoration. Second, we suggest using multiple references in restoration planning to avoid simplified reference characterization, and we advise assessing ecosystem recovery with indicators that better incorporate ecosystem complexity in recovery assessments. Finally, we propose initiatives to encourage scientific communication outside academia to diminish the communication gap between scientists and practitioners. © 2019 Society for Ecological RestorationA.R.U. was funded by Environmental Fellowship Programme of Tatiana PĂ©rez de GuzmĂĄn el Bueno Foundation (2016) and MarĂa de Maeztu excellence accreditation (MDM-2017-0714) from the Spanish Government; V.C.A. by REMEDINAL4 (Madrid Government, TE-CM S2018/EMT-4338); Z.R. by the LafargeHolcim, FIRE Foundation, and UAH partnership; and L.M.B. by the FPI Fellowship (BES-2015-075276) from the Spanish Government
Exploring experiences and needs of spousal carers of people with behavioural variant frontotemporal dementia (bvFTD) including those with familial FTD (fFTD): a qualitative study
INTRODUCTION: Carers of people with frontotemporal dementia (FTD) experience greater challenges than carers of people with other dementias due to the younger age of onset and the challenging presentation of symptoms. The aim of the present study was to explore experiences of spousal carers of people with bvFTD, including those with the familial form of the disease (fFTD). METHOD: Fourteen qualitative interviews were analysed using an inductive approach to Thematic Analysis to understand experiences of spousal carers of people with bvFTD including those with fFTD. RESULTS: Five main themes were identified including: a) The "Constant Battle" - A journey toward an FTD diagnosis, b) Shock, Relief and Fear - Challenges persist post diagnosis, c) The "Life Altering" impact - The loss of the spousal relationship and shifting roles, d) Adapting, Managing Symptoms and Receiving Carer Support, e) Lack of General Knowledge - Barriers to support. CONCLUSIONS: Healthcare professionals should be educated on the initial presentations of FTD, to enable carers and families receive timely diagnosis and appropriate support. Future research should investigate the impact of fFTD on carers and families, to explore positive or meaningful experiences in caring, as well as theory-driven research to identify helpful coping strategies for carers of people with FTD
Spin-Correlation Coefficients and Phase-Shift Analysis for p+He Elastic Scattering
Angular Distributions for the target spin-dependent observables A,
A, and A have been measured using polarized proton beams at
several energies between 2 and 6 MeV and a spin-exchange optical pumping
polarized He target. These measurements have been included in a global
phase-shift analysis following that of George and Knutson, who reported two
best-fit phase-shift solutions to the previous global p+He elastic
scattering database below 12 MeV. These new measurements, along with
measurements of cross-section and beam-analyzing power made over a similar
energy range by Fisher \textit{et al.}, allowed a single, unique solution to be
obtained. The new measurements and phase-shifts are compared with theoretical
calculations using realistic nucleon-nucleon potential models.Comment: Submitted to Phys. Rev.
Spin-flop transition in uniaxial antiferromagnets: magnetic phases, reorientation effects, multidomain states
The classical spin-flop is the field-driven first-order reorientation
transition in easy-axis antiferromagnets. A comprehensive phenomenological
theory of easy-axis antiferromagnets displaying spin-flops is developed. It is
shown how the hierarchy of magnetic coupling strengths in these
antiferromagnets causes a strongly pronounced two-scale character in their
magnetic phase structure. In contrast to the major part of the magnetic phase
diagram, these antiferromagnets near the spin-flop region are described by an
effective model akin to uniaxial ferromagnets. For a consistent theoretical
description both higher-order anisotropy contributions and dipolar stray-fields
have to be taken into account near the spin-flop. In particular,
thermodynamically stable multidomain states exist in the spin-flop region,
owing to the phase coexistence at this first-order transition. For this region,
equilibrium spin-configurations and parameters of the multidomain states are
derived as functions of the external magnetic field. The components of the
magnetic susceptibility tensor are calculated for homogeneous and multidomain
states in the vicinity of the spin-flop. The remarkable anomalies in these
measurable quantities provide an efficient method to investigate magnetic
states and to determine materials parameters in bulk and confined
antiferromagnets, as well as in nanoscale synthetic antiferromagnets. The
method is demonstrated for experimental data on the magnetic properties near
the spin-flop region in the orthorhombic layered antiferromagnet
(C_2H_5NH_3)_2CuCl_4.Comment: (15 pages, 12 figures; 2nd version: improved notation and figures,
correction of various typos
Predictors of survival in frontotemporal lobar degeneration syndromes
After decades of research, large-scale clinical trials in patients diagnosed with frontotemporal lobar degeneration (FTLD) are now underway across multiple centres worldwide. As such, refining the determinants of survival in FTLD represents a timely and important challenge. Specifically, disease outcome measures need greater clarity of definition to enable accurate tracking of therapeutic interventions in both clinical and research settings. Multiple factors potentially determine survival, including the clinical phenotype at presentation; radiological patterns of atrophy including markers on both structural and functional imaging; metabolic factors including eating behaviour and lipid metabolism; biomarkers including both serum and cerebrospinal fluid markers of underlying pathology; as well as genetic factors, including both dominantly inherited genes, but also genetic modifiers. The present review synthesises the effect of these factors on disease survival across the syndromes of frontotemporal dementia, with comparison to amyotrophic lateral sclerosis, progressive supranuclear palsy and corticobasal syndrome. A pathway is presented that outlines the utility of these varied survival factors for future clinical trials and drug development. Given the complexity of the FTLD spectrum, it seems unlikely that any single factor may predict overall survival in individual patients, further suggesting that a precision medicine approach will need to be developed in predicting disease survival in FTLD, to enhance drug target development and future clinical trial methodologies
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Non-stoichiometric oxide and metal interfaces and reactions
We have employed a combination of experimental surface science techniques and density functional calculations to study the reduction of TiO2(110) surfaces through the doping with submonolayer transition metals. We concentrate on the role of Ti adatoms in self doping of rutile and contrast the behaviour to that of Cr. DFT+U calculations enable identification of probable adsorption structures and their spectroscopic characteristics. Adsorption of both metals leads to a broken symmetry and an asymmetric charge transfer localised around the defect site of a mixed localised/delocalised character. Charge transfer creates defect states with Ti 3d character in the band gap at similar to 1-eV binding energy. Cr adsorption, however, leads to a very large shift in the valence-band edge to higher binding energy and the creation of Cr 3d states at 2.8-eV binding energy. Low-temperature oxidation lifts the Ti-derived band-gap states and modifies the intensity of the Cr features, indicative of a change of oxidation state from Cr3+ to Cr4+. Higher temperature processing leads to a loss of Cr from the surface region, indicative of its substitution into the bulk
Gender bias in ecosystem restoration: from science to practice
The declaration of the United Nations Decade on Ecosystem Restoration 2020â2030 has established the need to focus on human rights in restoration initiatives, including gender equality. Although this goal raises a need to monitor gender biases on ecosystem restoration, we still lack basic gender information and evaluations on the current situation. The main purpose of this study is to analyze gender bias in ecosystem restoration covering three dimensions: research, outreach, and practice. We used scientific publications from the Restoration Ecology journal, mentions of these articles in Altmetric Explorer and Twitter, and projects from the Society for Ecological Restoration's database. First, we study gender bias among people leading ecosystem restoration initiatives in the three dimensions. Second, we assessed factors that could influence gender bias, including year, target ecosystem, and socioeconomic country development. Third, we analyzed whether the impact of scientific knowledge in society depends on the gender of the scientific team. Our results indicate that men were primary leaders in research, outreach, and practice initiatives in ecosystem restoration. There seems to be a trend over time toward equality in research, but gender inequality is still present in most types of ecosystems, with women leading more projects in more developed countries. The impact of scientific knowledge is independent of the author's gender, but research of male senior authors seems to reach society more easily. This broad perspective of inequality in the three dimensions can evolve toward gender equality, by applying gender approaches in restoration policies and initiatives. © 2022 Society for Ecological Restoration.Raw data is publicly available thanks to Web of Science, Altmetrics, Twitter and SER. Data and scripts used for the analysis are available via Figshare (CruzâAlonso et al. 2022 ). Funding: V.C.âA.âReal Colegio Complutense postdoc fellowship; A.R.âU.âSpanish State Research Agency through MarĂa de Maeztu Excellence Unit accreditation 2018â2022 (MDMâ2017â0714); L.M.âSwiss National Science Foundation (PCEFP2_181115) and a Margarita Salas Postdoctoral Fellowship from Universidad de AlcalĂĄ; L.M.âB.âMinisterio de Ciencia e InnovaciĂłn (PID2019â106806GBâI00) and a Margarita Salas Postdoctoral Fellowship from Universidad de AlcalĂĄ; N.M.âpredoctoral grant from Universidad de AlcalĂĄ; E.V.âA.âEuropean Commission (project SHOWCASE, H2020: 862480). We appreciate the support of the FIRE Foundation and the comments of M. Almaraz, M. Pajares, A. S. Moya, and D. Rohrer to improve the manuscript.Raw data is publicly available thanks to Web of Science, Altmetrics, Twitter and SER. Data and scripts used for the analysis are available via Figshare (CruzâAlonso et al. 2022 ). Funding: V.C.âA.âReal Colegio Complutense postdoc fellowship; A.R.âU.âSpanish State Research Agency through MarĂa de Maeztu Excellence Unit accreditation 2018â2022 (MDMâ2017â0714); L.M.âSwiss National Science Foundation (PCEFP2_181115) and a Margarita Salas Postdoctoral Fellowship from Universidad de AlcalĂĄ; L.M.âB.âMinisterio de Ciencia e InnovaciĂłn (PID2019â106806GBâI00) and a Margarita Salas Postdoctoral Fellowship from Universidad de AlcalĂĄ; N.M.âpredoctoral grant from Universidad de AlcalĂĄ; E.V.âA.âEuropean Commission (project SHOWCASE, H2020: 862480). We appreciate the support of the FIRE Foundation and the comments of M. Almaraz, M. Pajares, A. S. Moya, and D. Rohrer to improve the manuscript
Accelerator Testing of the General Antiparticle Spectrometer, a Novel Approach to Indirect Dark Matter Detection
We report on recent accelerator testing of a prototype general antiparticle
spectrometer (GAPS). GAPS is a novel approach for indirect dark matter searches
that exploits the antideuterons produced in neutralino-neutralino
annihilations. GAPS captures these antideuterons into a target with the
subsequent formation of exotic atoms. These exotic atoms decay with the
emission of X-rays of precisely defined energy and a correlated pion signature
from nuclear annihilation. This signature uniquely characterizes the
antideuterons. Preliminary analysis of data from a prototype GAPS in an
antiproton beam at the KEK accelerator in Japan has confirmed the
multi-X-ray/pion star topology and indicated X-ray yields consistent with prior
expectations. Moreover our success in utilizing solid rather than gas targets
represents a significant simplification over our original approach and offers
potential gains in sensitivity through reduced dead mass in the target area.Comment: 18 pages, 9 figures, submitted to JCA
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