Bound States of Conical Singularities in Graphene-Based Topological Insulators

We investigate the electronic structure induced by wedge-disclinations (conical singularities) in a honeycomb lattice model realizing Chern numbers $\gamma=\pm 1$. We establish a correspondence between the bound state of (i) an isolated $\Phi_0/2$-flux, (ii) an isolated pentagon $(n=1)$ or heptagon $(n=-1)$ defect with an external flux of magnitude $n\gamma \Phi_0/4$ through the center and (iii) an isolated square or octagon defect without external flux, where $\Phi_0=h/e$ is the flux quantum. Due to the above correspondence, the existence of isolated electronic states bound to the disclinations is robust against various perturbations. These results are also generalized to graphene-based time-reversal invariant topological insulators.Comment: 5+4 pages, 4+3 figures, revised introduction and Fig.

Age-dependent dynamics of Theileria equi and Babesia caballi infections in southwest Mongolia based on IFAT and/or PCR prevalence data from domestic horses and ticks

Epidemiological factors of tick-borne equine piroplasmoses, caused by Theileria equi and Babesia caballi, were investigated using logistic regression (GLM) and general additive models (GAM) based on the prevalences determined in 510 domestic horses and in ticks in S.W. Mongolia by indirect immunofluorescence antibody test (IFAT) and/or multiplex PCR. Prevalences of T. equi and B. caballi in horses were 66·5% (95% CI: 62·1-70·7) and 19·1% (15·6-22·9), respectively by PCR and 78·8% (74·9-82·3) and 65·7% (61·3-69·9) by IFAT. Of 166 ticks analysed from PCR- and IFAT-negative horses 1 was PCR positive for B. caballi and none for T. equi. GAM demonstrated non-linear increasing proportions of T. equi-PCR and -IFAT positive horses with age suggesting persistent infection. In contrast, the B. caballi-PCR prevalence decreased with age despite a concurrent increase in the proportion of IFAT-positive animals suggesting parasite elimination. The tick (Dermacentor nuttalli) burden of the horses increased with age and decreased with advancing season. Geldings were more likely to be infected with, and seroconvert to, T. equi. Neither herd affiliation, date of sample collection nor abundance of tick infestation had a significant influence on parasite prevalenc

Fibroblast surface-associated FGF-2 promotes contact-dependent colorectal cancer cell migration and invasion through FGFR-SRC signaling and integrin αvβ5-mediated adhesion.

Carcinoma-associated fibroblasts were reported to promote colorectal cancer (CRC) invasion by secreting motility factors and extracellular matrix processing enzymes. Less is known whether fibroblasts may induce CRC cancer cell motility by contact-dependent mechanisms. To address this question we characterized the interaction between fibroblasts and SW620 and HT29 colorectal cancer cells in 2D and 3D co-culture models in vitro. Here we show that fibroblasts induce contact-dependent cancer cell elongation, motility and invasiveness independently of deposited matrix or secreted factors. These effects depend on fibroblast cell surface-associated fibroblast growth factor (FGF) -2. Inhibition of FGF-2 or FGF receptors (FGFRs) signaling abolishes these effects. FGFRs activate SRC in cancer cells and inhibition or silencing of SRC in cancer cells, but not in fibroblasts, prevents fibroblasts-mediated effects. Using an RGD-based integrin antagonist and function-blocking antibodies we demonstrate that cancer cell adhesion to fibroblasts requires integrin αvβ5. Taken together, these results demonstrate that fibroblasts induce cell-contact-dependent colorectal cancer cell migration and invasion under 2D and 3D conditions in vitro through fibroblast cell surface-associated FGF-2, FGF receptor-mediated SRC activation and αvβ5 integrin-dependent cancer cell adhesion to fibroblasts. The FGF-2-FGFRs-SRC-αvβ5 integrin loop might be explored as candidate therapeutic target to block colorectal cancer invasion

Neutron scattering study of the field-dependent ground state and the spin dynamics in S=1/2 NH4CuCl3

Elastic and inelastic neutron scattering experiments have been performed on the dimer spin system NH4CuCl3, which shows plateaus in the magnetization curve at m=1/4 and m=3/4 of the saturation value. Two structural phase transitions at T1≈156  K and at T2=70  K lead to a doubling of the crystallographic unit cell along the b direction and as a consequence a segregation into different dimer subsystems. Long-range magnetic ordering is reported below TN=1.3  K. The magnetic field dependence of the excitation spectrum identifies successive quantum phase transitions of the dimer subsystems as the driving mechanism for the unconventional magnetization process in agreement with a recent theoretical model

Quantum and classical criticality in a dimerized quantum antiferromagnet

A quantum critical point (QCP) is a singularity in the phase diagram arising due to quantum mechanical fluctuations. The exotic properties of some of the most enigmatic physical systems, including unconventional metals and superconductors, quantum magnets, and ultracold atomic condensates, have been related to the importance of the critical quantum and thermal fluctuations near such a point. However, direct and continuous control of these fluctuations has been difficult to realize, and complete thermodynamic and spectroscopic information is required to disentangle the effects of quantum and classical physics around a QCP. Here we achieve this control in a high-pressure, high-resolution neutron scattering experiment on the quantum dimer material TlCuCl3. By measuring the magnetic excitation spectrum across the entire quantum critical phase diagram, we illustrate the similarities between quantum and thermal melting of magnetic order. We prove the critical nature of the unconventional longitudinal ("Higgs") mode of the ordered phase by damping it thermally. We demonstrate the development of two types of criticality, quantum and classical, and use their static and dynamic scaling properties to conclude that quantum and thermal fluctuations can behave largely independently near a QCP.Comment: 6 pages, 4 figures. Original version, published version available from Nature Physics websit

Pressure-induced electronic phase separation of magnetism and superconductivity in CrAs

The recent discovery of pressure induced superconductivity in the binary helimagnet CrAs has attracted much attention. How superconductivity emerges from the magnetic state and what is the mechanism of the superconducting pairing are two important issues which need to be resolved. In the present work, the suppression of magnetism and the occurrence of superconductivity in CrAs as a function of pressure ($p$) were studied by means of muon spin rotation. The magnetism remains bulk up to $p\simeq3.5$~kbar while its volume fraction gradually decreases with increasing pressure until it vanishes at $p\simeq$7~kbar. At 3.5 kbar superconductivity abruptly appears with its maximum $T_c \simeq 1.2$~K which decreases upon increasing the pressure. In the intermediate pressure region ($3.5\lesssim p\lesssim 7$~kbar) the superconducting and the magnetic volume fractions are spatially phase separated and compete for phase volume. Our results indicate that the less conductive magnetic phase provides additional carriers (doping) to the superconducting parts of the CrAs sample thus leading to an increase of the transition temperature ($T_c$) and of the superfluid density ($\rho_s$). A scaling of $\rho_s$ with $T_c^{3.2}$ as well as the phase separation between magnetism and superconductivity point to a conventional mechanism of the Cooper-pairing in CrAs.Comment: 9 pages, 8 figure

Protocol of the Dual Burden of Animal and Human Zoonoses: A Systematic Review

Background: When we talk about zoonoses, it is undeniable that we have a human and animal population that has been isolated in studies over time. Besides human and animal health, zoonoses also impact the economy and society. Therefore, the integration of the analysis in this area is essential to optimize resources in public health decisions. We have new challenges in public health that we need to overcome in a more comprehensive method such as One Health. For better measures in public health, the dual burden of zoonoses seems a logical way to determine the integral impact of such diseases in society and thus take better measures to prevent and reduce the impact of these diseases. Methods: We follow the guidelines for “Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). We search human and animal zoonoses on Embase, Ovid Medline, Scopus, Web of Science, and Google Scholar, from an unrestricted period until November 2021. For the search, we consider the Disability Adjusted Life Years (DALYs) for the human zoonotic burden and the animal zoonotic burden in monetary terms. A librarian collaborates to optimize the search string for the databases, and two reviewers screen eligible articles (first by title, then by abstracts, and finally, by full-text assessment.) For the analysis, we aim to convert the burden of zoonoses of all selected studies into the zoonotic Disability Adjusted Life Years (zDALYs) – including the human and animal components. Discussion: The study results will provide information on published studies that have accounted for the dual burden of zoonoses (both human and animal health aspects.) In addition, the synthesis of the available literature will address the knowledge gap in this area in order to know to what extent it is possible to convert the burden of human zoonoses to the animal burden of zoonoses and integrate them into a more comprehensive approach (dual burden of zoonoses.

The dual burden of animal and human zoonoses: A systematic review

Background Zoonoses can cause a substantial burden on both human and animal health. Globally, estimates of the dual (human and animal) burden of zoonoses are scarce. Therefore, this study aims to quantify the dual burden of zoonoses using a comparable metric, “zoonosis Disability Adjusted Life Years” (zDALY). Methodology We systematically reviewed studies that quantify in the same article zoonoses in animals, through monetary losses, and in humans in terms of Disability Adjusted Life Years (DALYs). We searched EMBASE, Web of Science, Scopus, PubMed, and Google Scholar. We excluded articles that did not provide the data to estimate the zDALY or those for which full text was not available. This study was registered at PROSPERO, CRD42022313081. Principal findings/Significance We identified 512 potentially eligible records. After deduplication and screening of the title and abstract, 23 records were assessed for full-text review. Fourteen studies were included in this systematic review. The data contains estimates from 10 countries, a study at continental level (Asia and Africa), and 2 studies on a global scale. Rabies was the most frequently reported zoonosis where zDALYs were calculated, based on the following included studies: for Kazakhstan 457 (95% CI 342–597), Viet Nam 5316 (95% CI 4382–6244), Asia 1,145,287 (90% CI 388,592–1,902,310), Africa 837,158 (90% CI 283,087–1,388,963), and worldwide rabies 5,920,014 (95% CI 1,547,860–10,290,815). This was followed by echinococcosis, the zDALYs in Peru were 2238 (95% CI 1931–2546), in China 1490 (95% CI 1442–1537), and worldwide cystic echinococcosis 5,935,463 (95% CI 4,497,316–7,377,636). Then, the zDALYs on cysticercosis for Mozambique were 2075 (95% CI 1476–2809), Cameroon 59,540 (95% CR 16,896–101,803), and Tanzania 34,455 (95% CI 12,993–76,193). Brucellosis in Kazakhstan were 2443 zDALYs (95% CI 2391–2496), and brucellosis and anthrax in Turkey 3538 zDALYs (95% CI 2567–6706). Finally, zDALYs on leptospirosis in New Zealand were 196, and Q fever in Netherlands 2843 (95% CI 1071–4603). The animal burden was superior to the human burden in the following studies: worldwide cystic echinococcosis (83%), brucellosis in Kazakhstan (71%), leptospirosis in New Zealand (91%), and brucellosis, and anthrax in Turkey (52%). Countries priorities on zoonoses can change if animal populations are taken into consideration