186 research outputs found
Spin gating electrical current
We use an aluminium single electron transistor with a magnetic gate to
directly quantify the chemical potential anisotropy of GaMnAs materials.
Uniaxial and cubic contributions to the chemical potential anisotropy are
determined from field rotation experiments. In performing magnetic field sweeps
we observe additional isotropic magnetic field dependence of the chemical
potential which shows a non-monotonic behavior. The observed effects are
explained by calculations based on the kinetic
exchange model of ferromagnetism in GaMnAs. Our device inverts the conventional
approach for constructing spin transistors: instead of spin-transport
controlled by ordinary gates we spin-gate ordinary charge transport.Comment: 5 pages, 4 figure
Reconfigurable Boolean Logic using Magnetic Single-Electron Transistors
We propose a novel hybrid single-electron device for reprogrammable low-power
logic operations, the magnetic single-electron transistor (MSET). The device
consists of an aluminium single-electron transistors with a GaMnAs magnetic
back-gate. Changing between different logic gate functions is realized by
reorienting the magnetic moments of the magnetic layer which induce a voltage
shift on the Coulomb blockade oscillations of the MSET. We show that we can
arbitrarily reprogram the function of the device from an n-type SET for
in-plane magnetization of the GaMnAs layer to p-type SET for out-of-plane
magnetization orientation. Moreover, we demonstrate a set of reprogrammable
Boolean gates and its logical complement at the single device level. Finally,
we propose two sets of reconfigurable binary gates using combinations of two
MSETs in a pull-down network
Spin Hall effect transistor
Spin transistors and spin Hall effects have been two separate leading
directions of research in semiconductor spintronics which seeks new paradigms
for information processing technologies. We have brought the two directions
together to realize an all-semiconductor spin Hall effect transistor. Our
scheme circumvents semiconductor-ferromagnet interface problems of the original
Datta-Das spin transistor concept and demonstrates the utility of the spin Hall
effects in microelectronics. The devices use diffusive transport and operate
without electrical current, i.e., without Joule heating in the active part of
the transistor. We demonstrate a spin AND logic function in a semiconductor
channel with two gates. Our experimental study is complemented by numerical
Monte Carlo simulations of spin-diffusion through the transistor channel.Comment: 11 pages, 3 figure
Spatial Current Patterns, Dephasing and Current Imaging in Graphene Nanoribbons
Using the non-equilibrium Keldysh Green's function formalism, we investigate
the local, non-equilibrium charge transport in graphene nanoribbons (GNRs). In
particular, we demonstrate that the spatial current patterns associated with
discrete transmission resonances sensitively depend on the GNRs' geometry,
size, and aspect ratio, the location and number of leads, and the presence of
dephasing. We identify a relation between the spatial form of the current
patterns, and the number of degenerate energy states participating in the
charge transport. Furthermore, we demonstrate a principle of superposition for
the conductance and spatial current patterns in multiple-lead configurations.
We demonstrate that scanning tunneling microscopy (STM) can be employed to
image spatial current paths in GNR with atomic resolution, providing important
insight into the form of local charge transport. Finally, we investigate the
effects of dephasing on the spatial current patterns, and show that with
decreasing dephasing time, the current patterns evolve smoothly from those of a
ballistic quantum network to those of classical resistor network.Comment: 25 pages, 12 figure
Advances in the Diagnosis of Urothelial Neoplasia
Urothelial neoplasia is a unique cancer in that it consists of a spectrum of tumors with different biologic behaviors. The most common urothelial neoplasm is the low grade superficial papillary carcinoma or papilloma which may recur numerous times but does not result in significant morbidity or mortality. A variant of the superficial papillary carcinoma, which represents approximately 10% of the tumors, is the noninvasive papillary neoplasm which progresses to a less differentiated invasive transitional cell carcinoma (TCC). Considerable effort has been directed at identifying which of the superficial well differentiated papillary tumors will persist, recur and progress to invasive cancer Current approaches to identifying such tumors include cytogenetics, molecular biology, and flow cytometric DNA analysis. In the final group of bladder carcinomas, the high grade invasive neoplasms, evidence suggests that these life-threatening tumors arise de novo without identifiable precursors. Unfortunately, 75% to 90% of invasive TCCs are classified in this group, with the remaining minority progressing from preexisting recurrent superficial papillary carcinomas. Obviously the biologic behavior of these aggressive poorly differentiated tumors is life-threatening, and application of traditional diagnostic procedures and new technologies need to be directed at early diagnosis
COVID-19 Vaccine Hesitancy in Italy: Predictors of Acceptance, Fence Sitting and Refusal of the COVID-19 Vaccination
Background: The hesitancy in taking the COVID-19 vaccine is a global challenge. The need to identify predictors of COVID-19 vaccine reluctance is critical. Our objectives were to evaluate sociodemographic, psychological, and behavioral factors, as well as attitudes and beliefs that influence COVID-19 vaccination hesitancy in the general population of Italy. Methods: A total of 2,015 people were assessed in two waves (March, April and May, 2021). Participants were divided into three groups: (1) individuals who accepted the vaccination (âacceptersâ); (2) individuals who refused the vaccination (ârejectersâ); and (3) individuals who were uncertain about their attitudes toward the vaccination (âfence sittersâ). Group comparisons were performed using ANOVA, the Kruskal-Wallis test and chi-square tests. The strength of the association between the groups and the participants' characteristics was analyzed using a series of multinomial logistic regression models with bootstrap internal validation (one for each factor). Results: The âfence sittersâ group, when compared to the others, included individuals of younger age, lower educational level, and worsening economic situation in the previous 3 months. After controlling for sociodemographic factors, the following features emerged as the main risk factors for being âfence sittersâ (compared with vaccine âacceptersâ): reporting lower levels of protective behaviors, trust in institutions and informational sources, frequency of use of informational sources, agreement with restrictions and higher conspirative mentality. Higher levels of COVID-19 perceived risk, trust in institutions and informational sources, frequency of use of informational sources, agreement with restrictions and protective behaviors were associated with a higher likelihood of becoming âfence sittersâ rather than vaccine ârejecters.â Conclusions: The âfence sittersâ profile revealed by this study is intriguing and should be the focus of public programmes aimed at improving adherence to the COVID-19 vaccination campaign
Erratum: Internet and mobile-based psychological interventions: Applications, efficacy and potential for improving mental health. A report of the EFPA E-Health Taskforce (European Psychologist (2018) 23 (167-187) DOI: 10.1027/1016-9040/a000318)
© 2018 2018 Hogrefe Publishing. The article entitled Internet and mobile-based psychological interventions: Applications, efficacy and potential for improving mental health. A report of the EFPA E-Health Taskforce. by Ebert, D. D., Van Daele, T., Nordgreen, T., Karekla, M., Compare, A., Zarbo, C., Brugnera, B., Overland, S., Trebbi, G., Jensen, K. L., Kaehlke, F. (on behalf of the EFPA E-Health Taskforce), & Baumeister, H. (2018, European Psychologist, 23(2), 167-187. https://doi.org/ 10.1027/1016-9040/a000318) contained an error on the first page: The author Jacqui Taylor is missing and the list of authors should correctly read as follows: David Daniel Ebert1, Tom Van Daele2, Tine Nordgreen3, Maria Karekla4, Angelo Compare6, Cristina Zarbo5, Agostino Brugnera5, Svein Overland7, Glauco Trebbi8, Kit L. Jensen9, Fanny Kaehlke (on behalf of the EFPA E-Health Taskforce)1, Harald Baumeister10, and Jacqui Taylor11 1Department of Clinical Psychology and Psychotherapy, Friedrich-Alexander University of Erlangen- Nrnberg, Erlangen, Germany 2Department of Applied Psychology, Thomas More University of Applied Sciences, Antwerp, Belgium 3Division of Psychiatry, Haukeland University Hospital, Bergen, Norway 4Department of Psychology, University of Cyprus, Nicosia, Republic of Cyprus 5Department of Human and Social Science, University of Bergamo, Bergamo, Italy 6Human Factors and Technology in Healthcare, University of Bergamo, Bergamo, BG, Italy 7SuperEgo AS, Trondheim, Norway 8Trebbipsicologie, Luxembourg & Societe Luxembourgeoise de Psychologie SLP, Luxembourg 9Private Practice, Skagen, Denmark 10Department of Clinical Psychology and Psychotherapy, University of Ulm, Germany 11Psychology Department, Bournemouth University, UK The authors regret any inconvenience or confusion this error may have caused
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