59 research outputs found
Spin-to-Orbital Angular Momentum Conversion in Semiconductor Microcavities
We experimentally demonstrate a technique for the generation of optical beams
carrying orbital angular momentum using a planar semiconductor microcavity.
Despite being isotropic systems, the transverse electric - transverse magnetic
(TE-TM) polarization splitting featured by semiconductor microcavities allows
for the conversion of the circular polarization of an incoming laser beam into
the orbital angular momentum of the transmitted light field. The process
implies the formation of topological entities, a pair of optical half-vortices,
in the intracavity field
Preventing sexism and sexual harassment in medical schools by using Theater of the Oppressed as an interactive and reflexive tool.
Among the measures taken to combat sexism and sexual harassment, prevention courses for medical students are one possibility. We aimed to describe the process of implementing a training course on the prevention of sexism and sexual harassment for medical students in two Swiss medical schools by using the Theater of the Oppressed as an interactive and reflexive tool within the course. The purpose of this theater was to give the students the opportunity to express themselves and to collectively look for and discuss ways to combat and escape from oppressive situations.
This collaborative, innovative, and interactive implementation showed that different forms of a training course can be implemented with similar objectives in an adaptable and transferable manner. The interactive and reflexive Theater of the Oppressed was an appropriate option to reach the objectives. Courses were based on identifying and acting on concrete problematic situations by focusing on individual, collective, and institutional resources. Students reported a high level of satisfaction
Classical Logical versus Quantum Conceptual Thought: Examples in Economics, Decision theory and Concept Theory
Inspired by a quantum mechanical formalism to model concepts and their
disjunctions and conjunctions, we put forward in this paper a specific
hypothesis. Namely that within human thought two superposed layers can be
distinguished: (i) a layer given form by an underlying classical deterministic
process, incorporating essentially logical thought and its indeterministic
version modeled by classical probability theory; (ii) a layer given form under
influence of the totality of the surrounding conceptual landscape, where the
different concepts figure as individual entities rather than (logical)
combinations of others, with measurable quantities such as 'typicality',
'membership', 'representativeness', 'similarity', 'applicability', 'preference'
or 'utility' carrying the influences. We call the process in this second layer
'quantum conceptual thought', which is indeterministic in essence, and contains
holistic aspects, but is equally well, although very differently, organized
than logical thought. A substantial part of the 'quantum conceptual thought
process' can be modeled by quantum mechanical probabilistic and mathematical
structures. We consider examples of three specific domains of research where
the effects of the presence of quantum conceptual thought and its deviations
from classical logical thought have been noticed and studied, i.e. economics,
decision theory, and concept theories and which provide experimental evidence
for our hypothesis.Comment: 14 page
Three-Dimensional Multiple-Order Twinning of Self-Catalyzed GaAs Nanowires on Si Substrates
In this paper we introduce a new paradigm for nanowire growth that explains the unwanted appearance of parasitic nonvertical nanowires. With a crystal structure polarization analysis of the initial stages of GaAs nanowire growth on Si substrates, we demonstrate that secondary seeds form due to a three-dimensional twinning phenomenon. We derive the geometrical rules that underlie the multiple growth directions observed experimentally. These rules help optimizing nanowire array devices such as solar or water splitting cells or of more complex hierarchical branched nanowire devices
Femtosecond pulse generation with a diode-pumped Yb3+:YVO4 laser
A diode-pumped Yb:YVO4 laser has been passively mode locked for the first time, to our knowledge. 120 fs pulses with an average output power of 300 mW and a peak power as high as 14.5 kW are obtained by use of a semiconductor saturable-absorber mirror for passive mode locking. The optical spectrum has a 10 nm bandwidth (full width at half-maximum) and is centered at 1021 nm
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The Galaxy platform for accessible, reproducible, and collaborative data analyses: 2024 update
YesGalaxy (https://galaxyproject.org) is deployed globally, predominantly through free-to-use services, supporting user-driven research that broadens in scope each year. Users are attracted to public Galaxy services by platform stability, tool and reference dataset diversity, training, support and integration, which enables complex, reproducible, shareable data analysis. Applying the principles of user experience design (UXD), has driven improvements in accessibility, tool discoverability through Galaxy Labs/subdomains, and a redesigned Galaxy ToolShed. Galaxy tool capabilities are progressing in two strategic directions: integrating general purpose graphical processing units (GPGPU) access for cutting-edge methods, and licensed tool support. Engagement with global research consortia is being increased by developing more workflows in Galaxy and by resourcing the public Galaxy services to run them. The Galaxy Training Network (GTN) portfolio has grown in both size, and accessibility, through learning paths and direct integration with Galaxy tools that feature in training courses. Code development continues in line with the Galaxy Project roadmap, with improvements to job scheduling and the user interface. Environmental impact assessment is also helping engage users and developers, reminding them of their role in sustainability, by displaying estimated CO2 emissions generated by each Galaxy job.NIH [U41 HG006620, U24 HG010263, U24 CA231877, U01 CA253481]; US National Science Foundation [1661497, 1758800, 2216612]; computational resources are provided by the Advanced Cyberinfrastructure Coordination Ecosystem (ACCESS-CI), Texas Advanced Computing Center, and the JetStream2 scientific cloud. Funding for open access charge: NIH. ELIXIR IS and Travel grants; EU Horizon Europe [HORIZON-INFRA-2021-EOSC-01-04, 101057388]; EU Horizon Europe under the Biodiversity, Circular Economy and Environment program (REA.B.3, BGE 101059492); German Federal Ministry of Education and Research, BMBF [031 A538A de.NBI-RBC]; Ministry of Science, Research and the Arts Baden-Württemberg (MWK) within the framework of LIBIS/de.NBI Freiburg. Galaxy Australia is supported by the Australian BioCommons which is funded through Australian Government NCRIS investments from Bioplatforms Australia and the Australian Research Data Commons, as well as investment from the Queensland Government RICF program.Please note, contributors are listed in alphabetical order
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