2,902 research outputs found
Attention to Exploration: The Effect of Academic Entrepreneurship on the Production of Scientific Knowledge
We study how becoming an entrepreneur affects academic scientists' research. We propose that entrepreneurship will shift scientists' attention away from intradisciplinary research questions and toward new bodies of knowledge relevant for downstream technology development. This will propel scientists to engage in exploration, meaning they work on topics new to them. In turn, this shift toward exploration will enhance the impact of the entrepreneurial scientist's subsequent research, as concepts and models from other bodies of knowledge are combined in novel ways. Entrepreneurship leads to more impactful research, mediated by exploration. Using panel data on the full population of scientists at a large research university, we find support for this argument. Our study is novel in that it identifies a shift of attention as the mechanism underpinning the beneficial spillover effects from founding a venture on the production of public science. A key implication of our study is that commercial work by academics can drive fundamental advances in science
Surface nanoscale axial photonics: Robust fabrication of high quality factor microresonators
Recently introduced Surface Nanoscale Axial Photonics (SNAP) makes it
possible to fabricate high Q-factor microresonators and other photonic
microdevices by dramatically small deformation of the optical fiber surface. To
become a practical and robust technology, the SNAP platform requires methods
enabling reproducible modification of the optical fiber radius at nanoscale. In
this Letter, we demonstrate super-accurate fabrication of high Q-factor
microresonators by nanoscale modification of the optical fiber radius and
refractive index using the CO2 laser and the UV excimer laser beam exposures.
The achieved fabrication accuracy is better than 2 angstroms in variation of
the effective fiber radius
QGP fireball explosion
We identify the major physics milestones in the development of strange
hadrons as an observable for both the formation of quark-gluon plasma, and of
the ensuing explosive disintegration of deconfined matter fireball formed in
relativistic heavy ion collisions at 160--20A GeV. We describe the physical
properties of QGP phase and show agreement with the expectations based on an
analysis of hadron abundances. We than also demonstrate that the m_t shape of
hadron spectra is in qualitative agreement with the sudden breakup of a
supercooled QGP fireball.Comment: 10 pages, incl. 4 figures J. Phys. G in press; presented at
STRANGENESS2000 International Conference, Berkeley July 200
On-sky observations with an achromatic hybrid phase knife coronagraph in the visible
CONTEXT: The four-quadrant phase mask stellar coronagraph, introduced by D.
Rouan et al., is capable of achieving very high dynamical range imaging and was
studied in the context of the direct detection of extra-solar planets.
Achromatic four-quadrant phase mask is currently being developed for broadband
IR applications. AIMS: We report on laboratory and on-sky tests of a prototype
coronagraph in the visible. This prototype, the achromatic hybrid phase knife
coronagraph, was derived from the four-quadrant phase mask principle. METHODS:
The instrumental setup implementing the coronagraph itself was designed to
record the pre- and post-coronagraphic images simultaneously so that an
efficient real-time image selection procedure can be performed. We describe the
coronagraph and the associated tools that enable robust and repeatable
observations. We present an algorithm of image selection that has been tested
against the real on-sky data of the binary star HD80081 (* 38 Lyn). RESULTS
Although the observing conditions were poor, the efficiency of the proposed
method is proven. From this experiment, we derive procedures that can apply to
future focal instruments associating adaptive optics and coronagraphy,
targeting high dynamic range imaging in astronomy, such as detecting
extra-solar planets
Co-axial dual-core resonant leaky fibre for optical amplifiers
We present a co-axial dual-core resonant leaky optical fibre design, in which
the outer core is made highly leaky. A suitable choice of parameters can enable
us to resonantly couple power from the inner core to the outer core. In a
large-core fibre, such a resonant coupling can considerably increase the
differential leakage loss between the fundamental and the higher order modes
and can result in effective single-mode operation. In a small-core single-mode
fibre, such a coupling can lead to sharp increase in the wavelength dependent
leakage loss near the resonant wavelength and can be utilized for the
suppression of amplified spontaneous emission and thereby gain equalization of
an optical amplifier. We study the propagation characteristics of the fibre
using the transfer matrix method and present an example of each, the
large-mode-area design for high power amplifiers and the wavelength tunable
leakage loss design for inherent gain equalization of optical amplifiers.Comment: 6 page
How entrepreneurial intentions influence entrepreneurial career choices: The moderating influence of social context
In this paper, we build on social cognitive career theory to examine the relation between entrepreneurial intention and new venture creation (i.e., the entrepreneurial career choice). We model how contextual influences at different levels may favor or inhibit the translation of entrepreneurial intention into new venture creation. Using unique longitudinal data from almost the entire population of Italian university graduates, we are able to assess how the immediate (i.e., the influence of relevant others) and larger context (i.e., organizational and environmental influences) affect new venture creation. Our research contributes to the emerging literature of the intention–behavior link in entrepreneurship
A Variant in TBCD Associated with Motoneuronopathy and Corpus Callosum Hypoplasia: A Case Report
Mutations in the tubulin-specific chaperon D (TBCD) gene, involved in the assembly and disassembly of the α/β-tubulin heterodimers, have been reported in early-onset progressive neurodevelopment regression, with epilepsy and mental retardation. We describe a rare homozygous variant in TBCD, namely c.881G>A/p.Arg294Gln, in a young woman with a phenotype dominated by distal motorneuronopathy and mild mental retardation, with neuroimaging evidence of corpus callosum hypoplasia. The peculiar phenotype is discussed in light of the molecular interpretation, enriching the literature data on tubulinopathies generated from TBCD mutations
Dynamical quantum noise in Bose-Einstein condensates
We introduce the study of dynamical quantum noise in Bose-Einstein
condensates through numerical simulation of stochastic partial differential
equations obtained using phase space representations. We derive evolution
equations for a single trapped condensate in both the positive- and Wigner
representations, and perform simulations to compare the predictions of the two
methods. The positive- approach is found to be highly susceptible to the
stability problems that have been observed in other strongly nonlinear, weakly
damped systems. Using the Wigner representation, we examine the evolution of
several quantities of interest using from a variety of choices of initial state
for the condensate, and compare results to those for single-mode models.Comment: 8 figures, submitted to Phys. Rev.
- …