1,315 research outputs found
Optical coherence tomography (OCT) as a 3-dimensional imaging technique for non-destructive testing of roll-to-roll coated polymer solar cells
Generational Differences in Information Technology Use and Political Involvement
A structural equation model analysis of data from a 2003 national random sample survey (n = 478) on informational technology (IT) reveals important direct and indirect effects of generational demographic and attitudinal differences on electronic forms of political participation. Younger respondents reported more support for IT and fewer technological disadvantages compared to older respondents. Younger respondents showed more desire for public IT availability and e-political participation, whereas older respondents preferred traditional electoral involvement. The more educated held more favorable views of IT generally and of public IT access more specifically. Bettereducated respondents were more active civically in both traditional and electronic forms of participation. Supportive technological views led to greater e-political participation and stronger interest in e-elections. Respondents with less concern and fear about IT were more likely to act as digital citizens and were more involved in epolitics and e-elections. Proponents of public IT access were more supportive of eelections. Our model suggests that e-citizenry will compound existing social divisions, as non-electronic voices are marginalized and electronic voices are amplified
Identification of potentially safe promising fungal cell factories for the production of polyketide natural food colorants using chemotaxonomic rationale
Photoinjector-generation of a flat electron beam with transverse emittance ratio of 100
The generation of a flat electron beam directly from a photoinjector is an
attractive alternative to the electron damping ring as envisioned for linear
colliders. It also has potential applications to light sources such as the
generation of ultra-short x-ray pulses or Smith-Purcell free electron lasers.
In this Letter, we report on the experimental generation of a flat-beam with a
measured transverse emittance ratio of for a bunch charge of
nC; the smaller measured normalized root-mean-square emittance is
m and is limited by the resolution of our experimental setup.
The experimental data, obtained at the Fermilab/NICADD Photoinjector
Laboratory, are compared with numerical simulations and the expected scaling
laws.Comment: 5 pages, 3 figure
Effect of temperature and water activity on the production of fumonisins by Aspergillus niger and different Fusarium species
<p>Abstract</p> <p>Background</p> <p>Fumonisins are economically important mycotoxins which until recently were considered to originate from only a few <it>Fusarium </it>species. However recently a putative fumonisin gene cluster was discovered in two different <it>Aspergillus niger </it>strains followed by detection of an actual fumonisin B<sub>2 </sub>(FB<sub>2</sub>) production in four strains of this biotechnologically important workhorse.</p> <p>Results</p> <p>In the present study, a screening of 5 <it>A. niger </it>strains and 25 assumed fumonisin producing <it>Fusarium </it>strains from 6 species, showed that all 5 <it>A. niger </it>strains produced FB<sub>2 </sub>and 23 of 25 <it>Fusarium </it>produced fumonisin B<sub>1 </sub>and other isoforms (fumonisin B<sub>2 </sub>and B<sub>3</sub>). Five <it>A. niger </it>and five <it>Fusarium </it>spp. were incubated at six different temperatures from 15-42°C on Czapek Yeast Agar +5% salt or Potato Dextrose Agar. <it>A. niger </it>had the highest production of FB<sub>2 </sub>at 25-30°C whereas <it>Fusarium </it>spp. had the maximal production of FB<sub>1 </sub>and FB<sub>2 </sub>at 20-25°C. Addition of 2.5-5% NaCl, or 10-20% sucrose increased the FB<sub>2 </sub>production of <it>A. niger</it>, whereas addition of glycerol reduced FB<sub>2 </sub>production. All three water activity lowering solutes reduced the fumonisin production of the <it>Fusarium </it>species.</p> <p>Conclusion</p> <p>The present study shows that the regulation of fumonisin production is very different in <it>A. niger </it>and <it>Fusarium</it>, and that food and feeds preserved by addition of sugar or salts may be good substrates for fumonisin B<sub>2 </sub>production by <it>A. niger</it>.</p
Gravitational waves from Sco X-1: A comparison of search methods and prospects for detection with advanced detectors
The low-mass X-ray binary Scorpius X-1 (Sco X-1) is potentially the most
luminous source of continuous gravitational-wave radiation for interferometers
such as LIGO and Virgo. For low-mass X-ray binaries this radiation would be
sustained by active accretion of matter from its binary companion. With the
Advanced Detector Era fast approaching, work is underway to develop an array of
robust tools for maximizing the science and detection potential of Sco X-1. We
describe the plans and progress of a project designed to compare the numerous
independent search algorithms currently available. We employ a mock-data
challenge in which the search pipelines are tested for their relative
proficiencies in parameter estimation, computational efficiency, robust- ness,
and most importantly, search sensitivity. The mock-data challenge data contains
an ensemble of 50 Scorpius X-1 (Sco X-1) type signals, simulated within a
frequency band of 50-1500 Hz. Simulated detector noise was generated assuming
the expected best strain sensitivity of Advanced LIGO and Advanced VIRGO ( Hz). A distribution of signal amplitudes was then
chosen so as to allow a useful comparison of search methodologies. A factor of
2 in strain separates the quietest detected signal, at
strain, from the torque-balance limit at a spin frequency of 300 Hz, although
this limit could range from (25 Hz) to (750 Hz) depending on the unknown frequency of Sco X-1. With future
improvements to the search algorithms and using advanced detector data, our
expectations for probing below the theoretical torque-balance strain limit are
optimistic.Comment: 33 pages, 11 figure
mHealth Support to Stimulate Physical Activity in Individuals With Intellectual Disability: Protocol for a Mixed Methods Pilot Study
Background: Several studies have shown that individuals with intellectual disabilities (IDs) have low levels of physical activity
(PA), and intervention studies on PA suggest inconsistent evidence. The use of technology as a means of motivation for PA has
yet to be extensively explored and needs to be further investigated.
Objective: We aim to assess the feasibility and acceptability of procedures for an intervention arm in a future trial on mobile
health (mHealth) to support PA for individuals with IDs. In addition, we aim to examine how the use of technology can influence
motivation for PA among participants, their caregivers, and staff members.
Methods: A mixed methods pilot study of an intervention arm will be carried out in a planned randomized controlled trial
(RCT). Ten participants with ID and their caregivers or a staff member will be included. Information will always be provided by
a caregiver or a staff member, or participants with ID if possible. Assessments will be carried out at baseline, follow-up after 4
weeks, and 12 weeks, and include questionnaires on PA, social support, self-efficacy, and challenging behavior. PA will be
measured with 2 different activity trackers (Fitbit and Axivity) for 1 week at all assessments. Feasibility will be assessed as
recruitment and adherence rate, missing data, usability of the motivational mHealth tool, and estimates of effectiveness. Acceptability
of study procedures, activity measures, and motivation for participation in PA will be additionally assessed with qualitative
methods at the end of the intervention.
Results: Enrollment commenced in May 2021. Data collection was completed in March 2022.
Conclusions: This pilot study will evaluate the feasibility and acceptability of study procedures of the intervention arm of a
planned RCT to address feasibility issues, improve study procedures, and estimate effectiveness of the study measures. How the
use of technology can influence motivation for PA will also be examined, which can help guide and improve future PA interventions
involving the use of technology
The Supernova Triggered Formation and Enrichment of Our Solar System
We investigate the enrichment of the pre-solar cloud core with short lived
radionuclides (SLRs), especially 26Al. The homogeneity and the surprisingly
small spread in the ratio 26Al/27Al observed in the overwhelming majority of
calcium-aluminium-rich inclusions (CAIs) in a vast variety of primitive
chondritic meteorites places strong constraints on the formation of the the
solar system. Freshly synthesized radioactive 26Al has to be included and well
mixed within 20kyr. After discussing various scenarios including X-winds, AGB
stars and Wolf-Rayet stars, we come to the conclusion that triggering the
collapse of a cold cloud core by a nearby supernova is the most promising
scenario. We then narrow down the vast parameter space by considering the
pre-explosion survivability of such a clump as well as the cross-section
necessary for sufficient enrichment. We employ numerical simulations to address
the mixing of the radioactively enriched SN gas with the pre-existing gas and
the forced collapse within 20kyr. We show that a cold clump of 10Msun at a
distance of 5pc can be sufficiently enriched in 26Al and triggered into
collapse fast enough - within 18kyr after encountering the supernova shock -
for a range of different metallicities and progenitor masses, even if the
enriched material is assumed to be distributed homogeneously in the entire
supernova bubble. In summary, we envision an environment for the birth place of
the Solar System 4.567Gyr ago similar to the situation of the pillars in M16
nowadays, where molecular cloud cores adjacent to an HII region will be hit by
a supernova explosion in the future. We show that the triggered collapse and
formation of the Solar System as well as the required enrichment with
radioactive 26Al are possible in this scenario.Comment: 12 pages, 8 figures, accepted for publication in ApJ. Resolution of
most figures degraded to fit within arXiv size limits. A full resolution
version is available at
http://www.usm.uni-muenchen.de/~gritschm/Gritschneder_2011_sun.pd
Generation of angular-momentum-dominated electron beams from a photoinjector
Various projects under study require an angular-momentum-dominated electron
beam generated by a photoinjector. Some of the proposals directly use the
angular-momentum-dominated beams (e.g. electron cooling of heavy ions), while
others require the beam to be transformed into a flat beam (e.g. possible
electron injectors for light sources and linear colliders). In this paper, we
report our experimental study of an angular-momentum-dominated beam produced in
a photoinjector, addressing the dependencies of angular momentum on initial
conditions. We also briefly discuss the removal of angular momentum. The
results of the experiment, carried out at the Fermilab/NICADD Photoinjector
Laboratory, are found to be in good agreement with theoretical and numerical
models.Comment: 8 pages, 7 figures, submitted to Phys. Rev. ST Accel. Beam
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