12,933 research outputs found
Linearity of charge measurement in laser filaments
We evaluate the linearity of three electric measurement techniques of the
initial electron density in laser filaments by comparing their results for a
pair of filaments and for the sum of each individual filament. The conductivity
measured between two plane electrodes in a longitudinal configuration is linear
within 2% provided the electric field is kept below 100 kV/m. Furthermore,
simulations show that the signal behaves like the amount of generated free
electrons. The slow ionic current measured with plane electrodes in a parallel
configuration is representative of the ionic charge available in the filament,
after several s, when the free electrons have recombined. It is linear
within 2% with the amount of ions and is insensitive to misalignment. Finally,
the fast polarization signal in the same configuration deviates from linearity
by up to 80% and can only be considered as a semi-qualitative indication of the
presence of charges, e.g., to characterize the filament length.Comment: 17 pages, 7 figure
Bosonization as Duality
We show that bosonization in two dimensions can be derived as a special case
of the duality transformations that have recently been used to good effect in
string theory. This allows the construction of the bosonic counterpart of any
fermionic theory simply by `following your nose' using the standard duality
transformation rules. We work through the bosonization of the Dirac fermion,
the massive and massless Thirring models, and a fermion on a cylindrical
spacetime as illustrative examples.Comment: plain TeX, 21 page
Intumescences On Poplar Leaves. I. Structure And Development
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141211/1/ajb208869.pd
Pronouncing French Names in New Orleans
This article, based on 984 interviews with bearers of French names in the city of New Orleans, investigates the use of the notion of pronunciation as a device by which speakers manage their talk. The investigation proceeded primarily by eliciting ways in which people employ devices for talking about talk in everyday communicative interactions, as a means to manage various types of communicational phenomena and to deal with communication difficulties emerging from a clash of phonetic traditions. The result is a definition of pronunciation in terms which are used by a majority of speakers. An appendix gives a list of names, with comments by their bearers concerning ways in which those bearers would attempt to convey to mispronouncers the correct pronunciation of their names
The XMM-Newton Serendipitous Survey. VI. The X-ray Luminosity Function
We present the X-ray luminosity function of AGN in three energy bands (Soft:
0.5-2 keV, Hard: 2-10 keV and Ultrahard: 4.5-7.5 keV). We have used the XMS
survey along with other highly complete flux-limited deeper and shallower
surveys for a total of 1009, 435 and 119 sources in the Soft, Hard and
Ultrahard bands, respectively. We have modeled the intrinsic absorption of the
Hard and Ultrahard sources (NH function) and computed the intrinsic X-ray
luminosity function in all bands using a Maximum Likelihood fit technique to an
analytical model. We find that the X-ray luminosity function (XLF) is best
described by a Luminosity-Dependent Density Evolution (LDDE) model. Our results
show a good overall agreement with previous results in the Hard band, although
with slightly weaker evolution. Our model in the Soft band present slight
discrepancies with other works in this band, the shape of our present day XLF
being significantly flatter. We find faster evolution in the AGN detected in
the Ultrahard band than those in the Hard band. The fraction of absorbed AGN in
the Hard and Ultrahard bands is dependent on the X-ray luminosity. We find
evidence of evolution of this fraction with redshift in the Hard band but not
in the Ultrahard band, possibly due to the low statistics. Our best-fit XLF
shows that the high-luminosity AGN are fully formed earlier than the less
luminous AGN. The latter sources account for the vast majority of the accretion
rate and mass density of the Universe, according to an anti-hierarchical black
hole growth scenario.Comment: 16 pages, 12 figures, accepted for publication in Astronomy and
Astrophysic
The remittances behaviour of the second generation in Europe: altruism or self-interest?
Whereas most research on remittances focuses on first-generation migrants, the aim of this paper is to investigate the remitting behaviour of the host country-born children of migrants - the second generation - in various European cities. Some important studies found that migrant transnationalism is not only a phenomenon for the first generation, but
also apply to the second and higher generations, through, among other things, family visits, elder care, and remittances. At the same time, the maintenance of a strong ethnic identity in the ‘host’ society does not necessarily mean that second-generation migrants have strong transnational ties to their ‘home’ country.
The data used in this paper is from “The Integration of the European Second Generation” (TIES) project. The survey collected information on approximately 6,250 individuals aged 18-35 with at least one migrant parent from Morocco, Turkey or former Yugoslavia, in 15 European cities, regrouped in 8 ‘countries’. For the purpose of this paper, only
analyses for Austria (Linz and Vienna); Switzerland (Basle and Zurich); Germany (Berlin and Frankfurt); France (Paris and Strasbourg); the Netherlands (Amsterdam and Rotterdam); Spain (Barcelona and Madrid); and Sweden (Stockholm) will be presented.
Older Adult Preferences of Mobile Application Functionality Supporting Medication Self-Management
Health systems and insurers alike are increasingly interested in leveraging mHealth (mobile health) tools to support patient health-related behaviors
including medication adherence. However, these tools are not widely used by older patients. This study explores patient preferences for
functionality in a smartphone application (app) that supports medication self-management among older adults with multiple chronic conditions.
We conducted six discussion groups in Chicago, Miami, and Denver (N = 46). English-speaking older adults (55 and older) who owned
smartphones and took five or more prescription medicines were invited to participate. Discussions covered familiarity with and use of current
apps and challenges with taking multidrug regimens. Participants reviewed a range of possible mobile app functions and were asked to give
feedback regarding the acceptability and desirability of each to support medication management. Very few participants (n = 3) reported current use
of a mobile app for medication support, although all were receptive. Challenges to medication use were forgetfulness, fear of adverse events, and
managing medication information from multiple sources. Desired features included (1) a list and consolidated schedule of medications, (2)
identification and warning of unsafemedication interactions, (3) reminder alerts to take medicine, and (4) the ability record when medications were
taken. Features relating to refill ordering, pharmacy information, and comparing costs for medication were not considered to be as important for an
app
Locomotor adaptability in persons with unilateral transtibial amputation
Background
Locomotor adaptation enables walkers to modify strategies when faced with challenging walking conditions. While a variety of neurological injuries can impair locomotor adaptability, the effect of a lower extremity amputation on adaptability is poorly understood. Objective
Determine if locomotor adaptability is impaired in persons with unilateral transtibial amputation (TTA). Methods
The locomotor adaptability of 10 persons with a TTA and 8 persons without an amputation was tested while walking on a split-belt treadmill with the parallel belts running at the same (tied) or different (split) speeds. In the split condition, participants walked for 15 minutes with the respective belts moving at 0.5 m/s and 1.5 m/s. Temporal spatial symmetry measures were used to evaluate reactive accommodations to the perturbation, and the adaptive/de-adaptive response. Results
Persons with TTA and the reference group of persons without amputation both demonstrated highly symmetric walking at baseline. During the split adaptation and tied post-adaptation walking both groups responded with the expected reactive accommodations. Likewise, adaptive and de-adaptive responses were observed. The magnitude and rate of change in the adaptive and de-adaptive responses were similar for persons with TTA and those without an amputation. Furthermore, adaptability was no different based on belt assignment for the prosthetic limb during split adaptation walking. Conclusions
Reactive changes and locomotor adaptation in response to a challenging and novel walking condition were similar in persons with TTA to those without an amputation. Results suggest persons with TTA have the capacity to modify locomotor strategies to meet the demands of most walking conditions despite challenges imposed by an amputation and use of a prosthetic limb
The evolution of the Compton thick fraction and the nature of obscuration for AGN in the Chandra Deep Field South
(Abridged) We present the results from the X-ray spectral analysis of high-z
AGN in the CDFS, making use of the new 4Ms data set and new X-ray spectral
models from Brightman & Nandra, which account for Compton scattering and the
geometry of the circumnuclear material. Our goals are to ascertain to what
extent the torus paradigm of local AGN is applicable at earlier epochs and to
evaluate the evolution of the Compton thick fraction (f_CT) with z, important
for XRB synthesis models and understanding the accretion history of the
universe. In addition to the torus models, we measure the fraction of scattered
nuclear light, f_scatt known to be dependant on covering factor of the
circumnuclear materal, and use this to aid in our understanding of its
geometry. We find that the covering factor of the circumnuclear material is
correlated with NH, and as such the most heavily obscured AGN are in fact also
the most geometrically buried. We come to these conclusions from the result
that f_scatt decreases as NH increases and from the prevalence of the torus
model with the smallest opening angle as best fit model in the fits to the most
obscured AGN. We find that a significant fraction of sources (~ 20%) in the
CDFS are likely to be buried in material with close to 4 pi coverage having
been best fit by the torus model with a 0\degree opening angle. Furthermore, we
find 41 CTAGN in the CDFS using the new torus models, 29 of which we report
here for the first time. We bin our sample by z in order to investigate the
evolution of f_CT. Once we have accounted for biases and incompleteness we find
a significant increase in the intrinsic f_CT, normalised to LX= 10^43.5 erg/s,
from \approx 20% in the local universe to \approx 40% at z=1-4.Comment: Accepted for publication in MNRA
NFC as an Alternative for Improving Videogame Development in Mobile Devices
La aparición de nuevas alternativas de interacción puede llevar a generar videojuegos cada vez más interesantes, este es el caso de la interacción con el teléfono móvil, especialmente la tecnología NFC. Sin embargo no existe un referente para conocer qué tipos de videojuegos serían los más apropiados para desarrollar con NFC. Por tanto, este artículo aporta una revisión de varias fuentes para determinar el estado actual de videojuegos con NFC para futuras referencias de generadores de contenido y emprendedores en el campo de los videojuegos; como contribuciones se tiene una revisión en varias fuentes a nivel comercial, bibliográfico y de tiendas de aplicaciones para generar el estado actual y el esquema de posibles videojuegos con los cuales NFC podría interactuar, determinando las categorías de videojuegos más apropiadas para desarrollar con dicha tecnología y proponiendo algunas características que NFC permite implementar.The emergence of new interaction alternatives can result in increasingly interesting videogames; this is the case of the interaction with the mobile phone, especially NFC technology. However, there is not a model to get to know the types of videogames that would be more appropriate to be developed with NFC. Therefore, this article provides a review of several sources to determine current state of videogames with NFC for future reference of content generators and entrepreneurs in the field of videogames; as a contribution, there is a review of several commercial, bibliographic sources and applications shops to generate current state and a scheme of potential videogames with which NFC could interact by determining categories of the most appropriate videogames to be developed with such a technology and proposing some features that can be implemented with the NFC
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