5,653 research outputs found
The nonperturbative closed string tachyon vacuum to high level
We compute the action of closed bosonic string field theory at quartic order
with fields up to level ten. After level four, the value of the potential at
the minimum starts oscillating around a nonzero negative value, in contrast
with the proposition made in [5]. We try a different truncation scheme in which
the value of the potential converges faster with the level. By extrapolating
these values, we are able to give a rather precise value for the depth of the
potential.Comment: 24 pages. v2: typos corrected, clarified extrapolation in scheme B,
and added extrapolated tachyon and dilaton vev's at the end of Section
Reading the Mind in the Eyes of Children Test (RME-C-T): Development and Validation of a Complex Emotion Recognition Test
Much research has been devoted to the development of emotion recognition tests that can be used to investigate how individuals identify and discriminate emotional expressions of other individuals. One of the most prominent emotion recognition tests is the Reading the Mind in the Eyes Test (RME-T). The original RME-T has been widely used to investigate how individuals recognize complex emotional expressions from the eye region of adult faces. However, the RME-T can only be used to investigate inter-individual differences in complex emotion recognition during the processing of adult faces. To extend its usefulness, we developed a modified version of the RME-T, the Reading the Mind in the Eyes of Children Test (RME-C-T). The RME-C-T can be used to investigate how individuals recognize complex emotional expressions from the eye region of child faces. However, the validity of the RME-C-T has not been evaluated yet. We, thus, administered the RME-C-T together with the RME-T to a sample of healthy adult participants (n = 119). The Interpersonal Reactivity Index (IRI) and the Toronto Alexithymia Scale (TAS) were also administered. Participants’ RME-C-T performance correlated with participants’ RME-T performance, implying that the RME-C-T measures similar emotion recognition abilities as the RME-T. Participants’ RME-C-T performance also correlated with participants’ IRI and TAS scores, indicating that these emotion recognition abilities are affected by empathetic and alexithymic traits. Moreover, participants’ RME-C-T performance differed between participants with high and low TAS scores, suggesting that the RME-C-T is sensitive enough to detect impairments in these emotion recognition abilities. The RME-C-T, thus, turned out to be a valid measure of inter-individual differences in complex emotion recognition during the processing of child faces
Why does the clustering of haloes depend on their formation history
We discuss in the framework of the excursion set formalism a recent discovery
from N-body simulations that the clustering of haloes of given mass depends on
their formation history. We review why the standard implementation of this
formalism is unable to explain such dependencies, and we show that this can, in
principle, be rectified by implementing in full an ellipsoidal collapse model
where collapse depends not only on the overdensity but also on the shape of the
initial density field. We also present an alternative remedy for this
deficiency, namely the inclusion of collapse barriers for pancakes and
filaments, together with the assumption that formation history depends on when
these barriers are crossed. We implement both these extensions in a generalised
excursion set method, and run large Monte Carlo realisations to quantify the
effects. Our results suggest that effects as large as those found in
simulations can only arise in the excursion set formalism if the formation
history of a halo does indeed depend on the size of its progenitor filaments
and pancakes. We also present conditional distributions of progenitor pancakes
and filaments for low-mass haloes identified at present epoch, and discuss a
recent claim by Mo et.al. that most low-mass haloes were embedded in massive
pancakes at .Comment: 11 pages, 8 figures, submitted to MNRA
Erythropoietin in the critically ill: do we ask the right questions?
Creative Commons Attribution LicensePR received research funding from Polymun Scientific GmbH (Klosterneuburg, Austria), a company involved in the commercial development of cEPO-FC
Deep Depth From Focus
Depth from focus (DFF) is one of the classical ill-posed inverse problems in
computer vision. Most approaches recover the depth at each pixel based on the
focal setting which exhibits maximal sharpness. Yet, it is not obvious how to
reliably estimate the sharpness level, particularly in low-textured areas. In
this paper, we propose `Deep Depth From Focus (DDFF)' as the first end-to-end
learning approach to this problem. One of the main challenges we face is the
hunger for data of deep neural networks. In order to obtain a significant
amount of focal stacks with corresponding groundtruth depth, we propose to
leverage a light-field camera with a co-calibrated RGB-D sensor. This allows us
to digitally create focal stacks of varying sizes. Compared to existing
benchmarks our dataset is 25 times larger, enabling the use of machine learning
for this inverse problem. We compare our results with state-of-the-art DFF
methods and we also analyze the effect of several key deep architectural
components. These experiments show that our proposed method `DDFFNet' achieves
state-of-the-art performance in all scenes, reducing depth error by more than
75% compared to the classical DFF methods.Comment: accepted to Asian Conference on Computer Vision (ACCV) 201
Determining the global minimum of Higgs potentials via Groebner bases - applied to the NMSSM
Determining the global minimum of Higgs potentials with several Higgs fields
like the next-to-minimal supersymmetric extension of the Standard Model (NMSSM)
is a non-trivial task already at the tree level. The global minimum of a Higgs
potential can be found from the set of all its stationary points defined by a
multivariate polynomial system of equations. We introduce here the algebraic
Groebner basis approach to solve this system of equations. We apply the method
to the NMSSM with CP conserving as well as CP violating parameters. The results
reveal an interesting stationary-point structure of the potential. Requiring
the global minimum to give the electroweak symmetry breaking observed in Nature
excludes large parts of the parameter space.Comment: 10 pages, 2 figure
On fluctuations of closed string tachyon solitons
We discuss fluctuations on solitons in the dilaton/graviton/tachyon system
using the low energy effective field theory approach. It is shown that closed
string solitons are free of tachyons in this approximation, regardless of the
exact shape of the tachyon potential.Comment: 13 pages, 1 figure, uses JHEP3.cl
Spirometry reference equations for central European populations from school age to old age.
Spirometry reference values are important for the interpretation of spirometry results. Reference values should be updated regularly, derived from a population as similar to the population for which they are to be used and span across all ages. Such spirometry reference equations are currently lacking for central European populations. To develop spirometry reference equations for central European populations between 8 and 90 years of age. We used data collected between January 1993 and December 2010 from a central European population. The data was modelled using "Generalized Additive Models for Location, Scale and Shape" (GAMLSS). The spirometry reference equations were derived from 118'891 individuals consisting of 60'624 (51%) females and 58'267 (49%) males. Altogether, there were 18'211 (15.3%) children under the age of 18 years. We developed spirometry reference equations for a central European population between 8 and 90 years of age that can be implemented in a wide range of clinical settings
CO2 exchange and carbon balance in two grassland sites on eutrophic drained peat soils.
In this study we investigated the role of intensive and extensive dairy farm practices on CO<sub>2</sub> exchange and the carbon balance of peatlands by means of eddy covariance (EC) measurements. Year long EC measurements were made in two adjacent farm sites on peat soil in the western part of the Netherlands. One site (Stein) is a new meadow bird reserve and is managed predominantly by mowing in June and August. The second site (Oukoop) is an intensive dairy farm. Maximum photosynthetic uptake of the grass sward (range 2 to 34 mu mol CO<sub>2</sub> m(-2) s(-1)) showed a close and similar linear relationship with Leaf Area Index (LAI; range 1 to 5) except in maturing hay meadows, where maximum photosynthetic uptake did not increase further. Apparent quantum yield varied between 0.02 and 0.08 (mean 0.045) mu mol CO<sub>2</sub> mu mol(-1) photons at both sites and was significantly correlated with LAI during the growth season. Ecosystem Respiration at 10 degrees C (R-10) calculated from the year round data set was 3.35 mu mol CO<sub>2</sub> m(-2) s(-1) at Stein and 3.69 mu mol CO<sub>2</sub> m(-2) s(-1) at Oukoop. Both sites were a source of carbon in winter and a sink during summer with net ecosystem exchange varying between 50 to 100 mmol CO<sub>2</sub> m(-2) d(-1) in winter to below -400 mmol CO<sub>2</sub> m(-2) d(-1) in summer. Periodically, both sites became a source after mowing. Net annual ecosystem exchange (NEE) for Stein was -5.7 g C m(-2) a(-1) and for Oukoop 133.9 g C m(-2) a(-1). When biomass removal, manure applications and estimates of methane emissions ware taken into account, both eutrophic peat meadows are a strong source for C around 420 g C m(-2) a(-1)
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