3,051 research outputs found
The effect of the linear term on the wavelet estimator of primordial non-Gaussianity
In this work we present constraints on different shapes of primordial
non-Gaussianity using the Wilkinson Microwave Anisotropy Probe (WMAP) 7-year
data and the spherical Mexican hat wavelet fnl estimator including the linear
term correction. In particular we focus on the local, equilateral and
orthogonal shapes. We first analyse the main statistical properties of the
wavelet estimator and show the conditions to reach optimality. We include the
linear term correction in our estimators and compare the estimates with the
values already published using only the cubic term. The estimators are tested
with realistic WMAP simulations with anisotropic noise and the WMAP KQ75 sky
cut. The inclusion of the linear term correction shows a negligible improvement
(< 1 per cent) in the error-bar for any of the shapes considered. The results
of this analysis show that, in the particular case of the wavelet estimator,
the optimality for WMAP anisotropy levels is basically achieved with the mean
subtraction and in practical terms there is no need of including a linear term
once the mean has been subtracted. Our best estimates are now: local fnl = 39.0
+/ 21.4, equilateral fnl = -62.8 +/- 154.0 and orthogonal fnl = -159.8 +/-
115.1 (all cases 68 per cent CL). We have also computed the expected linear
term correction for simulated Planck maps with anisotropic noise at 143 GHz
following the Planck Sky Model and including a mask. The improvement achieved
in this case for the local fnl error-bar is also negligible (0.4 per cent).Comment: 8 pages, 5 figures, 4 tables. Minor revision, one figure added,
accepted for publication in MNRA
Truncated K-moment problems in several variables
Let be an N-dimensional real multi-sequence of
degree 2n, with associated moment matrix , and let . We prove that if
is positive semidefinite and admits a rank-preserving moment
matrix extension , then has a unique
representing measure \mu, which is r-atomic, with supp \mu\mathcal{V}(\mathcal{M}(n+1))\mathcal{M}(n+1)K_{\mathcal{Q}}\mathcal{Q}%
\equiv\{q_{i}\}_{i=1}^{m}\subseteq\mathbb{R}[t_{1},...,t_{N}]\mathcal{M}(n)\mathcal{M}(n+1)\mathcal{M}_{q_{i}}(n+[\frac{1+\deg q_{i}}{2}])(1\leq i\leq m), and \mu has precisely rank \mathcal{M}(n)-rank
\mathcal{M}_{q_{i}}(n+[\frac{1+\deg q_{i}}{2}])\mathcal{Z}(q_{i})\equiv {t\in\mathbb{R}^{N}:q_{i}(t)=0}1\leq i\leq m$.Comment: 33 pages; to appear in J. Operator Theor
Effectiveness of entomopathogenic nematodes in the control of Cydia pomonella larvae in Northern Italy
Since 2006, a large scale research on the effectiveness of entomopathogenic nematodes
(EPN) in the control of codling moth (CM), Cydia pomonella, overwintering larvae has
been performed on about 35 ha of pear orchards per year in Emilia-Romagna, Northern
Italy. Steinernema carpocapsae and Steinernema feltiae activity was checked after spray
applications of EPNs to the trunk and branches. In 2006, the treatment was applied either
in spring or in autumn at different doses, before CM pupation; in 2007 the EPN treatment
was applied only in autumn at 1.5 x 109 I.J. ha –1. Every year it was distributed by means of
a conventional mist blower. The larval mortality was assessed directly on sentinel larvae in
card boards on the trunks and indirectly on the eggs laid by the females of the first CM
generation in spring. Moreover, each year, a trial was performed applying only S.
carpocapsae on sentinel larvae with the aim of testing this nematode at suitable
temperatures but at different water volumes.
The CM sentinel larvae were effectively parasitized after autumnal EPN application.
Moreover, the egg assessment demonstrated a good decrease in CM population in spring
2007, when EPNs had been applied at the best weather conditions (t° 12-14 °C and rain)
in the previous autumn
Nanofacies de los sedimentos terciarios de las béticas
Diferenciamos en los sedimentos marinos del Oligoceno superior- Mioceno superior de las Béticas ("moronitas")i nco nanofacies: de diatomeas aciculares, biogénica, cocolítico-detrítica, espicularcocolítico- detritica y detritica. Establecemos las relaciones existentes entre ellas discutiendo su origen y formación
Factors associated with costs of hospitalization of severely mentally Ill patients
Background: Efforts to contain costs associated with general medical care include particular efforts for
psychiatric disorders. Hospitalization represents the largest component of costs for psychiatric care and there is
growing interest in balancing clinical needs against limiting costs of inpatient psychiatric care of patients with severe
mental illnesses. This study aimed to evaluate clinical factors associated with actual costs of inpatient psychiatric
care.
Method: We evaluated a cohort of 589 hospitalized psychiatric patients with severe mental illnesses at a
nonprofit, university-affiliated psychiatric hospital for factors associated with annualized total costs of inpatient care
over a three-year period, using bivariate and multivariate analyses.
Results: As expected, days-hospitalized was the major determinant of total costs of hospital care. In addition,
several clinical and treatment factors also were associated significantly and independently with costs in multivariate
modeling. These included presence of psychosis, electroconvulsive treatment, specialist consultations, use of
multiple antipsychotics or of clozapine, and being discharged to a supervised living arrangement, but not sex, age,
marital status, employment, or substance abuse.
Discussion: As expected, costs of psychiatric hospitalization were dominated by per-diem charges, but also
influenced by other, potentially modifiable treatment factors generally associated with more severe psychotic
illnesses. The study is based on actual costs rather than on insurer-reimbursements and a large study-sample,
though at a single institution. Specific factors identified encourage focusing on patient characteristics associated
with greater costs and redoubled efforts to apply and improve alternative, cost-effective interventions such as partialhospital
and intensive outpatient treatment
Wilkinson Microwave Anisotropy Probe 7-yr constraints on fNL with a fast wavelet estimator
A new method to constrain the local non-linear coupling parameter fNL based
on a fast wavelet decomposition is presented. Using a multiresolution wavelet
adapted to the HEALPix pixelization, we have developed a method that is 10^2
times faster than previous estimators based on isotropic wavelets and 10^3
faster than the KSW bispectrum estimator, at the resolution of the Wilkinson
Microwave Anisotropy Probe (WMAP) data. The method has been applied to the WMAP
7-yr V+W combined map, imposing constraints on fNL of -69 < fNL < 65 at the 95
per cent CL. This result has been obtained after correcting for the
contribution of the residual point sources which has been estimated to be fNL =
7 +/- 6. In addition, a Gaussianity analysis of the data has been carried out
using the third order moments of the wavelet coefficients, finding consistency
with Gaussianity. Although the constrainsts imposed on fNL are less stringent
than those found with optimal estimators, we believe that a very fast method,
as the one proposed in this work, can be very useful, especially bearing in
mind the large amount of data that will be provided by future experiments, such
as the Planck satellite. Moreover, the localisation of wavelets allows one to
carry out analyses on different regions of the sky. As an application, we have
separately analysed the two hemispheres defined by the dipolar modulation
proposed by Hoftuft et al. (2009). We do not find any significant asymmetry
regarding the estimated value of fNL in those hemispheres.Comment: 8 pages, 5 figures. Submitted and Accepted for publication in MNRA
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