11,911 research outputs found
A Taste of Cosmology
This is the summary of two lectures that aim to give an overview of
cosmology. I will not try to be too rigorous in derivations, nor to give a full
historical overview. The idea is to provide a "taste" of cosmology and some of
the interesting topics it covers. The standard cosmological model is presented
and I highlight the successes of cosmology over the past decade or so. Keys to
the development of the standard cosmological model are observations of the
cosmic microwave background and of large-scale structure, which are introduced.
Inflation and dark energy and the outlook for the future are also discussed.
Slides from the lectures are available from the school website:
physicschool.web.cern.ch/PhysicSchool/CLASHEP/CLASHEP2011/.Comment: 16 pages, contribution to the 2011 CERN-Latin-American School of
High-Energy Physics, Natal, Brazil, 23 March-5 April 2011, edited by C.
Grojean, M. Mulders and M. Spiropul
The use of kaolin to control Ceratitis capitata in organic citrus groves.
The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera Tephritidae), is the key pest in some organically managed citrus orchards in Sicily. The effectiveness of processed kaolin (Surround WP) for control of C. capitata damage was tested in field trials carried out in 2003-2004 on two early ripening citrus species: satsuma (Citrus unshiu Markow.) and clementine (Citrus clementina Hort. ex Tan.). Although the number of males captured in trimedlure baited traps was high in both years and in both orchards, the percentage of damaged fruit varied greatly from almost 0% (satsuma 2003) to more than 60% (clementine, both years). Nevertheless, the application of processed kaolin significantly reduced damage caused by C. capitata on both citrus spe- cies on preharvest fruit on some dates and on harvested fruits in both years. The kaolin was easily removed from harvested fruit by washing. Processed kaolin has potential for reducing damage caused by C. capitata in organic and conventional citrus or- chards
Non-Gaussianity from Large-Scale Structure Surveys
With the advent of galaxy surveys which provide large samples of galaxies or
galaxy clusters over a volume comparable to the horizon size (SDSS-III, HETDEX,
Euclid, JDEM, LSST, Pan-STARRS, CIP etc.) or mass-selected large cluster
samples over a large fraction of the extra-galactic sky (Planck, SPT, ACT,
CMBPol, B-Pol), it is timely to investigate what constraints these surveys can
impose on primordial non-Gaussianity. I illustrate here three different
approaches: higher-order correlations of the three dimensional galaxy
distribution, abundance of rare objects (extrema of the density distribution),
and the large-scale clustering of halos (peaks of the density distribution).
Each of these avenues has its own advantages, but, more importantly, these
approaches are highly complementary under many respects.Comment: 20 pages, 8 figures, submitted to the special issue "Testing the
Gaussianity and Statistical Isotropy of the Universe" of Advances in
Astronom
Basic statistics for probabilistic symbolic variables: a novel metric-based approach
In data mining, it is usually to describe a set of individuals using some
summaries (means, standard deviations, histograms, confidence intervals) that
generalize individual descriptions into a typology description. In this case,
data can be described by several values. In this paper, we propose an approach
for computing basic statics for such data, and, in particular, for data
described by numerical multi-valued variables (interval, histograms, discrete
multi-valued descriptions). We propose to treat all numerical multi-valued
variables as distributional data, i.e. as individuals described by
distributions. To obtain new basic statistics for measuring the variability and
the association between such variables, we extend the classic measure of
inertia, calculated with the Euclidean distance, using the squared Wasserstein
distance defined between probability measures. The distance is a generalization
of the Wasserstein distance, that is a distance between quantile functions of
two distributions. Some properties of such a distance are shown. Among them, we
prove the Huygens theorem of decomposition of the inertia. We show the use of
the Wasserstein distance and of the basic statistics presenting a k-means like
clustering algorithm, for the clustering of a set of data described by modal
numerical variables (distributional variables), on a real data set. Keywords:
Wasserstein distance, inertia, dependence, distributional data, modal
variables.Comment: 19 pages, 3 figure
Control of Bactrocera oleae and Ceratitis capitata in Organic Orchards: Use of Clays and Copper Products.
Tests on the effect of clays (kaolin and bentonite) and copper products
(hydroxide and oxychloride) in the control of olive fruit fly, Bactrocera oleae (Rossi), and Mediterranean fruit fly, Ceratitis capitata (Wiedemann), were carried out from 2003 to 2006 in olive groves and in organic citrus orchards (satsuma, clementine, ‘Navelina’ orange). Results demonstrate an efficacy of kaolin products in reducing attacks of B. oleae on olives and those of C. capitata on citrus fruits; in olive groves the clays gave similar or better results than copper hydroxide. Bentonite AG/8W showed a significant reduction in punctures by C. capitata. Bentonite products and BPLK kaolin are washed off by rainfall more easily than Surround WP kaolin. In contrast to the effect of copper hydroxide on B. oleae in olive groves, no tested copper product showed a significant reduction in C. capitata punctures on citrus fruits. Clays are very useful tools to control tephritid and other insects and are also environmentally friendly, but currently, they are not permitted as products for plant protection in European and Swiss organic farming
First record of the non-pollinating fig wasp Odontofroggatia galili Wiebes, 1980 from Malta (Hymenoptera, Chalcidoidea, Agaonidae)
The fig wasp Odontofroggatia galili is reported for the first time from Malta. Odontofroggatia is a non-pollinating fig wasp genus associated with a narrow range of host plant species, among them Ficus microcarpa, a widespread ornamental tree native to Asia.peer-reviewe
Planck and the local Universe: quantifying the tension
We use the latest Planck constraints, and in particular constraints on the
derived parameters (Hubble constant and age of the Universe) for the local
universe and compare them with local measurements of the same quantities. We
propose a way to quantify whether cosmological parameters constraints from two
different experiments are in tension or not. Our statistic, T, is an evidence
ratio and therefore can be interpreted with the widely used Jeffrey's scale. We
find that in the framework of the LCDM model, the Planck inferred two
dimensional, joint, posterior distribution for the Hubble constant and age of
the Universe is in "strong" tension with the local measurements; the odds being
~ 1:50. We explore several possibilities for explaining this tension and
examine the consequences both in terms of unknown errors and deviations from
the LCDM model. In some one-parameter LCDM model extensions, tension is reduced
whereas in other extensions, tension is instead increased. In particular, small
total neutrino masses are favored and a total neutrino mass above 0.15 eV makes
the tension "highly significant" (odds ~ 1:150). A consequence of accepting
this interpretation of the tension is that the degenerate neutrino hierarchy is
highly disfavoured by cosmological data and the direct hierarchy is slightly
favored over the inverse.Comment: Submitted to Physics of the Dark Univers
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