68 research outputs found
Catalytic Conversion Probabilities for Bipartite Pure States
For two given bipartite-entangled pure states, an expression is obtained for
the least upper bound of conversion probabilities using catalysis. The
attainability of the upper bound can also be decided if that bound is less than
one.Comment: 4 pages; comments appreciated; the article is a modified version of
this preprint combined with arXiv:0707.044
Random quantum channels I: graphical calculus and the Bell state phenomenon
This paper is the first of a series where we study quantum channels from the
random matrix point of view. We develop a graphical tool that allows us to
compute the expected moments of the output of a random quantum channel. As an
application, we study variations of random matrix models introduced by Hayden
\cite{hayden}, and show that their eigenvalues converge almost surely. In
particular we obtain for some models sharp improvements on the value of the
largest eigenvalue, and this is shown in a further work to have new
applications to minimal output entropy inequalities.Comment: Several typos were correcte
Research on artificial infection to sunflower leaves grown in conditions of the Ezăreni Farm
Sunflower is the most imporant oil crop grown in Romania, with wide use in the food and industry sector. The fungus
Sclerotinia sclerotiorum (Lib) de Bary, is a class Ascomycetes, order Heliotiales, family Sclerotinacea. The disease
causes economic losses in entire world, particulary the culture on sunflower, Helianthus annuus, was the object of
research and disease for decades (Gulya et al., 1997). Sclerotinia sclerotiorum (Lib. de Bary) was described in 1837 by
Libert and indentified by Fuckel in 1861(Purdy) is the fungus that causes the most damage up to 100% in many
cultures(Sackston, 1992). In all temperate climates regions in the world, white rot disease is the most important, because
the fungus remains in the ground,for a period of many years, and range of host plants. This fungus attacks various
organs of the plant, the root, stem, leaveas, and head root. This fungus is a parasite polifag which attack over 400 plant
species belonging to 75 botanical families, of which many species are plants of cultura of a particular importance in
agricultura (sunflower, rapeseed, soybeans) (Boland and Hall 1994). For developing hybrids with genetic resistance,
we must reduce the loss caused by this pathogen. The objective in this study was to test some sunflower hybrids under
Ezăreni farm with resistant pathogen attack
Random positive operator valued measures
We introduce several notions of random positive operator valued measures (POVMs), and we prove that some of them are equivalent. We then study statistical properties of the effect operators for the canonical examples, starting from the limiting eigenvalue distribution. We derive the large system limit for several quantities of interest in quantum information theory, such as the sharpness, the noise content, and the probability range. Finally, we study different compatibility criteria, and we compare them for generic POVMs
Evidenţa principalilor agenţi patogeni şi dăunători ai viţei de vie şi controlul fitosanitar al acestora în condiţiile climatice ale anului 2019
The careful monitoring of vineyards plays a particularly important role in creating forecasts and warnings to help combat the main pathogens and pests. Mainvine diseases such as downy mildew, powdery mildew and gray rot can cause significant production losses if not combated according to well-established phytosanitary programs. On the other hand, their irrational control can lead to the emergence of phytotoxicity phenomena, or forms of resistance to pests. The present paper aims to present the evolution of the main viticultural diseases that appeared in the SCDVV Iaşi vineyards, in the climatic conditions of 2019
Random graph states, maximal flow and Fuss-Catalan distributions
For any graph consisting of vertices and edges we construct an
ensemble of random pure quantum states which describe a system composed of
subsystems. Each edge of the graph represents a bi-partite, maximally entangled
state. Each vertex represents a random unitary matrix generated according to
the Haar measure, which describes the coupling between subsystems. Dividing all
subsystems into two parts, one may study entanglement with respect to this
partition. A general technique to derive an expression for the average
entanglement entropy of random pure states associated to a given graph is
presented. Our technique relies on Weingarten calculus and flow problems. We
analyze statistical properties of spectra of such random density matrices and
show for which cases they are described by the free Poissonian
(Marchenko-Pastur) distribution. We derive a discrete family of generalized,
Fuss-Catalan distributions and explicitly construct graphs which lead to
ensembles of random states characterized by these novel distributions of
eigenvalues.Comment: 37 pages, 24 figure
Random repeated quantum interactions and random invariant states
We consider a generalized model of repeated quantum interactions, where a
system is interacting in a random way with a sequence of
independent quantum systems . Two types of randomness
are studied in detail. One is provided by considering Haar-distributed
unitaries to describe each interaction between and
. The other involves random quantum states describing each copy
. In the limit of a large number of interactions, we present
convergence results for the asymptotic state of . This is achieved
by studying spectral properties of (random) quantum channels which guarantee
the existence of unique invariant states. Finally this allows to introduce a
new physically motivated ensemble of random density matrices called the
\emph{asymptotic induced ensemble}
A review of exposure assessment methods for epidemiological studies of health effects related to industrially contaminated sites
BACKGROUND: this paper is based upon work from COST Action ICSHNet. Health risks related to living close to industrially contaminated sites (ICSs) are a public concern. Toxicology-based risk assessment of single contaminants is the main approach to assess health risks, but epidemiological studies which investigate the relationships between exposure and health directly in the affected population have contributed important evidence. Limitations in exposure assessment have substantially contributed to uncertainty about associations found in epidemiological studies.
OBJECTIVES: to examine exposure assessment methods that have been used in epidemiological studies on ICSs and to provide recommendations for improved exposure assessment in epidemiological studies by comparing exposure assessment methods in epidemiological studies and risk assessments.
METHODS: after defining the multi-media framework of exposure related to ICSs, we discussed selected multi-media models applied in Europe. We provided an overview of exposure assessment in 54 epidemiological studies from a systematic review of hazardous waste sites; a systematic review of 41 epidemiological studies on incinerators and 52 additional studies on ICSs and health identified for this review.
RESULTS: we identified 10 multi-media models used in Europe primarily for risk assessment. Recent models incorporated estimation of internal biomarker levels. Predictions of the models differ particularly for the routes ‘indoor air inhalation’ and ‘vegetable consumption’. Virtually all of the 54 hazardous waste studies used proximity indicators of exposure, based on municipality or zip code of residence (28 studies) or distance to a contaminated site (25 studies). One study used human biomonitoring. In virtually all epidemiological studies, actual land use was ignored. In the 52 additional studies on contaminated sites, proximity indicators were applied in 39 studies, air pollution dispersion modelling in 6 studies, and human biomonitoring in 9 studies. Exposure assessment in epidemiological studies on incinerators included indicators (presence of source in municipality and distance to the incinerator) and air dispersion modelling. Environmental multi-media modelling methods were not applied in any of the three groups of studies.
CONCLUSIONS: recommendations for refined exposure assessment in epidemiological studies included the use of more sophisticated exposure metrics instead of simple proximity indicators where feasible, as distance from a source results in misclassification of exposure as it ignores key determinants of environmental fate and transport, source characteristics, land use, and human consumption behaviour. More validation studies using personal exposure or human biomonitoring are needed to assess misclassification of exposure. Exposure assessment should take more advantage of the detailed multi-media exposure assessment procedures developed for risk assessment. The use of indicators can be substantially improved by linking definition of zones of exposure to existing knowledge of extent of dispersion. Studies should incorporate more often land use and individual behaviour
Stable oxygen isotopes in Romanian oak tree rings record summer droughts and associated large-scale circulation patterns over Europe
We present the first annual oxygen isotope record (1900 – 2016) from the latewood (LW) cellulose of oak trees (Quercus robur) from NW Romania. As expected, the results correlate negatively with summer relative humidity, sunshine duration and precipitation and positively with summer maximum temperature. Spatial correlation analysis reveals a clear signal reflecting drought conditions at a European scale. Interannual variability is influenced by large-scale atmospheric circulation and by surface temperatures in the North Atlantic Ocean and the Mediterranean Sea. There is considerable potential to produce long and well-replicated oak tree ring stable isotope chronologies in Romania which would allow reconstructions of both regional drought and large-scale circulation variability over southern and central Europe
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