1,054 research outputs found
Quantifying Genuine Multipartite Correlations and their Pattern Complexity
We propose an information-theoretic framework to quantify multipartite correlations in classical and quantum systems, answering questions such as what is the amount of seven-partite correlations in a given state of ten particles? We identify measures of genuine multipartite correlations, i.e., statistical dependencies that cannot be ascribed to bipartite correlations, satisfying a set of desirable properties. Inspired by ideas developed in complexity science, we then introduce the concept of weaving to classify states that display different correlation patterns, but cannot be distinguished by correlation measures. The weaving of a state is defined as the weighted sum of correlations of every order. Weaving measures are good descriptors of the complexity of correlation structures in multipartite systems
Coherence and quantum correlations measure sensitivity to dephasing channels
We introduce measures of quantum coherence as the speed of evolution of a system under decoherence. That is, coherence is the ability to estimate a dephasing channel, quantified by the quantum Fisher information. We extend the analysis to interferometric noise estimation, proving that quantum discord is the minimum sensitivity to local dephasing. A physically motivated set of free operations for discord is proposed. The amount of discord created by strictly incoherent operations is upper bounded by the initial coherence
Acquisition efficiency of Flavescence dorée phytoplasma by Scaphoideus titanus Ball from infected tolerant or susceptible grapevine cultivars or experimental host plants
The rate of Flavescence dorée phytoplasma (FDP) acquisition by the leafhopper vector Scaphoideus titanus Ball was tested under field and glass house conditions confining healthy reared nymphs on canes of FDP-infected grapevines or on FDP-infected cuttings collected in the field during the dormant season. Acquisition tests were performed using FD-tolerant (Merlot) or highly susceptible (Pinot blanc) grapevine cultivars, or alternatively using experimentally infected broadbean plants. Frequency of FDP acquisition by leafhoppers was evaluated using a polymerase chain reaction (PCR) assay. Different batches of insects were confined on the same infected source plants in the vineyard for acquisition access periods (AAP) of 7 d at a time at intervals of 15-20 d during spring and summer. When diseased Pinot blanc grapevines were used as source plants, acquisition by leafhoppers and transmission to healthy grapevines increased over summer, while almost no acquisition or transmission was observed when diseased Merlot grapevines were used as source plants. Tests conducted under controlled conditions confirmed that Merlot is a poorer source of FDP than Pinot blanc; the optimum FDP source for S. titanus was broadbean although this plant is not a natural host of the leafhopper. It is assumed that grapevine cultivars play an important role in influencing the proportion of FDP-infected leafhoppers in the vineyards and therefore influencing the rate of disease progress.
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A new method to assess the acute toxicity toward honeybees of the abrasion particles generated from seeds coated with insecticides
Abstract
Background: Large amounts of insecticide-containing dusts produced from abrasion of the seed dressing can be
released into the atmosphere during sowing operations. Neonicotinoid pesticides, introduced in the 1990s for several
crops, are the leading products for seed-coating treatments in many countries. Neonicotinoid containing dusts can
be efectively intercepted by bees in fight over the sowing feld, inducing lethal acute efects, so that restrictions in
the use of the main neonicotinoids have been adopted in the European Union. This led to the consequent introduction of replacement insecticides for seed-coating, i.e. methiocarb and thiacloprid, despite the lack of information on
both the toxicity and the exposure scenarios for honeybees.
Results: In this study, a laboratory apparatus was developed in order to quantify the toxicity of the dusts produced
from the abrasion of the seed coating. This quantifcation is based on (i) an airstream transporting coating particles
into an exposure chamber; (ii) exposure of bees to reproducible and measurable concentrations of insecticide, and
(iii) direct measurement of the exposure dose on single bees. The method allowed us to perform in vivo experiments
of honeybee exposure to provide toxicity data in more realistic exposure conditions. In fact, the formulation rather
than the active principle alone can be tested, and the exposure is through dusts rather than a solution so that specifc
absorption behavior can be studied in representative environmental conditions. The method was used to quantify
the acute toxicity (LD50) of dusts obtained from the abrasion of corn seeds coated with clothianidin, thiacloprid and
methiocarb.
Conclusions: Our results show that, surprisingly, the replacement insecticide methiocarb has a toxicity (LD50=421–
693 ng/bee) in the same order of magnitude as clothianidin (LD50=113–451 ng/bee) through this specifc exposure
route, while thiacloprid (LD50=16.9·103 ng/bee) has a signifcantly lower acute toxicity. Moreover, dusts containing
methiocarb and clothianidin show a signifcant increase in toxicity when, after exposure, bees are kept under high
humidity conditions. This suggests that the method here presented can be used to obtain complementary toxicity
data in the risk assessment procedure for the authorization of new seed-coating insecticides or new formulations.
Keywords: Systemic insecticides, Neonicotinoids, Methiocarb, Seed coating, Abrasion dusts, Honeybees, Pollinator
insects, Acute toxicity, Exposure measuremen
consumer preference for chicken breast may be more affected by information on organic production than by product sensory properties
ABSTRACT Conventional chicken from a fast-growing strain (CC), organic chicken from a slow-growing strain (OSG), and organic chicken from a fast-growing strain (OFG) were used to assess descriptive sensory differences between organic and conventional breasts, to verify whether differences were perceived by consumers and to evaluate the effect of information about organic production on liking. A conventional quantitative–descriptive analysis was performed by a trained panel of 10 members on breast slices (1 cm thick) grilled at 300°C. A 150-member consumer panel (from southern, central, and northern Italy) rated CC, OSG, and OFG breasts according to 3 types of evaluation: tasting without information (perceived liking), information without tasting (expected liking), and tasting with information (actual liking). Breasts from different sources were clearly discriminated by the trained panel as meat from CC was perceived more tender than OFG (
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