Search results for "quantitative"
showing 10 items of 2409 documents
Sexual selection on male body size and assortative pairing in Gammarus pulex (Crustacea: Amphipoda): field surveys and laboratory experiments
2004
Variation in size-assortative pairing was studied in relation to sexual selection on male body size in the amphipod Gammarus pulex, using both transverse and longitudinal surveys of natural populations. In addition, the influence of male–male competition on size-assortative pairing was tested in the laboratory. In both surveys, the intensity of sexual selection was positive and significant for male body size but not for females, and size-assortative pairing was positive and significant. The magnitude of size-assortative pairing, however, varied significantly between populations. The magnitude of size-assortative pairing was positively correlated with the intensity of sexual selection on mal…
Pool punishment in public goods games: How do sanctioners’ incentives affect us?
2021
Abstract Centralized sanctioning in social dilemmas has been shown to increase efficiency with respect to standard decentralized peer punishment. In this context, we explore the impact of sanctioners’ motivations through their payoff scheme, not only on their actions but also on the actions of the monitored individuals. To do so, we compare the implementation of two different payoff schemes for the monitor in a centralized sanctioning framework: (i) a fixed payoff scheme and (ii) a variable payoff scheme contingent on the level of cooperation achieved. We find that providing the sanctioner with a contingent payoff has a negative impact on contributions. This occurs although sanctioners impl…
Local dimensions in Moran constructions
2015
We study the dimensional properties of Moran sets and Moran measures in doubling metric spaces. In particular, we consider local dimensions and $L^q$-dimensions. We generalize and extend several existing results in this area.
Models and solution methods for the uncapacitatedr-allocationp-hub equitable center problem
2017
Hub networks are commonly used in telecommunications and logistics to connect origins to destinations in situations where a direct connection between each origin–destination (o-d) pair is impractical or too costly. Hubs serve as switching points to consolidate and route traffic in order to realize economies of scale. The main decisions associated with hub-network problems include (1) determining the number of hubs (p), (2) selecting the p-nodes in the network that will serve as hubs, (3) allocating non-hub nodes (terminals) to up to r-hubs, and (4) routing the pairwise o-d traffic. Typically, hub location problems include all four decisions while hub allocation problems assume that the valu…
Stock markets and quantum dynamics: A second quantized description
2009
In this paper we continue our description of stock markets in terms of some non-abelian operators which are used to describe the portfolio of the various traders and other observable quantities. After a first prototype model with only two traders, we discuss a more realistic model of market involving an arbitrary number of traders. For both models we find approximated solutions for the time evolution of the portfolio of each trader. In particular, for the more realistic model, we use the stochastic limit approach and a fixed point like approximation. © 2007 Elsevier B.V. All rights reserved
Cyclic fluctuations, climatic changes and role of noise in planktonic foraminifera in the Mediterranean Sea
2005
The study of Planktonic Foraminifera abundances permits to obtain climatic curves on the basis of percentage ratio between tropical and temperate/polar forms. Climatic changes were controlled by several phenomena as: (i) Milankovitch's cycles, produced by variations of astronomical parameters such as precession, obliquity and eccentricity; (ii) continental geodynamic evolution and orogenic belt; (iii) variations of atmospheric and oceanic currents; (iv) volcanic eruptions; (v) meteor impacts. But while astronomical parameters have a quasi-regular periodicity, the other phenomena can be considered as "noise signal" in natural systems. The interplay between cyclical astronomical variations, t…
A quantitative analysis of wild herbaceous plant species for medicinal uses in four Regional Parks in Sicily (Italy)
2019
This paper illustrates the results of a study carried out in 4 regional Parks in Sicily (Italy) from 2009 to 2010. The study area covers a surface of 2076 km2, the 8% of the territory of Sicily, includes 90 towns and it is characterized by a high degree of plant biodiversity. The main aim of the study was to analyse the extent of the current knowledge on medicinal uses of wild shrub and herbaceous plants in the area, using quantitative indices. The information was obtained using semi-structured interview format performed on a sample of 802 people over the age of 60 who were considered experts in rural traditions. The results highlight that most of the species are used against general health…
TRIC: an automated alignment strategy for reproducible protein quantification in targeted proteomics
2016
Nature Methods, 13 (9)
Simultaneous determination of 4-nitroanisole, 4-nitrophenol, and 4-nitrocatechol by phase-sensitive ac polarography.
1977
Abstract Phase‐sensitive ac polarography was applied to the simultaneous quantitative determination of 4‐nitroanisole, 4‐nitrophenol and 4‐nitrocatechol in alkaline solutions. Certain experimental precautions are necessary to determine each compound in the presence of the other two. Thus, 4‐nitrocatechol is determined indirectly by forming a yellow ratio chelate with cupric ions, whereas 4‐nitroanisole is determined directly by the reduction waves of the nitro group. For the determination of 4‐nitrophenol, the interference by the simultaneously present 4‐nitrocatechol must be eliminated by masking it by the addition of magnesium ions. The method described permits a qualitative and quantitat…
Ascorbic Acid Stability in Ground Asparagus Samples and in Oxalic Acid Extracts
1995
To establish the storage conditions for asparagus preparation before ascorbic acid determination, samples were ground, the mass was divided into three aliquots that were, respectively, stored at 4°C, – 18°C, or extracted with 1% oxalic acid. The extract was further split into aliquots and stored at 25°, 4°, –18° and -75°C. Ascorbic acid content was measured at different times of storage by a polarographic method. The rate of degradation increased with storage temperature; the degradation rate was higher in ground samples than in extracts; no significant changes in ascorbic acid content were observed in extracts stored for 7 days at -18° or for 90 days at -75°C.