Search results for "relationship"
showing 10 items of 3616 documents
Assessing nonlinear structures in real exchange rates using recurrence plot strategies
2002
Purchasing power parity (PPP) is an important theory at the basis of a large number of economic models. However, the implication derived from the theory that real exchange rates must follow stationary processes is not conclusively supported by empirical studies. In a recent paper, Serletis and Gogas [Appl. Finance Econ. 10 (2000) 615] show evidence of deterministic chaos in several OECD exchange rates. As a consequence, PPP rejections could be spurious. In this work, we follow a two-stage testing procedure to test for nonlinearities and chaos in real exchange rates, using a new set of techniques designed by Webber and Zbilut [J. Appl. Physiol. 76 (1994) 965], called recurrence quantificatio…
How to make head or tail of ‘bridging’ and ‘bonding’?: addressing the methodological ambiguity1
2008
A distinction has recently been proposed between bridging (or encompassing) and bonding (or inward-looking) social networks. However, existing theoretical contributions remain vague as to the fundamental meaning of both concepts. As a consequence, two distinct interpretations have developed alongside each other. In the present paper, we employ data on voluntary association membership in Flanders to empirically illustrate that both approaches can lead to substantially different outcomes and therefore appear to tap into different dimensions of bridging versus bonding. These findings underline the problematic nature of the current conceptual ambiguity. We conclude that should the bridging/bond…
A method of magnetic storage of ultra-cold neutrons for a precise measurement of the neutron lifetime
1999
The beta-decay lifetime of the free neutron has been determined most precisely using storage of ultra-cold neutrons (UCNs) in material bottles. The quantity measured is the storage time which is substantially smaller than due to spurious losses of UCNs at collisions with the bottle walls. The systematic uncertainty of the correction - to the true lifetime is presently the main obstacle towards higher precision in this measurement. In the alternative magnetic trapping of UCNs, storage conditions can be realized where this correction becomes vanishingly small. This paper gives a method to measure the neutron lifetime with very low systematic errors, using confinement of UCNs in vacuum by magn…
Is adherence to the Mediterranean diet associated with healthy habits and physical fitness? A systematic review and meta-analysis including 565 421 y…
2020
AbstractThe relationship between adherence to the Mediterranean diet (MD), physical activity (PA), sedentary behaviour and physical fitness levels has been analysed in several studies; however, there is mixed evidence among youth. Thus, this study aimed to meta-analyse the associations between adherence to the MD, PA, sedentary behaviour and physical fitness among children and adolescents. Three databases were systematically searched, including cross-sectional and prospective designs with a sample of healthy youth aged 3–18 years. Random effects inverse-variance model with the Hartung–Knapp–Sidik–Jonkman adjustment was used to estimate the pooled effect size (correlation coefficient (r)). T…
Phytosterols: to be or not to be toxic; that is the question
2008
Plant sterols (phytosterols) are membrane constituents of all plants with a structure analogous to that of cholesterol. Thus, phytosterols have either an additional methyl or ethyl group on the carbon-24 position or an additional double bond in the side chain (1) . Noteworthy, in patients with the rare inherited disease of phytosterolaemia characterized by a hyperabsorption and diminished biliary secretion of cholesterol and phytosterols as well as by tendon and tuberous xanthoma, elevated plasma concentrations of phytosterols (campesterol, sitosterol) have been shown to constitute a risk factor for premature atherosclerosis (2) . However, whether plasma concentrations of campesterol and si…
CHEMICAL AND PHYSICAL SIGNALS MEDIATING CONSPECIFIC AND HETEROSPECIFIC AGGREGATION BEHAVIOR OF FIRST INSTAR STINK BUGS
2004
We investigated cues that mediate the aggregation behavior of immature pentatomid bugs by using nymphs of six different pentatomid bug species (Nezara viridula, Acrosternum hilare, Chlorochroa ligata, Chlorochroa sayi, Thyanta pallidovirens, and Euschistus conspersus). When first instars of any two species were put together in a Petri dish, they readily formed heterospecific aggregations similar to their natural conspecific aggregations. The chemical profiles of first and second instar nymphs of each species were determined by solvent extraction with pentane, followed by GC-MS analysis. Immature bugs of the different species had some compounds in common, and some that were more species spec…
Retention-release equilibrium of aroma compounds in polysaccharide gels: study by quantitative structure-activity/property relationships approach
2010
The nature and amount of constituents in food greatly influence aroma release. Pectins and carrageenans are common used thickeners, but their effect on the release of aroma compounds has been studied more frequently for non- homogeneous products than for thickeners separately. The purpose of this work was to study and compare their respective effects in simple model systems. In this way, the release of 13 aroma compounds was analysed by headspace analysis at equilibrium in pure water, i-carrageenan and pectin gels. To evaluate the influence of the chemical structure of aroma com- pounds on retention/release equilibrium between vapour phase and gels, we used a quantitative structure-activity…
Mycotoxin contamination of animal feedingstuff: detoxification by gamma irradiation and reduction of aflatoxins and ochratoxin A concentrations
2014
Mycotoxins are fungal secondary metabolites identified in many agricultural products screened for toxigenic moulds. They have been reported to be carcinogenic, teratogenic, tremorogenic, haemorrhagic and dermatitic to a wide range of organisms. With the increasing stringent regulations for mycotoxins imposed by importing countries such as those of the European Union, many cereals that are not safe for human consumption are used in formulations intended for animal feed. Gamma-rays are reported in the scientific literature to destroy ochratoxin A and aflatoxin in food crops and feed. The present study provides preliminary data for establishing the effect of dose of gamma-irradiation, ranging …
Effect of carbendazim and physicochemical factors on the growth and ochratoxin A production of Aspergillus carbonarius isolated from grapes.
2007
Carbendazim is a systemic fungicide that is commonly used on several crops (tobacco, fruit, vegetables, cereals, etc.). This fungicide is used to control fungal infections in vineyards. It is indicated against Botrytis cinerea, Uncinula necator, Plasmopara viticola and other fungi and can be used either alone or coupled with other fungicides. However, there is a lack of in-depth studies to evaluate its effectiveness against growth of Aspergillus carbonarius isolated from grapes and OTA production. A medium based on red grape juice was used in this study. Preliminary studies were performed at 0.98 a(w) and 25 degrees C using carbendazim concentrations over a wide range (1-2000 ng/ml medium) …
Heart rate variability during sleep in patients with schizophrenia treated with olanzapine.
2004
Cardiac adverse events in patients treated with atypical antipsychotics have gained increasing interest in recent years. In the present study, heart rate variability (HRV), which is a sensitive parameter reflecting central autonomic cardiac control, was investigated during treatment with olanzapine. Ten physically healthy male patients with schizophrenia, who displayed predominantly negative symptoms, were studied in the sleep laboratory under drug-free baseline conditions and after 4 weeks of olanzapine medication. HRV was assessed during different sleep stages both in the time and frequency domains. Only slight changes in HRV were shown during treatment, and appeared to be independent of …