Search results for "BIF"
showing 10 items of 539 documents
Indoor air pesticide in dwellings of breastfeeding mothers of the Valencian Region (Spain): Levels, exposure and risk assessment
2021
This study assessed the inhalation risk associated with indoor pesticide concentrations in the dwellings of 41 lactating mothers living in the Valencian Region, Spain, who were participants in the BETTERMILK project. Twenty-eight substances were investigated, including pyrethroid (PYRs), organophosphate (OPPs), and organochlorine (OCPs) pesticides. Bifenthrin, cypermethrin, lambda-cyhalothrin, malathion, permethrin and pyrimethanil were detected with frequencies ranging from 2% (malathion) to 80% (cypermethrin), and with an arithmetic mean concentration ranging from 4.1 ng m(-3) (bifenthrin) to 12.1 ng m-(3) (cypermethrin). The indoor air analysis was combined with several surveys to assess…
Quotients of the Dwork Pencil
2012
In this paper we investigate the geometry of the Dwork pencil in any dimension. More specifically, we study the automorphism group G of the generic fiber of the pencil over the complex projective line, and the quotients of it by various subgroups of G. In particular, we compute the Hodge numbers of these quotients via orbifold cohomology.
Mechanistic Investigations of the BZ Reaction with Oxalic Acid Substrate. I. The Oscillatory Parameter Region and Rate Constants Measured for the Rea…
2004
This paper is the first part of a study reinvestigating the mechanism of the Belousov-Zhabotinsky (BZ) reaction of oxalic acid, which is the simplest organic substrate for a BZ oscillator. New experiments are performed to find the oscillatory region in 1 M sulfuric acid at 20 °C. The removal rate of the end product bromine by an inert gas stream is a critical parameter here: oscillations can be observed only in a window of that parameter. The “rate constant” for the physical removal of bromine is measured as a function of the gas flow rate and reactor volume; furthermore, the rate constants of three component reactions important in this system are also determined. These are oxygen atom tran…
Double precision errors in the logistic map: statistical study and dynamical interpretation.
2007
The nature of the round-off errors that occur in the usual double precision computation of the logistic map is studied in detail. Different iterative regimes from the whole panoply of behaviors exhibited in the bifurcation diagram are examined, histograms of errors in trajectories given, and for the case of fully developed chaos an explicit formula is found. It is shown that the statistics of the largest double precision error as a function of the map parameter is characterized by jumps whose location is determined by certain boundary crossings in the bifurcation diagram. Both jumps and locations seem to present geometric convergence characterized by the two first Feigenbaum constants. Even…
Zur Autoxydation von Polystyrol
1971
Die mit Azoisobuttersauredinitril (AIBN) initiierte Autoxydation von Polystyrol (PS) in Chlorbenzol bei 60°C ist von der Ordnung 0,75, bezogen auf AIBN, und 0,34, bezogen auf PS. Der niedrige Exponent der Polystyrolkonzentration weist neben intermolekularen Wachstumsschritten auf intramolekulare Reaktionsschritte bei der Autoxydation hin. Die bei der Autoxydation am Polystyrol gebildeten Hydroperoxidgruppen zerfallen in Essigsathylester als Losungsmittel mit einer Aktivierungsenthalpie von 19,7 kcal/Mol und einer Aktivierungsentropie von −29 cal/Mol Grad. Das spricht fur einen monomolekularen bifunktionellen Zerfallsmechanismus. Als fluchtige Produkte bei diesem Hydroperoxidzerfall werden P…
Experimental investigation and characterization of innovative bifacial silicon solar cells
2019
The interest towards bifacial PV technology has increased over the last years, due to its potential capability of obtaining higher efficiencies with respect to traditional monofacial cells. Thus, the aim of this work is to present an experimental investigation on an innovative photovoltaic technology, such as the bifacial solar cells based on monocrystalline substrate. This analysis is mainly based on the determination of the current density/voltage, power density/voltage, External Quantum Efficiency (EQE) and Laser Beam Induced Current (LBIC) characterization. Interesting results are presented and discussed, demonstrating that the bifacial silicon solar cells can be a very promising techno…
Competing factor structures of the Rosenberg Self-Esteem Scale (RSES) and its measurement invariance across clinical and non-clinical samples
2017
Abstract Although several studies have investigated the factor structure of the Rosenberg Self-Esteem Scale (RSES), there are still disagreements about it. The present study assessed: a) the goodness of fit of nine competing factor models for the RSES using data from a clinical sample of 855 women with eating/weight disorders; and b) its measurement invariance across clinical and non-clinical (n = 943) samples. A bifactor model, with a general self-esteem factor, plus positive and negative method factors, provided a better fit with the data than alternative models. However, the results showed the high reliability of the general self-esteem factor, and a low reliability of the two method fac…
Influence of pro- and prebiotics on gastric, duodenal and colonic bioaccessibility of the mycotoxin beauvericin
2013
Abstract Beauvericin (BEA) is a bioactive compound produced by the secondary metabolism of several Fusarium strains and known to have various biological activities. This study investigates the influence of several dietary fibers (galactomanan, glucomannan, citrus fiber, bamboo fiber, carrot fiber, pie fiber, β-glucan, xilan, and cellulose) and probiotic strains ( Lactobacillus animalis , Lb. casei , Lb. casei , Lb. plantarum , Lb. rhuminis , Lb. casei casei , Bifidobacterium breve , Bf. Adolescents , Bf. bifidum , Corynebacterium vitaeruminis , Streptococcus faecalis , Eubacterium crispatus , and Saccharomyces cerevisiae ) on the minor Fusarium mycotoxin BEA bioaccessibility employing a mod…
Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 cell surface hydrophobicity and survival of the cells under adverse environmental condi…
2012
Abstract Changes in the cell surface hydrophobicity (CSH) of probiotic bacteria Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 and the survival of these cells were examined in response to varied cultivation conditions and adverse environmental conditions. An inverse linear relationship (P < 0.01) was detected between the CSH of intact L. acidophilus La5 and B. lactis Bb12 and survival of cells subjected to subsequent freezing/thawing, long-term storage or exposure to mineral and bile acids. The observed relationships were supported by significant correlations between the CSH and changes in composition of the cell envelopes (proteins, lipids and carbohydrates) of L. aci…
Membrane fatty acid composition and fluidity are involved in the resistance to freezing of Lactobacillus buchneri R1102 and Bifidobacterium longum R0…
2015
International audience; Determinations of membrane fatty acid composition and fluidity were used together with acidification activity and viability measurements to characterize the physiological state after freezing of Lactobacillus buchneri R1102 and Bifidobacterium longum R0175 cells harvested in the exponential and stationary growth phases. For both strains, lower membrane fluidity was achieved in cells harvested in the stationary growth phase. This change was linked to a lower unsaturated-to-saturated fatty acid ratio for both strains and a higher cyclic-to-saturated fatty acid ratio for L. buchneri R1102 alone. These membrane properties were linked to survival and to maintenance of aci…