50 research outputs found
Characterization of Indoor Extremely Low Frequency and Low Frequency Electromagnetic Fields in the INMA-Granada Cohort
Objective:
To characterize the exposure to electric fields and magnetic fields of non-ionizing radiation in the electromagnetic spectrum (15 Hz to 100 kHz) in the dwellings of children from the Spanish Environment and Childhood-âINMAâ population-based birth cohort.
Methodology:
The study sample was drawn from the INMA-Granada cohort. Out of 300 boys participating in the 9â10 year follow-up, 123 families agreed to the exposure assessment at home and completed a specific ad hoc questionnaire gathering information on sources of non-ionizing radiation electric and magnetic fields inside the homes and on patterns of use. Long-term indoor measurements were carried out in the living room and bedroom.
Results:
Survey data showed a low exposure in the children's homes according to reference levels of the International Commission on Non-Ionizing Radiation Protection but with large differences among homes in mean and maximum values. Daytime electrostatic and magnetic fields were below the quantification limit in 78.6% (92 dwellings) and 92.3% (108 dwellings) of houses, with an arithmetic mean value (± standard deviation) of 7.31±9.32 V/m and 162.30±91.16 nT, respectively. Mean magnetic field values were 1.6 lower during the night than the day. Nocturnal electrostatic values were not measured. Exposure levels were influenced by the area of residence (higher values in urban/semi-urban versus rural areas), type of dwelling, age of dwelling, floor of the dwelling, and season.
Conclusion:
Given the greater sensitivity to extremely low-frequency electromagnetic fields of children and following the precautionary principle, preventive measures are warranted to reduce their exposure.This work was supported by the Spanish Ministry of Health (CIBERESP and FIS PI11/0610) and the Andalusia Regional Government, Council of Innovation, Science and Enterprise (Excellence Project P09-CTS-5488) and Council of Health (SAS PI-0675-2010)
An experimental test of hostâs life history traits modulation in response to cuckoo parasitism risk
Hosts can counteract parasites through defences based on resistance and/or tolerance.
The mechanistic basis of tolerance, which involve defensive mechanisms minimizing parasite
damage after a successful parasitic attack, remains poorly explored in the study of
cuckoo-host interactions. Here, we experimentally explore the possibility that the risk of
great spotted cuckoo Clamator glandarius parasitism may induce tolerance defences in
magpie Pica pica hosts through plasticity in life-history traits. We predict that magpies
exposed to auditory cues indicating high parasitism risk will more likely exhibit resistance
and/or modify their life-history traits to minimize parasitism costs (i.e. tolerance) compared
to magpies under low parasitism risk. We found that manipulating the perceived parasitism
risk did not affect host resistance (i.e. rejection of parasitic eggs) nor host life-history traits.
Unexpectedly, host's egg volume increased over the season in nests exposed to auditory
cues of control non-harmful hoopoes Upupa epops. Our results do not provide support for
inducible defences (either based on resistance or tolerance) in response to risk of parasitism
in magpie hosts. Even so, we encourage studying plastic expression of breeding strategies
in response to risk of cuckoo parasitism to achieve a better understanding of the mechanistic
basis of tolerance defences.This work was supported by the Spanish
Ministry of Education and Science/FEDER (Projects
CGL2011-27561/BOS and CGL2014-56769-P to D.
P. and J.M.A.). D.P. was supported by the
Government of Extremadura while writing (contract
number TA13002). M.E.G. was supported by the
Spanish Ministry of Economy and Competitiveness
(grant number BES-2012-051898).
Supreme activity of gramicidin S against resistant, persistent and biofilm cells of staphylococci and enterococci.
Three promising antibacterial peptides were studied with regard to their ability to inhibit the growth and kill the cells of clinical strains of Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium. The multifunctional gramicidin S (GS) was the most potent, compared to the membranotropic temporin L (TL), being more effective than the innate-defence regulator IDR-1018 (IDR). These activities, compared across 16 strains as minimal bactericidal and minimal inhibitory concentrations (MIC), are independent of bacterial resistance pattern, phenotype variations and/or biofilm-forming potency. For S. aureus strains, complete killing is accomplished by all peptides at 5âĂâMIC. For E. faecalis strains, only GS exhibits a rapid bactericidal effect at 5âĂâMIC, while TL and IDR require higher concentrations. The biofilm-preventing activities of all peptides against the six strains with the largest biofilm biomass were compared. GS demonstrates the lowest minimal biofilm inhibiting concentrations, whereas TL and IDR are consistently less effective. In mature biofilms, only GS completely kills the cells of all studied strains. We compare the physicochemical properties, membranolytic activities, model pharmacokinetics and eukaryotic toxicities of the peptides and explain the bactericidal, antipersister and antibiofilm activities of GS by its elevated stability, pronounced cell-penetration ability and effective utilization of multiple modes of antibacterial action
Wheat Straw as a Bio-Sorbent for Arsenate, Chromate, Fluoride, and Nickel
Batch-type experiments were used to study As(V), Cr(VI), Fâ, and Ni2+ sorption/desorption on wheat straw. For the lowest concentration added (0.5 mmol·Lâ1), the sorption sequence was Fâ > Ni2+ > Cr(VI) >> As(V) (93%, 61%, 29%, 0.3%), but changed to Ni2+ > Fâ > Cr(VI) >> As(V) when 3.0 and 6.0 mmol·Lâ1 were added (with 65%, 54%, 25%, 0%, and 68%, 52%, 27%, 0% sorption, respectively). Overall, As(V) showed the lowest sorption, whereas it was 25â37% for Cr(VI), 61â68% for Ni2+, and 52â93% for Fâ. For As(V), pH in the equilibrium solution was always above the pH of the point of zero charge (pHPZC) for wheat straw, decreasing sorption efficiency. For Cr(VI), pH was below pHPZC, but not enough to reach high sorption. For Fâ, pH in the equilibrium was above pHPZC, which could reduce sorption. For Ni2+, pH in the equilibrium was always below pHPZC, which made sorption difficult. The satisfactory fitting of Cr(VI), Fâ, and Ni2+ data to the Freundlich model suggests multilayer-type adsorption. Desorption was high for Fâ, whereas Ni2+ showed the lowest desorption. This research could be especially relevant when focusing on the use of wheat straw as a bio-sorbent, and in cases where straw mulching is used
Effect of Acute Physical Exercise on Executive Functions and Emotional Recognition: Analysis of Moderate to High Intensity in Young Adults
Physical exercise (PE) is associated with cognitive changes and brain function. However, it is required to clarify the effect of PE in different intensities, population groups conditions and the EF duration over different cognitive domains. Besides, no studies are known to have evaluated the contextual emotional recognition. Therefore, we studied the effect of acute PE of moderate intensities up to higher ones to the executive functions and the contextual emotional recognition. The participants were evaluated and classified in two experiments according to the IPAQ short form self-report and control measures. In both experiments, the groups were randomized, controlled, and exposed to one session of indoor cycling through intervals of high measure intensity (75â85% HRmax). Experiment 1 comprised young adults who were physically active (PA) and healthy, apparently (n = 54, Mage = 20.7, SD = 2.5). Experiment 2 involved young adults who were physically inactive (IP) and healthy, apparently (n = 36, Mage = 21.6, SD = 1.8). The duration was the only factor that varied: 45 min for PA and 30 min for PI. The executive functions were evaluated by the Stroop, TMT A/B, and verbal fluency, and the emotional recognition through a task that includes body and facial emotions in context, simultaneously. The analysis of factorial mixed ANOVA showed effects on the right choices of the indoor cycling groups in the PA, and the time response in PI. Also, other effects were observed in the controlled groups. TMT-A/B measures showed changes in the pre-testâpost-test measures for both experiments. Verbal fluency performance favored the control group in both experiments. Meanwhile, the emotional recognition showed an effect of the PE in error-reduction and enhanced the scores in the right choices of body emotions. These results suggest that the EF with intensities favored cognitive processes such as inhibitory control and emotional recognition in context. We took into account the importance of high-complexity tasks design that avoid a ceiling effect. This study is the first on reporting a positive effect of PE over the emotional contextual recognition. Important clinical and educational implications are presented implications which highlight the modulatory role of EF with moderate to high intensities. © Copyright © 2019 Aguirre-Loaiza, Arenas, Arias, Franco-JĂmenez, Barbosa-Granados, Ramos-BermĂșdez, Ayala-Zuluaga, NĂșñez and GarcĂ[email protected]