Paula S.,Instituto Universitario |
Paula S.,Austral University of Chile
Global Ecology and Biogeography | Year: 2012
Aim To understand how vegetation mediates the interplay between fire and climate. Specifically, we predict that neither the switching of climatic conditions to high flammability nor the sensitivity of fire to such conditions are universal, but rather depend on fuel (vegetation) structure, which in turn changes with productivity. Location An aridity/productivity gradient on the Iberian Peninsula (Mediterranean Basin). Methods We defined 13 regions distributed along an aridity gradient, which thus differ in productivity and fuel structure. We then assessed the changes in the temporal fire-climate relationship across regions. Specifically, for each region we estimated three variables: the aridity level for switching to flammable conditions (i.e. climatic conditions conducive to fire), the frequency of these flammable conditions and the area burnt under such conditions. These variables were then related to regional aridity and fuel structure indicators. Results In mediterranean ecosystems, the aridity level for switching to flammable conditions increased along the aridity gradient. Differences in fire activity between regions were not explained by the frequency of flammable conditions but by the sensitivity of fire to such conditions, which was higher in wetter and more productive regions. Main conclusions Under mediterranean climatic conditions, fuel structure is more relevant in driving fire activity than the frequency of climatic conditions conducive to fire. At a global scale, fuel also drives the fire-climate relationship because it determines the climatic (aridity) threshold for switching to flammable conditions. Our results emphasize the role of landscape structure in shaping current and future fire-climate relationships at a regional scale, and suggest that future changes in the fire regime (i.e. under global warming) might be different from what it is predicted by climate alone. © 2012 Blackwell Publishing Ltd.
Jordao J.M.,University of Lisbon |
Fonseca P.J.,University of Lisbon |
Amorim M.C.P.,Instituto Universitario
Ethology | Year: 2012
Choruses have been described mostly in birds, anurans and insects but have been poorly studied in fish. Research in batrachoidid (toadfishes) species suggest vocal facilitation among neighbouring males, but whether chorusing fish present more complex interactions is unknown. In this study, we test the hypothesis that chorusing fish males compete actively to increase attractiveness to females. We first describe vocal interactions in natural choruses of Lusitanian toadfish males. Our analysis found positive correlations between the calling rates of neighbouring males in several occasions. However, we also found that males that showed an overall low vocal activity throughout the observation period exhibited peaks of increased calling activity when neighbours decreased their calling rate, suggesting an opportunistic maximisation of attractiveness. We further test with playback experiments how toadfish males adjust calling activity relative to their neighbours'. We observed that males silent at the time of the playbacks but who had an overall high vocal performance tended to start calling when exposed to playbacks in contrast to low-activity males. Playback experiments further showed that males initially calling at a high rate adjust their calling rate according to the neighbour's vocal activity level, that is, they increased calling rate when exposed to a high calling rate and decreased it when confronted with a low calling rate. However, males calling at a low rate did not significantly alter their calling rate when presented with a low (similar) or higher calling rate, probably due to temporary physiological and/or ecological constraints. We argue that Lusitanian toadfish males tend to optimise calling effort in relation to their neighbours when they are actively advertising. Further studies are necessary to better understand vocal behaviour with increased chorus size. © 2012 Blackwell Verlag GmbH.
Amorim M.C.P.,Instituto Universitario |
Pedroso S.S.,Instituto Universitario |
Bolgan M.,University of Lisbon |
Bolgan M.,University of Trieste |
And 3 more authors.
Functional Ecology | Year: 2013
Females use multiple cues from different sensory modalities to choose males of high phenotypic or genetic quality to mate with. Fish may use visual and acoustic communication during mating, but few studies have associated multimodal signals with male quality and reproductive success. We examined whether visual and acoustic courtship signals reflect male quality and influence mating success in the painted goby (Pomatoschistus pictus), a highly visual and vocal fish species with paternal care. Painted gobies make conspicuous courtship visual displays such as body quivering and eight-shaped swimming patterns and two types of sounds: drums that are composed of a sequence of low-frequency pulses and a thump-like non-pulsed sound. We predicted that both sensory modalities would advertise male size and condition and influence mating success. We found that larger number of pulses in a drum, lower fatigue (where fatigue is the increase in pulse period during drum production) and higher drum absolute amplitude levels were good predictors of larger male size. Males with high condition factor (Fulton's K) showed high drumming activity and low thumping and visual courtship levels. Drumming activity was a good predictor of male fat reserves. Males that succeeded to mate emitted sounds with higher number of pulses and longer pulse periods and showed higher drumming but lower thumping activity than unsuccessful males. All traits (except pulse period) reflected higher male Fulton's K or fat reserves, suggesting that females are selecting for male condition. Neither male size nor visual courtship was apparently used in mate selection. Contrary to our expectations, females did not seem to prefer larger or vigorous visually displaying males but chose mates in better condition using multiple cues of drumming sounds. We suggest that preference for high mate condition is related to preference for increased parental ability and hatching success in species with paternal care. To the best of our knowledge, this is the first study that addresses the relative role of signals from different sensory modalities including acoustics, in advertising male quality and in contributing to reproductive success in fish. © 2013 British Ecological Society.
Calatayud V.,Instituto Universitario |
Cervero J.,Instituto Universitario |
Calvo E.,Instituto Universitario |
Garcia-Breijo F.-J.,University of Valencia |
And 3 more authors.
Environmental Pollution | Year: 2011
Plants of one evergreen oak (Quercus ilex) and three deciduous oaks (Q. faginea, with small leaves; Q. pyrenaica and Q. robur, with large leaves) were exposed both to filtered air and to enhanced ozone levels in Open-Top Chambers. Q. faginea and Q. pyrenaica were studied for the first time. Based on visible injury, gas exchange, chlorophyll content and biomass responses, Q. pyrenaica was the most sensitive species, and Q. ilex was the most tolerant, followed by Q. faginea. Functional leaf traits of the species were related to differences in sensitivity, while accumulated ozone flux via stomata (POD1.6) partly contributed to the observed differences. For risk assessment of Mediterranean vegetation, the diversity of responses detected in this study should be taken into account, applying appropriate critical levels. © 2010 Elsevier Ltd. All rights reserved.
Graca A.,University of Algarve |
Abadias M.,IRTA - Institute of Agricultural-Alimentary Research and Technology |
Salazar M.,Instituto Universitario |
Nunes C.,University of Algarve
Postharvest Biology and Technology | Year: 2011
Chlorine (sodium hypochlorite solution) is the most common disinfectant used in the fresh-cut industry, however, environmental and health risks related to its use have resulted in a need to find new sanitizers. Electrolyzed water (EW) is a promising alternative, showing a broad spectrum of microbial decontamination. In this study the efficacy of acidic electrolyzed water (AEW) and neutral electrolyzed water (NEW) as disinfectants of apple slices inoculated with Escherichia coli, Listeria innocua or Salmonella choleraesuis, individually or in a mixture, were compared to that of sodium hypochlorite solution and distilled water. Apple slices were inoculated with a 107cfu/mL suspension of the pathogens and treated with diluted electrolyzed water. Bactericidal activity of washing treatments was assessed after 30min and after storage for 5 days at 4°C. AEW and NEW disinfection efficacy was compared to that of washings with sodium hypochlorite at the same free chlorine concentration and with distilled water. AEW diluted to 100mg/L of free chlorine was the treatment with the highest bactericidal activity in all tested conditions (reductions obtained ranged from 1.2 to 2.4 log units) followed by NEW and AEW at 100 and 50mg/L of free chlorine respectively. In general these treatments were equal or more effective than sodium hypochlorite washings at 100mg/L of free chlorine. The effect of the different sanitizer washings when pathogens where in a mixture was similar to that which occurred when pathogens were individually inoculated. The effectiveness of all washings slightly decreased when apple slices were stored for 5 days at 4°C. © 2011 Elsevier B.V.
Newland M.J.,University of Birmingham |
Rickard A.R.,University of York |
Alam M.S.,University of Birmingham |
Vereecken L.,Max Planck Institute for Chemistry |
And 3 more authors.
Physical Chemistry Chemical Physics | Year: 2015
The removal of SO2 in the presence of alkene-ozone systems has been studied for ethene, cis-but-2-ene, trans-but-2-ene and 2,3-dimethyl-but-2-ene, as a function of humidity, under atmospheric boundary layer conditions. The SO2 removal displays a clear dependence on relative humidity for all four alkene-ozone systems confirming a significant reaction for stabilised Criegee intermediates (SCI) with H2O. The observed SO2 removal kinetics are consistent with relative rate constants, k(SCI + H2O)/k(SCI + SO2), of 3.3 (±1.1) × 10-5 for CH2OO, 26 (±10) × 10-5 for CH3CHOO derived from cis-but-2-ene, 33 (±10) × 10-5 for CH3CHOO derived from trans-but-2-ene, and 8.7 (±2.5) × 10-5 for (CH3)2COO derived from 2,3-dimethyl-but-2-ene. The relative rate constants for k(SCI decomposition)/k(SCI + SO2) are -2.3 (±3.5) × 1011 cm-3 for CH2OO, 13 (±43) × 1011 cm-3 for CH3CHOO derived from cis-but-2-ene, -14 (±31) × 1011 cm-3 for CH3CHOO derived from trans-but-2-ene and 63 (±14) × 1011 cm-3 for (CH3)2COO. Uncertainties are ±2σ and represent combined systematic and precision components. These values are derived following the approximation that a single SCI is present for each system; a more comprehensive interpretation, explicitly considering the differing reactivity for syn- and anti-SCI conformers, is also presented. This yields values of 3.5 (±3.1) × 10-4 for k(SCI + H2O)/k(SCI + SO2) of anti-CH3CHOO and 1.2 (±1.1) × 1013 for k(SCI decomposition)/k(SCI + SO2) of syn-CH3CHOO. The reaction of the water dimer with CH2OO is also considered, with a derived value for k(CH2OO + (H2O)2)/k(CH2OO + SO2) of 1.4 (±1.8) × 10-2. The observed SO2 removal rate constants, which technically represent upper limits, are consistent with decomposition being a significant, structure dependent, sink in the atmosphere for syn-SCI. © the Owner Societies 2015.
Miravet-Valenciano J.A.,University of Valencia |
Rincon-Bertolin A.,University of Valencia |
Vilella F.,Instituto Universitario |
Simon C.,Instituto Universitario |
Simon C.,Stanford University
Current Opinion in Obstetrics and Gynecology | Year: 2015
Purpose of the review For a successful pregnancy, the synchronic coordination between the embryonic development and the endometrial status is crucial. The endometrium is a hormonally regulated organ that is nonadhesive to embryos throughout most of the menstrual cycle in humans. Endometrial receptivity refers to a hormone-limited period in which the endometrial tissue acquires a functional and transient ovarian steroid-dependent status allowing blastocyst implantation and therefore pregnancy initiation. Recent findings Our group has developed the endometrial receptivity array (ERA), a customized array based on the expression of 238 genes coupled to a computational predictor capable of diagnosing a functionally receptive endometrium regardless of its histological appearance. Clinical results obtained in our laboratory demonstrate the diagnostic and therapeutic efficiency of the ERA test in patients with implantation failure, allowing the personalization of the optimal day for embryo transfer. Summary To keep improving the global knowledge of endometrial receptivity stage, new high-throughput techniques like RNA-seq or genome-wide association studies will be crucial in the near future. Also the identification of new biomarkers of endometrial receptivity that could be assessed by noninvasive methods has become a challenging goal to help diagnose the endometrial status to increase implantation rates and pregnancy outcomes in patients undergoing assisted reproductive treatments. © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Soriano E.R.,Hospital Italiano Of Buenos Aires |
Soriano E.R.,Instituto Universitario
Journal of Rheumatology | Year: 2012
Although several reviews and metaanalyses have shown lack of evidence of efficacy of traditional disease-modifying antirheumatic drugs (DMARD) in psoriatic arthritis (PsA), these drugs are very often used and are recommended by treatment guidelines around the world as first-line therapy for most patients with PsA. Some new investigations showed that higher doses of methotrexate (MTX) are more beneficial for patients with PsA with peripheral involvement. Also, observational studies have shown that retention of MTX for patients with PsA is comparable to that of patients with rheumatoid arthritis (RA), and that with MTX, remission is achievable by around 20% of patients with PsA. Sulfasalazine, leflunomide, and cyclosporine have also been shown to be effective in a small number of patients, although the overall effect on disease activity for these drugs is small. Although combination of anti-tumor necrosis factor agents with traditional DMARD is not mandatory in PsA as it is in RA, there is evidence that some extra benefit might be achieved when combinations are used, not only for the joints but for the skin. There is still room for the use of traditional DMARD in PsA, and for the time being, DMARD should still be considered as first-line therapy for most patients with PsA. The Journal of Rheumatology Copyright © 2012. All rights reserved.
Ferreira I.S.,University of Coimbra |
Simoes M.R.,University of Coimbra |
Maroco J.,Instituto Universitario
Accident Analysis and Prevention | Year: 2012
Considerable research has shown that neuropsychological tests are predictive of real-world driving ability. The Mini-Mental State Examination (MMSE) is a brief cognitive test that has been commonly used in the assessment of older drivers. However, this test has inherent problems that limit its validity to evaluate cognitive abilities related to driving and to screen for driving impairments in non-demented people. Therefore, it is useful to test new screening instruments that may predict potential unsafe drivers who require an in-depth neuropsychological assessment in a specialised centre. To date, the utility of the Addenbrooke's Cognitive Examination Revised (ACE-R) as an indicator of driving ability has not been established. In the current study, fifty older drivers (mean age = 73.1 years) who were referred for a psychological assessment, the protocol of which included the ACE-R, underwent an on-road driving test. Using linear discriminant analyses, the results highlighted the higher classification accuracy of the ACE-R compared to the MMSE score, particularly for detecting unsafe drivers. Measures of visuospatial and executive functions, which are not incorporated in the MMSE score, had an incremental value in the prediction of driving ability. This emerging brief cognitive test may warrant additional study for use in the fitness to drive assessment of older adults. © 2012 Elsevier Ltd.
Borras E.,Instituto Universitario |
Tortajada-Genaro L.A.,Polytechnic University of Valencia
International Journal of Environmental Analytical Chemistry | Year: 2012
The determination of multifunctional oxygenated compounds in secondary organic aerosols (SOA) usually requires a derivatisation protocol prior to gas chromatography-mass spectrometry analysis (GC-MS). Our proposed protocol, a combination of O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA) plus diluted N-methyl-N-trimethyl-silyltrifluoroacetamide (MSTFA) without catalyst, has improved the determination of carbonyls, polyhydroxyl-compounds, hydroxyl- carbonyls, hydroxyl-carboxylic acids and di-carboxylic acids. The optimised derivatisation protocol has been successfully used for blanks, standard mixtures and photo-oxidation products from isoprene and toluene generated in a high-volume simulation chamber (European Photoreactor, EUPHORE). Some previously identified degradation products for isoprene including tetrols such as threitol, erythritol; 2-methyltetrols and 2-methylglyceric acid; and for toluene including nitrophenols, methyl-nitrophenols, benzaldehyde, p-cresol, benzoic acid, glyoxylic acid and methyl-glyoxylic acid, have been identified in our aerosol samples, thus confirming the successful applicability of the proposed derivatisation protocol. Moreover, the reduction of artefacts and enhanced signal-to-noise ratio, have allowed us to extend the number of multifunctional compounds determined. These findings have demonstrated the validity of this analytical strategy, which will contribute to a better understanding of the atmospheric degradation chemistry of biogenic and anthropogenic pollutants. © 2012 Taylor & Francis.