Vacuum fluctuations of a scalar field near a reflecting boundary and their effects on the motion of a test particle

The contribution from quantum vacuum fluctuations of a real massless scalar field to the motion of a test particle that interacts with the field in the presence of a perfectly reflecting flat boundary is here investigated. There is no quantum induced dispersions on the motion of the particle when it is alone in the empty space. However, when a reflecting wall is introduced, dispersions occur with magnitude dependent on how fast the system evolves between the two scenarios. A possible way of implementing this process would be by means of an idealized sudden switching, for which the transition occurs instantaneously. Although the sudden process is a simple and mathematically convenient idealization it brings some divergences to the results, particularly at a time corresponding to a round trip of a light signal between the particle and the wall. It is shown that the use of smooth switching functions, besides regularizing such divergences, enables us to better understand the behavior of the quantum dispersions induced on the motion of the particle. Furthermore, the action of modifying the vacuum state of the system leads to a change in the particle energy that depends on how fast the transition between these states is implemented. Possible implications of these results to the similar case of an electric charge near a perfectly conducting wall are discussed.Comment: 17 pages, 8 figure

Scaling laws and universality in the choice of election candidates

Nowadays there is an increasing interest of physicists in finding regularities related to social phenomena. This interest is clearly motivated by applications that a statistical mechanical description of the human behavior may have in our society. By using this framework, we address this work to cover an open question related to elections: the choice of elections candidates (candidature process). Our analysis reveals that, apart from the social motivations, this system displays features of traditional out-of-equilibrium physical phenomena such as scale-free statistics and universality. Basically, we found a non-linear (power law) mean correspondence between the number of candidates and the size of the electorate (number of voters), and also that this choice has a multiplicative underlying process (lognormal behavior). The universality of our findings is supported by data from 16 elections from 5 countries. In addition, we show that aspects of network scale-free can be connected to this universal behavior.Comment: Accepted for publication in EP

Comparison between Poaceae Airborne Pollen Counts and Phl p5 Aeroallergen Quantification in South Europe

The European project HIALINE: Comparison between Poaceae Airborne Pollen Counts and Phl p5 Aeroallergen Quantification in South Europe C. Antunes1,2, R. Ferro2, R. Ribeiro2, Torres M.C.4, M.J. Velasco4H. García-Mozo4, Galán, C4 , R.Brandao1,3, M.Thibaudon5, R. Albertini6 Ugolotti. M.6, Usberti I.6, Dall’Aglio P.6 and the HIALINE team7 1DInstitute of Mediterranean Agricultural and Environmental Sciences –ICAAM, University of Évora, Portugal 2Department of Chemistry, University of Évora, Portugal 3Department of Biology, University of Évora, Portugal 4Department of Botany, Ecology and Plant Physiology, University of Córdoba 5Réseau National de l Surveillance Aerobiologique, Saint-Genis-l’Argentière, France 6Department of Clinical Medicine, Nephrology and Health Sciences, University of Parma, Italy 7J.T.M. Buters, Germany, M. Thibaudon, France, M. Smith, Great Britain, C. Galan, Spain, R. Brandao and C.M. Antunes, Portugal, G. Reese, Germany, R. Albertini, Italy, L. Grewling, Poland, A. Rantio-Lehtimäki, Finland, S. Jäger and U. Berger, Austria, I. Sauliene, Lithuania, L. Cecchi, Italy Introduction: Nowadays, pollinosis is affecting a large percentage of population in countries with a western life style. The existence of allergenic activity in the atmosphere is not only associated to pollen grains and fungal spores, but also to submicronic and paucimicronic biological particles. The origin of these allergens can be due to the rupture of pollen transported in the atmosphere or to the presence of allergens from other parts of the plant making amorphous material with an allergen load. Poaceae pollen is recognized as one of the main causes of allergic disease in all Europe. In this study we have tried to compare Poaceae pollen counts in the air and Phl p 5, one of the major allergens of this family, through the use of a high-volume cascade impactor (Chemvol). This study was done in the frame of the European project HIALINE and it compares the results obtained in 2009 by 4 different partners participating in this project: in Córdoba (Spain), Évora (Portugal), Lyon (France) and Parma (Italy). Methodology: Pollen grains were sampled using a 7-day volumetric Hirst type spore trap. Chemvol high-volume cascade impactor equipped with stages PM>10µm, 10 µm>PM>2.5µm was used for detecting aeroallergens. In each stage polyurethane filters were use as an impacting substrate. Phl p 5 allergen was determined using an allergen specific ELISA. Antibodies for analysis were delivered by Allergopharma Joachim Ganzer KG, the industrial partner in this project. At each location both samplers were placed side-by-side. Results: Most of the allergen was collected in the PM>10µm fraction. Similar profiles between airborne pollen and the total allergenic load was observed during the pollen season. A good correlation was obtained between pollen count and allergen content of the air and a value of 2.5 pg/pollen grain of Poaceae was estimated. Discussion: This is the first year of this project. Nevertheless, results suggest that the allergenic load in outdoor air might be mainly due to pollen bursts. It supports the hypothesis that monitoring the allergens itself in ambient air might be an improvement in allergen exposure assessment. This work was supported in part by the European Agency for Health and Consumers EAHC, Luxembourg, under the grant agreement 2008110

Comparison between Airborne Pollen and Aeroallergen Quantification with the ChemVol Impact Sampler. Olive pollen vs Ole e 1

Comparison between Airborne Pollen and Aeroallergen Quantification with the ChemVol Impact Sampler. Olive pollen vs Ole e 1. Torres M.C.1, C. Antunes2, M.J. Velasco1, R. Ferro2, H. García-Mozo1, R. Ribeiro2, R.Brandao3, Galán, C1 and the HIALINE team4 1Department of Botany, Ecology and Plant Physiology, University of Córdoba 2Department of Chemistry, University of Évora, Portugal 3Department of Biology, University of Évora, Portugal 4J.T.M. Buters, Germany, M. Thibaudon, France, M. Smith, Great Britain, C. Galan, Spain, R. Brandao and C. Antunes, Portugal, G. Reese, Germany, R. Albertini, Italy, L. Grewling, Poland, A. Rantio-Lehtimäki, Finland, S. Jäger and U. Berger, Austria, I. Sauliene, Lithuania, L. Cecchi, Italy Nowadays, pollinosis is affecting a large percentage of population in the countries with a western life style. The existence of allergenic activity in the atmosphere is not only associated to pollen grains and fungal spores, but also to submicronic and paucimicronic biological particles. The origin of these allergens can be due to the rupture of pollen transported in the atmosphere or to the presence of allergens from other parts of the plant making amorphous material with an allergen load. Olive pollen is recognized as one of the main causes of allergic disease in the Mediterranean area. In this study we have tried to compare olive pollen count in the air and Ole e 1 as major allergen of this species, at two different localities in South of Europe: Evora (Portugal) and Córdoba (Spain). At each location both samplers were placed side-by-side. Pollen grains have been sampled using a volumetric Hirst type spore trap. Chemvol high-volume cascade impactor equipped with stages PM>10µm, 10 µm>PM>2.5µm were used for detecting aeroallergens. Ole e 1 major allergen was determined using allergen specific ELISA´s. Similar behaviour between pollen and the total allergenic load was observed during the pollen season. Nevertheless, at some occasions, during the previous and later period of the pollen season, airborne allergenic load was detected in South Spain, due to the contributions from other Oleaceae species. For this reason the use of these two different methodologies allow a better understanding of the allergenic load in the atmosphere. This work was supported in part by the European Agency for Health and Consumers EAHC, Luxembourg, under the grant agreement 20081107

The European project HIALINE: Comparison between Poaceae Airborne Pollen Counts and Phl p5 Aeroallergen Quantification in SW Europe

The European project HIALINE: Comparison between Poaceae Airborne Pollen Counts and Phl p5 Aeroallergen Quantification in SW Europe C. Antunes1*, R. Ferro1, R. Ribeiro1, Torres M.C.3, M.J. Velasco3H. García-Mozo3, Galán, C3 , R.Brandao2, M.Thibaudon4 and the HIALINE team5 1Department of Chemistry, University of Évora, Portugal 2Department of Biology, University of Évora, Portugal 3Department of Botany, Ecology and Plant Physiology, University of Córdoba 4Réseau National de l Surveillance Aerobiologique, Saint-Genis-l’Argentière, France 5J.Buters, Germanny, M. Thibaudon, France, M. Smith, Great Britain, C. Galan, Spain, R. Brandao and C.M. Antunes, Portugal, R. Albertini, Italy, L. Grewling, Poland, A. Rantio-Lehtimäki, Finland, S. Jäger and U. Berger, Austria, I. Sauliene, Lithuania, L. Cecchi, Italy * Presenting Author: Antunes, C. Department of Chemistry, University of Évora, Portugal. Phone +351 266745319 ; email: [email protected] Introduction: Nowadays, pollinosis is affecting in a large percentage of population in the developed countries. The existence of allergenic activity in the atmosphere is not only associated to pollen grains and fungal spores, but also to submicronic and paucimicronic biological particles. The origin of these allergens can be due to the rupture of pollen transported in the atmosphere or to the presence of allergens from other parts of the plant making amorphous material with allergenic load. Poaceae pollen is recognized as one of the main causes of allergic disease in all Europe. In this study we have tried to compare Poaceae pollen counts in the air and Phl p 5, one of the major allergens of this family, through the use of a high-volume cascade impactor (Chemvol). This study was done in the frame of the European project HIALINE and it compares the results obtained in 2009 by 3 different partners participating in this project: in Córdoba (Spain), Évora (Portugal) and Lyon (France). Methodology: Pollen grains have been taken out using a 7-day volumetric Hirst type spore trap. Chemvol high-volume cascade impactor equipped with stages PM>10µm, 10 µm>PM>2.5µm were used for detecting aeroallergens. In each stage polyurethane filters were applied. Phl p5 allergen was determined using allergen specific ELISA´s. Antibodies for analysis are delivered by Allergopharma Joachim Ganzer KG, the industrial partner in this project. Both samplers were placed side-by-side. Results: Most of the allergen was collected in the PM>10µm fraction. Similar profiles between airborne pollen and the total allergenic load was observed during the pollen season. A good correlation was obtained and a value of 2.5 pg/pollen grain of Poaceae was estimated. Discussion: These results suggest that the allergenic load in outdoor air might be mainly due to pollen bursts. It supports the hypothesis that monitoring the allergens itself in ambient air might be an improvement in allergen exposure assessment. This work was supported in part by the European Agency for Health and Consumers EAHC, Luxembourg, under the grant agreement 2008110

Irrigação do cajueiro-anão-precoce na região de Teresina.

bitstream/CPAMN-2009-09/20953/1/CT186.pd

Experimental investigation of quantum key distribution with position and momentum of photon pairs

We investigate the utility of Einstein-Podolsky-Rosen correlations of the position and momentum of photon pairs from parametric down-conversion in the implementation of a secure quantum key distribution protocol. We show that security is guaranteed by the entanglement between downconverted pairs, and can be checked by either direct comparison of Alice and Bob's measurement results or evaluation of an inequality of the sort proposed by Mancini et al. (Phys. Rev. Lett. 88, 120401 (2002)).Comment: 6 pages, 6 figures, subimitted for publicatio