Highly sensitive frequency metrology for optical anisotropy measurements

In this paper we present a novel apparatus aimed at measuring very small birefringences and anisotropies, based on frequency metrology and not on polarimetry as usual. In our experiment, a very high finesse resonant cavity is used to convert the phase difference into a resonance frequency difference, which can then be measured with very high accuracy. We describe the set-up and present the results of experimental tests which exhibited a sensitivity dn ~ 2 x 10?18, allowing for the measurement of long-predicted magneto-electro-optical effects in gases. Since the shotnoise limited sensitivity of our apparatus lies well below the state-of-the-art sensitivity, frequency metrology appears as a promising technique for small birefringence measurements.Comment: Accepted for publication in Review of Scientific Instrument

Food Habits of Blueline Tilefish, Caulolatilus microps, and Snowy Grouper, Epinephelus niveatus, from the Lower Florida Keys

Dietary analyses of Intestinal contents from 96 blueline tileflsh Caulolatilus microps (mean TL = 528 ± 94 mm SO) and 32 snowy grouper Epinephelus nlveatus (mean TL = 609 ± 146mm SD) collected from the shelf environments (123-256 m) in the lower Florida Keys during July 1980 and May-October 1981, revealed that the two predatory species exhibited different feeding strategies. Blueline tileflsh preyed principally on benthic Invertebrates, and snowy grouper on fish. Copepods, ophluroids, and gastropods comprised 60% of the numerical, and urochordates 40% of the volumetric intestinal contents of blueline tilefish. Frequency of occurrence of prey consumed by tileflsh exceeded 50% only for two major taxa - Polychaeta and Natantla. Osteichthyes comprised 47% and 52% of the numerical and volumetric consumption of prey, respectively, by snowy grouper, and occurred in 72% of the Intestines; cephalopods ranked second in numerical importance (18%), and brachyuran crabs second in volumetric Importance (29%). Differences in prey taxa, space niche, and fish anatomy Indicated that blueline tilefish and snowy grouper occupy different trophic niches, which reduce Interspecific competition

The BMV project: Search for photon oscillations into massive particles

In this contribution to PSAS08 we report on the research activities developed in our Toulouse group, in the framework of the BMV project, concerning the search for photon oscillations into massive particles, such as axion-like particles in the presence of a strong transverse magnetic field. We recall our main result obtained in collaboration with LULI at \'Ecole Polytechnique (Palaiseau, France). We also present the very preliminary results obtained with the BMV experiment which is set up at LNCMP (Toulouse, France).Comment: Proceedings of PSAS'08, to be published in Can. J. Phy

Acceleration and vacuum temperature

The quantum fluctuations of an "accelerated" vacuum state, that is vacuum fluctuations in the presence of a constant electromagnetic field, can be described by the temperature \TEH. Considering \TEH for the gyromagnetic factor $g=1$ we show that \TEH(g=1)=\THU, where \THU is the Unruh temperature experienced by an accelerated observer. We conjecture that both particle production and nonlinear field effects inherent in the Unruh accelerated observer case are described by the case $g=1$ QED of strong fields. We present rates of particle production for $g=0,1,2$ and show that the case $g=1$ is experimentally distinguishable from $g=0,2$. Therefore, either accelerated observers are distinguishable from accelerated vacuum or there is unexpected modification of the theoretical framework.Comment: 4 pages, 1 figure; expanded discussion of experimental observables, added references, version appearing in Phys Rev

Current status of bacterial spot of stone fruits and almond caused by Xanthomonas arboricola pv. pruni in Spain

In 2002, typical symptoms of bacterial spot disease of stone fruits caused by Xanthomomas arboricola pv. pruni (Xap) were observed for the first time on Japanese plum in Badajoz (south-western Spain). During the following years, the pathogen was found in seven other eastern and northern Spanish provinces (Valencia, Alicante, Zaragoza, Huesca, Navarra, Lérida and Mallorca) affecting different cultivars of Japanese plum, nectarine, peach and almond. There are few previous reports of Xap on almond, the Spanish outbreaks constituting its first detection on this host in the European Union (EU). Identification of the pathogen was performed using biochemical tests, fatty acid methyl esters (FAME) profiles, conventional and real-time PCR, and hypersensitivity reaction on tobacco leaves. Pathogenicity was demonstrated by inoculation of young potted plants of peach, plum or almond and successful re-isolations from plants with symptoms. In areas where infected plants were found, eradication programs were set up since Xap has a quarantine status according to phytosanitary EU legislation.Publishe

"Ethnic disparities in the prevalence of Molar-Incisor-Hypomineralisation (MIH) and caries among 6-12-year-old children in Catalonia, Spain"

AIM: To study the prevalence of MIH and caries in 6- and 12-year-old schoolchildren and their association with ethnic disparities and other relevant factors. BACKGROUND: In recent years, there has been uneven improvement in school children's oral health, highlighting inequalities in access to dental care and health outcomes, particularly among ethnic minorities. The most prevalent oral disease in childhood, caries, is preventable, as its risk factors are well known. However, MIH, a common condition affecting the enamel of permanent incisors and/or molars, has no established aetiology or preventive measures. METHODS: A cross-sectional study among schoolchildren was conducted in 725 children from Masnou (Barcelona, 2013) and in 577 children from Sant Andreu de Llavaneres (Barcelona, 2018-2020). Data collection was carried out by means of clinical examination and a selfreferenced questionnaire. Oral health outcomes included: presence of dental caries, presence of MIH, hypomineralised second primary molars (HSPM). All variables were analysed according to ethnic disparities and other variables such as socioeconomics, diet, hygiene habits, plaque and access to dental services. We performed multivariate Poisson regression models with robust variance to examine ethnic disparities in MIH and caries. CONCLUSION: This cross-sectional study based in Catalonia, Spain showed that there are ethnic disparities in caries as observed with other child's diseases; however, they do not seem to follow the same pattern for MIH. More studies are needed (i) to explore how MIH behaves among populations in terms of inequality; (ii) to study the aetiological factors of MIH; and (iii) to identify potential factors associated with MIH and caries that have not been studied and that may contribute to the observed ethnic disparities.</p

"Ethnic disparities in the prevalence of Molar-Incisor-Hypomineralisation (MIH) and caries among 6-12-year-old children in Catalonia, Spain"

AIM: To study the prevalence of MIH and caries in 6- and 12-year-old schoolchildren and their association with ethnic disparities and other relevant factors. BACKGROUND: In recent years, there has been uneven improvement in school children's oral health, highlighting inequalities in access to dental care and health outcomes, particularly among ethnic minorities. The most prevalent oral disease in childhood, caries, is preventable, as its risk factors are well known. However, MIH, a common condition affecting the enamel of permanent incisors and/or molars, has no established aetiology or preventive measures. METHODS: A cross-sectional study among schoolchildren was conducted in 725 children from Masnou (Barcelona, 2013) and in 577 children from Sant Andreu de Llavaneres (Barcelona, 2018-2020). Data collection was carried out by means of clinical examination and a selfreferenced questionnaire. Oral health outcomes included: presence of dental caries, presence of MIH, hypomineralised second primary molars (HSPM). All variables were analysed according to ethnic disparities and other variables such as socioeconomics, diet, hygiene habits, plaque and access to dental services. We performed multivariate Poisson regression models with robust variance to examine ethnic disparities in MIH and caries. CONCLUSION: This cross-sectional study based in Catalonia, Spain showed that there are ethnic disparities in caries as observed with other child's diseases; however, they do not seem to follow the same pattern for MIH. More studies are needed (i) to explore how MIH behaves among populations in terms of inequality; (ii) to study the aetiological factors of MIH; and (iii) to identify potential factors associated with MIH and caries that have not been studied and that may contribute to the observed ethnic disparities.</p

"Pilowred": un nuevo portainjerto resistente a nemátodos que confiere un vigor reducido. Resultados preliminares en varias localizaciones

Este trabajo forma parte del Proyecto de I+D+I. RTI2018-094210-R-I00 financiado por MCIN/AEI/ 10.13039/501100011033, además de por el Gobierno de Aragón (Grupo Consolidado A12)Publishe

Birefringence of interferential mirrors at normal incidence Experimental and computational study

In this paper we present a review of the existing data on interferential mirror birefringence. We also report new measurements of two sets of mirrors that confirm that mirror phase retardation per reflection decreases when mirror reflectivity increases. We finally developed a computational code to calculate the expected phase retardation per reflection as a function of the total number of layers constituting the mirror. Different cases have been studied and we have compared computational results with the trend of the experimental data. Our study indicates that the origin of the mirror intrinsic birefringence can be ascribed to the reflecting layers close to the substrate.Comment: To be published in Applied Physics

Primera detección de Lonsdalea quercina subsp. populi en chopo en España (abstract)

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