Femtosecond frequency comb measurement of absolute frequencies and hyperfine coupling constants in cesium vapor

We report measurements of absolute transition frequencies and hyperfine coupling constants for the 8S_{1/2}, 9S_{1/2}, 7D_{3/2}, and 7D_{5/2} states in ^{133}Cs vapor. The stepwise excitation through either the 6P_{1/2} or 6P_{3/2} intermediate state is performed directly with broadband laser light from a stabilized femtosecond laser optical-frequency comb. The laser beam is split, counter-propagated and focused into a room-temperature Cs vapor cell. The repetition rate of the frequency comb is scanned and we detect the fluorescence on the 7P_{1/2,3/2} -> 6S_{1/2} branches of the decay of the excited states. The excitations to the different states are isolated by the introduction of narrow-bandwidth interference filters in the laser beam paths. Using a nonlinear least-squares method we find measurements of transition frequencies and hyperfine coupling constants that are in agreement with other recent measurements for the 8S state and provide improvement by two orders of magnitude over previously published results for the 9S and 7D states.Comment: 14 pages, 14 figure

Gipsy 3D: Analysis, Visualization and Vo-Tools

The scientific goals of the AMIGA project are based on the analysis of a significant amount of spectroscopic 3D data. In order to perform this work we present an initiative to develop a new VO compliant package, including present core applications and tasks offered by the Groningen Image Processing System (GIPSY), and new ones based on use cases elaborated in collaboration with ad- vanced users. One of the main goals is to provide local interoperability between GIPSY (visualization and data analysis) and other VO software. The connectivity with the Virtual Observatory environment will provide general access to 3D data VO archives and services, maximizing the potential for scientific discovery.Comment: 2 pages, 1 figure, to appear in the proceedings of the "Multi-wavelength Astronomy and Virtual Observatory" Workshop held at ESAC 1-3 Dec 200

Clinical characterization of patients with anal fistula during follow-up of anorectal abscess: a large population-based study

PurposeApproximately 15-50% of patients with an anorectal abscess will develop an anal fistula, but the true incidence of this entity is currently unknown. The aim of the study was to determine the incidence of anorectal abscess and development of a fistula in a specific population area and to identify potential risk factors associated with demographic, socioeconomic and pre-existing disease (e.g. diabetes and inflammatory bowel disease).MethodsA longitudinal observational study was designed including a large cohort study in an area with 7,553,650 inhabitants in Spain 1st january 2014 to 31st december 2019. Adults who attended for the first time with an anorectal abscess and had a minimum of 1-year follow-up were included. The diagnosis was made using ICD-10 codes for anorectal abscess and anal fistula.ResultsDuring the study period, we included 27,821 patients with anorectal abscess. There was a predominance of men (70%) and an overall incidence of 596 per million population. The overall incidence of anal fistula developing from abscesses was 20%, with predominance in men, and a lower incidence in the lowest income level. The cumulative incidence of fistula was higher in men and in younger patients (p < 0.0001). On multivariate analysis, patients aged 60-69 years (hazard ratio 2.0) and those with inflammatory bowel disease (hazard ratio 1.8-2.0) had a strong association with fistula development (hazard ratio 2.0).ConclusionsOne in five patients with an anorectal abscess will develop a fistula, with a higher likelihood in men. Fistula formation was strongly associated with inflammatory bowel disease

On Some Open Problems in Many-Electron Theory

Mel Levy and Elliott Lieb are two of the most prominent researchers who have dedicated their efforts to the investigation of fundamental questions in many-electron theory. Their results have not only revolutionized the theoretical approach of the field, but, directly or indirectly, allowed for a quantum jump in the computational treatment of realistic systems as well. For this reason, at the conclusion of our book where the subject is treated across different disciplines, we have asked Mel Levy and Elliott Lieb to provide us with some open problems, which they believe will be a worth challenge for the future also in the perspective of a synergy among the various disciplines.Comment: "Epilogue" chapter in "Many-Electron Approaches in Physics, Chemistry and Mathematics: A Multidisciplinary View", Volker Bach and Luigi Delle Site Eds. pages 411-416; Book Series: Mathematical Physics Studies, Springer International Publishing Switzerland, 2014. The original title has been modified in order to clarify the subject of the chapter out of the context of the boo

The Libyan collections in FI (Herbarium Centrale Italicum and Webb Herbarium) and studies on the Libyan Flora by R. Pampanini - Part 2

This work is the continuation of Part 1, published in 2015, and comprises the reconstruction of the original collections of new taxa described by R. Pampanini and other botanists and, where possible, typification of the new names and taxonomical updating. The material studied for the most part concerns Libyan specimens held in the FI and FI-W herbaria but in some case also K, LD, MPU, P, PAD, PAL, ULT. Other material, which Pampanini studied in Florence was subsequently conserved in other herbaria. Specimens belonging to 21 families have been examined, from the Najadaceae to Zygophyllaceae. As well as typification, bibliographical data have been provided for those already typified. In this second part, a total of 113 names have been indexed and 91 typified, taking the names validly published in the entire work to 353, of which 286 are typified. Also on this occasion, we have provided taxonomic updates for each taxon. The Conclusions present a synthetic sum of the taxa still recognised taxonomically (entirely, in new combinations, or with a new status) in recent works on the Flora of N. Africa, in general revisions of various systematic groups, or reconsidered by the authors of this present work. We have also investigated the phyto-geographic origins of the taxa [according to the dominions proposed by Quézel (1978) for N. Africa]. Finally we have very briefly indicated the presence of material of the R. Pampanini collections (for Cyrenaica, together with R. E. G. Pichi Sermolli in 1934) in the most important herbaria. The paragraph "Addenda et Corrigenda" has been added to the final part of the treatise and relates chiefly to taxa omitted from the first part, either on account of new information or as a result of errors which came to light after publication

Subharmonic bifurcation cascade of pattern oscillations caused by winding number increasing entrainment

Convection structures in binary fluid mixtures are investigated for positive Soret coupling in the driving regime where solutal and thermal contributions to the buoyancy forces compete. Bifurcation properties of stable and unstable stationary square, roll, and crossroll (CR) structures and the oscillatory competition between rolls and squares are determined numerically as a function of fluid parameters. A novel type of subharmonic bifurcation cascade (SC) where the oscillation period grows in integer steps as $n (2\pi)/(\omega)$ is found and elucidated to be an entrainment process.Comment: 7 pages, 4 figure

Security devices based on liquid crystals doped with a colour dye

Liquid crystal properties make them useful for the development of security devices in applications of authentication and detection of fakes. Induced orientation of liquid crystal molecules and birefringence are the two main properties used in security devices. Employing liquid crystal and dichroic colorants, we have developed devices that show, with the aid of a polarizer, multiple images on each side of the device. Rubbed polyimide is used as alignment layer on each substrate of the LC cell. By rubbing the polyimide in different directions in each substrate it is possible to create any kind of symbols, drawings or motifs with a greyscale; the more complex the created device is, the more difficult is to fake it. To identify the motifs it is necessary to use polarized light. Depending on whether the polarizer is located in front of the LC cell or behind it, different motifs from one or the other substrate are shown. The effect arises from the dopant colour dye added to the liquid crystal, the induced orientation and the twist structure. In practice, a grazing reflection on a dielectric surface is polarized enough to see the effect. Any LC flat panel display can obviously be used as backlight as well

Pneumococcal surface protein A of invasive Streptococcus pneumoniae isolates from Colombian children.

Pneumococcal surface protein A (PspA) elicits protection in mice against fatal bacteremia and sepsis caused by genetically diverse pneumococci and protects against carriage and lung infection. We determined the PspA families of invasive isolates of Streptococcus pneumoniae recovered from Colombian children <5 years of age. That 97.5% of Colombian isolates belong to PspA families 1 and 2 supports the hypothesis that a human PspA vaccine covering a few PspA families could be broadly effective

Determinación de la betalactamasa en cepas de Neisseria gonorrhoeae

The appearance of strains of N. gonorrhoeae resistant to different antibiotics, which could be caused by plasmids or by mutations, require constant surveillance so as to revise the schemes of treatment. In our country the existent studies to determine the problem of strains of N. gonorrhoeae resistent to penicilin have been scarce therefore it was decided to determine the presence of beta lactamase and antimicrobe susceptibility from isolates of this pathogen obtained from different health services around the country. From 89 strains studied 46 (52%) were producers of beta lactamase; 11% of these presented resistance to spectinomycin and 96% to tetracycline. In the strains which did not produce beta lactamase, 61% were resistant to tetracycline and 2% to penicilin: additionally 98% of the NPBL strains presented a moderate sensitivity to penicilin. All the PBL and NPBL strains were sensitive to ceftriaxone. This data confirms the circulation of PBL strains of N. gonorrhoeae throughout different regions of the country and supports the recommendation to maintain surveillance, permitting the determination of the real frequency of these strains in our country.La aparición de cepas de N. gonorrhoeae resistentes a diferentes antibióticos, la cual puede estar mediada por plásmidos o por mutaciones, requiere una continua vigilancia, con el fin de revisar los esquemas de tratamiento. En nuestro medio, los estudios realizados para establecer el problema de resistencia de cepas de N. gonorrhoeae a la penicilina han sido escasos, por esto decidimos determinar, en aislamientos de este patógeno obtenidos en diferentes servicios de salud del país, la presencia de la betalactamasa y la susceptibilidad antimicrobiana. De 89 cepas estudiadas, 46 (52%) fueron productoras de beta lactamasa (PBL); 11% de ellas presentaron resistencia a la espectinomicina y 96% a la tetraciclina. En las cepas no productoras de beta lactamasa, el 61% fue resistente a la tetraciclina y el 2% a la penicilina; adicionalmente el 98% de las cepas NPBL presentaron una sensibilidad moderada a la penicilina. Todas las cepas, PBL y NPBL, fueron sensibles a la ceftriaxona. Estos datos confirman la circulación de cepas de N. gonorrhoeae PBL en diferentes regiones del país y apoyan la recomendación de mantener una vigilancia que nos permita conocer la verdadera frecuencia de ellas en nuestro medio