Phase correlation of laser waves with arbitrary frequency spacing

The theoretically predicted correlation of laser phase fluctuations in Lambda-type interaction schemes is experimentally demonstrated. We show, that the mechanism of correlation in a Lambda scheme is restricted to high frequency noise components, whereas in a double-$\Lambda$ scheme, due to the laser phase locking in closed-loop interaction, it extends to all noise frequencies. In this case the correlation is weakly sensitive to coherence losses. Thus the double-Lambda scheme can be used to correlate e.m. fields with carrier frequency differences beyond the GHz regime.Comment: 4 pages, 4 figure

Quantum coherence in a degenerate two-level atomic ensemble: for a transition Fe=0↔Fg=1F_e=0\leftrightarrow F_g=1

For a transition $F_e=0\leftrightarrow F_g=1$ driven by a linearly polarized light and probed by a circularly light, quantum coherence effects are investigated. Due to the coherence between the drive Rabi frequency and Zeeman splitting, electromagnetically induced transparency, electromagnetically induced absorption, and the transition from positive to negative dispersion are obtained, as well as the populations coherently oscillating in a wide spectral region. At the zero pump-probe detuning, the subluminal and superluminal light propagation is predicted. Finally, coherent population trapping states are not highly sensitive to the refraction and absorption in such ensemble.Comment: 9 pages, 6 figure

On dicraeosaurid (sauropoda) vertebra from the la amarga formation (barremian–aptian, lower cretaceous), Neuquén basin, patagonia, Argentina

Field works carried out by Dr. Bonaparte and collaborators in the La Amarga Formation (Barremian–Aptian) in 2000, allowed the collecting of a vertebral element not previously communicated. This material has not been properly protected, so it is broken and kept in paleontological collection of Museo Provincial “Olsacher” of Zapala city. The descriptions were based solely on a photograph. The parapophyses are located on the dorsal part of the centrum, like in the anterior dorsal vertebrae of Dicraeosaurus hansemanni Janensch and Amargasaurus cazaui Salgado and Bonaparte. The posterior articular surface of the centrum is strongly concave with an elliptical outline. The neural arch bears two deep and wide centropostzygapophyseal fossae with a triangular outline. These fossae are framed laterally by stout centropostzygapophyseal laminae, project dorsoventrally like a massive columnar bone. The transverse processes are inclined dorsally more than 30° from the horizontal axis, as in the dorsal vertebrae of D. hansemanni, A. cazaui, Brachytrachelopan mesai Rauhut, Remes, Fechner, Cladera and Puerta and Pilmatueia faundezi Coria, Windholz, Ortega and Currie. The element bears an elongate bifid neural spine, character that share with the most of presacral vertebrae of the dicraeosaurids. This structure is straight, dorsoanteriorly oriented and its degree of development reminds to the presacral vertebrae of A. cazaui. This element is similar to the anterior dorsal vertebrae of A. cazaui, although it could be comparable with Amargatitanis macni Apesteguía, come from the same locality and lithostratigraphic unit, whose presacral vertebrae are unknown.Fil: Windholz, Guillermo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina. Provincia del Neuquén. Municipalidad de Plaza Huincul. Museo "Carmen Funes"; ArgentinaFil: Baiano, Mattia Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina. Provincia del Neuquén. Municipalidad de Plaza Huincul. Museo "Carmen Funes"; ArgentinaFil: Bellardini, Flavio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; Argentina. Gobierno de la Provincia de la Pampa. Secretaria de Cultura. Direccion Provincial de Patrimonio Cultural.; ArgentinaFil: Meso, Jorge Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Juáres Valieri, R.. Gobierno de la Provincia de Río Negro. Ministerio de Turismo, Cultura y Deporte. Secretaría de Cultura; Argentina. Museo de Ciencias de Añelo; ArgentinaFil: Porfiri, J.. Museo de Ciencias de Añelo; Argentina. Universidad Nacional del Comahue; ArgentinaFil: Filippi, L.. Gobierno de la Provincia del Neuquén. Municipalidad de Rincón de Los Sauces. Secretaria de Turismo y Patrimonio. Museo Municipal Argentino Urquiza; ArgentinaFil: Garrido, A.. Provincia de Neuquén. Ministerio de Energía, Ambiente y Servicios Públicos. Dirección Provincial de Minería. Museo Provincial de Ciencias Naturales Prof. "Dr. Juan A. Olsacher"; Argentina. Universidad Nacional del Comahue. Facultad de Ingeniería. Departamento de Geología y Petróleo; Argentina2das Jornadas de Paleovertebrados de la Cuenca NeuquinaNeuquénArgentinaAsociación Paleontológica Argentin

Efficient Raman Sideband Generation in a Coherent Atomic Medium

We demonstrate the efficient generation of Raman sidebands in a medium coherently prepared in a dark state by continuous-wave low-intensity laser radiation. Our experiment is performed in sodium vapor excited in $\Lambda$ configuration on the D$_{1}$ line by two laser fields of resonant frequencies $\omega_{1}$ and $\omega_{2}$, and probed by a third field $$. First-order sidebands for frequencies $\omega_{1}$, $\omega_{2}$ and up to the third-order sidebands for frequency $\omega_{3}$ are observed. The generation starts at a power as low as 10 microwatt for each input field. Dependencies of the intensities of both input and generated waves on the frequency difference ($\omega_{1}-\omega_{2}$), on the frequency $\omega_{3}$ and on the optical density are investigated.Comment: 7 pages, 6 figure

Preliminary studies of a new dinosaur track locality from the Candeleros Formation (Cenomanian, Upper Cretaceous), Neuquén Basin, Argentina

.

Ultrastable CO2 Laser Trapping of Lithium Fermions

We demonstrate an ultrastable CO2 laser trap that provides tight confinement of neutral atoms with negligible optical scattering and minimal laser-noise- induced heating. Using this method, fermionic 6Li atoms are stored in a 0.4 mK deep well with a 1/e trap lifetime of 300 sec, consistent with a background pressure of 10^(-11) Torr. To our knowledge, this is the longest storage time ever achieved with an all-optical trap, comparable to the best reported magnetic traps.Comment: 4 pages using REVTeX, 1 eps figur

Effects of Genetic Variants in ADCY5, GIPR, GCKR and VPS13C on Early Impairment of Glucose and Insulin Metabolism in Children

OBJECTIVE: Recent genome-wide association studies identified novel candidate genes for fasting and 2 h blood glucose and insulin levels in adults. We investigated the role of four of these loci (ADCY5, GIPR, GCKR and VPS13C) in early impairment of glucose and insulin metabolism in children. RESEARCH DESIGN AND METHODS: We genotyped four variants (rs2877716; rs1260326; rs10423928; rs17271305) in 638 Caucasian children with detailed metabolic testing including an oGTT and assessed associations with measures of glucose and insulin metabolism (including fasting blood glucose, insulin levels and insulin sensitivity/secretion indices) by linear regression analyses adjusted for age, sex, BMI-SDS and pubertal stage. RESULTS: The major allele (C) of rs2877716 (ADCY5) was nominally associated with decreased fasting plasma insulin (P = 0.008), peak insulin (P = 0.009) and increased QUICKI (P = 0.016) and Matsuda insulin sensitivity index (P = 0.013). rs17271305 (VPS13C) was nominally associated with 2 h blood glucose (P = 0.009), but not with any of the insulin or insulin sensitivity parameters. We found no association of the GIPR and GCKR variants with parameters of glucose and insulin metabolism. None of the variants correlated with anthropometric traits such as height, WHR or BMI-SDS, which excluded potential underlying associations with obesity. CONCLUSIONS: Our data on obese children indicate effects of genetic variation within ADCY5 in early impairment of insulin metabolism and VPS13C in early impairment of blood glucose homeostasis

Laser Machining by short and ultrashort pulses, state of the art and new opportunities in the age of the photons

An overview is given of the applications of short and ultrashort lasers in material processing. Shorter pulses reduce heat-affected damage of the material and opens new ways for nanometer accuracy. Even forty years after the development of the laser there is a lot of effort in developing new and better performing lasers. The driving force is higher accuracy at reasonable cost, which is realised by compact systems delivering short laser pulses of high beam quality. Another trend is the shift towards shorter wavelengths, which are better absorbed by the material and which allows smaller feature sizes to be produced. Examples of new products, which became possible by this technique, are given. The trends in miniaturization as predicted by Moore and Taniguchi are expected to continue over the next decade too thanks to short and ultrashort laser machining techniques. After the age of steam and the age of electricity we have entered the age of photons now