High harmonic generation and periodic level crossings

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Theory of dressed states in quantum optics

The dual Dyson series [M.Frasca, Phys. Rev. A {\bf 58}, 3439 (1998)], is used to develop a general perturbative method for the study of atom-field interaction in quantum optics. In fact, both Dyson series and its dual, through renormalization group methods to remove secular terms from the perturbation series, give the opportunity of a full study of the solution of the Schr\"{o}dinger equation in different ranges of the parameters of the given hamiltonian. In view of recent experiments with strong laser fields, this approach seems well-suited to give a clarification and an improvement of the applications of the dressed states as currently done through the eigenstates of the atom-field interaction, showing that these are just the leading order of the dual Dyson series when the Hamiltonian is expressed in the interaction picture. In order to exploit the method at the best, a study is accomplished of the well-known Jaynes-Cummings model in the rotating wave approximation, whose exact solution is known, comparing the perturbative solutions obtained by the Dyson series and its dual with the same approximations obtained by Taylor expanding the exact solution. Finally, a full perturbative study of high-order harmonic generation is given obtaining, through analytical expressions, a clear account of the power spectrum using a two-level model, even if the method can be successfully applied to a more general model that can account for ionization too. The analysis shows that to account for the power spectrum it is needed to go to first order in the perturbative analysis. The spectrum obtained gives a way to measure experimentally the shift of the energy levels of the atom interacting with the laser field by looking at the shifting of hyper-Raman lines.Comment: Revtex, 17 page

Non-invasive imaging reveals convergence in root and stem vulnerability to cavitation across five tree species

Root vulnerability to cavitation is challenging to measure and under-represented in current datasets. This gap limits the precision of models used to predict plant responses to drought because roots comprise the critical interface between plant and soil. In this study we measured vulnerability to drought induced cavitation in woody roots and stems of five tree species (Acacia aneura, Cedrus deodara, Eucalyptus crebra, Eucalytus saligna, and Quercus palustris) with a wide range of xylem anatomies. X-ray microtomography was used to visualize the accumulation of xylem embolism in stems and roots of intact plants that were naturally dehydrated to varying levels of water stress. Vulnerability to cavitation, defined as the water potential causing a 50% loss of hydraulic function (P50), varied broadly among the species (-4.51 to -11.93 MPa in stems and -3.13 to -9.64 MPa in roots). The P50 of roots and stems was significantly related across species, with species that had more vulnerable stems also having more vulnerable roots. While there was strong convergence in root and stem vulnerability to cavitation, the P50 of roots was significantly higher than the P50 of stems in three species. However, the difference in root and stem vulnerability for these species was small; between 1% to 31% of stem P50. Thus, while some differences existed between organs, roots were not dramatically more vulnerable to embolism than stems and the differences observed were less than those reported in previous studies. Further study is required to evaluate the vulnerability across root orders and to extend these conclusions to a greater number of species and xylem functional types

Genetic testing for Inherited Arrhythmia Syndromes and Cardiomyopathies: results of the European Heart Rhythm Association Survey.

Indications and clinical impact of genetic testing for cardiac diseases have increased significantly over the past years. The aim of this physician-based EHRA survey was to assess current clinical practice and access to genetic testing for cardiac diseases across ESC countries and to evaluate adherence to the 2022 EHRA/HRS/APHRS/LAHRS Expert Consensus Statement on genetic testing. An online questionnaire composed of 28 questions was submitted to the EHRA Research Network and European Reference Network GUARD-Heart healthcare partners and promoted via dedicated social media channels. There were 357 respondents from 69 countries, 40% working in a hospital setting with a cardiac genetic service and/or a dedicated clinic focusing on inherited cardiac diseases and 27% with an onsite genetic laboratory. No genetic testing or low annual rate (<10/y) was declared by 39% of respondents. The majority of respondents (78%) declared issues or limitations to genetic testing access in their clinical practice. The main reasons for not providing or limited access to genetic testing were no availability of dedicated unit or genetic laboratory (35%) or reimbursement issues (25%). The most frequently reported indication for genetic testing was diagnostic purpose (55%). Most respondents (92%) declared offering genetic testing preceded by genetic counselling and 42% regular multidisciplinary evaluations for patients with cardiac genetic diseases. The perceived value of genetic testing in the diagnostic, prognostic, and therapeutic assessment was variable (67%, 39%, and 29%, respectively) and primarily based on the specific inherited disease. The majority of respondents recommended cascade genetic testing for the first-degree family members in case of pathogenic/likely pathogenic (P/LP) variant in the proband. This survey highlights a significant heterogeneity of genetic testing access and provision and issues attributable to the availability of dedicated unit/genetic laboratory and reimbursement. However, adequate adherence to indications in the current recommendations for genetic testing in patients with cardiac diseases was observed

Wave-packet recollision and pulse-shape effects in high-harmonic generation

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Journeys from quantum optics to quantum technology

Sir Peter Knight is a pioneer in quantum optics which has now grown to an important branch of modern physics to study the foundations and applications of quantum physics. He is leading an effort to develop new technologies from quantum mechanics. In this collection of essays, we recall the time we were working with him as a postdoc or a PhD student and look at how the time with him has influenced our research

Effect of Imidocarb on Babesia canis, agent of canine piroplasmosis in Europe

L'Imidocarb, administré à la dose unique de 3 mg/kg par voie intramusculaire : — exerce un effet curatif radical chez les chiens atteints de babésiose clinique et parasitologique caractérisée ; — exerce un effet chimio-préventif pendant au moins 6 semaines. L'Imidocarb, administré à la dose unique de 1 mg/kg, 30 min après une infection expérimentale, exerce un effet préventif sur les manifestations cliniques de l'infection, sans empêcher une parasitémie légère, qui se maintient pendant 16 jours. L'animal ainsi traité a acquis l’immunité. Cependant, nos observations sont encore trop peu nombreuses pour nous autoriser une conclusion définitive sur ce point.Three milligrams per kg Imidocarb, given to dogs with clinical babesiosis cures the dogs definitely with only one treatment and make Babesia disappear from blood. The same dose acts as a chemio-preventive drug for at least 6 weeks. One milligram per kg Imidocarb prevents clinical babesiosis in dogs experimentally infected when given 30 min after infection and it appears that the infection so caught vaccinates dogs against further infection

Expérimentation des propriétés antipiroplasmiques de l'Imidocarb sur Babesia canis, agent de la piroplasmose canine en Europe

Three milligrams per kg Imidocarb, given to dogs with clinical babesiosis cures the dogs definitely with only one treatment and make Babesia disappear from blood. The same dose acts as a chemio-preventive drug for at least 6 weeks. One milligram per kg Imidocarb prevents clinical babesiosis in dogs experimentally infected when given 30 min after infection and it appears that the infection so caught vaccinates dogs against further infection.L’Imidocarb, administré à la dose unique de 3 mg/kg par voie intramusculaire : — exerce un effet curatif radical chez les chiens atteints de babésiose clinique et parasitologique caractérisée ; — exerce un effet chimio-préventif pendant au moins 6 semaines. L'Imidocarb, administré à la dose unique de 1 mg/kg, 30 min après une infection expérimentale, exerce un effet préventif sur les manifestations cliniques de l’infection, sans empêcher une parasitémie légère, qui se maintient pendant 16 jours. L’animal ainsi traité a acquis l'immunité. Cependant, nos observations sont encore trop peu nombreuses pour nous autoriser une conclusion définitive sur ce point.Euzéby Jacques, Moreau Y., Chauve Claude, Gevrey J., Gauthey M. Expérimentation des propriétés antipiroplasmiques de l'Imidocarb sur Babesia canis, agent de la piroplasmose canine en Europe. In: Bulletin de l'Académie Vétérinaire de France tome 133 n°4, 1980. pp. 475-480