A theoretical study of ultrafast phenomena in complex atoms

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química. Fecha de lectura: 15-11-2019Esta tesis tiene embargado el acceso al texto completo hasta el 15-05-2021The ultrafast movement of electrons is a driving force of chemical reactions, making it a highly desirable avenue for study. This thesis studies such movements, making use of pump-probe methods such as attosecond transient absorption spectroscopy (ATAS) and reconstruction of attosecond beatings by interference of two-photon transitions (RABITT), in complex atomic systems. The main approach used to solve the time-dependent Schr¨odinger equation (TDSE) was exact, attosecond, full-electron, ab-initio calculations. Firstly, helium was probed above the second ionisation threshold, where severalionisationchannelsareopen, usingaccurateab-initiocalculations. Here, the ATAS method was employed to predict beatings between the autoionising 3snp1Po resonances and nearby 1Se and 1De states. More surprisingly, twophoton beatings between the doubly-excited 3s3p state and the 1Po continuum werealsoobserved,demonstratingcontrolofthecorrelated,two-electron,multichannel wave packet. Secondly, two studies of neon were carried out below the second ionisation threshold. The first makes use of ATAS calculations to probe beatings between the autoionising neon states. Using a two-colour, mixed extreme-ultraviolet (XUV) near-infrared (NIR) pump, one-photon beatings between the 2s−13p1Po and the nearby 2s−13s1Se and 2s−13d1De resonances are observed. Further, oneand two-photonbeatings between the autoionising 2s−13`, `∈{0,1}and the 1Po continuum are predicted. The second uses the RABITT method to probe the atomic phase in the vicinity of multiple resonances. This is far from trivial, and interferometric methods have until now been restricted to simpler energy-regions, due to the difficulty of accurately describing the electron correlation associated with the more complex case, making accurate ab-initio calculations needed to guide experiments unavailable. Despite the complex energy-dependence of the phase when several resonances are present, presented results from experiment and abinitiotheoryareinexcellentagreement. Further,usingasimpleextensionofthe Fano model for resonant continua, the contributions of the different involved resonances are disentangled. Such simple models are highly desirable in more advanced systems, where accurate ab-initio calculations are inaccessible. The ab-initio results of both neon studies were carried out using the newly developed XCHEM methodology, which is thus further validated by the excellent agreement with presented experiments and previous studies. Finally,aRABITTstudyofargoninthevicinityofthe3s−1n` resonanceswas performed. Angularly resolved, experimental results are presented, showing the anisotropy of the atomic phase in smooth continua as well as the vicinity of resonances. Due to the complexity of the system,no ab-initio results a represent. Instead, simpler interferometric models are used to successfully explain the anisotropic behaviour of the phaseEl movimiento ultrarrápido de electrones es la fuerza motriz de las reacciones químicas, por lo cual su estudio resulta muy atractivo. Esta tesis se dedica al estudio de ese tipo de movimientos, utilizando métodos de bombeo y sonda, como espectroscopia de absorción transitoria de attosegundos (ATAS) y reconstrucción de ”beatings” de attosegundo por interferencia de transiciones de dos fotones (RABITT), en átomos complejos. El método principal utilizado para resolver de la ecuación de Schrödinger dependiente del tiempo fue la propagación exacta (ab-initio) considerando todos los electrones. En primer lugar, se investigó el átomo de helio por encima del segundo umbral de ionización, donde existen varios canales de ionización. Aquí, el método de ATAS se empleó para predecir beatings entre las resonancias 3snp1Po y estados 1Se y 1De cercanos. Sorprendentemente, también se observaron beatings de dos fotones, lo cual muestra control del paquete de ondas correlacionado multicanal de dos electrones. En segundo lugar, dos estudios por debajo del segundo umbral de ionización del neón se llevaron a cabo. El primero utiliza cálculos de ATAS para investigar los beatings entre estados auto ionizantes de neón. Utilizando un bombeo de dos colores, radiación ultravioleta extrema (XUV) mezclada con radiación infrarrojo cercano (NIR), es posible observar beatings entre la resonancia del 2s−13p1Po y las 2s−13s1Se y 2s−13d1De. Además, se predicen beatings de uno y dos fotones entre las resonancias auto ionizantes 2s−13`, `∈{0,1}y el continuo 1Po. El segundo usa el método de RABITT para estudiar la fase atómica en las cercanías de las resonancias múltiples. Hasta ahora, los métodos interferométricos han estado restringidos a regiones de energía de hasta una resonancia, a causa de las dificultades en llevar a cabo propagaciones exactas (ab-initio), las cuales dependen de la correlación electrónica para describir bien los experimentos. A pesar de la complejidad de la dependencia de la energíac con la fase, debido a la presencia de varias resonancias, los resultados teóricos obtenidos comparan muy bien con los resultados experimentales presentados. Además, usando una extensión del modelo de Fano para continuos resonantes, las contribuciones de las distintas resonancias se han podido resolver. Modelos más simples son necesarios en sistemas más avanzados, donde cálculos ab-initio son inaccesibles. Los resultados ab-initio presentados en ambos estudios se realizaron con el método XCHEM recientemente propuesto, dando así validez al método. Finalmente, se realizó un estudio RABITT cerca de las resonancias 3s−1n` del argón. Se presentan experimentos mostrando la dependencia angular de la fase atómica, tanto en continuos suaves como en las cercanías de resonancias. Debido a la complejidad del sistema, no se presentan resultados ab-initio. En cambio, mediante modelos interferométricos se ha podido explicar el comportamiento anisótropo de la fas

Phase metrology with multi-cycle two-colour pulses

Strong-field phenomena driven by an intense infrared (IR) laser depend on during what part of the field cycle they are initiated. By changing the sub-cycle character of the laser electric field it is possible to control such phenomena. For long pulses, sub-cycle shaping of the field can be done by adding a relatively weak, second harmonic of the driving field to the pulse. Through constructive and destructive interference, the combination of strong and weak fields can be used to change the probability of a strong-field process being initiated at any given part of the cycle. In order to control sub-cycle phenomena with optimal accuracy, it is necessary to know the phase difference of the strong and the weak fields precisely. If the weaker field is an even harmonic of the driving field, electrons ionized by the field will be asymmetrically distributed between the positive and negative directions of the combined fields. Information about the asymmetry can yield information about the phase difference. A technique to measure asymmetry for few-cycle pulses, called Stereo-ATI (Above Threshold Ionization), has been developed by [Paulus G G, et al 2003 Phys. Rev. Lett. 91]. This paper outlines an extension of this method to measure the phase difference between a strong IR and its second harmonic

A comprehensive transition matrix model for projecting production and resource consumption in reindeer herds

A deterministic herd model was developed for projecting the dynamic changes in reindeer herd size and structure under defined harvest policies. The model distinguishes between females, males and castrates up to an optional number of age-classes. Calves are further classified based on the age and status (present/absent) of their mother. The yearly cycle is divided up into a maximum of 11 time steps, including five grazing seasons. The model is described in general terms using the Leslie matrix approach in order to suit different computer implementations. The conventional Leslie matrix solution was extended so that nonlinear features and stochastic variation in performance parameters could be considered. Computational procedures for making detailed economic evaluations of harvest output and herd feed requirements or consumption are given. This general purpose model can be tailored to specific study conditions. An advantage of this is that the sensitivity to necessary approximations can be tested with the general purpose model. The model is intended for use in both research and extension work

Growth and relationship of live weight to body measurements in semi-domesticated reindeer (Rangifer tarandus tarandus L.)

Estimation of live weight from measurements of body dimensions is useful in many management activities with domestic animals. In present study live weight was measured from 2932 female and 1037 male semi-domesticated reindeer (Rangifer tarandus tarandus L.) during different seasons in 1969-85. The age of reindeer varied between 1 day and 14 yrs. Back length (along back from second spinous process to base of tail) and chest girth (just behind front legs) were taken also from 1490 female and 510 male reindeer. The growth of reindeer from birth to adulthood was cumulative consisting of a rapid weight accretion during summers followed by a weight loss or stasis during winters. The mathematical analyses of the growth based on exponential solutions gave average values for growth of female and male reindeer. Body weight of females increased until the age of 4.5 yrs and that of males until the age of 5.5 yrs. During winter and spring body weight of hinds decreased 10 to 15 kg and that of stags 30 to 50 kg in different age groups. Significant linear regressions were found between live weight and back length (r = 0.809 and 0.892), live weight and chest girth (r = 0.860 and 0.872) and live weight and combined body measure (back length + chest girth) (r = 0.877 and 0.941) and live weight and body volume (r = 0.905 and 0.954, respectively) in female and male reindeer. Exponential regressions gave, however, the best estimations of live weight with combined body measure

En genväg till ett vägvinnande förändringsarbete för idrottsföreningar i ekonomisk kris

Syfte: Syftet med uppsatsen är att utveckla en anpassad rekommendation med förändringsåtgärder för idrottsföreningar vars ekonomiska situation är ohållbar. Med ledning ur redan befintliga dokumenterade teorier kommer rekommendationen att utformas som en samling insatser som kan göras för att åstadkomma förändring i organisationen och balansera föreningens ekonomi. Genom rekommendationen vill vi erbjuda idrottsföreningar en genväg till att hitta ett vägvinnande sätt att hantera en förändringsprocess. Metod: En deduktiv studie med en kvalitativ forskningsdesign. Studien är baserad på primärdata från intervjuer och sekundärdata från idrottsföreningarnas årsredovisningar, hemsidor och diverse nyhetsartiklar skrivna om dem. Teoretiska perspektiv: Studien tar utgångspunkt i teorier om turnarounds, som innehåller olika förändringsmetoder och åtgärder för att lyckas åstadkomma en förändringsprocess i ett företag. Empiri: Empirin har utförts i tre steg. Först gjordes en noggrann genomgång av sekundär data. Med utgångspunkt i denna utformades sedan en intervjumall för att kunna utföra intervjuer. Slutligen, med stöd av intervjumallen, utfördes ett antal djupgående intervjuer med ledande personer, främst Vd och styrelseordförande, från de olika idrottsföreningarna. Resultat/slutsats: Slutsatserna som presenteras i slutet av uppsatsen är följande punkter som är rekommendationer till idrottsföreningar i ekonomiskt ohållbara situationer: ● Öka kompetensnivån bland personalen. ● Förändra organisationens förväntningar på kostnadsstrukturen. ● Professionalisera säljarbetet. ● Utveckla idrottsevenemanget till något mer än bara idrott. ● Anpassa erbjudandet till sponsorer

Usability of computerised physician order entry in primary care: assessing ePrescribing with a new evaluation model

Background The incorrect use of medications may result from improper prescribing. The poor interface and design of computerised physician order entry (CPOE) systems may contribute. To improve the quality of electronic drug prescription, ePrescribing, there is a need for an evaluation model that is able to assess the quality of the CPOE, focusing on usability. Objective To develop and apply a model to evaluate the usability of different CPOEs used for ePrescribing in electronic health records (EHRs) in primary care. Method An evaluation model for CPOEs was designed by assembling existing quality criteria for ePrescribing, supplemented with new criteria. The evaluation model was used to assess CPOEs from seven EHRs in primary care. Results The evaluation model included five categories comprising 73 single criteria. The model was found to be easy to use, and facilitated the assessment process. Evaluation of the EHRs revealed differences and similarities between the systems. None of the CPOEs was perfect in that all of them had distinct shortcomings. The most prominent deficiencies were a non-intuitive interface and incorrect dosage function. Conclusion The model developed might be used not only to evaluate usability in ePrescribing, but also as a basis for studying the usability of other CPOEs. To reduce the risk of drugs being prescribed with incorrect dosages, the most urgent improvement is the development of a more consistent and intuitive interface for the EHRs and an improvement in the dosage function

Health-care cost reduction resulting from primary-care allergy testing in children in Italy

<p>Abstract</p> <p>Background</p> <p>Allergy places a considerable cost burden on society. Specific immunoglobulin E (spIgE) testing may improve the management of allergy patients. There is therefore a reason to quantify the economic consequences of the use of spIgE testing in the diagnosis of allergic conditions.</p> <p>Methods</p> <p>The expected costs of spIgE testing versus no-testing were calculated using a clinical decision model based on a prospective clinical trial performed in primary care.</p> <p>Results</p> <p>The expected costs per patient over 2 years decreased from 802 euros in the "no-test strategy" to 560 euros in the spIgE "test strategy". Cost savings persisted even after assumptions about the prevalence of allergy and the prices of medications were changed. The "test strategy" increased the percentage of patients correctly diagnosed from 54 to 87%.</p> <p>Conclusions</p> <p>spIgE testing of children with respiratory and/or skin problems in primary care in Italy reduces overall costs to society. These cost savings mostly result from a reduction in the use of medications, particularly corticosteroids. The study indicates that spIgE testing of all children with respiratory and/or skin symptoms would be a cost-effective strategy.</p

Decrease in the incidence of total hip arthroplasties in patients with rheumatoid arthritis - results from a well defined population in south Sweden

To access publisher full text version of this article. Please click on the hyperlink in Additional Links field.INTRODUCTION: One aim of modern pharmacologic treatment in rheumatoid arthritis (RA) is to prevent joint destruction and reduce the need for surgery. Our purpose was to investigate secular trends in the incidence of primary total hip and knee arthroplasties in a well defined sample of patients with RA. METHODS: Prevalent cases with RA in 1997 and incident cases from 1997 to 2007 in a community based register in Malmö, south Sweden, were included. Based on a structured review of the medical records, patients were classified according to the 1987 ACR criteria for RA. This cohort was linked to the Swedish Hip Arthroplasty Register (through December 2006) and the Swedish Knee Arthroplasty Register (through October 2007). Patients with a registered total hip or knee arthroplasty before 1997 or before RA diagnosis were excluded. Incidence rates for the period of introduction of TNF inhibitors (1998 to 2001) were compared to the period when biologics were part of the established treatment for severe RA (2002 to 2006/2007). RESULTS: In the cohort (n = 2,164; 71% women) a primary hip arthroplasty was registered for 115 patients and a primary knee arthroplasty for 82 patients. The incidence of primary total hip arthroplasties decreased from the period 1998 to 2001 (12.6/1,000 person-years (pyr)) to 2002 to 2006 (6.6/1,000 pyr) (rate ratio (RR) 0.52; 95% confidence interval (CI) 0.35 to 0.76). There was a trend towards an increase of primary knee arthroplasties (incidence 4.8/1,000 pyr vs. 6.8/1,000 pyr; RR 1.43; 95% CI 0.89 to 2.31). CONCLUSIONS: Our investigation shows a significant decrease in the incidence of total hip arthroplasties in patients with RA after 2001. Possible explanations include a positive effect on joint damage from more aggressive pharmacological treatment.The Swedish Research Council Lund University Crafoord Foundation Swedish Rheumatism Associatio

Sensitization to secretoglobin and lipocalins in a group of young children with risk of developing respiratory allergy

Background: Multiple sensitizations in early age have been reported to be a risk for development of asthma. This study evaluates the emergence and evolution of IgE to aeroallergens among a cohort of children with physician-diagnosed atopic dermatitis and/or showing food allergy symptoms and to examine the relation to asthma development. Methods: Three-hundred and four children (median age 13.4 months at entry) with food allergy symptoms and/or atopic dermatitis without asthma at inclusion were analysed for IgE antibodies against food-, indoor- and outdoor-allergens and pet allergen components and correlated to the individuals’ outcome on asthma inception. Results: At 2 years of follow-up, physician-diagnosed asthma was 19.7% (n = 49) and asthma diagnosed any time was 24% (n = 67). History of persistent cough and asthma of father, combination of milk- and wheat-allergy symptoms and dual sensitization to house dust mite and Japanese cedar were independent risk factors for asthma. Sensitization to dog was the most prevalent inhalant allergen at entry. Asthma children had a higher proportion of sensitization to dog, cat and horse allergens at entry compared with non-asthma children. Being sensitized to both food, house dust mite and pet allergens was strongly associated with asthma (p = 0.0006). Component resolved diagnosis for dog and cat allergens showed that IgE antibodies to Can f 1 and Fel d 1 was common even at very young age. Conclusions: Early sensitization to inhalant allergens increases the risk of developing asthma as well as having milk and wheat allergy symptoms. Sensitization to dog, was common at an early age despite dog ownership. Sensitization to secretoglobin and lipocalins and less to serum albumins explained the pet sensitization

Zenseact Open Dataset: A large-scale and diverse multimodal dataset for autonomous driving

Existing datasets for autonomous driving (AD) often lack diversity and long-range capabilities, focusing instead on 360{\deg} perception and temporal reasoning. To address this gap, we introduce Zenseact Open Dataset (ZOD), a large-scale and diverse multimodal dataset collected over two years in various European countries, covering an area 9x that of existing datasets. ZOD boasts the highest range and resolution sensors among comparable datasets, coupled with detailed keyframe annotations for 2D and 3D objects (up to 245m), road instance/semantic segmentation, traffic sign recognition, and road classification. We believe that this unique combination will facilitate breakthroughs in long-range perception and multi-task learning. The dataset is composed of Frames, Sequences, and Drives, designed to encompass both data diversity and support for spatio-temporal learning, sensor fusion, localization, and mapping. Frames consist of 100k curated camera images with two seconds of other supporting sensor data, while the 1473 Sequences and 29 Drives include the entire sensor suite for 20 seconds and a few minutes, respectively. ZOD is the only large-scale AD dataset released under a permissive license, allowing for both research and commercial use. More information, and an extensive devkit, can be found at https://zod.zenseact.comComment: International Conference on Computer Vision (ICCV) 202