Three level atom optics in dipole traps and waveguides

An analogy is explored between a setup of three atomic traps coupled via tunneling and an internal atomic three-level system interacting with two laser fields. Within this scenario we describe a STIRAP like process which allows to move an atom between the ground states of two trapping potentials and analyze its robustness. This analogy is extended to other robust and coherent transport schemes and to systems of more than a single atom. Finally it is applied to manipulate external degrees of freedom of atomic wave packets propagating in waveguides.Comment: 14 pages, 6 figures; submitted to special issue 'Quantum Control of Light and Matter' of Optics Communication

Towards a personalized task selection model with shared instructional control

Corbalan, G., Kester, L., & Van Merriënboer, J .J. G. (2006). Towards a personalized task selection model with shared instructional control. Instructional Science, 34 , 399-422.Modern education emphasizes the need to flexibly personalize learning tasks to individual learners. This article discusses a personalized task-selection model with shared instructional control based on two current tendencies for the dynamic sequencing of learning tasks: (1) personalization by an instructional agent which makes sequencing decisions on the basis of learner’s expertise, and (2) personalization by the learner who is given control over –final—task selection. The model combines both trends in a model with shared instructional control. From all available learning tasks, an instructional agent selects a subset of tasks based on the learner’s performance scores and invested mental effort (i.e., system-control). Subsequently, this subset is presented to the learner who makes the final decision (i.e., learner control). A computer-assisted instructional program has been developed to put the model into practice and preliminary results are discussed. The model can be used to increase the efficiency and effectiveness of instruction and to make it more appealing by providing the learner an optimal level of control over task selection

Learner-controlled selection of tasks with different surface and structural features: Effects on transfer and efficiency

Surface task features are more salient than structural task features and thus easier to recognize for novices. It is predicted that the more salient the task features the better learners can choose personally relevant and varied tasks, which enhances learning transfer. To investigate this prediction, a 2 x 2 factorial experiment with 72 participants studied the effects of control over tasks that differ in their surface features (learner, program) and in their structural features (learner, program). Learner control over the selection of tasks with salient surface features enables learners to select personally relevant and varied tasks. This is believed to yield higher effectiveness (i.e., higher near and far transfer test performance) as well as higher efficiency (i.e. higher transfer test performance combined with lower associated mental effort). Learner control over the selection of tasks with non-salient structural features does not enable learners to select personally relevant and varied tasks and is therefore not expected to yield beneficial effects on learning. The results show positive effects of learner control over the selection of tasks with salient surface features for efficiency on the far transfer test but not for effectiveness. Theoretical and practical implications are discussed

Coherent population trapping in two-electron three-level systems with aligned spins

The possibility of coherent population trapping in two electron states with aligned spins (ortho-system) is evidenced. From the analysis of a three-level atomic system containing two electrons, and driven by the two laser fields needed for coherent population trapping, a conceptually new kind of two-electron dark state appears. The properties of this trapping are studied and are physically interpreted in terms of a dark hole, instead of a dark two-electron state. This technique, among many other applications, offers the possibility of measuring, with subnatural resolution, some superposition-state matrix-elements of the electron-electron correlation that due to their time dependent nature are inaccesible by standard measuring procedures.Comment: 10 pages and 4 figure

Development of an international standard set of outcome measures for patients with atrial fibrillation: a report of the International Consortium for Health Outcomes Measurement (ICHOM) atrial fibrillation working group.

AIMS: As health systems around the world increasingly look to measure and improve the value of care that they provide to patients, being able to measure the outcomes that matter most to patients is vital. To support the shift towards value-based health care in atrial fibrillation (AF), the International Consortium for Health Outcomes Measurement (ICHOM) assembled an international Working Group (WG) of 30 volunteers, including health professionals and patient representatives to develop a standardized minimum set of outcomes for benchmarking care delivery in clinical settings. METHODS AND RESULTS: Using an online-modified Delphi process, outcomes important to patients and health professionals were selected and categorized into (i) long-term consequences of disease outcomes, (ii) complications of treatment outcomes, and (iii) patient-reported outcomes. The WG identified demographic and clinical variables for use as case-mix risk adjusters. These included baseline demographics, comorbidities, cognitive function, date of diagnosis, disease duration, medications prescribed and AF procedures, as well as smoking, body mass index (BMI), alcohol intake, and physical activity. Where appropriate, and for ease of implementation, standardization of outcomes and case-mix variables was achieved using ICD codes. The standard set underwent an open review process in which over 80% of patients surveyed agreed with the outcomes captured by the standard set. CONCLUSION: Implementation of these consensus recommendations could help institutions to monitor, compare and improve the quality and delivery of chronic AF care. Their consistent definition and collection, using ICD codes where applicable, could also broaden the implementation of more patient-centric clinical outcomes research in AF

Characteristics, treatment, and outcomes of newly diagnosed atrial fibrillation patients with heart failure: GARFIELD-AF.

AIMS: Heart failure (HF) and atrial fibrillation (AF) may coexist and influence each other. However, characteristics, anticoagulant treatment, and outcomes of contemporary AF patients with concurrent HF are ill-defined. This study analyses characteristics, treatment, and 2 year outcomes in newly diagnosed Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) patients with vs. without HF. METHODS AND RESULTS: GARFIELD-AF is the world's largest observational AF patient study. At enrolment, 11 758 of 52 072 patients (22.6%) had HF; 76.3% were New York Heart Association class II-III. Patients with HF had comparable demographics, blood pressure, and heart rate but more likely had permanent (15.6% vs. 11.9%) or persistent AF (18.9% vs. 13.8%), acute coronary syndromes (16.7% vs. 8.9%), vascular disease (40.8% vs. 20.2%), and moderate-to-severe chronic kidney disease (14.6% vs. 9.0%) than those without. Anticoagulant prescription was similar between the two groups. At 2 year follow-up, patients with HF showed a greater risk of all-cause mortality [hazard ratio (HR), 2.06; 95% confidence interval (CI), 1.91-2.21; P < 0.0001], cardiovascular mortality (HR, 2.91; 95% CI, 2.58-3.29; P < 0.0001), acute coronary syndromes (HR, 1.25; 95% CI, 1.02-1.52; P = 0.03), and stroke/systemic embolism (HR, 1.24; 95% CI, 1.07-1.43; P = 0.0044). Major bleeding rate was comparable (adjusted HR, 1.00; 95% CI, 0.84-1.18; P = 0.968). Among patients without HF at baseline, incidence of new HF was low [0.69 (95% CI, 0.63-0.75) per 100 person-years], whereas propensity to develop worsening HF was higher in those with HF [1.62 (95% CI, 1.45-1.80) per 100 person-years]. CONCLUSIONS: Patients with AF and HF have a high risk of all-cause and cardiovascular mortality and stroke/systemic embolism and may develop worsening HF

Quality of Vitamin K Antagonist Control and 1-Year Outcomes in Patients with Atrial Fibrillation: A Global Perspective from the GARFIELD-AF Registry.

AIMS: Vitamin K antagonists (VKAs) need to be individually dosed. International guidelines recommend a target range of international normalised ratio (INR) of 2.0-3.0 for stroke prevention in atrial fibrillation (AF). We analysed the time in this therapeutic range (TTR) of VKA-treated patients with newly diagnosed AF in the ongoing, global, observational registry GARFIELD-AF. Taking TTR as a measure of the quality of patient management, we analysed its relationship with 1-year outcomes, including stroke/systemic embolism (SE), major bleeding, and all-cause mortality. METHODS AND RESULTS: TTR was calculated for 9934 patients using 136,082 INR measurements during 1-year follow-up. The mean TTR was 55.0%; values were similar for different VKAs. 5851 (58.9%) patients had TTR<65%; 4083 (41.1%) TTR≥65%. The proportion of patients with TTR≥65% varied from 16.7% in Asia to 49.4% in Europe. There was a 2.6-fold increase in the risk of stroke/SE, 1.5-fold increase in the risk of major bleeding, and 2.4-fold increase in the risk of all-cause mortality with TTR<65% versus ≥65% after adjusting for potential confounders. The population attributable fraction, i.e. the proportion of events attributable to suboptimal anticoagulation among VKA users, was 47.7% for stroke/SE, 16.7% for major bleeding, and 45.4% for all-cause mortality. In patients with TTR<65%, the risk of first stroke/SE was highest in the first 4 months and decreased thereafter (test for trend, p = 0.021). In these patients, the risk of first major bleed declined during follow-up (p = 0.005), whereas in patients with TTR≥65%, the risk increased over time (p = 0.027). CONCLUSION: A large proportion of patients with AF had poor VKA control and these patients had higher risks of stroke/SE, major bleeding, and all-cause mortality. Our data suggest that there is room for improvement of VKA control in routine clinical practice and that this could substantially reduce adverse outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT01090362

Liver fluke in Irish sheep: prevalence and associations with management practices and co-infection with rumen fluke

peer-reviewedBackground: The present study aimed to identify the national prevalence of Fasciola hepatica in Irish sheep and to conduct a risk analysis assessment based on management and treatment practices in participating focks. Also, co-infection with rumen fuke was quantifed and its association with liver fuke and management practices was assessed. Methods: A total of 305 sheep focks were selected ensuring even national representation of the sheep population. Participating farms were asked to complete a survey questionnaire on farm management practices and submit faecal samples during the winter of 2014–2015. Pooled faecal samples were analysed for the presence of F. hepatica and coinfection with rumen fuke. Apparent and true prevalence were calculated, additionally, the rate of co-infection with rumen fuke was also obtained. Correlation and regression analyses were used for assessing associations between management practices, liver fuke infection and co-infection with rumen fuke. Results: The national true prevalence of F. hepatica was 50.4% (n=305). Regional prevalence varied from 41% in the east to 52% in the south. Co-infection with rumen fuke was observed in 40% of the studied population and corre‑ lated with increased F. hepatica egg counts (OR=2.9; P≤0.001). Predominant breeds were Sufolk, Texel and Horned Mountain breeds. Beef cattle were the most frequent type of other livestock present on farms and mixed species grazing was frequently reported (73%). More than half of the focks reported a mid-to-late lambing period (MarchApril). Use of mountain land for grazing was of 32%. Flukicides were most commonly used twice over the autumnwinter period. Regression analyses highlighted signifcant association of F. hepatica status, with the presence of other livestock on farm, frequency of fukicides used during the winter and clinical presentation of liver fuke. A signifcant increase in eggs per gram of faeces was observed in Charollais sheep in comparison with all other breeds. Co-infec‑ tion with F. hepatica and Calicophoron daubneyi was also signifcantly associated with the presence of other livestock on the farm, type of fukicide used and clinical fasciolosis. Conclusions: The present study provides up-to-date information on the prevalence of F. hepatica in Irish sheep and adds insight to the epidemiology of the disease. These fndings will be useful for designing new holistic control meas‑ ures for F. hepatica infection

The Evolution of Cognitive Load Theory and the Measurement of Its Intrinsic, Extraneous and Germane Loads: A Review

Cognitive Load Theory has been conceived for supporting instructional design through the use of the construct of cognitive load. This is believed to be built upon three types of load: intrinsic, extraneous and germane. Although Cognitive Load Theory and its assumptions are clear and well-known, its three types of load have been going through a continuous investigation and re-definition. Additionally, it is still not clear whether these are independent and can be added to each other towards an overall measure of load. The purpose of this research is to inform the reader about the theoretical evolution of Cognitive Load Theory as well as the measurement techniques and measures emerged for its cognitive load types. It also synthesises the main critiques of scholars and the scientific value of the theory from a rationalist and structuralist perspective

Quality of Vitamin K Antagonist Control and 1-Year Outcomes in Patients with Atrial Fibrillation: A Global Perspective from the GARFIELD-AF Registry

AimsVitamin K antagonists (VKAs) need to be individually dosed. International guidelines recommend a target range of international normalised ratio (INR) of 2.0–3.0 for stroke prevention in atrial fibrillation (AF). We analysed the time in this therapeutic range (TTR) of VKA-treated patients with newly diagnosed AF in the ongoing, global, observational registry GARFIELD-AF. Taking TTR as a measure of the quality of patient management, we analysed its relationship with 1-year outcomes, including stroke/systemic embolism (SE), major bleeding, and all-cause mortality.Methods and ResultsTTR was calculated for 9934 patients using 136,082 INR measurements during 1-year follow-up. The mean TTR was 55.0%; values were similar for different VKAs. 5851 (58.9%) patients had TTRConclusionA large proportion of patients with AF had poor VKA control and these patients had higher risks of stroke/SE, major bleeding, and all-cause mortality. Our data suggest that there is room for improvement of VKA control in routine clinical practice and that this could substantially reduce adverse outcomes.</div