Studies of planning behavior of aircraft pilots in normal, abnormal and emergency situations

A methodology for the study of planning is presented and the results of applying the methodology within two experimental investigations of planning behavior of aircraft pilots in normal, abnormal, and emergency situations are discussed. Beyond showing that the methodology yields consistent results, these experiments also lead to concepts in terms of a dichotomy between event driven and time driven planning, subtle effects of automation on planning, and the relationship of planning to workload and flight performance

Vergleich der muttergebundenen und der künstlichen Aufzucht in Bezug auf Gesundheit, Gewichtsentwicklung und chronischen Stress bei Milchviehkälbern

In artificial rearing, calves are separated from their dam usually within 24h after birth and any further social contacts to the mother are prevented. Although this is common in practice we expect severe consequences on the health state, weight gain and stress response of the young calf. Two groups of calves suckled by their mother (unrestricted contact, n=14; contact twice daily for 15 minutes each before milking, n=15) were compared to two control groups that were both fed via automatic milk feeder (maximal six times daily, n=14; twice daily, n=14). The calves of the four treatment groups were kept in the same barn and cows were milked twice daily. All calves were weaned at 13 weeks of age. The calves were weighed weekly until 3 weeks after weaning. The health state of each animal was assessed daily and all veterinary treatments were recorded until weaning. Stress response to a long-term stressor (absence of the mother) was assessed by stimulation of the HPA axis by ACTH administration (at 11 weeks of age). For statistical analyses, linear mixed-effects models were used. The health state of both suckled groups was poorer (p=0.046, caused by diarrhoea), but the number of animals that had to be treated by a veterinarian did not differ. During the milk feeding period, weight gain was better in suckled calves (p<0.001). After weaning, the weight gain of all treatment groups was diminished, especially in suckled calves (p<0.001). Cortisol response to ACTH administration was reduced in calves fed via an automatic milk feeder (p<0.001). The higher weight gain in suckled calves before weaning can be explained by the large milk amounts the calves received. These results suggest that suckled calves show fewer signs of chronic stress. We conclude that rearing without contact with the mother causes chronic stress in young calves in terms of desensitization of the HPA axis

E7(7) invariant Lagrangian of d=4 N=8 supergravity

We present an E7(7) invariant Lagrangian that leads to the equations of motion of d=4 N=8 supergravity without using Lagrange multipliers. The superinvariance of this new action and the closure of the supersymmetry algebra are proved explicitly for the terms that differ from the Cremmer--Julia formulation. Since the diffeomorphism symmetry is not realized in the standard way on the vector fields, we switch to the Hamiltonian formulation in order to prove the invariance of the E7(7) invariant action under general coordinate transformations. We also construct the conserved E7(7)-Noether current of maximal supergravity and we conclude with comments on the implications of this manifest off-shell E7(7)-symmetry for quantizing d=4 N=8 supergravity, in particular on the E7(7)-action on phase space.Comment: 45 pages, references adde

Generalized E(7(7)) coset dynamics and D=11 supergravity

The hidden on-shell E(7(7)) symmetry of maximal supergravity is usually discussed in a truncation from D=11 to four dimensions. In this article, we reverse the logic and start from a theory with manifest off-shell E(7(7)) symmetry inspired by West's coset construction. Following de Wit's and Nicolai's idea that a 4+56 dimensional "exceptional geometry" underlies maximal supergravity, we construct the corresponding Lagrangian and the supersymmetry variations for the 56 dimensional subsector. We prove that both the dynamics and the supersymmetry coincide with D=11 supergravity in a truncation to d=7 in the expected way.Comment: 42 pages, v2: references adde

Plasma 25-Hydroxyvitamin D and Progression to Diabetes in Patients at Risk for Diabetes

OBJECTIVE To investigate the association between vitamin D status, assessed by plasma 25-hydroxyvitamin D, and risk of incident diabetes. RESEARCH DESIGN AND METHODS Prospective observational study with a mean follow-up of 2.7 years in the Diabetes Prevention Program (DPP), a multicenter trial comparing different strategies for prevention of diabetes in patients with prediabetes. We assessed the association between plasma 25-hydroxyvitamin D, measured repeatedly during follow-up, and incident diabetes in the combined placebo (n = 1,022) and intensive lifestyle (n = 1,017) randomized arms of the DPP. Variables measured at multiple study time points (25-hydroxyvitamin D, BMI, and physical activity) entered the analyses as time-varying “lagged” covariates, as the mean of the previous and current visits at which diabetes status was assessed. RESULTS After multivariate adjustment, including for the DPP intervention, participants in the highest tertile of 25-hydroxyvitamin D (median concentration, 30.1 ng/mL) had a hazard ratio of 0.72 (95% CI 0.56–0.90) for developing diabetes compared with participants in the lowest tertile (median concentration, 12.8 ng/mL). The association was in the same direction in placebo (0.70; 0.52–0.94) versus lifestyle arm (0.80; 0.54–1.17). CONCLUSIONS Higher plasma 25-hydroxyvitamin D, assessed repeatedly, was associated with lower risk of incident diabetes in high-risk patients, after adjusting for lifestyle interventions (dietary changes, increased physical activity, and weight loss) known to decrease diabetes risk. Because of the observational nature of the study, the potential association between vitamin D and diabetes needs to be confirmed in intervention studies

Long-Term Cell Tracking Following Local Injection of Mesenchymal Stromal Cells in the Equine Model of Induced Tendon Disease

Tendon disease has been treated with multipotent mesenchymal stromal cells (MSCs) in the equine large-animal model with promising success. The aim of this study was to gain more insight into the fate and biodistribution of MSCs after local application into tendon lesions by long-term cell tracking in this large-animal model. Superficial digital flexor tendon lesions were induced in all limbs in six horses and injected with 10106 Molday ION Rhodamine B-labeled MSCs suspended in serum or serum alone. Follow-up was performed using low-field magnetic resonance imaging (MRI), flow cytometry, and histology. Cell tracking based on the hypointense artifacts induced by the superparamagnetic iron oxide (SPIO) labeling agent in MRI as well as based on Rhodamine B fluorescence was feasible. However, Prussian blue staining for assessment of histology was not entirely specific for SPIO. Labeled cells could be traced at their injection site by MRI as well as histology for the whole follow-up period of 24 weeks. Although the numbers of labeled cells within the injected tendon lesions decreased over time, part of the applied cells appeared to remain viable and integrated within the injured tissue. Furthermore, small numbers of labeled cells were identified in peripheral blood within the first 24 h after cell injection and could also be found until week 24 within the contralateral control tendon lesions that had been injected with serum. The present findings unveil details on MSC biodistribution and persistence after their local application, which are of clinical relevance with regard to MSC safety and mechanisms of action

K(E10), Supergravity and Fermions

We study the fermionic extension of the E10/K(E10) coset model and its relation to eleven-dimensional supergravity. Finite-dimensional spinor representations of the compact subgroup K(E10) of E(10,R) are studied and the supergravity equations are rewritten using the resulting algebraic variables. The canonical bosonic and fermionic constraints are also analysed in this way, and the compatibility of supersymmetry with local K(E10) is investigated. We find that all structures involving A9 levels 0,1 and 2 nicely agree with expectations, and provide many non-trivial consistency checks of the existence of a supersymmetric extension of the E10/K(E10) coset model, as well as a new derivation of the `bosonic dictionary' between supergravity and coset variables. However, there are also definite discrepancies in some terms involving level 3, which suggest the need for an extension of the model to infinite-dimensional faithful representations of the fermionic degrees of freedom.Comment: 50 page

Counterterms vs. Dualities

We investigate and clarify the mutual compatibility of the higher order corrections arising in supergravity and string theory effective actions and the non-linear duality symmetries of these theories. Starting from a conventional tree level action leading to duality invariant equations of motion, we show how to accommodate duality invariant counterterms given as functionals of both electric and magnetic fields in a perturbative expansion, and to deduce from them a non-polynomial bona fide action satisfying the Gaillard-Zumino constraint. There exists a corresponding consistency constraint in the non-covariant Henneaux-Teitelboim formalism which ensures that one can always restore diffeomorphism invariance by perturbatively solving this functional identity. We illustrate how this procedure works for the R^2 \nabla F \nabla F and F^4 counterterms in Maxwell theory.Comment: 15 page