Studies on the flight medical aspects of the German Lufthansa non-stop route from Frankfurt to Rio de Janeiro, part 1

The problem of crew size for regularly scheduled flights between Frankfurt and Rio de Janeiro is discussed. Factors affecting crew performance are examined, comparisons are drawn to regulations of other countries and crew questionnaires and tests are presented

Multiprocessor Out-of-Core FFTs with Distributed Memory and Parallel Disks

This paper extends an earlier out-of-core Fast Fourier Transform (FFT) method for a uniprocessor with the Parallel Disk Model (PDM) to use multiple processors. Four out-of-core multiprocessor methods are examined. Operationally, these methods differ in the size of mini-butterfly computed in memory and how the data are organized on the disks and in the distributed memory of the multiprocessor. The methods also perform differing amounts of I/O and communication. Two of them have the remarkable property that even though they are computing the FFT on a multiprocessor, all interprocessor communication occurs outside the mini-butterfly computations. Performance results on a small workstation cluster indicate that except for unusual combinations of problem size and memory size, the methods that do not perform interprocessor communication during the mini-butterfly computations require approximately 86% of the time of those that do. Moreover, the faster methods are much easier to implement

Evaluation of the QBC-vet autoread haematology system for domestic and pet animal species

A comprehensive evaluation was initiated to determine the suitability of the QBC-Vet Autoread haematology system for veterinary purposes in domestic and pet animal species. The system determines haematocrit (HCT), haemoglobin (HGB), white blood cell (WBC) count, granulocyte count, combined lymphocyte and monocyte count (L/M), platelet count, as well as eosinophil and neutrophil counts (canine samples only), and reticulocyte count (canine and feline samples only). Linearity assessed for a canine sample usually surpassed the physiological range. Within-batch precision was very good for the majority of the parameters in feline and canine samples: Coefficients of variation (CV) were below 5.5% for HCT, HGB and WBC. In order to test the accuracy of the system with respect to reference methods, a total of 300 blood samples from the Clinics of Internal Veterinary Medicine and Surgery (101 canine, 99 feline and 100 equine) were analysed. Strong linear correlation was demonstrated for HCT, HGB (rτ;/0.96) and WBC (rτ;/0.93) based on high correlation coefficients and narrow confidence intervals. A somewhat higher degree of variation from the estimated regression lines was found in differential blood cell counts, especially for eosinophil counts of the dog where the automated reader erroneously attributed some lymphocytes or monocytes to eosinophil counts. Accuracy of the system was also assessed with respect to clinical relevance of results. The majority of leukocytosis (50 of 53), neutrophilias (3 of 4), or eosinophilias (4 of 5) was detected properly by the QBC-Vet Autoread haematology system, but only 20 out of 35 leukopenic samples were identified correctly. The system detected the presence of reticulocytes in the majority of feline (9 of 10) and canine (6 of 7) samples with a regenerative anaemia. Unexpectedly, platelets of cats were measured with high within-batch precision (mean CV=4.64%). No ‘streaming' effect (no discrimination between erythrocytes and granulocytes) was observed with this advanced QBC system. The system was found to be easy both in handling and interpretation of results. The buffy coat profile appeared particularly useful and informative. In conclusion, the QBC-Vet Autoread-System has excellent analytical properties and is well suited for veterinary purpose

High power arcjet

The activities on the development of the high power arc jet HIPARC, the thrust balance, and plasma diagnostic probes are discussed. Modifications of the HIPARC design and a synopsis of the materials used are given. Further experimental results with the TT30 thruster in the 50 kW range are presented. Some first calibration measurements of the thrust balance are also included. Progress concerning the development of plasma diagnostic devices is documented

Spectral Analysis of the Chandra Comet Survey

We present results of the analysis of cometary X-ray spectra with an extended version of our charge exchange emission model (Bodewits et al. 2006). We have applied this model to the sample of 8 comets thus far observed with the Chandra X-ray observatory and ACIS spectrometer in the 300-1000 eV range. The surveyed comets are C/1999 S4 (LINEAR), C/1999 T1 (McNaught-Hartley), C/2000 WM1 (LINEAR), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), C/2001 Q4 (NEAT), 9P/2005 (Tempel 1) and 73P/2006-B (Schwassmann-Wachmann 3) and the observations include a broad variety of comets, solar wind environments and observational conditions. The interaction model is based on state selective, velocity dependent charge exchange cross sections and is used to explore how cometary X-ray emission depend on cometary, observational and solar wind characteristics. It is further demonstrated that cometary X-ray spectra mainly reflect the state of the local solar wind. The current sample of Chandra observations was fit using the constrains of the charge exchange model, and relative solar wind abundances were derived from the X-ray spectra. Our analysis showed that spectral differences can be ascribed to different solar wind states, as such identifying comets interacting with (I) fast, cold wind, (II), slow, warm wind and (III) disturbed, fast, hot winds associated with interplanetary coronal mass ejections. We furthermore predict the existence of a fourth spectral class, associated with the cool, fast high latitude wind.Comment: 16 pages, 16 figures, and 7 Tables; accepted A&A (Due to space limits, this version has lower resolution jpeg images.

Plasmonic nanorods for enhanced absorption in mid-wavelength infrared detectors

The absorption properties of HgCdTe-based infrared detectors can be greatly increased in the mid-infrared band, by incorporating nanostructured plasmonic arrays on the illuminated detector face. The array periodicity, combined with the excitation of surface plasmon-polariton stationary modes, enhances the absorption efficiency by a substantial amount, allowing to reduce in turn the HgCdTe absorption thickness

Laboratory simulation of cometary x rays using a high-resolution microcalorimeter

X-ray emission following charge exchange has been studied on the University of California Lawrence Livermore National Laboratory electron beam ion traps EBIT-I and EBIT-II using a high-resolution microcalorimeter. The measured spectra include the K-shell emission from hydrogenlike and heliumlike C, N, O, and Ne needed for simulations of cometary x-ray emission. A comparison of the spectra produced in the interaction of O8+ with N2 and CH4 is presented that illustrates the dependence of the observed spectrum on the interaction gas.Comment: 11 pages, 2 figure

Many-body approach to proton emission and the role of spectroscopic factors

The process of proton emission from nuclei is studied by utilizing the two-potential approach of Gurvitz and Kalbermann in the context of the full many-body problem. A time-dependent approach is used for calculating the decay width. Starting from an initial many-body quasi-stationary state, we employ the Feshbach projection operator approach and reduce the formalism to an effective one-body problem. We show that the decay width can be expressed in terms of a one-body matrix element multiplied by a normalization factor. We demonstrate that the traditional interpretation of this normalization as the square root of a spectroscopic factor is only valid for one particular choice of projection operator. This causes no problem for the calculation of the decay width in a consistent microscopic approach, but it leads to ambiguities in the interpretation of experimental results. In particular, spectroscopic factors extracted from a comparison of the measured decay width with a calculated single-particle width may be affected.Comment: 17 pages, Revte

Microtubules gate tau condensation to spatially regulate microtubule functions.

Tau is an abundant microtubule-associated protein in neurons. Tau aggregation into insoluble fibrils is a hallmark of Alzheimer's disease and other types of dementia1, yet the physiological state of tau molecules within cells remains unclear. Using single-molecule imaging, we directly observe that the microtubule lattice regulates reversible tau self-association, leading to localized, dynamic condensation of tau molecules on the microtubule surface. Tau condensates form selectively permissible barriers, spatially regulating the activity of microtubule-severing enzymes and the movement of molecular motors through their boundaries. We propose that reversible self-association of tau molecules, gated by the microtubule lattice, is an important mechanism of the biological functions of tau, and that oligomerization of tau is a common property shared between the physiological and disease-associated forms of the molecule

Discovery of a novel lantibiotic nisin O from Blautia obeum A2-162, isolated from the human 2 gastrointestinal tract

The Institute of Food Research is funded by the BBSRC (strategic core grants IFR/08/1 BB/J004529/1); SHD and HJF acknowledge support from the Scottish Government Food Land and People programme. DH and CGF received BBSRC PhD studentship grants. Acknowledgements We are grateful to Kathryn Cross for the EM analysis and Neil Rigby for helpful advice.Peer reviewedPostprin