Shuttle program: OFT ascent/descent ancillary data requirements document

Requirements are presented for the ascent/descent (A/D) navigation and attitude-dependent ancillary data products to be generated for the space shuttle orbiter in support of the orbital flight test (OFT) flight test requirements, MPAD guidance and navigation performance assessment, and the mission evaluation team. The A/D ancillary data support for OFT mission evaluation activities is confined to providing postflight position, velocity, attitude, and associated navigation and attitude derived parameters for the Orbiter over particular flight phases and time intervals

OFT ascent/descent ancillary data requirements document

Requirements are presented for the ascent/descent (A/D) navigation and attitude-dependent ancillary data products to be generated for the space shuttle orbiter in support of orbital flight test requirements, MPAD guidance and navigation performance assessment, and the mission evaluation team. It was intended that this document serve as the sole requirements control instrument between MPB/MPAD and the A/D ancillary data users. The requirements are primarily functional in nature, but some detail level requirements are also included

An Early Cambrian Rift to Post-Rift Transition in the Cordillera of Western North America

The upper Proterozoic and lower Palaeozoic wedge of miogeoclinal strata in the North American Cordillera is widely regarded as evidence for a proto-Pacific passive margin. The rifting history of this margin appears to have been protracted, possibly spanning more than 200 Myr in a tectonic setting that is not well understood. Quantitative subsidence analyses of lower Palaeozoic strata between British Columbia and Utah, however, provide indirect evidence that the transition from rifting to post-rift cooling occurred within a relatively short interval of time, although probably not synchronously, between 600 and 555 Myr. This age is significantly younger than that implied in previous studies. We describe here new field data, which, together with published geological data, provide direct evidence of a latest Proterozoic or early Cambrian age for the rift to post-rift transition. The data support recent arguments for widespread initiation of passive margins around the edge of the North American craton close to the Cambrian-Precambrian boundary

Frustrated trimer chain model and Cu3Cl6(H2O)2 2H8C4SO2 in a magnetic field

Recent magnetization and susceptibility measurements on Cu3Cl6(H2O)2 2H8C4SO2 by Ishii et.al. [J. Phys. Soc. Jpn. 69, 340 (2000)] have demonstrated the existence of a spin gap. In order to explain the opening of a spin gap in this copper-trimer system, Ishii et.al. have proposed a frustrated trimer chain model. Since the exchange constants for this model have not yet been determined, we develop a twelfth-order high-temperature series for the magnetic susceptibility and fit it to the experimentally measured one. We find that some of the coupling constants are likely to be ferromagnetic. The combination of several arguments does not provide any evidence for a spin gap in the parameter region with ferromagnetic coupling constants, but further results e.g. for the magnetization process are in qualitative agreement with the experimental observations.Comment: 9 pages REVTeX, 4 PostScript figures included using psfig.sty; for series and supplementary material see http://www.tu-bs.de/~honecker/3mer/ or http://www.itp.phys.ethz.ch/staff/laeuchli/3mer ; substantial reorganization including shifting part of the discussion to WWW pages with "supplementary material"; new appendix shows that antiferromagnetic J_i > 0 are not compatible with the experimental data for the magnetic susceptibilit

Using Rasch analysis to form plausible health states amenable to valuation: the development of CORE-6D from CORE-OM in order to elicit preferences for common mental health problems

Purpose: To describe a new approach for deriving a preference-based index from a condition specific measure that uses Rasch analysis to develop health states. Methods: CORE-OM is a 34-item instrument monitoring clinical outcomes of people with common mental health problems. CORE-OM is characterised by high correlation across its domains. Rasch analysis was used to reduce the number of items and response levels in order to produce a set of unidimensionally-behaving items, and to generate a credible set of health states corresponding to different levels of symptom severity using the Rasch item threshold map. Results: The proposed methodology resulted in the development of CORE-6D, a 2-dimensional health state description system consisting of a unidimensionally-behaving 5-item emotional component and a physical symptom item. Inspection of the Rasch item threshold map of the emotional component helped identify a set of 11 plausible health states, which, combined with the physical symptom item levels, will be used for the valuation of the instrument, resulting in the development of a preference-based index. Conclusions: This is a useful new approach to develop preference-based measures where the domains of a measure are characterised by high correlation. The CORE-6D preference-based index will enable calculation of Quality Adjusted Life Years in people with common mental health problems

A filament of dark matter between two clusters of galaxies

It is a firm prediction of the concordance Cold Dark Matter (CDM) cosmological model that galaxy clusters live at the intersection of large-scale structure filaments. The thread-like structure of this "cosmic web" has been traced by galaxy redshift surveys for decades. More recently the Warm-Hot Intergalactic Medium (WHIM) residing in low redshift filaments has been observed in emission and absorption. However, a reliable direct detection of the underlying Dark Matter skeleton, which should contain more than half of all matter, remained elusive, as earlier candidates for such detections were either falsified or suffered from low signal-to-noise ratios and unphysical misalignements of dark and luminous matter. Here we report the detection of a dark matter filament connecting the two main components of the Abell 222/223 supercluster system from its weak gravitational lensing signal, both in a non-parametric mass reconstruction and in parametric model fits. This filament is coincident with an overdensity of galaxies and diffuse, soft X-ray emission and contributes mass comparable to that of an additional galaxy cluster to the total mass of the supercluster. Combined with X-ray observations, we place an upper limit of 0.09 on the hot gas fraction, the mass of X-ray emitting gas divided by the total mass, in the filament.Comment: Nature, in pres

Neurodegeneration and Epilepsy in a Zebrafish Model of CLN3 Disease (Batten Disease)

The neuronal ceroid lipofuscinoses are a group of lysosomal storage disorders that comprise the most common, genetically heterogeneous, fatal neurodegenerative disorders of children. They are characterised by childhood onset, visual failure, epileptic seizures, psychomotor retardation and dementia. CLN3 disease, also known as Batten disease, is caused by autosomal recessive mutations in the CLN3 gene, 80–85% of which are a ~1 kb deletion. Currently no treatments exist, and after much suffering, the disease inevitably results in premature death. The aim of this study was to generate a zebrafish model of CLN3 disease using antisense morpholino injection, and characterise the pathological and functional consequences of Cln3 deficiency, thereby providing a tool for future drug discovery. The model was shown to faithfully recapitulate the pathological signs of CLN3 disease, including reduced survival, neuronal loss, retinopathy, axonopathy, loss of motor function, lysosomal storage of subunit c of mitochondrial ATP synthase, and epileptic seizures, albeit with an earlier onset and faster progression than the human disease. Our study provides proof of principle that the advantages of the zebrafish over other model systems can be utilised to further our understanding of the pathogenesis of CLN3 disease and accelerate drug discovery

Adiabatic and entropy perturbations propagation in a bouncing Universe

By studying some bouncing universe models dominated by a specific class of hydrodynamical fluids, we show that the primordial cosmological perturbations may propagate smoothly through a general relativistic bounce. We also find that the purely adiabatic modes, although almost always fruitfully investigated in all other contexts in cosmology, are meaningless in the bounce or null energy condition (NEC) violation cases since the entropy modes can never be neglected in these situations: the adiabatic modes exhibit a fake divergence that is compensated in the total Bardeen gravitational potential by inclusion of the entropy perturbations.Comment: 25 pages, no figure, LaTe

The Thermal Design, Characterization, and Performance of the SPIDER Long-Duration Balloon Cryostat

We describe the SPIDER flight cryostat, which is designed to cool six millimeter-wavelength telescopes during an Antarctic long-duration balloon flight. The cryostat, one of the largest to have flown on a stratospheric payload, uses liquid helium-4 to deliver cooling power to stages at 4.2 and 1.6 K. Stainless steel capillaries facilitate a high flow impedance connection between the main liquid helium tank and a smaller superfluid tank, allowing the latter to operate at 1.6 K as long as there is liquid in the 4.2 K main tank. Each telescope houses a closed cycle helium-3 adsorption refrigerator that further cools the focal planes down to 300 mK. Liquid helium vapor from the main tank is routed through heat exchangers that cool radiation shields, providing negative thermal feedback. The system performed successfully during a 17 day flight in the 2014-2015 Antarctic summer. The cryostat had a total hold time of 16.8 days, with 15.9 days occurring during flight.Comment: 15 pgs, 17 fig

Evidence for solar cycles in a late Holocene speleothem record from Dongge Cave, China

The association between solar activity and Asian monsoon (AM) remains unclear. Here we evaluate the possible connection between them based on a precisely-dated, high-resolution speleothem oxygen isotope record from Dongge Cave, southwest China during the past 4.2 thousand years (ka). Without being adjusted chronologically to the solar signal, our record shows a distinct peak-to-peak correlation with cosmogenic nuclide 14C, total solar irradiance (TSI) and sunspot number (SN) at multi-decadal to centennial timescales. Further cross-wavelet analyses between our calcite δ18O and atmospheric 14C show statistically strong coherence at three typical periodicities of ~80, 200 and 340 years, suggesting important roles of solar activities in modulating AM changes at those timescales. Our result has further indicated a better correlation between our calcite δ18O record and atmospheric 14C than between our record and TSI. This better correlation may imply that the Sun–monsoon connection is dominated most likely by cosmic rays and oceanic circulation (both associated to atmospheric 14C), instead of the direct solar heating (TSI)