9,295 research outputs found
Two conversational languages for control theoretical computations in the time sharing mode
Two conversational languages for control theory applications on direct-access time sharing compute
HAL/S programmer's guide
HAL/S is a programming language developed to satisfy the flight software requirements for the space shuttle program. The user's guide explains pertinent language operating procedures and described the various HAL/S facilities for manipulating integer, scalar, vector, and matrix data types
Detection of changes in the characteristics of a Gauss-Markov process
Sequential detection of changes in Gauss-Markov process achieved through probability ratio tes
A stochastic approximation scheme with accelerated convergence properties
Stochastic approximation scheme with accelerated convergence propertie
U.S. and U.K. Interest Rates 1890 - 1934: New Evidence on Structural Breaks
This paper presents econometric evidence on whether the founding of the Federal Reserve in 1914 caused a structural change from level-stationarity to difference-stationarity in U.S. and U.K. short-term nominal interest rates. We develop new econometric tests that allow for parameter transitions to test for a break of this kind and undertake a grid search analysis of dates and speeds for the change. We find that U.S. nominal interest rates most likely evolved rapidly to difference-stationarity in June 1917. For the U.K. we fail to reject the null that U.K. interest rate series follow a difference stationary process over the entire period 1890-1934. Our analysis differs from previous research on this topic in that we take care to explore statistical uncertainty around parameter estimates, and incorporate higher order dynamics into our econometric analysis.
HAL/S programmer's guide
This programming language was developed for the flight software of the NASA space shuttle program. HAL/S is intended to satisfy virtually all of the flight software requirements of the space shuttle. To achieve this, HAL/s incorporates a wide range of features, including applications-oriented data types and organizations, real time control mechanisms, and constructs for systems programming tasks. As the name indicates, HAL/S is a dialect of the original HAL language previously developed. Changes have been incorporated to simplify syntax, curb excessive generality, or facilitate flight code emission
Policy Areas Impinging on Elderly Transportation Mobility: An Explanation with Ontario, Canada as Example
As countries face the challenges posed by rising numbers of older persons, the need to reassess their respective policies to address transport needs in aging societies is increasingly recognized in relation to health and sustainability goals. This paper proposes the examination of six interrelated policy areas affecting elderly mobility in a country or administrative region. A general survey of policy developments in each of these areas could improve current strategies and existing processes in the planning and implementation of mobility services that will be responsive to both elderly and the general population now and in the future. These include: 1) general transport policy framework; 2) travel mode preference; 3) alternative transport infrastructure stock and investments; 4) housing-land-use-transportation linkage; 5) research and technology applications that improve travel mode and environment; and 6) institutional and legal reforms. These policy areas are discussed and given concrete elucidation in the case of Ontario, Canada. Reflections and recommendations for further research and policy action deemed critical in the case region are highlighted.transportation, aging, regional policy, Canada
Mapping functional traits: comparing abundance and presence-absence estimates at large spatial scales
Efforts to quantify the composition of biological communities increasingly focus on functional traits. The composition of communities in terms of traits can be summarized in several ways. Ecologists are beginning to map the geographic distribution of trait-based metrics from various sources of data, but the maps have not been tested against independent data. Using data for birds of the Western Hemisphere, we test for the first time the most commonly used method for mapping community trait composition – overlaying range maps, which assumes that the local abundance of a given species is unrelated to the traits in question – and three new methods that as well as the range maps include varying degrees of information about interspecific and geographic variation in abundance. For each method, and for four traits (body mass, generation length, migratory behaviour, diet) we calculated community-weighted mean of trait values, functional richness and functional divergence. The maps based on species ranges and limited abundance data were compared with independent data on community species composition from the American Christmas Bird Count (CBC) scheme coupled with data on traits. The correspondence with observed community composition at the CBC sites was mostly positive (62/73 correlations) but varied widely depending on the metric of community composition and method used (R2: 5.6×10−7 to 0.82, with a median of 0.12). Importantly, the commonly-used range-overlap method resulted in the best fit (21/22 correlations positive; R2: 0.004 to 0.8, with a median of 0.33). Given the paucity of data on the local abundance of species, overlaying range maps appears to be the best available method for estimating patterns of community composition, but the poor fit for some metrics suggests that local abundance data are urgently needed to allow more accurate estimates of the composition of communities
Advanced software techniques for data management systems. Volume 3: Programming language characteristics and comparison reference
A comparative evaluation was made of eight higher order languages of general interest in the aerospace field: PL/1; HAL; JOVIAL/J3; SPL/J6; CLASP; ALGOL 60; FORTRAN 4; and MAC360. A summary of the functional requirements for a language for general use in manned aerodynamic applications is presented. The evaluation supplies background material to be used in assessing the worth of each language for some particular application
Gene identification for the cblD defect of vitamin B12 metabolism
Background Vitamin B12 (cobalamin) is an essential cofactor in several metabolic pathways. Intracellular conversion of cobalamin to its two coenzymes, adenosylcobalamin in mitochondria and methylcobalamin in the cytoplasm, is necessary for the homeostasis of methylmalonic acid and homocysteine. Nine defects of intracellular cobalamin metabolism have been defined by means of somatic complementation analysis. One of these defects, the cblD defect, can cause isolated methylmalonic aciduria, isolated homocystinuria, or both. Affected persons present with multisystem clinical abnormalities, including developmental, hematologic, neurologic, and metabolic findings. The gene responsible for the cblD defect has not been identified.
Methods We studied seven patients with the cblD defect, and skin fibroblasts from each were investigated in cell culture. Microcell-mediated chromosome transfer and refined genetic mapping were used to localize the responsible gene. This gene was transfected into cblD fibroblasts to test for the rescue of adenosylcobalamin and methylcobalamin synthesis.
Results The cblD gene was localized to human chromosome 2q23.2, and a candidate gene, designated MMADHC (methylmalonic aciduria, cblD type, and homocystinuria), was identified in this region. Transfection of wild-type MMADHC rescued the cellular phenotype, and the functional importance of mutant alleles was shown by means of transfection with mutant constructs. The predicted MMADHC protein has sequence homology with a bacterial ATP-binding cassette transporter and contains a putative cobalamin binding motif and a putative mitochondrial targeting sequence.
Conclusions Mutations in a gene we designated MMADHC are responsible for the cblD defect in vitamin B12 metabolism. Various mutations are associated with each of the three biochemical phenotypes of the disorder
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