2,527 research outputs found
Estimating Aging Effects in Running Events
This paper uses world running records by age to estimate a biological frontier of decline rates. Two models are compared: a linear/quadratic (LQ) model and a non-parametric model. Two estimation methods are used: 1) minimizing the squared diïŹerence between the observed records and the modeled biological frontier and 2) using extreme value theory to estimate the biological frontier that maximizes the probability of observing the existing world records by age. The results support the LQ model and suggest there is linear percentage decline up to the late 70âs and quadratic decline after that. The extreme value estimates suggest that the true biological frontier is on average about 8 percent below the existing world records. The estimated age factors are also compared to the World Master Athletics (WMA) age factors. The two sets of age factors are close except at the old ages, where the WMA factors are noticeably smaller. Also, the WMA age factors do not meet an important biological constraint
Combination of automated solid-phase and enzymatic oligosaccharide synthesis provides access to α(2,3)-sialylated glycans
A synthetic strategy combining automated solid-phase chemical synthesis and enzymatic sialylation was developed to access α(2,3)-sialylated glycans.</p
Combination of automated solid-phase and enzymatic oligosaccharide synthesis provides access to α(2,3)-sialylated glycans
Information Content of DSGE Forecasts
This paper examines the question whether information is contained in forecasts from DSGE models beyond that contained in lagged values, which are extensively used in the models. Four sets of forecasts are examined. The results are encouraging for DSGE forecasts of real GDP. The results suggest that there is information in the DSGE forecasts not contained in forecasts based only on lagged values and that there is no information in the lagged-value forecasts not contained in the DSGE forecasts. The opposite is true for forecasts of the GDP deflator
Systematic HydrogenâBond Manipulations To Establish Polysaccharide StructureâProperty Correlations
A dense hydrogenâbond network is responsible for the mechanical and structural properties of polysaccharides. Random derivatization alters the properties of the bulk material by disrupting the hydrogen bonds, but obstructs detailed structureâfunction correlations. We have prepared wellâdefined unnatural oligosaccharides including methylated, deoxygenated, deoxyfluorinated, as well as carboxymethylated cellulose and chitin analogues with full control over the degree and pattern of substitution. Molecular dynamics simulations and crystallographic analysis show how distinct hydrogenâbond modifications drastically affect the solubility, aggregation behavior, and crystallinity of carbohydrate materials. This systematic approach to establishing detailed structureâproperty correlations will guide the synthesis of novel, tailorâmade carbohydrate materials
Systematic HydrogenâBond Manipulations To Establish Polysaccharide StructureâProperty Correlations
A dense hydrogenâbond network is responsible for the mechanical and structural properties of polysaccharides. Random derivatization alters the properties of the bulk material by disrupting the hydrogen bonds, but obstructs detailed structureâfunction correlations. We have prepared wellâdefined unnatural oligosaccharides including methylated, deoxygenated, deoxyfluorinated, as well as carboxymethylated cellulose and chitin analogues with full control over the degree and pattern of substitution. Molecular dynamics simulations and crystallographic analysis show how distinct hydrogenâbond modifications drastically affect the solubility, aggregation behavior, and crystallinity of carbohydrate materials. This systematic approach to establishing detailed structureâproperty correlations will guide the synthesis of novel, tailorâmade carbohydrate materials
Recommended from our members
Anthropocene
âThe Anthropoceneâ is a term that is increasingly used to define a new planetary epoch: one in which humans have become the dominant force shaping Earthâs bio-geophysical composition and processes. Although it originated in the Earth Sciences, it has since been widely adopted across academia and the public sphere as a catch-all description for the overwhelming impact of human activity on the planet. This entry examines how anthropologists have engaged with the Anthropocene, both as a set of phenomena (e.g. climate change, mass extinction) and as a politically and morally loaded concept. It identifies four main anthropological approaches to the Anthropocene, those that: 1) take the Anthropocene as a context for or backdrop to ethnographic inquiry; 2) interrogate âthe Anthropoceneâ as a socially and politically constructed idea; 3) treat the Anthropocene as an opportunity for creativity and hopeful speculation; and 4) view the Anthropocene as the outcome of long-standing global political and socio-economic inequalities. Such approaches entail distinct methods, analytical frameworks, concepts, and ethico-political programmes. Collectively, they form a large and still-evolving body of work that destabilizes divisions between ânatureâ and âcultureâ and âhumansâ and ânon-humansâ, as well as the scholarly disciplines traditionally built around them. In this capacity, they are also pushing anthropologists to ask what distinctive methodological, analytical, and ethico-political contributions their discipline can make to the burgeoning interdisciplinary field of Anthropocene studies
Focused ion beam tomography of WC-Co cemented carbides
The microstructure of three different grades of WC-Co cemented carbides (hardmetals) has been reconstructed in three dimensions after sequential images obtained by focused ion beam. The three dimensional microstructual parameters are compared against the well-known two dimensional parameters of grain size, phase percentages and mean free path. Results show good agreement with the exception of individual grain recognition, which could not be univocally segmented. In the case of mean free path, the three-dimensional image depicts a more realistic description of the metal interconnections in the composite. Aiming for a simple example of direct application of these FIB tomography outcomes, reconstructed real microstructure for the coarser hardmetal grade studied was translated in a finite element modelling mesh, and elastic residual stresses were estimated from sintering to room temperature. Calculated thermal stresses agree with experimental results and show significant local variations in their value due to the complex microstructure of cemented carbides.Postprint (author's final draft
The future impact of changes in rate parity agreements on hotel chains: the long-term implications of the removal of rate parity agreements between hotels and online travel agents using closed consumer group booking models
The Office of Fair Trading, a not-for-profit and non-ministerial government department of the United Kingdom (from April 2014 incorporated within the Competition and Markets Authority), investigated the legality of rate parity from 2012, particularly rate parity agreements made between Intercontinental Hotel Group, Booking.com, and Expedia. Consequently, these major hotel brands and agents have committed to remove rate parity for closed consumer groups. This article identifies confusion over such groups and longer term implications. Smaller agents will enter the market, leading to increased fragmentation and competition. Branded hotels will face tough challenges in protecting prices and value from aggressive agents suddenly facing a more competitive market and independent hoteliers able to establish effective relationships with the new, smaller agents.
Keywords : Rate parity, pricing, closed consumer groups, hotels
- âŠ