Eulerian bias and the galaxy density field

We investigate the effects on cosmological clustering statistics of empirical biasing, where the galaxy distribution is a local transformation of the present-day Eulerian density field. The effects of the suppression of galaxy numbers in voids, and their enhancement in regions of high density, are considered, independently and in combination. We compare results from numerical simulations with the predictions of simple analytic models. We find that the bias is generally scale-dependent, so that the shape of the galaxy power spectrum differs from that of the underlying mass distribution. The degree of bias is always a monotonic function of scale, tending to an asymptotic value on scales where the density fluctuations are linear. The scale dependence is often rather weak, with many reasonable prescriptions giving a bias which is nearly independent of scale. We have investigated whether such an Eulerian bias can reconcile a range of theoretical power spectra with the twin requirements of fitting the galaxy power spectrum and reproducing the observed mass-to-light ratios in clusters. It is not possible to satisfy these constraints for any member of the family of CDM-like power spectra in an Einstein - de Sitter universe when normalised to match COBE on large scales and galaxy cluster abundances on intermediate scales. We discuss what modifications of the mass power spectrum might produce agreement with the observational data.Comment: 14 pages, LaTeX (using mn.sty, epsfig), 17 Postscript figures included. Accepted for publication in MNRA

Estimating Government Policy Preferences to Predict New Firm Formation

Entrepreneurship, Entrepreneurial Climate, Subsistance, Discretionary Spending, Community/Rural/Urban Development, Public Economics,

Children’s Creativity Lab : creating a ‘pen of the future’

This work is funded by EPSRC and SICSA.Technology is changing the way we acquire new skills and proficiencies and handwriting is no exception to this. However, while some technological advancements exist in this area, the question of how we can digitally enhance the process of learning handwriting remains under-explored. Being immersed in this process on an everyday basis, we believe that school aged children can provide valuable ideas and insights into the design of future writing tools for learners developing their (hand)writing skills. As end-users of the proposed technology, we explore including children in a form of informed participatory design during a creativity lab where we invited 12 children, aged 11–12, to put themselves into the shoes of a product designers and create a Pen of the Future using prototyping materials. In this paper we describe our methodology and discuss the design ideas that children came up with and how these may inform the design of future writing tools.Postprin

How lipids may affect risk for suicidal behavior

Suicide and nonfatal suicidal behaviors are major causes of mortality and morbidity worldwide. Variability in rates of suicide and suicidal behaviors within and between countries has been attributed to population and individual risk factors, including economic status and cultural differences, both of which can have suicide risk effects mediated through a variety of factors, of which perhaps the least understood is the role of diet. We therefore review the scientific literature concerning two major dietary lipid classes, cholesterol and polyunsaturated fatty acids (PUFAs), that have been associated with higher risk of suicide attempts and suicide. We consider potential mechanistic intermediates including serotonin transporters and receptors, toll-like receptors (TLRs), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and peroxisome proliferator activated receptors (PPARs). Based on this review, we describe a theoretical model linking cholesterol and PUFA status to suicide risk, taking into account the effects of cholesterol-lowering interventions on PUFA balance, membrane lipid microdomains (rafts) as a nexus of interaction between cholesterol and omega-3 PUFAs, and downstream effects on serotonergic neurotransmission and specific inflammatory pathways.Fil: Daray, Federico Manuel. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Mann, John. Columbia University. Department of Psychiatry. New York State Psychiatric Institute; Estados UnidosFil: Sublette, M. Elizabeth. Columbia University. Department of Psychiatry. New York State Psychiatric Institute; Estados Unido

Aid for trade facilitation

Does foreign aid spent on trade facilitation increase trade flows of developing countries? There is an on-going and high profile discussion of aid-for-trade associated with the Doha negotiations of the World Trade Organization. There continue also questions about how best to achieve the Millennium Development Goals. The analysis in this paper explicitly considers how to target aid most effectively to increase trade – a fundamental question related to the crisis and policy debate over restarting the world trading system. Using detailed data on aid flows from the OECD, the analysis here estimates the responsiveness of trade flows to specific types of foreign aid. The findings indicate that aid directed toward promoting trade enhances the trade performance of recipient countries: a 1 percent increase in aid directed toward trade policy and regulatory reform (amounting to about US$11.7 million more such aid) could generate an increase in global trade of about US$818 million. This yields a"rate of return"on every dollar of this type of aid of about US$697 in additional trade. As the dollar aid flow is relatively small, such targeted aid mitigates concerns about absorptive capacity and real exchange rate appreciation, which may accompany larger disbursements.

Relatedness Measures to Aid the Transfer of Building Blocks among Multiple Tasks

Multitask Learning is a learning paradigm that deals with multiple different tasks in parallel and transfers knowledge among them. XOF, a Learning Classifier System using tree-based programs to encode building blocks (meta-features), constructs and collects features with rich discriminative information for classification tasks in an observed list. This paper seeks to facilitate the automation of feature transferring in between tasks by utilising the observed list. We hypothesise that the best discriminative features of a classification task carry its characteristics. Therefore, the relatedness between any two tasks can be estimated by comparing their most appropriate patterns. We propose a multiple-XOF system, called mXOF, that can dynamically adapt feature transfer among XOFs. This system utilises the observed list to estimate the task relatedness. This method enables the automation of transferring features. In terms of knowledge discovery, the resemblance estimation provides insightful relations among multiple data. We experimented mXOF on various scenarios, e.g. representative Hierarchical Boolean problems, classification of distinct classes in the UCI Zoo dataset, and unrelated tasks, to validate its abilities of automatic knowledge-transfer and estimating task relatedness. Results show that mXOF can estimate the relatedness reasonably between multiple tasks to aid the learning performance with the dynamic feature transferring.Comment: accepted by The Genetic and Evolutionary Computation Conference (GECCO 2020

Electro-Thermal Transport in Metallic Single-Wall Carbon Nanotubes for Interconnect Applications

This work represents the first electro-thermal study of metallic single-wall carbon nanotubes (SWNTs) for interconnect applications. Experimental data and careful modeling reveal that self-heating is of significance in short (1 < L < 10 um) nanotubes under high-bias. The low-bias resistance of micron scale SWNTs is also found to be affected by optical phonon absorption (a scattering mechanism previously neglected) above 250 K. We also explore length-dependent electrical breakdown of SWNTs in ambient air. Significant self-heating in SWNT interconnects can be avoided if power densities per unit length are limited to less than 5 uW/um.Comment: IEEE Intl. Electron Devices Meeting (IEDM), Dec. 2005, Washington D

Assessing the potential benefit of trade facilitation : A global perspective

The relationships between trade facilitation, trade flows, and capacity building are complex and challenging to assess, both empirically and in implementation. The authors measure and estimate the relationship between trade facilitation and trade flows across 75 countries in global trade, considering four important categories: port efficiency, customs environment, regulatory environment, and service sector infrastructure. A gravity model is employed that accounts for bilateral trade flows in manufactured goods in 2000-01 between the 75 countries, using traditional factors such as GDP, distance, language, and trade areas, and is augmented by the trade facilitation measures in the four categories for each country. The results suggest that both imports and exports for a country and for the world will increase with improvements in these trade facilitation measures. Potential gains from trade facilitation reforms are predicted by using the estimated parameters. The gains from trade facilitation are presented by comparing the gains across geographical regions and trade facilitation categories, and by domestic and partner improvements. The total gain in trade flow in manufacturing goods from trade facilitation improvements in all the four areas is estimated to be $377 billion. All regions gain in imports and exports. Most regions gain more in terms of exports than imports, in large part through increasing exports to the OECD market. The most important ingredient in getting these gains, particularly to the OECD market, is the country's own trade facilitation efforts. The detailed presentation of the results of the analysis may help inform policy decisions and capacity building choices.Transport and Trade Logistics,Trade Policy,Economic Theory&Research,Common Carriers Industry,Environmental Economics&Policies,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Common Carriers Industry,Transport and Trade Logistics,Trade Policy,Environmental Economics&Policies