1,492 research outputs found
A Leading Indicator for the Dutch Economy â Methodological and Empirical Revision of the CPB System
Since 1990 the Netherlands Bureau for Economic Policy Analysis (CPB) uses a leading indicator in preparing short-term forecasts for the Dutch economy. This paper describes some recent methodological innovations as well as the current structure and empirical results of the revised CPB leading indicator. Special attention is paid to the role and significance of IFO data. The structure of the CPB leading indicator is tailored to its use as a supplement to model-based projections, and thus has a unique character in several respects. The system of the CPB leading indicator is composed of ten separate composite indicators, seven for expenditure categories (âdemandâ) and three for the main production sectors (âsupplyâ). This system approach has important advantages over the usual structure, in which the basis series are directly linked to a single reference series. The revised system, which uses 25 different basic series, performs quite well in describing the economic cycle of GDP, in indicating the upturns and downturns, and in telling the story behind the business cycle.leading indicator, short-term forecasts
Specialist nectar-yeasts decline with urbanization in Berlin
Nectar yeasts are common inhabitants of insect-pollinated flowers but factors
determining their distribution are not well understood. We studied the
influence of host identity, environmental factors related to
pollution/urbanization, and the distance to a target beehive on local
distribution of nectar yeasts within Robinia pseudoacacia L. and Tilia
tomentosa Moench in Berlin, Germany. Nectar samples of six individuals per
species were collected at seven sites in a 2âkm radius from each target
beehive and plated on YM-Agar to visualise the different morphotypes, which
were then identified by sequencing a section of the 26S rDNA gene.
Multivariate linear models were used to analyze the effects of all
investigated factors on yeast occurrence per tree. Yeast distribution was
mainly driven by host identity. The influence of the environmental factors
(NO2, height of construction, soil sealing) strongly depended on the radius
around the tree, similar to the distance of the sampled beehive. Incidence of
specialist nectar-borne yeast species decreased with increasing
pollution/urbanization index. Given that specialist yeast species gave way to
generalist yeasts that have a reduced dependency on pollinators for between-
flower dispersal, our results indicate that increased urbanization may
restrict the movement of nectar-specialized yeasts, via limitations of
pollinator foraging behavior
A new approach to the evolution of the so-called surface peat in the western coastal plain of Belgium
Sulphur cement pre-composition and process for preparing such sulphur cement pre-composition
The invention provides a process for the preparation of a sulphur cement pre-composition comprising reacting sulphur modifier with polysulphide-containing organosilane to obtain in the presence of sulphur the sulphur cement pre-composition, wherein the organosilane has the general molecular formula: (X 3 Si) m H (2n+1) C n -S a -C n' H (2n'+1-m') (SiX' 3 ) m' (1) wherein a is an integer in the range of from 2 to 8, X and X' each are, independently, a hydrolysable group, n and n' each are, independently, an integer in the range of from 1 to 4, and m and m' each are, independently, an integer in the range of from 1 to (2n+1)
Pigeonsâ performance in a tracking change-signal procedure is consistent with the independent horse-race mode
This is the author accepted manuscript. The final version is available from the American Psychological Association via the DOI in this record.In many cognitive tasks where humans are thought to rely on executive functioning,
pigeonsâ behavior can be explained by associative processes. A key form of executive
functioning is inhibiting prepotent responses, often investigated in humans by means of
âStop-signalâ or âChange-signalâ procedures. In these procedures, execution of a wellpractised (âGoâ) response to a stimulus is occasionally interrupted by a signal to withhold or
alter the practised response. Performance in such tasks is usually described by the
âindependent horse horse-race modelâ model. This model assumes that the processes that
cause the Go and inhibitory responses occur independently; the process that finishes first
determines the response observed. We further tested this model by training pigeons to
track the circular movement of a colored patch around a touchscreen by pecking it; the spot
occasionally deviated from its normal path (the Change signal). The pigeons had to inhibit
the habitual movement of their heads in order to land a peck on the spot in its unexpected
position. The key predictions of the independent horse-race model were confirmed in the
pigeonsâ latency data. Thus, the independent race model can also successfully describe
Stop-change performance of subjects that do not rely on executive control
Switching off perceptual learning: tDCS to left DLPFC eliminates perceptual learning in humans.
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Perceptual learning can be acquired as a result of experience with stimuli that would otherwise be difficult to tell apart, and is often explained in terms of the modulation of feature salience by an error signal based on how well that feature can be predicted by the others that make up the stimulus. In this article we show that anodal transcranial Direct Current Stimulation (tDCS) at Fp3 directly influences this modulation process so as to eliminate and possibly reverse perceptual learning. In 2 experiments, anodal stimulation disrupted perceptual learning (indexed by an inversion effect) compared with sham (Experiment 1) or cathodal (Experiment 2) stimulation. Our findings can be interpreted as showing that anodal tDCS severely reduced or even abolished the modulation of salience based on error, greatly increasing generalization between stimuli. This result supports accounts of perceptual learning based on variations in salience as a consequence of pre-exposure, and opens up the possibility of controlling this phenomenon.IPLM and FV are supported by a grant from the ESRC (ES/J00815X/1), and FV is
supported by a starting grant from the European Research Council (ERC) under the European
Union's Seventh Framework Programme (FP7/2007-2013)/ ERC Grant Agreement No.
312445. CC was supported by an Overseas Scholarship from the International Office at the
University of Exeter and Yixuan Ku by the National Key Fundamental Research (973)
Program (2013CB329501) of China
Bio-ORACLE: a global environmental dataset for marine species distribution modeling
The oceans harbor a great diversity of organisms whose distribution and ecological preferences are often poorly understood. Species distribution modeling (SDM) could improve our knowledge and inform marine ecosystem management and conservation. Although marine environmental data are available from various sources, there are currently no user-friendly, high-resolution global datasets designed for SDM applications. This study aims to ?ll this gap by assembling a comprehensive, uniform, high-resolution and readily usable package of global environmental rasters. We compiled global coverage data, e.g. satellite-based and in situ measured data, representing various aspects of the marine environment relevant for species distributions. Rasters were assembled at a resolution of 5 arcmin (c. 9.2 km) and a uniform landmask was applied. The utility of the dataset was evaluated by maximum entropy SDM of the invasive seaweed Codium fragile ssp. fragile. We present Bio-ORACLE (ocean rasters for analysis of climate and environment), a global dataset consisting of 23 geophysical, biotic and climate rasters. This user-friendly data package for marine species distribution modeling is available for download at http://www.bio-oracle.ugent.be. The high predictive power of the distribution model of C. fragile ssp. fragile clearly illustrates the potential of the data package for SDM of shallow-water marine organisms. The availability of this global environmental data package has the potential to stimulate marine SDM. The high predictive success of the presence-only model of a notorious invasive seaweed shows that the information contained in Bio-ORACLE can be informative about marine distributions and permits building highly accurate species distribution models
Superconductor-insulator transition in nanowires and nanowire arrays
Superconducting nanowires are the dual elements to Josephson junctions, with
quantum phase-slip processes replacing the tunneling of Cooper pairs. When the
quantum phase-slip amplitude ES is much smaller than the inductive energy EL,
the nanowire responds as a superconducting inductor. When the inductive energy
is small, the response is capacitive. The crossover at low temperatures as a
function of ES/EL is discussed and compared with earlier experimental results.
For one-dimensional and two-dimensional arrays of nanowires quantum phase
transitions are expected as a function of ES/EL. They can be tuned by a
homogeneous magnetic frustration.Comment: 15 pages, 10 figure
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