131,187 research outputs found
Estimating the Size and Growth of Unrecorded Economic Activity in Transition Countries: A Re-evaluation of Electric Consumption Method Estimates and their Implications
No full textIt is widely acknowledged that underground (unrecorded) economic activities play a major role in transition economies. Evaluations of the success and failure of the transition experience should therefore be based on total economic activity [TEA], namely, the sum of recorded and unrecorded economic activity. Substantive conclusions concerning the effects of unrecorded activities on the transition process as well as investigations of the causes and consequences of unrecorded activities have to date, relied extensively on estimates of unrecorded income based on variants of the electric consumption method [ECM] during the first half of the transition process. We first attempt to replicate these estimates employing improved data series. We then go on to extend and update alternative versions of the ECM estimates of unrecorded income for twenty five transition countries for the period 1989-2001. These new estimates enable us to examine the sensitivity of the results to alternative specifying assumptions, particularly, initial conditions. We find that our updated ECM estimates of the size of the unrecorded sector are not only highly sensitive to initial conditions, but they produce negative estimates of unrecorded income for many transition countries. Our findings are also compared to the new national accounting procedures that attempt to estimate exhaustive measures of the “non-observed economy”. Our disturbing results call into question many of the substantive conclusions reached by other scholars who relied on earlier ECM estimates to draw inferences about the transition process as well as the causes and consequences of underground economies in transition. In short, while we conclude that ECM estimates of the size of the unrecorded economy are unreliable, it is still possible to use the growth rate of the unrecorded sector to make important inferences about the transition process by examining the dynamic relationship between recorded and unrecorded sectors. The extension of our data base to cover the entire transition period will hopefully result in new investigations employing panel data rather than the more traditional method of applying simple cross country test procedures.underground, unreported, unrecorded, unobserved, hidden, informal, shadow economy, transition economies, electric consumption method
New estimates of U.S. currency abroad, the domestic money supply and the unreported Economy
No full textNew Estimates of U.S. Currency Abroad, the Domestic Money Supply and the Unreported Economy Edgar L. Feige * Abstract Despite financial innovations that have created important new substitutes for cash usage, per capita holdings of U.S. currency amount to 287 billion windfall for U.S. taxpayers. Overseas currency stock data are also used to derive estimates of the domestically held stock of currency as well as narrow and broad measures of domestic monetary aggregates. These domestic monetary aggregates are believed to be better predictors of future economic activity than traditional monetary aggregates and are tested to determine their ability to predict fluctuations in real output and prices. Domestic cash holdings are finally used to estimate the size of the U.S. unreported economy as measured by the amount of income that is not properly reported to the IRS. By 2010, we estimate that legal and illegal source unreported income” is 2.4 trillion, implying a “tax gap” in the range of 550 billion. Currently, we estimate that 18-23 percent of total reportable income is not properly reported to the IRS.Overseas currency; currency abroad; underground economy; unreported economy; domestic money supply; tax gap; tax evasion; cash payments; monetary aggregates
REM sleep alterations in primary insomnia
No full textObjectives: We previously (2008) found an association between
REM sleep duration and perceived wakefulness in 81 patients with primary insomnia (PI) in addition to a clearly increased arousal index in REM sleep. The current study aimed to replicate and extend the previous findings.
Methods: Polysomnogram (PSG) and subjective sleep quality
questionnaire (Schlaffragebogen A, SFA) data of PI patients and
matched good sleeper controls (GSC) were evaluated for group
differences.
Results: One hundred and fifty-six new PI patients could be
matched to the same number of GSC (GSC; 60M, 96F; Mean age PI: 42.6 ± 12.4 years, GSC: 42.2 ± 13.4 years). PI patients had a higher wake time within bed time as well as lower REM and sleep stage 2 time. The association between perceived wake time and REM sleep time could be replicated in this new and larger group, as well as a clearly increased arousal index in REM sleep, while the arousal index in NREM sleep was significantly but less strongly increased.
Conclusion: We postulate that the psychophysiological hyperarousal characteristic for primary insomnia is particularly expressed as a REM sleep alteration. REM sleep appears to be particularly vulnerable to pre-sleep worries, leading to increased retrospective recall of this time as wake time and a lower restorative sleep quality
REM Sleep Instability – A New Pathway for Insomnia?
No full textChronic insomnia afflicts approximately 10% of the adult population and is associated with daytime impairments and an elevated risk for developing somatic and mental disorders. Current pathophysiological models propose a persistent hyperarousal on the cognitive, emotional and physiological levels. However, the marked discrepancy between minor objective alterations in standard parameters of sleep continuity and the profound subjective impairment in patients with insomnia is unresolved. We propose that "instability" of REM sleep contributes to the experience of disrupted and non-restorative sleep and to the explanation of this discrepancy. This concept is based on evidence showing increased micro- and macro-arousals during REM sleep in insomnia patients. As REM sleep represents the most highly aroused brain state during sleep it seems particularly prone to fragmentation in individuals with persistent hyperarousal. The continuity hypothesis of dream production suggests that pre-sleep concerns of patients with insomnia, i. e., worries about poor sleep and its consequences, dominate their dream content. Enhanced arousal during REM sleep may render these wake-like cognitions more accessible to conscious perception, memory storage and morning recall, resulting in the experience of disrupted and non-restorative sleep. Furthermore, chronic fragmentation of REM sleep might lead to dysfunction in a ventral emotional neural network, including limbic and paralimbic areas that are specifically activated during REM sleep. This dysfunction, along with attenuated functioning in a dorsal executive neural network, including frontal and prefrontal areas, might contribute to emotional and cognitive alterations and an elevated risk of developing depression
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Detection of a companion to the pulsating sdB Feige 48
No full textWe present the discovery of a binary companion to the pulsating sdB Feige 48. Using HST/STIS and archival FUSE spectra, we measure a period of
d and a velocity semi-amplitude of
km s-1. This implies that the companion star must either
be of very low mass, or the orbit is at low inclination. Combining
2MASS fluxes, the lack of a reflection effect, results from
asteroseismology and a measurement of the rotation velocity of Feige 48, we
show that the orbital inclination must be ≤11.4° and that the
unseen companion is a white dwarf with mass ≥0.46 .
The implications of this discovery, and of
binarity amongst sdB pulsators, is then discussed in the context of recent
theoretical work on sdB formation. In particular we suggest that radial
velocity studies focus on sdB pulsators with no known companion, and that
asteroseismological studies of sdBs investigate a larger mass range than
previously considered in order to test formation models
High Sensitivity Observations and Detailed Asteroseismological Analysis of the EC14026 Star Feige 48
No full textWe present a detailed asteroseismic analysis of the rapidly pulsating sdB star -- or EC14026 star -- Feige 48 based on data obtained with the Montréal 3-channel fast photometer Lapoune attached at the Canada-France-Hawaii 3.6 m telescope. Located near the red edge of the EC14026 instability domain, Feige 48 provides us with less independent modes to constrain its structure through asteroseismological means than other rapidly pulsating sdB stars analyzed so far. Nonetheless, combining various sources of Teff and log g spectroscopic determinations and perfoming an objective search in the parameter space domain allowed us to identify a family of models that can simultaneously best fit the periods while being fully consistent with all spectroscopic measurements. In addition, the fine structure in the period spectrum allows us to derive the rotation period of Feige 48. Other fundamental parameters that follow from our asteroseismic analysis are the surface gravity (to a much higher accuracy than provided by spectroscopy), the total mass of the star, the mass of its H-rich envelope, its radius, total luminosity, absolute magnitude in the V band, as well as its distance from the Earth
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Stereoscopic families of permutations, and their applications (Extended Abstract)
No full text) Uriel Feige Robert Krauthgamer y Abstract A stereoscopic family of permutations maps an m- dimensional mesh into several 1-dimensional lines, in a way that jointly preserves distance information. Specifically, consider any two points and denote their distance on the m-dimensional mesh by d. Then the distance between their images, on the line on which these images are closest together, is O(d m ). We initiate a systematic study of stereoscopic families of permutations. We show a construction of these families that involves the use of m + 1 images. We also show that under some additional restrictions (namely, adjacent points on the image lines originate at points which are not too far away on the mesh), three images are necessary in order to construct such a family for the 2-dimensional mesh. We present two applications for stereoscopic families of permutations. One application is an algorithm for routing on the mesh that guarantees delivery of each packet within a number of s..
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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