2,176 research outputs found
Core measures of inflation as predictors of total inflation
Two rationales offered for policymakers' focus on core measures of inflation as a guide to underlying inflation are that core inflation omits food and energy prices, which are thought to be more volatile than other components, and that core inflation is thought to be a better predictor of total inflation over time horizons of import to policymakers. The authors' investigation finds little support for either rationale. They find that food and energy prices are not the most volatile components of inflation and that depending on which inflation measure is used, core inflation is not necessarily the best predictor of total inflation. However, they do find that combining CPI and PCE inflation measures can lead to statistically significant more accurate forecasts of each inflation measure, suggesting that each measure includes independent information that can be exploited to yield better forecasts.Inflation (Finance)
Core measures of inflation as predictors of total inflation
Policymakers tend to focus on core inflation measures because they are thought to be better predictors of total inflation over time horizons of import to policymakers. The authors find little support for this assumption. While some measures of core inflation are less volatile than total inflation, core inflation is not necessarily the best predictor of total inflation. The relative forecasting performance of models using core inflation and those using only total inflation depends on the inflation measure and time horizon of the forecast. Unlike previous studies, the authors provide a measure of the statistical significance of the difference in forecast errors. ; Supersedes Working Paper 08-9.Inflation (Finance)
Automated data pre-processing via meta-learning
The final publication is available at link.springer.comA data mining algorithm may perform differently on datasets with different characteristics, e.g., it might perform better on a dataset with continuous attributes rather than with categorical attributes, or the other way around.
As a matter of fact, a dataset usually needs to be pre-processed. Taking into account all the possible pre-processing operators, there exists a staggeringly large number of alternatives and nonexperienced users become overwhelmed.
We show that this problem can be addressed by an automated approach, leveraging ideas from metalearning.
Specifically, we consider a wide range of data pre-processing techniques and a set of data mining algorithms. For each data mining algorithm and selected dataset, we are able to predict the transformations that improve the result
of the algorithm on the respective dataset. Our approach will help non-expert users to more effectively identify the transformations appropriate to their applications, and hence to achieve improved results.Peer ReviewedPostprint (published version
Medial Prefrontal Cortical Thinning Mediates Shifts in Other-Regarding Preferences during Adolescence
Adolescence is a time of significant cortical changes in the ‘social brain’, a set of brain regions involved in sophisticated social inference. However, there is limited evidence linking the structural changes in social brain to development of social behavior. The present study investigated how cortical development of the social brain relates to other-regarding behavior, in the context of fairness concerns. Participants aged between 9 to 23 years old responded to multiple rounds of ultimatum game proposals. The degree to which each participant considers fairness of intention (i.e., intention-based reciprocity) vs. outcome (i.e., egalitarianism) was quantified using economic utility models. We observed a gradual shift in other-regarding preferences from simple rule-based egalitarianism to complex intention-based reciprocity from early childhood to young adulthood. The preference shift was associated with cortical thinning of the dorsomedial prefrontal cortex and posterior temporal cortex. Meta-analytic reverse-inference analysis showed that these regions were involved in social inference. Importantly, the other-regarding preference shift was statistically mediated by cortical thinning in the dorsomedial prefrontal cortex. Together these findings suggest that development of the ability to perform sophisticated other-regarding social inference is associated with the structural changes of specific social brain regions in late adolescence
Simulation studies of improved sounding systems
Two instrument designs for indirect satellite sounding of the atmosphere in the infrared are represented by the High Resolution Infra-Red Sounder, Model 2 (HIRS-2) and by the Advanced Meteorological Temperature Sounder (AMTS). The relative capabilities of the two instruments were tested by simulating satellite measurements from a group of temperature soundings, allowing the two participants to retrieve the temperature profiles from the simulated data, and comparing the results with the original temperature profiles. Four data sets were produced from radiosondes data extrapolated to a suitable altitude, representing continents and oceans, between 30S and 30N. From the information available, temperature profiles were retrieved by two different methods, statistical regression and inversion of the radiative transfer equation. Results show the consequence of greater spectral purity, concomitant increase in the number of spectral intervals, and the better spatial resolution in partly clouded areas. At the same time, the limitation of the HIRS-2 without its companion instrument leads to some results which should be ignored in comparing the two instruments. A clear superiority of AMTS results is shown
Neural crest stem cells undergo multilineage differentiation in developing peripheral nerves to generate endoneurial fibroblasts in addition to Schwann cells
Neural crest stem cells (NCSCs) persist in peripheral nerves throughout late gestation but their function is unknown. Current models of nerve development only consider the generation of Schwann cells from neural crest, but the presence of NCSCs raises the possibility of multilineage differentiation. We performed Cre-recombinase fate mapping to determine which nerve cells are neural crest derived. Endoneurial fibroblasts, in addition to myelinating and non-myelinating Schwann cells, were neural crest derived, whereas perineurial cells, pericytes and endothelial cells were not. This identified endoneurial fibroblasts as a novel neural crest derivative, and demonstrated that trunk neural crest does give rise to fibroblasts in vivo, consistent with previous studies of trunk NCSCs in culture. The multilineage differentiation of NCSCs into glial and non-glial derivatives in the developing nerve appears to be regulated by neuregulin, notch ligands, and bone morphogenic proteins, as these factors are expressed in the developing nerve, and cause nerve NCSCs to generate Schwann cells and fibroblasts, but not neurons, in culture. Nerve development is thus more complex than was previously thought, involving NCSC self-renewal, lineage commitment and multilineage differentiation
Morphology Effectively Controls Singlet-Triplet Exciton Relaxation and Charge Transport in Organic Semiconductors
We present a comparative study of ultrafast photo-conversion dynamics in
tetracene (Tc) and pentacene (Pc) single crystals and Pc films using optical
pump-probe spectroscopy. Photo-induced absorption in Tc and Pc crystals is
activated and temperature-independent respectively, demonstrating dominant
singlet-triplet exciton fission. In Pc films (as well as C-doped films)
this decay channel is suppressed by electron trapping. These results
demonstrate the central role of crystallinity and purity in photogeneration
processes and will constrain the design of future photovoltaic devices.Comment:
Developing body estimation in adolescence is associated with neural regions that support self-concept
Both self-concept, the evaluation of who you are, and the physical body undergo changes throughout adolescence. These two processes might affect the development of body image, a complex construct that comprises one's thoughts, feelings, and perception of one's body. This study aims to better understand the development of body image in relation to self-concept development and its neural correlates. Adolescents (aged 11-24) from the longitudinal Leiden Self-Concept study were followed for three consecutive years (NT1 = 160, NT2 = 151, and NT3 = 144). Their body image was measured using a figure rating scale and body dissatisfaction questionnaire. Body estimation was calculated based on figure ratings relative to their actual body mass index (BMI). Additionally, participants evaluated their physical appearance traits in an functional magnetic resonance imaging (fMRI) task. Results revealed that body estimation and body dissatisfaction increased with age. Heightened inferior parietal lobe (IPL) activation during physical self-evaluation was associated with lower body estimation, meaning that the neural network involved in thinking about one's physical traits is more active for individuals who perceive themselves as larger than they are. IPL activity showed continued development during adolescence, suggesting an interaction between neural development and body perception. These findings highlight the complex interplay between affective, perceptual, and biological factors in shaping body image.</p
Education in the working-class home: modes of learning as revealed by nineteenth-century criminal records
The transmission of knowledge and skills within the working-class household greatly troubled social commentators and social policy experts during the first half of the nineteenth century. To prove theories which related criminality to failures in working-class up-bringing, experts and officials embarked upon an ambitious collection of data on incarcerated criminals at various penal institutions. One such institution was the County Gaol at Ipswich. The exceptionally detailed information that survives on families, literacy, education and apprenticeships of the men, women and children imprisoned there has the potential to transform our understanding of the nature of home schooling (broadly interpreted) amongst the working classes in nineteenth-century England. This article uses data sets from prison registers to chart both the incidence and ‘success’ of instruction in reading and writing within the domestic environment. In the process, it highlights the importance of schooling in working-class families, but also the potentially growing significance of the family in occupational training
Desynchronization and re-synchronization of reproduction by Astragalus scaphoides, a plant that flowers in alternate years
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