161,669 research outputs found
The Hodrick-Prescott (HP) Filter as a Bayesian Regression Model
No full textThe Hodrick-Prescott (HP) method is a popular smoothing method for economic time series to get a smooth or long-term component of stationary series like growth rates. We show that the HP smoother can be viewed as a Bayesian linear model with a strong prior using differencing matrices for the smoothness component. The HP smoothing approach requires a linear regression model with a Bayesian conjugate multi-normalgamma distribution. The Bayesian approach also allows to make predictions of the HP smoother on both ends of the time series. Furthermore, we show how Bayes tests can determine the order of smoothness in the HP smoothing model. The extended HP smoothing approach is demonstrated for the non-stationary (textbook) airline passenger time series. Thus, the Bayesian extension of the HP model defines a new class of model-based smoothers for (non-stationary) time series and spatial models.Hodrick-Prescott (HP) smoothers, model selection by marginal likelihoods, multi-normal-gamma distribution, Spatial sales growth data, Bayesian econometrics
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
The Extended Hodrick-Prescott (HP) Filter for Spatial Regression Smoothing
No full textThe Hodrick-Prescott (HP) method is a popular smoothing method for economic time series to get a longterm component of stationary series like growth rates. The new extended HP smoothing model is applied to data-sets with an underlying metric and requires a Bayesian linear regression model with a strong prior based on differencing matrices for the smoothness parameter and a weak prior for the regression part. We define a Bayesian spatial smoothing model with neighbors for each observation and we define a smoothness prior similar to the HP filter in time series. This opens a new approach to model-based smoothers for time series and spatial models based on MCMC. We apply it to the NUTS-2 regions of the European Union for regional GDP and GDP per capita, where the fixed effects are removed by an extended HP smoothing model.Hodrick-Prescott (HP) smoothers, smoothed square loss function, spatial smoothing, smoothness prior, Bayesian econometrics
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
Larry O. Spencer, Conference Author Presentation
No full textGen. Larry O. Spencer, USAF (Ret.), author of Dark Horse: A Journey from the Horseshoe to the Pentago
Mediterranean diet and mental distress: “10,001 Dalmatians” study
No full textPurpose - The impact of eating habits on mental health is gaining more attention recently. The purpose of this paper is to investigate the association between mental distress and the Mediterranean diet (MD) in a community-dwelling adult population of Dalmatia, Croatia.Design/methodology/approach - Participants from the "10,001 Dalmatians" study from the Island of Korcula and the City of Split were included (n = 3,392). Lifestyle habits were investigated using a self-administered questionnaire, while mental distress was evaluated using the General Health Questionnaire-30 (GHQ-30) in a cross-sectional design. MD compliance was assessed using the Mediterranean Diet Serving Score. Multivariate linear regression analysis was used in the analysis.Findings - MD compliance was associated with lesser mental distress (beta = -1.96, 95% CI -2.75, -1.17; po0.001). Inverse association was found between mental distress and higher intake of fruits (beta = -0.64; 95% CI -0.89, -0.39; p < 0.001), vegetables (beta = -0.39; 95% CI -0.65, -0.13; p = 0.003), olive oil (beta = -0.30; 95% CI -0.56, -0.04; p = 0.022) and legumes (beta = -0.83; 95% CI -1.66, 0.00; p = 0.049). Mental distress was more intense in women, older participants, those with worse material status, subjects with previously diagnosed chronic diseases and in current smokers.Originality/value - This study suggests beneficial association of MD and overall mental health, offering important implications for public health provisions. Since the literature search did not reveal any previous study on the association between the MD and GHQ-based mental distress in the general population, this study delivers interesting results and fills this knowledge gap
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Interactions Between Genetic Variants in Glucose Transporter Type 9 (SLC2A9) and Dietary Habits in Serum Uric Acid Regulation
No full textAim To investigate possible interactions between genetic
variants in glucose transporter type 9 (SLC2A9) gene and
dietary habits in serum uric acid regulation.
Methods Participants for this study were recruited from
two isolated Croatian island communities of Vis (n = 918)
and Korčula (n = 898). Three single nucleotide polymorphisms
(SNP) from the SLC2A9 gene (rs1014290, rs6449213,
rs737267) were correlated with dietary habits and uric
acid.
Results A significant decrease in uric acid levels was recorded
with increasing consumption of milk, sour cream,
duck and turkey, and eggs. The only significant interaction
was found between potato consumption and rs737267
and a near-significant interaction was found between soft
drinks and rs1014290 (interaction P = 0.068). Increased
consumption of soft drinks interacting with the TT genotype
at rs1014290 increased serum uric acid. No significant
interactions were observed between food products consumption
and rs6449213.
Conclusion There is a certain extent of interaction between
SLC2A9 and dietary patterns in serum uric acid determination.
The metabolic effect of soft drinks seems to
be determined by the underlying genotype of rs1014290
Investigating the role of human genomewide heterozygosity as a health risk factor
No full textAim
The aim of this study was to investigate the most commonly used approaches to
measure individual genome-wide heterozygosity (IGWH) and to investigate whether
IGWH can be considered as a health risk factor or a protective factor in humans.
Methods
This study was based on two samples from isolated communities of Croatian
Adriatic islands, with a total of 1,930 adult examinees from Islands of Vis (N=986)
and Korcula (N=944). Examinees were genotyped with a total of 302,662 single
nucleotide polymorphisms. Heterozygosity was estimated using five commonly
calculated methods.
Results
Correlation coefficients between different heterozygosity methods were generally in
the range of 0.7-0.8. A worsening in some phenotypic traits, including cholesterol
and triglycerides as well as increased odds for osteoporosis and metabolic syndrome
was recorded in cases of IGWH reduction. Nevertheless, in these cases
heterozygosity explained a relatively low amount of variance, generally in range of
0.4-0.6% of total trait variance.
Conclusion
However, these results were significant in Vis Island sample, while in the replication
sample, Korcula Island, most of the associations were not significant, possibly due to
the overall lower amount of inbreeding and higher heterozygosity in Korcula Island
sample. The results warrant further research in order to provide more information on
the extent and importance of individual genome-wide heterozygosity, which might
have an important role in communities which experience consanguinity on a greater
scale. Two main shortcomings of the study include possible lack of power to detect
inbreeding depression and the need to replicate the results in other populations
MCMC Estimation of Extended Hodrick-Prescott (HP) Filtering Models
No full textThe Hodrick-Prescott (HP) method was originally developed to smooth time series, i.e. to get a smooth (long-term) component. We show that the HP smoother can be viewed as a Bayesian linear model with a strong prior for the smoothness component. Extending this Bayesian approach in a linear model set-up is possible by a conjugate and a non-conjugate model using MCMC. The Bayesian HP smoothing model is also extended to a spatial smoothing model. We have to define spatial neighbors for each observation and we can use in a similar way a smoothness prior as for the HP filter in time series. The new smoothing approaches are applied to the (textbook) airline passenger data for time series and to the problem of smoothing spatial regional data. This new approach can be used for a new class of model-based smoothers for time series and spatial models.Hodrick-Prescott (HP) smoothers, Spatial econometrics, MCMC estimation, Airline passenger time series, Spatial smoothing of regional data, NUTS: nomenclature of territorial units for statistics
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