2,325 research outputs found
High‐Dimensional Dynamic Panel with Correlated Random Effects: A Semiparametric Hierarchical Empirical Bayes Approach
A novel multivariate dynamic panel data analysis with correlated random effects
is proposed for estimating high-dimensional parameter spaces. A semiparametric
hierarchical Bayesian strategy is used to jointly address incidental parameters, endogeneity issues, and model mis-specification problems. The underlying methodology involves an ad-hoc model selection based on conjugate informative proper mixture priors to select promising subsets of predictors affecting outcomes. Monte Carlo algorithms are then conducted on the resulting submodels to construct empirical Bayes estimators and investigate ratio-optimality and posterior consistency for forecasting purposes and policy issues. An empirical approach is applied to a large
panel of economies, describing the functioning of the model. Simulations based on
Monte Carlo designs are also performed to account for relative regrets dealing with
cross-sectional heterogeneity
Chemical Constituents of the Aquatic Plant Schoenoplectus lacustris: Evaluation of Phytotoxic Effects on the Green Alga Selenastrum capricornutum.
Forty-nine secondary metabolites were isolated from aqueous and
alcoholic extracts of the aquatic plant Shoenoplectus lacustris. All compounds were characterized based on spectroscopic data. Eleven free and glycosylated low-molecular polyphenols, 17 cinnamic acid and dihydrocinnamic acid derivatives,
11 flavonoids, and 10 C13 nor-isoprenoids were identified. The structure of the new compound, 1-benzoyl-glycerol-2-a-L-arabinopyranoside, was elucidated by 2D NMR experiments (COSY, HSQC, HMBC, NOESY). To evaluate potential phytotoxic effects, all compounds were tested on the green alga Selenastrum capricornutum, a unicellular organism commonly used in tests of toxicity as a bioindicator of eutrophic sites. The most active compound was (j)-catechin, showing an inhibition similar to that of the algaecide CuSO4
Synthesis of glass nanocomposite powders
The aim of the present study was to synthesize CaO·GeO2 nanocomposite poweders glasses. The sample were prepared to 1450°C°. To investigate the structure of the samples, Differential Thermal Analysis (DSC), X-ray diffraction and Fourier Transform Infrared (FTIR) spectroscopy were used. The main crystallising phase was found to be CaGe205 crystals. The molar ratio of Ge06/Ge04 groups increases with the CaO·GeO2 molar ratio. Furthermore, in order to study the potential antibacterial properties of the materials the Gram-negative (Escherichia coli) bacteria was used and the diameter of zone of inhibition was observed
An Italian survey on dietary habits and changes during the COVID-19 lockdown
The World Health Organization has declared the coronavirus outbreak a Public Health Emergency of International Concern; the outbreak has led to lockdowns in several parts of the world, and sudden changes in people’s lifestyles. This study explores the impact of the first coronavirus disease 2019 (COVID-19) pandemic period on dietary habits, lifestyle changes, and adherence to the Mediterranean diet among the Italian population, through an online questionnaire, conducted from April to May 2020, involving 1519 participants. The 14-point Mediterranean Diet Adherence Screener (MEDAS) highlighted a medium Mediterranean diet adherence in 73.5% of responders, which principally included the younger population, aged 18–30 years (p < 0.05). In regards to changes in eating habits, 33.5% of responders declared an influence of the pandemic period on nutritional practice. A decrease in alcohol consumption was reported by 81% of responders, while an increase in frozen food consumption was reported by 81.3% of responders. In addition, 58.8% reported positive weight modification (40.8%, +1–3 kg); physical activity reduction was reported for 70.5% of responders. Our study contributes toward amplifying the investigation on the dietary habits and changes of the Italian population during the COVID-19 lockdown, although the pandemic is ongoing. Similar studies should be performed around the world to understand how the emergency has impacted people’s habits
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